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Journal of Biomedical Optics • Open Access

Transurethral light delivery for prostate photoacoustic imaging
Author(s): Muyinatu A. Lediju Bell; Xiaoyu Guo; Danny Y. Song; Emad M. Boctor

Paper Abstract

Photoacoustic imaging has broad clinical potential to enhance prostate cancer detection and treatment, yet it is challenged by the lack of minimally invasive, deeply penetrating light delivery methods that provide sufficient visualization of targets (e.g., tumors, contrast agents, brachytherapy seeds). We constructed a side-firing fiber prototype for transurethral photoacoustic imaging of prostates with a dual-array (linear and curvilinear) transrectal ultrasound probe. A method to calculate the surface area and, thereby, estimate the laser fluence at this fiber tip was derived, validated, applied to various design parameters, and used as an input to three-dimensional Monte Carlo simulations. Brachytherapy seeds implanted in phantom, <italic<ex vivo</italic<, and <italic<in vivo</italic< canine prostates at radial distances of 5 to 30 mm from the urethra were imaged with the fiber prototype transmitting 1064 nm wavelength light with 2 to 8 mJ pulse energy. Prebeamformed images were displayed in real time at a rate of 3 to 5 frames per second to guide fiber placement and beamformed offline. A conventional delay-and-sum beamformer provided decreasing seed contrast (23 to 9 dB) with increasing urethra-to-target distance, while the short-lag spatial coherence beamformer provided improved and relatively constant seed contrast (28 to 32 dB) regardless of distance, thus improving multitarget visualization in single and combined curvilinear images acquired with the fiber rotating and the probe fixed. The proposed light delivery and beamforming methods promise to improve key prostate cancer detection and treatment strategies.

Paper Details

Date Published: 2 March 2015
PDF: 11 pages
J. Biomed. Opt. 20(3) 036002 doi: 10.1117/1.JBO.20.3.036002
Published in: Journal of Biomedical Optics Volume 20, Issue 3
Show Author Affiliations
Muyinatu A. Lediju Bell, Johns Hopkins Univ. (United States)
Johns Hopkins Univ. School of Medicine (United States)
Xiaoyu Guo, Johns Hopkins Univ. (United States)
Danny Y. Song, Johns Hopkins Univ. School of Medicine (United States)
Emad M. Boctor, Johns Hopkins Univ. (United States)
Johns Hopkins Univ. School of Medicine (United States)

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