Characterizing B0 field inhomogeneity, B1+ variations, and respiratory motion for breast MRI in the supine position

Motivation: Supine breast MRI would overcome many drawbacks of prone breast imaging, including patient discomfort, claustrophobia, misalignment with other procedures, and setup times. But, certain challenges must be assessed. Goal(s): To characterize B0 (free-breathing, end-exhale, end-inhale), B1+, and respiratory motion in prone versus supine breast MRI. Approach: Ten volunteers were scanned in prone and supine at 3T. B0 field inhomogeneity, B1+ variations, and respiratory-induced motion were analyzed. Results: Comparing supine versus prone, field inhomogeneity increased by 28% in supine, and B1+ variations between left and right breast were greater in supine. Respiratory-induced breast motion was up to 10 mm. Impact: In supine breast MRI, B0 inhomogeneity and B1+ variations and respiratory-induced motion all increase, posing new technical challenges that must be addressed for robust supine breast imaging, and to ultimately overcome limitations of standard-of-care prone imaging.