Hyperdense middle cerebral arteries identified on CT as a false sign of vascular occlusion.

PURPOSE To evaluate the middle cerebral artery (MCA) on CT, including its relationship to cerebral infarction. METHODS Thirteen patients with either a unilateral or bilateral hyperdense M1 segment of the MCA were evaluated. History of hypertension, diabetes, and hematocrit were obtained and compared with a control group of patients without a hyperdense MCA. RESULTS None of the patients had a unilateral hyperdense MCA ipsilateral to a clinically identifiable stroke. Patients with a hyperdense MCA had a statistically higher hematocrit and also a higher prevalence of hypertension and diabetes mellitus than patients without a hyperdense MCA. The higher hematocrit may have increased the density of the blood, while both diabetes and hypertension are associated with calcification within blood vessel walls. CONCLUSION A hyperdense MCA is not a reliable indicator of occlusion of this vessel or subsequent infarction.