Choi S H, Lee S S, Choi S I, Kim S T, Lim K H, Lim C H, Weinmann H J, Lim T H
Department of Diagnostic Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-Dong, Songpa-Gu, Seoul 138-736, Korea.
Radiology. 2001 Aug;220(2):436-40. doi: 10.1148/radiology.220.2.r01au04436.
To test whether bis-gadolinium mesoporphyrins-enhanced magnetic resonance (MR) imaging can accurately depict irreversibly damaged myocardium in occlusive myocardial infarction.
Ten cats were subjected to 90 minutes of occlusion of the left anterior descending coronary artery. Bis-gadolinium mesoporphyrins-enhanced T1-weighted MR imaging was performed in the cats for 6 hours. Histopathologic examinations with 2'3'5-triphenyl tetrazolium chloride (TTC) staining and electron microscopy were performed on the resected specimens. The time course and pattern of signal intensity enhancement were evaluated. The size of the infarcted myocardium was estimated on the MR images by measuring the size of the signal intensity-enhanced area.
In eight of 10 cats, it was impossible to distinguish infarcted myocardium from normal myocardium at visual inspection of T1-weighted MR images. The contrast ratio between infarcted and normal myocardium did not increase significantly over time. In one of the two remaining cats, a doughnut pattern of signal intensity enhancement was noted. The other cat showed intensely homogeneous enhancement of infarcted myocardium at MR imaging. The size of the area of signal intensity enhancement at MR imaging in these two cats was accurately mapped to that of the infarction on the TTC-stained specimens.
Occlusive myocardial infarction cannot be accurately detected at bis-gadolinium mesoporphyrins-enhanced MR imaging.
测试双钆中卟啉增强磁共振（MR）成像能否准确描绘闭塞性心肌梗死中不可逆损伤的心肌。
对10只猫进行90分钟的左前降支冠状动脉闭塞。对这些猫进行6小时的双钆中卟啉增强T1加权MR成像。对切除的标本进行2,3,5-三苯基氯化四氮唑（TTC）染色和电子显微镜检查的组织病理学检查。评估信号强度增强的时间进程和模式。通过测量信号强度增强区域的大小在MR图像上估计梗死心肌的大小。
在10只猫中的8只中，在T1加权MR图像的目视检查中无法区分梗死心肌和正常心肌。梗死心肌与正常心肌之间的对比率并未随时间显著增加。在其余两只猫中的一只中，观察到信号强度增强的甜甜圈模式。另一只猫在MR成像中显示梗死心肌有强烈的均匀增强。这两只猫在MR成像中信号强度增强区域的大小与TTC染色标本上的梗死区域准确对应。
在双钆中卟啉增强MR成像中无法准确检测出闭塞性心肌梗死。
