Print

Print
Hi Michael
 
I have already reversed the sign of the y component of the bvec, but results didn't change a lot, which really confused me now.
Because our DTI data were acquired from Phillips MR scanner, they were in Par-rec format. I used MRIcron to convert Par-rec file to nifit format.
 
Regards,
 
Zhuang 
 
Date: Wed, 20 Jan 2010 00:37:08 +0100
From: [log in to unmask]
Subject: Re: [FSL] Tractography error
To: [log in to unmask]

Hi Zhuang, I've encountered a similar error a while ago.
I suspect that the y-coordinates of your bvec file need to be flipped.
Have a look at the FA with V1 overlaid as red lines (not color) and zoom in on the splenium or forceps minor.
If I'm correct the V1-vectors don't follow the paths that you'd expect but instead are flipped along the y axis.
What program did you use for dicom conversion?

best, michael

On 20.01.2010, at 00:13, ZhuangJohnny wrote:



Dear FSL experts
 
Recently, i have been trying to run the tractography to reconstructure the fibres from the corpus callosum. However, the results from fibre tracking seemed weired to me. For example, the fibre generating from the genu of the corpus callosum did not connect to the frontal lobe, but instead went to the opposite direction and passed via the ventricle. Similary, the tracjectory of the fibre from the splenium of the CC was also the other way around (pls see the attached image). I'm just wondering if it is the problem of the gradient table? 
 
Thanks in advance for any suggestion and advice.
 
Johnny 

搜索本应是彩色的,快来体验新一代搜索引擎-必应,精美图片每天换哦! 立即试用！ <genu.jpg>


使用新一代 Windows Live Messenger 轻松交流和共享！ 立刻下载！