Tracking delivery of a drug surrogate in the porcine heart using photoacoustic imaging and spectroscopy

• Main Authors: Furdella, Kenneth J., Witte, Russell S., Vande Geest, Jonathan P.
• Other Authors: Univ Arizona, Dept Med Imaging
• Language: en
• Published: SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS 2017
• Subjects: photoacoustic imaging; coronary heart disease; left anterior descending coronary artery; tracking diffusion; drug-eluting stent; ultrasound imaging; spectroscopy; intravascular ultrasound
• Online Access: http://hdl.handle.net/10150/624370; http://arizona.openrepository.com/arizona/handle/10150/624370

Although the drug-eluting stent (DES) has dramatically reduced the rate of coronary restenosis, it still occurs in up to 20% of patients with a DES. Monitoring drug delivery could be one way to decrease restenosis rates. We demonstrate real-time photoacoustic imaging and spectroscopy (PAIS) using a wavelength-tunable visible laser and clinical ultrasound scanner to track cardiac drug delivery. The photoacoustic signal was initially calibrated using porcine myocardial samples soaked with a known concentration of a drug surrogate (Dil). Next, an in situ coronary artery was perfused with DiI for 20 min and imaged to monitor dye transport in the tissue. Finally, a partially DiI-coated stent was inserted into the porcine brachiocephalic trunk for imaging. The photoacoustic signal was proportional to the DiI concentration between 2.4 and 120 mu g/ml, and the dye was detected over 1.5 mm from the targeted coronary vessel. Photoacoustic imaging was also able to differentiate the DiI-coated portion of the stent from the uncoated region. These results suggest that PAIS can track drug delivery to cardiac tissue and detect drugs loaded onto a stent with sub-mm precision. Future work using PAIS may help improve DES design and reduce the probability of restenosis. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)