I was thinking it would be great to amass a collection of images that demonstrate some of the more obscure (or not so obscure) radiographic signs, especially since many of them I can't seem to find in textbooks or even on the internet. For example:
The Viking Helmet Sign (Pulmonary venous HTN)
Perhaps people can provide images and/or suggest other signs in which they need images.
Here is a good example of the "pseudo-Madelung deformity" of the wrist in a patient with Multiple Hereditary Exostoses (MHE). Courtesy of AFIP & Radiographics.