Hahn P F, Stark D D, Weissleder R, Elizondo G, Saini S, Ferrucci J T
Department of Radiology, Harvard Medical School, Boston, MA 02114.
Radiology. 1990 Feb;174(2):361-6. doi: 10.1148/radiology.174.2.2296646.
Previous studies of AMI-25, a particulate iron oxide magnetic resonance contrast agent, imaged liver tumors 1 or more hours after injection, in the retention phase after complete clearance of AMI-25 from the circulation. In the present study, imaging was performed in the distribution phase, during the first 12 minutes after injection while contrast agent remain in circulation, and these images were compared with those obtained in the retention phase. Nineteen patients with cancer were studied, including 15 imaged during the distribution phase. T2-weighted distribution phase images demonstrated 90% of the lesions detected by means of T2-weighted retention phase images, showed a 3.5-fold increase in contrast-to-noise ratio over images obtained before administration of AMI-25, and increased diagnostic confidence by reducing signal from small intrahepatic blood vessels. Distribution phase images showed little contrast agent uptake by cancer tissue. Both distribution and retention phase images demonstrated greater contrast agent uptake by hemangiomas than by malignant neoplasms (P less than .01). The use of both distribution phase and retention phase AMI-25-enhanced images offers improved diagnostic accuracy in the detection and characterization of focal liver lesions.
先前对颗粒状氧化铁磁共振造影剂AMI-25的研究，是在注射后1个或更多小时、即AMI-25从循环中完全清除后的滞留期对肝肿瘤进行成像的。在本研究中，成像在注射后最初12分钟的分布期进行，此时造影剂仍在循环中，并将这些图像与在滞留期获得的图像进行比较。对19例癌症患者进行了研究，其中15例在分布期成像。T2加权分布期图像显示，通过T2加权滞留期图像检测到的病变中有90%，与注射AMI-25前获得的图像相比，对比度噪声比增加了3.5倍，并且通过减少肝内小血管的信号提高了诊断可信度。分布期图像显示癌组织对造影剂的摄取很少。分布期和滞留期图像均显示，血管瘤对造影剂的摄取比恶性肿瘤更多（P小于0.01）。使用分布期和滞留期的AMI-25增强图像可提高局灶性肝病变检测和特征描述的诊断准确性。
