The Kety-Schmidt Technique for Quantitative Perfusion and Oxygen Metabolism Measurements in the MR Imaging Environment

The Kety-Schmidt technique provides quantitative measurement of whole brain cerebral blood flow (CBF). CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous samples. In this report we present a method for performing these measurements in an MR environment. This technique could be useful for validation of MR methods of hemodynamic and metabolic measurements in humans

Expansion of a Haematoma after Urokinase Thrombolysis of Superior Sagittal Sinus Thrombosis

Thrombosis of the superior sagittal sinus may result in significant morbidity and recently up to 20% mortality. Primary treatment has consisted of anticoagulation and methods for controlling increased intracranial pressure. The development of interventional neuroradiologic techniques has enabled infusion of thrombolytics at the clot. We describe a woman with a cerebral haemorrhage due to a thrombosed superior sagittal sinus. Her decreased level of consciousness and increasing hemiparesis prompted direct thrombolytic therapy (urokinase). Flow was restored in the occluded sinus, but an acute expansion of the haematoma an hour after conclusion of the infusion resulted in temporary worsening of her neurologic deficits. Although the ultimate outcome was satisfactory, the possibility of further intracranial bleeding must be balanced against the risk of death with conservative therapy. </jats:p