ADC measurements in various patterns of multiple sclerosis lesions.
OBJECTIVE
To determine the difference of mean apparent diffusion coefficients (ADC) among different patterns of focal multiple sclerosis (MS) lesions, to compare mean lesion ADC between 2 clinical subgroups and to correlate mean lesion ADC with disability.


METHODS
Thirty seven patients (26 with relapsing-remitting multiple sclerosis (MS) and 11 with secondary-progressive MS) underwent both conventional and diffusion-weighted MR imaging of the brain. After creating ADC maps, region identification was done by using b = 0 images and T2-weighted images. ADC values were measured for MS lesions and (NAWM).


RESULTS
A total of 288 lesions were identified on the images. The mean ADC for the lesions was significantly higher than that of NAWM Hypointense T1 lesions (n = 221) had a significantly higher mean ADC than isointense T1 lesions (n = 67) in both nonenhancing lesions (n = 250) and enhancing lesions (n = 38). The enhanced rim of ring-enhancing lesions (n = 18) had lower ADC than the central nonenhanced portions. Confluent lesions (n = 62) had a substantially higher mean ADC than discrete lesion (n = 226). Mean lesion ADC of secondary progressive MS was significantly higher than relapsing remitting MS. No correlation between mean lesion ADC and (EDSS) score was found


CONCLUSIONS
Quantitative diffusion-weighted imaging is useful to elucidate the heterogeneous pathological substrate of MS in different patterns of MS lesions, to differentiate 2 major clinical subgroups.
Department of Radiology, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. koiwww@yahoo.com
Warinthorn
W
Phuttharak
Waneerat
W
Galassi
Vallop
V
Laopaiboon
Malinee
M
Laopaiboon
John R
JR
Hesselink
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D016001:Confidence Intervals; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004185:Disability Evaluation; D018450:Disease Progression; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000453:epidemiology; D020528:Multiple Sclerosis, Chronic Progressive / Q000175:diagnosis* / Q000453:epidemiology; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis* / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors; D018709:Statistics, Nonparametric
D019786:Gadolinium DTPA