Adzamli I K, Blau M, Pfeffer M A, Davis M A
Department of Radiology, University of Massachusetts Medical Center, Worcester 01655.
Magn Reson Med. 1993 Apr;29(4):505-11. doi: 10.1002/mrm.1910290412.
The potential of a phosphonate-modified-Gd-DTPA for MR image enhancement of myocardial infarction has been demonstrated in imaging experiments on rats. The agent, 1-hydroxy-3-aminopropane-1,1-diphosphonate-modified-Gd-DTPA (Gd-DTPA-HPDP) accumulates in two models of myocardial infarction, (i.e., drug-induced diffusely infarcted whole hearts and in focal acute myocardial infarction from a left coronary artery ligation). The time course of the accumulation of the agent in the focal model of infarction and subsequent washout has also been followed in vitro. Results of this kinetics demonstrate that the agent first perfuses all normal fluid spaces and then slowly diffuses into the occluded zone where it is retained for a prolonged period, in sufficient quantities to be useful as an MRI contrast agent. Wash-out of the agent from normal myocardium is fast and complete with MR signal returning to background in minutes. The specificity of Gd-DTPA-HPDP for soft-tissue calcification and its retention within the infarcts permitted imaging at 1 to 2 h postinjection, (after unbound material has cleared the normal tissues). Infarcted tissue appeared as regions of increased signal intensity in T1-weighted images (> 200% enhancement), and correlated with histopathology. Unmodified Gd-DTPA was not retained under identical conditions. Gd-DTPA-HPDP permits a more accurate infarct delineation than is possible with the unmodified agent.
在大鼠成像实验中已证明，膦酸盐修饰的钆-二乙三胺五乙酸（Gd-DTPA）在心肌梗死磁共振成像增强方面具有潜力。该试剂，即1-羟基-3-氨基丙烷-1,1-二膦酸盐修饰的钆-二乙三胺五乙酸（Gd-DTPA-HPDP），在两种心肌梗死模型中蓄积，（即药物诱导的弥漫性梗死全心脏以及左冠状动脉结扎所致的局灶性急性心肌梗死）。在体外也追踪了该试剂在局灶性梗死模型中的蓄积及随后的洗脱时间进程。该动力学结果表明，该试剂首先灌注所有正常液体间隙，然后缓慢扩散到闭塞区域并在其中长时间滞留，其数量足以用作磁共振成像造影剂。该试剂从正常心肌中的洗脱迅速且完全，数分钟内磁共振信号就恢复到背景水平。Gd-DTPA-HPDP对软组织钙化的特异性及其在梗死灶内的滞留使得在注射后1至2小时（未结合物质已清除正常组织后）即可成像。梗死组织在T1加权图像中表现为信号强度增加的区域（增强>200%），且与组织病理学相关。未修饰的Gd-DTPA在相同条件下不会滞留。与未修饰的试剂相比，Gd-DTPA-HPDP能更准确地勾勒梗死灶。
