[The basic concepts of the use of magnetic resonance in neuropediatrics]

Before the development of X-ray computed tomography (CT) and magnetic resonance imaging (MRI), it was not possible to analyze normal brain maturation in vivo. Only autopsy studies were really able to show changes in the maturing brain, nevertheless these studies did not represent an homogeneous and correct appearance of the sample population by the various causes of infant death. MR shows gross morphologic changes in the maturing brain, and the high contrast resolution of MR scans permits highly sensitive assessment of white matter changes. Changes of white matter maturation are seen best on T1 weighted images (TR = 600 msec., TE = 15 msec., SL = 4, AL = 2, FOV = 200 mm, 1 acquisition), specially on sagittal scans, during the first 6 months of life and the second echo of T2 images (TR = 2500 msec., TE = 40-50 msec., FOV = 200 mm, 1 acquisition), between the ages of 6 and 18 months. The most important factor in obtaining high quality MR images in children is adequate sedation. In this report the authors explain MR imaging of white matter changes in a period from birth to 18 months of age of normal postnatal brain development.