Devoted to diagnostic and interventional spine imaging and therapeutics

Library

High-Resolution Diffusion Weighted Imaging (DWI) of Metastatic Myeloma to the Spine with Readout-Segmentation of Long Variable Echo-Trains Echo Planar Imaging (RESOLVE 2014

Category General Spine Vivek Joshi, MD Puneet Pawha, MD Lawrence Tanenbaum, MD Purpose DWI is prone to numerous imaging restraints, including susceptibility artifacts, accumulation of phase errors, T2* blurring due to long data sampling intervals and long echo time -- issues especially problematic in the spine. These challenges can be addressed by reduction in the sampling time through reduced echo spacing. In readout-segmented echo planar imaging (EPI), k-space is filled with a series of concentrated segments in the readout direction, which leads to shorter readout gradient pulses and shorter EPI readout. Shorter readout times result in lowering susceptibility artifacts and distortion. In DWI readout-segmented EPI the segments are well suited to the application of 2D non-linear phase correction. Further, with modifications in the sequence for supporting parallel imaging, the readout time can be further shortened along with the lowering of the level of susceptibility artifact. Our goal was to compare a newly commercially available technique -- RESOLVE (readout-segmentation of long variable echo-trains (Siemens. Erlangen, Germany) --to existing techniques in evaluating myelomatous involvement in the spine. Materials & Methods A retrospective analysis of the quality and efficacy of RESOLVE MRI exams was performed in 7 patients with known multiple myeloma suspected to have spinal involvement. A total of 94 lesions were evaluated on both conventional (T2, FLAIR, STIR, and contrast enhanced T1 if available) and RESOLVE sequences. Each lesion was ranked from 1 to 4 (1- No lesion visible; 2- Possible lesion; 3- Probable lesion; 4- Definite lesion ;) Results RESOLVE DWI of the spine showed improved conspicuity of myelomatous lesions (RESOLVE = 3.6 vs. Conventional = 3.32 ; p = .01). 5 lesions (5%) were only seen on RESOLVE and 6 (6%) lesions were only seen on conventional sequences of the 94 lesions identified. Conclusion RESOLVE imaging presents an advance in obtaining less distorted, higher-resolution images in reasonable scan times. When used in conjunction with conventional techniques, both lesion conspicuity and confidence of lesion detection is improved. This now clinically available imaging technique should improve the acceptance of spine DWI and lead to its wider use in practice References 1. Hara K, Watanabe H, Ito M, Tsuboi T, Watanabe H,. Potential of a new MRI for visualizing cerebellar involvement in progressive supranuclear palsy. Parkinsonism Relat Disord. 2013 Oct 16. pii: S1353-8020(13)00362-3.