Automated segmentation of cerebral deep gray matter from MRI scans: effect of field strength on sensitivity and reliability

Abstract

BackgroundThe cerebral subcortical deep gray matter nuclei (DGM) are a common, early, and clinically-relevant site of atrophy in multiple sclerosis (MS). Robust and reliable DGM segmentation could prove useful to evaluate putative neuroprotective MS therapies. The objective of the study was to compare the sensitivity and reliability of DGM volumes obtained from 1.5T vs. 3T MRI.MethodsFourteen patients with MS [age (mean, range) 50.2 (32.0–60.8) years, disease duration 18.4 (8.2–35.5) years, Expanded Disability Status Scale score 3.1 (0–6), median 3.0] and 15 normal controls (NC) underwent brain 3D T1-weighted paired scan-rescans at 1.5T and 3T. DGM (caudate, thalamus, globus pallidus, and putamen) segmentation was obtained by the fully automated FSL-FIRST pipeline. Both raw and normalized volumes were derived.ResultsDGM volumes were generally higher at 3T vs. 1.5T in both groups. For raw volumes, 3T showed slightly better sensitivity (thalamus: p = 0.02; caudate: p = 0.10; putamen: p = 0.02; globus pallidus: p = 0.0004; total DGM: p = 0.01) than 1.5T (thalamus: p = 0.05; caudate: p = 0.09; putamen: p = 0.03; globus pallidus: p = 0.0006; total DGM: p = 0.02) for detecting DGM atrophy in MS vs. NC. For normalized volumes, 3T but not 1.5T detected atrophy in the globus pallidus in the MS group. Across all subjects, scan-rescan reliability was generally very high for both platforms, showing slightly higher reliability for some DGM volumes at 3T. Raw volumes showed higher reliability than normalized volumes. Raw DGM volume showed higher reliability than the individual structures.ConclusionsThese results suggest somewhat higher sensitivity and reliability of DGM volumes obtained from 3T vs. 1.5T MRI. Further studies should assess the role of this 3T pipeline in tracking potential MS neurotherapeutic effects.

MS optic neuritis-induced long-term structural changes within the visual pathway

“…To date, combined OCT and MRI studies in MS have not considered the timespan after the clinical episode of ON 9,10 or have focused on short-term structural changes within the WM, such as the optic radiation (OR) 8,11 or global GM, 12 as well as cortical abnormalities. 13 In addition, the sensitivity and reliability of volumetric measures of deep GM were lower when MRIs had been acquired on 1.5 T scanners 14 and OR results depended critically on the fiber tracking techniques applied. [15][16][17] In a recent previous study, we have already documented significant changes in retinal structures and diffusion values within the OR by comparing patients with MS with healthy controls.…”

Sex‐Specific Differences in Life Span Brain Volumes in Multiple Sclerosis

“…Therefore, when compared to SIENAX and FIRST protocols, the LVV measure derived in such manner may prove itself as a more reliable brain atrophy proxy that can be utilized on a wider array of imaging circumstances 15 . Despite the brain structure in question, such effects derived from field strength differences (either from 1.5‐T to 3‐T or from different scanner manufacturers) have been previously demonstrated in the literature 35,36 . For example, WBV measurements acquired at 1.5‐T scanner may significantly overestimate the total WBV 35 .…”

Dual‐Sensitivity Multiple Sclerosis Lesion and CSF Segmentation for Multichannel 3T Brain MRI

“…Disease subtypes were relapsing‐remitting ( n = 21), secondary progressive ( n = 5), primary progressive ( n = 2), and clinically isolated demyelinating syndrome ( n = 1). The scan‐rescan experiment included a different set of another 13 patients with MS (50 ± 8 years old, with 18 ± 10 years disease duration) and 15 healthy volunteers (38 ± 10 years old); these images have contributed to separate studies, in which the recruitment and acquisition procedures have been detailed . The patients with MS were selected to represent a broad spectrum of disease severity to assess accuracy and precision of WML volume and brain atrophy.…”

“…Any discrepancies were resolved by a senior faculty member, the LNR director (R. Bakshi). Precision was evaluated in an additional scan‐rescan experiment of 13 patients with MS and 15 healthy volunteers, where subjects were scanned twice within hours, leaving the scanner in between …”