CT angiography – abdomen and pelvis

Computed tomography angiography – abdomen and pelvis; CTA – abdomen and pelvis; Renal artery – CTA; Aortic – CTA; Mesenteric CTA

CT angiography combines a CT scan with the injection of dye. This technique is able to create pictures of the blood vessels in your belly (abdomen) or pelvis area. CT stands for computed tomography.

How the Test is Performed

You will lie on a narrow table that slides into the center of the CT scanner. Most often, you will lie on your back with your arms raised above your head.

Once you are inside the scanner, the machine’s x-ray beam rotates around you. Modern “spiral” scanners can perform the exam without stopping.

A computer creates separate images of the belly area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the belly area can be made by stacking the slices together.

You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time.

The scan should take less than 30 minutes.

How to Prepare for the Test

You need to have a special dye, called contrast, put into your body before some exams. Contrast helps certain areas show up better on the x-rays.

• Contrast can be given through a vein (IV) in your hand or forearm. If contrast is used, you also may be asked not to eat or drink anything for 4 to 6 hours before the test.
• You may also have to drink a different contrast before the exam. When you drink it will depend on the type of exam being done.Contrast has a chalky taste, although some have flavors so that they taste a little better. The contrast will pass out of your body through your stools.
• Let your health care provider know if you have ever had a reaction to contrast. You may need to take medicines before the test in order to safely receive this substance.
• Before receiving the contrast, tell your provider if you take the diabetes medication metformin (Glucophage). People taking this medicine may have to stop taking it for a while before the test.

The contrast can worsen kidney function problems in patients with poorly functioning kidneys. Talk to your provider if you have a history of kidney problems.

Too much weight can damage the scanner. If you weigh more than 300 pounds (135 kilograms), talk to your provider about the weight limit before the test.

You will need to take off your jewelry and wear a hospital gown during the study.

How the Test will Feel

Lying on the hard table may be a little bit uncomfortable.

If you have contrast through a vein, you may have a:

• Slight burning sensation
• Metallic taste in your mouth
• Warm flushing of your body

These feelings are normal and go away within a few seconds.

Why the Test is Performed

A CT angiography scan quickly makes detailed pictures of the blood vessels inside your belly or pelvis.

This test may be used to look for:

• Abnormal widening or ballooning of part of an artery (aneurysm)
• The source of bleeding that starts in the intestines or elsewhere in the belly or pelvis
• Masses and tumors in the abdomen or pelvis, including cancer, when needed to help plan treatment
• Cause of pain in the abdomen thought to be due to narrowing or blockage of one or more of the arteries that supply the small and large intestines
• Pain in the legs is thought to be due to the narrowing of blood vessels that supply the legs and feet
• High blood pressure due to narrowing of the arteries that carry blood to the kidneys

The test also may be used before:

• Surgery on blood vessels of liver
• Kidney transplant

Normal Results

Results are considered normal if no problems are seen.

What Abnormal Results Mean

The abdominal results may show:

• The source of bleeding inside the belly or pelvis
• Narrowing of the artery that supplies the kidneys
• Narrowing of arteries that supply the intestines
• Narrowing of arteries that supply the legs
• Ballooning or swelling of an artery (aneurysm), including the aorta
• A tear in the wall of the major artery carrying blood out of the heart (aorta)

Risks

Risks of CT scans include:

• Allergy to contrast dye
• Exposure to radiation
• Damage to kidneys from contrast dye

CT scans expose you to more radiation than regular x-rays. Many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. Talk to your health care provider about this risk and the benefit of the test for getting a correct diagnosis of your medical problem.  Most modern scanners use techniques to use less radiation.

Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.

The most common type of contrast given into a vein contains iodine. If you have an iodine allergy, you may have nausea or vomiting , sneezing , itching , or hives if you get this type of contrast.

If you must be given such contrast, your provider may give you antihistamines (such as Benadryl) or steroids before the test.

Your kidneys help remove iodine out of the body. You may need extra fluids after the test to help flush the iodine out of your body if you have kidney disease or diabetes.

Rarely, the dye may cause a life-threatening allergic response called anaphylaxis . Tell the scanner operator right away if you have any trouble breathing during the test. Scanners come with an intercom and speakers, so the operator can hear you at all times.

CT angiography – head and neck

Computed tomography angiography – brain; CTA – skull; CTA – cranial; TIA-CTA head; Stroke-CTA head; Computed tomography angiography – neck; CTA – neck; Vertebral artery – CTA; Carotid artery stenosis – CTA; Vertebrobasilar – CTA; Posterior circulation ischemia – CTA; TIA – CTA neck; Stroke – CTA neck

CT angiography (CTA) combines a CT scan with the injection of dye. CT stands for computed tomography. This technique is able to create pictures of the blood vessels in the head and neck.

How the Test is Performed

You will be asked to lie on a narrow table that slides into the center of the CT scanner.

While inside the scanner, the machine’s x-ray beam rotates around you.

A computer creates many separate images of the body area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the head and neck area can be created by stacking the slices together.

You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time.

Complete scans usually take only a few seconds. The newest scanners can image your entire body, head to toe, in less than 30 seconds.

How to Prepare for the Test

Certain exams require a special dye, called contrast, to be delivered into the body before the test starts. Contrast helps certain areas show up better on x-rays.

• Contrast can be given through a vein (IV) in your hand or forearm. If contrast is used, you may also be asked not to eat or drink anything for 4 to 6 hours before the test.
• Let your health care provider know if you have ever had a reaction to contrast. You may need to take medicines before the test in order to safely receive it.
• Before receiving the contrast, tell your provider if you take the diabetes medicine metformin (Glucophage). You may need to take extra precautions.

The contrast can worsen kidney function problems in people with poorly functioning kidneys. Talk to your provider if you have a history of kidney problems.

Too much weight can damage the scanner. If you weigh more than 300 pounds (135 kilograms), talk to your provider about the weight limit before the test.

You will be asked to remove jewelry and wear a hospital gown during the study.

How the Test will Feel

Some people may have discomfort from lying on the hard table.

If you have contrast through a vein, you may have a:

• Slight burning feeling
• Metallic taste in your mouth
• Warm flushing of your body

This is normal and usually goes away within a few seconds.

Why the Test is Performed

CTA of the head may be done to look for the cause of:

• Changes in thinking or behavior
• Difficulty pronouncing words
• Dizziness or vertigo
• Double vision or vision loss
• Fainting
• Headache, when you have certain other signs or symptoms
• Hearing loss (in some people)
• Numbness or tingling, most often on the face or scalp
• Swallowing problems
• Stroke
• Transient ischemic attack (TIA)
• Weakness in one part of your body

CTA of the neck may also be done:

• After trauma to the neck to look for damage to blood vessels
• For planning before carotid artery surgery
• For planning for brain tumor surgery
• For suspected vasculitis (inflammation of the blood vessel walls)
• Suspected abnormal blood vessels in the brain

Normal Results

Results are considered normal if no problems are seen.

What Abnormal Results Mean

Abnormal results may be due to:

• Abnormal blood vessels (arteriovenous malformation).
• Bleeding in the brain (for example, subdural hematoma or an area of bleeding).
• Brain tumor or other growth (mass).
• Stroke .
• Narrowed or blocked carotid arteries . (The carotid arteries provide the main blood supply to your brain. They are located on each side of your neck.)
• Narrowed or blocked vertebral artery in the neck . (The vertebral arteries provide blood flow to the back of the brain.)
• A tear in the wall of an artery (dissection).
• A weak area in the wall of a blood vessel that causes the blood vessel to bulge or balloon out ( aneurysm ).

Risks

Risks of CT scans include:

• Being exposed to radiation
• Allergic reaction to the contrast dye
• Damage to the kidneys from the dye

CT scans use more radiation than regular x-rays. Having many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. You and your provider should weigh this risk against the benefits of getting a correct diagnosis for a medical problem.  Most modern scanners use techniques to use less radiation.

Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.

• The most common type of contrast given into a vein contains iodine. If you have an iodine allergy, you may have nausea or vomiting , sneezing , itching , or hives if you get this type of contrast.
• If you absolutely must be given such contrast, your provider may give you antihistamines (such as Benadryl) or steroids before the test.
• The kidneys help remove iodine out of the body. People with kidney disease or diabetes may need to receive extra fluids after the test to help flush the iodine out of the body.

Rarely, the dye may cause a life-threatening allergic response called called anaphylaxis . Tell the scanner operator right away if you have any trouble breathing during the test. Scanners come with an intercom and speakers, so the operator can hear you at all times.

Considerations

A CT scan can reduce or avoid the need for invasive procedures to diagnose problems in the skull. This is one of the safest ways to study the head and neck.

Other tests that may be done instead of CT scan of the head include:

• MRI of the head
• Positron emission tomography (PET) scan of the head

CT angiography – chest

Computed tomography angiography – thorax; CTA – lungs; Pulmonary embolism – CTA chest; Thoracic aortic aneurysm – CTA chest; Venous thromboembolism – CTA lung; Blood clot – CTA lung; Embolus – CTA lung;  CT pulmonary angiogram

CT angiography combines a CT scan with the injection of dye. This technique is able to create pictures of the blood vessels in the chest and upper abdomen. CT stands for computed tomography.

How the Test is Performed

You will be asked to lie on a narrow table that slides into the center of the CT scanner.

While inside the scanner, the machine’s x-ray beam rotates around you.

A computer creates multiple separate images of the body area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the chest area can be created by stacking the slices together.

You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time.

Complete scans usually take only a few minutes. The newest scanners can image your entire body, head to toe, in less than 30 seconds.

How to Prepare for the Test

Certain exams require a special dye, called contrast, to be delivered into the body before the test starts. Contrast helps certain areas show up better on x-rays.

• Contrast can be given through a vein (IV) in your hand or forearm. If contrast is used, you may also be asked not to eat or drink anything for 4 to 6 hours before the test.
• Let your health care provider know if you have ever had a reaction to contrast. You may need to take medications before the test in order to safely receive it.
• Before receiving the contrast, tell your provider if you take the diabetes medication metformin (Glucophage). You may need to take extra precautions.

The contrast can worsen kidney function problems in people with poorly functioning kidneys.  Talk to your provider if you have a history of kidney problems.

Too much weight can damage the scanner. If you weigh more than 300 pounds (135 kilograms), talk to your provider about the weight limit before the test.

You will be asked to remove jewelry and wear a hospital gown during the study.

How the Test will Feel

The x-rays produced by the CT scan are painless. Some people may have discomfort from lying on the hard table.

If you have contrast through a vein, you may have a:

• Slight burning feeling
• Metallic taste in your mouth
• Warm flushing of your body

This is normal and usually goes away within a few seconds.

Why the Test is Performed

A chest CT angiogram may be done:

• For symptoms that suggest blood clots in the lungs, such as chest pain, rapid breathing, or shortness of breath
• After a chest injury or trauma
• Before surgery in the lung or chest
• To look for a possible site to insert a catheter for hemodialysis
• For swelling of the face or upper arms that cannot be explained
• To look for a suspected birth defect of the aorta or other blood vessels in the chest
• To look for a balloon dilation of an artery (aneurysm)
• To look for a tear in an artery (dissection)

Normal Results

Results are considered normal if no problems are seen.

What Abnormal Results Mean

A chest CT may show many disorders of the heart, lungs, or chest area, including:

• Suspected blockage of the superior vena cava : This large vein moves blood from the upper half of the body to the heart.
• Blood clot(s) in the lungs .
• Abnormalities of the blood vessels in the lungs or chest, such as aortic arch syndrome .
• Aortic aneurysm (in the chest area) .
• Narrowing of part of the major artery leading out of the heart (aorta).
• Tear in the wall of an artery (dissection).
• Inflammation of the blood vessel walls (vasculitis).

Risks

Risks of CT scans include:

• Being exposed to radiation
• Allergic reaction to contrast dye
• Damage to kidneys from contrast dye

CT scans use more radiation than regular x-rays. Having many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. You and your provider should weigh this risk against the benefits of getting a correct diagnosis for a medical problem.  Most modern scanners use techniques to use less radiation.

Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.

• The most common type of contrast given into a vein contains iodine. If you have an iodine allergy, you may have nausea or vomiting , sneezing , itching , or hives if you get this type of contrast.
• If you absolutely must be given such contrast, your provider may give you antihistamines (such as Benadryl) or steroids before the test.
• The kidneys help remove iodine out of the body. Those with kidney disease or diabetes may need to receive extra fluids after the test to help flush the iodine out of the body.

Rarely, the dye may cause a life-threatening allergic response called called anaphylaxis . If you have any trouble breathing during the test, you should notify the scanner operator immediately. Scanners come with an intercom and speakers, so someone can hear you at all times.

CT angiography – arms and legs

Computed tomography angiography – peripheral; CTA – peripheral; CTA – Runoff

CT angiography combines a CT scan with the injection of dye. This technique is able to create pictures of the blood vessels in the arms or legs. CT stands for computed tomography.

How the Test is Performed

You will lie on a narrow table that slides into the center of the CT scanner.

When you are inside the scanner, the machine’s x-ray beam rotates around you. Modern “spiral” scanners can perform the exam without stopping.

A computer makes multiple images of the body area, called slices. These images can be stored, viewed on a monitor, or printed on film. Models of the body area in three-dimension can be created by adding the slices together.

You must stay still during the exam, because movement blurs the pictures. You may have to hold your breath for short periods of time.

The scan should take only about 5 minutes.

How to Prepare for the Test

Some exams require a special dye, called contrast, to be injected into your body before the test. Contrast helps certain areas show up better on the x-rays.

• Contrast can be given through a vein (IV) in your hand or forearm. If contrast is used, you also may be asked not to eat or drink anything for 4 to 6 hours before the test.
• Let your health care provider know if you have ever had a reaction to contrast. You may need to take medicines before the test to avoid this problem.
• Before receiving the contrast, tell your provider if you take the diabetes medicine metformin (Glucophage). You may need to take extra steps if you are taking this medicine.

The contrast can worsen kidney function problems in people with poorly functioning kidneys.  Talk to your provider if you have a history of kidney problems.

Too much weight can cause damage to the scanner’s working parts. If you weigh more than 300 pounds (135 kilograms), talk to your doctor about the weight limit before the test.

You will need to remove jewelry and wear a hospital gown during the CT exam.

How the Test will Feel

Some people may be uncomfortable lying on the hard table.

Contrast given through an IV may cause a:

• Slight burning feeling
• Metallic taste in your mouth
• Warm flushing of your body

These feelings are normal and usually go away within a few seconds.

Why the Test is Performed

You may need this test if you have symptoms of a narrowed or blocked blood vessel in the arms, hands, legs, or feet.

The test may also be done to diagnose:

• Abnormal widening or ballooning of part of an artery (aneurysm)
• Bleeding
• Swelling or inflammation of the blood vessels (vasculitis)
• Leg pain during walking or exercise (claudication)

Normal Results

Results are considered normal if no problems are seen.

What Abnormal Results Mean

An abnormal result is commonly due to narrowing and hardening of the arteries in the arms or legs from plaque buildup in the artery walls .

The x-ray may show a blockage in the vessels caused by:

• Abnormal widening or ballooning of part of an artery ( aneurysm )
• Blood clots
• Other diseases of the arteries

Abnormal results may also be due to:

• Inflammation of the blood vessels
• Injury to the blood vessels
• Buerger disease (thromboangiitis obliterans) , a rare disease in which blood vessels of the hands and feet become blocked

Risks

Risks of CT scans include:

• Exposure to radiation
• Allergy to contrast dye
• Damage to the kidneys from the contrast dye

CT scans give off more radiation than regular x-rays. Having many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. You and your provider should discuss this risk compared with the value of an accurate diagnosis for the problem. Most modern scanners use techniques to use less radiation.

Let your provider know if you have ever had an allergic reaction to injected contrast dye.

• The most common type of contrast contains iodine. If you have an iodine allergy, you may have nausea or vomiting , sneezing , itching , or hives if you get this type of contrast.
• If you need to have this kind of contrast, your provider may give you antihistamines (such as Benadryl) or steroids before the test.
• The kidneys help remove iodine out of the body. You may need extra fluids after the test to help rid your body of the iodine if you have kidney disease or diabetes.

Rarely, the dye may cause a serious allergic response called anaphylaxis . This can be life-threatening. Notify the scanner operator right away if you have any trouble breathing during the test. Scanners have an intercom and speakers so the operator can hear you at all times.