Liu Zhonglin, Kastis George A, Stevenson Gail D, Barrett Harrison H, Furenlid Lars R, Kupinski Matthew A, Patton Dennis D, Wilson Donald W
Department of Radiology, University of Arizona Health Sciences Center, Tucson 85724-5067, USA.
J Nucl Med. 2002 Jul;43(7):933-9.
The purpose of this study was to develop an in vivo imaging protocol for a high-resolution stationary SPECT system, called FASTSPECT, in a rat heart model of ischemia-reperfusion (IR) and to compare 99mTc-sestamibi imaging and triphenyltetrazolium chloride (TTC) staining for reliability and accuracy in the measurement of myocardial infarcts.
FASTSPECT consists of 24 modular cameras and a 24-pinhole aperture with 1.5-mm spatial resolution and 13.3 cps/microCi (0.359 cps/kBq) sensitivity. The IR heart model was created by ligating the left coronary artery for 90 min and then releasing the ligature for 30 min. Two hours after 99mTc-sestamibi injection (5-10 mCi [185-370 MBq]), images were acquired for 5-10 min for 5 control rats and 11 IR rats. The hearts were excised, and the left ventricle was sectioned into 4 slices for TTC staining.
Left and right ventricular myocardium in control rats was shown clearly, with uniform 99mTc-sestamibi distribution and 100% TTC staining for viable myocardium. Nine of 11 rats with IR survived throughout imaging and exhibited 50.8% +/- 2.7% ischemic area and 37.9% +/- 3.9% infarct in the left ventricle on TTC staining. The infarct size measured by FASTSPECT imaging was 37.6% +/- 3.6%, which correlated significantly with that measured by TTC staining (r = 0.974; P < 0.01).
The results confirmed the accuracy of FASTSPECT imaging for measurement of acute myocardial infarcts in rat hearts. Application of FASTSPECT imaging in small animals may be feasible for investigating myocardial IR injury and the effects of revascularization.
本研究的目的是为一种名为FASTSPECT的高分辨率静态单光子发射计算机断层扫描（SPECT）系统开发一种体内成像方案，用于缺血再灌注（IR）大鼠心脏模型，并比较99mTc-甲氧基异丁基异腈成像和氯化三苯基四氮唑（TTC）染色在测量心肌梗死方面的可靠性和准确性。
FASTSPECT由24个模块化相机和一个24针孔孔径组成，空间分辨率为1.5毫米，灵敏度为13.3计数/秒/微居里（0.359计数/秒/千贝克勒尔）。通过结扎左冠状动脉90分钟，然后松开结扎30分钟来创建IR心脏模型。在注射99mTc-甲氧基异丁基异腈（5-10毫居里[185-370兆贝克勒尔]）两小时后，对5只对照大鼠和11只IR大鼠采集图像5-10分钟。取出心脏，将左心室切成4片进行TTC染色。
对照大鼠的左、右心室心肌显示清晰，99mTc-甲氧基异丁基异腈分布均匀，存活心肌的TTC染色率为100%。11只IR大鼠中有9只在整个成像过程中存活，TTC染色显示左心室缺血面积为50.8%±2.7%，梗死面积为37.9%±3.9%。FASTSPECT成像测量的梗死面积为37.6%±3.6%，与TTC染色测量的结果显著相关（r = 0.974；P < 0.01）。
结果证实了FASTSPECT成像在测量大鼠心脏急性心肌梗死方面的准确性。FASTSPECT成像在小动物中的应用对于研究心肌IR损伤和血管重建的效果可能是可行的。
