Brain perfusion abnormalities in patients with compromised venous outflow.

Elevated intracranial intravenous pressure is not routinely measured in clinical practice. Indirect evidence of increased venous pressure is reflected in the size change of the cerebral sinuses and the presence of venous infarctions. The purpose of this study is to evaluate the role of brain perfusion venous time-density curves in the diagnosis of cerebral venous hypertension. A retrospective review of four cases in which increased cerebral intravenous pressure was reflected in abnormal time-density curves on CT brain perfusion studies was completed. The abnormal venous time-density curves correlated with clinically increased intravenous pressure and normalized after treating the underlying pathology. Abnormal venous outflow affects brain perfusion. This could be identified on a CT brain-perfusion study based on characteristic venous time-density curves. These curves may appear quite similar even when the underlying etiologies are different. Normalization of the venous time-density curves may be observed after the underlying pathology was treated.