Luxia Liang MD, PhD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To compare signal intensity findings indicating myelination and fractional anisotropy (FA) values on diffusion tensor images in infants. Methods and Materials: 50 consecutive healthy subjects (33 boys, 18 girls) under one year old underwent T1-weighted (T1WI) and T2-weighted (T2WI) imaging and diffusion tensor images with gradient encoding in 6 directions on a 1.5 T MR scanner. FA values were obtained by Functool software. Two neuroradiologists scored the signal intensity with consensus of the following 7 structures on T1- and T2WI using the signal intensity of cortex as a standard: genu of corpus callosum, splenium of corpus callosum, posterior limb of internal capsule (PLIC), anterior limb of internal capsule (ALIC), coronal radiata (CR), cerebral peduncle (CP) and middle cerebellar peduncle (MCP). The scoring criteria were as follows: for T1WI: 0 (isointense to cortex), 1 (mildly increased), 2 (moderately increased), 3 (markedly increased); for T2WI: 0 (isointensity), 1 (mildly decreased), 2 (moderately decreased), 3 (markedly decreased). FA values were measured in correlated structures using a region of interest of 44+4 cm2 (Student t-test , p<0.05). Results: On T1WI, the signal intensity of all 7 white matter structures increased with advancing age. Associated FA values increased as the score rose. Mean FA values and corresponding scores (in parenthesis) were showed as follows: for genu and splenium, 0.48 (0), 0.57(1), 0.64(2) and 0.70 (3, splenium only); for CR and ALIC, 0.29(0, ALIC only), 0.36(1) and 0.41(2); for PLIC and MCP, 0.50(1), 0.60(2); and for CP, 0.37(0), 0.46(1) and 0.52(2). Significant differences were seen in mean FA values between contiguous scores except for score 2 and 3 in the splenium, and score 1 and 2 in the ALIC. On T2WI, the signal intensity of all 7 structures decreased with advancing age. Associated FA values increased as the score rose. Mean FA values and corresponding scores were as follows: for genu and splenium, 0.49 (0), 0.56(1, genu only), 0.64 (2) and 0.70 (3, splenium only); for CR and ALIC, 0.33 (0) and 0.42 (1); for PLIC and MCP, 0.43 (1), 0.56(2) and 0.62(3); and for CP, 0.38(0) and 0.49(1). Significant differences were seen in mean FA values between contiguous scores except for score 2 and 3 in the splenium and in middle cerebellar peduncle. Conclusion: Signal intensity on T1WI and T2WI during the first year of life correlated well with FA values and significant differences between mean FA values for each score and various scores were generally seen.       Questions about this event email: liang006@mc.duke.edu

Liang MD, PhD, L, Correlation between Conventional MR Images and Diffusion Tensor Images in the First Year of Life.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3108173.html