Adaptation of a Clinical High-Frequency Transrectal Ultrasound System for Prostate Photoacoustic Imaging: Implementation and Pre-clinical Demonstration.

Autor:	Singh N; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Sunnybrook Research Institute, Toronto, ON, Canada. Electronic address: nidhi.singh@mail.utoronto.ca., Chérin E; Sunnybrook Research Institute, Toronto, ON, Canada., Roa CF; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Sunnybrook Research Institute, Toronto, ON, Canada., Soenjaya Y; Sunnybrook Research Institute, Toronto, ON, Canada., Wodlinger B; Exact Imaging Inc., Markham, ON, Canada., Zheng G; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Princess Margret Cancer Center, Toronto, ON, Canada., Wilson BC; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Princess Margret Cancer Center, Toronto, ON, Canada., Foster FS; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Sunnybrook Research Institute, Toronto, ON, Canada., Demore CEM; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Sunnybrook Research Institute, Toronto, ON, Canada.
Jazyk:	angličtina
Zdroj:	Ultrasound in medicine & biology [Ultrasound Med Biol] 2024 Apr; Vol. 50 (4), pp. 457-466. Date of Electronic Publication: 2024 Jan 18.
DOI:	10.1016/j.ultrasmedbio.2023.11.010
Abstrakt:	Objective: High-frequency, high-resolution transrectal micro-ultrasound (micro-US: ≥15 MHz) imaging of the prostate is emerging as a beneficial tool for scoring disease risk and accurately targeting biopsies. Adding photoacoustic (PA) imaging to visualize abnormal vascularization and accumulation of contrast agents in tumors has potential for guiding focal therapies. In this work, we describe a new imaging platform that combines a transrectal micro-US system with transurethral light delivery for PA imaging. Methods: A clinical transrectal micro-US system was adapted to acquire PA images synchronous to a tunable laser pulse. A transurethral side-firing optical fiber was developed for light delivery. A polyvinyl chloride (PVC)-plastisol phantom was developed and characterized to image PA contrast agents in wall-less channels. After resolution measurement in water, PA imaging was demonstrated in phantom channels with dyes and biodegradable nanoparticle contrast agents called porphysomes. In vivo imaging of a tumor model was performed, with porphysomes administered intravenously. Results: Photoacoustic imaging data were acquired at 5 Hz, and image reconstruction was performed offline. PA image resolution at a 14-mm depth was 74 and 261 μm in the axial and lateral directions, respectively. The speed of sound in PVC-plastisol was 1383 m/s, and the attenuation was 4 dB/mm at 20 MHz. PA signal from porphysomes was spectrally unmixed from blood signals in the tumor, and a signal increase was observed 3 h after porphysome injection. Conclusion: A combined transrectal micro-US and PA imaging system was developed and characterized, and in vivo imaging demonstrated. High-resolution PA imaging may provide valuable additional information for diagnostic and therapeutic applications in the prostate. Competing Interests: Conflict of interest The laboratory has received equipment and technical support from Exact Imaging Inc. (Markham, ON, Canada). B.W. is an employee of Exact Imaging. F. Stuart Foster holds minor equity in and receives royalties from Exact Imaging. All other authors declare no competing interests. (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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