How does a CT or CAT scan work. What are the main differences between CT and MRI scans. Why are CT scans preferred for certain medical conditions. How should patients prepare for a CT scan procedure.

The Basics of CT and CAT Scans: Unveiling the Technology Behind Medical Imaging

Computerized tomography (CT) and computerized axial tomography (CAT) scans are advanced medical imaging techniques that have revolutionized diagnostic capabilities in modern healthcare. These scans combine data from multiple X-rays to create detailed images of internal body structures, offering healthcare professionals a non-invasive way to examine organs, tissues, and bones.

CT and CAT scans are essentially the same thing, with the terms often used interchangeably. The technology works by emitting a series of narrow X-ray beams through the body as the scanner rotates around the patient. This process differs from traditional X-ray machines, which send only one radiation beam. The result is a more comprehensive and detailed final image.

How do CT scanners create detailed images?

CT scanners use X-ray detectors capable of distinguishing hundreds of different density levels. This sensitivity allows the scanner to visualize tissues within solid organs, providing a level of detail unattainable with conventional X-rays. The data collected by the scanner is then transmitted to a computer, which constructs a three-dimensional cross-sectional image of the scanned body part.

What types of images can CT scans produce?

CT scans can generate both 2D and 3D images:

• 2D images: These represent “slices” or sections of the body, similar to looking at a single slice of bread within a whole loaf.
• 3D images: The data collected can be used to construct three-dimensional representations of internal structures, offering a more comprehensive view.

Enhancing Image Clarity: The Role of Contrast Dyes in CT Scans

To improve the visibility of certain structures, contrast dyes are often used during CT scans. These dyes can be administered in various ways, depending on the area being examined:

1. Oral contrast: Patients may be asked to drink a barium meal for abdominal scans. The barium appears white on the scan as it travels through the digestive system.
2. Rectal contrast: For lower abdominal or rectal imaging, a barium enema might be administered.
3. Intravenous contrast: When imaging blood vessels, a contrast agent is injected directly into the veins.

The use of contrast agents helps highlight specific structures, making them more easily distinguishable on the resulting images. This enhanced clarity aids in more accurate diagnoses and treatment planning.

Spiral CT: Advancing the Speed and Accuracy of Medical Imaging

A relatively new technology called spiral CT has further improved the accuracy and speed of CT scans. In spiral CT, the X-ray beam follows a spiral path during the scanning process, allowing for continuous data collection without gaps between images. This technique offers several advantages over traditional CT scanning:

• Faster scan times
• Reduced radiation exposure
• Improved image quality
• Better 3D reconstruction capabilities

The continuous nature of spiral CT scanning makes it particularly useful for imaging moving structures, such as the heart or lungs, and for capturing large areas of the body in a single breath-hold.

CT Scan Applications: Diagnosing a Wide Range of Medical Conditions

CT scans have become an indispensable tool in modern medicine, offering detailed imaging for a variety of medical conditions and body parts. Some of the most common applications of CT scans include:

Which body parts can CT scans effectively image?

CT scans are particularly effective for imaging:

• Soft tissues
• The pelvis
• Blood vessels
• Lungs
• Brain
• Abdomen
• Bones

How are CT scans used in cancer diagnosis and treatment?

CT scans are often the preferred method for diagnosing and monitoring various types of cancer, including:

• Liver cancer
• Lung cancer
• Pancreatic cancer

The detailed images produced by CT scans allow doctors to confirm the presence of tumors, determine their size and location, and assess how much they have affected nearby tissues. This information is crucial for treatment planning and monitoring the effectiveness of therapies.

What neurological conditions can CT scans help diagnose?

CT scans of the head can provide vital information about the brain, including:

• Detecting bleeding
• Identifying swelling of the arteries
• Locating tumors
• Assessing damage from stroke or trauma

CT Scans vs. MRI: Choosing the Right Imaging Technique

While both CT scans and Magnetic Resonance Imaging (MRI) are powerful diagnostic tools, they have distinct differences and are suited for different medical situations. Understanding these differences can help healthcare providers choose the most appropriate imaging technique for each patient’s needs.

What are the key differences between CT and MRI scans?

The main differences between CT and MRI scans include:

• Technology: CT scans use X-rays, while MRI uses magnets and radio waves.
• Tissue visualization: CT scans are better for visualizing bones and organs, while MRI excels at showing soft tissues, tendons, and ligaments.
• Scan duration: CT scans are generally faster than MRI scans.
• Radiation exposure: CT scans involve ionizing radiation, while MRI does not.

When is a CT scan preferred over an MRI?

CT scans are often the preferred choice for:

• Emergency situations, such as trauma cases, due to their speed
• Diagnosing and monitoring cancer
• Detecting pneumonia
• Investigating abnormal chest X-rays
• Identifying bleeding in the brain, especially after an injury
• Examining broken bones and vertebrae
• Imaging the lungs and organs in the chest cavity

When is an MRI preferred over a CT scan?

MRI is typically the better choice for:

• Examining the spinal cord
• Visualizing tendons and ligaments
• Detecting and monitoring brain tumors
• Diagnosing certain neurological conditions
• Assessing joint injuries

Preparing for a CT Scan: What Patients Need to Know

Proper preparation is essential for ensuring the best possible results from a CT scan. Patients should be aware of several important factors before their scheduled scan:

What dietary restrictions apply before a CT scan?

Patients may be instructed to:

• Abstain from food for a specific period before the scan, typically 4-6 hours
• Avoid drinking anything other than water in the hours leading up to the scan
• Follow any specific dietary instructions provided by their healthcare provider

These restrictions help ensure clear images and reduce the risk of complications, especially if contrast dye will be used during the scan.

How should patients dress for a CT scan?

On the day of the scan:

• Patients may need to undress down to their underwear and wear a hospital-provided gown
• If no gown is provided, wear loose-fitting clothes free of metal buttons and zippers
• Remove all jewelry and metal accessories, as these can interfere with the scanner

What should patients tell their healthcare provider before the scan?

It’s important to inform the healthcare team about:

• Any allergies, especially to contrast materials
• Current medications
• Pregnancy or the possibility of pregnancy
• Any implanted medical devices
• History of kidney problems

This information helps ensure the safety and effectiveness of the CT scan procedure.

The CT Scan Procedure: What to Expect During the Examination

Understanding the CT scan procedure can help alleviate anxiety and ensure a smooth experience for patients. Here’s what typically happens during a CT scan:

How is the patient positioned for a CT scan?

The patient will:

• Lie down on a motorized examination table
• Usually lie on their back, facing up, though sometimes they may need to lie facedown or sideways
• Be positioned so that the area to be scanned is in the center of the large, doughnut-shaped CT scanner

What happens during the scanning process?

Once positioned:

• The examination table will move slowly through the CT scanner
• The scanner will rotate around the patient, taking multiple X-ray images
• Patients may hear whirring or buzzing noises as the scanner operates
• The technologist will communicate with the patient via intercom, providing instructions and updates

It’s crucial for patients to remain as still as possible during the scan to ensure clear, accurate images.

How long does a typical CT scan take?

The duration of a CT scan can vary depending on the area being scanned and whether contrast dye is used. However:

• Most CT scans take between 10 to 30 minutes
• Some more complex scans may take up to an hour
• The actual scanning time is often just a few minutes, with most of the time spent on preparation and positioning

After the scan is complete, patients can usually resume their normal activities immediately, unless they’ve been given contrast dye, in which case they may be asked to wait briefly to ensure no adverse reactions occur.

Weighing the Benefits and Risks: Considerations for CT Scan Usage

While CT scans are invaluable diagnostic tools, it’s important to consider both their benefits and potential risks when determining their appropriate use.

What are the primary benefits of CT scans?

CT scans offer numerous advantages in medical diagnosis and treatment planning:

• Non-invasive imaging of internal structures
• Rapid acquisition of detailed images
• Ability to detect a wide range of conditions
• Guidance for biopsies and other interventional procedures
• Monitoring of treatment effectiveness

What are the potential risks associated with CT scans?

The main concern with CT scans is the exposure to ionizing radiation:

• Radiation exposure can potentially increase the risk of cancer, particularly with repeated scans
• The risk is generally considered small compared to the immediate benefit of the scan
• Children and young adults are more sensitive to radiation and may be at higher risk

Additionally, some patients may experience allergic reactions to contrast dyes used in CT scans, though severe reactions are rare.

How can the risks of CT scans be minimized?

To reduce the potential risks associated with CT scans:

• Healthcare providers should only order CT scans when necessary
• Alternative imaging methods should be considered when appropriate
• Radiation doses should be optimized, especially for pediatric patients
• Patients should discuss the risks and benefits with their doctors before undergoing a CT scan

The National Cancer Institute advises patients to have an open dialogue with their healthcare providers about the necessity and potential risks of CT scans. This ensures that the benefits of the diagnostic information outweigh any potential risks associated with the procedure.

CT scan or CAT scan: How does it work?

A computerized tomography (CT) or computerized axial tomography (CAT) scan combines data from several X-rays to produce a detailed image of structures inside the body.

CT scans produce 2-dimensional images of a “slice” or section of the body, but the data can also be used to construct 3-dimensional images. A CT scan can be compared to looking at one slice of bread within a whole loaf.

CT scans are used in hospitals worldwide.

A CT scanner emits a series of narrow beams through the human body as it moves through an arc.

This is different from an X-ray machine, which sends just one radiation beam. The CT scan produces a more detailed final picture than an X-ray image.

The CT scanner’s X-ray detector can see hundreds of different levels of density. It can see tissues within a solid organ.

This data is transmitted to a computer, which builds up a 3-D cross-sectional picture of the part of the body and displays it on the screen.

Sometimes, a contrast dye is used because it can help show certain structures more clearly.

For instance, if a 3-D image of the abdomen is required, the patient may have to drink a barium meal. The barium appears white on the scan as it travels through the digestive system.

If images lower down the body are required, such as the rectum, the patient may be given a barium enema. If blood vessel images are the target, a contrast agent will be injected into the veins.

The accuracy and speed of CT scans may be improved with the application of spiral CT, a relatively new technology. The beam takes a spiral path during the scanning, so it gathers continuous data with no gaps between images.

CT is a useful tool for assisting diagnosis in medicine, but it is a source of ionizing radiation, and it can potentially cause cancer.

The National Cancer Institute advise patients to discuss the risks and benefits of CT scans with their doctors.

It is useful for obtaining images of:

• soft tissues
• the pelvis
• blood vessels
• lungs
• brain
• abdomen
• bones

CT is often the preferred way of diagnosing many cancers, such as liver, lung, and pancreatic cancers.

The image allows a doctor to confirm the presence and location of a tumor, its size, and how much it has affected nearby tissue.

A scan of the head can provide important information about the brain, for instance, if there is any bleeding, swelling of the arteries, or a tumor.

A CT scan can reveal a tumor in the abdomen, and any swelling or inflammation in nearby internal organs. It can show any lacerations of the spleen, kidneys, or liver.

As a CT scan detects abnormal tissue, it is useful for planning areas for radiotherapy and biopsies, and it can provide valuable data on blood flow and other vascular conditions.

It can help a doctor assess bone diseases, bone density, and the state of the patient’s spine.

It can also provide vital data about injuries to a patient’s hands, feet, and other skeletal structures. Even small bones are clearly visible, as well as their surrounding tissue.

CT versus MRI

The main differences between CT and MRI are:

• A CT scan uses X-rays, but an MRI uses magnets and radio waves.
• Unlike an MRI, a CT scan does not show tendons and ligaments.
• MRI is better for examining the spinal cord.
• A CT scan is better suited to cancer, pneumonia, abnormal chest x-rays, bleeding in the brain, especially after an injury.
• A brain tumor is more clearly visible on MRI.
• A CT scan shows organ tear and organ injury more quickly, so it may be more suitable for trauma cases.
• Broken bones and vertebrae are more clearly visible on a CT scan.
• CT scans provide a better image of the lungs and organs in the chest cavity between the lungs.

The patient may need to abstain from food, and possibly drink, for a specific period before the scan.

On the day

In most places, the patient will need to undress, usually down to their underwear, and put on a gown that the health center will provide. Avoid wearing jewelry.

If the hospital does not provide a gown, the patient should wear loose-fitting clothes free of metal buttons and zippers.

Some patients may have to drink a contrast dye, or the dye may be given as an enema, or injected.This improves the picture of some blood vessels or tissues.

Any patient who has an allergy to contrast material should tell the doctor beforehand. Some medications can reduce allergic reactions to contrast materials.

As metal interferes with the workings of the CT scanner, the patient will need to remove all jewelry and metal fastenings.

During the scan

The patient will need to lie down on a motorized examination table that slides into a doughnut-shaped CT scanner machine.

In most cases, the patient will lie on their back, facing up. But, sometimes, they may need to lie facedown or sideways.

After one x-ray picture, the couch will move slightly, and then the machine will take another image, and so on. The patient needs to lie very still for the best results.

During the scan, everybody except for the patient will leave the room. An intercom will enable two-way communication between the radiographer and the patient.

If the patient is a child, a parent or adult might be allowed to stand or sit nearby, but they will have to wear a lead apron to prevent radiation exposure.

Share on PinterestThe doctor should explain why the scan is needed, any other options available, and the pros and cons of having a CT scan.

A CT scan involves a small, targeted dose of radiation.

These levels of radiation, even in people who have undergone several scans, has not proven to be harmful.

The chance of developing cancer as the result of a CT scan is thought to be less than 1 in 2,000.

The amount of radiation involved is estimated to be around the same as a person would be exposed to in a space of between several months and several years of natural exposure in the environment.

A scan is only given if there is a clear medical reason to do so. The results can lead to treatment for conditions that could otherwise be serious. When the decision is taken to perform a scan, doctors will ensure that the benefits outweigh any risk.

Problems that could possibly arise from radiation exposure include cancer and thyroid issues.

This is extremely unlikely in adults, and also unlikely in children. However, are more susceptible to the effects of radiation. This does not mean that health issues will result, but any CT scans should be noted on the child’s medical record.

In some cases, only a CT scan can show the required results. For some conditions, an ultrasound or MRI might be possible.

Can I have a CT scan if I am pregnant?

Any woman who suspects she may be pregnant should tell her doctor beforehand, because there is a risk that the x-rays could harm the fetus.

Citing the American College of Radiography, the American Pregnancy Association (APA) point out that “No single diagnostic x-ray has a radiation dose significant enough to cause adverse effects in a developing embryo or fetus.”

However, the APA notes that CT scans are not recommended for pregnant women, “Unless the benefits clearly outweigh the risk.”

CT scans and breastfeeding

If a lactating, or breastfeeding, mother needs an iodinated intravenous dye for contrast, she should avoid breastfeeding for about 24 hours as may pass into the breast milk.

I have claustrophobia: Can I have a CT scan?

A patient who has claustrophobia should tell their doctor or radiographer beforehand. The patient may be given an injection or tablet to calm them down before the scan.

Your health care provider will usually be able to recommend a suitable facility for a scan. You can check if a radiologist is accredited by searching on the website of the American College of Radiology.

CT scan or CAT scan: How does it work?

A computerized tomography (CT) or computerized axial tomography (CAT) scan combines data from several X-rays to produce a detailed image of structures inside the body.

CT scans produce 2-dimensional images of a “slice” or section of the body, but the data can also be used to construct 3-dimensional images. A CT scan can be compared to looking at one slice of bread within a whole loaf.

CT scans are used in hospitals worldwide.

A CT scanner emits a series of narrow beams through the human body as it moves through an arc.

This is different from an X-ray machine, which sends just one radiation beam. The CT scan produces a more detailed final picture than an X-ray image.

The CT scanner’s X-ray detector can see hundreds of different levels of density. It can see tissues within a solid organ.

This data is transmitted to a computer, which builds up a 3-D cross-sectional picture of the part of the body and displays it on the screen.

Sometimes, a contrast dye is used because it can help show certain structures more clearly.

For instance, if a 3-D image of the abdomen is required, the patient may have to drink a barium meal. The barium appears white on the scan as it travels through the digestive system.

If images lower down the body are required, such as the rectum, the patient may be given a barium enema. If blood vessel images are the target, a contrast agent will be injected into the veins.

The accuracy and speed of CT scans may be improved with the application of spiral CT, a relatively new technology. The beam takes a spiral path during the scanning, so it gathers continuous data with no gaps between images.

CT is a useful tool for assisting diagnosis in medicine, but it is a source of ionizing radiation, and it can potentially cause cancer.

The National Cancer Institute advise patients to discuss the risks and benefits of CT scans with their doctors.

It is useful for obtaining images of:

• soft tissues
• the pelvis
• blood vessels
• lungs
• brain
• abdomen
• bones

CT is often the preferred way of diagnosing many cancers, such as liver, lung, and pancreatic cancers.

The image allows a doctor to confirm the presence and location of a tumor, its size, and how much it has affected nearby tissue.

A scan of the head can provide important information about the brain, for instance, if there is any bleeding, swelling of the arteries, or a tumor.

A CT scan can reveal a tumor in the abdomen, and any swelling or inflammation in nearby internal organs. It can show any lacerations of the spleen, kidneys, or liver.

As a CT scan detects abnormal tissue, it is useful for planning areas for radiotherapy and biopsies, and it can provide valuable data on blood flow and other vascular conditions.

It can help a doctor assess bone diseases, bone density, and the state of the patient’s spine.

It can also provide vital data about injuries to a patient’s hands, feet, and other skeletal structures. Even small bones are clearly visible, as well as their surrounding tissue.

CT versus MRI

The main differences between CT and MRI are:

• A CT scan uses X-rays, but an MRI uses magnets and radio waves.
• Unlike an MRI, a CT scan does not show tendons and ligaments.
• MRI is better for examining the spinal cord.
• A CT scan is better suited to cancer, pneumonia, abnormal chest x-rays, bleeding in the brain, especially after an injury.
• A brain tumor is more clearly visible on MRI.
• A CT scan shows organ tear and organ injury more quickly, so it may be more suitable for trauma cases.
• Broken bones and vertebrae are more clearly visible on a CT scan.
• CT scans provide a better image of the lungs and organs in the chest cavity between the lungs.

The patient may need to abstain from food, and possibly drink, for a specific period before the scan.

On the day

In most places, the patient will need to undress, usually down to their underwear, and put on a gown that the health center will provide. Avoid wearing jewelry.

If the hospital does not provide a gown, the patient should wear loose-fitting clothes free of metal buttons and zippers.

Some patients may have to drink a contrast dye, or the dye may be given as an enema, or injected.This improves the picture of some blood vessels or tissues.

Any patient who has an allergy to contrast material should tell the doctor beforehand. Some medications can reduce allergic reactions to contrast materials.

As metal interferes with the workings of the CT scanner, the patient will need to remove all jewelry and metal fastenings.

During the scan

The patient will need to lie down on a motorized examination table that slides into a doughnut-shaped CT scanner machine.

In most cases, the patient will lie on their back, facing up. But, sometimes, they may need to lie facedown or sideways.

After one x-ray picture, the couch will move slightly, and then the machine will take another image, and so on. The patient needs to lie very still for the best results.

During the scan, everybody except for the patient will leave the room. An intercom will enable two-way communication between the radiographer and the patient.

If the patient is a child, a parent or adult might be allowed to stand or sit nearby, but they will have to wear a lead apron to prevent radiation exposure.

Share on PinterestThe doctor should explain why the scan is needed, any other options available, and the pros and cons of having a CT scan.

A CT scan involves a small, targeted dose of radiation.

These levels of radiation, even in people who have undergone several scans, has not proven to be harmful.

The chance of developing cancer as the result of a CT scan is thought to be less than 1 in 2,000.

The amount of radiation involved is estimated to be around the same as a person would be exposed to in a space of between several months and several years of natural exposure in the environment.

A scan is only given if there is a clear medical reason to do so. The results can lead to treatment for conditions that could otherwise be serious. When the decision is taken to perform a scan, doctors will ensure that the benefits outweigh any risk.

Problems that could possibly arise from radiation exposure include cancer and thyroid issues.

This is extremely unlikely in adults, and also unlikely in children. However, are more susceptible to the effects of radiation. This does not mean that health issues will result, but any CT scans should be noted on the child’s medical record.

In some cases, only a CT scan can show the required results. For some conditions, an ultrasound or MRI might be possible.

Can I have a CT scan if I am pregnant?

Any woman who suspects she may be pregnant should tell her doctor beforehand, because there is a risk that the x-rays could harm the fetus.

Citing the American College of Radiography, the American Pregnancy Association (APA) point out that “No single diagnostic x-ray has a radiation dose significant enough to cause adverse effects in a developing embryo or fetus.”

However, the APA notes that CT scans are not recommended for pregnant women, “Unless the benefits clearly outweigh the risk.”

CT scans and breastfeeding

If a lactating, or breastfeeding, mother needs an iodinated intravenous dye for contrast, she should avoid breastfeeding for about 24 hours as may pass into the breast milk.

I have claustrophobia: Can I have a CT scan?

A patient who has claustrophobia should tell their doctor or radiographer beforehand. The patient may be given an injection or tablet to calm them down before the scan.

Your health care provider will usually be able to recommend a suitable facility for a scan. You can check if a radiologist is accredited by searching on the website of the American College of Radiology.

CT scan or CAT scan: How does it work?

A computerized tomography (CT) or computerized axial tomography (CAT) scan combines data from several X-rays to produce a detailed image of structures inside the body.

CT scans produce 2-dimensional images of a “slice” or section of the body, but the data can also be used to construct 3-dimensional images. A CT scan can be compared to looking at one slice of bread within a whole loaf.

CT scans are used in hospitals worldwide.

A CT scanner emits a series of narrow beams through the human body as it moves through an arc.

This is different from an X-ray machine, which sends just one radiation beam. The CT scan produces a more detailed final picture than an X-ray image.

The CT scanner’s X-ray detector can see hundreds of different levels of density. It can see tissues within a solid organ.

This data is transmitted to a computer, which builds up a 3-D cross-sectional picture of the part of the body and displays it on the screen.

Sometimes, a contrast dye is used because it can help show certain structures more clearly.

For instance, if a 3-D image of the abdomen is required, the patient may have to drink a barium meal. The barium appears white on the scan as it travels through the digestive system.

If images lower down the body are required, such as the rectum, the patient may be given a barium enema. If blood vessel images are the target, a contrast agent will be injected into the veins.

The accuracy and speed of CT scans may be improved with the application of spiral CT, a relatively new technology. The beam takes a spiral path during the scanning, so it gathers continuous data with no gaps between images.

CT is a useful tool for assisting diagnosis in medicine, but it is a source of ionizing radiation, and it can potentially cause cancer.

The National Cancer Institute advise patients to discuss the risks and benefits of CT scans with their doctors.

It is useful for obtaining images of:

• soft tissues
• the pelvis
• blood vessels
• lungs
• brain
• abdomen
• bones

CT is often the preferred way of diagnosing many cancers, such as liver, lung, and pancreatic cancers.

The image allows a doctor to confirm the presence and location of a tumor, its size, and how much it has affected nearby tissue.

A scan of the head can provide important information about the brain, for instance, if there is any bleeding, swelling of the arteries, or a tumor.

A CT scan can reveal a tumor in the abdomen, and any swelling or inflammation in nearby internal organs. It can show any lacerations of the spleen, kidneys, or liver.

As a CT scan detects abnormal tissue, it is useful for planning areas for radiotherapy and biopsies, and it can provide valuable data on blood flow and other vascular conditions.

It can help a doctor assess bone diseases, bone density, and the state of the patient’s spine.

It can also provide vital data about injuries to a patient’s hands, feet, and other skeletal structures. Even small bones are clearly visible, as well as their surrounding tissue.

CT versus MRI

The main differences between CT and MRI are:

• A CT scan uses X-rays, but an MRI uses magnets and radio waves.
• Unlike an MRI, a CT scan does not show tendons and ligaments.
• MRI is better for examining the spinal cord.
• A CT scan is better suited to cancer, pneumonia, abnormal chest x-rays, bleeding in the brain, especially after an injury.
• A brain tumor is more clearly visible on MRI.
• A CT scan shows organ tear and organ injury more quickly, so it may be more suitable for trauma cases.
• Broken bones and vertebrae are more clearly visible on a CT scan.
• CT scans provide a better image of the lungs and organs in the chest cavity between the lungs.

The patient may need to abstain from food, and possibly drink, for a specific period before the scan.

On the day

In most places, the patient will need to undress, usually down to their underwear, and put on a gown that the health center will provide. Avoid wearing jewelry.

If the hospital does not provide a gown, the patient should wear loose-fitting clothes free of metal buttons and zippers.

Some patients may have to drink a contrast dye, or the dye may be given as an enema, or injected.This improves the picture of some blood vessels or tissues.

Any patient who has an allergy to contrast material should tell the doctor beforehand. Some medications can reduce allergic reactions to contrast materials.

As metal interferes with the workings of the CT scanner, the patient will need to remove all jewelry and metal fastenings.

During the scan

The patient will need to lie down on a motorized examination table that slides into a doughnut-shaped CT scanner machine.

In most cases, the patient will lie on their back, facing up. But, sometimes, they may need to lie facedown or sideways.

After one x-ray picture, the couch will move slightly, and then the machine will take another image, and so on. The patient needs to lie very still for the best results.

During the scan, everybody except for the patient will leave the room. An intercom will enable two-way communication between the radiographer and the patient.

If the patient is a child, a parent or adult might be allowed to stand or sit nearby, but they will have to wear a lead apron to prevent radiation exposure.

Share on PinterestThe doctor should explain why the scan is needed, any other options available, and the pros and cons of having a CT scan.

A CT scan involves a small, targeted dose of radiation.

These levels of radiation, even in people who have undergone several scans, has not proven to be harmful.

The chance of developing cancer as the result of a CT scan is thought to be less than 1 in 2,000.

The amount of radiation involved is estimated to be around the same as a person would be exposed to in a space of between several months and several years of natural exposure in the environment.

A scan is only given if there is a clear medical reason to do so. The results can lead to treatment for conditions that could otherwise be serious. When the decision is taken to perform a scan, doctors will ensure that the benefits outweigh any risk.

Problems that could possibly arise from radiation exposure include cancer and thyroid issues.

This is extremely unlikely in adults, and also unlikely in children. However, are more susceptible to the effects of radiation. This does not mean that health issues will result, but any CT scans should be noted on the child’s medical record.

In some cases, only a CT scan can show the required results. For some conditions, an ultrasound or MRI might be possible.

Can I have a CT scan if I am pregnant?

Any woman who suspects she may be pregnant should tell her doctor beforehand, because there is a risk that the x-rays could harm the fetus.

Citing the American College of Radiography, the American Pregnancy Association (APA) point out that “No single diagnostic x-ray has a radiation dose significant enough to cause adverse effects in a developing embryo or fetus.”

However, the APA notes that CT scans are not recommended for pregnant women, “Unless the benefits clearly outweigh the risk.”

CT scans and breastfeeding

If a lactating, or breastfeeding, mother needs an iodinated intravenous dye for contrast, she should avoid breastfeeding for about 24 hours as may pass into the breast milk.

I have claustrophobia: Can I have a CT scan?

A patient who has claustrophobia should tell their doctor or radiographer beforehand. The patient may be given an injection or tablet to calm them down before the scan.

Your health care provider will usually be able to recommend a suitable facility for a scan. You can check if a radiologist is accredited by searching on the website of the American College of Radiology.

CT scan or CAT scan: How does it work?

A computerized tomography (CT) or computerized axial tomography (CAT) scan combines data from several X-rays to produce a detailed image of structures inside the body.

CT scans produce 2-dimensional images of a “slice” or section of the body, but the data can also be used to construct 3-dimensional images. A CT scan can be compared to looking at one slice of bread within a whole loaf.

CT scans are used in hospitals worldwide.

A CT scanner emits a series of narrow beams through the human body as it moves through an arc.

This is different from an X-ray machine, which sends just one radiation beam. The CT scan produces a more detailed final picture than an X-ray image.

The CT scanner’s X-ray detector can see hundreds of different levels of density. It can see tissues within a solid organ.

This data is transmitted to a computer, which builds up a 3-D cross-sectional picture of the part of the body and displays it on the screen.

Sometimes, a contrast dye is used because it can help show certain structures more clearly.

For instance, if a 3-D image of the abdomen is required, the patient may have to drink a barium meal. The barium appears white on the scan as it travels through the digestive system.

If images lower down the body are required, such as the rectum, the patient may be given a barium enema. If blood vessel images are the target, a contrast agent will be injected into the veins.

The accuracy and speed of CT scans may be improved with the application of spiral CT, a relatively new technology. The beam takes a spiral path during the scanning, so it gathers continuous data with no gaps between images.

CT is a useful tool for assisting diagnosis in medicine, but it is a source of ionizing radiation, and it can potentially cause cancer.

The National Cancer Institute advise patients to discuss the risks and benefits of CT scans with their doctors.

It is useful for obtaining images of:

• soft tissues
• the pelvis
• blood vessels
• lungs
• brain
• abdomen
• bones

CT is often the preferred way of diagnosing many cancers, such as liver, lung, and pancreatic cancers.

The image allows a doctor to confirm the presence and location of a tumor, its size, and how much it has affected nearby tissue.

A scan of the head can provide important information about the brain, for instance, if there is any bleeding, swelling of the arteries, or a tumor.

A CT scan can reveal a tumor in the abdomen, and any swelling or inflammation in nearby internal organs. It can show any lacerations of the spleen, kidneys, or liver.

As a CT scan detects abnormal tissue, it is useful for planning areas for radiotherapy and biopsies, and it can provide valuable data on blood flow and other vascular conditions.

It can help a doctor assess bone diseases, bone density, and the state of the patient’s spine.

It can also provide vital data about injuries to a patient’s hands, feet, and other skeletal structures. Even small bones are clearly visible, as well as their surrounding tissue.

CT versus MRI

The main differences between CT and MRI are:

• A CT scan uses X-rays, but an MRI uses magnets and radio waves.
• Unlike an MRI, a CT scan does not show tendons and ligaments.
• MRI is better for examining the spinal cord.
• A CT scan is better suited to cancer, pneumonia, abnormal chest x-rays, bleeding in the brain, especially after an injury.
• A brain tumor is more clearly visible on MRI.
• A CT scan shows organ tear and organ injury more quickly, so it may be more suitable for trauma cases.
• Broken bones and vertebrae are more clearly visible on a CT scan.
• CT scans provide a better image of the lungs and organs in the chest cavity between the lungs.

The patient may need to abstain from food, and possibly drink, for a specific period before the scan.

On the day

In most places, the patient will need to undress, usually down to their underwear, and put on a gown that the health center will provide. Avoid wearing jewelry.

If the hospital does not provide a gown, the patient should wear loose-fitting clothes free of metal buttons and zippers.

Some patients may have to drink a contrast dye, or the dye may be given as an enema, or injected.This improves the picture of some blood vessels or tissues.

Any patient who has an allergy to contrast material should tell the doctor beforehand. Some medications can reduce allergic reactions to contrast materials.

As metal interferes with the workings of the CT scanner, the patient will need to remove all jewelry and metal fastenings.

During the scan

The patient will need to lie down on a motorized examination table that slides into a doughnut-shaped CT scanner machine.

In most cases, the patient will lie on their back, facing up. But, sometimes, they may need to lie facedown or sideways.

After one x-ray picture, the couch will move slightly, and then the machine will take another image, and so on. The patient needs to lie very still for the best results.

During the scan, everybody except for the patient will leave the room. An intercom will enable two-way communication between the radiographer and the patient.

If the patient is a child, a parent or adult might be allowed to stand or sit nearby, but they will have to wear a lead apron to prevent radiation exposure.

Share on PinterestThe doctor should explain why the scan is needed, any other options available, and the pros and cons of having a CT scan.

A CT scan involves a small, targeted dose of radiation.

These levels of radiation, even in people who have undergone several scans, has not proven to be harmful.

The chance of developing cancer as the result of a CT scan is thought to be less than 1 in 2,000.

The amount of radiation involved is estimated to be around the same as a person would be exposed to in a space of between several months and several years of natural exposure in the environment.

A scan is only given if there is a clear medical reason to do so. The results can lead to treatment for conditions that could otherwise be serious. When the decision is taken to perform a scan, doctors will ensure that the benefits outweigh any risk.

Problems that could possibly arise from radiation exposure include cancer and thyroid issues.

This is extremely unlikely in adults, and also unlikely in children. However, are more susceptible to the effects of radiation. This does not mean that health issues will result, but any CT scans should be noted on the child’s medical record.

In some cases, only a CT scan can show the required results. For some conditions, an ultrasound or MRI might be possible.

Can I have a CT scan if I am pregnant?

Any woman who suspects she may be pregnant should tell her doctor beforehand, because there is a risk that the x-rays could harm the fetus.

Citing the American College of Radiography, the American Pregnancy Association (APA) point out that “No single diagnostic x-ray has a radiation dose significant enough to cause adverse effects in a developing embryo or fetus.”

However, the APA notes that CT scans are not recommended for pregnant women, “Unless the benefits clearly outweigh the risk.”

CT scans and breastfeeding

If a lactating, or breastfeeding, mother needs an iodinated intravenous dye for contrast, she should avoid breastfeeding for about 24 hours as may pass into the breast milk.

I have claustrophobia: Can I have a CT scan?

A patient who has claustrophobia should tell their doctor or radiographer beforehand. The patient may be given an injection or tablet to calm them down before the scan.

Your health care provider will usually be able to recommend a suitable facility for a scan. You can check if a radiologist is accredited by searching on the website of the American College of Radiology.

Computed Tomography (CT)

Breast CT scanner.
Credit: John Boone, UC Davis

Dedicated Breast CT Scanner: NIBIB is funding research for development of a dedicated breast CT scanner that allows the breast to be imaged in 3D and could help radiologists detect hard-to-find tumors. The scanner produces a radiation dose comparable to that of a standard x-ray mammogram and doesn’t require compression of the breast. In this breast CT scanner, a woman lies prone in a specially designed large table with her breast suspended in a special opening in the scanning bed. The scanner rotates around the breast, without passing through the chest, thus reducing the radiation that would be delivered to the chest in a conventional CT scanner. Listen to a podcast about the scanner.

Reduction in Radiation from Routine CT Scans: NIBIB put out a call for researchers to submit groundbreaking ideas that will help to radically decrease the amount of radiation used in CT scans. Five new projects are underway from this new funding opportunity, representing creative, innovative, interdisciplinary approaches that would not have been funded otherwise. You can read more about them below:

Customized imaging
Web Stayman, Johns Hopkins University
The amount of radiation required for a CT scan depends on a number of variables, including the size of the patient, the part of the body being scanned, and the diagnostic task at hand. For example, smaller patients require less radiation than larger patients, and scanning a denser part of the body, such as soft tissue near the pelvis, requires more radiation than scanning the lungs. In addition, diagnostic tasks that require high image clarity, such as locating a faint tumor, generally require more radiation. The goal of this project is to modify both the hardware and software of modern CT systems so that the device can adapt the shape, position, and intensity of the x-ray beam to the specific imaging scenario. The research leverages patient-specific anatomical models and mathematical models of imaging performance to direct x-rays where they are needed and, consequently, to avoid or to limit x-ray exposure where it is not needed. This will help maximize imaging performance for specific diagnostic tasks while minimizing radiation exposures.

Constructing tools for researchers
Cynthia McCollough, Mayo Clinic
The goal of this work is to develop resources that enable the research community to easily create and compare new approaches to reducing radiation dose of routine CT scans without compromising diagnostic accuracy. So far, this has entailed creating a library of raw data from patient CT scans that researchers can manipulate to test new approaches, and developing computer-based methods for evaluating new approaches, so that researchers don’t have to rely on radiologists, which can be costly and time consuming. Using these assets, researchers have demonstrated that there is considerable potential for radiation dose reduction in CT exams of the abdomen, which are among the highest dose CT exams in common clinical use.

Faster processing
Jeffrey Fessler, University of Michigan
To reduce radiation yet still produce good quality CT images, more sophisticated methods are needed to process the raw data from the CT system. Those advanced methods, called image reconstruction algorithms, can require undesirably long computing times, so they can be used only for some patients currently. The goal of this project is to develop algorithms that are fast enough to allow low-dose CT imaging to be used for every patient.>

An integrated approach
Norbert Pelc, Stanford Medical School
At every stage in the design of CT scanners, there are opportunities to make changes that reduce radiation dose. Because these changes are inter-related, the goal of this project is to take an integrated approach, exploring approaches such as modifying the photon counting detector (the part of the CT scanner that detects x-rays), dynamic x-ray illumination (adjusting the amount of radiation used throughout the duration of a scan), and image reconstruction methods. These will be tested using a table top experimental system. The researchers believe that these combined strategies can lead to as much as 80% reduction in radiation dose compared to today’s typical systems, and also enable higher resolution images.

SparseCT
Ricardo Otazo and Daniel Sodickson, New York University School of Medicine
Investigators at New York University School of Medicine, Brigham and Women’s Hospital, and Siemens Healthineers are working together to develop a new ultra-low-dose CT technique called SparseCT. The key idea behind SparseCT is to block most of the X-rays in a CT scan before they reach the patient, but to do so in a way that preserves all the essential image information. The approach combines a new x-ray blocking device with the mathematics of compressed sensing, which allows images to be reconstructed from reduced datasets. Compression sensing can be likened to filming a movie with a very fast, but low-pixel camera and then using math to convert the image to high-definition quality.

CT Scan vs. CAT Scan | What Is A CT Scan For?

CAT Scan vs. CT Scan

Medicine is a field with countless acronyms. Two that can be confusing are CAT scan and CT scan. Sometimes thought to be different types of diagnostic tests, they actually refer to the same X-ray procedure. CAT stands for “computed axial tomography” and CT is simply “computed tomography.” CAT scan was the first of the two terms to be used; CT scan has become more common in recent years.

What is a CT Scan For?

A CT scan produces images using an X-ray tube that travels 360 degrees around your body. As it moves, it gathers information from multiple angles to create cross-sectional images.

Doctors order CT scans for a number of reasons, including to:

• Look for bone and joint problems such as complex fractures and tumors
• Detect masses and spots associated with conditions like heart disease, cancer and emphysema
• Locate clots, tumors, infection or fluid buildup
• Check for internal injuries and bleeding following a traumatic event like a car accident
• Provide information in preparation for a surgery, biopsy or other procedure
• Compare images taken over a period of time to gauge the effectiveness of a treatment such as the chemotherapy or radiation used to shrink a tumor

In some cases, what’s called a CT scan “with contrast” is needed. With this procedure, the technician performing the procedure inserts a catheter into one of your arms in order to administer a special dye called contrast material. This dye makes it easier for the scan to create a crisp image of tissues and organs that are less dense than bone and therefore may not show up as clearly.

The detail in a CT scan with contrast may make it the preferred approach over other imaging techniques in some instances. For example, a CT scan can provide better information on the bones of the spine than either a standard X-ray or an MRI (magnetic resonance imaging) scan, which is helpful when assessing conditions that affect the vertebrae and other bones.

There are some instances when a CT scan isn’t advisable. If you’re pregnant or think you may be pregnant, you should tell your doctor. There is also a weight limit for receiving a CT scan.

A Pain-Free Procedure That Produces Crucial Images

Other than the poke if contrast material is needed, a CT scan is completely painless and provides your care team with critically important information on your condition. For many patients, the only unpleasant aspect of the scan is the feeling of being enclosed in the CT scan machine. However, that temporary discomfort is worth the valuable information the procedure produces.

At Baptist Health, the procedure takes place as follows:

• Preparation. How you prepare for your CT scan will depend on the type of scan performed. If your abdomen/pelvis, chest or head is being scanned with contrast, you may be instructed not to eat or drink for several hours prior to your exam. You may also have to drink a contrast medium or have it administered intravenously. If you’re having a head scan with no contrast, you can eat up until the time of the exam, and no liquid or intravenous contrast medium is required.
• Exam. A CT scan typically takes 15-30 minutes. A certified technologist helps you get positioned on the scan table, which is then moved into the machine. You’ll hear humming as the machine works and the table may move as different images are captured. You may also receive instructions, such as holding your breath for a short time, from the technologist, who observes the entire test and communicates with you through two-way microphones.
• Side effects. Depending on the type of exam, afterward, you may experience a metallic taste in your mouth (if contrast dye is used), fatigue, headache, weakness or constipation.
• Follow-up. After your exam, a radiologist (a doctor that specializes in imaging) reviews the images and sends a report to your physician who will discuss it with you at your next appointment.

Learn more about CT scans available from Baptist Health, along with pre- and post-exam expectations.

What is It, Preparation & Test Details

Overview

Patient Entering CT Scanner.

What is a CT scan?

Medical professionals use computed tomography, also known as CT scan, to examine structures inside your body. A CT scan uses X-rays and computers to produce images of a cross-section of your body. It takes pictures that show very thin “slices” of your bones, muscles, organs and blood vessels so that healthcare providers can see your body in great detail.

Traditional X-ray machines use a fixed tube to point X-rays at a single spot. As X-rays travel through the body, they are absorbed in different amounts by different tissues. Higher density tissue create a whiter image than other tissues against the black background of the film. X-rays produce 2D images. CT scans have a doughnut-shaped tube that rotates the X-ray 360 degrees around you. The data captured provides a detailed 3D view of the inside of your body.

Are a CT scan and CAT scan the same thing?

CT scans and CAT scans describe the same imaging test. CAT scan stands for computed axial tomography.

Test Details

Patient Fully Inside a CT Scanner.

What is a CT scan with contrast?

Sometimes, your scan uses a contrast agent. This contrast agent, sometimes called a dye, improves the images by highlighting certain features. Your healthcare provider will either have you drink a special liquid containing the contrast agent or give you an IV injection with the contrast or both depending on the type of CT scan and the reason for the scan. The contrast agent is cleared from your body through your urine, first rapidly then more slowly over the next 24 hours.

How do I prepare for a CT scan?

Your healthcare provider will give you instructions on how to prepare for your CT scan. On the day of the exam, you should pay attention to:

• Arrival: You should plan to arrive early, depending on your healthcare provider’s instructions. Arriving early helps the testing stay on schedule.
• Diet: Avoid eating and drinking for four hours before your exam.
• Medications: Ask your healthcare provider if you should take your regular medicines before the CT scan.
• Comfort: You should wear comfortable clothes. You may need to change into a gown before the exam and remove your watch and jewelry, including any piercings you can remove. You may need to remove dentures and hearing aids, too. Zippers and metal objects can obstruct the scan.

If your CT scan uses dye or contrast, your provider may give you some specific preparation guidelines:

• Blood test: You may need a blood test before your scheduled CT scan. The blood test will make sure the healthcare provider chooses the right dye.
• Diet restrictions: You will need to watch what you eat and drink for the four hours before your CT scan. Consuming only clear liquids helps prevent nausea when you receive the contrast dye. You can generally have broth, tea or black coffee, strained fruit juices, plain gelatin and soft drinks, like ginger ale.
• Allergy medication: If you are allergic to the contrast agent used for CT (which contains iodine), you may need to take a steroid medication the night before and morning of your procedure along with an antihistamine, such as benedryl, before the exam. Be sure to check with your healthcare provider and have them order these medications for you if needed. Contrast agents for MRI and CT are different; being allergic to one doesn’t mean you are allergic to the other.
• Preparation solution: You should drink the oral contrast solution as instructed by your technologist or nurse.

What happens during the test?

During the test, you will lie on your back on a table (like a bed). If your test requires it, a healthcare provider may inject the contrast dye intravenously (into your vein). This dye can make you feel flushed or have a metallic taste in your mouth.

When the scan begins:

1. The bed slowly moves into the doughnut-shaped scanner. At this point, you will need to stay as still as possible because movement can create blurry images.
2. The scanner takes pictures of the area the healthcare provider needs to see. Unlike an MRI scan, a CT scan is silent.
3. When the exam is over, the table moves back out of the scanner.

How long does the test take?

Typically, you should plan for an hour for a CT scan. Most of that time is for preparation. The scan itself takes between 10 and 30 minutes or less. Generally, you can resume your activities after a healthcare provider says it is safe to do so — usually after they complete the scan and verify clear images.

Results and Follow-Up

How long does it take to get results?

The results of the scan usually take 24 hours. A radiologist, a physician who specializes in reading and interpreting CT scan and other radiologic images, will review your scan and prepare a report that explains them. In an emergency setting, such as a hospital or emergency room, healthcare providers often receive results within an hour.

Once a radiologist and your healthcare provider have reviewed the results, you will either have another appointment or receive a call. Your healthcare provider will discuss the results with you.

Additional Details

What does a CT scan show?

Your healthcare provider will order a CT scan to help make a diagnosis of your health. The scan enables providers to closely examine bones, organs and other soft tissues, blood vessels and suspicious growths. Things that a CT scan can find include:

Healthcare providers can also see organs and tissues on X-rays. But on X-rays, body structures appear to overlap, making it difficult to see everything. The CT scan shows spaces between organs for a clearer view.

Are CT scans safe?

Healthcare providers consider CT scans generally safe. CT scans for children are safe, too. For children, your CT technician may use machines adjusted for children to reduce their radiation exposure.

CT scans, like other diagnostics, use a small amount of ionizing radiation to capture the image. Some risks associated with CT scans include:

• Cancer risk: All types of imaging using radiation, such as X-rays, cause a small increase in your risk of developing cancer. The difference is too tiny to measure effectively.
• Allergic reactions: Occasionally, people have a minor or more serious allergic reaction to the contrast agent.

If you have concerns about the health risks of CT scans, talk to your healthcare provider. They will discuss your concerns and help you make an informed decision about the scan.

Can I have a CT scan if I’m pregnant?

If you are or might be pregnant, you should tell the CT technician. CT scans of the pelvis and abdomen can subject the unborn baby to radiation, but it’s not enough to cause actual harm. CT scans in other parts of the body don’t put your baby at any risk.

A note from Cleveland Clinic

CT scans are an excellent diagnostic tool. You may have worries when your provider orders a CT scan. But this safe, painless test is noninvasive and has very little risk. The reward is that a CT scan can help your providers accurately diagnose a health concern and provide the right treatment for you. Talk to your healthcare provider about any concerns you may have, including other options for testing.

90,000 What is a PET-CT scan?

Currently, innovative technology PET-CT scanning (Positron emission tomography – computed tomography) is used for the diagnosis, treatment and control of cancer and other research in modern medicine – the technology includes a combination of two different examination methods: positron emission tomography (PET) and computed tomography (CT). Both modules of medical diagnostics perfectly complement each other, and make it possible to examine the organs and systems of a person to the smallest detail, when only one examination is carried out.PET scans can reveal even the smallest tumor structures, and CT scans their exact localization.
Positron emission tomography opens up the possibility of displaying metabolic processes in the cells of the body. Before the examination, patients receive an injection of a low-level radioactivity fructose molecule, which in the scientific world is referred to as fluoro-deoxyglucose (FDG). Fructose is a staple food – which is involved in all metabolic processes in the body.This means that after the patient receives FDG, the drug accumulates in the cells of the body in the same way as fructose. Since cancer cells divide more intensively and more often than healthy cells, they require significantly more energy. Their increased metabolism leads to a higher accumulation of FDG. With the help of positron emission tomography, this process becomes visible: groups of highly active cancer cells appear on the PET image as luminous dots, because the concentration of the accumulated diagnostic isotope in them is much higher.Thus, tumor cells are clearly delineated from healthy organ cells. Even millimeter tumor nodes are clearly visible during examination. However, it is often difficult to localize tumor formations using PET, since the structures and tissues displayed by it are sometimes not entirely clear. In other words, organs or bone structures appear less clearly on PET. Computed tomography is ideal for these purposes.
In computed tomography (CT), a layer-by-layer image or display of organs on serial sections is obtained – in this case, the anatomical structures of the human body.In a CT scan, X-rays are directed through the body. The higher the density of biological tissue, the less it is permeable to rays. Therefore, different tissue structures are clearly visible in the CT image, since bones, internal organs or cavities in them, such as the lungs, are respectively depicted in different gray tones due to their different density. Differences in organ density are clearly recognized on CT scans and indicate the presence of possible malignant changes or other diseases in them.The combination of PET and CT perfectly integrates the advantages of both diagnostic systems. In the composite image, CT is a kind of three-dimensional anatomical map of the human body, on which a PET pattern is superimposed on top, which accurately identifies areas of tissue with increased biological activity. PET / CT.

Example PET-CT scan:
A- (CT) Computed tomography, layered image of internal organs
B- (PET) Positron Emission Tomography, an area of ​​increased concentration of the diagnostic isotope
C- (PET-CT) is visible. , the location of the concentration of isotopes on the internal organs is clearly visible on the screen.

Today it is difficult to imagine modern diagnostics of oncological diseases, without PET-CT, this method is one of the most highly informative in modern medicine. With its help, it is possible to reliably identify and display on the screen even the smallest cancerous structures, and the size of the formations. This diagnostic method also helps to recognize at an early stage a possible relapse – a new growth of a cancerous tumor. The main advantage of PET / CT scanning is the precise localization of the desired organ fragment before the operation to remove the tumor or when taking tissue to clarify the diagnosis (biopsy).Modern research indicates that the method is becoming more and more important in the planning of tumor irradiation. In addition, with its help, it is possible to objectively and more detailed observation of the changes in the tumor after radiation or chemotherapy, which makes it possible to draw conclusions on the choice of the necessary treatment strategy. PET can also be used to diagnose diseases of the heart (areas of the heart muscle in which blood supply is impaired) and the brain (epilepsy, Alzheimer’s disease, the consequences of trauma, ischemic disorders).

The device is equipped with two scanner diagnostic rings, thus two examinations are carried out simultaneously. Diagnosis usually takes about 30 minutes. 45 minutes before the examination, the patient is given FDG molecules and a special contrast agent for CT. After receiving fructose and contrast agent and until the moment of examination, the patient is recommended to be at complete rest. The radiation load on the body that arose during examination with PET / CT is extremely low and is quickly eliminated from it.The diagnostic benefit of this method far outweighs the potential risk of radiation exposure. The doctor receives PET / CT scans in a few hours, so patients can count on a reliable diagnosis within a few days.

90,000 Clinical investigation Coronary angiography: Multislice computed tomography, Rest-stress Nuclear perfusion imaging of the myocardium, Multilayer computed tomography – Clinical trial registry

Inclusion criteria:

– Chest pain or similar angina symptoms indicating acute intracoronary ischemia …

– TIMI risk score less than or equal to 4.

– Possibility to give informed consent.

– At least 25 years old.

Exclusion Criterion:

– The attending physician makes the clinical decision for an immediate invasive assessment.

– Electrographic evidence of ischemia, including non-ST-segment elevation acute myocardial infarction (STEMI) or ST-segment elevation myocardial infarction (STEMI) with ST segment elevation or depression equal to or greater than 1 mm in two or more adjacent leads, and / or T wave inversion is greater than or equal to 2 mm.

– Positive cardiac biomarkers (troponin, CK and / or CK-MB) compatible with AMI for initial laboratory testing based on laboratory standard values.

– Pre-existing coronary artery disease, including previous MI, prior angiographic evidence of significant coronary artery disease, defined as stenosis greater than or equal to 25%, or a history of coronary artery bypass grafting (CABG).

– Renal failure (creatinine more than 1.5 mg / dL) or renal failure requiring dialysis.

– Atrial fibrillation or other apparently irregular rhythm.

– Psychological unfitness or extreme claustrophobia.

– Pregnancy or unknown pregnancy status.

– Clinical instability, including cardiogenic shock, hypotension (systolic blood pressure 180 mm Hg. On therapy), persistent ventricular or atrial arrhythmia requiring intravenous medication.

– Known allergy to iodine or iodine-containing contrast.

– Failure to tolerate beta-blockers, including patients with asthma or chronic obstructive pulmonary disease (COPD) requiring maintenance, i.e. the use of inhaled bronchodilators or steroids, or patients with complete heart block or second-degree atrioventricular blockade.

– Administration of iodinated contrast agent or X-ray scan within the last 48 hours.

– Use of any erectile dysfunction medications such as Viagra or Cialis in the last 24 years.hours.

– Body mass index (BMI) greater than or equal to 39 kg / m2. … Use of biguanides in the last 48 hours

Specialized scientific and practical publications for veterinarians and students of veterinary universities.

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90,000 CT Scan (Computed Tomography) | Cancer Treatment | Treatments

What is a computer scan (computed tomography)?

Computed tomography (CT) is a radiological technique that creates cross-sectional images or slices of internal organs and structures of the body using a series of X-rays directed at different angles.

CT gives a more detailed image than X-rays, which uses only one beam taken from one angle. CT can be used to visualize almost all parts of the body and is used by doctors to diagnose diseases and injuries, and to monitor the progress of a patient’s treatment.

How is CT scan performed?

When undergoing computed tomography, the patient is placed on a movable table in the supine position, which will slide into the computed tomograph.Depending on the view required by the doctor, you may be placed face down or face up on the table. You should not be wearing any jewelry or metal objects, as they may distort the image.

You will be instructed to lie as still as possible in order to obtain clear, undistorted images. The radiologist performing the scan will be in a different room, but communication with you will be via audio.

If a small child is tested, the parent is asked to stay close to keep the child calm.However, the parent will need to wear a protective apron to prevent exposure to radiation.

How does a CT scanner work?

The CT scanner generates a series of narrow beams that pass through the patient’s body as he moves through the machine. Beams of X-rays pass through different parts of the body with different densities, all information is transmitted to a computer, which, in turn, creates a 3D image of this part of the body.

In some cases, contrast agents can be used that can be injected intravenously, rectally or orally (through the mouth) to improve the quality of images of individual parts of the body.This form of computed tomography is called CT with contrast.

When is computed tomography performed?

The ability of computed tomography to produce clear and detailed images of body structures makes it the preferred method for diagnosing cancer. CT scans can reveal the exact location of the tumor, its size, and the extent of tissue damage around it.

CT is also used to diagnose muscle and bone diseases such as fractures and tumors.CT is also effective in detecting internal trauma and internal bleeding.

What are the risks associated with performing a CT scan?

Although the exposure to ionizing radiation is greater in CT scan than in X-ray, this radiation is insufficient to cause any adverse effects. Typically, the advantages of computed tomography outweigh the disadvantages. In addition, there are newer and faster CT scanners that use much less radiation than previous ones.

When CT is performed with contrast, allergic reactions to contrast material may develop. Reactions can range from mild to life-threatening.

In addition, because exposure to radiation can cause certain problems in the fetus, computed tomography is not recommended for pregnant women.

Micro-CT unravels the mystery of the mummy

06/05/2018

A scan of a 2100-year-old mummy from the Ptolemy period – previously thought to be a hawk – surprised experts by revealing that it was in fact a human fetus.

Maidstone Museum UK, worked with Andrew Nelson (Western University) and the team to determine the dates, origins and methods of mummification of their artifacts. With the help of Nikon CT (computed tomography), an unexpected discovery was made.

The Maidstone Museum is home to an extensive collection of fine art and historical artifacts with over 600,000 items of international importance. Among these items are various mummies. Most of them are animals such as snakes, crocodiles, cats and birds, except for one human mummy – Ta-Kush.A recent project called “Ancient Lives” at the museum has led to these artifacts being scanned with CT scans to determine dates and places of origin, as well as mummification techniques.

The resulting CT scan provided some interesting information about the mummies, but the EA 493 mummified hawk from the Ptolemy period held a much greater secret inside. The experts were incredibly surprised to see that the initial scan identified a human fetus.

Bioarchaeologist Andrew Nelson, professor of anthropology and mummy expert at Western University, worked closely with the Maidstone Museum and Nikon Metrology to conduct micro-CT scans and closely examine objects. Thanks to the extremely high resolution micro-CT scans, the team was able to actually deploy the mummy.

The digital model, created with 360-degree CT scan, can be virtually cut and slice infinitely, while maintaining the original sample without causing damage.

Source

Computed tomography – Independent Physicians Medical Center

Have you ever bought sliced ​​bread? If you look between the slices, you can immediately see if something is wrong with the bread. Computed tomography (“tomo” -slice, “graph” -image) is also arranged approximately. The required body part is placed in a virtual slicer, which creates images at small intervals.

In IPMC, CT scans are performed using the 64-slice Siemens Spiral CT Somatom Sensation, an open-ended, non-claustrophobic scanner. The patient lies on a comfortable table while cross-sectional images are taken from the table, which are then assembled with the help of a computer into a single highly detailed reconstruction of bones and soft tissues.

Although it has been widely used for diagnostics since the inception of computed tomography in the 1970s, CT is now also used for prophylaxis.This is especially valuable for patients at increased risk of developing cancer and for those with previous history of cancer.

The

CT scanner uses X-rays to create images, but continuous advances in technology have allowed Siemens to dramatically reduce scan times and radiation exposure. However, radiological procedures should always be performed with caution and only when necessary. This is why we never conduct such research without a valid prescription from a doctor.

CT scans can be performed on virtually any part of the body, so there are many different types of scans with different protocols and preparation conditions. Your doctor must decide which procedure is best for you. Depending on this, you may be given an oral or intravenous contrast agent, but more often both are given. For patient safety, the screening process for all contrast-enhanced studies is performed with extreme caution.Please read our instructions on how to prepare for your CT scan.

If you have any further questions, please consult your referring or treating physician.

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