The availability of color flow Doppler combined with effective ultrasound contrast agents in transcranial sonography serves as a low cost, bedside method for evaluation and management of patients with cerebrovascular disease in spite of the image degrading properties of the skull.

Activated DEFINITY® (Perflutren Lipid Microsphere) Injectable Suspension is indicated for use in patients with suboptimal echocardiograms to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border.Bolus: The recommended dose for activated DEFINITY® is 10 microliters (μL)/kg of the activated product by intravenous bolus injection within 30-60 seconds, followed by a 10 mL saline flush. If necessary, a second 10 microliters (μL)/kg dose followed by a second 10 mL saline flush may be administered 30 minutes after the first injection to prolong contrast enhancement. Infusion: The recommended dose for activated DEFINITY® is via an IV infusion of 1.3 mL added to 50 mL of preservative-free saline. The rate of infusion should be initiated at 4.0 mL/minute, but titrated as necessary to achieve optimal image enhancement, not to exceed 10 mL/minute.

This study will look to improve adaptive signal processing techniques for phase aberration correction of the skull while incorporating ultrasound contrast agent to increase signal to noise ratio in an ultrasound B-scan system with high speed RF data acquisition and 2-D arrays.In addition,we hope to develop adaptive transcranial real time 3D ultrasound and real time 3D color flow Doppler scanning of the brain incorporating ultrasound contrast agent to increase signal to noise ratio. A clinical evaluation of adaptive transcranial ultrasound imaging of the brain with phase aberration correction and ultrasound contrast agent will be conducted.