Childhood white matter disorders: quantitative MR imaging and spectroscopy.
OBJECTIVE
To prospectively investigate whether quantitative magnetic resonance (MR) parameters, including magnetization transfer ratio (MTR), apparent diffusion coefficient (ADC), fractional anisotropy (FA), and MR spectroscopic metabolite concentrations, allow for discrimination between different types of pathologic conditions that underlie signal intensity abnormalities in white matter.


METHODS
Institutional review board approval and informed consent were obtained. Forty-one patients (19 male, 22 female; mean age, 15.4 years) and 41 control subjects (25 male, 16 female; mean age, 11.3 years) were included. Twelve patients had a hypomyelinating disorder; 14, a demyelinating disorder; five, a disorder characterized by myelin vacuolation; and 10, a disorder characterized by cystic degeneration. Regions of interest were selected within the parietal white matter and were transferred to the corresponding sections of the generated ADC, FA, and MTR maps to extract quantitative measurements. Linear discriminant analysis and univariate analysis of covariance were used for statistical evaluation.


RESULTS
Linear discriminant analysis showed that 95% of patients were correctly classified by using total creatine, choline-containing compounds, myo-inositol, MTR, and ADC. In the hypomyelination group, all MR parameters were close to normal, with the exception of elevated total creatine (P = .03) and myo-inositol (P < .001) levels and decreased MTR values (P < .001). In the demyelination group, the levels of choline-containing compounds (P = .02) and myo-inositol (P < .001) were highly elevated. In the myelin vacuolation and cystic degeneration groups, high ADC values (P < .001) and variable decreases in all MR spectroscopic metabolites were seen. MTR was significantly reduced (P < .001) in the cystic degeneration group.


CONCLUSIONS
Quantitative MR techniques can be used to discriminate between different types of white matter disorders and to classify white matter lesions of unknown origin with respect to underlying pathologic conditions.
van der Voorn
J Patrick
JP
Department of Child Neurology, Vrije Universiteit Medical Center, De Boelelaan 1117, 1007 MB Amsterdam, the Netherlands. jp.vandervoom@vumc.nl
Pouwels
Petra J W
PJ
Hart
Augustinus A M
AA
Serrarens
Judith
J
Willemsen
Michèl A A P
MA
Kremer
Hubertus P H
HP
Barkhof
Frederik
F
van der Knaap
Marjo S
MS
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D016880:Anisotropy; D001923:Brain Chemistry; D001927:Brain Diseases / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D011446:Prospective Studies