S Gayathri, A Prasad, S Aggarwal, B Baruah
S Gayathri, A Prasad, S Aggarwal, B Baruah. Unique Features Of Polycythemia Observed On Plain Non Contrast Ct Head. The Internet Journal of Radiology. 2009 Volume 11 Number 1.
We present a case of Polycythemia secondary to a congenital cardiac anomaly presenting with acute neurological complications showing hyperdense venous sinuses and cerebral vasculature in association with a cerebral abscess.
Neurological conditions associated with Polycythemia may warrant an emergency non contrast CT scan of the head. The unique findings associated with Polycythemia have not been well characterized in literature. We present a case of Polycythemia associated with hyperdense dural venous sinuses and cerebral vasculature hence simulating the appearance of a contrast enhanced CT on Plain CT films.
A 27 year old male patient presented to our emergency with history of fever and headache for the past 4 days with altered sensorium for 2 days and a brief episode of loss of consciousness two days back. Patient had a history of breathlessness on and off since three years of age. He was diagnosed as a case of heart disease but financial constraints prevented timely treatment. Examination revealed central cyanosis , rt hemiparesis and a pansystolic murmur over the epicardium.
NCCT findings were suggestive of a left temporoparietal cerebral abscess associated with hyperdensity of all cerebral venous sinuses and cerebral vasculature. (patient had not been given any intravenous contrast agents ).
Findings suggestive of Lt temporoparietal Cerebral abscess with Hyper-attenuating Cerebral Vasculature, Lt Transverse sinus, Straight sinus and parts of Superior sagittal and Sigmoid sinus (appearance simulating CECT on an NCCT Head)
Echocardiography suggestive of Complex cyanotic heart disease with transposition of great arteries with a pulmonary stenosis and bidirectional shunt associated with a large VSD and ASD .
Features of polycythemia on NCCT head are not well characterised in literature however it includes Increased attenuation of cerebral vessels and subtle increase in radiographic attenuation of venous sinuses. Increased radiographic attenuation is primarily a reflection of haemoconcentration and attenuation of the haemoglobin protein (with minimal contribution from increased iron content1.
However increases attenuation of venous sinuses is typically seen in cerebral venous sinus thrombosis. Cerebral venous thrombosis is a known complication of polycythemia and hypercoagulable states and hence may coexist. MR Venography , CT venography2 or Catheter venography may be required to differentiate between cerebral venous thrombosis in a patient of polycythemia with hyper dense venous sinuses.
Haematocrit levels help in the diagnosis of a patient with hyperdense venous sinuses on a non contrast ct scan. Haematocrit in this case – 76.3% and Hb level – 25.8 gm%.
Polycythemia may mimic cerebral venous thrombosis AND polycythemia may cause cerebral venous thrombosis.
We hence conclude that hyperdensity of cerebral vessels and venous sinuses may be associated with Polycythemia and cerebral venous thrombosis must be meticulously ruled out in such cases as the two may coexist.