A cryogenic 14-channel ¹³C receiver array for 3T human head imaging

This article presents a novel 14-channel receive-only array for ¹³C human head imaging at 3 T that explores the SNR gain by operating at cryogenic temperature cooled by liquid nitrogen. Cryostats are developed to evaluate single-coil bench SNR performance and cool the 14-channel array with liquid nitrogen while having enough thermal insulation between the coils and the sample. The temperature distribution for the coil array is measured. Circuits are adapted to the -189°C environment and implemented in the 14-channel array. ¹³C images are acquired with the array at cryogenic and room temperature in a 3T scanner. Compared with room temperature, the array at cryogenic temperature provides 27%-168% SNR improvement over all voxels and 47% SNR improvement near the image center. The measurements show a decrease of the element noise correlation at cryogenic temperature. It is demonstrated that higher SNR can be achieved by cryogenically cooling the 14-channel array. A cryogenic array suitable for clinical imaging can be further developed on the array proposed. The cryogenic coil array is most likely suited for scenarios in which high SNR deep in a head and decent SNR on the periphery are required.