QUANTITATIVE DOUBLE-TRACER DIGITALRADIOGRAPHY BASED ON DESMETHYLIMIPRAMINE DEPOSITION: APPLICATION TO STUDIES ON MYOCARDIAL PERFUSION HETEROGENEITY
QUANTITATIVE DOUBLE-TRACER DIGITALRADIOGRAPHY BASED ON DESMETHYLIMIPRAMINE DEPOSITION: APPLICATION TO STUDIES ON MYOCARDIAL PERFUSION HETEROGENEITY
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基于去甲丙咪嗪沉积的定量双示踪数字放射成像：在心肌灌注异质性研究中的应用
DOI：
10.1142/s0219519403000776
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发表时间：
2003
影响因子：
0.8
通讯作者：
F. Kajiya
中科院分区：
文献类型：
--
作者：
H. Tachibana;Takeshi Matsumoto;Y. Ogasawara;T. Kodama;F. Kajiya
去甲基丙咪嗪 (DMI) 是一种 α2-肾上腺素能拮抗剂，是一种近乎理想的沉积示踪剂，用于评估心肌血流分布，对微循环的人为影响最小。氚和碘 125 标记的 DMI（HDMI、IDMI）的心肌保留被证实是令人满意的；在以 8.1 ml/min/g 的灌注速率进行 Tyrode 灌注的离体兔心脏 (n=6) 中，1 分钟时的 IDMI 和 HDMI 保留率分别为 95% 和 91%；在以 3.1 ml/min/g 的灌注速率进行血液灌注的大鼠心脏 (n=4) 中，1 分钟时的 IDMI 和 HDMI 保留率分别为 98% 和 96%。使用这些示踪剂与减影数字放射线摄影相结合，可以以 400×400 μm2 分辨率评估心肌血流分布的变化。在血液灌注的大鼠心脏（n=4）中，同时注射的两种示踪剂的区域密度（r=0.94）和斜率接近1的回归线之间的强互相关性验证了该方法的有效性。此外，在 Tyrode 灌注的兔心脏中，评估了灌注率中度降低 34% (n=7) 和严重降低 70% (n=7) 之前和之后的流量分布。严重流量减少使示踪剂密度 (CV) 的变异系数显着增加，从 19% 增加到 25%，但 CV 并没有随流量适度减少而变化（20% 对 19%）。两种示踪剂的区域密度在严重低流量灌注下仍然具有显着的互相关性（r=0.84）。因此，在流量严重减少的情况下，原本高流量区域和低流量区域之间的流量差异被扩大。总之，基于 DMI 沉积的双示踪数字放射成像将成为分析微血管水平血流不均匀性的有效方法。
Desmethylimipramine (DMI), an α2-adrenergic antagonist, is a nearly ideal deposition tracer for evaluating the myocardial flow distribution with the least artifactual effects on microcirculation. Myocardial retentions of tritium- and iodine-125-labeled DMI (HDMI, IDMI) were confirmed to be satisfactory; the retentions of IDMI and HDMI at 1 min were 95 and 91% respectively in isolated Tyrode-perfused rabbit hearts (n=6) at a perfusion rate of 8.1 ml/min/g, and 98 and 96% respectively, in blood-perfused rat hearts (n=4) at a perfusion rate of 3.1 ml/min/g. Using these tracers combined with subtraction digitalradiography, it allowed the assessing of changes of myocardial flow distribution with 400×400 μm2 resolution. In blood-perfused rat hearts (n=4), the validity of this method was verified by the strong cross-correlation between regional densities of two tracers injected simultaneously (r=0.94) and the regression line having a slope close to one. Furthermore, in Tyrode-perfused rabbit hearts, the flow distributions were evaluated before and after decreasing perfusion rate moderately by 34% (n=7) and severely by 70% (n=7). Severe flow reduction increased the coefficient of variation of tracer density (CV) significantly from 19 to 25%, but CV did not change with moderate flow reduction (20 vs. 19%). Regional densities of two tracers were cross-correlated still substantially under severe low-flow perfusion (r=0.84). Accordingly, flow differences between originally high- and low-flow regions were enlarged under severe flow reduction. In conclusion, double-tracer digitalradiography based on the DMI deposition will be a potent method for the analysis of flow heterogeneity at microvascular levels.
内源性一氧化氮掩盖了缺血性心脏运动期间的α2-肾上腺素能冠状血管收缩。
影响因子：
20.1
作者：
Ishibashi,Y;Duncker,DJ;Bache,RJ
通讯作者：
Bache,RJ