Recent Posts

NON-INVASIVE 3D PHOTOACOUSTIC TOMOGRAPHY OF ANGIOGRAPHIC ANATOMY AND HEMODYNAMICS OF FATTY LIVERS IN RATS

17 November 2022

Author(s): Xin Tong, Li Lin, Peng Hu, Rui Cao, Yang Zhang, Joshua Olick-Gibson,and Lihong V. Wang


ABSTRACT

Non-alcoholic fatty liver disease is the most common liver disorder worldwide, which strongly correlates to obesity, diabetes, and metabolic syndromes. Complementary to mainstream liver diagnostic modalities, photoacoustic tomography (PAT) can provide high-speed images with functional optical contrast. However, PAT has not been demonstrated to study fatty liver anatomy with clear volumetric vasculatures. The livers of multiple rats are non-invasively imaged in vivo using the recently developed 3D PAT platform. The system provides isotropically high spatial resolution in 3D space, presenting clear angiographic structures of rat livers without injecting contrast agents. Furthermore, to quantitatively analyze the difference between the livers of lean and obese rats, the authors measured several PAT features and statistical differences between the two groups are observed. In addition to the anatomy, a time-gated strategy is applied to correct respiration-induced motion artifacts and extracted the hemodynamics of major blood vessels during the breathing cycles. This study demonstrates the capabilities of 3D-PAT to reveal both angiographic anatomy and function in rat livers, providing hematogenous information for fatty liver diagnosis. 3D-PAT, as a new tool for preclinical research, warrants further improvements to be transferred to human pediatric liver imaging.

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WHOLE-BODY HUMAN UTLRASOUND TOMOGRAPHY

ABSTRACT

We developed a system for whole-body human ultrasound tomography in reflection and
transmission modes. A custom 512-element ultrasound receiver array with a rotating single-element ultrasound transmitter are used to generate 2D isotropically resolved images across the entire human cross-section. We demonstrate this technique in regions such as the abdomen and legs in healthy volunteers. Compared to handheld-probe-based ultrasonography, this approach provides a substantially larger field of view, depends less on operator training, and obtains quantitative tissue parameter profiles in addition to reflectivity images. Whole-body ultrasound tomography could be valuable in applications such as organ disease screening, image-guided needle biopsy, and treatment monitoring.

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A COMBINED ULTRASOUND AND PHOTOACOUSTIC IMAGING PLATFORM FOR CLINICAL RESEARCH APPLICATIONS

3 March 2022

Author(s): Weylan ThompsonHans-Peter BrechtSergey A. ErmilovVassili Ivanov


ABSTRACT

We present the continued development of a clinical ultrasound (US) imaging device with a photoacoustic (PA) mode. The combined USPA imaging platform is designed around a compact US component capable of B-mode, M-mode, color Doppler, and pulsed wave Doppler US imaging modes with a 128-element US probe. The PA mode can support a 256-element PA probe with real-time 2D imaging up to 20 Hz. The PA signals are amplified by a 40 dB pre-amplifier while US mode signals bypass the circuit, resulting in high-quality PA images. We demonstrate the USPA platform’s capabilities using tissue-mimicking phantoms.

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HYBRID PHOTOACOUSTIC ULTRASOUND IMAGING SYSTEM FOR COLD-INDUCED VASOCONSTRICTION AND VASODILATION MONITORING

02 August 2023

Author(s): Ruochong Zhang, Xiuting Li, Ghayathri Balasundaram, Baocheng Li, Yi Qi, Anindita Santosa, Tze Chin Tan, Malini Olivo, Renzhe Bi


ABSTRACT

Lewis hunting reaction refers to the alternating cold-induced vasoconstriction and dilation in extremities, whose underlying mechanism is complex. While numerous studies reported this intriguing phenomenon by measuring cutaneous temperature fluctuation under cold exposure, few of them tracked peripheral vascular responses in real-time, lacking a non-invasive and quantitative imaging tool. To better monitor hunting reaction and diagnose relevant diseases, we developed a hybrid photoacoustic ultrasound (PAUS) tomography system to monitor finger vessels’ dynamic response to cold, together with simultaneous temperature measurement. We also came out a standard workflow for image analysis with self-defined indices. In the small cohort observational study, vascular changes in the first cycle of hunting reaction were successfully captured by the image series and quantified. Time difference between vasodilation and temperature recovery was noticed and reported for the first time, thanks to the unique capability of the PAUS imaging system in real-time and continuous vascular monitoring. The developed imaging system and indices enabled more objective and quantitative monitoring of peripheral vascular activities, indicating its great potential in numerous clinical applications.

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A 3D IMAGING SYSTEM INTEGRATING PHOTOACOUSTIC AND FLUORESCENCE ORTHOGONAL PROJECTIONS FOR ANATOMICAL, FUNCTIONAL, AND MOLECULAR ASSESSMENT OF RODENT MODELS

16 March 2018

Authors: Hans P. BrechtVassili IvanovDiego S. DumaniStanislav Y. EmelianovMark A. AnastasioSergey A. Ermilov


ABSTRACT

We have developed a preclinical 3D imaging instrument integrating photoacoustic tomography and fluorescence (PAFT) addressing known deficiencies in sensitivity and spatial resolution of the individual imaging components. PAFT is designed for simultaneous acquisition of photoacoustic and fluorescence orthogonal projections at each rotational position of a biological object, enabling direct registration of the two imaging modalities. Orthogonal photoacoustic projections are utilized to reconstruct large (21 cm3 ) volumes showing vascularized anatomical structures and regions of induced optical contrast with spatial resolution exceeding 100 µm. The major advantage of orthogonal fluorescence projections is significant reduction of background noise associated with transmitted or backscattered photons. The fluorescence imaging component of PAFT is used to boost detection sensitivity by providing low-resolution spatial constraint for the fluorescent biomarkers. PAFT performance characteristics were assessed by imaging optical and fluorescent contrast agents in tissue mimicking phantoms and in vivo. The proposed PAFT technology will enable functional and molecular volumetric imaging using fluorescent biomarkers, nanoparticles, and other photosensitive constructs mapped with high fidelity over robust anatomical structures, such as skin, central and peripheral vasculature, and internal organs.

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COMPARATIVE EVALUATION OF A NIR-II NANOPARTICLE WITH AND WITHOUT THE LEGION AMP

Overview:

The Legion AMP webinar series is hosted by PhotoSound Technologies Marketing Specialist Sarah Argo. In the first webinar of the Legion AMP Webinar Series, Sergey Ermilov (CEO), discussed the Legion AMP design, motivation, and benefits in relation to how it could optimize your research. Vinoin Devpaul Vincely, from Carolyn Bayer’s lab at Tulane University, shares a live demo of the Legion AMP along with his research to cover the Comparative Evaluation of a NIR-II Nanoparticle with and without the Legion AMP.

  • Topics Covered:
    • Legion AMP design
    • Legion AMP motivation
    • Legion AMP noise measurements
    • Legion AMP variations
    • Objective of Studies
    • Legion AMP demo
    • Results of Studies
Comparative Evaluation of a NIR-II Nanoparticle with and without the Legion AMP

FIBER TIP TRACKING WITH PHOTOACOUSTIC IMAGING BY USING LEGION AMP

Overview:

The Legion AMP webinar series is hosted by PhotoSound Technologies Marketing Specialist’s Sarah Argo. In the second webinar of the Legion Amp Webinar Series, Samuel Toler (System Test Engineer I), discussed the Legion Amp design, motivation, and benefits in relation to how it could optimize your research. Samuel John and Dr. Yan Yan, from the Photoacoustic & Ultrasonic Research & Engineering (PURE) Laboratory, led by Dr. Mohammad Mehrmohammadi at Wayne State University, shares a live demo of the Legion Amp along along with their research to cover fiber tip tracking with photoacoustic imaging by using the Legion Amp.

  • Topics Covered:
    • Legion Amp design
    • Legion Amp motivation
    • Legion Amp noise measurements
    • Legion Amp variations
    • Objective of studies
    • Legion Amp demo
    • Results of studies

DUAL-MODALITY X-RAY-INDUCED RADIATION ACOUSTIC AND ULTRASOUND IMAGING FOR REAL-TIME MONITORING OF RADIOTHERAPY

This is the third webinar of the Legion AMP webinar series, hosted by PhotoSound Technologies. This webinar covers dual-modality, ultrasound, and thermoacoustic imaging in real-time, while using an ionizing radiation source, for the purpose of monitoring radiation therapy, as presented by Dr. Wei Zhang from the Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA. During the introduction, Sam Toler, System Test Engineer I, provides a brief explanation of how the Legion AMP can optimize the SNR and low-frequency bandwidth of your photoacoustic/thermoacoustic system.

  • Topics Covered:
    • Legion AMP design
    • Legion AMP motivation
    • Legion AMP noise measurements
    • Legion AMP variations
    • Objective of Studies
    • Legion AMP demo
    • Results of Studies