Comparison of mean 31P-MRS peak SNRs in-vivo in the mid-short axis segments for the two coils. Solid bars denote the single-transmit coil and cross-hatched bars denote the dual-transmit coil. P values from a paired t-test using all subject and all peaks are reported for each segment. In the regions of the heart closest to the surface (the anterior - inferoseptal segments) there is no significant difference between the performance of the two coils, but in the deeper regions of the heart (the inferior - anterolateral segments) the dual-transmit coil has significantly higher spectral SNR. The dual-transmit coil has a significant advantage for studies requiring whole-heart coverage.