Table 6.

Levelsi of lipid and lactate normalized to the level of NAA in normal appearing white matter

Grade	Lip median in CNI >2	Lip max in CNI >2	Sum (Lip) In CNI >2	Lac median In CNI >2	Lac max in CNI >2	Sum (Lac) in CNI >2
II	−0.03	0.21	0.40	0.03	0.14	1.84
N = 40	sd = 0.06	sd = 0.13	sd = 0.98	sd = 0.08	sd = 0.15	sd = 2.93
III	0.04	0.19	0.66	0.12*	0.21*	2.88*
N = 25	sd = 0.03	sd = 0.16	sd = 1.40	sd = 0.12	sd = 0.42	sd = 4.48
IV	0.14*	0.55*	3.94*	0.17*	0.45*	5.29*
N = 35	sd = 0.17	sd = 0.83	sd = 7.55	sd = 0.08	sd = 0.29	sd = 5.32

Values are evaluated within voxels that have CNI >2 to avoid cysts or necrosis. Four of the patients from the grade II population were eliminated from the analysis of lipid after visual examination of the spectral data due to concern about the possibility of contamination from signals arising from subcutaneous lipids. The values estimated from analysis for the grade II subtypes gave similar results and so only the overall results are given