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Sample records for 3d cardiac ultrasound

  1. Mapping cardiac fiber orientations from high-resolution DTI to high-frequency 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Wagner, Mary B.; Fei, Baowei

    2014-03-01

    The orientation of cardiac fibers affects the anatomical, mechanical, and electrophysiological properties of the heart. Although echocardiography is the most common imaging modality in clinical cardiac examination, it can only provide the cardiac geometry or motion information without cardiac fiber orientations. If the patient's cardiac fiber orientations can be mapped to his/her echocardiography images in clinical examinations, it may provide quantitative measures for diagnosis, personalized modeling, and image-guided cardiac therapies. Therefore, this project addresses the feasibility of mapping personalized cardiac fiber orientations to three-dimensional (3D) ultrasound image volumes. First, the geometry of the heart extracted from the MRI is translated to 3D ultrasound by rigid and deformable registration. Deformation fields between both geometries from MRI and ultrasound are obtained after registration. Three different deformable registration methods were utilized for the MRI-ultrasound registration. Finally, the cardiac fiber orientations imaged by DTI are mapped to ultrasound volumes based on the extracted deformation fields. Moreover, this study also demonstrated the ability to simulate electricity activations during the cardiac resynchronization therapy (CRT) process. The proposed method has been validated in two rat hearts and three canine hearts. After MRI/ultrasound image registration, the Dice similarity scores were more than 90% and the corresponding target errors were less than 0.25 mm. This proposed approach can provide cardiac fiber orientations to ultrasound images and can have a variety of potential applications in cardiac imaging.

  2. DTI template-based estimation of cardiac fiber orientations from 3D ultrasound

    PubMed Central

    Qin, Xulei; Fei, Baowei

    2015-01-01

    Purpose: Cardiac muscle fibers directly affect the mechanical, physiological, and pathological properties of the heart. Patient-specific quantification of cardiac fiber orientations is an important but difficult problem in cardiac imaging research. In this study, the authors proposed a cardiac fiber orientation estimation method based on three-dimensional (3D) ultrasound images and a cardiac fiber template that was obtained from magnetic resonance diffusion tensor imaging (DTI). Methods: A DTI template-based framework was developed to estimate cardiac fiber orientations from 3D ultrasound images using an animal model. It estimated the cardiac fiber orientations of the target heart by deforming the fiber orientations of the template heart, based on the deformation field of the registration between the ultrasound geometry of the target heart and the MRI geometry of the template heart. In the experiments, the animal hearts were imaged by high-frequency ultrasound, T1-weighted MRI, and high-resolution DTI. Results: The proposed method was evaluated by four different parameters: Dice similarity coefficient (DSC), target errors, acute angle error (AAE), and inclination angle error (IAE). Its ability of estimating cardiac fiber orientations was first validated by a public database. Then, the performance of the proposed method on 3D ultrasound data was evaluated by an acquired database. Their average values were 95.4% ± 2.0% for the DSC of geometric registrations, 21.0° ± 0.76° for AAE, and 19.4° ± 1.2° for IAE of fiber orientation estimations. Furthermore, the feasibility of this framework was also performed on 3D ultrasound images of a beating heart. Conclusions: The proposed framework demonstrated the feasibility of using 3D ultrasound imaging to estimate cardiac fiber orientation of in vivo beating hearts and its further improvements could contribute to understanding the dynamic mechanism of the beating heart and has the potential to help diagnosis and therapy

  3. Spatiotemporal non-rigid image registration for 3D ultrasound cardiac motion estimation

    NASA Astrophysics Data System (ADS)

    Loeckx, D.; Ector, J.; Maes, F.; D'hooge, J.; Vandermeulen, D.; Voigt, J.-U.; Heidbüchel, H.; Suetens, P.

    2007-03-01

    We present a new method to evaluate 4D (3D + time) cardiac ultrasound data sets by nonrigid spatio-temporal image registration. First, a frame-to-frame registration is performed that yields a dense deformation field. The deformation field is used to calculate local spatiotemporal properties of the myocardium, such as the velocity, strain and strain rate. The field is also used to propagate particular points and surfaces, representing e.g. the endo-cardial surface over the different frames. As such, the 4D path of these point is obtained, which can be used to calculate the velocity by which the wall moves and the evolution of the local surface area over time. The wall velocity is not angle-dependent as in classical Doppler imaging, since the 4D data allows calculating the true 3D motion. Similarly, all 3D myocardium strain components can be estimated. Combined they result in local surface area or volume changes which van be color-coded as a measure of local contractability. A diagnostic method that strongly benefits from this technique is cardiac motion and deformation analysis, which is an important aid to quantify the mechanical properties of the myocardium.

  4. Estimation of 3D cardiac deformation using spatio-temporal elastic registration of non-scanconverted ultrasound data

    NASA Astrophysics Data System (ADS)

    Elen, An; Loeckx, Dirk; Choi, Hon Fai; Gao, Hang; Claus, Piet; Maes, Frederik; Suetens, Paul; D'hooge, Jan

    2008-03-01

    Current ultrasound methods for measuring myocardial strain are often limited to measurements in one or two dimensions. Spatio-temporal elastic registration of 3D cardiac ultrasound data can however be used to estimate the 3D motion and full 3D strain tensor. In this work, the spatio-temporal elastic registration method was validated for both non-scanconverted and scanconverted images. This was done using simulated 3D pyramidal ultrasound data sets based on a thick-walled deforming ellipsoid and an adapted convolution model. A B-spline based frame-to-frame elastic registration method was applied to both the scanconverted and non-scanconverded data sets and the accuracy of the resulting deformation fields was quantified. The mean accuracy of the estimated displacement was very similar for the scanconverted and non-scanconverted data sets and thus, it was shown that 3D elastic registration to estimate the cardiac deformation from ultrasound images can be performed on non-scanconverted images, but that avoiding of the scanconversion step does not significantly improve the results of the displacement estimation.

  5. Register cardiac fiber orientations from 3D DTI volume to 2D ultrasound image of rat hearts

    PubMed Central

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-01-01

    Two-dimensional (2D) ultrasound or echocardiography is one of the most widely used examinations for the diagnosis of cardiac diseases. However, it only supplies the geometric and structural information of the myocardium. In order to supply more detailed microstructure information of the myocardium, this paper proposes a registration method to map cardiac fiber orientations from three-dimensional (3D) magnetic resonance diffusion tensor imaging (MR-DTI) volume to the 2D ultrasound image. It utilizes a 2D/3D intensity based registration procedure including rigid, log-demons, and affine transformations to search the best similar slice from the template volume. After registration, the cardiac fiber orientations are mapped to the 2D ultrasound image via fiber relocations and reorientations. This method was validated by six images of rat hearts ex vivo. The evaluation results indicated that the final Dice similarity coefficient (DSC) achieved more than 90% after geometric registrations; and the inclination angle errors (IAE) between the mapped fiber orientations and the gold standards were less than 15 degree. This method may provide a practical tool for cardiologists to examine cardiac fiber orientations on ultrasound images and have the potential to supply additional information for diagnosis of cardiac diseases. PMID:26855466

  6. Register cardiac fiber orientations from 3D DTI volume to 2D ultrasound image of rat hearts

    NASA Astrophysics Data System (ADS)

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-03-01

    Two-dimensional (2D) ultrasound or echocardiography is one of the most widely used examinations for the diagnosis of cardiac diseases. However, it only supplies the geometric and structural information of the myocardium. In order to supply more detailed microstructure information of the myocardium, this paper proposes a registration method to map cardiac fiber orientations from three-dimensional (3D) magnetic resonance diffusion tensor imaging (MR-DTI) volume to the 2D ultrasound image. It utilizes a 2D/3D intensity based registration procedure including rigid, log-demons, and affine transformations to search the best similar slice from the template volume. After registration, the cardiac fiber orientations are mapped to the 2D ultrasound image via fiber relocations and reorientations. This method was validated by six images of rat hearts ex vivo. The evaluation results indicated that the final Dice similarity coefficient (DSC) achieved more than 90% after geometric registrations; and the inclination angle errors (IAE) between the mapped fiber orientations and the gold standards were less than 15 degree. This method may provide a practical tool for cardiologists to examine cardiac fiber orientations on ultrasound images and have the potential to supply additional information for diagnosis of cardiac diseases.

  7. Automatic left-atrial segmentation from cardiac 3D ultrasound: a dual-chamber model-based approach

    NASA Astrophysics Data System (ADS)

    Almeida, Nuno; Sarvari, Sebastian I.; Orderud, Fredrik; Gérard, Olivier; D'hooge, Jan; Samset, Eigil

    2016-04-01

    In this paper, we present an automatic solution for segmentation and quantification of the left atrium (LA) from 3D cardiac ultrasound. A model-based framework is applied, making use of (deformable) active surfaces to model the endocardial surfaces of cardiac chambers, allowing incorporation of a priori anatomical information in a simple fashion. A dual-chamber model (LA and left ventricle) is used to detect and track the atrio-ventricular (AV) plane, without any user input. Both chambers are represented by parametric surfaces and a Kalman filter is used to fit the model to the position of the endocardial walls detected in the image, providing accurate detection and tracking during the whole cardiac cycle. This framework was tested in 20 transthoracic cardiac ultrasound volumetric recordings of healthy volunteers, and evaluated using manual traces of a clinical expert as a reference. The 3D meshes obtained with the automatic method were close to the reference contours at all cardiac phases (mean distance of 0.03+/-0.6 mm). The AV plane was detected with an accuracy of -0.6+/-1.0 mm. The LA volumes assessed automatically were also in agreement with the reference (mean +/-1.96 SD): 0.4+/-5.3 ml, 2.1+/-12.6 ml, and 1.5+/-7.8 ml at end-diastolic, end-systolic and pre-atrial-contraction frames, respectively. This study shows that the proposed method can be used for automatic volumetric assessment of the LA, considerably reducing the analysis time and effort when compared to manual analysis.

  8. 3D ultrafast ultrasound imaging in vivo.

    PubMed

    Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-10-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra--and inter-observer variability.

  9. 3D ultrafast ultrasound imaging in vivo

    NASA Astrophysics Data System (ADS)

    Provost, Jean; Papadacci, Clement; Esteban Arango, Juan; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-10-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra—and inter-observer variability.

  10. 3D ultrafast ultrasound imaging in vivo.

    PubMed

    Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-10-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra--and inter-observer variability. PMID:25207828

  11. 3D Ultrafast Ultrasound Imaging In Vivo

    PubMed Central

    Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-01-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative real-time imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in three dimensions based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32×32 matrix-array probe. Its capability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3-D Shear-Wave Imaging, 3-D Ultrafast Doppler Imaging and finally 3D Ultrafast combined Tissue and Flow Doppler. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3-D Ultrafast Doppler was used to obtain 3-D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, for the first time, the complex 3-D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, and the 3-D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3-D Ultrafast Ultrasound Imaging for the 3-D real-time mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra- and inter-observer variability. PMID:25207828

  12. [3-D ultrasound in gastroenterology].

    PubMed

    Zoller, W G; Liess, H

    1994-06-01

    Three-dimensional (3D) sonography represents a development of noninvasive diagnostic imaging by real-time two-dimensional (2D) sonography. The use of transparent rotating scans, comparable to a block of glass, generates a 3D effect. The objective of the present study was to optimate 3D presentation of abdominal findings. Additional investigations were made with a new volumetric program to determine the volume of selected findings of the liver. The results were compared with the estimated volumes of 2D sonography and 2D computer tomography (CT). For the processing of 3D images, typical parameter constellations were found for the different findings, which facilitated processing of 3D images. In more than 75% of the cases examined we found an optimal 3D presentation of sonographic findings with respect to the evaluation criteria developed by us for the 3D imaging of processed data. Great differences were found for the estimated volumes of the findings of the liver concerning the three different techniques applied. 3D ultrasound represents a valuable method to judge morphological appearance in abdominal findings. The possibility of volumetric measurements enlarges its potential diagnostic significance. Further clinical investigations are necessary to find out if definite differentiation between benign and malign findings is possible.

  13. 3D culture for cardiac cells.

    PubMed

    Zuppinger, Christian

    2016-07-01

    This review discusses historical milestones, recent developments and challenges in the area of 3D culture models with cardiovascular cell types. Expectations in this area have been raised in recent years, but more relevant in vitro research, more accurate drug testing results, reliable disease models and insights leading to bioartificial organs are expected from the transition to 3D cell culture. However, the construction of organ-like cardiac 3D models currently remains a difficult challenge. The heart consists of highly differentiated cells in an intricate arrangement.Furthermore, electrical “wiring”, a vascular system and multiple cell types act in concert to respond to the rapidly changing demands of the body. Although cardiovascular 3D culture models have been predominantly developed for regenerative medicine in the past, their use in drug screening and for disease models has become more popular recently. Many sophisticated 3D culture models are currently being developed in this dynamic area of life science. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  14. Role of 3-D ultrasound in clinical obstetric practice: evolution over 20 years.

    PubMed

    Tonni, Gabriele; Martins, Wellington P; Guimarães Filho, Hélio; Araujo Júnior, Edward

    2015-05-01

    The use of 3-D ultrasound in obstetrics has undergone dramatic development over the past 20 years. Since the first publications on this application in clinical practice, several 3-D ultrasound techniques and rendering modes have been proposed and applied to the study of fetal brain, face and cardiac anatomy. In addition, 3-D ultrasound has improved calculations of the volume of fetal organs and limbs and estimations of fetal birth weight. And furthermore, angiographic patterns of fetal organs and the placenta have been assessed using 3-D power Doppler ultrasound quantification. In this review, we aim to summarize current evidence on the clinical relevance of these methodologies and their application in obstetric practice.

  15. A method for the calibration of 3D ultrasound transducers

    NASA Astrophysics Data System (ADS)

    Hastenteufel, Mark; Mottl-Link, Sibylle; Wolf, Ivo; de Simone, Raffaele; Meinzer, Hans-Peter

    2003-05-01

    Background: Three-dimensional (3D) ultrasound has a great potential in medical diagnostics. However, there are also some limitations of 3D ultrasound, e.g., in some situations morphology cannot be imaged accurately due to acoustical shadows. Acquiring 3D datasets from multiple positions can overcome some of these limitations. Prior to that a calibration of the ultrasound probe is necessary. Most calibration methods descibed rely on two-dimensional data. We describe a calibration method that uses 3D data. Methods: We have developed a 3D calibration method based on single-point cross-wire calibration using registration techniques for automatic detection of cross centers. For the calibration a cross consisting of three orthogonal wires is imaged. A model-to-image registration method is used to determine the cross center. Results: Due to the use of 3D data less acquisitions and no special protocols are necessary. The influence of noise is reduced. By means of the registration method the time-consuming steps of image plane alignment and manual cross center determination becomes dispensable. Conclusion: A 3D calibration method for ultrasound transducers is described. The calibration method is the base to extend state-of-the-art 3D ultrasound devices, i.e., to acquire multiple 3D, either morphological or functional (Doppler), datasets.

  16. Cardiac 4D Ultrasound Imaging

    NASA Astrophysics Data System (ADS)

    D'hooge, Jan

    Volumetric cardiac ultrasound imaging has steadily evolved over the last 20 years from an electrocardiography (ECC) gated imaging technique to a true real-time imaging modality. Although the clinical use of echocardiography is still to a large extent based on conventional 2D ultrasound imaging it can be anticipated that the further developments in image quality, data visualization and interaction and image quantification of three-dimensional cardiac ultrasound will gradually make volumetric ultrasound the modality of choice. In this chapter, an overview is given of the technological developments that allow for volumetric imaging of the beating heart by ultrasound.

  17. MMSE Reconstruction for 3D Freehand Ultrasound Imaging

    PubMed Central

    Huang, Wei; Zheng, Yibin

    2008-01-01

    The reconstruction of 3D ultrasound (US) images from mechanically registered, but otherwise irregularly positioned, B-scan slices is of great interest in image guided therapy procedures. Conventional 3D ultrasound algorithms have low computational complexity, but the reconstructed volume suffers from severe speckle contamination. Furthermore, the current method cannot reconstruct uniform high-resolution data from several low-resolution B-scans. In this paper, the minimum mean-squared error (MMSE) method is applied to 3D ultrasound reconstruction. Data redundancies due to overlapping samples as well as correlation of the target and speckle are naturally accounted for in the MMSE reconstruction algorithm. Thus, the reconstruction process unifies the interpolation and spatial compounding. Simulation results for synthetic US images are presented to demonstrate the excellent reconstruction. PMID:18382623

  18. Chest wall segmentation in automated 3D breast ultrasound scans.

    PubMed

    Tan, Tao; Platel, Bram; Mann, Ritse M; Huisman, Henkjan; Karssemeijer, Nico

    2013-12-01

    In this paper, we present an automatic method to segment the chest wall in automated 3D breast ultrasound images. Determining the location of the chest wall in automated 3D breast ultrasound images is necessary in computer-aided detection systems to remove automatically detected cancer candidates beyond the chest wall and it can be of great help for inter- and intra-modal image registration. We show that the visible part of the chest wall in an automated 3D breast ultrasound image can be accurately modeled by a cylinder. We fit the surface of our cylinder model to a set of automatically detected rib-surface points. The detection of the rib-surface points is done by a classifier using features representing local image intensity patterns and presence of rib shadows. Due to attenuation of the ultrasound signal, a clear shadow is visible behind the ribs. Evaluation of our segmentation method is done by computing the distance of manually annotated rib points to the surface of the automatically detected chest wall. We examined the performance on images obtained with the two most common 3D breast ultrasound devices in the market. In a dataset of 142 images, the average mean distance of the annotated points to the segmented chest wall was 5.59 ± 3.08 mm.

  19. [An integrated segmentation method for 3D ultrasound carotid artery].

    PubMed

    Yang, Xin; Wu, Huihui; Liu, Yang; Xu, Hongwei; Liang, Huageng; Cai, Wenjuan; Fang, Mengjie; Wang, Yujie

    2013-07-01

    An integrated segmentation method for 3D ultrasound carotid artery was proposed. 3D ultrasound image was sliced into transverse, coronal and sagittal 2D images on the carotid bifurcation point. Then, the three images were processed respectively, and the carotid artery contours and thickness were obtained finally. This paper tries to overcome the disadvantages of current computer aided diagnosis method, such as high computational complexity, easily introduced subjective errors et al. The proposed method could get the carotid artery overall information rapidly, accurately and completely. It could be transplanted into clinical usage for atherosclerosis diagnosis and prevention. PMID:24195385

  20. Linear tracking for 3-D medical ultrasound imaging.

    PubMed

    Huang, Qing-Hua; Yang, Zhao; Hu, Wei; Jin, Lian-Wen; Wei, Gang; Li, Xuelong

    2013-12-01

    As the clinical application grows, there is a rapid technical development of 3-D ultrasound imaging. Compared with 2-D ultrasound imaging, 3-D ultrasound imaging can provide improved qualitative and quantitative information for various clinical applications. In this paper, we proposed a novel tracking method for a freehand 3-D ultrasound imaging system with improved portability, reduced degree of freedom, and cost. We designed a sliding track with a linear position sensor attached, and it transmitted positional data via a wireless communication module based on Bluetooth, resulting in a wireless spatial tracking modality. A traditional 2-D ultrasound probe fixed to the position sensor on the sliding track was used to obtain real-time B-scans, and the positions of the B-scans were simultaneously acquired when moving the probe along the track in a freehand manner. In the experiments, the proposed method was applied to ultrasound phantoms and real human tissues. The results demonstrated that the new system outperformed a previously developed freehand system based on a traditional six-degree-of-freedom spatial sensor in phantom and in vivo studies, indicating its merit in clinical applications for human tissues and organs. PMID:23757592

  1. Automatic 3D lesion segmentation on breast ultrasound images

    NASA Astrophysics Data System (ADS)

    Kuo, Hsien-Chi; Giger, Maryellen L.; Reiser, Ingrid; Drukker, Karen; Edwards, Alexandra; Sennett, Charlene A.

    2013-02-01

    Automatically acquired and reconstructed 3D breast ultrasound images allow radiologists to detect and evaluate breast lesions in 3D. However, assessing potential cancers in 3D ultrasound can be difficult and time consuming. In this study, we evaluate a 3D lesion segmentation method, which we had previously developed for breast CT, and investigate its robustness on lesions on 3D breast ultrasound images. Our dataset includes 98 3D breast ultrasound images obtained on an ABUS system from 55 patients containing 64 cancers. Cancers depicted on 54 US images had been clinically interpreted as negative on screening mammography and 44 had been clinically visible on mammography. All were from women with breast density BI-RADS 3 or 4. Tumor centers and margins were indicated and outlined by radiologists. Initial RGI-eroded contours were automatically calculated and served as input to the active contour segmentation algorithm yielding the final lesion contour. Tumor segmentation was evaluated by determining the overlap ratio (OR) between computer-determined and manually-drawn outlines. Resulting average overlap ratios on coronal, transverse, and sagittal views were 0.60 +/- 0.17, 0.57 +/- 0.18, and 0.58 +/- 0.17, respectively. All OR values were significantly higher the 0.4, which is deemed "acceptable". Within the groups of mammogram-negative and mammogram-positive cancers, the overlap ratios were 0.63 +/- 0.17 and 0.56 +/- 0.16, respectively, on the coronal views; with similar results on the other views. The segmentation performance was not found to be correlated to tumor size. Results indicate robustness of the 3D lesion segmentation technique in multi-modality 3D breast imaging.

  2. 3D in vivo imaging of rat hearts by high frequency ultrasound and its application in myofiber orientation wrapping

    PubMed Central

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-01-01

    Cardiac ultrasound plays an important role in the imaging of hearts in basic cardiovascular research and clinical examinations. 3D ultrasound imaging can provide the geometry or motion information of the heart. Especially, the wrapping of cardiac fiber orientations to the ultrasound volume could supply useful information on the stress distributions and electric action spreading. However, how to acquire 3D ultrasound volumes of the heart of small animals in vivo for cardiac fiber wrapping is still a challenging problem. In this study, we provide an approach to acquire 3D ultrasound volumes of the rat hearts in vivo. The comparison between both in vivo and ex vivo geometries indicated 90.1% Dice similarity. In this preliminary study, the evaluations of the cardiac fiber orientation wrapping errors were 24.7° for the acute angle error and were 22.4° for the inclination angle error. This 3D ultrasound imaging and fiber orientation estimation technique have potential applications in cardiac imaging. PMID:26412926

  3. 3D in vivo imaging of rat hearts by high frequency ultrasound and its application in myofiber orientation wrapping

    NASA Astrophysics Data System (ADS)

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-03-01

    Cardiac ultrasound plays an important role in the imaging of hearts in basic cardiovascular research and clinical examinations. 3D ultrasound imaging can provide the geometry or motion information of the heart. Especially, the wrapping of cardiac fiber orientations to the ultrasound volume could supply useful information on the stress distributions and electric action spreading. However, how to acquire 3D ultrasound volumes of the heart of small animals in vivo for cardiac fiber wrapping is still a challenging problem. In this study, we provide an approach to acquire 3D ultrasound volumes of the rat hearts in vivo. The comparison between both in vivo and ex vivo geometries indicated 90.1% Dice similarity. In this preliminary study, the evaluations of the cardiac fiber orientation wrapping errors were 24.7° for the acute angle error and were 22.4° for the inclination angle error. This 3D ultrasound imaging and fiber orientation estimation technique have potential applications in cardiac imaging.

  4. The Application of Ultrasound in 3D Bio-Printing.

    PubMed

    Zhou, Yufeng

    2016-01-01

    Three-dimensional (3D) bioprinting is an emerging and promising technology in tissue engineering to construct tissues and organs for implantation. Alignment of self-assembly cell spheroids that are used as bioink could be very accurate after droplet ejection from bioprinter. Complex and heterogeneous tissue structures could be built using rapid additive manufacture technology and multiple cell lines. Effective vascularization in the engineered tissue samples is critical in any clinical application. In this review paper, the current technologies and processing steps (such as printing, preparation of bioink, cross-linking, tissue fusion and maturation) in 3D bio-printing are introduced, and their specifications are compared with each other. In addition, the application of ultrasound in this novel field is also introduced. Cells experience acoustic radiation force in ultrasound standing wave field (USWF) and then accumulate at the pressure node at low acoustic pressure. Formation of cell spheroids by this method is within minutes with uniform size and homogeneous cell distribution. Neovessel formation from USWF-induced endothelial cell spheroids is significant. Low-intensity ultrasound could enhance the proliferation and differentiation of stem cells. Its use is at low cost and compatible with current bioreactor. In summary, ultrasound application in 3D bio-printing may solve some challenges and enhance the outcomes. PMID:27164066

  5. The Application of Ultrasound in 3D Bio-Printing.

    PubMed

    Zhou, Yufeng

    2016-05-05

    Three-dimensional (3D) bioprinting is an emerging and promising technology in tissue engineering to construct tissues and organs for implantation. Alignment of self-assembly cell spheroids that are used as bioink could be very accurate after droplet ejection from bioprinter. Complex and heterogeneous tissue structures could be built using rapid additive manufacture technology and multiple cell lines. Effective vascularization in the engineered tissue samples is critical in any clinical application. In this review paper, the current technologies and processing steps (such as printing, preparation of bioink, cross-linking, tissue fusion and maturation) in 3D bio-printing are introduced, and their specifications are compared with each other. In addition, the application of ultrasound in this novel field is also introduced. Cells experience acoustic radiation force in ultrasound standing wave field (USWF) and then accumulate at the pressure node at low acoustic pressure. Formation of cell spheroids by this method is within minutes with uniform size and homogeneous cell distribution. Neovessel formation from USWF-induced endothelial cell spheroids is significant. Low-intensity ultrasound could enhance the proliferation and differentiation of stem cells. Its use is at low cost and compatible with current bioreactor. In summary, ultrasound application in 3D bio-printing may solve some challenges and enhance the outcomes.

  6. 3D ultrasound imaging for prosthesis fabrication and diagnostic imaging

    SciTech Connect

    Morimoto, A.K.; Bow, W.J.; Strong, D.S.

    1995-06-01

    The fabrication of a prosthetic socket for a below-the-knee amputee requires knowledge of the underlying bone structure in order to provide pressure relief for sensitive areas and support for load bearing areas. The goal is to enable the residual limb to bear pressure with greater ease and utility. Conventional methods of prosthesis fabrication are based on limited knowledge about the patient`s underlying bone structure. A 3D ultrasound imaging system was developed at Sandia National Laboratories. The imaging system provides information about the location of the bones in the residual limb along with the shape of the skin surface. Computer assisted design (CAD) software can use this data to design prosthetic sockets for amputees. Ultrasound was selected as the imaging modality. A computer model was developed to analyze the effect of the various scanning parameters and to assist in the design of the overall system. The 3D ultrasound imaging system combines off-the-shelf technology for image capturing, custom hardware, and control and image processing software to generate two types of image data -- volumetric and planar. Both volumetric and planar images reveal definition of skin and bone geometry with planar images providing details on muscle fascial planes, muscle/fat interfaces, and blood vessel definition. The 3D ultrasound imaging system was tested on 9 unilateral below-the- knee amputees. Image data was acquired from both the sound limb and the residual limb. The imaging system was operated in both volumetric and planar formats. An x-ray CT (Computed Tomography) scan was performed on each amputee for comparison. Results of the test indicate beneficial use of ultrasound to generate databases for fabrication of prostheses at a lower cost and with better initial fit as compared to manually fabricated prostheses.

  7. Myosin filament 3D structure in mammalian cardiac muscle☆

    PubMed Central

    AL-Khayat, Hind A.; Morris, Edward P.; Kensler, Robert W.; Squire, John M.

    2008-01-01

    A number of cardiac myopathies (e.g. familial hypertrophic cardiomyopathy and dilated cardiomyopathy) are linked to mutations in cardiac muscle myosin filament proteins, including myosin and myosin binding protein C (MyBP-C). To understand the myopathies it is necessary to know the normal 3D structure of these filaments. We have carried out 3D single particle analysis of electron micrograph images of negatively stained isolated myosin filaments from rabbit cardiac muscle. Single filament images were aligned and divided into segments about 2 × 430 Å long, each of which was treated as an independent ‘particle’. The resulting 40 Å resolution 3D reconstruction showed both axial and azimuthal (no radial) myosin head perturbations within the 430 Å repeat, with successive crown rotations of approximately 60°, 60° and 0°, rather than the regular 40° for an unperturbed helix. However, it is shown that the projecting density peaks appear to start at low radius from origins closer to those expected for an unperturbed helical filament, and that the azimuthal perturbation especially increases with radius. The head arrangements in rabbit cardiac myosin filaments are very similar to those in fish skeletal muscle myosin filaments, suggesting a possible general structural theme for myosin filaments in all vertebrate striated muscles (skeletal and cardiac). PMID:18472277

  8. Breast tumour visualization using 3D quantitative ultrasound methods

    NASA Astrophysics Data System (ADS)

    Gangeh, Mehrdad J.; Raheem, Abdul; Tadayyon, Hadi; Liu, Simon; Hadizad, Farnoosh; Czarnota, Gregory J.

    2016-04-01

    Breast cancer is one of the most common cancer types accounting for 29% of all cancer cases. Early detection and treatment has a crucial impact on improving the survival of affected patients. Ultrasound (US) is non-ionizing, portable, inexpensive, and real-time imaging modality for screening and quantifying breast cancer. Due to these attractive attributes, the last decade has witnessed many studies on using quantitative ultrasound (QUS) methods in tissue characterization. However, these studies have mainly been limited to 2-D QUS methods using hand-held US (HHUS) scanners. With the availability of automated breast ultrasound (ABUS) technology, this study is the first to develop 3-D QUS methods for the ABUS visualization of breast tumours. Using an ABUS system, unlike the manual 2-D HHUS device, the whole patient's breast was scanned in an automated manner. The acquired frames were subsequently examined and a region of interest (ROI) was selected in each frame where tumour was identified. Standard 2-D QUS methods were used to compute spectral and backscatter coefficient (BSC) parametric maps on the selected ROIs. Next, the computed 2-D parameters were mapped to a Cartesian 3-D space, interpolated, and rendered to provide a transparent color-coded visualization of the entire breast tumour. Such 3-D visualization can potentially be used for further analysis of the breast tumours in terms of their size and extension. Moreover, the 3-D volumetric scans can be used for tissue characterization and the categorization of breast tumours as benign or malignant by quantifying the computed parametric maps over the whole tumour volume.

  9. Reduction of attenuation effects in 3D transrectal ultrasound images

    NASA Astrophysics Data System (ADS)

    Frimmel, Hans; Acosta, Oscar; Fenster, Aaron; Ourselin, Sébastien

    2007-03-01

    Ultrasound (US) is one of the most used imaging modalities today as it is cheap, reliable, safe and widely available. There are a number of issues with US images in general. Besides reflections which is the basis of ultrasonic imaging, other phenomena such as diffraction, refraction, attenuation, dispersion and scattering appear when ultrasound propagates through different tissues. The generated images are therefore corrupted by false boundaries, lack of signal for surface tangential to ultrasound propagation, large amount of noise giving rise to local properties, and anisotropic sampling space complicating image processing tasks. Although 3D Transrectal US (TRUS) probes are not yet widely available, within a few years they will likely be introduced in hospitals. Therefore, the improvement of automatic segmentation from 3D TRUS images, making the process independent of human factor is desirable. We introduce an algorithm for attenuation correction, reducing enhancement/shadowing effects and average attenuation effects in 3D US images, taking into account the physical properties of US. The parameters of acquisition such as logarithmic correction are unknown, therefore no additional information is available to restore the image. As the physical properties are related to the direction of each US ray, the 3D US data set is resampled into cylindrical coordinates using a fully automatic algorithm. Enhancement and shadowing effects, as well as average attenuation effects, are then removed with a rescaling process optimizing simultaneously in and perpendicular to the US ray direction. A set of tests using anisotropic diffusion are performed to illustrate the improvement in image quality, where well defined structures are visible. The evolution of both the entropy and the contrast show that our algorithm is a suitable pre-processing step for segmentation tasks.

  10. Refraction Correction in 3D Transcranial Ultrasound Imaging

    PubMed Central

    Lindsey, Brooks D.; Smith, Stephen W.

    2014-01-01

    We present the first correction of refraction in three-dimensional (3D) ultrasound imaging using an iterative approach that traces propagation paths through a two-layer planar tissue model, applying Snell’s law in 3D. This approach is applied to real-time 3D transcranial ultrasound imaging by precomputing delays offline for several skull thicknesses, allowing the user to switch between three sets of delays for phased array imaging at the push of a button. Simulations indicate that refraction correction may be expected to increase sensitivity, reduce beam steering errors, and partially restore lost spatial resolution, with the greatest improvements occurring at the largest steering angles. Distorted images of cylindrical lesions were created by imaging through an acrylic plate in a tissue-mimicking phantom. As a result of correcting for refraction, lesions were restored to 93.6% of their original diameter in the lateral direction and 98.1% of their original shape along the long axis of the cylinders. In imaging two healthy volunteers, the mean brightness increased by 8.3% and showed no spatial dependency. PMID:24275538

  11. Ultrasound image guidance of cardiac interventions

    NASA Astrophysics Data System (ADS)

    Peters, Terry M.; Pace, Danielle F.; Lang, Pencilla; Guiraudon, Gérard M.; Jones, Douglas L.; Linte, Cristian A.

    2011-03-01

    Surgical procedures often have the unfortunate side-effect of causing the patient significant trauma while accessing the target site. Indeed, in some cases the trauma inflicted on the patient during access to the target greatly exceeds that caused by performing the therapy. Heart disease has traditionally been treated surgically using open chest techniques with the patient being placed "on pump" - i.e. their circulation being maintained by a cardio-pulmonary bypass or "heart-lung" machine. Recently, techniques have been developed for performing minimally invasive interventions on the heart, obviating the formerly invasive procedures. These new approaches rely on pre-operative images, combined with real-time images acquired during the procedure. Our approach is to register intra-operative images to the patient, and use a navigation system that combines intra-operative ultrasound with virtual models of instrumentation that has been introduced into the chamber through the heart wall. This paper illustrates the problems associated with traditional ultrasound guidance, and reviews the state of the art in real-time 3D cardiac ultrasound technology. In addition, it discusses the implementation of an image-guided intervention platform that integrates real-time ultrasound with a virtual reality environment, bringing together the pre-operative anatomy derived from MRI or CT, representations of tracked instrumentation inside the heart chamber, and the intra-operatively acquired ultrasound images.

  12. Glasses for 3D ultrasound computer tomography: phase compensation

    NASA Astrophysics Data System (ADS)

    Zapf, M.; Hopp, T.; Ruiter, N. V.

    2016-03-01

    Ultrasound Computer Tomography (USCT), developed at KIT, is a promising new imaging system for breast cancer diagnosis, and was successfully tested in a pilot study. The 3D USCT II prototype consists of several hundreds of ultrasound (US) transducers on a semi-ellipsoidal aperture. Spherical waves are sequentially emitted by individual transducers and received in parallel by many transducers. Reflectivity volumes are reconstructed by synthetic aperture focusing (SAFT). However, straight forward SAFT imaging leads to blurred images due to system imperfections. We present an extension of a previously proposed approach to enhance the images. This approach includes additional a priori information and system characteristics. Now spatial phase compensation was included. The approach was evaluated with a simulation and clinical data sets. An increase in the image quality was observed and quantitatively measured by SNR and other metrics.

  13. 3D segmentation and reconstruction of endobronchial ultrasound

    NASA Astrophysics Data System (ADS)

    Zang, Xiaonan; Breslav, Mikhail; Higgins, William E.

    2013-03-01

    State-of-the-art practice for lung-cancer staging bronchoscopy often draws upon a combination of endobronchial ultrasound (EBUS) and multidetector computed-tomography (MDCT) imaging. While EBUS offers real-time in vivo imaging of suspicious lesions and lymph nodes, its low signal-to-noise ratio and tendency to exhibit missing region-of-interest (ROI) boundaries complicate diagnostic tasks. Furthermore, past efforts did not incorporate automated analysis of EBUS images and a subsequent fusion of the EBUS and MDCT data. To address these issues, we propose near real-time automated methods for three-dimensional (3D) EBUS segmentation and reconstruction that generate a 3D ROI model along with ROI measurements. Results derived from phantom data and lung-cancer patients show the promise of the methods. In addition, we present a preliminary image-guided intervention (IGI) system example, whereby EBUS imagery is registered to a patient's MDCT chest scan.

  14. Mechanically assisted 3D ultrasound guided prostate biopsy system.

    PubMed

    Bax, Jeffrey; Cool, Derek; Gardi, Lori; Knight, Kerry; Smith, David; Montreuil, Jacques; Sherebrin, Shi; Romagnoli, Cesare; Fenster, Aaron

    2008-12-01

    There are currently limitations associated with the prostate biopsy procedure, which is the most commonly used method for a definitive diagnosis of prostate cancer. With the use of two-dimensional (2D) transrectal ultrasound (TRUS) for needle-guidance in this procedure, the physician has restricted anatomical reference points for guiding the needle to target sites. Further, any motion of the physician's hand during the procedure may cause the prostate to move or deform to a prohibitive extent. These variations make it difficult to establish a consistent reference frame for guiding a needle. We have developed a 3D navigation system for prostate biopsy, which addresses these shortcomings. This system is composed of a 3D US imaging subsystem and a passive mechanical arm to minimize prostate motion. To validate our prototype, a series of experiments were performed on prostate phantoms. The 3D scan of the string phantom produced minimal geometric distortions, and the geometric error of the 3D imaging subsystem was 0.37 mm. The accuracy of 3D prostate segmentation was determined by comparing the known volume in a certified phantom to a reconstructed volume generated by our system and was shown to estimate the volume with less then 5% error. Biopsy needle guidance accuracy tests in agar prostate phantoms showed that the mean error was 2.1 mm and the 3D location of the biopsy core was recorded with a mean error of 1.8 mm. In this paper, we describe the mechanical design and validation of the prototype system using an in vitro prostate phantom. Preliminary results from an ongoing clinical trial show that prostate motion is small with an in-plane displacement of less than 1 mm during the biopsy procedure.

  15. Detection of Curved Robots using 3D Ultrasound.

    PubMed

    Ren, Hongliang; Vasilyev, Nikolay V; Dupont, Pierre E

    2011-09-25

    Three-dimensional ultrasound can be an effective imaging modality for image-guided interventions since it enables visualization of both the instruments and the tissue. For robotic applications, its realtime frame rates create the potential for image-based instrument tracking and servoing. These capabilities can enable improved instrument visualization, compensation for tissue motion as well as surgical task automation. Continuum robots, whose shape comprises a smooth curve along their length, are well suited for minimally invasive procedures. Existing techniques for ultrasound tracking, however, are limited to straight, laparoscopic-type instruments and thus are not applicable to continuum robot tracking. Toward the goal of developing tracking algorithms for continuum robots, this paper presents a method for detecting a robot comprised of a single constant curvature in a 3D ultrasound volume. Computational efficiency is achieved by decomposing the six-dimensional circle estimation problem into two sequential three-dimensional estimation problems. Simulation and experiment are used to evaluate the proposed method. PMID:22229110

  16. Detection of Curved Robots using 3D Ultrasound.

    PubMed

    Ren, Hongliang; Vasilyev, Nikolay V; Dupont, Pierre E

    2011-09-25

    Three-dimensional ultrasound can be an effective imaging modality for image-guided interventions since it enables visualization of both the instruments and the tissue. For robotic applications, its realtime frame rates create the potential for image-based instrument tracking and servoing. These capabilities can enable improved instrument visualization, compensation for tissue motion as well as surgical task automation. Continuum robots, whose shape comprises a smooth curve along their length, are well suited for minimally invasive procedures. Existing techniques for ultrasound tracking, however, are limited to straight, laparoscopic-type instruments and thus are not applicable to continuum robot tracking. Toward the goal of developing tracking algorithms for continuum robots, this paper presents a method for detecting a robot comprised of a single constant curvature in a 3D ultrasound volume. Computational efficiency is achieved by decomposing the six-dimensional circle estimation problem into two sequential three-dimensional estimation problems. Simulation and experiment are used to evaluate the proposed method.

  17. Density-tapered spiral arrays for ultrasound 3-D imaging.

    PubMed

    Ramalli, Alessandro; Boni, Enrico; Savoia, Alessandro Stuart; Tortoli, Piero

    2015-08-01

    The current high interest in 3-D ultrasound imaging is pushing the development of 2-D probes with a challenging number of active elements. The most popular approach to limit this number is the sparse array technique, which designs the array layout by means of complex optimization algorithms. These algorithms are typically constrained by a few steering conditions, and, as such, cannot guarantee uniform side-lobe performance at all angles. The performance may be improved by the ungridded extensions of the sparse array technique, but this result is achieved at the expense of a further complication of the optimization process. In this paper, a method to design the layout of large circular arrays with a limited number of elements according to Fermat's spiral seeds and spatial density modulation is proposed and shown to be suitable for application to 3-D ultrasound imaging. This deterministic, aperiodic, and balanced positioning procedure attempts to guarantee uniform performance over a wide range of steering angles. The capabilities of the method are demonstrated by simulating and comparing the performance of spiral and dense arrays. A good trade-off for small vessel imaging is found, e.g., in the 60λ spiral array with 1.0λ elements and Blackman density tapering window. Here, the grating lobe level is -16 dB, the lateral resolution is lower than 6λ the depth of field is 120λ and, the average contrast is 10.3 dB, while the sensitivity remains in a 5 dB range for a wide selection of steering angles. The simulation results may represent a reference guide to the design of spiral sparse array probes for different application fields. PMID:26285181

  18. Breast tumor angiogenesis analysis using 3D power Doppler ultrasound

    NASA Astrophysics Data System (ADS)

    Chang, Ruey-Feng; Huang, Sheng-Fang; Lee, Yu-Hau; Chen, Dar-Ren; Moon, Woo Kyung

    2006-03-01

    Angiogenesis is the process that correlates to tumor growth, invasion, and metastasis. Breast cancer angiogenesis has been the most extensively studied and now serves as a paradigm for understanding the biology of angiogenesis and its effects on tumor outcome and patient prognosis. Most studies on characterization of angiogenesis focus on pixel/voxel counts more than morphological analysis. Nevertheless, in cancer, the blood flow is greatly affected by the morphological changes, such as the number of vessels, branching pattern, length, and diameter. This paper presents a computer-aided diagnostic (CAD) system that can quantify vascular morphology using 3-D power Doppler ultrasound (US) on breast tumors. We propose a scheme to extract the morphological information from angiography and to relate them to tumor diagnosis outcome. At first, a 3-D thinning algorithm helps narrow down the vessels into their skeletons. The measurements of vascular morphology significantly rely on the traversing of the vascular trees produced from skeletons. Our study of 3-D assessment of vascular morphological features regards vessel count, length, bifurcation, and diameter of vessels. Investigations into 221 solid breast tumors including 110 benign and 111 malignant cases, the p values using the Student's t-test for all features are less than 0.05 indicating that the proposed features are deemed statistically significant. Our scheme focuses on the vascular architecture without involving the technique of tumor segmentation. The results show that the proposed method is feasible, and have a good agreement with the diagnosis of the pathologists.

  19. Double Ring Array Catheter for In Vivo Real-Time 3D Ultrasound.

    PubMed

    Smith, Stephen W; Gardea, Paul; Patel, Vivek; Douglas, Stephen J; Wolf, Patrick D

    2014-03-12

    We developed new forward-viewing matrix transducers consisting of double ring arrays of 118 total PZT elements integrated into catheters used to deploy medical interventional devices. Our goal is 3D ultrasound guidance of medical device implantation to reduce x-ray fluoroscopy exposure. The double ring arrays were fabricated on inner and outer custom polyimide flexible circuits with inter-element spacing of 0.20 mm and then wrapped around an 11 French (Fr) catheter to produce a 15 Fr catheter (outer diameter [O.D.]). We used a braided cabling technology to connect the elements to the Volumetrics Medical Imaging (VMI) real-time 3D ultrasound scanner. Transducer performance yielded an average -6 dB fractional bandwidth of 49% ± 11% centered at 4.4 MHz for 118 elements. Real-time 3D cardiac scans of the in vivo pig model yielded good image quality including en face views of the tricuspid valve and real-time 3D guidance of an endo-myocardial biopsy catheter introduced into the left ventricle. PMID:24626564

  20. Intraoperative 3D stereo visualization for image-guided cardiac ablation

    NASA Astrophysics Data System (ADS)

    Azizian, Mahdi; Patel, Rajni

    2011-03-01

    There are commercial products which provide 3D rendered volumes, reconstructed from electro-anatomical mapping and/or pre-operative CT/MR images of a patient's heart with tools for highlighting target locations for cardiac ablation applications. However, it is not possible to update the three-dimensional (3D) volume intraoperatively to provide the interventional cardiologist with more up-to-date feedback at each instant of time. In this paper, we describe the system we have developed for real-time three-dimensional stereo visualization for cardiac ablation. A 4D ultrasound probe is used to acquire and update a 3D image volume. A magnetic tracking device is used to track the distal part of the ablation catheter in real time and a master-slave robot-assisted system is developed for actuation of a steerable catheter. Three-dimensional ultrasound image volumes go through some processing to make the heart tissue and the catheter more visible. The rendered volume is shown in a virtual environment. The catheter can also be added as a virtual tool to this environment to achieve a higher update rate on the catheter's position. The ultrasound probe is also equipped with an EM tracker which is used for online registration of the ultrasound images and the catheter tracking data. The whole augmented reality scene can be shown stereoscopically to enhance depth perception for the user. We have used transthoracic echocardiography (TTE) instead of the conventional transoesophageal (TEE) or intracardiac (ICE) echocardiogram. A beating heart model has been used to perform the experiments. This method can be used both for diagnostic and therapeutic applications as well as training interventional cardiologists.

  1. Compensation of log-compressed images for 3-D ultrasound.

    PubMed

    Sanches, João M; Marques, Jorge S

    2003-02-01

    In this study, a Bayesian approach was used for 3-D reconstruction in the presence of multiplicative noise and nonlinear compression of the ultrasound (US) data. Ultrasound images are often considered as being corrupted by multiplicative noise (speckle). Several statistical models have been developed to represent the US data. However, commercial US equipment performs a nonlinear image compression that reduces the dynamic range of the US signal for visualization purposes. This operation changes the distribution of the image pixels, preventing a straightforward application of the models. In this paper, the nonlinear compression is explicitly modeled and considered in the reconstruction process, where the speckle noise present in the radio frequency (RF) US data is modeled with a Rayleigh distribution. The results obtained by considering the compression of the US data are then compared with those obtained assuming no compression. It is shown that the estimation performed using the nonlinear log-compression model leads to better results than those obtained with the Rayleigh reconstruction method. The proposed algorithm is tested with synthetic and real data and the results are discussed. The results have shown an improvement in the reconstruction results when the compression operation is included in the image formation model, leading to sharper images with enhanced anatomical details.

  2. 3D ultrasound computer tomography: update from a clinical study

    NASA Astrophysics Data System (ADS)

    Hopp, T.; Zapf, M.; Kretzek, E.; Henrich, J.; Tukalo, A.; Gemmeke, H.; Kaiser, C.; Knaudt, J.; Ruiter, N. V.

    2016-04-01

    Ultrasound Computer Tomography (USCT) is a promising new imaging method for breast cancer diagnosis. We developed a 3D USCT system and tested it in a pilot study with encouraging results: 3D USCT was able to depict two carcinomas, which were present in contrast enhanced MRI volumes serving as ground truth. To overcome severe differences in the breast shape, an image registration was applied. We analyzed the correlation between average sound speed in the breast and the breast density estimated from segmented MRIs and found a positive correlation with R=0.70. Based on the results of the pilot study we now carry out a successive clinical study with 200 patients. For this we integrated our reconstruction methods and image post-processing into a comprehensive workflow. It includes a dedicated DICOM viewer for interactive assessment of fused USCT images. A new preview mode now allows intuitive and faster patient positioning. We updated the USCT system to decrease the data acquisition time by approximately factor two and to increase the penetration depth of the breast into the USCT aperture by 1 cm. Furthermore the compute-intensive reflectivity reconstruction was considerably accelerated, now allowing a sub-millimeter volume reconstruction in approximately 16 minutes. The updates made it possible to successfully image first patients in our ongoing clinical study.

  3. Fast myocardial strain estimation from 3D ultrasound through elastic image registration with analytic regularization

    NASA Astrophysics Data System (ADS)

    Chakraborty, Bidisha; Heyde, Brecht; Alessandrini, Martino; D'hooge, Jan

    2016-04-01

    Image registration techniques using free-form deformation models have shown promising results for 3D myocardial strain estimation from ultrasound. However, the use of this technique has mostly been limited to research institutes due to the high computational demand, which is primarily due to the computational load of the regularization term ensuring spatially smooth cardiac strain estimates. Indeed, this term typically requires evaluating derivatives of the transformation field numerically in each voxel of the image during every iteration of the optimization process. In this paper, we replace this time-consuming step with a closed-form solution directly associated with the transformation field resulting in a speed up factor of ~10-60,000, for a typical 3D B-mode image of 2503 and 5003 voxels, depending upon the size and the parametrization of the transformation field. The performance of the numeric and the analytic solutions was contrasted by computing tracking and strain accuracy on two realistic synthetic 3D cardiac ultrasound sequences, mimicking two ischemic motion patterns. Mean and standard deviation of the displacement errors over the cardiac cycle for the numeric and analytic solutions were 0.68+/-0.40 mm and 0.75+/-0.43 mm respectively. Correlations for the radial, longitudinal and circumferential strain components at end-systole were 0.89, 0.83 and 0.95 versus 0.90, 0.88 and 0.92 for the numeric and analytic regularization respectively. The analytic solution matched the performance of the numeric solution as no statistically significant differences (p>0.05) were found when expressed in terms of bias or limits-of-agreement.

  4. METHODS FOR USING 3-D ULTRASOUND SPECKLE TRACKING IN BIAXIAL MECHANICAL TESTING OF BIOLOGICAL TISSUE SAMPLES

    PubMed Central

    Yap, Choon Hwai; Park, Dae Woo; Dutta, Debaditya; Simon, Marc; Kim, Kang

    2014-01-01

    Being multilayered and anisotropic, biological tissues such as cardiac and arterial walls are structurally complex, making full assessment and understanding of their mechanical behavior challenging. Current standard mechanical testing uses surface markers to track tissue deformations and does not provide deformation data below the surface. In the study described here, we found that combining mechanical testing with 3-D ultrasound speckle tracking could overcome this limitation. Rat myocardium was tested with a biaxial tester and was concurrently scanned with high-frequency ultrasound in three dimensions. The strain energy function was computed from stresses and strains using an iterative non-linear curve-fitting algorithm. Because the strain energy function consists of terms for the base matrix and for embedded fibers, spatially varying fiber orientation was also computed by curve fitting. Using finite-element simulations, we first validated the accuracy of the non-linear curve-fitting algorithm. Next, we compared experimentally measured rat myocardium strain energy function values with those in the literature and found a matching order of magnitude. Finally, we retained samples after the experiments for fiber orientation quantification using histology and found that the results satisfactorily matched those computed in the experiments. We conclude that 3-D ultrasound speckle tracking can be a useful addition to traditional mechanical testing of biological tissues and may provide the benefit of enabling fiber orientation computation. PMID:25616585

  5. Electroactive 3D materials for cardiac tissue engineering

    NASA Astrophysics Data System (ADS)

    Gelmi, Amy; Zhang, Jiabin; Cieslar-Pobuda, Artur; Ljunngren, Monika K.; Los, Marek Jan; Rafat, Mehrdad; Jager, Edwin W. H.

    2015-04-01

    By-pass surgery and heart transplantation are traditionally used to restore the heart's functionality after a myocardial Infarction (MI or heart attack) that results in scar tissue formation and impaired cardiac function. However, both procedures are associated with serious post-surgical complications. Therefore, new strategies to help re-establish heart functionality are necessary. Tissue engineering and stem cell therapy are the promising approaches that are being explored for the treatment of MI. The stem cell niche is extremely important for the proliferation and differentiation of stem cells and tissue regeneration. For the introduction of stem cells into the host tissue an artificial carrier such as a scaffold is preferred as direct injection of stem cells has resulted in fast stem cell death. Such scaffold will provide the proper microenvironment that can be altered electronically to provide temporal stimulation to the cells. We have developed an electroactive polymer (EAP) scaffold for cardiac tissue engineering. The EAP scaffold mimics the extracellular matrix and provides a 3D microenvironment that can be easily tuned during fabrication, such as controllable fibre dimensions, alignment, and coating. In addition, the scaffold can provide electrical and electromechanical stimulation to the stem cells which are important external stimuli to stem cell differentiation. We tested the initial biocompatibility of these scaffolds using cardiac progenitor cells (CPCs), and continued onto more sensitive induced pluripotent stem cells (iPS). We present the fabrication and characterisation of these electroactive fibres as well as the response of increasingly sensitive cell types to the scaffolds.

  6. Real-time cylindrical curvilinear 3-D ultrasound imaging.

    PubMed

    Pua, E C; Yen, J T; Smith, S W

    2003-07-01

    In patients who are obese or exhibit signs of pulmonary disease, standard transthoracic scanning may yield poor quality cardiac images. For these conditions, two-dimensional transesophageal echocardiography (TEE) is established as an essential diagnostic tool. Current techniques in transesophageal scanning, though, are limited by incomplete visualization of cardiac structures in close proximity to the transducer. Thus, we propose a 2D curvilinear array for 3D transesophageal echocardiography in order to widen the field of view and increase visualization close to the transducer face. In this project, a 440 channel 5 MHz two-dimensional array with a 12.6 mm aperture diameter on a flexible interconnect circuit has been molded to a 4 mm radius of curvature. A 75% element yield was achieved during fabrication and an average -6dB bandwidth of 30% was observed in pulse-echo tests. Using this transducer in conjunction with modifications to the beam former delay software and scan converter display software of the our 3D scanner, we obtained cylindrical real-time curvilinear volumetric scans of tissue phantoms, including a field of view of greater than 120 degrees in the curved, azimuth direction and 65 degrees phased array sector scans in the elevation direction. These images were achieved using a stepped subaperture across the cylindrical curvilinear direction of the transducer face and phased array sector scanning in the noncurved plane. In addition, real-time volume rendered images of a tissue mimicking phantom with holes ranging from 1 cm to less than 4 mm have been obtained. 3D color flow Doppler results have also been acquired. This configuration can theoretically achieve volumes displaying 180 degrees by 120 degrees. The transducer is also capable of obtaining images through a curvilinear stepped subaperture in azimuth in conjunction with a rectilinear stepped subaperture in elevation, further increasing the field of view close to the transducer face. Future work

  7. Automated 3D whole-breast ultrasound imaging: results of a clinical pilot study

    NASA Astrophysics Data System (ADS)

    Leproux, Anaïs; van Beek, Michiel; de Vries, Ute; Wasser, Martin; Bakker, Leon; Cuisenaire, Olivier; van der Mark, Martin; Entrekin, Rob

    2010-03-01

    We present the first clinical results of a novel fully automated 3D breast ultrasound system. This system was designed to match a Philips diffuse optical mammography system to enable straightforward coregistration of optical and ultrasound images. During a measurement, three 3D transducers scan the breast at 4 different views. The resulting 12 datasets are registered together into a single volume using spatial compounding. In a pilot study, benign and malignant masses could be identified in the 3D images, however lesion visibility is less compared to conventional breast ultrasound. Clear breast shape visualization suggests that ultrasound could support the reconstruction and interpretation of diffuse optical tomography images.

  8. Cardiac phase detection in intravascular ultrasound images

    NASA Astrophysics Data System (ADS)

    Matsumoto, Monica M. S.; Lemos, Pedro Alves; Yoneyama, Takashi; Furuie, Sergio Shiguemi

    2008-03-01

    Image gating is related to image modalities that involve quasi-periodic moving organs. Therefore, during intravascular ultrasound (IVUS) examination, there is cardiac movement interference. In this paper, we aim to obtain IVUS gated images based on the images themselves. This would allow the reconstruction of 3D coronaries with temporal accuracy for any cardiac phase, which is an advantage over the ECG-gated acquisition that shows a single one. It is also important for retrospective studies, as in existing IVUS databases there are no additional reference signals (ECG). From the images, we calculated signals based on average intensity (AI), and, from consecutive frames, average intensity difference (AID), cross-correlation coefficient (CC) and mutual information (MI). The process includes a wavelet-based filter step and ascendant zero-cross detection in order to obtain the phase information. Firstly, we tested 90 simulated sequences with 1025 frames each. Our method was able to achieve more than 95.0% of true positives and less than 2.3% of false positives ratio, for all signals. Afterwards, we tested in a real examination, with 897 frames and ECG as gold-standard. We achieved 97.4% of true positives (CC and MI), and 2.5% of false positives. For future works, methodology should be tested in wider range of IVUS examinations.

  9. PET-directed, 3D Ultrasound-guided prostate biopsy

    PubMed Central

    Fei, Baowei; Nieh, Peter T; Schuster, David M; Master, Viraj A

    2013-01-01

    Multimodatity imaging is a promising approach for improving prostate cancer detection and diagnosis. This article describes various concepts in PET-directed, ultrasound-guided biopsies and highlights a new PET/ultrasound fusion targeted biopsy system for prostate cancer detection. PMID:25392702

  10. Ultrasound Imaging in Teaching Cardiac Physiology

    ERIC Educational Resources Information Center

    Johnson, Christopher D.; Montgomery, Laura E. A.; Quinn, Joe G.; Roe, Sean M.; Stewart, Michael T.; Tansey, Etain A.

    2016-01-01

    This laboratory session provides hands-on experience for students to visualize the beating human heart with ultrasound imaging. Simple views are obtained from which students can directly measure important cardiac dimensions in systole and diastole. This allows students to derive, from first principles, important measures of cardiac function, such…

  11. Measuring Femoral Torsion In Vivo Using Freehand 3-D Ultrasound Imaging.

    PubMed

    Passmore, Elyse; Pandy, Marcus G; Graham, H Kerr; Sangeux, Morgan

    2016-02-01

    Despite variation in bone geometry, muscle and joint function is often investigated using generic musculoskeletal models. Patient-specific bone geometry can be obtained from computerised tomography, which involves ionising radiation, or magnetic resonance imaging (MRI), which is costly and time consuming. Freehand 3-D ultrasound provides an alternative to obtain bony geometry. The purpose of this study was to determine the accuracy and repeatability of 3-D ultrasound in measuring femoral torsion. Measurements of femoral torsion were performed on 10 healthy adults using MRI and 3-D ultrasound. Measurements of femoral torsion from 3-D ultrasound were, on average, smaller than those from MRI (mean difference = 1.8°; 95% confidence interval: -3.9°, 7.5°). MRI and 3-D ultrasound had Bland and Altman repeatability coefficients of 3.1° and 3.7°, respectively. Accurate measurements of femoral torsion were obtained with 3-D ultrasound offering the potential to acquire patient-specific bone geometry for musculoskeletal modelling. Three-dimensional ultrasound is non-invasive and relatively inexpensive and can be integrated into gait analysis.

  12. Comparison of 3-D synthetic aperture phased-array ultrasound imaging and parallel beamforming.

    PubMed

    Rasmussen, Morten Fischer; Jensen, Jørgen Arendt

    2014-10-01

    This paper demonstrates that synthetic aperture imaging (SAI) can be used to achieve real-time 3-D ultrasound phased-array imaging. It investigates whether SAI increases the image quality compared with the parallel beamforming (PB) technique for real-time 3-D imaging. Data are obtained using both simulations and measurements with an ultrasound research scanner and a commercially available 3.5- MHz 1024-element 2-D transducer array. To limit the probe cable thickness, 256 active elements are used in transmit and receive for both techniques. The two imaging techniques were designed for cardiac imaging, which requires sequences designed for imaging down to 15 cm of depth and a frame rate of at least 20 Hz. The imaging quality of the two techniques is investigated through simulations as a function of depth and angle. SAI improved the full-width at half-maximum (FWHM) at low steering angles by 35%, and the 20-dB cystic resolution by up to 62%. The FWHM of the measured line spread function (LSF) at 80 mm depth showed a difference of 20% in favor of SAI. SAI reduced the cyst radius at 60 mm depth by 39% in measurements. SAI improved the contrast-to-noise ratio measured on anechoic cysts embedded in a tissue-mimicking material by 29% at 70 mm depth. The estimated penetration depth on the same tissue-mimicking phantom shows that SAI increased the penetration by 24% compared with PB. Neither SAI nor PB achieved the design goal of 15 cm penetration depth. This is likely due to the limited transducer surface area and a low SNR of the experimental scanner used.

  13. A Molecular Image-directed, 3D Ultrasound-guided Biopsy System for the Prostate

    PubMed Central

    Fei, Baowei; Schuster, David M.; Master, Viraj; Akbari, Hamed; Fenster, Aaron; Nieh, Peter

    2012-01-01

    Systematic transrectal ultrasound (TRUS)-guided biopsy is the standard method for a definitive diagnosis of prostate cancer. However, this biopsy approach uses two-dimensional (2D) ultrasound images to guide biopsy and can miss up to 30% of prostate cancers. We are developing a molecular image-directed, three-dimensional (3D) ultrasound image-guided biopsy system for improved detection of prostate cancer. The system consists of a 3D mechanical localization system and software workstation for image segmentation, registration, and biopsy planning. In order to plan biopsy in a 3D prostate, we developed an automatic segmentation method based wavelet transform. In order to incorporate PET/CT images into ultrasound-guided biopsy, we developed image registration methods to fuse TRUS and PET/CT images. The segmentation method was tested in ten patients with a DICE overlap ratio of 92.4% ± 1.1 %. The registration method has been tested in phantoms. The biopsy system was tested in prostate phantoms and 3D ultrasound images were acquired from two human patients. We are integrating the system for PET/CT directed, 3D ultrasound-guided, targeted biopsy in human patients. PMID:22708023

  14. 3D temperature field reconstruction using ultrasound sensing system

    NASA Astrophysics Data System (ADS)

    Liu, Yuqian; Ma, Tong; Cao, Chengyu; Wang, Xingwei

    2016-04-01

    3D temperature field reconstruction is of practical interest to the power, transportation and aviation industries and it also opens up opportunities for real time control or optimization of high temperature fluid or combustion process. In our paper, a new distributed optical fiber sensing system consisting of a series of elements will be used to generate and receive acoustic signals. This system is the first active temperature field sensing system that features the advantages of the optical fiber sensors (distributed sensing capability) and the acoustic sensors (non-contact measurement). Signals along multiple paths will be measured simultaneously enabled by a code division multiple access (CDMA) technique. Then a proposed Gaussian Radial Basis Functions (GRBF)-based approach can approximate the temperature field as a finite summation of space-dependent basis functions and time-dependent coefficients. The travel time of the acoustic signals depends on the temperature of the media. On this basis, the Gaussian functions are integrated along a number of paths which are determined by the number and distribution of sensors. The inversion problem to estimate the unknown parameters of the Gaussian functions can be solved with the measured times-of-flight (ToF) of acoustic waves and the length of propagation paths using the recursive least square method (RLS). The simulation results show an approximation error less than 2% in 2D and 5% in 3D respectively. It demonstrates the availability and efficiency of our proposed 3D temperature field reconstruction mechanism.

  15. Reproducibility of Acetabular Landmarks and a Standardized Coordinate System Obtained from 3D Hip Ultrasound.

    PubMed

    Mabee, Myles; Dulai, Sukhdeep; Thompson, Richard B; Jaremko, Jacob L

    2015-10-01

    Two-dimensional (2D) ultrasound detection of developmental dysplasia of the hip (DDH) is limited by variation in acetabular appearance and alpha angle measurements, which change with position of the ultrasound probe. Three-dimensional (3D) ultrasound captures the entire acetabular shape, and a reproducible "standard central plane" may be generated, from two landmarks located on opposite ends of the acetabulum, for measurement of alpha angle and other indices. Two users identified landmarks on 51 3D ultrasounds, with ranging severity of disease, and inter- and intra-observer reproducibility of landmark and "standard plane" locations was compared; landmarks were chosen within 2 mm, and the "standard plane" rotation was reproducible within 10° between observers. We observed no difference in variability between alpha angles measured on the "standard plane" in comparison with 2D ultrasound. Applications of the standardized 3D ultrasound central plane will be to fuse serial ultrasounds for follow-up and development of new indices of 3D deformity. PMID:25394808

  16. Vascular Structure Identification in Intraoperative 3D Contrast-Enhanced Ultrasound Data.

    PubMed

    Ilunga-Mbuyamba, Elisee; Avina-Cervantes, Juan Gabriel; Lindner, Dirk; Cruz-Aceves, Ivan; Arlt, Felix; Chalopin, Claire

    2016-04-08

    In this paper, a method of vascular structure identification in intraoperative 3D Contrast-Enhanced Ultrasound (CEUS) data is presented. Ultrasound imaging is commonly used in brain tumor surgery to investigate in real time the current status of cerebral structures. The use of an ultrasound contrast agent enables to highlight tumor tissue, but also surrounding blood vessels. However, these structures can be used as landmarks to estimate and correct the brain shift. This work proposes an alternative method for extracting small vascular segments close to the tumor as landmark. The patient image dataset involved in brain tumor operations includes preoperative contrast T1MR (cT1MR) data and 3D intraoperative contrast enhanced ultrasound data acquired before (3D-iCEUS(start) and after (3D-iCEUS(end) tumor resection. Based on rigid registration techniques, a preselected vascular segment in cT1MR is searched in 3D-iCEUS(start) and 3D-iCEUS(end) data. The method was validated by using three similarity measures (Normalized Gradient Field, Normalized Mutual Information and Normalized Cross Correlation). Tests were performed on data obtained from ten patients overcoming a brain tumor operation and it succeeded in nine cases. Despite the small size of the vascular structures, the artifacts in the ultrasound images and the brain tissue deformations, blood vessels were successfully identified.

  17. Vascular Structure Identification in Intraoperative 3D Contrast-Enhanced Ultrasound Data

    PubMed Central

    Ilunga-Mbuyamba, Elisee; Avina-Cervantes, Juan Gabriel; Lindner, Dirk; Cruz-Aceves, Ivan; Arlt, Felix; Chalopin, Claire

    2016-01-01

    In this paper, a method of vascular structure identification in intraoperative 3D Contrast-Enhanced Ultrasound (CEUS) data is presented. Ultrasound imaging is commonly used in brain tumor surgery to investigate in real time the current status of cerebral structures. The use of an ultrasound contrast agent enables to highlight tumor tissue, but also surrounding blood vessels. However, these structures can be used as landmarks to estimate and correct the brain shift. This work proposes an alternative method for extracting small vascular segments close to the tumor as landmark. The patient image dataset involved in brain tumor operations includes preoperative contrast T1MR (cT1MR) data and 3D intraoperative contrast enhanced ultrasound data acquired before (3D-iCEUSstart) and after (3D-iCEUSend) tumor resection. Based on rigid registration techniques, a preselected vascular segment in cT1MR is searched in 3D-iCEUSstart and 3D-iCEUSend data. The method was validated by using three similarity measures (Normalized Gradient Field, Normalized Mutual Information and Normalized Cross Correlation). Tests were performed on data obtained from ten patients overcoming a brain tumor operation and it succeeded in nine cases. Despite the small size of the vascular structures, the artifacts in the ultrasound images and the brain tissue deformations, blood vessels were successfully identified. PMID:27070610

  18. In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

    NASA Astrophysics Data System (ADS)

    Nillesen, M. M.; Lopata, R. G. P.; de Boode, W. P.; Gerrits, I. H.; Huisman, H. J.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

    2009-04-01

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was

  19. Hybrid 3D printing: a game-changer in personalized cardiac medicine?

    PubMed

    Kurup, Harikrishnan K N; Samuel, Bennett P; Vettukattil, Joseph J

    2015-12-01

    Three-dimensional (3D) printing in congenital heart disease has the potential to increase procedural efficiency and patient safety by improving interventional and surgical planning and reducing radiation exposure. Cardiac magnetic resonance imaging and computed tomography are usually the source datasets to derive 3D printing. More recently, 3D echocardiography has been demonstrated to derive 3D-printed models. The integration of multiple imaging modalities for hybrid 3D printing has also been shown to create accurate printed heart models, which may prove to be beneficial for interventional cardiologists, cardiothoracic surgeons, and as an educational tool. Further advancements in the integration of different imaging modalities into a single platform for hybrid 3D printing and virtual 3D models will drive the future of personalized cardiac medicine.

  20. Hybrid 3D printing: a game-changer in personalized cardiac medicine?

    PubMed

    Kurup, Harikrishnan K N; Samuel, Bennett P; Vettukattil, Joseph J

    2015-12-01

    Three-dimensional (3D) printing in congenital heart disease has the potential to increase procedural efficiency and patient safety by improving interventional and surgical planning and reducing radiation exposure. Cardiac magnetic resonance imaging and computed tomography are usually the source datasets to derive 3D printing. More recently, 3D echocardiography has been demonstrated to derive 3D-printed models. The integration of multiple imaging modalities for hybrid 3D printing has also been shown to create accurate printed heart models, which may prove to be beneficial for interventional cardiologists, cardiothoracic surgeons, and as an educational tool. Further advancements in the integration of different imaging modalities into a single platform for hybrid 3D printing and virtual 3D models will drive the future of personalized cardiac medicine. PMID:26465262

  1. Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU

    PubMed Central

    Xia, Yong; Wang, Kuanquan; Zhang, Henggui

    2015-01-01

    Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations. PMID:26581957

  2. Automated 3D ultrasound image segmentation to aid breast cancer image interpretation.

    PubMed

    Gu, Peng; Lee, Won-Mean; Roubidoux, Marilyn A; Yuan, Jie; Wang, Xueding; Carson, Paul L

    2016-02-01

    Segmentation of an ultrasound image into functional tissues is of great importance to clinical diagnosis of breast cancer. However, many studies are found to segment only the mass of interest and not all major tissues. Differences and inconsistencies in ultrasound interpretation call for an automated segmentation method to make results operator-independent. Furthermore, manual segmentation of entire three-dimensional (3D) ultrasound volumes is time-consuming, resource-intensive, and clinically impractical. Here, we propose an automated algorithm to segment 3D ultrasound volumes into three major tissue types: cyst/mass, fatty tissue, and fibro-glandular tissue. To test its efficacy and consistency, the proposed automated method was employed on a database of 21 cases of whole breast ultrasound. Experimental results show that our proposed method not only distinguishes fat and non-fat tissues correctly, but performs well in classifying cyst/mass. Comparison of density assessment between the automated method and manual segmentation demonstrates good consistency with an accuracy of 85.7%. Quantitative comparison of corresponding tissue volumes, which uses overlap ratio, gives an average similarity of 74.54%, consistent with values seen in MRI brain segmentations. Thus, our proposed method exhibits great potential as an automated approach to segment 3D whole breast ultrasound volumes into functionally distinct tissues that may help to correct ultrasound speed of sound aberrations and assist in density based prognosis of breast cancer.

  3. Automated 3D ultrasound image segmentation for assistant diagnosis of breast cancer

    NASA Astrophysics Data System (ADS)

    Wang, Yuxin; Gu, Peng; Lee, Won-Mean; Roubidoux, Marilyn A.; Du, Sidan; Yuan, Jie; Wang, Xueding; Carson, Paul L.

    2016-04-01

    Segmentation of an ultrasound image into functional tissues is of great importance to clinical diagnosis of breast cancer. However, many studies are found to segment only the mass of interest and not all major tissues. Differences and inconsistencies in ultrasound interpretation call for an automated segmentation method to make results operator-independent. Furthermore, manual segmentation of entire three-dimensional (3D) ultrasound volumes is time-consuming, resource-intensive, and clinically impractical. Here, we propose an automated algorithm to segment 3D ultrasound volumes into three major tissue types: cyst/mass, fatty tissue, and fibro-glandular tissue. To test its efficacy and consistency, the proposed automated method was employed on a database of 21 cases of whole breast ultrasound. Experimental results show that our proposed method not only distinguishes fat and non-fat tissues correctly, but performs well in classifying cyst/mass. Comparison of density assessment between the automated method and manual segmentation demonstrates good consistency with an accuracy of 85.7%. Quantitative comparison of corresponding tissue volumes, which uses overlap ratio, gives an average similarity of 74.54%, consistent with values seen in MRI brain segmentations. Thus, our proposed method exhibits great potential as an automated approach to segment 3D whole breast ultrasound volumes into functionally distinct tissues that may help to correct ultrasound speed of sound aberrations and assist in density based prognosis of breast cancer.

  4. 3D ultrasound to stereoscopic camera registration through an air-tissue boundary.

    PubMed

    Yip, Michael C; Adebar, Troy K; Rohling, Robert N; Salcudean, Septimiu E; Nguan, Christopher Y

    2010-01-01

    A novel registration method between 3D ultrasound and stereoscopic cameras is proposed based on tracking a registration tool featuring both ultrasound fiducials and optical markers. The registration tool is pressed against an air-tissue boundary where it can be seen both in ultrasound and in the camera view. By localizing the fiducials in the ultrasound volume, knowing the registration tool geometry, and tracking the tool with the cameras, a registration is found. This method eliminates the need for external tracking, requires minimal setup, and may be suitable for a range of minimally invasive surgeries. A study of the appearance of ultrasound fiducials on an air-tissue boundary is presented, and an initial assessment of the ability to localize the fiducials in ultrasound with sub-millimeter accuracy is provided. The overall accuracy of registration (1.69 +/- 0.60 mm) is a noticeable improvement over other reported methods and warrants patient studies.

  5. Dynamic 2D ultrasound and 3D CT image registration of the beating heart.

    PubMed

    Huang, Xishi; Moore, John; Guiraudon, Gerard; Jones, Douglas L; Bainbridge, Daniel; Ren, Jing; Peters, Terry M

    2009-08-01

    Two-dimensional ultrasound (US) is widely used in minimally invasive cardiac procedures due to its convenience of use and noninvasive nature. However, the low quality of US images often limits their utility as a means for guiding procedures, since it is often difficult to relate the images to their anatomical context. To improve the interpretability of the US images while maintaining US as a flexible anatomical and functional real-time imaging modality, we describe a multimodality image navigation system that integrates 2D US images with their 3D context by registering them to high quality preoperative models based on magnetic resonance imaging (MRI) or computed tomography (CT) images. The mapping from such a model to the patient is completed using spatial and temporal registrations. Spatial registration is performed by a two-step rapid registration method that first approximately aligns the two images as a starting point to an automatic registration procedure. Temporal alignment is performed with the aid of electrocardiograph (ECG) signals and a latency compensation method. Registration accuracy is measured by calculating the TRE. Results show that the error between the US and preoperative images of a beating heart phantom is 1.7 +/-0.4 mm, with a similar performance being observed in in vivo animal experiments.

  6. Proximal femoral focal deficiency of the fetus - early 3D/4D prenatal ultrasound diagnosis.

    PubMed

    Kudla, Marek J; Beczkowska-Kielek, Aleksandra; Kutta, Katarzyna; Partyka-Lasota, Justyna

    2016-09-01

    Proximal Femoral Focal Deficiency (PFFD) is a rare congenital syndrome of unknown etiology. Additional disorders can be present up to 70% of PFFD cases. Management (including termination) depends on the severity of the malformation. We present a case of a 32-year-old woman referred for routine ultrasound examination in the 12th week of pregnancy. Detailed 3D/4D evaluation revealed asymmetry of lower limbs and diagnosis of isolated PFFD was established. Parents were fully informed and decided to continue the pregnancy. We stress here the importance of early 3D/4D ultrasound diagnosis. Our paper presents the earliest case where the diagnosis of PFFD was established with 3D/4D ultrasound. PMID:27622419

  7. 3D freehand ultrasound for medical assistance in diagnosis and treatment of breast cancer: preliminary results

    NASA Astrophysics Data System (ADS)

    Torres, Fabian; Fanti, Zian; Arambula Cosío, F.

    2013-11-01

    Image-guided interventions allow the physician to have a better planning and visualization of a procedure. 3D freehand ultrasound is a non-invasive and low-cost imaging tool that can be used to assist medical procedures. This tool can be used in the diagnosis and treatment of breast cancer. There are common medical practices that involve large needles to obtain an accurate diagnosis and treatment of breast cancer. In this study we propose the use of 3D freehand ultrasound for planning and guiding such procedures as core needle biopsy and radiofrequency ablation. The proposed system will help the physician to identify the lesion area, using image-processing techniques in the 3D freehand ultrasound images, and guide the needle to this area using the information of position and orientation of the surgical tools. We think that this system can upgrade the accuracy and efficiency of these procedures.

  8. FPGA-based real-time anisotropic diffusion filtering of 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Castro-Pareja, Carlos R.; Dandekar, Omkar S.; Shekhar, Raj

    2005-02-01

    Three-dimensional ultrasonic imaging, especially the emerging real-time version of it, is particularly valuable in medical applications such as echocardiography, obstetrics and surgical navigation. A known problem with ultrasound images is their high level of speckle noise. Anisotropic diffusion filtering has been shown to be effective in enhancing the visual quality of 3D ultrasound images and as preprocessing prior to advanced image processing. However, due to its arithmetic complexity and the sheer size of 3D ultrasound images, it is not possible to perform online, real-time anisotropic diffusion filtering using standard software implementations. We present an FPGA-based architecture that allows performing anisotropic diffusion filtering of 3D images at acquisition rates, thus enabling the use of this filtering technique in real-time applications, such as visualization, registration and volume rendering.

  9. 3D reconstruction of a carotid bifurcation from 2D transversal ultrasound images.

    PubMed

    Yeom, Eunseop; Nam, Kweon-Ho; Jin, Changzhu; Paeng, Dong-Guk; Lee, Sang-Joon

    2014-12-01

    Visualizing and analyzing the morphological structure of carotid bifurcations are important for understanding the etiology of carotid atherosclerosis, which is a major cause of stroke and transient ischemic attack. For delineation of vasculatures in the carotid artery, ultrasound examinations have been widely employed because of a noninvasive procedure without ionizing radiation. However, conventional 2D ultrasound imaging has technical limitations in observing the complicated 3D shapes and asymmetric vasodilation of bifurcations. This study aims to propose image-processing techniques for better 3D reconstruction of a carotid bifurcation in a rat by using 2D cross-sectional ultrasound images. A high-resolution ultrasound imaging system with a probe centered at 40MHz was employed to obtain 2D transversal images. The lumen boundaries in each transverse ultrasound image were detected by using three different techniques; an ellipse-fitting, a correlation mapping to visualize the decorrelation of blood flow, and the ellipse-fitting on the correlation map. When the results are compared, the third technique provides relatively good boundary extraction. The incomplete boundaries of arterial lumen caused by acoustic artifacts are somewhat resolved by adopting the correlation mapping and the distortion in the boundary detection near the bifurcation apex was largely reduced by using the ellipse-fitting technique. The 3D lumen geometry of a carotid artery was obtained by volumetric rendering of several 2D slices. For the 3D vasodilatation of the carotid bifurcation, lumen geometries at the contraction and expansion states were simultaneously depicted at various view angles. The present 3D reconstruction methods would be useful for efficient extraction and construction of the 3D lumen geometries of carotid bifurcations from 2D ultrasound images.

  10. A framework for human spine imaging using a freehand 3D ultrasound system.

    PubMed

    Purnama, Ketut E; Wilkinson, Michael H F; Veldhuizen, Albert G; van Ooijen, Peter M A; Lubbers, Jaap; Burgerhof, Johannes G M; Sardjono, Tri A; Verkerke, Gijbertus J

    2010-01-01

    The use of 3D ultrasound imaging to follow the progression of scoliosis, i.e., a 3D deformation of the spine, is described. Unlike other current examination modalities, in particular based on X-ray, its non-detrimental effect enables it to be used frequently to follow the progression of scoliosis which sometimes may develop rapidly. Furthermore, 3D ultrasound imaging provides information in 3D directly in contrast to projection methods. This paper describes a feasibility study of an ultrasound system to provide a 3D image of the human spine, and presents a framework of procedures to perform this task. The framework consist of an ultrasound image acquisition procedure to image a large part of the human spine by means of a freehand 3D ultrasound system and a volume reconstruction procedure which was performed in four stages: bin-filling, hole-filling, volume segment alignment, and volume segment compounding. The overall results of the procedures in this framework show that imaging of the human spine using ultrasound is feasible. Vertebral parts such as the transverse processes, laminae, superior articular processes, and spinous process of the vertebrae appear as clouds of voxels having intensities higher than the surrounding voxels. In sagittal slices, a string of transverse processes appears representing the curvature of the spine. In the bin-filling stage the estimated mean absolute noise level of a single measurement of a single voxel was determined. Our comparative study for the hole-filling methods based on rank sum statistics proved that the pixel nearest neighbour (PNN) method with variable radius and with the proposed olympic operation is the best method. Its mean absolute grey value error was less in magnitude than the noise level of a single measurement.

  11. Ultrasound imaging in teaching cardiac physiology.

    PubMed

    Johnson, Christopher D; Montgomery, Laura E A; Quinn, Joe G; Roe, Sean M; Stewart, Michael T; Tansey, Etain A

    2016-09-01

    This laboratory session provides hands-on experience for students to visualize the beating human heart with ultrasound imaging. Simple views are obtained from which students can directly measure important cardiac dimensions in systole and diastole. This allows students to derive, from first principles, important measures of cardiac function, such as stroke volume, ejection fraction, and cardiac output. By repeating the measurements from a subject after a brief exercise period, an increase in stroke volume and ejection fraction are easily demonstrable, potentially with or without an increase in left ventricular end-diastolic volume (which indicates preload). Thus, factors that affect cardiac performance can readily be discussed. This activity may be performed as a practical demonstration and visualized using an overhead projector or networked computers, concentrating on using the ultrasound images to teach basic physiological principles. This has proved to be highly popular with students, who reported a significant improvement in their understanding of Frank-Starling's law of the heart with ultrasound imaging. PMID:27445285

  12. Image enhancement and segmentation of fluid-filled structures in 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Chalana, Vikram; Dudycha, Stephen; McMorrow, Gerald

    2003-05-01

    Segmentation of fluid-filled structures, such as the urinary bladder, from three-dimensional ultrasound images is necessary for measuring their volume. This paper describes a system for image enhancement, segmentation and volume measurement of fluid-filled structures on 3D ultrasound images. The system was applied for the measurement of urinary bladder volume. Results show an average error of less than 10% in the estimation of the total bladder volume.

  13. 3D X-ray imaging methods in support catheter ablations of cardiac arrhythmias.

    PubMed

    Stárek, Zdeněk; Lehar, František; Jež, Jiří; Wolf, Jiří; Novák, Miroslav

    2014-10-01

    Cardiac arrhythmias are a very frequent illness. Pharmacotherapy is not very effective in persistent arrhythmias and brings along a number of risks. Catheter ablation has became an effective and curative treatment method over the past 20 years. To support complex arrhythmia ablations, the 3D X-ray cardiac cavities imaging is used, most frequently the 3D reconstruction of CT images. The 3D cardiac rotational angiography (3DRA) represents a modern method enabling to create CT like 3D images on a standard X-ray machine equipped with special software. Its advantage lies in the possibility to obtain images during the procedure, decreased radiation dose and reduction of amount of the contrast agent. The left atrium model is the one most frequently used for complex atrial arrhythmia ablations, particularly for atrial fibrillation. CT data allow for creation and segmentation of 3D models of all cardiac cavities. Recently, a research has been made proving the use of 3DRA to create 3D models of other cardiac (right ventricle, left ventricle, aorta) and non-cardiac structures (oesophagus). They can be used during catheter ablation of complex arrhythmias to improve orientation during the construction of 3D electroanatomic maps, directly fused with 3D electroanatomic systems and/or fused with fluoroscopy. An intensive development in the 3D model creation and use has taken place over the past years and they became routinely used during catheter ablations of arrhythmias, mainly atrial fibrillation ablation procedures. Further development may be anticipated in the future in both the creation and use of these models.

  14. Two-dimensional ultrasound and cardiac operations.

    PubMed

    Spotnitz, H M

    1982-01-01

    Two-dimensional ultrasound was employed for qualitative and quantitative studies during cardiac operations in 74 patients. A gas-sterilized phased-array transducer applied directly to the anterior surface of the heart produced high-quality images without a water path or other special manipulations. The techniques employed were successful in demonstrating alterations in cardiac anatomy associated with valve disease and cardiac tumors. Continuous clouds of microbubbles ejected from the left ventricle immediately following cardiopulmonary bypass were detected in 42% of 45 patients studied. Measurement of short-axis area change during systole proved useful for evaluation of intraoperative changes in left ventricular function. In the perioperative period, with the chest closed, the method detected increasing left ventricular mass during transplant rejection and was useful for monitoring changes in left ventricular performance when image quality was sufficient. The capabilities and limitations of this technique for special studies during cardiac operations should be familiar to surgeons with access to the method.

  15. Intelligent speckle reducing anisotropic diffusion algorithm for automated 3-D ultrasound images.

    PubMed

    Wu, Jun; Wang, Yuanyuan; Yu, Jinhua; Shi, Xinling; Zhang, Junhua; Chen, Yue; Pang, Yun

    2015-02-01

    A novel 3-D filtering method is presented for speckle reduction and detail preservation in automated 3-D ultrasound images. First, texture features of an image are analyzed by using the improved quadtree (QT) decomposition. Then, the optimal homogeneous and the obvious heterogeneous regions are selected from QT decomposition results. Finally, diffusion parameters and diffusion process are automatically decided based on the properties of these two selected regions. The computing time needed for 2-D speckle reduction is very short. However, the computing time required for 3-D speckle reduction is often hundreds of times longer than 2-D speckle reduction. This may limit its potential application in practice. Because this new filter can adaptively adjust the time step of iteration, the computation time is reduced effectively. Both synthetic and real 3-D ultrasound images are used to evaluate the proposed filter. It is shown that this filter is superior to other methods in both practicality and efficiency. PMID:26366596

  16. A 3D Freehand Ultrasound System for Multi-view Reconstructions from Sparse 2D Scanning Planes

    PubMed Central

    2011-01-01

    Background A significant limitation of existing 3D ultrasound systems comes from the fact that the majority of them work with fixed acquisition geometries. As a result, the users have very limited control over the geometry of the 2D scanning planes. Methods We present a low-cost and flexible ultrasound imaging system that integrates several image processing components to allow for 3D reconstructions from limited numbers of 2D image planes and multiple acoustic views. Our approach is based on a 3D freehand ultrasound system that allows users to control the 2D acquisition imaging using conventional 2D probes. For reliable performance, we develop new methods for image segmentation and robust multi-view registration. We first present a new hybrid geometric level-set approach that provides reliable segmentation performance with relatively simple initializations and minimum edge leakage. Optimization of the segmentation model parameters and its effect on performance is carefully discussed. Second, using the segmented images, a new coarse to fine automatic multi-view registration method is introduced. The approach uses a 3D Hotelling transform to initialize an optimization search. Then, the fine scale feature-based registration is performed using a robust, non-linear least squares algorithm. The robustness of the multi-view registration system allows for accurate 3D reconstructions from sparse 2D image planes. Results Volume measurements from multi-view 3D reconstructions are found to be consistently and significantly more accurate than measurements from single view reconstructions. The volume error of multi-view reconstruction is measured to be less than 5% of the true volume. We show that volume reconstruction accuracy is a function of the total number of 2D image planes and the number of views for calibrated phantom. In clinical in-vivo cardiac experiments, we show that volume estimates of the left ventricle from multi-view reconstructions are found to be in better

  17. Mechanically assisted 3D prostate ultrasound imaging and biopsy needle-guidance system

    NASA Astrophysics Data System (ADS)

    Bax, Jeffrey; Williams, Jackie; Cool, Derek; Gardi, Lori; Montreuil, Jacques; Karnik, Vaishali; Sherebrin, Shi; Romagnoli, Cesare; Fenster, Aaron

    2010-02-01

    Prostate biopsy procedures are currently limited to using 2D transrectal ultrasound (TRUS) imaging to guide the biopsy needle. Being limited to 2D causes ambiguity in needle guidance and provides an insufficient record to allow guidance to the same suspicious locations or avoid regions that are negative during previous biopsy sessions. We have developed a mechanically assisted 3D ultrasound imaging and needle tracking system, which supports a commercially available TRUS probe and integrated needle guide for prostate biopsy. The mechanical device is fixed to a cart and the mechanical tracking linkage allows its joints to be manually manipulated while fully supporting the weight of the ultrasound probe. The computer interface is provided in order to track the needle trajectory and display its path on a corresponding 3D TRUS image, allowing the physician to aim the needle-guide at predefined targets within the prostate. The system has been designed for use with several end-fired transducers that can be rotated about the longitudinal axis of the probe in order to generate 3D image for 3D navigation. Using the system, 3D TRUS prostate images can be generated in approximately 10 seconds. The system reduces most of the user variability from conventional hand-held probes, which make them unsuitable for precision biopsy, while preserving some of the user familiarity and procedural workflow. In this paper, we describe the 3D TRUS guided biopsy system and report on the initial clinical use of this system for prostate biopsy.

  18. 3D ultrasound imaging method to assess the true spinal deformity.

    PubMed

    Vo, Quang N; Lou, Edmond H M; Le, Lawrence H

    2015-08-01

    Spinal deformity is a three-dimensional (3D) spinal disorder with a lateral deviation and coupled with axial vertebral rotation (AVR). The current clinical practice only measures its severity on postero-anterior (PA) radiographs, which may underestimate the deformity. The actual severity should be obtained on the plane of maximal curvature (PMC), which requires a 3D spinal image. There are many approaches to reconstruct 3D spinal images; however, ultrasound is one of the promising techniques with its non-ionizing characteristic. This study proposed an image processing method using the voxel-based bilinear interpolation to reconstruct a 3D spinal image from ultrasound data, from which the AVR was measured and the spinal curvature on the PMC was determined. In-vitro and in-vivo experiments were performed to determine the accuracy of the measurements from the ultrasound method. The results showed that the 3D ultrasound spinal image could be reconstructed. The curvature angle on the PA and the PMC planes could also be determined. The tilt angle of each individual vertebra in in-vitro study showed high accuracy and correlation (MAD <; 0.9° ± 0.2° and r(2) > 0.87) when comparing the measurements from CT with ultrasound. In in-vivo study, the curvature angles measured on the PA radiographs and ultrasound images yielded a small difference (MAD 3.4° ± 1.0°) and a strong correlation (r(2) = 0.63) within a clinical accepted error of 5°. PMID:26736565

  19. OVERALL PROCEDURES PROTOCOL AND PATIENT ENROLLMENT PROTOCOL: TESTING FEASIBILITY OF 3D ULTRASOUND DATA ACQUISITION AND RELIABILITY OF DATA RETRIEVAL FROM STORED 3D IMAGES

    EPA Science Inventory

    The purpose of this study is to examine the feasibility of collecting, transmitting,

    and analyzing 3-D ultrasound data in the context of a multi-center study of pregnant

    women. The study will also examine the reliability of measurements obtained from 3-D

    imag...

  20. Novel 3-D laparoscopic magnetic ultrasound image guidance for lesion targeting

    PubMed Central

    Sindram, David; McKillop, Iain H; Martinie, John B; Iannitti, David A

    2010-01-01

    Objectives: Accurate laparoscopic liver lesion targeting for biopsy or ablation depends on the ability to merge laparoscopic and ultrasound images with proprioceptive instrument positioning, a skill that can be acquired only through extensive experience. The aim of this study was to determine whether using magnetic positional tracking to provide three-dimensional, real-time guidance improves accuracy during laparoscopic needle placement. Methods: Magnetic sensors were embedded into a needle and laparoscopic ultrasound transducer. These sensors interrupted the magnetic fields produced by an electromagnetic field generator, allowing for real-time, 3-D guidance on a stereoscopic monitor. Targets measuring 5 mm were embedded 3–5 cm deep in agar and placed inside a laparoscopic trainer box. Two novices (a college student and an intern) and two experts (hepatopancreatobiliary surgeons) targeted the lesions out of the ultrasound plane using either traditional or 3-D guidance. Results: Each subject targeted 22 lesions, 11 with traditional and 11 with the novel guidance (n = 88). Hit rates of 32% (14/44) and 100% (44/44) were observed with the traditional approach and the 3-D magnetic guidance approach, respectively. The novices were essentially unable to hit the targets using the traditional approach, but did not miss using the novel system. The hit rate of experts improved from 59% (13/22) to 100% (22/22) (P < 0.0001). Conclusions: The novel magnetic 3-D laparoscopic ultrasound guidance results in perfect targeting of 5-mm lesions, even by surgical novices. PMID:21083797

  1. Validity Study of Vertebral Rotation Measurement Using 3-D Ultrasound in Adolescent Idiopathic Scoliosis.

    PubMed

    Wang, Qian; Li, Meng; Lou, Edmond H M; Chu, Winnie C W; Lam, Tsz-Ping; Cheng, Jack C Y; Wong, Man-Sang

    2016-07-01

    This study aimed to assess the validity of 3-D ultrasound measurements on the vertebral rotation of adolescent idiopathic scoliosis (AIS) under clinical settings. Thirty curves (mean Cobb angle: 21.7° ± 15.9°) from 16 patients with AIS were recruited. 3-D ultrasound and magnetic resonance imaging scans were performed at the supine position. Each of the two raters measured the apical vertebral rotation using the center of laminae (COL) method in the 3-D ultrasound images and the Aaro-Dahlborn method in the magnetic resonance images. The intra- and inter-reliability of the COL method was demonstrated by the intra-class correlation coefficient (ICC) (both [2, K] >0.9, p < 0.05). The COL method showed no significant difference (p < 0.05) compared with the Aaro-Dahlborn method. Furthermore, the agreement between these two methods was demonstrated by the Bland-Altman method, and high correlation was found (r > 0.9, p < 0.05). These results validated the proposed 3-D ultrasound method in the measurements of vertebral rotation in the patients with AIS. PMID:27083978

  2. Visualization of hepatic arteries with 3D ultrasound during intra-arterial therapies

    NASA Astrophysics Data System (ADS)

    Gérard, Maxime; Tang, An; Badoual, Anaïs.; Michaud, François; Bigot, Alexandre; Soulez, Gilles; Kadoury, Samuel

    2016-03-01

    Liver cancer represents the second most common cause of cancer-related mortality worldwide. The prognosis is poor with an overall mortality of 95%. Moreover, most hepatic tumors are unresectable due to their advanced stage at discovery or poor underlying liver function. Tumor embolization by intra-arterial approaches is the current standard of care for advanced cases of hepatocellular carcinoma. These therapies rely on the fact that the blood supply of primary hepatic tumors is predominantly arterial. Feedback on blood flow velocities in the hepatic arteries is crucial to ensure maximal treatment efficacy on the targeted masses. Based on these velocities, the intra-arterial injection rate is modulated for optimal infusion of the chemotherapeutic drugs into the tumorous tissue. While Doppler ultrasound is a well-documented technique for the assessment of blood flow, 3D visualization of vascular anatomy with ultrasound remains challenging. In this paper we present an image-guidance pipeline that enables the localization of the hepatic arterial branches within a 3D ultrasound image of the liver. A diagnostic Magnetic resonance angiography (MRA) is first processed to automatically segment the hepatic arteries. A non-rigid registration method is then applied on the portal phase of the MRA volume with a 3D ultrasound to enable the visualization of the 3D mesh of the hepatic arteries in the Doppler images. To evaluate the performance of the proposed workflow, we present initial results from porcine models and patient images.

  3. Modeling of multi-view 3D freehand radio frequency ultrasound.

    PubMed

    Klein, T; Hansson, M; Navab, Nassir

    2012-01-01

    Nowadays ultrasound (US) examinations are typically performed with conventional machines providing two dimensional imagery. However, there exist a multitude of applications where doctors could benefit from three dimensional ultrasound providing better judgment, due to the extended spatial view. 3D freehand US allows acquisition of images by means of a tracking device attached to the ultrasound transducer. Unfortunately, view dependency makes the 3D representation of ultrasound a non-trivial task. To address this we model speckle statistics, in envelope-detected radio frequency (RF) data, using a finite mixture model (FMM), assuming a parametric representation of data, in which the multiple views are treated as components of the FMM. The proposed model is show-cased with registration, using an ultrasound specific distribution based pseudo-distance, and reconstruction tasks, performed on the manifold of Gamma model parameters. Example field of application is neurology using transcranial US, as this domain requires high accuracy and data systematically features low SNR, making intensity based registration difficult. In particular, 3D US can be specifically used to improve differential diagnosis of Parkinson's disease (PD) compared to conventional approaches and is therefore of high relevance for future application. PMID:23285579

  4. Model based assessment of vestibular jawbone thickness using high frequency 3D ultrasound micro-scanning

    NASA Astrophysics Data System (ADS)

    Habor, Daniel; Neuhaus, Sarah; Vollborn, Thorsten; Wolfart, Stefan; Radermacher, Klaus; Heger, Stefan

    2013-03-01

    Endosseous implants are well-established in modern dentistry. However, without appropriate therapeutic intervention, progressive peri-implant bone loss may lead to failing implants. Conventionally, the particularly relevant vestibular jawbone thickness is monitored using radiographic 3D imaging methods. Ionizing radiation, as well as imaging artifacts caused by metallic implants and superstructures are major drawbacks of these imaging modalities. In this study, a high frequency ultrasound (HFUS) based approach to assess the vestibular jawbone thickness is being introduced. It should be emphasized that the presented method does not require ultrasound penetration of the jawbone. An in-vitro study using two porcine specimens with inserted endosseous implants has been carried out to assess the accuracy of our approach. The implant of the first specimen was equipped with a gingiva former while a polymer superstructure was mounted onto the implant of the second specimen. Ultrasound data has been acquired using a 4 degree of freedom (DOF) high frequency (<50MHz) laboratory ultrasound scanner. The ultrasound raw data has been converted to polygon meshes including the surfaces of bone, gingiva, gingiva former (first specimen) and superstructure (second specimen). The meshes are matched with a-priori acquired 3D models of the implant, the superstructure and the gingiva former using a best-fit algorithm. Finally, the vestibular peri-implant bone thickness has been assessed in the resulting 3D models. The accuracy of this approach has been evaluated by comparing the ultrasound based thickness measurement with a reference measurement acquired with an optical extra-oral 3D scanner prior to covering the specimens with gingiva. As a final result, the bone thicknesses of the two specimens were measured yielding an error of -46+/-89μm (first specimen) and 70+/-93μm (second specimen).

  5. An optical system for detecting 3D high-speed oscillation of a single ultrasound microbubble

    PubMed Central

    Liu, Yuan; Yuan, Baohong

    2013-01-01

    As contrast agents, microbubbles have been playing significant roles in ultrasound imaging. Investigation of microbubble oscillation is crucial for microbubble characterization and detection. Unfortunately, 3-dimensional (3D) observation of microbubble oscillation is challenging and costly because of the bubble size—a few microns in diameter—and the high-speed dynamics under MHz ultrasound pressure waves. In this study, a cost-efficient optical confocal microscopic system combined with a gated and intensified charge-coupled device (ICCD) camera were developed to detect 3D microbubble oscillation. The capability of imaging microbubble high-speed oscillation with much lower costs than with an ultra-fast framing or streak camera system was demonstrated. In addition, microbubble oscillations along both lateral (x and y) and axial (z) directions were demonstrated. Accordingly, this system is an excellent alternative for 3D investigation of microbubble high-speed oscillation, especially when budgets are limited. PMID:24049677

  6. An optical system for detecting 3D high-speed oscillation of a single ultrasound microbubble.

    PubMed

    Liu, Yuan; Yuan, Baohong

    2013-01-01

    As contrast agents, microbubbles have been playing significant roles in ultrasound imaging. Investigation of microbubble oscillation is crucial for microbubble characterization and detection. Unfortunately, 3-dimensional (3D) observation of microbubble oscillation is challenging and costly because of the bubble size-a few microns in diameter-and the high-speed dynamics under MHz ultrasound pressure waves. In this study, a cost-efficient optical confocal microscopic system combined with a gated and intensified charge-coupled device (ICCD) camera were developed to detect 3D microbubble oscillation. The capability of imaging microbubble high-speed oscillation with much lower costs than with an ultra-fast framing or streak camera system was demonstrated. In addition, microbubble oscillations along both lateral (x and y) and axial (z) directions were demonstrated. Accordingly, this system is an excellent alternative for 3D investigation of microbubble high-speed oscillation, especially when budgets are limited. PMID:24049677

  7. A navigation system for flexible endoscopes using abdominal 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Hoffmann, R.; Kaar, M.; Bathia, Amon; Bathia, Amar; Lampret, A.; Birkfellner, W.; Hummel, J.; Figl, M.

    2014-09-01

    A navigation system for flexible endoscopes equipped with ultrasound (US) scan heads is presented. In contrast to similar systems, abdominal 3D-US is used for image fusion of the pre-interventional computed tomography (CT) to the endoscopic US. A 3D-US scan, tracked with an optical tracking system (OTS), is taken pre-operatively together with the CT scan. The CT is calibrated using the OTS, providing the transformation from CT to 3D-US. Immediately before intervention a 3D-US tracked with an electromagnetic tracking system (EMTS) is acquired and registered intra-modal to the preoperative 3D-US. The endoscopic US is calibrated using the EMTS and registered to the pre-operative CT by an intra-modal 3D-US/3D-US registration. Phantom studies showed a registration error for the US to CT registration of 5.1 mm ± 2.8 mm. 3D-US/3D-US registration of patient data gave an error of 4.1 mm compared to 2.8 mm with the phantom. From this we estimate an error on patient experiments of 5.6 mm.

  8. Passive Markers for Tracking Surgical Instruments in Real-Time 3-D Ultrasound Imaging

    PubMed Central

    Stoll, Jeffrey; Ren, Hongliang; Dupont, Pierre E.

    2013-01-01

    A family of passive echogenic markers is presented by which the position and orientation of a surgical instrument can be determined in a 3-D ultrasound volume, using simple image processing. Markers are attached near the distal end of the instrument so that they appear in the ultrasound volume along with the instrument tip. They are detected and measured within the ultrasound image, thus requiring no external tracking device. This approach facilitates imaging instruments and tissue simultaneously in ultrasound-guided interventions. Marker-based estimates of instrument pose can be used in augmented reality displays or for image-based servoing. Design principles for marker shapes are presented that ensure imaging system and measurement uniqueness constraints are met. An error analysis is included that can be used to guide marker design and which also establishes a lower bound on measurement uncertainty. Finally, examples of marker measurement and tracking algorithms are presented along with experimental validation of the concepts. PMID:22042148

  9. Materials and fractal designs for 3D multifunctional integumentary membranes with capabilities in cardiac electrotherapy.

    PubMed

    Xu, Lizhi; Gutbrod, Sarah R; Ma, Yinji; Petrossians, Artin; Liu, Yuhao; Webb, R Chad; Fan, Jonathan A; Yang, Zijian; Xu, Renxiao; Whalen, John J; Weiland, James D; Huang, Yonggang; Efimov, Igor R; Rogers, John A

    2015-03-11

    Advanced materials and fractal design concepts form the basis of a 3D conformal electronic platform with unique capabilities in cardiac electrotherapies. Fractal geometries, advanced electrode materials, and thin, elastomeric membranes yield a class of device capable of integration with the entire 3D surface of the heart, with unique operational capabilities in low power defibrillation. Co-integrated collections of sensors allow simultaneous monitoring of physiological responses. Animal experiments on Langendorff-perfused rabbit hearts demonstrate the key features of these systems.

  10. Multi-resolution Gabor wavelet feature extraction for needle detection in 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Pourtaherian, Arash; Zinger, Svitlana; Mihajlovic, Nenad; de With, Peter H. N.; Huang, Jinfeng; Ng, Gary C.; Korsten, Hendrikus H. M.

    2015-12-01

    Ultrasound imaging is employed for needle guidance in various minimally invasive procedures such as biopsy guidance, regional anesthesia and brachytherapy. Unfortunately, a needle guidance using 2D ultrasound is very challenging, due to a poor needle visibility and a limited field of view. Nowadays, 3D ultrasound systems are available and more widely used. Consequently, with an appropriate 3D image-based needle detection technique, needle guidance and interventions may significantly be improved and simplified. In this paper, we present a multi-resolution Gabor transformation for an automated and reliable extraction of the needle-like structures in a 3D ultrasound volume. We study and identify the best combination of the Gabor wavelet frequencies. High precision in detecting the needle voxels leads to a robust and accurate localization of the needle for the intervention support. Evaluation in several ex-vivo cases shows that the multi-resolution analysis significantly improves the precision of the needle voxel detection from 0.23 to 0.32 at a high recall rate of 0.75 (gain 40%), where a better robustness and confidence were confirmed in the practical experiments.

  11. Ultrasound catheters for circumferential cardiac ablation

    NASA Astrophysics Data System (ADS)

    Diederich, Chris J.; Nau, William H.; Taylor, Kevin; Maguire, Mark T.; Picazo, Guillermo; Gangu, Madhuri; Lesh, Michael D.

    1999-05-01

    The purpose of this study was to investigate performance characteristics of a catheter-based ultrasound applicator intended for circumferential ablation of cardiac tissue. The catheter design integrates a cylindrical ultrasound transducer within a distendable water filled balloon in order to produce circumferential lesions at sites in the atria (i.e., pulmonary vein ostia), intended for treatment of certain atrial arrhythmias. Biothermal simulations were used to investigate thermal lesion depths corresponding to variations in applied power, duration, balloon diameter, and acoustic efficiency. Prototype applicators of varying frequency (7 - 12 MHz) and balloon diameter were constructed and characterized using measurements of acoustic efficiency and rotational beam plots. In vitro studies were performed in freshly excised beef hearts to characterize the radial penetration, axial length, and angular uniformity of thermal lesions produced by these applicators. Selected applicators were tested in vivo within pulmonary veins, coronary sinus, and atrial appendage of canine and porcine hearts. These preliminary efforts have indicated that circumferential ablation of cardiac tissue using ultrasound balloon catheters is feasible, and devices between 7 - 12 MHz with balloon diameters of 1.5 - 2.0 cm are capable of producing uniform lesions between 1 - 5 mm depth or greater for treatment durations of 120 seconds or less.

  12. Reconfigurable 2D cMUT-ASIC arrays for 3D ultrasound image

    NASA Astrophysics Data System (ADS)

    Song, Jongkeun; Jung, Sungjin; Kim, Youngil; Cho, Kyungil; Kim, Baehyung; Lee, Seunghun; Na, Junseok; Yang, Ikseok; Kwon, Oh-kyong; Kim, Dongwook

    2012-03-01

    This paper describes the design and implementations of the complete 2D capacitive micromachined ultrasound transducer electronics and its analog front-end module for transmitting high voltage ultrasound pulses and receiving its echo signals to realize 3D ultrasound image. In order to minimize parasitic capacitances and ultimately improve signal-to- noise ratio (SNR), cMUT has to be integrate with Tx/Rx electronics. Additionally, in order to integrate 2D cMUT array module, significant optimized high voltage pulser circuitry, low voltage analog/digital circuit design and packaging challenges are required due to high density of elements and small pitch of each element. We designed 256(16x16)- element cMUT and reconfigurable driving ASIC composed of 120V high voltage pulser, T/R switch, low noise preamplifier and digital control block to set Tx frequency of ultrasound and pulse train in each element. Designed high voltage analog ASIC was successfully bonded with 2D cMUT array by flip-chip bonding process and it connected with analog front-end board to transmit pulse-echo signals. This implementation of reconfigurable cMUT-ASIC-AFE board enables us to produce large aperture 2D transducer array and acquire high quality of 3D ultrasound image.

  13. Development of a 3D ultrasound-guided prostate biopsy system

    NASA Astrophysics Data System (ADS)

    Cool, Derek; Sherebrin, Shi; Izawa, Jonathan; Fenster, Aaron

    2007-03-01

    Biopsy of the prostate using ultrasound guidance is the clinical gold standard for diagnosis of prostate adenocarinoma. However, because early stage tumors are rarely visible under US, the procedure carries high false-negative rates and often patients require multiple biopsies before cancer is detected. To improve cancer detection, it is imperative that throughout the biopsy procedure, physicians know where they are within the prostate and where they have sampled during prior biopsies. The current biopsy procedure is limited to using only 2D ultrasound images to find and record target biopsy core sample sites. This information leaves ambiguity as the physician tries to interpret the 2D information and apply it to their 3D workspace. We have developed a 3D ultrasound-guided prostate biopsy system that provides 3D intra-biopsy information to physicians for needle guidance and biopsy location recording. The system is designed to conform to the workflow of the current prostate biopsy procedure, making it easier for clinical integration. In this paper, we describe the system design and validate its accuracy by performing an in vitro biopsy procedure on US/CT multi-modal patient-specific prostate phantoms. A clinical sextant biopsy was performed by a urologist on the phantoms and the 3D models of the prostates were generated with volume errors less than 4% and mean boundary errors of less than 1 mm. Using the 3D biopsy system, needles were guided to within 1.36 +/- 0.83 mm of 3D targets and the position of the biopsy sites were accurately localized to 1.06 +/- 0.89 mm for the two prostates.

  14. Reconstruction of 3D ultrasound images based on Cyclic Regularized Savitzky-Golay filters.

    PubMed

    Toonkum, Pollakrit; Suwanwela, Nijasri C; Chinrungrueng, Chedsada

    2011-02-01

    This paper presents a new three-dimensional (3D) ultrasound reconstruction algorithm for generation of 3D images from a series of two-dimensional (2D) B-scans acquired in the mechanical linear scanning framework. Unlike most existing 3D ultrasound reconstruction algorithms, which have been developed and evaluated in the freehand scanning framework, the new algorithm has been designed to capitalize the regularity pattern of the mechanical linear scanning, where all the B-scan slices are precisely parallel and evenly spaced. The new reconstruction algorithm, referred to as the Cyclic Regularized Savitzky-Golay (CRSG) filter, is a new variant of the Savitzky-Golay (SG) smoothing filter. The CRSG filter has been improved upon the original SG filter in two respects: First, the cyclic indicator function has been incorporated into the least square cost function to enable the CRSG filter to approximate nonuniformly spaced data of the unobserved image intensities contained in unfilled voxels and reduce speckle noise of the observed image intensities contained in filled voxels. Second, the regularization function has been augmented to the least squares cost function as a mechanism to balance between the degree of speckle reduction and the degree of detail preservation. The CRSG filter has been evaluated and compared with the Voxel Nearest-Neighbor (VNN) interpolation post-processed by the Adaptive Speckle Reduction (ASR) filter, the VNN interpolation post-processed by the Adaptive Weighted Median (AWM) filter, the Distance-Weighted (DW) interpolation, and the Adaptive Distance-Weighted (ADW) interpolation, on reconstructing a synthetic 3D spherical image and a clinical 3D carotid artery bifurcation in the mechanical linear scanning framework. This preliminary evaluation indicates that the CRSG filter is more effective in both speckle reduction and geometric reconstruction of 3D ultrasound images than the other methods. PMID:20696448

  15. Use of 3D Printed Models in Medical Education: A Randomized Control Trial Comparing 3D Prints versus Cadaveric Materials for Learning External Cardiac Anatomy

    ERIC Educational Resources Information Center

    Lim, Kah Heng Alexander; Loo, Zhou Yaw; Goldie, Stephen J.; Adams, Justin W.; McMenamin, Paul G.

    2016-01-01

    Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized…

  16. Quantification of carotid arteries atherosclerosis using 3D ultrasound images and area-preserving flattened maps

    NASA Astrophysics Data System (ADS)

    Chiu, Bernard; Egger, Micaela; Spence, J. David; Parraga, Grace; Fenster, Aaron

    2008-03-01

    Quantitative measurements of the progression (or regression) of carotid plaque burden are important in monitoring patients and evaluating new treatment options. 3D ultrasound (US) has been used to monitor the progression of carotid artery plaques in symptomatic and asymptomatic patients. Different methods of measuring various ultrasound phenotypes of atherosclerosis have been developed. In this work, we extended concepts used in intima-media thickness (IMT) measurements based on 2D images and introduced a metric called 3D vessel-wall-plus-plaque thickness (3D VWT), which was obtained by computing the distance between the carotid wall and lumen surfaces on a point-by-point basis in a 3D image of the carotid arteries. The VWT measurements were then superimposed on the arterial wall to produce the VWT map. Since the progression of plaque thickness is important in monitoring patients who are at risk for stroke, we also computed the change of VWT by comparing the VWT maps obtained for a patient at two different time points. In order to facilitate the visualization and interpretation of the 3D VWT and VWT-Change maps, we proposed a technique to flatten these maps in an area-preserving manner.

  17. Accurate Diagnosis of Severe Hypospadias Using 2D and 3D Ultrasounds

    PubMed Central

    López Ramón y Cajal, Carlos; Marín Ortiz, Elena; Sarmiento Carrera, Nerea

    2016-01-01

    The hypospadias is the most common urogenital anomaly of male neonates but the prenatal diagnosis of this is often missed before birth. We present the prenatal diagnosis of a severe penoscrotal hypospadias using 2D and 3D ultrasounds. 3D sonography allowed us the best evaluation of the genitals and their anatomical relations. This ample detailed study allowed us to show the findings to the parents and the pediatric surgeon and to configure the best information about the prognosis and surgical treatment. PMID:27774326

  18. 2D array transducers for real-time 3D ultrasound guidance of interventional devices

    NASA Astrophysics Data System (ADS)

    Light, Edward D.; Smith, Stephen W.

    2009-02-01

    We describe catheter ring arrays for real-time 3D ultrasound guidance of devices such as vascular grafts, heart valves and vena cava filters. We have constructed several prototypes operating at 5 MHz and consisting of 54 elements using the W.L. Gore & Associates, Inc. micro-miniature ribbon cables. We have recently constructed a new transducer using a braided wiring technology from Precision Interconnect. This transducer consists of 54 elements at 4.8 MHz with pitch of 0.20 mm and typical -6 dB bandwidth of 22%. In all cases, the transducer and wiring assembly were integrated with an 11 French catheter of a Cook Medical deployment device for vena cava filters. Preliminary in vivo and in vitro testing is ongoing including simultaneous 3D ultrasound and x-ray fluoroscopy.

  19. Registration of Real-Time 3-D Ultrasound to Tomographic Images of the Abdominal Aorta.

    PubMed

    Brekken, Reidar; Iversen, Daniel Høyer; Tangen, Geir Arne; Dahl, Torbjørn

    2016-08-01

    The purpose of this study was to develop an image-based method for registration of real-time 3-D ultrasound to computed tomography (CT) of the abdominal aorta, targeting future use in ultrasound-guided endovascular intervention. We proposed a method in which a surface model of the aortic wall was segmented from CT, and the approximate initial location of this model relative to the ultrasound volume was manually indicated. The model was iteratively transformed to automatically optimize correspondence to the ultrasound data. Feasibility was studied using data from a silicon phantom and in vivo data from a volunteer with previously acquired CT. Through visual evaluation, the ultrasound and CT data were seen to correspond well after registration. Both aortic lumen and branching arteries were well aligned. The processing was done offline, and the registration took approximately 0.2 s per ultrasound volume. The results encourage further patient studies to investigate accuracy, robustness and clinical value of the approach. PMID:27156015

  20. Human cardiac telocytes: 3D imaging by FIB-SEM tomography.

    PubMed

    Cretoiu, D; Hummel, E; Zimmermann, H; Gherghiceanu, M; Popescu, L M

    2014-11-01

    Telocyte (TC) is a newly identified type of cell in the cardiac interstitium (www.telocytes.com). TCs are described by classical transmission electron microscopy as cells with very thin and long telopodes (Tps; cellular prolongations) having podoms (dilations) and podomers (very thin segments). TCs' three-dimensional (3D) morphology is still unknown. Cardiac TCs seem to be particularly involved in long and short distance intercellular signalling and, therefore, their 3D architecture is important for understanding their spatial connections. Using focused ion beam scanning electron microscopy (FIB-SEM) we show, for the first time, the whole ultrastructural anatomy of cardiac TCs. 3D reconstruction of cardiac TCs by FIB-SEM tomography confirms that they have long, narrow but flattened (ribbon-like) telopodes, with humps generated by the podoms. FIB-SEM tomography also confirms the network made by TCs in the cardiac interstitium through adherens junctions. This study provides the first FIB-SEM tomography of a human cell type.

  1. Random Walk Based Segmentation for the Prostate on 3D Transrectal Ultrasound Images

    PubMed Central

    Ma, Ling; Guo, Rongrong; Tian, Zhiqiang; Venkataraman, Rajesh; Sarkar, Saradwata; Liu, Xiabi; Nieh, Peter T.; Master, Viraj V.; Schuster, David M.; Fei, Baowei

    2016-01-01

    This paper proposes a new semi-automatic segmentation method for the prostate on 3D transrectal ultrasound images (TRUS) by combining the region and classification information. We use a random walk algorithm to express the region information efficiently and flexibly because it can avoid segmentation leakage and shrinking bias. We further use the decision tree as the classifier to distinguish the prostate from the non-prostate tissue because of its fast speed and superior performance, especially for a binary classification problem. Our segmentation algorithm is initialized with the user roughly marking the prostate and non-prostate points on the mid-gland slice which are fitted into an ellipse for obtaining more points. Based on these fitted seed points, we run the random walk algorithm to segment the prostate on the mid-gland slice. The segmented contour and the information from the decision tree classification are combined to determine the initial seed points for the other slices. The random walk algorithm is then used to segment the prostate on the adjacent slice. We propagate the process until all slices are segmented. The segmentation method was tested in 32 3D transrectal ultrasound images. Manual segmentation by a radiologist serves as the gold standard for the validation. The experimental results show that the proposed method achieved a Dice similarity coefficient of 91.37±0.05%. The segmentation method can be applied to 3D ultrasound-guided prostate biopsy and other applications. PMID:27660383

  2. Random walk based segmentation for the prostate on 3D transrectal ultrasound images

    NASA Astrophysics Data System (ADS)

    Ma, Ling; Guo, Rongrong; Tian, Zhiqiang; Venkataraman, Rajesh; Sarkar, Saradwata; Liu, Xiabi; Nieh, Peter T.; Master, Viraj V.; Schuster, David M.; Fei, Baowei

    2016-03-01

    This paper proposes a new semi-automatic segmentation method for the prostate on 3D transrectal ultrasound images (TRUS) by combining the region and classification information. We use a random walk algorithm to express the region information efficiently and flexibly because it can avoid segmentation leakage and shrinking bias. We further use the decision tree as the classifier to distinguish the prostate from the non-prostate tissue because of its fast speed and superior performance, especially for a binary classification problem. Our segmentation algorithm is initialized with the user roughly marking the prostate and non-prostate points on the mid-gland slice which are fitted into an ellipse for obtaining more points. Based on these fitted seed points, we run the random walk algorithm to segment the prostate on the mid-gland slice. The segmented contour and the information from the decision tree classification are combined to determine the initial seed points for the other slices. The random walk algorithm is then used to segment the prostate on the adjacent slice. We propagate the process until all slices are segmented. The segmentation method was tested in 32 3D transrectal ultrasound images. Manual segmentation by a radiologist serves as the gold standard for the validation. The experimental results show that the proposed method achieved a Dice similarity coefficient of 91.37+/-0.05%. The segmentation method can be applied to 3D ultrasound-guided prostate biopsy and other applications.

  3. Automatic nipple detection on 3D images of an automated breast ultrasound system (ABUS)

    NASA Astrophysics Data System (ADS)

    Javanshir Moghaddam, Mandana; Tan, Tao; Karssemeijer, Nico; Platel, Bram

    2014-03-01

    Recent studies have demonstrated that applying Automated Breast Ultrasound in addition to mammography in women with dense breasts can lead to additional detection of small, early stage breast cancers which are occult in corresponding mammograms. In this paper, we proposed a fully automatic method for detecting the nipple location in 3D ultrasound breast images acquired from Automated Breast Ultrasound Systems. The nipple location is a valuable landmark to report the position of possible abnormalities in a breast or to guide image registration. To detect the nipple location, all images were normalized. Subsequently, features have been extracted in a multi scale approach and classification experiments were performed using a gentle boost classifier to identify the nipple location. The method was applied on a dataset of 100 patients with 294 different 3D ultrasound views from Siemens and U-systems acquisition systems. Our database is a representative sample of cases obtained in clinical practice by four medical centers. The automatic method could accurately locate the nipple in 90% of AP (Anterior-Posterior) views and in 79% of the other views.

  4. 3D ultrasound Nakagami imaging for radiation-induced vaginal fibrosis

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofeng; Rossi, Peter; Shelton, Joseph; Bruner, Debrorah; Tridandapani, Srini; Liu, Tian

    2014-03-01

    Radiation-induced vaginal fibrosis is a debilitating side-effect affecting up to 80% of women receiving radiotherapy for their gynecological (GYN) malignancies. Despite the significant incidence and severity, little research has been conducted to identify the pathophysiologic changes of vaginal toxicity. In a previous study, we have demonstrated that ultrasound Nakagami shape and PDF parameters can be used to quantify radiation-induced vaginal toxicity. These Nakagami parameters are derived from the statistics of ultrasound backscattered signals to capture the physical properties (e.g., arrangement and distribution) of the biological tissues. In this paper, we propose to expand this Nakagami imaging concept from 2D to 3D to fully characterize radiation-induced changes to the vaginal wall within the radiation treatment field. A pilot study with 5 post-radiotherapy GYN patients was conducted using a clinical ultrasound scanner (6 MHz) with a mechanical stepper. A serial of 2D ultrasound images, with radio-frequency (RF) signals, were acquired at 1 mm step size. The 2D Nakagami shape and PDF parameters were calculated from the RF signal envelope with a sliding window, and then 3D Nakagami parameter images were generated from the parallel 2D images. This imaging method may be useful as we try to monitor radiation-induced vaginal injury, and address vaginal toxicities and sexual dysfunction in women after radiotherapy for GYN malignancies.

  5. 3-D ultrasound-guided robotic needle steering in biological tissue.

    PubMed

    Adebar, Troy K; Fletcher, Ashley E; Okamura, Allison M

    2014-12-01

    Robotic needle steering systems have the potential to greatly improve medical interventions, but they require new methods for medical image guidance. Three-dimensional (3-D) ultrasound is a widely available, low-cost imaging modality that may be used to provide real-time feedback to needle steering robots. Unfortunately, the poor visibility of steerable needles in standard grayscale ultrasound makes automatic segmentation of the needles impractical. A new imaging approach is proposed, in which high-frequency vibration of a steerable needle makes it visible in ultrasound Doppler images. Experiments demonstrate that segmentation from this Doppler data is accurate to within 1-2 mm. An image-guided control algorithm that incorporates the segmentation data as feedback is also described. In experimental tests in ex vivo bovine liver tissue, a robotic needle steering system implementing this control scheme was able to consistently steer a needle tip to a simulated target with an average error of 1.57 mm. Implementation of 3-D ultrasound-guided needle steering in biological tissue represents a significant step toward the clinical application of robotic needle steering.

  6. Image guidance using 3D-ultrasound (3D-US) for daily positioning of lumpectomy cavity for boost irradiation

    PubMed Central

    2011-01-01

    Purpose The goal of this study was to evaluate the use of 3D ultrasound (3DUS) breast IGRT for electron and photon lumpectomy site boost treatments. Materials and methods 20 patients with a prescribed photon or electron boost were enrolled in this study. 3DUS images were acquired both at time of simulation, to form a coregistered CT/3DUS dataset, and at the time of daily treatment delivery. Intrafractional motion between treatment and simulation 3DUS datasets were calculated to determine IGRT shifts. Photon shifts were evaluated isocentrically, while electron shifts were evaluated in the beam's-eye-view. Volume differences between simulation and first boost fraction were calculated. Further, to control for the effect of change in seroma/cavity volume due to time lapse between the 2 sets of images, interfraction IGRT shifts using the first boost fraction as reference for all subsequent treatment fractions were also calculated. Results For photon boosts, IGRT shifts were 1.1 ± 0.5 cm and 50% of fractions required a shift >1.0 cm. Volume change between simulation and boost was 49 ± 31%. Shifts when using the first boost fraction as reference were 0.8 ± 0.4 cm and 24% required a shift >1.0 cm. For electron boosts, shifts were 1.0 ± 0.5 cm and 52% fell outside the dosimetric penumbra. Interfraction analysis relative to the first fraction noted the shifts to be 0.8 ± 0.4 cm and 36% fell outside the penumbra. Conclusion The lumpectomy cavity can shift significantly during fractionated radiation therapy. 3DUS can be used to image the cavity and correct for interfractional motion. Further studies to better define the protocol for clinical application of IGRT in breast cancer is needed. PMID:21554697

  7. Inter-rater reliability in the classification of supraspinatus tendon tears using 3D ultrasound – a question of experience?

    PubMed Central

    Marx, Christian; Micheroli, Raphael

    2016-01-01

    Background Three-dimensional (3D) ultrasound of the shoulder is characterized by a comparable accuracy to two-dimensional (2D) ultrasound. No studies investigating 2D versus 3D inter-rater reliability in the detection of supraspinatus tendon tears taking into account the level of experience of the raters have been carried out so far. Objectives The aim of this study was to determine the inter-rater reliability in the analysis of 3D ultrasound image sets of the supraspinatus tendon between sonographer with different levels of experience. Patients and methods Non-interventional, prospective, observational pilot study of 2309 images of 127 adult patients suffering from unilateral shoulder pain. 3D ultrasound image sets were scored by three raters independently. The intra-and interrater reliabilities were calculated. Results There was an excellent intra-rater reliability of rater A in the overall classification of supraspinatus tendon tears (2D vs 3D κ = 0.892, pairwise reliability 93.81%, 3D scoring round 1 vs 3D scoring round 2 κ = 0.875, pairwise reliability 92.857%). The inter-rater reliability was only moderate compared to rater B on 3D (κ = 0.497, pairwise reliability 70.95%) and fair compared to rater C (κ = 0.238, pairwise reliability 42.38%). Conclusions The reliability of 3D ultrasound of the supraspinatus tendon depends on the level of experience of the sonographer. Experience in 2D ultrasound does not seem to be sufficient for the analysis of 3D ultrasound imaging sets. Therefore, for a 3D ultrasound analysis new diagnostic criteria have to be established and taught even to experienced 2D sonographers to improve reproducibility. PMID:27679728

  8. Inter-rater reliability in the classification of supraspinatus tendon tears using 3D ultrasound – a question of experience?

    PubMed Central

    Marx, Christian; Micheroli, Raphael

    2016-01-01

    Background Three-dimensional (3D) ultrasound of the shoulder is characterized by a comparable accuracy to two-dimensional (2D) ultrasound. No studies investigating 2D versus 3D inter-rater reliability in the detection of supraspinatus tendon tears taking into account the level of experience of the raters have been carried out so far. Objectives The aim of this study was to determine the inter-rater reliability in the analysis of 3D ultrasound image sets of the supraspinatus tendon between sonographer with different levels of experience. Patients and methods Non-interventional, prospective, observational pilot study of 2309 images of 127 adult patients suffering from unilateral shoulder pain. 3D ultrasound image sets were scored by three raters independently. The intra-and interrater reliabilities were calculated. Results There was an excellent intra-rater reliability of rater A in the overall classification of supraspinatus tendon tears (2D vs 3D κ = 0.892, pairwise reliability 93.81%, 3D scoring round 1 vs 3D scoring round 2 κ = 0.875, pairwise reliability 92.857%). The inter-rater reliability was only moderate compared to rater B on 3D (κ = 0.497, pairwise reliability 70.95%) and fair compared to rater C (κ = 0.238, pairwise reliability 42.38%). Conclusions The reliability of 3D ultrasound of the supraspinatus tendon depends on the level of experience of the sonographer. Experience in 2D ultrasound does not seem to be sufficient for the analysis of 3D ultrasound imaging sets. Therefore, for a 3D ultrasound analysis new diagnostic criteria have to be established and taught even to experienced 2D sonographers to improve reproducibility.

  9. 3D deformable organ model based liver motion tracking in ultrasound videos

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Bae; Hwang, Youngkyoo; Oh, Young-Taek; Bang, Won-Chul; Lee, Heesae; Kim, James D. K.; Kim, Chang Yeong

    2013-03-01

    This paper presents a novel method of using 2D ultrasound (US) cine images during image-guided therapy to accurately track the 3D position of a tumor even when the organ of interest is in motion due to patient respiration. Tracking is possible thanks to a 3D deformable organ model we have developed. The method consists of three processes in succession. The first process is organ modeling where we generate a personalized 3D organ model from high quality 3D CT or MR data sets captured during three different respiratory phases. The model includes the organ surface, vessel and tumor, which can all deform and move in accord with patient respiration. The second process is registration of the organ model to 3D US images. From 133 respiratory phase candidates generated from the deformable organ model, we resolve the candidate that best matches the 3D US images according to vessel centerline and surface. As a result, we can determine the position of the US probe. The final process is real-time tracking using 2D US cine images captured by the US probe. We determine the respiratory phase by tracking the diaphragm on the image. The 3D model is then deformed according to respiration phase and is fitted to the image by considering the positions of the vessels. The tumor's 3D positions are then inferred based on respiration phase. Testing our method on real patient data, we have found the accuracy of 3D position is within 3.79mm and processing time is 5.4ms during tracking.

  10. 3D ultrasound volume stitching using phase symmetry and harris corner detection for orthopaedic applications

    NASA Astrophysics Data System (ADS)

    Dalvi, Rupin; Hacihaliloglu, Ilker; Abugharbieh, Rafeef

    2010-03-01

    Stitching of volumes obtained from three dimensional (3D) ultrasound (US) scanners improves visualization of anatomy in many clinical applications. Fast but accurate volume registration remains the key challenge in this area.We propose a volume stitching method based on efficient registration of 3D US volumes obtained from a tracked US probe. Since the volumes, after adjusting for probe motion, are coarsely registered, we obtain salient correspondence points in the central slices of these volumes. This is done by first removing artifacts in the US slices using intensity invariant local phase image processing and then applying the Harris Corner detection algorithm. Fast sub-volume registration on a small neighborhood around the points then gives fast, accurate 3D registration parameters. The method has been tested on 3D US scans of phantom and real human radius and pelvis bones and a phantom human fetus. The method has also been compared to volumetric registration, as well as feature based registration using 3D-SIFT. Quantitative results show average post-registration error of 0.33mm which is comparable to volumetric registration accuracy (0.31mm) and much better than 3D-SIFT based registration which failed to register the volumes. The proposed method was also much faster than volumetric registration (~4.5 seconds versus 83 seconds).

  11. Local phase tensor features for 3-D ultrasound to statistical shape+pose spine model registration.

    PubMed

    Hacihaliloglu, Ilker; Rasoulian, Abtin; Rohling, Robert N; Abolmaesumi, Purang

    2014-11-01

    Most conventional spine interventions are performed under X-ray fluoroscopy guidance. In recent years, there has been a growing interest to develop nonionizing imaging alternatives to guide these procedures. Ultrasound guidance has emerged as a leading alternative. However, a challenging problem is automatic identification of the spinal anatomy in ultrasound data. In this paper, we propose a local phase-based bone feature enhancement technique that can robustly identify the spine surface in ultrasound images. The local phase information is obtained using a gradient energy tensor filter. This information is used to construct local phase tensors in ultrasound images, which highlight the spine surface. We show that our proposed approach results in a more distinct enhancement of the bone surfaces compared to recently proposed techniques based on monogenic scale-space filters and logarithmic Gabor filters. We also demonstrate that registration accuracy of a statistical shape+pose model of the spine to 3-D ultrasound images can be significantly improved, using the proposed method, compared to those obtained using monogenic scale-space filters and logarithmic Gabor filters.

  12. Motion corrected LV quantification based on 3D modelling for improved functional assessment in cardiac MRI

    NASA Astrophysics Data System (ADS)

    Liew, Y. M.; McLaughlin, R. A.; Chan, B. T.; Aziz, Y. F. Abdul; Chee, K. H.; Ung, N. M.; Tan, L. K.; Lai, K. W.; Ng, S.; Lim, E.

    2015-04-01

    Cine MRI is a clinical reference standard for the quantitative assessment of cardiac function, but reproducibility is confounded by motion artefacts. We explore the feasibility of a motion corrected 3D left ventricle (LV) quantification method, incorporating multislice image registration into the 3D model reconstruction, to improve reproducibility of 3D LV functional quantification. Multi-breath-hold short-axis and radial long-axis images were acquired from 10 patients and 10 healthy subjects. The proposed framework reduced misalignment between slices to subpixel accuracy (2.88 to 1.21 mm), and improved interstudy reproducibility for 5 important clinical functional measures, i.e. end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and 3D-sphericity index, as reflected in a reduction in the sample size required to detect statistically significant cardiac changes: a reduction of 21-66%. Our investigation on the optimum registration parameters, including both cardiac time frames and number of long-axis (LA) slices, suggested that a single time frame is adequate for motion correction whereas integrating more LA slices can improve registration and model reconstruction accuracy for improved functional quantification especially on datasets with severe motion artefacts.

  13. Simulation of MRI-Guided Transurethral Conformal 3-D Ultrasound Therapy of the Prostate

    NASA Astrophysics Data System (ADS)

    Burtnyk, Mathieu; Chopra, Rajiv; Bronskill, Michael

    2007-05-01

    The capability of MRI to measure spatial heating patterns during therapy delivery with ultrasound makes adaptive thermal therapy possible. Active feedback provided by MR thermometry enables on-line adjustment of the treatment to compensate for tissue/perfusion changes during heating. The feasibility of performing 3-D conformal thermal therapy of the entire prostate gland with a multi-element transurethral ultrasound heating applicator was considered in this study. The major challenge was using MR temperature feedback to adjust simultaneously the device's rate of rotation and the power and frequency of multiple independent ultrasound transducers, to shape the region of thermal damage to the prostate gland in all spatial dimensions while sparing surrounding tissues from damage. The 3-D Bioheat Transfer Equation was used to model the ultrasound therapy using manually segmented MRI prostate geometries from 20 prostate cancer patients. Average prostate dimensions (±SD) were: length: 37.8±7.2 mm, width: 47.1±5.5 mm, height: 28.9±5.7 mm. Typical treatments of the entire prostate volume take less than 30 min. Results from various treatment strategies were compared by calculating the percentage volume of under- and over-treated tissue and the potential thermal damage incurred by important adjacent anatomical structures using "dose-effect" curves. Visualization tools were developed to investigate patient-specific prostate and periprostatic anatomy, as well as the simulated coagulated volumes in 3-D, enabling evaluation of individual patient outcomes. These simulations also enabled the investigation of the number and size of transducer segments required for accurate treatment delivery. In general, the under-treated fraction can be maintained below 1% of the prostate volume, but the over-treated fraction can range up to 15%, emphasizing the importance of accurate location of sensitive adjacent structures.

  14. Accuracy assessment of high frequency 3D ultrasound for digital impression-taking of prepared teeth

    NASA Astrophysics Data System (ADS)

    Heger, Stefan; Vollborn, Thorsten; Tinschert, Joachim; Wolfart, Stefan; Radermacher, Klaus

    2013-03-01

    Silicone based impression-taking of prepared teeth followed by plaster casting is well-established but potentially less reliable, error-prone and inefficient, particularly in combination with emerging techniques like computer aided design and manufacturing (CAD/CAM) of dental prosthesis. Intra-oral optical scanners for digital impression-taking have been introduced but until now some drawbacks still exist. Because optical waves can hardly penetrate liquids or soft-tissues, sub-gingival preparations still need to be uncovered invasively prior to scanning. High frequency ultrasound (HFUS) based micro-scanning has been recently investigated as an alternative to optical intra-oral scanning. Ultrasound is less sensitive against oral fluids and in principal able to penetrate gingiva without invasively exposing of sub-gingival preparations. Nevertheless, spatial resolution as well as digitization accuracy of an ultrasound based micro-scanning system remains a critical parameter because the ultrasound wavelength in water-like media such as gingiva is typically smaller than that of optical waves. In this contribution, the in-vitro accuracy of ultrasound based micro-scanning for tooth geometry reconstruction is being investigated and compared to its extra-oral optical counterpart. In order to increase the spatial resolution of the system, 2nd harmonic frequencies from a mechanically driven focused single element transducer were separated and corresponding 3D surface models were calculated for both fundamentals and 2nd harmonics. Measurements on phantoms, model teeth and human teeth were carried out for evaluation of spatial resolution and surface detection accuracy. Comparison of optical and ultrasound digital impression taking indicate that, in terms of accuracy, ultrasound based tooth digitization can be an alternative for optical impression-taking.

  15. Determining cardiac fiber orientation using FSL and registered ultrasound/DTI volumes

    NASA Astrophysics Data System (ADS)

    Dormer, James; Qin, Xulei; Shen, Ming; Wang, Silun; Zhang, Xiaodong; Jiang, Rong; Wagner, Mary B.; Fei, Baowei

    2016-04-01

    Accurate extraction of cardiac fiber orientation from diffusion tensor imaging is important for determining heart structure and function. However, the acquisition of magnetic resonance (MR) diffusion tensor images is costly and time consuming. By comparison, cardiac ultrasound imaging is rapid and relatively inexpensive, but it lacks the capability to directly measure fiber orientations. In order to create a detailed heart model from ultrasound data, a three-dimensional (3D) diffusion tensor imaging (DTI) with known fiber orientations can be registered to an ultrasound volume through a geometric mask. After registration, the cardiac orientations from the template DTI can be mapped to the heart using a deformable transformation field. This process depends heavily on accurate fiber orientation extraction from the DTI. In this study, we use the FMRIB Software Library (FSL) to determine cardiac fiber orientations in diffusion weighted images. For the registration between ultrasound and MRI volumes, we achieved an average Dice similarity coefficient (DSC) of 81.6+/-2.1%. For the estimation of fiber orientations from the proposed method, we achieved an acute angle error (AAE) of 22.7+/-3.1° as compared to the direct measurements from DTI. This work provides a new approach to generate cardiac fiber orientation that may be used for many cardiac applications.

  16. Determining Cardiac Fiber Orientation Using FSL and Registered Ultrasound/DTI volumes

    PubMed Central

    Dormer, James; Qin, Xulei; Shen, Ming; Wang, Silun; Zhang, Xiaodong; Jiang, Rong; Wagner, Mary B.; Fei, Baowei

    2016-01-01

    Accurate extraction of cardiac fiber orientation from diffusion tensor imaging is important for determining heart structure and function. However, the acquisition of magnetic resonance (MR) diffusion tensor images is costly and time consuming. By comparison, cardiac ultrasound imaging is rapid and relatively inexpensive, but it lacks the capability to directly measure fiber orientations. In order to create a detailed heart model from ultrasound data, a three-dimensional (3D) diffusion tensor imaging (DTI) with known fiber orientations can be registered to an ultrasound volume through a geometric mask. After registration, the cardiac orientations from the template DTI can be mapped to the heart using a deformable transformation field. This process depends heavily on accurate fiber orientation extraction from the DTI. In this study, we use the FMRIB Software Library (FSL) to determine cardiac fiber orientations in diffusion weighted images. For the registration between ultrasound and MRI volumes, we achieved an average Dice similarity coefficient (DSC) of 81.6±2.1%. For the estimation of fiber orientations from the proposed method, we achieved an acute angle error (AAE) of 22.7±3.1° as compared to the direct measurements from DTI. This work provides a new approach to generate cardiac fiber orientation that may be used for many cardiac applications. PMID:27660384

  17. Preliminary results in large bone segmentation from 3D freehand ultrasound

    NASA Astrophysics Data System (ADS)

    Fanti, Zian; Torres, Fabian; Arámbula Cosío, Fernando

    2013-11-01

    Computer Assisted Orthopedic Surgery (CAOS) requires a correct registration between the patient in the operating room and the virtual models representing the patient in the computer. In order to increase the precision and accuracy of the registration a set of new techniques that eliminated the need to use fiducial markers have been developed. The majority of these newly developed registration systems are based on costly intraoperative imaging systems like Computed Tomography (CT scan) or Magnetic resonance imaging (MRI). An alternative to these methods is the use of an Ultrasound (US) imaging system for the implementation of a more cost efficient intraoperative registration solution. In order to develop the registration solution with the US imaging system, the bone surface is segmented in both preoperative and intraoperative images, and the registration is done using the acquire surface. In this paper, we present the a preliminary results of a new approach to segment bone surface from ultrasound volumes acquired by means 3D freehand ultrasound. The method is based on the enhancement of the voxels that belongs to surface and its posterior segmentation. The enhancement process is based on the information provided by eigenanalisis of the multiscale 3D Hessian matrix. The preliminary results shows that from the enhance volume the final bone surfaces can be extracted using a singular value thresholding.

  18. Development of a Wireless and Near Real-Time 3D Ultrasound Strain Imaging System.

    PubMed

    Chen, Zhaohong; Chen, Yongdong; Huang, Qinghua

    2016-04-01

    Ultrasound elastography is an important medical imaging tool for characterization of lesions. In this paper, we present a wireless and near real-time 3D ultrasound strain imaging system. It uses a 3D translating device to control a commercial linear ultrasound transducer to collect pre-compression and post-compression radio-frequency (RF) echo signal frames. The RF frames are wirelessly transferred to a high-performance server via a local area network (LAN). A dynamic programming strain estimation algorithm is implemented with the compute unified device architecture (CUDA) on the graphic processing unit (GPU) in the server to calculate the strain image after receiving a pre-compression RF frame and a post-compression RF frame at the same position. Each strain image is inserted into a strain volume which can be rendered in near real-time. We take full advantage of the translating device to precisely control the probe movement and compression. The GPU-based parallel computing techniques are designed to reduce the computation time. Phantom and in vivo experimental results demonstrate that our system can generate strain volumes with good quality and display an incrementally reconstructed volume image in near real-time. PMID:26954841

  19. A PET/CT Directed, 3D Ultrasound-Guided Biopsy System for Prostate Cancer

    PubMed Central

    Master, Viraj; Nieh, Peter; Akbari, Hamed; Yang, Xiaofeng; Fenster, Aaron; Schuster, David

    2015-01-01

    Prostate cancer affects 1 in 6 men in the USA. Systematic transrectal ultrasound (TRUS)-guided biopsy is the standard method for a definitive diagnosis of prostate cancer. However, this “blind” biopsy approach can miss at least 20% of prostate cancers. In this study, we are developing a PET/CT directed, 3D ultrasound image-guided biopsy system for improved detection of prostate cancer. In order to plan biopsy in three dimensions, we developed an automatic segmentation method based wavelet transform for 3D TRUS images of the prostate. The segmentation was tested in five patients with a DICE overlap ratio of more than 91%. In order to incorporate PET/CT images into ultrasound-guided biopsy, we developed a nonrigid registration algorithm for TRUS and PET/CT images. The registration method has been tested in a prostate phantom with a target registration error (TRE) of less than 0.4 mm. The segmentation and registration methods are two key components of the multimodality molecular image-guided biopsy system. PMID:26866061

  20. Benchmarking of state-of-the-art needle detection algorithms in 3D ultrasound data volumes

    NASA Astrophysics Data System (ADS)

    Pourtaherian, Arash; Zinger, Svitlana; de With, Peter H. N.; Korsten, Hendrikus H. M.; Mihajlovic, Nenad

    2015-03-01

    Ultrasound-guided needle interventions are widely practiced in medical diagnostics and therapy, i.e. for biopsy guidance, regional anesthesia or for brachytherapy. Needle guidance using 2D ultrasound can be very challenging due to the poor needle visibility and the limited field of view. Since 3D ultrasound transducers are becoming more widely used, needle guidance can be improved and simplified with appropriate computer-aided analyses. In this paper, we compare two state-of-the-art 3D needle detection techniques: a technique based on line filtering from literature and a system employing Gabor transformation. Both algorithms utilize supervised classification to pre-select candidate needle voxels in the volume and then fit a model of the needle on the selected voxels. The major differences between the two approaches are in extracting the feature vectors for classification and selecting the criterion for fitting. We evaluate the performance of the two techniques using manually-annotated ground truth in several ex-vivo situations of different complexities, containing three different needle types with various insertion angles. This extensive evaluation provides better understanding on the limitations and advantages of each technique under different acquisition conditions, which is leading to the development of improved techniques for more reliable and accurate localization. Benchmarking results that the Gabor features are better capable of distinguishing the needle voxels in all datasets. Moreover, it is shown that the complete processing chain of the Gabor-based method outperforms the line filtering in accuracy and stability of the detection results.

  1. Accuracy of volume measurement using 3D ultrasound and development of CT-3D US image fusion algorithm for prostate cancer radiotherapy

    SciTech Connect

    Baek, Jihye; Huh, Jangyoung; Hyun An, So; Oh, Yoonjin; Kim, Myungsoo; Kim, DongYoung; Chung, Kwangzoo; Cho, Sungho; Lee, Rena

    2013-02-15

    Purpose: To evaluate the accuracy of measuring volumes using three-dimensional ultrasound (3D US), and to verify the feasibility of the replacement of CT-MR fusion images with CT-3D US in radiotherapy treatment planning. Methods: Phantoms, consisting of water, contrast agent, and agarose, were manufactured. The volume was measured using 3D US, CT, and MR devices. A CT-3D US and MR-3D US image fusion software was developed using the Insight Toolkit library in order to acquire three-dimensional fusion images. The quality of the image fusion was evaluated using metric value and fusion images. Results: Volume measurement, using 3D US, shows a 2.8 {+-} 1.5% error, 4.4 {+-} 3.0% error for CT, and 3.1 {+-} 2.0% error for MR. The results imply that volume measurement using the 3D US devices has a similar accuracy level to that of CT and MR. Three-dimensional image fusion of CT-3D US and MR-3D US was successfully performed using phantom images. Moreover, MR-3D US image fusion was performed using human bladder images. Conclusions: 3D US could be used in the volume measurement of human bladders and prostates. CT-3D US image fusion could be used in monitoring the target position in each fraction of external beam radiation therapy. Moreover, the feasibility of replacing the CT-MR image fusion to the CT-3D US in radiotherapy treatment planning was verified.

  2. A compact robotic apparatus and method for 3-D ultrasound guided prostate therapy

    NASA Astrophysics Data System (ADS)

    Bax, Jeffrey; Gardi, Lori; Montreuil, Jacques; Smith, David; Fenster, Aaron

    2007-03-01

    Ultrasound imaging has revolutionized the treatment of prostate cancer by producing increasingly accurate models of the prostate and influencing sophisticated targeting procedures for the insertion of radioactive seeds during brachytherapy. Three-dimensional (3D) ultrasound imaging, which allows 3D models of the prostate to be constructed from a series of two-dimensional images, helps to accurately target and implant seeds into the prostate. We have developed a compact robotic apparatus, as well as an effective method for guiding and controlling the insertion of transperineal needles into the prostate. This device has been designed to accurately guide a needle in 3D space so that the needle can be inserted into the prostate at an angle that does not interfere with the pubic arch. The physician can adjust manually or automatically the position of the apparatus in order to place several radioactive seeds into the prostate at designated target locations. Because many physicians are wary of conducting robotic surgical procedures, the apparatus has been developed so that the physician can position the needle for manual insertion and apply a method for manually releasing the needle without damaging the apparatus or endangering the patient.

  3. Needle Trajectory and Tip Localization in Real-Time 3-D Ultrasound Using a Moving Stylus.

    PubMed

    Beigi, Parmida; Rohling, Robert; Salcudean, Tim; Lessoway, Victoria A; Ng, Gary C

    2015-07-01

    Described here is a novel approach to needle localization in 3-D ultrasound based on automatic detection of small changes in appearance on movement of the needle stylus. By stylus oscillation, including its full insertion into the cannula to the tip, the image processing techniques can localize the needle trajectory and the tip in the 3-D ultrasound volume. The 3-D needle localization task is reduced to two 2-D localizations using orthogonal projections. To evaluate our method, we tested it on three different ex vivo tissue types, and the preliminary results indicated that the method accuracy lies within clinical acceptance, with average error ranges of 0.9°-1.4° in needle trajectory and 0.8-1.1 mm in needle tip. Results also indicate that method performance is independent of the echogenicity of the tissue. This technique is a safe way of producing ultrasonic intensity changes and appears to introduce negligible risk to the patient, as the outer cannula remains fixed.

  4. Pitch-catch phase aberration correction of multiple isoplanatic patches for 3-D transcranial ultrasound imaging.

    PubMed

    Lindsey, Brooks D; Smith, Stephen W

    2013-03-01

    Having previously presented the ultrasound brain helmet, a system for simultaneous 3-D ultrasound imaging via both temporal bone acoustic windows, the scanning geometry of this system is utilized to allow each matrix array to serve as a correction source for the opposing array. Aberration is estimated using cross-correlation of RF channel signals, followed by least mean squares solution of the resulting overdetermined system. Delay maps are updated and real-time 3-D scanning resumes. A first attempt is made at using multiple arrival time maps to correct multiple unique aberrators within a single transcranial imaging volume, i.e., several isoplanatic patches. This adaptive imaging technique, which uses steered unfocused waves transmitted by the opposing, or beacon, array, updates the transmit and receive delays of 5 isoplanatic patches within a 64° x 64° volume. In phantom experiments, color flow voxels above a common threshold have also increased by an average of 92%, whereas color flow variance decreased by an average of 10%. This approach has been applied to both temporal acoustic windows of two human subjects, yielding increases in echo brightness in 5 isoplanatic patches with a mean value of 24.3 ± 9.1%, suggesting that such a technique may be beneficial in the future for performing noninvasive 3-D color flow imaging of cerebrovascular disease, including stroke.

  5. Pitch–Catch Phase Aberration Correction of Multiple Isoplanatic Patches for 3-D Transcranial Ultrasound Imaging

    PubMed Central

    Lindsey, Brooks D.; Smith, Stephen W.

    2013-01-01

    Having previously presented the ultrasound brain helmet, a system for simultaneous 3-D ultrasound imaging via both temporal bone acoustic windows, the scanning geometry of this system is utilized to allow each matrix array to serve as a correction source for the opposing array. Aberration is estimated using cross-correlation of RF channel signals, followed by least mean squares solution of the resulting overdetermined system. Delay maps are updated and real-time 3-D scanning resumes. A first attempt is made at using multiple arrival time maps to correct multiple unique aberrators within a single transcranial imaging volume, i.e., several isoplanatic patches. This adaptive imaging technique, which uses steered unfocused waves transmitted by the opposing, or beacon, array, updates the transmit and receive delays of 5 isoplanatic patches within a 64° × 64° volume. In phantom experiments, color flow voxels above a common threshold have also increased by an average of 92%, whereas color flow variance decreased by an average of 10%. This approach has been applied to both temporal acoustic windows of two human subjects, yielding increases in echo brightness in 5 isoplanatic patches with a mean value of 24.3 ± 9.1%, suggesting that such a technique may be beneficial in the future for performing noninvasive 3-D color flow imaging of cerebrovascular disease, including stroke. PMID:23475914

  6. Towards real-time 3D US-CT registration on the beating heart for guidance of minimally invasive cardiac interventions

    NASA Astrophysics Data System (ADS)

    Li, Feng; Lang, Pencilla; Rajchl, Martin; Chen, Elvis C. S.; Guiraudon, Gerard; Peters, Terry M.

    2012-02-01

    Compared to conventional open-heart surgeries, minimally invasive cardiac interventions cause less trauma and sideeffects to patients. However, the direct view of surgical targets and tools is usually not available in minimally invasive procedures, which makes image-guided navigation systems essential. The choice of imaging modalities used in the navigation systems must consider the capability of imaging soft tissues, spatial and temporal resolution, compatibility and flexibility in the OR, and financial cost. In this paper, we propose a new means of guidance for minimally invasive cardiac interventions using 3D real-time ultrasound images to show the intra-operative heart motion together with preoperative CT image(s) employed to demonstrate high-quality 3D anatomical context. We also develop a method to register intra-operative ultrasound and pre-operative CT images in close to real-time. The registration method has two stages. In the first, anatomical features are segmented from the first frame of ultrasound images and the CT image(s). A feature based registration is used to align those features. The result of this is used as an initialization in the second stage, in which a mutual information based registration is used to register every ultrasound frame to the CT image(s). A GPU based implementation is used to accelerate the registration.

  7. 3D visualization of strain in abdominal aortic aneurysms based on navigated ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Brekken, Reidar; Kaspersen, Jon Harald; Tangen, Geir Arne; Dahl, Torbjørn; Hernes, Toril A. N.; Myhre, Hans Olav

    2007-03-01

    The criterion for recommending treatment of an abdominal aortic aneurysm is that the diameter exceeds 50-55 mm or shows a rapid increase. Our hypothesis is that a more accurate prediction of aneurysm rupture is obtained by estimating arterial wall strain from patient specific measurements. Measuring strain in specific parts of the aneurysm reveals differences in load or tissue properties. We have previously presented a method for in vivo estimation of circumferential strain by ultrasound. In the present work, a position sensor attached to the ultrasound probe was used for combining several 2D ultrasound sectors into a 3D model. The ultrasound was registered to a computed-tomography scan (CT), and the strain values were mapped onto a model segmented from these CT data. This gave an intuitive coupling between anatomy and strain, which may benefit both data acquisition and the interpretation of strain. In addition to potentially provide information relevant for assessing the rupture risk of the aneurysm in itself, this model could be used for validating simulations of fluid-structure interactions. Further, the measurements could be integrated with the simulations in order to increase the amount of patient specific information, thus producing a more reliable and accurate model of the biomechanics of the individual aneurysm. This approach makes it possible to extract several parameters potentially relevant for predicting rupture risk, and may therefore extend the basis for clinical decision making.

  8. Improved Visualization of Intracranial Vessels with Intraoperative Coregistration of Rotational Digital Subtraction Angiography and Intraoperative 3D Ultrasound

    PubMed Central

    Podlesek, Dino; Meyer, Tobias; Morgenstern, Ute; Schackert, Gabriele; Kirsch, Matthias

    2015-01-01

    Introduction Ultrasound can visualize and update the vessel status in real time during cerebral vascular surgery. We studied the depiction of parent vessels and aneurysms with a high-resolution 3D intraoperative ultrasound imaging system during aneurysm clipping using rotational digital subtraction angiography as a reference. Methods We analyzed 3D intraoperative ultrasound in 39 patients with cerebral aneurysms to visualize the aneurysm intraoperatively and the nearby vascular tree before and after clipping. Simultaneous coregistration of preoperative subtraction angiography data with 3D intraoperative ultrasound was performed to verify the anatomical assignment. Results Intraoperative ultrasound detected 35 of 43 aneurysms (81%) in 39 patients. Thirty-nine intraoperative ultrasound measurements were matched with rotational digital subtraction angiography and were successfully reconstructed during the procedure. In 7 patients, the aneurysm was partially visualized by 3D-ioUS or was not in field of view. Post-clipping intraoperative ultrasound was obtained in 26 and successfully reconstructed in 18 patients (69%) despite clip related artefacts. The overlap between 3D-ioUS aneurysm volume and preoperative rDSA aneurysm volume resulted in a mean accuracy of 0.71 (Dice coefficient). Conclusions Intraoperative coregistration of 3D intraoperative ultrasound data with preoperative rotational digital subtraction angiography is possible with high accuracy. It allows the immediate visualization of vessels beyond the microscopic field, as well as parallel assessment of blood velocity, aneurysm and vascular tree configuration. Although spatial resolution is lower than for standard angiography, the method provides an excellent vascular overview, advantageous interpretation of 3D-ioUS and immediate intraoperative feedback of the vascular status. A prerequisite for understanding vascular intraoperative ultrasound is image quality and a successful match with preoperative

  9. Acquisition and automated 3-D segmentation of respiratory/cardiac-gated PET transmission images

    SciTech Connect

    Reutter, B.W.; Klein, G.J.; Brennan, K.M.; Huesman, R.H. |

    1996-12-31

    To evaluate the impact of respiratory motion on attenuation correction of cardiac PET data, we acquired and automatically segmented gated transmission data for a dog breathing on its own under gas anesthesia. Data were acquired for 20 min on a CTI/Siemens ECAT EXACT HR (47-slice) scanner configured for 12 gates in a static study, Two respiratory gates were obtained using data from a pneumatic bellows placed around the dog`s chest, in conjunction with 6 cardiac gates from standard EKG gating. Both signals were directed to a LabVIEW-controlled Macintosh, which translated them into one of 12 gate addresses. The respiratory gating threshold was placed near end-expiration to acquire 6 cardiac-gated datasets at end-expiration and 6 cardiac-gated datasets during breaths. Breaths occurred about once every 10 sec and lasted about 1-1.5 sec. For each respiratory gate, data were summed over cardiac gates and torso and lung surfaces were segmented automatically using a differential 3-D edge detection algorithm. Three-dimensional visualizations showed that lung surfaces adjacent to the heart translated 9 mm inferiorly during breaths. Our results suggest that respiration-compensated attenuation correction is feasible with a modest amount of gated transmission data and is necessary for accurate quantitation of high-resolution gated cardiac PET data.

  10. Cardiac Limited Ultrasound Examination Techniques to Augment the Bedside Cardiac Physical Examination.

    PubMed

    Kimura, Bruce J; Shaw, David J; Amundson, Stan A; Phan, James N; Blanchard, Daniel G; DeMaria, Anthony N

    2015-09-01

    The current practice of physical diagnosis is dependent on physician skills and biases, inductive reasoning, and time efficiency. Although the clinical utility of echocardiography is well known, few data exist on how to integrate 2-dimensional screening "quick-look" ultrasound applications into a novel, modernized cardiac physical examination. We discuss the evidence basis behind ultrasound "signs" pertinent to the cardiovascular system and elemental in synthesis of bedside diagnoses and propose the application of a brief cardiac limited ultrasound examination based on these signs. An ultrasound-augmented cardiac physical examination can be taught in traditional medical education and has the potential to improve bedside diagnosis and patient care.

  11. Improving Low-dose Cardiac CT Images based on 3D Sparse Representation

    NASA Astrophysics Data System (ADS)

    Shi, Luyao; Hu, Yining; Chen, Yang; Yin, Xindao; Shu, Huazhong; Luo, Limin; Coatrieux, Jean-Louis

    2016-03-01

    Cardiac computed tomography (CCT) is a reliable and accurate tool for diagnosis of coronary artery diseases and is also frequently used in surgery guidance. Low-dose scans should be considered in order to alleviate the harm to patients caused by X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. In order to improve the cardiac LDCT image quality, a 3D sparse representation-based processing (3D SR) is proposed by exploiting the sparsity and regularity of 3D anatomical features in CCT. The proposed method was evaluated by a clinical study of 14 patients. The performance of the proposed method was compared to the 2D spares representation-based processing (2D SR) and the state-of-the-art noise reduction algorithm BM4D. The visual assessment, quantitative assessment and qualitative assessment results show that the proposed approach can lead to effective noise/artifact suppression and detail preservation. Compared to the other two tested methods, 3D SR method can obtain results with image quality most close to the reference standard dose CT (SDCT) images.

  12. Improving Low-dose Cardiac CT Images based on 3D Sparse Representation

    PubMed Central

    Shi, Luyao; Hu, Yining; Chen, Yang; Yin, Xindao; Shu, Huazhong; Luo, Limin; Coatrieux, Jean-Louis

    2016-01-01

    Cardiac computed tomography (CCT) is a reliable and accurate tool for diagnosis of coronary artery diseases and is also frequently used in surgery guidance. Low-dose scans should be considered in order to alleviate the harm to patients caused by X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. In order to improve the cardiac LDCT image quality, a 3D sparse representation-based processing (3D SR) is proposed by exploiting the sparsity and regularity of 3D anatomical features in CCT. The proposed method was evaluated by a clinical study of 14 patients. The performance of the proposed method was compared to the 2D spares representation-based processing (2D SR) and the state-of-the-art noise reduction algorithm BM4D. The visual assessment, quantitative assessment and qualitative assessment results show that the proposed approach can lead to effective noise/artifact suppression and detail preservation. Compared to the other two tested methods, 3D SR method can obtain results with image quality most close to the reference standard dose CT (SDCT) images. PMID:26980176

  13. Improving Low-dose Cardiac CT Images based on 3D Sparse Representation.

    PubMed

    Shi, Luyao; Hu, Yining; Chen, Yang; Yin, Xindao; Shu, Huazhong; Luo, Limin; Coatrieux, Jean-Louis

    2016-03-16

    Cardiac computed tomography (CCT) is a reliable and accurate tool for diagnosis of coronary artery diseases and is also frequently used in surgery guidance. Low-dose scans should be considered in order to alleviate the harm to patients caused by X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. In order to improve the cardiac LDCT image quality, a 3D sparse representation-based processing (3D SR) is proposed by exploiting the sparsity and regularity of 3D anatomical features in CCT. The proposed method was evaluated by a clinical study of 14 patients. The performance of the proposed method was compared to the 2D spares representation-based processing (2D SR) and the state-of-the-art noise reduction algorithm BM4D. The visual assessment, quantitative assessment and qualitative assessment results show that the proposed approach can lead to effective noise/artifact suppression and detail preservation. Compared to the other two tested methods, 3D SR method can obtain results with image quality most close to the reference standard dose CT (SDCT) images.

  14. A 3D reconstruction solution to ultrasound Joule heat density tomography based on acousto-electric effect: a simulation study

    NASA Astrophysics Data System (ADS)

    Yang, R.; Song, A.; Li, X. D.; Lu, Y.; Yan, R.; Xu, B.; Li, X.

    2014-10-01

    A 3D reconstruction solution to ultrasound Joule heat density tomography based on acousto-electric effect by deconvolution is proposed for noninvasive imaging of biological tissue. Compared with ultrasound current source density imaging, ultrasound Joule heat density tomography doesn't require any priori knowledge of conductivity distribution and lead fields, so it can gain better imaging result, more adaptive to environment and with wider application scope. For a general 3D volume conductor with broadly distributed current density field, in the AE equation the ultrasound pressure can't simply be separated from the 3D integration, so it is not a common modulation and basebanding (heterodyning) method is no longer suitable to separate Joule heat density from the AE signals. In the proposed method the measurement signal is viewed as the output of Joule heat density convolving with ultrasound wave. As a result, the internal 3D Joule heat density can be reconstructed by means of Wiener deconvolution. A series of computer simulations set for breast cancer imaging applications, with consideration of ultrasound beam diameter, noise level, conductivity contrast, position dependency and size of simulated tumors, have been conducted to evaluate the feasibility and performance of the proposed reconstruction method. The computer simulation results demonstrate that high spatial resolution 3D ultrasound Joule heat density imaging is feasible using the proposed method, and it has potential applications to breast cancer detection and imaging of other organs.

  15. Use of 3D printed models in medical education: A randomized control trial comparing 3D prints versus cadaveric materials for learning external cardiac anatomy.

    PubMed

    Lim, Kah Heng Alexander; Loo, Zhou Yaw; Goldie, Stephen J; Adams, Justin W; McMenamin, Paul G

    2016-05-01

    Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized controlled trial was undertaken on undergraduate medical students without prior formal cardiac anatomy teaching. Following a pre-test examining baseline external cardiac anatomy knowledge, participants were randomly assigned to three groups who underwent self-directed learning sessions using either cadaveric materials, 3D prints, or a combination of cadaveric materials/3D prints (combined materials). Participants were then subjected to a post-test written by a third party. Fifty-two participants completed the trial; 18 using cadaveric materials, 16 using 3D models, and 18 using combined materials. Age and time since completion of high school were equally distributed between groups. Pre-test scores were not significantly different (P = 0.231), however, post-test scores were significantly higher for 3D prints group compared to the cadaveric materials or combined materials groups (mean of 60.83% vs. 44.81% and 44.62%, P = 0.010, adjusted P = 0.012). A significant improvement in test scores was detected for the 3D prints group (P = 0.003) but not for the other two groups. The finding of this pilot study suggests that use of 3D prints do not disadvantage students relative to cadaveric materials; maximally, results suggest that 3D may confer certain benefits to anatomy learning and supports their use and ongoing evaluation as supplements to cadaver-based curriculums. Anat Sci Educ 9: 213-221. © 2015 American Association of Anatomists.

  16. Evaluation of Gastric Volumes: Comparison of 3-D Ultrasound and Magnetic Resonance Imaging.

    PubMed

    Buisman, Wijnand J; Mauritz, Femke A; Westerhuis, Wouter E; Gilja, Odd Helge; van der Zee, David C; van Herwaarden-Lindeboom, Maud Y A

    2016-07-01

    To investigate gastric accommodation, accurate measurements of gastric volumes are necessary. An excellent technique to measure gastric volumes is dynamic magnetic resonance imaging (MRI). Unfortunately, dynamic MRI is expensive and not always available. A new 3-D ultrasound (US) method using a matrix transducer was developed to measure gastric volumes. In this prospective study, 14 healthy volunteers underwent a dynamic MRI and a 3-D US. Gastric volumes were calculated with intra-gastric liquid content and total gastric volume. Mean postprandial liquid gastric content was 397 ± 96.5 mL. Mean volume difference was 1.0 mL with limits of agreement of -8.9 to 10.9 mL. When gastric air was taken into account, mean total gastric volume was 540 ± 115.4 mL SD. Mean volume difference was 2.3 mL with limits of agreement of -21.1 to 26.4 mL. The matrix 3-D US showed excellent agreement with dynamic MRI. Therefore matrix 3-D US is a reliable alternative to measure gastric volumes. PMID:27067418

  17. 3D conformal MRI-guided transurethral ultrasound therapy: results of gel phantom experiments

    NASA Astrophysics Data System (ADS)

    N'Djin, W. A.; Burtnyk, M.; McCormick, S.; Bronskill, M.; Chopra, R.

    2011-09-01

    MRI-guided transurethral ultrasound therapy shows promise for minimally invasive treatment of localized prostate cancer. Previous in-vivo studies demonstrated the feasibility of performing conservative treatments using real-time temperature feedback to control accurately the establishment of coagulative lesions within circumscribed prostate regions. This in-vitro study tested device configuration and control options for achieving full prostate treatments. A multi-channel MRI compatible ultrasound therapy system was evaluated in gel phantoms using 3 canine prostate models. Prostate profiles were 5 mm-step-segmented from T2-weighted MR images performed during previous in-vivo experiments. During ultrasound exposures, each ultrasound element was controlled independently by the 3D controller. Decisions on acoustic power, frequency, and device rotation rate were made in real time based on MR thermometry feedback and prostate radii. Low and high power treatment approaches using maximum acoustic powers of 10 or 20 W.cm-2 were tested as well as single and dual-frequency strategies (4.05/13.10 MHz). The dual-frequency strategy used either the fundamental frequency or the 3rd harmonic component, depending on the prostate radius. The 20 W.cm-2 dual frequency approach was the most efficient configuration in achieving full prostate treatments. Treatment times were about half the duration of those performed with 10 W.cm-2 configurations. Full prostate coagulations were performed in 16.3±6.1 min at a rate of 1.8±0.2 cm3.min-1, and resulted in very little undertreated tissue (<3%). Surrounding organs positioned beyond a safety distance of 1.4±1.0 mm from prostate boundaries were not damaged, particularly rectal wall tissues. In this study, a 3D, MR-thermometry-guided transurethral ultrasound therapy was validated in vitro in a tissue-mimicking phantom for performing full prostate treatment. A dual-frequency configuration with 20 W.cm-2 ultrasound intensity exposure showed good

  18. Meshless deformable models for 3D cardiac motion and strain analysis from tagged MRI.

    PubMed

    Wang, Xiaoxu; Chen, Ting; Zhang, Shaoting; Schaerer, Joël; Qian, Zhen; Huh, Suejung; Metaxas, Dimitris; Axel, Leon

    2015-01-01

    Tagged magnetic resonance imaging (TMRI) provides a direct and noninvasive way to visualize the in-wall deformation of the myocardium. Due to the through-plane motion, the tracking of 3D trajectories of the material points and the computation of 3D strain field call for the necessity of building 3D cardiac deformable models. The intersections of three stacks of orthogonal tagging planes are material points in the myocardium. With these intersections as control points, 3D motion can be reconstructed with a novel meshless deformable model (MDM). Volumetric MDMs describe an object as point cloud inside the object boundary and the coordinate of each point can be written in parametric functions. A generic heart mesh is registered on the TMRI with polar decomposition. A 3D MDM is generated and deformed with MR image tagging lines. Volumetric MDMs are deformed by calculating the dynamics function and minimizing the local Laplacian coordinates. The similarity transformation of each point is computed by assuming its neighboring points are making the same transformation. The deformation is computed iteratively until the control points match the target positions in the consecutive image frame. The 3D strain field is computed from the 3D displacement field with moving least squares. We demonstrate that MDMs outperformed the finite element method and the spline method with a numerical phantom. Meshless deformable models can track the trajectory of any material point in the myocardium and compute the 3D strain field of any particular area. The experimental results on in vivo healthy and patient heart MRI show that the MDM can fully recover the myocardium motion in three dimensions.

  19. Meshless deformable models for 3D cardiac motion and strain analysis from tagged MRI.

    PubMed

    Wang, Xiaoxu; Chen, Ting; Zhang, Shaoting; Schaerer, Joël; Qian, Zhen; Huh, Suejung; Metaxas, Dimitris; Axel, Leon

    2015-01-01

    Tagged magnetic resonance imaging (TMRI) provides a direct and noninvasive way to visualize the in-wall deformation of the myocardium. Due to the through-plane motion, the tracking of 3D trajectories of the material points and the computation of 3D strain field call for the necessity of building 3D cardiac deformable models. The intersections of three stacks of orthogonal tagging planes are material points in the myocardium. With these intersections as control points, 3D motion can be reconstructed with a novel meshless deformable model (MDM). Volumetric MDMs describe an object as point cloud inside the object boundary and the coordinate of each point can be written in parametric functions. A generic heart mesh is registered on the TMRI with polar decomposition. A 3D MDM is generated and deformed with MR image tagging lines. Volumetric MDMs are deformed by calculating the dynamics function and minimizing the local Laplacian coordinates. The similarity transformation of each point is computed by assuming its neighboring points are making the same transformation. The deformation is computed iteratively until the control points match the target positions in the consecutive image frame. The 3D strain field is computed from the 3D displacement field with moving least squares. We demonstrate that MDMs outperformed the finite element method and the spline method with a numerical phantom. Meshless deformable models can track the trajectory of any material point in the myocardium and compute the 3D strain field of any particular area. The experimental results on in vivo healthy and patient heart MRI show that the MDM can fully recover the myocardium motion in three dimensions. PMID:25157446

  20. Meshless deformable models for 3D cardiac motion and strain analysis from tagged MRI

    PubMed Central

    Wang, Xiaoxu; Chen, Ting; Zhang, Shaoting; Schaerer, Joël; Qian, Zhen; Huh, Suejung; Metaxas, Dimitris; Axel, Leon

    2016-01-01

    Tagged magnetic resonance imaging (TMRI) provides a direct and noninvasive way to visualize the in-wall deformation of the myocardium. Due to the through-plane motion, the tracking of 3D trajectories of the material points and the computation of 3D strain field call for the necessity of building 3D cardiac deformable models. The intersections of three stacks of orthogonal tagging planes are material points in the myocardium. With these intersections as control points, 3D motion can be reconstructed with a novel meshless deformable model (MDM). Volumetric MDMs describe an object as point cloud inside the object boundary and the coordinate of each point can be written in parametric functions. A generic heart mesh is registered on the TMRI with polar decomposition. A 3D MDM is generated and deformed with MR image tagging lines. Volumetric MDMs are deformed by calculating the dynamics function and minimizing the local Laplacian coordinates. The similarity transformation of each point is computed by assuming its neighboring points are making the same transformation. The deformation is computed iteratively until the control points match the target positions in the consecutive image frame. The 3D strain field is computed from the 3D displacement field with moving least squares. We demonstrate that MDMs outperformed the finite element method and the spline method with a numerical phantom. Meshless deformable models can track the trajectory of any material point in the myocardium and compute the 3D strain field of any particular area. The experimental results on in vivo healthy and patient heart MRI show that the MDM can fully recover the myocardium motion in three dimensions. PMID:25157446

  1. Simulating cardiac ultrasound image based on MR diffusion tensor imaging

    PubMed Central

    Qin, Xulei; Wang, Silun; Shen, Ming; Lu, Guolan; Zhang, Xiaodong; Wagner, Mary B.; Fei, Baowei

    2015-01-01

    Purpose: Cardiac ultrasound simulation can have important applications in the design of ultrasound systems, understanding the interaction effect between ultrasound and tissue and setting the ground truth for validating quantification methods. Current ultrasound simulation methods fail to simulate the myocardial intensity anisotropies. New simulation methods are needed in order to simulate realistic ultrasound images of the heart. Methods: The proposed cardiac ultrasound image simulation method is based on diffusion tensor imaging (DTI) data of the heart. The method utilizes both the cardiac geometry and the fiber orientation information to simulate the anisotropic intensities in B-mode ultrasound images. Before the simulation procedure, the geometry and fiber orientations of the heart are obtained from high-resolution structural MRI and DTI data, respectively. The simulation includes two important steps. First, the backscatter coefficients of the point scatterers inside the myocardium are processed according to the fiber orientations using an anisotropic model. Second, the cardiac ultrasound images are simulated with anisotropic myocardial intensities. The proposed method was also compared with two other nonanisotropic intensity methods using 50 B-mode ultrasound image volumes of five different rat hearts. The simulated images were also compared with the ultrasound images of a diseased rat heart in vivo. A new segmental evaluation method is proposed to validate the simulation results. The average relative errors (AREs) of five parameters, i.e., mean intensity, Rayleigh distribution parameter σ, and first, second, and third quartiles, were utilized as the evaluation metrics. The simulated images were quantitatively compared with real ultrasound images in both ex vivo and in vivo experiments. Results: The proposed ultrasound image simulation method can realistically simulate cardiac ultrasound images of the heart using high-resolution MR-DTI data. The AREs of their

  2. 3D printed cardiac phantom for procedural planning of a transcatheter native mitral valve replacement

    NASA Astrophysics Data System (ADS)

    Izzo, Richard L.; O'Hara, Ryan P.; Iyer, Vijay; Hansen, Rose; Meess, Karen M.; Nagesh, S. V. Setlur; Rudin, Stephen; Siddiqui, Adnan H.; Springer, Michael; Ionita, Ciprian N.

    2016-03-01

    3D printing an anatomically accurate, functional flow loop phantom of a patient's cardiac vasculature was used to assist in the surgical planning of one of the first native transcatheter mitral valve replacement (TMVR) procedures. CTA scans were acquired from a patient about to undergo the first minimally-invasive native TMVR procedure at the Gates Vascular Institute in Buffalo, NY. A python scripting library, the Vascular Modeling Toolkit (VMTK), was used to segment the 3D geometry of the patient's cardiac chambers and mitral valve with severe stenosis, calcific in nature. A stereolithographic (STL) mesh was generated and AutoDesk Meshmixer was used to transform the vascular surface into a functioning closed flow loop. A Stratasys Objet 500 Connex3 multi-material printer was used to fabricate the phantom with distinguishable material features of the vasculature and calcified valve. The interventional team performed a mock procedure on the phantom, embedding valve cages in the model and imaging the phantom with a Toshiba Infinix INFX-8000V 5-axis Carm bi-Plane angiography system. Results: After performing the mock-procedure on the cardiac phantom, the cardiologists optimized their transapical surgical approach. The mitral valve stenosis and calcification were clearly visible. The phantom was used to inform the sizing of the valve to be implanted. Conclusion: With advances in image processing and 3D printing technology, it is possible to create realistic patientspecific phantoms which can act as a guide for the interventional team. Using 3D printed phantoms as a valve sizing method shows potential as a more informative technique than typical CTA reconstruction alone.

  3. Correlation-based discrimination between cardiac tissue and blood for segmentation of 3D echocardiographic images

    NASA Astrophysics Data System (ADS)

    Saris, Anne E. C. M.; Nillesen, Maartje M.; Lopata, Richard G. P.; de Korte, Chris L.

    2013-03-01

    Automated segmentation of 3D echocardiographic images in patients with congenital heart disease is challenging, because the boundary between blood and cardiac tissue is poorly defined in some regions. Cardiologists mentally incorporate movement of the heart, using temporal coherence of structures to resolve ambiguities. Therefore, we investigated the merit of temporal cross-correlation for automated segmentation over the entire cardiac cycle. Optimal settings for maximum cross-correlation (MCC) calculation, based on a 3D cross-correlation based displacement estimation algorithm, were determined to obtain the best contrast between blood and myocardial tissue over the entire cardiac cycle. Resulting envelope-based as well as RF-based MCC values were used as additional external force in a deformable model approach, to segment the left-ventricular cavity in entire systolic phase. MCC values were tested against, and combined with, adaptive filtered, demodulated RF-data. Segmentation results were compared with manually segmented volumes using a 3D Dice Similarity Index (3DSI). Results in 3D pediatric echocardiographic images sequences (n = 4) demonstrate that incorporation of temporal information improves segmentation. The use of MCC values, either alone or in combination with adaptive filtered, demodulated RF-data, resulted in an increase of the 3DSI in 75% of the cases (average 3DSI increase: 0.71 to 0.82). Results might be further improved by optimizing MCC-contrast locally, in regions with low blood-tissue contrast. Reducing underestimation of the endocardial volume due to MCC processing scheme (choice of window size) and consequential border-misalignment, could also lead to more accurate segmentations. Furthermore, increasing the frame rate will also increase MCC-contrast and thus improve segmentation.

  4. Visualization of a newborn's hip joint using 3D ultrasound and automatic image processing

    NASA Astrophysics Data System (ADS)

    Overhoff, Heinrich M.; Lazovic, Djordje; von Jan, Ute

    1999-05-01

    Graf's method is a successful procedure for the diagnostic screening of developmental dysplasia of the hip. In a defined 2-D ultrasound (US) scan, which virtually cuts the hip joint, landmarks are interactively identified to derive congruence indicators. As the indicators do not reflect the spatial joint structure, and the femoral head is not clearly visible in the US scan, here 3-D US is used to gain insight to the hip joint in its spatial form. Hip joints of newborns were free-hand scanned using a conventional ultrasound transducer and a localizer system fixed on the scanhead. To overcome examiner- dependent findings the landmarks were detected by automatic segmentation of the image volume. The landmark image volumes and an automatically determined virtual sphere approximating the femoral head were visualized color-coded on a computer screen. The visualization was found to be intuitive and to simplify the diagnostic substantially. By the visualization of the 3-D relations between acetabulum and femoral head the reliability of diagnostics is improved by finding the entire joint geometry.

  5. Accuracy evaluation of a 3D ultrasound-guided biopsy system

    NASA Astrophysics Data System (ADS)

    Wooten, Walter J.; Nye, Jonathan A.; Schuster, David M.; Nieh, Peter T.; Master, Viraj A.; Votaw, John R.; Fei, Baowei

    2013-03-01

    Early detection of prostate cancer is critical in maximizing the probability of successful treatment. Current systematic biopsy approach takes 12 or more randomly distributed core tissue samples within the prostate and can have a high potential, especially with early disease, for a false negative diagnosis. The purpose of this study is to determine the accuracy of a 3D ultrasound-guided biopsy system. Testing was conducted on prostate phantoms created from an agar mixture which had embedded markers. The phantoms were scanned and the 3D ultrasound system was used to direct the biopsy. Each phantom was analyzed with a CT scan to obtain needle deflection measurements. The deflection experienced throughout the biopsy process was dependent on the depth of the biopsy target. The results for markers at a depth of less than 20 mm, 20-30 mm, and greater than 30 mm were 3.3 mm, 4.7 mm, and 6.2 mm, respectively. This measurement encapsulates the entire biopsy process, from the scanning of the phantom to the firing of the biopsy needle. Increased depth of the biopsy target caused a greater deflection from the intended path in most cases which was due to an angular incidence of the biopsy needle. Although some deflection was present, this system exhibits a clear advantage in the targeted biopsy of prostate cancer and has the potential to reduce the number of false negative biopsies for large lesions.

  6. Using ultrasound to teach medical students cardiac physiology.

    PubMed

    Bell, Floyd E; Wilson, L Britt; Hoppmann, Richard A

    2015-12-01

    Ultrasound is being incorporated more into undergraduate medical education. Studies have shown that medical students have positive perceptions about the value of ultrasound in teaching courses like anatomy and physiology. The purpose of the present study was to provide objective evidence of whether ultrasound helps students learn cardiac physiology. In this study, 20 medical students took a pretest to assess their background knowledge of cardiac physiology. Next, they acquired ultrasound video loops of the heart. Faculty members taught them nonelectrical aspects of cardiac physiology using those loops. Finally, students took a posttest to evaluate for improvements in their knowledge. Students also completed an anonymous questionnaire about their experience. The mean pretest score was 4.8 of 9 (53.3%). The mean posttest score was 7.35 of 9 (81.7%). The mean difference was significant at P < 0.0001. Student feedback was very positive about the ultrasound laboratory. Ninety-five percent of the students agreed or strongly agreed that the ultrasound laboratory was a valuable teaching tool and that it improved their understanding of cardiac physiology. All students agreed or strongly agreed the laboratory was helpful from a visual learning standpoint. A hands-on ultrasound laboratory can indeed help medical students learn the nonelectrical components of cardiac physiology.

  7. Craniosynostosis: prenatal diagnosis by 2D/3D ultrasound, magnetic resonance imaging and computed tomography.

    PubMed

    Helfer, Talita Micheletti; Peixoto, Alberto Borges; Tonni, Gabriele; Araujo Júnior, Edward

    2016-09-01

    Craniosynostosis is defined as the process of premature fusion of one or more of the cranial sutures. It is a common condition that occurs in about 1 to 2,000 live births. Craniosynostosis may be classified in primary or secondary. It is also classified as nonsyndromic or syndromic. According to suture commitment, craniosynostosis may affect a single suture or multiple sutures. There is a wide range of syndromes involving craniosynostosis and the most common are Apert, Pffeifer, Crouzon, Shaethre-Chotzen and Muenke syndromes. The underlying etiology of nonsyndromic craniosynostosis is unknown. Mutations in the fibroblast growth factor (FGF) signalling pathway play a crucial role in the etiology of craniosynostosis syndromes. Prenatal ultrasound`s detection rate of craniosynostosis is low. Nowadays, different methods can be applied for prenatal diagnosis of craniosynostosis, such as two-dimensional (2D) and three-dimensional (3D) ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) scan and, finally, molecular diagnosis. The presence of craniosynostosis may affect the birthing process. Fetuses with craniosynostosis also have higher rates of perinatal complications. In order to avoid the risks of untreated craniosynostosis, children are usually treated surgically soon after postnatal diagnosis. PMID:27622416

  8. Experimental Evaluation of Ultrasound-Guided 3D Needle Steering in Biological Tissue

    PubMed Central

    Abayazid, Momen; Vrooijink, Gustaaf J.; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    2014-01-01

    Purpose In this paper, we present a system capable of automatically steering bevel-tip flexible needles under ultrasound guidance towards stationary and moving targets in gelatin phantoms and biological tissue while avoiding stationary and moving obstacles. We use three-dimensional (3D) ultrasound to track the needle tip during the procedure. Methods Our system uses a fast sampling-based path planner to compute and periodically update a feasible path to the target that avoids obstacles. We then use a novel control algorithm to steer the needle along the path in a manner that reduces the number of needle rotations, thus reducing tissue damage. We present experimental results for needle insertion procedures for both stationary and moving targets and obstacles for up to 90 mm of needle insertion. Results We obtained a mean targeting error of 0.32 ± 0.10 mm and 0.38 ± 0.19 mm in gelatin-based phantom and biological tissue, respectively. Conclusions The achieved submillimeter accuracy suggests that our approach is sufficient to target the smallest lesions (ϕ2 mm) that can be detected using state-of-the-art ultrasound imaging systems. PMID:24562744

  9. 3-D statistical cancer atlas-based targeting of prostate biopsy using ultrasound image guidance

    NASA Astrophysics Data System (ADS)

    Narayanan, Ramkrishnan; Shen, Dinggang; Davatzikos, Christos A.; Crawford, E. David; Barqawi, Albaha; Werahera, Priya; Kumar, Dinesh; Suri, Jasjit S.

    2008-03-01

    Prostate cancer is a multifocal disease and lesions are not distributed uniformly within the gland. Several biopsy protocols concerning spatially specific targeting have been reported urology literature. Recently a statistical cancer atlas of the prostate was constructed providing voxelwise probabilities of cancers in the prostate. Additionally an optimized set of biopsy sites was computed with 94 - 96% detection accuracy was reported using only 6-7 needles. Here we discuss the warping of this atlas to prostate segmented side-fire ultrasound images of the patient. A shape model was used to speed up registration. The model was trained from over 38 expert segmented subjects off-line. This training yielded as few as 15-20 degrees of freedom that were optimized to warp the atlas surface to the patient's ultrasound image followed by elastic interpolation of the 3-D atlas. As a result the atlas is completely mapped to the patient's prostate anatomy along with optimal predetermined needle locations for biopsy. These do not preclude the use of additional biopsies if desired. A color overlay of the atlas is also displayed on the ultrasound image showing high cancer zones within the prostate. Finally current biopsy locations are saved in the atlas space and may be used to update the atlas based on the pathology report. In addition to the optimal atlas plan, previous biopsy locations and alternate plans can also be stored in the atlas space and warped to the patient with no additional time overhead.

  10. Thermal analysis of the surrounding anatomy during 3-D MRI-guided transurethral ultrasound prostate therapy

    NASA Astrophysics Data System (ADS)

    Burtnyk, Mathieu; Chopra, Rajiv; Bronskill, Michael

    2010-03-01

    Previous numerical simulations have shown that MRI-guided transurethral ultrasound therapy can generate highly accurate volumes of thermal coagulation conforming to 3-D human prostate geometries. The goal of this work is to simulate, quantify and evaluate the thermal impact of these treatments on the rectum, pelvic bone, neurovascular bundles (NVB) and urinary sphincters. This study used twenty 3-D anatomical models of prostate cancer patients and detailed bio-acoustic simulations incorporating an active feedback algorithm which controlled a rotating, planar ultrasound transducer (17-4×3 mm elements, 4.7/9.7 MHz, 10 Wac/cm2). Heating of the adjacent surrounding anatomy was evaluated using thermal tolerances reported in the literature. Heating of the rectum poses the most important safety concern and is influenced largely by the water temperature flowing through an endorectal cooling device; temperatures of 7-37° C are required to limit potential damage to less than 10 mm3 on the outer 1 mm layer of rectum. Significant heating of the pelvic bone was predicted in 30% of the patient models with an ultrasound frequency of 4.7 MHz; setting the frequency to 9.7 MHz when the bone is less than 10 mm away from the prostate reduced heating in all cases below the threshold for irreversible damage. Heating of the NVB was significant in 75% of the patient models in the absence of treatment planning; this proportion was reduced to 5% by using treatment margins of up to 4 mm. To avoid damaging the urinary sphincters, margins from the transducer of 2-4 mm should be used, depending on the transurethral cooling temperature. Simulations show that MRI-guided transurethral therapy can treat the entire prostate accurately. Strategies have been developed which, along with careful treatment planning, can be used to avoid causing thermal injury to the rectum, pelvic bone, NVB and urinary sphincters.

  11. [Cesarean scar ectopic pregnancy: diagnosis with 2D, three-dimensional (3D) ultrasound and 3D power doppler of a case and review of the literature].

    PubMed

    Pavlova, E; Gunev, D; Diavolov, V; Slavchev, B

    2013-01-01

    Cesarean scar pregnancy is rare type of ectopic pregnancy. It is associated with severe complication if it is not diagnosed early in pregnancy. We present a case of difficult first-trimester diagnosis of Cesarean scar pregnancy. In this paper we discuss the incidence of this condition, the antenatal diagnosis, the prognosis and management and the importance of 2D and 3D ultrasound technique as a diagnostic tool. PMID:24501880

  12. The role of 3D and speckle tracking echocardiography in cardiac amyloidosis: a case report.

    PubMed

    Nucci, E M; Lisi, M; Cameli, M; Baldi, L; Puccetti, L; Mondillo, S; Favilli, R; Lunghetti, S

    2014-01-01

    Cardiac amyloidosis (CA) is a disorder characterized by amyloid fibrils deposition in cardiac interstitium; it results in a restrictive cardiomyopathy with heart failure (HF) and conduction abnormalities. The "gold standard" for diagnosis of CA is myocardial biopsy but possible sampling errors and procedural risks, limit it's use. Magnetic resonance (RMN) offers more information than traditional echocardiography and allows diagnosis of CA but often it's impossible to perform. We report the case of a man with HF and symptomatic bradyarrhythmia that required an urgent pacemaker implant. Echocardiography was strongly suggestive of CA but wasn't impossible to perform an RMN to confirm this hypothesis because the patient was implanted with a definitive pacemaker. So was performed a Speckle Tracking Echocardiography (STE) and a 3D echocardiography: STE allows to differentiate CA from others hypertrophic cardiomyopathy by longitudinal strain value < 12% and 3D echocardiography shows regional left ventricular dyssynchrony with a characteristic temporal pattern of dispersion of regional volume systolic change. On the basis of these results, finally was performed an endomyocardial biopsy that confirmed the diagnosis of CA. This case underlines the importance of news, noninvasive techniques such as eco 3D and STE for early diagnosis of CA, especially when RMN cannot be performed.

  13. Defining the medial-lateral axis of an anatomical femur coordinate system using freehand 3D ultrasound imaging.

    PubMed

    Passmore, Elyse; Sangeux, Morgan

    2016-03-01

    Hip rotation from gait analysis informs clinical decisions regarding correction of femoral torsional deformities. However, it is among the least repeatable due to discrepancies in determining the medial-lateral axis of the femur. Conventional or functional calibration methods may be used to define the axis but there is no benchmark to evaluate these methods. Freehand 3D ultrasound, the coupling of ultrasound with 3D motion capture, may provide such a benchmark. We measured the accuracy in vitro and repeatability in vivo of determining the femur condylar axis from freehand 3D ultrasound. The condylar axis provided the reference medial-lateral axis of the femur and was used to evaluate one conventional method and three functional calibration methods, applied to three calibration movements. Ten healthy subjects (20 limbs) underwent 3D gait analysis and freehand 3D ultrasound. The functional calibration methods were a transformation technique, a geometrical method and a method that minimises variance of knee varus-valgus kinematics (DynaKAD). The conventional method used markers over the femoral epicondyles. The condylar axis determined by 3D ultrasound showed good accuracy in vitro, 1.6° (SD: 0.3°) and good repeatability in vivo, 0.2° (RSMD: 2.3°). The DynaKAD method applied to the walking calibration movement determined the medial-lateral axis closest to the ultrasound reference. The average angular difference in the transverse plane was 3.1° (SD: 6.1°). Freehand 3D ultrasound offers an accurate, non-invasive and relatively fast method to locate the medial-lateral axis of the femur for gait analysis.

  14. Intracranial Catheter for Integrated 3D Ultrasound Imaging & Hyperthermia: Feasibility Study

    NASA Astrophysics Data System (ADS)

    Herickhoff, Carl D.; Light, Edward D.; Bing, Kristin Frinkley; Mukundan, Srinivasan; Grant, Gerald A.; Wolf, Patrick D.; Dixon-Tulloch, Ellen; Shih, Timothy; Hsu, Stephen J.; Smith, Stephen W.

    2009-04-01

    In this study, we investigated the feasibility of an intracranial catheter transducer capable of real-time 3D (RT3D) imaging and ultrasound hyperthermia, for application in the visualization and treatment of tumors in the brain. We designed and constructed a 12 Fr, integrated matrix and linear array catheter transducer prototype for combined RT3D imaging and heating capability. This dual-mode catheter incorporated 153 matrix array elements and 11 linear array elements, on a 0.2 mm pitch, with a total aperture size of 8.4 mm×2.3 mm. This array achieved a 3.5° C in vitro temperature rise at a 2 cm focal distance in tissue-mimicking material. The dual-mode catheter prototype was compared with a Siemens 10 Fr AcuNav™ catheter as a gold standard in experiments assessing image quality and therapeutic potential, and both probes were used in a canine brain model to image anatomical structures and color Doppler blood flow and to attempt in vivo heating.

  15. The Effect of Ultrasound Stimulation on the Cytoskeletal Organization of Chondrocytes Seeded In 3D Matrices

    PubMed Central

    Noriega, Sandra; Hasanova, Gulnara; Subramanian, Anuradha

    2013-01-01

    The impact of low intensity diffuse ultrasound (LIDUS) stimulation on the cytoskeletal organization of chondrocytes seeded in 3D scaffolds was evaluated. Chondrocytes seeded on 3D chitosan matrices were exposed to LIDUS at 5.0 MHz (~15kPa, 51-secs, 4-applications/day) in order to study the organization of actin, tubulin and vimentin. The results showed that actin presented a cytosolic punctuated distribution, tubulin presented a quasi parallel organization of microtubules whereas vimentin distribution was unaffected. Chondrocytes seeded on 3D scaffolds responded to US stimulation by the disruption of actin stress fibers and were sensitive to the presence of ROCK inhibitor (Y27632). The gene expression of ROCK-I, a key element in the formation of stress fibers and mDia1, was significantly up-regulated under the application of US. We conclude that the results of both the cytoskeletal analyses and gene expression support the argument that the presence of punctuated actin upon US stimulation was accompanied by the up-regulation of the RhoA/ROCK pathway. PMID:22987069

  16. A new combined prior based reconstruction method for compressed sensing in 3D ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Uddin, Muhammad S.; Islam, Rafiqul; Tahtali, Murat; Lambert, Andrew J.; Pickering, Mark R.

    2015-03-01

    Ultrasound (US) imaging is one of the most popular medical imaging modalities, with 3D US imaging gaining popularity recently due to its considerable advantages over 2D US imaging. However, as it is limited by long acquisition times and the huge amount of data processing it requires, methods for reducing these factors have attracted considerable research interest. Compressed sensing (CS) is one of the best candidates for accelerating the acquisition rate and reducing the data processing time without degrading image quality. However, CS is prone to introduce noise-like artefacts due to random under-sampling. To address this issue, we propose a combined prior-based reconstruction method for 3D US imaging. A Laplacian mixture model (LMM) constraint in the wavelet domain is combined with a total variation (TV) constraint to create a new regularization regularization prior. An experimental evaluation conducted to validate our method using synthetic 3D US images shows that it performs better than other approaches in terms of both qualitative and quantitative measures.

  17. Quantification of avian embryonic cardiac outflow hemodynamics through 3D-0D coupling

    NASA Astrophysics Data System (ADS)

    Lindsey, Stephanie; Vignon-Clementel, Irene; Butcher, Jonathan

    2014-11-01

    Outflow malformations account for over 20% of CHDs in the US. While the etiology of these malformations is poorly understood, most can be traced back to perturbations in the patterning of the pharyngeal arch arteries (PAAs), the precursors to the great vessels. Here, we examine the effects of normal and aberrant PAA flow, through the use of two computational models. A 0D electric analog model allows for rapid computation and global tuning of the embryo's vasculature relative to the arches. A second 3D-0D model replaces the electric analog representation of the arches with a 3D reconstruction, thereby leading to more extensive pressure and flow characterization. We obtain 3D arch artery reconstructions from nano-CT stacks and couple them to 0D outlets. In contrast to standard boundary conditions, such coupling maintains the physiologically desired cranial-caudal flow split in control embryos and predicts how this will change with vessel occlusion. We use flow inputs from Doppler velocity tracings to compute 0D and 3D-0D pulsatile hemodynamic simulations in HH18 (day 3), HH24 (day 4), and HH26 (day 5) geometries. We then calculate flow distributions and wall shear stress maps for control embryos. From here, we modify HH18 geometries to simulate varying levels of PAA occlusion. Pulsatile simulations are run in each geometry and results compared to that of controls. Results serve as a basis for examining flow-mediated growth and adaptation in cardiac outflow morphogenesis.

  18. Segmentation of the common carotid artery with active shape models from 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Yang, Xin; Jin, Jiaoying; He, Wanji; Yuchi, Ming; Ding, Mingyue

    2012-03-01

    Carotid atherosclerosis is a major cause of stroke, a leading cause of death and disability. In this paper, we develop and evaluate a new segmentation method for outlining both lumen and adventitia (inner and outer walls) of common carotid artery (CCA) from three-dimensional ultrasound (3D US) images for carotid atherosclerosis diagnosis and evaluation. The data set consists of sixty-eight, 17× 2× 2, 3D US volume data acquired from the left and right carotid arteries of seventeen patients (eight treated with 80mg atorvastain and nine with placebo), who had carotid stenosis of 60% or more, at baseline and after three months of treatment. We investigate the use of Active Shape Models (ASMs) to segment CCA inner and outer walls after statin therapy. The proposed method was evaluated with respect to expert manually outlined boundaries as a surrogate for ground truth. For the lumen and adventitia segmentations, respectively, the algorithm yielded Dice Similarity Coefficient (DSC) of 93.6%+/- 2.6%, 91.8%+/- 3.5%, mean absolute distances (MAD) of 0.28+/- 0.17mm and 0.34 +/- 0.19mm, maximum absolute distances (MAXD) of 0.87 +/- 0.37mm and 0.74 +/- 0.49mm. The proposed algorithm took 4.4 +/- 0.6min to segment a single 3D US images, compared to 11.7+/-1.2min for manual segmentation. Therefore, the method would promote the translation of carotid 3D US to clinical care for the fast, safety and economical monitoring of the atherosclerotic disease progression and regression during therapy.

  19. Quantification of cerebral ventricle volume change of preterm neonates using 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Chen, Yimin; Kishimoto, Jessica; Qiu, Wu; de Ribaupierre, Sandrine; Fenster, Aaron; Chiu, Bernard

    2015-03-01

    Intraventricular hemorrhage (IVH) is a major cause of brain injury in preterm neonates. Quantitative measurement of ventricular dilation or shrinkage is important for monitoring patients and in evaluation of treatment options. 3D ultrasound (US) has been used to monitor the ventricle volume as a biomarker for ventricular dilation. However, volumetric quantification does not provide information as to where dilation occurs. The location where dilation occurs may be related to specific neurological problems later in life. For example, posterior horn enlargement, with thinning of the corpus callosum and parietal white matter fibres, could be linked to poor visuo-spatial abilities seen in hydrocephalic children. In this work, we report on the development and application of a method used to analyze local surface change of the ventricles of preterm neonates with IVH from 3D US images. The technique is evaluated using manual segmentations from 3D US images acquired in two imaging sessions. The surfaces from baseline and follow-up were registered and then matched on a point-by-point basis. The distance between each pair of corresponding points served as an estimate of local surface change of the brain ventricle at each vertex. The measurements of local surface change were then superimposed on the ventricle surface to produce the 3D local surface change map that provide information on the spatio-temporal dilation pattern of brain ventricles following IVH. This tool can be used to monitor responses to different treatment options, and may provide important information for elucidating the deficiencies a patient will have later in life.

  20. Automated 3D ultrasound elastography of the breast: a phantom validation study

    NASA Astrophysics Data System (ADS)

    Hendriks, Gijs A. G. M.; Holländer, Branislav; Menssen, Jan; Milkowski, Andy; Hansen, Hendrik H. G.; de Korte, Chris L.

    2016-04-01

    In breast cancer screening, the automated breast volume scanner (ABVS) was introduced as an alternative for mammography since the latter technique is less suitable for women with dense breasts. Although clinical studies show promising results, clinicians report two disadvantages: long acquisition times (>90 s) introducing breathing artefacts, and high recall rates due to detection of many small lesions of uncertain malignant potential. Technical improvements for faster image acquisition and better discrimination between benign and malignant lesions are thus required. Therefore, the aim of this study was to investigate if 3D ultrasound elastography using plane-wave imaging is feasible. Strain images of a breast elastography phantom were acquired by an ABVS-mimicking device that allowed axial and elevational movement of the attached transducer. Pre- and post-deformation volumes were acquired with different constant speeds (between 1.25 and 40.0 mm s-1) and by three protocols: Go-Go (pre- and post-volumes with identical start and end positions), Go-Return (similar to Go-Go with opposite scanning directions) and Control (pre- and post-volumes acquired per position, this protocol can be seen as reference). Afterwards, 2D and 3D cross-correlation and strain algorithms were applied to the acquired volumes and the results were compared. The Go-Go protocol was shown to be superior with better strain image quality (CNRe and SNRe) than Go-Return and to be similar as Control. This can be attributed to applying opposite mechanical forces to the phantom during the Go-Return protocol, leading to out-of-plane motion. This motion was partly compensated by using 3D cross-correlation. However, the quality was still inferior to Go-Go. Since these results were obtained in a phantom study with controlled deformations, the effect of possible uncontrolled in vivo tissue motion artefacts has to be addressed in future studies. In conclusion, it seems feasible to implement 3D ultrasound

  1. Automated 3D ultrasound elastography of the breast: a phantom validation study.

    PubMed

    Hendriks, Gijs A G M; Holländer, Branislav; Menssen, Jan; Milkowski, Andy; Hansen, Hendrik H G; de Korte, Chris L

    2016-04-01

    In breast cancer screening, the automated breast volume scanner (ABVS) was introduced as an alternative for mammography since the latter technique is less suitable for women with dense breasts. Although clinical studies show promising results, clinicians report two disadvantages: long acquisition times (>90 s) introducing breathing artefacts, and high recall rates due to detection of many small lesions of uncertain malignant potential. Technical improvements for faster image acquisition and better discrimination between benign and malignant lesions are thus required. Therefore, the aim of this study was to investigate if 3D ultrasound elastography using plane-wave imaging is feasible. Strain images of a breast elastography phantom were acquired by an ABVS-mimicking device that allowed axial and elevational movement of the attached transducer. Pre- and post-deformation volumes were acquired with different constant speeds (between 1.25 and 40.0 mm s(-1)) and by three protocols: Go-Go (pre- and post-volumes with identical start and end positions), Go-Return (similar to Go-Go with opposite scanning directions) and Control (pre- and post-volumes acquired per position, this protocol can be seen as reference). Afterwards, 2D and 3D cross-correlation and strain algorithms were applied to the acquired volumes and the results were compared. The Go-Go protocol was shown to be superior with better strain image quality (CNRe and SNRe) than Go-Return and to be similar as Control. This can be attributed to applying opposite mechanical forces to the phantom during the Go-Return protocol, leading to out-of-plane motion. This motion was partly compensated by using 3D cross-correlation. However, the quality was still inferior to Go-Go. Since these results were obtained in a phantom study with controlled deformations, the effect of possible uncontrolled in vivo tissue motion artefacts has to be addressed in future studies. In conclusion, it seems feasible to implement 3D

  2. 3D Prostate Segmentation of Ultrasound Images Combining Longitudinal Image Registration and Machine Learning

    PubMed Central

    Yang, Xiaofeng; Fei, Baowei

    2012-01-01

    We developed a three-dimensional (3D) segmentation method for transrectal ultrasound (TRUS) images, which is based on longitudinal image registration and machine learning. Using longitudinal images of each individual patient, we register previously acquired images to the new images of the same subject. Three orthogonal Gabor filter banks were used to extract texture features from each registered image. Patient-specific Gabor features from the registered images are used to train kernel support vector machines (KSVMs) and then to segment the newly acquired prostate image. The segmentation method was tested in TRUS data from five patients. The average surface distance between our and manual segmentation is 1.18 ± 0.31 mm, indicating that our automatic segmentation method based on longitudinal image registration is feasible for segmenting the prostate in TRUS images. PMID:24027622

  3. GPCA vs. PCA in recognition and 3-D localization of ultrasound reflectors.

    PubMed

    Luna, Carlos A; Jiménez, José A; Pizarro, Daniel; Losada, Cristina; Rodriguez, José M

    2010-01-01

    In this paper, a new method of classification and localization of reflectors, using the time-of-flight (TOF) data obtained from ultrasonic transducers, is presented. The method of classification and localization is based on Generalized Principal Component Analysis (GPCA) applied to the TOF values obtained from a sensor that contains four ultrasound emitters and 16 receivers. Since PCA works with vectorized representations of TOF, it does not take into account the spatial locality of receivers. The GPCA works with two-dimensional representations of TOF, taking into account information on the spatial position of the receivers. This report includes a detailed description of the method of classification and localization and the results of achieved tests with three types of reflectors in 3-D environments: planes, edges, and corners. The results in terms of processing time, classification and localization were very satisfactory for the reflectors located in the range of 50-350 cm.

  4. Constitutive Modeling of Porcine Liver in Indentation Using 3D Ultrasound Imaging

    PubMed Central

    Jordan, P.; Socrate, S.; Zickler, T.E.; Howe, R.D.

    2009-01-01

    In this work we present an inverse finite-element modeling framework for constitutive modeling and parameter estimation of soft tissues using full-field volumetric deformation data obtained from 3D ultrasound. The finite-element model is coupled to full-field visual measurements by regularization springs attached at nodal locations. The free ends of the springs are displaced according to the locally estimated tissue motion and the normalized potential energy stored in all springs serves as a measure of model-experiment agreement for material parameter optimization. We demonstrate good accuracy of estimated parameters and consistent convergence properties on synthetically generated data. We present constitutive model selection and parameter estimation for perfused porcine liver in indentation and demonstrate that a quasilinear viscoelastic model with shear modulus relaxation offers good model-experiment agreement in terms of indenter displacement (0.19 mm RMS error) and tissue displacement field (0.97 mm RMS error). PMID:19627823

  5. 3D transrectal ultrasound (TRUS) prostate segmentation based on optimal feature learning framework

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofeng; Rossi, Peter J.; Jani, Ashesh B.; Mao, Hui; Curran, Walter J.; Liu, Tian

    2016-03-01

    We propose a 3D prostate segmentation method for transrectal ultrasound (TRUS) images, which is based on patch-based feature learning framework. Patient-specific anatomical features are extracted from aligned training images and adopted as signatures for each voxel. The most robust and informative features are identified by the feature selection process to train the kernel support vector machine (KSVM). The well-trained SVM was used to localize the prostate of the new patient. Our segmentation technique was validated with a clinical study of 10 patients. The accuracy of our approach was assessed using the manual segmentations (gold standard). The mean volume Dice overlap coefficient was 89.7%. In this study, we have developed a new prostate segmentation approach based on the optimal feature learning framework, demonstrated its clinical feasibility, and validated its accuracy with manual segmentations.

  6. A method for 3D reconstruction of coronary arteries using biplane angiography and intravascular ultrasound images.

    PubMed

    Bourantas, Christos V; Kourtis, Iraklis C; Plissiti, Marina E; Fotiadis, Dimitrios I; Katsouras, Christos S; Papafaklis, Michail I; Michalis, Lampros K

    2005-12-01

    The aim of this study is to describe a new method for the three-dimensional reconstruction of coronary arteries and its quantitative validation. Our approach is based on the fusion of the data provided by intravascular ultrasound images (IVUS) and biplane angiographies. A specific segmentation algorithm is used for the detection of the regions of interest in intravascular ultrasound images. A new methodology is also introduced for the accurate extraction of the catheter path. In detail, a cubic B-spline is used for approximating the catheter path in each biplane projection. Each B-spline curve is swept along the normal direction of its X-ray angiographic plane forming a surface. The intersection of the two surfaces is a 3D curve, which represents the reconstructed path. The detected regions of interest in the IVUS images are placed perpendicularly onto the path and their relative axial twist is computed using the sequential triangulation algorithm. Then, an efficient algorithm is applied to estimate the absolute orientation of the first IVUS frame. In order to obtain 3D visualization the commercial package Geomagic Studio 4.0 is used. The performance of the proposed method is assessed using a validation methodology which addresses the separate validation of each step followed for obtaining the coronary reconstruction. The performance of the segmentation algorithm was examined in 80 IVUS images. The reliability of the path extraction method was studied in vitro using a metal wire model and in vivo in a dataset of 11 patients. The performance of the sequential triangulation algorithm was tested in two gutter models and in the coronary arteries (marked with metal clips) of six cadaveric sheep hearts. Finally, the accuracy in the estimation of the first IVUS frame absolute orientation was examined in the same set of cadaveric sheep hearts. The obtained results demonstrate that the proposed reconstruction method is reliable and capable of depicting the morphology of

  7. Catheter-Based Ultrasound for 3D Control of Thermal Therapy

    NASA Astrophysics Data System (ADS)

    Diederich, Chris; Chen, Xin; Wootton, Jeffery; Juang, Titania; Nau, Will H.; Kinsey, Adam; Hsu, I.-Chow; Rieke, Viola; Pauly, Kim Butts; Sommer, Graham; Bouley, Donna

    2009-04-01

    Catheter-based ultrasound applicators have been investigated for delivering hyperthermia and thermal ablation for the treatment of cancer and benign diseases. Technology includes an intrauterine applicator integrated with an HDR ring applicator, interstitial applicators for hyperthermia delivery during brachytherapy, interstitial applicators for tumor ablation, and transurethral devices for conformal prostate ablation. Arrays of multiple sectored tubular transducers have been fabricated for interstitial and intrauterine hyperthermia applicators. High-power interstitial versions have been evaluated for percutaneous implantation with directional or dynamic angular control of thermal ablation. Transurethral applicators include curvilinear transducers with rotational sweeping of narrow heating patterns, and multi-sectored tubular devices capable of dynamic angular control without applicator movement. Performance was evaluated in phantom, excised tissue, in vivo experiments in canine prostate under MR temperature monitoring, clinical hyperthermia, and 3D-biothermal simulations with patient anatomy. Interstitial and intrauterine devices can tailor hyperthermia to large treatment volumes, with multisectored control useful to limit exposure to rectum and bladder. Curvilinear transurethral devices with sequential rotation produce target conforming coagulation zones that can cover either the whole gland or defined focal regions. Multi-sectored transurethral applicators can dynamically control the angular heating profile and target large regions of the prostate without applicator manipulation. High-power interstitial implants with directional devices can be used to effectively ablate defined target regions while avoiding sensitive tissues. MR temperature monitoring can effectively define the extent of thermal damage and provided a means for real-time control of the applicators. In summary, these catheter-based ultrasound devices allow for dynamic control of heating profiles

  8. CISUS: an integrated 3D ultrasound system for IGT using a modular tracking API

    NASA Astrophysics Data System (ADS)

    Boctor, Emad M.; Viswanathan, Anand; Pieper, Steve; Choti, Michael A.; Taylor, Russell H.; Kikinis, Ron; Fichtinger, Gabor

    2004-05-01

    Ultrasound has become popular in clinical/surgical applications, both as the primary image guidance modality and also in conjunction with other modalities like CT or MRI. Three dimensional ultrasound (3DUS) systems have also demonstrated usefulness in image-guided therapy (IGT). At the same time, however, current lack of open-source and open-architecture multi-modal medical visualization systems prevents 3DUS from fulfilling its potential. Several stand-alone 3DUS systems, like Stradx or In-Vivo exist today. Although these systems have been found to be useful in real clinical setting, it is difficult to augment their functionality and integrate them in versatile IGT systems. To address these limitations, a robotic/freehand 3DUS open environment (CISUS) is being integrated into the 3D Slicer, an open-source research tool developed for medical image analysis and surgical planning. In addition, the system capitalizes on generic application programming interfaces (APIs) for tracking devices and robotic control. The resulting platform-independent open-source system may serve as a valuable tool to the image guided surgery community. Other researchers could straightforwardly integrate the generic CISUS system along with other functionalities (i.e. dual view visualization, registration, real-time tracking, segmentation, etc) to rapidly create their medical/surgical applications. Our current driving clinical application is robotically assisted and freehand 3DUS-guided liver ablation, which is fully being integrated under the CISUS-3D Slicer. Initial functionality and pre-clinical feasibility are demonstrated on phantom and ex-vivo animal models.

  9. Transvaginal 3D Image-Guided High Intensity Focused Ultrasound Array

    NASA Astrophysics Data System (ADS)

    Held, Robert; Nguyen, Thuc Nghi; Vaezy, Shahram

    2005-03-01

    The goal of this project is to develop a transvaginal image-guided High Intensity Focused Ultrasound (HIFU) device using piezocomposite HIFU array technology, and commercially-available ultrasound imaging. Potential applications include treatment of uterine fibroids and abnormal uterine bleeding. The HIFU transducer was an annular phased array, with a focal length range of 30-60 mm, an elliptically-shaped aperture of 35×60 mm, and an operating frequency of 3 MHz. A pillow-shaped bag with water circulation will be used for coupling the HIFU energy into the tissue. An intra-cavity imaging probe (C9-5, Philips) was integrated with the HIFU array such that the focal axis of the HIFU transducer was within the image plane. The entire device will be covered by a gel-filled condom when inserted in the vaginal cavity. To control it, software packages were developed in the LabView programming environment. An imaging algorithm processed the ultrasound image to remove noise patterns due to the HIFU signal. The device will be equipped with a three-dimensional tracking system, using a six-degrees-of-freedom articulating arm. Necrotic lesions were produced in a tissue-mimicking phantom and a turkey breast sample for all focal lengths. Various HIFU doses allow various necrotic lesion shapes, including thin ellipsoidal, spherical, wide cylindrical, and teardrop-shaped. Software control of the device allows multiple foci to be activated sequentially for desired lesion patterns. Ultrasound imaging synchronization can be achieved using hardware signals obtained from the imaging system, or software signals determined empirically for various imaging probes. The image-guided HIFU device will provide a valuable tool in visualization of uterine fibroid tumors for the purposes of planning and subsequent HIFU treatment of the tumor, all in a 3D environment. The control system allows for various lesions of different shapes to be optimally positioned in the tumor to cover the entire tumor

  10. Accurate 3D reconstruction of complex blood vessel geometries from intravascular ultrasound images: in vitro study.

    PubMed

    Subramanian, K R; Thubrikar, M J; Fowler, B; Mostafavi, M T; Funk, M W

    2000-01-01

    We present a technique that accurately reconstructs complex three dimensional blood vessel geometry from 2D intravascular ultrasound (IVUS) images. Biplane x-ray fluoroscopy is used to image the ultrasound catheter tip at a few key points along its path as the catheter is pulled through the blood vessel. An interpolating spline describes the continuous catheter path. The IVUS images are located orthogonal to the path, resulting in a non-uniform structured scalar volume of echo densities. Isocontour surfaces are used to view the vessel geometry, while transparency and clipping enable interactive exploration of interior structures. The two geometries studied are a bovine artery vascular graft having U-shape and a constriction, and a canine carotid artery having multiple branches and a constriction. Accuracy of the reconstructions is established by comparing the reconstructions to (1) silicone moulds of the vessel interior, (2) biplane x-ray images, and (3) the original echo images. Excellent shape and geometry correspondence was observed in both geometries. Quantitative measurements made at key locations of the 3D reconstructions also were in good agreement with those made in silicone moulds. The proposed technique is easily adoptable in clinical practice, since it uses x-rays with minimal exposure and existing IVUS technology. PMID:11105284

  11. 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium

    NASA Astrophysics Data System (ADS)

    Xu, Lizhi; Gutbrod, Sarah R.; Bonifas, Andrew P.; Su, Yewang; Sulkin, Matthew S.; Lu, Nanshu; Chung, Hyun-Joong; Jang, Kyung-In; Liu, Zhuangjian; Ying, Ming; Lu, Chi; Webb, R. Chad; Kim, Jong-Seon; Laughner, Jacob I.; Cheng, Huanyu; Liu, Yuhao; Ameen, Abid; Jeong, Jae-Woong; Kim, Gwang-Tae; Huang, Yonggang; Efimov, Igor R.; Rogers, John A.

    2014-02-01

    Means for high-density multiparametric physiological mapping and stimulation are critically important in both basic and clinical cardiology. Current conformal electronic systems are essentially 2D sheets, which cannot cover the full epicardial surface or maintain reliable contact for chronic use without sutures or adhesives. Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic and optoelectronic components. Such integumentary devices completely envelop the heart, in a form-fitting manner, and possess inherent elasticity, providing a mechanically stable biotic/abiotic interface during normal cardiac cycles. Component examples range from actuators for electrical, thermal and optical stimulation, to sensors for pH, temperature and mechanical strain. The semiconductor materials include silicon, gallium arsenide and gallium nitride, co-integrated with metals, metal oxides and polymers, to provide these and other operational capabilities. Ex vivo physiological experiments demonstrate various functions and methodological possibilities for cardiac research and therapy.

  12. Effect of fiber diameter on the assembly of functional 3D cardiac patches

    NASA Astrophysics Data System (ADS)

    Fleischer, Sharon; Miller, Jacob; Hurowitz, Haley; Shapira, Assaf; Dvir, Tal

    2015-07-01

    The cardiac ECM has a unique 3D structure responsible for tissue morphogenesis and strong contractions. It is divided into three fiber groups with specific roles and distinct dimensions; nanoscale endomysial fibers, perimysial fibers with a diameter of 1 μm, and epimysial fibers, which have a diameter of several micrometers. We report here on our work, where distinct 3D fibrous scaffolds, each of them recapitulating the dimension scales of a single fiber population in the heart matrix, were fabricated. We have assessed the mechanical properties of these scaffolds and the contribution of each fiber population to cardiomyocyte morphogenesis, tissue assembly and function. Our results show that the nanoscale fiber scaffolds were more elastic than the microscale scaffolds, however, cardiomyocytes cultured on microscale fiber scaffolds exhibited enhanced spreading and elongation, both on the single cell and on the engineered tissue levels. In addition, lower fibroblast proliferation rates were observed on these microscale topographies. Based on the collected data we have fabricated composite scaffolds containing micro and nanoscale fibers, promoting superior tissue morphogenesis without compromising tissue contraction. Cardiac tissues, engineered within these composite scaffolds exhibited superior function, including lower excitation threshold and stronger contraction forces than tissue engineered within the single-population fiber scaffolds.

  13. Analysis of passive cardiac constitutive laws for parameter estimation using 3D tagged MRI.

    PubMed

    Hadjicharalambous, Myrianthi; Chabiniok, Radomir; Asner, Liya; Sammut, Eva; Wong, James; Carr-White, Gerald; Lee, Jack; Razavi, Reza; Smith, Nicolas; Nordsletten, David

    2015-08-01

    An unresolved issue in patient-specific models of cardiac mechanics is the choice of an appropriate constitutive law, able to accurately capture the passive behavior of the myocardium, while still having uniquely identifiable parameters tunable from available clinical data. In this paper, we aim to facilitate this choice by examining the practical identifiability and model fidelity of constitutive laws often used in cardiac mechanics. Our analysis focuses on the use of novel 3D tagged MRI, providing detailed displacement information in three dimensions. The practical identifiability of each law is examined by generating synthetic 3D tags from in silico simulations, allowing mapping of the objective function landscape over parameter space and comparison of minimizing parameter values with original ground truth values. Model fidelity was tested by comparing these laws with the more complex transversely isotropic Guccione law, by characterizing their passive end-diastolic pressure-volume relation behavior, as well as by considering the in vivo case of a healthy volunteer. These results show that a reduced form of the Holzapfel-Ogden law provides the best balance between identifiability and model fidelity across the tests considered. PMID:25510227

  14. 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium.

    PubMed

    Xu, Lizhi; Gutbrod, Sarah R; Bonifas, Andrew P; Su, Yewang; Sulkin, Matthew S; Lu, Nanshu; Chung, Hyun-Joong; Jang, Kyung-In; Liu, Zhuangjian; Ying, Ming; Lu, Chi; Webb, R Chad; Kim, Jong-Seon; Laughner, Jacob I; Cheng, Huanyu; Liu, Yuhao; Ameen, Abid; Jeong, Jae-Woong; Kim, Gwang-Tae; Huang, Yonggang; Efimov, Igor R; Rogers, John A

    2014-01-01

    Means for high-density multiparametric physiological mapping and stimulation are critically important in both basic and clinical cardiology. Current conformal electronic systems are essentially 2D sheets, which cannot cover the full epicardial surface or maintain reliable contact for chronic use without sutures or adhesives. Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic and optoelectronic components. Such integumentary devices completely envelop the heart, in a form-fitting manner, and possess inherent elasticity, providing a mechanically stable biotic/abiotic interface during normal cardiac cycles. Component examples range from actuators for electrical, thermal and optical stimulation, to sensors for pH, temperature and mechanical strain. The semiconductor materials include silicon, gallium arsenide and gallium nitride, co-integrated with metals, metal oxides and polymers, to provide these and other operational capabilities. Ex vivo physiological experiments demonstrate various functions and methodological possibilities for cardiac research and therapy. PMID:24569383

  15. 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium

    PubMed Central

    Xu, Lizhi; Gutbrod, Sarah R.; Bonifas, Andrew P.; Su, Yewang; Sulkin, Matthew S.; Lu, Nanshu; Chung, Hyun-Joong; Jang, Kyung-In; Liu, Zhuangjian; Ying, Ming; Lu, Chi; Webb, R. Chad; Kim, Jong-Seon; Laughner, Jacob I.; Cheng, Huanyu; Liu, Yuhao; Ameen, Abid; Jeong, Jae-Woong; Kim, Gwang-Tae; Huang, Yonggang; Efimov, Igor R.; Rogers, John A.

    2015-01-01

    Means for high-density multiparametric physiological mapping and stimulation are critically important in both basic and clinical cardiology. Current conformal electronic systems are essentially 2D sheets, which cannot cover the full epicardial surface or maintain reliable contact for chronic use without sutures or adhesives. Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic and optoelectronic components. Such integumentary devices completely envelop the heart, in a form-fitting manner, and possess inherent elasticity, providing a mechanically stable bioti-/abiotic interface during normal cardiac cycles. Component examples range from actuators for electrical, thermal and optical stimulation, to sensors for pH, temperature and mechanical strain. The semiconductor materials include silicon, gallium arsenide and gallium nitride, co-integrated with metals, metal oxides and polymers, to provide these and other operational capabilities. Ex vivo physiological experiments demonstrate various functions and methodological possibilities for cardiac research and therapy. PMID:24569383

  16. Ultrasound and 3D Skin Imaging: Methods to Evaluate Efficacy of Striae Distensae Treatment

    PubMed Central

    Bleve, Mariella; Capra, Priscilla; Pavanetto, Franca; Perugini, Paola

    2012-01-01

    Background. Over time, the striae rubra develop into striae alba that appear white, flat, and depressed. It is very important to determine the optimum striae management. In order to evaluate the effectiveness of these therapies, objective measurement tools are necessary. Objective. The aim of this study is to evaluate if ultrasonography and PRIMOS can be used to obtain an objective assessment of stretch marks type and stage; furthermore, we aim to apply these techniques to evaluate the efficacy of a topical treatment. Methods. 20 volunteers were enrolled with a two-month study. A marketed cosmetic product was used as the active over one body area. The controlateral area with stretch marks was treated with a “placebo” formulation without active, as a control. The instrumental evaluation was carried out at the beginning of the trial (baseline values or t0), after 1 month (t1), and at the end of the study (t2). Results. PRIMOS was able to measure and document striae distensae maturation; furthermore, ultrasound imaging permitted to visualize and diagnose the striae. Statistical analysis of skin roughness demonstrated a statistically significant reduction of Rp value only in a treated group. In fact, the Rp value represented a maximum peak height in the area selected. These results demonstrated that after two months of treatment only the striae rubra can be treated successfully. Conclusions. This work demonstrated that the 22MHz ultrasound can diagnose stretch marks; PRIMOS device can detect and measure striae distensae type and maturation. Furthermore, the high-frequency ultrasound and the 3D image device, described in this work, can be successfully employed in order to evaluate the efficacy of a topical treatment. PMID:22203840

  17. Beating heart on a chip: a novel microfluidic platform to generate functional 3D cardiac microtissues.

    PubMed

    Marsano, Anna; Conficconi, Chiara; Lemme, Marta; Occhetta, Paola; Gaudiello, Emanuele; Votta, Emiliano; Cerino, Giulia; Redaelli, Alberto; Rasponi, Marco

    2016-02-01

    In the past few years, microfluidic-based technology has developed microscale models recapitulating key physical and biological cues typical of the native myocardium. However, the application of controlled physiological uniaxial cyclic strains on a defined three-dimension cellular environment is not yet possible. Two-dimension mechanical stimulation was particularly investigated, neglecting the complex three-dimensional cell-cell and cell-matrix interactions. For this purpose, we developed a heart-on-a-chip platform, which recapitulates the physiologic mechanical environment experienced by cells in the native myocardium. The device includes an array of hanging posts to confine cell-laden gels, and a pneumatic actuation system to induce homogeneous uniaxial cyclic strains to the 3D cell constructs during culture. The device was used to generate mature and highly functional micro-engineered cardiac tissues (μECTs), from both neonatal rat and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM), strongly suggesting the robustness of our engineered cardiac micro-niche. Our results demonstrated that the cyclic strain was effectively highly uniaxial and uniformly transferred to cells in culture. As compared to control, stimulated μECTs showed superior cardiac differentiation, as well as electrical and mechanical coupling, owing to a remarkable increase in junction complexes. Mechanical stimulation also promoted early spontaneous synchronous beating and better contractile capability in response to electric pacing. Pacing analyses of hiPSC-CM constructs upon controlled administration of isoprenaline showed further promising applications of our platform in drug discovery, delivery and toxicology fields. The proposed heart-on-a-chip device represents a relevant step forward in the field, providing a standard functional three-dimensional cardiac model to possibly predict signs of hypertrophic changes in cardiac phenotype by mechanical and biochemical co-stimulation.

  18. Beating heart on a chip: a novel microfluidic platform to generate functional 3D cardiac microtissues.

    PubMed

    Marsano, Anna; Conficconi, Chiara; Lemme, Marta; Occhetta, Paola; Gaudiello, Emanuele; Votta, Emiliano; Cerino, Giulia; Redaelli, Alberto; Rasponi, Marco

    2016-02-01

    In the past few years, microfluidic-based technology has developed microscale models recapitulating key physical and biological cues typical of the native myocardium. However, the application of controlled physiological uniaxial cyclic strains on a defined three-dimension cellular environment is not yet possible. Two-dimension mechanical stimulation was particularly investigated, neglecting the complex three-dimensional cell-cell and cell-matrix interactions. For this purpose, we developed a heart-on-a-chip platform, which recapitulates the physiologic mechanical environment experienced by cells in the native myocardium. The device includes an array of hanging posts to confine cell-laden gels, and a pneumatic actuation system to induce homogeneous uniaxial cyclic strains to the 3D cell constructs during culture. The device was used to generate mature and highly functional micro-engineered cardiac tissues (μECTs), from both neonatal rat and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM), strongly suggesting the robustness of our engineered cardiac micro-niche. Our results demonstrated that the cyclic strain was effectively highly uniaxial and uniformly transferred to cells in culture. As compared to control, stimulated μECTs showed superior cardiac differentiation, as well as electrical and mechanical coupling, owing to a remarkable increase in junction complexes. Mechanical stimulation also promoted early spontaneous synchronous beating and better contractile capability in response to electric pacing. Pacing analyses of hiPSC-CM constructs upon controlled administration of isoprenaline showed further promising applications of our platform in drug discovery, delivery and toxicology fields. The proposed heart-on-a-chip device represents a relevant step forward in the field, providing a standard functional three-dimensional cardiac model to possibly predict signs of hypertrophic changes in cardiac phenotype by mechanical and biochemical co

  19. A preliminary evaluation work on a 3D ultrasound imaging system for 2D array transducer

    NASA Astrophysics Data System (ADS)

    Zhong, Xiaoli; Li, Xu; Yang, Jiali; Li, Chunyu; Song, Junjie; Ding, Mingyue; Yuchi, Ming

    2016-04-01

    This paper presents a preliminary evaluation work on a pre-designed 3-D ultrasound imaging system. The system mainly consists of four parts, a 7.5MHz, 24×24 2-D array transducer, the transmit/receive circuit, power supply, data acquisition and real-time imaging module. The row-column addressing scheme is adopted for the transducer fabrication, which greatly reduces the number of active channels . The element area of the transducer is 4.6mm by 4.6mm. Four kinds of tests were carried out to evaluate the imaging performance, including the penetration depth range, axial and lateral resolution, positioning accuracy and 3-D imaging frame rate. Several strong reflection metal objects , fixed in a water tank, were selected for the purpose of imaging due to a low signal-to-noise ratio of the transducer. The distance between the transducer and the tested objects , the thickness of aluminum, and the seam width of the aluminum sheet were measured by a calibrated micrometer to evaluate the penetration depth, the axial and lateral resolution, respectively. The experiment al results showed that the imaging penetration depth range was from 1.0cm to 6.2cm, the axial and lateral resolution were 0.32mm and 1.37mm respectively, the imaging speed was up to 27 frames per second and the positioning accuracy was 9.2%.

  20. Tracking the interframe deformation of structures in 3D ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Syn, M.; Gosling, J. P.; Prager, Richard W.; Berman, Laurence; Crowley, J.

    1994-09-01

    Three dimensional ultrasound imaging with a freehand probe allows a flexible approach to medical visualization and diagnosis. Given the imperfect accuracy of proprioceptive devices used to log the position and tilt of the probe, it is important to utilize the position constraints provided by image evidence. This is also important if we wish to consider the visualization of structures which move significantly during acquisition, such as a heart of fetus. We present here an initial approach to more robust segmentation and shape recovery in a particularly noisy modality. We consider 2D segmentation based on edge evidence, using first an active contour, then finding an optimal segmentation using simulated annealing. Correspondence between contours in adjacent frames can only be solved in general cases by use of a 3D prior model. Dynamic physics-based mesh models as used by Pentland [20] and Nastar [17], allow for shape modelling, then over-constrained 3D shape recovery can be performed using the intrinsic vibration modes of the model.

  1. Automatic 3D ultrasound calibration for image guided therapy using intramodality image registration

    NASA Astrophysics Data System (ADS)

    Schlosser, Jeffrey; Kirmizibayrak, Can; Shamdasani, Vijay; Metz, Steve; Hristov, Dimitre

    2013-11-01

    Many real time ultrasound (US) guided therapies can benefit from management of motion-induced anatomical changes with respect to a previously acquired computerized anatomy model. Spatial calibration is a prerequisite to transforming US image information to the reference frame of the anatomy model. We present a new method for calibrating 3D US volumes using intramodality image registration, derived from the ‘hand-eye’ calibration technique. The method is fully automated by implementing data rejection based on sensor displacements, automatic registration over overlapping image regions, and a self-consistency error metric evaluated continuously during calibration. We also present a novel method for validating US calibrations based on measurement of physical phantom displacements within US images. Both calibration and validation can be performed on arbitrary phantoms. Results indicate that normalized mutual information and localized cross correlation produce the most accurate 3D US registrations for calibration. Volumetric image alignment is more accurate and reproducible than point selection for validating the calibrations, yielding <1.5 mm root mean square error, a significant improvement relative to previously reported hand-eye US calibration results. Comparison of two different phantoms for calibration and for validation revealed significant differences for validation (p = 0.003) but not for calibration (p = 0.795).

  2. Automated Computed Tomography-Ultrasound Cross-Modality 3-D Contouring Algorithm for Prostate.

    PubMed

    Ermacora, Denis; Pesente, Silvia; Pascoli, Francesco; Raducci, Sebastian; Mauro, Rudy; Rumeileh, Imad Abu; Verhaegen, Frank; Fontanarosa, Davide

    2015-10-01

    A novel fully automated algorithm is introduced for 3-D cross-modality image segmentation of the prostate, based on the simultaneous use of co-registered computed tomography (CT) and 3-D ultrasound (US) images. By use of a Gabor feature detector, the algorithm can outline in three dimensions and in cross-modality the prostate, and it can be trained and optimized on specific patient populations. We applied it to 16 prostate cancer patients and evaluated the conformity between the automatically segmented prostate contours and the contours manually outlined by an experienced physician, on the CT-US fusion, using the mean distance to conformity (MDC) index. When only the CT scans were used, the average MDC value was 4.5 ± 1.7 mm (maximum value = 9.0 mm). When the US scans also were considered, the mean ± standard deviation was reduced to 3.9 ± 0.7 mm (maximum value = 5.5 mm). The cross-modality approach acted on all the largest distance values, reducing them to acceptable discrepancies.

  3. Automated kidney detection for 3D ultrasound using scan line searching

    NASA Astrophysics Data System (ADS)

    Noll, Matthias; Nadolny, Anne; Wesarg, Stefan

    2016-04-01

    Ultrasound (U/S) is a fast and non-expensive imaging modality that is used for the examination of various anatomical structures, e.g. the kidneys. One important task for automatic organ tracking or computer-aided diagnosis is the identification of the organ region. During this process the exact information about the transducer location and orientation is usually unavailable. This renders the implementation of such automatic methods exceedingly challenging. In this work we like to introduce a new automatic method for the detection of the kidney in 3D U/S images. This novel technique analyses the U/S image data along virtual scan lines. Here, characteristic texture changes when entering and leaving the symmetric tissue regions of the renal cortex are searched for. A subsequent feature accumulation along a second scan direction produces a 2D heat map of renal cortex candidates, from which the kidney location is extracted in two steps. First, the strongest candidate as well as its counterpart are extracted by heat map intensity ranking and renal cortex size analysis. This process exploits the heat map gap caused by the renal pelvis region. Substituting the renal pelvis detection with this combined cortex tissue feature increases the detection robustness. In contrast to model based methods that generate characteristic pattern matches, our method is simpler and therefore faster. An evaluation performed on 61 3D U/S data sets showed, that in 55 cases showing none or minor shadowing the kidney location could be correctly identified.

  4. Characterization of neonatal patients with intraventricular hemorrhage using 3D ultrasound cerebral ventricle volumes

    NASA Astrophysics Data System (ADS)

    Kishimoto, Jessica; Fenster, Aaron; Lee, David S. C.; de Ribaupierre, Sandrine

    2015-03-01

    One of the major non-congenital cause of neurological impairment among neonates born very preterm is intraventricular hemorrhage (IVH) - bleeding within the lateral ventricles. Most IVH patients will have a transient period of ventricle dilation that resolves spontaneously. However, those patients most at risk of long-term impairment are those who have progressive ventricle dilation as this causes macrocephaly, an abnormally enlarged head, then later causes increases intracranial pressure (ICP). 2D ultrasound (US) images through the fontanelles of the patients are serially acquired to monitor the progression of the ventricle dilation. These images are used to determine when interventional therapies such as needle aspiration of the built up CSF might be indicated for a patient. Initial therapies usually begin during the third week of life. Such interventions have been shown to decrease morbidity and mortality in IVH patients; however, this comes with risks of further hemorrhage or infection; therefore only patients requiring it should be treated. Previously we have developed and validated a 3D US system to monitor the progression of ventricle volumes (VV) in IVH patients. This system has been validated using phantoms and a small set of patient images. The aim of this work is to determine the ability of 3D US generated VV to categorize patients into those who will require interventional therapies, and those who will have spontaneous resolution. Patients with higher risks could therefore be monitored better, by re-allocating some of the resources as the low risks infants would need less monitoring.

  5. 2-D array for 3-D Ultrasound Imaging Using Synthetic Aperture Techniques

    PubMed Central

    Daher, Nadim M.; Yen, Jesse T.

    2010-01-01

    A 2-D array of 256 × 256 = 65,536 elements, with total area 4 × 4 = 16 cm2, serves as a flexible platform for developing acquisition schemes for 3-D rectilinear ultrasound imaging at 10 MHz using synthetic aperture techniques. This innovative system combines a simplified interconnect scheme and synthetic aperture techniques with a 2-D array for 3-D imaging. A row-column addressing scheme is used to access different elements for different transmit events. This addressing scheme is achieved through a simple interconnect, consisting of one top, one bottom single layer flex circuits, which, compared to multi-layer flex circuits, are simpler to design, cheaper to manufacture and thinner so their effect on the acoustic response is minimized. We present three designs that prioritize different design objectives: volume acquisiton time, resolution, and sensitivity, while maintaining acceptable figures for the other design objectives. For example, one design overlooks time acquisition requirements, assumes good noise conditions, and optimizes for resolution, achieving −6 dB and −20 dB beamwidths of less than 0.2 and 0.5 millimeters, respectively, for an F/2 aperture. Another design can acquire an entire volume in 256 transmit events, with −6dB and −20 dB beamwidths in the order of 0.4 and 0.8 millimeters, respectively. PMID:16764446

  6. 3D ultrasound system to investigate intraventricular hemorrhage in preterm neonates

    NASA Astrophysics Data System (ADS)

    Kishimoto, J.; de Ribaupierre, S.; Lee, D. S. C.; Mehta, R.; St. Lawrence, K.; Fenster, A.

    2013-11-01

    Intraventricular hemorrhage (IVH) is a common disorder among preterm neonates that is routinely diagnosed and monitored by 2D cranial ultrasound (US). The cerebral ventricles of patients with IVH often have a period of ventricular dilation (ventriculomegaly). This initial increase in ventricle size can either spontaneously resolve, which often shows clinically as a period of stabilization in ventricle size and eventual decline back towards a more normal size, or progressive ventricular dilation that does not stabilize and which may require interventional therapy to reduce symptoms relating to increased intracranial pressure. To improve the characterization of ventricle dilation, we developed a 3D US imaging system that can be used with a conventional clinical US scanner to image the ventricular system of preterm neonates at risk of ventriculomegaly. A motorized transducer housing was designed specifically for hand-held use inside an incubator using a transducer commonly used for cranial 2D US scans. This system was validated using geometric phantoms, US/MRI compatible ventricle volume phantoms, and patient images to determine 3D reconstruction accuracy and inter- and intra-observer volume estimation variability. 3D US geometric reconstruction was found to be accurate with an error of <0.2%. Measured volumes of a US/MRI compatible ventricle-like phantom were within 5% of gold standard water displacement measurements. Intra-class correlation for the three observers was 0.97, showing very high agreement between observers. The coefficient of variation was between 1.8-6.3% for repeated segmentations of the same patient. The minimum detectable difference was calculated to be 0.63 cm3 for a single observer. Results from ANOVA for three observers segmenting three patients of IVH grade II did not show any significant differences (p > 0.05) for the measured ventricle volumes between observers. This 3D US system can reliably produce 3D US images of the neonatal ventricular

  7. A compact mechatronic system for 3D ultrasound guided prostate interventions

    SciTech Connect

    Bax, Jeffrey; Smith, David; Bartha, Laura; Montreuil, Jacques; Sherebrin, Shi; Gardi, Lori; Edirisinghe, Chandima; Fenster, Aaron

    2011-02-15

    Purpose: Ultrasound imaging has improved the treatment of prostate cancer by producing increasingly higher quality images and influencing sophisticated targeting procedures for the insertion of radioactive seeds during brachytherapy. However, it is critical that the needles be placed accurately within the prostate to deliver the therapy to the planned location and avoid complications of damaging surrounding tissues. Methods: The authors have developed a compact mechatronic system, as well as an effective method for guiding and controlling the insertion of transperineal needles into the prostate. This system has been designed to allow guidance of a needle obliquely in 3D space into the prostate, thereby reducing pubic arch interference. The choice of needle trajectory and location in the prostate can be adjusted manually or with computer control. Results: To validate the system, a series of experiments were performed on phantoms. The 3D scan of the string phantom produced minimal geometric error, which was less than 0.4 mm. Needle guidance accuracy tests in agar prostate phantoms showed that the mean error of bead placement was less then 1.6 mm along parallel needle paths that were within 1.2 mm of the intended target and 1 deg. from the preplanned trajectory. At oblique angles of up to 15 deg. relative to the probe axis, beads were placed to within 3.0 mm along a trajectory that were within 2.0 mm of the target with an angular error less than 2 deg. Conclusions: By combining 3D TRUS imaging system to a needle tracking linkage, this system should improve the physician's ability to target and accurately guide a needle to selected targets without the need for the computer to directly manipulate and insert the needle. This would be beneficial as the physician has complete control of the system and can safely maneuver the needle guide around obstacles such as previously placed needles.

  8. Real-time 3D visualization of cellular rearrangements during cardiac valve formation.

    PubMed

    Pestel, Jenny; Ramadass, Radhan; Gauvrit, Sebastien; Helker, Christian; Herzog, Wiebke; Stainier, Didier Y R

    2016-06-15

    During cardiac valve development, the single-layered endocardial sheet at the atrioventricular canal (AVC) is remodeled into multilayered immature valve leaflets. Most of our knowledge about this process comes from examining fixed samples that do not allow a real-time appreciation of the intricacies of valve formation. Here, we exploit non-invasive in vivo imaging techniques to identify the dynamic cell behaviors that lead to the formation of the immature valve leaflets. We find that in zebrafish, the valve leaflets consist of two sets of endocardial cells at the luminal and abluminal side, which we refer to as luminal cells (LCs) and abluminal cells (ALCs), respectively. By analyzing cellular rearrangements during valve formation, we observed that the LCs and ALCs originate from the atrium and ventricle, respectively. Furthermore, we utilized Wnt/β-catenin and Notch signaling reporter lines to distinguish between the LCs and ALCs, and also found that cardiac contractility and/or blood flow is necessary for the endocardial expression of these signaling reporters. Thus, our 3D analyses of cardiac valve formation in zebrafish provide fundamental insights into the cellular rearrangements underlying this process.

  9. Mapping 3D Strains with Ultrasound Speckle Tracking: Method Validation and Initial Results in Porcine Scleral Inflation.

    PubMed

    Cruz Perez, Benjamin; Pavlatos, Elias; Morris, Hugh J; Chen, Hong; Pan, Xueliang; Hart, Richard T; Liu, Jun

    2016-07-01

    This study aimed to develop and validate a high frequency ultrasound method for measuring distributive, 3D strains in the sclera during elevations of intraocular pressure. A 3D cross-correlation based speckle-tracking algorithm was implemented to compute the 3D displacement vector and strain tensor at each tracking point. Simulated ultrasound radiofrequency data from a sclera-like structure at undeformed and deformed states with known strains were used to evaluate the accuracy and signal-to-noise ratio (SNR) of strain estimation. An experimental high frequency ultrasound (55 MHz) system was built to acquire 3D scans of porcine eyes inflated from 15 to 17 and then 19 mmHg. Simulations confirmed good strain estimation accuracy and SNR (e.g., the axial strains had less than 4.5% error with SNRs greater than 16.5 for strains from 0.005 to 0.05). Experimental data in porcine eyes showed increasing tensile, compressive, and shear strains in the posterior sclera during inflation, with a volume ratio close to one suggesting near-incompressibility. This study established the feasibility of using high frequency ultrasound speckle tracking for measuring 3D tissue strains and its potential to characterize physiological deformations in the posterior eye. PMID:26563101

  10. Transvaginal 3-d power Doppler ultrasound evaluation of the fetal brain at 10-13 weeks' gestation.

    PubMed

    Hata, Toshiyuki; Tanaka, Hirokazu; Noguchi, Junko

    2012-03-01

    The objective of this study was to measure the fetal brain volume (FBV) and vascularization and blood flow using transvaginal 3-D power Doppler (3DPD) ultrasound late in the first trimester of pregnancy. 3DPD ultrasound examinations with the VOCAL imaging analysis program were performed on 36 normal fetuses from 10-13 weeks' gestation. FBV and 3DPD indices related to the fetal brain vascularization (vascularization index [VI], flow index [FI] and vascularization flow index [VFI]) were calculated in each fetus. Intra- and interclass correlation coefficients and intra- and interobserver agreements of measurements were assessed. FBV was curvilinearly correlated well with the gestational age (R2 = 0.861, p < 0.0001). All 3-D power Doppler indices (VI, FI and VFI) showed no change at 10-13 weeks' gestation. FBV and all 3-D power Doppler indices (VI, FI and VFI) showed a correlation > 0.82, with good intra- and interobserver agreement. Our findings suggest that 3-D ultrasound is a superior means of evaluating the FBV in utero, and that 3-D power Doppler ultrasound histogram analysis may provide new information on the assessment of fetal brain perfusion.

  11. In vitro in-stent restenoses evaluated by 3D ultrasound.

    PubMed

    Lécart, Myriam; Cardinal, Marie-Hélène Roy; Qin, Zhao; Soulez, Gilles; Cloutier, Guy

    2009-02-01

    The purpose of this study was to quantify in-stent restenoses with 3D B mode and power Doppler ultrasound (U.S.) imaging. In-stent restenoses were mimicked with vascular phantoms in which a nonferromagnetic prototype stent (Boston Scientific) and a ferromagnetic clinical stainless steel stent (Palmaz P295) were embedded. Each phantom had an 80% in-stent stenosis and a 75% stenosis located outside the stent. These phantoms were compared to a reference phantom reproducing both stenoses without stent. Data sets of 2D cross-sectional U.S. images were acquired in freehand scanning using a magnetic sensor attached to the U.S. probe and in mechanical linear scanning with the probe attached to a step motor device. Each 2D image was automatically segmented before 3D reconstruction of the vessel. Results indicate that the reference phantom (without stent) was accurately assessed with errors below 1.8% for the 75% stenosis and 3.2% for the 80% stenosis in both B mode and power Doppler for the two scanning methods. The 80% in-stent stenoses in Boston Scientific and Palmaz stents were, respectively, evaluated at 73.8 (+/-3.2)% and 75.8 (+/- 3)% in B mode and at 82 (+/- 2.5)% and 86.2 (+/- 6.4)% in power Doppler when freehand scans were used. For comparison, when linear scans were selected, in-stent stenoses in the Boston Scientific or Palmaz stent were, respectively, evaluated at 77.4 (+/- 2.0)% and 73.8 (+/- 2.5)% in B mode and at 87.0 (+/- 1.3)% and 85.6 (+/- 5.8)% in power Doppler. To conclude, 3D freehand U.S. is a valuable method to quantify in-stent restenoses, particularly in B mode. It is thus hoped that, in the clinical setting, noninvasive 3D U.S. may provide sufficient precision to grade in-stent restenoses. PMID:19291990

  12. Semiautomatic registration of 3D transabdominal ultrasound images for patient repositioning during postprostatectomy radiotherapy

    SciTech Connect

    Presles, Benoît Rit, Simon; Sarrut, David; Fargier-Voiron, Marie; Liebgott, Hervé; Biston, Marie-Claude; Munoz, Alexandre; Pommier, Pascal; Lynch, Rod

    2014-12-15

    Purpose: The aim of the present work is to propose and evaluate registration algorithms of three-dimensional (3D) transabdominal (TA) ultrasound (US) images to setup postprostatectomy patients during radiation therapy. Methods: Three registration methods have been developed and evaluated to register a reference 3D-TA-US image acquired during the planning CT session and a 3D-TA-US image acquired before each treatment session. The first method (method A) uses only gray value information, whereas the second one (method B) uses only gradient information. The third one (method C) combines both sets of information. All methods restrict the comparison to a region of interest computed from the dilated reference positioning volume drawn on the reference image and use mutual information as a similarity measure. The considered geometric transformations are translations and have been optimized by using the adaptive stochastic gradient descent algorithm. Validation has been carried out using manual registration by three operators of the same set of image pairs as the algorithms. Sixty-two treatment US images of seven patients irradiated after a prostatectomy have been registered to their corresponding reference US image. The reference registration has been defined as the average of the manual registration values. Registration error has been calculated by subtracting the reference registration from the algorithm result. For each session, the method has been considered a failure if the registration error was above both the interoperator variability of the session and a global threshold of 3.0 mm. Results: All proposed registration algorithms have no systematic bias. Method B leads to the best results with mean errors of −0.6, 0.7, and −0.2 mm in left–right (LR), superior–inferior (SI), and anterior–posterior (AP) directions, respectively. With this method, the standard deviations of the mean error are of 1.7, 2.4, and 2.6 mm in LR, SI, and AP directions, respectively

  13. Blood Pool Segmentation Results in Superior Virtual Cardiac Models than Myocardial Segmentation for 3D Printing.

    PubMed

    Farooqi, Kanwal M; Lengua, Carlos Gonzalez; Weinberg, Alan D; Nielsen, James C; Sanz, Javier

    2016-08-01

    The method of cardiac magnetic resonance (CMR) three-dimensional (3D) image acquisition and post-processing which should be used to create optimal virtual models for 3D printing has not been studied systematically. Patients (n = 19) who had undergone CMR including both 3D balanced steady-state free precession (bSSFP) imaging and contrast-enhanced magnetic resonance angiography (MRA) were retrospectively identified. Post-processing for the creation of virtual 3D models involved using both myocardial (MS) and blood pool (BP) segmentation, resulting in four groups: Group 1-bSSFP/MS, Group 2-bSSFP/BP, Group 3-MRA/MS and Group 4-MRA/BP. The models created were assessed by two raters for overall quality (1-poor; 2-good; 3-excellent) and ability to identify predefined vessels (1-5: superior vena cava, inferior vena cava, main pulmonary artery, ascending aorta and at least one pulmonary vein). A total of 76 virtual models were created from 19 patient CMR datasets. The mean overall quality scores for Raters 1/2 were 1.63 ± 0.50/1.26 ± 0.45 for Group 1, 2.12 ± 0.50/2.26 ± 0.73 for Group 2, 1.74 ± 0.56/1.53 ± 0.61 for Group 3 and 2.26 ± 0.65/2.68 ± 0.48 for Group 4. The numbers of identified vessels for Raters 1/2 were 4.11 ± 1.32/4.05 ± 1.31 for Group 1, 4.90 ± 0.46/4.95 ± 0.23 for Group 2, 4.32 ± 1.00/4.47 ± 0.84 for Group 3 and 4.74 ± 0.56/4.63 ± 0.49 for Group 4. Models created using BP segmentation (Groups 2 and 4) received significantly higher ratings than those created using MS for both overall quality and number of vessels visualized (p < 0.05), regardless of the acquisition technique. There were no significant differences between Groups 1 and 3. The ratings for Raters 1 and 2 had good correlation for overall quality (ICC = 0.63) and excellent correlation for the total number of vessels visualized (ICC = 0.77). The intra-rater reliability was good for Rater A (ICC = 0.65). Three models were successfully printed

  14. Blood Pool Segmentation Results in Superior Virtual Cardiac Models than Myocardial Segmentation for 3D Printing.

    PubMed

    Farooqi, Kanwal M; Lengua, Carlos Gonzalez; Weinberg, Alan D; Nielsen, James C; Sanz, Javier

    2016-08-01

    The method of cardiac magnetic resonance (CMR) three-dimensional (3D) image acquisition and post-processing which should be used to create optimal virtual models for 3D printing has not been studied systematically. Patients (n = 19) who had undergone CMR including both 3D balanced steady-state free precession (bSSFP) imaging and contrast-enhanced magnetic resonance angiography (MRA) were retrospectively identified. Post-processing for the creation of virtual 3D models involved using both myocardial (MS) and blood pool (BP) segmentation, resulting in four groups: Group 1-bSSFP/MS, Group 2-bSSFP/BP, Group 3-MRA/MS and Group 4-MRA/BP. The models created were assessed by two raters for overall quality (1-poor; 2-good; 3-excellent) and ability to identify predefined vessels (1-5: superior vena cava, inferior vena cava, main pulmonary artery, ascending aorta and at least one pulmonary vein). A total of 76 virtual models were created from 19 patient CMR datasets. The mean overall quality scores for Raters 1/2 were 1.63 ± 0.50/1.26 ± 0.45 for Group 1, 2.12 ± 0.50/2.26 ± 0.73 for Group 2, 1.74 ± 0.56/1.53 ± 0.61 for Group 3 and 2.26 ± 0.65/2.68 ± 0.48 for Group 4. The numbers of identified vessels for Raters 1/2 were 4.11 ± 1.32/4.05 ± 1.31 for Group 1, 4.90 ± 0.46/4.95 ± 0.23 for Group 2, 4.32 ± 1.00/4.47 ± 0.84 for Group 3 and 4.74 ± 0.56/4.63 ± 0.49 for Group 4. Models created using BP segmentation (Groups 2 and 4) received significantly higher ratings than those created using MS for both overall quality and number of vessels visualized (p < 0.05), regardless of the acquisition technique. There were no significant differences between Groups 1 and 3. The ratings for Raters 1 and 2 had good correlation for overall quality (ICC = 0.63) and excellent correlation for the total number of vessels visualized (ICC = 0.77). The intra-rater reliability was good for Rater A (ICC = 0.65). Three models were successfully printed

  15. Histological Evaluation of 3D MRI-Guided Transurethral Ultrasound Therapy in the Prostate

    NASA Astrophysics Data System (ADS)

    Vedula, Siddharth; Boyes, Aaron; Chopra, Rajiv; Bronskill, Michael

    2010-03-01

    Previous work from our group has shown that transurethral ultrasound therapy, with a single ultrasound transducer guided by temperature feedback from a single MRI plane (slice), can be used to treat a targeted region accurately in the prostate gland. We have extended this approach to a larger, 3D, targeted volume within the prostate, using a multi-element transducer controlled concurrently by temperature feedback from multiple imaging planes. Animals were placed supine in a 1.5 T clinical MRI, and the transurethral heating device was positioned with image guidance. A four-element transducer (each element was 5 mm long, operating at ˜8 MHz) was rotated to treat a targeted volume around the device. Temperature maps transverse to each element were acquired during heating and used to control the acoustic power of each element and the rate of rotation of the device. T2-weighted and contrast-enhanced (CE) MR images were obtained pre- and post-heating. Following the treatment, prostates were removed and fixed, axially sliced, stained with H&E, and digitally imaged at high-resolution to outline boundaries of cell death. Slice alignment and image registration techniques were developed to enable quantitative comparison of the axial MRI images and matching histological sections. Prostate sections showed clear regions of coagulative necrosis, extending ˜20 mm along the urethra, which correlated well with CE MRI data and transducer length. After registration, the outer border of coagulative necrosis on H&E conformed well to the target isotherm, similar to results from our previous (single element) acute studies. These results confirm that our previous analysis techniques for a single transducer can be extended to multiple elements, and that a large volumetric ablation of the prostate gland is feasible with a high degree of accuracy.

  16. Ex Vivo 3D Diffusion Tensor Imaging and Quantification of Cardiac Laminar Structure

    PubMed Central

    Helm, Patrick A.; Tseng, Hsiang-Jer; Younes, Laurent; McVeigh, Elliot R.; Winslow, Raimond L.

    2007-01-01

    A three-dimensional (3D) diffusion-weighted imaging (DWI) method for measuring cardiac fiber structure at high spatial resolution is presented. The method was applied to the ex vivo reconstruction of the fiber architecture of seven canine hearts. A novel hypothesis-testing method was developed and used to show that distinct populations of secondary and tertiary eigenvalues may be distinguished at reasonable confidence levels (P ≤ 0.01) within the canine ventricle. Fiber inclination and sheet angles are reported as a function of transmural depth through the anterior, lateral, and posterior left ventricle (LV) free wall. Within anisotropic regions, two consistent and dominant orientations were identified, supporting published results from histological studies and providing strong evidence that the tertiary eigenvector of the diffusion tensor (DT) defines the sheet normal. PMID:16149057

  17. Ex vivo 3D diffusion tensor imaging and quantification of cardiac laminar structure.

    PubMed

    Helm, Patrick A; Tseng, Hsiang-Jer; Younes, Laurent; McVeigh, Elliot R; Winslow, Raimond L

    2005-10-01

    A three-dimensional (3D) diffusion-weighted imaging (DWI) method for measuring cardiac fiber structure at high spatial resolution is presented. The method was applied to the ex vivo reconstruction of the fiber architecture of seven canine hearts. A novel hypothesis-testing method was developed and used to show that distinct populations of secondary and tertiary eigenvalues may be distinguished at reasonable confidence levels (P < or = 0.01) within the canine ventricle. Fiber inclination and sheet angles are reported as a function of transmural depth through the anterior, lateral, and posterior left ventricle (LV) free wall. Within anisotropic regions, two consistent and dominant orientations were identified, supporting published results from histological studies and providing strong evidence that the tertiary eigenvector of the diffusion tensor (DT) defines the sheet normal.

  18. Anechoic Sphere Phantoms for Estimating 3-D Resolution of Very High Frequency Ultrasound Scanners

    PubMed Central

    Madsen, Ernest L.; Frank, Gary R.; McCormick, Matthew M.; Deaner, Meagan E.; Stiles, Timothy A.

    2013-01-01

    Two phantoms have been constructed for assessing the performance of high frequency ultrasound imagers. They also allow for periodic quality assurance tests. The phantoms contain eight blocks of tissue-mimicking material where each block contains a spatially random distribution of suitably small anechoic spheres having a small distribution of diameters. The eight mean sphere diameters are distributed from 0.10 to 1.09 mm. The two phantoms differ primarily in terms of the backscatter coefficient of the background material in which the spheres are suspended. The mean scatterer diameter for one phantom is larger than that for the other phantom resulting in a lesser increase in backscatter coefficient for the second phantom; however, the backscatter curves cross at about 35 MHz. Since spheres have no preferred orientation, all three (spatial) dimensions of resolution contribute to sphere detection on an equal basis; thus, the resolution is termed 3-D. Two high frequency scanners are compared. One employs single-element (fixed focus) transducers, and the other employs variable focus linear arrays. The nominal frequency for the single element transducers were 25 and 55 MHz and for the linear array transducers were 20, 30 and 40 MHz. The depth range for detection of spheres of each size is determined corresponding to determination of 3-D resolution as a function of depth. As expected, the single-element transducers are severely limited in useful imaging depth ranges compared with the linear arrays. Note that these phantoms could also be useful for training technicians in using higher frequency scanners. PMID:20889416

  19. Compressed Sensing Reconstruction of 3D Ultrasound Data Using Dictionary Learning and Line-Wise Subsampling.

    PubMed

    Lorintiu, Oana; Liebgott, Hervé; Alessandrini, Martino; Bernard, Olivier; Friboulet, Denis

    2015-12-01

    In this paper we present a compressed sensing (CS) method adapted to 3D ultrasound imaging (US). In contrast to previous work, we propose a new approach based on the use of learned overcomplete dictionaries that allow for much sparser representations of the signals since they are optimized for a particular class of images such as US images. In this study, the dictionary was learned using the K-SVD algorithm and CS reconstruction was performed on the non-log envelope data by removing 20% to 80% of the original data. Using numerically simulated images, we evaluate the influence of the training parameters and of the sampling strategy. The latter is done by comparing the two most common sampling patterns, i.e., point-wise and line-wise random patterns. The results show in particular that line-wise sampling yields an accuracy comparable to the conventional point-wise sampling. This indicates that CS acquisition of 3D data is feasible in a relatively simple setting, and thus offers the perspective of increasing the frame rate by skipping the acquisition of RF lines. Next, we evaluated this approach on US volumes of several ex vivo and in vivo organs. We first show that the learned dictionary approach yields better performances than conventional fixed transforms such as Fourier or discrete cosine. Finally, we investigate the generality of the learned dictionary approach and show that it is possible to build a general dictionary allowing to reliably reconstruct different volumes of different ex vivo or in vivo organs.

  20. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation

    PubMed Central

    Zhou, Xuan; Castro, Nathan J.; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-01-01

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm2 intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application. PMID:27597635

  1. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation.

    PubMed

    Zhou, Xuan; Castro, Nathan J; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-01-01

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm(2) intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application. PMID:27597635

  2. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation.

    PubMed

    Zhou, Xuan; Castro, Nathan J; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-09-06

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm(2) intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application.

  3. Surgical Planning by 3D Printing for Primary Cardiac Schwannoma Resection.

    PubMed

    Son, Kuk Hui; Kim, Kun-Woo; Ahn, Chi Bum; Choi, Chang Hu; Park, Kook Yang; Park, Chul Hyun; Lee, Jae-Ik; Jeon, Yang Bin

    2015-11-01

    We report herein a case of benign cardiac schwannoma in the interatrial septum. A 42-year-old woman was transferred from a clinic because of cardiomegaly as determined by chest X-ray. A transthoracic echocardiography and chest computed tomography examination revealed a huge mass in the pericardium compressing the right atrium, superior vena cava (SVC), left atrium, and superior pulmonary vein. To confirm that the tumor originated from either heart or mediastinum, cine magnetic resonance imaging was performed, but the result was not conclusive. To facilitate surgical planning, we used 3D printing. Using a printed heart model, we decided that tumor resection under cardiopulmonary bypass (CPB) through sternotomy would be technically feasible. At surgery, a huge tumor in the interatrial septum was confirmed. By incision on the atrial roof between the aorta and SVC, tumor enucleation was performed successfully under CPB. Pathology revealed benign schwannoma. The patient was discharged without complication. 3D printing of the heart and tumor was found to be helpful when deciding optimal surgical approach.

  4. Surgical Planning by 3D Printing for Primary Cardiac Schwannoma Resection

    PubMed Central

    Son, Kuk Hui; Kim, Kun-Woo; Ahn, Chi Bum; Choi, Chang Hu; Park, Kook Yang; Park, Chul Hyun

    2015-01-01

    We report herein a case of benign cardiac schwannoma in the interatrial septum. A 42-year-old woman was transferred from a clinic because of cardiomegaly as determined by chest X-ray. A transthoracic echocardiography and chest computed tomography examination revealed a huge mass in the pericardium compressing the right atrium, superior vena cava (SVC), left atrium, and superior pulmonary vein. To confirm that the tumor originated from either heart or mediastinum, cine magnetic resonance imaging was performed, but the result was not conclusive. To facilitate surgical planning, we used 3D printing. Using a printed heart model, we decided that tumor resection under cardiopulmonary bypass (CPB) through sternotomy would be technically feasible. At surgery, a huge tumor in the interatrial septum was confirmed. By incision on the atrial roof between the aorta and SVC, tumor enucleation was performed successfully under CPB. Pathology revealed benign schwannoma. The patient was discharged without complication. 3D printing of the heart and tumor was found to be helpful when deciding optimal surgical approach. PMID:26446661

  5. Ultrasonic diaphragm tracking for cardiac interventional navigation on 3D motion compensated static roadmaps

    NASA Astrophysics Data System (ADS)

    Timinger, Holger; Kruger, Sascha; Dietmayer, Klaus; Borgert, Joern

    2005-04-01

    In this paper, a novel approach to cardiac interventional navigation on 3D motion-compensated static roadmaps is presented. Current coronary interventions, e.g. percutaneous transluminal coronary angioplasties, are performed using 2D X-ray fluoroscopy. This comes along with well-known drawbacks like radiation exposure, use of contrast agent, and limited visualization, e.g. overlap and foreshortening, due to projection imaging. In the presented approach, the interventional device, i.e. the catheter, is tracked using an electromagnetic tracking system (MTS). Therefore, the catheters position is mapped into a static 3D image of the volume of interest (VOI) by means of an affine registration. In order to compensate for respiratory motion of the catheter with respect to the static image, a parameterized affine motion model is used which is driven by a respiratory sensor signal. This signal is derived from ultrasonic diaphragm tracking. The motion compensation for the heartbeat is done using ECG-gating. The methods are validated using a heart- and diaphragm-phantom. The mean displacement of the catheter due to the simulated organ motion decreases from approximately 9 mm to 1.3 mm. This result indicates that the proposed method is able to reconstruct the catheter position within the VOI accurately and that it can help to overcome drawbacks of current interventional procedures.

  6. Portable high-intensity focused ultrasound system with 3D electronic steering, real-time cavitation monitoring, and 3D image reconstruction algorithms: a preclinical study in pigs

    PubMed Central

    2014-01-01

    Purpose: The aim of this study was to evaluate the safety and accuracy of a new portable ultrasonography-guided high-intensity focused ultrasound (USg-HIFU) system with a 3-dimensional (3D) electronic steering transducer, a simultaneous ablation and imaging module, real-time cavitation monitoring, and 3D image reconstruction algorithms. Methods: To address the accuracy of the transducer, hydrophones in a water chamber were used to assess the generation of sonic fields. An animal study was also performed in five pigs by ablating in vivo thighs by single-point sonication (n=10) or volume sonication (n=10) and ex vivo kidneys by single-point sonication (n=10). Histological and statistical analyses were performed. Results: In the hydrophone study, peak voltages were detected within 1.0 mm from the targets on the y- and z-axes and within 2.0-mm intervals along the x-axis (z-axis, direction of ultrasound propagation; y- and x-axes, perpendicular to the direction of ultrasound propagation). Twenty-nine of 30 HIFU sessions successfully created ablations at the target. The in vivo porcine thigh study showed only a small discrepancy (width, 0.5-1.1 mm; length, 3.0 mm) between the planning ultrasonograms and the pathological specimens. Inordinate thermal damage was not observed in the adjacent tissues or sonic pathways in the in vivo thigh and ex vivo kidney studies. Conclusion: Our study suggests that this new USg-HIFU system may be a safe and accurate technique for ablating soft tissues and encapsulated organs. PMID:25038809

  7. Chest-wall segmentation in automated 3D breast ultrasound images using thoracic volume classification

    NASA Astrophysics Data System (ADS)

    Tan, Tao; van Zelst, Jan; Zhang, Wei; Mann, Ritse M.; Platel, Bram; Karssemeijer, Nico

    2014-03-01

    Computer-aided detection (CAD) systems are expected to improve effectiveness and efficiency of radiologists in reading automated 3D breast ultrasound (ABUS) images. One challenging task on developing CAD is to reduce a large number of false positives. A large amount of false positives originate from acoustic shadowing caused by ribs. Therefore determining the location of the chestwall in ABUS is necessary in CAD systems to remove these false positives. Additionally it can be used as an anatomical landmark for inter- and intra-modal image registration. In this work, we extended our previous developed chestwall segmentation method that fits a cylinder to automated detected rib-surface points and we fit the cylinder model by minimizing a cost function which adopted a term of region cost computed from a thoracic volume classifier to improve segmentation accuracy. We examined the performance on a dataset of 52 images where our previous developed method fails. Using region-based cost, the average mean distance of the annotated points to the segmented chest wall decreased from 7.57±2.76 mm to 6.22±2.86 mm.art.

  8. Automated linking of suspicious findings between automated 3D breast ultrasound volumes

    NASA Astrophysics Data System (ADS)

    Gubern-Mérida, Albert; Tan, Tao; van Zelst, Jan; Mann, Ritse M.; Karssemeijer, Nico

    2016-03-01

    Automated breast ultrasound (ABUS) is a 3D imaging technique which is rapidly emerging as a safe and relatively inexpensive modality for screening of women with dense breasts. However, reading ABUS examinations is very time consuming task since radiologists need to manually identify suspicious findings in all the different ABUS volumes available for each patient. Image analysis techniques to automatically link findings across volumes are required to speed up clinical workflow and make ABUS screening more efficient. In this study, we propose an automated system to, given the location in the ABUS volume being inspected (source), find the corresponding location in a target volume. The target volume can be a different view of the same study or the same view from a prior examination. The algorithm was evaluated using 118 linkages between suspicious abnormalities annotated in a dataset of ABUS images of 27 patients participating in a high risk screening program. The distance between the predicted location and the center of the annotated lesion in the target volume was computed for evaluation. The mean ± stdev and median distance error achieved by the presented algorithm for linkages between volumes of the same study was 7.75±6.71 mm and 5.16 mm, respectively. The performance was 9.54±7.87 and 8.00 mm (mean ± stdev and median) for linkages between volumes from current and prior examinations. The proposed approach has the potential to minimize user interaction for finding correspondences among ABUS volumes.

  9. Simulated Microgravity and 3D Culture Enhance Induction, Viability, Proliferation and Differentiation of Cardiac Progenitors from Human Pluripotent Stem Cells

    PubMed Central

    Jha, Rajneesh; Wu, Qingling; Singh, Monalisa; Preininger, Marcela K.; Han, Pengcheng; Ding, Gouliang; Cho, Hee Cheol; Jo, Hanjoong; Maher, Kevin O.; Wagner, Mary B.; Xu, Chunhui

    2016-01-01

    Efficient generation of cardiomyocytes from human pluripotent stem cells is critical for their regenerative applications. Microgravity and 3D culture can profoundly modulate cell proliferation and survival. Here, we engineered microscale progenitor cardiac spheres from human pluripotent stem cells and exposed the spheres to simulated microgravity using a random positioning machine for 3 days during their differentiation to cardiomyocytes. This process resulted in the production of highly enriched cardiomyocytes (99% purity) with high viability (90%) and expected functional properties, with a 1.5 to 4-fold higher yield of cardiomyocytes from each undifferentiated stem cell as compared with 3D-standard gravity culture. Increased induction, proliferation and viability of cardiac progenitors as well as up-regulation of genes associated with proliferation and survival at the early stage of differentiation were observed in the 3D culture under simulated microgravity. Therefore, a combination of 3D culture and simulated microgravity can be used to efficiently generate highly enriched cardiomyocytes. PMID:27492371

  10. Simulated Microgravity and 3D Culture Enhance Induction, Viability, Proliferation and Differentiation of Cardiac Progenitors from Human Pluripotent Stem Cells.

    PubMed

    Jha, Rajneesh; Wu, Qingling; Singh, Monalisa; Preininger, Marcela K; Han, Pengcheng; Ding, Gouliang; Cho, Hee Cheol; Jo, Hanjoong; Maher, Kevin O; Wagner, Mary B; Xu, Chunhui

    2016-01-01

    Efficient generation of cardiomyocytes from human pluripotent stem cells is critical for their regenerative applications. Microgravity and 3D culture can profoundly modulate cell proliferation and survival. Here, we engineered microscale progenitor cardiac spheres from human pluripotent stem cells and exposed the spheres to simulated microgravity using a random positioning machine for 3 days during their differentiation to cardiomyocytes. This process resulted in the production of highly enriched cardiomyocytes (99% purity) with high viability (90%) and expected functional properties, with a 1.5 to 4-fold higher yield of cardiomyocytes from each undifferentiated stem cell as compared with 3D-standard gravity culture. Increased induction, proliferation and viability of cardiac progenitors as well as up-regulation of genes associated with proliferation and survival at the early stage of differentiation were observed in the 3D culture under simulated microgravity. Therefore, a combination of 3D culture and simulated microgravity can be used to efficiently generate highly enriched cardiomyocytes. PMID:27492371

  11. Quantitative Analysis of Vascular Heterogeneity in Breast Lesions Using Contrast-Enhanced 3-D Harmonic and Subharmonic Ultrasound Imaging

    PubMed Central

    Sridharan, Anush; Eisenbrey, John R.; Machado, Priscilla; Ojeda-Fournier, Haydee; Wilkes, Annina; Sevrukov, Alexander; Mattrey, Robert F.; Wallace, Kirk; Chalek, Carl L.; Thomenius, Kai E.; Forsberg, Flemming

    2015-01-01

    Ability to visualize breast lesion vascularity and quantify the vascular heterogeneity using contrast-enhanced 3-D harmonic (HI) and subharmonic (SHI) ultrasound imaging was investigated in a clinical population. Patients (n = 134) identified with breast lesions on mammography were scanned using power Doppler imaging, contrast-enhanced 3-D HI, and 3-D SHI on a modified Logiq 9 scanner (GE Healthcare). A region of interest corresponding to ultrasound contrast agent flow was identified in 4D View (GE Medical Systems) and mapped to raw slice data to generate a map of time-intensity curves for the lesion volume. Time points corresponding to baseline, peak intensity, and washout of ultrasound contrast agent were identified and used to generate and compare vascular heterogeneity plots for malignant and benign lesions. Vascularity was observed with power Doppler imaging in 84 lesions (63 benign and 21 malignant). The 3-D HI showed flow in 8 lesions (5 benign and 3 malignant), whereas 3-D SHI visualized flow in 68 lesions (49 benign and 19 malignant). Analysis of vascular heterogeneity in the 3-D SHI volumes found benign lesions having a significant difference in vascularity between central and peripheral sections (1.71 ± 0.96 vs. 1.13 ± 0.79 dB, p < 0.001, respectively), whereas malignant lesions showed no difference (1.66 ± 1.39 vs. 1.24 ± 1.14 dB, p = 0.24), indicative of more vascular coverage. These preliminary results suggest quantitative evaluation of vascular heterogeneity in breast lesions using contrast-enhanced 3-D SHI is feasible and able to detect variations in vascularity between central and peripheral sections for benign and malignant lesions. PMID:25935933

  12. 3D thoracoscopic ultrasound volume measurement validation in an ex vivo and in vivo porcine model of lung tumours

    NASA Astrophysics Data System (ADS)

    Hornblower, V. D. M.; Yu, E.; Fenster, A.; Battista, J. J.; Malthaner, R. A.

    2007-01-01

    The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial 'tumours' were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the 'tumours' were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the ultrasound images and a manual-radial segmentation technique and these were compared with the known volumes of the agar. In vitro measurements had average accuracy and precision of 4.76% and 1.77%, respectively; in vivo measurements had average accuracy and precision of 8.18% and 1.75%, respectively. The 3D thoracoscopic ultrasound can be used to accurately and reproducibly measure 'tumour' volumes both in vivo and ex vivo.

  13. A fast slam approach to freehand 3-d ultrasound reconstruction for catheter ablation guidance in the left atrium.

    PubMed

    Koolwal, Aditya B; Barbagli, Federico; Carlson, Christopher R; Liang, David H

    2011-12-01

    We present a method for real-time, freehand 3D ultrasound (3D-US) reconstruction of moving anatomy, with specific application towards guiding the catheter ablation procedure in the left atrium. Using an intracardiac echo (ICE) catheter with a pose (position/orientation) sensor mounted to its tip, we continually mosaic 2D-ICE images of a left atrium phantom model to form a 3D-US volume. Our mosaicing strategy employs a probabilistic framework based on simultaneous localization and mapping (SLAM), a technique commonly used in mobile robotics for creating maps of unexplored environments. The measured ICE catheter tip pose provides an initial estimate for compounding 2D-ICE image data into the 3D-US volume. However, we simultaneously consider the overlap-consistency shared between 2D-ICE images and the 3D-US volume, computing a "corrected" tip pose if need be to ensure spatially-consistent reconstruction. This allows us to compensate for anatomic movement and sensor drift that would otherwise cause motion artifacts in the 3D-US volume. Our approach incorporates 2D-ICE data immediately after acquisition, allowing us to continuously update the registration parameters linking sensor coordinates to 3D-US coordinates. This, in turn, enables real-time localization and display of sensorized therapeutic catheters within the 3D-US volume for facilitating procedural guidance.

  14. A fast slam approach to freehand 3-d ultrasound reconstruction for catheter ablation guidance in the left atrium.

    PubMed

    Koolwal, Aditya B; Barbagli, Federico; Carlson, Christopher R; Liang, David H

    2011-12-01

    We present a method for real-time, freehand 3D ultrasound (3D-US) reconstruction of moving anatomy, with specific application towards guiding the catheter ablation procedure in the left atrium. Using an intracardiac echo (ICE) catheter with a pose (position/orientation) sensor mounted to its tip, we continually mosaic 2D-ICE images of a left atrium phantom model to form a 3D-US volume. Our mosaicing strategy employs a probabilistic framework based on simultaneous localization and mapping (SLAM), a technique commonly used in mobile robotics for creating maps of unexplored environments. The measured ICE catheter tip pose provides an initial estimate for compounding 2D-ICE image data into the 3D-US volume. However, we simultaneously consider the overlap-consistency shared between 2D-ICE images and the 3D-US volume, computing a "corrected" tip pose if need be to ensure spatially-consistent reconstruction. This allows us to compensate for anatomic movement and sensor drift that would otherwise cause motion artifacts in the 3D-US volume. Our approach incorporates 2D-ICE data immediately after acquisition, allowing us to continuously update the registration parameters linking sensor coordinates to 3D-US coordinates. This, in turn, enables real-time localization and display of sensorized therapeutic catheters within the 3D-US volume for facilitating procedural guidance. PMID:22014856

  15. Breast Density Analysis with Automated Whole-Breast Ultrasound: Comparison with 3-D Magnetic Resonance Imaging.

    PubMed

    Chen, Jeon-Hor; Lee, Yan-Wei; Chan, Si-Wa; Yeh, Dah-Cherng; Chang, Ruey-Feng

    2016-05-01

    In this study, a semi-automatic breast segmentation method was proposed on the basis of the rib shadow to extract breast regions from 3-D automated whole-breast ultrasound (ABUS) images. The density results were correlated with breast density values acquired with 3-D magnetic resonance imaging (MRI). MRI images of 46 breasts were collected from 23 women without a history of breast disease. Each subject also underwent ABUS. We used Otsu's thresholding method on ABUS images to obtain local rib shadow information, which was combined with the global rib shadow information (extracted from all slice projections) and integrated with the anatomy's breast tissue structure to determine the chest wall line. The fuzzy C-means classifier was used to extract the fibroglandular tissues from the acquired images. Whole-breast volume (WBV) and breast percentage density (BPD) were calculated in both modalities. Linear regression was used to compute the correlation of density results between the two modalities. The consistency of density measurement was also analyzed on the basis of intra- and inter-operator variation. There was a high correlation of density results between MRI and ABUS (R(2) = 0.798 for WBV, R(2) = 0.825 for PBD). The mean WBV from ABUS images was slightly smaller than the mean WBV from MR images (MRI: 342.24 ± 128.08 cm(3), ABUS: 325.47 ± 136.16 cm(3), p < 0.05). In addition, the BPD calculated from MR images was smaller than the BPD from ABUS images (MRI: 24.71 ± 15.16%, ABUS: 28.90 ± 17.73%, p < 0.05). The intra-operator and inter-operator variant analysis results indicated that there was no statistically significant difference in breast density measurement variation between the two modalities. Our results revealed a high correlation in WBV and BPD between MRI and ABUS. Our study suggests that ABUS provides breast density information useful in the assessment of breast health. PMID:26831342

  16. Breast Density Analysis with Automated Whole-Breast Ultrasound: Comparison with 3-D Magnetic Resonance Imaging.

    PubMed

    Chen, Jeon-Hor; Lee, Yan-Wei; Chan, Si-Wa; Yeh, Dah-Cherng; Chang, Ruey-Feng

    2016-05-01

    In this study, a semi-automatic breast segmentation method was proposed on the basis of the rib shadow to extract breast regions from 3-D automated whole-breast ultrasound (ABUS) images. The density results were correlated with breast density values acquired with 3-D magnetic resonance imaging (MRI). MRI images of 46 breasts were collected from 23 women without a history of breast disease. Each subject also underwent ABUS. We used Otsu's thresholding method on ABUS images to obtain local rib shadow information, which was combined with the global rib shadow information (extracted from all slice projections) and integrated with the anatomy's breast tissue structure to determine the chest wall line. The fuzzy C-means classifier was used to extract the fibroglandular tissues from the acquired images. Whole-breast volume (WBV) and breast percentage density (BPD) were calculated in both modalities. Linear regression was used to compute the correlation of density results between the two modalities. The consistency of density measurement was also analyzed on the basis of intra- and inter-operator variation. There was a high correlation of density results between MRI and ABUS (R(2) = 0.798 for WBV, R(2) = 0.825 for PBD). The mean WBV from ABUS images was slightly smaller than the mean WBV from MR images (MRI: 342.24 ± 128.08 cm(3), ABUS: 325.47 ± 136.16 cm(3), p < 0.05). In addition, the BPD calculated from MR images was smaller than the BPD from ABUS images (MRI: 24.71 ± 15.16%, ABUS: 28.90 ± 17.73%, p < 0.05). The intra-operator and inter-operator variant analysis results indicated that there was no statistically significant difference in breast density measurement variation between the two modalities. Our results revealed a high correlation in WBV and BPD between MRI and ABUS. Our study suggests that ABUS provides breast density information useful in the assessment of breast health.

  17. High-resolution 3D ultrasound jawbone surface imaging for diagnosis of periodontal bony defects: an in vitro study.

    PubMed

    Mahmoud, Ahmed M; Ngan, Peter; Crout, Richard; Mukdadi, Osama M

    2010-11-01

    Although medical specialties have recognized the importance of using ultrasonic imaging, dentistry is only beginning to discover its benefit. This has particularly been important in the field of periodontics which studies infections in the gum and bone tissues that surround the teeth. This study investigates the feasibility of using a custom-designed high-frequency ultrasound imaging system to reconstruct high-resolution (< 50 μm) three-dimensional (3D) surface images of periodontal defects in human jawbone. The system employs single-element focused ultrasound transducers with center frequencies ranging from 30 to 60 MHz. Continuous acquisition using a 1 GHz data acquisition card is synchronized with a high-precision two-dimensional (2D) positioning system of ±1 μm resolution for acquiring accurate measurements of the mandible, in vitro. Signal and image processing algorithms are applied to reconstruct high-resolution ultrasound images and extract the jawbone surface in each frame. Then, all edges are combined and smoothed in order to render a 3D surface image of the jawbone. In vitro experiments were performed to assess the system performance using mandibles with teeth (dentate) or without (nondentate). The system was able to reconstruct 3D images for the mandible's outer surface with superior spatial resolution down to 24 μm, and to perform the whole scanning in < 30 s. Major anatomical landmarks on the images were confirmed with the anatomical structures on the mandibles. All the anatomical landmarks were detected and fully described as 3D images using this novel ultrasound imaging technique, whereas the 2D X-ray radiographic images suffered from poor contrast. These results indicate the great potential of utilizing high-resolution ultrasound as a noninvasive, nonionizing imaging technique for the early diagnosis of the more severe form of periodontal disease.

  18. 3D inters-subject cardiac registration using 4D information

    NASA Astrophysics Data System (ADS)

    Lopez, Alfredo; Fritscher, Karl D.; Trieb, Thomas; Schubert, Rainer; Mattes, Julian

    2008-03-01

    In this paper we present a new approach for the registration of cardiac 4D image sequences of different subjects, where we assume that a temporal association between the sequences is given. Moreover, we allow for one (or two) selected pair(s) of associated points in time of both sequences, which we call the bridging points in time, the use of additional information such as the semi-automatic segmentation of the investigated structure. We establish the 3D inter-subject registration for all other pairs of points in time exploiting (1) the inter-subject registration for the bridging pair of points in time, (2) the intra-subject motion calculation in both sequences with respect to the bridging pair, and (3) the concatenation of the obtained transformations. We formulate a cost functional integrating the similarity measures comparing the images of the bridging pair(s) of points in time and of the current pair of points in time, respectively. We evaluated our algorithm on 8 healthy volunteers leading to 28 inter-subject combinations and we analyze the behaviour for different parameter settings weighting differently the involved pairs of points in time. The approach based on the bridging pairs outperforms a direct 3D registration of corresponding points in time, in particular in the right ventricle we gain up to 33% in registration accuracy. Starting with a cost functional taking into account the similarity at the first bridging point in time, the results improve stepwise by integrating, firstly, information from the current pair of points in time and secondly, from a second bridging point in time. Our results also show a steep rise of the importance of regularization on the registration accuracy when registering the current point in time with our procedure (17% gain in accuracy) with respect to a direct registration in the bridging point (less than 1%). However, regularization during intra-sequence registration had only minor effects on the accuracy of our registration

  19. New fabrication techniques for ring-array transducers for real-time 3D intravascular ultrasound.

    PubMed

    Light, Edward D; Lieu, Victor; Smith, Stephen W

    2009-10-01

    We have previously described miniature 2D array transducers integrated into a Cook Medical, Inc. vena cava filter deployment device. While functional, the fabrication technique was very labor intensive and did not lend itself well to efficient fabrication of large numbers of devices. We developed two new fabrication methods that we believe can be used to efficiently manufacture these types of devices in greater than prototype numbers. One transducer consisted of 55 elements operating near 5 MHz. The interelement spacing is 0.20 mm. It was constructed on a flat piece of copper-clad polyimide and then wrapped around an 11 French catheter of a Cook Medical, Inc. inferior vena cava (IVC) filter deployment device. We used a braided wiring technology from Tyco Electronics Corp. to connect the elements to our real-time 3D ultrasound scanner. Typical measured transducer element bandwidth was 20% centered at 4.7 MHz and the 50 Omega round trip insertion loss was --82 dB. The mean of the nearest neighbor cross talk was -37.0 dB. The second method consisted of a 46-cm long single layer flex circuit from MicroConnex that terminates in an interconnect that plugs directly into our system cable. This transducer had 70 elements at 0.157 mm interelement spacing operating at 4.8 MHz. Typical measured transducer element bandwidth was 29% and the 50 Omega round trip insertion loss was -83 dB. The mean of the nearest neighbor cross talk was -33.0 dB. PMID:20458877

  20. Critical assessment of intramodality 3D ultrasound imaging for prostate IGRT compared to fiducial markers

    SciTech Connect

    Meer, Skadi van der; Bloemen-van Gurp, Esther; Hermans, Jolanda; Voncken, Robert; Heuvelmans, Denys; Gubbels, Carol; Fontanarosa, Davide; Visser, Peter; Lutgens, Ludy; Gils, Francis van; Verhaegen, Frank

    2013-07-15

    Purpose: A quantitative 3D intramodality ultrasound (US) imaging system was verified for daily in-room prostate localization, and compared to prostate localization based on implanted fiducial markers (FMs).Methods: Thirteen prostate patients underwent multiple US scans during treatment. A total of 376 US-scans and 817 matches were used to determine the intra- and interoperator variability. Additionally, eight other patients underwent daily prostate localization using both US and electronic portal imaging (EPI) with FMs resulting in 244 combined US-EPI scans. Scanning was performed with minimal probe pressure and a correction for the speed of sound aberration was performed. Uncertainties of both US and FM methods were assessed. User variability of the US method was assessed.Results: The overall US user variability is 2.6 mm. The mean differences between US and FM are: 2.5 {+-} 4.0 mm (LR), 0.6 {+-} 4.9 mm (SI), and -2.3 {+-} 3.6 mm (AP). The intramodality character of this US system mitigates potential errors due to transducer pressure and speed of sound aberrations.Conclusions: The overall accuracy of US (3.0 mm) is comparable to our FM workflow (2.2 mm). Since neither US nor FM can be considered a gold standard no conclusions can be drawn on the superiority of either method. Because US imaging captures the prostate itself instead of surrogates no invasive procedure is required. It requires more effort to standardize US imaging than FM detection. Since US imaging does not involve a radiation burden, US prostate imaging offers an alternative for FM EPI positioning.

  1. 3D perfused brain phantom for interstitial ultrasound thermal therapy and imaging: design, construction and characterization.

    PubMed

    Martínez, José M; Jarosz, Boguslaw J

    2015-03-01

    Thermal therapy has emerged as an independent modality of treating some tumors. In many clinics the hyperthermia, one of the thermal therapy modalities, has been used adjuvant to radio- or chemotherapy to substantially improve the clinical treatment outcomes. In this work, a methodology for building a realistic brain phantom for interstitial ultrasound low dose-rate thermal therapy of the brain is proposed. A 3D brain phantom made of the tissue mimicking material (TMM) had the acoustic and thermal properties in the 20-32 °C range, which is similar to that of a brain at 37 °C. The phantom had 10-11% by mass of bovine gelatin powder dissolved in ethylene glycol. The TMM sonicated at 1 MHz, 1.6 MHz and 2.5 MHz yielded the amplitude attenuation coefficients of 62  ±  1 dB m(-1), 115  ±  4 dB m(-1) and 175  ±  9 dB m(-1), respectively. The density and acoustic speed determination at room temperature (~24 °C) gave 1040  ±  40 kg m(-3) and 1545  ±  44 m s(-1), respectively. The average thermal conductivity was 0.532 W m(-1) K(-1). The T1 and T2 values of the TMM were 207  ±  4 and 36.2  ±  0.4 ms, respectively. We envisage the use of our phantom for treatment planning and for quality assurance in MRI based temperature determination. Our phantom preparation methodology may be readily extended to other thermal therapy technologies.

  2. 3D perfused brain phantom for interstitial ultrasound thermal therapy and imaging: design, construction and characterization

    NASA Astrophysics Data System (ADS)

    Martínez, José M.; Jarosz, Boguslaw J.

    2015-03-01

    Thermal therapy has emerged as an independent modality of treating some tumors. In many clinics the hyperthermia, one of the thermal therapy modalities, has been used adjuvant to radio- or chemotherapy to substantially improve the clinical treatment outcomes. In this work, a methodology for building a realistic brain phantom for interstitial ultrasound low dose-rate thermal therapy of the brain is proposed. A 3D brain phantom made of the tissue mimicking material (TMM) had the acoustic and thermal properties in the 20-32 °C range, which is similar to that of a brain at 37 °C. The phantom had 10-11% by mass of bovine gelatin powder dissolved in ethylene glycol. The TMM sonicated at 1 MHz, 1.6 MHz and 2.5 MHz yielded the amplitude attenuation coefficients of 62  ±  1 dB m-1, 115  ±  4 dB m-1 and 175  ±  9 dB m-1, respectively. The density and acoustic speed determination at room temperature (~24 °C) gave 1040  ±  40 kg m-3 and 1545  ±  44 m s-1, respectively. The average thermal conductivity was 0.532 W m-1 K-1. The T1 and T2 values of the TMM were 207  ±  4 and 36.2  ±  0.4 ms, respectively. We envisage the use of our phantom for treatment planning and for quality assurance in MRI based temperature determination. Our phantom preparation methodology may be readily extended to other thermal therapy technologies.

  3. GPU accelerated registration of a statistical shape model of the lumbar spine to 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Khallaghi, Siavash; Abolmaesumi, Purang; Gong, Ren Hui; Chen, Elvis; Gill, Sean; Boisvert, Jonathan; Pichora, David; Borschneck, Dan; Fichtinger, Gabor; Mousavi, Parvin

    2011-03-01

    We present a parallel implementation of a statistical shape model registration to 3D ultrasound images of the lumbar vertebrae (L2-L4). Covariance Matrix Adaptation Evolution Strategy optimization technique, along with Linear Correlation of Linear Combination similarity metric have been used, to improve the robustness and capture range of the registration approach. Instantiation and ultrasound simulation have been implemented on a graphics processing unit for a faster registration. Phantom studies show a mean target registration error of 3.2 mm, while 80% of all the cases yield target registration error of below 3.5 mm.

  4. Low intensity pulse ultrasound stimulate chondrocytes growth in a 3-D alginate scaffold through improved porosity and permeability.

    PubMed

    Guo, Gepu; Lu, Lu; Ji, Hongfei; Ma, Yong; Dong, Rui; Tu, Juan; Guo, Xiasheng; Qiu, Yuanyuan; Wu, Junru; Zhang, Dong

    2015-04-01

    A 3-D scaffold culture system has been used to promote in producing functional chondrocytes for repairing damaged cartilage. In the present study, the low intensity pulse ultrasound (LIPUS) (P(-)=0, 0.055, 0.085 and 0.11 MPa) was applied to improve the porosity and permeability of a 3-D alginate scaffold which was beneficial for the nutrition supply and metabolism during cell growth in 3-D alginate scaffold. The porosity and permeability of the scaffold was quantitatively analyzed based on scanning electron microscopy examination and fluorescence image observation. The results suggest that, for the scaffold exposed to LIPUS, its porosity and permeability could be significantly enhanced by the increasing LIPUS amplitude, which might be induced by the microstreaming shear stress generated by ultrasound-driven microbubble oscillations. Furthermore, the assessments of cell proliferation and collagen II expression confirmed that chondrocytes growth could be effectively promoted in 3-D alginate scaffolds treated by LIPUS, because of the improved scaffold porosity and permeability might benefit cell growth space and nutrition supply. It should also be noticed that appropriate LIPUS driving parameters should be adapted to achieve optimized chondrocytes culture effect in 3-D alginate scaffold. PMID:25543661

  5. Low intensity pulse ultrasound stimulate chondrocytes growth in a 3-D alginate scaffold through improved porosity and permeability.

    PubMed

    Guo, Gepu; Lu, Lu; Ji, Hongfei; Ma, Yong; Dong, Rui; Tu, Juan; Guo, Xiasheng; Qiu, Yuanyuan; Wu, Junru; Zhang, Dong

    2015-04-01

    A 3-D scaffold culture system has been used to promote in producing functional chondrocytes for repairing damaged cartilage. In the present study, the low intensity pulse ultrasound (LIPUS) (P(-)=0, 0.055, 0.085 and 0.11 MPa) was applied to improve the porosity and permeability of a 3-D alginate scaffold which was beneficial for the nutrition supply and metabolism during cell growth in 3-D alginate scaffold. The porosity and permeability of the scaffold was quantitatively analyzed based on scanning electron microscopy examination and fluorescence image observation. The results suggest that, for the scaffold exposed to LIPUS, its porosity and permeability could be significantly enhanced by the increasing LIPUS amplitude, which might be induced by the microstreaming shear stress generated by ultrasound-driven microbubble oscillations. Furthermore, the assessments of cell proliferation and collagen II expression confirmed that chondrocytes growth could be effectively promoted in 3-D alginate scaffolds treated by LIPUS, because of the improved scaffold porosity and permeability might benefit cell growth space and nutrition supply. It should also be noticed that appropriate LIPUS driving parameters should be adapted to achieve optimized chondrocytes culture effect in 3-D alginate scaffold.

  6. Improving low-dose cardiac CT images using 3D sparse representation based processing

    NASA Astrophysics Data System (ADS)

    Shi, Luyao; Chen, Yang; Luo, Limin

    2015-03-01

    Cardiac computed tomography (CCT) has been widely used in diagnoses of coronary artery diseases due to the continuously improving temporal and spatial resolution. When helical CT with a lower pitch scanning mode is used, the effective radiation dose can be significant when compared to other radiological exams. Many methods have been developed to reduce radiation dose in coronary CT exams including high pitch scans using dual source CT scanners and step-and-shot scanning mode for both single source and dual source CT scanners. Additionally, software methods have also been proposed to reduce noise in the reconstructed CT images and thus offering the opportunity to reduce radiation dose while maintaining the desired diagnostic performance of a certain imaging task. In this paper, we propose that low-dose scans should be considered in order to avoid the harm from accumulating unnecessary X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. Accordingly, in this paper, a 3D dictionary representation based image processing method is proposed to reduce CT image noise. Information on both spatial and temporal structure continuity is utilized in sparse representation to improve the performance of the image processing method. Clinical cases were used to validate the proposed method.

  7. 3D cardiac motion reconstruction from CT data and tagged MRI.

    PubMed

    Wang, Xiaoxu; Mihalef, Viorel; Qian, Zhen; Voros, Szilard; Metaxas, Dimitris

    2012-01-01

    In this paper we present a novel method for left ventricle (LV) endocardium motion reconstruction using high resolution CT data and tagged MRI. High resolution CT data provide anatomic details on the LV endocardial surface, such as the papillary muscle and trabeculae carneae. Tagged MRI provides better time resolution. The combination of these two imaging techniques can give us better understanding on left ventricle motion. The high resolution CT images are segmented with mean shift method and generate the LV endocardium mesh. The meshless deformable model built with high resolution endocardium surface from CT data fit to the tagged MRI of the same phase. 3D deformation of the myocardium is computed with the Lagrangian dynamics and local Laplacian deformation. The segmented inner surface of left ventricle is compared with the heart inner surface picture and show high agreement. The papillary muscles are attached to the inner surface with roots. The free wall of the left ventricle inner surface is covered with trabeculae carneae. The deformation of the heart wall and the papillary muscle in the first half of the cardiac cycle is presented. The motion reconstruction results are very close to the live heart video. PMID:23366825

  8. 3D Cardiac Motion Reconstruction from CT Data and Tagged MRI

    PubMed Central

    Wang, Xiaoxu; Mihalef, Viorel; Qian, Zhen; Voros, Szilard; Metaxas, Dimitris

    2016-01-01

    In this paper we present a novel method for left ventricle (LV) endocardium motion reconstruction using high resolution CT data and tagged MRI. High resolution CT data provide anatomic details on the LV endocardial surface, such as the papillary muscle and trabeculae carneae. Tagged MRI provides better time resolution. The combination of these two imaging techniques can give us better understanding on left ventricle motion. The high resolution CT images are segmented with mean shift method and generate the LV endocardium mesh. The meshless deformable model built with high resolution endocardium surface from CT data fit to the tagged MRI of the same phase. 3D deformation of the myocardium is computed with the Lagrangian dynamics and local Laplacian deformation. The segmented inner surface of left ventricle is compared with the heart inner surface picture and show high agreement. The papillary muscles are attached to the inner surface with roots. The free wall of the left ventricle inner surface is covered with trabeculae carneae. The deformation of the heart wall and the papillary muscle in the first half of the cardiac cycle is presented. The motion reconstruction results are very close to the live heart video. PMID:23366825

  9. FINAL INTERIM REPORT, CANDIDATE SITES, MACHINES IN USE, DATA STORAGE AND TRANSMISSION METHODS: TESTING FEASIBILITY OF 3D ULTRASOUND DATA ACQUISITION AND RELIABILITY OF DATA RETRIEVAL FROM STORED 3D IMAGES

    EPA Science Inventory

    The purpose of this Work Assignment, 02-03, is to examine the feasibility of collecting transmitting, and analyzing 3-D ultrasound data in the context of a multi-center study of pregnant women. The study will also examine the reliability of measurements obtained from 3-D images< ...

  10. Theoretical Analysis of the Accuracy and Safety of MRI-Guided Transurethral 3-D Conformal Ultrasound Prostate Therapy

    NASA Astrophysics Data System (ADS)

    Burtnyk, Mathieu; Chopra, Rajiv; Bronskill, Michael

    2009-04-01

    MRI-guided transurethral ultrasound therapy is a promising new approach for the treatment of localized prostate cancer. Several studies have demonstrated the feasibility of producing large regions of thermal coagulation adequate for prostate therapy; however, the quantitative assessment of shaping these regions to complex 3-D human prostate geometries has not been fully explored. This study used numerical simulations and twenty manually-segmented pelvic anatomical models derived from high-quality MR images of prostate cancer patients to evaluate the treatment accuracy and safety of 3-D conformal MRI-guided transurethral ultrasound therapy. The simulations incorporated a rotating multi-element planar dual-frequency ultrasound transducer (seventeen 4×3 mm elements) operating at 4.7/9.7 MHz and 10 W/cm2 maximum acoustic power. Results using a novel feedback control algorithm which modulated the ultrasound frequency, power and device rate of rotation showed that regions of thermal coagulation could be shaped to predefined prostate volumes within 1.0 mm across the vast majority of these glands. Treatment times were typically 30 min and remained below 60 min for large 60 cc prostates. With a rectal cooling temperature of 15° C, the rectal wall did not exceed 30EM43 in half of the twenty patient models with only a few 1 mm3 voxels above this threshold in the other cases. At 4.7 MHz, heating of the pelvic bone can become significant when it is located less than 10 mm from the prostate. Numerical simulations show that MRI-guided transurethral ultrasound therapy can thermally coagulate whole prostate glands accurately and safely in 3-D.

  11. Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques.

    PubMed

    Parmar, Biren J; Longsine, Whitney; Sabonghy, Eric P; Han, Arum; Tasciotti, Ennio; Weiner, Bradley K; Ferrari, Mauro; Righetti, Raffaella

    2010-08-21

    Ultrasound is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. As of today, however, there is a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This study aims at understanding the performance limitations of new ultrasound techniques for imaging bones in controlled experiments in vitro. Experiments are performed on samples of mammalian and non-mammalian bones with controlled defects with size ranging from 400 microm to 5 mm. Ultrasound findings are statistically compared with those obtained from the same samples using standard x-ray imaging modalities and optical microscopy. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess sub-millimeter bone defects in real time and with high accuracy and precision. These results also demonstrate that ultrasound imaging techniques perform comparably better than x-ray imaging and optical imaging methods, in the assessment of a wide range of controlled defects both in mammalian and non-mammalian bones. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications.

  12. Hypertrophy, gene expression, and beating of neonatal cardiac myocytes are affected by microdomain heterogeneity in 3D

    PubMed Central

    Curtis, Matthew W.; Sharma, Sadhana; Desai, Tejal A.

    2011-01-01

    Cardiac myocytes are known to be influenced by the rigidity and topography of their physical microenvironment. It was hypothesized that 3D heterogeneity introduced by purely physical microdomains regulates cardiac myocyte size and contraction. This was tested in vitro using polymeric microstructures (G′=1.66 GPa) suspended with random orientation in 3D by a soft Matrigel matrix (G′=22.9 Pa). After 10 days of culture, the presence of 100 μm-long microstructures in 3D gels induced fold increases in neonatal rat ventricular myocyte size (1.61±0.06, p<0.01) and total protein/cell ratios (1.43± 0.08, p<0.05) that were comparable to those induced chemically by 50 μM phenylephrine treatment. Upon attachment to microstructures, individual myocytes also had larger cross-sectional areas (1.57±0.05, p<0.01) and higher average rates of spontaneous contraction (2.01±0.08, p<0.01) than unattached myocytes. Furthermore, the inclusion of microstructures in myocyte-seeded gels caused significant increases in the expression of beta-1 adrenergic receptor (β1-AR, 1.19±0.01), cardiac ankyrin repeat protein (CARP, 1.26±0.02), and sarcoplasmic reticulum calcium-ATPase (SERCA2, 1.59±0.12, p<0.05), genes implicated in hypertrophy and contractile activity. Together, the results demonstrate that cardiac myocyte behavior can be controlled through local 3D microdomains alone. This approach of defining physical cues as independent features may help to advance the elemental design considerations for scaffolds in cardiac tissue engineering and therapeutic microdevices. PMID:20668947

  13. Simultaneous bilateral real-time 3-d transcranial ultrasound imaging at 1 MHz through poor acoustic windows.

    PubMed

    Lindsey, Brooks D; Nicoletto, Heather A; Bennett, Ellen R; Laskowitz, Daniel T; Smith, Stephen W

    2013-04-01

    Ultrasound imaging has been proposed as a rapid, portable alternative imaging modality to examine stroke patients in pre-hospital or emergency room settings. However, in performing transcranial ultrasound examinations, 8%-29% of patients in a general population may present with window failure, in which case it is not possible to acquire clinically useful sonographic information through the temporal bone acoustic window. In this work, we describe the technical considerations, design and fabrication of low-frequency (1.2 MHz), large aperture (25.3 mm) sparse matrix array transducers for 3-D imaging in the event of window failure. These transducers are integrated into a system for real-time 3-D bilateral transcranial imaging-the ultrasound brain helmet-and color flow imaging capabilities at 1.2 MHz are directly compared with arrays operating at 1.8 MHz in a flow phantom with attenuation comparable to the in vivo case. Contrast-enhanced imaging allowed visualization of arteries of the Circle of Willis in 5 of 5 subjects and 8 of 10 sides of the head despite probe placement outside of the acoustic window. Results suggest that this type of transducer may allow acquisition of useful images either in individuals with poor windows or outside of the temporal acoustic window in the field.

  14. Development of a 3D patient-specific planning platform for interstitial and transurethral ultrasound thermal therapy

    NASA Astrophysics Data System (ADS)

    Prakash, Punit; Diederich, Chris J.

    2010-03-01

    Interstitial and transurethral catheter-based ultrasound devices are under development for treatment of prostate cancer and BPH, uterine fibroids, liver tumors and other soft tissue disease. Accurate 3D thermal modeling is essential for designing site-specific applicators, exploring treatment delivery strategies, and integration of patient-specific treatment planning of thermal ablations. We are developing a comprehensive 3D modeling and treatment planning platform for ultrasound ablation of tissue using catheter-based applicators. We explored the applicability of assessing thermal effects in tissue using critical temperature, thermal dose and Arrhenius thermal damage thresholds and performed a comparative analysis of dynamic tissue properties critical to accurate modeling. We used the model to assess the feasibility of automatic feedback control with MR thermometry, and demonstrated the utility of the modeling platform for 3D patient-specific treatment planning. We have identified critical temperature, thermal dose and thermal damage thresholds for assessing treatment endpoint. Dynamic changes in tissue attenuation/absorption and perfusion must be included for accurate prediction of temperature profiles and extents of the ablation zone. Lastly, we demonstrated use of the modeling platform for patient-specific treatment planning.

  15. Real-time cardiac synchronization with fixed volume frame rate for reducing physiological instabilities in 3D FMRI.

    PubMed

    Tijssen, Rob H N; Okell, Thomas W; Miller, Karla L

    2011-08-15

    Although 2D echo-planar imaging (EPI) remains the dominant method for functional MRI (FMRI), 3D readouts are receiving more interest as these sequences have favorable signal-to-noise ratio (SNR) and enable imaging at a high isotropic resolution. Spoiled gradient-echo (SPGR) and balanced steady-state free-precession (bSSFP) are rapid sequences that are typically acquired with highly segmented 3D readouts, and thus less sensitive to image distortion and signal dropout. They therefore provide a powerful alternative for FMRI in areas with strong susceptibility offsets, such as deep gray matter structures and the brainstem. Unfortunately, the multi-shot nature of the readout makes these sequences highly sensitive to physiological fluctuations, and large signal instabilities are observed in the inferior regions of the brain. In this work a characterization of the source of these instabilities is given and a new method is presented to reduce the instabilities observed in 3D SPGR and bSSFP. Rapidly acquired single-slice data, which critically sampled the respiratory and cardiac waveforms, showed that cardiac pulsation is the dominant source of the instabilities. Simulations further showed that synchronizing the readout to the cardiac cycle minimizes the instabilities considerably. A real-time synchronization method was therefore developed, which utilizes parallel-imaging techniques to allow cardiac synchronization without alteration of the volume acquisition rate. The implemented method significantly improves the temporal stability in areas that are affected by cardiac-related signal fluctuations. In bSSFP data the tSNR in the brainstem increased by 45%, at the cost of a small reduction in tSNR in the cortical areas. In SPGR the temporal stability is improved by approximately 20% in the subcortical structures and as well as cortical gray matter when synchronization was performed.

  16. A review of state-of-the-art stereology for better quantitative 3D morphology in cardiac research.

    PubMed

    Mühlfeld, Christian; Nyengaard, Jens Randel; Mayhew, Terry M

    2010-01-01

    The aim of stereological methods in biomedical research is to obtain quantitative information about three-dimensional (3D) features of tissues, cells, or organelles from two-dimensional physical or optical sections. With immunogold labeling, stereology can even be used for the quantitative analysis of the distribution of molecules within tissues and cells. Nowadays, a large number of design-based stereological methods offer an efficient quantitative approach to intriguing questions in cardiac research, such as "Is there a significant loss of cardiomyocytes during progression from ventricular hypertrophy to heart failure?" or "Does a specific treatment reduce the degree of fibrosis in the heart?" Nevertheless, the use of stereological methods in cardiac research is rare. The present review article demonstrates how some of the potential pitfalls in quantitative microscopy may be avoided. To this end, we outline the concepts of design-based stereology and illustrate their practical applications to a wide range of biological questions in cardiac research. We hope that the present article will stimulate researchers in cardiac research to incorporate design-based stereology into their study designs, thus promoting an unbiased quantitative 3D microscopy.

  17. 3D engineered cardiac tissue models of human heart disease: learning more from our mice.

    PubMed

    Ralphe, J Carter; de Lange, Willem J

    2013-02-01

    Mouse engineered cardiac tissue constructs (mECTs) are a new tool available to study human forms of genetic heart disease within the laboratory. The cultured strips of cardiac cells generate physiologic calcium transients and twitch force, and respond to electrical pacing and adrenergic stimulation. The mECT can be made using cells from existing mouse models of cardiac disease, providing a robust readout of contractile performance and allowing a rapid assessment of genotype-phenotype correlations and responses to therapies. mECT represents an efficient and economical extension to the existing tools for studying cardiac physiology. Human ECTs generated from iPSCMs represent the next logical step for this technology and offer significant promise of an integrated, fully human, cardiac tissue model.

  18. In vivo validation of a 3D ultrasound system for imaging the lateral ventricles of neonates

    NASA Astrophysics Data System (ADS)

    Kishimoto, J.; Fenster, A.; Chen, N.; Lee, D.; de Ribaupierre, S.

    2014-03-01

    Dilated lateral ventricles in neonates can be due to many different causes, such as brain loss, or congenital malformation; however, the main cause is hydrocephalus, which is the accumulation of fluid within the ventricular system. Hydrocephalus can raise intracranial pressure resulting in secondary brain damage, and up to 25% of patients with severely enlarged ventricles have epilepsy in later life. Ventricle enlargement is clinically monitored using 2D US through the fontanels. The sensitivity of 2D US to dilation is poor because it cannot provide accurate measurements of irregular volumes such as the ventricles, so most clinical evaluations are of a qualitative nature. We developed a 3D US system to image the cerebral ventricles of neonates within the confines of incubators that can be easily translated to more open environments. Ventricle volumes can be segmented from these images giving a quantitative volumetric measurement of ventricle enlargement without moving the patient into an imaging facility. In this paper, we report on in vivo validation studies: 1) comparing 3D US ventricle volumes before and after clinically necessary interventions removing CSF, and 2) comparing 3D US ventricle volumes to those from MRI. Post-intervention ventricle volumes were less than pre-intervention measurements for all patients and all interventions. We found high correlations (R = 0.97) between the difference in ventricle volume and the reported removed CSF with the slope not significantly different than 1 (p < 0.05). Comparisons between ventricle volumes from 3D US and MR images taken 4 (±3.8) days of each other did not show significant difference (p=0.44) between 3D US and MRI through paired t-test.

  19. Tubular structure enhancement for surgical instrument detection in 3D ultrasound.

    PubMed

    Ren, Hongliang; Dupont, Pierre E

    2011-01-01

    Three-dimensional ultrasound has been an effective imaging modality for diagnostics and is now an emerging modality for image-guided minimally-invasive interventions since it enables visualization of both instruments and tissue. Challenges to ultrasound-guided interventions arise, however, due to the low signal-to-noise ratio and the imaging artifacts created by the interventional instruments. Metallic instruments, in particular, are strong scatters and so produce a variety of artifacts. For many interventions, the manual or robotic instrument is comprised of a long curved tubular structure with specialized tooling at its tip. Toward the goal of developing a surgical navigation system, this paper proposes an image processing algorithm for enhancing the tubular structure of imaged instruments while also reducing imaging artifacts. Experiments are presented to evaluate the effectiveness of the approach in the context of robotic instruments whose shape comprises a smooth curve along their length.

  20. A computational model for estimating tumor margins in complementary tactile and 3D ultrasound images

    NASA Astrophysics Data System (ADS)

    Shamsil, Arefin; Escoto, Abelardo; Naish, Michael D.; Patel, Rajni V.

    2016-03-01

    Conventional surgical methods are effective for treating lung tumors; however, they impose high trauma and pain to patients. Minimally invasive surgery is a safer alternative as smaller incisions are required to reach the lung; however, it is challenging due to inadequate intraoperative tumor localization. To address this issue, a mechatronic palpation device was developed that incorporates tactile and ultrasound sensors capable of acquiring surface and cross-sectional images of palpated tissue. Initial work focused on tactile image segmentation and fusion of position-tracked tactile images, resulting in a reconstruction of the palpated surface to compute the spatial locations of underlying tumors. This paper presents a computational model capable of analyzing orthogonally-paired tactile and ultrasound images to compute the surface circumference and depth margins of a tumor. The framework also integrates an error compensation technique and an algebraic model to align all of the image pairs and to estimate the tumor depths within the tracked thickness of a palpated tissue. For validation, an ex vivo experimental study was conducted involving the complete palpation of 11 porcine liver tissues injected with iodine-agar tumors of varying sizes and shapes. The resulting tactile and ultrasound images were then processed using the proposed model to compute the tumor margins and compare them to fluoroscopy based physical measurements. The results show a good negative correlation (r = -0.783, p = 0.004) between the tumor surface margins and a good positive correlation (r = 0.743, p = 0.009) between the tumor depth margins.

  1. SU-E-J-135: An Investigation of Ultrasound Imaging for 3D Intra-Fraction Prostate Motion Estimation

    SciTech Connect

    O'Shea, T; Harris, E; Bamber, J; Evans, P

    2014-06-01

    Purpose: This study investigates the use of a mechanically swept 3D ultrasound (US) probe to estimate intra-fraction motion of the prostate during radiation therapy using an US phantom and simulated transperineal imaging. Methods: A 3D motion platform was used to translate an US speckle phantom while simulating transperineal US imaging. Motion patterns for five representative types of prostate motion, generated from patient data previously acquired with a Calypso system, were using to move the phantom in 3D. The phantom was also implanted with fiducial markers and subsequently tracked using the CyberKnife kV x-ray system for comparison. A normalised cross correlation block matching algorithm was used to track speckle patterns in 3D and 2D US data. Motion estimation results were compared with known phantom translations. Results: Transperineal 3D US could track superior-inferior (axial) and anterior-posterior (lateral) motion to better than 0.8 mm root-mean-square error (RMSE) at a volume rate of 1.7 Hz (comparable with kV x-ray tracking RMSE). Motion estimation accuracy was poorest along the US probe's swept axis (right-left; RL; RMSE < 4.2 mm) but simple regularisation methods could be used to improve RMSE (< 2 mm). 2D US was found to be feasible for slowly varying motion (RMSE < 0.5 mm). 3D US could also allow accurate radiation beam gating with displacement thresholds of 2 mm and 5 mm exhibiting a RMSE of less than 0.5 mm. Conclusion: 2D and 3D US speckle tracking is feasible for prostate motion estimation during radiation delivery. Since RL prostate motion is small in magnitude and frequency, 2D or a hybrid (2D/3D) US imaging approach which also accounts for potential prostate rotations could be used. Regularisation methods could be used to ensure the accuracy of tracking data, making US a feasible approach for gating or tracking in standard or hypo-fractionated prostate treatments.

  2. Computer-generated 3D ultrasound images of the carotid artery

    NASA Technical Reports Server (NTRS)

    Selzer, Robert H.; Lee, Paul L.; Lai, June Y.; Frieden, Howard J.; Blankenhorn, David H.

    1989-01-01

    A method is under development to measure carotid artery lesions from a computer-generated three-dimensional ultrasound image. For each image, the position of the transducer in six coordinates (x, y, z, azimuth, elevation, and roll) is recorded and used to position each B-mode picture element in its proper spatial position in a three-dimensional memory array. After all B-mode images have been assembled in the memory, the three-dimensional image is filtered and resampled to produce a new series of parallel-plane two-dimensional images from which arterial boundaries are determined using edge tracking methods.

  3. Computer-generated 3D ultrasound images of the carotid artery

    NASA Astrophysics Data System (ADS)

    Selzer, Robert H.; Lee, Paul L.; Lai, June Y.; Frieden, Howard J.; Blankenhorn, David H.

    A method is under development to measure carotid artery lesions from a computer-generated three-dimensional ultrasound image. For each image, the position of the transducer in six coordinates (x, y, z, azimuth, elevation, and roll) is recorded and used to position each B-mode picture element in its proper spatial position in a three-dimensional memory array. After all B-mode images have been assembled in the memory, the three-dimensional image is filtered and resampled to produce a new series of parallel-plane two-dimensional images from which arterial boundaries are determined using edge tracking methods.

  4. Minimally Invasive Cardiac Surgery Using a 3D High-Definition Endoscopic System.

    PubMed

    Ruttkay, Tamas; Götte, Julia; Walle, Ulrike; Doll, Nicolas

    2015-01-01

    We describe a minimally invasive heart surgery application of the EinsteinVision 2.0 3D high-definition endoscopic system (Aesculap AG, Tuttlingen, Germany) in an 81-year-old man with severe tricuspid valve insufficiency. Fourteen years ago, he underwent a Ross procedure followed by a DDD pacemaker implantation 4 years later for tachy-brady-syndrome. His biventricular function was normal. We recommended minimally invasive tricuspid valve repair. The application of the aformentioned endoscopic system was simple, and the impressive 3D depth view offered an easy and precise manipulation through a minimal thoracotomy incision, avoiding the need for a rib spreading retractor.

  5. 3D non-rigid registration using surface and local salient features for transrectal ultrasound image-guided prostate biopsy

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofeng; Akbari, Hamed; Halig, Luma; Fei, Baowei

    2011-03-01

    We present a 3D non-rigid registration algorithm for the potential use in combining PET/CT and transrectal ultrasound (TRUS) images for targeted prostate biopsy. Our registration is a hybrid approach that simultaneously optimizes the similarities from point-based registration and volume matching methods. The 3D registration is obtained by minimizing the distances of corresponding points at the surface and within the prostate and by maximizing the overlap ratio of the bladder neck on both images. The hybrid approach not only capture deformation at the prostate surface and internal landmarks but also the deformation at the bladder neck regions. The registration uses a soft assignment and deterministic annealing process. The correspondences are iteratively established in a fuzzy-to-deterministic approach. B-splines are used to generate a smooth non-rigid spatial transformation. In this study, we tested our registration with pre- and postbiopsy TRUS images of the same patients. Registration accuracy is evaluated using manual defined anatomic landmarks, i.e. calcification. The root-mean-squared (RMS) of the difference image between the reference and floating images was decreased by 62.6+/-9.1% after registration. The mean target registration error (TRE) was 0.88+/-0.16 mm, i.e. less than 3 voxels with a voxel size of 0.38×0.38×0.38 mm3 for all five patients. The experimental results demonstrate the robustness and accuracy of the 3D non-rigid registration algorithm.

  6. Focused cardiac ultrasound is feasible in the general practice setting and alters diagnosis and management of cardiac disease

    PubMed Central

    Yates, James; Royse, Colin Forbes; Royse, Carolyn; Royse, Alistair George

    2016-01-01

    Background Ultrasound-assisted examination of the cardiovascular system with focused cardiac ultrasound by the treating physician is non-invasive and changes diagnosis and management of patient’s with suspected cardiac disease. This has not been reported in a general practice setting. Aim To determine whether focused cardiac ultrasound performed on patients aged over 50 years changes the diagnosis and management of cardiac disease by a general practitioner. Design and setting A prospective observational study of 80 patients aged over 50years and who had not received echocardiography or chest CT within 12months presenting to a general practice. Method Clinical assessment and management of significant cardiac disorders in patients presenting to general practitioners were recorded before and after focused cardiac ultrasound. Echocardiography was performed by a medical student with sufficient training, which was verified by an expert. Differences in diagnosis and management between conventional and ultrasound-assisted assessment were recorded. Results and conclusion Echocardiography and interpretation were acceptable in all patients. Significant cardiac disease was detected in 16 (20%) patients, including aortic stenosis in 9 (11%) and cardiac failure in 7 (9%), which were missed by clinical examination in 10 (62.5%) of these patients. Changes in management occurred in 12 patients (15% overall and 75% of those found to have significant cardiac disease) including referral for diagnostic echocardiography in 8 (10%), commencement of heart failure treatment in 3 (4%) and referral to a cardiologist in 1 patient (1%). Routine focused cardiac ultrasound is feasible and frequently alters the diagnosis and management of cardiac disease in patients aged over 50years presenting to a general practice. PMID:27457967

  7. Using High Frequency Focused Water-Coupled Ultrasound for 3-D Surface Depression Profiling

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    1999-01-01

    Surface topography is an important variable in the performance of many industrial components and is normally measured with diamond-tip profilometry over a small area or using optical scattering methods for larger area measurement. A prior study was performed demonstrating that focused air-coupled ultrasound at 1 MHz was capable of profiling surfaces with 25 micron depth resolution and 400 micron lateral resolution over a 1.4 mm depth range. In this article, the question of whether higher-frequency focused water-coupled ultrasound can improve on these specifications is addressed. 10 and 25 MHz focused ultrasonic transducers were employed in the water-coupled mode. Time-of-flight images of the sample surface were acquired and converted to depth / surface profile images using the simple relation (d = V*t/2) between distance (d), time-of-flight (t), and the velocity of sound in water (V). Results are compared for the two frequencies used and with those from the 1 MHz air-coupled configuration.

  8. Analyzing Remodeling of Cardiac Tissue: A Comprehensive Approach Based on Confocal Microscopy and 3D Reconstructions.

    PubMed

    Seidel, Thomas; Edelmann, J-C; Sachse, Frank B

    2016-05-01

    Microstructural characterization of cardiac tissue and its remodeling in disease is a crucial step in many basic research projects. We present a comprehensive approach for three-dimensional characterization of cardiac tissue at the submicrometer scale. We developed a compression-free mounting method as well as labeling and imaging protocols that facilitate acquisition of three-dimensional image stacks with scanning confocal microscopy. We evaluated the approach with normal and infarcted ventricular tissue. We used the acquired image stacks for segmentation, quantitative analysis and visualization of important tissue components. In contrast to conventional mounting, compression-free mounting preserved cell shapes, capillary lumens and extracellular laminas. Furthermore, the new approach and imaging protocols resulted in high signal-to-noise ratios at depths up to 60 µm. This allowed extensive analyzes revealing major differences in volume fractions and distribution of cardiomyocytes, blood vessels, fibroblasts, myofibroblasts and extracellular space in control vs. infarct border zone. Our results show that the developed approach yields comprehensive data on microstructure of cardiac tissue and its remodeling in disease. In contrast to other approaches, it allows quantitative assessment of all major tissue components. Furthermore, we suggest that the approach will provide important data for physiological models of cardiac tissue at the submicrometer scale. PMID:26399990

  9. "Hyper-response" evaluated by 3D echocardiography after cardiac resynchronization therapy.

    PubMed

    Hotta, Viviane Tiemi; Vieira, Marcelo Luiz Campos; Rassi, Daniela do Carmo; Nishioka, Silvana Angelina D'orio; Martinelli Filho, Martino; Mathias, Wilson

    2011-06-01

    Cardiac resynchronization therapy consists of a promising treatment for patients with severe heart failure, but about 30% of patients do not exhibit clinical improvement with this procedure. However, approximately 10% of patients undergoing this therapy may have hyperresponsiveness, and three-dimensional echocardiography can provide an interesting option for the selection and evaluation of such patients. PMID:21789343

  10. Analyzing Remodeling of Cardiac Tissue: A Comprehensive Approach Based on Confocal Microscopy and 3D Reconstructions.

    PubMed

    Seidel, Thomas; Edelmann, J-C; Sachse, Frank B

    2016-05-01

    Microstructural characterization of cardiac tissue and its remodeling in disease is a crucial step in many basic research projects. We present a comprehensive approach for three-dimensional characterization of cardiac tissue at the submicrometer scale. We developed a compression-free mounting method as well as labeling and imaging protocols that facilitate acquisition of three-dimensional image stacks with scanning confocal microscopy. We evaluated the approach with normal and infarcted ventricular tissue. We used the acquired image stacks for segmentation, quantitative analysis and visualization of important tissue components. In contrast to conventional mounting, compression-free mounting preserved cell shapes, capillary lumens and extracellular laminas. Furthermore, the new approach and imaging protocols resulted in high signal-to-noise ratios at depths up to 60 µm. This allowed extensive analyzes revealing major differences in volume fractions and distribution of cardiomyocytes, blood vessels, fibroblasts, myofibroblasts and extracellular space in control vs. infarct border zone. Our results show that the developed approach yields comprehensive data on microstructure of cardiac tissue and its remodeling in disease. In contrast to other approaches, it allows quantitative assessment of all major tissue components. Furthermore, we suggest that the approach will provide important data for physiological models of cardiac tissue at the submicrometer scale.

  11. Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization

    SciTech Connect

    Mory, Cyril; Auvray, Vincent; Zhang, Bo; Grass, Michael; Schäfer, Dirk; Chen, S. James; Carroll, John D.; Rit, Simon; Peyrin, Françoise; Douek, Philippe; Boussel, Loïc

    2014-02-15

    Purpose: Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patient's electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition. Methods: The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization. Results: 4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patient's left ventricular ejection fraction. Conclusions: 4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.

  12. Statistically-driven 3D fiber reconstruction and denoising from multi-slice cardiac DTI using a Markov random field model.

    PubMed

    Lekadir, Karim; Lange, Matthias; Zimmer, Veronika A; Hoogendoorn, Corné; Frangi, Alejandro F

    2016-01-01

    The construction of subject-specific dense and realistic 3D meshes of the myocardial fibers is an important pre-requisite for the simulation of cardiac electrophysiology and mechanics. Current diffusion tensor imaging (DTI) techniques, however, provide only a sparse sampling of the 3D cardiac anatomy based on a limited number of 2D image slices. Moreover, heart motion affects the diffusion measurements, thus resulting in a significant amount of noisy fibers. This paper presents a Markov random field (MRF) approach for dense reconstruction of 3D cardiac fiber orientations from sparse DTI 2D slices. In the proposed MRF model, statistical constraints are used to relate the missing and the known fibers, while a consistency term is encoded to ensure that the obtained 3D meshes are locally continuous. The validation of the method using both synthetic and real DTI datasets demonstrates robust fiber reconstruction and denoising, as well as physiologically meaningful estimations of cardiac electrical activation.

  13. Automatic short axis orientation of the left ventricle in 3D ultrasound recordings

    NASA Astrophysics Data System (ADS)

    Pedrosa, João.; Heyde, Brecht; Heeren, Laurens; Engvall, Jan; Zamorano, Jose; Papachristidis, Alexandros; Edvardsen, Thor; Claus, Piet; D'hooge, Jan

    2016-04-01

    The recent advent of three-dimensional echocardiography has led to an increased interest from the scientific community in left ventricle segmentation frameworks for cardiac volume and function assessment. An automatic orientation of the segmented left ventricular mesh is an important step to obtain a point-to-point correspondence between the mesh and the cardiac anatomy. Furthermore, this would allow for an automatic division of the left ventricle into the standard 17 segments and, thus, fully automatic per-segment analysis, e.g. regional strain assessment. In this work, a method for fully automatic short axis orientation of the segmented left ventricle is presented. The proposed framework aims at detecting the inferior right ventricular insertion point. 211 three-dimensional echocardiographic images were used to validate this framework by comparison to manual annotation of the inferior right ventricular insertion point. A mean unsigned error of 8, 05° +/- 18, 50° was found, whereas the mean signed error was 1, 09°. Large deviations between the manual and automatic annotations (> 30°) only occurred in 3, 79% of cases. The average computation time was 666ms in a non-optimized MATLAB environment, which potentiates real-time application. In conclusion, a successful automatic real-time method for orientation of the segmented left ventricle is proposed.

  14. High-speed dynamic 3D photoacoustic imaging of sentinel lymph node in a murine model using an ultrasound array.

    PubMed

    Song, Liang; Kim, Chulhong; Maslov, Konstantin; Shung, K Kirk; Wang, Lihong V

    2009-08-01

    Noninvasive photoacoustic sentinel lymph node (SLN) mapping with high spatial resolution has the potential to improve the false negative rate and eliminate the use of radioactive tracers in SLN identification. In addition, the demonstrated high spatial resolution may enable physicians to replace SLN biopsy with fine needle aspiration biopsy, and thus reduce the risk of associated morbidity. The primary goal of this study is to demonstrate the feasibility of high-speed 3D photoacoustic imaging of the uptake and clearance dynamics of Evans blue dye in SLNs. The photoacoustic imaging system was developed with a 30 MHz ultrasound array and a kHz repetition rate laser system. It acquires one 3D photoacoustic image of 166 B-scan frames in 1 s, with axial, lateral, and elevational resolutions of 25, 70, and 200 microm, respectively. With optic-fiber based light delivery, the entire system is compact and is convenient to use. Upon injection of Evans blue, a blue dye currently used in clinical SLN biopsy, SLNs in mice and rats were accurately and noninvasively mapped in vivo using our imaging system. In our experiments, the SLNs were found to be located at approximately 0.65 mm below the skin surface in mice and approximately 1.2 mm in rats. In some cases, lymph vessels and lymphatic valves were also imaged. The dye dynamics--accumulation and clearance--in SLNs were quantitatively monitored by sequential 3D imaging with temporal resolution of as high as approximately 6 s. The demonstrated capability suggests that high-speed 3D photoacoustic imaging should facilitate the understanding of the dynamics of various dyes in SLNs and potentially help identify SLNs with high accuracy. PMID:19746805

  15. Development of 3D ultrasound needle guidance for high-dose-rate interstitial brachytherapy of gynaecological cancers

    NASA Astrophysics Data System (ADS)

    Rodgers, J.; Tessier, D.; D'Souza, D.; Leung, E.; Hajdok, G.; Fenster, A.

    2016-04-01

    High-dose-rate (HDR) interstitial brachytherapy is often included in standard-of-care for gynaecological cancers. Needles are currently inserted through a perineal template without any standard real-time imaging modality to assist needle guidance, causing physicians to rely on pre-operative imaging, clinical examination, and experience. While two-dimensional (2D) ultrasound (US) is sometimes used for real-time guidance, visualization of needle placement and depth is difficult and subject to variability and inaccuracy in 2D images. The close proximity to critical organs, in particular the rectum and bladder, can lead to serious complications. We have developed a three-dimensional (3D) transrectal US system and are investigating its use for intra-operative visualization of needle positions used in HDR gynaecological brachytherapy. As a proof-of-concept, four patients were imaged with post-insertion 3D US and x-ray CT. Using software developed in our laboratory, manual rigid registration of the two modalities was performed based on the perineal template's vaginal cylinder. The needle tip and a second point along the needle path were identified for each needle visible in US. The difference between modalities in the needle trajectory and needle tip position was calculated for each identified needle. For the 60 needles placed, the mean trajectory difference was 3.23 +/- 1.65° across the 53 visible needle paths and the mean difference in needle tip position was 3.89 +/- 1.92 mm across the 48 visible needles tips. Based on the preliminary results, 3D transrectal US shows potential for the development of a 3D US-based needle guidance system for interstitial gynaecological brachytherapy.

  16. Context indexing of digital cardiac ultrasound records in PACS

    NASA Astrophysics Data System (ADS)

    Lobodzinski, S. Suave; Meszaros, Georg N.

    1998-07-01

    Recent wide adoption of the DICOM 3.0 standard by ultrasound equipment vendors created a need for practical clinical implementations of cardiac imaging study visualization, management and archiving, DICOM 3.0 defines only a logical and physical format for exchanging image data (still images, video, patient and study demographics). All DICOM compliant imaging studies must presently be archived on a 650 Mb recordable compact disk. This is a severe limitation for ultrasound applications where studies of 3 to 10 minutes long are a common practice. In addition, DICOM digital echocardiography objects require physiological signal indexing, content segmentation and characterization. Since DICOM 3.0 is an interchange standard only, it does not define how to database composite video objects. The goal of this research was therefore to address the issues of efficient storage, retrieval and management of DICOM compliant cardiac video studies in a distributed PACS environment. Our Web based implementation has the advantage of accommodating both DICOM defined entity-relation modules (equipment data, patient data, video format, etc.) in standard relational database tables and digital indexed video with its attributes in an object relational database. Object relational data model facilitates content indexing of full motion cardiac imaging studies through bi-directional hyperlink generation that tie searchable video attributes and related objects to individual video frames in the temporal domain. Benefits realized from use of bi-directionally hyperlinked data models in an object relational database include: (1) real time video indexing during image acquisition, (2) random access and frame accurate instant playback of previously recorded full motion imaging data, and (3) time savings from faster and more accurate access to data through multiple navigation mechanisms such as multidimensional queries on an index, queries on a hyperlink attribute, free search and browsing.

  17. Analysis of cardiac development in the turtle Emys orbicularis (Testudines: Emidydae) using 3-D computer modeling from histological sections.

    PubMed

    Bertens, Laura M F; Richardson, M K; Verbeek, F J

    2010-07-01

    In this article we present a 3-D modeling study of cardiac development in the European pond turtle, Emys orbicularis (of the reptilian order Testudines). The study is aimed at elucidating the embryonic development of the horizontal septum in the ventricle and underscoring the importance of 3-D reconstructions in studying morphogenesis. Turtles possess one common ventricle, partly divided into three cava by a vertical and a horizontal septum, of which the embryonic origins have so far not been described. We used serial sectioning and computerized high-resolution 3-D reconstructions of different developmental stages to create a chronological overview of cardiogenesis, in order to study this process. This has yielded a new understanding of the development of the horizontal septum and (directly related) the looping of the heart tube. This looping is found to be markedly different from that in the human heart, with the turtle having two clear bends in the part of the heart tube leaving the primitive ventricle, as opposed to one in humans. It is this particular looping that is responsible for the formation of the horizontal septum. In addition to our findings on the ventricular septation this study has also yielded new insights into the developmental origins of the pulmonary vein. The 3-D reconstructions were built using our platform TDR-3-D base and enabled us to study the developmental processes in specific parts of the turtle heart separately and in three dimensions, over time. The complete 3-D reconstructions have been made available to the reader via internet using our 3-D model browser application, which allows interactive viewing of the models. The browser application can be found on bio-imaging.liacs.nl/galleries/emysorbicularis/TurtleGallery.html, along with additional images of both models and histological sections and animation sequences of the models. By allowing the reader to view the material in such an interactive way, we hope to make optimal use of the

  18. Free-breathing 3D cardiac MRI using iterative image-based respiratory motion correction.

    PubMed

    Moghari, Mehdi H; Roujol, Sébastien; Chan, Raymond H; Hong, Susie N; Bello, Natalie; Henningsson, Markus; Ngo, Long H; Goddu, Beth; Goepfert, Lois; Kissinger, Kraig V; Manning, Warren J; Nezafat, Reza

    2013-10-01

    Respiratory motion compensation using diaphragmatic navigator gating with a 5 mm gating window is conventionally used for free-breathing cardiac MRI. Because of the narrow gating window, scan efficiency is low resulting in long scan times, especially for patients with irregular breathing patterns. In this work, a new retrospective motion compensation algorithm is presented to reduce the scan time for free-breathing cardiac MRI that increasing the gating window to 15 mm without compromising image quality. The proposed algorithm iteratively corrects for respiratory-induced cardiac motion by optimizing the sharpness of the heart. To evaluate this technique, two coronary MRI datasets with 1.3 mm(3) resolution were acquired from 11 healthy subjects (seven females, 25 ± 9 years); one using a navigator with a 5 mm gating window acquired in 12.0 ± 2.0 min and one with a 15 mm gating window acquired in 7.1 ± 1.0 min. The images acquired with a 15 mm gating window were corrected using the proposed algorithm and compared to the uncorrected images acquired with the 5 and 15 mm gating windows. The image quality score, sharpness, and length of the three major coronary arteries were equivalent between the corrected images and the images acquired with a 5 mm gating window (P-value > 0.05), while the scan time was reduced by a factor of 1.7. PMID:23132549

  19. LBM-EP: Lattice-Boltzmann method for fast cardiac electrophysiology simulation from 3D images.

    PubMed

    Rapaka, S; Mansi, T; Georgescu, B; Pop, M; Wright, G A; Kamen, A; Comaniciu, Dorin

    2012-01-01

    Current treatments of heart rhythm troubles require careful planning and guidance for optimal outcomes. Computational models of cardiac electrophysiology are being proposed for therapy planning but current approaches are either too simplified or too computationally intensive for patient-specific simulations in clinical practice. This paper presents a novel approach, LBM-EP, to solve any type of mono-domain cardiac electrophysiology models at near real-time that is especially tailored for patient-specific simulations. The domain is discretized on a Cartesian grid with a level-set representation of patient's heart geometry, previously estimated from images automatically. The cell model is calculated node-wise, while the transmembrane potential is diffused using Lattice-Boltzmann method within the domain defined by the level-set. Experiments on synthetic cases, on a data set from CESC'10 and on one patient with myocardium scar showed that LBM-EP provides results comparable to an FEM implementation, while being 10 - 45 times faster. Fast, accurate, scalable and requiring no specific meshing, LBM-EP paves the way to efficient and detailed models of cardiac electrophysiology for therapy planning. PMID:23286029

  20. Development of a 3D ultrasound system to investigate post-hemorrhagic hydrocephalus in pre-term neonates

    NASA Astrophysics Data System (ADS)

    Kishimoto, J.; Lee, D.; St. Lawrence, K.; Romano, W.; Fenster, A.; de Ribaupierre, S.

    2013-03-01

    Clinical intracranial ultrasound (US) is performed as a standard of care on neonates at risk of intraventricular hemorrhaging (IVH) and is also used after a diagnosis to monitor for potential ventricular dilation. However, it is difficult to estimate the volume of ventricles with 2D US due to their irregular shape. We developed a 3D US system to be used as an adjunct to a clinical system to investigate volumetric changes in the ventricles of neonates with IVH. Our system has been found have an error of within 1% of actual distance measurements in all three directions and volume measurements of manually segmented volumes from phantoms were not statistically significantly different from the actual values (p>0.3). Interobserver volume measurements of the lateral ventricles in a patient with grade III IVH found no significant differences between measurements. There is the potential to use this system in IVH patients to monitor the progression of ventriculomegaly over time.

  1. Multi-atlas-based automatic 3D segmentation for prostate brachytherapy in transrectal ultrasound images

    NASA Astrophysics Data System (ADS)

    Nouranian, Saman; Mahdavi, S. Sara; Spadinger, Ingrid; Morris, William J.; Salcudean, S. E.; Abolmaesumi, P.

    2013-03-01

    One of the commonly used treatment methods for early-stage prostate cancer is brachytherapy. The standard of care for planning this procedure is segmentation of contours from transrectal ultrasound (TRUS) images, which closely follow the prostate boundary. This process is currently performed either manually or using semi-automatic techniques. This paper introduces a fully automatic segmentation algorithm which uses a priori knowledge of contours in a reference data set of TRUS volumes. A non-parametric deformable registration method is employed to transform the atlas prostate contours to a target image coordinates. All atlas images are sorted based on their registration results and the highest ranked registration results are selected for decision fusion. A Simultaneous Truth and Performance Level Estimation algorithm is utilized to fuse labels from registered atlases and produce a segmented target volume. In this experiment, 50 patient TRUS volumes are obtained and a leave-one-out study on TRUS volumes is reported. We also compare our results with a state-of-the-art semi-automatic prostate segmentation method that has been clinically used for planning prostate brachytherapy procedures and we show comparable accuracy and precision within clinically acceptable runtime.

  2. 3D optical imagery for motion compensation in a limb ultrasound system

    NASA Astrophysics Data System (ADS)

    Ranger, Bryan J.; Feigin, Micha; Zhang, Xiang; Mireault, Al; Raskar, Ramesh; Herr, Hugh M.; Anthony, Brian W.

    2016-04-01

    Conventional processes for prosthetic socket fabrication are heavily subjective, often resulting in an interface to the human body that is neither comfortable nor completely functional. With nearly 100% of amputees reporting that they experience discomfort with the wearing of their prosthetic limb, designing an effective interface to the body can significantly affect quality of life and future health outcomes. Active research in medical imaging and biomechanical tissue modeling of residual limbs has led to significant advances in computer aided prosthetic socket design, demonstrating an interest in moving toward more quantifiable processes that are still patient-specific. In our work, medical ultrasonography is being pursued to acquire data that may quantify and improve the design process and fabrication of prosthetic sockets while greatly reducing cost compared to an MRI-based framework. This paper presents a prototype limb imaging system that uses a medical ultrasound probe, mounted to a mechanical positioning system and submerged in a water bath. The limb imaging is combined with three-dimensional optical imaging for motion compensation. Images are collected circumferentially around the limb and combined into cross-sectional axial image slices, resulting in a compound image that shows tissue distributions and anatomical boundaries similar to magnetic resonance imaging. In this paper we provide a progress update on our system development, along with preliminary results as we move toward full volumetric imaging of residual limbs for prosthetic socket design. This demonstrates a novel multi-modal approach to residual limb imaging.

  3. A Longitudinal Study of Remodeling in a Revised Peripheral Artery Bypass Graft Using 3D Ultrasound Imaging and Computational Hemodynamics

    PubMed Central

    Leotta, Daniel F.; Beach, Kirk W.; Riley, James J.; Aliseda, Alberto

    2011-01-01

    We report a study of the role of hemodynamic shear stress in the remodeling and failure of a peripheral artery bypass graft. Three separate scans of a femoral to popliteal above-knee bypass graft were taken over the course of a 16 month period following a revision of the graft. The morphology of the lumen is reconstructed from data obtained by a custom 3D ultrasound system. Numerical simulations are performed with the patient-specific geometries and physiologically realistic flow rates. The ultrasound reconstructions reveal two significant areas of remodeling: a stenosis with over 85% reduction in area, which ultimately caused graft failure, and a poststenotic dilatation or widening of the lumen. Likewise, the simulations reveal a complicated hemodynamic environment within the graft. Preliminary comparisons with in vivo velocimetry also showed qualitative agreement with the flow dynamics observed in the simulations. Two distinct flow features are discerned and are hypothesized to directly initiate the observed in vivo remodeling. First, a flow separation occurs at the stenosis. A low shear recirculation region subsequently develops distal to the stenosis. The low shear region is thought to be conducive to smooth muscle cell proliferation and intimal growth. A poststenotic jet issues from the stenosis and subsequently impinges onto the lumen wall. The lumen dilation is thought to be a direct result of the high shear stress and high frequency pressure fluctuations associated with the jet impingement. PMID:21428682

  4. Noninvasive quantification of in vitro osteoblastic differentiation in 3D engineered tissue constructs using spectral ultrasound imaging.

    PubMed

    Gudur, Madhu Sudhan Reddy; Rao, Rameshwar R; Peterson, Alexis W; Caldwell, David J; Stegemann, Jan P; Deng, Cheri X

    2014-01-01

    Non-destructive monitoring of engineered tissues is needed for translation of these products from the lab to the clinic. In this study, non-invasive, high resolution spectral ultrasound imaging (SUSI) was used to monitor the differentiation of MC3T3 pre-osteoblasts seeded within collagen hydrogels. SUSI was used to measure the diameter, concentration and acoustic attenuation of scatterers within such constructs cultured in either control or osteogenic medium over 21 days. Conventional biochemical assays were used on parallel samples to determine DNA content and calcium deposition. Construct volume and morphology were accurately imaged using ultrasound. Cell diameter was estimated to be approximately 12.5-15.5 µm using SUSI, which corresponded well to measurements of fluorescently stained cells. The total number of cells per construct assessed by quantitation of DNA content decreased from 5.6±2.4×10(4) at day 1 to 0.9±0.2×10(4) at day 21. SUSI estimation of the equivalent number of acoustic scatters showed a similar decreasing trend, except at day 21 in the osteogenic samples, which showed a marked increase in both scatterer number and acoustic impedance, suggestive of mineral deposition by the differentiating MC3T3 cells. Estimation of calcium content by SUSI was 41.7±11.4 µg/ml, which agreed well with the biochemical measurement of 38.7±16.7 µg/ml. Color coded maps of parameter values were overlaid on B-mode images to show spatiotemporal changes in cell diameter and calcium deposition. This study demonstrates the use of non-destructive ultrasound imaging to provide quantitative information on the number and differentiated state of cells embedded within 3D engineered constructs, and therefore presents a valuable tool for longitudinal monitoring of engineered tissue development.

  5. The Ultrasound Brain Helmet: New Transducers and Volume Registration for In Vivo Simultaneous Multi-Transducer 3-D Transcranial Imaging

    PubMed Central

    Lindsey, Brooks D.; Light, Edward D.; Nicoletto, Heather A.; Bennett, Ellen R.; Laskowitz, Daniel T.; Smith, Stephen W.

    2012-01-01

    Because stroke remains an important and time-sensitive health concern in developed nations, we present a system capable of fusing 3-D transcranial ultrasound volumes acquired from two sides of the head. This system uses custom sparse array transducers built on flexible multilayer circuits that can be positioned for simultaneous imaging through both temporal acoustic windows, allowing for potential registration of multiple real-time 3-D scans of cerebral vasculature. We examine hardware considerations for new matrix arrays—transducer design and interconnects—in this application. Specifically, it is proposed that SNR may be increased by reducing the length of probe cables. This claim is evaluated as part of the presented system through simulation, experimental data, and in vivo imaging. Ultimately, gains in SNR of 7 dB are realized by replacing a standard probe cable with a much shorter flex interconnect; higher gains may be possible using ribbon-based probe cables. In vivo images are presented, showing cerebral arteries with and without the use of microbubble contrast agent; they have been registered and fused using a simple algorithm which maximizes normalized cross-correlation. PMID:21693401

  6. Accurate quantification of local changes for carotid arteries in 3D ultrasound images using convex optimization-based deformable registration

    NASA Astrophysics Data System (ADS)

    Cheng, Jieyu; Qiu, Wu; Yuan, Jing; Fenster, Aaron; Chiu, Bernard

    2016-03-01

    Registration of longitudinally acquired 3D ultrasound (US) images plays an important role in monitoring and quantifying progression/regression of carotid atherosclerosis. We introduce an image-based non-rigid registration algorithm to align the baseline 3D carotid US with longitudinal images acquired over several follow-up time points. This algorithm minimizes the sum of absolute intensity differences (SAD) under a variational optical-flow perspective within a multi-scale optimization framework to capture local and global deformations. Outer wall and lumen were segmented manually on each image, and the performance of the registration algorithm was quantified by Dice similarity coefficient (DSC) and mean absolute distance (MAD) of the outer wall and lumen surfaces after registration. In this study, images for 5 subjects were registered initially by rigid registration, followed by the proposed algorithm. Mean DSC generated by the proposed algorithm was 79:3+/-3:8% for lumen and 85:9+/-4:0% for outer wall, compared to 73:9+/-3:4% and 84:7+/-3:2% generated by rigid registration. Mean MAD of 0:46+/-0:08mm and 0:52+/-0:13mm were generated for lumen and outer wall respectively by the proposed algorithm, compared to 0:55+/-0:08mm and 0:54+/-0:11mm generated by rigid registration. The mean registration time of our method per image pair was 143+/-23s.

  7. Quantitative 3-d diagnostic ultrasound imaging using a modified transducer array and an automated image tracking technique.

    PubMed

    Hossack, John A; Sumanaweera, Thilaka S; Napel, Sandy; Ha, Jun S

    2002-08-01

    An approach for acquiring dimensionally accurate three-dimensional (3-D) ultrasound data from multiple 2-D image planes is presented. This is based on the use of a modified linear-phased array comprising a central imaging array that acquires multiple, essentially parallel, 2-D slices as the transducer is translated over the tissue of interest. Small, perpendicularly oriented, tracking arrays are integrally mounted on each end of the imaging transducer. As the transducer is translated in an elevational direction with respect to the central imaging array, the images obtained by the tracking arrays remain largely coplanar. The motion between successive tracking images is determined using a minimum sum of absolute difference (MSAD) image matching technique with subpixel matching resolution. An initial phantom scanning-based test of a prototype 8 MHz array indicates that linear dimensional accuracy of 4.6% (2 sigma) is achievable. This result compares favorably with those obtained using an assumed average velocity [31.5% (2 sigma) accuracy] and using an approach based on measuring image-to-image decorrelation [8.4% (2 sigma) accuracy]. The prototype array and imaging system were also tested in a clinical environment, and early results suggest that the approach has the potential to enable a low cost, rapid, screening method for detecting carotid artery stenosis. The average time for performing a screening test for carotid stenosis was reduced from an average of 45 minutes using 2-D duplex Doppler to 12 minutes using the new 3-D scanning approach.

  8. Mapping and characterizing endometrial implants by registering 2D transvaginal ultrasound to 3D pelvic magnetic resonance images.

    PubMed

    Yavariabdi, Amir; Bartoli, Adrien; Samir, Chafik; Artigues, Maxime; Canis, Michel

    2015-10-01

    We propose a new deformable slice-to-volume registration method to register a 2D Transvaginal Ultrasound (TVUS) to a 3D Magnetic Resonance (MR) volume. Our main goal is to find a cross-section of the MR volume such that the endometrial implants and their depth of infiltration can be mapped from TVUS to MR. The proposed TVUS-MR registration method uses contour to surface correspondences through a novel variational one-step deformable Iterative Closest Point (ICP) method. Specifically, we find a smooth deformation field while establishing point correspondences automatically. We demonstrate the accuracy of the proposed method by quantitative and qualitative tests on both semi-synthetic and clinical data. To generate semi-synthetic data sets, 3D surfaces are deformed with 4-40% degrees of deformation and then various intersection curves are obtained at 0-20° cutting angles. Results show an average mean square error of 5.7934±0.4615mm, average Hausdorff distance of 2.493±0.14mm, and average Dice similarity coefficient of 0.9750±0.0030.

  9. Semi-automatic assessment of pediatric hydronephrosis severity in 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Cerrolaza, Juan J.; Otero, Hansel; Yao, Peter; Biggs, Elijah; Mansoor, Awais; Ardon, Roberto; Jago, James; Peters, Craig A.; Linguraru, Marius George

    2016-03-01

    Hydronephrosis is the most common abnormal finding in pediatric urology. Thanks to its non-ionizing nature, ultrasound (US) imaging is the preferred diagnostic modality for the evaluation of the kidney and the urinary track. However, due to the lack of correlation of US with renal function, further invasive and/or ionizing studies might be required (e.g., diuretic renograms). This paper presents a computer-aided diagnosis (CAD) tool for the accurate and objective assessment of pediatric hydronephrosis based on morphological analysis of kidney from 3DUS scans. The integration of specific segmentation tools in the system, allows to delineate the relevant renal structures from 3DUS scans of the patients with minimal user interaction, and the automatic computation of 90 anatomical features. Using the washout half time (T1/2) as indicative of renal obstruction, an optimal subset of predictive features is selected to differentiate, with maximum sensitivity, those severe cases where further attention is required (e.g., in the form of diuretic renograms), from the noncritical ones. The performance of this new 3DUS-based CAD system is studied for two clinically relevant T1/2 thresholds, 20 and 30 min. Using a dataset of 20 hydronephrotic cases, pilot experiments show how the system outperforms previous 2D implementations by successfully identifying all the critical cases (100% of sensitivity), and detecting up to 100% (T1/2 = 20 min) and 67% (T1/2 = 30 min) of non-critical ones for T1/2 thresholds of 20 and 30 min, respectively.

  10. Quantitative analysis of 3D stent reconstruction from a limited number of views in cardiac rotational angiography

    NASA Astrophysics Data System (ADS)

    Perrenot, Béatrice; Vaillant, Régis; Prost, Rémy; Finet, Gérard; Douek, Philippe; Peyrin, Françoise

    2007-03-01

    Percutaneous coronary angioplasty consists in conducting a guidewire carrying a balloon and a stent through the lesion and deploying the stent by balloon inflation. A stent is a small 3D complex mesh hardly visible in X-ray images : the control of stent deployment is difficult although it is important to avoid post intervention complications. In a previous work, we proposed a method to reconstruct 3D stent images from a set of 2D cone-beam projections acquired in rotational acquisition mode. The process involves a motion compensation procedure based on the position of two markers located on the guidewire in the 2D radiographic sequence. Under the hypothesis that the stent and markers motions are identical, the method was shown to generate a negligible error. If this hypothesis is not fulfilled, a solution could be to use only the images where motion is weakest, at the detriment of having a limiter number of views. In this paper, we propose a simulation based study of the impact of a limited number of views in our context. The chain image involved in the acquisition of X-ray sequences is first modeled to simulate realistic noisy projections of stent animated by a motion close to cardiac motion. Then, the 3D stent images are reconstructed using the proposed motion compensation method from gated projections. Two gating strategies are examined to select projection in the sequences. A quantitative analysis is carried out to assess reconstruction quality as a function of noise and acquisition strategy.

  11. Mechanically assisted 3D ultrasound for pre-operative assessment and guiding percutaneous treatment of focal liver tumors

    NASA Astrophysics Data System (ADS)

    Sadeghi Neshat, Hamid; Bax, Jeffery; Barker, Kevin; Gardi, Lori; Chedalavada, Jason; Kakani, Nirmal; Fenster, Aaron

    2014-03-01

    Image-guided percutaneous ablation is the standard treatment for focal liver tumors deemed inoperable and is commonly used to maintain eligibility for patients on transplant waitlists. Radiofrequency (RFA), microwave (MWA) and cryoablation technologies are all delivered via one or a number of needle-shaped probes inserted directly into the tumor. Planning is mostly based on contrast CT/MRI. While intra-procedural CT is commonly used to confirm the intended probe placement, 2D ultrasound (US) remains the main, and in some centers the only imaging modality used for needle guidance. Corresponding intraoperative 2D US with planning and other intra-procedural imaging modalities is essential for accurate needle placement. However, identification of matching features of interest among these images is often challenging given the limited field-of-view (FOV) and low quality of 2D US images. We have developed a passive tracking arm with a motorized scan-head and software tools to improve guiding capabilities of conventional US by large FOV 3D US scans that provides more anatomical landmarks that can facilitate registration of US with both planning and intra-procedural images. The tracker arm is used to scan the whole liver with a high geometrical accuracy that facilitates multi-modality landmark based image registration. Software tools are provided to assist with the segmentation of the ablation probes and tumors, find the 2D view that best shows the probe(s) from a 3D US image, and to identify the corresponding image from planning CT scans. In this paper, evaluation results from laboratory testing and a phase 1 clinical trial for planning and guiding RFA and MWA procedures using the developed system will be presented. Early clinical results show a comparable performance to intra-procedural CT that suggests 3D US as a cost-effective alternative with no side-effects in centers where CT is not available.

  12. 3-D visualization and non-linear tissue classification of breast tumors using ultrasound elastography in vivo.

    PubMed

    Sayed, Ahmed; Layne, Ginger; Abraham, Jame; Mukdadi, Osama M

    2014-07-01

    The goal of the study described here was to introduce new methods for the classification and visualization of human breast tumors using 3-D ultrasound elastography. A tumor's type, shape and size are key features that can help the physician to decide the sort and extent of necessary treatment. In this work, tumor type, being either benign or malignant, was classified non-invasively for nine volunteer patients. The classification was based on estimating four parameters that reflect the tumor's non-linear biomechanical behavior, under multi-compression levels. Tumor prognosis using non-linear elastography was confirmed with biopsy as a gold standard. Three tissue classification parameters were found to be statistically significant with a p-value < 0.05, whereas the fourth non-linear parameter was highly significant, having a p-value < 0.001. Furthermore, each breast tumor's shape and size were estimated in vivo using 3-D elastography, and were enhanced using interactive segmentation. Segmentation with level sets was used to isolate the stiff tumor from the surrounding soft tissue. Segmentation also provided a reliable means to estimate tumors volumes. Four volumetric strains were investigated: the traditional normal axial strain, the first principal strain, von Mises strain and maximum shear strain. It was noted that these strains can provide varying degrees of boundary enhancement to the stiff tumor in the constructed elastograms. The enhanced boundary improved the performance of the segmentation process. In summary, the proposed methods can be employed as a 3-D non-invasive tool for characterization of breast tumors, and may provide early prognosis with minimal pain, as well as diminish the risk of late-stage breast cancer.

  13. Correlation-based discrimination between cardiac tissue and blood for segmentation of the left ventricle in 3-D echocardiographic images.

    PubMed

    Saris, Anne E C M; Nillesen, Maartje M; Lopata, Richard G P; de Korte, Chris L

    2014-03-01

    For automated segmentation of 3-D echocardiographic images, incorporation of temporal information may be helpful. In this study, optimal settings for calculation of temporal cross-correlations between subsequent time frames were determined, to obtain the maximum cross-correlation (MCC) values that provided the best contrast between blood and cardiac tissue over the entire cardiac cycle. Both contrast and boundary gradient quality measures were assessed to optimize MCC values with respect to signal choice (radiofrequency or envelope data) and axial window size. Optimal MCC values were incorporated into a deformable model to automatically segment the left ventricular cavity. MCC values were tested against, and combined with, filtered, demodulated radiofrequency data. Results reveal that using envelope data in combination with a relatively small axial window (0.7-1.25 mm) at fine scale results in optimal contrast and boundary gradient between the two tissues over the entire cardiac cycle. Preliminary segmentation results indicate that incorporation of MCC values has additional value for automated segmentation of the left ventricle. PMID:24412178

  14. Epicardial application of cardiac progenitor cells in a 3D-printed gelatin/hyaluronic acid patch preserves cardiac function after myocardial infarction.

    PubMed

    Gaetani, Roberto; Feyen, Dries A M; Verhage, Vera; Slaats, Rolf; Messina, Elisa; Christman, Karen L; Giacomello, Alessandro; Doevendans, Pieter A F M; Sluijter, Joost P G

    2015-08-01

    Cardiac cell therapy suffers from limitations related to poor engraftment and significant cell death after transplantation. In this regard, ex vivo tissue engineering is a tool that has been demonstrated to increase cell retention and survival. The aim of our study was to evaluate the therapeutic potential of a 3D-printed patch composed of human cardiac-derived progenitor cells (hCMPCs) in a hyaluronic acid/gelatin (HA/gel) based matrix. hCMPCs were printed in the HA/gel matrix (30 × 10(6) cells/ml) to form a biocomplex made of six perpendicularly printed layers with a surface of 2 × 2 cm and thickness of 400 μm, in which they retained their viability, proliferation and differentiation capability. The printed biocomplex was transplanted in a mouse model of myocardial infarction (MI). The application of the patch led to a significant reduction in adverse remodeling and preservation of cardiac performance as was shown by both MRI and histology. Furthermore, the matrix supported the long-term in vivo survival and engraftment of hCMPCs, which exhibited a temporal increase in cardiac and vascular differentiation markers over the course of the 4 week follow-up period. Overall, we developed an effective and translational approach to enhance hCMPC delivery and action in the heart.

  15. Single breath hold 3D cardiac cine MRI using kat-ARC: preliminary results at 1.5T.

    PubMed

    Jeong, Daniel; Schiebler, Mark L; Lai, Peng; Wang, Kang; Vigen, Karl K; François, Christopher J

    2015-04-01

    Validation of a new single breath-hold, three-dimensional, cine balanced steady-state free precession (3D cine bSSFP) cardiac magnetic resonance (CMR) sequence for left ventricular function. CMR examinations were performed on fifteen patients and three healthy volunteers on a clinical 1.5T scanner using a two-dimensional (2D) cine balanced SSFP CMR sequence (2D cine bSSFP) followed by an investigational 3D cine bSSFP pulse sequence acquired within a single breath hold. Left ventricular end diastolic volume (LVEDV), end systolic volume (LVESV), ejection fraction (LVEF), and myocardial mass were independently segmented on a workstation by two experienced radiologists. Blood pool to myocardial contrast was evaluated in consensus using a Likert scale. Bland-Altman analysis was used to compare these quantitative and nominal measurements for the two sequences. The average acquisition time was significantly shorter for the 3D cine bSSFP than for 2D cine bSSFP (0.36 ± 0.03 vs. 8.5 ± 2.3 min) p = 0.0002. Bland-Altman analyses [bias and (limits of agreement)] of the data derived from these two methods revealed that the LVEF 0.9% (-4.7, 6.4), LVEDV 4.9 ml (-23.0, 32.8), LVESV -0.2 ml (-22.4, 21.9), and myocardial mass -0.4 g (-23.8, 23.0) were not significantly different. There was excellent intraclass correlation for intra-observer variability (0.981, 0.989, 0.997, 0.985) and inter-observer variability (0.903, 0.954, 0.970, 0.842) for LVEF, LVEDV, LVESV, and myocardial mass respectively. 3D cine bSSFP allows for accurate single breath-hold volumetric cine CMR which enables substantial improvements in scanner time efficiency without sacrificing diagnostic accuracy.

  16. Efficient feature-based 2D/3D registration of transesophageal echocardiography to x-ray fluoroscopy for cardiac interventions

    NASA Astrophysics Data System (ADS)

    Hatt, Charles R.; Speidel, Michael A.; Raval, Amish N.

    2014-03-01

    We present a novel 2D/ 3D registration algorithm for fusion between transesophageal echocardiography (TEE) and X-ray fluoroscopy (XRF). The TEE probe is modeled as a subset of 3D gradient and intensity point features, which facilitates efficient 3D-to-2D perspective projection. A novel cost-function, based on a combination of intensity and edge features, evaluates the registration cost value without the need for time-consuming generation of digitally reconstructed radiographs (DRRs). Validation experiments were performed with simulations and phantom data. For simulations, in silica XRF images of a TEE probe were generated in a number of different pose configurations using a previously acquired CT image. Random misregistrations were applied and our method was used to recover the TEE probe pose and compare the result to the ground truth. Phantom experiments were performed by attaching fiducial markers externally to a TEE probe, imaging the probe with an interventional cardiac angiographic x-ray system, and comparing the pose estimated from the external markers to that estimated from the TEE probe using our algorithm. Simulations found a 3D target registration error of 1.08(1.92) mm for biplane (monoplane) geometries, while the phantom experiment found a 2D target registration error of 0.69mm. For phantom experiments, we demonstrated a monoplane tracking frame-rate of 1.38 fps. The proposed feature-based registration method is computationally efficient, resulting in near real-time, accurate image based registration between TEE and XRF.

  17. New developments in paediatric cardiac functional ultrasound imaging.

    PubMed

    de Korte, Chris L; Nillesen, Maartje M; Saris, Anne E C M; Lopata, Richard G P; Thijssen, Johan M; Kapusta, Livia

    2014-07-01

    Ultrasound imaging can be used to estimate the morphology as well as the motion and deformation of tissues. If the interrogated tissue is actively deforming, this deformation is directly related to its function and quantification of this deformation is normally referred as 'strain imaging'. Tissue can also be deformed by applying an internal or external force and the resulting, induced deformation is a function of the mechanical tissue characteristics. In combination with the load applied, these strain maps can be used to estimate or reconstruct the mechanical properties of tissue. This technique was named 'elastography' by Ophir et al. in 1991. Elastography can be used for atherosclerotic plaque characterisation, while the contractility of the heart or skeletal muscles can be assessed with strain imaging. Rather than using the conventional video format (DICOM) image information, radio frequency (RF)-based ultrasound methods enable estimation of the deformation at higher resolution and with higher precision than commercial methods using Doppler (tissue Doppler imaging) or video image data (2D speckle tracking methods). However, the improvement in accuracy is mainly achieved when measuring strain along the ultrasound beam direction, so it has to be considered a 1D technique. Recently, this method has been extended to multiple directions and precision further improved by using spatial compounding of data acquired at multiple beam steered angles. Using similar techniques, the blood velocity and flow can be determined. RF-based techniques are also beneficial for automated segmentation of the ventricular cavities. In this paper, new developments in different techniques of quantifying cardiac function by strain imaging, automated segmentation, and methods of performing blood flow imaging are reviewed and their application in paediatric cardiology is discussed. PMID:27277901

  18. 3D Quantitative Assessment of Lesion Response to MR-guided High-Intensity Focused Ultrasound Treatment of Uterine Fibroids

    PubMed Central

    Savic, Lynn J.; Lin, MingDe; Duran, Rafael; Schernthaner, Rüdiger E.; Hamm, Bernd; Geschwind, Jean-François; Hong, Kelvin; Chapiro, Julius

    2015-01-01

    Rationale and Objectives To investigate the response after MR-guided high-intensity focused ultrasound (MRgHIFU) treatment of uterine fibroids (UF) using a 3D quantification of total and enhancing lesion volume (TLV, ELV) on contrast-enhanced MRI (ceMRI) scans. Methods and Materials In a total of 24 patients, ceMRI scans were obtained at baseline and 24 hrs, 6, 12 and 24 months after MRgHIFU treatment. The dominant lesion was assessed using a semi-automatic quantitative 3D segmentation technique. Agreement between software-assisted and manual measurements was then analyzed using a linear regression model. Patients were classified as responders (R) or non-responders (NR) based on their symptom report after 6 months. Statistical analysis included the paired t-test and Mann-Whitney-test. Results Preprocedurally, the median TLV and ELV were 263.74cm3 (30.45–689.56cm3) and 210.13cm3 (14.43–689.53cm3), respectively. The 6-month follow-up demonstrated a reduction of TLV in 21 patients (87.5%) with a median TLV of 171.7cm3 (8.5–791.2cm3) (p<.0001). TLV remained stable with significant differences compared to baseline (p<.001 and p=.047 after 12 and 24 months). A reduction of ELV was apparent in 16 patients (66.6%) with a median ELV of 158.91cm3 (8.55–779.61cm3) after 6 months (p=.065). 3D quantification and manual measurements showed strong intermethod-agreement for fibroid volumes (R2=.889 and R2=.917) but greater discrepancy for enhancement calculations (R2=.659 and R2=.419) at baseline and 6 mo. No significant differences in TLV or ELV were observed between clinical R (n=15) and NR (n=3). Conclusion The 3D assessment has proven feasible and accurate in the quantification of fibroid response to MRgHIFU. Contrary to ELV, changes in TLV may be representative of the clinical outcome. PMID:26160057

  19. Cell therapy, 3D culture systems and tissue engineering for cardiac regeneration.

    PubMed

    Emmert, Maximilian Y; Hitchcock, Robert W; Hoerstrup, Simon P

    2014-04-01

    Ischemic Heart Disease (IHD) still represents the "Number One Killer" worldwide accounting for the death of numerous patients. However the capacity for self-regeneration of the adult heart is very limited and the loss of cardiomyocytes in the infarcted heart leads to continuous adverse cardiac-remodeling which often leads to heart-failure (HF). The concept of regenerative medicine comprising cell-based therapies, bio-engineering technologies and hybrid solutions has been proposed as a promising next-generation approach to address IHD and HF. Numerous strategies are under investigation evaluating the potential of regenerative medicine on the failing myocardium including classical cell-therapy concepts, three-dimensional culture techniques and tissue-engineering approaches. While most of these regenerative strategies have shown great potential in experimental studies, the translation into a clinical setting has either been limited or too rapid leaving many key questions unanswered. This review summarizes the current state-of-the-art, important challenges and future research directions as to regenerative approaches addressing IHD and resulting HF.

  20. Real-time dynamic display of registered 4D cardiac MR and ultrasound images using a GPU

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Huang, X.; Eagleson, R.; Guiraudon, G.; Peters, T. M.

    2007-03-01

    In minimally invasive image-guided surgical interventions, different imaging modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), and real-time three-dimensional (3D) ultrasound (US), can provide complementary, multi-spectral image information. Multimodality dynamic image registration is a well-established approach that permits real-time diagnostic information to be enhanced by placing lower-quality real-time images within a high quality anatomical context. For the guidance of cardiac procedures, it would be valuable to register dynamic MRI or CT with intraoperative US. However, in practice, either the high computational cost prohibits such real-time visualization of volumetric multimodal images in a real-world medical environment, or else the resulting image quality is not satisfactory for accurate guidance during the intervention. Modern graphics processing units (GPUs) provide the programmability, parallelism and increased computational precision to begin to address this problem. In this work, we first outline our research on dynamic 3D cardiac MR and US image acquisition, real-time dual-modality registration and US tracking. Then we describe image processing and optimization techniques for 4D (3D + time) cardiac image real-time rendering. We also present our multimodality 4D medical image visualization engine, which directly runs on a GPU in real-time by exploiting the advantages of the graphics hardware. In addition, techniques such as multiple transfer functions for different imaging modalities, dynamic texture binding, advanced texture sampling and multimodality image compositing are employed to facilitate the real-time display and manipulation of the registered dual-modality dynamic 3D MR and US cardiac datasets.

  1. Elsevier Trophoblast Research Award Lecture: Searching for an early pregnancy 3-D morphometric ultrasound marker to predict fetal growth restriction.

    PubMed

    Collins, S L; Stevenson, G N; Noble, J A; Impey, L

    2013-03-01

    Fetal growth restriction (FGR) is a major cause of perinatal morbidity and mortality, even in term babies. An effective screening test to identify pregnancies at risk of FGR, leading to increased antenatal surveillance with timely delivery, could decrease perinatal mortality and morbidity. Placental volume, measured with commercially available packages and a novel, semi-automated technique, has been shown to predict small for gestational age babies. Placental morphology measured in 2-D in the second trimester and ex-vivo post delivery, correlates with FGR. This has also been investigated using 2-D estimates of diameter and site of cord insertion obtained using the Virtual Organ Computer-aided AnaLysis (VOCAL) software. Data is presented describing a pilot study of a novel 3-D method for defining compactness of placental shape. We prospectively recruited women with a singleton pregnancy and BMI of <35. A 3-D ultrasound scan was performed between 11 and 13 + 6 weeks' gestation. The placental volume, total placental surface area and the area of the utero-placental interface were calculated using our validated technique. From these we generated dimensionless indices including sphericity (ψ), standardised placental volume (sPlaV) and standardised functional area (sFA) using Buckingham π theorem. The marker for FGR used was small for gestational age, defined as <10th customised birth weight centile (cSGA). Regression analysis examined which of the morphometric indices were independent predictors of cSGA. Data were collected for 143 women, 20 had cSGA babies. Only sPlaV and sFA were significantly correlated to birth weight (p < 0.001). Regression demonstrated all dimensionless indices were inter-dependent co-factors. ROC curves showed no advantage for using sFA over the simpler sPlaV. The generated placental indices are not independent of placental volume this early in gestation. It is hoped that another placental ultrasound marker based on vascularity can improve the

  2. Non-rigid registration between 3D ultrasound and CT images of the liver based on intensity and gradient information

    NASA Astrophysics Data System (ADS)

    Lee, Duhgoon; Nam, Woo Hyun; Lee, Jae Young; Ra, Jong Beom

    2011-01-01

    In order to utilize both ultrasound (US) and computed tomography (CT) images of the liver concurrently for medical applications such as diagnosis and image-guided intervention, non-rigid registration between these two types of images is an essential step, as local deformation between US and CT images exists due to the different respiratory phases involved and due to the probe pressure that occurs in US imaging. This paper introduces a voxel-based non-rigid registration algorithm between the 3D B-mode US and CT images of the liver. In the proposed algorithm, to improve the registration accuracy, we utilize the surface information of the liver and gallbladder in addition to the information of the vessels inside the liver. For an effective correlation between US and CT images, we treat those anatomical regions separately according to their characteristics in US and CT images. Based on a novel objective function using a 3D joint histogram of the intensity and gradient information, vessel-based non-rigid registration is followed by surface-based non-rigid registration in sequence, which improves the registration accuracy. The proposed algorithm is tested for ten clinical datasets and quantitative evaluations are conducted. Experimental results show that the registration error between anatomical features of US and CT images is less than 2 mm on average, even with local deformation due to different respiratory phases and probe pressure. In addition, the lesion registration error is less than 3 mm on average with a maximum of 4.5 mm that is considered acceptable for clinical applications.

  3. A framework for quantification of regional cardiac fibrosis from serial sections using 3D whole slide imaging.

    PubMed

    Gilbert, Stephen H; Bernus, Olivier; White, Ed; Roberts, Nick; Treanor, Darren; Magee, Derek

    2014-01-01

    Pathological cardiac fibrosis is important in predisposing the heart to arrhythmia and mechanical failure. The regional distribution of fibrosis is often described qualitatively and quantitatively in histological studies of animal hearts after staining collagen with specific colored stains. Currently this description is often piecemeal, as it lacks rigorous spatial registration, matching and methodological standardization between animals and between study groups. We propose a strategy for the quantification of regional fibrosis using the American Heart Association (AHA) cardiac segmentation model. We quantify fibrosis after whole heart 3D histological reconstruction in one normal rat heart and in one rat heart in right heart failure induced by monocrotaline. We then assess the minimum spaced histological sampling which allows for accurate assessment of regional fibrosis. We show that using every section of a set of 5 μm serial sections quantifies regional right ventricular fibrosis, with highly significant (p <; 0.001) differences between heart failure and control hearts. We show that the absolute error of collagen quantification is low when sections are taken spaced by up to 100 μm (error 5.7±5.8%). Likewise, absolute error associated with sectioning starting position is low for sections spaced up to 100 μm (error 13.3±17.2%). Above 100 μm section spacing quantification error is large (tending to 50%) and error associated with sectioning starting position is large (tending to 60%).

  4. An algorithm to correct 2D near-infrared fluorescence signals using 3D intravascular ultrasound architectural information

    NASA Astrophysics Data System (ADS)

    Mallas, Georgios; Brooks, Dana H.; Rosenthal, Amir; Vinegoni, Claudio; Calfon, Marcella A.; Razansky, R. Nika; Jaffer, Farouc A.; Ntziachristos, Vasilis

    2011-03-01

    Intravascular Near-Infrared Fluorescence (NIRF) imaging is a promising imaging modality to image vessel biology and high-risk plaques in vivo. We have developed a NIRF fiber optic catheter and have presented the ability to image atherosclerotic plaques in vivo, using appropriate NIR fluorescent probes. Our catheter consists of a 100/140 μm core/clad diameter housed in polyethylene tubing, emitting NIR laser light at a 90 degree angle compared to the fiber's axis. The system utilizes a rotational and a translational motor for true 2D imaging and operates in conjunction with a coaxial intravascular ultrasound (IVUS) device. IVUS datasets provide 3D images of the internal structure of arteries and are used in our system for anatomical mapping. Using the IVUS images, we are building an accurate hybrid fluorescence-IVUS data inversion scheme that takes into account photon propagation through the blood filled lumen. This hybrid imaging approach can then correct for the non-linear dependence of light intensity on the distance of the fluorescence region from the fiber tip, leading to quantitative imaging. The experimental and algorithmic developments will be presented and the effectiveness of the algorithm showcased with experimental results in both saline and blood-like preparations. The combined structural and molecular information obtained from these two imaging modalities are positioned to enable the accurate diagnosis of biologically high-risk atherosclerotic plaques in the coronary arteries that are responsible for heart attacks.

  5. Physical model from 3D ultrasound and magnetic resonance imaging scan data reconstruction of lumbosacral myelomeningocele in a fetus with Chiari II malformation.

    PubMed

    Werner, Heron; Lopes, Jorge; Tonni, Gabriele; Araujo Júnior, Edward

    2015-04-01

    Rapid prototyping is becoming a fast-growing and valuable technique for physical models in case of congenital anomalies. Manufacturing models are generally built from three-dimensional (3D) ultrasound, computed tomography, and fetal magnetic resonance imaging (MRI) scan data. Physical prototype has demonstrated to be clinically of value in case of complex fetal malformations and may improve antenatal management especially in cases of craniosynostosis, orofacial clefts, and giant epignathus. In addition, it may enhance parental bonding in visually impaired parents and have didactic value in teaching program. Hereby, the first 3D physical model from 3D ultrasound and MRI scan data reconstruction of lumbosacral myelomeningocele in a third trimester fetus affected by Chiari II malformation is reported. PMID:25686895

  6. Physical model from 3D ultrasound and magnetic resonance imaging scan data reconstruction of lumbosacral myelomeningocele in a fetus with Chiari II malformation.

    PubMed

    Werner, Heron; Lopes, Jorge; Tonni, Gabriele; Araujo Júnior, Edward

    2015-04-01

    Rapid prototyping is becoming a fast-growing and valuable technique for physical models in case of congenital anomalies. Manufacturing models are generally built from three-dimensional (3D) ultrasound, computed tomography, and fetal magnetic resonance imaging (MRI) scan data. Physical prototype has demonstrated to be clinically of value in case of complex fetal malformations and may improve antenatal management especially in cases of craniosynostosis, orofacial clefts, and giant epignathus. In addition, it may enhance parental bonding in visually impaired parents and have didactic value in teaching program. Hereby, the first 3D physical model from 3D ultrasound and MRI scan data reconstruction of lumbosacral myelomeningocele in a third trimester fetus affected by Chiari II malformation is reported.

  7. Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound.

    PubMed

    Kopechek, Jonathan A; Carson, Andrew R; McTiernan, Charles F; Chen, Xucai; Klein, Edwin C; Villanueva, Flordeliza S

    2016-01-01

    RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14). Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9) or control RNA (n = 8) during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3) confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively). Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease. PMID:27471848

  8. Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound

    PubMed Central

    McTiernan, Charles F.; Chen, Xucai; Klein, Edwin C.; Villanueva, Flordeliza S.

    2016-01-01

    RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14). Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9) or control RNA (n = 8) during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3) confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively). Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease. PMID:27471848

  9. Ultrasound and Cadaveric Prosections as Methods for Teaching Cardiac Anatomy: A Comparative Study

    ERIC Educational Resources Information Center

    Griksaitis, Michael J.; Sawdon, Marina A.; Finn, Gabrielle M.

    2012-01-01

    This study compared the efficacy of two cardiac anatomy teaching modalities, ultrasound imaging and cadaveric prosections, for learning cardiac gross anatomy. One hundred and eight first-year medical students participated. Two weeks prior to the teaching intervention, students completed a pretest to assess their prior knowledge and to ensure that…

  10. Determining inter-fractional motion of the uterus using 3D ultrasound imaging during radiotherapy for cervical cancer

    NASA Astrophysics Data System (ADS)

    Baker, Mariwan; Jensen, Jørgen Arendt; Behrens, Claus F.

    2014-03-01

    Uterine positional changes can reduce the accuracy of radiotherapy for cervical cancer patients. The purpose of this study was to; 1) Quantify the inter-fractional uterine displacement using a novel 3D ultrasound (US) imaging system, and 2) Compare the result with the bone match shift determined by Cone- Beam CT (CBCT) imaging.Five cervical cancer patients were enrolled in the study. Three of them underwent weekly CBCT imaging prior to treatment and bone match shift was applied. After treatment delivery they underwent a weekly US scan. The transabdominal scans were conducted using a Clarity US system (Clarity® Model 310C00). Uterine positional shifts based on soft-tissue match using US was performed and compared to bone match shifts for the three directions. Mean value (+/-1 SD) of the US shifts were (mm); anterior-posterior (A/P): (3.8+/-5.5), superior-inferior (S/I) (-3.5+/-5.2), and left-right (L/R): (0.4+/-4.9). The variations were larger than the CBCT shifts. The largest inter-fractional displacement was from -2 mm to +14 mm in the AP-direction for patient 3. Thus, CBCT bone matching underestimates the uterine positional displacement due to neglecting internal uterine positional change to the bone structures. Since the US images were significantly better than the CBCT images in terms of soft-tissue visualization, the US system can provide an optional image-guided radiation therapy (IGRT) system. US imaging might be a better IGRT system than CBCT, despite difficulty in capturing the entire uterus. Uterine shifts based on US imaging contains relative uterus-bone displacement, which is not taken into consideration using CBCT bone match.

  11. Quantitative description of the 3D regional mechanics of the left atrium using cardiac magnetic resonance imaging.

    PubMed

    Kuklik, P; Molaee, P; Podziemski, P; Ganesan, A N; Brooks, A G; Worthley, S G; Sanders, P

    2014-05-01

    The left atrium (LA) plays an important role in the maintenance of hemodynamic and electrical stability of the heart. One of the conditions altering the atrial mechanical function is atrial fibrillation (AF), leading to an increased thromboembolic risk due to impaired mechanical function. Preserving the regions of the LA that contribute the greatest to atrial mechanical function during curative strategies for AF is important. The purpose of this study is to introduce a novel method of regional assessment of mechanical function of the LA. We used cardiac MRI to reconstruct the 3D geometry of the LA in nine control and nine patients with paroxysmal atrial fibrillation (PAF). Regional mechanical function of the LA in pre-defined segments of the atrium was calculated using regional ejection fraction and wall velocity. We found significantly greater mechanical function in anterior, septal and lateral segments as opposed to roof and posterior segments, as well as a significant decrease of mechanical function in the PAF group. We suggest that in order to minimize the impact of the AF treatment on global atrial mechanical function, damage related to therapeutic intervention, such as catheter ablation, in those areas should be minimized.

  12. 2D/3D registration using only single-view fluoroscopy to guide cardiac ablation procedures: a feasibility study

    NASA Astrophysics Data System (ADS)

    Fallavollita, Pascal

    2010-02-01

    The CARTO XP is an electroanatomical cardiac mapping system that provides 3D color-coded maps of the electrical activity of the heart, however it is expensive and it can only use a single costly magnetic catheter for each patient intervention. Aim: To develop an affordable fluoroscopic navigation system that could shorten the duration of RF ablation procedures and increase its efficacy. Methodology: A 4-step filtering technique was implemented in order to project the tip electrode of an ablation catheter visible in single-view C-arm images in order to calculate its width. The width is directly proportional to the depth of the catheter. Results: For phantom experimentation, when displacing a 7- French catheter at 1cm intervals away from an X-ray source, the recovered depth using a single image was 2.05 +/- 1.47 mm, whereas depth errors improved to 1.55 +/- 1.30 mm when using an 8-French catheter. In clinic experimentation, twenty posterior and left lateral images of a catheter inside the left ventricle of a mongrel dog were acquired. The standard error of estimate for the recovered depth of the tip-electrode of the mapping catheter was 13.1 mm and 10.1 mm respectively for the posterior and lateral views. Conclusions: A filtering implementation using single-view C-arm images showed that it was possible to recover depth in phantom study and proved adequate in clinical experimentation based on isochronal map fusion results.

  13. Using Ultrasound to Teach Medical Students Cardiac Physiology

    ERIC Educational Resources Information Center

    Bell, Floyd E., III; Wilson, L. Britt; Hoppmann, Richard A.

    2015-01-01

    Ultrasound is being incorporated more into undergraduate medical education. Studies have shown that medical students have positive perceptions about the value of ultrasound in teaching courses like anatomy and physiology. The purpose of the present study was to provide objective evidence of whether ultrasound helps students learn cardiac…

  14. A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography.

    PubMed

    Carlier, Stéphane; Didday, Rich; Slots, Tristan; Kayaert, Peter; Sonck, Jeroen; El-Mourad, Mike; Preumont, Nicolas; Schoors, Dany; Van Camp, Guy

    2014-06-01

    We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization.

  15. Computer-aided classification of liver tumors in 3D ultrasound images with combined deformable model segmentation and support vector machine

    NASA Astrophysics Data System (ADS)

    Lee, Myungeun; Kim, Jong Hyo; Park, Moon Ho; Kim, Ye-Hoon; Seong, Yeong Kyeong; Cho, Baek Hwan; Woo, Kyoung-Gu

    2014-03-01

    In this study, we propose a computer-aided classification scheme of liver tumor in 3D ultrasound by using a combination of deformable model segmentation and support vector machine. For segmentation of tumors in 3D ultrasound images, a novel segmentation model was used which combined edge, region, and contour smoothness energies. Then four features were extracted from the segmented tumor including tumor edge, roundness, contrast, and internal texture. We used a support vector machine for the classification of features. The performance of the developed method was evaluated with a dataset of 79 cases including 20 cysts, 20 hemangiomas, and 39 hepatocellular carcinomas, as determined by the radiologist's visual scoring. Evaluation of the results showed that our proposed method produced tumor boundaries that were equal to or better than acceptable in 89.8% of cases, and achieved 93.7% accuracy in classification of cyst and hemangioma.

  16. Evaluating the extent of cell death in 3D high frequency ultrasound by registration with whole-mount tumor histopathology

    SciTech Connect

    Vlad, Roxana M.; Kolios, Michael C.; Moseley, Joanne L.; Czarnota, Gregory J.; Brock, Kristy K.

    2010-08-15

    Purpose: High frequency ultrasound imaging, 10-30 MHz, has the capability to assess tumor response to radiotherapy in mouse tumors as early as 24 h after treatment administration. The advantage of this technique is that the image contrast is generated by changes in the physical properties of dying cells. Therefore, a subject can be imaged before and multiple times during the treatment without the requirement of injecting specialized contrast agents. This study is motivated by a need to provide metrics of comparison between the volume and localization of cell death, assessed from histology, with the volume and localization of cell death surrogate, assessed as regions with increased echogeneity from ultrasound images. Methods: The mice were exposed to radiation doses of 2, 4, and 8 Gy. Ultrasound images were collected from each tumor before and 24 h after exposure to radiation using a broadband 25 MHz center frequency transducer. After radiotherapy, tumors exhibited hyperechoic regions in ultrasound images that corresponded to areas of cell death in histology. The ultrasound and histological images were rigidly registered. The tumors and regions of cell death were manually outlined on histological images. Similarly, the tumors and hyperechoic regions were outlined on the ultrasound images. Each set of contours was converted to a volumetric mesh in order to compare the volumes and the localization of cell death in histological and ultrasound images. Results: A shrinkage factor of 17{+-}2% was calculated from the difference in the tumor volumes evaluated from histological and ultrasound images. This was used to correct the tumor and cell death volumes assessed from histology. After this correction, the average absolute difference between the volume of cell death assessed from ultrasound and histological images was 11{+-}14% and the volume overlap was 70{+-}12%. Conclusions: The method provided metrics of comparison between the volume of cell death assessed from

  17. Infrared thermography and ultrasound C-scan for non-destructive evaluation of 3D carbon fiber materials: a comparative study

    NASA Astrophysics Data System (ADS)

    Zhang, Hai; Genest, Marc; Robitaille, Francois; Maldague, Xavier; West, Lucas; Joncas, Simon; Leduc, Catherine

    2015-05-01

    3D Carbon fiber polymer matrix composites (3D CF PMCs) are increasingly used for aircraft construction due to their exceptional stiffness and strength-to-mass ratios. However, defects are common in the 3D combining areas and are challenging to inspect. In this paper, Stitching is used to decrease these defects, but causes some new types of defects. Infrared NDT (non-destructive testing) and ultrasound NDT are used. In particular, a micro-laser line thermography technique (micro-LLT) and a micro-laser spot thermography (micro-LST) with locked-in technique are used to detect the micro-defects. In addition, a comparative study is conducted by using pulsed thermography (PT), vibrothermography (VT). In order to confirm the types of the defects, microscopic inspection is carried out before NDT work, after sectioning and polishing a small part of the sample..

  18. An ultrasound tomography system with polyvinyl alcohol (PVA) moldings for coupling: in vivo results for 3-D pulse-echo imaging of the female breast.

    PubMed

    Koch, Andreas; Stiller, Florian; Lerch, Reinhard; Ermert, Helmut

    2015-02-01

    Full-angle spatial compounding (FASC) is a concept for pulse-echo imaging using an ultrasound tomography (UST) system. With FASC, resolution is increased and speckles are suppressed by averaging pulse-echo data from 360°. In vivo investigations have already shown a great potential for 2-D FASC in the female breast as well as for finger-joint imaging. However, providing a small number of images of parallel cross-sectional planes with enhanced image quality is not sufficient for diagnosis. Therefore, volume data (3-D) is needed. For this purpose, we further developed our UST add-on system to automatically rotate a motorized array (3-D probe) around the object of investigation. Full integration of external motor and ultrasound electronics control in a custom-made program allows acquisition of 3-D pulse-echo RF datasets within 10 min. In case of breast cancer imaging, this concept also enables imaging of near-thorax tissue regions which cannot be achieved by 2-D FASC. Furthermore, moldings made of polyvinyl alcohol hydrogel (PVA-H) have been developed as a new acoustic coupling concept. It has a great potential to replace the water bath technique in UST, which is a critical concept with respect to clinical investigations. In this contribution, we present in vivo results for 3-D FASC applied to imaging a female breast which has been placed in a PVA-H molding during data acquisition. An algorithm is described to compensate time-of-flight and consider refraction at the water-PVA-H molding and molding-tissue interfaces. Therefore, the mean speed of sound (SOS) for the breast tissue is estimated with an image-based method. Our results show that the PVA-H molding concept is applicable and feasible and delivers good results. 3-D FASC is superior to 2-D FASC and provides 3-D volume data at increased image quality.

  19. 3D conformal MRI-controlled transurethral ultrasound prostate therapy: validation of numerical simulations and demonstration in tissue-mimicking gel phantoms.

    PubMed

    Burtnyk, Mathieu; N'Djin, William Apoutou; Kobelevskiy, Ilya; Bronskill, Michael; Chopra, Rajiv

    2010-11-21

    MRI-controlled transurethral ultrasound therapy uses a linear array of transducer elements and active temperature feedback to create volumes of thermal coagulation shaped to predefined prostate geometries in 3D. The specific aims of this work were to demonstrate the accuracy and repeatability of producing large volumes of thermal coagulation (>10 cc) that conform to 3D human prostate shapes in a tissue-mimicking gel phantom, and to evaluate quantitatively the accuracy with which numerical simulations predict these 3D heating volumes under carefully controlled conditions. Eleven conformal 3D experiments were performed in a tissue-mimicking phantom within a 1.5T MR imager to obtain non-invasive temperature measurements during heating. Temperature feedback was used to control the rotation rate and ultrasound power of transurethral devices with up to five 3.5 × 5 mm active transducer elements. Heating patterns shaped to human prostate geometries were generated using devices operating at 4.7 or 8.0 MHz with surface acoustic intensities of up to 10 W cm(-2). Simulations were informed by transducer surface velocity measurements acquired with a scanning laser vibrometer enabling improved calculations of the acoustic pressure distribution in a gel phantom. Temperature dynamics were determined according to a FDTD solution to Pennes' BHTE. The 3D heating patterns produced in vitro were shaped very accurately to the prostate target volumes, within the spatial resolution of the MRI thermometry images. The volume of the treatment difference falling outside ± 1 mm of the target boundary was, on average, 0.21 cc or 1.5% of the prostate volume. The numerical simulations predicted the extent and shape of the coagulation boundary produced in gel to within (mean ± stdev [min, max]): 0.5 ± 0.4 [-1.0, 2.1] and -0.05 ± 0.4 [-1.2, 1.4] mm for the treatments at 4.7 and 8.0 MHz, respectively. The temperatures across all MRI thermometry images were predicted within -0.3 ± 1.6 °C and 0

  20. Lung ultrasound in adult and paediatric cardiac surgery: is it time for routine use?

    PubMed

    Cantinotti, Massimiliano; Giordano, Raffaele; Volpicelli, Giovanni; Kutty, Shelby; Murzi, Bruno; Assanta, Nadia; Gargani, Luna

    2016-02-01

    Respiratory complications are common causes of morbidity and the need of repeated X-ray examinations after cardiac surgery. Ultrasound of the chest, including the lung parenchyma, has been recently introduced as a new tool to detect many pulmonary abnormalities. Despite this, the use of lung ultrasound (LUS) in adult and congenital cardiac surgery remains limited. In particular, lung ultrasound has been mainly used in the evaluation of pleural effusion (PLE), but no consensus exists on methods to quantify the volume of the effusion. Usefulness of LUS for the assessment of diaphragmatic motion in children has also been highlighted, but no clear recommendation exists regarding its routine use. Accuracy of LUS in detecting pulmonary congestion after adult cardiac surgery has been demonstrated, whereas studies in children are still scarce, and data on pneumothorax and lung consolidations are limited in the paediatric population. There are methodological and practicality issues regarding diagnostic protocols (i.e. image views and their sequential order) and instrumentation (transducers and their setting) used in different studies. It also remains unclear which practitioner-the cardiologist, intensivist, pulmonologist or the radiologist, should perform the examination. Cost analysis pertaining to extensive clinical application of lung ultrasound in cardiac surgery has never been performed. Guidelines and recommendations are warranted for a systematic and extensive use of this technique in cardiac surgery at different ages, as it could serve as a useful, versatile tool that could potentially decrease time, radiation exposure and costs. PMID:26586677

  1. Quantitative assessment of cancer vascular architecture by skeletonization of high-resolution 3-D contrast-enhanced ultrasound images: role of liposomes and microbubbles.

    PubMed

    Molinari, F; Meiburger, K M; Giustetto, P; Rizzitelli, S; Boffa, C; Castano, M; Terreno, E

    2014-12-01

    The accurate characterization and description of the vascular network of a cancer lesion is of paramount importance in clinical practice and cancer research in order to improve diagnostic accuracy or to assess the effectiveness of a treatment. The aim of this study was to show the effectiveness of liposomes as an ultrasound contrast agent to describe the 3-D vascular architecture of a tumor. Eight C57BL/6 mice grafted with syngeneic B16-F10 murine melanoma cells were injected with a bolus of 1,2-Distearoyl-sn-glycero-3-phosphocoline (DSPC)-based non-targeted liposomes and with a bolus of microbubbles. 3-D contrast-enhanced images of the tumor lesions were acquired in three conditions: pre-contrast, after the injection of microbubbles, and after the injection of liposomes. By using a previously developed reconstruction and characterization image processing technique, we obtained the 3-D representation of the vascular architecture in these three conditions. Six descriptive parameters of these networks were also computed: the number of vascular trees (NT), the vascular density (VD), the number of branches, the 2-D curvature measure, the number of vascular flexes of the vessels, and the 3-D curvature. Results showed that all the vascular descriptors obtained by liposome-based images were statistically equal to those obtained by using microbubbles, except the VD which was found to be lower for liposome images. All the six descriptors computed in pre-contrast conditions had values that were statistically lower than those computed in presence of contrast, both for liposomes and microbubbles. Liposomes have already been used in cancer therapy for the selective ultrasound-mediated delivery of drugs. This work demonstrated their effectiveness also as vascular diagnostic contrast agents, therefore proving that liposomes can be used as efficient "theranostic" (i.e. therapeutic 1 diagnostic) ultrasound probes.

  2. Quantitative assessment of cancer vascular architecture by skeletonization of high-resolution 3-D contrast-enhanced ultrasound images: role of liposomes and microbubbles.

    PubMed

    Molinari, F; Meiburger, K M; Giustetto, P; Rizzitelli, S; Boffa, C; Castano, M; Terreno, E

    2014-12-01

    The accurate characterization and description of the vascular network of a cancer lesion is of paramount importance in clinical practice and cancer research in order to improve diagnostic accuracy or to assess the effectiveness of a treatment. The aim of this study was to show the effectiveness of liposomes as an ultrasound contrast agent to describe the 3-D vascular architecture of a tumor. Eight C57BL/6 mice grafted with syngeneic B16-F10 murine melanoma cells were injected with a bolus of 1,2-Distearoyl-sn-glycero-3-phosphocoline (DSPC)-based non-targeted liposomes and with a bolus of microbubbles. 3-D contrast-enhanced images of the tumor lesions were acquired in three conditions: pre-contrast, after the injection of microbubbles, and after the injection of liposomes. By using a previously developed reconstruction and characterization image processing technique, we obtained the 3-D representation of the vascular architecture in these three conditions. Six descriptive parameters of these networks were also computed: the number of vascular trees (NT), the vascular density (VD), the number of branches, the 2-D curvature measure, the number of vascular flexes of the vessels, and the 3-D curvature. Results showed that all the vascular descriptors obtained by liposome-based images were statistically equal to those obtained by using microbubbles, except the VD which was found to be lower for liposome images. All the six descriptors computed in pre-contrast conditions had values that were statistically lower than those computed in presence of contrast, both for liposomes and microbubbles. Liposomes have already been used in cancer therapy for the selective ultrasound-mediated delivery of drugs. This work demonstrated their effectiveness also as vascular diagnostic contrast agents, therefore proving that liposomes can be used as efficient "theranostic" (i.e. therapeutic 1 diagnostic) ultrasound probes. PMID:24206210

  3. Cardiac differentiation potential of human induced pluripotent stem cells in a 3D self-assembling peptide scaffold.

    PubMed

    Puig-Sanvicens, Veronica A C; Semino, Carlos E; Zur Nieden, Nicole I

    2015-01-01

    In the past decade, various strategies for cardiac reparative medicine involving stem cells from multiple sources have been investigated. However, the intra-cardiac implantation of cells with contractile ability may seriously disrupt the cardiac syncytium and de-synchronize cardiac rhythm. For this reason, bioactive cardiac implants, consisting of stem cells embedded in biomaterials that act like band aids, have been exploited to repair the cardiac wall after myocardial infarction. For such bioactive implants to function properly after transplantation, the choice of biomaterial is equally important as the selection of the stem cell source. While adult stem cells have shown promising results, they have various disadvantages including low proliferative potential in vitro, which make their successful usage in human transplants difficult. As a first step towards the development of a bioactive cardiac patch, we investigate here the cardiac differentiation properties of human induced pluripotent stem cells (hiPSCs) when cultured with and without ascorbic acid (AA) and when embedded in RAD16-I, a biomaterial commonly used to develop cardiac implants. In adherent cultures and in the absence of RAD16-I, AA promotes the cardiac differentiation of hiPSCs by enhancing the expression of specific cardiac genes and proteins and by increasing the number of contracting clusters. In turn, embedding in peptide hydrogel based on RAD16-I interferes with the normal cardiac differentiation progression. Embedded hiPSCs up-regulate genes associated with early cardiogenesis by up to 105 times independently of the presence of AA. However, neither connexin 43 nor troponin I proteins, which are related with mature cardiomyocytes, were detected and no contraction was noted in the constructs. Future experiments will need to focus on characterizing the mature cardiac phenotype of these cells when implanted into infarcted myocardia and assess their regenerative potential in vivo. PMID:26707885

  4. Registration of fast cine cardiac MR slices to 3D preprocedural images: toward real-time registration for MRI-guided procedures

    NASA Astrophysics Data System (ADS)

    Smolikova, Renata; Wachowiak, Mark P.; Drangova, Maria

    2004-05-01

    Interventional cardiac magnetic resonance (MR) procedures are the subject of an increasing number of research studies. Typically, during the procedure only two-dimensional images of oblique slices can be presented to the interventionalist in real time. There is a clear benefit to being able to register the real-time 2D slices to a previously acquired 3D computed tomography (CT) or MR image of the heart. Results from a study of the accuracy of registration of 2D cardiac images of an anesthetized pig to a 3D volume obtained in diastole are presented. Fast cine MR images representing twenty phases of the cardiac cycle were obtained of a 2D slice in a known oblique orientation. The 2D images were initially mis-oriented at distances ranging from 2 to 20 mm, and rotations of +/-10 degrees about all three axes. Images from all 20 cardiac phases were registered to examine the effect of timing between the 2D image and the 3D pre-procedural image. Linear registration using mutual information computed with 64 histogram bins yielded the highest accuracy. For the diastolic phases, mean translation and rotation errors ranged between 0.91 and 1.32 mm and between 1.73 and 2.10 degrees. Scans acquired at other phases also had high accuracy. These results are promising for the use of real time MR in image-guided cardiac interventions, and demonstrate the feasibility of registering 2D oblique MR slices to previously acquired single-phase volumes without preprocessing.

  5. Influence of ultrasound power on acoustic streaming and micro-bubbles formations in a low frequency sono-reactor: mathematical and 3D computational simulation.

    PubMed

    Sajjadi, Baharak; Raman, Abdul Aziz Abdul; Ibrahim, Shaliza

    2015-05-01

    This paper aims at investigating the influence of ultrasound power amplitude on liquid behaviour in a low-frequency (24 kHz) sono-reactor. Three types of analysis were employed: (i) mechanical analysis of micro-bubbles formation and their activities/characteristics using mathematical modelling. (ii) Numerical analysis of acoustic streaming, fluid flow pattern, volume fraction of micro-bubbles and turbulence using 3D CFD simulation. (iii) Practical analysis of fluid flow pattern and acoustic streaming under ultrasound irradiation using Particle Image Velocimetry (PIV). In mathematical modelling, a lone micro bubble generated under power ultrasound irradiation was mechanistically analysed. Its characteristics were illustrated as a function of bubble radius, internal temperature and pressure (hot spot conditions) and oscillation (pulsation) velocity. The results showed that ultrasound power significantly affected the conditions of hotspots and bubbles oscillation velocity. From the CFD results, it was observed that the total volume of the micro-bubbles increased by about 4.95% with each 100 W-increase in power amplitude. Furthermore, velocity of acoustic streaming increased from 29 to 119 cm/s as power increased, which was in good agreement with the PIV analysis.

  6. Free-Breathing 3D Imaging of Right Ventricular Structure and Function Using Respiratory and Cardiac Self-Gated Cine MRI

    PubMed Central

    Zhu, Yanchun; Liu, Jing; Weinsaft, Jonathan; Spincemaille, Pascal; Nguyen, Thanh D.; Prince, Martin R.; Bao, Shanglian; Xie, Yaoqin; Wang, Yi

    2015-01-01

    Providing a movie of the beating heart in a single prescribed plane, cine MRI has been widely used in clinical cardiac diagnosis, especially in the left ventricle (LV). Right ventricular (RV) morphology and function are also important for the diagnosis of cardiopulmonary diseases and serve as predictors for the long term outcome. The purpose of this study is to develop a self-gated free-breathing 3D imaging method for RV quantification and to evaluate its performance by comparing it with breath-hold 2D cine imaging in 7 healthy volunteers. Compared with 2D, the 3D RV functional measurements show a reduction of RV end-diastole volume (RVEDV) by 10%, increase of RV end-systole volume (RVESV) by 1.8%, reduction of RV systole volume (RVSV) by 21%, and reduction of RV ejection fraction (RVEF) by 12%. High correlations between the two techniques were found (RVEDV: 0.94; RVESV: 0.85; RVSV: 0.95; and RVEF: 0.89). Compared with 2D, the 3D image quality measurements show a small reduction in blood SNR, myocardium-blood CNR, myocardium contrast, and image sharpness. In conclusion, the proposed self-gated free-breathing 3D cardiac cine imaging technique provides comparable image quality and correlated functional measurements to those acquired with the multiple breath-hold 2D technique in RV. PMID:26185764

  7. Quantification of Coupled Stiffness and Fiber Orientation Remodeling in Hypertensive Rat Right-Ventricular Myocardium Using 3D Ultrasound Speckle Tracking with Biaxial Testing

    PubMed Central

    Park, Dae Woo; Sebastiani, Andrea; Yap, Choon Hwai; Simon, Marc A.; Kim, Kang

    2016-01-01

    Mechanical and structural changes of right ventricular (RV) in response to pulmonary hypertension (PH) are inadequately understood. While current standard biaxial testing provides information on the mechanical behavior of RV tissues using surface markers, it is unable to fully assess structural and mechanical properties across the full tissue thickness. In this study, the mechanical and structural properties of normotensive and pulmonary hypertension right ventricular (PHRV) myocardium through its full thickness were examined using mechanical testing combined with 3D ultrasound speckle tracking (3D-UST). RV pressure overload was induced in Sprague–Dawley rats by pulmonary artery (PA) banding. The second Piola–Kirchhoff stress tensors and Green-Lagrangian strain tensors were computed in the RV myocardium using the biaxial testing combined with 3D-UST. A previously established non-linear curve-fitting algorithm was applied to fit experimental data to a Strain Energy Function (SEF) for computation of myofiber orientation. The fiber orientations obtained by the biaxial testing with 3D-UST compared well with the fiber orientations computed from the histology. In addition, the re-orientation of myofiber in the right ventricular free wall (RVFW) along longitudinal direction (apex-to-outflow-tract direction) was noticeable in response to PH. For normotensive RVFW samples, the average fiber orientation angles obtained by 3D-UST with biaxial test spiraled from 20° at the endo-cardium to -42° at the epi-cardium (Δ = 62°). For PHRV samples, the average fiber orientation angles obtained by 3D-UST with biaxial test had much less spiral across tissue thickness: 3° at endo-cardium to -7° at epi-cardium (Δ = 10°, P<0.005 compared to normotensive). PMID:27780271

  8. Automatic registration between 3D intra-operative ultrasound and pre-operative CT images of the liver based on robust edge matching

    NASA Astrophysics Data System (ADS)

    Nam, Woo Hyun; Kang, Dong-Goo; Lee, Duhgoon; Lee, Jae Young; Ra, Jong Beom

    2012-01-01

    The registration of a three-dimensional (3D) ultrasound (US) image with a computed tomography (CT) or magnetic resonance image is beneficial in various clinical applications such as diagnosis and image-guided intervention of the liver. However, conventional methods usually require a time-consuming and inconvenient manual process for pre-alignment, and the success of this process strongly depends on the proper selection of initial transformation parameters. In this paper, we present an automatic feature-based affine registration procedure of 3D intra-operative US and pre-operative CT images of the liver. In the registration procedure, we first segment vessel lumens and the liver surface from a 3D B-mode US image. We then automatically estimate an initial registration transformation by using the proposed edge matching algorithm. The algorithm finds the most likely correspondences between the vessel centerlines of both images in a non-iterative manner based on a modified Viterbi algorithm. Finally, the registration is iteratively refined on the basis of the global affine transformation by jointly using the vessel and liver surface information. The proposed registration algorithm is validated on synthesized datasets and 20 clinical datasets, through both qualitative and quantitative evaluations. Experimental results show that automatic registration can be successfully achieved between 3D B-mode US and CT images even with a large initial misalignment.

  9. The role of surgeon-performed ultrasound in patients with possible cardiac wounds.

    PubMed Central

    Rozycki, G S; Feliciano, D V; Schmidt, J A; Cushman, J G; Sisley, A C; Ingram, W; Ansley, J D

    1996-01-01

    OBJECTIVE: The authors evaluate surgeon-performed ultrasound in determining the need for operation in patients with possible cardiac wounds. BACKGROUND DATA: Ultrasound quickly is becoming part of the surgeon's diagnostic armamentarium; however, its role for the patient with penetrating injury is less well-defined. Although accurate for the detection of hemopericardium, the lack of immediate availability of the cardiologist to perform the test may delay the diagnosis, adversely affecting patient outcome. To be an effective diagnostic test in trauma centers, ultrasound must be immediately available in the resuscitation area and performed and interpreted by surgeons. METHODS: Surgeons performed pericardial ultrasound examinations on patients with penetrating truncal wounds but no immediate indication for operation. The subcostal view detected hemopericardium, and patients with positive examinations underwent immediate operation by the same surgeon. Vital signs, base deficit, time from examination to operation, operative findings, treatment, and outcome were recorded. RESULTS: During 13 months, 247 patients had surgeon-performed ultrasound. There were 236 true-negative and 10 true-positive results, and no false-negative or false-positive results; however, the pericardial region could not be visualized in one patient. Sensitivity, specificity, and accuracy were 100%; mean examination time was 0.8 minute (246 patients). Of the ten true-positive examinations, three were hypotensive. The mean time (8 patients) from ultrasound to operation was 12.1 minutes; all survived. Operative findings (site of cardiac wounds) were: left ventricle (4), right ventricle (3), right atrium (2), right atrium/superior vena cava (1), and right atrium/inferior vena cava (1). CONCLUSIONS: Surgeon-performed ultrasound is a rapid and accurate technique for diagnosing hemopericardium. Delay times from admission to operating room are minimized when the surgeon performs the ultrasound examination

  10. Improved image guidance technique for minimally invasive mitral valve repair using real-time tracked 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Rankin, Adam; Moore, John; Bainbridge, Daniel; Peters, Terry

    2016-03-01

    In the past ten years, numerous new surgical and interventional techniques have been developed for treating heart valve disease without the need for cardiopulmonary bypass. Heart valve repair is now being performed in a blood-filled environment, reinforcing the need for accurate and intuitive imaging techniques. Previous work has demonstrated how augmenting ultrasound with virtual representations of specific anatomical landmarks can greatly simplify interventional navigation challenges and increase patient safety. These techniques often complicate interventions by requiring additional steps taken to manually define and initialize virtual models. Furthermore, overlaying virtual elements into real-time image data can also obstruct the view of salient image information. To address these limitations, a system was developed that uses real-time volumetric ultrasound alongside magnetically tracked tools presented in an augmented virtuality environment to provide a streamlined navigation guidance platform. In phantom studies simulating a beating-heart navigation task, procedure duration and tool path metrics have achieved comparable performance to previous work in augmented virtuality techniques, and considerable improvement over standard of care ultrasound guidance.

  11. Evaluation of a prototype 3D ultrasound system for multimodality imaging of cervical nodes for adaptive radiation therapy

    NASA Astrophysics Data System (ADS)

    Fraser, Danielle; Fava, Palma; Cury, Fabio; Vuong, Te; Falco, Tony; Verhaegen, Frank

    2007-03-01

    Sonography has good topographic accuracy for superficial lymph node assessment in patients with head and neck cancers. It is therefore an ideal non-invasive tool for precise inter-fraction volumetric analysis of enlarged cervical nodes. In addition, when registered with computed tomography (CT) images, ultrasound information may improve target volume delineation and facilitate image-guided adaptive radiation therapy. A feasibility study was developed to evaluate the use of a prototype ultrasound system capable of three dimensional visualization and multi-modality image fusion for cervical node geometry. A ceiling-mounted optical tracking camera recorded the position and orientation of a transducer in order to synchronize the transducer's position with respect to the room's coordinate system. Tracking systems were installed in both the CT-simulator and radiation therapy treatment rooms. Serial images were collected at the time of treatment planning and at subsequent treatment fractions. Volume reconstruction was performed by generating surfaces around contours. The quality of the spatial reconstruction and semi-automatic segmentation was highly dependent on the system's ability to track the transducer throughout each scan procedure. The ultrasound information provided enhanced soft tissue contrast and facilitated node delineation. Manual segmentation was the preferred method to contour structures due to their sonographic topography.

  12. Investigation and optimization of a finite element simulation of transducer array systems for 3D ultrasound computer tomography with respect to electrical impedance characteristics

    NASA Astrophysics Data System (ADS)

    Kohout, B.; Pirinen, J.; Ruiter, N. V.

    2012-03-01

    The established standard screening method to detect breast cancer is X-ray mammography. However X-ray mammography often has low contrast for tumors located within glandular tissue. A new approach is 3D Ultrasound Computer Tomography (USCT), which is expected to detect small tumors at an early stage. This paper describes the development, improvement and the results of Finite Element Method (FEM) simulations of the Transducer Array System (TAS) used in our 3D USCT. The focus of this work is on researching the influence of meshing and material parameters on the electrical impedance curves. Thereafter, these findings are used to optimize the simulation model. The quality of the simulation was evaluated by comparing simulated impedance characteristics with measured data of the real TAS. The resulting FEM simulation model is a powerful tool to analyze and optimize transducer array systems applied for USCT. With this simulation model, the behavior of TAS for different geometry modifications was researched. It provides a means to understand the acoustical performances inside of any ultrasound transducer represented by its electrical impedance characteristic.

  13. A comparison of needle tip localization accuracy using 2D and 3D trans-rectal ultrasound for high-dose-rate prostate cancer brachytherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Hrinivich, W. Thomas; Hoover, Douglas A.; Surry, Kathleen; Edirisinghe, Chandima; Montreuil, Jacques; D'Souza, David; Fenster, Aaron; Wong, Eugene

    2016-03-01

    Background: High-dose-rate brachytherapy (HDR-BT) is a prostate cancer treatment option involving the insertion of hollow needles into the gland through the perineum to deliver a radioactive source. Conventional needle imaging involves indexing a trans-rectal ultrasound (TRUS) probe in the superior/inferior (S/I) direction, using the axial transducer to produce an image set for organ segmentation. These images have limited resolution in the needle insertion direction (S/I), so the sagittal transducer is used to identify needle tips, requiring a manual registration with the axial view. This registration introduces a source of uncertainty in the final segmentations and subsequent treatment plan. Our lab has developed a device enabling 3D-TRUS guided insertions with high S/I spatial resolution, eliminating the need to align axial and sagittal views. Purpose: To compare HDR-BT needle tip localization accuracy between 2D and 3D-TRUS. Methods: 5 prostate cancer patients underwent conventional 2D TRUS guided HDR-BT, during which 3D images were also acquired for post-operative registration and segmentation. Needle end-length measurements were taken, providing a gold standard for insertion depths. Results: 73 needles were analyzed from all 5 patients. Needle tip position differences between imaging techniques was found to be largest in the S/I direction with mean+/-SD of -2.5+/-4.0 mm. End-length measurements indicated that 3D TRUS provided statistically significantly lower mean+/-SD insertion depth error of -0.2+/-3.4 mm versus 2.3+/-3.7 mm with 2D guidance (p < .001). Conclusions: 3D TRUS may provide more accurate HDR-BT needle localization than conventional 2D TRUS guidance for the majority of HDR-BT needles.

  14. NOTE: Adaptation of a 3D prostate cancer atlas for transrectal ultrasound guided target-specific biopsy

    NASA Astrophysics Data System (ADS)

    Narayanan, R.; Werahera, P. N.; Barqawi, A.; Crawford, E. D.; Shinohara, K.; Simoneau, A. R.; Suri, J. S.

    2008-10-01

    Due to lack of imaging modalities to identify prostate cancer in vivo, current TRUS guided prostate biopsies are taken randomly. Consequently, many important cancers are missed during initial biopsies. The purpose of this study was to determine the potential clinical utility of a high-speed registration algorithm for a 3D prostate cancer atlas. This 3D prostate cancer atlas provides voxel-level likelihood of cancer and optimized biopsy locations on a template space (Zhan et al 2007). The atlas was constructed from 158 expert annotated, 3D reconstructed radical prostatectomy specimens outlined for cancers (Shen et al 2004). For successful clinical implementation, the prostate atlas needs to be registered to each patient's TRUS image with high registration accuracy in a time-efficient manner. This is implemented in a two-step procedure, the segmentation of the prostate gland from a patient's TRUS image followed by the registration of the prostate atlas. We have developed a fast registration algorithm suitable for clinical applications of this prostate cancer atlas. The registration algorithm was implemented on a graphical processing unit (GPU) to meet the critical processing speed requirements for atlas guided biopsy. A color overlay of the atlas superposed on the TRUS image was presented to help pick statistically likely regions known to harbor cancer. We validated our fast registration algorithm using computer simulations of two optimized 7- and 12-core biopsy protocols to maximize the overall detection rate. Using a GPU, patient's TRUS image segmentation and atlas registration took less than 12 s. The prostate cancer atlas guided 7- and 12-core biopsy protocols had cancer detection rates of 84.81% and 89.87% respectively when validated on the same set of data. Whereas the sextant biopsy approach without the utility of 3D cancer atlas detected only 70.5% of the cancers using the same histology data. We estimate 10-20% increase in prostate cancer detection rates

  15. Reduced serum content and increased matrix stiffness promote the cardiac myofibroblast transition in 3D collagen matrices.

    PubMed Central

    Galie, Peter A.; Westfall, Margaret V.; Stegemann, Jan P.

    2011-01-01

    Introduction The fibroblast-myofibroblast transition is an important event in the development of cardiac fibrosis and scar formation initiated after myocardial ischemia. The goals of the present study were to better understand the contribution of environmental factors to this transition and determine whether myofibroblasts provide equally important feedback to the surrounding environment. Methods The influence of matrix stiffness and serum concentration on the myofibroblast transition was assessed by measuring message levels of a panel of cardiac fibroblast phenotype markers using quantitative rtPCR. Cell-mediated gel compaction measured the influence of environmental factors on cardiac fibroblast contractility. Immunohistochemistry characterized α-SMA expression and cell morphology, while static and dynamic compression testing evaluated the effect of the cell response on the mechanical properties of the cell-seeded collagen hydrogels. Results Both reduced serum content and increased matrix stiffness contributed to the myofibroblast transition, as indicated by contractile compaction of the gels, increased message levels of col3α1 and α-SMA, and a less stellate morphology. However, the effects of serum and matrix stiffness were not additive. Mechanical testing indicated the cell-seeded gels became less viscoelastic with time, and that reduced serum content also increased the initial elastic properties of the gel. Conclusions The results suggest that reduced serum and increased matrix stiffness promote the myofibroblast phenotype in the myocardium. This transition both enhances and is promoted by matrix stiffness, indicating the presence of positive feedback that may contribute to the pathogenesis of cardiac fibrosis. Summary Lower serum content and increased matrix stiffness accelerated the transition of cardiac fibroblasts seeded in collagen hydrogels to a myofibroblast phenotype, though their effects were not additive. Reduced serum also affected mechanical

  16. A comparison study of atlas-based 3D cardiac MRI segmentation: global versus global and local transformations

    NASA Astrophysics Data System (ADS)

    Daryanani, Aditya; Dangi, Shusil; Ben-Zikri, Yehuda Kfir; Linte, Cristian A.

    2016-03-01

    Magnetic Resonance Imaging (MRI) is a standard-of-care imaging modality for cardiac function assessment and guidance of cardiac interventions thanks to its high image quality and lack of exposure to ionizing radiation. Cardiac health parameters such as left ventricular volume, ejection fraction, myocardial mass, thickness, and strain can be assessed by segmenting the heart from cardiac MRI images. Furthermore, the segmented pre-operative anatomical heart models can be used to precisely identify regions of interest to be treated during minimally invasive therapy. Hence, the use of accurate and computationally efficient segmentation techniques is critical, especially for intra-procedural guidance applications that rely on the peri-operative segmentation of subject-specific datasets without delaying the procedure workflow. Atlas-based segmentation incorporates prior knowledge of the anatomy of interest from expertly annotated image datasets. Typically, the ground truth atlas label is propagated to a test image using a combination of global and local registration. The high computational cost of non-rigid registration motivated us to obtain an initial segmentation using global transformations based on an atlas of the left ventricle from a population of patient MRI images and refine it using well developed technique based on graph cuts. Here we quantitatively compare the segmentations obtained from the global and global plus local atlases and refined using graph cut-based techniques with the expert segmentations according to several similarity metrics, including Dice correlation coefficient, Jaccard coefficient, Hausdorff distance, and Mean absolute distance error.

  17. Therapeutic Ultrasound to Non-Invasively Create Intra-Cardiac Communications in an Intact Animal Model

    PubMed Central

    Owens, Gabe E.; Miller, Ryan M.; Ensing, Greg; Ives, Kimberly; Gordon, David; Ludomirsky, Achi; Xu, Zhen

    2010-01-01

    Objective To determine if pulsed cavitational ultrasound therapy (histotripsy) can accurately and safely generate ventricular septal defects (VSDs) through the intact chest of a neonatal animal, with the eventual goal of developing a non-invasive technique of creating intra-cardiac communications in patients with congenital heart disease. Background Histotripsy is an innovative ultrasonic technique that generates demarcated, mechanical tissue fractionation utilizing high intensity ultrasound pulses. Previous work has shown that histotripsy can create atrial septal defects in a beating heart in an open-chest canine model. Methods Nine neonatal pigs were treated with transcutaneous histotripsy targeting the ventricular septum. Ultrasound pulses of 5μs duration at a peak negative pressure of 13 MPa and a pulse repetition frequency of 1 kHz were generated by a 1 MHz focused transducer. The procedure was guided by real-time ultrasound imaging. Results VSDs were created in all pigs with diameters ranging from 2–6.5mm. Six pigs were euthanized within 2 hrs of treatment, while 3 were recovered and maintained for 2–3 days to evaluate lesion maturation and clinical side effects. There were only transient clinical effects and pathology revealed mild collateral damage around the VSD with no significant damage to other cardiac or extra-cardiac structures. Conclusions Histotripsy can accurately and safely generate VSDs through the intact chest in a neonatal animal model. These results suggest that with further advances, histotripsy can be a useful, non-invasive technique to create intra-cardiac communications, which currently require invasive catheter-based or surgical procedures, to clinically stabilize newborn infants with complex congenital heart disease. PMID:20853366

  18. Free Tools and Strategies for the Generation of 3D Finite Element Meshes: Modeling of the Cardiac Structures

    PubMed Central

    Pavarino, E.; Neves, L. A.; Machado, J. M.; de Godoy, M. F.; Shiyou, Y.; Momente, J. C.; Zafalon, G. F. D.; Pinto, A. R.; Valêncio, C. R.

    2013-01-01

    The Finite Element Method is a well-known technique, being extensively applied in different areas. Studies using the Finite Element Method (FEM) are targeted to improve cardiac ablation procedures. For such simulations, the finite element meshes should consider the size and histological features of the target structures. However, it is possible to verify that some methods or tools used to generate meshes of human body structures are still limited, due to nondetailed models, nontrivial preprocessing, or mainly limitation in the use condition. In this paper, alternatives are demonstrated to solid modeling and automatic generation of highly refined tetrahedral meshes, with quality compatible with other studies focused on mesh generation. The innovations presented here are strategies to integrate Open Source Software (OSS). The chosen techniques and strategies are presented and discussed, considering cardiac structures as a first application context. PMID:23762031

  19. Free Tools and Strategies for the Generation of 3D Finite Element Meshes: Modeling of the Cardiac Structures.

    PubMed

    Pavarino, E; Neves, L A; Machado, J M; de Godoy, M F; Shiyou, Y; Momente, J C; Zafalon, G F D; Pinto, A R; Valêncio, C R

    2013-01-01

    The Finite Element Method is a well-known technique, being extensively applied in different areas. Studies using the Finite Element Method (FEM) are targeted to improve cardiac ablation procedures. For such simulations, the finite element meshes should consider the size and histological features of the target structures. However, it is possible to verify that some methods or tools used to generate meshes of human body structures are still limited, due to nondetailed models, nontrivial preprocessing, or mainly limitation in the use condition. In this paper, alternatives are demonstrated to solid modeling and automatic generation of highly refined tetrahedral meshes, with quality compatible with other studies focused on mesh generation. The innovations presented here are strategies to integrate Open Source Software (OSS). The chosen techniques and strategies are presented and discussed, considering cardiac structures as a first application context. PMID:23762031

  20. Numerical modeling of the 3D dynamics of ultrasound contrast agent microbubbles using the boundary integral method

    NASA Astrophysics Data System (ADS)

    Wang, Qianxi; Manmi, Kawa; Calvisi, Michael L.

    2015-02-01

    Ultrasound contrast agents (UCAs) are microbubbles stabilized with a shell typically of lipid, polymer, or protein and are emerging as a unique tool for noninvasive therapies ranging from gene delivery to tumor ablation. While various models have been developed to describe the spherical oscillations of contrast agents, the treatment of nonspherical behavior has received less attention. However, the nonspherical dynamics of contrast agents are thought to play an important role in therapeutic applications, for example, enhancing the uptake of therapeutic agents across cell membranes and tissue interfaces, and causing tissue ablation. In this paper, a model for nonspherical contrast agent dynamics based on the boundary integral method is described. The effects of the encapsulating shell are approximated by adapting Hoff's model for thin-shell, spherical contrast agents. A high-quality mesh of the bubble surface is maintained by implementing a hybrid approach of the Lagrangian method and elastic mesh technique. The numerical model agrees well with a modified Rayleigh-Plesset equation for encapsulated spherical bubbles. Numerical analyses of the dynamics of UCAs in an infinite liquid and near a rigid wall are performed in parameter regimes of clinical relevance. The oscillation amplitude and period decrease significantly due to the coating. A bubble jet forms when the amplitude of ultrasound is sufficiently large, as occurs for bubbles without a coating; however, the threshold amplitude required to incite jetting increases due to the coating. When a UCA is near a rigid boundary subject to acoustic forcing, the jet is directed towards the wall if the acoustic wave propagates perpendicular to the boundary. When the acoustic wave propagates parallel to the rigid boundary, the jet direction has components both along the wave direction and towards the boundary that depend mainly on the dimensionless standoff distance of the bubble from the boundary. In all cases, the jet

  1. Position tracking of moving liver lesion based on real-time registration between 2D ultrasound and 3D preoperative images

    SciTech Connect

    Weon, Chijun; Hyun Nam, Woo; Lee, Duhgoon; Ra, Jong Beom; Lee, Jae Young

    2015-01-15

    Purpose: Registration between 2D ultrasound (US) and 3D preoperative magnetic resonance (MR) (or computed tomography, CT) images has been studied recently for US-guided intervention. However, the existing techniques have some limits, either in the registration speed or the performance. The purpose of this work is to develop a real-time and fully automatic registration system between two intermodal images of the liver, and subsequently an indirect lesion positioning/tracking algorithm based on the registration result, for image-guided interventions. Methods: The proposed position tracking system consists of three stages. In the preoperative stage, the authors acquire several 3D preoperative MR (or CT) images at different respiratory phases. Based on the transformations obtained from nonrigid registration of the acquired 3D images, they then generate a 4D preoperative image along the respiratory phase. In the intraoperative preparatory stage, they properly attach a 3D US transducer to the patient’s body and fix its pose using a holding mechanism. They then acquire a couple of respiratory-controlled 3D US images. Via the rigid registration of these US images to the 3D preoperative images in the 4D image, the pose information of the fixed-pose 3D US transducer is determined with respect to the preoperative image coordinates. As feature(s) to use for the rigid registration, they may choose either internal liver vessels or the inferior vena cava. Since the latter is especially useful in patients with a diffuse liver disease, the authors newly propose using it. In the intraoperative real-time stage, they acquire 2D US images in real-time from the fixed-pose transducer. For each US image, they select candidates for its corresponding 2D preoperative slice from the 4D preoperative MR (or CT) image, based on the predetermined pose information of the transducer. The correct corresponding image is then found among those candidates via real-time 2D registration based on a

  2. Non-rigid registration of a 3D ultrasound and a MR image data set of the female pelvic floor using a biomechanical model

    PubMed Central

    Verhey, Janko F; Wisser, Josef; Warfield, Simon K; Rexilius, Jan; Kikinis, Ron

    2005-01-01

    Background The visual combination of different modalities is essential for many medical imaging applications in the field of Computer-Assisted medical Diagnosis (CAD) to enhance the clinical information content. Clinically, incontinence is a diagnosis with high clinical prevalence and morbidity rate. The search for a method to identify risk patients and to control the success of operations is still a challenging task. The conjunction of magnetic resonance (MR) and 3D ultrasound (US) image data sets could lead to a new clinical visual representation of the morphology as we show with corresponding data sets of the female anal canal with this paper. Methods We present a feasibility study for a non-rigid registration technique based on a biomechanical model for MR and US image data sets of the female anal canal as a base for a new innovative clinical visual representation. Results It is shown in this case study that the internal and external sphincter region could be registered elastically and the registration partially corrects the compression induced by the ultrasound transducer, so the MR data set showing the native anatomy is used as a frame for the US data set showing the same region with higher resolution but distorted by the transducer Conclusion The morphology is of special interest in the assessment of anal incontinence and the non-rigid registration of normal clinical MR and US image data sets is a new field of the adaptation of this method incorporating the advantages of both technologies. PMID:15777475

  3. 3D Multi-Object Segmentation of Cardiac MSCT Imaging by using a Multi-Agent Approach

    PubMed Central

    Fleureau, Julien; Garreau, Mireille; Boulmier, Dominique; Hernandez, Alfredo

    2007-01-01

    We propose a new technique for general purpose, semi-interactive and multi-object segmentation in N-dimensional images, applied to the extraction of cardiac structures in MultiSlice Computed Tomography (MSCT) imaging. The proposed approach makes use of a multi-agent scheme combined with a supervised classification methodology allowing the introduction of a priori information and presenting fast computing times. The multi-agent system is organised around a communicating agent which manages a population of situated agents which segment the image through cooperative and competitive interactions. The proposed technique has been tested on several patient data sets. Some typical results are finally presented and discussed. PMID:18003382

  4. Development of transrectal diffuse optical tomography combined with 3D-transrectal ultrasound imaging to monitor the photocoagulation front during interstitial photothermal therapy of primary focal prostate cancer

    NASA Astrophysics Data System (ADS)

    He, Jie; Weersink, Robert; Veilleux, Israel; Mayo, Kenwrick; Zhang, Anqi; Piao, Daqing; Alam, Adeel; Trachtenberg, John; Wilson, Brian C.

    2013-03-01

    Interstitial near-infrared laser thermal therapy (LITT) is currently undergoing clinical trials as an alternative to watchful waiting or radical surgery in patients with low-risk focal prostate cancer. Currently, we use magnetic resonance image (MRI)-based thermography to monitor treatment delivery and determine indirectly the completeness of the target tissue destruction while avoiding damage to adjacent normal tissues, particularly the rectal wall. However, incomplete tumor destruction has occurred in a significant fraction of patients due to premature termination of treatment, since the photocoagulation zone is not directly observed. Hence, we are developing transrectal diffuse optical tomography (TRDOT), in combination with transrectal 3D ultrasound (3D-TRUS), to address his limitation. This is based on the large changes in optical scattering expected upon tissue coagulation. Here, we present forward simulations of a growing coagulated lesion with optical scattering contrast, using an established finite element analysis software platform (NIRFAST). The simulations were validated in tissue-simulating phantoms, with measurements acquired by a state-of-the-art continuous wave (CW) TRDOT system and a recently assembled bench-top CW-DOT system, with specific source-detector configurations. Two image reconstruction schemes were investigated and evaluated, specifically for the accurate delineation of the posterior boundary of the coagulation zone as the critical parameter for treatment guidance in this clinical application.

  5. Spread of excitation in 3-D models of the anisotropic cardiac tissue. II. Effects of fiber architecture and ventricular geometry.

    PubMed

    Franzone, P C; Guerri, L; Pennacchio, M; Taccardi, B

    1998-01-15

    We investigate a three-dimensional macroscopic model of wave-front propagation related to the excitation process in the left ventricular wall represented by an anisotropic bidomain. The whole left ventricle is modeled, whereas, in a previous paper, only a flat slab of myocardial tissue was considered. The direction of cardiac fibers, which affects the anisotropic conductivity of the myocardium, rotates from the epi- to the endocardium. If the ventricular wall is conceived as a set of packed surfaces, the fibers may be tangent to them or more generally may cross them obliquely; the latter case is described by an "imbrication angle." The effect of a simplified Purkinje network also is investigated. The cardiac excitation process, more particularly the depolarization phase, is modeled by a nonlinear elliptic equation, called an eikonal equation, in the activation time. The numerical solution of this equation is obtained by means of the finite element method, which includes an upwind treatment of the Hamiltonian part of the equation. By means of numerical simulations in an idealized model of the left ventricle, we try to establish whether the eikonal approach contains the essential basic elements for predicting the features of the activation patterns experimentally observed. We discuss and compare these results with those obtained in our previous papers for a flat part of myocardium. The general rules governing the spread of excitation after local stimulations, previously delineated for the flat geometry, are extended to the present, more realistic monoventricular model.

  6. A 3-D finite-element model for computation of temperature profiles and regions of thermal damage during focused ultrasound surgery exposures.

    PubMed

    Meaney, P M; Clarke, R L; ter Haar, G R; Rivens, I H

    1998-11-01

    Although there have been numerous models implemented for modeling thermal diffusion effects during focused ultrasound surgery (FUS), most have limited themselves to representing simple situations for which analytical solutions and the use of cylindrical geometries sufficed. For modeling single lesion formation and the heating patterns from a single exposure, good results were achieved in comparison with experimental results for predicting lesion size, shape and location. However, these types of approaches are insufficient when considering the heating of multiple sites with FUS exposures when the time interval between exposures is short. In such cases, the heat dissipation patterns from initial exposures in the lesion array formation can play a significant role in the heating patterns for later exposures. Understanding the effects of adjacent lesion formation, such as this, requires a three-dimensional (3-D) representation of the bioheat equation. Thus, we have developed a 3-D finite-element representation for modeling the thermal diffusion effects during FUS exposures in clinically relevant tissue volumes. The strength of this approach over past methods is its ability to represent arbitrarily shaped 3-D situations. Initial simulations have allowed calculation of the temperature distribution as a function of time for adjacent FUS exposures in excised bovine liver, with the individually computed point temperatures comparing favorably with published measurements. In addition to modeling these temperature distributions, the model was implemented in conjunction with an algorithm for calculating the thermal dose as a way of predicting lesion shape. Although used extensively in conventional hyperthermia applications, this thermal dose criterion has only been applied in a limited number of simulations in FUS for comparison with experimental measurements. In this study, simulations were run for focal depths 2 and 3 cm below the surface of pig's liver, using multiple

  7. Multiple capture locations for 3D ultrasound-guided robotic retrieval of moving bodies from a beating heart

    NASA Astrophysics Data System (ADS)

    Thienphrapa, Paul; Ramachandran, Bharat; Elhawary, Haytham; Taylor, Russell H.; Popovic, Aleksandra

    2012-02-01

    Free moving bodies in the heart pose a serious health risk as they may be released in the arteries causing blood flow disruption. These bodies may be the result of various medical conditions and trauma. The conventional approach to removing these objects involves open surgery with sternotomy, the use of cardiopulmonary bypass, and a wide resection of the heart muscle. We advocate a minimally invasive surgical approach using a flexible robotic end effector guided by 3D transesophageal echocardiography. In a phantom study, we track a moving body in a beating heart using a modified normalized cross-correlation method, with mean RMS errors of 2.3 mm. We previously found the foreign body motion to be fast and abrupt, rendering infeasible a retrieval method based on direct tracking. We proposed a strategy based on guiding a robot to the most spatially probable location of the fragment and securing it upon its reentry to said location. To improve efficacy in the context of a robotic retrieval system, we extend this approach by exploring multiple candidate capture locations. Salient locations are identified based on spatial probability, dwell time, and visit frequency; secondary locations are also examined. Aggregate results indicate that the location of highest spatial probability (50% occupancy) is distinct from the longest-dwelled location (0.84 seconds). Such metrics are vital in informing the design of a retrieval system and capture strategies, and they can be computed intraoperatively to select the best capture location based on constraints such as workspace, time, and device manipulability. Given the complex nature of fragment motion, the ability to analyze multiple capture locations is a desirable capability in an interventional system.

  8. The study of simulated microgravity effects on cardiac myocytes using a 3D heart tissue-equivalent model encapsulated in alginate microbeads

    NASA Astrophysics Data System (ADS)

    Li, Yu; Tian, Weiming; Zheng, Hongxia; Yu, Lei; Zhang, Yao; Han, Fengtong

    Long duration spaceflight may increase the risk and occurrence of potentially life-threatening heart rhythm disturbances associated with alterations of cardiac myocytes, myocyte connec-tivity, and extracellular matrix resulting from prolonged exposure to zero-or low-gravity. For understanding of the effects of microgravity, either traditional 2-dimensional (2D) cell cultures of adherent cell populations or animal models were typically used. The 2D in vitro systems do not allow assessment of the dynamic effects of intercellular interactions within tissues, whereas potentially confounding factors tend to be overlooked in animal models. Therefore novel cell culture model representative of the cellular interactions and with extracellular matrix present in tissues needs to be used. In this study, 3D multi-cellular heart tissue-equivalent model was constructed by culturing neonatal rat myocardial cells in alginate microbeads for one week. With this model we studied the simulated microgravity effects on myocardiocytes by incubat-ing the microbeads in NASA rotary cell culture system with a rate of 15rpm. Cytoskeletal changes, mitochondrial membrane potential and reactive oxygen production were studied after incubating for 24h, 48h and 72h respectively. Compared with 3D ground-culture group, sig-nificant cytoskeleton depolymerization characterized by pseudo-feet disappearance, significant increase of mitochondrial membrane potential, and greater reactive oxygen production were observed in after incubating 24h, 48h, and 72h, in NASA system. The beating rate of 3D heart tissue-equivalent decreased significantly at 24h, and all the samples stopped beating after 48h incubation while the beating rate of control group did not change. This study indicated that mi-crogravity affects both the structure and function of myocardial cells. Our results suggest that a 3D heart tissue-equivalent model maybe better for attempting to elucidate the microgravity effects on myocardiocytes in

  9. Robust spatio-temporal registration of 4D cardiac ultrasound sequences

    NASA Astrophysics Data System (ADS)

    Bersvendsen, Jørn; Toews, Matthew; Danudibroto, Adriyana; Wells, William M.; Urheim, Stig; Estépar, Raúl San José; Samset, Eigil

    2016-04-01

    Registration of multiple 3D ultrasound sectors in order to provide an extended field of view is important for the appreciation of larger anatomical structures at high spatial and temporal resolution. In this paper, we present a method for fully automatic spatio-temporal registration between two partially overlapping 3D ultrasound sequences. The temporal alignment is solved by aligning the normalized cross correlation-over-time curves of the sequences. For the spatial alignment, corresponding 3D Scale Invariant Feature Transform (SIFT) features are extracted from all frames of both sequences independently of the temporal alignment. A rigid transform is then calculated by least squares minimization in combination with random sample consensus. The method is applied to 16 echocardiographic sequences of the left and right ventricles and evaluated against manually annotated temporal events and spatial anatomical landmarks. The mean distances between manually identified landmarks in the left and right ventricles after automatic registration were (mean+/-SD) 4.3+/-1.2 mm compared to a reference error of 2.8 +/- 0.6 mm with manual registration. For the temporal alignment, the absolute errors in valvular event times were 14.4 +/- 11.6 ms for Aortic Valve (AV) opening, 18.6 +/- 16.0 ms for AV closing, and 34.6 +/- 26.4 ms for mitral valve opening, compared to a mean inter-frame time of 29 ms.

  10. Magnetic resonance imaging-targeted, 3D transrectal ultrasound-guided fusion biopsy for prostate cancer: Quantifying the impact of needle delivery error on diagnosis

    SciTech Connect

    Martin, Peter R.; Cool, Derek W.; Romagnoli, Cesare; Fenster, Aaron; Ward, Aaron D.

    2014-07-15

    Purpose: Magnetic resonance imaging (MRI)-targeted, 3D transrectal ultrasound (TRUS)-guided “fusion” prostate biopsy intends to reduce the ∼23% false negative rate of clinical two-dimensional TRUS-guided sextant biopsy. Although it has been reported to double the positive yield, MRI-targeted biopsies continue to yield false negatives. Therefore, the authors propose to investigate how biopsy system needle delivery error affects the probability of sampling each tumor, by accounting for uncertainties due to guidance system error, image registration error, and irregular tumor shapes. Methods: T2-weighted, dynamic contrast-enhanced T1-weighted, and diffusion-weighted prostate MRI and 3D TRUS images were obtained from 49 patients. A radiologist and radiology resident contoured 81 suspicious regions, yielding 3D tumor surfaces that were registered to the 3D TRUS images using an iterative closest point prostate surface-based method to yield 3D binary images of the suspicious regions in the TRUS context. The probabilityP of obtaining a sample of tumor tissue in one biopsy core was calculated by integrating a 3D Gaussian distribution over each suspicious region domain. Next, the authors performed an exhaustive search to determine the maximum root mean squared error (RMSE, in mm) of a biopsy system that gives P ≥ 95% for each tumor sample, and then repeated this procedure for equal-volume spheres corresponding to each tumor sample. Finally, the authors investigated the effect of probe-axis-direction error on measured tumor burden by studying the relationship between the error and estimated percentage of core involvement. Results: Given a 3.5 mm RMSE for contemporary fusion biopsy systems,P ≥ 95% for 21 out of 81 tumors. The authors determined that for a biopsy system with 3.5 mm RMSE, one cannot expect to sample tumors of approximately 1 cm{sup 3} or smaller with 95% probability with only one biopsy core. The predicted maximum RMSE giving P ≥ 95% for each

  11. A coupled 3D-1D numerical monodomain solver for cardiac electrical activation in the myocardium with detailed Purkinje network

    NASA Astrophysics Data System (ADS)

    Vergara, Christian; Lange, Matthias; Palamara, Simone; Lassila, Toni; Frangi, Alejandro F.; Quarteroni, Alfio

    2016-03-01

    We present a model for the electrophysiology in the heart to handle the electrical propagation through the Purkinje system and in the myocardium, with two-way coupling at the Purkinje-muscle junctions. In both the subproblems the monodomain model is considered, whereas at the junctions a resistor element is included that induces an orthodromic propagation delay from the Purkinje network towards the heart muscle. We prove a sufficient condition for convergence of a fixed-point iterative algorithm to the numerical solution of the coupled problem. Numerical comparison of activation patterns is made with two different combinations of models for the coupled Purkinje network/myocardium system, the eikonal/eikonal and the monodomain/monodomain models. Test cases are investigated for both physiological and pathological activation of a model left ventricle. Finally, we prove the reliability of the monodomain/monodomain coupling on a realistic scenario. Our results underlie the importance of using physiologically realistic Purkinje-trees with propagation solved using the monodomain model for simulating cardiac activation.

  12. Spreading of excitation in 3-D models of the anisotropic cardiac tissue. I. Validation of the eikonal model.

    PubMed

    Franzone, P C; Guerri, L

    1993-02-01

    In this work we investigate, by means of numerical simulations, the performance of two mathematical models describing the spread of excitation in a three dimensional block representing anisotropic cardiac tissue. The first model is characterized by a reaction-diffusion system in the transmembrane and extracellular potentials v and u. The second model is derived from the first by means of a perturbation technique. It is characterized by an eikonal equation, nonlinear and elliptic in the activation time psi(x). The level surfaces psi(x) = t represent the wave-front positions. The numerical procedures based on the two models were applied to test functions and to excitation processes elicited by local stimulations in a relatively small block. The results are in excellent agreement, and for the same problem the computation time required by the eikonal equation is a small fraction of that needed for the reaction-diffusion system. Thus we have strong evidence that the eikonal equation provides a reliable and numerically efficient model of the excitation process. Moreover, numerical simulations have been performed to validate an approximate model for the extracellular potential based on knowledge of the excitation sequence. The features of the extracellular potential distribution affected by the anisotropic conductivity of the medium were investigated.

  13. In Vivo Evaluations of a Phased Ultrasound Array for Transesophageal Cardiac Ablation

    NASA Astrophysics Data System (ADS)

    Jaiswal, Devina; Werner, Jacob; Park, Eun-Joo; Francischelli, David; Smith, Nadine Barrie

    2010-03-01

    Atrial fibrillation is one of the most common arrhythmias that affects over 2.2 million Americans each year. Catheter ablation, one of the effective treatments, has shown high rate of success in treating paroxysmal atrial fibrillation. Currently, radiofrequency which is being used for catheter ablation is an invasive procedure. Measurable morbidity and significant costs and time are associated with this modality of treatment of permanent or persistent atrial fibrillation. In order to address these issues, a transesophageal ultrasound applicator for noninvasive cardiac ablation was designed, developed and evaluated. The ultrasound energy delivered by the phased array was used to create a lesion in the myocardial tissue. Various factors, simulation results of transducer arrays, current transesophageal medical devices, and throat anatomy, were considered while designing a phased ultrasound transducer that can be inserted into the esophagus. For this research, a two-dimensional sparse phased array with flat tapered elements was fabricated and evaluated in in vivo experiments. Five pigs were anesthetized; the array was passed transesophagealy and positioned over the heart. An operating frequency of 1.6 MHz and 8˜15 minutes of array operation resulted in both single and multiple lesions on atrial and ventricular myocardium. The average size of lesions was 5.1±2.1 mm in diameter and 7.8±2.5 mm in length. Experimental results indicate that the array delivered sufficient power to produce ablation at the focal point while not grossly damaging the tissue surrounding the area of interest. These results demonstrate a potential application of the ultrasound applicator for noninvasive transesophageal cardiac surgery in atrial fibrillation treatment.

  14. Ultrasound Dilution: An Accurate Means of Determining Cardiac Output in Children

    PubMed Central

    Crittendon, Ivory; Dreyer, William J.; Decker, Jamie A; Kim, Jeffrey J.

    2011-01-01

    Background Cardiac output (CO) is a useful measure of myocardial performance. CO monitoring is frequently performed in critically ill adults in order to guide physicians’ treatment strategies. However, standard methods of determining CO in children are not without risk and can be problematic secondary to their invasive nature and other technical problems. COstatus® system (Transonic Systems Inc, NY, USA), which is based on ultrasound dilution technology, works off in situ catheters and uses an innocuous indicator to allow for routine measurements of cardiac output and blood volumes in pediatric patients. The purpose of this study was to validate CO measured by COstatus® with those obtained by the clinical standard technique of pulmonary artery (PAC) thermodilution. Methods This was a prospective evaluation performed at a single institution. Any child with a structurally normal heart undergoing hemodynamic evaluation in the cardiac catheterization laboratory was included. A prograde right heart catheterization was performed, and CO was first determined by using the PAC thermodilution technique. Thermodilution results were then compared with CO measurements obtained using the COstatus system. The results were analyzed by standard correlation, Bland-Altman, and Crichtley and Critchley analyses. Results Twenty-eight patients were evaluated with a median age of 8 yrs and a median weight of 31 kg. The mean thermodilution cardiac index = 3.18 L/min (+/− 1.35 L/min), and the mean COstatus® cardiac index = 3.17 L/min (+/− 1.31 L/min). Standard Pearson correlation tests revealed an excellent correlation coefficient of 0.95 (p<0.0001). Bland-Altman analysis revealed good clinical agreement with a mean difference of −0.004 L/min with a precision of 0.8 L/min/ at 2 SD. A percentage error of 25.4% was noticed in this study which is less than the clinically acceptable limit. Conclusion The ultrasound dilution technique of determining CO using the COstatus® system

  15. Novel System for Real-Time Integration of 3-D Echocardiography and Fluoroscopy for Image-Guided Cardiac Interventions: Preclinical Validation and Clinical Feasibility Evaluation

    PubMed Central

    Housden, R. James; Ma, Yingliang; Rajani, Ronak; Gao, Gang; Nijhof, Niels; Cathier, Pascal; Bullens, Roland; Gijsbers, Geert; Parish, Victoria; Kapetanakis, Stamatis; Hancock, Jane; Rinaldi, C. Aldo; Cooklin, Michael; Gill, Jaswinder; Thomas, Martyn; O'neill, Mark D.; Razavi, Reza; Rhode, Kawal S.

    2014-01-01

    Real-time imaging is required to guide minimally invasive catheter-based cardiac interventions. While transesophageal echocardiography allows for high-quality visualization of cardiac anatomy, X-ray fluoroscopy provides excellent visualization of devices. We have developed a novel image fusion system that allows real-time integration of 3-D echocardiography and the X-ray fluoroscopy. The system was validated in the following two stages: 1) preclinical to determine function and validate accuracy; and 2) in the clinical setting to assess clinical workflow feasibility and determine overall system accuracy. In the preclinical phase, the system was assessed using both phantom and porcine experimental studies. Median 2-D projection errors of 4.5 and 3.3 mm were found for the phantom and porcine studies, respectively. The clinical phase focused on extending the use of the system to interventions in patients undergoing either atrial fibrillation catheter ablation (CA) or transcatheter aortic valve implantation (TAVI). Eleven patients were studied with nine in the CA group and two in the TAVI group. Successful real-time view synchronization was achieved in all cases with a calculated median distance error of 2.2 mm in the CA group and 3.4 mm in the TAVI group. A standard clinical workflow was established using the image fusion system. These pilot data confirm the technical feasibility of accurate real-time echo-fluoroscopic image overlay in clinical practice, which may be a useful adjunct for real-time guidance during interventional cardiac procedures. PMID:27170872

  16. An Experimental Model Using Cultured Cardiac Myocytes for a Study of the Generation of Premature Ventricular Contractions Under Ultrasound Exposure

    NASA Astrophysics Data System (ADS)

    Kudo, Nobuki; Yamamoto, Masaya

    2011-09-01

    It is known that use of a contrast agents in echocardiography increases the probability of generation of premature ventricular contractions (PVCs). As a basic study to elucidate the mechanisms and to reduce adverse effects, the generation of PVCs was investigated using cultured cardiac myocytes instead of the intact heart in vivo. Cardiac myocytes were isolated from neonatal rats and cultured on a cover slip. The myocyte sample was exposed to pulsed ultrasound with microbubbles adjacent to the myocytes, and generation of PVCs was examined with ultrasound exposure at various delay times after onset of myocyte contraction. The experimental results showed that generation of PVCs had a stable threshold delay time and that PVCs were generated only when myocytes were exposed to ultrasound with delay times longer than the threshold. The results indicate that the model used in this study is useful for revealing the mechanisms by which PVCs are induced by ultrasound exposure.

  17. Feasibility of Using Volumetric Contrast-Enhanced Ultrasound with a 3-D Transducer to Evaluate Therapeutic Response after Targeted Therapy in Rabbit Hepatic VX2 Carcinoma.

    PubMed

    Kim, Jeehyun; Kim, Jung Hoon; Yoon, Soon Ho; Choi, Won Seok; Kim, Young Jae; Han, Joon Koo; Choi, Byung-Ihn

    2015-12-01

    The aim of this study was to assess the feasibility of using dynamic contrast-enhanced ultrasound (DCE-US) with a 3-D transducer to evaluate therapeutic responses to targeted therapy. Rabbits with hepatic VX2 carcinomas, divided into a treatment group (n = 22, 30 mg/kg/d sorafenib) and a control group (n = 13), were evaluated with DCE-US using 2-D and 3-D transducers and computed tomography (CT) perfusion imaging at baseline and 1 d after the first treatment. Perfusion parameters were collected, and correlations between parameters were analyzed. In the treatment group, both volumetric and 2-D DCE-US perfusion parameters, including peak intensity (33.2 ± 19.9 vs. 16.6 ± 10.7, 63.7 ± 20.0 vs. 30.1 ± 19.8), slope (15.3 ± 12.4 vs. 5.7 ± 4.5, 37.3 ± 20.4 vs. 15.7 ± 13.0) and area under the curve (AUC; 1004.1 ± 560.3 vs. 611.4 ± 421.1, 1332.2 ± 708.3 vs. 670.4 ± 388.3), had significantly decreased 1 d after the first treatment (p = 0.00). In the control group, 2-D DCE-US revealed that peak intensity, time to peak and slope had significantly changed (p < 0.05); however, volumetric DCE-US revealed that peak intensity, time-intensity AUC, AUC during wash-in and AUC during wash-out had significantly changed (p = 0.00). CT perfusion imaging parameters, including blood flow, blood volume and permeability of the capillary vessel surface, had significantly decreased in the treatment group (p = 0.00); however, in the control group, peak intensity and blood volume had significantly increased (p = 0.00). It is feasible to use DCE-US with a 3-D transducer to predict early therapeutic response after targeted therapy because perfusion parameters, including peak intensity, slope and AUC, significantly decreased, which is similar to the trend observed for 2-D DCE-US and CT perfusion imaging parameters. PMID:26365926

  18. Focused ultrasound of the pleural cavities and the pericardium by nurses after cardiac surgery

    PubMed Central

    Wahba, Alexander; Hammer, Anne Marie; Sagen, Ove; Olsen, Øystein; Skjetne, Kyrre; Kleinau, Jens Olaf; Dalen, Havard

    2015-01-01

    Objectives. We aimed to study the feasibility and reliability of focused ultrasound (US) examinations to quantify pericardial (PE)- and pleural effusion (PLE) by a pocket-size imaging device (PSID) performed by nurses in patients early after cardiac surgery. Design. After a 3-month training period, with cardiologists as supervisors, two nurses examined 59 patients (20 women) with US using a PSID at a median of 5 days after cardiac surgery. The amount of PE and PLE was classified in four categories by US (both) and chest x-ray (PLE only). Echocardiography, including US of the pleural cavities, by experienced cardiologists was used as reference. Results. Focused US by the nurses was more sensitive than x-ray to detect PLE. The correlations of the quantification of PE and PLE by the nurses and reference was r (95% confidence interval) 0.76 (0.46–0.89) and 0.81 (0.73–0.89), both p < 0.001. PE and PLE were drained in one and six (eight cavities) patients, all classified as large amount by the nurses. Conclusions. Cardiac nurses were able to obtain reliable measurements and quantification of both PE and PLE bedside by focused US and outperform the commonly used chest x-ray regarding PLE after cardiac surgery. PMID:25611808

  19. Enhancing Macrophage Drug Delivery Efficiency via Co-Localization of Cells and Drug-Loaded Microcarriers in 3D Resonant Ultrasound Field.

    PubMed

    Lee, Yu-Hsiang; Wu, Zhen-Yu

    2015-01-01

    In this study, a novel synthetic 3D molecular transfer system which involved the use of model drug calcein-AM-encapsulated poly(lactic-co-glycolic acid) microspheres (CAPMs) and resonant ultrasound field (RUF) with frequency of 1 MHz and output intensity of 0.5 W/cm2 for macrophage drug delivery was explored. We hypothesized that the efficiency of CAPMs-mediated drug delivery aided by RUF can be promoted by increasing the contact opportunities between cells and the micrometer-sized drug carriers due to effects of acoustic radiation forces generated by RUF. Through the fluoromicroscopic and flow cytometric analyses, our results showed that both DH82 macrophages and CAPMs can be quickly brought to acoustic pressure nodes within 20 sec under RUF exposure, and were consequently aggregated throughout the time course. The efficacy of cellular uptake of CAPMs was enhanced with increased RUF exposure time where a 3-fold augmentation (P < 0.05) was obtained after 15 min of RUF exposure. We further demonstrated that the enhanced CAPM delivery efficiency was mainly contributed by the co-localization of cells and CAPMs resulting from the application of the RUF, rather than from sonoporation. In summary, the developed molecular delivery approach provides a feasible means for macrophage drug delivery. PMID:26267789

  20. Enhancing Macrophage Drug Delivery Efficiency via Co-Localization of Cells and Drug-Loaded Microcarriers in 3D Resonant Ultrasound Field

    PubMed Central

    Lee, Yu-Hsiang; Wu, Zhen-Yu

    2015-01-01

    In this study, a novel synthetic 3D molecular transfer system which involved the use of model drug calcein-AM-encapsulated poly(lactic-co-glycolic acid) microspheres (CAPMs) and resonant ultrasound field (RUF) with frequency of 1 MHz and output intensity of 0.5 W/cm2 for macrophage drug delivery was explored. We hypothesized that the efficiency of CAPMs-mediated drug delivery aided by RUF can be promoted by increasing the contact opportunities between cells and the micrometer-sized drug carriers due to effects of acoustic radiation forces generated by RUF. Through the fluoromicroscopic and flow cytometric analyses, our results showed that both DH82 macrophages and CAPMs can be quickly brought to acoustic pressure nodes within 20 sec under RUF exposure, and were consequently aggregated throughout the time course. The efficacy of cellular uptake of CAPMs was enhanced with increased RUF exposure time where a 3-fold augmentation (P < 0.05) was obtained after 15 min of RUF exposure. We further demonstrated that the enhanced CAPM delivery efficiency was mainly contributed by the co-localization of cells and CAPMs resulting from the application of the RUF, rather than from sonoporation. In summary, the developed molecular delivery approach provides a feasible means for macrophage drug delivery. PMID:26267789

  1. 3D Reconstruction of Chick Embryo Vascular Geometries Using Non-invasive High-Frequency Ultrasound for Computational Fluid Dynamics Studies.

    PubMed

    Tan, Germaine Xin Yi; Jamil, Muhammad; Tee, Nicole Gui Zhen; Zhong, Liang; Yap, Choon Hwai

    2015-11-01

    Recent animal studies have provided evidence that prenatal blood flow fluid mechanics may play a role in the pathogenesis of congenital cardiovascular malformations. To further these researches, it is important to have an imaging technique for small animal embryos with sufficient resolution to support computational fluid dynamics studies, and that is also non-invasive and non-destructive to allow for subject-specific, longitudinal studies. In the current study, we developed such a technique, based on ultrasound biomicroscopy scans on chick embryos. Our technique included a motion cancelation algorithm to negate embryonic body motion, a temporal averaging algorithm to differentiate blood spaces from tissue spaces, and 3D reconstruction of blood volumes in the embryo. The accuracy of the reconstructed models was validated with direct stereoscopic measurements. A computational fluid dynamics simulation was performed to model fluid flow in the generated construct of a Hamburger-Hamilton (HH) stage 27 embryo. Simulation results showed that there were divergent streamlines and a low shear region at the carotid duct, which may be linked to the carotid duct's eventual regression and disappearance by HH stage 34. We show that our technique has sufficient resolution to produce accurate geometries for computational fluid dynamics simulations to quantify embryonic cardiovascular fluid mechanics.

  2. Image fusion of Ultrasound Computer Tomography volumes with X-ray mammograms using a biomechanical model based 2D/3D registration.

    PubMed

    Hopp, T; Duric, N; Ruiter, N V

    2015-03-01

    Ultrasound Computer Tomography (USCT) is a promising breast imaging modality under development. Comparison to a standard method like mammography is essential for further development. Due to significant differences in image dimensionality and compression state of the breast, correlating USCT images and X-ray mammograms is challenging. In this paper we present a 2D/3D registration method to improve the spatial correspondence and allow direct comparison of the images. It is based on biomechanical modeling of the breast and simulation of the mammographic compression. We investigate the effect of including patient-specific material parameters estimated automatically from USCT images. The method was systematically evaluated using numerical phantoms and in-vivo data. The average registration accuracy using the automated registration was 11.9mm. Based on the registered images a method for analysis of the diagnostic value of the USCT images was developed and initially applied to analyze sound speed and attenuation images based on X-ray mammograms as ground truth. Combining sound speed and attenuation allows differentiating lesions from surrounding tissue. Overlaying this information on mammograms, combines quantitative and morphological information for multimodal diagnosis. PMID:25456144

  3. MRI-3D ultrasound-X-ray image fusion with electromagnetic tracking for transendocardial therapeutic injections: in-vitro validation and in-vivo feasibility.

    PubMed

    Hatt, Charles R; Jain, Ameet K; Parthasarathy, Vijay; Lang, Andrew; Raval, Amish N

    2013-03-01

    Myocardial infarction (MI) is one of the leading causes of death in the world. Small animal studies have shown that stem-cell therapy offers dramatic functional improvement post-MI. An endomyocardial catheter injection approach to therapeutic agent delivery has been proposed to improve efficacy through increased cell retention. Accurate targeting is critical for reaching areas of greatest therapeutic potential while avoiding a life-threatening myocardial perforation. Multimodal image fusion has been proposed as a way to improve these procedures by augmenting traditional intra-operative imaging modalities with high resolution pre-procedural images. Previous approaches have suffered from a lack of real-time tissue imaging and dependence on X-ray imaging to track devices, leading to increased ionizing radiation dose. In this paper, we present a new image fusion system for catheter-based targeted delivery of therapeutic agents. The system registers real-time 3D echocardiography, magnetic resonance, X-ray, and electromagnetic sensor tracking within a single flexible framework. All system calibrations and registrations were validated and found to have target registration errors less than 5 mm in the worst case. Injection accuracy was validated in a motion enabled cardiac injection phantom, where targeting accuracy ranged from 0.57 to 3.81 mm. Clinical feasibility was demonstrated with in-vivo swine experiments, where injections were successfully made into targeted regions of the heart.

  4. Critical care ultrasound in cardiac arrest. Technological requirements for performing the SESAME-protocol--a holistic approach.

    PubMed

    Lichtenstein, Daniel; Malbrain, Manu L N G

    2015-01-01

    The use of ultrasound has gained its place in critical care as part of our day-to-day monitoring tools. A better understanding of ultrasound techniques and recent publications including protocols for the lungs, the abdomen and the blood vessels has introduced ultrasound to the bedside of our ICU patients. However, we will prove in this paper that early machines, dating back more than 25 years, were perfectly able to do the job as compared to modern laptop machines with more features but few additional advantages. Ultrasound is not only a diagnostic tool, but should also be seen as an extension of the traditional physical examination. This paper will focus on the use of the SESAME-protocol in cardiac arrest. The SESAME-protocol suggests starting with a lung scan to rule out possible causes leading to cardiac arrest. Firstly, pneumothorax needs to be ruled out. Secondly, a partial diagnosis of pulmonary embolism is done following the BLUE-protocol. Thirdly, fluid therapy can be guided, following the FALLS-protocol. The SESAME-protocol continues by scanning the lower femoral veins to check for signs of deep venous thrombosis, followed by (or before, in case of trauma) the abdomen to detect massive bleeding. Next comes the pericardium, to exclude pericardial tamponade. Finally, a transthoracic cardiac ultrasound is performed to check for other (cardiac) causes leading to cardiac arrest. The emphasis is on a holistic approach, where ultrasound can be seen as the modern stethoscope needed by clinicians to complete the full physiological examination of their critically ill unstable patients.

  5. Four-chamber heart modeling and automatic segmentation for 3-D cardiac CT volumes using marginal space learning and steerable features.

    PubMed

    Zheng, Yefeng; Barbu, Adrian; Georgescu, Bogdan; Scheuering, Michael; Comaniciu, Dorin

    2008-11-01

    We propose an automatic four-chamber heart segmentation system for the quantitative functional analysis of the heart from cardiac computed tomography (CT) volumes. Two topics are discussed: heart modeling and automatic model fitting to an unseen volume. Heart modeling is a nontrivial task since the heart is a complex nonrigid organ. The model must be anatomically accurate, allow manual editing, and provide sufficient information to guide automatic detection and segmentation. Unlike previous work, we explicitly represent important landmarks (such as the valves and the ventricular septum cusps) among the control points of the model. The control points can be detected reliably to guide the automatic model fitting process. Using this model, we develop an efficient and robust approach for automatic heart chamber segmentation in 3-D CT volumes. We formulate the segmentation as a two-step learning problem: anatomical structure localization and boundary delineation. In both steps, we exploit the recent advances in learning discriminative models. A novel algorithm, marginal space learning (MSL), is introduced to solve the 9-D similarity transformation search problem for localizing the heart chambers. After determining the pose of the heart chambers, we estimate the 3-D shape through learning-based boundary delineation. The proposed method has been extensively tested on the largest dataset (with 323 volumes from 137 patients) ever reported in the literature. To the best of our knowledge, our system is the fastest with a speed of 4.0 s per volume (on a dual-core 3.2-GHz processor) for the automatic segmentation of all four chambers.

  6. The Use of Standard Gastrointestinal Endoscopic Ultrasound to Assess Cardiac Anatomy.

    PubMed

    Sentissi, Kinza; Sawhney, Mandeep S; Pleskow, Douglas; Sepe, Paul; Mella, Jose M; Kwittken, Benjamin; Ketwaroo, Gyanprakash; Subramaniam, Balachundhar

    2016-09-01

    In this prospective observational study, conducted at an academic medical center, we evaluated the feasibility of performing a basic transesophageal echocardiography (TEE) examination using endoscopic ultrasound (EUS) technology to determine what cardiac structures could be assessed. This may be potentially beneficial during hemodynamic emergencies in the endoscopy suite resulting from hypovolemia, depressed ventricular function, aortic dissection, pericardial effusions, or aortic stenosis. Of the 20 patients enrolled, 18 underwent EUS with a linear echoendoscope for standard clinical indications followed by a cardiac assessment performed under the guidance of a TEE-certified cardiac anesthesiologist. Eight of the 20 standard views of cardiovascular structures per the 1999 American Society of Echocardiography/Society of Cardiovascular Anesthesiologists guidelines for TEE could be obtained using the linear echoendoscope. The following cardiac valvular structures were visualized: aortic valve (100%), mitral valve (100%), tricuspid valve (33%), and pulmonic valve (11%). Left ventricular and right ventricular systolic function could be assessed in 89% and 67% of patients, respectively. Other structures such as the ascending and descending aorta, pericardium, left atrial appendage, and interatrial septum were identified in 100% of patients. Doppler-dependent functions could not be assessed. Given that the EUS images were not directly compared with TEE in these patients, we cannot comment definitively on the quality of these assessments and further studies would need to be performed to make a formal comparison. Based on this study, EUS technology can consistently assess the mitral valve, aortic valve, aorta, pericardium, and left ventricular function. Given its limitations, EUS technology, although not a substitute for formal echocardiography, could be a helpful early diagnostic tool in an emergency setting. PMID:27541718

  7. Ultrasound

    MedlinePlus

    Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and ... liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound ...

  8. Ultrasound

    MedlinePlus

    Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two- ... sound waves and appear dark or black. An ultrasound can supply vital information about a mother's pregnancy ...

  9. [Cardiac tamponade following sternal puncture. Usefulness of ultrasound focussed assessment with sonography for trauma].

    PubMed

    Magaldi, M; Hervías, A; Perelló, L; Fontanals, J

    2014-03-01

    One of the aims of the medical profession is to be able to detect complications in patients during diagnostic tests and treatments. The early diagnosis of these complications can prevent a fatal outcome. The diagnosis is often based on clinical symptoms and supported by complementary tests. Diagnostic tests have been developed in the last few years that are rapid and easy to use, as well as being cost effective and minimally invasive. Focussed assessment with sonography for trauma ultrasound (echo-FAST) was introduced in the 1990s in the field of resuscitation as a test for the rapid detection of intra-abdominal and pericardial fluid in multiple injury patients, but its uses in other cases not involving trauma still raise doubts and controversy. A case is presented of a patient subjected to a sternal puncture for a bone marrow aspirate, who had a complication of a secondary cardiac tamponade, which was diagnosed early using echo-FAST.

  10. 3D reconstruction of tensors and vectors

    SciTech Connect

    Defrise, Michel; Gullberg, Grant T.

    2005-02-17

    Here we have developed formulations for the reconstruction of 3D tensor fields from planar (Radon) and line-integral (X-ray) projections of 3D vector and tensor fields. Much of the motivation for this work is the potential application of MRI to perform diffusion tensor tomography. The goal is to develop a theory for the reconstruction of both Radon planar and X-ray or line-integral projections because of the flexibility of MRI to obtain both of these type of projections in 3D. The development presented here for the linear tensor tomography problem provides insight into the structure of the nonlinear MRI diffusion tensor inverse problem. A particular application of tensor imaging in MRI is the potential application of cardiac diffusion tensor tomography for determining in vivo cardiac fiber structure. One difficulty in the cardiac application is the motion of the heart. This presents a need for developing future theory for tensor tomography in a motion field. This means developing a better understanding of the MRI signal for diffusion processes in a deforming media. The techniques developed may allow the application of MRI tensor tomography for the study of structure of fiber tracts in the brain, atherosclerotic plaque, and spine in addition to fiber structure in the heart. However, the relations presented are also applicable to other fields in medical imaging such as diffraction tomography using ultrasound. The mathematics presented can also be extended to exponential Radon transform of tensor fields and to other geometric acquisitions such as cone beam tomography of tensor fields.

  11. How can the use of lung ultrasound in cardiac arrest make ultrasound a holistic discipline. The example of the SESAME-protocol.

    PubMed

    Lichtenstein, Daniel A

    2014-09-01

    The most critical application of critical ultrasound - cardiac arrest - is the opportunity for technical considerations. The necessity to immediately detect reversible causes is integrated in the concept of holistic ultrasound. Holistic ultrasound is defined as a discipline where each element interacts with the others, and where the understanding of each of them allows understanding the whole. A narrow machine (not necessarily a laptop), a fast start-on time, a simple keyboard highlighting three useful buttons, a universal microconvex probe able to immediately detect pneumothorax, then deep venous thrombosis, then abdominal bleeding, then pericardial tamponade, then cardiac anomalies will allow a fast protocol. The concept of holistic ultrasound is particularly on focus in the first step done at the lung (search for pneumothorax and clearance for fluid therapy), since the best image is obtained with the simplest equipment devoid of traditional facilities (image filtering, harmonics, time lag, Doppler...). The same simple gray-scale equipment is used for the other steps, all what is needed is to see the real-time image of what is facing the probe: the very principle of visual medicine. The same approach can be used with no change, just more quietly, for many less urgent settings.

  12. Role and importance of ultrasound lung comets in acute cardiac care.

    PubMed

    Ricci, Fabrizio; Aquilani, Roberta; Radico, Francesco; Bianco, Francesco; Dipace, Gioacchino Giuseppe; Miniero, Ester; De Caterina, Raffaele; Gallina, Sabina

    2015-04-01

    Lung ultrasonography is an emerging, user-friendly and easy-to-use technique that can be performed quickly at the patient's bedside to evaluate several pathologic conditions affecting the lung. Ultrasound lung comets (ULCs) are an echographic sign of uncertain biophysical characterisation mostly attributed to water-thickened subpleural interlobular septa, but invariably associated with increased extravascular lung water. ULCs have thus been proposed as a complementary tool for the assessment and monitoring of acute heart failure and are now entering into statements in international recommendation documents. Adding lung ultrasonography to conventional echocardiography allows for performing an integrated cardiopulmonary ultrasound examination, and this is an important opportunity for the cardiologist. The technique allows the simultaneous gathering of considerable information about the heart and the lungs to investigate acute and chronic cardio-pulmonary conditions within a non-invasive, radiation-free, single-probe, all-in-one examination. We have here reviewed the pertinent literature on the physical origin of ULCs and on their role and importance in intensive and acute cardiac care settings. We also here propose a new algorithm aimed at implementing evaluation in the diagnostic work-up of patients with suspected acute heart failure. PMID:25267879

  13. High-frequency ultrasound M-mode monitoring of HIFU ablation in cardiac tissue

    NASA Astrophysics Data System (ADS)

    Kumon, R. E.; Gudur, M. S. R.; Zhou, Y.; Deng, C. X.

    2012-10-01

    Effective real-time HIFU lesion detection is important for expanded use of HIFU in interventional electrophysiology (e.g., epicardial ablation of cardiac arrhythmia). The goal of this study was to investigate rapid, high-frequency M-mode ultrasound imaging for monitoring spatiotemporal changes in tissue during HIFU application. The HIFU application (4.33 MHz, 1000 Hz PRF, 50% duty cycle, 1 s exposure, 6100 W/cm2) was perpendicularly applied to porcine cardiac tissue with a high-frequency imaging system (Visualsonics Vevo 770, 55 MHz, 4.5 mm focal distance) confocally aligned. Radiofrequency (RF) M-mode data (1 kHz PRF, 4 s × 7 mm) was acquired before, during, and after HIFU treatment. Gross lesions were compared with M-mode data to correlate lesion and cavity formation. Integrated backscatter, echo-decorrelation parameters, and their cumulative extrema over time were analyzed for automatically identifying lesion width and bubble formation. Cumulative maximum integrated backscatter showed the best results for identifying the final lesion width, and a criterion based on line-to-line decorrelation was proposed for identification of transient bubble activity.

  14. Transmural Ultrasound Imaging of Thermal Lesion and Action Potential Changes in Perfused Canine Cardiac Wedge Preparations by High Intensity Focused Ultrasound Ablation

    PubMed Central

    Wu, Ziqi; Gudur, Madhu S. R.; Deng, Cheri X.

    2013-01-01

    Intra-procedural imaging is important for guiding cardiac arrhythmia ablation. It is difficult to obtain intra-procedural correlation of thermal lesion formation with action potential (AP) changes in the transmural plane during ablation. This study tested parametric ultrasound imaging for transmural imaging of lesion and AP changes in high intensity focused ultrasound (HIFU) ablation using coronary perfused canine ventricular wedge preparations (n = 13). The preparations were paced from epi/endocardial surfaces and subjected to HIFU application (3.5 MHz, 11 Hz pulse-repetition-frequency, 70% duty cycle, duration 4 s, 3500 W/cm2), during which simultaneous optical mapping (1 kframes/s) using di-4-ANEPPS and ultrasound imaging (30 MHz) of the same transmural surface of the wedge were performed. Spatiotemporally correlated AP measurements and ultrasound imaging allowed quantification of the reduction of AP amplitude (APA), shortening of AP duration at 50% repolarization, AP triangulation, decrease of optical AP rise, and change of conduction velocity along tissue depth direction within and surrounding HIFU lesions. The threshold of irreversible change in APA correlating to lesions was determined to be 43±1% with a receiver operating characteristic (ROC) area under curve (AUC) of 0.96±0.01 (n = 13). Ultrasound imaging parameters such as integrated backscatter, Rayleigh (α) and log-normal (σ) parameters, cumulative extrema of σ were tested, with the cumulative extrema of σ performing the best in detecting lesion (ROC AUC 0.89±0.01, n = 13) and change of APA (ROC AUC 0.79±0.03, n = 13). In conclusion, characteristic tissue and AP changes in HIFU ablation were identified and spatiotemporally correlated using optical mapping and ultrasound imaging. Parametric ultrasound imaging using cumulative extrema of σ can detect HIFU lesion and APA reduction. PMID:24349337

  15. The newly developed three-dimensional (3D) and two-dimensional (2D) thyroid ultrasound are strongly correlated, but 2D overestimates thyroid volume in the presence of nodules.

    PubMed

    Rago, T; Bencivelli, W; Scutari, M; Di Cosmo, C; Rizzo, C; Berti, P; Miccoli, P; Pinchera, A; Vitti, P

    2006-05-01

    The newly developed three-dimensional (3D) and two-dimensional (2D) thyroid ultrasound (US) were compared in assessing thyroid volume (TV) in 104 patients: 53 had an isolated thyroid nodule, 32 toxic diffuse goiter, 17 non-toxic multinodular goiter, 1 toxic multinodular goiter and 1 a toxic adenoma. A real-time Technos apparatus (Esaote SpA, Italy) with a 7,5 MHz linear transducer was used. The volume of thyroid lobes by 2D was calculated according to the ellipsoid formula. In the same session, TV by 3D US was calculated using a probe tracking system (in vivo ScanNT Esaote 3.4 MedCom. Darmasdt) and software to reconstruct 3D images, directly giving the lobe volume. There was a very good agreement between 2D and 3D, but in 94/208 lobes with nodular lesions 2D showed a 10% systematic overestimation compared to 3D, the percentage error being higher in lobes with lower volumes. A possible explanation for this result is the inadequacy of the ellipsoid formula in forecasting the correct lobe profile in the presence of nodules. This intrinsic defect of 2D US should be taken into account when evaluating TV in patients with nodular goiter.

  16. Focused Cardiac Ultrasound in Place of Repeat Echocardiography: Reliability and Cost Implications

    PubMed Central

    Kini, Vinay; Mehta, Nidhi; Mazurek, Jeremy A.; Ferrari, Victor A.; Epstein, Andrew J.; Groeneveld, Peter W.; Kirkpatrick, James N.

    2016-01-01

    Background Health care systems are increasingly moving toward models that emphasize the delivery of high-quality health care at lower costs. Rates of repeat echocardiography (two or more transthoracic echocardiographic studies performed within a short interval) are high and can contribute substantially to the cost of providing cardiovascular care. Certain findings from handheld ultrasound scans performed by echocardiographers have been shown to correlate well with findings on transthoracic echocardiography (TTE). It therefore may be feasible and cost effective to use expert focused cardiac ultrasound (eFCU) in place of repeat TTE for highly selected indications in certain settings. The aim of this study was to determine the reliability and cost implications of using eFCU in place of repeat TTE in selected inpatients. Methods Inpatients who underwent repeat TTE (prior TTE within 30 days) ordered for the assessment of ventricular function, pericardial effusion, or inferior vena cava collapse were prospectively enrolled. Subjects underwent eFCU in addition to TTE, and results were compared for correlation using the weighted κ statistic. The potential cost savings of using eFCU in place of TTE were modeled from the provider perspective (i.e., physicians and hospitals). Results Over 45 days, 105 patients were enrolled. The majority of scans were performed for assessment of left ventricular function and pericardial effusions. eFCU showed excellent correlation with TTE for most parameters, including left ventricular systolic function (κ = 0.80) and the presence and size of pericardial effusions (κ = 0.81) (P < .001 for both). Adoption of this eFCU protocol could save between $41 and $64 per study, or between $34,512 and $53,871 annually at the authors’ institution. Conclusions Findings from eFCU correlate well with those from TTE when used in the setting of repeat testing for assessment of ventricular function, pericardial effusion, and inferior vena cava collapse

  17. Noninvasive Ambient Pressure Estimation using Ultrasound Contrast Agents -- Invoking Subharmonics for Cardiac and Hepatic Applications

    NASA Astrophysics Data System (ADS)

    Dave, Jaydev K.

    Ultrasound contrast agents (UCAs) are encapsulated microbubbles that provide a source for acoustic impedance mismatch with the blood, due to difference in compressibility between the gas contained within these microbubbles and the blood. When insonified by an ultrasound beam, these UCAs act as nonlinear scatterers and enhance the echoes of the incident pulse, resulting in scattering of the incident ultrasound beam and emission of fundamental (f0), subharmonic (f0/2), harmonic (n*f0; n ∈ N) and ultraharmonic (((2n-1)/2)*f0; n ∈ N & n > 1) components in the echo response. A promising approach to monitor in vivo pressures revolves around the fact that the ultrasound transmit and receive parameters can be selected to induce an ambient pressure amplitude dependent subharmonic signal. This subharmonic signal may be used to estimate ambient pressure amplitude; such technique of estimating ambient pressure amplitude is referred to as subharmonic aided pressure estimation or SHAPE. This project develops and evaluates the feasibility of SHAPE to noninvasively monitor cardiac and hepatic pressures (using commercially available ultrasound scanners and UCAs) because invasive catheter based pressure measurements are used currently for these applications. Invasive catheter based pressure measurements pose risk of introducing infection while the catheter is guided towards the region of interest in the body through a percutaneous incision, pose risk of death due to structural or mechanical failure of the catheter (which has also triggered product recalls by the USA Food and Drug Administration) and may potentially modulate the pressures that are being measured. Also, catheterization procedures require fluoroscopic guidance to advance the catheter to the site of pressure measurements and such catheterization procedures are not performed in all clinical centers. Thus, a noninvasive technique to obtain ambient pressure values without the catheterization process is clinically

  18. Precise reconstruction of fast moving cardiac valve in high frame rate synthetic transmit aperture ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Suzuki, Mayumi; Ikeda, Teiichiro; Ishihara, Chizue; Takano, Shinta; Masuzawa, Hiroshi

    2016-04-01

    To diagnose heart valve incompetence, i.e., one of the most serious cardiac dysfunctions, it is essential to obtain images of fast-moving valves at high spatial and temporal resolution. Ultrasound synthetic transmit aperture (STA) imaging has the potential to achieve high spatial resolution by synthesizing multiple pre-beamformed images obtained with corresponding multiple transmissions. However, applying STA to fast-moving targets is difficult due to serious target deformation. We propose a high-frame-rate STA (fast STA) imaging method that uses a reduced number of transmission events needed for each image. Fast STA is expected to suppress deformation of moving targets; however, it may result in deteriorated spatial resolution. In this study, we conducted a simulation study to evaluate fast STA. We quantitatively evaluated the reduction in deformation and deterioration of spatial resolution with a model involving a radially moving valve at the maximum speed of 0.5 m/s. The simulated raw channel data of the valve phantom was processed with offline beamforming programs. We compared B-mode images obtained through single received-line in a transmission (SRT) method, STA, and fast STA. The results show that fast STA with four-times-reduced events is superior in reconstructing the original shape of the moving valve to other methods. The accuracy of valve location is 97 and 100% better than those with SRT and STA, respectively. The resolution deterioration was found to be below the annoyance threshold considering the improved performance of the shape reconstruction. The obtained results are promising for providing more precise diagnostic information on cardiovascular diseases.

  19. Coupling of a 3D Finite Element Model of Cardiac Ventricular Mechanics to Lumped Systems Models of the Systemic and Pulmonic Circulation

    PubMed Central

    Kerckhoffs, Roy C. P.; Neal, Maxwell L.; Gu, Quan; Bassingthwaighte, James B.; Omens, Jeff H.; McCulloch, Andrew D.

    2010-01-01

    In this study we present a novel, robust method to couple finite element (FE) models of cardiac mechanics to systems models of the circulation (CIRC), independent of cardiac phase. For each time step through a cardiac cycle, left and right ventricular pressures were calculated using ventricular compliances from the FE and CIRC models. These pressures served as boundary conditions in the FE and CIRC models. In succeeding steps, pressures were updated to minimize cavity volume error (FE minus CIRC volume) using Newton iterations. Coupling was achieved when a predefined criterion for the volume error was satisfied. Initial conditions for the multi-scale model were obtained by replacing the FE model with a varying elastance model, which takes into account direct ventricular interactions. Applying the coupling, a novel multi-scale model of the canine cardiovascular system was developed. Global hemodynamics and regional mechanics were calculated for multiple beats in two separate simulations with a left ventricular ischemic region and pulmonary artery constriction, respectively. After the interventions, global hemodynamics changed due to direct and indirect ventricular interactions, in agreement with previously published experimental results. The coupling method allows for simulations of multiple cardiac cycles for normal and pathophysiology, encompassing levels from cell to system. PMID:17111210

  20. An In Vivo Validation of the Application of Acoustic Radiation Force to Enhance the Diagnostic Utility of Molecular Imaging Using 3D Ultrasound

    PubMed Central

    Gessner, Ryan C.; Streeter, Jason E.; Kothadia, Roshni; Feingold, Steven; Dayton, Paul A.

    2012-01-01

    For over a decade, the application of acoustic radiation force (ARF) has been proposed as a mechanism to increase ultrasonic molecular imaging (MI) sensitivity in vivo. Presented herein is the first noninvasive in vivo validation of ARF-enhanced MI with an unmodified clinical system. First, an in vitro optical-acoustical setup was used to optimize system parameters and ensure sufficient microbubble translation when exposed to ARF. 3D ARF-enhanced MI was then performed on 7 rat fibrosarcoma tumors using microbubbles targeted to αvβ3 and non-targeted microbubbles. Low-amplitude (< 25 kPa) 3D ARF pulse sequences were tested and compared to passive targeting studies in the same animal. Our results demonstrate that a 78% increase in image intensity from targeted microbubbles can be achieved when using ARF relative to the passive targeting studies. Furthermore, ARF did not significantly increase image contrast when applied to non-targeted agents, suggesting that ARF did not increase non-specific adhesion. PMID:22341052

  1. Ultrasound

    MedlinePlus

    ... reflect off body structures. A computer receives the waves and uses them to create a picture. Unlike with an x-ray or CT scan, this test does not use ionizing radiation. The test is done in the ultrasound ...

  2. Non-Invasive Targeted Peripheral Nerve Ablation Using 3D MR Neurography and MRI-Guided High-Intensity Focused Ultrasound (MR-HIFU): Pilot Study in a Swine Model

    PubMed Central

    Huisman, Merel; Staruch, Robert M.; Ladouceur-Wodzak, Michelle; van den Bosch, Maurice A.; Burns, Dennis K.; Chhabra, Avneesh; Chopra, Rajiv

    2015-01-01

    Purpose Ultrasound (US)-guided high intensity focused ultrasound (HIFU) has been proposed for noninvasive treatment of neuropathic pain and has been investigated in in-vivo studies. However, ultrasound has important limitations regarding treatment guidance and temperature monitoring. Magnetic resonance (MR)-imaging guidance may overcome these limitations and MR-guided HIFU (MR-HIFU) has been used successfully for other clinical indications. The primary purpose of this study was to evaluate the feasibility of utilizing 3D MR neurography to identify and guide ablation of peripheral nerves using a clinical MR-HIFU system. Methods Volumetric MR-HIFU was used to induce lesions in the peripheral nerves of the lower limbs in three pigs. Diffusion-prep MR neurography and T1-weighted images were utilized to identify the target, plan treatment and immediate post-treatment evaluation. For each treatment, one 8 or 12 mm diameter treatment cell was used (sonication duration 20 s and 36 s, power 160–300 W). Peripheral nerves were extracted < 3 hours after treatment. Ablation dimensions were calculated from thermal maps, post-contrast MRI and macroscopy. Histological analysis included standard H&E staining, Masson’s trichrome and toluidine blue staining. Results All targeted peripheral nerves were identifiable on MR neurography and T1-weighted images and could be accurately ablated with a single exposure of focused ultrasound, with peak temperatures of 60.3 to 85.7°C. The lesion dimensions as measured on MR neurography were similar to the lesion dimensions as measured on CE-T1, thermal dose maps, and macroscopy. Histology indicated major hyperacute peripheral nerve damage, mostly confined to the location targeted for ablation. Conclusion Our preliminary results indicate that targeted peripheral nerve ablation is feasible with MR-HIFU. Diffusion-prep 3D MR neurography has potential for guiding therapy procedures where either nerve targeting or avoidance is desired, and may

  3. Comparison of prostate MRI-3D transrectal ultrasound fusion biopsy for first-time and repeat biopsy patients with previous atypical small acinar proliferation

    PubMed Central

    Cool, Derek W.; Romagnoli, Cesare; Izawa, Jonathan I.; Chin, Joseph; Gardi, Lori; Tessier, David; Mercado, Ashley; Mandel, Jonathan; Ward, Aaron D.; Fenster, Aaron

    2016-01-01

    Introduction: This study evaluates the clinical benefit of magnetic resonance-transrectal ultrasound (MR-TRUS) fusion biopsy over systematic biopsy between first-time and repeat prostate biopsy patients with prior atypical small acinar proliferation (ASAP). Materials: 100 patients were enrolled in a single-centre prospective cohort study: 50 for first biopsy, 50 for repeat biopsy with prior ASAP. Multiparameteric magnetic resonance imaging (MP-MRI) and standard 12-core ultrasound biopsy (Std-Bx) were performed on all patients. Targeted biopsy using MRI-TRUS fusion (Fn-Bx) was performed f suspicious lesions were identified on the pre-biopsy MP-MRI. Classification of clinically significant disease was assessed independently for the Std-Bx vs. Fn-Bx cores to compare the two approaches. Results: Adenocarcinoma was detected in 49/100 patients (26 first biopsy, 23 ASAP biopsy), with 25 having significant disease (17 first, 8 ASAP). Fn-Bx demonstrated significantly higher per-core cancer detection rates, cancer involvement, and Gleason scores for first-time and ASAP patients. However, Fn-Bx was significantly more likely to detect significant cancer missed on Std-Bx for ASAP patients than first-time biopsy patients. The addition of Fn-Bx to Std-Bx for ASAP patients had a 166.7% relative risk reduction for missing Gleason ≥ 3 + 4 disease (number needed to image with MP-MRI=10 patients) compared to 6.3% for first biopsy (number to image=50 patients). Negative predictive value of MP-MRI for negative biopsy was 79% for first-time and 100% for ASAP patients, with median followup of 32.1 ± 15.5 months. Conclusions: MR-TRUS Fn-Bx has a greater clinical impact for repeat biopsy patients with prior ASAP than biopsy-naïve patients by detecting more significant cancers that are missed on Std-Bx. PMID:27800057

  4. Engineered 3D bioimplants using elastomeric scaffold, self-assembling peptide hydrogel, and adipose tissue-derived progenitor cells for cardiac regeneration

    PubMed Central

    Soler-Botija, Carolina; Bagó, Juli R; Llucià-Valldeperas, Aida; Vallés-Lluch, Ana; Castells-Sala, Cristina; Martínez-Ramos, Cristina; Fernández-Muiños, Teresa; Chachques, Juan Carlos; Pradas, Manuel Monleón; Semino, Carlos E; Bayes-Genis, Antoni

    2014-01-01

    Contractile restoration of myocardial scars remains a challenge with important clinical implications. Here, a combination of porous elastomeric membrane, peptide hydrogel, and subcutaneous adipose tissue-derived progenitor cells (subATDPCs) was designed and evaluated as a bioimplant for cardiac regeneration in a mouse model of myocardial infarction. SubATDPCs were doubly transduced with lentiviral vectors to express bioluminescent-fluorescent reporters driven by constitutively active, cardiac tissue-specific promoters. Cells were seeded into an engineered bioimplant consisting of a scaffold (polycaprolactone methacryloyloxyethyl ester) filled with a peptide hydrogel (PuraMatrix™), and transplanted to cover injured myocardium. Bioluminescence and fluorescence quantifications showed de novo and progressive increases in promoter expression in bioactive implant-treated animals. The bioactive implant was well adapted to the heart, and fully functional vessels traversed the myocardium-bioactive implant interface. Treatment translated into a detectable positive effect on cardiac function, as revealed by echocardiography. Thus, this novel implant is a promising construct for supporting myocardial regeneration. PMID:24936221

  5. Performance assessment of HIFU lesion detection by harmonic motion imaging for focused ultrasound (HMIFU): a 3-D finite-element-based framework with experimental validation.

    PubMed

    Hou, Gary Y; Luo, Jianwen; Marquet, Fabrice; Maleke, Caroline; Vappou, Jonathan; Konofagou, Elisa E

    2011-12-01

    Harmonic motion imaging for focused ultrasound (HMIFU) is a novel high-intensity focused ultrasound (HIFU) therapy monitoring method with feasibilities demonstrated in vitro, ex vivo and in vivo. Its principle is based on amplitude-modulated (AM) - harmonic motion imaging (HMI), an oscillatory radiation force used for imaging the tissue mechanical response during thermal ablation. In this study, a theoretical framework of HMIFU is presented, comprising a customized nonlinear wave propagation model, a finite-element (FE) analysis module and an image-formation model. The objective of this study is to develop such a framework to (1) assess the fundamental performance of HMIFU in detecting HIFU lesions based on the change in tissue apparent elasticity, i.e., the increasing Young's modulus, and the HIFU lesion size with respect to the HIFU exposure time and (2) validate the simulation findings ex vivo. The same HMI and HMIFU parameters as in the experimental studies were used, i.e., 4.5-MHz HIFU frequency and 25 Hz AM frequency. For a lesion-to-background Young's modulus ratio of 3, 6 and 9, the FE and estimated HMI displacement ratios were equal to 1.83, 3.69 and 5.39 and 1.65, 3.19 and 4.59, respectively. In experiments, the HMI displacement followed a similar increasing trend of 1.19, 1.28 and 1.78 at 10-s, 20-s and 30-s HIFU exposure, respectively. In addition, moderate agreement in lesion size growth was found in both simulations (16.2, 73.1 and 334.7 mm(2)) and experiments (26.2, 94.2 and 206.2 mm(2)). Therefore, the feasibility of HMIFU for HIFU lesion detection based on the underlying tissue elasticity changes was verified through the developed theoretical framework, i.e., validation of the fundamental performance of the HMIFU system for lesion detection, localization and quantification, was demonstrated both theoretically and ex vivo.

  6. Ultrasound-Guided Transesophageal High-Intensity Focused Ultrasound Cardiac Ablation in a Beating Heart: A Pilot Feasibility Study in Pigs.

    PubMed

    Bessiere, Francis; N'djin, W Apoutou; Colas, Elodie Constanciel; Chavrier, Françoise; Greillier, Paul; Chapelon, Jean Yves; Chevalier, Philippe; Lafon, Cyril

    2016-08-01

    Catheter ablation for the treatment of arrhythmia is associated with significant complications and often-repeated procedures. Consequently, a less invasive and more efficient technique is required. Because high-intensity focused ultrasound (HIFU) enables the generation of precise thermal ablations in deep-seated tissues without harming the tissues in the propagation path, it has the potential to be used as a new ablation technique. A system capable of delivering HIFU into the heart by a transesophageal route using ultrasound (US) imaging guidance was developed and tested in vivo in six male pigs. HIFU exposures were performed on atria and ventricles. At the time of autopsy, visual inspection identified thermal lesions in the targeted areas in three of the animals. These lesions were confirmed by histologic analysis (mean size: 5.5 mm(2) × 11 mm(2)). No esophageal thermal injury was observed. One animal presented with bradycardia due to an atrio-ventricular block, which provides real-time confirmation of an interaction between HIFU and the electrical circuits of the heart. Thus, US-guided HIFU has the potential to minimally invasively create myocardial lesions without an intra-cardiac device.

  7. Ultrasound-assisted synthesis of nano-structured 3D zinc(II) metal-organic polymer: precursor for the fabrication of ZnO nano-structure.

    PubMed

    Karizi, Farnoosh Zare; Safarifard, Vahid; Khani, Sarah Karbalaei; Morsali, Ali

    2015-03-01

    Nanorods of a three-dimensional Zn(II) metal-organic framework, [Zn₂(btec)(DMF)₂]n (1) (btec=1,2,4,5-benzenetetracarboxylate, DMF=N,N-dimethylformamide), have been synthesized by a sonochemical process and characterized by field emission scanning electron microscopy (FE-SEM), powder XRD and FT-IR spectroscopy. Structural determination of compound 1 was determined by single crystal X-ray diffraction. The thermal stability of compound 1 has been studied by thermal gravimetric analysis (TGA), too. The role of initial reagent concentrations and power ultrasound irradiation and also time, on size and morphology of nano-structured compound 1 have been studied. ZnO nano-structures also were simply synthesized by direct calcination of the single crystals and nano-sized compound 1 at 600 °C. The size and morphology of the ZnO nano-structures are dependent upon the particles size of compound 1. A decrease in the particles size of compound 1 leads to a decrease in the particles size of the ZnO.

  8. Fast and Accurate Data Extraction for Near Real-Time Registration of 3-D Ultrasound and Computed Tomography in Orthopedic Surgery.

    PubMed

    Brounstein, Anna; Hacihaliloglu, Ilker; Guy, Pierre; Hodgson, Antony; Abugharbieh, Rafeef

    2015-12-01

    Automatic, accurate and real-time registration is an important step in providing effective guidance and successful anatomic restoration in ultrasound (US)-based computer assisted orthopedic surgery. We propose a method in which local phase-based bone surfaces, extracted from intra-operative US data, are registered to pre-operatively segmented computed tomography data. Extracted bone surfaces are downsampled and reinforced with high curvature features. A novel hierarchical simplification algorithm is used to further optimize the point clouds. The final point clouds are represented as Gaussian mixture models and iteratively matched by minimizing the dissimilarity between them using an L2 metric. For 44 clinical data sets from 25 pelvic fracture patients and 49 phantom data sets, we report mean surface registration accuracies of 0.31 and 0.77 mm, respectively, with an average registration time of 1.41 s. Our results suggest the viability and potential of the chosen method for real-time intra-operative registration in orthopedic surgery.

  9. Fast and Accurate Data Extraction for Near Real-Time Registration of 3-D Ultrasound and Computed Tomography in Orthopedic Surgery.

    PubMed

    Brounstein, Anna; Hacihaliloglu, Ilker; Guy, Pierre; Hodgson, Antony; Abugharbieh, Rafeef

    2015-12-01

    Automatic, accurate and real-time registration is an important step in providing effective guidance and successful anatomic restoration in ultrasound (US)-based computer assisted orthopedic surgery. We propose a method in which local phase-based bone surfaces, extracted from intra-operative US data, are registered to pre-operatively segmented computed tomography data. Extracted bone surfaces are downsampled and reinforced with high curvature features. A novel hierarchical simplification algorithm is used to further optimize the point clouds. The final point clouds are represented as Gaussian mixture models and iteratively matched by minimizing the dissimilarity between them using an L2 metric. For 44 clinical data sets from 25 pelvic fracture patients and 49 phantom data sets, we report mean surface registration accuracies of 0.31 and 0.77 mm, respectively, with an average registration time of 1.41 s. Our results suggest the viability and potential of the chosen method for real-time intra-operative registration in orthopedic surgery. PMID:26365924

  10. Automatic multimodal 2D/3D image fusion of ultrasound computer tomography and x-ray mammography for breast cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Hopp, Torsten; Duric, Neb; Ruiter, Nicole V.

    2012-03-01

    Breast cancer is the most common cancer among women. The established screening method to detect breast cancer in an early state is X-ray mammography. However, X-ray frequently provides limited contrast of tumors located within glandular tissue. A new imaging approach is Ultrasound Computer Tomography generating threedimensional volumes of the breast. Three different images are available: reflectivity, attenuation and speed of sound. The correlation of USCT volumes with X-ray mammograms is of interest for evaluation of the new imaging modality as well as for a multimodal diagnosis. Yet, both modalities differ in image dimensionality, patient positioning and deformation state of the breast. In earlier work we proposed a methodology based on Finite Element Method to register speed of sound images with the according mammogram. In this work, we enhanced the methodology to register all three image types provided by USCT. Furthermore, the methodology is now completely automated using image similarity measures to estimate rotations in datasets. A fusion methodology is proposed which combines the information of the three USCT image types with the X-ray mammogram via semitransparent overlay images. The evaluation was done using 13 datasets from a clinical study. The registration accuracy was measured by the displacement of the center of a lesion marked in both modalities. Using the automated rotation estimation, a mean displacement of 10.4 mm was achieved. Due to the clinically relevant registration accuracy, the methodology provides a basis for evaluation of the new imaging device USCT as well as for multimodal diagnosis.

  11. Effectiveness of evaluating tumor vascularization using 3D power Doppler ultrasound with high-definition flow technology in the prediction of the response to neoadjuvant chemotherapy for T2 breast cancer: a preliminary report

    NASA Astrophysics Data System (ADS)

    Shia, Wei-Chung; Chen, Dar-Ren; Huang, Yu-Len; Wu, Hwa-Koon; Kuo, Shou-Jen

    2015-10-01

    The aim of this study was to evaluate the effectiveness of advanced ultrasound (US) imaging of vascular flow and morphological features in the prediction of a pathologic complete response (pCR) and a partial response (PR) to neoadjuvant chemotherapy for T2 breast cancer. Twenty-nine consecutive patients with T2 breast cancer treated with six courses of anthracycline-based neoadjuvant chemotherapy were enrolled. Three-dimensional (3D) power Doppler US with high-definition flow (HDF) technology was used to investigate the blood flow in and morphological features of the tumors. Six vascularity quantization features, three morphological features, and two vascular direction features were selected and extracted from the US images. A support vector machine was used to evaluate the changes in vascularity after neoadjuvant chemotherapy, and pCR and PR were predicted on the basis of these changes. The most accurate prediction of pCR was achieved after the first chemotherapy cycle, with an accuracy of 93.1% and a specificity of 85.5%, while that of a PR was achieved after the second cycle, with an accuracy of 79.31% and a specificity of 72.22%. Vascularity data can be useful to predict the effects of neoadjuvant chemotherapy. Determination of changes in vascularity after neoadjuvant chemotherapy using 3D power Doppler US with HDF can generate accurate predictions of the patient response, facilitating early decision-making.

  12. Fast Gated EPR Imaging of the Beating Heart: Spatiotemporally-Resolved 3D Imaging of Free Radical Distribution during the Cardiac Cycle

    PubMed Central

    Chen, Zhiyu; Reyes, Levy A.; Johnson, David H.; Velayutham, Murugesan; Yang, Changjun; Samouilov, Alexandre; Zweier, Jay L.

    2012-01-01

    In vivo or ex vivo electron paramagnetic resonance imaging (EPRI) is a powerful technique for determining the spatial distribution of free radicals and other paramagnetic species in living organs and tissues. However, applications of EPRI have been limited by long projection acquisition times and the consequent fact that rapid gated EPRI was not possible. Hence in vivo EPRI typically provided only time-averaged information. In order to achieve direct gated EPRI, a fast EPR acquisition scheme was developed to decrease EPR projection acquisition time down to 10 – 20 ms, along with corresponding software and instrumentation to achieve fast gated EPRI of the isolated beating heart with submillimeter spatial resolution in as little as 2 to 3 minutes. Reconstructed images display temporal and spatial variations of the free radical distribution, anatomical structure, and contractile function within the rat heart during the cardiac cycle. PMID:22473660

  13. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation.

    PubMed

    Kwiecinski, Wojciech; Bessière, Francis; Colas, Elodie Constanciel; N'Djin, W Apoutou; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-21

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion's extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n = 11) and mapped (n = 7). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n = 2) and ventricular (left n = 1, right n = 1) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8

  14. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation.

    PubMed

    Kwiecinski, Wojciech; Bessière, Francis; Colas, Elodie Constanciel; N'Djin, W Apoutou; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-21

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion's extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n = 11) and mapped (n = 7). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n = 2) and ventricular (left n = 1, right n = 1) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8

  15. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation

    NASA Astrophysics Data System (ADS)

    Kwiecinski, Wojciech; Bessière, Francis; Constanciel Colas, Elodie; Apoutou N'Djin, W.; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-01

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion’s extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n=11 ) and mapped (n= 7 ). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n= 2 ) and ventricular (left n=1 , right n=1 ) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8   ±   13

  16. Speeding up 3D speckle tracking using PatchMatch

    NASA Astrophysics Data System (ADS)

    Zontak, Maria; O'Donnell, Matthew

    2016-03-01

    Echocardiography provides valuable information to diagnose heart dysfunction. A typical exam records several minutes of real-time cardiac images. To enable complete analysis of 3D cardiac strains, 4-D (3-D+t) echocardiography is used. This results in a huge dataset and requires effective automated analysis. Ultrasound speckle tracking is an effective method for tissue motion analysis. It involves correlation of a 3D kernel (block) around a voxel with kernels in later frames. The search region is usually confined to a local neighborhood, due to biomechanical and computational constraints. For high strains and moderate frame-rates, however, this search region will remain large, leading to a considerable computational burden. Moreover, speckle decorrelation (due to high strains) leads to errors in tracking. To solve this, spatial motion coherency between adjacent voxels should be imposed, e.g., by averaging their correlation functions.1 This requires storing correlation functions for neighboring voxels, thus increasing memory demands. In this work, we propose an efficient search using PatchMatch, 2 a powerful method to find correspondences between images. Here we adopt PatchMatch for 3D volumes and radio-frequency signals. As opposed to an exact search, PatchMatch performs random sampling of the search region and propagates successive matches among neighboring voxels. We show that: 1) Inherently smooth offset propagation in PatchMatch contributes to spatial motion coherence without any additional processing or memory demand. 2) For typical scenarios, PatchMatch is at least 20 times faster than the exact search, while maintaining comparable tracking accuracy.

  17. Catheter-based endomyocardial delivery of mesenchymal precursor cells using 3D echo guidance improves cardiac function in a chronic myocardial injury ovine model.

    PubMed

    Cheng, Yanping; Yi, Genghua; Conditt, Gerard B; Sheehy, Alexander; Kolodgie, Frank D; Tellez, Armando; Polyakov, Igor; Gu, Anguo; Aboodi, Michael S; Wallace-Bradley, David; Schuster, Michael; Martens, Timothy; Itescu, Silviu; Kaluza, Greg L; Basu, Shubhayu; Virmani, Renu; Granada, Juan F; Sherman, Warren

    2013-01-01

    The administration of bone marrow-derived stem cells may provide a new treatment option for patients with heart failure. Transcatheter cell injection may require multi-imaging modalities to optimize delivery. This study sought to evaluate whether endomyocardial injection of mesenchymal precursor cells (MPCs) could be guided by real-time 3D echocardiography (RT3DE) in treating chronic, postinfarction (MI) left ventricular (LV) dysfunction in sheep. Four weeks after induction of an anterior wall myocardial infarction in 39 sheep, allogeneic MPCs in doses of either 25 × 10(6) (n = 10), 75 × 10(6) (n = 9), or 225 × 10(6) (n = 10) cells or nonconditioned control media (n = 10) were administered intramyocardially into infarct and border zone areas using a catheter designed for combined fluoroscopic and RT3DE-guided injections. LV function was assessed before and after injection. Infarct dimension and vascular density were evaluated histologically. RT3DE-guided injection procedures were safe. Compared to controls, the highest dose MPC treatment led to increments in ejection fraction (3 ventricula 3% in 225M MPCs vs. -5 ± 4% in the control group, p < 0.01) and wall thickening in both infarct (4 ± 4% in 225M MPCs vs. -3 ± 6% in the control group, p = 0.02) and border zones (4 ± 6% in 225M MPCs vs. -8 ± 9% in the control group, p = 0.01). Histology analysis demonstrated significantly higher arteriole density in the infarct and border zones in the highest dose MPC-treated animals compared to the lower dose or control groups. Endomyocardial implantation of MPCs under RT3DE guidance was safe and without observed logistical obstacles. Significant increases in LV performance (ejection fraction and wall thickening) and neovascularization resulted from this technique, and so this technique has important implications for treating patients with postischemic LV dysfunction.

  18. Europeana and 3D

    NASA Astrophysics Data System (ADS)

    Pletinckx, D.

    2011-09-01

    The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  19. Color Doppler Imaging of Cardiac Catheters Using Vibrating Motors

    PubMed Central

    Reddy, Kalyan E.; Light, Edward D.; Rivera, Danny J.; Kisslo, Joseph A.; Smith, Stephen W.

    2010-01-01

    We attached a miniature motor rotating at 11,000 rpm onto the proximal end of cardiac electrophysiological (EP) catheters in order to produce vibrations at the tip which were then visualized by color Doppler on ultrasound scanners. We imaged the catheter tip within a vascular graft submerged in a water tank using the Volumetrics Medical Imaging 3D scanner, the Siemens Sonoline Antares 2D scanner, and the Philips ie33 3D ultrasound scanner with TEE probe. The vibrating catheter tip was visualized in each case though results varied with the color Doppler properties of the individual scanner. PMID:19514134

  20. Point of Care Cardiac Ultrasound Applications in the Emergency Department and Intensive Care Unit - A Review

    PubMed Central

    Arntfield, Robert T; Millington, Scott J

    2012-01-01

    The use of point of care echocardiography by non-cardiologist in acute care settings such as the emergency department (ED) or the intensive care unit (ICU) is very common. Unlike diagnostic echocardiography, the scope of such point of care exams is often restricted to address the clinical questions raised by the patient’s differential diagnosis or chief complaint in order to inform immediate management decisions. In this article, an overview of the most common applications of this focused echocardiography in the ED and ICU is provided. This includes but is not limited to the evaluation of patients experiencing hypotension, cardiac arrest, cardiac trauma, chest pain and patients after cardiac surgery. PMID:22894759

  1. Focused Cardiac Ultrasound Using a Pocket-Size Device in the Emergency Room

    PubMed Central

    Mancuso, Frederico José Neves; Siqueira, Vicente Nicoliello; Moisés, Valdir Ambrósio; Gois, Aécio Flavio Teixeira; de Paola, Angelo Amato Vincenzo; Carvalho, Antonio Carlos Camargo; Campos, Orlando

    2014-01-01

    Background Cardiovascular urgencies are frequent reasons for seeking medical care. Prompt and accurate medical diagnosis is critical to reduce the morbidity and mortality of these conditions. Objective To evaluate the use of a pocket-size echocardiography in addition to clinical history and physical exam in a tertiary medical emergency care. Methods One hundred adult patients without known cardiac or lung diseases who sought emergency care with cardiac complaints were included. Patients with ischemic changes in the electrocardiography or fever were excluded. A focused echocardiography with GE Vscan equipment was performed after the initial evaluation in the emergency room. Cardiac chambers dimensions, left and right ventricular systolic function, intracardiac flows with color, pericardium, and aorta were evaluated. Results The mean age was 61 ± 17 years old. The patient complaint was chest pain in 51 patients, dyspnea in 32 patients, arrhythmia to evaluate the left ventricular function in ten patients, hypotension/dizziness in five patients and edema in one patient. In 28 patients, the focused echocardiography allowed to confirm the initial diagnosis: 19 patients with heart failure, five with acute coronary syndrome, two with pulmonary embolism and two patients with cardiac tamponade. In 17 patients, the echocardiography changed the diagnosis: ten with suspicious of heart failure, two with pulmonary embolism suspicious, two with hypotension without cause, one suspicious of acute coronary syndrome, one of cardiac tamponade and one of aortic dissection. Conclusion The focused echocardiography with pocket-size equipment in the emergency care may allow a prompt diagnosis and, consequently, an earlier initiation of the therapy. PMID:25590933

  2. 3d-3d correspondence revisited

    NASA Astrophysics Data System (ADS)

    Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-01

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  3. 3d-3d correspondence revisited

    DOE PAGES

    Chung, Hee -Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-21

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d N = 2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. As a result, we also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  4. 3D simulation of parametric ultrasound fields

    NASA Astrophysics Data System (ADS)

    Prieur, Fabrice

    2012-09-01

    Parametric sonar is widely used for seafloor characterization, sub-bottom object detection, or underwater communication. It takes advantage of the interaction between two primary beams transmitted at slightly different frequencies. Due to nonlinear propagation, two secondary beams at the sum and difference frequency are generated. The signal at the difference frequency combines sub-bottom penetration due to low attenuation, and high resolution due to an acoustic beam with a narrow mainlobe and negligible sidelobes. A method is presented that provides a full three dimensional estimate for the amplitude of the secondary fields at any depth without the need for stepwise propagation. The method applies to two dimensional transducers of arbitrary geometry and distribution transmitting wideband pulses. The method is limited by the assumption of a quasi-linear propagation in a homogeneous medium. The obtained results in the case of a flat piston transducer compare favorably to previous measurements and numerical estimates from proved methods.

  5. Left Ventricular Flow Analysis: Recent Advances in Numerical Methods and Applications in Cardiac Ultrasound

    PubMed Central

    Borazjani, Iman; Westerdale, John; McMahon, Eileen M.; Rajaraman, Prathish K.; Heys, Jeffrey J.

    2013-01-01

    The left ventricle (LV) pumps oxygenated blood from the lungs to the rest of the body through systemic circulation. The efficiency of such a pumping function is dependent on blood flow within the LV chamber. It is therefore crucial to accurately characterize LV hemodynamics. Improved understanding of LV hemodynamics is expected to provide important clinical diagnostic and prognostic information. We review the recent advances in numerical and experimental methods for characterizing LV flows and focus on analysis of intraventricular flow fields by echocardiographic particle image velocimetry (echo-PIV), due to its potential for broad and practical utility. Future research directions to advance patient-specific LV simulations include development of methods capable of resolving heart valves, higher temporal resolution, automated generation of three-dimensional (3D) geometry, and incorporating actual flow measurements into the numerical solution of the 3D cardiovascular fluid dynamics. PMID:23690874

  6. Electromagnetically navigated laparoscopic ultrasound.

    PubMed

    Wilheim, Dirk; Feussner, Hubertus; Schneider, Armin; Harms, Jens

    2003-01-01

    A three-dimensional (3D) representation of laparoscopic ultrasound examinations could be helpful in diagnostic and therapeutic laparoscopy, but has not yet been realised with flexible laparoscopic ultrasound probes. Therefore, an electromagnetic navigation system was integrated into the tip of a conventional laparoscopic ultrasound probe. Navigated 3D laparoscopic ultrasound was compared with the imaging data of 3D navigated transcutaneous ultrasound and 3D computed tomography (CT) scan. The 3D CT scan served as the "gold standard". Clinical applicability in standardized operating room (OR) settings, imaging quality, diagnostic potential, and accuracy in volumetric assessment of various well-defined hepatic lesions were analyzed. Navigated 3D laparoscopic ultrasound facilitates exact definition of tumor location and margins. As compared with the "gold standard" of the 3D CT scans, 3D laparoscopic ultrasound has a tendency to underestimate the volume of the region of interest (ROI) (Delta3.1%). A comparison of 3D laparoscopy and transcutaneous 3D ultrasonography demonstrated clearly that the former is more accurate for volumetric assessment of the ROI and facilitates a more detailed display of the lesions. 3D laparoscopic ultrasound imaging with a navigated probe is technically feasible. The technique facilitates detailed ultrasound evaluation of laparoscopic procedures that involve visual, in-depth, and volumetric perception of complex liver pathologies. Navigated 3D laparoscopic ultrasound may have the potential to promote the practical role of laparoscopic ultrasonography, and become a valuable tool for local ablative therapy. In this article, our clinical experiences with a certified prototype of a 3D laparoscopic ultrasound probe, as well as its in vitro and in vivo evaluation, is reported.

  7. Update on the safety and efficacy of commercial ultrasound contrast agents in cardiac applications

    PubMed Central

    Tracy, Melissa J; Feinstein, Steven B

    2015-01-01

    Ultrasound contrast agents (UCAs) are currently used throughout the world in both clinical and research settings. The concept of contrast-enhanced ultrasound imaging originated in the late 1960s, and the first commercially available agents were initially developed in the 1980s. Today's microbubbles are designed for greater utility and are used for both approved and off-label indications. In October 2007, the US Food and Drug Administration (FDA) imposed additional product label warnings that included serious cardiopulmonary reactions, several new disease-state contraindications, and a mandated 30 min post-procedure monitoring period for the agents Optison and Definity. These additional warnings were prompted by reports of cardiopulmonary reactions that were temporally related but were not clearly attributable to these UCAs. Subsequent published reports over the following months established not only the safety but also the improved efficacy of clinical ultrasound applications with UCAs. The FDA consequently updated the product labeling in June 2008 and reduced contraindications, although it continued to monitor select patients. In addition, a post-marketing program was proposed to the sponsors for a series of safety studies to further assess the risk of UCAs. Then in October 2011, the FDA leadership further downgraded the warnings after hearing the results of the post-marketing data, which revealed continued safety and improved efficacy. The present review focuses on the use of UCAs in today's clinical practice, including the approved indications, a variety of off-label uses, and the most recent data, which affirms the safety and efficacy of UCAs. PMID:26693339

  8. 3D and Education

    NASA Astrophysics Data System (ADS)

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  9. Outpatient Use of Focused Cardiac Ultrasound to Assess the Inferior Vena Cava in Patients With Heart Failure.

    PubMed

    Saha, Narayan M; Barbat, Julian J; Fedson, Savitri; Anderson, Allen; Rich, Jonathan D; Spencer, Kirk T

    2015-10-15

    Accurate assessment of volume status is critical in the management of patients with heart failure (HF). We studied the utility of a pocket-sized ultrasound device in an outpatient cardiology clinic as a tool to guide volume assessment. Inferior vena cava (IVC) size and collapsibility were assessed in 95 patients by residents briefly trained in focused cardiac ultrasound (FCU). Cardiologist assessment of volume status and changes in diuretic medication were also recorded. Patients were followed for occurrence of 30-day events. There was a 94% success rate of obtaining IVC size and collapsibility, and agreement between visual and calculated IVC parameters was excellent. Most patients were euvolemic by both FCU IVC and clinical bedside assessment (51%) and had no change in diuretic dose. Thirty-two percent had discrepant FCU IVC and clinical volume assessments. In clinically hypervolemic patients, the FCU evaluation of the IVC suggested that the wrong diuretic management plan might have been made 46% of the time. At 30 days, 14 events occurred. The incidence of events increased significantly with FCU IVC imaging categorization, from 11% to 23% to 36% in patients with normal, intermediate, and plethoric IVCs. By comparison, when grouped in a binary manner, there was no significant difference in event rates for patients who were deemed to be clinically volume overloaded. Assessment of volume status in an outpatient cardiology clinic using FCU imaging of the IVC is feasible in a high percentage of patients. A group of patients were identified with volume status discordant between FCU IVC and routine clinic assessment, suggesting that IVC parameters may provide a valuable supplement to the in-office physical examination.

  10. Novel 3D ultrasound image-based biomarkers based on a feature selection from a 2D standardized vessel wall thickness map: a tool for sensitive assessment of therapies for carotid atherosclerosis

    NASA Astrophysics Data System (ADS)

    Chiu, Bernard; Li, Bing; Chow, Tommy W. S.

    2013-09-01

    With the advent of new therapies and management strategies for carotid atherosclerosis, there is a parallel need for measurement tools or biomarkers to evaluate the efficacy of these new strategies. 3D ultrasound has been shown to provide reproducible measurements of plaque area/volume and vessel wall volume. However, since carotid atherosclerosis is a focal disease that predominantly occurs at bifurcations, biomarkers based on local plaque change may be more sensitive than global volumetric measurements in demonstrating efficacy of new therapies. The ultimate goal of this paper is to develop a biomarker that is based on the local distribution of vessel-wall-plus-plaque thickness change (VWT-Change) that has occurred during the course of a clinical study. To allow comparison between different treatment groups, the VWT-Change distribution of each subject must first be mapped to a standardized domain. In this study, we developed a technique to map the 3D VWT-Change distribution to a 2D standardized template. We then applied a feature selection technique to identify regions on the 2D standardized map on which subjects in different treatment groups exhibit greater difference in VWT-Change. The proposed algorithm was applied to analyse the VWT-Change of 20 subjects in a placebo-controlled study of the effect of atorvastatin (Lipitor). The average VWT-Change for each subject was computed (i) over all points in the 2D map and (ii) over feature points only. For the average computed over all points, 97 subjects per group would be required to detect an effect size of 25% that of atorvastatin in a six-month study. The sample size is reduced to 25 subjects if the average were computed over feature points only. The introduction of this sensitive quantification technique for carotid atherosclerosis progression/regression would allow many proof-of-principle studies to be performed before a more costly and longer study involving a larger population is held to confirm the treatment

  11. Clinical Applicability of Assessment of Jugular Flow over the Individual Cardiac Cycle Compared with Current Ultrasound Methodology.

    PubMed

    Sisini, Francesco; Tessari, Mirko; Menegatti, Erica; Vannini, Maria Elena; Gianesini, Sergio; Tavoni, Valentina; Gadda, Giacomo; Gambaccini, Mauro; Taibi, Angelo; Zamboni, Paolo

    2016-08-01

    There is growing interest in measuring cerebral venous outflow with ultrasound (US). However, results obtained with the current US Doppler methodology, which uses just a single value of cross-sectional area (CSA) of the vessel, are highly variable and inconclusive. The product of CSA and time-averaged velocity in the case of pulsatile vessels may be a possible source of error, particularly for a pulsatile vein like the internal jugular vein (IJV), where the cardiac pump transmits a sequence of well-established waves along the conduit. We herein propose a novel technique for US IJV flow assessment that accurately accounts for IJV CSA variations during the cardiac cycle. Five subjects were investigated with a high-resolution real-time B-mode video, synchronized with an electrocardiography trace. In this approach, CSA variations representing the pulsatility of the IJV are overlapped with the velocity curve obtained by the usual spectral Doppler trace. The overlap is then phased point by point using the electrocardiography pacemaker. This allows us to experimentally measure the velocity variation in relation to the change in CSA precisely, ultimately enabling calculation of IJV flow. (i) The sequence of CSA variation with respect to the electrocardiography waves corresponds exactly to the jugular venous pulse as measured in physiology. (ii) The methodology permits us to phase the velocity and CSA, which is ultimately what is currently lacking to precisely calculate the flow in the IJV with US. (iii) The time-averaged flow, calculated with the described technique, is very close to that calculated assuming a constant IJV CSA, whereas the time-dependent flow shows differs as much as 40%. (iv) Finally, we tested the accuracy of the technique with a methodology that may allow for universal assessment of the accuracy of each personal US-based evaluation of flow rate. PMID:27108038

  12. 3D Imaging.

    ERIC Educational Resources Information Center

    Hastings, S. K.

    2002-01-01

    Discusses 3 D imaging as it relates to digital representations in virtual library collections. Highlights include X-ray computed tomography (X-ray CT); the National Science Foundation (NSF) Digital Library Initiatives; output peripherals; image retrieval systems, including metadata; and applications of 3 D imaging for libraries and museums. (LRW)

  13. [Real time 3D echocardiography

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Thomas, J. D.

    2001-01-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

  14. [Real time 3D echocardiography].

    PubMed

    Bauer, F; Shiota, T; Thomas, J D

    2001-07-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients. PMID:11494630

  15. Ultrasound simulator-assisted teaching of cardiac anatomy to preclinical anatomy students: A pilot randomized trial of a three-hour learning exposure.

    PubMed

    Canty, David Jeffrey; Hayes, Jenny A; Story, David Andrew; Royse, Colin Forbes

    2015-01-01

    Ultrasound simulation allows students to virtually explore internal anatomy by producing accurate, moving, color, three-dimensional rendered slices from any angle or approach leaving the organs and their relationships intact without requirement for consumables. The aim was to determine the feasibility and efficacy of self-directed learning of cardiac anatomy with an ultrasound simulator compared to cadavers and plastic models. After a single cardiac anatomy lecture, fifty university anatomy students participated in a three-hour supervised self-directed learning exposure in groups of five, randomized to an ultrasound simulator or human cadaveric specimens and plastic models. Pre- and post-tests were conducted using pictorial and non-pictorial multiple-choice questions (MCQs). Simulator students completed a survey on their experience. Four simulator and seven cadaver group students did not attend after randomization. Simulator use in groups of five students was feasible and feedback from participants was very positive. Baseline test scores were similar (P = 0.9) between groups. After the learning intervention, there was no difference between groups in change in total test score (P = 0.37), whether they were pictorial (P = 0.6) or non-pictorial (P = 0.21). In both groups there was an increase in total test scores (simulator +19.8 ±12.4%% and cadaver: +16.4% ± 10.2, P < 0.0001), pictorial question scores (+22.9 ±18.0%, 19.7 ±19.3%, P < 0.001) and non-pictorial question scores (+16.7 ±18.2%, +13 ±15.4%, P = 0.002). The ultrasound simulator appears equivalent to human cadaveric prosections for learning cardiac anatomy.

  16. Detection and display of acoustic window for guiding and training cardiac ultrasound users

    NASA Astrophysics Data System (ADS)

    Huang, Sheng-Wen; Radulescu, Emil; Wang, Shougang; Thiele, Karl; Prater, David; Maxwell, Douglas; Rafter, Patrick; Dupuy, Clement; Drysdale, Jeremy; Erkamp, Ramon

    2014-03-01

    Successful ultrasound data collection strongly relies on the skills of the operator. Among different scans, echocardiography is especially challenging as the heart is surrounded by ribs and lung tissue. Less experienced users might acquire compromised images because of suboptimal hand-eye coordination and less awareness of artifacts. Clearly, there is a need for a tool that can guide and train less experienced users to position the probe optimally. We propose to help users with hand-eye coordination by displaying lines overlaid on B-mode images. The lines indicate the edges of blockages (e.g., ribs) and are updated in real time according to movement of the probe relative to the blockages. They provide information about how probe positioning can be improved. To distinguish between blockage and acoustic window, we use coherence, an indicator of channel data similarity after applying focusing delays. Specialized beamforming was developed to estimate coherence. Image processing is applied to coherence maps to detect unblocked beams and the angle of the lines for display. We built a demonstrator based on a Philips iE33 scanner, from which beamsummed RF data and video output are transferred to a workstation for processing. The detected lines are overlaid on B-mode images and fed back to the scanner display to provide users real-time guidance. Using such information in addition to B-mode images, users will be able to quickly find a suitable acoustic window for optimal image quality, and improve their skill.

  17. Focused Cardiac Ultrasound Using a Pocket-Size Device in the Emergency Room.

    PubMed

    Mancuso, Frederico José Neves; Siqueira, Vicente Nicoliello; Moisés, Valdir Ambrósio; Gois, Aécio Flavio Teixeira; Paola, Angelo Amato Vincenzo de; Carvalho, Antonio Carlos Camargo; Campos, Orlando

    2014-10-28

    Background: Cardiovascular urgencies are frequent reasons for seeking medical care. Prompt and accurate medical diagnosis is critical to reduce the morbidity and mortality of these conditions. Objective: To evaluate the use of a pocket-size echocardiography in addition to clinical history and physical exam in a tertiary medical emergency care. Methods: One hundred adult patients without known cardiac or lung diseases who sought emergency care with cardiac complaints were included. Patients with ischemic changes in the electrocardiography or fever were excluded. A focused echocardiography with GE Vscan equipment was performed after the initial evaluation in the emergency room. Cardiac chambers dimensions, left and right ventricular systolic function, intracardiac flows with color, pericardium, and aorta were evaluated. Results: The mean age was 61 ± 17 years old. The patient complaint was chest pain in 51 patients, dyspnea in 32 patients, arrhythmia to evaluate the left ventricular function in ten patients, hypotension/dizziness in five patients and edema in one patient. In 28 patients, the focused echocardiography allowed to confirm the initial diagnosis: 19 patients with heart failure, five with acute coronary syndrome, two with pulmonary embolism and two patients with cardiac tamponade. In 17 patients, the echocardiography changed the diagnosis: ten with suspicious of heart failure, two with pulmonary embolism suspicious, two with hypotension without cause, one suspicious of acute coronary syndrome, one of cardiac tamponade and one of aortic dissection. Conclusion: The focused echocardiography with pocket-size equipment in the emergency care may allow a prompt diagnosis and, consequently, an earlier initiation of the therapy.Fundamento: As urgências cardiovasculares são causas importantes de procura por atendimento médico, sendo fundamentais a rapidez e a precisão no diagnóstico para diminuir sua morbimortalidade. Objetivo: Avaliar o uso da ecocardiografia

  18. Focused Cardiac Ultrasound Using a Pocket-Size Device in the Emergency Room.

    PubMed

    Mancuso, Frederico José Neves; Siqueira, Vicente Nicoliello; Moisés, Valdir Ambrósio; Gois, Aécio Flavio Teixeira; Paola, Angelo Amato Vincenzo de; Carvalho, Antonio Carlos Camargo; Campos, Orlando

    2014-10-28

    Background: Cardiovascular urgencies are frequent reasons for seeking medical care. Prompt and accurate medical diagnosis is critical to reduce the morbidity and mortality of these conditions. Objective: To evaluate the use of a pocket-size echocardiography in addition to clinical history and physical exam in a tertiary medical emergency care. Methods: One hundred adult patients without known cardiac or lung diseases who sought emergency care with cardiac complaints were included. Patients with ischemic changes in the electrocardiography or fever were excluded. A focused echocardiography with GE Vscan equipment was performed after the initial evaluation in the emergency room. Cardiac chambers dimensions, left and right ventricular systolic function, intracardiac flows with color, pericardium, and aorta were evaluated. Results: The mean age was 61 ± 17 years old. The patient complaint was chest pain in 51 patients, dyspnea in 32 patients, arrhythmia to evaluate the left ventricular function in ten patients, hypotension/dizziness in five patients and edema in one patient. In 28 patients, the focused echocardiography allowed to confirm the initial diagnosis: 19 patients with heart failure, five with acute coronary syndrome, two with pulmonary embolism and two patients with cardiac tamponade. In 17 patients, the echocardiography changed the diagnosis: ten with suspicious of heart failure, two with pulmonary embolism suspicious, two with hypotension without cause, one suspicious of acute coronary syndrome, one of cardiac tamponade and one of aortic dissection. Conclusion: The focused echocardiography with pocket-size equipment in the emergency care may allow a prompt diagnosis and, consequently, an earlier initiation of the therapy.Fundamento: As urgências cardiovasculares são causas importantes de procura por atendimento médico, sendo fundamentais a rapidez e a precisão no diagnóstico para diminuir sua morbimortalidade. Objetivo: Avaliar o uso da ecocardiografia

  19. Intima-media thickness evaluation by B-mode ultrasound. Correlation with blood pressure levels and cardiac structures.

    PubMed

    Plavnik, F L; Ajzen, S; Kohlmann, O; Tavares, A; Zanella, M T; Ribeiro, A B; Ramos, O L

    2000-01-01

    The aim of this study was to analyze the thickness of the intima-media complex (IMC) using a noninvasive method. The carotid and femoral common arteries were evaluated by noninvasive B-mode ultrasound in 63 normotensive and in 52 hypertensive subjects and the thickness of the IMC was tested for correlation with blood pressure, cardiac structures and several clinical and biological parameters. The IMC was thicker in hypertensive than in normotensive subjects (0.67 +/- 0.13 and 0.62 +/- 0.16 vs 0.54 +/- 0.09 and 0.52 +/- 0.11 mm, respectively, P<0.0001). In normotensive patients, the simple linear regression showed significant correlations between IMC and age, body mass index and 24-h systolic blood pressure for both the carotid and femoral arteries. In hypertensives the carotid IMC was correlated with age and 24-h systolic blood pressure while femoral IMC was correlated only with 24-h diastolic blood pressure. Forward stepwise regression showed that age, body mass index and 24-h systolic blood pressure influenced the carotid IMC relationship (r2 = 0.39) in normotensives. On the other hand, the femoral IMC relationship was influenced by 24-h systolic blood pressure and age (r2 = 0.40). In hypertensives, age and 24-h systolic blood pressure were the most important determinants of carotid IMC (r2 = 0.37), while femoral IMC was influenced only by 24-h diastolic blood pressure (r2 = 0.10). There was an association between carotid IMC and echocardiographic findings in normotensives, while in hypertensives only the left posterior wall and interventricular septum were associated with femoral IMC. We conclude that age and blood pressure influence the intima-media thickness, while echocardiographic changes are associated with the IMC. PMID:10625875

  20. Cerebral Autoregulation Monitoring with Ultrasound-Tagged Near-Infrared Spectroscopy in Cardiac Surgery Patients

    PubMed Central

    Hori, Daijiro; Hogue, Charles W.; Shah, Ashish; Brown, Charles; Neufeld, Karin J; Conte, John V; Price, Joel; Sciortino, Christopher; Max, Laura; Laflam, Andrew; Adachi, Hideo; Cameron, Duke E; Mandal, Kaushik

    2015-01-01

    Background Individualizing mean arterial blood pressure (MAP) based on cerebral blood flow (CBF) autoregulation monitoring during cardiopulmonary bypass (CPB) holds promise as a strategy to optimize organ perfusion. The purpose of this study was to evaluate the accuracy of cerebral autoregulation monitoring using microcirculatory flow measured with innovative ultrasound -tagged near infrared spectroscopy (UT-NIRS) noninvasive technology compared with transcranial Doppler (TCD). Methods Sixty-four patients undergoing CPB were monitored with TCD and UT-NIRS (CerOx™, Israel). The mean velocity index (Mx) was calculated as a moving, linear correlation coefficient between slow waves of TCD-measured CBF velocity and MAP. The cerebral flow velocity index (CFVx) was calculated as a similar coefficient between slow waves of cerebral flow index measured using UT-NIRS and MAP. When MAP is outside the autoregulation range, Mx is progressively more positive. Optimal blood pressure was defined as the MAP with the lowest Mx and CFVx. The right- and left-sided optimal MAP values were averaged to define the individual optimal MAP and was the variable used for analysis Results The mean velocity index (Mx) for the left side was 0.31±0.17 and for the right side 0.32±0.17. The mean cerebral flow velocity index (CFVx) for the left side was 0.33 ± 0.19 and for the right side 0.35 ± 0.19. Time averaged Mx and CFVx during CPB had a statistically significant “among subject” correlation (r=0.39, 95% CI 0.22 to 0.53, p<0.001) but had only a modest agreement within subjects (bias 0.03±0.20, 95% prediction interval for the difference between Mx & CFVx, −0.37 to 0.42). The MAP with the lowest Mx and CFVx (“optimal blood pressure”) were correlated (r=0.71, 95% CI, 0.56 to 0.81, p< 0.0001) and were in modest within-subject agreement (bias −2.85±8.54, 95% limits of agreement for MAP predicted by Mx & CFVx −19.60 to 13.89). Coherence between ipsilateral middle CBF velocity and

  1. 3D motion and strain estimation of the heart: initial clinical findings

    NASA Astrophysics Data System (ADS)

    Barbosa, Daniel; Hristova, Krassimira; Loeckx, Dirk; Rademakers, Frank; Claus, Piet; D'hooge, Jan

    2010-03-01

    The quantitative assessment of regional myocardial function remains an important goal in clinical cardiology. As such, tissue Doppler imaging and speckle tracking based methods have been introduced to estimate local myocardial strain. Recently, volumetric ultrasound has become more readily available, allowing therefore the 3D estimation of motion and myocardial deformation. Our lab has previously presented a method based on spatio-temporal elastic registration of ultrasound volumes to estimate myocardial motion and deformation in 3D, overcoming the spatial limitations of the existing methods. This method was optimized on simulated data sets in previous work and is currently tested in a clinical setting. In this manuscript, 10 healthy volunteers, 10 patient with myocardial infarction and 10 patients with arterial hypertension were included. The cardiac strain values extracted with the proposed method were compared with the ones estimated with 1D tissue Doppler imaging and 2D speckle tracking in all patient groups. Although the absolute values of the 3D strain components assessed by this new methodology were not identical to the reference methods, the relationship between the different patient groups was similar.

  2. Radiochromic 3D Detectors

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2015-01-01

    Radiochromic materials exhibit a colour change when exposed to ionising radiation. Radiochromic film has been used for clinical dosimetry for many years and increasingly so recently, as films of higher sensitivities have become available. The two principle advantages of radiochromic dosimetry include greater tissue equivalence (radiologically) and the lack of requirement for development of the colour change. In a radiochromic material, the colour change arises direct from ionising interactions affecting dye molecules, without requiring any latent chemical, optical or thermal development, with important implications for increased accuracy and convenience. It is only relatively recently however, that 3D radiochromic dosimetry has become possible. In this article we review recent developments and the current state-of-the-art of 3D radiochromic dosimetry, and the potential for a more comprehensive solution for the verification of complex radiation therapy treatments, and 3D dose measurement in general.

  3. 3-D Seismic Interpretation

    NASA Astrophysics Data System (ADS)

    Moore, Gregory F.

    2009-05-01

    This volume is a brief introduction aimed at those who wish to gain a basic and relatively quick understanding of the interpretation of three-dimensional (3-D) seismic reflection data. The book is well written, clearly illustrated, and easy to follow. Enough elementary mathematics are presented for a basic understanding of seismic methods, but more complex mathematical derivations are avoided. References are listed for readers interested in more advanced explanations. After a brief introduction, the book logically begins with a succinct chapter on modern 3-D seismic data acquisition and processing. Standard 3-D acquisition methods are presented, and an appendix expands on more recent acquisition techniques, such as multiple-azimuth and wide-azimuth acquisition. Although this chapter covers the basics of standard time processing quite well, there is only a single sentence about prestack depth imaging, and anisotropic processing is not mentioned at all, even though both techniques are now becoming standard.

  4. Bootstrapping 3D fermions

    DOE PAGES

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-17

    We study the conformal bootstrap for a 4-point function of fermions <ψψψψ> in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge CT. We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N. Finally, we also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  5. Validation of On-Orbit Methodology for the Assessment of Cardiac Function and Changes in the Circulating Volume Using Ultrasound and Braslet-M Occlusion Cuffs

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas; Sargsyan, Ashot E.; Ebert, Douglas; Duncan, Michael; Bogomolov, Valery V.; Alferova, Irina V.; Matveev, Vladimir P.; Dulchavsky, Scott A.

    2010-01-01

    The objective of this joint U.S. - Russian project was the development and validation of an in-flight methodology to assess a number of cardiac and vascular parameters associated with circulating volume and its manipulation in long-duration space flight. Responses to modified Valsalva and Mueller maneuvers were measured by cardiac and vascular ultrasound (US) before, during, and after temporary volume reduction by means of Braslet-M thigh occlusion cuffs (Russia). Materials and Methods: The study protocol was conducted in 14 sessions on 9 ISS crewmembers, with an average exposure to microgravity of 122 days. Baseline cardiovascular measurements were taken by echocardiography in multiple modes (including tissue Doppler of both ventricles) and femoral and jugular vein imaging on the International Space Station (ISS). The Braslet devices were then applied and measurements were repeated after >10 minutes. The cuffs were then released and the hemodynamic recovery process was monitored. Modified Valsalva and Mueller maneuvers were used throughout the protocol. All US data were acquired by the HDI-5000 ultrasound system aboard the ISS (ATL/Philips, USA) during remotely guided sessions. The study protocol, including the use of Braslet-M for this purpose, was approved by the ISS Human Research Multilateral Review Board (HRMRB). Results: The effects of fluid sequestration on a number of echocardiographic and vascular parameters were readily detectable by in-flight US, as were responses to respiratory maneuvers. The overall volume status assessment methodology appears to be valid and practical, with a decrease in left heart lateral E (tissue Doppler) as one of the most reliable measures. Increase in the femoral vein cross-sectional areas was consistently observed with Braslet application. Other significant differences and trends within the extensive cardiovascular data were also observed. (Decreased - RV and LV preload indices, Cardiac Output, LV E all maneuvers, LV Stroke

  6. Venus in 3D

    NASA Astrophysics Data System (ADS)

    Plaut, J. J.

    1993-08-01

    Stereographic images of the surface of Venus which enable geologists to reconstruct the details of the planet's evolution are discussed. The 120-meter resolution of these 3D images make it possible to construct digital topographic maps from which precise measurements can be made of the heights, depths, slopes, and volumes of geologic structures.

  7. 3D reservoir visualization

    SciTech Connect

    Van, B.T.; Pajon, J.L.; Joseph, P. )

    1991-11-01

    This paper shows how some simple 3D computer graphics tools can be combined to provide efficient software for visualizing and analyzing data obtained from reservoir simulators and geological simulations. The animation and interactive capabilities of the software quickly provide a deep understanding of the fluid-flow behavior and an accurate idea of the internal architecture of a reservoir.

  8. Registration of 3D fetal neurosonography and MRI☆

    PubMed Central

    Kuklisova-Murgasova, Maria; Cifor, Amalia; Napolitano, Raffaele; Papageorghiou, Aris; Quaghebeur, Gerardine; Rutherford, Mary A.; Hajnal, Joseph V.; Noble, J. Alison; Schnabel, Julia A.

    2013-01-01

    We propose a method for registration of 3D fetal brain ultrasound with a reconstructed magnetic resonance fetal brain volume. This method, for the first time, allows the alignment of models of the fetal brain built from magnetic resonance images with 3D fetal brain ultrasound, opening possibilities to develop new, prior information based image analysis methods for 3D fetal neurosonography. The reconstructed magnetic resonance volume is first segmented using a probabilistic atlas and a pseudo ultrasound image volume is simulated from the segmentation. This pseudo ultrasound image is then affinely aligned with clinical ultrasound fetal brain volumes using a robust block-matching approach that can deal with intensity artefacts and missing features in the ultrasound images. A qualitative and quantitative evaluation demonstrates good performance of the method for our application, in comparison with other tested approaches. The intensity average of 27 ultrasound images co-aligned with the pseudo ultrasound template shows good correlation with anatomy of the fetal brain as seen in the reconstructed magnetic resonance image. PMID:23969169

  9. 3D rapid mapping

    NASA Astrophysics Data System (ADS)

    Isaksson, Folke; Borg, Johan; Haglund, Leif

    2008-04-01

    In this paper the performance of passive range measurement imaging using stereo technique in real time applications is described. Stereo vision uses multiple images to get depth resolution in a similar way as Synthetic Aperture Radar (SAR) uses multiple measurements to obtain better spatial resolution. This technique has been used in photogrammetry for a long time but it will be shown that it is now possible to do the calculations, with carefully designed image processing algorithms, in e.g. a PC in real time. In order to get high resolution and quantitative data in the stereo estimation a mathematical camera model is used. The parameters to the camera model are settled in a calibration rig or in the case of a moving camera the scene itself can be used for calibration of most of the parameters. After calibration an ordinary TV camera has an angular resolution like a theodolite, but to a much lower price. The paper will present results from high resolution 3D imagery from air to ground. The 3D-results from stereo calculation of image pairs are stitched together into a large database to form a 3D-model of the area covered.

  10. Taming supersymmetric defects in 3d-3d correspondence

    NASA Astrophysics Data System (ADS)

    Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito

    2016-07-01

    We study knots in 3d Chern-Simons theory with complex gauge group {SL}(N,{{C}}), in the context of its relation with 3d { N }=2 theory (the so-called 3d-3d correspondence). The defect has either co-dimension 2 or co-dimension 4 inside the 6d (2,0) theory, which is compactified on a 3-manifold \\hat{M}. We identify such defects in various corners of the 3d-3d correspondence, namely in 3d {SL}(N,{{C}}) CS theory, in 3d { N }=2 theory, in 5d { N }=2 super Yang-Mills theory, and in the M-theory holographic dual. We can make quantitative checks of the 3d-3d correspondence by computing partition functions at each of these theories. This Letter is a companion to a longer paper [1], which contains more details and more results.

  11. 3D Audio System

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Ames Research Center research into virtual reality led to the development of the Convolvotron, a high speed digital audio processing system that delivers three-dimensional sound over headphones. It consists of a two-card set designed for use with a personal computer. The Convolvotron's primary application is presentation of 3D audio signals over headphones. Four independent sound sources are filtered with large time-varying filters that compensate for motion. The perceived location of the sound remains constant. Possible applications are in air traffic control towers or airplane cockpits, hearing and perception research and virtual reality development.

  12. Ultrasound pregnancy

    MedlinePlus

    Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; Placenta previa - ultrasound; Multiple ...

  13. Sonography in Hypotension and Cardiac Arrest (SHoC): Rates of Abnormal Findings in Undifferentiated Hypotension and During Cardiac Arrest as a Basis for Consensus on a Hierarchical Point of Care Ultrasound Protocol

    PubMed Central

    Milne, James; Lewis, David; Fraser, Jacqueline; Diegelmann, Laura; Olszynski, Paul; Stander, Melanie; Lamprecht, Hein

    2016-01-01

    Introduction Point of care ultrasound (PoCUS) has become an established tool in the initial management of patients with undifferentiated hypotension. Current established protocols (RUSH and ACES) were developed by expert user opinion, rather than objective, prospective data. PoCUS also provides invaluable information during resuscitation efforts in cardiac arrest by determining presence/absence of cardiac activity and identifying reversible causes such as pericardial tamponade. There is no agreed guideline on how to safely and effectively incorporate PoCUS into the advanced cardiac life support (ACLS) algorithm. We wished to report disease incidence as a basis to develop a hierarchical approach to PoCUS in hypotension and during cardiac arrest. Methods We summarized the recorded incidence of PoCUS findings from the initial cohort during the interim analysis of two prospective studies. We propose that this will form the basis for developing a modified Delphi approach incorporating this data to obtain the input of a panel of international experts associated with five professional organizations led by the International Federation of Emergency Medicine (IFEM). The modified Delphi tool will be developed to reach an international consensus on how to integrate PoCUS for hypotensive emergency department patients as well as into cardiac arrest algorithms. Results Rates of abnormal PoCUS findings from 151 patients with undifferentiated hypotension included left ventricular dynamic changes (43%), IVC abnormalities (27%), pericardial effusion (16%), and pleural fluid (8%). Abdominal pathology was rare (fluid 5%, AAA 2%). During cardiac arrest there were no pericardial effusions, however abnormalities of ventricular contraction (45%) and valvular motion (39%) were common among the 43 patients included. Conclusions A prospectively collected disease incidence-based hierarchy of scanning can be developed based on the reported findings. This will inform an international consensus

  14. Point-of-care pleural and lung ultrasound in a newborn suffering from cardiac arrest due to tension pneumothorax after cardiac surgery.

    PubMed

    Polito, Angelo; Biasucci, Daniele G; Cogo, Paola

    2016-02-01

    We report the case of a 12-day-old newborn affected by coarctation of the aorta and intraventricular defect who underwent coarctectomy and pulmonary artery banding. On post-operative day 7, the patient suffered from pulseless electric activity due to tension pneumothorax. Point-of-care ultrasound was performed during cardiopulmonary resuscitation in an attempt to diagnose pneumothorax. The diagnosis was made without delaying or interrupting chest compressions, and the pneumothorax was promptly treated.

  15. Heart wall motion analysis by dynamic 3D strain rate imaging from tissue Doppler echocardiography

    NASA Astrophysics Data System (ADS)

    Hastenteufel, Mark; Wolf, Ivo; de Simone, Raffaele; Mottl-Link, Sibylle; Meinzer, Hans-Peter

    2002-04-01

    The knowledge about the complex three-dimensional (3D) heart wall motion pattern, particular in the left ventricle, provides valuable information about potential malfunctions, e.g., myocardial ischemia. Nowadays, echocardiography (cardiac ultrasound) is the predominant technique for evaluation of cardiac function. Beside morphology, tissue velocities can be obtained by Doppler techniques (tissue Doppler imaging, TDI). Strain rate imaging (SRI) is a new technique to diagnose heart vitality. It provides information about the contraction ability of the myocardium. Two-dimensional color Doppler echocardiography is still the most important clinical method for estimation of morphology and function. Two-dimensional methods leads to a lack of information due to the three-dimensional overall nature of the heart movement. Due to this complex three-dimensional motion pattern of the heart, the knowledge about velocity and strain rate distribution over the whole ventricle can provide more valuable diagnostic information about motion disorders. For the assessment of intracardiac blood flow three-dimensional color Doppler has already shown its clinical utility. We have developed methods to produce strain rate images by means of 3D tissue Doppler echocardiography. The tissue Doppler and strain rate images can be visualized and quantified by different methods. The methods are integrated into an interactively usable software environment, making them available in clinical everyday life. Our software provides the physician with a valuable tool for diagnosis of heart wall motion.

  16. Prominent rocks - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Many prominent rocks near the Sagan Memorial Station are featured in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. Wedge is at lower left; Shark, Half-Dome, and Pumpkin are at center. Flat Top, about four inches high, is at lower right. The horizon in the distance is one to two kilometers away.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  17. 'Diamond' in 3-D

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 3-D, microscopic imager mosaic of a target area on a rock called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  18. Martian terrain - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This area of terrain near the Sagan Memorial Station was taken on Sol 3 by the Imager for Mars Pathfinder (IMP). 3D glasses are necessary to identify surface detail.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  19. Feasibility of remote real-time guidance of a cardiac examination performed by novices using a pocket-sized ultrasound device.

    PubMed

    Mai, Tuan V; Ahn, David T; Phillips, Colin T; Agan, Donna L; Kimura, Bruce J

    2013-01-01

    Background. The potential of pocket-sized ultrasound devices (PUDs) to improve global healthcare delivery is limited by the lack of a suitable imaging protocol and trained users. Therefore, we investigated the feasibility of performing a brief, evidence-based cardiac limited ultrasound exam (CLUE) through wireless guidance of novice users. Methods. Three trainees applied PUDs on 27 subjects while directed by an off-site cardiologist to obtain a CLUE to screen for LV systolic dysfunction (LVSD), LA enlargement (LAE), ultrasound lung comets (ULC+), and elevated CVP (eCVP). Real-time remote audiovisual guidance and interpretation by the cardiologist were performed using the iPhone 4/iPod (FaceTime, Apple, Inc.) attached to the PUD and transmitted data wirelessly. Accuracy and technical quality of transmitted images were compared to on-site, gold-standard echo thresholds. Results. Novice versus sonographer imaging yielded technically adequate views in 122/135 (90%) versus 130/135 (96%) (P < 0.05). CLUE's combined SN, SP, and ACC were 0.67, 0.96, and 0.90. Technical adequacy (%) and accuracy for each abnormality (n) were LVSD (85%, 0.93, n = 5), LAE (89%, 0.74, n = 16), ULC+ (100%, 0.94, n = 5), and eCVP (78%, 0.91, n = 1). Conclusion. A novice can perform the CLUE using PUD when wirelessly guided by an expert. This method could facilitate PUD use for off-site bedside medical decision making and triaging of patients. PMID:24024032

  20. Three- and four-dimensional ultrasound in fetal echocardiography: an up-to-date overview.

    PubMed

    Adriaanse, B M E; van Vugt, J M G; Haak, M C

    2016-09-01

    Congenital heart diseases (CHD) are the most commonly overlooked lesions in prenatal screening programs. Real-time two-dimensional ultrasound (2DUS) is the conventionally used tool for fetal echocardiography. Although continuous improvements in the hardware and post-processing software have resulted in a good image quality even in late first trimester, 2DUS still has its limitations. Four-dimensional ultrasound with spatiotemporal image correlation (STIC) is an automated volume acquisition, recording a single three-dimensional (3D) volume throughout a complete cardiac cycle, which results in a four-dimensional (4D) volume. STIC has the potential to increase the detection rate of CHD. The aim of this study is to provide a practical overview of the possibilities and (dis)advantages of STIC. A review of literature and evaluation of the current status and clinical value of 3D/4D ultrasound in prenatal screening and diagnosis of congenital heart disease are presented.

  1. Robust temporal alignment of multimodal cardiac sequences

    NASA Astrophysics Data System (ADS)

    Perissinotto, Andrea; Queirós, Sandro; Morais, Pedro; Baptista, Maria J.; Monaghan, Mark; Rodrigues, Nuno F.; D'hooge, Jan; Vilaça, João. L.; Barbosa, Daniel

    2015-03-01

    Given the dynamic nature of cardiac function, correct temporal alignment of pre-operative models and intraoperative images is crucial for augmented reality in cardiac image-guided interventions. As such, the current study focuses on the development of an image-based strategy for temporal alignment of multimodal cardiac imaging sequences, such as cine Magnetic Resonance Imaging (MRI) or 3D Ultrasound (US). First, we derive a robust, modality-independent signal from the image sequences, estimated by computing the normalized cross-correlation between each frame in the temporal sequence and the end-diastolic frame. This signal is a resembler for the left-ventricle (LV) volume curve over time, whose variation indicates different temporal landmarks of the cardiac cycle. We then perform the temporal alignment of these surrogate signals derived from MRI and US sequences of the same patient through Dynamic Time Warping (DTW), allowing to synchronize both sequences. The proposed framework was evaluated in 98 patients, which have undergone both 3D+t MRI and US scans. The end-systolic frame could be accurately estimated as the minimum of the image-derived surrogate signal, presenting a relative error of 1.6 +/- 1.9% and 4.0 +/- 4.2% for the MRI and US sequences, respectively, thus supporting its association with key temporal instants of the cardiac cycle. The use of DTW reduces the desynchronization of the cardiac events in MRI and US sequences, allowing to temporally align multimodal cardiac imaging sequences. Overall, a generic, fast and accurate method for temporal synchronization of MRI and US sequences of the same patient was introduced. This approach could be straightforwardly used for the correct temporal alignment of pre-operative MRI information and intra-operative US images.

  2. Needle segmentation using 3D Hough transform in 3D TRUS guided prostate transperineal therapy

    SciTech Connect

    Qiu Wu; Yuchi Ming; Ding Mingyue; Tessier, David; Fenster, Aaron

    2013-04-15

    Purpose: Prostate adenocarcinoma is the most common noncutaneous malignancy in American men with over 200 000 new cases diagnosed each year. Prostate interventional therapy, such as cryotherapy and brachytherapy, is an effective treatment for prostate cancer. Its success relies on the correct needle implant position. This paper proposes a robust and efficient needle segmentation method, which acts as an aid to localize the needle in three-dimensional (3D) transrectal ultrasound (TRUS) guided prostate therapy. Methods: The procedure of locating the needle in a 3D TRUS image is a three-step process. First, the original 3D ultrasound image containing a needle is cropped; the cropped image is then converted to a binary format based on its histogram. Second, a 3D Hough transform based needle segmentation method is applied to the 3D binary image in order to locate the needle axis. The position of the needle endpoint is finally determined by an optimal threshold based analysis of the intensity probability distribution. The overall efficiency is improved through implementing a coarse-fine searching strategy. The proposed method was validated in tissue-mimicking agar phantoms, chicken breast phantoms, and 3D TRUS patient images from prostate brachytherapy and cryotherapy procedures by comparison to the manual segmentation. The robustness of the proposed approach was tested by means of varying parameters such as needle insertion angle, needle insertion length, binarization threshold level, and cropping size. Results: The validation results indicate that the proposed Hough transform based method is accurate and robust, with an achieved endpoint localization accuracy of 0.5 mm for agar phantom images, 0.7 mm for chicken breast phantom images, and 1 mm for in vivo patient cryotherapy and brachytherapy images. The mean execution time of needle segmentation algorithm was 2 s for a 3D TRUS image with size of 264 Multiplication-Sign 376 Multiplication-Sign 630 voxels. Conclusions

  3. Improved cardiac motion detection from ultrasound images using TDIOF: a combined B-mode/ tissue Doppler approach

    NASA Astrophysics Data System (ADS)

    Tavakoli, Vahid; Stoddard, Marcus F.; Amini, Amir A.

    2013-03-01

    Quantitative motion analysis of echocardiographic images helps clinicians with the diagnosis and therapy of patients suffering from cardiac disease. Quantitative analysis is usually based on TDI (Tissue Doppler Imaging) or speckle tracking. These methods are based on two independent techniques - the Doppler Effect and image registration, respectively. In order to increase the accuracy of the speckle tracking technique and cope with the angle dependency of TDI, herein, a combined approach dubbed TDIOF (Tissue Doppler Imaging Optical Flow) is proposed. TDIOF is formulated based on the combination of B-mode and Doppler energy terms in an optical flow framework and minimized using algebraic equations. In this paper, we report on validations with simulated, physical cardiac phantom, and in-vivo patient data. It is shown that the additional Doppler term is able to increase the accuracy of speckle tracking, the basis for several commercially available echocardiography analysis techniques.

  4. 3D Elevation Program—Virtual USA in 3D

    USGS Publications Warehouse

    Lukas, Vicki; Stoker, J.M.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  5. 3D Elevation Program—Virtual USA in 3D

    USGS Publications Warehouse

    Lukas, Vicki; Stoker, J.M.

    2016-04-14

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  6. Feasibility Study on Prenatal Cardiac Screening Using Four-Dimensional Ultrasound with Spatiotemporal Image Correlation: A Multicenter Study

    PubMed Central

    Chen, Sun; Ren, Yunyun; Chen, Ping; Niu, Jianmei; Li, Cao; Sun, Kun

    2016-01-01

    Objective This study aimed at investigating the feasibility of using the spatiotemporal image correlation (STIC) technology for prenatal cardiac screening, finding factors that influence the offline evaluation of reconstructed fetal heart, and establishing an optimal acquisition scheme. Methods The study included 452 gravidae presenting for routine screening at 3 maternity centers at 20–38 gestational weeks. The factors influencing the quality of STIC volume data were evaluated using t test, chi-square test, and logistic regression analysis. The predictive power was evaluated using the receiver operating characteristic (ROC) curve. Results Among the 452 fetuses enrolled, 353 (78.1%) were identified as successful and 99 (21.9%) as failure of evaluation of the reconstructed fetal heart. The total success rate of qualified STIC images was 78.1%. The display rates of reconstructed cardiac views were 86.5% (four-chamber view), 92.5% (left ventricular outflow tract view), 92.7% (right ventricular outflow tract view), 89.9% (three-vessel trachea view), 63.9% (aortic arch view), 81.4% (ductal arch view), 81% (short-axis view of great vessels), 80.1% (long-cava view), and 86.9% (abdominal view). A logistic regression analysis showed that more than 28 gestational weeks [OR = 0.39 (CI 95% 0.16, 0.19), P = 0.035], frequent fetal movements [OR = 0.37 (CI 95% 0.16, 0.87), P = 0.022], shadowing [OR = 0.36 (CI 95% 0.19, 0.72), P = 0.004], spine location at 10–2 o’clock [OR = 0.08 (CI 95% 0.02, 0.27), P = 0.0], and original cardiac view [OR = 0.51 (0.25, 0.89), P = 0.019] had a significant impact on the quality of STIC. The area under the ROC curve was 0.775. Conclusions Fetal cardiac-STIC seems a feasible tool for prenatal screening of congenital heart diseases. The influence factors on the quality of STIC images included the intensity of training, gestational age, fetal conditions and parameter settings. The optimal acquisition scheme may improve the application and

  7. ECG gated tomographic reconstruction for 3-D rotational coronary angiography

    PubMed Central

    Hu, Yining; Xie, Lizhe; Nunes, Jean Claude; Bellanger, Jean Jacques; Bedossa, Marc; Toumoulin, Christine

    2010-01-01

    A method is proposed for 3-D reconstruction of coronary from a limited number of projections in rotational angiography. A Bayesian maximum a posteriori (MAP) estimation is applied with a Poisson distributed projection to reconstruct the 3D coronary tree at a given instant of the cardiac cycle. Several regularizers are investigated L0-norm, L1 and L2 -norm in order to take into account the sparsity of the data. Evaluations are reported on simulated data obtained from a 3D dynamic sequence acquired on a 64-slice GE LightSpeed CT scan. A performance study is conducted to evaluate the quality of the reconstruction of the structures. PMID:21096844

  8. Market study: 3-D eyetracker

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.

  9. 3D World Building System

    ScienceCinema

    None

    2016-07-12

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  10. 3D World Building System

    SciTech Connect

    2013-10-30

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  11. LLNL-Earth3D

    SciTech Connect

    2013-10-01

    Earth3D is a computer code designed to allow fast calculation of seismic rays and travel times through a 3D model of the Earth. LLNL is using this for earthquake location and global tomography efforts and such codes are of great interest to the Earth Science community.

  12. Euro3D Science Conference

    NASA Astrophysics Data System (ADS)

    Walsh, J. R.

    2004-02-01

    The Euro3D RTN is an EU funded Research Training Network to foster the exploitation of 3D spectroscopy in Europe. 3D spectroscopy is a general term for spectroscopy of an area of the sky and derives its name from its two spatial + one spectral dimensions. There are an increasing number of instruments which use integral field devices to achieve spectroscopy of an area of the sky, either using lens arrays, optical fibres or image slicers, to pack spectra of multiple pixels on the sky (``spaxels'') onto a 2D detector. On account of the large volume of data and the special methods required to reduce and analyse 3D data, there are only a few centres of expertise and these are mostly involved with instrument developments. There is a perceived lack of expertise in 3D spectroscopy spread though the astronomical community and its use in the armoury of the observational astronomer is viewed as being highly specialised. For precisely this reason the Euro3D RTN was proposed to train young researchers in this area and develop user tools to widen the experience with this particular type of data in Europe. The Euro3D RTN is coordinated by Martin M. Roth (Astrophysikalisches Institut Potsdam) and has been running since July 2002. The first Euro3D science conference was held in Cambridge, UK from 22 to 23 May 2003. The main emphasis of the conference was, in keeping with the RTN, to expose the work of the young post-docs who are funded by the RTN. In addition the team members from the eleven European institutes involved in Euro3D also presented instrumental and observational developments. The conference was organized by Andy Bunker and held at the Institute of Astronomy. There were over thirty participants and 26 talks covered the whole range of application of 3D techniques. The science ranged from Galactic planetary nebulae and globular clusters to kinematics of nearby galaxies out to objects at high redshift. Several talks were devoted to reporting recent observations with newly

  13. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery. PMID:26657435

  14. PLOT3D user's manual

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.

    1990-01-01

    PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.

  15. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.

  16. Current progress in 3D printing for cardiovascular tissue engineering.

    PubMed

    Mosadegh, Bobak; Xiong, Guanglei; Dunham, Simon; Min, James K

    2015-03-16

    3D printing is a technology that allows the fabrication of structures with arbitrary geometries and heterogeneous material properties. The application of this technology to biological structures that match the complexity of native tissue is of great interest to researchers. This mini-review highlights the current progress of 3D printing for fabricating artificial tissues of the cardiovascular system, specifically the myocardium, heart valves, and coronary arteries. In addition, how 3D printed sensors and actuators can play a role in tissue engineering is discussed. To date, all the work with building 3D cardiac tissues have been proof-of-principle demonstrations, and in most cases, yielded products less effective than other traditional tissue engineering strategies. However, this technology is in its infancy and therefore there is much promise that through collaboration between biologists, engineers and material scientists, 3D bioprinting can make a significant impact on the field of cardiovascular tissue engineering.

  17. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  18. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  19. Unassisted 3D camera calibration

    NASA Astrophysics Data System (ADS)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  20. 3D Ultrasonic Wave Simulations for Structural Health Monitoring

    NASA Technical Reports Server (NTRS)

    Campbell, Leckey Cara A/; Miler, Corey A.; Hinders, Mark K.

    2011-01-01

    Structural health monitoring (SHM) for the detection of damage in aerospace materials is an important area of research at NASA. Ultrasonic guided Lamb waves are a promising SHM damage detection technique since the waves can propagate long distances. For complicated flaw geometries experimental signals can be difficult to interpret. High performance computing can now handle full 3-dimensional (3D) simulations of elastic wave propagation in materials. We have developed and implemented parallel 3D elastodynamic finite integration technique (3D EFIT) code to investigate ultrasound scattering from flaws in materials. EFIT results have been compared to experimental data and the simulations provide unique insight into details of the wave behavior. This type of insight is useful for developing optimized experimental SHM techniques. 3D EFIT can also be expanded to model wave propagation and scattering in anisotropic composite materials.

  1. Spatially resolved 3D noise

    NASA Astrophysics Data System (ADS)

    Haefner, David P.; Preece, Bradley L.; Doe, Joshua M.; Burks, Stephen D.

    2016-05-01

    When evaluated with a spatially uniform irradiance, an imaging sensor exhibits both spatial and temporal variations, which can be described as a three-dimensional (3D) random process considered as noise. In the 1990s, NVESD engineers developed an approximation to the 3D power spectral density (PSD) for noise in imaging systems known as 3D noise. In this correspondence, we describe how the confidence intervals for the 3D noise measurement allows for determination of the sampling necessary to reach a desired precision. We then apply that knowledge to create a smaller cube that can be evaluated spatially across the 2D image giving the noise as a function of position. The method presented here allows for both defective pixel identification and implements the finite sampling correction matrix. In support of the reproducible research effort, the Matlab functions associated with this work can be found on the Mathworks file exchange [1].

  2. Autofocus for 3D imaging

    NASA Astrophysics Data System (ADS)

    Lee-Elkin, Forest

    2008-04-01

    Three dimensional (3D) autofocus remains a significant challenge for the development of practical 3D multipass radar imaging. The current 2D radar autofocus methods are not readily extendable across sensor passes. We propose a general framework that allows a class of data adaptive solutions for 3D auto-focus across pa