High b-value diffusion tensor imaging of the neonatal brain at 3T.
OBJECTIVE
Diffusion-weighted MR imaging studies of the adult brain have shown that contrast between lesions and normal tissue is increased at high b-values. We designed a prospective study to test the hypothesis that diffusion tensor imaging (DTI) obtained at high b-values increases image contrast and lesion conspicuity in the neonatal brain.


METHODS
We studied 17 neonates, median (range) age of 10 (2-96) days, who were undergoing MR imaging for clinical indications. DTI was performed on a Philips 3T Intera system with b-values of 350, 700, 1500, and 3000 s/mm(2). Image contrast and lesion conspicuity at each b-value were visually assessed. In addition, regions of interest were positioned in the central white matter at the level of the centrum semiovale, frontal and occipital white matter, splenium of the corpus callosum, posterior limb of the internal capsule, and the thalamus. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values for these regions were calculated.


RESULTS
Isotropic diffusion image contrast and lesion-to-normal-tissue contrast increased with increasing b-value. ADC values decreased with increasing b-value in all regions studied; however, there was no change in FA with increasing b-value.


CONCLUSIONS
Diffusion image contrast increased at high b-values may be useful in identifying lesions in the neonatal brain.
Dudink
J
J
Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, London, United Kingdom.
Larkman
D J
DJ
Kapellou
O
O
Boardman
J P
JP
Allsop
J M
JM
Cowan
F M
FM
Hajnal
J V
JV
Edwards
A D
AD
Rutherford
M A
MA
Counsell
S J
SJ
D001921:Brain / Q000033:anatomy & histology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity