RT Journal Article
SR Electronic
T1 High-b-value Diffusion-weighted MR Imaging of Adult Brain: Image Contrast and Apparent Diffusion Coefficient Map Features
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1830
OP 1836
VO 21
IS 10
A1 DeLano, Mark C.
A1 Cooper, Thomas G.
A1 Siebert, James E.
A1 Potchen, Michael J.
A1 Kuppusamy, Karthik
YR 2000
UL http://www.ajnr.org/content/21/10/1830.abstract
AB BACKGROUND AND PURPOSE: Recent improvements in MR gradient technology allow significant increases in diffusion weighting without prohibitive signal-to-noise degradation. The purpose of our investigation was to establish normative references for the signal intensity characteristics and apparent diffusion coefficient values of the adult brain at high b values.METHODS: Fifty adults underwent diffusion-weighted single-shot spin-echo echo-planar MR imaging. Isotropic diffusion-weighted images were obtained with b values of 0, 1000, 2000, 2500, 3000, and 3500 s/mm2. Qualitative assessments were made in multiple regions of interest in gray and white matter. Three apparent diffusion coefficient maps were generated for each of six patients with a 2-point technique at a b value of 0 and at b values of 1000, 2000, and 3000 s/mm2.RESULTS: Increasing b values result in a progressive decrease in the gray to white matter signal intensity ratio. Isointensity between gray and white matter results at b values between 1000 and 2000 s/mm2. At b values greater than 2000, the gray-white pattern reverses relative to the usual b value of 1000. Apparent diffusion coefficient values were shown to decrease with increasing b values.CONCLUSION: Attention to the reversal of gray-white contrast and the dependence of apparent diffusion coefficient on the b value are important in avoiding erroneous assignment of pathologic abnormalities to normal regions. This study provides the normative data for future diffusion investigations performed at high b values.