Automatic segmentation of the intracranial volume in fetal MR images

\u3cp\u3eMR images of the fetus allow non-invasive analysis of the fetal brain. Quantitative analysis of fetal brain development requires automatic brain tissue segmentation that is typically preceded by segmentation of the intracranial volume (ICV). This is challenging because fetal MR images visualize the whole moving fetus and in addition partially visualize the maternal body. This paper presents an automatic method for segmentation of the ICV in fetal MR images. The method employs a multi-scale convolutional neural network in 2D slices to enable learning spatial information from larger context as well as detailed local information. The method is developed and evaluated with 30 fetal T2-weighted MRI scans (average age 33.2\pm 1.2 weeks postmenstrual age). The set contains 10 scans acquired in axial, 10 in coronal and 10 in sagittal imaging planes. A reference standard was defined in all images by manual annotation of the intracranial volume in 10 equidistantly distributed slices. The automatic analysis was performed by training and testing the network using scans acquired in the representative imaging plane as well as combining the training data from all imaging planes. On average, the automatic method achieved Dice coefficients of 0.90 for the axial images, 0.90 for the coronal images and 0.92 for the sagittal images. Combining the training sets resulted in average Dice coefficients of 0.91 for the axial images, 0.95 for the coronal images, and 0.92 for the sagittal images. The results demonstrate that the evaluated method achieved good performance in extracting ICV in fetal MR scans regardless of the imaging plane.\u3c/p\u3

Delayed cortical gray matter development in neonates with severe congenital heart disease

\u3cp\u3eBACKGROUND: This study aimed to assess cortical gray matter growth and maturation in neonates with congenital heart disease (CHD).\u3c/p\u3e\u3cp\u3eMETHODS: 31 (near) term neonates with severe CHD (8 univentricular heart malformation (UVH), 21 d-transposition of great arteries (d-TGA) and 2 aortic coarctation) underwent cerebral MRI before (postnatal-day 7) and after (postnatal-day 24) surgery. 18 controls with similar gestational age had one MRI (postnatal-day 23). Cortical gray matter volume (CGM), inner cortical surface (iCS) and median cortical thickness were extracted as measures of volumetric growth, and gyrification index (GI) as measure of maturation.\u3c/p\u3e\u3cp\u3eRESULTS: Over a median of 18 days CGM increased by 21%, iCS by 17%, thickness and GI both by 9%. Decreased post-operative CGM and iCS were seen for CHD compared to controls (p-values < 0.01), however with similar thickness and GI. UVH showed lower post-operative iCS, thickness (p-values < 0.05) and GI (p-value < 0.01) than d-TGA and controls. Infants requiring pre-operative balloon-atrioseptostomy (BAS, 61%) had reduced post-operative CGM, iCS and GI (p-values< 0.05).\u3c/p\u3e\u3cp\u3eCONCLUSIONS: Infants with severe CHD show reduced cortical volumes compared to controls with gyrification being delayed in UVH, but not in d-TGA. Infants requiring BAS show higher risk of impaired cortical volume and gyrification.\u3c/p\u3

Relation between clinical risk factors, early cortical changes, and neurodevelopmental outcome in preterm infants

\u3cp\u3eCortical folding mainly takes place in the third trimester of pregnancy and may therefore be influenced by preterm birth. The aim of this study was to evaluate the development of specific cortical structures between early age (around 30weeks postmenstrual age) and term-equivalent age (TEA, around 40weeks postmenstrual age) in 71 extremely preterm infants, and to associate this to clinical characteristics and neurodevelopmental outcome at two years of age. First, analysis showed that the central sulcus (CS), lateral fissure (LF) and insula (INS) were present at early MRI in all infants, whereas the other sulci (post-central sulcus [PCS], superior temporal sulcus [STS], superior [SFS] and inferior [IFS] frontal sulcus) were only seen in part of the infants. Relative growth from early to TEA examination was largest in the SFS. A rightward asymmetry of the surface area was seen in development between both examinations except for the LF, which showed a leftward asymmetry at both time points. Second, lower birth weight z-score, multiple pregnancy and prolonged mechanical ventilation showed negative effects on cortical folding of the CS, LF, INS, STS and PCS, mainly on the first examination, suggesting that sulci developing the earliest were the most affected by clinical factors. Finally, in this cohort, a clear association between cortical folding and neurodevelopmental outcome at two years corrected age was found, particularly for receptive language.\u3c/p\u3