CT Angiogram Procedure

CT angiography uses computed tomography technology to examine the arteries and veins in the body. Angiography is used to determine any kind of narrowing in the blood vessels or disease due to atherosclerosis. It is an invasive medical test which helps the physicians in diagnosing and treating medical conditions.

Angiography is performed by using any of the three methods; x-rays with catheters, computer tomography (CT) and magnetic resonance imaging (MRI). It is mainly used for following reasons:

• It helps in identifying disease and aneurysm in the aorta or any other blood vessels.
• It detects atherosclerosis disease in the carotid artery of the neck, which limits the blood flow to the brain and causes a stroke.
• It is used to sample blood from specific veins in the body to detect any kind of endocrine disease.
• It identifies a small aneurysm or arteriovenous malformation inside the brain.
• It indicates any abnormality in the renal artery and visualizes blood flow to help prepare for a kidney transplant.
• It examines pulmonary arteries in the lungs to detect pulmonary embolism (blood clots from leg veins).

CT Angiogram Procedure

Before the procedure starts, the patient is asked to drink only water and remove all metal objects off his body. The physician should make sure that the patient isn't allergic to the contrast material used during the angiography. The physician places an IV into a peripheral vein in the patient's forearm. Then the patient is brought near the CT scanner and a dose of contrast agent is administered into the IV. This is done to ensure that the arteries will stand out when the physician reads the scan. The patient has to lay down and the scanner is rotated around his body. A large number of X-ray images are taken and sent to the computer. These images are taken from different angles to create a 3-dimensional image of the patient, which is extremely beneficial while diagnosing the disease.

Benefits

• Angiography almost eliminates the need for surgery, and in case surgery is needed, it can be done more accurately after this procedure.
• It detects narrowing of blood vessels in time which helps in taking necessary and preventive measures.
• It is more accurate than the MRI and gives an exact anatomical detail of the blood vessels.
• CT angiography is a less invasive and more patient-friendly as compared to the catheter angiography procedures which require placing of the catheter (plastic tube) and injecting of the contrast material into the blood vessels.
• After the examination, there are no radiation remains in the patient's body.
• CT angiography is safe, less time-consuming and more cost-effective.

Risks and Limitations

• There may be a slight risk of cancer due to excessive exposure to radiation. But the advantage of a correct diagnosis outweighs this risk.
• It can cause skin allergies, especially if a person is allergic to the contrast material used in the process. Hence, a different exam can be undergone that does not call for contrast material injection.
• Sometimes leakage of the contrast material from the vessel can damage the skin, blood vessels and nerves. In such cases, the physician should be informed immediately and the procedure should be stopped at once.
• After contrast material injection, nursing mothers have to wait for 24 hours before resuming breast-feeding.
• CT angiography should be avoided in patients suffering with kidney diseases or diabetes, as the contrast material used during the scanning can further damage the kidney functioning.
• If a patient is suffering from severe heart disease or multiple blocked blood vessels, CT angiograms can be hard to interpret.

Modern CT angiograms use multiple detectors to capture images from different rotations of the CT scanner. These machines use 64 detectors or scanners which helps in reducing the scanning time and increases the efficiency to a high level.