Deuterium brain imaging at 7T during D2O dosing

Abstract

Purpose: To characterize the (2H) deuterium MR signal measured from human brain at 7T in participants loading with D2O to ~1.5% enrichment over a six-week period. Method(s): 2H spectroscopy and imaging measurements were used to track the time-course of 2H enrichment within the brain during the initial eight-hour loading period in two participants. Multi-echo gradient echo (MEGE) images were acquired at a range of TR values from four participants during the steady-state loading period and used for mapping 2H T1 and T2 * relaxation times. Co-registration to higher resolution 1H images allowed T1 and T2 * relaxation times of deuterium in HDO in cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM) to be estimated. Result(s): 2H concentrations measured during the eight-hour loading were consistent with values estimated from cumulative D2O dose and body mass. Signal changes measured from three different regions of the brain during loading showed similar time-courses. After summing over echoes, gradient echo brain images acquired in 7.5 minutes with a voxel volume of 0.36 ml showed an SNR of ~16 in subjects loaded to 1.5%. T1-values for deuterium in HDO were significantly shorter than corresponding values for 1H in H2O, while T2 * values were similar. 2H relaxation times in CSF were significantly longer than in GM or WM. Conclusion(s): Deuterium MR Measurements at 7T were used to track the increase in concentration of 2H in brain during heavy water loading. 2H T1 and T2 * relaxation times from water in GM, WM, and CSF are reported.Copyright © 2022 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.