Cross‐vendor multiparametric mapping of the human brain using 3D‐QALAS: A multicenter and multivendor study

Abstract

AbstractPurposeTo evaluate a vendor‐agnostic multiparametric mapping scheme based on 3D quantification using an interleaved Look–Locker acquisition sequence with a T2 preparation pulse (3D‐QALAS) for whole‐brain T1, T2, and proton density (PD) mapping.MethodsThis prospective, multi‐institutional study was conducted between September 2021 and February 2022 using five different 3T systems from four prominent MRI vendors. The accuracy of this technique was evaluated using a standardized MRI system phantom. Intra‐scanner repeatability and inter‐vendor reproducibility of T1, T2, and PD values were evaluated in 10 healthy volunteers (6 men; mean age ± SD, 28.0 ± 5.6 y) who underwent scan‐rescan sessions on each scanner (total scans = 100). To evaluate the feasibility of 3D‐QALAS, nine patients with multiple sclerosis (nine women; mean age ± SD, 48.2 ± 11.5 y) underwent imaging examination on two 3T MRI systems from different manufacturers.ResultsQuantitative maps obtained with 3D‐QALAS showed high linearity (R2 = 0.998 and 0.998 for T1 and T2, respectively) with respect to reference measurements. The mean intra‐scanner coefficients of variation for each scanner and structure ranged from 0.4% to 2.6%. The mean structure‐wise test–retest repeatabilities were 1.6%, 1.1%, and 0.7% for T1, T2, and PD, respectively. Overall, high inter‐vendor reproducibility was observed for all parameter maps and all structure measurements, including white matter lesions in patients with multiple sclerosis.ConclusionThe vendor‐agnostic multiparametric mapping technique 3D‐QALAS provided reproducible measurements of T1, T2, and PD for human tissues within a typical physiological range using 3T scanners from four different MRI manufacturers.