Schuijf JD et al. (2006) Relationship between noninvasive coronary angiography with multi-slice computed tomography and myocardial perfusion imaging. J Am Coll Cardiol 48: 2508–2514

Myocardial perfusion imaging (MPI) and multislice CT (MSCT) both enable noninvasive imaging of suspected coronary artery disease (CAD). The former detects ischemia, whereas the latter identifies atherosclerosis through visualization of coronary artery stenosis. A comparison of these techniques shows that they provide complementary information in patients with an intermediate likelihood of CAD, indicating that the methods might best be used in combination.

Both MPI and MSCT were performed in 114 patients who had presented to outpatient clinics with chest pain and no history of CAD. Of the 41 (36%) patients with normal MSCT findings, 37 (90%) also had normal MPI results. Over half of the 73 patients with abnormal MSCT findings, however—including those with obstructive CAD—had normal MPI findings. Likewise, approximately half of the patients with normal MPI results had abnormal MSCT findings. Importantly, these data indicate that the degree of stenosis doesn't necessarily reflect the hemodynamic significance of a lesion. A subcomparison of MSCT with invasive coronary angiography showed good correlation of results, inferring that MSCT has high diagnostic accuracy in individuals with an intermediate likelihood of CAD.

How MPI and MSCT can best be combined in the clinical setting is unclear, say the authors. They suggest, however, that MSCT could be used as a first-line test, with patients undergoing further imaging if the results are positive in order to determine the hemodynamic significance of the lesion.