Hi Wang,

this is only a warning. Usually it is a bad idea to input two different images into the longitudinal pipeline. It would be good to find out why your inputs have different geometries. You should find the answers to these questions in order to know what you are working with: Has someone changed the protocol on the scanner? What else has changed? Maybe hardware? That would be a problem.

Best, Martin


On 07/03/2014 09:38 AM, wang kangcheng wrote:
Dear experts
   Today, I conduct the longitudinal analysis according to tutorials of freesurfer (https://surfer.nmr.mgh.harvard.edu/fswiki/LongitudinalProcessing). But, when I do  recon-all -base <templateid> -tp <tp1id> -tp <tp2id> ... -all, it report the error:
  ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
mri_diff --notallow-pix /Users/wangkangcheng/Desktop/long_fs_test/long/s12002_MRI2/mri/rawavg.mgz /Users/wangkangcheng/Desktop/long_fs_test/long/s12002_MRI1/mri/rawavg.mgz \n
Volumes differ in dimension
v1dim 176 256 256 1
v2dim 176 184 200 1
\n*******************************************************************************
WARNING: Image geometries differ across time, maybe due to aquisition changes?
         This can potentially bias a longitudinal study! Will continue in 10s.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
When I check the raw data and find that the structural data of s12002_MRI1 was the file which was converted by the command of dcm2nii and begin with "co". However, data of s12002_MRI2 was the file which begin with "o". But, when I used the file which begin with "co", they did not have same dimension. How could I solve the problem?  (PS: have processed hundreds of data for subject of MRI1)

Thank you

Wang Kangcheng




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-- 
Martin Reuter, Ph.D.

Instructor in Neurology
  Harvard Medical School
Assistant in Neuroscience
  Dept. of Radiology, Massachusetts General Hospital
  Dept. of Neurology, Massachusetts General Hospital
Research Affiliate
  Computer Science and Artificial Intelligence Lab,
  Dept. of Electrical Engineering and Computer Science,
  Massachusetts Institute of Technology

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