In vivo potassium MRI of the human heart

PURPOSE: 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. METHODS: 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. RESULTS: For in vivo (39)K MRI of the human heart, a nominal spatial resolution of 14.5 × 14.5 × 14.5 mm(3) within a total scan time of 30 min was achieved. The average SNR within the heart was 9.6 ± 2.4. CONCLUSION: 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.