Comparison of 99mTc-hexakis 2-methoxy-2-isobutyl isonitrile and 201Tl SPECT imaging for evaluation of coronary artery disease

To evaluate clinical value of 99mTc-hexakis 2-methoxy-2-isobutyl isonitrile (MIBI) imaging for assessing coronary artery disease (CAD), 99mTc-MIBI SPECT imaging at post-exercise and at rest was compared with 201Tl SPECT imaging at post-exercise and 3 hours redistribution in 27 patients suspected with CAD. The sensitivities for detecting CAD patients were 94% (17/18) by both studies. The specificities were 71% (5/7) by 99mTc-MIBI and 57% (4/7) by 201Tl (p = NS). The sensitivities for detecting stenosed coronary arteries (greater than or equal to 75% stenosis) were also similar between 99mTc-MIBI (78%) and 201Tl (74%) (p = NS). The similar specificity values were obtained by 99mTc-MIBI (84%) and by 201Tl (82%) (p = NS). The patterns of abnormality (normal, ischemia and scar) were similar between 99mTc-MIBI and 201Tl images in 22 of the 25 cases (88%) and 117 of the 125 segments (94%). However, these patterns were occasionally different particularly in patients who received PTCA or CABG. Thus, 99mTc-MIBI SPECT imaging seems to be as accurate as 201Tl SPECT imaging for the detecting and evaluating CAD.