The Experts below are selected from a list of 5565 Experts worldwide ranked by ideXlab platform
Pengfei Song - One of the best experts on this subject based on the ideXlab platform.
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super resolution Ultrasound localization microscopy based on a high frame rate clinical Ultrasound Scanner an in human feasibility study
Physics in Medicine and Biology, 2021Co-Authors: Chengwu Huang, Wei Zhang, Ping Gong, Uwai Lok, Shanshan Tang, Tinghui Yin, Xirui Zhang, Lei Zhu, Maodong Sang, Pengfei SongAbstract:Non-invasive detection of microvascular alterations in deep tissuesin vivoprovides critical information for clinical diagnosis and evaluation of a broad-spectrum of pathologies. Recently, the emergence of super-resolution Ultrasound localization microscopy (ULM) offers new possibilities for clinical imaging of microvasculature at capillary level. Currently, the clinical utility of ULM on clinical Ultrasound Scanners is hindered by the technical limitations, such as long data acquisition time, high microbubble (MB) concentration, and compromised tracking performance associated with low imaging frame-rate. Here we present a robust in-human ULM on a high frame-rate (HFR) clinical Ultrasound Scanner to achieve super-resolution microvessel imaging using a short acquisition time (<10 s). Ultrasound MB data were acquired from different human tissues, including a healthy liver and a diseased liver with acute-on-chronic liver failure, a kidney, a pancreatic tumor, and a breast mass using an HFR clinical Scanner. By leveraging the HFR and advanced processing techniques including sub-pixel motion registration, MB signal separation, and Kalman filter-based tracking, MBs can be robustly localized and tracked for ULM under the circumstances of relatively high MB concentration associated with standard clinical MB administration and limited data acquisition time in humans. Subtle morphological and hemodynamic information in microvasculature were shown based on data acquired with single breath-hold and free-hand scanning. Compared with contrast-enhanced power Doppler generated based on the same MB dataset, ULM showed a 5.7-fold resolution improvement in a vessel based on a linear transducer, and provided a wide-range blood flow speed measurement that is Doppler angle-independent. Microvasculatures with complex hemodynamics can be well-differentiated at super-resolution in both normal and pathological tissues. This preliminary study implemented the ultrafast in-human ULM in various human tissues based on a clinical Scanner that supports HFR imaging, indicating the potentials of the technique for various clinical applications. However, rigorous validation of the technique in imaging human microvasculature (especially for those tiny vessel structure), preferably with a gold standard, is still required.
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super resolution Ultrasound localization microscopy based on a high frame rate clinical Ultrasound Scanner an in human feasibility study
arXiv: Medical Physics, 2020Co-Authors: Chengwu Huang, Wei Zhang, Ping Gong, Uwai Lok, Shanshan Tang, Tinghui Yin, Xirui Zhang, Lei Zhu, Maodong Sang, Pengfei SongAbstract:Non-invasive detection of microvascular alterations in deep tissues in vivo provides critical information for clinical diagnosis and evaluation of a broad-spectrum of pathologies. Recently, the emergence of super-resolution Ultrasound localization microscopy (ULM) offers new possibilities for clinical imaging of microvasculature at capillary level. Currently, the clinical utility of ULM on clinical Ultrasound Scanners is hindered by the technical limitations, such as long data acquisition time, and compromised tracking performance associated with low imaging frame-rate. Here we present an in-human ULM on a high frame-rate (HFR) clinical Ultrasound Scanner to achieve super-resolution microvessel imaging using a short acquisition time (<10s). Ultrasound MB data were acquired from different human tissues, (liver, kidney, pancreatic, and breast tumor) using an HFR clinical Scanner. By leveraging the HFR and advanced processing techniques including sub-pixel motion registration, MB signal separation, and Kalman filter-based tracking, MBs can be robustly localized and tracked for successful ULM under the circumstances of relatively high MB concentration and limited data acquisition time in humans. Subtle morphological and hemodynamic information were demonstrated on data acquired with single breath-hold and free-hand scanning. Compared with contrast-enhanced power Doppler generated based on the same MB dataset, ULM showed a 5.7-fold resolution improvement in a vessel, and provided a wide-range flow speed measurement that is Doppler angle-independent. This study demonstrated the feasibility of ultrafast in-human ULM in various human tissues based on a clinical Scanner that supports HFR imaging, and showed a great potential for the implementation of super-resolution Ultrasound microvessel imaging in a myriad of clinical applications involving microvascular abnormalities and pathologies.
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two dimensional shear wave elastography on conventional Ultrasound Scanners with time aligned sequential tracking tast and comb push Ultrasound shear elastography cuse
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2015Co-Authors: Pengfei Song, Michael Macdonald, Russell H Behler, Justin D Lanning, Michael H Wang, Matthew W Urban, Armando Manduca, Heng Zhao, Matthew R Callstrom, Azra AlizadAbstract:Two-dimensional shear-wave elastography presents 2-D quantitative shear elasticity maps of tissue, which are clinically useful for both focal lesion detection and diffuse disease diagnosis. Realization of 2-D shear-wave elastography on conventional Ultrasound Scanners, however, is challenging because of the low tracking pulse-repetition-frequency (PRF) of these systems. Although some clinical and research platforms support software beamforming and plane-wave imaging with high PRF, the majority of current clinical Ultrasound systems do not have the software beamforming capability, which presents a critical challenge for translating the 2-D shear-wave elastography technique from laboratory to clinical Scanners. To address this challenge, this paper presents a time-aligned sequential tracking (TAST) method for shear-wave tracking on conventional Ultrasound Scanners. TAST takes advantage of the parallel beamforming capability of conventional systems and realizes high-PRF shear-wave tracking by sequentially firing tracking vectors and aligning shear wave data in the temporal direction. The comb-push Ultrasound shear elastography (CUSE) technique was used to simultaneously produce multiple shear wave sources within the field-of-view (FOV) to enhance shear wave SNR and facilitate robust reconstructions of 2-D elasticity maps. TAST and CUSE were realized on a conventional Ultrasound Scanner. A phantom study showed that the shear-wave speed measurements from the conventional Ultrasound Scanner were in good agreement with the values measured from other 2-D shear wave imaging technologies. An inclusion phantom study showed that the conventional Ultrasound Scanner had comparable performance to a state-of-the-art shear-wave imaging system in terms of bias and precision in measuring different sized inclusions. Finally, in vivo case analysis of a breast with a malignant mass, and a liver from a healthy subject demonstrated the feasibility of using the conventional Ultrasound Scanner for in vivo 2-D shear-wave elastography. These promising results indicate that the proposed technique can enable the implementation of 2-D shear-wave elastography on conventional Ultrasound Scanners and potentially facilitate wider clinical applications with shear-wave elastography.
Septimiu E Salcudean - One of the best experts on this subject based on the ideXlab platform.
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integrating photoacoustic tomography into a multimodal automated breast Ultrasound Scanner
Journal of Biomedical Optics, 2020Co-Authors: Corey J Kelly, Amir Refaee, Septimiu E SalcudeanAbstract:Significance: Photoacoustic tomography (PAT) is a promising emergent modality for the screening and staging of breast cancer. To minimize barriers to clinical translation, it is common to develop PAT systems based upon existing Ultrasound hardware, which can entail significant design challenges in terms of light delivery. This often results in inherently non-uniform fluence within the tissue and should be accounted for during image reconstruction. Aim: We aim to integrate PAT into an automated breast Ultrasound Scanner with minimal change to the existing system. Approach: We designed and implemented an illuminator that directs spatially non-uniform light to the tissue near the acquisition plane of the imaging array. We developed a graphics processing unit-accelerated reconstruction method, which accounts for this illumination geometry by modeling the structure of the light in the sample. We quantified the performance of this system using a custom, modular photoacoustic phantom and graphite rods embedded in chicken breast tissue. Results: Our illuminator provides a fluence of 2.5 mJ cm − 2 at the tissue surface, which was sufficient to attain a signal-to-noise ratio (SNR) of 8 dB at 2 cm in chicken breast tissue and image 0.25-mm features at depths of up to 3 cm in a medium with moderate optical scattering. Our reconstruction scheme is 200 × faster than a CPU implementation; it provides a 25% increase in SNR at 2 cm in chicken breast tissue and lowers image error by an average of 31% at imaging depths >1.5 cm compared with a method that does not account for the inhomogeneity of the illumination or the transducer directivity. Conclusions: A fan-shaped illumination geometry is feasible for PAT; however, it is important to account for non-uniform fluence in illumination scenarios such as this. Future work will focus on increasing fluence and further optimizing the Ultrasound hardware to improve SNR and overall image quality.
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an automated breast Ultrasound Scanner with integrated shear wave elastography doppler flow imaging and photoacoustic tomography
Internaltional Ultrasonics Symposium, 2018Co-Authors: Corey J Kelly, Julio Lobo, Mohammad Honarvar, Yanan Shao, Septimiu E SalcudeanAbstract:We have integrated shear wave elasticity, Doppler flow imaging, and photoacoustic tomography into the SonixEm-brace automated breast Ultrasound Scanner (ABUS). This system can acquire a multimodal volumetric scan of the entire breast in under ten minutes. We present here a series of phantom studies demonstrating the capabilities of this combined system for the first time. We imaged a commercially available elastography training phantom, measuring the stiffness of the background material to be 17.5 ± 0.1 kPa and the stiffness of the inclusions to be 32.3 ± 0.3 kPa, as compared to the manufacturer's provided values of 20 ± 5 kPa and ~40 kPa, respectively. We imaged a knotted tube phantom, demonstrating the computation and scan conversion of volumetric Doppler flow data. Finally, we developed and imaged a multimodal phantom incorporating inclusions which are uniquely visible in either elasticity or photoacoustic imaging.
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an automated breast Ultrasound Scanner with integrated photoacoustic tomography
Proceedings of SPIE, 2016Co-Authors: Corey J Kelly, Hamid Moradi, Septimiu E SalcudeanAbstract:We have integrated photo-acoustic imaging into an automated breast Ultrasound Scanner (ABUS) with the goal of simultaneously performing Ultrasound (US) and multi-spectral photo-acoustic tomography (PAT). This was accomplished with minimal change to the existing automated Scanner by coupling laser light into an optical fiber for flexible and robust light delivery. We present preliminary tomography data acquired with this setup, including a simple resolution-testing geometry and a tissue phantom. Integrating PAT into the ABUS such that breast imaging is possible will require illumination from below the transducer dome. To that end, we are moving towards a fiber-based, localized illumination geometry which is fixed relative to the transducer. By illuminating locally (only near the current acquisition slice), this approach reduces overall light exposure at the tissue surface, allowing higher light intensity per acquisition (which translates to higher absorber contrast), while remaining below safe exposure thresholds. We present time-domain simulations of photo-acoustic imaging under non-uniform illumination conditions, and test one potential weighting scheme which can be used to extract absorber locations.
Tomasz Gorzelanczyk - One of the best experts on this subject based on the ideXlab platform.
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a nondestructive methodology for the testing of fibre cement boards by means of a non contact Ultrasound Scanner
Construction and Building Materials, 2016Co-Authors: Krzysztof Schabowicz, Tomasz GorzelanczykAbstract:Abstract This paper presents a new nondestructive technique using a non-contact Ultrasound Scanner, suitable for the testing of fibre cement boards. The capabilities of this technique for locating defects in usually unilaterally accessible fibre cement boards during their production are described. An original test methodology developed for this purpose is included. The methodology was verified through laboratory tests on specimens and through trials on a production line. The suitability of this technique for testing fibre cement boards and its reliability have been confirmed.
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automated control of cellulose fibre cement boards with a non contact Ultrasound Scanner
Automation in Construction, 2015Co-Authors: Radoslaw Drelich, Tomasz Gorzelanczyk, Michal Pakula, Krzysztof SchabowiczAbstract:Abstract This paper presents a non-contact ultrasonic method using Lamb waves, for the automatic quality control of cellulose fibre cement boards during their production. The causes of typical material imperfections: delamination, cracks, material heterogeneity and areas of excessive moisture content, disqualifying such boards from sale, are described. Tests were carried out using an Ultrasound Scanner specially constructed to identify the imperfections. The Lamb wave amplitude-signal registration position characteristics were determined and the defective areas were identified on their basis. Also the influence of board moisture content on ultrasonic test results was taken into account. The moisture content in the boards was measured in all the stages of their production and maps showing the distribution of average mass moisture content in the finished cellulose fibre cement boards were plotted. The studies have shown the non-contact Ultrasound method based on Lamb waves to be a suitable tool for the testing of all the boards being in production without halting the latter.
Juliana Marotti - One of the best experts on this subject based on the ideXlab platform.
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Scanning of a Dental Implant with a High-Frequency Ultrasound Scanner: A Pilot Study
'MDPI AG', 2021Co-Authors: Lauren Bohner, Daniel Habor, Klaus Radermacher, Stefan Wolfart, Juliana MarottiAbstract:The purpose of this in vitro study was to assess the trueness of a dental implant scanned using an intraoral high-frequency Ultrasound prototype and compared with conventional optical Scanners. An acrylic resin cast containing a dental implant at position 11 was scanned with a fringe projection 3D sensor for use as a reference dataset. The same cast was scanned 10 times for each group. Ultrasound scanning was performed with a high-frequency probe (42 MHz, aperture diameter of 4 mm and focus length of 8 mm), and 3D images were reconstructed based on the depth of each surface point echo. Optical scans were performed in a laboratory and with an intraoral Scanner. A region of interest consisting of the dental implant site was segmented and matched to the reference dataset. Trueness was defined as the closeness between experimental data and the reference surface. Statistical analysis was performed with one-way ANOVA and post-hoc tests with a significance level of p = 0.05. No statistical difference was found among the evaluated Scanners. The mean deviation error was 57.40 ± 17.44 µm for the Ultrasound Scanner, 75.40 ± 41.43 µm for the laboratory Scanner and 38.55 ± 24.34 µm for the intraoral Scanner. The high-frequency Ultrasound Scanner showed similar trueness to optical Scanners for digital implant impression
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assessment of buccal bone surrounding dental implants using a high frequency Ultrasound Scanner
Ultrasound in Medicine and Biology, 2019Co-Authors: Lauren Bohner, Daniel Habor, Klaus Radermacher, Stefan Wolfart, Pedro Tortamano, Juliana MarottiAbstract:Abstract The purpose of this study was to determine the buccal bone dimensions surrounding dental implants using a high-frequency Ultrasound (US) Scanner and cone-beam computed tomography (CBCT). Dental implants (n = 10) inserted in the maxilla of dry skulls were scanned using US (28 MHz, bandwidth 84%, aperture 6 mm, focal depth 13.2 mm) and CBCT (70 kV, 6.3 mA, voxel size 0.18 mm). The bone level and buccal bone thickness were determined on the buccal–lingual diameter of the implant. As a control group, the evaluated site was represented by a stone block containing the dental implant, and measurements were performed using an optical microscope. Statistical analysis was performed using a mixed linear regression model at a significance level of p
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accuracy of high frequency Ultrasound Scanner in detecting peri implant bone defects
Ultrasound in Medicine and Biology, 2019Co-Authors: Lauren Bohner, Daniel Habor, Stefan Wolfart, Felix Gremse, Pedro Tortamano, Juliana MarottiAbstract:Abstract The purpose of this study was to assess the accuracy of high-frequency Ultrasound (US) in the measurement of peri-implant bone defects in comparison with cone-beam computed tomography (CBCT) and micro-computed tomography (µCT). Bone defects were mechanically created around dental implants inserted into porcine ribs (n = 10). The bone samples were scanned by CBCT, µCT and US. Linear dimensions of the peri-implant defects were determined for supra-alveolar component, intra-bony component and width. The accuracy of measurements was evaluated with repeated-measures analysis of variance and the intra-class correlation coefficient at p ≤ 0.05. US underestimated the measurements for the supra-alveolar and intra-bony components in comparison to CBCT and µCT, and there were no statistically significant differences in the measurements of width. The intra-class correlation coefficient of US ranged from 0.96 to 0.98, whereas that for CBCT ranged from 0.77 to 0.97. US was accurate in measuring the width of peri-implant defects, although vertical measurements were underestimated by approximately 1 mm in comparison to those of CBCT and µCT.
Chulhong Kim - One of the best experts on this subject based on the ideXlab platform.
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three dimensional clinical handheld photoacoustic Ultrasound Scanner
Photoacoustics, 2020Co-Authors: Changyeop Lee, Wonseok Choi, Jeesu Kim, Chulhong KimAbstract:Clinical 2D photoacoustic (PA) imaging can be easily implemented in a traditional Ultrasound (US) system. However, 3D PA imaging is still preferable because 2D B-mode PA/US imaging suffers from low reproducibility and high-operator dependency. Here, we demonstrate a compact clinical handheld 3D PA/US Scanner using an 1D linear array US transducer combined with a mechanical scanning stage working via a Scotch yoke mechanism. The entire Scanner measures just 100 × 80 × 100 mm3 and weighs only 950 g, so it can easily be operated by hand. Blood vessels and hemoglobin oxygen saturation images of different parts of the human body (e.g., neck, wrist, thigh, and instep) have been successfully acquired. The system can potentially be used for clinical applications in fields such as oncology, dermatology, nephrology, and internal medicine.
