Single shot T1rho magnetic resonance imaging of metabolically generated water in vivo.

The use of Oxygen-17 MRI provides great promise for the clinically-useful quantification of metabolism. To bring techniques based on 17O closer to clinical application, we demonstrate imaging of metabolically generated H2 17O in pigs after 17O2 delivery with increased temporal resolution T1rho-weighted imaging and precision delivery of 17O2 gas. The kinetics of the appearance of H2 17O in pig brains are displayed with one to two minutes of 17O2 delivery, the shortest delivery times reported in the literature. It is also shown that H2 17O concentrations can be quantified with single shot T1rho imaging based on a balanced steady state free precession readout, and that with this strategy pausing to reduce T1 saturation increases sensitivity to H2 17O over acquisition in the steady state. Several additional considerations with this sequence, which can be generalized to any pre-encoding cluster, such as energy deposition are considered.