Figure 1.

Water‐scaled NAA levels obtained from short TE ${}^1\mathrm{H}$ MRS in vivo spectra (a), water‐scaled NAA levels obtained from long TE ${}^1\mathrm{H}$ MRS in vivo spectra (b), NAA levels determined based on absolute standard (before application of $f_T$ coefficient) from short TE ${}^1\mathrm{H}$ MRS in vivo spectra (c), and NAA levels determined based on absolute standard (before application off $f_T$ coefficient) from long TE ${}^1\mathrm{H}$ MRS in vivo spectra (d). Full triangles represent two cases diagnosed with Canavan disease, open triangles represent patients diagnosed with other neurological disorders, dashed lines indicate the threshold of ‘mean + 2 SD’ computed separately for patients aged 2‐12 months and 12‐24 months. The NAA concentrations were not corrected for relaxation and are expressed in institutional units.