An 8‐channel receive array for improved 31P MRSI of the whole brain at 3T

Abstract

PurposeTo demonstrate a 1H/31P whole human brain volume coil configuration for 3 Tesla with separate 31P transmit and receive components that maintains 1H MRS performance and delivers optimal 31P MRSI with 1H decoupling.MethodsWe developed an 8‐channel 31P receive array coil covering the head to be used as an insert for a commercial double‐tuned 1H/31P birdcage transmit‐receive coil. This retains the possibility of using low‐power rectangular pulses for 1H‐decoupled 3D 31P MRSI (nominal resolution 17.6 cm3; acquisition duration 13 min) but increases the SNR with the receive sensitivity of 31P surface coils. The performance of the combined coil setup was evaluated by measuring 1H and 31P SNR with and without the 31P receive array and by assessing the effect of the receive array on the transmit efficiencies of the birdcage coil.ResultsCompared to the birdcage coil alone, the 31P insert in combination with the birdcage achieved an average 31P SNR gain of 1.4 ± 0.4 in a center partition of the brain. The insert did not cause losses in 1H MRS performance and transmit efficiency, whereas for 31P approximately 20% more power was needed to achieve the same γB1.ConclusionThe new coil configuration allows 1H MRSI and optimal 1H‐decoupled 3D 31P MRSI, with increased SNR of the human brain without patient repositioning, for clinical and research purposes at 3 Tesla.