Spiral CT Scan for Detecting Coronary Artery Stenosis

Background/ Coronary vessel calcification is an obvious sign of atherosclerotic disease of coronary arteries. Electron beam CT scan is currently the imaging modality of choice for assessing coronary artery calcifications. However, its high cost makes it unavailable to a large number of medical centers. We carried out this study to compare the diagnostic yield of spiral CT scans as an alternative, to coronary angiography. Patients and A hundred patients suspicious of having coronary artery disease (CAD) underwent angiography as well as spiral CT scan of the heart. On CT scan, calcification of >90 Hounsfield on a surface area of >0.5 mm2, anatomically superimposed on coronary arteries were highlighted as calcified areas using the volumetric feature of the scanner. The findings were compared to angiographic results. Of 100 patients enrolled (62 males), 69 had coronary artery obstruction (>50% stenosis on angiography). Angiography was normal in the rest. Spiral CT scan had a sensitivity of 94% and a specificity of 61% for the diagnosis of coronary artery disease. The PPV and NPV were 84% and 79%, respectively. Among the coronary arteries, LAD findings had the highest sensitivity (92%) and the lowest specificity (65%) in the diagnosis of CAD. With age, spiral CT scan had more sensitivity and less specificity for CAD. Detecting calcification by spiral CT scanning could be a useful non-invasive method for diagnosis and evaluation of coronary artery stenosis.