Singe-
You cannot treat the image data at each time point-- 2 per patient-- and independent measures.
It is a "repeated measures" issue, and randomization does not account for the dependence of the measures (as some might claim).
The most straight forward approach would be a repeated-measures (or equivalent regression) ANOVA analysis.
If you are correlating image data at time 1, time 2 and some 3rd measure, there are methods to determine if the r(1 w/ measure) and r(2 w/measure) are reliably different.
A very good treatment and general references for this is "Biostatistical Analyses" (5th edition) by J. Zar.
Regards,
William
|-----Original Message-----
|From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf
|Of Signe Jeppesen
|Sent: Friday, April 13, 2012 12:44 AM
|To: [log in to unmask]
|Subject: [FSL] Correlation analysis on repeated measures
|
|Hi FSL
|
|I am trying to do a correlation analysis on my dataset of patients that have
|been scanned twice with 5 years in between.
|
|I would like to do a correlation analysis of the data and my EV´s but still
|account for the repeated measures.
|
|So far I have done a correlation analysis in randomise including a group file
|(.grp ) that links the 2 scans of the patient together.
|Is this the right way to do it?
|
|Or should I not do a repeated measure analysis and just treat every scan as a
|different patient in my correlation analysis?
|
|Thank you
|Signe
|