A 4‐minute solution for submillimeter whole‐brain T 1ρ quantification

Purpose To develop a robust, accurate, and accelerated T 1ρ quantification solution for submillimeter in vivo whole‐brain imaging. Methods A multislice T 1ρ mapping solution (MS‐T 1ρ ) was developed based on a two‐acquisition scheme using turbo spin echo with RF cycling to allow for whole‐brain coverage with 0.8‐mm in‐plane resolution. A compressed sensing–based fast imaging method, SCOPE, was used to accelerate the MS‐T 1ρ acquisition time to a total scan time of 3 minutes 31 seconds. A phantom experiment was conducted to assess the accuracy of MS‐T 1ρ by comparing the T 1ρ value obtained using MS‐T 1ρ with the reference value obtained using the standard single‐slice T 1ρ mapping method. In vivo scans of 13 volunteers were acquired prospectively to validate the robustness of MS‐T 1ρ . Results In the phantom study, the T 1ρ values obtained with MS‐T 1ρ were in good agreement with the reference T 1ρ values ( R 2 = 0.9991) and showed high consistency throughout all slices (coefficient of variation = 2.2 ± 2.43%). In the in vivo experiments, T 1ρ maps were successfully acquired for all volunteers with no visually noticeable artifacts. There was no significant difference in T 1ρ values between MS‐T 1ρ acquisitions and fully sampled acquisitions for all brain tissues ( p ‐value > .05). In the intraclass correlation coefficient and Bland‐Altman analyses, the accelerated T 1ρ measurements show moderate to good agreement to the fully sampled reference values. Conclusion The proposed MS‐T 1ρ solution allows for high‐resolution whole‐brain T 1ρ mapping within 4 minutes and may provide a potential tool for investigating neural diseases.