Normal white matter development from infancy to adulthood: comparing diffusion tensor and high b value diffusion weighted MR images.
OBJECTIVE
To evaluate the sensitivity of high b value diffusion weight magnetic resonance imaging (DWI) in detecting normal white matter maturation, compare it to conventional diffusion tensor imaging (DTI), and to obtain normative quantitative data using this method.


METHODS
High b value DWI (b(max) = 6000 sec/mm(2)) using q-space analysis and conventional DTI (b = 1000 sec/mm(2)) were performed on 36 healthy subjects aged 4 months to 23 years. Fractional-anisotropy (FA), apparent-displacement, and apparent-probability values were measured in all slices and in six regions of interest (ROIs) of large fiber tracks. Values were correlated with each other and with age using regression analysis.


RESULTS
FA, displacement, and probability indices from all slices were highly correlated with each other (r > 0.87, P < 0.0001) and with age (r > 0.82, P < 0.0001). All age-related changes in the six pre-determined ROIs were best fitted by mono-exponential functions. Changes in the splenium extended to a later age when compared with the genu of the corpus-callosum, while the centrum semi-ovale demonstrated the latest changes with age.


CONCLUSIONS
High b-value DWI and DTI showed changes in white matter from infancy through adulthood. However, high b-value detects a signal that is likely to originate mainly from the intra-axonal water population, and thus may represent different aspects of development and different sensitivity to pathology.
Ben Bashat
Dafna
D
The Wohl Institute for Advanced Imaging, Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. dafnab@tasmc.health.gov.il
Ben Sira
Liat
L
Graif
Moshe
M
Pianka
Pazit
P
Hendler
Talma
T
Cohen
Yoram
Y
Assaf
Yaniv
Y
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies; D012044:Regression Analysis; D012680:Sensitivity and Specificity