Advisor:

Dr. Stanislav Emelianov (Georgia Institute of Technology, Emory University)

Committee Members:

Dr. Brooks Lindsey (Georgia Institute of Technology, Emory University)

Dr. David Ku (Georgia Institute of Technology)

Dr. Muralidhar Padala (Emory University, Georgia Institute of Technology)

Dr. Levent Degertekin (Georgia Institute of Technology)

Diagnosis and Characterization of Atherosclerotic Plaques with Photoacoustic Imaging

Cardiovascular disease is the primary cause of death worldwide.  Coronary artery disease, a subset of cardiovascular disease, caused an estimated 7.4 million deaths in 2015.  Physicians' inability to accurately locate plaques is a current impediment to diagnosis and treatment.  Photoacoustics is being developed to address this deficiency.  Photoacoustic imaging is a technique in which nanosecond laser pulses are used to locally heat tissue, producing a thermal expansion and resultant ultrasonic wave that can be measured with an ultrasound transducer.  The intensity of the ultrasonic signal is proportional to the tissue’s optical absorption coefficient, which will vary by tissue type and light wavelength.  Thus, the distinct optical spectra of lipid make it an identifiable marker of atherosclerotic plaques.  The work that will be proposed for this dissertation consists of advancing photoacoustic imaging of atherosclerotic plaques with three specific aims.  First, Monte Carlo simulations will be conducted to determine the optimal geometry for imaging using an ultrasound array and external light delivery.  Second, the safety of intravascular photoacoustic imaging, a catheter-based technique, will be assessed to determine if light absorption is likely to cause tissue damage.  Third, nanoscale contrast agents that enhance photoacoustic identification of lipid plaque will be tested.