Superparamagnetic Iron Oxide-Enhanced Liver MRI With SHU 555 A (RESOVIST®): New Protocol Infusion to Improve Arterial Phase Evaluation-A Prospective Study

Purpose: To compare the arterial enhancement of hypervascular hepatic lesions by T1-weighted 3D-GRE (gradient-recalled echo) fat-sat sequence after slow (0.5 mL/sec) and fast (2 mL/sec) RESOVIST (R) infusion. Materials and Methods: We prospectively enrolled 71 patients with hypervascular hepatic lesions to undergo dynamic magnetic resonance imaging (MRI) examination with RESOVIST (R). A total of 92 benign and malignant lesions, 44 of which histologically confirmed, were examined. Three blinded and independent readers visually assessed the arterial enhancement using a score from 0 (none) to 3 (maximum), the latter score comparable to that achievable by MultiHance administration. Results: Out of the 92 hypervascular lesions, 41, 31, and 20 nodules were examined using the slow, fast, and both protocols, respectively. Relevant enhancement (scores 2-3) was found in 42% vs. 14.5% of cases for slow and fast protocols, respectively. Intraindividual comparison evaluation confirmed the better results obtained by slow than fast protocol (25% vs. 10%), with statistically relevant difference in distribution of scores (P = 0.0004). The slow protocol showed values between 0 and 3 with an arithmetic mean of 1.1; the fast one, on the other hand. showed values between 0 and 2 with an arithmetic mean of 0.66. Conclusion: Slow infusion improves arterial enhancement after RESOVIST (R) administration.