T1- and T2-weighted fast spin-echo imaging of the brachial plexus and cervical spine with IDEAL water-fat separation

Purpose: To compare the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) method with fat-saturated T1-weighted (T1W) and T2W fast spin-echo (FSE) and short-TI inversion recovery (STIR) imaging of the brachial plexus and cervical spine. Materials and Methods: Images acquired at 1.5T in five volunteers using fat-saturated T1W and T2W FSE imaging and STIR were compared with T1W and T2W IDEAL-FSE images. Examples of T1W and T2W IDEAL-FSE images acquired in patients are also shown. Results: T1W and T2W IDEAL-FSE demonstrated superior fat suppression (P < 0.05) and image quality (P < 0.05), compared to T1W and T2W fat-saturated FSE, respectively. SNR performance of TIW-IDEAL-FSE was similar to T1W FSE in the spinal cord (P = 0.250) and paraspinous muscles (P = 0.78), while T2W IDEAL-FSE had superior SNR in muscle (P = 0.02) and CSF (P = 0.02), and marginally higher cord SNR (P = 0.09). Compared to STIR, T2W IDEAL-FSE demonstrated superior image quality [P < 0.05), comparable fat suppression (excellent, P = 1.0), and higher SNR performance (P < 0.001). Conclusion: IDEAL-FSE is a promising method for T1W and T2W imaging of the brachial plexus and cervical spine.