The increase in cardiovascular disease in the United States has created a need for methods that can screen high-risk patients for life-threatening plaques and assess the effectiveness of new cardiovascular drugs. Abnormal proliferation of the vasa vasorum in diseased vessels may promote the progression of atherosclerosis and increase the propensity of plaque rupture. Consequently, we and others are actively developing methods for visualizing the vasa vasorum. Contrast-enhanced ultrasound (CEU) imaging is frequently used to visualize the vasa vasorum within the carotid artery; however, the lack of sensitive high frequency broadband catheters has prevented researchers from advancing CEU to the smaller coronary artery. To overcome this technological challenge, we plan to use the principle of optomechanical transduction to develop high-performance (sensitive and broadband) tunable ultrasound catheters. Specifically, we will design and fabricate a novel high quality optomechanical resonator from silicon carbide (Aim 1). This optomechanical resonator will form the backbone of a tunable ultrasound transducer that we plan to develop (Aim 2). We will use the optomechanical resonator to detect harmonic signals (subharmonic, fundamental, second harmonic, ultra-harmonic, and super-harmonic) emitted when microbubble ultrasound contrast agents are excited with a 20 MHz piezoelectric transducer. We plan to perform phantom studies to evaluate the performance of the integrated optomechanical/piezoelectric transducer. We will use an embryonic chick model to assess the sensitivity of harmonic images created with the proposed integrated optomechanical/piezoelectric transducer and dual frequency transducers (a competing technology) to changes in vessel size and density. If successful, the proposed technology could revolutionize ultrasonic imaging by providing a novel approach for fabricating reliable broadband transducers desired by several clinical applications. Additionally, the proposed research represents a critical step towards establishing vasa vasorum imaging as a technique for evaluating the efficacy of new cardiovascular drugs.

Public Health Relevance

Without sensitive broadband transducers, clinicians cannot use contrast-enhanced ultrasound imaging to detect vasa vasorum hyperplasia in coronary arteries. Vasa vasorum hyperplasia promotes the progression of atherosclerosis and increases the risk of heart attacks and sudden cardiac deaths in individuals with cardiovascular disease. To address this technological challenge, in this research we plan to develop high performance tunable transducers for cardiovascular imaging.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21EB024998-01
Application #
9383331
Study Section
Biomedical Imaging Technology Study Section (BMIT)
Program Officer
King, Randy Lee
Project Start
2017-09-15
Project End
2019-06-30
Budget Start
2017-09-15
Budget End
2018-06-30
Support Year
1
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Rochester
Department
Engineering (All Types)
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
041294109
City
Rochester
State
NY
Country
United States
Zip Code
14627