Reimer P, Marx C, Rummeny E J, Müller M, Lentschig M, Balzer T, Dietl K H, Sulkowski U, Berns T, Shamsi K, Peters P E
Institute of Clinical Radiology, Westfalian Wilhelms-University Muenster, Münster, Germany.
J Magn Reson Imaging. 1997 Nov-Dec;7(6):945-9. doi: 10.1002/jmri.1880070602.
The purpose of this study was to investigate whether MR angiography (MRA) of the portal venous system may be improved by means of superparamagnetic iron oxides (SPIOs) during accumulation phase imaging and to study the underlying contrast mechanisms. MRA of the portal venous system was performed on 48 patients before and after intravenous injection of a new SPIO (Resovist, Schering AG, Berlin, Germany). Resovist, as a predominantly liver parenchymal darkening agent on T2-weighted MR images with uptake into the reticuloendothelial cell system, was administered intravenously by bolus injection of 8 to 12 micromol Fe/kg body weight. Patients were scanned with breath-hold coronal and axial two-dimensional (2D) time of flight (TOF) MRA (TR = 31.0 msec, TE = 9.8 msec, flip angle (FA) = 50 degrees, and 6.9-second acquisition time per section) sequences. Signal intensity values of liver parenchyma, the portal venous system, and background were obtained for quantitative analysis. The clinical relevance of additional plain and contrast-enhanced MRA studies for surgical planning was assessed by independent reading of three readers. Liver signal-to-noise ratio (SNR) significantly decreased following iv injection of Resovist; however, SNR values of the portal veins or hepatic veins did not change significantly. Visibility of the portal venous system improved significantly (tertiary branches visible: pre in 15.2% versus post in 87.0% of patients). Resovist-enhanced 2D-TOF MRA may improve planning of liver resections by better demonstrating the relationship of central liver lesions and vessels on source images. The decrease in liver SNR at a constant vessel SNR after iv injection of Resovist improves MRA of the liver. SPIO-enhanced 2D-TOF MRA scans are superior to plain 2D-TOF MRA studies and may be added for the workup of preoperative patients.
本研究的目的是探讨在门静脉系统的累积期成像过程中，超顺磁性氧化铁（SPIO）是否可改善门静脉系统的磁共振血管造影（MRA），并研究其潜在的对比机制。对48例患者在静脉注射一种新型SPIO（Resovist，先灵公司，柏林，德国）前后进行门静脉系统的MRA检查。Resovist作为一种主要在T2加权磁共振图像上使肝实质变暗的药物，可被网状内皮细胞系统摄取，通过静脉推注8至12微摩尔铁/千克体重给药。患者采用屏气冠状位和轴位二维（2D）时间飞跃（TOF）MRA序列进行扫描（TR = 31.0毫秒，TE = 9.8毫秒，翻转角（FA）= 50度，每层面采集时间为6.9秒）。获取肝实质、门静脉系统和背景的信号强度值进行定量分析。由三位阅片者独立解读，评估额外的平扫和对比增强MRA检查对手术规划的临床相关性。静脉注射Resovist后，肝脏信噪比（SNR）显著降低；然而，门静脉或肝静脉的SNR值没有显著变化。门静脉系统的可视性显著提高（三级分支可见：患者术前为15.2%，术后为87.0%）。Resovist增强的2D-TOF MRA通过在源图像上更好地显示肝脏中央病变与血管的关系，可改善肝切除术的规划。静脉注射Resovist后，在血管SNR恒定的情况下肝脏SNR降低，改善了肝脏的MRA。SPIO增强的2D-TOF MRA扫描优于平扫2D-TOF MRA检查，可用于术前患者的检查。
