Effects of mri on the body: Benefits and Risks | FDA
Benefits and Risks | FDA
An MRI scanner can be used to take images of any part of the body (e.g., head, joints, abdomen, legs, etc.), in any imaging direction. MRI provides better soft tissue contrast than CT and can differentiate better between fat, water, muscle, and other soft tissue than CT (CT is usually better at imaging bones). These images provide information to physicians and can be useful in diagnosing a wide variety of diseases and conditions.
MR images are made without using any ionizing radiation, so patients are not exposed to the harmful effects of ionizing radiation. But while there are no known health hazards from temporary exposure to the MR environment, the MR environment involves a strong, static magnetic field, a magnetic field that changes with time (pulsed gradient field), and radiofrequency energy, each of which carry specific safety concerns:
- The strong, static magnetic field will attract magnetic objects (from small items such as keys and cell phones, to large, heavy items such as oxygen tanks and floor buffers) and may cause damage to the scanner or injury to the patient or medical professionals if those objects become projectiles. Careful screening of people and objects entering the MR environment is critical to ensure nothing enters the magnet area that may become a projectile.
- The magnetic fields that change with time create loud knocking noises which may harm hearing if adequate ear protection is not used. They may also cause peripheral muscle or nerve stimulation that may feel like a twitching sensation.
- The radiofrequency energy used during the MRI scan could lead to heating of the body. The potential for heating is greater during long MRI examinations.
The use of gadolinium-based contrast agents (GBCAs) also carries some risk, including side effects such as allergic reactions to the contrast agent. See GBCAs for more information.
Some patients find the inside of the MRI scanner to be uncomfortably small and may experience claustrophobia. Imaging in an open MRI scanner may be an option for some patients, but not all MRI systems can perform all examinations, so you should discuss these options with your doctor. Your doctor may also be able to prescribe medication to make the experience easier for you.
To produce good quality images, patients must generally remain very still throughout the entire MRI procedure. Infants, small children, and other patients who are unable to lay still may need to be sedated or anesthetized for the procedure. Sedation and anesthesia carry risks not specific to the MRI procedure, such as slowed or difficult breathing, and low blood pressure.
Patients with implants, external and accessory devices
The MR environment presents unique safety hazards for patients with implants, external devices and accessory medical devices. Examples of implanted devices include artificial joints, stents, cochlear implants, and pacemakers. An external device is a device that may touch the patient like an external insulin pump, a leg brace, or a wound dressing. An accessory device is a non-implanted medical device (such as a ventilator, patient monitor) that is used to monitor or support the patient.
- The strong, static magnetic field of the MRI scanner will pull on magnetic materials and may cause unwanted movement of the medical device.
- The radiofrequency energy and magnetic fields that change with time may cause heating of the implanted medical device and the surrounding tissue, which could lead to burns.
- The magnetic fields and radiofrequency energy produced by an MRI scanner may also cause electrically active medical devices to malfunction, which can result in a failure of the device to deliver the intended therapy.
- The presence of the medical device will degrade the quality of the MR image, which may make the MRI scan uninformative or may lead to an inaccurate clinical diagnosis, potentially resulting in inappropriate medical treatment.
Therefore patients with implanted medical devices should not receive an MRI exam unless the implanted medical device has been positively identified as MR Safe or MR Conditional. An MR Safe device is nonmagnetic, contains no metal, does not conduct electricity and poses no known hazards in all MR environments. An MR Conditional device may be used safely only within an MR environment that matches its conditions of safe use. Any device with an unknown MRI safety status should be assumed to be MR Unsafe.
Adverse events for MRI scans are very rare. Millions of MRI scans are performed in the US every year, and the FDA receives around 300 adverse event reports for MRI scanners and coils each year from manufacturers, distributors, user facilities, and patients. The majority of these reports describe heating and/or burns (thermal injuries). Second degree burns are the most commonly reported patient problem. Other reported problems include injuries from projectile events (objects being drawn toward the MRI scanner), crushed and pinched fingers from the patient table, patient falls, and hearing loss or a ringing in the ear (tinnitus). The FDA has also received reports concerning the inadequate display or quality of the MR images.
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Do MRI Scans Have Side Effects? |
Having to get an MRI can seem intimidating, and when you aren’t sure what to expect the process can lead to anxiety. Here at Medical Imaging Express, we want to make your process as smooth as possible. Your experience should be as enjoyable as it can be. One of the biggest worries people have about MRIs is the potential side effects they may experience. While it’s good to be concerned about any medical procedure, MRI’s are a safe procedure and should cause little to no concern.
What Are The Side Effects Of An MRI?
Magnetic Resonance Imaging, also known as MRI scanning, is a painless type of scanning that uses magnetism and radio waves to produce images of body structures. This type of scanning does not involve x-ray radiation, and in return, there is no risk of exposure to radiation during an MRI.
There are no known side effects from an MRI scan. Patients with claustrophobia or anxiety may be given a sedative medicine to relax during the process and any medication can have side effects. Make sure to tell your doctor of any allergies you may have to avoid negative reactions to medication. If you are given sedation medicine, you may need to arrange for a ride home.
Once the MRI is complete, you are free to continue with your day as normal. While there are no side effects from an MRI, one of the biggest drawbacks is the amount of time they take. Most scans last anywhere from 30 to 90 minutes, in rare cases they last even longer. This time period can seem long, however, because you are not exposed to radiation, and there is no recovery period, the benefits often outweigh the drawbacks when considering an MRI.
Can Anyone Get An MRI?
Since the MRI scanning process uses magnetism, any patients with metallic materials on or in their bodies may be ineligible for MRI scans. These metallic materials can be a variety of things including surgical clips, artificial joints, metallic bone plates, heart pacemakers, metal implants, prosthetic devices, and metal chips. Also items such as metallic ear implants, chemotherapy or insulin pumps, bullet fragments, artificial heart valves, or other metallic materials. These types of materials can significantly distort the MRI images and risk the possibility of being moved by the magnet. If you are pregnant or have epilepsy, an MRI is not advised for you. Talk with your doctor, and be upfront about yourself to determine if an MRI is the right choice for you.
How Does Medical Imaging Express Help?
Unique to Medical Imaging Express, we have the only weight-bearing open-room MRI of its kind. This style of MRI offers relief from claustrophobia and gives unmatched patient comfort. Our open-style MRI allows you to look around the room, interact with others, and use headphones during your procedure. This gives anxiety relief to many patients, making the process even less stressful than a typical MRI scan.
We also offer the option of a standing MRI scan with our weight-bearing MRI machine. This machine allows us to scan patients in an upright or semi-upright position. This is beneficial to many patients that have difficulty laying down due to medical conditions or chronic pain. The natural, stand-up position that this style of MRI offers, allows you to get additional information that may not be possible to see in a traditional MRI.
With this knowledge, you can go into your MRI scan worry-free. Always make sure to listen to instructions given to you by your doctor before, during, and after a medical procedure. Here at Medical Imaging Express, we want to make your experience go as smoothly as possible, in a comfortable, open, and friendly environment. Read our other blogs to learn more about our services and what to expect. We are always happy to talk, so contact us with any questions or concerns you may have.
Body MRI – magnetic resonance imaging of the chest, abdomen and pelvis
Magnetic resonance imaging (MRI) of the body uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the inside of your body. It may be used to help diagnose or monitor treatment for a variety of conditions within the chest, abdomen and pelvis. If you’re pregnant, body MRI may be used to safely monitor your baby.
Tell your doctor about any health problems, recent surgeries or allergies and whether there’s a possibility you are pregnant. The magnetic field is not harmful, but it may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should always tell the technologist if you have any devices or metal in your body. Guidelines about eating and drinking before your exam vary between facilities. Unless you are told otherwise, take your regular medications as usual. Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. If you have claustrophobia or anxiety, you may want to ask your doctor for a mild sedative prior to the exam.
What is MRI of the Body?
Magnetic resonance imaging (MRI) is a noninvasive test doctors use to diagnose medical conditions.
MRI uses a powerful magnetic field, radiofrequency pulses, and a computer to produce detailed pictures of internal body structures. MRI does not use radiation (x-rays).
Detailed MR images allow doctors to examine the body and detect disease.
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What are some common uses of the procedure?
MR imaging of the body is performed to evaluate:
- organs of the chest and abdomen—including the heart, liver, biliary tract, kidneys, spleen, bowel, pancreas, and adrenal glands.
- pelvic organs including the bladder and the reproductive organs such as the uterus and ovaries in females and the prostate gland in males.
- blood vessels (including MR Angiography).
- lymph nodes.
Physicians use an MR examination to help diagnose or monitor treatment for conditions such as:
- tumors of the chest, abdomen or pelvis.
- diseases of the liver, such as cirrhosis, and abnormalities of the bile ducts and pancreas.
- inflammatory bowel disease such as Crohn’s disease and ulcerative colitis.
- heart problems, such as congenital heart disease.
- malformations of the blood vessels and inflammation of the vessels (vasculitis).
- a fetus in the womb of a pregnant woman.
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How should I prepare for the procedure?
You will need to change into a hospital gown. This is to prevent artifacts appearing on the final images and to comply with safety regulations related to the strong magnetic field.
Guidelines about eating and drinking before an MRI vary between specific exams and facilities. Take food and medications as usual unless your doctor tells you otherwise.
Some MRI exams use an injection of contrast material. The doctor may ask if you have asthma or allergies to contrast material, drugs, food, or the environment. MRI exams commonly use a contrast material called gadolinium. Doctors can use gadolinium in patients who are allergic to iodine contrast. A patient is much less likely to be allergic to gadolinium than to iodine contrast. However, even if the patient has a known allergy to gadolinium, it may be possible to use it after appropriate pre-medication. For more information on allergic reactions to gadolinium contrast, please consult the ACR Manual on Contrast Media.
Tell the technologist or radiologist if you have any serious health problems or recent surgeries. Some conditions, such as severe kidney disease, may mean that you cannot safely receive gadolinium. You may need a blood test to confirm your kidneys are functioning normally.
Women should always tell their doctor and technologist if they are pregnant. MRI has been used since the 1980s with no reports of any ill effects on pregnant women or their unborn babies. However, the baby will be in a strong magnetic field. Therefore, pregnant women should not have an MRI in the first trimester unless the benefit of the exam clearly outweighs any potential risks. Pregnant women should not receive gadolinium contrast unless absolutely necessary. See the MRI Safety During Pregnancy page for more information about pregnancy and MRI.
If you have claustrophobia (fear of enclosed spaces) or anxiety, ask your doctor to prescribe a mild sedative prior to the date of your exam.
Leave all jewelry and other accessories at home or remove them prior to the MRI scan. Metal and electronic items are not allowed in the exam room. They can interfere with the magnetic field of the MRI unit, cause burns, or become harmful projectiles. These items include:
- jewelry, watches, credit cards, and hearing aids, all of which can be damaged
- pins, hairpins, metal zippers, and similar metallic items, which can distort MRI images
- removable dental work
- pens, pocketknives, and eyeglasses
- body piercings
- mobile phones, electronic watches, and tracking devices.
In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the following implants may not be scanned and should not enter the MRI scanning area without first being evaluated for safety:
Tell the technologist if you have medical or electronic devices in your body. These devices may interfere with the exam or pose a risk. Many implanted devices will have a pamphlet explaining the MRI risks for that device. If you have the pamphlet, bring it to the attention of the scheduler before the exam. MRI cannot be performed without confirmation and documentation of the type of implant and MRI compatibility. You should also bring any pamphlet to your exam in case the radiologist or technologist has any questions.
If there is any question, an x-ray can detect and identify any metal objects. Metal objects used in orthopedic surgery generally pose no risk during MRI. However, a recently placed artificial joint may require the use of a different imaging exam.
Tell the technologist or radiologist about any shrapnel, bullets, or other metal that may be in your body. Foreign bodies near and especially lodged in the eyes are very important because they may move or heat up during the scan and cause blindness. Dyes used in tattoos may contain iron and could heat up during an MRI scan. This is rare. The magnetic field will usually not affect tooth fillings, braces, eyeshadows, and other cosmetics. However, these items may distort images of the facial area or brain. Tell the radiologist about them.
Infants and young children often require sedation or anesthesia to complete an MRI exam without moving. This depends on the child’s age, intellectual development, and the type of exam. Sedation can be provided at many facilities. A specialist in pediatric sedation or anesthesia should be available during the exam for your child’s safety. You will be told how to prepare your child.
Some facilities may have personnel who work with children to help avoid the need for sedation or anesthesia. They may prepare children by showing them a model MRI scanner and playing the noises they might hear during the exam. They also answer any questions and explain the procedure to relieve anxiety. Some facilities also provide goggles or headsets so the child can watch a movie during the exam. This helps the child stay still and allows for good quality images.
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What does the equipment look like?
The traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie on a table that slides into a tunnel towards the center of the magnet.
Some MRI units, called short-bore systems, are designed so that the magnet does not completely surround you. Some newer MRI machines have a larger diameter bore, which can be more comfortable for larger patients or those with claustrophobia. “Open” MRI units are open on the sides. They are especially helpful for examining larger patients or those with claustrophobia. Open MRI units can provide high quality images for many types of exams. Open MRI may not be used for certain exams. For more information, consult your radiologist.
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How does the procedure work?
Unlike x-ray and computed tomography (CT) exams, MRI does not use radiation. Instead, radio waves re-align hydrogen atoms that naturally exist within the body. This does not cause any chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit different amounts of energy depending on the type of tissue they are in. The scanner captures this energy and creates a picture using this information.
In most MRI units, the magnetic field is produced by passing an electric current through wire coils. Other coils are inside the machine and, in some cases, are placed around the part of the body being imaged. These coils send and receive radio waves, producing signals that are detected by the machine. The electric current does not come into contact with the patient.
A computer processes the signals and creates a series of images, each of which shows a thin slice of the body. The radiologist can study these images from different angles.
MRI is often able to tell the difference between diseased tissue and normal tissue better than x-ray, CT, and ultrasound.
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How is the procedure performed?
MRI exams may be done on an outpatient basis.
The technologist will position you on the moveable exam table. They may use straps and bolsters to help you stay still and maintain your position.
The technologist may place devices that contain coils capable of sending and receiving radio waves around or next to the area of the body under examination.
MRI exams generally include multiple runs (sequences), some of which may last several minutes. Each run will create a different set of noises.
If your exam uses a contrast material, a doctor, nurse, or technologist will insert an intravenous catheter (IV line) into a vein in your hand or arm. They will use this IV to inject the contrast material.
You will be placed into the magnet of the MRI unit. The technologist will perform the exam while working at a computer outside of the room. You will be able to talk to the technologist via an intercom.
If your exam uses a contrast material, the technologist will inject it into the intravenous line (IV) after an initial series of scans. They will take more images during or following the injection.
When the exam is complete, the technologist may ask you to wait while the radiologist checks the images in case more are needed.
The technologist will remove your IV line after the exam is over and place a small dressing over the insertion site.
Depending on the type of exam and the equipment used, the entire exam is usually completed in 30 to 50 minutes.
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What will I experience during and after the procedure?
Most MRI exams are painless. However, some patients find it uncomfortable to remain still. Others may feel closed-in (claustrophobic) while in the MRI scanner. The scanner can be noisy.
It is normal for the area of your body being imaged to feel slightly warm. If it bothers you, tell the radiologist or technologist. It is important that you remain perfectly still while the images are being taken. This is typically only a few seconds to a few minutes at a time. You will know when images are being recorded because you will hear and feel loud tapping or thumping sounds. The coils that generate the radio waves make these sounds when they are activated. You will be provided with earplugs or headphones to reduce the noise made by the scanner. You may be able to relax between imaging sequences. However, you will need to keep the same position as much as possible without moving.
You will usually be alone in the exam room. However, the technologist will be able to see, hear, and speak with you at all times using a two-way intercom. They will give you a “squeeze-ball” that alerts the technologist that you need attention right away. Many facilities allow a friend or parent to stay in the room if they have also been screened for safety.
Children will be given appropriately sized earplugs or headphones during the exam. Music may be played through the headphones to help pass the time. MRI scanners are air-conditioned and well-lit.
In some cases, IV injection of contrast material may be given before the images are obtained. The IV needle may cause you some discomfort and you may experience some bruising. There is also a very small chance of skin irritation at the site of the IV tube insertion. Some patients may have a temporary metallic taste in their mouth after the contrast injection.
If you do not require sedation, no recovery period is necessary. You may resume your usual activities and normal diet immediately after the exam. On very rare occasions, a few patients experience side effects from the contrast material. These may include nausea, headache, and pain at the site of injection. It is very rare that patients experience hives, itchy eyes, or other allergic reactions to the contrast material. If you have allergic symptoms, tell the technologist. A radiologist or other doctor will be available for immediate assistance.
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Who interprets the results and how do I get them?
A radiologist, a doctor trained to supervise and interpret radiology exams, will analyze the images. The radiologist will send a signed report to your primary care or referring physician, who will share the results with you.
You may need a follow-up exam. If so, your doctor will explain why. Sometimes a follow-up exam further evaluates a potential issue with more views or a special imaging technique. It may also see if there has been any change in an issue over time. Follow-up exams are often the best way to see if treatment is working or if a problem needs attention.
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What are the benefits vs. risks?
- MRI is a noninvasive imaging technique that does not involve exposure to radiation.
- MR images of the soft-tissue structures of the body—such as the heart, liver and many other organs— is more likely in some instances to identify and accurately characterize diseases than other imaging methods. This detail makes MRI an invaluable tool in early diagnosis and evaluation of many focal lesions and tumors.
- MRI has proven valuable in diagnosing a broad range of conditions, including cancer, heart and vascular disease, and muscular and bone abnormalities.
- MRI can detect abnormalities that might be obscured by bone with other imaging methods.
- MRI allows physicians to assess the biliary system noninvasively and without contrast injection.
- The MRI gadolinium contrast material is less likely to cause an allergic reaction than the iodine-based contrast materials used for x-rays and CT scanning.
- MRI provides a noninvasive alternative to x-ray, angiography and CT for diagnosing problems of the heart and blood vessels.
- The MRI exam poses almost no risk to the average patient when appropriate safety guidelines are followed.
- If sedation is used, there is a risk of using too much. However, your vital signs will be monitored to minimize this risk.
- The strong magnetic field is not harmful to you. However, it may cause implanted medical devices to malfunction or distort the images.
- Nephrogenic systemic fibrosis is a recognized complication related to injection of gadolinium contrast. It is exceptionally rare with the use of newer gadolinium contrast agents. It usually occurs in patients with serious kidney disease. Your doctor will carefully assess your kidney function before considering a contrast injection.
- There is a very slight risk of an allergic reaction if your exam uses contrast material. Such reactions are usually mild and controlled by medication. If you have an allergic reaction, a doctor will be available for immediate assistance.
- Although there are no known health effects, evidence has shown that very small amounts of gadolinium can remain in the body, particularly the brain, after multiple MRI exams. This is most likely to occur in patients receiving multiple MRI exams over their lifetime for monitoring chronic or high-risk health conditions. The contrast agent is mostly eliminated from the body through the kidneys. If you are a patient in this category, consult with your doctor about the possibility of gadolinium retention, as this effect varies from patient to patient.
- IV contrast manufacturers indicate mothers should not breastfeed their babies for 24-48 hours after contrast material is given. However, the most recent American College of Radiology (ACR) Manual on Contrast Media reports that studies show the amount of contrast absorbed by the infant during breastfeeding is extremely low. For further information please consult the ACR Manual on Contrast Media and its references.
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What are the limitations of MRI of the Body?
High-quality images depend on your ability to remain perfectly still and follow breath-holding instructions while the images are being recorded. If you are anxious, confused or in severe pain, you may find it difficult to lie still during imaging.
A person who is very large may not fit into certain types of MRI machines. There are weight limits on the scanners.
Implants and other metallic objects can make it difficult to obtain clear images. Patient movement can have the same effect.
A very irregular heartbeat may affect the quality of images. This is because some techniques time the imaging based on the electrical activity of the heart.
Breathing may cause artifacts, or image distortions, during MRIs of the chest, abdomen and pelvis. Bowel motion is another source of motion artifacts in abdomen and pelvic MRI studies. This is less of a problem with state-of-the art scanners and techniques.
Present data show no convincing evidence that non contrast MRI harms the fetus of a pregnant woman. However, if the need for the exam is not time sensitive your doctor may delay the exam until after delivery. MRI gadolinium contrast agents are generally avoided during pregnancy except in very specific circumstances. Your doctor will discuss the benefits and risks of any MRI procedure with you. Doctors may perform MRI after the first trimester to assess the fetus for findings that are not fully evaluated by ultrasound.
MRI may not always distinguish between cancer tissue and fluid, known as edema.
An MRI exam typically costs more and may take more time than other imaging exams. Talk to your insurance provider if you have concerns about the cost of MRI.
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Which test, procedure or treatment is best for me?
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This page was reviewed on June, 18, 2018
Magnetic Resonance Imaging (MRI) of the Bones, Joints, and Soft Tissues
What is magnetic resonance imaging (MRI)?
Magnetic resonance imaging (MRI) is a diagnostic exam that uses a
combination of a large magnet, radiofrequencies and a computer to produce
detailed images of organs and structures within the body. MRI does not use
How does an MRI scan work?
The MRI machine is a large, cylindrical (tube-shaped) machine that creates
a strong magnetic field around the patient and pulses of radio waves are
sent from a scanner. The radio waves knock the nuclei of the atoms in your
body out of their natural position. As the nuclei realign into proper
position, they send out radio signals. These signals are received by a
computer that analyzes and converts them to form a two-dimensional (2D)
image of the part of the body being examined. This image then appears on a
Some MRI machines look like narrow tunnels, while others are more spacious
or wider. MRI scans can last from 30 minutes to two hours.
What are the reasons for an MRI of the bones, joints or soft tissues?
orthopedics, an MRI may be used to examine bones, joints, and soft tissues such as
cartilage, muscles, and tendons for injuries or the presence of structural
abnormalities or certain other conditions, such as tumors, inflammatory
disease, congenital abnormalities, osteonecrosis, bone marrow disease, and
herniation or degeneration of discs of the spinal cord. MRI may be used to
assess the results of corrective orthopedic procedures. Joint deterioration
may be monitored by using magnetic resonance imaging.
There may be other reasons for your physician to recommend an MRI of the
bones, joints, or soft tissue.
What are the risks of an MRI?
Because radiation is not used, there is no risk of exposure to ionizing
radiation during an MRI procedure. Each patient must be screened before
exposure to the MRI magnetic field.
Due to the use of the strong magnet, special precautions must be taken to
perform an MRI on patients with certain implanted devices such as
pacemakers or cochlear implants. The MRI technologist will need some
information regarding the implanted decide, such as the make and model
number, to determine if it is safe for you to have an MRI. Patients who
have internal metal objects, such as surgical clips, plates, screws or wire
mesh, might not be eligible for an MRI exam.
If there is a possibility that you are claustrophobic then you should ask
your physician to provide you with anti-anxiety medication that you can
take prior to your MRI examination. You should plan to have someone drive
you home afterward.
If you are pregnant or suspect that you may be pregnant, you should notify
your health care provider. To date, there is no information indicating that
MRI is harmful to an unborn child, however, MRI testing during the first
trimester is discouraged.
A doctor may order a contrast dye to be used during some MRI exams in order
for the radiologist to better view internal tissues and blood vessels on
the completed images.
If contrast is used, there is a risk for allergic reaction to the contrast.
Patients who are allergic or sensitive to contrast dye or iodine should
notify the radiologist or technologist.
If you have severe kidney disease or are on kidney dialysis, there is a
risk of a condition called “nephrogenic systemic fibrosis” from the
contrast dye. You should discuss this risk with your doctor prior to the
Nephrogenic Systemic Fibrosis (NSF) is a very rare but serious complication
of MRI contrast use in patients with kidney disease or kidney failure. If
you have a history of kidney disease, kidney failure, kidney transplant,
liver disease or are on dialysis, you must inform the MRI technologist or
radiologist prior to receiving contrast.
MRI contrast may have an effect on other conditions, such as allergies,
asthma, anemia, hypotension (low blood pressure), kidney disease, and
sickle cell disease.
There may be other risks depending on your specific medical condition. Be
sure to discuss any concerns with your doctor prior to the procedure.
How do I prepare for an MRI?
EAT/DRINK: You may eat, drink and take medications as usual for most MRI exams. There are some specialty MRI exams that require certain restrictions. You will be provided detailed preparations instructions by Johns Hopkins Medical Imaging when you schedule your exam.
CLOTHING: You must completely change into a patient gown and lock up all personal
belongings. A locker will be provided for you to use. Please remove all
piercings and leave all jewelry and valuables at home.
WHAT TO EXPECT: Imaging takes place inside of a large tube-like structure, open on both
ends. You must lie perfectly still for quality images. Due to the loud
noise of the MRI machine, earplugs are required and will be provided.
ALLERGY: If you have had an allergic reaction to contrast that required medical
treatment, contact your ordering physician to obtain the recommended
prescription. You will likely take this by mouth 24, 12 and two hours prior
ANTI-ANXIETY MEDICATION: If you require anti-anxiety medication due to claustrophobia, contact
your ordering physician for a prescription. Please note that you will need
some else to drive you home.
STRONG MAGNETIC ENVIRONMENT: If you have metal within your body that was not disclosed prior to your
appointment, your study may be delayed, rescheduled or canceled upon your
arrival until further information can be obtained.
Based on your medical condition, your health care provider may require
other specific preparation.
When you call to make an appointment, it is extremely important that you
inform if any of the following apply to you:
You have a pacemaker or have had heart valves replaced
You have any type of implantable pumps, such as an insulin pump
You have vessel coils, filters, stents, or clips
You are pregnant or think you might be pregnant
You have any body piercing
You are wearing a medication patch
You have permanent eyeliner or tattoos
You have ever had a bullet wound
You have ever worked with metal (for example, a metal grinder or
You have metallic fragments anywhere in the body
You are not able to lie down for 30 to 60 minutes.
What happens during an MRI?
MRI may be performed on an outpatient basis or as part of your stay in a
hospital. Procedures may vary depending on your condition and your doctor’s
Generally, MRI follows this process:
You will be asked to remove any clothing, jewelry, eyeglasses,
hearing aids, hairpins, removable dental work, or other objects
that may interfere with the procedure.
If you are asked to remove clothing, you will be given a gown to
If you are to have a procedure done with contrast, an intravenous
(IV) line will be started in the hand or arm for injection of the
You will lie on a scan table that slides into a large circular
opening of the scanning machine. Pillows and straps may be used to
prevent movement during the procedure.
The technologist will be in another room where the scanner controls
are located. However, you will be in constant sight of the technologist through a window. Speakers inside the scanner will enable the technologist to communicate with and hear you. You will have a call button so that you can let the technologist know if you have any problems during the procedure. The technologist will be
watching you at all times and will be in constant communication.
You will be given earplugs or a headset to wear to help block out
the noise from the scanner. Some headsets may provide music for you
to listen to.
During the scanning process, a clicking noise will sound as the magnetic field is created and pulses of radio waves are sent from
It will be important for you to remain very still during the
examination, as any movement could cause distortion and affect the
quality of the scan.
At intervals, you may be instructed to hold your breath or to not
breathe, for a few seconds, depending on the body part being examined. You will then be told when you can breathe. You should
not have to hold your breath for longer than a few seconds.
If contrast dye is used for your procedure, you may feel some
effects when the dye is injected into the IV line. These effects include a flushing sensation or a feeling of coldness, a salty or metallic taste in the mouth, a brief headache, itching, or nausea and/or vomiting. These effects usually last for a few moments.
You should notify the technologist if you feel any breathing
difficulties, sweating, numbness, or heart palpitations.
Once the scan is complete, the table will slide out of the scanner
and you will be assisted off the table.
If an IV line was inserted for contrast administration, the line
will be removed.
While the MRI procedure itself causes no pain, having to lie still for the
length of the procedure might cause some discomfort or pain, particularly
in the case of a recent injury or invasive procedure such as surgery. The technologist will use all possible comfort measures and complete the
procedure as quickly as possible to minimize any discomfort or pain.
What happens after an MRI?
You should move slowly when getting up from the scanner table to avoid any
dizziness or lightheadedness from lying flat for the length of the
If any sedatives were taken for the procedure, you may be required to rest
until the sedatives have worn off. You will also need to avoid driving.
If contrast dye is used during your procedure, you may be monitored for a
period of time for any side effects or reactions to the contrast dye, such
as itching, swelling, rash, or difficulty breathing.
If you notice any pain, redness, and/or swelling at the IV site after you
return home following your procedure, you should notify your physician as
this could indicate an infection or another type of reaction.
Otherwise, there is no special type of care required after an MRI scan of
the bones, joints, and soft tissues. You may resume your usual diet and
activities unless your physician advises you differently.
Your physician may give you additional or alternate instructions after the procedure, depending on your particular situation.
Biological Effects and Safety in Magnetic Resonance Imaging: A Review
During an MRI examination, three types of MF are employed to produce three dimensional images : I) a high static MF, which generates a net magnetization vector in the human body, that is a measure of the proton density; II) a gradient MF (100 to 1,000 Hz), used to localize aligned protons inside the body, thus allowing spatial reconstruction of tissue sections into images; III) a RF electromagnetic wave (10 to 400 MHz), which energizes the magnetization vector allowing its detection by the MRI scanner, converting tissue properties into MR images. Different levels of contrast are based on the different magnetic properties and physical structure of the biological tissues (i. e. density of hydrogen atoms) .
The major recognized mechanical risk associated with MR scanner is the presence of ferromagnetic devices and equipments, including biomedical implants. These equipments will be subject to the attractive (projectile effect) and rotational forces, caused by the static field, whose magnitude depends on their mass and distance from the bore entrance .
The projectile effect caused the most serious accident reported to date: a 6-year-old boy died after an MRI exam, when the machine’s powerful MF jerked a metal oxygen tank across the room, crushing the child’s head . Other accidents have been related to thermal injuries that usually occur where the skin is in contact with a monitoring sensor or cable [8,9].
Cardiovascular MRI is an increasingly adopted modality for the evaluation of patients with cardiovascular diseases. Potential hazards are associated with the presence of cardiac devices and implants, such as heart valve protheses, coronary artery stents, aortic stent grafts, pacemakers and implantable cardioverter-defribrillators, due to possible movement, dislodgment, dysfunction or damaging of the cardiac device caused by the interactions with the MF .
3.1. MRI Biological Effects
Magnetic Resonance Imaging is considered a safe technology since it just has the ability to change the position of atoms, but not to alter their structure, composition, and properties, as the ionizing radiations attempt to do. However, as in any sanitary interventions, there are intrinsic hazards that must be understood, acknowledged and taken into consideration. These hazards are relative to all three types of fields which can affect patients, staff and other persons within the MR environment .
To assess the potential dangerous biological effects associated with MRI environment and procedures, several studies have been conducted over the past thirty years, often producing controversial results.
Most of these studies are relative to the biological effects of a particular electromagnetic source utilized in MRI, while there is a lack of knowledge about the combination of three MF components. Thus, there is a need to integrate the current findings to better understand the interactions between EMF related to MRI and biological systems.
This review is divided in three sections, according to the three sources of EMF utilized in MRI procedures. In each section, the risk assessment related to each field component is summarized. We focus only on mammalian/human biological systems for their obvious strict correlation with human health.
3.1.1. Effects of Static MF
The safety of static MFs has been discussed for more than a century: in 1921 Drinker and Thompson  carried out numerous experiments to investigate possible effects on workers exposed to MF in industrial applications. They concluded that the static MF had no significant hazard effects on human health.
More than 400 papers have been published on the biological effects of static MF, but the results were often contradictory and confusing .
With the advent of MRI at the beginning of the eighties, the interest in understanding the potential hazards associated with static MF exposure has increased. A recent review concluded that it was very difficult to prove the existence of significant biological effects of static MF , with the exception of force orientation effects on biological molecules with particular magnetic properties (i.e. haemoglobin, free radicals), without apparent side effects for humans , and some sensory effects such as nausea, vertigo and metallic taste .
A recent paper of ICNIRP reviewed in vivo and in vitro studies carried out to detect biological responses to static MF in the range of milli T up to several T, in order to give new guidelines on limits of occupational exposures and exposure of general public . The new proposed values are 2T for the occupational exposure of head and trunk, 8T for the occupational exposure of the limbs and, finally, 400mT for the general public exposure of any part of the body. These new guidelines do not apply to patients undergoing medical diagnosis or treatment: detailed considerations on the protection of patients are in preparation.
In vitro effects
Many studies have been carried out on the in vitro effects of static MF. Cell growth, cell proliferation, cell cycle distribution pattern and apoptotic cell death seem not to be affected by an exposure up to four days at field strengths up to 10T , while an exposure of 10-17T for 30–60 minutes can reduce number and size, cells organization and vitality as observed in cultured mammalian cells . A blood oxygenation dependent increase in blood viscosity due to an exposure of 1.5T was also observed in .
Genotoxic or carcinogenic effects have also been studied  and it was suggested that static MF might affect the process of cancer induction and/or progression by altering cellular responses to some known carcinogens (chemicals, radiation). In any case, the body of results available in the literature are often not comparable and in some cases also not reproducible making a definitive conclusion premature.
In vivo and ex vivo effects
Various experimental studies carried out over the last 30–40 years have examined the effects of chronic or acute exposure of laboratory animals to static MFs. Four main areas of investigation have been covered: nervous system and behavioural studies, cardiovascular system responses, reproduction and development, and genotoxicity and cancer.
No effects were found on neurophysiological responses (ion channel conduction properties, nerve conduction velocity, excitation threshold) in rats, cats, monkeys and frogs after an exposure at static MFs of up to 2T [22,23].
Neurobehavioral studies have shown a lack of effects on the normal activity of animals under exposure up to 1.5T, while exposures higher than 1.5T have led to adverse responses .
A change in Na+ or K+ ion channel conductivity produced by an exposure at 24T , and a reduction of visual evoked potential in the cat brain following an exposures to 120mT for 150s [25,26] were reported. It was suggested  that these effects result from the slow re-orientation of aligned groups of diamagnetic phospholipid molecules within the cell membrane.
Effects on cardiovascular function, including arterial blood pressure and peripheral blood flow, are less clearly established [22,28].
Few studies have examined the effect of static MFs on reproduction and development: there are generally no effects by exposure up to 9.4T, but the studies showed several inconsistencies .
Also, sub-chronic exposure (10 weeks to a 9.4T static MF) seems to have no biological effects (alterations in heart rates, body weights, food and water consumption, blood biochemical and urinary parameters and major organ weights) in male and female adult rats or their progeny .
It is generally accepted that static fields below 1T are not genotoxic [30,31]. However, a recent study  reported significant, time and dose-dependent increases of the micronuclei frequency in mice exposed to static MFs of 2, 3 or 4.7T. Again, the general consensus is that there are insufficient studies to draw any conclusions relative to the genotoxicity or the carcinogenicity of static MF .
Studies on human volunteers exposed up to 8T, carried out to assess information about the relationship between exposure to high static MFs and human health, took into account as endpoints central and peripheral nervous activities, behavioural and cognitive functions, sensory perception, cardiac function, respiratory frequency, body temperature, but no conclusion could be drawn .
Temporary and dose-correlated vertigo and nausea in workers and patients exposed to static MFs higher than 2T have been found in several studies [34,35], while the correlation between the exposure and the metallic taste has not been confirmed . No significant differences among several physiological parameters (heart rate, blood pressure, blood oxygenation, core temperature, ECG, respiratory rate) have been checked during the exposure at 8T, together with complete reversible tachycardia imputable to the stress correlated with the exam .
Finally, acute neurobehavioral effects, such as eye–hand coordination speed and visual and auditive working memory problems after exposure to static fields at 1.5 and 3T have been reported for health volunteers in .
A non statistically significant increase in the number of spontaneous abortion of MRI workers has been reported . Different effects, such as fertility, length of gestation, birth weight, pregnancy outcome and offspring gender for pregnancies exposed to the MRI have also been reported , but these studies present methodological limitations and cannot be considered conclusive.
A recent review summarizes the epidemiological evidence of static MF exposure and long-term health effects: the few studies available have focused on cancer risks and the results from these studies are not sufficient to draw any conclusions .
Finally, the available data do not allow one to reach a firm conclusion about the health effects of the static MF .
A document of the World Health Organization (2006, ), stated that there are no evidences on the short and long term adverse effects of the MRI static MF on human health. This statement has been confirmed also more recently [16,17]. Considering the increased use of MR scanners with higher static MF values, there is an urgent need to perform studies to provide assurance about their safety.
3.1.2. Effects of Gradient MF
During an MRI examination, the gradient MF, which serves for the spatial localization in the image reconstruction process, is often switched on and off. For this reason, they are considered time varying MFs ranging between ELF and IF. Most of the available studies deal with possible association between residential ELF and cancer . ELF MF has been classified in group 2B (“possibly carcinogenic to humans”), due to the possible association between residential MFs and childhood leukaemia . Furthermore, a decreased survival of children with leukaemia after exposure to ELF magnetic fields has been observed , while no correlations have been established between ELF field exposure and breast cancer risk .
The time variation induces in the patient undergoing a MR scan, an electric field which could stimulate nerves and muscles, and could generate cardiac stimulation or even ventricular fibrillation. While the latter is a primary concern, being a life-threatening condition, possible peripheral nerve stimulation may cause discomfort and could not be tolerated by the subjects, thus interfering with the examination (e.g. due to patient movements) or would result in a request to stop the examination .
Due to technical difficulties for obtaining a reliable measure of induced electric currents, several works now are dealing with numerical simulations in human models .
In vitro effects
A significant increase of DNA strand breaks after ELF exposure was reported , while non-genotoxic mechanisms, such as stimulation of cell proliferation and apoptosis inhibition, can act as environmental agents for promoting cancer development . An increase of micronucleus frequency in human fibroblasts exposed to a 50 Hz power line signal has been reported .
Mouse cell cultures exposed to gradient fields for hours did not show any effects with gradient fields of 25 mT/m in 300 ms . Other studies [49,50] report no significant genotoxic effects as measured by sister chromatid exchange frequencies in human lymphocytes exposed to time varying fields of up to 220 μT, suggesting they are unlikely to act as carcinogens. Other studies report increased DNA synthesis in human fibroblast with exposure at 4 to 15 kHz , while fetal cell growth and cell cycle distribution of human lung fibroblasts exposed to gradient of 10mT/m are not affected . These results provided no support for a teratogenic effect of this type of MF.
Detrimental effects of co-exposure to ELF and environmental carcinogens are reported, such as recombination of radical pairs alterations, indicating interactions among MF and chemical and/or physical agents . This fact suggests that human population could be exposed to a variety of environmental insults which may not be genotoxic “per se”, but they may enhance the negative effects induced by other contaminants .
In vivo and ex vivo effects
In vivo studies on gradient MFs mainly deal with the importance of determining a threshold value and aim to understand any possible carcinogenic potential.
It was observed that dogs’ peripheral nerves are more sensitive to gradient MF, thus showing the lowest stimulation threshold . In other studies, it was observed that the threshold for respiration was three times more than the peripheral nerve stimulation threshold, while the cardiac one was about nine times greater than the peripheral nerve one [55,56]. Studies on reproduction and development of mammals showed that these parameters are not affected by IF field exposure .
A 2000’s review  analyzed patient safety in time-varying gradient fields associated to a MR scan and concluded that cardiac stimulation is very unlikely in present-day systems, while at sufficient amplitudes, peripheral nerve stimulation is perceptible (tingling or tapping sensations) and can cause patient discomfort. Current safety standards have been developed by the International Electrotechnical Commission , establishing that the threshold for cardiac stimulation is largely above the value causing peripheral nerve stimulation, thus avoiding subjects’ ventricular fibrillation .
The use of MRI gradient MF represents a potential health risk beside peripheral nerve and cardiac stimulation to the patient. With the advent of the new generation of MR systems characterized by higher static MF and faster gradient fields, their effects on human health should be the object of further and properly designed studies.
3.1.3. Effects of RF Fields
During an MRI scan, the patient is exposed to a time varying electromagnetic field in the RF range. It has been suggested that RF can induce effects via multiphoton absorption, i.e. through direct heating .
Thus, biological effects caused by RF field can be classified into two categories :
The non thermal effects have been less studied, however adverse effects mainly arise from a direct energy transfer from the field to the living system, which might be strongly non linear, and are dependent on the field frequency .
The temperature increase of the tissues due to the RF energy absorption, depends on parameters such as the electrical and geometrical tissue properties, the type of RF pulse used, its repetition time and the frequency of the radiation. The frequencies generally used in a MRI scanner are in the range at which high absorption occurs in the whole body . Certain organs, such as the eyes and testes are, particularly sensitive to heating due to lack of perfusion, so the presence of “hot spots” at those sites can be very dangerous for the patient safety [64,65].
Moreover, tattoos and permanent cosmetics realized with iron oxide or other metal-based pigments, can cause reactions or adverse events (including first and second-degree burns) [66–68].
The dosimetric parameter, normally used in safety standard and guidelines to quantify the energy absorption caused by RF, is the SAR . During a MR scan the patient’s temperature is not easy to measure so SAR represents a convenient parameter to control any possible temperature increases. Generally, the MRI scanner software allows monitoring of the SAR for the whole body: these values have to be always below the limits values set by IEC standard  and must be recognizable by the software, so that if the SAR value exceeds the standard limits, the software stops the scanning process. The admitted SAR is usually 4 W/kg for a whole body scanner, calculated for a body temperature increase up to a 0.6 °C and a scanning period of 20–30 min [70,71].
It has been reported that, while average whole body SAR remains below the safety limits [72,73], hot spots could occur all the same making the automatic control system of the scanner not totally sufficient to assure patient safety.
In vitro effects
There is a very wide body of literature regarding the possible induction of toxicity, genotoxicity, and transformation on mammalian cells in vitro due to high RF fields employed in cellular telephones (900-1,100 MHz) . Although it is well known that the radiation energy from mobile phones is much lower than the energy necessary to break chemical bonds, several authors have reported DNA strand breaks, micronuclei induction and chromosomal aberrations  in human fibroblasts. Transient increase of DNA strand breaks in embryonic stem cell have also been reported .
An attempt to independently replicate those results with the same biological system, under the same RF exposure, failed and negative results were obtained . Cell cycle kinetics  and apoptosis induction  has been reported to be unaffected.
It has been also investigated whether 24 h exposure to RFs, similar to those emitted by mobile phones, could affect micronuclei frequency and cell proliferation in cultured human peripheral blood lymphocytes: no evidence of genotoxicity or cytotoxicity was found .
Furthermore, possible effects related to the third generation wireless technology (1,950 MHz Universal Mobile Telecommunication System, UMTS) were investigated in human. The results indicated that both long and short duration intermittent exposures induce neither an increase in micronucleated cells, nor changes in cell cycle kinetics .
Studies on effects due to RF at frequencies related to MR procedures are far less available. The whole data on mammalian cell cultures  suggest that RF exposure does not cause an increase in gene mutation, in chromosome aberration frequency or in sister chromatid exchange frequencies, suggesting that RF exposure during a MR procedure is unlikely to be genotoxic.
Similar results, using the same biological endpoints, are obtained treating human lymphocytes .
To exclude thermal effects, in our study  the temperature of the liquid in the flasks was continuously monitored using a fiber optic temperature sensor: the observed thermal increase observed was always below 1 °C. This increase is known to be under the risk level, provided the thermoregulatory function of the patient undergoing MRI scan is not compromised .
In vivo and ex vivo effects
Several studies have been carried out on animals to determine thermoregulatory reactions to tissue heating due to RF radiation at typical MR frequencies. These experiments demonstrated that RF exposure can cause a body temperature increase . However, the results from animals cannot be extrapolated directly to humans since the pattern of the RF absorption strongly depends on the body size, the anatomical features and the sensitivity of the tissues .
As for in vitro experiments, most of the in vivo/ex vivo data on RF effects are related to mobile phone frequencies. The possible association between RF exposure due to mobile phone use and cancer has been largely subjected to epidemiological studies. Most of these studies found no association [84,85], while only a few suggested possible links . Data on cancer induction, mainly intracranial tumours, are contradictory [87,88].
The cancer risk related to RF fields generated by television and radio transmitters was also analysed : no study has confidently suggested any clear links to health effects .
Due to the increasing use of mobile phone by even young children, one important issue is related to and the question is about the possible differences in RF absorption between children and adults during the use of mobile phone .
Few studies have addressed the correlation between RF field exposure and the so-called “electromagnetic hypersensitivity”, which includes non-specific self-reported symptoms (headaches, fatigue, concentration difficulties). The data suggest that these symptoms cannot be correlated to RF exposure .
The first experiment on human thermal response to RF during a MR procedure was performed in 1985 : in subjects exposed to a SAR value equal to 4 W/kg, the temperature changes and other physiological parameters, such as heart rate, were monitored. No abnormal temperature increase or changes in physiological parameters were observed. Other studies on volunteers have always reported changes in body temperature of less than 0.6 °C, without alterations in parameters like heart rate, blood pressure and blood flow [94,95].
Another study on volunteers  exposed to MR procedures with a high whole body SAR value (6 W/kg) monitored tympanic and skin temperature, heart rate, blood pressure, oxygen saturation and skin blood flow: statistically significant changes where found in some parameters such as skin blood flow, systolic blood pressure and heart rate, but all these changes were within acceptable safety levels.
A 2000’s review summarized physiological alterations in visual, auditory, endocrine, neural, cardiovascular, immune, reproductive, and developmental functions, under RF exposure: high levels of exposure were found to be related to an alteration of these functions .
Special attention was paid to over-heating of gonads  and eyes [65,97] for their reduced capabilities of heat dissipation thus becoming possible hot spots. In these experiments the observed temperature, however, was always below the recognized safety thresholds.
To date there have been no epidemiological studies regarding RF fields associated with MR procedures. The ICNIRP therefore recommends epidemiological studies to be done on subjects with high levels of cumulative exposure or with particular conditions, like pregnant occupational workers. Because of the advent of new generation MRI scanners with higher MFs, there is an urgent need for monitoring workers .
Interactions between RF and biological tissues during MR procedures could be unsafe for patients . Most of the reported accidents are burns due to hot spots in presence of conducting materials close to the patient such as the leads of physiological parameters (heart rate, blood pressure, oxygen saturation and temperature) monitoring equipment. This kind of risk can be more serious in case of internal biomedical implants (aneurism clips, stent, etc) especially for implants that have elongated configurations and/or are electronically activated (neurostimulation systems, cardiac pacemakers) [10,99,100].
MRI generated RF are unlikely to be genotoxic, but unfortunately, to date no epidemiological studies are available to assess possible long term health effects due to these radiations.
3.1.4. Effects of combination of Static, Gradient and RF fields during MRI scan
During a MRI scan, patients are exposed to combinations of static, gradient and RF fields. Besides minor adverse events, such as nausea and rare allergic reactions or tissue necrosis, associated with containing-gadolinium-contrast agents used routinely for MR examinations , more relevant for human health are the effects on biological parameters. Unluckily, very few works deal with the biological effects due to the simultaneous exposure to the three types of MF.
The cell cycle progression was studied in human cell lines under conditions similar to MRI clinical routine exams and no alterations were observed . The effects of long duration high field MRI on fetal growth and postnatal development of mice were also studied in , without any statistically significant changes being observed.
Recently, some biophysical properties of erythrocytes were analyzed in 25 patients during a MRI scan . The results showed a significant decrease in red blood cells membrane permeability, membrane elasticity and erythrocytes sedimentation rate during MRI, but the removal of the MF resulted in a rapid return to the normal conditions.
In our work, the possibility that MRI tests could be associated to DNA damage was investigated by in vitro as well as in vivo experiments . Experiments were carried out both in vitro, by exposing lymphocyte cultures from healthy subjects to MRI for different periods and different variable magnetic fields (MFs) obtaining dose-effect curves, and in vivo, analyzing lymphocyte cultures set up from individuals before and after cardiac MRI scan. Statistically significant induction of MN was found consistently both in vitro and in vivo experiments. A certain degree of repair of the genetic damage across time was also observed. This former result is quite relevant for patient’s safety: after 48 hrs, the MN numbers returned into control values, suggesting that two cell divisions are enough to eliminate all MN from the lymphocytes population. This short recovery time may be due to death of micronucleated cells or to their dilution in the pool of unaffected dividing cells. In the in vivo experiments we used a clinical protocol for cardiac examinations but we consider our results to have a general impact for all MR procedures.
The observed increase of the MN frequency, followed by a rapid return to normal values, although not confirmative of a hypothesis of risk for people undergoing MRI examinations, strongly suggests the need for further studies.
3.2. Occupational Risk
The staff operating in the environment of MRI scanners is exposed daily for hours to essentially static MFs, as the other two kind of radiation, gradients and RF, are present only inside the scanner. However, when the clinical needs force them to move close to the scanner during the examination, they could also be exposed to the other two types of radiation. These concerns have also been raised recently [16,105] and to protect occupational workers, European Union has required to incorporate the physical agents directive (PAD) 2004/40/EC  into its legislation, which, in some cases, could restrict the use of MRIs.
A 2008’s review summarized studies on health effects of occupational exposure to static MFs : with the available data no firm conclusions can be drawn about these effects. According to the Directive 2004/40/EC , the workers exposed to MF should receive all necessary information about the potential risks; due to the uncertainties resulting from the available evidence, it is needed ability to find a balance between few certainties and several doubts.
Our work  also pinpointed the relevance of (sub)chronical exposure: during the in vitro experiments we used control flasks located in the console room, and other flasks, named as “room controls”, located in the scanner room, around three meters far from the scanner bore. These flasks were exposed to 1 Gauss static MF and to negligible RF and gradients fields. Room control data showed no statistically significant differences, even though a weak increase was always observed (data not shown). This observation suggests a need of awareness on occupational risk assessment for MRI operators, but also for the general population that could be exposed to different environmental insults, not genotoxic “per se”, which may enhance the negative effects induced by other biological, chemical and/or physical agents.
Are There Any Side Effects to Getting an MRI?
If you’ve never had an MRI, the prospect can be daunting. The procedure involves a large metal tube that may make loud noises or feel claustrophobic. However, MRIs are actually a very common and safe procedure that can have great benefits. The more you know about what to expect when you visit an Atlanta imaging center, the more likely you are to have a smooth process as you undergo these scans.
Many people worry that the MRI will have negative side effects, and while this is possible, it is very rare. Any information you have on how MRIs work and why they may pose risks will help you to feel good about your diagnostic scans.
What Is an MRI For?
MRI stands for Magnetic Resonance Imaging. These scans make use of a strong magnetic field and radio waves to produce pictures that are rendered on a computer screen. MRIs are powerful tools for diagnosis because they can show tissues, organs, and other structures inside your body. Where some tests like x-rays can show only single structures like bones, an MRI can give a complete picture of many body parts. For this reason, it can be used to detect abnormalities and tumors in the brain and spinal cords. MRIs are also commonly used to detect sports injuries like torn ligaments.
Preparing for Your MRI
Usually, there is very little you will need to do to prepare for your scan, besides understanding the process and setting your expectations. Because of the use of magnetics, you may need to remove any jewelry or medical devices that contain metal. Their function and position can be impacted by the magnets. If you are not able to remove an item, disclose it to your doctor and radiologist beforehand so they can determine the best option for you.
Once it is time for your scan, you will lie on a small bed that slides into the scanner, which is a large metal tube. A receiving device will be placed on the part of your body to be examined, and you will likely have a speaker or other communication device in the tube with you. In some cases, you may be given an injection of contrast dye to increase the picture quality.
When pictures are being taken, you will need to lie completely still for a couple of minutes to ensure no blurring. The scan is painless as there is little touching your body. The tube may also be very noisy, so you will usually be offered music or headphones. For some people, despite being a safe procedure, the tube can be claustrophobic and cause anxiety; if this may apply to you, speak with your care provider ahead of time to see if there are options for open scan machines or sedation.
Risks of an MRI Scan
Once all medical devices are accounted for and anxiety is controlled, there is no known risk involved in undergoing an MRI scan at a reputable Atlanta imaging center. The scan does not involve radiation like an x-ray, and therefore exposure is not a concern. If you do require medication to help with nerves, you will need to discuss any potential side effects with your doctor. There is also a very slight chance of a reaction to the contrast dye used.
Unless you were sedated, there are no after-effects of the scan and you should be able to continue your day as normal. The typical MRI lasts for 30-90 minutes, which is the biggest drawback. But because there is no exposure to radiation at this time, it is not a concern. A specialist will take the pictures generated by the MRI and interpret them to share with you at a later date.
It is not advised that pregnant women have an MRI scan unless it is urgent. This is not because there are known side effects on a fetus, but as a precaution.
MRI Scans in Atlanta
If you have been told an MRI would be beneficial, do not be scared of the process. MRIs are not known to cause side effects in most people and can be powerful tools to provide an accurate diagnosis. The images generated by an MRI can help diagnose complex and rare conditions, allowing them to be treated quickly and efficiently.
At AICA Orthopedics, we offer a state-of-the-art Atlanta imaging center staffed with experts. Our team of radiologists and doctors will make your MRI process as smooth and efficient as possible, providing not only results but personalized plans to address your conditions. Contact us today!
Potential Hazards and Risks | UCSF Radiology
Magnetic Field Risk The static magnetic field of the MRI system is exceptionally strong. A 1.5 T magnet generates a magnetic that is approximately 21,000 greater than the earth’s natural field. In such an environment ferromagnetic metal objects can become airborne as projectiles. Small objects such as paper clips and hairpins have a terminal velocity of 40mph when pulled into a 1.5 T magnet and therefore pose a serious risk to the patient and anyone else in the scan room. The force with which projectiles are pulled toward a magnetic field is proportional to the mass of the object and distance from the magnet. Even surgical tools such as hemostats, scissors and clamps, although made of a material known as surgical stainless steel, are strongly attracted to the main magnetic field. Oxygen tanks, gurneys, floor buffing machines, and construction tools are highly magnetic and should never be brought into the scan room. However there are non-ferrous oxygen tanks and gurneys available, which are MRI compatible. Sand bags must also be inspected since some are filled, not with sand, but with steel shot which is highly magnetic.
Consumer products such as pagers, cell phones, cameras and analog watches may be damaged by the magnetic field. Pacemakers may be reprogrammed or turned off by the magnetic field. The magnet field erases credit cards with magnetic strips. Patients with ferrous intra-cranial vascular clips may be at risk due to the possible movement of the clip. See Contraindications for MRI below.
Radio-frequency (RF) Field Risk The radio-frequency field may induce currents in wires that are adjacent or on the patient, causing skin burns. It may induce currents in intra-cardiac leads, resulting in inadvertent cardiac pacing. Prolonged imaging may cause the patient’s core body temperature to rise. In practice, significant patient heating is only encountered in infants.
Due to the risk of RF current induced thermal burns:
- To minimize the risk of synthetic fibers in clothes acting as a current inducer, all patients having a MR exam must be changed into hospital provided clothing (gowns) prior to imaging.
- All patients having a MR exam must be padded during imaging in accordance to manufacturer guidelines to minimize skin to skin, and skin to magnet bore contact.
- All patients must be provided a working alert device (squeeze ball), to able to communicate with the MRI technologist during imaging when in distress.
Cryogen Risk During a planned or accidental shutdown of the magnetic field (aka “quench”), the liquid Helium in the magnet turns into gas and may escape into the scan room displacing the oxygen in the room leading to asphyxia.
Biological Effects Due to Magnetic Field For the static magnetic fields currently used in MRI up to 2 Tesla, there are no known biological effects. The majority of studies show no effects on cell growth and morphology. Data accumulated by the National Institute for Occupational Safety, the World Health Organization, and the US State Department show no increased risk for leukemia or other cancer. Some reversible biological effects have been observed on human subjects exposed to 2.0 T and above. These effects include fatigue, headaches, hypotension and irritability.
90,000 Is MRI harmful? – DocDoc.ru
Is MRI harmful?
MRI is an informative method that allows you to diagnose diseases at the earliest stages. Its main advantage is the absence of harmful ionizing radiation. Tomography is based on the electromagnetic characteristics of hydrogen atoms, which are predominantly quantitative in human tissues.
A constant magnetic field of high power is maintained inside the apparatus.Radio signals pass through it, the frequency of which is close to the frequency of hydrogen vibrations. Due to a sharp increase in the amplitude of forced oscillations (resonance), radio waves are amplified. This is captured in a special matrix and converted into an image using a computer.
To date, there is no evidence that the condition of at least one patient has worsened due to MRI. Only a few patients experienced allergic reactions to the drug injected with contrast. However, the risk of developing allergies persists when taking absolutely all drugs, even ordinary vitamins.Therefore, it is safe to say that doing an MRI is not harmful.
How often can you undergo the procedure
MRI can be done as often as the situation requires. The electromagnetic waves used during the examination do not have a negative effect on internal organs (for example, as X-rays in X-ray examination). Usually, a second procedure is prescribed by a doctor to assess the effectiveness of the treatment performed or to study the state of organs after surgery.
Refusal of the next tomography is fraught with the progression of the disease, untimely adjustment of the treatment regimen.
If you are worried about a health problem, sign up for a diagnosis. The success of treatment depends on the correct diagnosis.
Who should not undergo the procedure
Magnetic resonance imaging, despite its safety, can not be done by all patients. It is contraindicated:
- in the first trimester of pregnancy,
- if there are metal objects in the body (hemostatic clips, pacemakers, wires in bones, artificial joints, etc.)),
- if a person is afraid of a confined space (claustrophobia).
This article is posted for educational purposes only, does not replace a doctor’s appointment and cannot be used for self-diagnosis.
19 December 2014
Harm to MRI
Often before the examination, the patient asks the question: “What is MRI and is MRI harmful?”
During the study, the patient is exposed to a strong magnetic field, but the negative effect of the field on human cells has not been proven by science at the moment.For this reason, tomography can be considered a safe and harmless way of examining and detecting pathologies for the body, in contrast, for example, to X-ray diagnostic methods, in which the body is exposed to harmful radiation.
In modern medicine, magnetic resonance imaging is an indispensable method for diagnosing pathologies of internal organs and tissues:
- brain, pituitary gland, orbits;
- liver, kidneys, gallbladder, pancreas, adrenal glands, other organs of the retroperitoneal space, abdominal cavity, small pelvis;
90,056 spine, spinal cord;
90,056 joints, elements of the musculoskeletal system;
90,056 vessels of the neck, head, internal organs, extremities;
90,056 soft tissues, lymph nodes.
Despite the safety of the study, harm to MRI can bring in cases where there are limitations and contraindications to diagnosis.
Sometimes patients ask: “ MRI: is it dangerous to conduct an examination?” This question should be answered in the negative, since there is no influence of harmful radiation during diagnostics, as in X-ray examinations, ultrasound, and the study is carried out by exposure to a magnetic field, about which the fact of a negative effect on human cellular structures has not been scientifically established.
However, tomography can be unsafe if contraindications are not taken into account. Diagnostics is prohibited if the patient has installed hearing aids, hemostatic clips of cerebral vessels (the field can cause bleeding), pacemakers (a magnetic field can interfere with his rhythm), other electronic devices, joint prostheses, metal fragments, tattoos. This is due to the peculiarities of the effect of the magnetic field and its ability to attract metal objects and disrupt the operation of electronic devices.Tomography is not indicated during the first trimester of pregnancy due to the peculiarities of its course during this period. Patients suffering from claustrophobia are advised to undergo diagnostics using open-type devices.
If the patient’s body does not have the listed limiting factors, magnetic resonance imaging is the most gentle, harmless, painless and informative diagnostic method.
In conclusion, it should be noted that one more point “for” tomography on the question of whether MRI is harmful to health is that in medical practice there were no cases when a patient became ill after diagnosis.Moreover, MRI is indicated for re-passage without any restrictions, unlike CT.
Why MRI is harmful for those who have contraindications to diagnostics, you can read in more detail on the corresponding section of the site.
When conducting diagnostics in closed devices, MRI has a certain danger with claustrophobia. This can cause panic attacks, restlessness and anxiety in the patient, increased heart rate, increased heart rate, and dizziness.
Is MRI Harmful – Healthcare Institution “Grodno University Clinic”
Everyone knows that not only the effectiveness of the prescribed treatment depends on the correctness of the diagnosis, but also the favorable outcome itself, or rather, the patient’s recovery.Modern medicine, in order to make an accurate diagnosis of a patient, often resorts to various complex examinations of internal organs and systems, and is not limited to blood tests alone. Today, with the help of ultrasound, you can not only detect tumors, but also learn about the state of your internal organs. But, ultrasound is not the only way to look inside the human body. There is also magnetic resonance imaging, or MRI. About this examination, about the possibilities that it provides, as well as about contraindications and more, about many other things – “magnetic resonance” in our today’s publication.
The tomographic method, which is used to study tissues and internal organs, by using such a physical phenomenon as nuclear magnetic resonance, is called magnetic resonance imaging or MRI. This research method is based on measuring the electromagnetic responses from the nucleus of the hydrogen atom, as well as the level of their activity under certain combinations of electromagnetic waves at a constant magnetic field and high voltage.
For those who are “you” with physics, one thing becomes clear from what has been said above – again, the human body is investigated with the help of electromagnetic waves, and a magnetic field, into which a person is placed, whose body is scanned by radio waves.All indicators and data of such studies fall into a special matrix, then into a computer, which processes all this data and gives the result in indicators and pictures.
If we talk about the duration of such a study, then, depending on the scope of the examination, the session of magnetic resonance imaging itself can take from twenty minutes to one and a half hours.
As a rule, this examination method is used to diagnose the spinal cord, brain, nervous system, cancer, tumors, neoplasms, as well as a number of other diseases.
As for the cost of such an examination, it is quite high and MRI is carried out solely as prescribed by a doctor, as well as, if there are certain indications.
Not many people know that earlier this type of research had a different, more complete name – nuclear magnetic resonance imaging. But, since the prefix “nuclear” was associated in patients with radiation and radiation, it had to be removed from the name. According to science and medicine, in fact, magnetic resonance imaging has nothing to do with radiation or even X-rays.Simply, all changes in the molecular composition of organs and systems of the human body are transmitted to the computer screen and make it possible to judge changes in the structure of organs.
Well, with how this type of examination goes and what it allows to diagnose – everything is clear. But, isn’t such interference harmful to our health?
Despite all the statements that the magnetic field is harmless to the human body, nevertheless, official medicine is inclined to believe that for the appointment of an MRI there should be weighty indications and it should be carried out exclusively according to the doctor’s prescription, who, having weighed on one scale, is possible harm to health that this type of examination can cause, and on the other – the benefit of making the correct diagnosis and the importance of an objective picture of the disease, decides whether to prescribe an MRI to his patient or not.
As for those for whom MRI is not recommended, these are pregnant women, patients with pacemakers, defibrillators, ferrimagnetic or other metal implants.
With regard to relative contraindications, the risk group includes people with insulin pumps, nerve stimulants, implants in the inner ear, prosthetic heart valves, hemostatic clips, patients with heart failure, claustrophobia, and nervous disorders.
Well, if you followed the fashion and decorated your body with a harmful tattoo, which was applied using special dyes, which included metal compounds, with the exception of titanium, this type of examination is also unsafe for you.
As you can see, we face a difficult choice. On the one hand, it is possible to conduct a fairly complete type of examination, which will allow us to form an objective picture of inflammatory processes, neoplasms in various organs of the human body, and, on the other hand, there is still a possible risk to which this type of diagnosis exposes us.
But we cannot say unequivocally whether MRI is harmful to human health or not, if only because each individual case has its own ratio of benefit, harm and risk.
In conclusion, I would like to wish one thing – be healthy and do not get sick!
Then, you will not have the need for examinations such as magnetic resonance imaging.
MRI doctor (head) of the MRI room Novitsky Yu.G.
90,000 Is MRI harmful to human health?
MRI uses a magnetic field, not ionizing radiation like X-rays or computed tomography
Despite the fact that magnetic resonance imaging as a diagnostic method appeared relatively recently, today it firmly occupies a leading position in the diagnosis of a number of diseases, visualization of organs and body systems, as well as the assessment of traumatic injuries of a very diverse nature.
Despite the fact that magnetic resonance imaging as a diagnostic method appeared relatively recently, today it firmly occupies a leading position in the diagnosis of a number of diseases, visualization of organs and body systems, as well as the assessment of traumatic injuries of a very diverse nature.
One of the most common myths about MRI is the myth that magnetic resonance imaging is radiation.This is based on the fact that the method is based on the phenomenon of nuclear magnetic resonance. In fact, the tomograph has no connection with nuclear reactors. Magnetic resonance imaging is not associated with ionizing radiation or the administration of any radioactive substances.
The essence of the method is the effect of a magnetic field on the human body and the registration of electro-magnetic impulses of the cells of our body with highly sensitive recording coils of an MRI tomograph. The difference in the frequency of these pulses is displayed on the screen in the form of a very detailed picture – images of thin sections of organs in different projections.Based on the images obtained, the doctor can establish, confirm or deny the alleged diagnosis.
There is no scientific fact that would prove the harm of MRI. According to statistics, among the millions of people who underwent this study, there were no cases of complications or consequences of the effect of the magnetic resonance imaging on the body. No radiation exposure occurs at the time of the study. The only inconvenience during MRI is the noise that the apparatus makes and the need to lie still for some time, the very action of the magnetic waves does not cause any harm to the body.
For example, the magnetic field that acts on the body at the moment of examination in an MRI scanner is comparable, and sometimes even less, to the magnetic radiation of a cell phone, laptop and, just imagine, an electric stove on which we cook food every day.
However, despite the fact that the study is safe, an MRI scan is necessary only after the doctor’s recommendation, since there are still contraindications to the procedure.
Conducting MRI is contraindicated. in the following cases:
– If the patient has a pacemaker or an artificial pacemaker.
– With ferromagnetic or electronic implants in the middle ear.
– Epileptic or convulsive seizures.
– Chronic diseases in the stage of decompensation.
– Renal failure (in cases of carrying out with contrast enhancement).
Magnetic resonance imaging is an absolutely painless and safe study , which can be performed at any age, both for children and the elderly. Due to the absence of radiation exposure to the body, magnetic resonance imaging can be performed as many times as necessary, without significant intervals in time, which makes it possible to evaluate the effectiveness of the therapy and promptly correct the treatment regimen.
But computed tomography (CT) refers to radiation diagnostic methods and when it is performed, X-rays are used, we will tell you about this in the following articles.
How does MRI work? Is MRI harmful? How often can you get an MRI scan? – these and many other questions arise when a person first encounters magnetic resonance imaging. These questions are absolutely logical, and our task is to give the most complete and reliable answers to them.Thank you for your confidence in MIBS-Moscow!
90,000 What is MRI? How does it happen, is it harmful to health?
Magnetic resonance imaging is one of the types of examination of the body using a special apparatus – a tomograph. In Brest, such a procedure is prescribed for the diagnosis of diseases:
- Cervical spine;
- Knee joint;
- Other bodies.
The tomographic diagnostic method is mainly prescribed for detecting malignant and benign tumors, examining the functioning of the nervous system, checking blood vessels. Doctors say this is a safe procedure. However, the presence of a number of contraindications raises doubts about this.
How is an MRI done?
MRI in Brest is carried out according to the same algorithm, regardless of which part of the body is being examined. First, the patient is given a referral for the procedure with recommendations regarding preparation for it.On the appointed day, a person arrives at the diagnostic room, removes all metal accessories and lies down on the moving part of the apparatus.
Unlike computed tomography or X-ray, this examination is carried out without the use of harmful ionizing radiation. Magnetic resonance imaging is performed by exposing the body to electromagnetic waves. A person is placed in a magnetic field and scanned with radio waves. Therefore, the tomographic method does not carry the risk of developing tumors.
Before the procedure, people with suspected oncological diseases are given a clear liquid to drink without a pronounced taste and smell. This is the so-called “contrast”, which allows you to better see the development of tumors.
The duration of the survey depends on the scale of the problems identified. On average, one session takes 20 to 90 minutes.
Is MRI harmful to health?
Exposure to magnetic fields, radio waves, electromagnetic waves is safe for humans.Therefore, the direction for magnetic resonance imaging is given to almost everyone, including young children. Only patients with:
- Implantable electrostimulators;
- Metal implants;
- Metallic ink tattoos.
Also, the procedure is not recommended for pregnant women, patients with decompensated heart failure and people suffering from claustrophobia.There is only one reason for this – a long stay in the confined space of the tomograph causes nervous feelings in such people. They are prescribed such a diagnosis only as a last resort.
What about an MRI of the brain? Are there any side effects?
The magnetic field created by the tomograph does not cause headaches and other negative reactions. Moreover, this is the only way to effectively detect aneurysms, tumors, damaged areas in the brain.
The results of the influence of electromagnetic waves on the body are transmitted to the matrix of the device, and from there to the computer screen.The received information is displayed in the form of a list of indicators, images, graphs.
A tomograph is a complex device that requires large financial investments, settings, and expensive maintenance. And in order to decipher the results of the examination, an experienced specialist is needed. Therefore, the prices for magnetic resonance imaging are always high. But since this type of diagnosis is both highly effective and safe, you can only sign up for the procedure in advance.
90,000 Is MRI harmful to health, is there a danger to the human body.
Today, in order to diagnose a patient or find out the cause of a disease, doctors of medical clinics in St. Petersburg have a wide range of diagnostic capabilities, including CT, ultrasound, X-ray, endoscopy, PET, MRI. One of the important criteria for choosing a research method is its safety. How can an ordinary patient understand if MRI is harmful to human health?
Some people are suspicious of this method of examination, believing that a person may receive radiation or the risk of developing cancer after a tomography.The patient has natural questions when the doctor directs for magnetic resonance imaging:
- Is this survey really safe?
- Is the tomograph reliable, won’t it bring even more health problems?
- How does it affect a person in the short and long term?
- Is it possible to carry out MRI for children and pregnant women?
- Are electromagnet waves harmful to the brain matter?
In our article we will try to figure it out and answer all the exciting questions.And then those patients who are wary of any modern diagnostic methods will be convinced of their effectiveness, and they will no longer have doubts about MRI – whether this examination is harmful for the patient’s organs, cells and internal tissues.
If in doubt, sign up for a free consultation.
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Is MRI dangerous for the human body
Magnetic resonance imaging (MRI) – a method for studying the soft and bone structures of the body by scanning due to the effect of resonance of electromagnetic waves in a constant magnetic field of the tomograph.MRI is considered a modern, high-tech form of hardware diagnostics. It gives a detailed picture of the patient’s condition, while acting non-invasively – without punctures, cuts and other negative consequences. The scanning procedure takes from 20 minutes to an hour, depending on the screening area and the study protocol. The doctor can see the results of diagnostics in the form of volumetric tomograms immediately during the examination and, if necessary, correct the screening process if any problem areas were found.
For a patient, an MRI procedure is an atraumatic event. The effect of MRI on the human body is not felt. There are no changes either in the structure of cells, or in mood and well-being, or in the psyche of the patient. MRI is a time-tested diagnostic method that has been tested in millions of patients. They began to diagnose the human body using MRI in the 70s of the last century. Although complete information about the principles of operation of MRI can be found on the Internet, not all people understand what a modern MRI machine is, how it differs from a computed tomography or X-ray machine, and whether it is safe.
How does the MRI scanner work on the human body
Magnetic resonance imaging is safe for humans, since its principle of operation is not based on X-rays, but on the strength of a magnetic field, and it cannot in any way affect the general state of human health. A tomograph is a large apparatus consisting of a camera in which a magnetic field is created, a table, and a complex system of sensors and computer installations. Before starting the scan, the patient is in the desired position lying on the table.When the examination begins, the table “enters” into the cylindrical chamber or under the canopy of the tomograph, depending on the model of the apparatus – closed or open. When the device is turned on, high-frequency vibrations of the device’s magnetic waves begin to interact with the hydrogen atoms of human cells. From this, the atoms line up along the north-south axis for a very short period of time. When the field of installation weakens, they return to their original position, while emitting energy, which is captured by the sensor system.These signals from the sensors are sent to the machine computer and digitized. Modern technology of the device makes it possible to make three-dimensional images from these signals.
During the examination, the radiologist decrypts all the collected data, and writes the resulting images to an electronic disk. The results of the examination (written interpretation, tomograms) provide the attending physician with comprehensive information for making a diagnosis and prescribing treatment. During the scan, no significant changes in the patient’s body at the cellular level occur.
Is it harmful to do MRI
There are categories of people who believe that if an MRI examination is prescribed, then it is not only dangerous for a person, but also affects the future health of his children. Some, for example, believe that due to tomography, headaches or oncology may subsequently appear. But long-term global diagnostic practice shows that MRI is completely safe for humans, if contraindications are not neglected.The consequences of MRI in the form of headache, dizziness, pain in the spine, the appearance of cancer cells are nothing more than myths and horror stories. And a person’s head can spin from banal overexcitement and excessive excitement, and the tomograph has absolutely nothing to do with it.
It is important to remember that MRI is a non-ionizing examination without any radiation. The patient does not receive any dose of radiation during screening, and MRI should not be confused with CT and X-ray (you can learn more about the compatibility of MRI and other types of diagnostics here).However, magnetic resonance imaging has its own contraindications and limitations. It is dangerous to perform tomography only for those people who have metal and electrostimulators in their bodies. Therefore, before signing up for an MRI scan, be sure to inform your doctor about any foreign bodies in your body. Some of them: dentures and implants, braces, modern hip joint or knee prostheses – are not a contraindication to tomography. But a number of incorporated objects such as: pacemakers, the Elizarov apparatus, old steel prostheses, small fragments of bullets will become a ban on scanning.
Is MRI of the brain harmful
The brain performs a vital function in the human body, so it is especially important to monitor its condition. During a routine examination by a neurologist, it is not always possible to make an accurate diagnosis based only on the collection of anamnesis data and laboratory tests, therefore, the patient is often prescribed an MRI of the brain. If the patient is often dizzy, pain relievers do not help, then an MRI scan of the head will show the cause of these pains.In this case, this research is simply necessary. It may be a simple migraine, or it may be a tumor, or some dangerous vascular pathology. Oddly enough, it is this procedure that people have the most mistrust: is MRI of the brain harmful? What if after an MRI you develop oncology or dementia? These fears are to some extent justified.
The brain is designed in such a way that any radiation effects from CT and X-ray are highly undesirable for it, therefore doctors always choose MRI as a priority method for diagnosing the head.If a person is prescribed an MRI of the brain, then there is a need for this and it is inappropriate to refuse this diagnosis due to fear of mythical harm. MRI, like ultrasound, does not give any harmful radiation to the structures of the brain. But ultrasound, as a way to diagnose the head, is not effective for adults. It is used to examine only infants up to one year old, while the baby’s fontanel is still open, and the ultrasound signal can break through the cranial plates. There is no point in postponing a CT scan due to fears of harming your brain.It is more important not to miss the moment, to figure out what is happening in the brain tissues, and to start therapy on time. As you can see, there is no harm here, but only the diagnostic benefit of the procedure.
MRI of the spine
MRI of internal organs
Is spine tomography harmful
When asked whether it is harmful to do an MRI of the spine, we can confidently say that it is not. MRI of the spine is prescribed by neurologists, surgeons, traumatologists in a huge number of cases: from injury and suspected tumor to attacks of intercostal neuralgia and osteochondrosis.With back pain, the patient himself, even without a doctor’s referral, can safely go to the procedure and not be afraid of whether an MRI of the spine is harmful. No need to listen to “smart” neighbors and acquaintances or pseudo healers. Indeed, in the treatment of any disease, the main thing is not to waste time, and MRI can detect any pathology of the spine, even at an early stage.
Influence of MRI on the child’s body
The best proof of the safety of magnetic resonance imaging is the ability to diagnose the body of a child of any age.It’s hard to watch when an adult is sick, even harder when a child is sick. When prescribing tomography for children, the reaction of parents is sometimes the question of whether MRI is harmful for a fragile child’s body. For very young children, MRI screening is prescribed if the diagnosis after ultrasound is unclear, or the cause of the brain or spinal cord disease cannot be established. The study takes place using a magnetic field, so there is no harm from the scan itself, but side effects from anesthesia are possible.Most of all, a small patient can be frightened by the absence of a mother nearby, the noise of the apparatus, an unfamiliar environment. In addition, he cannot lie still for a long time. Therefore, if an MRI is prescribed for a child under 4-5 years of age, it usually goes away under amnesia. Then the baby just sleeps while the scan is in progress.
Is MRI with contrast agent dangerous
If a person has a suspicion of oncology, then contrast-enhanced MRI is often performed. Then, before the examination, specialists always ask whether the patient has chronic liver and liver diseases or a high probability of pregnancy.The contrast agent is synthesized from the rare earth metal gadolinium. It is a hypoallergenic compound that rarely causes allergies. But if the patient suffers from acute renal or hepatic failure, his weak liver or kidneys may not be able to cope with the additional stress. Therefore, these patients are asked to be tested for iron and creatinine in the blood before MR screening. This allows the physician to evaluate the possibility of using the diagnosis without complications. During the contrasting procedure, the patient is injected intravenously with a special drug – a contrast agent.The drug tends to accumulate in areas of pathological tissue changes, and thus helps to identify oncology or any abnormal changes.
How often can MRI be done
MRI can be done with any frequency and frequency, at least 10 times a day, since it does not cause any harm to the body. It can be safely combined with X-ray or CT on the same day. A possible negative reaction of the patient to the tomography does not come from the physical impact of the tomograph on the cells of the body, but from the emotional state of the subject.If a person is very worried, took a lot of sedatives, did anesthesia in some part of the body to cope with the whole procedure, all this can cause a headache or dizziness after an MRI.
When MRI can harm a person
When a doctor asks a patient questions, it is important that the patient is honest. Does a person have magnetizable metal objects or electrical stimuli in their body? If yes, then examination is prohibited. For example, a pacemaker can break when exposed to a strong magnetic field and the person can die.Metal objects can become hot or move during the CT scan, causing severe pain to the patient and may cause internal bleeding.
If the client has tattoos or permanent make-up on his body, the radiologist should also be warned about this. This is because some tattoo inks contain metal elements. They can give a burning sensation while in the tomograph.
If a person is intoxicated, the diagnosis is not carried out. Remember, alcohol and MRI are incompatible.There will be no diagnostic effect from tomography if the subject cannot lie motionless. All MRI scans will be blurry and uninformative.
If there is an allergic reaction to gadolinium, then MRI with contrast is not done. When MRI cannot be done for contraindications, doctors will offer alternative types of hardware diagnostics: CT, ultrasound, colonoscopy, gastroscopy, mammography, endoscopy, laproscopy, angiography, PET or biopsy.
Do not be afraid of any diagnostics if it is prescribed by a specialist.You need to use the benefits of modern medicine and then you will not have to worry about the fact that it is too late to treat something. It is better to pass the examination on time and hear the cherished words from the doctor: You are healthy. If you have any questions about the possibility of using MRI in your particular case, the specialists of the City Recording Center will always be happy to help you get comments from experienced doctors. Call us – we are trying to help everyone!
List of primary sources
- Bulas D, Egloff A.Benefits and risks of MRI in pregnancy. Semin Perinatol. 2013; 37 (5): 301-304.
- Ivanov V.A. Nuclear magnetic resonance // Inventor-rationalizer.- I960.- No. 4.- P. 14-18.
- Hao D, Ai T, Goerner F, Hu X, Runge VM, Tweedle M. MRI contrast agents: basic chemistry and safety. J Magn Reson Imaging. 2012; 36 (5): 1060-1071.
- Panych LP, Madore B. The physics of MRI safety. J Magn Reson Imaging. 2018; 47 (1): 28-43.
MRI for claustrophobia
MRI is a type of examination that quickly and accurately shows diseases at an early stage. This procedure is painless and available to everyone, regardless of age, gender and degree of the disease.In most cases, magnetic resonance imaging does not require special training and is easily tolerated by patients. Claustrophobic people are a small exception. For this category of patients
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Indications and contraindications for MRI
The method of magnetic resonance imaging is based on the behavior of hydrogen proton nuclei in a magnetic field and has its own contraindications and indications, substantiated by the physics of this process.The main advantage of MRI is that no X-rays are used in scanning. Therefore, MRI has a minimum number of medical prohibitions and restrictions and is considered one of the safest methods.
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How to overcome your fear of MRI
Myths about MRI examinations paint a tomographic procedure as a horror story, in which the patient drives into a deep, dark cave, where he lies without lighting and is afraid of loud sounds, full of fear and horror.The fear of doing magnetic resonance imaging is not such a rare thing in the practice of doctors at medical centers in St. Petersburg, and in this article we will talk about how you can overcome the fear of MRI. It is no secret that many
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90,000 MRI: research features
Date of publication: .
It is not always possible to make an appointment for an MRI “today for tomorrow” even for a fee. Although in some centers there are no long queues, and one of the private Minsk clinics does this research around the clock. There are many who wish, and people are not deterred by the high cost of research.
Doctor of radiation diagnostics at the Minsk City Clinical Oncological Dispensary and the national representative of Belarus at the section of young scientists of the European Society of Radiology (ESR) and the European Congress of Radiology (ECR) Konstantin Kenigsberg told when it is worth doing an MRI scan, is it possible to go to the study with a tattoo, piercing or braces and what to do if you are claustrophobic and afraid of lying in the MRI machine.
1. What is the essence of the MRI method?
– Magnetic resonance imaging is one of the most sophisticated medical devices. To put it simply, there is a large cylinder-shaped magnet under the plastic shell of the tomograph, which creates a very powerful magnetic field in the room. As a result, with the help of additional parts of the apparatus, it is possible to receive a signal from hydrogen protons in our body.
Hydrogen in the human body is in the composition of various molecules, and they have different concentrations in different tissues.We act on hydrogen protons with energy and track how quickly the protons regain their original properties and emit energy back.
The device captures this energy and builds diagnostic images. Since the properties of protons differ depending on which molecules and tissues they are in, these tissues in the images differ in color, and, which is very important, by changing the settings of the programs, we ourselves can influence this. For example, make the liquid bright and the fatty tissue dark.This is one of the main advantages of the method – high soft tissue contrast.
2. How does MRI differ from computed tomography and X-ray?
– Externally, computed tomography (CT) and MRI machines are very similar to each other. There is the device itself, which has a tunnel, and the patient’s table, which is fed inside. However, the principle of operation of the technique is completely different.
The main advantages of the MRI method over all X-ray ones, including CT, are the absence of ionizing radiation and an amazing soft tissue contrast.
The CT method, in contrast to classical radiography, allows you to obtain not one image with summary information about all structures of the body within the frame, but many images of any area in high resolution with a certain slice thickness and step. But here it is important to understand the specific task of the study, because the more images and the better their quality, the greater the dose the patient will receive.
Radiography, fluoroscopy, X-ray computed tomography are based on the fact that on one side of the patient there is an X-ray tube that emits inhibitory X-ray radiation, and on the other side there is some kind of signal receiver – a screen, cassette or detector.Different tissues of the body inhibit the rays passing through them at different speeds. Therefore, for example, on X-rays, the lungs are black (the rays fly through them practically without stopping, because there is mainly air), and the bones are bright (it is not so easy to fly through a dense and strong bone).
3. When should you get an MRI?
– If we are not talking about traumatic brain injury or fractures, then MRI is several times more effective diagnostic method. We use additional programs that allow us to analyze biochemical and physiological processes in healthy and altered tissues and to accurately diagnose stroke even in the first hours when other methods are useless, tumors, infectious (encephalitis, meningitis) and inflammatory (eg, multiple sclerosis) diseases, developmental anomalies.With the help of MRI, the doctor can see the blood vessels of the brain, even without the use of contrast agents.
According to statistics, MRI of the spine is the most popular MRI study in our country, and this is no accident. Apart from the fact that there is nothing better for diagnosing spinal cord and nerves, vertebrae, herniated discs, spinal cord and nerves, as well as cerebrospinal fluid have different colors on MR images. This makes the diagnosis clear.
MRI is a non-alternative method for examining the bone marrow and all its pathology: benign and malignant tumors of the vertebrae, inflammatory and degenerative changes.
There is a misconception that if there is a problem with the bones, then a CT scan should be done. Actually this is not true. The bone is made up of the periosteum and the bone marrow. So, in case of bone fractures and bone tumors, it is imperative to start with an X-ray or CT scan, and for everything else, an MRI scan.
In addition to bones, joints have ligaments, tendons, menisci, cartilage … Something can be examined with good information content using ultrasound or radiography, but in order to get the maximum information about all the structures of the joint, it is better to undergo an MRI scan.
In terms of diagnostics of diseases of the abdominal cavity organs, there are specific features. In this case, ultrasound is a cheaper and harmless method, CT with contrast is more expensive, but much more informative, and MRI with or without contrast is expensive, time-consuming, but harmless and very informative. The choice is largely determined by a specific task, and the decision of which method to choose should be made by the attending physician. As a rule, they start with an ultrasound scan, and resort to contrast-enhanced CT or MRI for a detailed assessment.
If we are talking about a tumor, it is better to do an MRI immediately.MRI is the gold standard in the diagnosis of tumors of the cervix and body of the uterus, vagina, prostate and rectum. Most research is done for this very purpose. In the presence of a good apparatus and experienced doctors, the stage of the tumor process is taken out in the conclusion.
On the other hand, MRI is an openly weak method in lung diagnostics, at least because it is technically very difficult to get good images in a short time. X-ray methods do better here.The second weak point of MRI is the periosteum. She has a black signal, because there are simply not enough hydrogen protons, that is, to diagnose fractures, again, you need to use X-ray or CT.
4. How many times a year can an MRI be done?
– No restrictions. The method, in the absence of contraindications, is considered harmless.
5. Can MRI be done on the part of the body and head where there is a tattoo?
– It is possible, but no one can guarantee that the study will be described reliably, as the picture may be distorted.After all, the higher the magnetic field, the greater the distortion of the image due to the presence of metal in the tattoo in the area being examined. You also need to monitor your condition during the study and, if something happens, call a laboratory assistant in time.
Many watched the series “House Doctor”, where in one of the episodes the device “sucked” a tattoo from a patient’s skin due to a strong magnetic field. None of my colleagues, of course, have seen this in their practice, because the metal content in the tattoo paint is not that great.
It is worth making a reservation: the devices differ in many characteristics. The main one is the magnetic field strength, measured in Tesla. In our country, there are low-field (0.3-0.4 T), high-field (1.5 T) and ultra-high-field (3 T) machines.
Metal in the magnetic field of a tomograph has three properties that are unpleasant for us – it attracts, heats up and distorts the image. And although during the passage of an MRI at 1.5 T you will in no way see the “suction” of the tattoo from the skin, theoretically, in isolated cases in the field of 1.5-3 T of the tomograph, you can feel a slight heating of the skin in the area of the tattoo.Do not be afraid of this, because throughout the entire examination, the patient has a special signaling device in his hands – a pear. When you click on it, a laboratory assistant will immediately come to the patient, who will ask what happened and, if necessary, finish the procedure.
6. Is it possible to do an MRI of the brain if there is permanent makeup on the face?
– It is possible, but not to be expected, that the research area will be described in detail. Want to explore your eyeballs – come without makeup.They came with makeup – you felt a burning sensation in the eyelid area, press the pear that is given to you during the study, wait for the laboratory assistant and get out of the apparatus. You don’t need to endure.
The literature describes cases of minor burns of the eyelids during the passage of MRI on a 3-Tesla apparatus, but patients in those situations were in a serious condition and unconscious, therefore they could not inform the staff about their condition in time.
If you are going to an appointment with a doctor, and especially for an MRI scan for vision problems, then come without a make-up.This will give you more information. I can’t resist and ask you not to use an excess amount of perfume along the way. It is in your best interest for the staff to focus on your health problem rather than thinking about airing the room.
7. Can an MRI be done if you have braces?
– You can do it, but it is better to choose an apparatus with a field strength of 1.5 T or less. The braces will not vomit, but they may vibrate slightly during examination. Worse, the diagnostic images will not show anything within a radius of several centimeters from the braces.
But this information on braces is relevant for the study, for example, of the paranasal sinuses, but not for the diagnosis of the lumbar spine.
8. Can MRI be done if you have piercings?
– You can’t. The piercing must be removed before testing.
9. Is it necessary to remove rings, earrings, chains, bracelets before MRI?
– They must be removed. If you are doing an MRI and forgot to take off your watch, put your phone or bank card away, then the clock will stop, the phone will fly away and stop working, the plastic card will stop issuing money.
Before the examination, the patient is invited to the dressing room, where he completely empties his pockets, removes all jewelry and hairpins. When examining the spine, women must take off their bra. When examining the pelvis and lower back, jeans should be removed.
Operating temperature in the tomograph room – 17-22 degrees. Research takes from 10 minutes to an hour. It is better to take a cotton T-shirt and indoor pants without metal inserts. Research cannot be done in woolen clothing.
10. What are the contraindications for MRI?
– The strength of the magnetic field of the tomograph is more than 10 thousand times stronger than the magnetic field of the Earth. Therefore, when registering for a study, pay special attention to whether you have in your body:
- Pacemaker, neurostimulator, implanted hearing aid and other devices;
- clips on vessels. If there was an aneurysm of the artery and it was operated with the imposition of a metal clip, MRI is categorically contraindicated;
90,056 metal fragments, especially in the orbital area.There is a risk that the debris could dislodge and injure the surrounding tissue.
In the cases described above, MRI is not performed in principle, since this procedure is very dangerous for the patient.
As for joint prostheses, it is important to know from which metals and alloys they are made. Each prosthesis has its own name and passport, if it is not indicated there whether it is possible to undergo an MRI, there is an excellent online database where you can look. This site is also used by us, professionals.
If you do not know what the prosthesis is called, please check in the place where it was installed and take the corresponding extract. She may be asked in the MRI room.
All modern stents (metal meshes installed in the lumen of blood vessels to expand them) are made of non-magnetic metals. It is usually an alloy of nickel and titanium and is not a contraindication for MRI.
11. Can MRI be done for claustrophobia?
– If a person is really claustrophobic, he simply cannot withstand the examination inside the apparatus for 10-30 minutes.He will hit the pear in the first minute and ask him to remove it from the apparatus.
In this case, you should either turn to other methods (ultrasound, radiography, CT) or undergo an MRI on a low-field machine. There the magnet will be above and below, and on the sides there will be an open space. But these devices are much less powerful compared to 1.5 T, and the study will be much less informative.
12. Can MRI be done for pregnant women?
– Previously, MRI, just in case, was not performed on patients in the first trimester of pregnancy.Simply because teratogenic effects on the fetus have not been proven. But in 2016, a large scientific work of Canadian researchers came out, who tracked more than 15 thousand pregnant women and did not find any signs of the harmful effects of MRI either on pregnant women or on subsequently born children.
In general, there are not so many situations when an MRI scan is really necessary for pregnant women. We are talking here about very serious diseases, such as stroke, fetal anomalies (but most of these issues are solved by ultrasound), ischemia of the fetal brain (there is no alternative to MRI) and tumors in pregnant women themselves.
13. How to prepare for an MRI?
– First, you need to make sure that you have no contraindications.
Secondly, if you have prescribed an MRI of the abdominal cavity, small pelvis or the whole body, you need to start preparing for a day. It is necessary to exclude gas-forming food from the diet, if possible, come to the study on an empty stomach. If the study is in the afternoon, do not eat for six to eight hours. An adult needs to drink antispasmodics 30-40 minutes before the study, if the person tolerates them normally.The dosage and which drug to take is best specified when registering for a study. Immediately before the MRI, you need to go to the toilet and empty the rectum. Gas in the rectum creates artifacts and makes examining the prostate, uterus, or pelvis uninformative.
When examining the brain, spine, soft tissues of the neck and joints, special training is not required.
When choosing a location for the study, be guided by the profile of the institution: with a shoulder injury, it is better to go to clinics with a trauma bias, if a tumor is suspected, to oncological centers.Private centers usually have specialists of different profiles, but if in doubt, clarify these points when registering. The most important indicator of the study is precisely the qualifications and experience of the doctor.
The second important point is the choice of the device. If your back just hurts, and the doctor did not find signs of a serious illness, but there is a desire to see what the reason is, then you can choose any device. If the task is serious, I would recommend only 1.5- and 3-Tesla machines. Yes, 3-T diagnostics are more expensive, but when examining the nervous and musculoskeletal systems, small tumors, small regions (pituitary gland, orbits, prostate), the information content of the study increases.You can draw a parallel with the screen diagonal – you can watch a movie on your phone, but you won’t be able to examine the model of the protagonist’s clock in detail.
Among the 1.5-T machines there are devices of the initial, intermediate and expert level. This can also be clarified when registering for a study.
It is best to come to MRI with the results of laboratory tests, conclusions of narrow specialists and data from previous studies on disks. In international practice, MRI is a method of expert diagnostics.This test is designed to answer a specific question, such as ruling out a herniated disc, confirming a stroke, or evaluating the effect of chemotherapy for liver metastases. The specificity is such that the MRI doctor practically does not communicate with patients and must have all the necessary information along with the images. Then his work will be effective. If this does not happen, the doctor will not receive an answer to his question.