AJDRAJNR - American Journal of Neuroradiology

This Article
Right arrow Abstract Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ni, H.
Right arrow Articles by Zhong, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ni, H.
Right arrow Articles by Zhong, J.

Effects of Number of Diffusion Gradient Directions on Derived Diffusion Tensor Imaging Indices in Human Brain

H. Nia, V. Kavcicb, T. Zhuc, S. Ekholma and J. Zhonga,c

a Department of Radiology, University of Rochester Medical Center, Rochester, NY
b Department of Neurology, University of Rochester Medical Center, Rochester, NY
c Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY


Figure 1
View larger version (58K):

[in a new window]
  		Fig 1. A, An example of coregistration across 3 protocols. Images on the left, middle, and right are obtained with the 6-NDGD, 21-NDGD, and 31-NDGD protocols, respectively. A region of interest (ROI) of the splenium of CC is initially drawn on only 1 image from 1 of the 3 protocols and then translated to the corresponding images from the other 2 protocols.

B, Spatial definition of ROIs: all ROIs are positioned relative to CC in the anterior (A, CCA), middle [B, CCM, cingulum (D), SLF (E), and IC (F)], and posterior [C, CCP, cingulum (D), and SLF (E)] locations.


Figure 2
View larger version (40K):

[in a new window]
  		Fig 2. Mean value in 6 ROIs for the 3 protocols; A for FA, B for <D>, C for {lambda}1, D for {lambda}2, and E for {lambda}3. <D>, {lambda}1, {lambda}2, and {lambda}3 are measured in 10–3 mm2/s. White bars for 6-NDGD, gray bars for 21-NDGD, and black bars for 31-NDGD protocols. *, P < .05. Error bars are for 1 SEM.


Figure 3
View larger version (43K):

[in a new window]
  		Fig 3. Correlation coefficient (r) in 6 ROIs between 2 of the 3 protocols. A for FA, B for <D>, C for {lambda}1, D for {lambda}2, and E for {lambda}3. White bars are for r6–21, gray bars for r6–31, and black bars for r21–31. *, P < .05. Error bars are for 1 SEM.


Figure 4
View larger version (10K):

[in a new window]
  		Fig 4. The linear fitting between correlation coefficient of FA versus FA value of different ROIs.





Copyright © 2008 by the American Society of Neuroradiology. Print ISSN: 0195-6108 Online ISSN: 1936-959X