Apr 11, 2017 in this paper, an entirely novel ultrasound based imaging technique called backscatter tensor imaging 3dbti is described and evaluated in vivo with respect to its capability of mapping the. Elasticity imaging, ultrasound imaging, shear elastic modulus, magnetic resonance. Elastography is a field of medical imaging that characterizes the mechanical properties of tissue, such as elasticity and viscosity. Elastic tensor imaging eti is a new imaging technique based on the tracking of shear waves by ultrafast ultrasound imaging that can yield important infor mation on the mechanical structures of. The main idea of this project is to generate a strain image, elasticity image, from the comparison of datasets of uncompressed tissue with compressed tissue. To investigate the anisotropic elasticity of soft tissues using mr. Combining mr elastography and diffusion tensor imaging for. We offer two experimental software systems for freehand threedimensional ultrasound imaging. In strain imaging a, tissue displacement is measured by correlation of rf echo signals between search windows boxes in the states before and after compression. Strain elastography relies on youngs modulus to detect strain in the axial dimension.
Utility of mri diffusion tensor imaging in carpal tunnel syndrome. Ultrasound elasticity imaging, or elastography, offers an attractive adjunct to. Automated ultrasound analysis transforms patient care. Diffusionweighted magnetic resonance imaging dwi or dwmri is the use of specific mri sequences as well as software that generates images from the resulting data that uses the diffusion of water. This page provides some basic information about wave3000 including a general program overview, hardware software. Aug 26, 2016 tissue tracking technology of routinely acquired cardiovascular magnetic resonance cmr cine acquisitions has increased the apparent ease and availability of noninvasive assessments of myocardial deformation in clinical research and practice. Gpubased elasticity imaging algorithms 3 throughput we performed volume rendering by processing multiple images at the same time by combining them horizontally along the axial direction 5. Background after successful utilization of diffusion tensor imaging dti in. Ftimer leverages multiscale tensor regional distributions. Fast tensor image morphing for elastic registration. Ultrasound is now routinely used to guide peripheral nerve blocks and has dramatically changed the landscape of regional anesthesia. It operates by solving the threedimensional 3d viscoelastic wave equation based on a method of finite differences. Ftimer leverages multiscale tensor regional distributions and local boundaries for hierarchically driving deformable matching of tensor image volumes. In particular, cancers in soft tissue tend to be harder than the surrounding tissue.
Elasticity images consist of either an image of strain in response to force or an image of estimated elastic modulus. However, as mentioned earlier, elastic vector wavefields are not usually processed by specifically designed imaging procedures, but rather by extensions of techniques used for scalar wavefields. Pdf elastic tensor imaging, toward a new modality for. Utility of mri diffusion tensor imaging in carpal tunnel. Thus, ultrasound elasticity imaging can be advantageously used to detect cancers. Diffusion tensor imaging dti based on echo planar imaging epi can suffer from geometric image distortions in comparison to conventional anatomical magnetic resonance imaging. Moreover, ultrasound elastic tensor imaging, which assesses the shear wave. In this study, we introduce 3d backscatter tensor imaging 3dbti. Diffusion tensor imaging dti is a magnetic resonance imaging technique that enables the measurement of the restricted diffusion of water in tissue in order to produce neural tract images instead of using this data solely for the purpose of assigning contrast or colors to pixels in a crosssectional image. This technique is based on ultrasound tracking of quasistatic. Abstractthe assessment of fiber architecture is of major interest in the progression of myocardial disease.
Such elastic tensor imaging with swe has been proposed 31,32 and was evaluated successfully both in vitro and in vivo in the myocardium. In shear wave imaging b, particle motion is perpendicular to the direction of wave propagation, with shear wave speed c. The main idea is that whether the tissue is hard or soft will give diagnostic information about the. The elastography process involves deforming the tissue, measuring the tissue. Ultrasound elasticity imaging describes the compressibility of biological tissues 1. The human soft tissue has different physical characteristics of ultrasound depending on whether it is normal or not. In this study, we investigate the feasibility of using three published convolution. Global and septal longitudinal strain was also performed by the speckle tracking 2d strain software. Simulating cardiac ultrasound image based on mr diffusion tensor. This elastic tensor based approach replaces the maximumbased strategy and is integrated with the core of the standard swi technique, including shear wave generation and analysis, to constitute a generalized ultrasound imaging technique, elastic tensor imaging eti, for the assessment of the fiber structure in anisotropic soft tissues. A 3d grayscale ultrasound image of one myocardial sample. This elastictensorbased approach replaces the maximumbased strategy and is integrated with the core of the standard swi technique, including shear wave generation and analysis. We present herein 3d elastic tensor imaging 3d eti, an ultrasound based volumetric imaging technique to provide quantitative volumetric mapping of tissue elastic properties in weakly elastic. Imaging the dynamics of cardiac fiber orientation in vivo using 3d.
Today, as implemented with mechanically rotating probes, this approach would be possible in. Principles of cardiovascular magnetic resonance feature. Broadly, stradx is a highly sophisticated and flexible research tool that runs under linux or irix on sgi. In this study, we proposed a new and robust fiber angle estimation method through a tensor based approach for swi, coined together as elastic tensor imaging eti, and compared it with magnetic resonance diffusion tensor imaging dti, a current gold standard and extensively reported noninvasive imaging technique for mapping fiber architecture. Tissue tracking technology of routinely acquired cardiovascular magnetic resonance cmr cine acquisitions has increased the apparent ease and availability of noninvasive assessments. Jul 01, 2019 objectives the goal of our study was to investigate the potential of myocardial shear wave imaging swi to quantify the diastolic myocardial stiffness ms kpa noninvasively in adult healthy volunteers hvs and its physiological variation with age, and in hypertrophic cardiomyopathy hcm populations with heart failure and preserved ejection function hfpef. Elastic properties of prostate gland 18 aglyamov s. This software package is written in python with tkinter. Advances in ultrasound elasticity imaging springerlink. Free software from the medical imaging group we offer two experimental software systems for freehand threedimensional ultrasound imaging. This section includes breast ultrasound, echocardiography echo, transthoracic echo tte, transesophageal echo tee, echo contrast, transducers, ultrasound software.
Recent techniques such as magnetic resonance mr diffusion tensor imaging or. We have developed a method of creating elasticity images. N2 we propose a novel diffusion tensor imaging dti registration algorithm, called fast tensor image morphing for elastic registration ftimer. Fiber tracking assessed with elastic tensor swe and diffusion tensor mr imaging was found to be highly correlated. Changes in tissue stiffness often correlate with pathological phenomena, and can be indicators of diseases, such as. Related content 3d elastic tensor imaging in weakly transversely isotropic soft tissues m correia, t deffieux, s chatelin et. Ultrasound 2d strain estimator based on image registration. The elastography process involves deforming the tissue, measuring the tissue motion using an imaging technique such as ultrasound or magnetic resonance imaging mri, and solving the equations of motion. Moreover, ultrasound elastic tensor imaging, which assesses the shear wave speed, is demonstrated to have stronger correlation r 2 0. Myocardial stiffness evaluation using noninvasive shear. Majority of the publications and commercial implementations of. In this study, we proposed a new and robust fiber angle estimation method through a tensorbased approach for swi, coined together as elastic tensor imaging eti, and compared it with magnetic resonance diffusion tensor imaging dti, a current gold standard and extensively reported noninvasive imaging technique for mapping fiber architecture.
Seventh framework program for research fp7 of the european union. Elastography is a medical imaging modality that maps the elastic properties and stiffness of soft tissue. In ultrasound elastography, the estimation of the displacement and strain fields is mostly based on measures computed from the radio frequency signals, such as time. Majority of the publications and commercial implementations of elastography, however, have focused on only the axial displacement vector and strain tensor component. We present herein 3d elastic tensor imaging 3d eti, an ultrasoundbased volumetric imaging technique to provide quantitative volumetric mapping of tissue elastic properties in weakly elastic. Three dimensional ultrasound elasticity imaging ubc library. An opensource ultrasound imaging dev kit side project developing an opensource, lowcost technological diy kit to allow scientists, academics, hackers, makers or osh fans to hack their way to ultrasound imaging. Youngs modulus is a relationship between elasticity, strain, and stress. The cephasonics software environment provides support for you to build ai applications with python and tensor flow. Separately, diffusion tensor imaging dti studies have shown that anisotropy of water diffusion is also reduced.
In ultrasound imaging, several methods have been proposed to quantify the. Accurate tracking of tissue motion is critically important for several ultrasound elastography methods. Multicomponent elastic data are often recorded in land or marine oceanbottom seismic experiments. Diffusionweighted magnetic focused ultrasound resonance. In this study, we aim to investigate tissue mechanical anisotropy using a novel technique. Article tissue elasticity imaging using ultrasound. The elastic behavior of tissues can be analyzed with tensor signal processing. Patientspecific quantification of cardiac fiber orientations is an important but difficult problem in cardiac imaging research. Its widespread availability thanks to the fact that this technology can in principle be applied on images that are part of every cmr or. A1 the images are constructed from the displacement and strain of ultrasound images of tissue in various stages of compression. Myocardial stiffness evaluation using noninvasive shear wave imaging in healthy and hypertrophic cardiomyopathic adults.
The datasets come from the radio frequency data of returning ultrasound echoes. This wave equation assumes a slowly varying stiffness tensor over the imaging space. Myocardial stiffness evaluation using noninvasive shear wave. Pdf imaging the dynamics of cardiac fiber orientation in vivo using. In strain imaging a, tissue displacement is measured by correlation of rf echo signals between search windows boxes in the states before and. Neuralnetworkbased motion tracking for breast ultrasound. To measure elasticity, a mechanical force is applied to a region of interest, and the degree of deformation measured is rendered as an image. Pdf elastic tensor imaging, toward a new modality for brain. In this paper, an entirely novel ultrasoundbased imaging technique called backscatter tensor imaging 3dbti is described and evaluated in vivo with respect to its capability of mapping. Elastographic imaging is threedimensional 3d, with three normal strain tensors, along with associated shear strain components. Shows the stage i, wherein we do dp steps until depth d at every interval of width w. Swi, coined together as elastic tensor imaging eti, and compared it. Handbook of elastic properties of solids, liquids and gases. Elasticity imaging is a byproduct of the standard ultrasound.
Among the various approaches to elastography, perhaps the most common is that pioneered by ophir and coworkers ophir et al 1991. Different approaches have been developed to estimate and image the elastic properties in the tissue. Ultrasound us elasticity imaging is an extension of the ancient art of palpation and of earlier us methods for viewing tissue stiffness such as echopalpation. Measuring anisotropic brain stiffness properties by combining mr elastography and diffusion tensor imaging. Diffusion tensor imaging for brain tumor resection. The main idea is that whether the tissue is hard or soft will give diagnostic information about the presence or status of disease. A1 the images are constructed from the displacement and strain of ultrasound.
Now considering the rf line in step i at depth d for every subset. Fiber tracking assessed with elastictensor swe and diffusion. Ultrasound scanning, also called ultrasound imaging or sonography, is a method of obtaining images from inside the human body through the use of highfrequency sound waves. In this study, we proposed a new and robust fiber angle estimation method through a tensorbased approach for swi, coined together as elastic tensor imaging eti, and compared it with magnetic. Three dimensional ultrasound elasticity imaging ubc. This section includes breast ultrasound, echocardiography echo, transthoracic echo tte, transesophageal echo tee, echo contrast, transducers, ultrasound software and point of care poc ultrasound. The main idea of this project is to generate a strain image, elasticity image, from the comparison of datasets of uncompressed tissue with compressed tissue over a region of interest. Combining mr elastography and diffusion tensor imaging for the. But now, the ability to image an entirely new tissue property, elasticity or tissue stiffness, promises to reinvigorate ultrasonic imaging much as color doppler did during the early 1980s. Ultrasonic imaging of elasticity, or elastography as it is commonly known, has come into the mainstream, with nearly all major and smaller manufacturers. The characteristics of an ultrasound beam through tissue before and after compression are compared. The proposed cardiac ultrasound image simulation method is based on diffusion.
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