Functional Nmr Imaging Of The Human Brain

This is the authors' abstract. We don't add key points for this paper.

ce Abstracl Knowledge of regional hemodynamics has widespread application for both physiological research and clinical assessment because of the well-established interrelationship between physiological function, energy metabolism, and localized blood supply. External monitoring of the transit of either intravascular or diffusible tracers through the brain has been used for years to measure cerebral hemodynamics. Following bolus administration, the concentration of agent in an area of tissue at a given time is the convolution integral of the input function and the clearance function. Tracer kinetic analysis of these concentration-time data can yield both flow and volume information. In normal brain, lanthanide chelates are confined to the intravascular space by an intact blood-brain barrier. Because cerebral transit times are on the order of seconds, a highspeed imaging technique is needed to resolve the passage of an intravascular agent through the capillary bed. The advent of ultrafast NMR imaging has removed spatial-temporal limitations, allowing for real-time contrast enhanced movies of the transit of contrast agent through the brain. We report our results using the Instascan method (l), which provides a complete 2-D image from a single radio frequency excitation. Preliminary data in selected patients (including stroke, tumor, and neurodegenerative disorders) and normal volunteers are presented.