7-month-old girl with hypotonia. Pregnancy complicated by twin-twin transfusion. Born prematurely at 28 gestation. History of periventricular leukomalacia. Also history of pulmonic stenosis. There is no acute brain infarct or intracranial hemorrhage. There is moderate-to-severe enlargement of the lateral ventricles, especially posteriorly, associated with severe white-matter volume loss. The deep gray nuclei are small. The corpus callosum is diffusely, severely thinned. The third ventricle is widened again likely due to ex vacuo effect, but the fourth ventricle is normal in size. The brainstem and cerebellum are unremarkable. Despite the significantly diminished volume of the cerebral white-matter, there is a suggestion of delayed myelination even accounting for the adjusted gestational age. There is no definite myelination on T1 imaging in the perirolandic areas.There is fluid intensity in the mastoid air cells and middle ear cavities. There is also fluid intensity in the maxillary and ethmoid sinuses but this is nonspecific at this age.
Severe cerebral white-matter volume loss, especially posteriorly, most compatible with severe white matter injury of prematurity. Delayed myelination for adjusted gestational age is also suspected.