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

Purpose: To 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. Methods: This 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. Results: Quantitative 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. Conclusion: The 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. [ABSTRACT FROM AUTHOR]