In vivo potassium MRI of the human heart

Abstract

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 39K MRI of the human heart. To achieve this, we developed, evaluated, and applied a 39K/1H RF coil, which is tailored for 39K MRI of human heart at 7.0T. Methods The performance of the 39K/1H 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 39K 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. Conclusion This work validates the design of a 39K/1H RF coil for cardiac MR at 7.0T and demonstrates for the first time in vivo the feasibility of 39K MRI of the human heart.

Combined imaging of potassium and sodium in human skeletal muscle tissue at 7 T

“…Therefore, in vivo 39 K MRI was performed only on preclinical systems 24,25 or using experimental, custom‐built setups in humans 20,26,27 . Recently, the first 39 K images of human heart acquired at a clinical 7 T MR system were published 28 . However, all previous studies using 39 K MRI in humans did not examine the quantitative capability and especially not the reproducibility of 39 K imaging.…”

A Novel FBG-Based Triggering System for Cardiac MR Imaging at 3 Tesla: A Pilot Pre-Clinical Study

“…Building on more than 30 years of MRI clinical applications, the research on improvement of this imaging modality is continuing. Of particular importance is the research efforts aimed at improving the quality of acquired images despite the image distortion naturally induced by respiration [1], [2] and cardiac function [3]- [5], as movement of patient body degrades the quality of acquired images [6]- [8]. Since the movements due to respirator and cardiac function are unavoidable [9], researchers have explored ways of compensating for such movements.…”

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“…This is in stark contrast to scan durations of approximately 1-2 h available today for the same sub-millimetre spatial resolution [45][46][47]. MR of nuclei such as 35 Cl and 39 K will greatly benefit from 14 and 20 T. Arguably, 39 K MR remains quite challenging because the sensitivity is about six orders of magnitude less than that of 1 H MR [48]. Notwithstanding this constraint, it stands to reason that 39 K MR at 14 T or 20 T will enable, for the first time, quantitative in vivo assessment of myocardial potassium content on a cellular level, which would open an entirely new research field of MRI-based physio-metabolic fingerprinting as a link to personalised medicine, as pointed out in this Special Issue in [43].…”