Photoacoustic Tomography of Foreign Bodies in Soft Biological Tissue

Department of Biomedical Engineering, Optical Imaging Laboratory, Washington University, St Louis, Missouri 63130, USA.
Journal of Biomedical Optics (Impact Factor: 2.86). 04/2011; 16(4):046017. DOI: 10.1117/1.3569613
Source: PubMed


In detecting small foreign bodies in soft biological tissue, ultrasound imaging suffers from poor sensitivity (52.6%) and specificity (47.2%). Hence, alternative imaging methods are needed. Photoacoustic (PA) imaging takes advantage of strong optical absorption contrast and high ultrasonic resolution. A PA imaging system is employed to detect foreign bodies in biological tissues. To achieve deep penetration, we use near-infrared light ranging from 750 to 800 nm and a 5-MHz spherically focused ultrasonic transducer. PA images were obtained from various targets including glass, wood, cloth, plastic, and metal embedded more than 1 cm deep in chicken tissue. The locations and sizes of the targets from the PA images agreed well with those of the actual samples. Spectroscopic PA imaging was also performed on the objects. These results suggest that PA imaging can potentially be a useful intraoperative imaging tool to identify foreign bodies.

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Available from: Manojit Pramanik, Apr 03, 2014
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    • "Optoacoustic tomography (OAT) is an emerging hybrid imaging modality in which a nanosecond (ns) laser pulse irradiates the tissue and an ultrasonic transducer (UST) acquires the optoacoustic (OA) signals generated due to the absorption of light by the tissue chromophores [1] [2] [3] [4] [5] [6] [7]. The OA signal is generated due to the absorption of light by the chromophores present in the tissue (such as blood, melanin, water etc) and subsequent ultrasound emission due to the thermoelastic expansion of the tissue. "
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