Ji Soo Choi1, Myeong-Jin Kim1, Joo Hee Kim1, Jin-Young Choi1, Yong Eun Chung1
1Radiology, Severance Hospital, Seoul, Korea
At 3T MR system, SPIO)-enhanced liver MRI may have the theoretical advantage of high SNR and high liver to lesion contrast, because of stronger susceptibility effect compared with that at 1.5 T. On T2*-weighted gradient recalled echo (GRE) sequences essential for SPIO-enhanced liver MRI, positive effects of 3T on lesion-to-liver CNR were offset by the substantially reduced image quality, secondary to motion and susceptibility artifacts. MEDIC (multiple-echo data image combination) sequence can provides a potential solution by using a series of GRE images at different echo times. On MEDIC sequence, the combination of multiple echoes improves SNR. Receiver bandwidth can then be increased due to improved SNR. Consequently, T2* effects and impairment of the spatial resolution are reduced compared with conventional T2* GRE sequence. Although MEDIC was not superior to FISP for lesion detection, MEDIC showed significantly improved image quality compared with FISP in this study. At 3T system, MEDIC sequence can be a useful alternative sequence to replace FISP sequence for SPIO-enhanced MRI by improving overall image quality and decreasing flow artifact and undesired susceptibility artifacts.