Photoacoustic-based sO2 estimation through excised bovine prostate tissue with interstitial light delivery

• Main Authors: Trevor Mitcham, Houra Taghavi, James Long, Cayla Wood, David Fuentes, Wolfgang Stefan, John Ward, Richard Bouchard
• Format: Article
• Language: English
• Published: Elsevier 2017-09-01
• Series: Photoacoustics
• Subjects: Photoacoustic Imaging; Interstitial Irradiation; sO2 Estimation; Local Fluence Correction; Prostate
• Online Access: http://www.sciencedirect.com/science/article/pii/S2213597917300022
• ISSN: 2213-5979

Photoacoustic (PA) imaging is capable of probing blood oxygen saturation (sO2), which has been shown to correlate with tissue hypoxia, a promising cancer biomarker. However, wavelength-dependent local fluence changes can compromise sO2 estimation accuracy in tissue. This work investigates using PA imaging with interstitial irradiation and local fluence correction to assess precision and accuracy of sO2 estimation of blood samples through ex vivo bovine prostate tissue ranging from 14% to 100% sO2. Study results for bovine blood samples at distances up to 20 mm from the irradiation source show that local fluence correction improved average sO2 estimation error from 16.8% to 3.2% and maintained an average precision of 2.3% when compared to matched CO-oximeter sO2 measurements. This work demonstrates the potential for future clinical translation of using fluence-corrected and interstitially driven PA imaging to accurately and precisely assess sO2 at depth in tissue with high resolution.