[Imaging diagnosis of periventricular leukomalacia].

The neurodevelopmental prognosis of periventricular leukomalacia (PVL) has been predicted effectively by ultrasonography (US). US is the best imaging modality to identify both the early changes of PVL (echogenic phase) and the late changes (cystic phase). In cases with intraventricular hemorrhage, however, it was difficult to differentiate from periventricular hemorrhage in the echogenic phase by US. The PVL resolved to a discrete cyst separate from the ventricle, but periventricular hemorrhage developed a porencephalic cyst. Computed tomography is useful for distinguishing periventricular hemorrhage from PVL in the early changes. However, it is not particularly useful in the late changes, as only extensive cystic lesions can be seen. Magnetic resonance imaging is useful for following the progress in myelination.