OBJECTIVETo compare the differences between full-term and VLBW premature infants at term equivalent for the whole and sub-regional corpus callosum areas in order to provide reference for monitoring the extrauterine development of corpus callosum in VLBW premature infants.

METHODSBrain MR image data of 24 term infants with a gestational age of 39 weeks were collected within 24 hours after birth. Brain MR image of 30 VLBW neonates at 39 weeks' gestational age equivalent were successfully obtained. Routine T1WI, T2WI and DWI were applied. T1-weighted images on the mid-sagittal slice were selected, analyzed and measured. Forty-nine eligible MR images of them were chosen, 21 cases from the full-term infant group and 28 cases from the premature infant group. Corpus callosum and brain MR images were then sketched by two radiographic doctors. All data were analyzed by the Image Processing Function of MATLAB R2010a, and the whole corpus callosum and six sub-regions were obtained.

RESULTSThe whole corpus callosum, anterior mid-body, posterior mid-body, isthmus and splenium area in the premature infant group were smaller than those in the full-term infant group (P<0.05), but the differences of Genu and rostral body area between the two groups was not statistically significant (P>0.05).

CONCLUSIONSThe areas of the whole corpus callosum, anterior mid-body, posterior mid-body, isthmus and splenium in VLBW preterm infants at term are reduced, suggesting that the posterior end of the corpus callosum is probably most vulnerable to insults following pathogenic factors.

Corpus Callosum ; anatomy & histology ; Humans ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Magnetic Resonance Imaging

OBJECTIVE: Many diffusion tensor imaging (DTI) studies of the corpus callosum (CC) have been performed with a relatively thick slice thickness in the axial plane, which may result in underestimating the fractional anisotropy (FA) of the CC due to a partial volume effect. We hypothesized that the FA of the CC can be more accurately measured by using mid-sagittal DTI. We compared the FA values of the CC between the axial and mid-sagittal DTI. MATERIALS AND METHODS: Fourteen healthy volunteers underwent MRI at 3.0 T. DTI was performed in both the mid-sagittal and axial planes. One 5-mm mid-sagittal image and twenty-five 2-mm axial images were obtained for the CC. The five regions of interest (ROIs) that included the prefrontal (I), premotor and supplementary motor (II), motor (III), sensory (IV) and parietal, temporal and occipital regions (V) were drawn along the border of the CC on each sagittal FA map. The FA values obtained from each region were compared between the two sagittal maps. RESULTS: The FA values of all the regions, except for region V, were significantly increased on the mid-sagittal imaging. The FA values in region IV were significantly underestimated on the mid-sagittal image from the axial imaging, compared with those in the regions I and V (p = 0.037 and p = 0.001, respectively). CONCLUSION: The FA values of the CC were significantly higher on the mid-sagittal DTI than those on the axial DTI in regions I-IV, and particularly in the region IV. Mid-sagittal DTI may provide more accurate FA values of the CC than can the axial DTI, and mid-sagittal DTI may be more desirable for studies that compare between patients and healthy subjects.
Adult ; Analysis of Variance ; Anisotropy ; Brain Mapping/*methods ; Corpus Callosum/*anatomy & histology ; Diffusion Magnetic Resonance Imaging/*methods ; Female ; Humans ; Image Processing, Computer-Assisted ; Male ; Statistics, Nonparametric