Make sure you don't include the first few scans in the analysis. The image contrast generally hasn't reached equilibrium, so intensities in CSF are relatively different from those later on in the runs.

Best regards,

-John

On 19 November 2014 10:19, Andy Yeung <[log in to unmask]> wrote:

Dear all,

I encounter this ventricle activation problem again. This is healthy 23 years old female.
Are there any reasons and solutions? Thanks a lot.

Best,
Andy

On Tue, Feb 18, 2014 at 1:53 AM, H. Nebl <[log in to unmask]> wrote:
Dear Andy,

make sure your subject does not show fast scan-to-scan motion (something like >0.3 or >0.5 mm/TR), which might result in global intensity changes in affected volumes. This might lead to artificial activations in or around the ventricles. Just an idea :-)

Best,

Helmut