Superparamagnetic Iron Oxide Particle-Enhanced Hepatic MRI: Differentiation of Hepatic Lesions Using Dual Echo Field Echo Sequences without Obtaining Precontrast Images

Nineteen patients with 30 hepatic lesions (6 cysts, 11 hemangiomas, 13 metastases) were retrospectively evaluated using SPIO-enhanced MRI. Contrast agents (SPIO; ferumoxides, FeridexTM, Eiken-Tanabe) were administered (0.05 mL/kg) over 30 minutes, and images were obtained within 30 minutes following the administration of contrast agents. The MRI used in this study was 1.5T VISART EX (Toshiba, Nasu). Imaging sequences were dual echo field echo (FE) sequences with TEs of 2.4/4.8 msec and 5/14 msec. Other imaging parameters were TR of 170-185 msec, FA of 70 degree, a number of acquisition of 1, FOV of 28–35 28–35 cm, matrix of 128 256, slice thickness of 7–8 mm, slice gap of 1 mm, and imaging time of 22–26 seconds. Images using 3 TEs (2.4 msec, 4.8 or 5 msec, 14 msec) were evaluated for each lesion and compared to the consensus of 3 radiologists (RK, SI, and MA) without knowledge of the patient’s information.