I've solved this problem with Marko's help, and at his request am copying to the forum.
Problem - I was trying to segment an M0 image created from a Phillips ParRec file with writeanalyze.m written by Colin Humphries, Feb, 2000, University of California, Irvine.
The M0 image looks OK when viewed with MRIcro, but if displayed within SPM, while it looks OK, the voxel intensities are ~ 10 ^-43.
In fact the scaling factor is not set within writeanalyze.m and SPM8 within Windows XP defaults to
2 ^ -149. This is probably specific to the Windows environment, or even to the PC spec.
A temporary solution is to multiply the image by 2^149 with imcalc. If I do this, the segmentation works OK.
I am sure there is a better solution somewhere.
Helen Beaumont
ISBE
University of Manchester
Stopford Building, Oxford Rd
Manchester M13 9PT
Tel: 0161 275 1259
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