Postsurgical Spinal Magnetic Resonance Imaging With Iterative Decomposition of Water and Fat With Echo Asymmetry and Least-Squares EstimationMurakami, Mizuho MD*; Mori, Harushi MD*; Kunimatsu, Akira MD, PhD*; Abe, Osamu MD, PhD*; Chikuda, Hirotaka MD, PhD†; Ono, Takashi MD, PhD†; Kabasawa, Hiroyuki PhD*; Uchiumi, Kazuyuki PhD*; Sato, Jiro MD*; Amemiya, Shiori MD*; Komatsu, Shuhei MD*; Ohtomo, Kuni MD, PhD*Journal of Computer Assisted Tomography: January-February 2011 - Volume 35 - Issue 1 - p 16-20 doi: 10.1097/RCT.0b013e3181f8d30d Original Articles Abstract Author Information Objective: Magnetic resonance imaging (MRI) is the most popular follow-up study for patients who have undergone spinal surgery. However, the image quality often becomes poor because of artifacts from metal implants and/or from failed fat suppression, which obscure diagnosis. Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) is a new fat suppression method that is less affected by inhomogeneity of the magnetic field. Here, we compared postsurgical spinal MRI with IDEAL versus chemical shift selective saturation (CHESS). Methods: For 35 patients who had spinal surgery, we examined T2-weighted fast spin-echo sagittal images of the spine with both IDEAL and CHESS. Two radiologists evaluated the degrees of fat suppression and spinal canal projection from 0 (least/worst) to 2 (most/best). Results: Fat suppression and spinal canal scores for IDEAL were statistically higher than those for CHESS (P < 0.05). Conclusions: Iterative decomposition of water and fat with echo asymmetry and least-squares estimation is clinically useful for postoperative spinal MRI. From the Departments of *Radiology, and †Orthopedics, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. Received for publication July 13, 2010; accepted August 13, 2010. Reprints: Mizuho Murakami, MD, Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan (e-mail: firstname.lastname@example.org). © 2011 Lippincott Williams & Wilkins, Inc.