In vivo potassium MRI of the human heart

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.