Caldwell J H, Revenaugh J R, Martin G V, Johnson P M, Rasey J S, Krohn K A
Division of Cardiology, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA.
J Nucl Med. 1995 Sep;36(9):1633-8.
Fluorine-18-fluoromisonidazole (FMISO) is trapped in hypoxic but viable canine myocardium. Because of the potential for its use as a marker of myocardial viability, we compared FMISO activity to [18F]fluorodeoxyglucose (FDG) activity in the same myocardial samples from eight dogs subjected to 3 hr of moderate regional myocardial ischemia.
Tritiated FMISO was injected 15-30 min after onset of regional ischemia (40%-70% reduction in systolic wall thickening) which was maintained for 3 hr. FDG was injected after 2 hr of ischemia. Myocardial blood flow (MBF) was measured by the radiolabeled microsphere technique at the time of each radiotracer injection. At 3 hr of ischemia, the heart was excised and cut into short-axis slices. One slice encompassing both ischemic and normal tissue was cut into 64 samples. FMISO and FDG activity in each sample were normalized to the mean normal zone activity and further expressed as a function of regional MBF.
FMISO uptake was consistently greater than FDG uptake, although this was significantly different only for MBF, between 40%-60% of normal. When analyzed relative to endocardial-epicardial location, endocardial FMISO uptake was significantly greater in all hypoperfused samples.
These results suggest that FMISO is as sensitive as FDG for detecting myocardial ischemia and could be used for identification of viable myocardium.
氟-18-氟米索硝唑（FMISO）可滞留于缺氧但仍存活的犬心肌中。鉴于其有作为心肌存活标志物的潜在用途，我们在8只经历3小时中度局部心肌缺血的犬的相同心肌样本中，比较了FMISO活性与[18F]氟脱氧葡萄糖（FDG）活性。
在局部缺血开始后15 - 30分钟（收缩期室壁增厚减少40% - 70%）注射氚标记的FMISO，并维持3小时。缺血2小时后注射FDG。在每次注射放射性示踪剂时，用放射性微球技术测量心肌血流量（MBF）。缺血3小时时，切除心脏并切成短轴切片。将包含缺血和正常组织的一片切成64个样本。每个样本中的FMISO和FDG活性均以正常区域平均活性进行标准化，并进一步表示为局部MBF的函数。
FMISO摄取始终大于FDG摄取，尽管仅在MBF为正常的40% - 60%时，二者差异有统计学意义。相对于心内膜 - 心外膜位置进行分析时，所有灌注不足的样本中心内膜FMISO摄取均显著更高。
这些结果表明，FMISO在检测心肌缺血方面与FDG一样敏感，可用于识别存活心肌。
