Feasibility of simultaneous high‐resolution anatomical and quantitative magnetic resonance imaging of sciatic nerves in patients with Charcot–Marie–Tooth type 1A (CMT1A) at 7T. Issue 2 (13th June 2022)

• Record Type: Journal Article
• Authors: Sveinsson, Bragi; Rowe, Olivia E.; Stockmann, Jason P.; Park, Daniel J.; Lally, Peter J.; Rosen, Matthew S.; Barry, Robert L.; Eichler, Florian; Rosen, Bruce R.; Sadjadi, Reza
• Is Part Of: Muscle & nerve. Volume 66:Issue 2(2022)
• Page Start: 206
• Page End: 211
• Publication Date: 2022-06-13
• Subjects: 7T MRI -- CMT1A -- outcome measures -- peripheral nerve imaging; Neuromuscular diseases -- Periodicals; Muscles -- Periodicals; Nerves -- Periodicals; 616.74
• DOI: 10.1002/mus.27647
• Languages: English
• ISSNs: 0148-639X

Abstract

Abstract: Introduction/Aims: Magnetic resonance imaging (MRI) of peripheral nerves can provide image‐based anatomical information and quantitative measurement. The aim of this pilot study was to investigate the feasibility of high‐resolution anatomical and quantitative MRI assessment of sciatic nerve fascicles in patients with Charcot–Marie–Tooth (CMT) 1A using 7T field strength. Methods: Six patients with CMT1A underwent imaging on a high‐gradient 7T MRI scanner using a 28‐channel knee coil. Two high‐resolution axial images were simultaneously acquired using a quantitative double‐echo in steady‐state (DESS) sequence. By comparing the two DESS echoes, T2 and apparent diffusion coefficient (ADC) maps were calculated. The cross‐sectional areas and mean T2 and ADC were measured in individual fascicles of the tibial and fibular (peroneal) portions of the sciatic nerve at its bifurcation and 10 mm distally. Disease severity was measured using Charcot–Marie–Tooth Examination Score (CMTES) version 2 and compared to imaging findings. Results: We demonstrated the feasibility of 7T MRI of the proximal sciatic nerve in patients with CMT1A. Using the higher field, it was possible to measure individual bundles in the tibial and fibular divisions of the sciatic nerve. There was no apparent correlation between diffusion measures and disease severity in this small cohort. Discussion: This pilot study indicated that high‐resolution MRI that allows for combined anatomical and quantitative imaging in one scan is feasible at 7T field strengths and can be used to investigate the microstructure of individual nerve fascicles. Abstract : Sciatic nerve images in a patient with CMT1A using 7T MRI, a zoomed in region showing the fascicles of sciatic nerve in more detail with visible epineurium, corresponding T2 and ADC maps