Extended Data Fig. 8: Quantitative analysis of metabolic imaging for detecting MS lesions prior to the changes observable in conventional structural images.

a, Identification of the prelesion regions (yellow), based on the difference between initial and follow-up T2w images obtained from the patient. b, Regional average (solid line) and standard deviation (shaded area) of FID spectra in NAWM and prelesion regions, respectively. c, Box plots of mI/NAA and Lac levels in NAWM (n = 1103), prelesion 1 (n = 83) and prelesion 2 (n = 45) regions. Lac levels were shown in arbitrary units. Box plots are represented by median and interquartile range, with ±1.5 interquartile range as whiskers. Elevated mI/NAA and Lac were detected in the prelesion regions at the time of the initial scan, prior to noticeable changes in the structural image. The specific molecular changes were: prelesion 1 & 2 mI/NAA: 30.3%, P < 0.001; prelesion 1 mI/NAA: 31.5%, P < 0.001; prelesion 2 mI/NAA: 26.2%, P < 0.001; prelesion 1 & 2 Lac: 120.9%, P < 0.001; prelesion 1 Lac: 73.7%; P < 0.001; prelesion 2 Lac: 200.0%, P < 0.001). Unpaired two-tailed Student’s t-tests were performed. Abbreviations: T2w, T2-weighted; NAWM, normal-appearing white matter; NAA, N-acetyl aspartate; mI, myo-inositol; Lac, lactate.