In Vivo³⁹K MR Imaging of Human Muscle and Brain

Abstract

In vivo (39)K MR imaging in humans can be performed in clinically feasible measurement times (approximately 30 minutes) with voxel sizes of approximately 1 mL.

Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond

“…Some of the benefits are already clear: we have already seen progress in remotely probing local concentrations of fluorine, sodium, potassium and chlorine in human tissues (9)(10)(11)(12)(13)(14), in assessing bioenergetic conditions (15)(16)(17) and oxygen consumption (18) in vivo along with the advances in 9.4 T human MR (15,(19)(20)(21)(22)(23)(24). Pioneering reports on MR physics, radiofrequency (RF) power deposition considerations and novel RF antenna designs (25,26) spurred the installation of a 10.5 T whole-body MR system at the Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, USA (27).…”

X‐nuclei imaging: Current state, technical challenges, and future directions

“…Three decades after the first in vivo 23 Na images, the first 39 K and 35 Cl MR images in humans were shown . Compared with 39 K and 35 Cl MRI, the first in vivo 17 O image was published earlier .…”

Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale

“…Quantification of the ion concentrations has the potential to map ion gradients between different compartments of the brain. Sodium imaging [77–81], potassium imaging [82, 83], and chloride imaging [84] have been accomplished in the human brain at 7 T and 9.4 T. However, to exploit multiple quantum imaging methods to determine the separate concentrations of these ions in the intra- and extracellular compartments, the sensitivity must increase substantially. A field increase from 7 to 20 T can realize an increase in SNR of 6 that reflects a 36-fold decrease in acquisition time based on the theoretical prediction of the 7/4 power-dependence of field strength [43].…”