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Medical image simulation is useful for biological modeling, image analysis, and designing new imaging devices but it is not widely available due to the complexity of simulators, the scarcity of object models, and the heaviness of the associated computations. This paper presents the Virtual Imaging Platform, an openly-accessible web platform for multi-modality image simulation. The integration of simulators...
Due to high scattering effects inside lumen, detection of luminal borders in intravascular ultrasound (IVUS) images becomes challenging when high frequency transducers are employed. In this paper, we further study previously developed three-dimensional (3D) multiscale overcomplete brushlet-driven harmonic analysis, motivated by what experts visually do, to trace the lumen borders by exploiting spatial...
We present a novel method for tracking myocardial motion in 2D ultrasound sequences based on non-rigid registration using an anatomical free-form deformation (AFFD) model where the basis functions are locally oriented along the radial and circumferential direction of the left ventricle (LV). This formulation allows us to model the LV motion more naturally compared to previously proposed FFD's defined...
This paper is an extension of our ISBI 2011 work, where we proposed a novel variational approach to estimate dense myocardial velocity fields from 4D ultrasound (4DUS). In this paper, we present a thorough performance evaluation of our method by comparing it with the primary method of record, which relies on cross-correlation. Our comparative performance evaluation uses several data sources, including...
A level set-based method for tracking the endocardium from 3D ultrasound images is presented. The tracking process is initialized by a manual delineation and performed automatically. The method does not use a shape prior model, removing the requirement of acquiring large sets of training data, and providing adaptivity for abnormal cases. At each image frame, the edge strength is estimated and locations...
It is an exciting time for imaging in perinatal care. Technical advances in imaging technology mean that good quality clinical 3D ultrasound images of the growing fetus can be acquired from an early gestational age (GA) (11 weeks GA onwards). With the help of advances in MR-based reconstruction which compensate for fetal motion, high quality images of the fetal brain (and other organs) can be obtained...
One in ten children has neurodevelopmental disorders and it is estimated that in about two thirds the problem occurred during fetal or perinatal life. The development of imaging biomarkers to detect and monitor abnormal neurodevelopment is a research and innovation opportunity. There is a strong need of supra-disciplinary researchers with transversal skills encompassing biomedical neuroscience knowledge...
Traditional intensity-based registration methods are often insufficient for tumour tracking in time-series ultrasound, where the low signal-to-noise ratio significantly degrades the quality of the output images, and topological changes may occur as the anatomical structures slide in and out of the focus plane. To overcome these issues, we propose a hybrid feature-based Log-Demons registration method...
Our group is developing a method based on 3D high-frequency ultrasound (HFU) and 3D quantitative ultrasound (QUS) to help pathologists detect micrometastases in freshly-excised lymph nodes of patients with histologically-proven primary cancer. From a signal and image processing perspective, we report on our efforts to acquire and classify lymph-node tissue based on 3D QUS parameter estimates. We evaluated...
The shadow regions in ultrasound (US) B-mode images are due to severe reflection of backscattered signals from dense tissue/medium interface. The loss of ultrasound energy as well as lack of textural or spectral features in these regions raise uncertainty, resulting confusion among experts decisions and developed computer-aided diagnosis (CAD) algorithms outcomes. In this paper, we present a novel...
Registration of ultrasound images is often complicated due to inherent noise. Robust similarity metrics and optimization procedures are required to facilitate medical applicability. In this paper a novel hybrid procedure, incorporating global statistics and local textural features, is proposed for the registration of envelope detected radio frequency ultrasound data. On the global scale this is achieved...
Ultrasound guidance is used for many surgical applications such as biopsy and electrode insertion. This paper presents an improved method for tracking such micro tools inserted in human tissues. The RANSAC algorithm [1] has been implemented to detect the exact position of the needle in a stationary situation. In this paper, the Kalman filter is added to estimate the position of the needle in a dynamical...
Emerging sonography techniques often imply increasing in the number of transducer elements involved in the imaging process. Consequently, larger amounts of data must be acquired and processed by the beamformer. The significant growth in the amounts of data effects both machinery size and power consumption. Within the classical sampling framework, state of the art systems reduce processing rates by...
Spatial registration of 2D ultrasound (US) scans and 3D volume reconstruction are very useful tools for clinical diagnosis. However, the existing methods for freehand US scan registration tend to be hindered by physical constraints of the equipment and patient motion artifacts. This paper describes a low-cost and unobtrusive method for spatially registering 2D US scans with six degrees of freedom...
The use of ultrasound imaging for image guidance of cardiac procedures is limited by the small field of view of the ultrasound volume. A larger view can be created by image-based registration of partially overlapping volumes, but automatic registration often fails unless the volume alignment is initialised close to the volumes' correct alignment. In this paper, we use X-ray images to track a trans-esophageal...
We propose a region-based segmentation method based on local statistics. The adaptive spatial locality is defined using the Intersection of Confidence Intervals (ICI) approach. This pixel dependent local scale is estimated, conditionally on the current segmentation, in the sense of minimizing the mean-square error of a Local Polynomials Approximation (LPA). In other words, the scale is ‘optimal’ since...
Echocardiographic acquisition based on point spread function (PSF) with transverse oscillations (TO) has been shown to be an efficient image formation technique for improving the accuracy of motion estimation in the transverse direction (direction perpendicular to the propagation axis). To date, beamforming yielding TO has mainly been developed for acquisitions performed in linear geometry. However,...
Ultrasound elastography imaging is being increasingly used to indicate the functional properties of musculoskeletal pathologies. Usually, this involves a real-time free-hand acquisition which has questionable consistency and does not provide a material deformation that is representative of the material function. This paper presents a novel method for acquiring quantitative ultrasound lateral strain...
The present work presents a new approach, based on the elaboration of a whole video clip of the ecoghraphic acquisition describing the lesion from different viewpoints. The focus of the paper is in comparing performances which can be obtained, using a simple classification algorithm, using the full video clip against the more common single frame approach. The system consists of five modules: preprocessing,...
Clutter, a problematic noise artifact in echocardiography, appears as a diffuse haze that obscures endocardial borders and inhibits accurate diagnoses. Several approaches are available to reduce clutter in cardiac images, yet difficult-to-image patients still exist. We have recently developed a novel imaging method, termed short-lag spatial coherence (SLSC) imaging, that has demonstrated potential...
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