Quantitative abdominal sodium MRI combined with 32-channel proton pTx MRI at 7 Tesla in a large field-of-view

Abstract

Purpose: To combine large field-of-view abdominal (Formula presented.) and quantitative sodium ((Formula presented.)) MRI in the same position at 7 T to enable the quantification of the tissue sodium concentration via (Formula presented.) MRI and the anatomical assignment in (Formula presented.) images without repositioning in several tissues and organs at once. Methods: A custom-built (Formula presented.) birdcage coil and reference vial setup together with a 32-channel (Formula presented.) pTx array were employed at 7 T to allow dual-nuclei MRI in the same position for a field-of-view (FOV) of (Formula presented.). (Formula presented.) relaxation effects in the reference vials and phantom were corrected, (Formula presented.) maps were measured, and (Formula presented.) maps were simulated to correct the acquired (Formula presented.) data in post-processing. These corrections were evaluated in a phantom and then applied in vivo in three healthy volunteers. Results: In the phantom, it was demonstrated that proton and quantitative sodium MR images share the same large FOV. Phantom measurements showed an improved sodium concentration accuracy after the performed corrections. Large FOV (Formula presented.) and quantitative (Formula presented.) in vivo MRI was demonstrated in three healthy volunteers. Conclusion: This work shows the feasibility of combined (Formula presented.) and quantitative (Formula presented.) imaging at 7 T in a large FOV both under free breathing in (Formula presented.), laying the ground work for an accurate evaluation of the tissue sodium concentration in several organs at once.