MRI Goes Mobile: Assessing the Reliability and Repeatability of a Mobile vs. Stationary 1.5 T MRI for Functional...

Mobile MRI scanners could transform neuroimaging by expanding accessibility to diverse populations and enabling data collection in remote settings. This study serves as a short-term feasibility and system commissioning report, investigating the reliability and repeatability of two mobile 1.5 T MRI scanners compared to a stationary 1.5 T reference. To evaluate the technical impact of scanner relocation and mobile housing, a comprehensive protocol was implemented: five healthy subjects underwent 10 scans each (N = 50 total sessions) across three 1.5 T systems (one stationary; two mobile). The protocol employed a test-retest design with participant repositioning on each measurement day. Stability was assessed through longitudinal fBIRN phantom scans and human imaging of magnetic field homogeneity (ΔB₀), RF flip-angle mapping (B₁ ⁺), structural MP-RAGE, and functional EPI-BOLD. Initial commissioning results demonstrated that short-term relocation and mobile operation did not compromise hardware performance. Phantom QA showed stable tSNR and minimal signal drift. In human subjects, magnetic field stability (ΔB₀) and B₁ ⁺ distributions were equivalent across systems, with Bland-Altman plots confirming no systematic bias following transit. Structural MP-RAGE voxel-intensity distributions and tissue volumes were highly consistent, with ICCs between 0.99 and 1 for estimated WM and GM volumes. This technical validation study demonstrates the short-term feasibility of utilizing mobile 1.5 T platforms for high-quality neuroimaging. The results confirm that current mobile shielding and stabilization technologies effectively mitigate the environmental challenges of transit, establishing a reliable baseline for future longitudinal research in remote or underserved settings.