Blood Flow Velocimetry Using Digital Subtraction Angiography

PROJECT SUMMARYDiseases in the vascular system are still the leading cause of mortality and morbidity in developed countries despite considerable therapeutic progress in recent yearsBlood flow velocity provides critical information needed for the diagnosis of vascular diseasesplanning of interventional surgery treatmentand monitoring of endovascular treatment of brain arteriovenous malformationsThe present lack of knowledge of flow characteristicsarising from the limited temporal and spatial resolution and limited accuracies of the current metrology modalitiesaverts understanding of the underlying hemodynamics and its correlation with multiple cerebrovascular diseasesTo address issues with the current instrumentationwe are developing an ultrafasthigh resolution X ray blood flow velocimetry system that will provide real time in vivo quantitative blood velocity maps in the endovascular systemThe envisioned system utilizes three transformational technologiesan intenselow costpulsed X ray source with pulse widths down to microseconds and inter pulse durations of tens of microsecondsan ultrafast X ray imager with high spatial resolutionlarge active areaand wide dynamic rangeandan X ray to light converter that overcomes the afterglow and hysteresis limitations of the current high resolution sensorsThe system will enable inexpensive digital subtraction angiographyDSAthat can recover precise velocity distribution inside of the vascular systemsespecially for complex geometriesmaking it a unique technology that can be immediately translated into clinical practiceThe Phase I research has unequivocally demonstrated the feasibility of developing the proposed system for dynamic blood flow measurements through laboratory experimentation and extensive simulation workA detailed design of the Phase II system has been accomplished and system evaluation plans have been developedSpecificallyduring Phase I we have identified six beta test sites where the Phase II system will be evaluated for various medical applicationsthe data from which will form a firm foundation for the Phase III commercializationConsidering the commercial potential of the innovative technologies we have filed a US patent application based on the work done so farThis project is highly relevant to NIHandapos s mission because the precise real time assessment of blood velocities will lead to more educated therapeutic decisions which could save more livesimprove healthand reduce operation costThe expanded knowledge base will enhance the Nationandapos s economic well being and ensure a continued high return on the public investment in research PROJECT NARRATIVEThe goal of the proposed research is to develop a novel blood flow velocimetry system for the precise measurement of blood velocity in vivousing a combination of ultrafasthigh resolutionX ray imaging technique and an inexpensive digital subtraction angiography image processing toolThe system will provide critical information for clinical diagnosistreatment planningand treatment assessment of vascular diseasesThe development of such a velocimetry system is expected to have broad translational importance in the prevention and treatment planning of a wide range of vascular diseasesthereby saving lives and improving healthcare while reducing operation costs