SPIO-ENHANCED 2D-TOF MR-ANGIOGRAPHY OF THE PORTAL VENOUS SYSTEM - RESULTS OF AN INTRAINDIVIDUAL COMPARISON

The purpose of this study was to investigate whether MR angiography (M RA) of the portal venous system may be improved by means of superparam agnetic iron oxides (SPIOs) during accumulation phase imaging and to s tudy the underlying contrast mechanisms. MRA of the portal venous syst em 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 Ta-weighted MR im ages with uptake into the reticuloendothelial cell system, was adminis tered intravenously by bolus injection of 8 to 12 mu mol Fe/kg body we ight. Patients were scanned with breath-hold coronal and axial two-dim ensional (2D) time of night (TOF) MRA (TR = 31.0 msec, TE = 9.8 msec, flip angle (FA) = 50 degrees, and 6.9-second acquisition time per sect ion) sequences. Signal intensity values of liver parenchyma, the porta l venous system, and background were obtained for quantitative analysi s. The clinical relevance of additional plain and contrast-enhanced MR A studies for surgical planning was assessed by independent reading of three readers. Liver signal-to-noise ratio (SNR) significantly decrea sed following iv injection of Resovist; however, SNR values of the por tal veins or hepatic veins did not change significantly. Visibility of the portal venous system improved significantly (tertiary branches vi sible: pre in 15.2% versus post in 87.0% of patients), Resovist-enhanc ed 2D-TOF MRA may improve planning of liver resections by better demon strating the relationship of central liver lesions and vessels on sour ce images. The decrease in liver SNR at a constant vessel SNR after iv injection of Resovist improves MRA of the liver. SPIO-enhanced PD-TOF MRA scans are superior to plain PD-TOF MRA studies and may be added f or the workup of preoperative patients.