In vivo 31P magnetic resonance spectroscopy (MRS) provides a unique tool for the non-invasive study of brain energy metabolism and mitochondrial function. The assessment of bioenergetic impairment in different brain regions is essential to understand the pathophysiology and progression of human brain diseases. This article presents a simple and effective approach which allows the interleaved measurement of 31P spectra and imaging from two distinct human brain regions of interest with dynamic B0 shimming capability. A transistor–transistor logic controller was employed to actively switch the single-channel X-nuclear radiofrequency (RF) transmitter–receiver between two 31P RF surface coils, enabling the interleaved acquisition of two 31P free induction decays (FIDs) from human occipital and frontal lobes within the same repetition time. Linear gradients were incorporated into the RF pulse sequence to perform the first-order dynamic shimming to further improve spectral resolution. The overall results demonstrate that the approach provides a cost-effective and time-efficient solution for reliable 31P MRS measurement of cerebral phosphate metabolites and adenosine triphosphate (ATP) metabolic fluxes from two human brain regions with high detection sensitivity and spectral quality at 7 T. The same design concept can be extended to acquire multiple spectra from more than two brain regions or can be employed for other magnetic resonance applications beyond the 31P spin.
Bibliographical noteFunding Information:
National Institutes of Health (NIH), Grant/ Award Number: R01 NS070839 and MH111447, R24 MH106049 and MH106049S1, S10RR026783 and P41 EB015894 and P30 NS057091; AHC Faculty Research Development (FRD)
This work was supported in part by National Institutes of Health (NIH) grants (R01 NS070839 and MH111447, R24 MH106049 and MH106049S1, S10RR026783, P41 EB015894 and P30 NS057091) and the AHC Faculty Research Development (FRD) grant from the University of Minnesota.
- dynamic B shimming
- high-energy phosphorus metabolism
- human brain
- in vivo P MRS imaging