Are you looking for an open source DICOM viewer program for Mac OS X? Then your search is over!

Here a quote from the homepage:

"Osirix is ... a DICOM PACS workstation for medical imaging and an image processing software for medical research (radiology and nuclear imaging), functional imaging, 3D imaging, confocal microscopy and molecular imaging.

Here is the homepage and the newsgroup:

http://homepage.mac.com/rossetantoine/osirix/
http://groups.yahoo.com/group/osirix/