Topics in magnetic resonance imaging : TMRI
-
Spinal cord development occurs through three consecutive periods. Gastrulation (weeks 2-3) is characterized by conversion of the embryonic disk from a bilaminar to a trilaminar arrangement and establishment of a notochord. Primary neurulation (weeks 3-4) produces the uppermost nine tenths of the spinal cord. ⋯ Closed spinal dysraphisms with mass comprise lipomyeloschisis, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise complex dysraphic states (ranging from complete dorsal enteric fistula to neurenteric cysts, split cord malformations, dermal sinuses, caudal regression, and spinal segmental dysgenesis), bony spina bifida, tight filum terminale, filar and intradural lipomas, and persistent terminal ventricle. Magnetic resonance imaging is the imaging method of choice for investigation of this complex group of disorders.
-
Proton magnetic resonance (MR) spectroscopy is a complementary method to MR imaging for understanding disease processes in the pediatric brain. By demonstrating the presence of various metabolites in the sampled tissue, MR spectroscopy helps in the understanding of abnormalities detected by MR imaging or clinical examination. This capability is especially pertinent in the pediatric brain, where the manifestation of pathology is superimposed upon a background of normal or abnormal brain development. In this article, we review the major metabolites demonstrated by MR spectroscopy and present examples of MR spectra obtained in various pathological processes encountered in children.