CT of the skin and subcutaneous tissues

A broad spectrum of skin and subcutaneous (SQ) findings may be discovered in the emergency setting on CT examinations. There are some findings that are directly relevant to the reason or reasons why the patient has undergone the CT examination. However, other findings may be incidental. The skin and SQ tissues are by definition on the periphery of CT images and may be overlooked by the radiologist, although findings related to them can be of clinical importance. The purpose of this pictorial essay is to present a broad spectrum of skin and subcutaneous findings which may be identified on CT examinations in the emergency setting (and in some cases nonemergently), and to briefly review the relevant imaging literature, which surprisingly is relatively limited on this topic. Categories of cutaneous and subcutaneous abnormalities that will be covered include trauma and hemorrhage, iatrogenic findings, infection, neoplasms, calcification, and other miscellaneous entities, all of which may initially present on emergency CT examinations of the body.