CT CAROTID ANGIO

Computed Tomography (CT)

A CT scanner is a sophisticated machine that takes multiple X-ray images from various angles around your neck. Think of it like taking many individual pictures of a loaf of bread, but instead of slices of bread, the images are cross-sections of your body.

Contrast Dye

To make the blood vessels stand out from the surrounding tissues, an iodine-based contrast material (or dye) is injected into a vein, typically in your arm. This dye travels through your bloodstream, reaching the carotid arteries. As it flows through them, it makes the vessels appear bright white on the CT images, providing a clear roadmap of your vascular structure.

Types of CT Carotid Angio

Standard Procedure

The standard and most common type of this test is the CT angiography of the neck with contrast. This is the procedure described throughout this page and is the gold standard for this type of imaging.

Comparison with Other Tests

It is helpful to understand how it compares to alternative imaging tests:

• Magnetic Resonance Angiography (MRA): An MRA uses powerful magnets and radio waves instead of radiation to image blood vessels. It is a good alternative for patients who cannot receive iodine-based contrast. However, a CTA is often faster and can provide better detail of calcified (hard) plaque.
• Conventional Catheter Angiogram: This is a more invasive procedure where a catheter is threaded through an artery, usually from the groin, up to the neck. While it is considered the "gold standard" for detail, it carries higher risks. A CT Carotid Angio is preferred in most cases because it is much less invasive, faster, and carries fewer potential complications.

### Degree of Stenosis This is the most crucial measurement. It identifies the percentage of narrowing in an artery caused by plaque buildup. ### Plaque Characterization The scan can help determine if the plaque is "soft" (lipid-rich and more prone to rupture) or "calcified" (hardened and more stable). ### Vessel Integrity The radiologist will look for any signs of damage to the artery wall, such as ulcers (divots in the plaque), dissections (tears in the artery lining), or aneurysms (abnormal bulges). ### Vascular Anatomy The test provides a detailed map of the arteries, showing their origin, course, and any anatomical variations, which is essential for surgical planning. ### Occlusion This parameter determines if an artery is completely (100%) blocked, preventing any blood from passing through.

Core Reasons

To summarize, the core reasons for undergoing this test are centered on diagnosing and managing conditions that affect blood flow to the brain. Primary reasons include:

• To perform a detailed scan for carotid artery blockage or narrowing (stenosis).
• To investigate the cause of unexplained neurological symptoms like dizziness, syncope (fainting), or stroke-like events.
• To assess the blood vessels for potential injury after neck trauma.
• To monitor the progression of known carotid artery disease over time.

When and Who Needs to Take a CT Carotid Angio?

You Might Need This Test If:

• You've experienced symptoms of a TIA (Transient Ischemic Attack): Often called a "mini-stroke," a TIA causes temporary stroke-like symptoms such as sudden numbness or weakness on one side of the body, difficulty speaking, vision problems, or severe dizziness. A CT Carotid Angio helps identify if a blockage in the carotid artery is the cause.
• A "Bruit" is detected: During a routine physical exam, your doctor might listen to the arteries in your neck with a stethoscope. If they hear an abnormal whooshing sound, known as a bruit, it can suggest turbulent blood flow caused by a narrowing.
• You had an abnormal Carotid Ultrasound: A carotid ultrasound is often the first test used to screen the arteries. If it shows potential narrowing or provides unclear results, a CT Carotid Angio is often the next step for a more detailed and accurate assessment.
• It's needed for pre-surgical planning: Before performing procedures to fix a narrowed artery, such as a carotid endarterectomy (plaque removal surgery) or stenting, surgeons need a detailed map of the artery's anatomy. This test provides that precise information.

Benefits of Taking the Test

Key Advantages

Choosing to have a CT Carotid Angio offers several significant benefits for you and your doctor:

• High Accuracy: It is extremely precise in diagnosing significant carotid artery stenosis and other abnormalities.
• Comprehensive Detail: It provides excellent images of not only the blood vessels but also the surrounding bones and soft tissues of the neck.
• Speed and Availability: The scan itself is very fast—often completed in seconds—and CT scanners are widely available.
• Minimally Invasive: Unlike a conventional angiogram, it only requires a simple IV injection, making it safer and more comfortable for the patient.

Illnesses Diagnosed with CT Carotid Angiography (CTA)

Common Diagnoses

This powerful diagnostic tool can help identify a range of conditions affecting the carotid arteries. The most common diagnosis made with a carotid artery stenosis CT scan is:

• Carotid Artery Stenosis: A narrowing of the arteries due to atherosclerosis (the buildup of fatty plaque).
• Carotid Artery Occlusion: The complete blockage of a carotid artery.
• Carotid Artery Aneurysm or Dissection: A weakening or tear in the wall of the artery.
• Fibromuscular Dysplasia (FMD): An uncommon condition that causes abnormal cell growth in the artery walls, leading to narrowing.
• Vasculitis: Inflammation of the blood vessels, which can cause them to narrow.

Preparation Guidelines

Proper preparation is simple but essential for a successful and safe scan. Please follow these guidelines before your appointment at Cadabams Diagnostics:

• Inform Our Staff: Let us know about any allergies (especially to iodine or shellfish), any previous reactions to contrast dye, any kidney problems, or if you are taking medications for diabetes, particularly Metformin.
• Fasting: You may be asked not to eat or drink anything for 2-4 hours before your scheduled test.
• Hydration: Drink plenty of water in the day leading up to your scan and especially after. This helps your kidneys flush the contrast dye from your system.
• Clothing: Wear comfortable, loose-fitting clothes. You may be asked to change into a hospital gown. Avoid wearing clothing with metal zippers or buttons, and remove any jewelry or metallic items from your neck and chest area.

Pre-requisites

Necessary Requirements

• Doctor's Referral: A CT Carotid Angio must be prescribed by a doctor. You will need to bring your referral form to your appointment.
• Kidney Function Test: To ensure it is safe to administer the contrast dye, we will almost always require a recent blood test result (within the last 30 days) that shows your serum creatinine and eGFR levels.

Best Time to Take the CT Carotid Angio

Timing Considerations

There is no specific "best time" of day for this test. It is not affected by time or daily cycles. The test is performed based on clinical urgency and can be scheduled at your convenience, or performed emergently if your doctor deems it necessary.

Eligibility

Who Can Take the Test

The CT Carotid Angio is a suitable and safe test for most adults. However, special caution is exercised for certain individuals:

• Patients with known impaired kidney function.
• Patients with a history of a severe allergic reaction to iodine contrast material.
• Patients who are or might be pregnant.

Our team at Cadabams Diagnostics will carefully review your medical history to confirm your eligibility and ensure the utmost safety.

Procedure for Taking a CT Carotid Angio

Step-by-Step Process

Understanding the step-by-step CT carotid angiogram procedure can help you feel more comfortable and prepared on the day of your scan.

Step 1: Preparation

Upon arrival, you will confirm your details and may be asked to change into a hospital gown. A trained technologist or nurse will explain the procedure to you and answer any last-minute questions. They will then place a small IV (intravenous) line into a vein in your arm or hand. This is where the contrast dye will be administered.

Step 2: Positioning

You will be asked to lie down on your back on the padded CT scanner table. The technologist will help position you comfortably, often using a headrest to help you keep your head still. The table will then slide slowly into the center of the large, ring-shaped CT scanner (gantry). You will be able to communicate with the technologist through an intercom system at all times.

Step 3: Contrast Injection

The technologist, operating from an adjacent control room, will begin the injection of the contrast dye through your IV line. As the dye enters your bloodstream, it is very common to experience a warm or flushing sensation spreading through your body. Some people also notice a metallic taste in their mouth. These sensations are normal, expected, and pass very quickly.

Step 4: Scanning

As the contrast dye reaches your carotid arteries, the scanner will begin taking images. You will hear clicking and whirring sounds as the machine works. The technologist will instruct you to hold your breath for a few seconds during the scan. It is very important to remain as still as possible during this time to ensure the images are sharp and clear. The actual imaging process is incredibly fast, often taking less than 30 seconds.

Step 5: Post-Scan

Once the images are acquired, the table will slide back out of the scanner. The technologist will come in and remove the IV line from your arm, applying a small bandage. You may be asked to wait for a short period (15-20 minutes) for observation to ensure you have no adverse reaction to the dye before you are cleared to leave. You can typically eat, drink, and resume all normal activities immediately after the scan.

Caution Before Taking the Test

Important Considerations

For your safety, it is absolutely crucial that you inform the technologist and our staff before the scan if you:

• Are or think you might be pregnant.
• Are currently breastfeeding.
• Have ever had an allergic reaction to IV contrast dye in the past.
• Have diabetes, especially if you take Metformin (Glucophage).
• Have a known history of kidney disease, kidney failure, or are on dialysis.