MAGNETIC-RESONANCE-IMAGING OF FOCAL LIVER-LESIONS - COMPARISON OF THESUPERPARAMAGNETIC IRON-OXIDE RESOVIST VERSUS GADOLINIUM-DTPA IN THE SAME PATIENT

RATIONALE AND OBJECTIVES. The authors assess the efficacy of static an d dynamic magnetic resonance (MR) imaging using the superparamagnetic iron oxide SHU-555A (Resovist(R)) versus standard dose of gadolinium ( Gd)-DTPA in patients with focal liver lesions. METHODS. Magnetic reson ance imaging was performed in 30 patients suffering from histopatholog ically verified malignant (n = 22) and benign (n = 8) liver lesions, T 2-weighted conventional and fat-suppressed as well as T1-weighted sequ ences were used before, during, and after fast intravenous administrat ion of Resovist (1 mL/minute) at three doses of 4, 8, and 16 mu mol/kg body weight. One week before the Resovist-enhanced MR imaging study 2 0 patients underwent Gd-DTPA-enhanced MR imaging. RESULTS. Detection r ate was improved for metastatic lesions revealing 36 lesions unenhance d versus 53 focal lesions using Resovist-enhanced MR imaging. Gadolini um-DTPA-enhanced scans showed no additional lesion versus unenhanced a nd Resovist-enhanced MR imaging. Static and dynamic imaging demonstrat ed no measurable percentage signal intensity loss (PSIL) using Resovis t-enhanced MR imaging versus a percentage enhancement of 79.7% in Gd-D TPA enhanced scans. In the dynamic T2-weighted sequences, hepatocellul ar carcinoma nodules (n = 4) showed a rapid decrease in signal intensi ty starting at 44 seconds. Postinfusion of Resovist followed by a low, constant increase in signal intensity. Gadolinium-DTPA enhanced scans showed a percentage enhancement of 73.4 focal nodular hyperplasia (FN H) and hemangioma revealed a strong and early dose-dependent PSIL 44 t o 60 seconds postinfusion with a prolonged signal loss for the FNH in the late study. Statistical evaluation revealed a statistically signif icant superiority of Resovist-enhanced MR imaging concerning the detec tion and delineation of focal liver lesions compared with unenhanced a nd Gd-DTPA enhanced scans (P < 0.05). CONCLUSIONS. The fast infusion o f the new superparamagnetic contrast agent Resovist shows advantages f or dynamic and static MR imaging of focal liver lesions.