Emerging Clinical Applications of Coronary Multi-detector Computed Tomography (MDCT)
Paul Schoenhagen, Arthur E. Stillman, Richard D. White
Department of Diagnostic Radiology, Section of Cardiovascular Imaging, The Cleveland Clinic Foundation
A 55 year-old patient with mild hypertension and hypercholesterolaemia but no history of chest pain was undergoing a cardiac workup after an unexplained presyncopal event. A contrast-enhanced cardiac multi-detector computed tomography (MDCT) scan revealed a complex, partially calcified atherosclerotic plaque in the proximal to mid-left anterior descending coronary artery (LAD) involving the origins of the first two diagonal branches (Panel A, B). A subsequent stress-thallium scan demonstrated evidence of ischaemia in the distribution corresponding to the lesion (Panel C). Selective coronary angiography eventually confirmed significant obstructive disease in the proximal to mid-LAD and the first 2 diagonal branches (D). Based on lesion location and complexity, the patient was referred for bypass surgery rather than percutaneous coronary intervention. This case report demonstrates potential applications of noninvasive angiography with MDCT. Further clinical validation of this emerging, noninvasive technology is needed to provide recommendations for its rational use as a complement to other diagnostic modalities.
Figure legend
Panel A and B: Volume-rendered (A) and multiplanar-reformatted (B) CT images of the LAD. Volume-rendered imaging employs advanced image processing algorithms for three-dimensional visualisation of the entire heart. Multiplanar-reformations are two-dimensional planar thin images cutting through individual coronary segments. The volume-rendered image shows the course of the entire LAD, while the multiplanar-reformatted image provides a more detailed tomographic visualisation of the lumen and vessel wall of the proximal to mid-LAD. A complex, partially calcified plaque is seen in the origin of the first diagonal branch (small arrow) and the main LAD (large arrow) at the origin of the second diagonal branch.
Panel C: The stress thallium scan demonstrates stress-induced, dependent ischaemia of the apical myocardium.
Panel D: In comparison to selective coronary angiography (D), MDCT is relatively limited in the quantitative assessment of luminal stenosis because of lower resolution and an artefact introduced by coronary calcification. However, the simultaneous visualisation of the vessel wall allows noninvasive identification of dense plaque calcification at the lesion site (large arrow) and additional accumulation of calcified and uncalcified atherosclerotic plaque in an angiographic normal segments of the proximal LAD (*).
[Table of Contents]