Intra- and inter-site reproducibility of human brain single-voxel proton MRS at 3 T.

Introduction: Clinical trials that involve participants from multiple sites necessitate standardized and reliable quantitative MRI outcomes to detect significant group differences over time. Metabolite concentrations measured by proton MRS ( H-MRS) provide valuable information about in vivo metabolism of the central nervous system, but can vary based on the acquisition and quantitation methods used by different MR sites. Therefore, we investigated the intra- and inter-site reproducibility of metabolite concentrations measured by H-MRS on MRI scanners from a single manufacturer across six sites.

Multicenter Measurements of T Relaxation and Diffusion Tensor Imaging: Intra and Intersite Reproducibility.

Background And Purpose: Quantitative T and diffusion tensor imaging (DTI) may provide information about pathological changes underlying disability and progression in diseases like multiple sclerosis (MS). Imaging the corpus callosum (CC), a primary site of damage in MS with a critical role in interhemispheric connectivity, may be useful for assessing overall brain health, prognosis, and therapy efficacy. We assessed the feasibility of multisite clinical trials using advanced MRI by examining the intra and intersite reproducibility of T and DTI measurements in the CC and segmented white matter (WM).

Multicenter measurements of myelin water fraction and geometric mean T2 : intra- and intersite reproducibility.

Purpose: To assess the reproducibility of myelin water fraction (MWF) and geometric mean T2 (GMT2 ), which are in vivo markers of pathological changes underlying disability and progression in diseases such as multiple sclerosis.

Materials And Methods: Five healthy volunteers were scanned twice within 24 hours at six different sites using the same manufacturer's 3T magnetic resonance (MR) system. T2 distributions were produced by fitting multiecho 3D T2 data using non-negative least squares, with stimulated echo correction.