Table 3

Mean (SD) values for the metabolite ratios, and for the percentage asymmetry in relative cerebral blood volume related to (A) the Hunt and Hess clinical grade, (B) to the degree of oedema assessed on the T2 weighted image, and (C) individual values generated from follow up studies

(A) Changes with Hunt and Hess grade
Clinical grade 1 and 2 3 4
Lactate/(Ch+Cr)0.0 (0.0)0.09 (0.10)0.41 (0.58)
NAA/(Ch+Cr)0.84 (0.22)0.74 (0.18)0.29 (0.08)
Cr/Ch1.34 (0.26)1.03 (0.19)1.02 (0.16)
% relative CBV−8 (23)%52 (47)%79 (94)%
(B) Changes with oedema
Oedema Absent Moderate Pronounced
Lactate/(Ch+Cr)0.01 (0.02)0.01 (0.02)0.16 (0.24)
NAA/(Cr+Ch)0.83 (0.18)0.89 (0.24)0.63 (0.23)
Cr/Ch1.09 (0.23)1.23 (0.26)0.99 (0.16)
(C) Improved metabolite ratios on repeat studies (three patients)
Initial study Follow up study
Time from SAH (days)13, 13, 1219, 27, 15
Lactate/(Ch+Cr)0.25, 0.62, 0.820, 0, 0
NAA/(Cr+Ch)0.78, 0.62, 0.290.81, 0.83, 0.44
Cr/Ch1.02, 0.91, 1.101.00, 1.12, 1.02
  • Ch = choline; Cr = creatine; NAA = N=acetyl aspartate; CBV = cerebral blood volume; SAH = subarachnoid haemorrhage.