Daly P F, Zimmerman J B, Cannillo J A, Wolf G L
Pittsburgh NMR Institute, University of Pittsburgh, Pennsylvania 15213.
Am J Physiol Imaging. 1990;5(3):119-24.
Magnetic resonance images were performed using a gradient recalled echo sequence with acquisition of images every 30 s in anesthetized rats before and after intravenous bolus injections of 100 microns/kg GdDTPA, 60 microns/kg albumin-(GdDTPA), and 60 microns/kg Gd2O3 colloid. All three agents caused significant enhancement of the renal cortex, and even greater enhancement of the spleen. GdDTPA showed an early peak at 11 s followed by a wash-out as blood concentrations fell, whereas albumin-(GdDTPA) and Gd2O3 showed sustained tissue enhancement. The enhancement in each organ was equivalent for albumin-(GdDTPA) and Gd2O3 which stay intravascular; but 30% less for GdDTPA which enters the interstitial space. In addition GdDTPA showed an initial enhancement of the renal medulla but then a subsequent loss of signal, whereas albumin-(GdDTPA) resulted in a greater enhancement of the medulla as compared to the cortex. We conclude that time-intensity studies of local tissue response to MR indicators reflect tissue physiological parameters such as perfusion, blood volume, and concentrating ability in a semiquantitative manner.
在静脉推注100微克/千克钆喷酸葡胺（GdDTPA）、60微克/千克白蛋白 - （GdDTPA）和60微克/千克氧化钆（Gd2O3）胶体之前和之后，对麻醉大鼠使用梯度回波序列进行磁共振成像，每30秒采集一次图像。所有三种试剂均导致肾皮质显著增强，脾脏增强更为明显。GdDTPA在11秒时出现早期峰值，随后随着血药浓度下降而洗脱，而白蛋白 - （GdDTPA）和Gd2O3显示出持续的组织增强。对于留在血管内的白蛋白 - （GdDTPA）和Gd2O3，每个器官的增强程度相当；但进入间质空间的GdDTPA的增强程度少30%。此外，GdDTPA显示肾髓质最初增强，但随后信号丢失，而白蛋白 - （GdDTPA）导致髓质相对于皮质有更大的增强。我们得出结论，局部组织对磁共振指示剂反应的时间 - 强度研究以半定量方式反映了组织生理参数，如灌注、血容量和浓缩能力。
