MAGNETIC-RESONANCE SIGNAL INTENSITY RATIO OF GRAY WHITE-MATTER IN CHILDREN - QUANTITATIVE ASSESSMENT IN DEVELOPING BRAIN

Magnetic resonance imaging (MRI) findings in 87 children with various clinical entities were used to determine the signal intensity ratio of gray/white matter in T1- and T2-weighted images using a 1.5 T MR Scan ner. Signal intensity ratio changes in both T1- and T2-weighted images correlated well with advancing age (y=0.9349-0.001575, r=-0.584, P<0. 0001 in T1-weighted images; y=0.9798+0.002854, r=0.723, P<0.0001 in T2 -weighted images), but the correlation was more linear when we include d only normally developed (34) children (y=0.9689-0.001967, r= -0.654, P<0.0001 in T1-weighted images; y=0.9882+0.002965, r=0.747, P<0.0001 in T2-weighted images). Abnormal ratios were observed in patients with congenital hydrocephalus, inherited metabolic diseases and cerebral p alsy. Although the gray/white matter differentiation would not delinea te the myelination itself, measurement of the signal intensity ratio o f gray/white matter is a practical way to evaluate delayed myelination in a busy MR center.