Diffusion‐prepared neurography of the brachial plexus with a large field‐of‐view at 3T

Abstract

The use of a susceptibility-matched pillow in combination with IB-shimming enables robust and high-quality neurography of the complete brachial plexus.

Diffusion tensor MRI of the healthy brachial plexus

“…This voxel-size facilitated an adequate bandwidth, limiting geometrical distortions in the EPI readout. Additionally, we used a low-cost susceptibility matching pillow for improved field homogeneity [ 22 ]. Taken together, this enabled accurate DT-MRI reconstructions of the nerves that matched the MNR images all the way up to Erb’s point except for Th1.…”

“…To reduce susceptibility artefacts caused by the air tissue transitions in the neck, a tissue susceptibility matching pillow was used in conjunction with an image-based shimming method [ 22 ]. For anatomical reference and assessing gross-pathology by the radiologist a T 2 -weighted, fat-suppressed diffusion-prepared neurography sequence was used [ 22 , 35 ].…”

“…Reconstructions of the anatomical scans were made to match the orientation and x, y, and z coordinates of the DT-MRI scan. For 10 subjects the DT-MRI experiment was repeated with the radiofrequency (RF) pulses switched off to assess image noise for signal-to-noise ratio (SNR) calculations [ 22 ].…”

Assessment of acute thermal damage volumes in muscle using magnetization‐prepared 3D T2‐weighted imaging following MRI‐guided high‐intensity focused ultrasound therapy

“…The magnetization preparation uses the improved motion‐sensitization driven equilibrium (iMSDE) sequence for blood signal suppression combined with a spectrally selective adiabatic inversion recovery (SPAIR) pulse for fat suppression. The SHINKEI sequence was originally developed for peripheral nerve imaging by simultaneously suppressing fat and blood vessel signal, and using a long effective echo time to enhance the relatively long T 2 of nerves with respect to muscle for improved nerve conspicuity . In this study, we used SHINKEI to enhance the conspicuity of thermal damage, which also has a prolonged T 2 due to edema accumulation.…”

“…The SHINKEI sequence was originally developed for peripheral nerve imaging 21 by simultaneously suppressing fat and blood vessel signal, and using a long effective echo time to enhance the relatively long T 2 of nerves with respect to muscle for improved nerve conspicuity. 27 In this study, we used SHINKEI to enhance the conspicuity of thermal damage, which also has a prolonged T 2 due to edema accumulation. Additionally, the 50-msec T 2 preparation time of the iMSDE suppresses muscle signal and further accentuates the visualization of prolonged T 2 species present both in nerve pathologies and edema in thermal damage.…”