CT Coronary Angiography

What is it?

'CT coronary angiography is a non invasive, painless, fast, OPD basis examination of coronary arteries with the help of fast multislice CT scanner ( 16 slice Somatom Sensation Cardiac CT scanner). This fast subsecond scan with help of retrospective ECG gating allows to capture images of heart between beats and visualize coronary arteries in single breath hold. CT Coronary Angiography is much safer without the risks of invasive angiography & it can localize, visualize & quantify the earliest possible evidence of coronary artery disease.

CT coronary angiography , because of its non invasiveness, OPD basis & low cost is considered as a ‘gate keeper’ for the catheter coronary angiography. In only a few minutes you can find out if you have a problem that needs to be evaluated. Heart disease needs to be prevented & the sooner you find out if you have a problem the quicker you can reduce your risk.

Why it is done?

'As compared to conventional angiography, CT coronary angiography is able to visualize coronary wall as well as the coronary lumen. Calcified and non calcified atherosclerotic lesions can be visualized in the coronary wall, and the resulting stenosis of vessels. Anatomic variations of coronary arteries, presence of calcified & soft plaques, Post stent and post graft patency can all be visualized in a single breath hold procedure with better patient compliance.

How it is done?

CT coronary angiography is performed with the use of 16 slice multislice CT scanner with a 0.37sec/3600 rotation time ( Sensation Cardiac 16, Siemens). Patients who have a prescan heart rate > 75 bpm are given b blocker one hour prior to examination in absence of contraindication. You will be asked to lie down on your back on the CT scanning table. A bolus of nonionic contrast media is injected intravenously. Your heart rate is continuously monitored during the procedure with the help of ECG leads. You are asked to hold breath for 15-20 sec during the scan and CT scan data along with ECG tracing are acquired. Soon after the completion of your examination you may resume your normal routine.

When it is done/advised ?

CT coronary angiography is done to provide useful information for the following patients :

• Anyone who have symptoms of atypical chest pain with an equivocal stress echocardiogram.
• Anyone who is at high risk for coronary artery disease based on known risk factors like –high blood pressure, diabetes, high cholesterol, family history of heart disease, smoker, sedentary life style, overweight by 20% or more, high stress lifestyle, men over age 40 or greater and women overage 50 years.
• Patients who are on cholesterol reducing medications, or who are on exercise and nutrition therapies. For these patients it is useful to follow the progression or regression of coronary artery disease & modify treatment accordingly.
• Patients who had coronary artery bypass surgery in the past – to evaluate patency of the graft for further follow ups.
• Can also be done to evaluate patency of coronary artery stents ( in selective types of stents)

Before ... Precautions & prerequisites

CT coronary angiography is done to provide useful information for the following patients :

• You should directly contact the CT scan room or the reception of the department of radiodiagnosis & imaging for the appointment.
• Patient should be fasting for 4-5 hours on the day of appointment.
• Recent blood urea & Serum Creatinine levels should be within normal limits.
• Patient should bring previous medical records along with him on the day of examination.