Table 2

MRS data quality*

CharacteristicHealthy controls
n = 43		Ketamine users
n = 20		p value†
Full width at half maximum0.06 (0.05–0.06)0.05 (0.04–0.06)0.013
Signal-to-noise ratio41 (38–45)42 (35.75–46)0.046
Cramer–Rao lower bound values, %
 Myo-inositol3 (3–3)4 (3–4)0.008
 N-acetyl-aspartate2 (2–3)3 (2–3)0.046
 GPC+PC2 (2–2)2 (2–3)0.18
 PCr+Cr2 (1–2)2 (1–2)0.14
 Glx6 (5–7)5 (4.75–5)0.06
Tissue composition, %
 Grey matter48 (44–51)49 (44–51)0.35
 White matter33 (30–38)34 (29–36)0.48
 Cerebrospinal fluid17 (14–20)16 (14–20)0.44

  • Glx = glutamate and glutamine; GPC+PC = glycerophosphocholine and phosphocholine; PCr+Cr = phosphocreatine and creatine.

  • ↵* Data are presented as median (interquartile range).

  • ↵† p < 0.005 (0.05/10) was considered statistically significant (Bonferroni-corrected).