Biophotoacoustic Radar: Study of Tissue Phantoms, Tissues, Contrast Agent and Comparison to Ultrasound Imaging for Deep Subsurface Imaging

• Main Author: Alwi, Rudolf
• Other Authors: Mandelis, Andreas
• Language: en_ca
• Published: 2012
• Subjects: photoacoustic; ultrasound; nanoparticles; contrast; SPION; phantom; tissue; 0541
• Online Access: http://hdl.handle.net/1807/33321

This study explored the imaging capability of our frequency-domain photoacoustic (FD-PA) system that utilizes correlation processing alias “photoacoustic radar” and ultrasonic phased array for imaging of soft tissues. The probe imaging capabilities were studied using tissue-mimicking phantoms, tissue samples ex vivo, blood vessels in a human wrist and a rat tumour model in vivo. Our experimental results have shown decent image correlation between our FD-PA and a clinical ultrasound modality. In comparison with ultrasound, we have also demonstrated strong potential of the FD-PA for deep (~15 mm) subsurface imaging with excellent contrast and high signal-to-noise ratio. Additionally, we assessed the potential of silica-coated super paramagnetic iron oxide nanoparticles (SPION) as a novel PA contrast agent. Detection of the nanoparticles up to 24 mm inside an optically tissue-like turbid media and about 5-fold PA signal amplification due to their presence in sheep blood (~1.4 mg/ml) are presented.