Photons Plus Ultrasound: Imaging and Sensing

Imaging and sensing based on fusing the compelling features of optical and ultrasonic waves is the fastest growing area of research in biomedical optics. The annual SPIE conference on this topic, co-chaired by both of us, has been doubling in size approximately every three years since 2003 (Fig. 1). As of 2009, this conference has become the largest at SPIE Photonics West. Hybrid modalities such as photoacoustic or optoacoustic tomography can provide deep tissue penetration, high ultrasonic resolution, and speckle-free optical contrast. Applications include in vivo functional and molecular imaging of cancer, neurophysiology, and vascular disease in both animals and humans. Major challenges include development of quantitative imaging, improvement of contrast and resolution, and commercialization of the technology. We look forward to seeing significant preclinical and clinical impact from this emerging technology

Special Section Guest Editorial: Celebrating the Exponential Growth of Optoacoustic/Photoacoustic Imaging

Guest editors introduce contributors to the Special Section Celebrating the Exponential Growth of Optoacoustic/Photoacoustic Imaging. We are pleased to introduce the contributions to this JBO Special Section entitled “Celebrating the Exponential Growth of Biomedical Optoacoustic/Photoacoustic Imaging.” This title was chosen to reflect the strong growth of the field over the last two and a half decades. The diversity of papers in this special section bears witness to this, with contributions that encompass numerical modelling, advanced instrumentation, functional imaging, clinical translation, and novel biomedical applications

Photons Plus Ultrasound: Imaging and Sensing

Imaging and sensing based on fusing the compelling features of optical and ultrasonic waves is the fastest growing area of research in biomedical optics. The annual SPIE conference on this topic, co-chaired by both of us, has been doubling in size approximately every three years since 2003 (Fig. 1). As of 2009, this conference has become the largest at SPIE Photonics West. Hybrid modalities such as photoacoustic or optoacoustic tomography can provide deep tissue penetration, high ultrasonic resolution, and speckle-free optical contrast. Applications include in vivo functional and molecular imaging of cancer, neurophysiology, and vascular disease in both animals and humans. Major challenges include development of quantitative imaging, improvement of contrast and resolution, and commercialization of the technology. We look forward to seeing significant preclinical and clinical impact from this emerging technology

Investigation of iterative image reconstruction in three-dimensional optoacoustic tomography

Iterative image reconstruction algorithms for optoacoustic tomography (OAT), also known as photoacoustic tomography, have the ability to improve image quality over analytic algorithms due to their ability to incorporate accurate models of the imaging physics, instrument response, and measurement noise. However, to date, there have been few reported attempts to employ advanced iterative image reconstruction algorithms for improving image quality in three-dimensional (3D) OAT. In this work, we implement and investigate two iterative image reconstruction methods for use with a 3D OAT small animal imager: namely, a penalized least-squares (PLS) method employing a quadratic smoothness penalty and a PLS method employing a total variation norm penalty. The reconstruction algorithms employ accurate models of the ultrasonic transducer impulse responses. Experimental data sets are employed to compare the performances of the iterative reconstruction algorithms to that of a 3D filtered backprojection (FBP) algorithm. By use of quantitative measures of image quality, we demonstrate that the iterative reconstruction algorithms can mitigate image artifacts and preserve spatial resolution more effectively than FBP algorithms. These features suggest that the use of advanced image reconstruction algorithms can improve the effectiveness of 3D OAT while reducing the amount of data required for biomedical applications

Special Section Guest Editorial: Celebrating the Exponential Growth of Optoacoustic/Photoacoustic Imaging

Guest editors introduce contributors to the Special Section Celebrating the Exponential Growth of Optoacoustic/Photoacoustic Imaging. We are pleased to introduce the contributions to this JBO Special Section entitled “Celebrating the Exponential Growth of Biomedical Optoacoustic/Photoacoustic Imaging.” This title was chosen to reflect the strong growth of the field over the last two and a half decades. The diversity of papers in this special section bears witness to this, with contributions that encompass numerical modelling, advanced instrumentation, functional imaging, clinical translation, and novel biomedical applications

Laser-induced thermoelastic effects can evoke tactile sensations

Humans process a plethora of sensory information that is provided by various entities in the surrounding environment. Among the five major senses, technology for touch, haptics, is relatively young and has relatively limited applications largely due to its need for physical contact. In this article, we suggest a new way for non-contact haptic stimulation that uses laser, which has potential advantages such as mid-air stimulation, high spatial precision, and long working distance. We demonstrate such tactile stimulation can be enabled by laser-induced thermoelastic effects by means of physical and perceptual studies, as well as simulations. In the physical study, the mechanical effect of laser on a human skin sample is detected using low-power radiation in accordance with safety guidelines. Limited increases (< similar to 2.5 degrees C) in temperature at the surface of the skin, examined by both thermal camera and the Monte Carlo simulation, indicate that laser does not evoke heat-induced nociceptive sensation. In the human EEG study, brain responses to both mechanical and laser stimulation are consistent, along with subjective reports of the non-nociceptive sensation of laser stimuli.close1

A review of a strategic roadmapping exercise to advance clinical translation of photoacoustic imaging: From current barriers to future adoption

Photoacoustic imaging (PAI), also referred to as optoacoustic imaging, has shown promise in early-stage clinical trials in a range of applications from inflammatory diseases to cancer. While the first PAI systems have recently received regulatory approvals, successful adoption of PAI technology into healthcare systems for clinical decision making must still overcome a range of barriers, from education and training to data acquisition and interpretation. The International Photoacoustic Standardisation Consortium (IPASC) undertook an community exercise in 2022 to identify and understand these barriers, then develop a roadmap of strategic plans to address them. Here, we outline the nature and scope of the barriers that were identified, along with short-, medium- and long-term community efforts required to overcome them, both within and beyond the IPASC group.This article is published as Assi, Hisham, Rui Cao, Madhura Castelino, Ben Cox, Fiona J. Gilbert, Janek Gröhl, Kurinchi Gurusamy et al. "A review of a strategic roadmapping exercise to advance clinical translation of photoacoustic imaging: from current barriers to future adoption." Photoacoustics (2023): 100539. doi: https://doi.org/10.1016/j.pacs.2023.100539. © 2023 The Authors. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

A review of a strategic roadmapping exercise to advance clinical translation of photoacoustic imaging: From current barriers to future adoption

Photoacoustic imaging (PAI), also referred to as optoacoustic imaging, has shown promise in early-stage clinical trials in a range of applications from inflammatory diseases to cancer. While the first PAI systems have recently received regulatory approvals, successful adoption of PAI technology into healthcare systems for clinical decision making must still overcome a range of barriers, from education and training to data acquisition and interpretation. The International Photoacoustic Standardisation Consortium (IPASC) undertook an community exercise in 2022 to identify and understand these barriers, then develop a roadmap of strategic plans to address them. Here, we outline the nature and scope of the barriers that were identified, along with short-, medium- and longterm community efforts required to overcome them, both within and beyond the IPASC group