We often get asked to assess for osteomyelitis in the feet of diabetic patients. When undirected, this search is often like finding the proverbial needle in the proverbial haystack, however, there are clues that can aid in a more targeted review. 

Firstly, there may be an indication of the site of concern (ulcer or erythema) in the clinical notes written on the requisition form. Secondly, there may be other clues on the image. In this case, there is clearly a soft tissue defect at the posterior aspect of the heel, correlating with a site of ulceration. We can then direct our search to the underlying bone, which sure enough reveals the cortical erosion.

Another important consideration is a comparison with old images, as these patients are usually imaged on multiple occasions.