Noninvasive Assessment of Coronary Plaque Using Multidetector Row Computed Tomography: Does MDCT Accurately Estimate Plaque Vulnerability? (Con)

As a result of the advent and advances of multidetector row computed tomography (MDCT), coronary computed tomography (CT) has become popular and is performed at many institutions. Coronary CT is useful for diagnosing cases of moderate risk of coronary artery disease. On the other hand, it has been shown that most cardiac infarctions (≈70%) occur from mild to moderate stenoses (ie, ≤50%). Thus, conventional cardiac angiographic findings alone cannot predict developing cardiac infarction. The mechanism by which ruptured plaque and subsequent thrombus leads to developing cardiac infarction has been shown, so determining which plaque tended to rupture, the so-called "vulnerable plaque", and treatment of it are in the spotlight. Coronary CT can visualize and evaluate non-invasively not only the lumen but also the arterial wall. The findings that are suspicious for vulnerable plaque on coronary CT are low-density plaque, positive remodeling, and spotty calcification. However, CT is restricted in its resolution (temporal, spatial and contrast resolution). The diagnosis of vulnerable plaque by CT is still challenging. This report demonstrates the present conditions and problems for the characterization of the plaque using coronary CT. (Circ J 2011; 75: 1522-1528)