Iida H, Tamura Y, Kitamura K, Bloomfield P M, Eberl S, Ono Y
National Cardiovascular Center-Research Institute, Osaka, Japan.
J Nucl Med. 2000 Oct;41(10):1737-45.
A method has been proposed to quantitate the myocardial water-perfusable tissue fraction (PTF) in the area of hypoperfused asynergic segments using (15)O-water (H2(15)O) and PET. This study investigated the histochemical correlates of PTF (and perfusable tissue index, PTI) in a canine model of old myocardial infarction.
Myocardial infarction was produced in 12 mongrel dogs, and PET was performed 1 mo later, providing quantitative parametric images of PTF, regional myocardial blood flow (MBF), and extravascular density from H2(15)O, (15)O-carbon monoxide, and transmission datasets. At the end of scanning, the myocardium was sectioned, and the PET images were compared directly with the corresponding myocardial sections.
The distribution of tissue necrosis identified by histochemical staining corresponded well with the defect in PTF but not in MBF. PTF agreed with the equilibrium images of myocardial H2(15)O distribution, obtained after injection of a large bolus of H2(15)O. The defect surface area identified on PTF agreed well quantitatively with the morphometric estimates of the surface area of myocardial infarction. PTI agreed with the absolute proportion of histochemically defined normal myocardium (0.87 +/- 0.09 and 0.83 +/- 0.08, respectively; P < 0.01). Both PTF and PTI decreased significantly in segments of myocardial infarction and showed a significant difference between the transmural and nontransmural myocardial infarction.
The absolute mass and proportion of histochemically defined noninfarcted tissue may be quantitated with PTF and PTI in the area of myocardial infarction segments.
已经提出一种使用（15）O水（H2（15）O）和正电子发射断层扫描（PET）对灌注不足的运动失调节段区域的心肌水可灌注组织分数（PTF）进行定量的方法。本研究在陈旧性心肌梗死犬模型中研究了PTF（和可灌注组织指数，PTI）的组织化学相关性。
对12只杂种犬造成心肌梗死，1个月后进行PET检查，从H2（15）O、（15）O一氧化碳和透射数据集中获得PTF、局部心肌血流量（MBF）和血管外密度的定量参数图像。扫描结束时，将心肌切片，并将PET图像与相应的心肌切片直接比较。
组织化学染色确定的组织坏死分布与PTF中的缺损相符，但与MBF中的缺损不相符。PTF与注射大量H2（15）O后获得的心肌H2（15）O分布的平衡图像相符。PTF上确定的缺损表面积与心肌梗死表面积的形态学估计在数量上相符。PTI与组织化学定义的正常心肌的绝对比例相符（分别为0.87±0.09和0.83±0.08；P<0.01）。PTF和PTI在心肌梗死节段均显著降低，并且透壁性和非透壁性心肌梗死之间存在显著差异。
在心肌梗死节段区域，可以用PTF和PTI对组织化学定义的非梗死组织的绝对质量和比例进行定量。
