Probabilistic brain tissue segmentation in neonatal magnetic resonance imaging

A fully automated method has been developed for segmentation of four different structures in the neonatal brain: white matter (WM), central gray matter (CEGM), cortical gray matter (COGM), and cerebrospinal fluid (CSF). The segmentation algorithm is based on information from T2-weighted (T2-w) and inversion recovery (IR) scans. The method uses a K nearest neighbor (KNN) classification technique with features derived from spatial information and voxel intensities. Probabilistic segmentations of each tissue type were generated. By applying thresholds on these probability maps, binary segmentations were obtained. These final segmentations were evaluated by comparison with a gold standard. The sensitivity, specificity, and Dice similarity index (ST) were calculated for quantitative validation of the results. High sensitivity and specificity with respect to the gold standard were reached: sensitivity >0.82 and specificity >0.9 for all tissue types. Tissue volumes were calculated from the binary and probabilistic segmentations. The probabilistic segmentation volumes of all tissue types accurately estimated the gold standard volumes. The KNN approach offers valuable ways for neonatal brain segmentation. The probabilistic outcomes provide a useful tool for accurate volume measurements. The described method is based on routine diagnostic magnetic resonance imaging (MRI) and is suitable for large population studies

Brain development of the preterm neonate after neonatal hydrocortisone treatment for chronic lung disease

Previous studies reported impaired cerebral cortical gray matter (CGM) development and neurodevelopmental impairment after neonatal dexamethasone treatment for chronic lung disease (CLD) in preterm newborns. No long-term effects on neurocognitive outcome have yet been shown for hydrocortisone treatment. A prospective study was performed to evaluate the brain growth at term in preterm infants who did receive neonatal hydrocortisone for CLD. Thirty-eight preterm infants (n = 19 hydrocortisone, n = 19 controls) were matched for gestational age at birth. Gestational age and birth weight were 27.0+/- 1.4 versus 27.6+/- 1.1 wk (p = ns) and 826+/- 173 versus 1017+/- 202 g, respectively (p < 0.05). Infants were studied at term equivalent age. Hydrocortisone was started with a dose of 5 mg/kg/d for 1 wk, followed by a tapering course over 3 wk. A 3D-MRI technique was used to quantify cerebral tissue volumes: CGM, basal ganglia/thalami, unmyelinated white matter, myelinated white matter, cerebellum, and cerebrospinal fluid. Infants who were treated with hydrocortisone had more severe respiratory distress. There were no differences in cerebral tissue volumes between the two groups at term equivalent age. In conclusion, no effect on brain growth, measured at term equivalent age, was shown after treatment with hydrocortisone for CLD