Extracerebral anatomic blind spots in computed tomography (CT) head: a pictorial review of non-traumatic findings.

CT head has been increasingly performed in the Emergency Department for patients presented with trauma, acute neurological or psychological symptoms. Most of the emergency physicians and radiologists have undergone dedicated training and are capable of identifying and interpreting life-threatening cerebral pathologies. However, as most attention is directed to the brain, the extracerebral non-traumatic pathologies on CT head can easily be overlooked, and some of them harbour clinically significant pathologies. We categorise the extracerebral anatomic landmarks, illustrate and describe the representative pathologies from each category. The purpose of this article is to increase awareness and familiarity on the non-traumatic extracerebral pathologies, with the aim of achieving comprehensive interpretation of CT head.