Time filter

Source Type

HOUSTON, TX, United States

Wang K.,Washington University in St. Louis | Huang C.,Washington University in St. Louis | Kao Y.-J.,National Taiwan University | Chou C.-Y.,National Taiwan University | And 2 more authors.
Medical Physics | Year: 2013

Purpose: Optoacoustic tomography (OAT) is inherently a three-dimensional (3D) inverse problem. However, most studies of OAT image reconstruction still employ two-dimensional imaging models. One important reason is because 3D image reconstruction is computationally burdensome. The aim of this work is to accelerate existing image reconstruction algorithms for 3D OAT by use of parallel programming techniques. Methods: Parallelization strategies are proposed to accelerate a filtered backprojection (FBP) algorithm and two different pairs of projection/backprojection operations that correspond to two different numerical imaging models. The algorithms are designed to fully exploit the parallel computing power of graphics processing units (GPUs). In order to evaluate the parallelization strategies for the projection/backprojection pairs, an iterative image reconstruction algorithm is implemented. Computer simulation and experimental studies are conducted to investigate the computational efficiency and numerical accuracy of the developed algorithms. Results: The GPU implementations improve the computational efficiency by factors of 1000, 125, and 250 for the FBP algorithm and the two pairs of projection/backprojection operators, respectively. Accurate images are reconstructed by use of the FBP and iterative image reconstruction algorithms from both computer-simulated and experimental data. Conclusions: Parallelization strategies for 3D OAT image reconstruction are proposed for the first time. These GPU-based implementations significantly reduce the computational time for 3D image reconstruction, complementing our earlier work on 3D OAT iterative image reconstruction. © 2013 American Association of Physicists in Medicine.

Provided herein are dual modality imaging systems and methods within displayed anatomical structures of placenta in real time. The imaging system comprises a dual modality laser optoacoustic and ultrasonic platform with a plurality of subsystems for delivering near infrared light, optoacoustic and ultrasonic pulses to the placenta and/or associated tissue and deep anatomic structures, for detecting ultrasonic pulses generated or reflected within the tissue using a multi-channel optoacoustic-ultrasound probe and associated transducers. The dual modality imaging system displays the results obtained as quantitative functional images of the parameters coregistered with anatomic tissue images. A multichannel electronic system comprising a computer tangibly storing software enables processor-executable instructions to calculate quantitative functional parameters of the placental blood within specific anatomical tissue structures and display quantitative functional optoacoustic images of the functional parameters within specific anatomical structures in the tissue that are visualized by ultrasound.

Tomowave Laboratories, Inc. | Date: 2015-02-02

Provided herein are system and methods for monitoring and guiding thermal therapy procedures within a human or animal tissue. The system comprises a therapeutic module configured to apply thermal treatment to a subject; an ultrasound imaging module; an optoacoustic imaging module; a processing module connected to both ultrasound and optoacoustic based imaging module; and an operating controlling module connected with said processing module and configured to manipulate at least one of said therapeutic module, ultrasound imaging module or optoacoustic imaging module. The calibration method is able to eliminate the inconsistency of optoacoustic based temperature measurements caused by sample-to-sample and spatial variations of Gruneisen parameter for different tissues. The method for temperature-structure imaging is able to generate both two dimensional and three dimensional co-registered structure and temperature images for the tissues inside a region of interest of a subject.

Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 200.81K | Year: 2014

Summary / Abstract The objective of this Phase-I SBIR project is to develop a novel transrectal optoacoustic-ultrasonic (OU) imaging system for guiding cryotherapy of prostate cancer via real-time monitoring of ice ball formation and temperature distribution within the area of healthy tissues adjacent to the rectal wall. The proposed system will be capable of (i) non-invasive monitoring of spatial temperature distribution in areas of important innervation around rectal wall during cryotherapy and (ii) monitoring of development of the ice ball boundary. After encouraging additional preliminary studies we decided to restructure our Research Strategy and resubmit this proposal for development of a commercial prototype of the image-guided cryotherapy system andits in vivo evaluation of two canine prostates in the course of treatment. The proposed system will operate in real time and will be capable of imaging the prostate gland and assist in computer-controlled treatment procedure. Current methods of prostate c

Wang K.,Washington University in St. Louis | Su R.,Tomowave Laboratories, Inc. | Oraevsky A.A.,Tomowave Laboratories, Inc. | Anastasio M.A.,Washington University in St. Louis
Physics in Medicine and Biology | Year: 2012

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 the 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. © 2012 Institute of Physics and Engineering in Medicine.

Discover hidden collaborations