How to support .dcm image format file for uploading in an article? I want to upload .dcm image format file into Drupal7 article, but it's not allowed.

Suggestions about how to get this to work?
Unfortunately, it is not possible to allow image extension that cannot commonly displayed by a browser. You would have to use a filefield instead. 

This has been discussed at:

https://drupal.org/node/1081060

https://drupal.org/node/1014816

And for D6 at:

https://drupal.org/node/515152