DETECTION OF CORONARY-ARTERY DISEASE BY DYNAMIC PLANAR AND SINGLE-PHOTON EMISSION TOMOGRAPHIC IMAGING WITH TC-99M TEBOROXIME

To test the clinical significance of technetium-99m teboroxime regiona l myocardial clearance in the detection of coronary artery disease, 25 patients underwent dynamic planar or single-photon emission tomograph ic (SPET) myocardial imaging with Tc-99m-teboroxime after exercise and again 2 h later at rest. All patients underwent both thallium-201 exe rcise and redistribution SPET and coronary arteriography. The early ph ases of exercise Tc-99m-teboroxime myocardial clearance determined by dynamic planar imaging showed a significant difference between normal and post-stenotic myocardial regions (clearance rate constant k: 0.047 +/-0.005 min-1 versus 0.034+/-0.003 min-1, P <0.001). Reflecting this ''differential clearance'' between myocardial regions, an early redist ribution-like phenomenon was observed in a significant number of myoca ridal segments by comparing serially acquired post-exercise Tc-99m-teb oroxime SPET images. These results indicated that the analysis of Tc-9 9m-teboroxime myocardial clearance was of potential use in the detecti on of coronary artery disease, yielding additional information to that provided by the tracer distribution analysis. Although the early redi stribution-like phenomenon of Tc-99m-teboroxime could be the source of under-estimation of ischaemia if acquisition of the initial post-exer cise image were delayed, it could also prove useful in the early diffe rentiation of ischaemia from scar because when the phenomenon was obse rved in delayed post-exercise images, the rest study could be omitted under some circumstances.