GATED TC-99M METHOXY-ISOBUTYLISONITRILE PERFUSION IMAGING

Technetium-99m methoxy-isobutylisonitrile, has been shown to be a useful perfusion agent for detecting coronary artery disease. Gated acquisition of perfusion images may remove motion artefact and improve detection. We compared the results of sensitivity and specificity for detecting coronary artery disease using perfusion images from the whole cardiac cycle (ungated) or from end-diastolic (gated) frames in 46 subjects, 31 with significant coronary disease and 15 with normal coronary arteries. There was no significant difference in detection of patients with coronary disease between the ungated and end-diastolic images: 25/31 with the ungated image and 28/31 with the end-diastolic. An improvement was made in detecting defects in the left anterior descending artery territory: 17/20 with the end-diastolic vs 11/20 with the ungated image (P < 0.05) and in the right coronary artery region: 16/21 vs 10/21 (P < 0.05), with an overall improvement in detecting regions supplied by stenosed coronary arteries: 45/55 end-diastolic vs 31/55 ungated (P < 0.01). These results suggest use of the end-diastolic frame can significantly enhance the diagnostic capacity of methoxy-isobutylisonitrile perfusion imaging.