[Comparative assessment of resting myocardial perfusion in patients with postinfarct cardiosclerosis by electron-beam tomography and 99mTc-MIBI myocardial single-photon tomography].

The purpose of the study was to compare myocardial perfusion assessed by electron beam computed tomography (EBCT) with that obtained by 99mTc-sestamibi single photon emission computed tomography (SPECT) in patients with old myocardial infarction and control subjects at rest. A total of 42 patients with suspected and known ischaemic heart disease (IHD) were included in the study. 20 pts had a history of Q-wave myocardial infarction (MI), 12 pts had an old non-Q-wave MI and 10 served as controls (without perfusion defects on SPECT images at rest). Assessment of the myocardial perfusion by EBCT was performed using the short axis view and multislice mode (MSM) during injection of 50 ml of the nonionic contrast medium at 4 ml/s via cubital vein. Perfusion defects were localized by SPECT according to 6-segment model of the LV (septal, anterior, lateral, posterior, inferior and apical). Overall concordance between EBCT and SPECT was 67% for normal versus abnormal perfusion. Agreement between the 2 methods for each of the 6 segments was 81% (K = 0.62) for the anterior segment, 71% (K = 0.42) for the septal segment, 71% (K = 0.43) for the apical, 69% (K = 0.3) for the lateral segment, 48% (K = 0.13) for the posterior segment and 60% (K = -0.13) for the inferior segment. Discrepancies between the two of techniques were most notable in the posterior region. Beam hardening during passage of the contrast medium through the heart chambers and descending aorta is possible explanation of the artifacts on EBCT images. This study demonstrates that nowadays EBCT is not yet alternative to SPECT in the assessment of the myocardial perfusion in patients and further improvements of scanning techniques are necessary.