Recent Posts

Therapeutic Monitoring

PhotoSounds OEM Line of products is an ideal starting point for the development of custom systems where the parallel acquisition of multiple channels is required. All our ADCs are streaming and allow the continuous acquisition of data straight to the receiving computer for processing or storage.

PhotoSound’s ADCs are feature-rich, they have multiple electronic and optical trigger inputs as well as programmable outputs that allow the timing control of additional devices. It is possible to combine multiple ADCs in parallel. Simultaneous acquisition of 4096 channels has been realized routinely.

What is Therapeutic Monitoring?

Noninvasive imaging plays a critical role in the development of novel drugs by enabling safe, real-time evaluation of the systemic effects of therapeutic intervention in preclinical disease models.

therapy monitoring
These before and after images are from a mouse that had been administered a therapeutic agent that causes vasodilation. The change in blood vessel diameter over time is a metric of therapeutic response.

PhotoSound Product Used

TriTom

Characterizing a photoacoustic and fluorescence imaging platform for preclinical murine longitudinal studies

MoleculUS

Hybrid Photoacoustic Ultrasound Imaging System for Cold-induced Vasoconstriction and Vasodilation Monitoring

Legion ADC

High-speed three-dimensional photoacoustic computed tomography for preclinical research and clinical translation

Evaluation of ultrasound sensors for transcranial photoacoustic sensing and imaging

Automatic force-controlled 3D photoacoustic system for human peripheral vascular imaging

Radiation-induced Acoustic Signal Denoising using a Supervised Deep Learning Framework for Imaging and Therapy Monitoring

Legion AMP

Dual-Modality X-Ray-Induced Radiation Acoustic and Ultrasound Imaging for Real-Time Monitoring of Radiotherapy

Real-time, volumetric imaging of radiation dose delivery deep into the liver during cancer treatment

Molecular Imaging

What is Molecular Imaging?

Molecular imaging enables the visualization, characterization, and quantification of biological processes that take place at the cellular and subcellular levels.

Molecular Imaging
Cellular and Molecular Imaging

PhotoSound Product Used

TriTom

Commercial Small Animal Imaging Could Aid Disease Detection

Indocyanine green dye based bimodal contrast agent tested by photoacoustic/fluorescence tomography setup

A preclinical small animal imaging platform combining multi-angle photoacoustic and fluorescence projections into co-registered 3D maps

Spherical-view photoacoustic tomography for monitoring in vivo placental function

Preclinical Small Animal Imaging Platform Providing Co-registered 3D Maps of Photoacoustic Response and Fluorescence

A 3D imaging system integrating photoacoustic and fluorescence orthogonal projections for anatomical, functional and molecular assessment of rodent models

MoleculUS

A combined ultrasound and photoacoustic imaging platform for clinical research applications

Legion AMP

Real-time, volumetric imaging of radiation dose delivery deep into the liver during cancer treatment

REAL-TIME PHOTOACOUSTIC DATA ACQUISITION WITH A THOUSAND PARALLEL CHANNELS AT HUNDREDS FRAMES PER SECOND

Authors: Vassili Ivanov, Hans Peter Brecht, Sergey A. Ermilov

AFFILIATIONS

PhotoSound Technologies, Inc. (United States)

ABSTRACT

Large number of simultaneously acquired spatially distinct pressure signals is required to improve quality of real-time photoacoustic and x-ray acoustic biomedical images [1]. In the past this approach was limited by availability of commercial multi-channel analog-to-digital converter (ADC) systems and ability to operate multiple ADC boards with synchronized clock and trigger source. The new Legion series single-board 256-channel ADC (ADC256) was designed by PhotoSound for massive parallel data acquisition utilized in photoacoustic, laser-induced ultrasound, and X-ray acoustic real-time imaging applications. ADC256 is a 12-bit ADC with a sampling rate up to 40 MHz and a USB3 computer interface. It can run at 200 Hz frame rate with 4096 points per trigger acquired by each channel. Higher trigger rates without data loss are possible with smaller number of points per trigger. ADC256 has an integrated amplifier with programmable gain up to 51 dB. Additionally, it can be equipped with a matching photoacoustic preamplifier. The system architecture is scalable to 1024 channels using four synchronized boards with a single trigger source. The clock and the trigger can be delivered from the master ADC256 board (daisy chain) or from the clock and trigger server (star topology). The data collected by each ADC board has trigger and board stamps allowing to (a) use multiple computers for data acquisition, and (b) detection of lost data events, even if the trigger rate exceeds its maximum allowed value.

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CO-REGISTERED PHOTOACOUSTIC AND FLUORESCENT IMAGING OF A SWITCHABLE NANOPROBE BASED ON J-AGGREGATES OF INDOCYANINE GREEN

Authors: Diego S. Dumani, Hans-Peter Brecht, Vassili Ivanov, Ryan Deschner, Justin T. Harris, Kimberly A. Homan, Jason R. Cook, Stanislav Y. Emelianov, Sergey A. Ermilov

ABSTRACT

We introduce a preclinical imaging platform – a 3D photoacoustic/fluorescence tomography (PAFT) instrument augmented with an environmentally responsive dual-contrast biocompatible nanoprobe. The PAFT instrument was designed for simultaneous acquisition of photoacoustic and fluorescence orthogonal projections at each rotational position of a biological object, enabling direct co-registration of the two imaging modalities. The nanoprobe was based on liposomes loaded with J-aggregates of indocyanine green (PAtrace). Once PAtrace interacts with the environment, a transition from J-aggregate to monomeric ICG is induced. The subsequent recovery of monomeric ICG is characterized by dramatic changes in the optical absorption spectrum and reinstated fluorescence. In the activated state, PAtrace can be simultaneously detected by both imaging modes of the PAFT instrument using 780 nm excitation and fluorescence detection at 810 nm. The fluorescence imaging component is used to boost detection sensitivity by providing low resolution map of activated nanoprobes, which are then more precisely mapped in 3D by the photoacoustic imaging component. Activated vs non-activated particles can be distinguished based on their different optical absorption peaks, removing the requirements for complex image registration between reference and detection scans. Preliminary phantom and in vivo animal imaging results showed successful activation and visualization of PAtrace with high sensitivity and resolution. The proposed PAFT-PAtrace imaging platform could be used in various functional and molecular imaging applications including multi-point in vivo assessment of early metastasis.

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MASSIVE PARALLEL ULTRASOUND AND PHOTOACOUSTIC PC-BASED SYSTEM

Authors: Weylan Thompson, Hans Peter Brecht, Sergey Ermilov, Vassili Ivanov

ABSTRACT

PhotoSound Technologies specializes in the development of electronics solutions for massive parallel data acquisition applicable to the fields of photoacoustics (PA), X-ray acoustics, including 3D dosimetry, and ultrasound. PhotoSound’s Legion ADC256 R1.1, released in 2018, is a 256-channel 12-bit ADC with a sampling rate of 40 MHz. The ADC256’s average data bandwidth is limited by its USB3 PC interface, which has a data rate up to 3 Gbps per board. Multiple ADC256 boards can operate fully in parallel. On software level configurations, multiple ADC256 boards are represented as a single ADC board with increased number of channels. The incoming ultrasound (US) upgrades and modifications of ADC256 will enable combination and alternation of US and PA modes using the same probe. PhotoSound MoleculUS is a medical-grade Telemed US system combined with a PA-optimized ADC. MoleculUS utilizes clinical US probes to produce US images which can be interleaved with PA imaging by enabling optical fiber illumination. The other ADC256 modification, advanced PAUS oriented for research, will have PCIe PC interface for raw PA and US data and arbitrary software control over beamformer profiles, limited by high-voltage power only. The data in ultrasound and photoacoustics modes is user accessible in raw format and can be delivered to CUDA GPU using MATLAB parallel computing (CUDA) toolbox or other tools. Multiple PAUS boards can work in parallel in both PA and US modes.

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COMMERCIAL SMALL ANIMAL IMAGING COULD AID DISEASE DETECTION

Authors: Mark Little

ABSTRACT

The development of anticancer metastatic therapies for human clinical trials requires meticulous evaluation of efficacy and optimization of small animal test models in preclinical experimentation. Critical information on morphology and the molecular microenvironment of tumors is currently obtained and monitored using noninvasive, in vivo imaging methods. Detection of individual, small tumors (separated by 2 mm or less) pushes the limits of small animal imaging modalities currently on the market, which can prohibit noninvasive quantification of the volume of metastatic lesions. Commercial small animal imaging platforms that enable rendering and anatomical registration of metastatic lesions with true 3D isotropic submillimeter spatial resolution would help solve this problem. Such platforms would alleviate subjective interpretation and provide molecular and functional information on blood content. A multimodal approach could provide a more cost-effective implementation of all these features in a single configuration.

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A PRECLINICAL SMALL ANIMAL IMAGING PLATFORM COMBINING MULTI-ANGLE PHOTOACOUSTIC AND FLUORESCENCE PROJECTIONS INTO CO-REGISTERED 3D MAPS

Authors: Weylan Thompson, Anthony Yu, Diego S. Dumani, Jason Cook, Mark A. Anastasio, Stanislav Y. Emelianov, Sergey A. Ermilov

ABSTRACT

We present the results on development of the 3D imaging platform combining photoacoustic tomography and fluorescence (PAFT) for preclinical and biological research. This combined multimodal imaging instrument addresses known deficiencies in sensitivity, spatial resolution, and anatomical registration of the individual imaging components. Multiangle photoacoustic projections, excited by an OPO operating in the near-infrared window, of a live anesthetized animal are used to reconstruct large volumes (30 cm3) that show deep anatomical vasculature and blood-rich tissues with resolutions exceeding 150 μm. A sCMOS camera is used for simultaneous co-registered multi-angle optical imaging. The images of a fluorescent dual-contrast agent are then reconstructed into a 3D volume using a tomographic algorithm. A separate 532-nm low-energy pulsed laser excitation is used for skin topography and imaging of superficial vasculature. All three imaging channels can be combined to produce spatially accurate in vivo volumes showing an animal’s skin, deep anatomical structures, and distribution of photosensitive molecular contrast agents. PAFT’s photoacoustic sensitivity was assessed using contrast agents in a phantom study. We demonstrate biomedical imaging application of PAFT’s combined imaging modalities by observing biodistribution of a dual-contrast agent injected intravenously to in vivo preclinical murine models.

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PHOTOACOUSTIC IMAGE-GUIDED DELIVERY OF PLASMONIC-NANOPARTICLE-LABELED MESENCHYMAL STEM CELLS TO THE SPINAL CORD

Authors: Eleanor M. Donnelly, Kelsey P. Kubelick, Diego S. Dumani, and Stanislav Y. Emelianov

ABSTRACT

Regenerative therapies using stem cells have great potential for treating neurodegenerative diseases and traumatic injuries in the spinal cord. In spite of significant research efforts, many therapies fail at the clinical phase. As stem cell technologies advance toward clinical use, there is a need for a minimally invasive, safe, affordable, and real-time imaging technique that allows for the accurate and safe monitoring of stem cell delivery in the operating room. In this work, we present a combined ultrasound and photoacoustic imaging tool to provide image-guided needle placement and monitoring of nanoparticle-labeled stem cell delivery into the spinal cord. We successfully tagged stem cells using gold nanospheres and provided image-guided delivery of stem cells into the spinal cord in real-time, detecting as few as 1000 cells. Ultrasound and photoacoustic imaging was used to guide needle placement for direct stem cell injection to minimize the risk of needle shear and accidental injury and to improve therapeutic outcomes with accurate, localized stem cell delivery. Following injections of various volumes of cells, three-dimensional ultrasound and photoacoustic images allowed the visualization of stem cell distribution along the spinal cord, showing the potential to monitor the migration of the cells in the future. The feasibility of quantitative imaging was also shown by correlating the total photoacoustic signal over the imaging volume to the volume of cells injected. Overall, the presented method may allow clinicians to utilize imaged-guided delivery for more accurate and safer stem cell delivery to the spinal cord.

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TECHNICAL CONSIDERATIONS IN THE VERASONICS RESEARCH ULTRASOUND PLATFORM FOR DEVELOPING A PHOTOACOUSTIC IMAGING SYSTEM

Authors: Karl Kratkiewicz1,4,Rayyan Manwar2,4, Yang Zhou, Moein Mozaffarzadeh3, Kamran Avanaki2

ABSTRACT

Photoacoustic imaging (PAI) is an emerging functional and molecular imaging technology that has attracted much attention in the past decade. Recently, many researchers have used the vantage system from Verasonics for simultaneous ultrasound (US) and photoacoustic (PA) imaging. This was the motivation to write on the details of US/PA imaging system implementation and characterization using Verasonics platform. We have discussed the experimental considerations for linear array based PAI due to its popularity, simple setup, and high potential for clinical translatability. Specifically, we describe the strategies of US/PA imaging system setup, signal generation, amplification, data processing and study the system performance.

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PRECLINICAL SMALL ANIMAL IMAGING PLATFORM PROVIDING CO-REGISTERED 3D MAPS OF PHOTOACOUSTIC RESPONSE AND FLUORESCENCE

Authors: Diego S. Dumani1,2, Anthony Yu1,2, Weylan Thompson3, Hans-Peter Brecht3, Vassili Ivanov3, Mark A. Anastasio4, Jason Cook5, Sergey A. Ermilov3, Stanislav Y. Emelianov1,2

ABSTRACT

We report on the development of a preclinical 3D imaging platform integrating photoacoustic tomography and fluorescence (PAFT). The proposed multimodal imaging concept addresses known deficiencies in sensitivity, anatomical registration, and spatial resolution of the individual imaging modalities. Multi-view photoacoustic and optical projections of the studied animal are utilized to reconstruct large (27 cm3) volumes showing vascular network and blood-rich tissues, as well as regions with induced optical/fluorescence contrast with 3D resolution exceeding 150 μm. An additional 532-nm low-energy pulsed laser excitation is implemented as a separate imaging channel for registration over skin topography and superficial vasculature. PAFT technology enables functional and molecular volumetric imaging using wide range of fluorescent and luminescent biomarkers, nanoparticles, and other photosensitive constructs mapped with high fidelity over robust anatomical structures of the studied animal model. We demonstrated the PAFT performance using phantoms and by in vivo imaging of preclinical murine models.

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