Postsurgical Spinal Magnetic Resonance Imaging With Iterative Decomposition of Water and Fat With Echo Asymmetry and Least-Squares Estimation

Abstract

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). 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). Fat suppression and spinal canal scores for IDEAL were statistically higher than those for CHESS (P < 0.05). Iterative decomposition of water and fat with echo asymmetry and least-squares estimation is clinically useful for postoperative spinal MRI.