CT CAROTID ANGIO

CT Angiography (CTA) of the Carotid Arteries is a diagnostic imaging procedure which entails the utilization of computerized tomography (CT) and contrast material for the visualization of carotid arteries situated in the neck region. These arteries, which are critical as they deliver oxygenated blood to the brain, may cause strokes if they narrow or block. CTA images assist in defining possible stenosis or plaque in the arteries, which is required to modulate treatment to lower the risk of stroke. 

What Is CT Carotid Angiography (CTA)? 

CTA is an advanced CT scan that uses X-rays and computing to produce detailed images of the carotid arteries' cross-section. During the examination, an intravenous line is used to inject contrast dye into the patient’s veins, the blood vessels are made visible in contrast with the background. The scanner moves around the patient for a short time and captures many photos of the head while the contrast flows through the carotid arteries. 

Types of CT Carotid Angiography (CTA) 

• Native scan (without contrast): done to assess the carotid arteries without any contrast dye. 
• With contrast scan: done to assess the carotid arteries with the use of contrast dye. 
• Dual-energy CTA: This examines the carotid arteries with two distinct X-ray energy levels. This technique provides greater image detail as well as the ability to detect subtle variations in the arteries over time. 

List of Parameters Considered During CT Carotid Angiography (CTA)

• The existence of stenosis or obstruction of the carotid arteries. 
• The amount of stenosis or occlusion. 
• The site or region of the stenosis or occlusion. 
• The major components of the plaque – if any, such as calcified, fatty, or fibrotic material. 
• The plaque and its associated ulceration or irregularity. 
• The collateral blood perfusion to the brain. 

Reasons for Taking a CT Carotid Angiography (CTA)

• To confirm diagnosis for suspected carotid artery disease. 
• To determine the advancement of the disease process of carotid artery disease. 
• To check on how well the treatment for the carotid artery disease is working. 
• To assess the need for surgical or non-surgical interventions for the carotid artery disease. 

When and Who Needs to Take a CT Carotid Angiography (CTA)? 

This test is done for patients who have: 

• Symptoms that may indicate disease in carotid arteries, such as Transient ischemic attack (TIA), a stroke, or amaurosis fugax (sudden temporary loss of vision). 
• Hypertension, diabetes, or high cholesterol that puts a person at higher risk for developing carotid artery disease. 
• A family history of the disease. 
• Positive carotid bruit on physical exam, meaning abnormal sound heard over the carotid artery during auscultation. 

Benefits of Taking the Test

• Displays the carotid arteries in detail. 
• Helps determine the site, extent, and type of the plaque. 
• Assists in the management strategies of carotid artery disease. 

Illnesses Diagnosed with CT Carotid Angiography (CTA)

• Stenosis of the carotid artery 
• Occlusion of the carotid artery 
• Aneurysm of the carotid artery 
• Dissection of the carotid artery 
• Ruptured plaque and/or associated haemorrhage 

Preparing for CT Carotid Angiography (CTA)

• Take off any rings or clothes with metal parts. 
• Change into a hospital gown. 
• If possible, take out dental plates and metal dentures. 
• Do not eat or drink anything 4 to 6 hours prior to the test. 
• Tell the technologist about any allergies and medical conditions and previous contrast dye reactions. 

Pre-requisites 

• Patient’s full medical history 
• Check-up 
• Lab tests like serum creatinine to check kidney functions. 
• Always inform the technologist about any medications taken. 

Best Time to Take the CT Carotid Angiography (CTA) 

• The exam may be done at any time, but it is advisable not to do it during peak times at the emergency departments or when the department has too many urgent examinations. 

Eligibility 

• Generally recommended to know or suspected patients with carotid artery disease. 
• Cautioned in patients with renal disease, contrast dye allergies, or some other medical conditions such as acute stroke. 

Procedure for Taking CT Carotid Angiography CTA 

1. Patient Preparation (30 minutes) 
2. Scanning (15-30 minutes) 
3. Contrast Injection (1-2 minutes) 
4. Image acquisition and reconstruction (15-30 minutes) 
5. Total estimated time (approximately 1-2 hours) 

Caution Before taking the test 

• Notify the technologist of any allergic reactions or previous experiences with contrast dye. 
• Notify the technologist of any other relevant health concerns (e.g. diabetic or renal issues). 
• If applicable, refrain from taking metformin for 48 hours leading up to the exam.