Fig. 2.

Simulated and in vivo ³¹P MR spectra of the human brain at 7 T. (A) Model-simulated spectra of NAD⁺ quartet, NADH singlet, total NAD, and combined α-ATP and NAD signals with an HLW of 18 Hz and an NAD⁺/NADH RX of 3.35. (B) Experimentally measured in vivo ³¹P MR spectra of human occipital lobe processed with 10-Hz line broadening that have the same HLW and RX values as the simulated spectra in A. The individual and combined in vivo spectra of NAD⁺, NADH, and total NAD were obtained by subtracting corresponding fitting components from the original brain spectra.