Takahashi K, Takeishi Y, Fujiwara S, Atsumi H, Akutsu T, Komatani A, Yamaguchi K
Division of Radiology, Yamagata University School of Medicine.
Kaku Igaku. 1996 Jul;33(7):779-84.
The increase of myocardial 99mTc-MIBI accumulation during exercise was evaluated quantitatively, and the feasibility of response rate as a noninvasive marker of coronary stenosis was tested. Myocardial perfusion imaging with 99mTc-MIBI during exercise and at rest was performed in patients with suspected coronary artery disease. A dose of 296 MBq of 99mTc-MIBI was injected intravenously at maximal treadmill exercise, and myocardial image was obtained 90 min later (1st image). Then, 740 MBq of 99mTc-MIBI was administered at rest, and myocardial image was repeated (2nd image). These images were corrected for a decay and injected dose, and the 1st image was subtracted from the 2nd image to obtain the rest image. An increase of myocardial accumulation of 99mTc-MIBI during exercise was defined as (exercise image-rest image) x 100/rest image (response rate). A response rate of a patient with normal coronary artery was 102%, whereas a response rate in the area of severe coronary stenosis was 21% in a patients with angina pectoris. After successful PTCA to a stenosed coronary artery, a response rate increased to 75% in this patient. Coronary perfusion reserve during exercise can be assessed noninvasively by 99mTc-MIBI. Response rate of 99mTc-MIBI provides additional information to conventional perfusion imaging and may be a new marker of severity of coronary artery disease.
对运动期间心肌99mTc-MIBI蓄积的增加进行了定量评估，并测试了反应率作为冠状动脉狭窄无创标志物的可行性。对疑似冠心病患者进行了运动和静息状态下的99mTc-MIBI心肌灌注显像。在最大跑步机运动时静脉注射296 MBq的99mTc-MIBI，90分钟后获得心肌图像（第一张图像）。然后，静息状态下给予740 MBq的99mTc-MIBI，并重复采集心肌图像（第二张图像）。对这些图像进行衰减和注射剂量校正，从第二张图像中减去第一张图像以获得静息图像。运动期间心肌99mTc-MIBI蓄积的增加定义为（运动图像-静息图像）×100/静息图像（反应率）。冠状动脉正常患者的反应率为102%，而心绞痛患者严重冠状动脉狭窄区域的反应率为21%。对狭窄冠状动脉成功进行PTCA后，该患者的反应率增至75%。运动期间的冠状动脉灌注储备可通过99mTc-MIBI进行无创评估。99mTc-MIBI的反应率为传统灌注显像提供了额外信息，可能是冠状动脉疾病严重程度的一个新标志物。
