A 64-channel ex-vivo brain coil array for temperature-controlled diffusion imaging with the Connectome 2.0 MRI scanner

Motivation: Ex-vivo brain DWI with long scan times poses the problem of temperature-related drift of diffusion measurement results. Goal(s): The construction of a 64-channel ex-vivo brain coil with time-course temperature stabilization for obtaining accurate DWI measurements. Approach: Combining a newly developed high-density ex-vivo brain coil array with a forced-air cooling system and a multi-channel temperature recording. Results: The air circulation system was able to maintain the ambient temperature of the coil and, thus, stabilizing the mean diffusivity values over repeated lengthy scans. Without cooling, a drift of the mean diffusivity was overserved, peaking at a 35%-offset at approximately 11 hours. Impact: Temperature-stabilized post-mortem brain samples for diffusion MRI in combination with a dedicated large channel count ex-vivo brain coil improves image quality in terms of achievable SNR and greatly reduced temperature-induced diffusivity shifts.