Detection of noncalcified and mixed plaque by multirow detector computed tomography.

New tomographic cardiovascular imaging tests, such as intravascular ultrasonography and coronary computed tomography angiography, can be used to assess atherosclerotic plaques for the characterization and early staging of coronary artery disease (CAD). Although intravascular ultrasonography provides high-resolution images that are capable of revealing early preclinical CAD, it is a highly invasive technique used clinically only in conjunction with coronary interventions. Multidetector computed tomography angiography, which is noninvasive and corresponds well with plaque histology, shows promise as a diagnostic method for CAD and can provide general evaluation of noncalcified and mixed plaque composition. The current generation of 64-slice computed tomography scanners have high accuracy for detection of lesions obstructing more than 50% of the lumen, with sensitivity, specificity, and positive and negative predictive values all over 90% in patients without known CAD. They may have an important role in characterizing high-risk noncalcified and mixed plaques. Review of the currently available literature suggests that tissue density measured by multidetector computed tomography can be used to accurately characterize coronary atherosclerotic plaque composition. With further advances in tomographic angiography, the goal will be to detect plaques earlier in the development of CAD and to characterize the plaques most likely to generate a clinical event.