Publications
55 results found
Harput S, Christensen-Jeffries K, Brown J, et al., 2018, 3-D super-resolution ultrasound (SR-US) imaging using a 2-D sparse array with high volumetric imaging rate, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE
Super-resolution ultrasound imaging has been sofar achieved in 3-D by mechanically scanning a volume witha linear probe, by co-aligning multiple linear probes, by usingmultiplexed 3-D clinical ultrasound systems, or by using 3-D ultrasound research systems. In this study, a 2-D sparsearray was designed with 512 elements according to a density-tapered 2-D spiral layout and optimized to reduce the sidelobesof the transmitted beam profile. High frame rate volumetricimaging with compounded plane waves was performed usingtwo synchronized ULA-OP256 systems. Localization-based 3-Dsuper-resolution images of two touching sub-wavelength tubeswere generated from a 120 second acquisition.
Stanziola A, Toulemonde M, Corbett R, et al., 2018, Benefits of adaptive beamforming methods for contrast enhanced high frame-rate ultrasound, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719
Toulemonde MEG, Li Y, Lin S, et al., 2018, High-frame-rate contrast echocardiography using diverging waves: initial in-vitro and in-vivo evaluation, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol: 65, Pages: 2212-2221, ISSN: 0885-3010
Contrast Echocardiography (CE) ultrasound with microbubble contrast agents (UCA) has significantly advanced our capability for assessment of cardiac function, including myocardium perfusion quantification. However in standard CE techniques obtained with line by line scanning, the frame rate and image quality are limited. Recent research has shown significant frame rate improvement in non-contrast cardiac imaging. In this work we present and initially evaluate, both in-vitro and in-vivo, a high frame rate (HFR) CE imaging system using diverging waves and pulse inversion sequence. An imaging frame rate of 5500 frames per second before and 250 frames per second after compounding is achieved. A destruction-replenishment sequence has also been developed. The developed HFR CE is compared with standard CE in-vitro on a phantom and then in-vivo on a sheep heart. The image signal to noise ratio, contrast between the myocardium and the chamber are evaluated. Results show up to 13.4 dB improvement in contrast for HFR CE over standard CE when compared at the same display frame-rate even when the average spatial acoustic pressure in HFR CE is 36% lower than the standard CE. It is also found that when coherent compounding is used the HFR CE image intensity can be significantly modulated by the flow motion in the chamber.
Toulemonde M, Zhang G, Riemer K, et al., 2018, Locally activated nanodroplets and high frame rate imaging for real-time flow visualization – preliminary in-vivo demonstration, BioMedEng18
Toulemonde MEG, Corbett R, Papadopoulou V, et al., 2018, High frame rate contrast echocardiography –in human demonstration, JACC: Cardiovascular Imaging, Vol: 11, Pages: 923-924, ISSN: 1936-878X
Li Y, Ho CP, Toulemonde M, et al., 2018, Fully automatic myocardial segmentation of contrast echocardiography sequence using random forests guided by shape model, IEEE Transactions on Medical Imaging, Vol: 37, Pages: 1081-1091, ISSN: 0278-0062
Myocardial contrast echocardiography (MCE) is animaging technique that assesses left ventricle function and myocardialperfusion for the detection of coronary artery diseases.Automatic MCE perfusion quantification is challenging and requiresaccurate segmentation of the myocardium from noisy andtime-varying images. Random forests (RF) have been successfullyapplied to many medical image segmentation tasks. However, thepixel-wise RF classifier ignores contextual relationships betweenlabel outputs of individual pixels. RF which only utilizes localappearance features is also susceptible to data suffering fromlarge intensity variations. In this paper, we demonstrate howto overcome the above limitations of classic RF by presentinga fully automatic segmentation pipeline for myocardial segmentationin full-cycle 2D MCE data. Specifically, a statisticalshape model is used to provide shape prior information thatguide the RF segmentation in two ways. First, a novel shapemodel (SM) feature is incorporated into the RF frameworkto generate a more accurate RF probability map. Second, theshape model is fitted to the RF probability map to refineand constrain the final segmentation to plausible myocardialshapes. We further improve the performance by introducinga bounding box detection algorithm as a preprocessing stepin the segmentation pipeline. Our approach on 2D image isfurther extended to 2D+t sequences which ensures temporalconsistency in the final sequence segmentations. When evaluatedon clinical MCE datasets, our proposed method achieves notableimprovement in segmentation accuracy and outperforms otherstate-of-the-art methods including the classic RF and its variants,active shape model and image registration.
Toulemonde M, Eckersley RJ, Tang M-X, 2017, High frame rate contrast enhanced echocardiography: microbubbles stability and contrast evaluation, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719
Contrast Echocardiography (CE) with microbubble contrast agents have significantly advanced our capability in assessing cardiac function, including myocardium perfusion imaging and quantification. However in conventional CE techniques with line by line scanning, the frame rate is limited to tens of frames per second and image quality is low. Recent works in high frame-rate (HFR) ultrasound have shown significant improvement of the frame rate. The aim of this work is to investigate the MBs stability and the contrast improvement using HFR CE compared to CE transmission at an echocardiography relevant frequency for different mechanical indices (MIs). Our results show that the contrast and bubble destruction of HFR CE and standard CEUS varies differently as a function of space and MIs. At low MIs, HFR CE shows a similar behavior as focused CE with little MB destruction, and generates better CTR (up to 3 folds). As MI increases, the MB destruction is more significant for HFR CE with a reduction of the CTR.
Toulemonde M, Duncan WC, Leow C-H, et al., 2017, Cardiac flow mapping using high frame rate diverging wave contrast enhanced ultrasound and image tracking, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719
Contrast echocardiography (CE) ultrasound with microbubble contrast agents have significantly advanced our capability in assessing cardiac function. However in conventional CE techniques with line by line scanning, the frame rate is limited to tens of frames per second, making it difficult to track the fast flow within cardiac chamber. Recent research in high frame-rate (HFR) ultrasound have shown significant improvement of the frame rate in non-contrast cardiac imaging. In this work we show the feasibility of microbubbles flow tracking in HFR CE acquisition in vivo with a high temporal resolution and low MI as well as the detection of vortex near the valves during filling phases agreeing with previous study.
Toulemonde M, Stanziola A, Li Y, et al., 2017, Effects of motion on high frame rate contrast enhanced echocardiography and its correction, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719
Contrast echocardiography (CE) ultrasound with microbubble contrast agents have significantly advanced our capability in assessing cardiac function, including myocardium perfusion imaging and quantification. However in conventional CE techniques with line by line scanning, the frame rate is limited to tens of frames per second and image quality is low. Recent research works in high frame-rate (HFR) ultrasound have shown significant improvement of the frame rate in non-contrast cardiac imaging. But with a higher frame rate, the coherent compounding of HFR CE images shows some artifacts due to the motion of the microbubbles. In this work we demonstrate the impact of this motion on compounded HFR CE in simulation and then apply a motion correction algorithm on in-vivo data acquired from the left ventricle (LV) chamber of a sheep. It shows that even if with the fast flow found inside the LV, the contrast is improved at least 100%.
Toulemonde M, Leow CH, Eckersley RJ, et al., 2017, Cardiac flow mapping using high frame-rate diverging wave contrast enhanced ultrasound and image tracking, ISSN: 1948-5719
High frame-rate (HFR) contrast enhanced echocardiography (CE), based on pulse inversion (PI), diverging wave transmission, was recently proposed for improving the image contrast over standard CE with focused transmission [M. Toulemonde, IUS 2016]. Comparing to ∼30Hz in standard CE, HFR CE can reach a frame rate of up to 6000Hz, allowing accurate tracking of fast flow structure and dynamics in cardiac chambers. A recent study shows the benefit of HFR cardiac imaging for flow vortex detection by using a Duplex mode (B-mode + Doppler) but without microbubble contrast agents, the signals from blood cells are weak [J. Faurie, UFFC, 2017]. Another clinical research shows the potential of visualising and tracking vortex with a CE at a frame rate of 204 ± 39 frames / s but the field of view is limited and the frame rate is still low for tracking the very fast cardiac flow [H. Abe, Cardiovascular Imaging, 2013]. The aim of this work is to demonstrate the feasibility of flow mapping using HFR CE in-vivo cardiac imaging.
Papadopoulou V, Corbett R, Zhou X, et al., 2017, Notice of Removal: 3D flow velocity reconstruction in a human radial artery from measured 2D high-frame-rate plane wave contrast enhanced ultrasound in two scanning directions - A feasibility study, ISSN: 1948-5719
Hemodynamics play an important role in the development of cardiovascular disease, with atherosclerosis and intimal hyperplasia arising at sites with low wall shear stress and disturbed endoluminal mixing. Computational fluid dynamics (CFD) can study blood rheology, however performance relies on precise 3D anatomy and accurate blood flow measurements to seed the initial and boundary conditions. Recently, ultrasound (US) 2D high frame-rate (HFR) acquisitions using plane-wave (PW) imaging combined with contrast agent tracking have been used for US image velocimetry (UIV) to measure blood flow profiles (Leow CH, UMB 2015). Here we investigate the experimental feasibility of combining multiple 2D UIV acquired in two nonparallel scanning directions along a human brachial artery for estimating the 3D blood flow velocity profile.
Toulemonde M, Stanziola A, Li Y, et al., 2017, Effects of motion on high frame rate contrast enhanced echocardiography and its correction, ISSN: 1948-5719
Contrast enhanced ultrasound (CEUS) has shown great promise in quantifying myocardial perfusion and ventricular flow. More recently high frame-rate contrast enhanced echocardiography (HFR CE), based on pulse inversion (PI) and diverging waves, has shown to significantly improve the image contrast over standard CEUS [M. Toulemonde, IUS 2016]. Both contrast pulse sequences and spatial compounding involve coherent summation of echoes from a target at different time points. Consequently they are susceptible to target motion, and their effects are very different and it is not yet clear of their combined impact on compounded HFR CEUS PI images. Furthermore, there is no study to demonstrate motion corrected compounded HFR CEUS. The aim of this work is firstly to demonstrate the impact of the motion on compounded HFR CE in simulation and secondly to evaluate the motion correction algorithm in-vivo.
Toulemonde M, Eckersley RJ, Tang MX, 2017, High frame rate contrast enhanced echocardiography: Microbubbles stability and contrast evaluation, ISSN: 1948-5719
High frame-rate contrast enhanced echocardiography (HFR CE), based on pulse inversion (PI) and diverging wave transmission, was recently proposed for improving the image contrast over standard contrast enhanced ultrasound (CEUS) with focused transmission [M. Toulemonde, IUS 2016]. While it has great potential for improved quantification of myocardium perfusion, it is not clear as whether the stability of microbubbles (MBs) is reduced under HFR ultrasound. Existing studies on MBs stability in HFR CEUS are limited to plane wave imaging at high clinical frequency (3.5 and 7.5 MHz) [O. Couture, 2012 - J. Viti, 2016] where commercial MBs' behaviour is very different from that at lower clinical ultrasound frequency used in cardiac imaging. The aim of this work is to investigate the MBs stability and the contrast improvement using HFR CE compared to CEUS transmission at an echocardiography relevant frequency for different mechanical indices (MIs).
Zhu J, Lin S, Harput S, et al., 2017, Notice of Removal: Exploring mild bubble disruption and high frame rate contrast enhanced ultrasound for specific imaging of lymphatic vessel, ISSN: 1948-5719
Contrast enhanced ultrasound imaging shows great potential for visualising lymphatic vessels and identifying sentinel lymph nodes. However current approaches still have artefacts reducing the lymphatic vessel contrast against background tissue [A. Sever, Clinical Radiology, 2012]. Pulse inversion (PI) detects nonlinear echoes from microbubbles but also from tissue due to nonlinear propagation of ultrasound [M.X. Tang, UMB, 2010]. Doppler acquisition has difficulties due to slow lymph flow rate. In this study, we propose mild bubble disruption imaging (MIDI) that utilises high frame-rate (HFR) plane wave transmission at modest MI to reduce nonlinear tissue artefact for lymphatic imaging with slow flow.
Zhu J, Lin S, Harput S, et al., 2017, High Frame Rate Contrast Enhanced Ultrasound Imaging of Lymphatic Vessel Phantom, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719
Varray F, Toulemonde M, Bernard A, et al., 2017, Fast Nonlinear Ultrasound Propagation Simulation Using a Slowly Varying Envelope Approximation, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, Vol: 64, Pages: 1015-1022, ISSN: 0885-3010
Toulemonde M, Li Y, Lin S, et al., 2016, Cardiac imaging with high frame rate contrast enhanced ultrasound: in-vivo demonstration, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719
This work presents the first in-vivo High-frame rate Contrast Enhanced Ultrasound (HFR CEUS) for cardiac application. The in-vivo acquisition has been made on a sheep. A coherent compounding of diverging waves combined with Pulse Inversion (PI) transmission allow a frame rate of 250 frame per seconds which is 8 times faster than standard CEUS acquisition in cardiac application. The proposed method improves the image contrast compared to the CEUS and allows a better tracking of fast movement of the heart.
Stanziola A, Toulemonde M, Yildiz YO, et al., 2016, Ultrasound Imaging with Microbubbles, IEEE Signal Processing Magazine, Vol: 33, Pages: 111-117, ISSN: 1053-5888
Basset O, Bouakaz A, Senegond N, et al., 2015, Ultrasound imaging using CMUT - Techniques developed in the frame of the ANR BBMUT project, IRBM, Vol: 36, Pages: 126-132, ISSN: 1959-0318
Toulemonde M, Basset O, Tortoli P, et al., 2015, Thomson's multitaper approach combined with coherent plane-wave compounding to reduce speckle in ultrasound imaging, ULTRASONICS, Vol: 56, Pages: 390-398, ISSN: 0041-624X
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- Citations: 15
Toulemonde M, Varray F, Bernard A, et al., 2015, Nonlinearity parameter <i>B</i>/<i>A</i> of biological tissue ultrasound imaging in echo mode, 20th International Symposium on Nonlinear Acoustics (ISNA) including the 2nd International Sonic Boom Forum (ISBF), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
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- Citations: 1
Toulemonde M, Varray F, Basset O, et al., 2014, HIGH FRAME RATE COMPOUNDING FOR NONLINEAR B/A PARAMETER ULTRASOUND IMAGING IN ECHO MODE - SIMULATION RESULTS, IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Publisher: IEEE, ISSN: 1520-6149
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- Citations: 4
Toulemonde M, Basset O, Cachard C, et al., 2013, Thomson's multitaper high frame rate compounding for speckle reduction, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, Pages: 1444-1447, ISSN: 1948-5719
Toulemonde M, Basset O, Varray F, et al., 2012, Resolution improvement in Thomson's multitaper approach using the pulse inversion technique, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, Pages: 1934-1937, ISSN: 1948-5719
Varray F, Toulemonde M, Basset O, et al., 2012, Fast and accurate nonlinear pressure field simulation: a finite-difference scheme into the Fourier domain, IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, Pages: 1682-1685, ISSN: 1948-5719
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- Citations: 2
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