Recent Posts

Spatiotemporal Image Reconstruction to Enable High-Frame-Rate Dynamic Photoacoustic Tomography with Rotating-Gantry Volumetric Imagers

Author(s): Refik Mert Cam, Chao Wang, Weylan Thompson, Sergey A. Ermilov, Mark A. Anastasio, Umberto Villa

ABSTRACT

Significance

Dynamic photoacoustic computed tomography (PACT) is a valuable imaging technique for monitoring physiological processes. However, current dynamic PACT imaging techniques are often limited to two-dimensional spatial imaging. Although volumetric PACT imagers are commercially available, these systems typically employ a rotating measurement gantry in which the tomographic data are sequentially acquired as opposed to being acquired simultaneously at all views. Because the dynamic object varies during the data-acquisition process, the sequential data-acquisition process poses substantial challenges to image reconstruction associated with data incompleteness. The proposed image reconstruction method is highly significant in that it will address these challenges and enable volumetric dynamic PACT imaging with existing preclinical imagers.

Aim

The aim of this study is to develop a spatiotemporal image reconstruction (STIR) method for dynamic PACT that can be applied to commercially available volumetric PACT imagers that employ a sequential scanning strategy. The proposed reconstruction method aims to overcome the challenges caused by the limited number of tomographic measurements acquired per frame.

Approach

A low-rank matrix estimation-based STIR (LRME-STIR) method is proposed to enable dynamic volumetric PACT. The LRME-STIR method leverages the spatiotemporal redundancies in the dynamic object to accurately reconstruct a four-dimensional (4D) spatiotemporal image.

Results

The conducted numerical studies substantiate the LRME-STIR method’s efficacy in reconstructing 4D dynamic images from tomographic measurements acquired with a rotating measurement gantry. The experimental study demonstrates the method’s ability to faithfully recover the flow of a contrast agent with a frame rate of 10 frames per second, even when only a single tomographic measurement per frame is available.

Conclusions

The proposed LRME-STIR method offers a promising solution to the challenges faced by enabling 4D dynamic imaging using commercially available volumetric PACT imagers. By enabling accurate STIRs, this method has the potential to significantly advance preclinical research and facilitate the monitoring of critical physiological biomarkers.

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Water-Soluble Fe(II) Complexes for Theranostic Application: Synthesis, Photoacoustic Imaging, and Photothermal Conversion

Authors: Maeva Delcroix, Dr. Anil Reddy Marri, Stéphane Parant, Dr. Philippe C. Gros, Dr. Mathilde Bouché

ABSTRACT

Significant effort focused on developing photoactivatable theranostics for localized image guided therapy of cancer by thermal ablation. In this context iron complexes were recently identified as photoactivatable theranostic agents with adequate biocompatibility and body clearance. Herein, a series of FeII complexes bearing polypyridine or N-heterocyclic carbenes is reported that rely on rational complex engineering to red-shift their MLCT based excited-state deactivation via a straightforward approach. The non-radiative decay of their MLCT upon irradiation is exploited for theranostic purposes by combining both tracking in photoacoustic imaging (PA) and photothermal therapy (PTT). The influence of structural modifications introduced herein on the solubility and stability of the complexes in biorelevant aqueous media is discussed. The relationship between complexes’ design, production of contrast in photoacoustic and photothermal efficiency are explored to develop tailored PA/PTT theranostic agents.

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LIVE PRODUCT DEMONSTRATION AT THE PHOTOSOUND BOOTH 8539 DURING THE BiOS EXHIBITION

Visit the PhotoSound’s booth #8539 to meet our Production Manager, Sam Toler. Sam will have live product demonstrations featuring the MoleculUSTM, our dual-modality ultrasound and photoacoustic data acquisition unit that allows the simultaneous collection of ultrasound and photoacoustic channels sharing the same probe elements.

The MoleculUSTM can use linear, convex, and endocavitary handheld probes. Stop by PhotoSound’s booth #8539 to see live product demonstrations of the MoleculUSTM during the BiOS EXPO in San Francisco from January 27-28 2024.

We are excited to announce that PhotoSound Technologies Inc. has been selected as a finalist for the 2024 SPIE Prism Award for our new product, the MoleculUSTM, in the Biomedical category.

The SPIE Prism Awards recognize the best new photonics products and technologies on the market. We are honored to be among the finalists alongside such innovative companies at this year’s BIOS Exhibition at Photonics West.

SCIENTIFIC PRESENTATIONS USING PHOTOSOUND PRODUCTS AT SPIE 2024

We look forward to seeing you at one of the scientific presentations using PhotoSound Technologies, Inc. products during SPIE Photonics West 2024. See the list of presentations below.

12842-15

The new development of ionizing radiation acoustic imaging (iRAI) for mapping the dose deep in the patient body during radiation therapy

Author(s): Wei Zhang, Dale Litzenberg, Yaocai Huang, Scott Hadley, Kai-Wei Chang, Univ. of Michigan Medical School (United States); Ibrahim Oraiqat, Eduardo Moros, Moffitt Cancer Ctr. (United States); Man Zhang, Paul Carson, Kyle Cuneo, Univ. of Michigan Medical School (United States); Issam EI Naqa, Moffitt Cancer Ctr. (United States); Xueding Wang, Univ. of Michigan Medical School (United States)

28 January 2024 • 1:45 PM – 2:00 PM PST | Moscone Center, Room 54 (Lower Mezzanine South)

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Whole-body ultrasound and thermoacoustic tomography for human imaging, needle localization, and ablation monitoring

Author(s): David C. Garrett, Jinhua Xu, Geng Ku, Lihong V. Wang, Caltech (United States)

28 January 2024 • 2:00 PM – 2:15 PM PST | Moscone Center, Room 54 (Lower Mezzanine South)

12842-17

Rotational photoacoustic and ultrasound tomography of the human body

Author(s): Yang Zhang, Shuai Na, Jonathan J. Russin, Li Lin, Yilin Luo, Yujin An, Peng Hu, Karteekeya Sastry, Konstantin Maslov, Charles Y. Liu, Lihong V. Wang Caltech (United States)

28 January 2024 • 2:15 PM – 2:30 PM PST | Moscone Center, Room 54 (Lower Mezzanine South)

12842-93

Rational design of ICG-based contrast agents for near-infrared photoacoustic imaging

Author(s): Marzieh Hanafi, Nicholas Such, Giovanni Giammanco, Shrishti Singh, George Mason Univ. (United States); Dana Wegierak, Eric Abenojar, Pinunta Nittayacharn, Tessa Kosmides, Agata A. Exner, Case Western Reserve Univ. (United States); Remi Veneziano, Parag V. Chitnis, George Mason Univ. (United States)

28 January 2024 • 5:30 PM – 7:00 PM PST | Moscone Center, Room 2003 (Level 2 West)

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Combined ionizing radiation acoustic and ultrasound dual-modality volumetric imaging for mapping the dose on anatomical structure during radiation therapy

Author(s): Wei Zhang, Univ. of Michigan Medical School (United States); Ibrahim Oraiqat, Moffitt Cancer Ctr. (United States); Yaocai Huang, Kaiwei Chang, Univ. of Michigan Medical School (United States); Muhammad B. Alli, Moffitt Cancer Ctr. (United States); Dale Litzenberg, Scott Hadley, Univ. of Michigan Medical School (United States); Christopher Tichacek, Eduardo Moros, Moffitt Cancer Ctr. (United States); Man Zhang, Paul Carson, Kyle Cuneo, Univ. of Michigan Medical School (United States); Issam EI Naqa, Moffitt Cancer Ctr. (United States); Xueding Wang, Univ. of Michigan Medical School (United States)

29 January 2024 • 4:30 PM – 4:45 PM PST | Moscone Center, Room 54 (Lower Mezzanine South)

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High-throughput photoacoustic tomography by integrated robotics and automation

Author(s): Nathanael Marshall, Hans-Peter Brecht, Weylan Thompson, Dylan Lawrence, Vanessa Marshall, PhotoSound Technologies, Inc. (United States); Mark A. Anastasio, Univ. of Illinois (United States); Umberto Villa, The Univ. of Texas at Austin (United States); Sergey Ermilov, PhotoSound Technologies, Inc. (United States)

29 January 2024 • 4:45 PM – 5:00 PM PST | Moscone Center, Room 54 (Lower Mezzanine South)

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A fast fully automated dual-SOS reconstruction algorithm for full-ring array PACT

Author(s): Shunyao Zhang, Lei S. Li, Rice Univ. (United States)

29 January 2024 • 5:30 PM – 7:00 PM PST | Moscone Center, Room 2003 (Level 2 West)

12842-131

Optoacoustic imaging of coronary arteries for bypass surgery using a handheld lens-free probe

Author(s): Zohar Or, Technion-Israel Institute of Technology (Israel); Itay Or, Mahli Raad, Gil Bolotin, Rambam Medical Ctr. (Israel); Amir Rosenthal, Technion-Israel Institute of Technology (Israel)

30 January 2024 • 6:00 PM – 8:00 PM PST | Moscone Center, Room 2003 (Level 2 West)

#SPIEPhotonicsWest #BiOSExpo #2024 #photosoundtechnologies #photosound #photoacoustic #fluorescence #imaging #biomedicalscience #biomedicalresearch #science #tomography #productdemonstration #livedemonstration

SPIE Photonics West 2024

PhotoSound Technologies is excited to attend this year’s SPIE Photonics West BiOS -the industry’s most important biophotonics, biomedical optics, and imaging meeting being held in San Francisco, CA January 27 – February 1, 2024.  Come talk to us and see our products in person at this year’s BIOS Exhibition at Photonics West in San Francisco on January 27-28 2024. We will be at booth 8539.

We are excited to announce that PhotoSound Technologies Inc. has been selected as a finalist for the 2024 SPIE Prism Award for our revolutionary new product MoleculUS in the Biomedical category!

The SPIE Prism Awards recognize the best new photonics products and technologies on the market. We are honored to be among the finalists alongside such innovative companies. The SPIE Prism Awards will be presented during a gala at Photonics West on January 31, 2024. We are grateful to SPIE for recognizing our work, and we look forward to competing in the finals at Photonics West in January.

Congratulations to all of the finalists!

#photoacoustic #SPIE #photonicswest #BIOS #research

Model-Based 3-D X-Ray Induced Acoustic Computerized Tomography

Authors: Prabodh Kumar Pandey; Siqi Wang; Leshan Sun; Lei Xing; Liangzhong Xiang

ABSTRACT

X-ray-induced acoustic (XA) computerized tomography (XACT) is an evolving imaging technique that aims to reconstruct the X-ray energy deposition from XA measurements. Main challenges in XACT are the poor signal-to-noise ratio and limited field-of-view, which cause artifacts in the images. We demonstrate the efficacy of model-based (MB) algorithms for 3-D XACT and compare with the traditional algorithms. The MB algorithms are based on the matrix free approach for regularized-least-squares minimization corresponding to XACT. The matrix-free-LSQR (MF-LSQR) and the noniterative model-backprojection (MBP) reconstructions were evaluated and compared with universal backprojection (UBP), time-reversal (TR), and fast-Fourier transform (FFT)-based reconstructions for numerical and experimental XACT datasets. The results demonstrate the capability of the MF-LSQR algorithm to reduce noisy artifacts thus yielding better reconstructions. MBP and MF-LSQR algorithms perform particularly well with the experimental XACT dataset, where noise in signals significantly affects the reconstruction of the target in UBP and FFT-based reconstructions. The TR reconstruction for experimental XACT is comparable to MF-LSQR, but takes thrice as much time and filters the frequency components greater than maximum frequency supported by the grid, resulting loss of resolution. The MB algorithms are able to overcome the challenges in XACT and hence are vital for the clinical translation of XACT.

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Discrete Wavelet Transformation for the Sensitive Detection of Ultrashort Radiation Pulse with Radiation-Induced Acoustics

Authors: Rick Van Bergen, Leshan Sun, Prabodh Kumar Pandey, Siqi Wang, Kristina Bjegovic, Gilberto Gonzalez, Yong Chen, Richard Lopata, Liangzhong Xiang

ABSTRACT

Radiation-induced acoustics (RIA) shows promise in advancing radiological imaging and radiotherapy dosimetry methods. However, RIA signals often require extensive averaging to achieve reasonable signal-to-noise ratios, which increases patient radiation exposure and limits real-time applications. Therefore, this article proposes a discrete wavelet transform (DWT)-based filtering approach to denoise the RIA signals and avoid extensive averaging. The algorithm was benchmarked against low-pass filters and tested on various types of RIA sources, including low-energy X-rays, high-energy X-rays, and protons. The proposed method significantly reduced the required averages (1000 times less averaging for low-energy X-ray RIA, 32 times less averaging for high-energy X-ray RIA, and four times less averaging for proton RIA) and demonstrated robustness in filtering signals from different sources of radiation. The coif5 wavelet in conjunction with the sqtwolog threshold selection algorithm yielded the best results. The proposed DWT filtering method enables high-quality, automated, and robust filtering of RIA signals, with a performance similar to low-pass filtering, aiding in the clinical translation of radiation-based acoustic imaging for radiology and radiation oncology.

Click HERE for publication

Radiation Acoustics

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 Radiation Acoustics?

Radiation Acoustics is the conversion of pulsed energy in form of electrons, protons X-rays and microwaves into sound waves. For example the interaction of X-rays and tissue is weaker than that of optical light which allows for deep penetration. However, the same weak interaction is greatly reducing contrast. The long pulse duration of X-ray sources limits the spatial resolution of X-ray acoustic imaging systems.

While probably unable to compete as an imaging technique in comparison to conventional imaging solutions, it offers unique possibilities for monitoring and dosimetry of radiation therapy. Accurate real-time monitoring of dosage and placement can potentially be a game changer in radiation therapy and would reduce the amount of treatment cycles and time required.

Photosound products are uniquely suited for the acquisition of acoustic signals generated by pulsed X-rays. The high input impedance of our preamplifier ensures the faithful recording of low-frequency signals, their high gain, and low SNR along with the high channel count minimizes the amount of X-ray pulses required to require data.

PhotoSound Product Used

Legion AMP

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

Toward in vivo dosimetry in external beam radiotherapy using x-ray acoustic computed tomography: A soft-tissue phantom study validation

The development of ionizing radiation acoustic imaging (iRAI) for mapping the dose deep in the patient body during radiation therapy

Ionizing radiation acoustic and ultrasound dual-modality imaging for visualization of dose on anatomical structures during radiotherapy

Legion ADC

4D in vivo dosimetry for a FLASH electron beam using radiation-induced acoustic imaging

Discrete Wavelet Transformation for the Sensitive Detection of Ultrashort Radiation Pulse with Radiation-Induced Acoustics

Model-Based 3-D X-Ray Induced Acoustic Computerized Tomography

Real-time tracking of the Bragg peak during proton therapy via 3D protoacoustic Imaging in a clinical scenario

Toward real-time, volumetric dosimetry for FLASH-capable clinical synchrocyclotrons using protoacoustic imaging

3D protoacoustic radiography: A proof of principle study

TriTom

GPU-Accelerated 3D Volumetric X-Ray-Induced Acoustic Computed Tomography

In Situ X-Ray Induced Acoustic Computed Tomography with a Contrast Agent: A Proof of Concept

MONODISPERSE SUB-100 NM AU NANOSHELLS FOR LOW-FLUENCE DEEP-TISSUE PHOTOACOUSTIC IMAGING

August 4, 2023

Author(s): Luis D. B. Manuel, Vinion Devpaul Vincely, Carolyn Bayer, and Kevin M. McPeak

ABSTRACT

Nanoparticles with high absorption cross sections will advance therapeutic and bioimaging nanomedicine technologies. While Au nanoshells have shown great promise in nanomedicine, state-of-the-art synthesis methods result in scattering-dominant particles, mitigating their efficacy in absorption-based techniques that leverage the photothermal effect, such as photoacoustic (PA) imaging. We introduce a highly reproducible synthesis route to monodisperse sub-100 nm Au nanoshells with an absorption-dominant optical response. Au nanoshells with 48 nm SiO2 cores and 7 nm Au shells show a 14-fold increase in their volumetric absorption coefficient compared to commercial Au nanoshells with dimensions commonly used in nanomedicine. PA imaging with Au nanoshell contrast agents showed a 50% improvement in imaging depth for sub-100 nm Au nanoshells compared with the smallest commercially available nanoshells in a turbid phantom. Furthermore, the high PA signal at low fluences, enabled by sub-100 nm nanoshells, will aid the deployment of low-cost, low-fluence light-emitting diodes for PA imaging.

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