Measurement of NAD+ T1 relaxation time at 7T in the human brain using saturation recovery downfield MRS

Here we present a method based on spectrally selective saturation recovery 1H spectroscopy to measure the apparent T1 values of NAD+ in the downfield at 7T for the first time. With spectrally selective saturation and excitation, NAD+ exhibits enhanced T1 recovery do to cross relaxation with water, and we report values in three subjects between 200 and 300 ms. Measuring apparent T1 is crucial as a correction factor for quantitative spectroscopy of NAD+.