In vivo potassium MRI of the human heart.

Abstract

Potassium ions (K+ ) play a critical role in cardiac electrophysiology, and changes in their concentration reflect pathophysiological processes related to cardiovascular diseases. Here, we investigated the feasibility of in vivo 39 K MRI of the human heart. To achieve this, we developed, evaluated, and applied a 39 K/1 H RF coil, which is tailored for 39 K MRI of human heart at 7.0T. The performance of the 39 K/1 H RF coil was evaluated by electromagnetic field and specific absorption ratio simulations using 2 (male/female) human voxel models. The RF coil was evaluated at the bench and applied in an in vivo proof-of-principle study involving 7 healthy volunteers. The experiments were performed using a 7.0T whole-body MR system in conjunction with a 3D density-adapted projection reconstruction imaging technique. For in vivo 39 K MRI of the human heart, a nominal spatial resolution of 14.5 × 14.5 × 14.5 mm3 within a total scan time of 30 min was achieved. The average SNR within the heart was 9.6 ± 2.4. This work validates the design of a 39 K/1 H RF coil for cardiac MR at 7.0T and demonstrates for the first time in vivo the feasibility of 39 K MRI of the human heart.