[Importance of echocardiography and MRI in periventricular leukomalacia].

Periventricular leukomalacia (PVL) consists of focal coagulation necrosis and of more diffuse and mild white matter involvement as gliosis and lesions of immature oligodendrocytes. PVL affects essentially the premature newborn and has become the dominant form of perinatal neurological insults. Its diagnosis remains difficult to assess as neurological examination is poorly contributive. Diagnostic imaging plays an important role as it completes clinical, biological and electrophysiological data in depicting the cerebral lesions. Cerebral ultrasound remains the first imaging modality to perform in order to investigate and follow ill neonates. However ultrasound has a low sensitivity and specificity in depicting non cavitated PVL. Magnetic resonance imaging (MRI), in the acute stage, provides additional information about the extension and the depiction of hemorrhagic component of the lesions. Furthermore, diffusion-weighted MRI appears useful for the early identification of the diffuse component of PVL. MRI in the chronic stage is the only imaging method to study the progress of myelination and precise the extension of sequellar lesions.