This article is a US Government work and, as such, is in the public domain in the United States of America.
Anisotropy in high angular resolution diffusion-weighted MRI †
Article first published online: 23 MAY 2001
Published 2001 John Wiley & Sons, Inc.
Magnetic Resonance in Medicine
Volume 45, Issue 6, pages 935–939, June 2001
How to Cite
Frank, L. R. (2001), Anisotropy in high angular resolution diffusion-weighted MRI . Magn Reson Med, 45: 935–939. doi: 10.1002/mrm.1125
- Issue published online: 23 MAY 2001
- Article first published online: 23 MAY 2001
- Manuscript Accepted: 5 FEB 2001
- Manuscript Revised: 21 DEC 2000
- Manuscript Received: 5 JUL 2000
- VA. Grant Number: SA-321
- spherical diffusion variance;
- high angular resolution;
- white matter
The diffusion in voxels with multidirectional fibers can be quite complicated and not necessarily well characterized by the standard diffusion tensor model. High angular resolution diffusion-weighted acquisitions have recently been proposed as a method to investigate such voxels, but the reconstruction methods proposed require sophisticated estimation schemes. We present here a simple algorithm for the identification of diffusion anisotropy based upon the variance of the estimated apparent diffusion coefficient (ADC) as a function of measurement direction. The rationale for this method is discussed, and results in normal human subjects acquired with a novel diffusion-weighted stimulated-echo spiral acquisition are presented which distinguish areas of anisotropy that are not apparent in the relative anisotropy maps derived from the standard diffusion tensor model. Magn Reson Med 45:935–939, 2001. Published 2001 Wiley-Liss, Inc.