Grant: Operating Grant

This grant application is proposing the development of quantitative ultrasound imaging methods to quantify in vivo mechanical properties of blood under flowing and clotting conditions. Plane-wave image processing is proposed to optimize image accuracy and to allow implementing an innovative dynamic elastography method with in situ radiation pressure generation. Proposed plane-wave implementations of quantitative ultrasound imaging methods will constitute a new era in non-invasive imaging of blood. The dynamic reversible structural changes in red blood cell aggregation properties under flowing conditions will be monitored with cellular imaging methods based on the spectral properties of backscattered echoes, whereas dynamic ultrasound elastography methods are proposed to quantify the viscoelasticity of clotted blood. Validated methods will be applied to monitor hyper-aggregation of red blood cells promoted by acute inflammation during cardiopulmonary bypass surgeries in humans, and to follow the structural maturation of deep vein thromboses and the impact of thrombolytic therapies in a rabbit model. The implementation of proposed quantitative ultrasound imaging methods on a plane-wave scanner is highly innovative. Indeed, plane-wave imaging constitutes a new framework in ultrasound; it allows producing images at a high frame rate of a few kHz, thus permitting sufficient processing time for image quality optimization. Plane waves are also used to produce supersonic shear waves in dynamic elastography imaging; in this project plane-wave processing will allow implementing the original shear wave induced resonance elastography method developed by our group.