Development of a Double Tuned <sup>2</sup>H/<sup>31</sup>P Whole‐Body Birdcage Transmit Coil for <sup>2</sup>H and <sup>31</sup>P MR Applications From Head to Toe at 7 T
Ayhan Gürsan, Busra Kahraman‐Agir, Mark Gosselink, Dimitri Welting, Martijn Froeling, Hans Hoogduin, Evita Wiegers, Jeanine J. Prompers, Dennis W. J. Klomp
Abstract
ABSTRACT Deuterium ( 2 H) and phosphorus ( 31 P) magnetic resonance spectroscopy (MRS) are complementary methods for evaluating tissue metabolism noninvasively in vivo. Combined 2 H and 31 P MRS would therefore be of interest for various applications, from cancer to diabetes. Loop coils are commonly used in X‐nuclei studies in the human body for both transmit and receive. However, loop coils suffer from limited penetration depth and inhomogeneous B 1 + field. The purpose of this work is to develop a double tuned 2 H/ 31 P whole‐body birdcage transmit coil for 7 T for 2 H and 31 P MRS imaging (MRSI) with homogeneous excitation over a large field‐of‐view. The performance of the 2 H/ 31 P birdcage coil was assessed on B 1 + fields over a body‐sized phantom at 2 H and 31 P frequencies using an 8‐channel 2 H/ 31 P receive array. Using two elements of the 2 H/ 31 P receive array, natural abundance 2 H and 31 P 3D MRSI data at rest were acquired consecutively in the brain and lower leg muscles. Additionally, 2 H and 31 P 3D MRSI data were acquired from one volunteer 90 min after [6,6′‐ 2 H 2 ]‐glucose intake, using 8‐channel 2 H/ 31 P receive array around the abdomen. The B 1 + variation of the whole‐body birdcage coil over the phantom was 12.1% for 2 H and 19.2% for 31 P. High‐quality 2 H and 31 P 3D MRSI data were acquired from the brain and the lower leg. Whole liver coverage was achieved in both 2 H and 31 P 3D MRSI data. The developed 2 H/ 31 P whole‐body birdcage transmit coil allows simultaneous 3D mapping of glucose and energy metabolism and membrane turnover throughout the human body.