Polycythemia, a radiologic mimic in plain CT head: A case report

Polycythemia is a condition with abnormal increase in red blood cell mass and number in circulation. Increased attenuation with diffuse involvement of Circle of Willis and cerebral venous sinuses mimicking a contrast enhanced study is one of the early noncontrast CT findings in polycythemia. It can mimic venous sinus thrombosis which is its complication and thus warrants further imaging studies. Further imaging studies are needed for the dense vessel appearance in NCCT where the CT number is above a threshold value.