Detection of myocardial ischemia using 64-slice MDCT.

BACKGROUND

The purpose is to investigate the ability of 64-slice multidetector computed tomography (MDCT) at rest in detecting myocardial ischemia, conventionally depicted by myocardial perfusion scintigraphy (MPS).

METHODS AND RESULTS

In 75 patients with suspected coronary artery disease, cardiac CE-MDCT at rest and stress/rest MPS were performed. The 2D myocardial images were reconstructed in diastolic and systolic phases using raw data from coronary computed tomography (CT) angiography. CT numbers in the myocardium were used as an estimate of myocardial enhancement. The myocardium was shown using a color scale that depicts faint low-density areas more clearly than gray scale. The variation in myocardial enhancement was evaluated at systole and diastole for those segments depicted as ischemia on MPS. A pattern of transient endocardial hypo-enhancement at systole and normal enhancement at diastole as the ischemic pattern on CT myocardial image was defined. MPS diagnosed myocardial ischemia in 40 of 75 patients. Use of the ischemic pattern on CT images distinguished patients with and without ischemia with a sensitivity of 90%, specificity of 83%, positive predictive value of 86% and negative predictive value of 88%.

CONCLUSIONS

CT myocardial imaging at rest demonstrates a characteristic enhancement pattern for ischemia. This has potential as a non-invasive method for detecting ischemia.