you can use the binary mri_cnr to compute the CNR across a surface boundary (usually gray/white). What directory did you find the cnr.mgh file?
cheers, Bruce
On Thu, 8 Jan 2009, Jürgen Hänggi wrote:
Dear FS experts
I am not sure whether the file cnr.mgh represents the contrast-to-noise ration (CNR) on one hand and how to interpret it. When I loaded the cnr.mgh in tkmedit, there is actually no image visible and only one value is shown e.g., 0.355 or -0.965.
What do these values mean? In my opinion, these values are to small for a classical CNR, isn't it?
Can I use the cnr.mgh file to control the CNR (and also the SNR) of the FS surfaces derived from images acquired on two different scanners?
Is there another way in FS to check whether the SNR and CNR is comparable between surfaces derived from images acquired on different scanners?
Thanks in advance Kindly regards Jürgen
Juergen Haenggi Ph.D. (Dr. des.) Division Neuropsychology Institute of Psychology University of Zurich Binzmuehlestrasse 14, PO Box 25 8050 Zurich, Switzerland 0041 44 635 73 97 (phone office) 0041 76 445 86 84 (phone mobile) 0041 44 635 74 09 (fax office) BIN 4.D.04 (office room number) j.haenggi[at]psychologie.uzh.ch (email) http://www.psychologie.uzh.ch/neuropsy/ (website) http://www.juergenhaenggi.ch (private website)
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