Non-invasive CT Angiography

Non-invasive CT Angiography is a technique that shows the blood vessels of the body in great detail, without any discomfort to the patient. The scan hardly takes a few minutes to perform but the information it provides is very precious. It can show the functioning of the heart, the blood vessels of the legs, thigh, arms, abdomen, lungs etc in great detail.

Precautions to be taken before a non-invasive CT angiography:

• We need the patients kidneys to be working fine. For this we need the patients Kidney Function Tests to be done. We need the patients Blood Urea Nitrogen and Serum Creatinine reports
• The patient would need to be fasting for 4 hours prior to the test.

Non-invasive imaging technologies continue to revolutionize every subspecialty of medicine.
This scanner has a special x-ray tube and rotation speed, capable of performing 64 rotations in a second. In each rotation, 64-slices are produced, giving us approximately 194 slices per second. This is the fastest scanner in the industry, currently.

The introduction of 64-slice cardiac CT allows nearly all patients to be scanned with very high resolution. Scan times are now on the order of several seconds (usually 5-13 seconds); this means that even patients with severe pulmonary disease and congestive heart failure can hold their breath for the required length of time. Reduced time translates to minimal or no motion artifacts.

Furthermore, higher number of slices means higher resolution; Such high resolution allows visualization of the entire coronary tree with extremely high accuracy and detail. Individual atheromatous plaques can be detected and characterized. Calcification can be visualized and used as an added variable in disease management.

The 64-channel configuration also provides breakthrough performance in advanced pulmonary imaging, multi-organ trauma evaluation and low-dose pediatric applications to boost your clinical capabilities to the highest level attainable.

In cardiac CT all scans are gated to the ECG trace. This allows us to position our data acquisition accurately in specific phases.

Using this modality we can perform the following procedures as part of a cardiac CT examination.

• Calcium scoring
• Coronary artery imaging
• Functional assessment

Calcium scoring is a technique where the extent of calcification in the coronary arteries is measures and scored. There is a direct correlation between the extent of calcium in the coronary arteries and the risk of a future cardiac event. For example, a calcium score of more than 400 is considered severe and it would be necessary to take steps to prevent further advancement of atherosclerosis and plaque formation. The higher the calcium score, more likely is there a chance of severe stenosis as well. A calcium score of 0 does not rule of soft plaques, but statistically rules out significant coronary artery disease. Though the calcium score does not show soft plaques (which however are best seen on a CT angiogram), the higher the calcium score, the more is it likely that there are soft plaques as well. Rupture of a soft plaque is the commonest cause of an acute coronary syndrome (i.e. a heart attack). Calcium scoring is offered as a separate stand-alone test, but this is routinely performed as an initial part of the entire cardiac CT examination.

Indications of CT coronary angiography.

• Asymptomatic patient with family history of coronary artery disease
• Patient with high risk factors
• Prior to non-coronary surgery in the adult population, e.g.,
  • Pre – ASD repair
  • Pre – valvular repair
  • Pre – tumor surgery
• Follow up post CABG
• Atypical chest pain with doubtful coronary origin
• Evaluation of coronary anomalies
• Exclusion of coronary stenosis in symptomatic high risk patient
• Assessment of cardiac neoplasm
• Assessment of stent patency
• Detection and characterization of congenital heart disease
• Diagnosis of pericardial disease
• Prior to major (non-cardiac) surgery
• Non-conclusive stress tests