Evaluation of simultaneous 99mTc-MIBI and 201Tl dual-isotopic myocardial perfusion SPECT imaging for the detection of the hibernating myocardium

Objective; To study the clinical role of rest technetium-99m sestamibi (99mTc-MIBI) and stress-reinjection thallium-201 (201Tl) simultaneous dual-isotopic myocardial perfusion SPECT imaging in the detection of the 'hibernating myocardium'. Methods: 77 patients with suspected coronary artery disease underwent simultaneous dual-isotopic myocardial perfusion SPECT imaging with 99mTc-MIBI and 201Tl. 18mCi (666 MBq) 99mTc-MIBI was injected at rest, 15 min later dobutamine was instilled into vein begin with 5 mg·kg-1 min-1, before and after instilling the base ECG, blood pressure, heart rate was recorded, when the end point were reached, 3mCi (111 MBq) thallium-201 was injected, the early dual-isotopic simultaneously SPECT imagine was performed. After tomographic reconstruction, the defect were found on the stress 201Tl and rest 99mTc-MIBI image, 3 hr later 1mCi (37 MBq) thallium-201 was reinjected. 30 min later after that the delay dual-isotopic simultaneously SPECT imagine was performed. The images were interpreted by two experienced observers without previous knowledge of results of other studies. In two weeks, coronary angiography was performed. Results: (1) All of 77 patient were found abnormal by angiography, 39 of those with one coronary artery abnormality, 27 with two coronary artery abnormality, 11 with three coronary artery abnormality. (2) 23 with the radioactivity defect on the stress 201Tl and rest 99mTc-MIBI image showed radiofilling on the reinjection images, therefore 'hibernating myocardium' was suggested. (3) 54 with the radioactivity defect on the stress 201Tl and rest 99mTc-MIBI image didn't show radiofilling on the reinjection images, thus infarct myocardium or scar issue was suggested. Conclusion: Simultaneous rest 99mTc-MIBI and stress-reinjection 201Tl Dual-isotopic myocardial perfusion SPECT imaging is an effective method in the detection of the hibernating myocardium. (authors)