Internal-Illumination Photoacoustic Tomography Enhanced by a Graded-Scattering Fiber Diffuser
| Autor: | Pei Zhong, Junjie Yao, Kohldon Boydston, Georgy Sankin, Tri Vu, Brenton Winship, Mucong Li, Russell Terry |
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| Rok vydání: | 2021 |
| Předmět: |
Optical fiber
Materials science Swine Physics::Medical Physics FOS: Physical sciences Physics::Optics 01 natural sciences Article Light scattering 030218 nuclear medicine & medical imaging law.invention 010309 optics 03 medical and health sciences 0302 clinical medicine Optics law 0103 physical sciences Animals Fiber Electrical and Electronic Engineering Diffuser (optics) Lighting Radiological and Ultrasound Technology Phantoms Imaging Scattering business.industry Attenuation Physics - Medical Physics Computer Science Applications Photochemotherapy Light emission Medical Physics (physics.med-ph) Tomography X-Ray Computed business Monte Carlo Method Refractive index Software Optics (physics.optics) Physics - Optics |
| Zdroj: | IEEE Trans Med Imaging |
| ISSN: | 1558-254X 0278-0062 |
| DOI: | 10.1109/tmi.2020.3027199 |
| Popis: | The penetration depth of photoacoustic imaging in biological tissues has been fundamentally limited by the strong optical attenuation when light is delivered externally through the tissue surface. To address this issue, we previously reported internal-illumination photoacoustic imaging using a customized radial-emission optical fiber diffuser, which, however, has complex fabrication, high cost, and non-uniform light emission. To overcome these shortcomings, we have developed a new type of low-cost fiber diffusers based on a graded-scattering method in which the optical scattering of the fiber diffuser is gradually increased as the light travels. The graded scattering can compensate for the optical attenuation and provide relatively uniform light emission along the diffuser. We performed Monte Carlo numerical simulations to optimize several key design parameters, including the number of scattering segments, scattering anisotropy factor, divergence angle of the optical fiber, and reflective index of the surrounding medium. These optimized parameters collectively result in uniform light emission along the fiber diffuser and can be flexibly adjusted to accommodate different applications. We fabricated and characterized the prototype fiber diffuser made of agarose gel and intralipid. Equipped with the new fiber diffuser, we performed thorough proof-of-concept studies on ex vivo tissue phantoms and an in vivo swine model to demonstrate the deep-imaging capability (~10 cm achieved ex vivo) of photoacoustic tomography. We believe that the internal light delivery via the optimized fiber diffuser is an effective strategy to image deep targets (e.g., kidney) in large animals or humans. |
| Databáze: | OpenAIRE |
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