Gray matter volume decrements in preterm children with periventricular leukomalacia.

Periventricular leukomalacia (PVL) is the prototypic lesion in the encephalopathy of prematurity. Although PVL is identified by targeting cerebral white matter (WM), neuropathological and MRI studies document gray matter (GM) loss in cortical and subcortical structures. This study aimed to investigate the distribution of GM changes in children with a history of premature birth and PVL. Voxel-based morphometry was used to examine regional GM abnormalities in 22 children with a history of preterm birth and PVL. Preterms with PVL were compared with 22 terms and 14 preterms without PVL of similar GA and birth weight. GM and WM global volumetric volumes were found to decrease in comparison with both control groups. Regional GM volume abnormalities were also found: compared with their term peers, preterm children with PVL showed several regions of GM reduction. Moreover, PVL differed from preterms without PVL in the medial temporal lobe bilaterally, thalamus bilaterally, and caudate nuclei bilaterally. In addition, in our preterm sample with PVL, birth weight showed a statistical significant correlation with decreased GM regions. In conclusion, the voxel-based morphometry methodology revealed that PVL per se does involve GM reductions.

Congenital tumours involving the head, neck and central nervous system.

Congenital intracranial tumours are uncommon and differ from those occurring in older children in clinical presentation, imaging characteristics and prognosis. These tumours are often detected incidentally on routine prenatal US and/or fetal MRI. Hence, the paediatric radiologist should be familiar with the features of those lesions that should be included in the differential diagnosis. In general, the prognosis of these conditions is poor owing to large tumour size and the limitations of adjuvant therapy at such a young age. Congenital lesions involving the head and neck region require a meticulous imaging approach using both US and MRI techniques to better guide prenatal planning and fetal or neonatal surgical procedures.

Developmental abnormalities of temporal lobe in children.

A review of neuroimaging findings in diverse pathologies involving the temporal lobe in children is undertaken. Illustrative images of the developmental disorders that may cause temporal epilepsy in the pediatric context are provided. Brain malformations associated with hippocampal dysgenesis and related conditions such as epilepsy-associated tumors will be discussed with representative examples. Neurocutaneous syndromes that can involve the temporal lobe producing epilepsy or learning defects will be also discussed. Some other miscellaneous disorders occurring preferentially in the pediatric age such as hippocampal damage secondary to hypoxia or radiotherapy will be briefly exposed at the end of the article.