Brain lesions in preterm infants: initial diagnosis and follow-up.

Children surviving premature birth present with a wide spectrum of motor, sensory and cognitive disabilities, ranging from slight motor deficits, school difficulties and behavioural problems to cerebral palsy and mental retardation. The anatomic and functional substrate of these problems can be investigated using a variety of imaging techniques. Cranial US coupled with colour Doppler is a well-established method for the initial diagnosis of intraventricular haemorrhage, parenchymal haemorrhagic infarct and periventricular leukomalacia. MRI is useful for the follow-up study of brain maturation. Conventional T1- and T2-weighted sequences, magnetization transfer and diffusion tensor imaging coupled with sophisticated tools of tissue segmentation and analysis at a voxel level offer substantial anatomic and functional information on pathological conditions that define the prognosis of preterm infants.