What is a CT scan and how does it work. How are CT scans used in medical diagnosis. What types of CT scans are available. How should patients prepare for a CT scan. What happens during a CT examination. Are CT scans safe and what are the risks.

Understanding Computed Tomography (CT) Scans

Computed tomography, commonly known as CT or CAT scanning, is an advanced medical imaging technique that produces detailed cross-sectional images of the body. This technology uses a series of X-ray beams taken from multiple angles to create three-dimensional representations of internal structures, allowing healthcare professionals to examine organs, tissues, and bones with remarkable clarity.

How does a CT scan work? The process involves a patient lying on a table that moves through a doughnut-shaped machine housing an X-ray tube and detectors. As the X-ray beam rotates around the patient, it captures multiple images from different angles. These images are then processed by a computer to create detailed cross-sectional views, often described as “slices” of the body.

Key Features of CT Scans:

• Non-invasive imaging technique
• Provides detailed 3D images of internal structures
• Can image both soft tissues and bones
• Faster and more detailed than conventional X-rays
• Enables quick medical decision-making

Why are CT scans so valuable in modern medicine? CT scans offer a unique combination of speed, detail, and versatility. They can reveal internal injuries and diseases that were previously only detectable through invasive procedures or post-mortem examinations. This capability has revolutionized diagnostic medicine, allowing for earlier detection and treatment of various conditions.

Clinical Applications of CT Scans

CT scans have a wide range of applications in medical diagnosis and treatment planning. Their ability to provide detailed images of various body parts makes them invaluable in numerous clinical scenarios.

Common Uses of CT Scans:

1. Brain and Head Imaging: Detecting tumors, strokes, and head injuries
2. Chest and Lung Examinations: Identifying lung diseases, tumors, and pulmonary embolisms
3. Abdominal and Pelvic Scans: Diagnosing diseases of the liver, kidneys, pancreas, and intestines
4. Spinal Evaluations: Assessing herniated discs, spinal stenosis, and fractures
5. Cancer Staging: Determining the extent and spread of cancer
6. Trauma Assessment: Quickly identifying internal injuries in emergency situations
7. Cardiovascular Imaging: Examining the heart and blood vessels

How do CT scans aid in cancer diagnosis and treatment? CT scans play a crucial role in oncology by helping doctors detect tumors, determine their size and location, guide biopsies, and monitor the effectiveness of treatments. They are particularly useful in staging cancer, which involves assessing how far the disease has spread and informing treatment decisions.

Types of CT Scans and Their Specific Uses

Various types of CT scans are utilized depending on the area of the body being examined and the specific diagnostic requirements. Each type offers unique insights into different aspects of the body’s internal structures.

Specialized CT Scan Techniques:

• Computerized Axial Tomography (CAT): The standard CT scan providing cross-sectional images
• CT Angiography (CTA): Used to examine blood vessels and detect blockages or aneurysms
• CT Urography: Focused on evaluating the urinary tract, including kidneys, ureters, and bladder
• Cardiac CT: Provides detailed images of the heart and coronary arteries
• Low-Dose CT: Used for lung cancer screening with reduced radiation exposure
• 4D CT: Captures movement over time, useful for examining organs like the heart or lungs

What makes CT angiography different from a standard CT scan? CT angiography involves the injection of a contrast dye into the bloodstream before the scan. This dye enhances the visibility of blood vessels, allowing for detailed examination of the circulatory system. It’s particularly useful in diagnosing conditions like coronary artery disease, aneurysms, and arterial blockages.

Preparing for a CT Scan: What Patients Need to Know

Proper preparation is essential for ensuring the accuracy and efficiency of a CT scan. While specific instructions may vary depending on the type of scan and the area being examined, there are general guidelines that most patients should follow.

General Preparation Steps:

1. Inform your doctor of any allergies, especially to iodine or contrast materials
2. Notify the medical team if you’re pregnant or suspect you might be
3. Follow any fasting instructions provided by your healthcare provider
4. Wear comfortable, loose-fitting clothing without metal fasteners
5. Remove all jewelry, dentures, and other metallic objects before the scan
6. Bring previous imaging studies if available for comparison

How should patients prepare for a CT scan with contrast? If your CT scan requires contrast material, you may be asked to fast for several hours before the procedure. You’ll also need to drink plenty of water to stay hydrated. Some patients may require blood tests to check kidney function before receiving contrast material. Always follow the specific instructions provided by your healthcare team.

The CT Scan Procedure: What to Expect During the Examination

Understanding the CT scan process can help alleviate anxiety and ensure a smooth examination. While the specifics may vary depending on the type of scan, most CT procedures follow a similar format.

Typical Steps in a CT Scan Procedure:

• You’ll be positioned on the CT scanner table, usually lying on your back
• The table will move slowly through the doughnut-shaped scanner
• You’ll be asked to remain still and may be instructed to hold your breath briefly
• The scan itself usually takes only a few minutes
• If contrast is used, it may be administered orally, intravenously, or rectally
• The entire process, including preparation, typically lasts 15-30 minutes

Is a CT scan painful or uncomfortable? CT scans are generally painless and non-invasive. You may experience slight discomfort from lying still on the table or from the insertion of an IV for contrast material. Some patients report a warm sensation or metallic taste when contrast is injected. The scanner itself makes some noise, but it’s usually not loud enough to cause discomfort.

Safety Considerations and Potential Risks of CT Scans

While CT scans are generally considered safe and provide valuable diagnostic information, it’s important to understand the potential risks associated with the procedure. The primary concern with CT scans is exposure to ionizing radiation.

Key Safety Considerations:

1. Radiation Exposure: CT scans use X-rays, which are a form of ionizing radiation
2. Contrast Material Reactions: Some patients may experience allergic reactions to contrast dyes
3. Pregnancy Considerations: CT scans are generally avoided during pregnancy unless absolutely necessary
4. Cumulative Radiation Exposure: Frequent CT scans over time may increase long-term radiation risks
5. Children’s Sensitivity: Children are more sensitive to radiation and require special considerations

How do medical professionals balance the benefits and risks of CT scans? Healthcare providers carefully weigh the diagnostic benefits of CT scans against the potential risks of radiation exposure. They follow the ALARA principle (As Low As Reasonably Achievable) to minimize radiation dose while maintaining image quality. Advanced CT technologies and protocols have significantly reduced radiation exposure in recent years.

Interpreting CT Scan Results: From Images to Diagnosis

After a CT scan is completed, the images are carefully analyzed by radiologists and other specialized physicians. Understanding how these images are interpreted can help patients better comprehend their diagnostic process.

Steps in CT Scan Interpretation:

• Image Reconstruction: Raw data is processed to create detailed cross-sectional images
• Radiologist Review: A trained radiologist examines the images for abnormalities
• Comparison with Previous Studies: New images are often compared to prior scans if available
• Consultation with Referring Physician: The radiologist may discuss findings with the patient’s doctor
• Report Generation: A detailed report of the findings is prepared
• Patient Communication: Results are typically communicated to the patient by their referring physician

How long does it take to get CT scan results? The time to receive CT scan results can vary. In emergency situations, preliminary results may be available within minutes. For routine scans, it typically takes 24 to 48 hours for the radiologist to review the images and prepare a report. The referring physician will then review these results and discuss them with the patient, which may take a few additional days.

Advancements in CT Technology: The Future of Medical Imaging

CT technology continues to evolve, with new advancements improving image quality, reducing radiation exposure, and expanding diagnostic capabilities. These innovations are shaping the future of medical imaging and patient care.

Recent Innovations in CT Scanning:

1. Dual-Energy CT: Provides enhanced tissue characterization and reduces artifacts
2. Spectral CT: Allows for better material differentiation and contrast enhancement
3. Ultra-High Resolution CT: Offers unprecedented detail for small structure imaging
4. Artificial Intelligence Integration: Enhances image reconstruction and aids in diagnosis
5. Photon-Counting CT: Promises improved image quality with lower radiation doses
6. Mobile CT Units: Bring advanced imaging capabilities to remote or emergency settings

How will these advancements impact patient care? These technological improvements are expected to lead to earlier and more accurate diagnoses, reduced radiation exposure, and expanded applications of CT imaging. For instance, AI-assisted image analysis could help detect subtle abnormalities that might be missed by human observers, potentially improving early detection of diseases like cancer.

CT scanning has revolutionized medical imaging and diagnosis since its introduction in the 1970s. Its ability to provide detailed, cross-sectional images of the body’s internal structures has made it an indispensable tool in modern healthcare. From detecting brain tumors to guiding complex surgical procedures, CT scans continue to play a crucial role in improving patient outcomes across a wide range of medical specialties.

As technology advances, we can expect CT scanning to become even more precise, safer, and more widely accessible. The integration of artificial intelligence and machine learning algorithms promises to enhance image quality and diagnostic accuracy further. Meanwhile, ongoing efforts to reduce radiation exposure are making CT scans safer for patients of all ages.

For patients undergoing CT scans, understanding the process, its benefits, and potential risks can help alleviate anxiety and ensure optimal preparation. By working closely with healthcare providers and following recommended guidelines, patients can contribute to the success of their CT examinations and benefit from the valuable insights these scans provide.

As we look to the future, CT scanning will undoubtedly continue to evolve, offering new possibilities for non-invasive diagnosis and treatment planning. This ongoing progress in medical imaging technology holds the promise of earlier disease detection, more personalized treatment approaches, and ultimately, better health outcomes for patients worldwide.

CT Scans Denver, Fort Collins & more

Before you get a CT scan, here’s what you should know.

• What Is a Computed Tomography (CT) Scan?
• Uses for CT Scans
• Types of CT Scans
• CT Scan FAQ’s
  • How will I prepare for my CT Scan?
  • What will happen during the exam?

What Is a Computed Tomography (CT) Scan?

A computed tomography scan, more commonly referred to as CT or CAT scans, is medical imaging formed through a series of X-ray views taken from different angles, allowing for three-dimensional representations of bodily structures. The images produced enable doctors to look inside your body, similar to looking at the inside of a loaf of bread by slicing it. The special X-ray images are of the slices of bodily structures that doctors are interested in examining more closely. At Health Images, our CT scanner produces spiral slices, which is the latest and fastest CT scan technology available.

CT scans are frequently used to evaluate the brain, spine, neck, abdomen and chest, providing clear images of both soft and hard tissue.

The pictures produced by a CT scan allow doctors to make medical decisions very quickly if need be. Because of this, CT exams are one of the most commonly performed medical procedures in both hospitals and imaging centers. These scans help doctors find diseases and injuries that previously could only be found through surgery or an autopsy. Although it uses low dose radiation, CT scans are relatively safe and non-invasive.

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Uses for CT Scans

CT scans are useful in many different medical situations in which diagnostic imagery is needed. They can evaluate subtle abnormalities in your soft tissue, such as the brain or other organs. These images are also used when you have specific symptoms like pain or dizziness. They can even be helpful in examining the spread of diseases like cancer.

Depending on where the CT scan is directed in your body, there are a variety of uses:

• Head or Brain CT Scans: Look for masses, stroke, bleeds and other abnormalities, as well as examine the skull
• Neck CT Scans: Study lumps and look for enlarged lymph nodes or glands
• Chest CT Scans: Offer further insight into abnormalities caught by a regular chest X-ray
• Abdominal or Pelvic CT Scans: Check the organs found in this region and diagnose unexplained abdominal pain
• Sinus CT Scans: Diagnose and detect sinus disease or obstructions
• Spine CT Scans: Detect spine issues like narrowing of the spinal canal or a herniated disc, as well as fractures

Types of CT Scans

At Health Images, we specialize in various types of CT scans, including:

• Computerized Axial Tomography: Also referred to as a CT or CAT scan, this is a computerized X-ray procedure that provides a three-dimensional scan of your brain or other parts of your body. It’s commonly used to find irregularities, disease or internal damage, but can also help guide surgeons during complicated operations. During a CT scan, you must lay on your back as your body moves through a tube. The entire procedure usually takes 30 minutes or less.
• CT Angiography: This minimally invasive medical test helps doctors diagnose and treat a variety of medical conditions. Frequently, a contrast dye is injected through an IV during the CT scan to produce detailed images of your blood vessels and tissues. A CT angiogram helps us determine if a blood vessel is blocked. If it is blocked, the images then allow us to find where the blockage is, as well as how big it is. It also helps us identify aneurysms or plaque buildup. CT angiograms are less invasive than standard angiograms.
• CT Urography: A urography is a specialized radiological exam that focuses on evaluating the urinary tract, specifically the kidneys, ureters and bladder. It uses CT technology to produce cross-sectional images of these internal organs, which allows your physician to diagnose conditions and plan a course of action. It’s often used to detect kidney stones or evaluate patients who have blood in their urine.

What is a CT Scan?

Computer Assisted Tomography (CAT), also known as CT (computerized tomography) is an x-ray technique that uses a special scanner to create cross-sectional images of the body and head. This produces “slices” like the slices in a loaf of bread. Our CT scanner performs spiral slices – the newest and fastest scanning technology available.

CT’s can image the internal portion of the organs and separate overlapping structures precisely. Unlike standard X-rays which take a picture of the whole structure being examined, CT has the ability to image that same structure one cross-section or “slice” at a time. This allows the internal body area being examined to be depicted in much greater detail than standard X-rays. CT is also able to provide clear imaging of both soft tissues, such as the brain, as well as dense tissue like bone.

Because a CT scan uses an ultra-thin, low dose X-ray beam, radiation exposure is minimized.

How will I prepare for my CT Scan?

Depending on the area of the body being imaged, you may be asked to drink a flavored mixture called contrast that will aid in the evaluation of your stomach and intestines.

Certain types of studies also require an IV contrast material, which will be administered through a vein (usually in your arm), once you are in the exam room.

If your exam requires an IV contrast material to highlight certain parts of your body, you may feel a warm sensation throughout your body and/or a metallic taste in your mouth once the IV is administered.

What will happen during the exam?

When you enter the exam room, you will be asked to lie on the CT table. The technologist will explain the procedure to you and position you on the scanning table. The table will then move to the center on the part of your body being examined. You will be able to see out both ends of the scanner, and you will be able to talk to your technologist via a two-way microphone. The table will move within the scanner during the exam. It is normal to hear whirring or clicking noises while the exam is being done.

While the exam is being done, all you need to do is relax and remain as still as possible. You may be asked to hold your breath for short periods of time.

50 years ago, the first CT scan let doctors see inside a living skull – thanks to an eccentric engineer at the Beatles’ record company

The possibility of precious objects hidden in secret chambers can really ignite the imagination. In the mid-1960s, British engineer Godfrey Hounsfield pondered whether one could detect hidden areas in Egyptian pyramids by capturing cosmic rays that passed through unseen voids.

He held onto this idea over the years, which can be paraphrased as “looking inside a box without opening it. ” Ultimately he did figure how to use high-energy rays to reveal what’s invisible to the naked eye. He invented a way to see inside the hard skull and get a picture of the soft brain inside.

The first computed tomography image – a CT scan – of the human brain was made 50 years ago, on Oct. 1, 1971. Hounsfield never made it to Egypt, but his invention did take him to Stockholm and Buckingham Palace.

An engineer’s innovation

Godfrey Hounsfield’s early life did not suggest that he would accomplish much at all. He was not a particularly good student. As a young boy his teachers described him as “thick.”

He joined the British Royal Air Force at the start of the Second World War, but he wasn’t much of a soldier. He was, however, a wizard with electrical machinery – especially the newly invented radar that he would jury-rig to help pilots better find their way home on dark, cloudy nights.

After the war, Hounsfield followed his commander’s advice and got a degree in engineering. He practiced his trade at EMI – the company would become better known for selling Beatles albums, but started out as Electric and Music Industries, with a focus on electronics and electrical engineering.

Hounsfield’s natural talents propelled him to lead the team building the most advanced mainframe computer available in Britain. But by the ‘60s, EMI wanted out of the competitive computer market and wasn’t sure what to do with the brilliant, eccentric engineer.

While on a forced holiday to ponder his future and what he might do for the company, Hounsfield met a physician who complained about the poor quality of X-rays of the brain. Plain X-rays show marvelous details of bones, but the brain is an amorphous blob of tissue – on an X-ray it all looks like fog. This got Hounsfield thinking about his old idea of finding hidden structures without opening the box.

A new approach reveals the previously unseen

Hounsfield formulated a new way to approach the problem of imaging what’s inside the skull.

X-rays beam through each ‘slice’ of brain, oriented at each degree from 1 to 180 in a semicircle.
Edmund S. Higgins, CC BY-ND

First, he would conceptually divide the brain into consecutive slices – like a loaf of bread. Then he planned to beam a series of X-rays through each layer, repeating this for each degree of a half-circle. The strength of each beam would be captured on the opposite side of the brain – with stronger beams indicating they’d traveled through less dense material.

Calculating the strength of each X-ray once it’s passed through the object, and working backward with an impressive algorithm, it is possible to construct an image.
Edmund S. Higgins, CC BY-ND

Finally, in possibly his most ingenious invention, Hounsfield created an algorithm to reconstruct an image of the brain based on all these layers. By working backward and using one of the era’s fastest new computers, he could calculate the value for each little box of each brain layer. Eureka!

But there was a problem: EMI wasn’t involved in the medical market and had no desire to jump in. The company allowed Hounsfield to work on his product, but with scant funding. He was forced to scrounge through the scrap bin of the research facilities and cobbled together a primitive scanning machine – small enough to rest atop a dining table.

Even with successful scans of inanimate objects and, later, kosher cow brains, the powers that be at EMI remained underwhelmed. Hounsfield needed to find outside funding if he wanted to proceed with a human scanner.

Schematic diagram of the CT scanner included in Hounsfield’s U.S. patent.
Godfrey Newbold Hounsfield

Hounsfield was a brilliant, intuitive inventor, but not an effective communicator. Luckily he had a sympathetic boss, Bill Ingham, who saw the value in Hounsfield’s proposal and struggled with EMI to keep the project afloat.

He knew there were no grants they could obtain quickly, but reasoned the U. K. Department of Health and Social Security could purchase equipment for hospitals. Miraculously, Ingham sold them four scanners before they were even built. So, Hounsfield organized a team, and they raced to build a safe and effective human scanner.

Meanwhile, Hounsfield needed patients to try out his machine on. He found a somewhat reluctant neurologist who agreed to help. The team installed a full-sized scanner at the Atkinson Morley Hospital in London, and on Oct. 1, 1971, they scanned their first patient: a middle-aged woman who showed signs of a brain tumor.

It was not a fast process – 30 minutes for the scan, a drive across town with the magnetic tapes, 2.5 hours processing the data on an EMI mainframe computer and capturing the image with a Polaroid camera before racing back to the hospital.

The first clinical CT scan, with brain tumor visible as darker blob.
‘Medical Imaging Systems: An Introductory Guide,’ Maier A, Steidl S, Christlein V, et al. , editors., CC BY

And there it was – in her left frontal lobe – a cystic mass about the size of a plum. With that, every other method of imaging the brain was obsolete.

Millions of CT scans every year

EMI, with no experience in the medical market, suddenly held a monopoly for a machine in high demand. It jumped into production and was initially very successful at selling the scanners. But within five years, bigger, more experienced companies with more research capacity such as GE and Siemens were producing better scanners and gobbling up sales. EMI eventually exited the medical market – and became a case study in why it can be better to partner with one of the big guys instead of trying to go it alone.

King Carl Gustaf awards the Nobel Prize to Hounsfield in Stockholm on Dec. 11, 1979.
Keystone/Hulton Archive via Getty Images

Hounsfield’s innovation transformed medicine. He shared the Nobel Prize for Physiology or Medicine in 1979 and was knighted by the Queen in 1981. He continued to putter around with inventions until his final days in 2004, when he died at 84.

In 1973, American Robert Ledley developed a whole-body scanner that could image other organs, blood vessels and, of course, bones. Modern scanners are faster, provide better resolution, and most important, do it with less radiation exposure. There are even mobile scanners.

Modern CT scans provide much higher resolution images of the ‘slices’ of the brain than Hounsfield’s original scan did in 1971.

By 2020, technicians were performing more than 80 million scans annually in the U.S.. Some physicians argue that number is excessive and maybe a third are unnecessary. While that may be true, the CT scan has benefited the health of many patients around the world, helping identify tumors and determine if surgery is needed. They’re particularly useful for a quick search for internal injuries after accidents in the ER.

And remember Hounsfield’s idea about the pyramids? In 1970 scientists placed cosmic ray detectors in the lowest chamber in the Pyramid of Khafre. They concluded that no hidden chamber was present within the pyramid. In 2017, another team placed cosmic ray detectors in the Great Pyramid of Giza and found a hidden, but inaccessible, chamber. It’s unlikely it will be explored anytime soon.

This article has been updated to correct the spelling of the name of Hounsfield’s boss at EMI, Bill Ingham.

[You’re smart and curious about the world. So are The Conversation’s authors and editors. You can read us daily by subscribing to our newsletter.]

Principles of operation of MRI. MRI Center Siberian Regional Tomography Center in Novosibirsk

With the rapid development of global technology, many imaging techniques have been invented, such as computed tomography, radiography, and MRI imaging. Medical imaging is a technology that is used to obtain images of the human body for medical purposes such as diagnosing or investigating diseases. Imaging is also used for medical research, for example, using MRI technology, scientists have successfully obtained a three-dimensional image of the human brain, which has helped them in studying the functions and structure of this most important organ of the human body.

What is an MRI?

Magnetic resonance imaging (MRI) is one of the modern methods of radiation diagnostics, which allows non-invasively obtaining images of the internal structures of the human body.

The most important advantage of MRI in comparison with other methods of radiation diagnostics is the absence of ionizing radiation and, as a result, the effects of carcinogenesis and mutagenesis, which are associated with the risk of exposure to X-rays.

MRI is the only non-invasive diagnostic method with high sensitivity and specificity in detecting edema and bone tissue infiltration.

The development of MR spectroscopy and diffusion MRI, as well as the creation of new organotropic contrast agents is the basis for the development of “molecular imaging” and allows for histochemical studies in vivo.

MRI physics

MRI as a research method is based on measuring the electromagnetic response of atomic nuclei located in a strong constant magnetic field in response to their excitation by a certain combination of electromagnetic waves. In MRI, such nuclei are the nuclei of hydrogen atoms, which are present in large quantities in the human body as part of water and other substances.

The nuclei of hydrogen atoms – protons – have magnetic properties that can be used to create images.

Now more. The human body is 80% water. Water molecules are made up of one oxygen atom and two hydrogen atoms. All atoms are made up of nuclei around which there are a certain number of orbits of electrons. The nucleus of the hydrogen atom, the proton, emits pulses that are used to produce MR images.

Protons have a property called spin (from English – rotation). It can be thought of as a factor that causes the proton to rotate around its own axis and behave like a small two-pole magnet.

In a magnetic field, the axis of rotation can be oriented in the direction of the lines of force or against it, just as the poles of real magnets are attracted or repelled.

In practice, most protons are oriented in the direction of the magnetic field lines. The use of a beam of radio waves in MPT upsets this balance. When the radiation is turned off, the protons begin to return to their original state, which is different for different types of tissues. At the same time, they emit energy pulses, which are recorded by an MP tomograph. Based on these data, a tomogram is built.

The principle by which images can be built is that different organs or tissues inside the human body have a different number of water molecules, and therefore respond to electromagnetic waves at different speeds. Using a computer to calculate, it is possible to obtain images of organs and tissues just on the basis of this reaction rate.

About tomographs

The tomograph is a big magnet. According to the strength of the magnet, scanners are divided into low-field (up to 0.5T), medium-field (from 0.5T to 1.0T), high-field (from 1.0 to 3.0T) and ultra-high-field (more than 3.0T). The most widespread in clinical practice are 1.5 T tomographs, which in most cases provide comprehensive information about the structure of tissues and organs.

The process of obtaining images with MR tomography is longer compared to other studies (ultrasound diagnostics, X-ray and CT), on average, scanning one area is about 20 minutes, during which the patient must lie still. High-field MR systems (1.5T) have a relatively fast image acquisition and processing capability compared to low-field magnets.

During a long scan, RF radiation can cause the patient to feel hot, to prevent excessive heating of tissues in modern tomographs, protection is installed that limits the strength of the radio frequency pulse, in accordance with international safety standards.

MRI scanners are divided into “open” and “closed” types. The first type is characterized by the absence of a closed aperture, which plays an important role for patients with claustrophobia, but such tomographs usually have a low magnetic field strength, and, consequently, resolution, in addition, studies are performed for a longer time. The vast majority of tomographs in clinical practice are of a closed type. In a closed tomograph, the patient is almost completely in a closed aperture, which makes it possible to achieve high resolution and scanning speed.

What MRI shows

Magnetic resonance imaging is successfully used to diagnose diseases:

• brain;
• spine;
• thyroid;
• liver;
• gallbladder and ducts;
• pancreas;
• kidney;
• spleen;
• joints;
• spinal cord;
• vessels of the head, neck, abdominal region;
• pelvic organs;
• soft tissues;
• etc.

All of the above anatomical structures are perfectly visualized on MRI images. The results of diagnostics make it possible to identify deviations in the work of the organs under study with high accuracy.

When MRI is prescribed

The wide possibilities of magnetic resonance diagnostics make its use indispensable in the case of:

• the need for a primary diagnosis;
• conducting a comprehensive survey;
• preparation for surgery;
• tracking the effectiveness of the applied therapy and treatment methods.

In each individual case, the choice of diagnostic technique is carried out by the attending physician. Magnetic resonance imaging is more often than other methods used to detect diseases and injuries of soft tissues.

MRI is indispensable for diagnosis:

• Neoplasms.

Magnetic resonance imaging can clearly identify the boundaries and size of the tumor, as well as the degree of its germination in soft tissues. No other method of radiation diagnostics is able to give such a clear and detailed picture of diseases.

MRI also makes it possible to determine the nature of the tumor with a high degree of probability. Malignant neoplasms have fuzzy boundaries and grow into the surrounding tissues. Benign neoplasms, as a rule, are clearly differentiated from healthy tissues.

• Diseases of the brain.

The high accuracy of magnetic resonance imaging makes it possible to visualize such small anatomical structures as the pituitary gland and the sella turcica. Also, MRI with brain contrast is highly effective for diagnosing demyelinating diseases (multiple sclerosis, Parkinson’s disease, etc.), as it allows you to clearly see the structure of altered nerve tissues.

The image of the brain obtained using contrast-enhanced MRI of the brain is especially clear, since magnetic waves do not show hard anatomical structures well, and artefacts from the bones of the skull do not appear on brain images.

• Diseases of the intervertebral discs.

You can find detailed information about a particular area of ​​research on the relevant pages:

• Brain MRI;
• Head MRI;
• MRI of the spine;
• MRI of the abdominal organs;
• MRI of the pelvis;
• MRI of the joints;
• soft tissue MRI;
• MRI of vessels (angiography);
• Breast MRI.

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What MRI shows 🚩 indications and contraindications, preparation for MRI

MRI is a modern type of radiodiagnosis using magnetic radiation, which allows you to get a detailed and clear image of the internal anatomical structures of the body.

Operating principle of the tomograph

The physical phenomenon underlying the use of magnetic resonance imaging is called magnetic resonance. The essence of the physical law lies in the ability of the nuclei of some chemical elements that make up the human body to change their energy potential under the influence of an intense magnetic field. The energy released during this process is captured and converted by the tomograph into an image on the computer screen.

Advantages of MRI

Magnetic tomography allows you to get a three-dimensional image of the examined areas in three projections. During the procedure, the device makes many slices, the thickness of which can be set individually and is usually 2-4 mm.

Images obtained with a tomograph

Obtaining a large number of sections allows you to examine the entire organ as a whole, and detect even the slightest violations and pathologies.

Types of tomographs

Modern magnetic tomographs are produced in various variations with a wide variety of characteristics.

All tomography devices are divided into:

• open;
• closed.

While an open CT scanner is generally considered more comfortable for the patient, closed CT scanners offer more power and detail. If the patient does not experience a strong fear of an enclosed space and does not have weight restrictions, it is recommended to conduct a study in a closed-type apparatus.

Tomographs are also divided according to the strength of the radiation of the magnetic field, the unit of measurement of which is called Tesla. Magnetic tomographs can be:

• low-floor – up to 1.0 T;
• high-field – radiant power above 1.0 T.

Low-field scanners do not give a clear and detailed picture. A study on a high-field tomograph will allow you to examine the diagnosed area with the highest accuracy.

Modern high-field tomograph

A Philips closed-type tomograph with a power of 1.5 Tesla is installed in the DiMagnit clinic. With the help of the device it is possible to obtain images of the highest quality and detail.

Should I be afraid of the procedure

Some patients are anxious before the examination. But their fears are in vain – magnetic resonance imaging is absolutely painless, and the effect of magnetic radiation on the body is safe.

Unlike other imaging modalities, MRI does not use ionizing radiation. The magnetic field does not have a carcinogenic and mutagenic effect on the cells of the body. An MRI scan can be done as often as needed.

The difference between MRI and CT and ultrasound

Magnetic resonance imaging has a number of advantages over ultrasound and computed tomography.

Ultrasound provides a two-dimensional image of the area under examination, but does not allow you to see the three-dimensional image of soft structures.

Computed tomography can be compared to MRI in terms of image clarity, but has a number of serious contraindications. CT is more often used to visualize hollow organs and bone structures, while MRI is much more effective in visualizing soft tissues.

What MRI shows

Magnetic resonance imaging is successfully used to diagnose diseases:

• thyroid gland;
• liver;
• gallbladder and ducts;
• pancreas;
• kidney;
• spleen;
• joints;
• spinal cord;
• vessels of the head, neck, abdominal region;
• pelvic organs;
• soft tissues;
• etc.

All of the above anatomical structures are perfectly visualized on MR images. The results of diagnostics make it possible to identify deviations in the work of the organs under study with high accuracy.

In what cases is MRI prescribed?

In each individual case, the choice of diagnostic technique is carried out by the attending physician. Magnetic resonance imaging is more often than other methods used to detect diseases and injuries of soft tissues.

MRI is indispensable for diagnosis:

• Neoplasms.

Magnetic resonance imaging can clearly identify the boundaries and size of the tumor and the extent of its invasion into the soft tissues. No other method of radiation diagnostics is able to give such a clear and detailed picture of diseases.

MRI also makes it possible to determine the nature of the tumor with a high degree of probability. Malignant neoplasms have fuzzy boundaries and grow into the surrounding tissues. Benign neoplasms, as a rule, are clearly differentiated from healthy tissues.

• Diseases of the brain.

The high accuracy of magnetic resonance imaging allows visualization of small anatomical structures such as the pituitary gland and the sella turcica. Also, MRI with brain contrast shows a high efficiency for diagnosing demyelinating diseases (multiple sclerosis, Parkinson’s disease, etc. ), as it allows you to clearly see the structure of altered nerve tissues.

Brain MRI images with contrast are especially clear because magnetic waves do not show hard anatomical structures well and there are no artifacts from the skull bones on brain images.

• Diseases of the intervertebral discs.

MR images of the spine

Magnetic resonance imaging is the only diagnostic method that allows you to see the intervertebral discs. Even modern diagnostic methods, such as computed tomography, allow you to see only the space between the vertebrae, while MRI gives a complete picture of the condition of the discs, the possible presence of hernias and protrusions.

The use of MRI is not limited to the above diseases, but is used when it is necessary to identify and monitor a wide range of pathologies, congenital anomalies, consequences of injuries and previous surgical interventions.

When contrast is applied

Magnetic resonance imaging can provide a very high degree of image clarity. In most cases, the use of contrast is not required.

But when it comes to diagnosing tumors and small anatomical structures, a contrast medium can still be used.

Stain preparations are made from the rare earth metal gadolinium and are administered intravenously to the patient during an MRI scan.

MRI contrast agents are much better tolerated than similar CT drugs. This makes the use of the stain safe, even for patients with kidney disease, and does not require a preliminary creatinine test, which is necessary for CT diagnostics with contrast.

MRI with contrast is used in the following cases:

• suspected neoplasm;
• the need for differential diagnosis of a malignant tumor;
• pituitary examination;
• the need to diagnose demyelinating diseases.

The use of contrast allows you to get a comprehensive picture of the disease, its course and the effectiveness of the therapy used.

Contraindications to MRI

Despite the fact that magnetic resonance imaging is a safe technique, the study has a number of absolute contraindications, in the presence of which it is prohibited to perform diagnostics:

• presence of a pacemaker, neurostimulator, insulin pump;
• vascular clips on cerebral arteries;
• the inability of the patient to maintain a fixed position for various reasons;
• early childhood up to 5 years;
• patient weight over 130 kg and girth over 150 cm;
• first trimester of pregnancy;

There are also a number of conditions in which an MR examination should be performed with caution:

• severe pain syndrome, in which it is difficult for patients to be in a motionless position for a long time;
• fear of closed space;
• mental disorders;
• second and third trimester of pregnancy.

The presence of various prostheses and implants in the patient’s body may be a contraindication for MRI if they are made of metals that are sensitive to magnetic radiation. Modern medical devices are most often made of titanium and other materials that are inert to magnetic fields. Their presence in the body does not interfere with MRI.

Preparation for MRI

MRI diagnostics in most cases does not require special preparation from the patient. In the case of magnetic resonance scanning of the abdomen, retroperitoneal space and the pelvic area, the procedure should be carried out on an empty stomach, refraining from food high in fiber, alcohol, and smoking the day before.

The use of a contrast agent during the procedure does not require prior preparation or testing.

How long does an MRI take?

The duration of an MRI can vary depending on the scanned area:

• knee joints – 20 minutes;
• brain – 15 minutes;
• mammary glands – 30 minutes;
• abdominal organs – 40-45 minutes;
• organs located in the pelvic cavity – 40 minutes.

If a contrast agent is required, the procedure will take 15 minutes longer.

How MRI works

Before the procedure, the radiologist asks the patient if there are any contraindications to the examination. The patient is asked to remove metal accessories, including clothing with metal fittings, and lie down on a couch, which is then placed in the tube of the tomograph.

It is strictly forbidden to move during the diagnostics, as this may affect the clarity of the images obtained.

Scan procedure

High-field tomographs emit a sufficiently high level of noise that may cause some discomfort to patients. The DiMagnit Medical Center provides headphones with pleasant music that drowns out the sounds of the operating device.

Tomograph scans the patient’s body in different projections and instantly transfers images to the computer screen. Interpretation of the results by the investigator begins even before the completion of the procedure.