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Sample records for coregistered three-dimensional ultrasound

  1. Coregistered three-dimensional ultrasound and photoacoustic imaging system for ovarian tissue characterization

    NASA Astrophysics Data System (ADS)

    Aguirre, Andres; Guo, Puyun; Gamelin, John; Yan, Shikui; Sanders, Mary M.; Brewer, Molly; Zhu, Quing

    2009-09-01

    Ovarian cancer has the highest mortality of all gynecologic cancers, with a five-year survival rate of only 30% or less. Current imaging techniques are limited in sensitivity and specificity in detecting early stage ovarian cancer prior to its widespread metastasis. New imaging techniques that can provide functional and molecular contrasts are needed to reduce the high mortality of this disease. One such promising technique is photoacoustic imaging. We develop a 1280-element coregistered 3-D ultrasound and photoacoustic imaging system based on a 1.75-D acoustic array. Volumetric images over a scan range of 80 deg in azimuth and 20 deg in elevation can be achieved in minutes. The system has been used to image normal porcine ovarian tissue. This is an important step toward better understanding of ovarian cancer optical properties obtained with photoacoustic techniques. To the best of our knowledge, such data are not available in the literature. We present characterization measurements of the system and compare coregistered ultrasound and photoacoustic images of ovarian tissue to histological images. The results show excellent coregistration of ultrasound and photoacoustic images. Strong optical absorption from vasculature, especially highly vascularized corpora lutea and low absorption from follicles, is demonstrated.

  2. Back-to-back optical coherence tomography-ultrasound probe for co-registered three-dimensional intravascular imaging with real-time display

    NASA Astrophysics Data System (ADS)

    Li, Jiawen; Ma, Teng; Jing, Joseph; Zhang, Jun; Patel, Pranav M.; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping

    2014-03-01

    We have developed a novel integrated optical coherence tomography (OCT)-intravascular ultrasound (IVUS) probe, with a 1.5 mm-long rigid-part and 0.9 mm outer diameter, for real-time intracoronary imaging of atherosclerotic plaques and guiding interventional procedures. By placing the OCT ball lens and IVUS 45MHz single element transducer back-to-back at the same axial position, this probe can provide automatically co-registered, co-axial OCT-IVUS imaging. To demonstrate its capability, 3D OCT-IVUS imaging of a pig's coronary artery in real-time displayed in polar coordinates, as well as images of two major types of advanced plaques in human cadaver coronary segments, was obtained using this probe and our upgraded system. Histology validation is also presented.

  3. Three-dimensional ultrasound scanning.

    PubMed

    Fenster, Aaron; Parraga, Grace; Bax, Jeff

    2011-08-06

    The past two decades have witnessed developments of new imaging techniques that provide three-dimensional images about the interior of the human body in a manner never before available. Ultrasound (US) imaging is an important cost-effective technique used routinely in the management of a number of diseases. However, two-dimensional viewing of three-dimensional anatomy, using conventional two-dimensional US, limits our ability to quantify and visualize the anatomy and guide therapy, because multiple two-dimensional images must be integrated mentally. This practice is inefficient, and may lead to variability and incorrect diagnoses. Investigators and companies have addressed these limitations by developing three-dimensional US techniques. Thus, in this paper, we review the various techniques that are in current use in three-dimensional US imaging systems, with a particular emphasis placed on the geometric accuracy of the generation of three-dimensional images. The principles involved in three-dimensional US imaging are then illustrated with a diagnostic and an interventional application: (i) three-dimensional carotid US imaging for quantification and monitoring of carotid atherosclerosis and (ii) three-dimensional US-guided prostate biopsy.

  4. Three-dimensional ultrasound scanning

    PubMed Central

    Fenster, Aaron; Parraga, Grace; Bax, Jeff

    2011-01-01

    The past two decades have witnessed developments of new imaging techniques that provide three-dimensional images about the interior of the human body in a manner never before available. Ultrasound (US) imaging is an important cost-effective technique used routinely in the management of a number of diseases. However, two-dimensional viewing of three-dimensional anatomy, using conventional two-dimensional US, limits our ability to quantify and visualize the anatomy and guide therapy, because multiple two-dimensional images must be integrated mentally. This practice is inefficient, and may lead to variability and incorrect diagnoses. Investigators and companies have addressed these limitations by developing three-dimensional US techniques. Thus, in this paper, we review the various techniques that are in current use in three-dimensional US imaging systems, with a particular emphasis placed on the geometric accuracy of the generation of three-dimensional images. The principles involved in three-dimensional US imaging are then illustrated with a diagnostic and an interventional application: (i) three-dimensional carotid US imaging for quantification and monitoring of carotid atherosclerosis and (ii) three-dimensional US-guided prostate biopsy. PMID:22866228

  5. Three-dimensional ultrasound imaging.

    PubMed

    Fenster, A; Downey, D B; Cardinal, H N

    2001-05-01

    Ultrasound is an inexpensive and widely used imaging modality for the diagnosis and staging of a number of diseases. In the past two decades, it has benefited from major advances in technology and has become an indispensable imaging modality, due to its flexibility and non-invasive character. In the last decade, research investigators and commercial companies have further advanced ultrasound imaging with the development of 3D ultrasound. This new imaging approach is rapidly achieving widespread use with numerous applications. The major reason for the increase in the use of 3D ultrasound is related to the limitations of 2D viewing of 3D anatomy, using conventional ultrasound. This occurs because: (a) Conventional ultrasound images are 2D, yet the anatomy is 3D, hence the diagnostician must integrate multiple images in his mind. This practice is inefficient, and may lead to variability and incorrect diagnoses. (b) The 2D ultrasound image represents a thin plane at some arbitrary angle in the body. It is difficult to localize the image plane and reproduce it at a later time for follow-up studies. In this review article we describe how 3D ultrasound imaging overcomes these limitations. Specifically, we describe the developments of a number of 3D ultrasound imaging systems using mechanical, free-hand and 2D array scanning techniques. Reconstruction and viewing methods of the 3D images are described with specific examples. Since 3D ultrasound is used to quantify the volume of organs and pathology, the sources of errors in the reconstruction techniques as well as formulae relating design specification to geometric errors are provided. Finally, methods to measure organ volume from the 3D ultrasound images and sources of errors are described.

  6. Three-Dimensional Reconstruction Of Ultrasound Images

    NASA Astrophysics Data System (ADS)

    Lalouche, Robert C.; Bickmore, Dan; Tessler, Franklin N.; Mankovich, Nicholas J.; Huang, H. K.; Kangarloo, Hooshang

    1989-05-01

    We have established a three-dimensional (3-D) imaging facility for reconstruction of serial two-dimensional (2-D) ultrasound images. In the facility, contiguous 2-D images are captured directly at the clinical site from the real-time video signals of a Labsonics serial ultrasound imager. The images are digitized and stored on an IBM PC. They are then transferred over an Ethernet communication network to the Image Processing Laboratory. Finally, the serial images are reformatted and the 3-D images are reconstructed on a Pixar image computer. The reconstruction method involves grey level remapping, slice interpolation, tissue classification, surface enhancement, illumination, projection, and display. We have demonstrated that 3-D ultra-sound images can be created which bring out features difficult to discern in 2-D ultrasound images.

  7. Opto-acoustic breast imaging with co-registered ultrasound

    NASA Astrophysics Data System (ADS)

    Zalev, Jason; Clingman, Bryan; Herzog, Don; Miller, Tom; Stavros, A. Thomas; Oraevsky, Alexander; Kist, Kenneth; Dornbluth, N. Carol; Otto, Pamela

    2014-03-01

    We present results from a recent study involving the ImagioTM breast imaging system, which produces fused real-time two-dimensional color-coded opto-acoustic (OA) images that are co-registered and temporally inter- leaved with real-time gray scale ultrasound using a specialized duplex handheld probe. The use of dual optical wavelengths provides functional blood map images of breast tissue and tumors displayed with high contrast based on total hemoglobin and oxygen saturation of the blood. This provides functional diagnostic information pertaining to tumor metabolism. OA also shows morphologic information about tumor neo-vascularity that is complementary to the morphological information obtained with conventional gray scale ultrasound. This fusion technology conveniently enables real-time analysis of the functional opto-acoustic features of lesions detected by readers familiar with anatomical gray scale ultrasound. We demonstrate co-registered opto-acoustic and ultrasonic images of malignant and benign tumors from a recent clinical study that provide new insight into the function of tumors in-vivo. Results from the Feasibility Study show preliminary evidence that the technology may have the capability to improve characterization of benign and malignant breast masses over conventional diagnostic breast ultrasound alone and to improve overall accuracy of breast mass diagnosis. In particular, OA improved speci city over that of conventional diagnostic ultrasound, which could potentially reduce the number of negative biopsies performed without missing cancers.

  8. Three-dimensional ultrasound imaging of the vasculature.

    PubMed

    Fenster, A; Lee, D; Sherebrin, S; Rankin, R; Downey, D

    1998-02-01

    With conventional ultrasonography, the diagnostician must view a series of two-dimensional images in order to form a mental impression of the three-dimensional anatomy, an efficient and time consuming practice prone to operator variability, which may cause variable or even incorrect diagnoses. Also, a conventional two-dimensional ultrasound image represents a thin slice of the patients anatomy at a single location and orientation, which is difficult to reproduce at a later time. These factors make conventional ultrasonography non-optimal for prospective or follow-up studies. Our efforts have focused on overcoming these deficiencies by developing three-dimensional ultrasound imaging techniques that are capable of acquiring B-mode, colour Doppler and power Doppler images of the vasculature, by using a conventional ultrasound system to acquire a series of two-dimensional images and then mathematically reconstructing them into a single three-dimensional image, which may then be viewed interactively on an inexpensive desktop computer. We report here on two approaches: (1) free-hand scanning, in which a magnetic positioning device is attached to the ultrasound transducer to record the position and orientation of each two-dimensional image needed for the three-dimensional image reconstruction; and (2) mechanical scanning, in which a motor-driven assembly is used to translate the transducer linearly across the neck, yielding a set of uniformly-spaced parallel two-dimensional images.

  9. Three-dimensional ultrasound evaluation of the placenta.

    PubMed

    Hata, T; Tanaka, H; Noguchi, J; Hata, K

    2011-02-01

    Conventional two-dimensional (2D) ultrasound has been widely used for the evaluation of the placenta during pregnancy. This 2D ultrasound evaluation includes the morphology, anatomy, location, implantation, anomaly, size, and color/power and pulsed Doppler sonographic assessment of the placenta. The introduction of three-dimensional (3D) ultrasound would facilitate the novel assessment of the placenta, such as surface-rendered imaging and volume measurement. With the recent advances in 3D power Doppler (3DPD) ultrasound as well as quantitative 3DPD histogram analysis, quantitative and qualitative assessments of the vascularization and blood flow of the placenta have become feasible. These novel techniques may assist in the evaluation of the feto-placental function, and offer potential advantages relative to conventional 2D sonographic assessments. 3D ultrasound may be an important modality in future placental research, in the evaluation of feto-placental insufficiency in clinical practice, and in the prediction of fetal growth restriction and pre-eclampsia, although some limitations regarding the assessment of the placenta employing 3D ultrasound still remain unresolved. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Three-dimensional micro electromechanical system piezoelectric ultrasound transducer

    NASA Astrophysics Data System (ADS)

    Hajati, Arman; Latev, Dimitre; Gardner, Deane; Hajati, Azadeh; Imai, Darren; Torrey, Marc; Schoeppler, Martin

    2012-12-01

    Here we present the design and experimental acoustic test data for an ultrasound transducer technology based on a combination of micromachined dome-shaped piezoelectric resonators arranged in a flexible architecture. Our high performance niobium-doped lead zirconate titanate film is implemented in three-dimensional dome-shaped structures, which form the basic resonating cells. Adjustable frequency response is realized by mixing these basic cells and modifying their dimensions by lithography. Improved characteristics such as high sensitivity, adjustable wide-bandwidth frequency response, low transmit voltage compatible with ordinary integrated circuitry, low electrical impedance well matched to coaxial cabling, and intrinsic acoustic impedance match to water are demonstrated.

  11. In vivo three-dimensional photoacoustic imaging based on a clinical matrix array ultrasound probe

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Erpelding, Todd N.; Jankovic, Ladislav; Guo, Zijian; Robert, Jean-Luc; David, Guillaume; Wang, Lihong V.

    2012-06-01

    We present an integrated photoacoustic and ultrasonic three-dimensional (3-D) volumetric imaging system based on a two-dimensional (2-D) matrix array ultrasound probe. A wavelength-tunable dye laser pumped by a Q-switched Nd:YAG laser serves as the light source and a modified commercial ultrasound imaging system (iU22, Philips Healthcare) with a 2-D array transducer (X7-2, Philips Healthcare) detects both the pulse-echo ultrasound and photoacoustic signals. A multichannel data acquisition system acquires the RF channel data. The imaging system enables rendering of co-registered 3-D ultrasound and photoacoustic images without mechanical scanning. The resolution along the azimuth, elevation, and axial direction are measured to be 0.69, 0.90 and 0.84 mm for photoacoustic imaging. In vivo 3-D photoacoustic mapping of the sentinel lymph node was demonstrated in a rat model using methylene blue dye. These results highlight the clinical potential of 3-D PA imaging for identification of sentinel lymph nodes for cancer staging in humans.

  12. Three-Dimensional Ultrasound Speckle Characterization for Motion Detection

    NASA Astrophysics Data System (ADS)

    Bashford, Gregory Ray

    1995-11-01

    Currently blood flow is measured ultrasonically using Doppler techniques. These methods are essentially one-dimensional and cannot detect or quantify velocities in three dimensions. A new ultrasonic method is presented which may overcome these limitations of Doppler flow detection. This new technique allows detection and quantification of flow from a single transducer aperture by identifying and tracking three-dimensional peaks of the ultrasound speckle pattern. This method, termed feature tracking, was shown previously to permit accurate quantification of axially symmetric flow in one dimension. The hypothesis of this work is that feature tracking of the speckle pattern is an accurate method for motion detection and quantification in three dimensions. Further, it is hypothesized that the speckle pattern has a distinguishing structure in three dimensions including peaks, that these peaks move in correspondence with local blood or tissue motion, that this motion can be quantified in three dimensions by tracking these peaks, and that the quantification of three-dimensional speckle behavior can be used to define the performance bounds of a flow detection and quantification system based on feature tracking. The three-dimensional structure of speckle was studied by examination of pulse-echo ultrasound information from a scattering phantom. The amplitudes and lateral sizes of three-dimensional local maxima were statistically analyzed. These peaks were tracked at various magnitudes and directions of flow by a series of translation experiments. An analysis of the uncertainty of the peak location was formulated to predict the performance of a feature tracking instrument. It is concluded that feature tracking can be extended from one-dimensional velocity determination to three-dimensional motion detection and quantification. Specifically, it is concluded that: (A) Three-dimensional local maxima exist in the speckle pattern, and that they may be located in a volume and

  13. MRI Compatible Ultrasound Transducers for Simultaneous Acquisition of Coregistered Ultrasound to MRI Data

    NASA Astrophysics Data System (ADS)

    Speicher, Daniel; Bartscherer, T.; Becker, F. J.; Jenne, J. W.; Mrosk, K.; Degel, C.; Günther, M.; Tretbar, S.

    Magnetic resonance imaging has become an important part of radiological diagnostics as it shows high resolution volumes of human tissue without any radiation exposure. Beside the high costs for MR imaging the greatest disadvantage of this technology is that it is not real-time capable which leads to possible motion artifacts. Whereas Ultrasound is the most common diagnostic tool in radiology as it is real-time capable and cost effective. Therefore a combination of both modalities is obvious, not only to reduce motion artifacts in MR imaging but to save costs by reducing time in the MR scanner through coregistering ultrasound and MR images for deformation analysis. This work presents the manufacturing and measurement results of MR compatible ultrasound transducers for motion compensation and deformation analyses for clinical interventions under MRI conditions, based on ultrasound volumes acquired by a full MR compatible 180° rotating 8 MHz phased array.

  14. Three-Dimensional Optoacoustic and Laser-Induced Ultrasound Tomography System for Preclinical Research in Mice: Design and Phantom Validation.

    PubMed

    Ermilov, S A; Su, R; Conjusteau, A; Anis, F; Nadvoretskiy, V; Anastasio, M A; Oraevsky, A A

    2016-01-01

    In this work, we introduce a novel three-dimensional imaging system for in vivo high-resolution anatomical and functional whole-body visualization of small animal models developed for preclinical and other type of biomedical research. The system (LOUIS-3DM) combines a multiwavelength optoacoustic tomography (OAT) and laser-induced ultrasound tomography (LUT) to obtain coregistered maps of tissue optical absorption and speed of sound, displayed within the skin outline of the studied animal. The most promising applications of the LOUIS-3DM include 3D angiography, cancer research, and longitudinal studies of biological distributions of optoacoustic contrast agents.

  15. Three-dimensional photoacoustic imaging with a clinical two-dimensional matrix ultrasound transducer

    NASA Astrophysics Data System (ADS)

    Erpelding, Todd N.; Wang, Yu; Jankovic, Ladislav; Guo, Zijian; Robert, Jean-Luc; David, Guillaume; Kim, Chulhong; Wang, Lihong V.

    2011-03-01

    Photoacoustic tomography provides both structural and functional imaging in vivo based on optical absorption contrast. A novel imaging system that incorporates a two-dimensional matrix ultrasound probe for combined photoacoustic and ultrasonic three-dimensional (3D) volumetric imaging is presented. The system consists of a tunable dye laser pumped by a Nd:YAG laser, a commercial ultrasound imaging system (Philips iU22) with a two-dimensional matrix transducer (Philips X7-2, 2500 elements, 2-7 MHz), and a multichannel data acquisition system which allows us to acquire RF channel data. Compared with alternative 3D techniques, this system is attractive because it can generate co-registered 3D photoacoustic and ultrasound images without mechanical scanning. Moreover, the lateral resolution along the azimuth and elevational directions are measured to be 0.77 +/- 0.06 mm and 0.96 +/- 0.06 mm, respectively, based on reconstructed photoacoustic images of phantoms containing individual human hairs. Finally, in vivo 3D photoacoustic sentinel lymph node mapping using methylene blue dye in a rat model is demonstrated.

  16. Three-dimensional ultrasound palmprint recognition using curvature methods

    NASA Astrophysics Data System (ADS)

    Iula, Antonio; Nardiello, Donatella

    2016-05-01

    Palmprint recognition systems that use three-dimensional (3-D) information of the palm surface are the most recently explored techniques to overcome some two-dimensional palmprint difficulties. These techniques are based on light structural imaging. In this work, a 3-D ultrasound palmprint recognition system is proposed and evaluated. Volumetric images of a region of the human hand are obtained by moving an ultrasound linear array along its elevation direction and one by one acquiring a number of B-mode images, which are then grouped in a 3-D matrix. The acquisition time was contained in about 5 s. Much information that can be exploited for 3-D palmprint recognition is extracted from the ultrasound volumetric images, including palm curvature and other under-skin information as the depth of the various traits. The recognition procedure developed in this work is based on the analysis of the principal curvatures of palm surface, i.e., mean curvature image, Gaussian curvature image, and surface type. The proposed method is evaluated by performing verification and identification experiments. Preliminary results have shown that the proposed system exhibits an acceptable recognition rate. Further possible improvements of the proposed technique are finally highlighted and discussed.

  17. High resolution three-dimensional prostate ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Li, Yinbo; Patil, Abhay; Hossack, John A.

    2006-03-01

    This work reports on the application of ultrasound elastography to prostate cancer detection using a high resolution three-dimensional (3D) ultrasound imaging system. The imaging was performed at a relatively high frequency (14 MHz), yielding very fine resolution that is optimal for prostate ultrasound imaging. The fine resolution achieved aids in locating smaller lesions than are normally detectable. Elasticity was measured with a quantitative and automatically controlled "Synthetic Digital Rectal Examination (SDRE)" wherein a smoothly increasing force was applied by injecting water, controlled by an electronic syringe pump, into a latex cover over the transrectal transducer. The lesion identified as stiffened tissue was visually enhanced by colorizing and superimposing it over the conventional B-mode image. Experimental results using a tissue-mimicking phantom demonstrated that the reconstruction accuracy of the I-Beam transducer resulted in less than 15% volumetric error. Thus, this high resolution 3D prostate elastography is possible and may provide reliable and accurate determination of the size and the location of cancers, which may result in improved specificity and sensitivity of cancer detection.

  18. Freehand three-dimensional ultrasound: implementation and applications

    NASA Astrophysics Data System (ADS)

    Sherebrin, S.; Fenster, Aaron; Rankin, Richard N.; Spence, David

    1996-04-01

    Three-dimensional ultrasound (3DUS) offers a valuable approach to many diagnostic imaging problems and provides a relatively low cost alternative to 3D imaging modalities such as MRI and CT. To obtain a 3DUS image, a clinical ultrasound scanner is used to produce a sequence of adjacent 'slices' of the region of interest, which are recorded and used to reconstruct a volume. The required location of each slice may be found either by a priori knowledge of the scan path (mechanized scanning) or by tracking the path of the transducer at scan time (freehand scanning). For some imaging applications the scan path is irregular, making mechanized scanning difficult or impossible. Some examples are: imaging vascular disease in the carotid arteries, joint imaging and obstetrics. We have developed a freehand 3DUS system that is capable of such imaging tasks. We used phantoms containing a wire and a 50% stenosed cylinder phantom to test our system for vascular applications. We found the mean error in locating any image plane to be less than 0.1 mm ((sigma) equals 0.05 mm), with minimal geometric distortion. The degree of stenosis of the phantom was measured from a reconstructed volume to be 52.6% ((sigma) equals 2%). We have started a clinical stenosis study and a pilot joint imaging study. Our clinical results indicate that measurement of stenosis in patients should be possible.

  19. Three-dimensional segmentation of three-dimensional ultrasound carotid atherosclerosis using sparse field level sets.

    PubMed

    Ukwatta, E; Yuan, J; Buchanan, D; Chiu, B; Awad, J; Qiu, W; Parraga, G; Fenster, A

    2013-05-01

    Three-dimensional ultrasound (3DUS) vessel wall volume (VWV) provides a 3D measurement of carotid artery wall remodeling and atherosclerotic plaque and is sensitive to temporal changes of carotid plaque burden. Unfortunately, although 3DUS VWV provides many advantages compared to measurements of arterial wall thickening or plaque alone, it is still not widely used in research or clinical practice because of the inordinate amount of time required to train observers and to generate 3DUS VWV measurements. In this regard, semiautomated methods for segmentation of the carotid media-adventitia boundary (MAB) and the lumen-intima boundary (LIB) would greatly improve the time to train observers and for them to generate 3DUS VWV measurements with high reproducibility. The authors describe a 3D algorithm based on a modified sparse field level set method for segmenting the MAB and LIB of the common carotid artery (CCA) from 3DUS images. To the authors' knowledge, the proposed algorithm is the first direct 3D segmentation method, which has been validated for segmenting both the carotid MAB and the LIB from 3DUS images for the purpose of computing VWV. Initialization of the algorithm requires the observer to choose anchor points on each boundary on a set of transverse slices with a user-specified interslice distance (ISD), in which larger ISD requires fewer user interactions than smaller ISD. To address the challenges of the MAB and LIB segmentations from 3DUS images, the authors integrated regional- and boundary-based image statistics, expert initializations, and anatomically motivated boundary separation into the segmentation. The MAB is segmented by incorporating local region-based image information, image gradients, and the anchor points provided by the observer. Moreover, a local smoothness term is utilized to maintain the smooth surface of the MAB. The LIB is segmented by constraining its evolution using the already segmented surface of the MAB, in addition to the global

  20. Freehand three-dimensional ultrasound to assess semitendinosus muscle morphology.

    PubMed

    Haberfehlner, Helga; Maas, Huub; Harlaar, Jaap; Becher, Jules G; Buizer, Annemieke I; Jaspers, Richard T

    2016-10-01

    In several neurological disorders and muscle injuries, morphological changes of the m. semitendinosus (ST) are presumed to contribute to movement limitations around the knee. Freehand three-dimensional (3D) ultrasound (US), using position tracking of two-dimensional US images to reconstruct a 3D voxel array, can be used to assess muscle morphology in vivo. The aims of this study were: (i) to introduce a newly developed 3D US protocol for ST; and (ii) provide a first comparison of morphological characteristics determined by 3D US with those measured on dissected cadaveric muscles. Morphological characteristics of ST (e.g. muscle belly length, tendon length, fascicle length and whole muscle volume, and volumes of both compartments) were assessed in six cadavers using a 3D US protocol. Subsequently, ST muscles were removed from the body to measure the same morphological characteristics. Mean differences between morphological characteristics measured by 3D US and after dissection were smaller than 10%. Intra-class correlation coefficients (ICCs) were higher than 0.75 for all variables except for the lengths of proximal fascicles (ICC = 0.58). Measurement of the volume of proximal compartment by 3D US was not feasible, due to low US image quality proximally. We conclude that the presented 3D US protocol allows for reasonably accurate measurements of key morphological characteristics of ST muscle.

  1. Automated quality assessment in three-dimensional breast ultrasound images.

    PubMed

    Schwaab, Julia; Diez, Yago; Oliver, Arnau; Martí, Robert; van Zelst, Jan; Gubern-Mérida, Albert; Mourri, Ahmed Bensouda; Gregori, Johannes; Günther, Matthias

    2016-04-01

    Automated three-dimensional breast ultrasound (ABUS) is a valuable adjunct to x-ray mammography for breast cancer screening of women with dense breasts. High image quality is essential for proper diagnostics and computer-aided detection. We propose an automated image quality assessment system for ABUS images that detects artifacts at the time of acquisition. Therefore, we study three aspects that can corrupt ABUS images: the nipple position relative to the rest of the breast, the shadow caused by the nipple, and the shape of the breast contour on the image. Image processing and machine learning algorithms are combined to detect these artifacts based on 368 clinical ABUS images that have been rated manually by two experienced clinicians. At a specificity of 0.99, 55% of the images that were rated as low quality are detected by the proposed algorithms. The areas under the ROC curves of the single classifiers are 0.99 for the nipple position, 0.84 for the nipple shadow, and 0.89 for the breast contour shape. The proposed algorithms work fast and reliably, which makes them adequate for online evaluation of image quality during acquisition. The presented concept may be extended to further image modalities and quality aspects.

  2. Three-dimensional flow vectors from rf ultrasound signals

    NASA Astrophysics Data System (ADS)

    Tuthill, Theresa A.; Rubin, Jonathan M.; Fowlkes, J. B.

    2002-04-01

    A new ultrasound technique for determining three-dimensional velocity vectors has been devised using radio frequency (RF) data from commercially available scanners. Applied to blood flow, this technique could prove useful for evaluating hemodynamics and detecting stenoses. Three orthogonal velocity vectors are computed from the RF signals of two steered beams from a single array. The in-plane velocities are determined using standard Doppler analysis, while the out-of-plane component is derived from the total velocity as computed from temporal decorrelation and the in-plane components. The technique was tested using contrast agent pumped through a flow tube. A GE Vingmed SystemV scanner with a 10 MHz linear array provided scans at beam steering angles of +/- 20 degree(s). Both Doppler velocities and temporal complex decorrelation were computed for each digitized voxel. Additional studies were done on a blood mimicking fluid and in vivo with a canine femoral artery. Vector plots were constructed to show flow for various transducer angles. Angle estimates were within 20 degree(s), and the mean error for the velocity amplitude was less than 15%. The in vivo results provided velocity estimates consistent with the literature. The proposed method, unlike current Doppler velocity measurement techniques, provides quantitative velocity information independent of transducer orientation.

  3. Three-dimensional ultrasound system for guided breast brachytherapy.

    PubMed

    De Jean, Paul; Beaulieu, Luc; Fenster, Aaron

    2009-11-01

    Breast-conserving surgery combined with subsequent radiation therapy is a standard procedure in breast cancer treatment. The disadvantage of whole-breast beam irradiation is that it requires 20-25 treatment days, which is inconvenient for patients with limited mobility or who reside far from the treatment center. However, interstitial high-dose-rate (HDR) brachytherapy is an irradiation method requiring only 5 treatment days and that delivers a lower radiation dose to the surrounding healthy tissue. It involves delivering radiation through 192Ir seeds placed inside the catheters, which are inserted into the breast. The catheters are attached to a HDR afterloader, which controls the seed placement within the catheters and irradiation times to deliver the proper radiation dose. One disadvantage of using HDR brachytherapy is that it requires performing at least one CT scan during treatment planning. The procedure at our institution involves the use of two CT scans. Performing CT scans requires moving the patient from the brachytherapy suite with catheters inserted in their breasts. One alternative is using three-dimensional ultrasound (3DUS) to image the patient. In this study, the authors developed a 3DUS translation scanning system for use in breast brachytherapy. The new system was validated using CT, the current clinical standard, to image catheters in a breast phantom. Once the CT and 3DUS images were registered, the catheter trajectories were then compared. The results showed that the average angular separation between catheter trajectories was 2.4 degrees, the average maximum trajectory separation was 1.0 mm, and the average mean trajectory separation was found to be 0.7 mm. In this article, the authors present the 3DUS translation scanning system's capabilities as well as its potential to be used as the primary treatment planning imaging modality in breast brachytherapy.

  4. Three-dimensional ultrasound system for guided breast brachytherapy

    SciTech Connect

    De Jean, Paul; Beaulieu, Luc; Fenster, Aaron

    2009-11-15

    Breast-conserving surgery combined with subsequent radiation therapy is a standard procedure in breast cancer treatment. The disadvantage of whole-breast beam irradiation is that it requires 20-25 treatment days, which is inconvenient for patients with limited mobility or who reside far from the treatment center. However, interstitial high-dose-rate (HDR) brachytherapy is an irradiation method requiring only 5 treatment days and that delivers a lower radiation dose to the surrounding healthy tissue. It involves delivering radiation through {sup 192}Ir seeds placed inside the catheters, which are inserted into the breast. The catheters are attached to a HDR afterloader, which controls the seed placement within the catheters and irradiation times to deliver the proper radiation dose. One disadvantage of using HDR brachytherapy is that it requires performing at least one CT scan during treatment planning. The procedure at our institution involves the use of two CT scans. Performing CT scans requires moving the patient from the brachytherapy suite with catheters inserted in their breasts. One alternative is using three-dimensional ultrasound (3DUS) to image the patient. In this study, the authors developed a 3DUS translation scanning system for use in breast brachytherapy. The new system was validated using CT, the current clinical standard, to image catheters in a breast phantom. Once the CT and 3DUS images were registered, the catheter trajectories were then compared. The results showed that the average angular separation between catheter trajectories was 2.4 deg., the average maximum trajectory separation was 1.0 mm, and the average mean trajectory separation was found to be 0.7 mm. In this article, the authors present the 3DUS translation scanning system's capabilities as well as its potential to be used as the primary treatment planning imaging modality in breast brachytherapy.

  5. Ultrasound-Derived Three-Dimensional Printing in Congenital Heart Disease.

    PubMed

    Samuel, Bennett P; Pinto, Candida; Pietila, Todd; Vettukattil, Joseph J

    2015-08-01

    Three-dimensional printing technology has significant clinical implications for the management of congenital heart disease. Computed tomography and magnetic resonance imaging have been established as imaging tools for the creation of physical three-dimensional models. The potential use of non-invasive bedside imaging techniques such as three-dimensional echocardiography to derive three-dimensional printed models can revolutionize the planning of interventions for complex congenital malformations. The feasibility of deriving three-dimensional printing from ultrasound provides an additional cost-effective and patient-centered option for interventional cardiologists and surgeons for the management and care of congenital heart disease patients.

  6. Ultrafast ultrasound and photoacoustic co-registered imaging system based on FPGA parallel processing

    NASA Astrophysics Data System (ADS)

    Alqasemi, Umar; Li, Hai; Yuan, Guangqian; Aguirre, Andres; Zhu, Quing

    2012-02-01

    Co-registered Ultrasound and Photoacoustic images provide complimentary structure and functional information for cancer diagnosis and assessment of therapy response. In SPIE Photonics West 2011, we reported a system that acquires from 64 channels and displays up to 1 frame per second (fps) ultrasound pulse-echo images, 5 fps photoacoustic images, and 0.5 fps co-registered images. In this year, we report an upgraded system which acquires from 128 channels and displays up to 15 fps co-registered ultrasound and photoacoustic images limited by our laser pulse repetition rate. The system architecture is novel and it provides real-time co-registration of images, the ability of acquiring the channel RF data for both modalities, and the flexibility of adjusting every parameter involved in the imaging process for both modalities. The digital signal processor board is upgraded to an FPGA-based PCIe board that collects the data from the acquisition modules and transfers them to the PC memory at 2.5GT/s rate through an x8 DDR PCIe bus running at 100MHz clock frequency. The modules FPGA code is also upgraded to form a beam line in 90 microseconds and to communicate through ultrafast differential tracks with the PCIe board. Furthermore, the printed circuit board (PCB) design of the system was adjusted to provide a maximum of 80dB signal-to-noise ratio at 60dB gain, which is comparable to some commercial ultrasound machines. The real-time system allows capturing co-registered US/PAT images free of motion artifacts and also provides ultrafast dynamic information when a contrast agent is used. The system is built for clinical use to assist the diagnosis of ovarian cancer. However, the hardware is still under testing and evaluation stage, experimental and clinical results will be reported later.

  7. Three-dimensional assessment of scoliosis based on ultrasound data

    NASA Astrophysics Data System (ADS)

    Zhang, Junhua; Li, Hongjian; Yu, Bo

    2015-12-01

    In this study, an approach was proposed to assess the 3D scoliotic deformity based on ultrasound data. The 3D spine model was reconstructed by using a freehand 3D ultrasound imaging system. The geometric torsion was then calculated from the reconstructed spine model. A thoracic spine phantom set at a given pose was used in the experiment. The geometric torsion of the spine phantom calculated from the freehand ultrasound imaging system was 0.041 mm-1 which was close to that calculated from the biplanar radiographs (0.025 mm-1). Therefore, ultrasound is a promising technique for the 3D assessment of scoliosis.

  8. Three-dimensional ultrasound imaging of the prostate

    NASA Astrophysics Data System (ADS)

    Fenster, Aaron; Downey, Donal B.

    1999-05-01

    Ultrasonography, a widely used imaging modality for the diagnosis and staging of many diseases, is an important cost- effective technique, however, technical improvements are necessary to realize its full potential. Two-dimensional viewing of 3D anatomy, using conventional ultrasonography, limits our ability to quantify and visualize most diseases, causing, in part, the reported variability in diagnosis and ultrasound guided therapy and surgery. This occurs because conventional ultrasound images are 2D, yet the anatomy is 3D; hence the diagnostician must integrate multiple images in his mind. This practice is inefficient, and may lead to operator variability and incorrect diagnoses. In addition, the 2D ultrasound image represents a single thin plane at some arbitrary angle in the body. It is difficult to localize and reproduce the image plane subsequently, making conventional ultrasonography unsatisfactory for follow-up studies and for monitoring therapy. Our efforts have focused on overcoming these deficiencies by developing 3D ultrasound imaging techniques that can acquire B-mode, color Doppler and power Doppler images. An inexpensive desktop computer is used to reconstruct the information in 3D, and then is also used for interactive viewing of the 3D images. We have used 3D ultrasound images for the diagnosis of prostate cancer, carotid disease, breast cancer and liver disease and for applications in obstetrics and gynecology. In addition, we have also used 3D ultrasonography for image-guided minimally invasive therapeutic applications of the prostate such as cryotherapy and brachytherapy.

  9. Simultaneous three-dimensional laser-ultrasound and photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Wurzinger, Gerhild; Nuster, Robert; Schmitner, Nicole; Gratt, Sibylle; Paltauf, Günther

    2013-06-01

    A purely optical setup for simultaneous photoacoustic (PA) and laser-ultrasound (US) tomography is presented. It is shown that combined imaging can be achieved by using the same laser pulse for photoacoustic generation and for launching a broadband ultrasound pulse from an optically absorbing target. Detection of the laser-generated plane waves that have been scattered at the imaging object and of the photoacoustic signals emitted from the sample is done interferometrically. This way data for PA and US imaging are acquired within one single measurement. Distinction between the signals is possible due to their different times of flight. After data separation, image reconstruction is done using standard back-projection algorithms. The resolution of the setup was estimated and images of a zebra fish are shown, demonstrating the complementary information of the two imaging modalities.

  10. Three-dimensional ultrasound-guided breast biopsy system

    NASA Astrophysics Data System (ADS)

    Smith, Wendy L.; Surry, Kathleen J. M.; Campbell, Laura; Mills, Greg; Downey, Donal B.; Fenster, Aaron

    2001-05-01

    We introduce a mechanically constrained, 3D ultrasound- guided core-needle breast biopsy device. With modest breast compression, 3D ultrasound scans localize suspicious masses. A biopsy needle is mechanically guided into position for firing into the sampling region. Th needle is parallel to the transducer, allowing real-time guidance during needle insertion. Lesion sampling is verified by another ultrasound image after firing. Two procedures quantified targeting accuracy of this apparatus. First, we biopsied eleven breast phantoms containing 123 embedded, cylindrical lesions constructed from PVA-C (poly(vinyl alcohol) cryogel) with diameters ranging from 1.6 to 15.9mm. Identification of the colored lesion in the biopsy sample and analysis of the post-biopsy US images provided a model for the success rates. Using this, we predict that our apparatus will require six passes to biopsy a 3.0 mm lesion with 99% confidence. For the second experiment, agar phantoms were embedded with four rows of 0.8mm stainless steel beads. A 14-gauge needle was inserted to each bead position seen in a 3D ultrasound scan and the tip position was compared to the pre-insertion bead position. The inter-observer standard errors of measurement were less than 0.15 and 0.28mm for the bead and needle tip positions, respectively. The off-axis 3D 95% confidence intervals were determined to have widths between 0.43 and 1.71mm, depending on direction and bead position.

  11. Three-dimensional ultrasound imaging for diagnosis of urethrovaginal fistula.

    PubMed

    Quiroz, Lieschen H; Shobeiri, S Abbas; Nihira, Mikio A

    2010-08-01

    We present a novel technique for visualization of a urethrovaginal fistula. A 52-year-old patient presented with persistent urinary incontinence, after having three mid-urethral sling procedures performed within the past year. The diagnosis of a urethrovaginal fistula was made by endovaginal 3-D endovaginal ultrasound and confirmed intraoperatively. We have described a novel technique that may benefit patients with urethrovaginal fistulas that are difficult to visualize.

  12. Quantitative three-dimensional transrectal ultrasound (TRUS) for prostate imaging

    NASA Astrophysics Data System (ADS)

    Pathak, Sayan D.; Aarnink, Rene G.; de la Rosette, Jean J.; Chalana, Vikram; Wijkstra, Hessel; Haynor, David R.; Debruyne, Frans M. J.; Kim, Yongmin

    1998-06-01

    With the number of men seeking medical care for prostate diseases rising steadily, the need of a fast and accurate prostate boundary detection and volume estimation tool is being increasingly experienced by the clinicians. Currently, these measurements are made manually, which results in a large examination time. A possible solution is to improve the efficiency by automating the boundary detection and volume estimation process with minimal involvement from the human experts. In this paper, we present an algorithm based on SNAKES to detect the boundaries. Our approach is to selectively enhance the contrast along the edges using an algorithm called sticks and integrate it with a SNAKES model. This integrated algorithm requires an initial curve for each ultrasound image to initiate the boundary detection process. We have used different schemes to generate the curves with a varying degree of automation and evaluated its effects on the algorithm performance. After the boundaries are identified, the prostate volume is calculated using planimetric volumetry. We have tested our algorithm on 6 different prostate volumes and compared the performance against the volumes manually measured by 3 experts. With the increase in the user inputs, the algorithm performance improved as expected. The results demonstrate that given an initial contour reasonably close to the prostate boundaries, the algorithm successfully delineates the prostate boundaries in an image, and the resulting volume measurements are in close agreement with those made by the human experts.

  13. Three-dimensional freehand ultrasound: image reconstruction and volume analysis.

    PubMed

    Barry, C D; Allott, C P; John, N W; Mellor, P M; Arundel, P A; Thomson, D S; Waterton, J C

    1997-01-01

    A system is described that rapidly produces a regular 3-dimensional (3-D) data block suitable for processing by conventional image analysis and volume measurement software. The system uses electromagnetic spatial location of 2-dimensional (2-D) freehand-scanned ultrasound B-mode images, custom-built signal-conditioning hardware, UNIX-based computer processing and an efficient 3-D reconstruction algorithm. Utilisation of images from multiple angles of insonation, "compounding," reduces speckle contrast, improves structure coherence within the reconstructed grey-scale image and enhances the ability to detect structure boundaries and to segment and quantify features. Volume measurements using a series of water-filled latex and cylindrical foam rubber phantoms with volumes down to 0.7 mL show that a high degree of accuracy, precision and reproducibility can be obtained. Extension of the technique to handle in vivo data sets by allowing physiological criteria to be taken into account in selecting the images used for construction is also illustrated.

  14. Three-dimensional ultrasound strain imaging of skeletal muscles

    NASA Astrophysics Data System (ADS)

    Gijsbertse, K.; Sprengers, A. M. J.; Nillesen, M. M.; Hansen, H. H. G.; Lopata, R. G. P.; Verdonschot, N.; de Korte, C. L.

    2017-01-01

    In this study, a multi-dimensional strain estimation method is presented to assess local relative deformation in three orthogonal directions in 3D space of skeletal muscles during voluntary contractions. A rigid translation and compressive deformation of a block phantom, that mimics muscle contraction, is used as experimental validation of the 3D technique and to compare its performance with respect to a 2D based technique. Axial, lateral and (in case of 3D) elevational displacements are estimated using a cross-correlation based displacement estimation algorithm. After transformation of the displacements to a Cartesian coordinate system, strain is derived using a least-squares strain estimator. The performance of both methods is compared by calculating the root-mean-squared error of the estimated displacements with the calculated theoretical displacements of the phantom experiments. We observe that the 3D technique delivers more accurate displacement estimations compared to the 2D technique, especially in the translation experiment where out-of-plane motion hampers the 2D technique. In vivo application of the 3D technique in the musculus vastus intermedius shows good resemblance between measured strain and the force pattern. Similarity of the strain curves of repetitive measurements indicates the reproducibility of voluntary contractions. These results indicate that 3D ultrasound is a valuable imaging tool to quantify complex tissue motion, especially when there is motion in three directions, which results in out-of-plane errors for 2D techniques.

  15. Potential role of coregistered photoacoustic and ultrasound imaging in ovarian cancer detection and characterization.

    PubMed

    Aguirre, Andres; Ardeshirpour, Yasaman; Sanders, Mary M; Brewer, Molly; Zhu, Quing

    2011-02-01

    Currently, there is no adequate technology to detect early stage ovarian cancers. Most of the cancers in the ovary are detected when the cancer has already metastasized to other parts of the body. As a result, ovarian cancer has the highest mortality of all gynecologic cancers with a 5-year survival rate of 30% or less. Thus, there is an urgent need to improve the current diagnostic techniques. Photoacoustic imaging (PAI) is an emerging modality with a great potential to assist ultrasound for detecting ovarian cancer noninvasively. In this article, we report the first study of coregistered ultrasound and PAI of 33 ex vivo human ovaries. An assessment of the photoacoustic images has revealed light absorption distribution in the ovary, which is directly related to the vasculature distribution and amount. Quantification of the light absorption levels in the ovary has indicated that, in the postmenopausal group, malignant ovaries showed significantly higher light absorption than normal ones (P = .0237). For these two groups, we have obtained a sensitivity of 83% and a specificity of 83%. This result suggests that PAI is a promising modality for improving ultrasound diagnosis of ovarian cancer.

  16. The combination of pulsed acousto-optic imaging and B-mode diagnostic ultrasound for three-dimensional imaging in ex vivo biological tissue

    NASA Astrophysics Data System (ADS)

    Sui, Lei; Murray, Todd W.; Roy, Ronald A.

    2006-02-01

    A multimode imaging system, producing conventional ultrasound (US) and acousto-optic (AO) images, has been developed and used to detect optical absorbers buried in excised biological tissue. A commercially-available diagnostic ultrasound imaging transducer is used to both generate B-mode ultrasound images and as a pump for AO imaging. Due to the fact that the steered and focused beam used for US imaging and the US source for pumping the AO image are generated from the same ultrasound probe, the acoustical and optical images are intrinsically co-registered. AO imaging is performed using short ultrasound pulse trains at a frequency of 5 MHz. The phase-modulated light emitted from the interaction region is detected using a photorefractive-crystal based interferometry system. Experimental results have previously been presented for the two-dimensional imaging in tissue-mimicking phantoms. In this paper, we report further experimental developments demonstrating three-dimensional fusion of B-mode ultrasound imaging and pulsed acousto-optic imaging in excised biological tissue (~2 cm thick). By mechanically scanning the ultrasound transducer array in a direction perpendicular to its imaging plane, both the acoustical and optical properties of an embedded target are obtained in three dimensions. The results suggest that AO imaging could be used to supplement conventional B-mode ultrasound imaging with optical contrast, and the multimode imaging system may find application in the detection and diagnosis of cancer.

  17. Quantitative investigation of in vitro flow using three-dimensional colour Doppler ultrasound.

    PubMed

    Guo, Z; Moreau, M; Rickey, D W; Picot, P A; Fenster, A

    1995-01-01

    A quantitative in vitro flow study was performed by using a three-dimensional colour Doppler imaging system. This system was based on a clinical ultrasound instrument with its transducer mounted on a motor-driven translation stage. A vascular and tissue-mimicking phantom containing two wall-less vessels, one normal and another stenotic, was used to quantify the measurement accuracy of the flow velocity and the flow field. Steady state flows, having Reynolds numbers ranging between 460 and 1300, were generated by a computer-controlled positive displacement pump. Effects of the parameter settings of the ultrasound instrument on results of the estimation of flow field were also studied. Experimental results show that our three-dimensional colour Doppler system's velocity accuracy was better than 7% of the Nyquist velocity and its spatial accuracy was better than 0.5 mm. The system showed a good correlation (r = 0.999) between the estimated and the true mean flow velocity, and a good correlation (r = 0.998) between the estimated maximum and the true mean flow velocity. This study is our first step toward validating the measurement of the three-dimensional velocity and wall shear stress distributions by using three-dimensional colour Doppler ultrasound

  18. Development of a platform for co-registered ultrasound and MR contrast imaging in vivo

    NASA Astrophysics Data System (ADS)

    Chandrana, Chaitanya; Bevan, Peter; Hudson, John; Pang, Ian; Burns, Peter; Plewes, Donald; Chopra, Rajiv

    2011-02-01

    Imaging of the microvasculature is often performed using contrast agents in combination with either ultrasound (US) or magnetic resonance (MR) imaging. Contrast agents are used to enhance medical imaging by highlighting microvascular properties and function. Dynamic signal changes arising from the passage of contrast agents through the microvasculature can be used to characterize different pathologies; however, comparisons across modalities are difficult due to differences in the interactions of contrast agents with the microvasculature. Better knowledge of the relationship of contrast enhancement patterns with both modalities could enable better characterization of tissue microvasculature. We developed a co-registration platform for multi-modal US and MR imaging using clinical imaging systems in order to study the relationship between US and MR contrast enhancement. A preliminary validation study was performed in phantoms to determine the registration accuracy of the platform. In phantoms, the in-plane registration accuracy was measured to be 0.2 ± 0.2 and 0.3 ± 0.2 mm, in the lateral and axial directions, respectively. The out-of-plane registration accuracy was estimated to be 0.5 mm ±0.1. Co-registered US and MR imaging was performed in a rabbit model to evaluate contrast kinetics in different tissue types after bolus injections of US and MR contrast agents. The arrival time of the contrast agent in the plane of imaging was relatively similar for both modalities. We studied three different tissue types: muscle, large vessels and fat. In US, the temporal kinetics of signal enhancement were not strongly dependent on tissue type. In MR, however, due to the different amounts of agent extravasation in each tissue type, tissue-specific contrast kinetics were observed. This study demonstrates the feasibility of performing in vivo co-registered contrast US and MR imaging to study the relationships of the enhancement patterns with each modality.

  19. The effect of vascular curvature on three-dimensional reconstruction of intravascular ultrasound images.

    PubMed

    Wiet, S P; Vonesh, M J; Waligora, M J; Kane, B J; McPherson, D D

    1996-01-01

    To characterize the effect of vessel curvature on the geometric accuracy of conventional three-dimensional reconstruction (3DR) algorithms for intravascular ultrasound image data. A common method of 3DR for intravascular ultrasound image data involves geometric reassembly and volumetric interpolation of a spatially related sequence of tomographic cross sections generated by an ultrasound catheter withdrawn at a constant rate through a vascular segment of interest. The resulting 3DR is displayed as a straight segment, with inherent vascular curvature neglected. Most vascular structures, however, are not straight but curved to some degree. For this reason, vascular curvature may influence the accuracy of computer-generated 3DR. We collected image data using three different intravascular ultrasound catheters (2.9 Fr, 4.3 Fr, 8.0 Fr) during a constant-rate pullback of 1 mm/sec through tubing of known diameter with imposed radii of curvature ranging from 2 to 10 cm. Image data were also collected from straight tubing. Image data were digitized at 1.0-mm intervals through a length of 25 mm. Two passes through each radius of curvature were performed with each intravascular ultrasound catheter. 3DR lumen volume for each radius of curvature was compared to that theoretically expected from a straight cylindrical segment. Differences between 3DR lumen volume of theoretical versus curved (actual) tubes were quantified as absolute percentage error and categorized as a function of curvature. Tubing deformation error was quantified by quantitative coronary angiography (QCA). Volumetric errors ranged from 1% to 35%, with an inverse relationship demonstrated between 3DR lumen volume and segmental radius of curvature. Higher curvatures (r < 6.0 cm) induced greater lumen volume error when compared to lower curvatures (r > 6.0 cm). This trend was exhibited for all three catheters and was shown to be independent of tubing deformation artifacts. QCA-determined percentage diameter

  20. Image segmentation and tissue characterization in three-dimensional intravascular ultrasound images

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangmin; DeJong, Steven C.; McKay, Charles R.; Sonka, Milan

    1997-04-01

    In this paper, we report an automated approach to plaque tissue characterization in three-dimensional intravascular ultrasound images. Our previously reported automated method for coronary wall and plaque segmentation in intravascular ultrasound pullback sequences represent the first step of the method. Tissue characterization into two classes of soft and hard plaque is based on texture analysis and pattern recognition. Texture description features included gray- level-based measures, co-occurrence matrices, run length measures, and fractal-based measures. Performance of the method was assessed in cadaveric coronary arteries by comparison to the observer-defined plaque composition. Overall classification correctness of 90% was achieved.

  1. Three dimensional ultrasound and hdlive technology as possible tools in teaching embryology.

    PubMed

    Popovici, Razvan; Pristavu, Anda; Sava, Anca

    2017-10-01

    Embryology is an important subject in order to gain an understanding of medicine and surgery; however, sometimes students find the subject difficult to grasp and apply to clinical practice. Modern imaging techniques can be useful aids in teaching and understanding embryology. Imaging techniques have very rapidly evolved over the last few years, advancing from two- to three-dimensional (3D) ultrasound. HDlive is an innovative ultrasound technique that generates near-realistic images of the human fetus. In order to evince the capabilities of 3D ultrasound and HDlive technology in teaching embryology, we evaluated using this technique the normal evolution of the embryo and fetus from the fifth to eleventh week of amenorrhea. Our conclusion is that by yielding clear and impressive images, 3D ultrasound and HDlive could be useful tools in teaching embryology to medical students. Clin. Anat. 30:953-957, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Two-Dimensional and Three-Dimensional Ultrasound of Artificial Skin.

    PubMed

    Wortsman, Ximena; Navarrete, Nelson

    2017-01-01

    Wound healing may be a difficult problem, and variable types of artificial skin prototypes have been developed for supporting this process. Using ultrasound, we studied 4 cellulose-derived artificial skin prototypes and assessed their two-dimensional and three-dimensional morphology. These prototypes were identified on ultrasound both on in vitro and in vivo studies. They allowed the sonographic observation of deeper layers on different types of surfaces of the body with good definition on the in vivo examinations performed on healthy skin and cutaneous ulcers. The ultrasound detection of these artificial biomaterials may potentially support the noninvasive monitoring of wound healing. © 2016 by the American Institute of Ultrasound in Medicine.

  3. Coregistered photoacoustic and ultrasound imaging and classification of ovarian cancer: ex vivo and in vivo studies

    NASA Astrophysics Data System (ADS)

    Salehi, Hassan S.; Li, Hai; Merkulov, Alex; Kumavor, Patrick D.; Vavadi, Hamed; Sanders, Melinda; Kueck, Angela; Brewer, Molly A.; Zhu, Quing

    2016-04-01

    Most ovarian cancers are diagnosed at advanced stages due to the lack of efficacious screening techniques. Photoacoustic tomography (PAT) has a potential to image tumor angiogenesis and detect early neovascular changes of the ovary. We have developed a coregistered PAT and ultrasound (US) prototype system for real-time assessment of ovarian masses. Features extracted from PAT and US angular beams, envelopes, and images were input to a logistic classifier and a support vector machine (SVM) classifier to diagnose ovaries as benign or malignant. A total of 25 excised ovaries of 15 patients were studied and the logistic and SVM classifiers achieved sensitivities of 70.4 and 87.7%, and specificities of 95.6 and 97.9%, respectively. Furthermore, the ovaries of two patients were noninvasively imaged using the PAT/US system before surgical excision. By using five significant features and the logistic classifier, 12 out of 14 images (86% sensitivity) from a malignant ovarian mass and all 17 images (100% specificity) from a benign mass were accurately classified; the SVM correctly classified 10 out of 14 malignant images (71% sensitivity) and all 17 benign images (100% specificity). These initial results demonstrate the clinical potential of the PAT/US technique for ovarian cancer diagnosis.

  4. Recognition algorithm for assisting ovarian cancer diagnosis from coregistered ultrasound and photoacoustic images: ex vivo study

    NASA Astrophysics Data System (ADS)

    Alqasemi, Umar; Kumavor, Patrick; Aguirre, Andres; Zhu, Quing

    2012-12-01

    Unique features and the underlining hypotheses of how these features may relate to the tumor physiology in coregistered ultrasound and photoacoustic images of ex vivo ovarian tissue are introduced. The images were first compressed with wavelet transform. The mean Radon transform of photoacoustic images was then computed and fitted with a Gaussian function to find the centroid of a suspicious area for shift-invariant recognition process. Twenty-four features were extracted from a training set by several methods, including Fourier transform, image statistics, and different composite filters. The features were chosen from more than 400 training images obtained from 33 ex vivo ovaries of 24 patients, and used to train three classifiers, including generalized linear model, neural network, and support vector machine (SVM). The SVM achieved the best training performance and was able to exclusively separate cancerous from non-cancerous cases with 100% sensitivity and specificity. At the end, the classifiers were used to test 95 new images obtained from 37 ovaries of 20 additional patients. The SVM classifier achieved 76.92% sensitivity and 95.12% specificity. Furthermore, if we assume that recognizing one image as a cancer is sufficient to consider an ovary as malignant, the SVM classifier achieves 100% sensitivity and 87.88% specificity.

  5. Classification algorithm of ovarian tissue based on co-registered ultrasound and photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Li, Hai; Kumavor, Patrick D.; Alqasemi, Umar; Zhu, Quing

    2014-03-01

    Human ovarian tissue features extracted from photoacoustic spectra data, beam envelopes and co-registered ultrasound and photoacoustic images are used to characterize cancerous vs. normal processes using a support vector machine (SVM) classifier. The centers of suspicious tumor areas are estimated from the Gaussian fitting of the mean Radon transforms of the photoacoustic image along 0 and 90 degrees. Normalized power spectra are calculated using the Fourier transform of the photoacoustic beamformed data across these suspicious areas, where the spectral slope and 0-MHz intercepts are extracted. Image statistics, envelope histogram fitting and maximum output of 6 composite filters of cancerous or normal patterns along with other previously used features are calculated to compose a total of 17 features. These features are extracted from 169 datasets of 19 ex vivo ovaries. Half of the cancerous and normal datasets are randomly chosen to train a SVM classifier with polynomial kernel and the remainder is used for testing. With 50 times data resampling, the SVM classifier, for the training group, gives 100% sensitivity and 100% specificity. For the testing group, it gives 89.68+/- 6.37% sensitivity and 93.16+/- 3.70% specificity. These results are superior to those obtained earlier by our group using features extracted from photoacoustic raw data or image statistics only.

  6. Controlling collagen fiber microstructure in three-dimensional hydrogels using ultrasound

    PubMed Central

    Garvin, Kelley A.; VanderBurgh, Jacob; Hocking, Denise C.; Dalecki, Diane

    2013-01-01

    Type I collagen is the primary fibrillar component of the extracellular matrix, and functional properties of collagen arise from variations in fiber structure. This study investigated the ability of ultrasound to control collagen microstructure during hydrogel fabrication. Under appropriate conditions, ultrasound exposure of type I collagen during polymerization altered fiber microstructure. Scanning electron microscopy and second-harmonic generation microscopy revealed decreased collagen fiber diameters in response to ultrasound compared to sham-exposed samples. Results of mechanistic investigations were consistent with a thermal mechanism for the effects of ultrasound on collagen fiber structure. To control collagen microstructure site-specifically, a high frequency, 8.3-MHz, ultrasound beam was directed within the center of a large collagen sample producing dense networks of short, thin collagen fibrils within the central core of the gel and longer, thicker fibers outside the beam area. Fibroblasts seeded onto these gels migrated rapidly into small, circularly arranged aggregates only within the beam area, and clustered fibroblasts remodeled the central, ultrasound-exposed collagen fibrils into dense sheets. These investigations demonstrate the capability of ultrasound to spatially pattern various collagen microstructures within an engineered tissue noninvasively, thus enhancing the level of complexity of extracellular matrix microenvironments and cellular functions achievable within three-dimensional engineered tissues. PMID:23927189

  7. Experimental observation of ultrasound fast and slow waves through three-dimensional printed trabecular bone phantoms.

    PubMed

    Mézière, F; Juskova, P; Woittequand, J; Muller, M; Bossy, E; Boistel, Renaud; Malaquin, L; Derode, A

    2016-02-01

    In this paper, ultrasound measurements of 1:1 scale three-dimensional (3D) printed trabecular bone phantoms are reported. The micro-structure of a trabecular horse bone sample was obtained via synchrotron x-ray microtomography, converted to a 3D binary data set, and successfully 3D-printed at scale 1:1. Ultrasound through-transmission experiments were also performed through a highly anisotropic version of this structure, obtained by elongating the digitized structure prior to 3D printing. As in real anisotropic trabecular bone, both the fast and slow waves were observed. This illustrates the potential of stereolithography and the relevance of such bone phantoms for the study of ultrasound propagation in bone.

  8. Correlation between three-dimensional ultrasound features and pathological prognostic factors in breast cancer.

    PubMed

    Jiang, Jun; Chen, Ya-qing; Xu, Yi-zhuan; Chen, Ming-li; Zhu, Yun-kai; Guan, Wen-bin; Wang, Xiao-jin

    2014-06-01

    To investigate the correlation of three-dimensional (3D) ultrasound features with prognostic factors in invasive ductal carcinoma. Surgical resection specimens of 85 invasive ductal carcinomas of 85 women who had undergone 3D ultrasound were included. Morphology features and vascularization perfusion on 3D ultrasound were evaluated. Pathologic prognostic factors, including tumour size, histological grade, lymph node status, oestrogen and progesterone receptor status (ER, PR), c-erbB-2 and p53 expression, and microvessel density (MVD) were determined. Correlations of 3D ultrasound features and prognostic factors were analysed. The retraction pattern in the coronal plane had a significant value as an independent predictor of a small tumour size (P = 0.014), a lower histological grade (P = 0.009) and positive ER or PR expression status (P = 0.001, 0.044). The retraction pattern with a hyperechoic ring only existed in low-grade and ER-positive tumours. The presence of the hyperechoic ring strengthened the ability of the retraction pattern to predict a good prognosis of breast cancer. The increased intra-tumour vascularization index (VI, the mean tumour vascularity) reflected a higher histological grade (P = 0.025) and had a positive correlation with MVD (r = 0.530, P = 0.001). The retraction pattern and histogram indices of VI provided by 3D ultrasound may be useful in predicting prognostic information about breast cancer. Three-dimensional ultrasound can potentially provide prognostic evaluation of breast cancer. The retraction pattern and hyperechoic ring in the coronal plane suggest good prognosis. The increased intra-tumour vascularization index reflects a higher histological grade. The intra-tumour vascularization index is positively correlated with microvessel density.

  9. Three-dimensional ultrasound imaging of vessel wall for evaluating atherosclerosis risk and disease

    NASA Astrophysics Data System (ADS)

    Amin, Viren R.; Wang, Bo; Sonka, Milan; Lauer, Ronald M.

    2002-04-01

    This research aims at developing a three-dimensional (3D) ultrasound system for carotid and brachial artery scanning for evaluating vessel wall characteristics. In the long term, we seek to test hypothesis that the artery wall measurements of carotid intima-media-thickness and brachial flow mediated dilatation using 3D ultrasound data provide better repeatability than those derived from conventional 2D ultrasound scans. The approach is to implement a free-hand data acquisition scheme using conventional 2D medical ultrasound scanner, develop data processing algorithms for appropriately registering and displaying the volumetric ultrasound vessel scans, and develop techniques for measuring vessel wall characteristics. The system uses electromagnetic sensor mounted on the transducer to acquire position and orientation of each image slice as the transducer is moved freely to scan the area of interest. These non-parallel images are registered into a 3D dataset for reconstruction, segmentation, and measurements of the vessel wall structure. A simple calibration object is developed using a small stainless-steel sphere in a fixed position to perform coordinate transformations and pixel registration. A commercial 3D ultrasound tissue-mimicking phantom is used for assessment of freehand 3D data acquisition, calibration, registration, and visualization schemes. Early results of experimental carotid artery scans of volunteers are presented.

  10. High resolution three-dimensional robotic synthetic tracked aperture ultrasound imaging: feasibility study

    NASA Astrophysics Data System (ADS)

    Zhang, Haichong K.; Fang, Ting Yun; Finocchi, Rodolfo; Boctor, Emad M.

    2017-03-01

    Three dimensional (3D) ultrasound imaging is becoming a standard mode for medical ultrasound diagnoses. Conventional 3D ultrasound imaging is mostly scanned either by using a two dimensional matrix array or by motorizing a one dimensional array in the elevation direction. However, the former system is not widely assessable due to its cost, and the latter one has limited resolution and field-of-view in the elevation axis. Here, we propose a 3D ultrasound imaging system based on the synthetic tracked aperture approach, in which a robotic arm is used to provide accurate tracking and motion. While the ultrasound probe is moved by a robotic arm, each probe position is tracked and can be used to reconstruct a wider field-of-view as there are no physical barriers that restrict the elevational scanning. At the same time, synthetic aperture beamforming provides a better resolution in the elevation axis. To synthesize the elevational information, the single focal point is regarded as the virtual element, and forward and backward delay-andsum are applied to the radio-frequency (RF) data collected through the volume. The concept is experimentally validated using a general ultrasound phantom, and the elevational resolution improvement of 2.54 and 2.13 times was measured at the target depths of 20 mm and 110 mm, respectively.

  11. Three Dimensional Sheaf of Ultrasound Planes Reconstruction (SOUPR) of Ablated Volumes

    PubMed Central

    Ingle, Atul; Varghese, Tomy

    2014-01-01

    This paper presents an algorithm for three dimensional reconstruction of tumor ablations using ultrasound shear wave imaging with electrode vibration elastography. Radiofrequency ultrasound data frames are acquired over imaging planes that form a subset of a sheaf of planes sharing a common axis of intersection. Shear wave velocity is estimated separately on each imaging plane using a piecewise linear function fitting technique with a fast optimization routine. An interpolation algorithm then computes velocity maps on a fine grid over a set of C-planes that are perpendicular to the axis of the sheaf. A full three dimensional rendering of the ablation can then be created from this stack of C-planes; hence the name “Sheaf Of Ultrasound Planes Reconstruction” or SOUPR. The algorithm is evaluated through numerical simulations and also using data acquired from a tissue mimicking phantom. Reconstruction quality is gauged using contrast and contrast-to-noise ratio measurements and changes in quality from using increasing number of planes in the sheaf are quantified. The highest contrast of 5 dB is seen between the stiffest and softest regions of the phantom. Under certain idealizing assumptions on the true shape of the ablation, good reconstruction quality while maintaining fast processing rate can be obtained with as few as 6 imaging planes suggesting that the method is suited for parsimonious data acquisitions with very few sparsely chosen imaging planes. PMID:24808405

  12. Use of Three-Dimensional Ultrasound in the Detection of Breast Tumor Bed Displacement During Radiotherapy

    SciTech Connect

    Wong, Philip; Muanza, Thierry; Reynard, Eric; Robert, Karine; Barker, Jennifer; Sultanem, Khalil

    2011-01-01

    Purpose: To evaluate the feasibility and usefulness of a three-dimensional ultrasound (3D-US) image-guided system in identifying and tracking the tumor bed (TB) for planning and daily localization before radiation delivery for breast cancer. Methods and Materials: Twenty breast cancer patients underwent two CT scans at the time of simulation and just before their boost. Three-dimensional ultrasound images were acquired immediately after the CT scans, to which the images were automatically fused. Three-dimensional ultrasound images were also acquired immediately before treatment. Spatial and temporal TB differences between CT and US were evaluated. Results: The TB was not visible on US and CT in 1 subject who had and 1 subject who had not received chemotherapy before whole-breast radiotherapy. The mean (SD) TB volume overlap was 78% (14%). The mean centroid position of the TB on CT vs. US differed by 0.1, 0.2, and 0.4 mm in the anterior-posterior, left-right, and superior-inferior directions. The mean (SD) absolute radial displacement of the TB on each fraction from the treatment plan was 10.8 (6.3) mm. Conclusions: The TB was well visualized by US for the majority of patients. Clinically insignificant differences in the displacements calculated by paired CT vs. paired US demonstrate the feasibility of using 3D-US. The present study suggests that a 10-mm planning target volume margin could result in undercoverage of the clinical target volumes in 50% of treatments. Multimodality planning and image-guided radiotherapy with US potentially offers an accurate and non-ionizing solution for the daily definition of the TB position during partial-breast irradiation and boost treatments.

  13. Three dimensional full-wave nonlinear acoustic simulations: Applications to ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Pinton, Gianmarco

    2015-10-01

    Characterization of acoustic waves that propagate nonlinearly in an inhomogeneous medium has significant applications to diagnostic and therapeutic ultrasound. The generation of an ultrasound image of human tissue is based on the complex physics of acoustic wave propagation: diffraction, reflection, scattering, frequency dependent attenuation, and nonlinearity. The nonlinearity of wave propagation is used to the advantage of diagnostic scanners that use the harmonic components of the ultrasonic signal to improve the resolution and penetration of clinical scanners. One approach to simulating ultrasound images is to make approximations that can reduce the physics to systems that have a low computational cost. Here a maximalist approach is taken and the full three dimensional wave physics is simulated with finite differences. This paper demonstrates how finite difference simulations for the nonlinear acoustic wave equation can be used to generate physically realistic two and three dimensional ultrasound images anywhere in the body. A specific intercostal liver imaging scenario for two cases: with the ribs in place, and with the ribs removed. This configuration provides an imaging scenario that cannot be performed in vivo but that can test the influence of the ribs on image quality. Several imaging properties are studied, in particular the beamplots, the spatial coherence at the transducer surface, the distributed phase aberration, and the lesion detectability for imaging at the fundamental and harmonic frequencies. The results indicate, counterintuitively, that at the fundamental frequency the beamplot improves due to the apodization effect of the ribs but at the same time there is more degradation from reverberation clutter. At the harmonic frequency there is significantly less improvement in the beamplot and also significantly less degradation from reverberation. It is shown that even though simulating the full propagation physics is computationally challenging it

  14. Three dimensional full-wave nonlinear acoustic simulations: Applications to ultrasound imaging

    SciTech Connect

    Pinton, Gianmarco

    2015-10-28

    Characterization of acoustic waves that propagate nonlinearly in an inhomogeneous medium has significant applications to diagnostic and therapeutic ultrasound. The generation of an ultrasound image of human tissue is based on the complex physics of acoustic wave propagation: diffraction, reflection, scattering, frequency dependent attenuation, and nonlinearity. The nonlinearity of wave propagation is used to the advantage of diagnostic scanners that use the harmonic components of the ultrasonic signal to improve the resolution and penetration of clinical scanners. One approach to simulating ultrasound images is to make approximations that can reduce the physics to systems that have a low computational cost. Here a maximalist approach is taken and the full three dimensional wave physics is simulated with finite differences. This paper demonstrates how finite difference simulations for the nonlinear acoustic wave equation can be used to generate physically realistic two and three dimensional ultrasound images anywhere in the body. A specific intercostal liver imaging scenario for two cases: with the ribs in place, and with the ribs removed. This configuration provides an imaging scenario that cannot be performed in vivo but that can test the influence of the ribs on image quality. Several imaging properties are studied, in particular the beamplots, the spatial coherence at the transducer surface, the distributed phase aberration, and the lesion detectability for imaging at the fundamental and harmonic frequencies. The results indicate, counterintuitively, that at the fundamental frequency the beamplot improves due to the apodization effect of the ribs but at the same time there is more degradation from reverberation clutter. At the harmonic frequency there is significantly less improvement in the beamplot and also significantly less degradation from reverberation. It is shown that even though simulating the full propagation physics is computationally challenging it

  15. Three-dimensional Ultrasound Image Presentation on an Immersive Projection System

    NASA Astrophysics Data System (ADS)

    Oshiro, Osamu; Imura, Masataka; Chihara, Kunihiro; Mikami, Taisei; Kitabatake, Akira

    2002-05-01

    This paper describes the presentation of a three-dimensional (3D) ultrasound heart image on an immersive projection system (IPS). A 3D image was reconstructed from B-mode images that were acquired by transesophagel echocardiography. The reconstructed 3D image was presented on the IPS and the observer can see a stereoscopic image. The immersive environment could present a large field of view and enables interactive browsing and free movement of an eye position. Therefore, our developed system has the potential to be used as a visual interface in future robot surgery.

  16. Three-dimensional ultrasound does not improve diagnosis of retained placental tissue compared to two-dimensional ultrasound.

    PubMed

    Belachew, Johanna; Axelsson, Ove; Eurenius, Karin; Mulic-Lutvica, Ajlana

    2015-01-01

    The study objective was to improve ultrasonic diagnosis of retained placental tissue by measuring the volume of the uterine body and cavity using three-dimensional (3D) ultrasound. Twenty-five women who were to undergo surgical curettage due to suspected retained placental tissue were included. The volume of the uterine body and cavity was measured using the VOCAL imaging program. Twenty-one women had retained placental tissue histologically verified. Three of these had uterine volumes exceeding the largest volume observed in the normal puerperium. Seventeen of the 21 women had a uterine cavity volume exceeding the largest volume observed in the normal puerperium. In all 14 cases examined 28 days or more after delivery the cavity volume exceeded the largest volume observed in the normal puerperium. A large cavity volume estimated with 3D ultrasound is indicative of retained placental tissue. However, 3D ultrasound adds little or no diagnostic power compared to 2D ultrasound.

  17. Three-dimensional ultrasound guidance of autonomous robotic breast biopsy: feasibility study.

    PubMed

    Liang, Kaicheng; Rogers, Albert J; Light, Edward D; von Allmen, Daniel; Smith, Stephen W

    2010-01-01

    Feasibility studies of autonomous robot biopsies in tissue have been conducted using real-time three-dimensional (3-D) ultrasound combined with simple thresholding algorithms. The robot first autonomously processed 3-D image volumes received from the ultrasound scanner to locate a metal rod target embedded in turkey breast tissue simulating a calcification, and in a separate experiment, the center of a water-filled void in the breast tissue simulating a cyst. In both experiments the robot then directed a needle to the desired target, with no user input required. Separate needle-touch experiments performed by the image-guided robot in a water tank yielded an rms error of 1.15 mm. (E-mail: kaicheng.liang@duke.edu).

  18. Initial experience with stereoscopic visualization of three-dimensional ultrasound data in surgery.

    PubMed

    Gronningsaeter, A; Lie, T; Kleven, A; Mørland, T; Langø, T; Unsgård, G; Myhre, H O; Mårvik, R

    2000-11-01

    Initial in vivo and in vitro experiments were performed to evaluate the feasibility of stereoscopically displaying three-dimensional (3D) ultrasound data from neurosurgery, laparoscopic surgery, and vascular surgery. Stereoscopic visualization was illustrated by four video sequences, which can be downloaded from http://www.us.unimed. sintef.no/. These sequences show a brain tumor, hepatic arteries in relation to the gallbladder, a model that mimics a neuroendoscope in a cyst, and a "flight" into model of an artery with an intima flap. The experiments indicate that stereoscopic display of ultrasound data is feasible when there is sufficient contrast between the objects of interest and the surrounding tissue. True 3D vision improves perception, thus enhancing the ability to understand complex anatomic structures such as irregular lesions and tortuous vessels.

  19. Real-time three-dimensional ultrasound visualization of erection and artificial coitus.

    PubMed

    Deng, Jing; Hall-Craggs, Margaret A; Pellerin, D; Linney, Alfred D; Lees, William R; Rodeck, Charles H; Todd-Pokropek, Andrew

    2006-04-01

    To investigate the feasibility of imaging penile erection and coitus in real time and in three dimensions, a 'Live' three-dimensional (3-D) ultrasound system was used to acquire the volume of interest at 25 Hz from five healthy men. Water baths and gel-made artificial vaginas were devised to facilitate the 3-D scans without the probe being in direct contact with the penis. For the first volunteer scanned with the water bath alone, the penis failed to erect within 30 min. For the other four volunteers, the 'vagina' successfully initiated and maintained the erection and allowed artificial intercourse. Results have shown that the 'Live' 3-D ultrasound and minimally compressive imaging techniques together can offer an objective means for visualizing erection and coitus in spatial totality and temporal reality. They can be further developed to reveal more reliable details about the dynamic morphology, improving scientific understanding of sexual activities and clinical management of related problems.

  20. Concurrent photoacoustic markers for direct three-dimensional ultrasound to video registration

    NASA Astrophysics Data System (ADS)

    Cheng, Alexis; Guo, Xiaoyu; Kang, Hyun-Jae; Tavakoli, Behnoosh; Kang, Jin U.; Taylor, Russell H.; Boctor, Emad M.

    2014-03-01

    Fusion of video and other imaging modalities is common in modern surgical procedures to provide surgeons with additional information that can provide precise surgical guidance. An example of such uses interventional guidance equipment and surgical navigation systems to register the tools and devices used in surgery with each other. In this work, we focus explicitly on registering three-dimensional ultrasound with a stereocamera system. These surgical navigation systems often use optical or electromagnetic trackers. However, both of these tracking systems have various drawbacks leading to target registration errors of approximately 3mm. Previous work has shown that photoacoustic markers can be used to register three-dimensional ultrasound with video resulting in target registration errors which are much lower than the current state of the art. This work extends this idea by generating multiple photoacoustic markers concurrently as opposed to the sequential method used in the previous work. This development greatly enhances the acquisition time by a factor equal to the number of concurrently generated photoacoustic markers. This work is demonstrated on a synthetic phantom and an ex vivo porcine kidney phantom. The resulting target registration errors for these experiments ranged from 840 to 1360 μm and standard deviations from 370 to 640 μm.

  1. Detection of congenital uterine malformation by using transvaginal three-dimensional ultrasound.

    PubMed

    Yu, Li-Li; Zhang, Xuan; Zhang, Ting; Chen, Han-Rong; Wang, Ze-Hua

    2014-10-01

    This study assessed the clinical application of transvaginal three-dimensional ultrasound (3D TVUS) in the diagnosis of congenital uterine malformation. A retrospective study was performed on 62 patients with congenital uterine malformation confirmed hysteroscopically and/or laparoscopically. The patients were subjected to transvaginal two-dimensional ultrasound (2D TVUS) and 3D TVUS. The accuracy rate was compared between the two methods. The accuracy rate of 3D TVUS was (98.38%, 61/62), higher than that of 2D TVUS (80.65%, 50/62). 3D TVUS coronal plane imaging could demonstrate the internal shape of the endometrial cavity and the external contour of the uterine fundus. It allowed accurate measurement on the coronary plane, and could three-dimensionally show the image of cervical tube, thereby providing information for the diagnosis of some complex uterine malformation. 3D TVUS imaging can obtain comprehensive information of the uterus malformation, and it is superior to 2D TVUS for the diagnosis of congenital uterine malformations, especially complex uterine anomaly.

  2. Noninvasive Quantitative Imaging of Collagen Microstructure in Three-Dimensional Hydrogels Using High-Frequency Ultrasound

    PubMed Central

    Mercado, Karla P.; Helguera, María; Hocking, Denise C.

    2015-01-01

    Collagen I is widely used as a natural component of biomaterials for both tissue engineering and regenerative medicine applications. The physical and biological properties of fibrillar collagens are strongly tied to variations in collagen fiber microstructure. The goal of this study was to develop the use of high-frequency quantitative ultrasound to assess collagen microstructure within three-dimensional (3D) hydrogels noninvasively and nondestructively. The integrated backscatter coefficient (IBC) was employed as a quantitative ultrasound parameter to detect, image, and quantify spatial variations in collagen fiber density and diameter. Collagen fiber microstructure was varied by fabricating hydrogels with different collagen concentrations or polymerization temperatures. IBC values were computed from measurements of the backscattered radio-frequency ultrasound signals collected using a single-element transducer (38-MHz center frequency, 13–47 MHz bandwidth). The IBC increased linearly with increasing collagen concentration and decreasing polymerization temperature. Parametric 3D images of the IBC were generated to visualize and quantify regional variations in collagen microstructure throughout the volume of hydrogels fabricated in standard tissue culture plates. IBC parametric images of corresponding cell-embedded collagen gels showed cell accumulation within regions having elevated collagen IBC values. The capability of this ultrasound technique to noninvasively detect and quantify spatial differences in collagen microstructure offers a valuable tool to monitor the structural properties of collagen scaffolds during fabrication, to detect functional differences in collagen microstructure, and to guide fundamental research on the interactions of cells and collagen matrices. PMID:25517512

  3. Three dimensional microbubble dynamics near a wall subject to high intensity ultrasound

    NASA Astrophysics Data System (ADS)

    Wang, Q. X.; Manmi, K.

    2014-03-01

    Dynamics of cavitation microbubbles due to high intensity ultrasound are associated with important applications in biomedical ultrasound, ultrasonic cleaning, and sonochemistry. Previous numerical studies on this phenomenon were for an axisymmetric configuration. In this paper, a computational model is developed to simulate the three dimensional dynamics of acoustic bubbles by using the boundary integral method. A bubble collapses much more violently subjected to high intensity ultrasound than when under normal constant ambient pressure. A few techniques are thus implemented to address the associated numerical challenge. In particular, a high quality mesh of the bubble surface is maintained by implementing a new hybrid approach of the Lagrangian method and elastic mesh technique. It avoids the numerical instabilities which occur at a sharp jet surface as well as generates a fine mesh needed at the jet surface. The model is validated against the Rayleigh-Plesset equation and an axisymmetric model. We then explore microbubble dynamics near a wall subjected to high intensity ultrasound propagating parallel to the wall, where the Bjerknes forces due to the ultrasound and the wall are perpendicular to each other. The bubble system absorbs the energy from the ultrasound and transforms the uniform momentum of the ultrasound parallel to the wall to the highly concentrated momentum of a high-speed liquid jet pointing to the wall. The liquid jet forms towards the end of the collapse phase with a significantly higher speed than without the presence of ultrasound. The jet direction depends mainly on the dimensionless standoff distance γ = s/Rmax of the bubble from the wall, where s is the distance between the wall and the bubble centre at inception and Rmax is the maximum bubble radius. The jet is approximately directed to the wall when γ is 1.5 or smaller and rotates to the direction of the ultrasound as γ increases. When γ is about 10 or larger, the wall effect is

  4. Evaluation of Three-Dimensional Printed Materials for Simulation by Computed Tomography and Ultrasound Imaging.

    PubMed

    Mooney, James J; Sarwani, Nabeel; Coleman, Melissa L; Fotos, Joseph S

    2017-06-01

    The use of three-dimensional (3D) printing allows for creation of custom models for clinical care, education, and simulation. Medical imaging, given the significant role it plays in both clinical diagnostics and procedures, remains an important area for such education and simulation. Unfortunately, the materials appropriate for use in simulation involving radiographic or ultrasound imaging remains poorly understood. Therefore, our study was intended to explore the characteristics of readily available 3D printing materials when visualized by computed tomography (CT) and ultrasound. Seven 3D printing materials were examined in standard shapes (cube, cylinder, triangular prism) with a selection of printing methods ("open," "whole," and "solid" forms). For CT imaging, these objects were suspended in a gelatin matrix molded to match a standard human CT phantom. For ultrasound imaging, the objects were placed in acrylic forms filled with a gelatin matrix. All images were examined using OsiriX software. Computed tomography imaging revealed marked variation in materials' Hounsfield units as well as patterning and artifact. The Hounsfield unit variations revealed a number of materials suitable for simulation various human tissues. Ultrasound imaging showed echogenicity in all materials, with some variability in shadowing and posterior wall visualization. We were able to demonstrate the potential utility for 3D printing in the creation of CT and ultrasound simulation models. The similar appearance of materials via ultrasound supports their broad utility for select tissue types, whereas the more variable appearance via CT suggests greater potential for simulating differing tissues but requiring multiple printer technologies to do so.

  5. Surface refraction of sound waves affects calibration of three-dimensional ultrasound.

    PubMed

    Ballhausen, Hendrik; Ballhausen, Bianca Désirée; Lachaine, Martin; Li, Minglun; Parodi, Katia; Belka, Claus; Reiner, Michael

    2015-05-27

    Three-dimensional ultrasound (3D-US) is used in planning and treatment during external beam radiotherapy. The accuracy of the technique depends not only on the achievable image quality in clinical routine, but also on technical limitations of achievable precision during calibration. Refraction of ultrasound waves is a known source for geometric distortion, but such an effect was not expected in homogenous calibration phantoms. However, in this paper we demonstrate that the discontinuity of the refraction index at the phantom surface may affect the calibration unless the ultrasound probe is perfectly perpendicular to the phantom. A calibration phantom was repeatedly scanned with a 3D-US system (Elekta Clarity) by three independent observers. The ultrasound probe was moved horizontally at a fixed angle in the sagittal plane. The resulting wedge shaped volume between probe and phantom was filled with water to couple in the ultrasound waves. Because the speed of sound in water was smaller than the speed of sound in Zerdine, the main component of the phantom, the angle of the ultrasound waves inside the phantom increased. This caused an apparent shift in the calibration features which was recorded as a function of the impeding angle. To confirm the magnitude and temperature dependence, the experiment was repeated by two of the observers with a mixture of ice and water at 0 °C and with thermalized tap water at 21 °C room temperature. During the first series of measurements, a linear dependency of the displacements dx of the calibration features on the angle α of the ultrasound probe was observed. The three observers recorded significantly nonzero (p < 0.0001) and very consistent slopes of dx/dα of 0.12, 0.12, and 0.13 mm/°, respectively.. At 0 °C water temperature, the slope increased to 0.18 ± 0.04 mm/°. This matched the prediction of Snell's law of 0.185 mm/° for a speed of sound of 1,402 m/s at the melting point of ice. At 21 °C, slopes of 0.11 and 0

  6. Reconstruction of three-dimensional ultrasound images based on cyclic Savitzky-Golay filters

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

    We present a new algorithm for reconstructing a three-dimensional (3-D) ultrasound image from a series of two-dimensional B-scan ultrasound slices acquired in the mechanical linear scanning framework. Unlike most existing 3-D 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 Savitzky-Golay (CSG) reconstruction filter, is an improvement on the original Savitzky-Golay filter in two respects: First, it is extended to accept a 3-D array of data as the filter input instead of a one-dimensional data sequence. Second, it incorporates the cyclic indicator function in its least-squares objective function so that the CSG algorithm can simultaneously perform both smoothing and interpolating tasks. The performance of the CSG reconstruction filter compared to that of most existing reconstruction algorithms in generating a 3-D synthetic test image and a clinical 3-D carotid artery bifurcation in the mechanical linear scanning framework are also reported.

  7. Three-dimensional simulation of ultrasound propagation through trabecular bone structures measured by synchrotron microtomography.

    PubMed

    Bossy, Emmanuel; Padilla, Frédéric; Peyrin, Françoise; Laugier, Pascal

    2005-12-07

    Three-dimensional numerical simulations of ultrasound transmission were performed through 31 trabecular bone samples measured by synchrotron microtomography. The synchrotron microtomography provided high resolution 3D mappings of bone structures, which were used as the input geometry in the simulation software developed in our laboratory. While absorption (i.e. the absorption of ultrasound through dissipative mechanisms) was not taken into account in the algorithm, the simulations reproduced major phenomena observed in real through-transmission experiments in trabecular bone. The simulated attenuation (i.e. the decrease of the transmitted ultrasonic energy) varies linearly with frequency in the MHz frequency range. Both the speed of sound (SOS) and the slope of the normalized frequency-dependent attenuation (nBUA) increase with the bone volume fraction. Twenty-five out of the thirty-one samples exhibited negative velocity dispersion. One sample was rotated to align the main orientation of the trabecular structure with the direction of ultrasonic propagation, leading to the observation of a fast and a slow wave. Coupling numerical simulation with real bone architecture therefore provides a powerful tool to investigate the physics of ultrasound propagation in trabecular structures. As an illustration, comparison between results obtained on bone modelled either as a fluid or a solid structure suggested the major role of mode conversion of the incident acoustic wave to shear waves in bone to explain the large contribution of scattering to the overall attenuation.

  8. Three-dimensional simulation of ultrasound propagation through trabecular bone structures measured by synchrotron microtomography

    NASA Astrophysics Data System (ADS)

    Bossy, Emmanuel; Padilla, Frédéric; Peyrin, Françoise; Laugier, Pascal

    2005-12-01

    Three-dimensional numerical simulations of ultrasound transmission were performed through 31 trabecular bone samples measured by synchrotron microtomography. The synchrotron microtomography provided high resolution 3D mappings of bone structures, which were used as the input geometry in the simulation software developed in our laboratory. While absorption (i.e. the absorption of ultrasound through dissipative mechanisms) was not taken into account in the algorithm, the simulations reproduced major phenomena observed in real through-transmission experiments in trabecular bone. The simulated attenuation (i.e. the decrease of the transmitted ultrasonic energy) varies linearly with frequency in the MHz frequency range. Both the speed of sound (SOS) and the slope of the normalized frequency-dependent attenuation (nBUA) increase with the bone volume fraction. Twenty-five out of the thirty-one samples exhibited negative velocity dispersion. One sample was rotated to align the main orientation of the trabecular structure with the direction of ultrasonic propagation, leading to the observation of a fast and a slow wave. Coupling numerical simulation with real bone architecture therefore provides a powerful tool to investigate the physics of ultrasound propagation in trabecular structures. As an illustration, comparison between results obtained on bone modelled either as a fluid or a solid structure suggested the major role of mode conversion of the incident acoustic wave to shear waves in bone to explain the large contribution of scattering to the overall attenuation.

  9. Ultrasound-guided three-dimensional needle steering in biological tissue with curved surfaces

    PubMed Central

    Abayazid, Momen; Moreira, Pedro; Shahriari, Navid; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    2015-01-01

    In this paper, we present a system capable of automatically steering a bevel-tipped flexible needle under ultrasound guidance toward a physical target while avoiding a physical obstacle embedded in gelatin phantoms and biological tissue with curved surfaces. An ultrasound pre-operative scan is performed for three-dimensional (3D) target localization and shape reconstruction. A controller based on implicit force control is developed to align the transducer with curved surfaces to assure the maximum contact area, and thus obtain an image of sufficient quality. We experimentally investigate the effect of needle insertion system parameters such as insertion speed, needle diameter and bevel angle on target motion to adjust the parameters that minimize the target motion during insertion. A fast sampling-based path planner is used to compute and periodically update a feasible path to the target that avoids obstacles. We present experimental results for target reconstruction and needle insertion procedures in gelatin-based phantoms and biological tissue. Mean targeting errors of 1.46 ± 0.37 mm, 1.29 ± 0.29 mm and 1.82 ± 0.58 mm are obtained for phantoms with inclined, curved and combined (inclined and curved) surfaces, respectively, for insertion distance of 86–103 mm. The achieved targeting errors suggest that our approach is sufficient for targeting lesions of 3 mm radius that can be detected using clinical ultrasound imaging systems. PMID:25455165

  10. Ultrasound-guided three-dimensional needle steering in biological tissue with curved surfaces.

    PubMed

    Abayazid, Momen; Moreira, Pedro; Shahriari, Navid; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    2015-01-01

    In this paper, we present a system capable of automatically steering a bevel-tipped flexible needle under ultrasound guidance toward a physical target while avoiding a physical obstacle embedded in gelatin phantoms and biological tissue with curved surfaces. An ultrasound pre-operative scan is performed for three-dimensional (3D) target localization and shape reconstruction. A controller based on implicit force control is developed to align the transducer with curved surfaces to assure the maximum contact area, and thus obtain an image of sufficient quality. We experimentally investigate the effect of needle insertion system parameters such as insertion speed, needle diameter and bevel angle on target motion to adjust the parameters that minimize the target motion during insertion. A fast sampling-based path planner is used to compute and periodically update a feasible path to the target that avoids obstacles. We present experimental results for target reconstruction and needle insertion procedures in gelatin-based phantoms and biological tissue. Mean targeting errors of 1.46±0.37 mm, 1.29±0.29 mm and 1.82±0.58 mm are obtained for phantoms with inclined, curved and combined (inclined and curved) surfaces, respectively, for insertion distance of 86-103 mm. The achieved targeting errors suggest that our approach is sufficient for targeting lesions of 3mm radius that can be detected using clinical ultrasound imaging systems.

  11. Three-dimensional imaging in aortic disease by lighthouse transesophageal echocardiography using intravascular ultrasound catheters. Comparison to three-dimensional transesophageal echocardiography and three-dimensional intra-aortic ultrasound imaging.

    PubMed

    Buck, T; Görge, G; Hunold, P; Erbel, R

    1998-03-01

    Two-dimensional (2D) transesophageal echocardiography (TEE) and 2D intravascular ultrasound (IVUS) imaging face their greatest limitation in visualizing aortic disease in patients. With the aid of three-dimensional (3D) image reconstruction, TEE and IVUS can potentially overcome this limitation but still provide only limited spatial appreciation in aortic disease because 3D imaging of the thoracic aorta requires a broader spatial visualization of the mediastinum than provided by both techniques. Moreover, for timely decision making about aortic disease TEE is limited by a large probe, which requires sedation. Therefore, we developed an approach called 3D lighthouse transesophageal echocardiography (LTEE) using a thin intravascular ultrasound catheter, which provides a full circumferential (360 degree) image and requires no sedation. The purpose of this study was to compare the feasibility and accuracy of 3D TEE, 3D IVUS, and 3D LTEE for obtaining spatial visualization of the thoracic aorta to detect aortic diseases in patients. 3D image datasets were obtained for 3D LTEE by a manual pullback of a 3.3 mm thick, 10 MHz intravascular ultrasound catheter positioned in the esophagus; for 3D TEE using a conventional 15 mm thick probe; and for 3D IVUS using a 2.6 mm thick, 20 MHz intravascular ultrasound catheter. In 12 consecutive patients, three with aortic dissection (two with type III, one with type I) and 11 with suspected artherosclerosis, we analyzed and compared spatial visualization of the thoracic aorta, 3D image quality, patient discomfort, and study time. Providing a 3D dataset of 360-degree tomographic images of the mediastinum, 3D LTEE was the only approach that allowed broad spatial visualization of the aortic arch (9 of 12 patients) with the detection of aortic dissection or atherosclerotic plaques. Spatial visualization of the aortic arch by 3D TEE was incomplete because of the relatively narrow 90-degree image sector. However, in other segments 3D image

  12. Volume-preserving smoothing of three-dimensional surfaces: application to intravascular ultrasound.

    PubMed

    Zeng, C; Sonka, M

    1998-10-01

    A volume-preserving three-dimensional smoothing approach is described that can be directly applied to 3D medical image data consisting of sets of 2D image slices, e.g., segmented intravascular ultrasound image sequences. Two local smoothing filters ℱ and 𝒢 were designed according to different smoothing goals and their performance was compared. Filtering with the ℱ filter of a relatively large frequency window keeps the important local characteristics of the object and results in little shrinkage while removing noise. Filtering with the Gaussian filter G that has an added volume compensation step results in no global shrinkage and may be used for multiscale filtering. The two filters can be easily extended to n-dimensional filtering. Copyright 1998 Academic Press.

  13. Serial measurement of cross-sectional area in peripheral vein grafts using three-dimensional ultrasound.

    PubMed

    Leotta, D F; Primozich, J F; Beach, K W; Bergelin, R O; Strandness, D E

    2001-01-01

    Frequent surveillance of bypass grafts placed in the lower limbs can provide early detection of stenoses. A three-dimensional (3-D) ultrasound (US) imaging system has been used to produce serial surface reconstructions of regions of interest in vein grafts in the lower extremities. Using anatomical reference points, data sets from serial studies are registered in a common 3-D coordinate system. Cross-sectional area measurements are extracted from the surface reconstructions in planes normal to the vessel center axis. These measurements are compared at matched sites over time to track changes in the vessel configuration. The quantitative measurements are paired with surface displays of the vessels for a complete depiction of the changing geometry. Example studies from three patients are shown, for time periods up to 38 weeks. The cross-sectional area measurements highlight regions of remodeling and developing stenoses within the grafts.

  14. Image analysis of placental issues using three-dimensional ultrasound and color power doppler

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Cheng, Qiong; Liu, J. G.

    2007-12-01

    With the development of birthing-process medical science, and insurance requirement of prepotency, the ultrasound technique is widely used in the application of obstetrics realm, especially on the monitoring of embryo's growth. In the recent decade, the introduction of high resolution three-dimensional ultrasonic and color power Doppler scanner provides a much more direct, sensitive, forerunner method for the monitoring of embryo and gravida's prediction. A novel method that depends on examining images of vasculature of placenta to determine the growth of embryo is introduced in this paper. First, get a set of placenta vascularity images of the pregnant woman, taken by Color Doppler Ultrasonic Scanner, then mark some points in these images, where we get a section image, thus we can observe the internal blood vessel distribution at those points. This method provides an efficient tool for doctors.

  15. Three-dimensional ultrasound power Doppler assessment of the cervix: comparison between nulliparas and multiparas.

    PubMed

    Basgul, Alin; Kavak, Zehra Nese; Bakirci, Nadi; Gokaslan, Husnu

    2007-01-01

    To assess the sonographic cervical characteristics between nulliparous and multiparous women. Transvaginal three-dimensional ultrasound and power Doppler using the virtual organ computer-aided analysis (VOCAL) program were performed on 71 nulliparas and 59 multiparas at a mean gestational age of 25.3+/-7.9 weeks. We compared the cervical volume and power Doppler vascularization index (VI), flow index (FI), and vascularization-flow index (VFI) between nulliparas and multiparas. The mean cervical volume and mean VI, VFI, FI measurements were not significantly different between multiparas and nulliparas. Our observations suggest that the morphological changes in the cervix of parous women are merely configurational without a change in cervical mass and vascularization. These configurational changes might result from the inevitable cervical stretching during labor and represent a healing process that does not involve a subsequent change in mass or vascularity.

  16. Simulation of three-dimensional nonlinear fields of ultrasound therapeutic arrays

    NASA Astrophysics Data System (ADS)

    Yuldashev, P. V.; Khokhlova, V. A.

    2011-05-01

    A novel numerical model was developed to simulate three-dimensional nonlinear fields generated by high intensity focused ultrasound (HIFU) arrays. The model is based on the solution to the Westervelt equation; the developed algorithm makes it possible to model nonlinear pressure fields of periodic waves in the presence of shock fronts localized near the focus. The role of nonlinear effects in a focused beam of a two-dimensional array was investigated in a numerical experiment in water. The array consisting of 256 elements and intensity range on the array elements of up to 10 W/cm2 was considered. The results of simulations have shown that for characteristic intensity outputs of modern HIFU arrays, nonlinear effects play an important role and shock fronts develop in the pressure waveforms at the focus.

  17. Three-dimensional segmentation of luminal and adventitial borders in serial intravascular ultrasound images

    NASA Technical Reports Server (NTRS)

    Shekhar, R.; Cothren, R. M.; Vince, D. G.; Chandra, S.; Thomas, J. D.; Cornhill, J. F.

    1999-01-01

    Intravascular ultrasound (IVUS) provides exact anatomy of arteries, allowing accurate quantitative analysis. Automated segmentation of IVUS images is a prerequisite for routine quantitative analyses. We present a new three-dimensional (3D) segmentation technique, called active surface segmentation, which detects luminal and adventitial borders in IVUS pullback examinations of coronary arteries. The technique was validated against expert tracings by computing correlation coefficients (range 0.83-0.97) and William's index values (range 0.37-0.66). The technique was statistically accurate, robust to image artifacts, and capable of segmenting a large number of images rapidly. Active surface segmentation enabled geometrically accurate 3D reconstruction and visualization of coronary arteries and volumetric measurements.

  18. Three-dimensional segmentation of luminal and adventitial borders in serial intravascular ultrasound images

    NASA Technical Reports Server (NTRS)

    Shekhar, R.; Cothren, R. M.; Vince, D. G.; Chandra, S.; Thomas, J. D.; Cornhill, J. F.

    1999-01-01

    Intravascular ultrasound (IVUS) provides exact anatomy of arteries, allowing accurate quantitative analysis. Automated segmentation of IVUS images is a prerequisite for routine quantitative analyses. We present a new three-dimensional (3D) segmentation technique, called active surface segmentation, which detects luminal and adventitial borders in IVUS pullback examinations of coronary arteries. The technique was validated against expert tracings by computing correlation coefficients (range 0.83-0.97) and William's index values (range 0.37-0.66). The technique was statistically accurate, robust to image artifacts, and capable of segmenting a large number of images rapidly. Active surface segmentation enabled geometrically accurate 3D reconstruction and visualization of coronary arteries and volumetric measurements.

  19. Three-dimensional ultrasound reconstruction of the pelvicaliceal system: an in-vitro study.

    PubMed

    Ghani, Khurshid R; Pilcher, James; Patel, Uday; Rowland, David; Nassiri, Daruish; Anson, Ken

    2008-10-01

    Three-dimensional (3D) reconstruction of the pelvicaliceal system (PCS) can be helpful for percutaneous renal procedures. 3D reconstruction of the PCS using ultrasound (US) has not been studied. We determined the feasibility and accuracy of 3DUS reconstruction of the PCS in an in vitro model. Ten pig kidneys were scanned in vitro using freehand 3DUS (Logiq 9, GE medical systems). Multi-planar reformatted (MPR) and volume rendered (VR) reconstructions of the PCS were processed on a workstation. Using resin casts of the PCS as the reference standard, MPR reconstructions were compared for maximal polar and antero-posterior (AP) PCS length, lower pole infundibular (LPInf) diameter and number of calices. VR movies were compared for number of calices. Three blinded reviewers matched VR movies to casts and given an "anatomical representation" score using a five-point scale. There were no significant differences in maximal AP length, LPInf diameter or number of calices between MPR reconstructions and casts. Maximal polar length between MPR reconstructions and casts were different (t = 6.44, P = 0.0001). VR movie reconstructions underestimated the number of calices visualised (t = 3.23, P = 0.01). A total of 22 out of 30 (73%) 3D VR videos were accurately matched to their casts. The 3D VR median score for anatomical representation was 3 (fair representation). Three-dimensional ultrasound reconstruction of the porcine PCS is quantitatively comparable to corresponding casts of the PCS. 3D VR movies of the PCS were a fair representation of the PCS anatomy. 3DUS is a potential tool in the planning and execution of percutaneous renal procedures.

  20. Three-dimensional ultrasound molecular imaging of angiogenesis in colon cancer using a clinical matrix array ultrasound transducer.

    PubMed

    Wang, Huaijun; Kaneko, Osamu F; Tian, Lu; Hristov, Dimitre; Willmann, Jürgen K

    2015-05-01

    We sought to assess the feasibility and reproducibility of 3-dimensional ultrasound molecular imaging (USMI) of vascular endothelial growth factor receptor 2 (VEGFR2) expression in tumor angiogenesis using a clinical matrix array transducer and a clinical grade VEGFR2-targeted contrast agent in a murine model of human colon cancer. Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice with human colon cancer xenografts (n = 33) were imaged with a clinical ultrasound system and transducer (Philips iU22; X6-1) after intravenous injection of either clinical grade VEGFR2-targeted microbubbles or nontargeted control microbubbles. Nineteen mice were scanned twice to assess imaging reproducibility. Fourteen mice were scanned both before and 24 hours after treatment with either bevacizumab (n = 7) or saline only (n = 7). Three-dimensional USMI data sets were retrospectively reconstructed into multiple consecutive 1-mm-thick USMI data sets to simulate 2-dimensional imaging. Vascular VEGFR2 expression was assessed ex vivo using immunofluorescence. Three-dimensional USMI was highly reproducible using both VEGFR2-targeted microbubbles and nontargeted control microbubbles (intraclass correlation coefficient, 0.83). The VEGFR2-targeted USMI signal significantly (P = 0.02) decreased by 57% after antiangiogenic treatment compared with the control group, which correlated well with ex vivo VEGFR2 expression on immunofluorescence (ρ = 0.93, P = 0.003). If only central 1-mm tumor planes were analyzed to assess antiangiogenic treatment response, the USMI signal change was significantly (P = 0.006) overestimated by an average of 27% (range, 2%-73%) compared with 3-dimensional USMI. Three-dimensional USMI is feasible and highly reproducible and allows accurate assessment and monitoring of VEGFR2 expression in tumor angiogenesis in a murine model of human colon cancer.

  1. Computational synthesis of ultrasound breast images from a three-dimensional anatomical model

    NASA Astrophysics Data System (ADS)

    Shen, Yi-Ting; Lacefield, James C.

    2005-04-01

    A three-dimensional breast anatomy model has been implemented using spline surfaces and fractal structures to represent the architecture of the lactiferous ducts, mammary fat lobules, skin, and supporting connective tissues. The model randomly varies user-specified structural parameters to provide an unlimited number of realizations of the gross anatomy. Cross-sectional views extracted by slicing through a realization of the model are input to a two-dimensional k-space (i.e., spatial frequency domain) ultrasound propagation simulator. The k-space simulator iterates pressure and particle velocity fields in 30-ns steps to compute scattering from the structures defined by the anatomical model and small random variations in compressibility that are added to generate speckle. A synthetic aperture method is employed to simulate B-mode imaging with a 5 MHz, 192-element linear array operated using multiple transmit focal zones and dynamic receive focusing. Simulated images of random-scattering phantoms possess approximately Rayleigh speckle statistics. The anatomical model is expected to yield images with speckle statistics comparable to clinical breast images. The long-term objectives of these simulations are to investigate sources of focus aberration in ultrasound breast imaging and the impact of aberration on cancer detection. [Work supported by an NSERC Discovery Grant.

  2. A new technique for intraluminal hollow organ imaging: three-dimensional ultrasound.

    PubMed

    Cavaye, D M; Tabbara, M R; Kopchok, G E; Laas, T E; Cormier, F; White, R A

    1991-10-01

    Intraluminal ultrasound (ILUS) is a new catheter-based system which produces two-dimensional (2D), cross-sectional images of tubular structures. The principle of image acquisition using 5.0 Fr (30 MHz) and 8.0 Fr (20 MHz) ILUS catheters containing ultrasound transducers at the tip, is equally applicable to all tubular or hollow organs. This article illustrates the feasibility of intraluminal imaging of hollow organ structures, and describes computerized three-dimensional (3D) reconstruction of the 2D images, using a PC-based image analysis system. A set (n = 90) of longitudinally aligned, consecutive 2D images was sampled from various organs (canine bladder, urethra, jejunum, esophagus, and trachea) and computer processed to produce 3D images. By adjusting image density threshold and viewing angle, the lumen and wall morphology can be examined in any projection. Possible applications include diagnosis of lumen encroaching pathology, guidance of intraluminal instruments, and assessment of the effects of endoluminal interventions.

  3. Dynamic coherent backscattering of ultrasound in three-dimensional strongly-scattering media

    NASA Astrophysics Data System (ADS)

    Cobus, L. A.; Tiggelen, B. A. van; Derode, A.; Page, J. H.

    2017-05-01

    We present measurements of the diffusion coefficient of ultrasound in strongly scattering three-dimensional (3D) disordered media using the dynamic coherent backscattering (CBS) effect. Our experiments measure the CBS of ultrasonic waves using a transducer array placed in the far-field of a 3D slab sample of brazed aluminum beads surrounded by vacuum. We extend to 3D media the general microscopic theory of CBS that was developed initially for acoustic waves in 2D. This theory is valid in the strong scattering, but still diffuse, regime that is realized in our sample, and is evaluated in the diffuse far field limit encountered in our experiments. By comparing our theory with the experimental data, we obtain an accurate measurement of the Boltzmann diffusion coefficient of ultrasound in our sample. We find that the value of DB is quite small, 0.74 ± 0.03 mm2/μs, and comment on the implications of this slow transport for the energy velocity.

  4. Three-dimensional ultrasound-based texture analysis of the effect of atorvastatin on carotid atherosclerosis

    NASA Astrophysics Data System (ADS)

    Awad, Joseph; Krasinski, Adam; Spence, David; Parraga, Grace; Fenster, Aaron

    2010-03-01

    Carotid atherosclerosis is the major cause of ischemic stroke, a leading cause of death and disability. This is driving the development of image analysis methods to quantitatively evaluate local arterial effects of potential treatments of carotid disease. Here we investigate the use of novel texture analysis tools to detect potential changes in the carotid arteries after statin therapy. Three-dimensional (3D) carotid ultrasound images were acquired from the left and right carotid arteries of 35 subjects (16 treated with 80 mg atorvastatin and 19 treated with placebo) at baseline and after 3 months of treatment. Two-hundred and seventy texture features were extracted from 3D ultrasound carotid artery images. These images previously had their vessel walls (VW) manually segmented. Highly ranked individual texture features were selected and compared to the VW volume (VWV) change using 3 measures: distance between classes, Wilcoxon rank sum test, and accuracy of the classifiers. Six classifiers were used. Using texture feature (L7R7) increases the average accuracy and area under the ROC curve to 74.4% and 0.72 respectively compared to 57.2% and 0.61 using VWV change. Thus, the results demonstrate that texture features are more sensitive in detecting drug effects on the carotid vessel wall than VWV change.

  5. Monoamniotic twins with one fetal anencephaly and cord entanglement diagnosed with three dimensional ultrasound at 14 weeks of gestation.

    PubMed

    Jo, Yun Sung; Son, Hyun Joo; Jang, Dong Gyu; Kim, Narinay; Lee, Guisera

    2011-01-01

    A 29-year-old pregnant woman with parity 0-0-0-0 was diagnosed with monoamniotic twin pregnancy discordant for anencephaly at 14 weeks gestation. Umbilical cord entanglement, which is an important cause of fetal death in monoamniotic twins, was confirmed by three-dimensional ultrasound. Cesarean section was performed at 34 weeks of gestation, and the normal newborn infant was discharged without any complications. We report a case of monoamniotic twin pregnancy discordant for anencephaly and diagnosed with cord entanglement by three-dimensional ultrasound at 14 weeks of gestation, and now report it along with a literature review.

  6. Analysis of contact stiffness in ultrasound atomic force microscopy: three-dimensional time-dependent ultrasound modeling

    NASA Astrophysics Data System (ADS)

    Piras, Daniele; Sadeghian, Hamed

    2017-06-01

    Ultrasound atomic force microscopy (US-AFM) has been used for subsurface imaging of nanostructures. The contact stiffness variations have been suggested as the origin of the image contrast. Therefore, to analyze the image contrast, the local changes in the contact stiffness due to the presence of subsurface features should be calculated. So far, only static simulations have been conducted to analyze the local changes in the contact stiffness and, consequently, the contrast in US-AFM. Such a static approach does not fully represent the real US-AFM experiment, where an ultrasound wave is launched either into the sample or at the tip, which modulates the contact stiffness. This is a time-dependent nonlinear dynamic problem rather than a static and stationary one. This paper presents dynamic 3D ultrasound analysis of contact stiffness in US-AFM (in contrast to static analysis) to realistically predict the changes in contact stiffness and thus the changes in the subsurface image contrast. The modulation frequency also influences the contact stiffness variations and, thus, the image contrast. The three-dimensional time-dependent ultrasound analysis will greatly aid in the contrast optimization of subsurface nano imaging with US-AFM.

  7. Follow-up on Small Abdominal Aortic Aneurysms Using Three Dimensional Ultrasound: Volume Versus Diameter.

    PubMed

    Ghulam, Q M; Bredahl, K K; Lönn, L; Rouet, L; Sillesen, H H; Eiberg, J P

    2017-10-01

    Rupture risk in abdominal aortic aneurysms (AAAs) is assessed using AAA diameter; yet 10% of ruptures occur in a small aneurysm. This underlines the inadequacy of diameter as a standalone parameter. In this prospective follow-up study, ultrasound determined aneurysm diameter was compared with aneurysm volume determined by three dimensional ultrasound (3D-US) in a group of 179 AAAs. This was a prospective cohort study with repeated diameter and volume measurements by 3D-US. In total, 179 patients with small infrarenal AAAs (diameter 30-55 mm) were enrolled consecutively. At enrolment and at 12 month follow-up, maximum diameter, using dual plane technique, and three dimensional volume were measured. Based on a previous accuracy study, significant change in diameter and volume were defined as an increase exceeding the known range of variability (ROV) of each US technique; ±3.7 mm and ±8.8 mL, respectively. Post-hoc Kaplan-Meier analysis was performed to estimate time to conversion to treatment after the conclusion of the follow-up period between two groups. In total, 125 patients (70%) had an unchanged diameter during follow-up. In this group, 50 patients (40%) had an increasing aortic volume. Forty-five (83%) of the 54 patients with an increasing aortic diameter showed a corresponding volume increase. During a median follow-up of 367 days (364-380 days), a mean increase in diameter of 2.7 mm (±2.6 mm) and a mean increase in volume of 11.6 mL (±9.9 mL) were recorded. In post-hoc analysis, it was found that more AAAs with a stable diameter and a growing volume than AAAs with a stable diameter and volume were undergoing aortic repair during follow-up, based on the maximum diameter. In this cohort of small AAAs, 40% of patients with a stable diameter had an increasing volume at 12 month follow-up. From this perspective, 3D-US could have a future supplemental role in AAA surveillance programmes. Copyright © 2017 European Society for Vascular Surgery. Published

  8. Potentially accommodating intraocular lenses--an in vitro and in vivo study using three-dimensional high-frequency ultrasound.

    PubMed

    Stachs, Oliver; Schneider, Hanka; Stave, Joachim; Guthoff, Rudolf

    2005-01-01

    To investigate the accommodative performance of new intraocular lenses (IOL) using the advantages of three-dimensional ultrasound biomicroscopy. An in vitro simulation device was designed to study IOL performance using an artificial capsular bag and a stretching device. The haptic region of the Akkommodative 1CU (HumanOptics AG) and CrystaLens AT-45 (Eyeonics Inc) was visualized in vitro in three dimensions, using an in-house developed three-dimensional ultrasound biomicroscope. The in vitro results were used to describe the in vivo situation in four patients with accommodative implants. The haptic position and angulation in consideration of the accommodation state was distinguished and analyzed. In the simulation model, a maximal angulation change of 4.5 degrees and 4.3 degrees and a maximal forward shift of 0.33 mm and 0.28 mm was observed for the AT-45 and 1CU, respectively. In vivo, a change in haptic angulation <100 and a maximal forward shift of 0.50 mm was observed for the 1CU. These changes correspond to a theoretical approximate value of 0.50 diopters. The in vitro simulation device examined with three-dimensional ultrasound biomicroscopy provided information on the accommodative performance of these potentially accommodative IOL designs. Using three-dimensional ultrasound biomicroscopy, corresponding changes in haptic angulation during pharmacological-induced accommodation were observed.

  9. Comparison of two dimensional and live three dimensional ultrasounds for the diagnosis of septated uterus

    PubMed Central

    Niknejadi, Maryam; Akhbari, Farnaz; Niknejad, Fatemeh; Khalili, Gholamreza; Shiva, Marzieh

    2014-01-01

    Background: Traditionally, septate uterus was diagnosed with invasive method like hysterosalpingography and hysteroscopy. Nowadays transvaginal ultrasonography was reported to be a sensitive tool for detection of septate uterus too. Objective: The objective of the present study was to evaluate the application of two dimensional ultrasound (2-DUS) and real time three dimensional ultrasound (3-DUS) in differentiating various type of septated uterus. Hysteroscopy confirmation was assigned as the gold standard. Materials and Methods: This retrospective study was performed among 215 infertile women with suspected septate uterus from October 2008 to July 2012. An inclusion criterion was septated uterus based on HSG or experiencing abortion, preterm labor, or recurrent IVF failure. Fusion anomalies were excluded from the study (unicornuate, bicornuate and didelphys anomalies). The results of 3D and 2D sonographies were compared, while they were confirmed by hysteroscopy result in detection of septated uterus. Kappa index for agreement between 2DUS and hysteroscopy, as well as 3-DUS and hysteroscopy in detection of septate uterus was carried out. By receiver operating characteristic (ROC) curve, cut off points for predicting the kind of anomalies were proposed. Results: The women were evaluated by 2-DUS (n=89) and (II) 3-DUS (n=126). All women underwent hysteroscopy, following 2-DUS and 3-DUS at the same or subsequent cycle. The results of kappa (K) index were 0.575 and 0.291 for 3-DUS and hysteroscopy, as well as 2-DUS and hysteroscopy, respectively. Also, the cutoff points were 27% for arcuate and subseptate, and 35% for differentiating septate and subseptate. Conclusion: Real time 3-DUS has better ability for visualization both uterine cavity and the fundal uterine, so it has higher agreement in detection of septate uterus than 2-DUS. PMID:25408704

  10. Three-dimensional printed ultrasound and photoacoustic training phantoms for vasculature access (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Nikitichev, Daniil I.; Xia, Wenfeng; West, Simeon J.; Desjardins, Adrien E.; Ourselin, Sebastien; Vercauteren, Tom

    2017-03-01

    Ultrasound (US) imaging is widely used to guide vascular access procedures such as arterial and venous cannulation. As needle visualisation with US imaging can be very challenging, it is easy to misplace the needle in the patient and it can be life threating. Photoacoustic (PA) imaging is well suited to image medical needles and catheters that are commonly used for vascular access. To improve the success rate, a certain level of proficiency is required that can be gained through extensive practice on phantoms. Unfortunately, commercial training phantoms are expensive and custom-made phantoms usually do not replicate the anatomy very well. Thus, there is a great demand for more realistic and affordable ultrasound and photoacoustic imaging phantoms for vasculature access procedures training. Three-dimensional (3D) printing can help create models that replicate complex anatomical geometries. However, the available 3D printed materials do not possess realistic tissue properties. Alternatively, tissue-mimicking materials can be employed using casting and 3D printed moulds but this approach is limited to the creation of realistic outer shapes with no replication of complex internal structures. In this study, we developed a realistic vasculature access phantom using a combination of mineral oil based materials as background tissue and a non-toxic, water dissolvable filament material to create complex vascular structure using 3D printing. US and PA images of the phantoms comprising the complex vasculature network were acquired. The results show that 3D printing can facilitate the fabrication of anatomically realistic training phantoms, with designs that can be customized and shared electronically.

  11. Ultrasound assessment of the Essure contraceptive devices: is three-dimensional ultrasound really needed?

    PubMed

    Paladini, Dario; Di Spiezio Sardo, Attilio; Coppola, Carmela; Zizolfi, Brunella; Pastore, Gaetano; Nappi, Carmine

    2015-01-01

    To evaluate the feasibility of 3-dimensional ultrasound (3DUS) for sonographic localization of Essure microinserts, comparing it with 2-dimensional ultrasound (2DUS) insofar as time to visualize the inserts and accuracy in determining their localization. Prospective study (Canadian Task Force classification II-2). University clinic. Twenty-seven consecutive women undergoing hysteroscopic Essure device placement. Essure microinserts were inserted in the outpatient hysteroscopy clinic following the manufacturer's recommendations, leaving from 3 to 8 loops of the inserts in the uterine cavity. In all patients, 2DUS and 3DUS were performed 3 months after the procedure. 2DUS was performed first; the device(s) were located, and their position was recorded. Then 3DUS scans were acquired, trying when possible to have both devices at least at a 45-degree angle with the insonation beam for optimal rendering on 3DUS. The OmniView method with volume contrast imaging was used to show the relationships of the microinserts within the uterine cavity when possible. To define the position of the Essure device in relation to the uterus and the salpinges, we used the classification developed by Legendre and colleagues. After sonographic evaluation all women underwent hysterosalpingography to assess the success of sterilization. Hysteroscopic insertion was successful in all patients, with 2 Essure devices placed in 25 patients and 1 device in 2 patients (due to previous salpingectomy performed because of ectopic pregnancy), for a total of 52 devices. One spontaneous late (within 3 months) expulsion of the device occurred; the device had migrated almost completely into the uterine cavity. At 3-month follow-up, all 51 correctly placed devices were easily observed at 2DUS (mean [SD] duration of the procedure, 2.25 [0.8] minutes). At 3DUS in 51 cases, the device was in perfect position (1+2+3) in 21 (41.2%), in position 2+3 in 14 (27.4%), and in position +3 in 16 (31.4%). Both microinserts

  12. A novel three-dimensional endoscopic ultrasound technique for the freehand examination of the oesophagus.

    PubMed

    Inglis, Scott; Christie, Derek; Plevris, John N

    2011-11-01

    This study details the development and evaluation of a freehand radial three-dimensional endoscopic ultrasound (3D-EUS) technique for use in the upper gastro-intestinal tract. It comprised of a commercial EUS system, a custom acquisition system to simultaneous acquire radial B-mode images and corresponding incremental changes in position of the scope as it was withdrawn and a custom 3D-EUS package written in Matlab™, to reconstruct and analyse the volume. This technique was evaluated using an EUS phantom with embedded objects of known dimensions and volumes and with clinical images acquired during routine cancer staging. For the phantom measurements, average Z-dimensional error was <1% and volume errors were 1.4% (volume(1) = 48930 mm(3)) and 4.5% (volume(2) = 5100 mm(3)). Application of this technique to EUS acquired clinical images produced excellent characterisation of oesophageal structures and accurate dimension and volume measurements. It also enabled the endoscopist to review "off-line" the EUS examination in case important information was missed.

  13. Three-dimensional ultrasound in the prenatal diagnosis of osteogenesis imperfecta.

    PubMed

    Tsai, Pei-Yin; Chang, Chiung-Hsin; Yu, Chen-Hsiang; Cheng, Yueh-Chin; Chang, Fong-Ming

    2012-09-01

    Fetal osteogenesis imperfecta (OI) is a heterogeneous group of collagen disorders characterized by bone fragility, blue sclerae, deafness, and dentinogenesis imperfecta. Ultrasonography is acknowledged as a reliable diagnostic modality for the prenatal diagnosis of OI, especially type II. In the past, two-dimensional (2D) ultrasound (US) has been applied as the mainstay of prenatal diagnosis of OI. In this series, we report our work of detecting OI using three-dimensional (3D) US. We reviewed our computer database of prenatal diagnosis of OI at the National Cheng Kung University Hospital from April 1996 to July 2010. All the cases were scanned by 2D and 3D US. In total, six cases of fetal OI were diagnosed. Compared with 2D US, 3D US can detect fetal OI precisely, and provide additional vivid illustration after various modes of reconstruction that 2D US cannot. In conclusion, 3D US may contribute significantly to the detection of OI in utero and provide a novel visual depiction of this defect after reconstruction. The technique may thus substantially assist in prenatal diagnosis as well as consultations for fetal OI. Copyright © 2012. Published by Elsevier B.V.

  14. Direct three-dimensional ultrasound-to-video registration using photoacoustic markers

    NASA Astrophysics Data System (ADS)

    Cheng, Alexis; Kang, Jin U.; Taylor, Russell H.; Boctor, Emad M.

    2013-06-01

    Modern surgical procedures often have a fusion of video and other imaging modalities to provide the surgeon with information support. This requires interventional guidance equipment and surgical navigation systems to register different tools and devices together, such as stereoscopic endoscopes and ultrasound (US) transducers. In this work, the focus is specifically on the registration between these two devices. Electromagnetic and optical trackers are typically used to acquire this registration, but they have various drawbacks typically leading to target registration errors (TRE) of approximately 3 mm. We introduce photoacoustic markers for direct three-dimensional (3-D) US-to-video registration. The feasibility of this method was demonstrated on synthetic and ex vivo porcine liver, kidney, and fat phantoms with an air-coupled laser and a motorized 3-D US probe. The resulting TRE for each experiment ranged from 380 to 850 μm with standard deviations ranging from 150 to 450 μm. We also discuss a roadmap to bring this system into the surgical setting and possible challenges along the way.

  15. Direct three-dimensional ultrasound-to-video registration using photoacoustic markers.

    PubMed

    Cheng, Alexis; Kang, Jin U; Taylor, Russell H; Boctor, Emad M

    2013-06-01

    Modern surgical procedures often have a fusion of video and other imaging modalities to provide the surgeon with information support. This requires interventional guidance equipment and surgical navigation systems to register different tools and devices together, such as stereoscopic endoscopes and ultrasound (US) transducers. In this work, the focus is specifically on the registration between these two devices. Electromagnetic and optical trackers are typically used to acquire this registration, but they have various drawbacks typically leading to target registration errors (TRE) of approximately 3 mm. We introduce photoacoustic markers for direct three-dimensional (3-D) US-to-video registration. The feasibility of this method was demonstrated on synthetic and ex vivo porcine liver, kidney, and fat phantoms with an air-coupled laser and a motorized 3-D US probe. The resulting TRE for each experiment ranged from 380 to 850 μm with standard deviations ranging from 150 to 450 μm. We also discuss a roadmap to bring this system into the surgical setting and possible challenges along the way.

  16. Volumetric three-dimensional intravascular ultrasound visualization using shape-based nonlinear interpolation

    PubMed Central

    2013-01-01

    Background Intravascular ultrasound (IVUS) is a standard imaging modality for identification of plaque formation in the coronary and peripheral arteries. Volumetric three-dimensional (3D) IVUS visualization provides a powerful tool to overcome the limited comprehensive information of 2D IVUS in terms of complex spatial distribution of arterial morphology and acoustic backscatter information. Conventional 3D IVUS techniques provide sub-optimal visualization of arterial morphology or lack acoustic information concerning arterial structure due in part to low quality of image data and the use of pixel-based IVUS image reconstruction algorithms. In the present study, we describe a novel volumetric 3D IVUS reconstruction algorithm to utilize IVUS signal data and a shape-based nonlinear interpolation. Methods We developed an algorithm to convert a series of IVUS signal data into a fully volumetric 3D visualization. Intermediary slices between original 2D IVUS slices were generated utilizing the natural cubic spline interpolation to consider the nonlinearity of both vascular structure geometry and acoustic backscatter in the arterial wall. We evaluated differences in image quality between the conventional pixel-based interpolation and the shape-based nonlinear interpolation methods using both virtual vascular phantom data and in vivo IVUS data of a porcine femoral artery. Volumetric 3D IVUS images of the arterial segment reconstructed using the two interpolation methods were compared. Results In vitro validation and in vivo comparative studies with the conventional pixel-based interpolation method demonstrated more robustness of the shape-based nonlinear interpolation algorithm in determining intermediary 2D IVUS slices. Our shape-based nonlinear interpolation demonstrated improved volumetric 3D visualization of the in vivo arterial structure and more realistic acoustic backscatter distribution compared to the conventional pixel-based interpolation method. Conclusions This

  17. Perfusion estimation using contrast enhanced three-dimensional subharmonic ultrasound imaging: an in vivo study

    PubMed Central

    Sridharan, Anush; Eisenbrey, John R.; Liu, Ji-Bin; Machado, Priscilla; Halldorsdottir, Valgerdur G.; Dave, Jaydev K.; Zhao, Hongjia; He, Yu; Park, Suhyun; Dianis, Scott; Wallace, Kirk; Thomenius, Kai E.; Forsberg, Flemming

    2013-01-01

    Objectives The ability to estimate tissue perfusion (in mL/min/g) in vivo using contrast-enhanced three-dimensional (3D) harmonic and subharmonic ultrasound imaging was investigated. Materials and Methods A Logiq 9 scanner (GE Healthcare, Milwaukee, WI) equipped with a 4D10L probe was modified to perform 3D harmonic imaging (HI; ftransmit = 5 MHz and freceive = 10 MHz) and subharmonic imaging (SHI; ftransmit= 5.8 MHz and freceive= 2.9 MHz). In vivo imaging was performed in the lower pole of both kidneys in five open-abdomen canines after injection of the ultrasound contrast agent (UCA) Definity (Lantheus Medical Imaging, N Billerica, MA). The canines received a 5 μL/kg bolus injection of Definity for HI and a 20 μL/kg bolus for SHI in triplicate for each kidney. Ultrasound data acquisition was started just prior to injection of UCA (in order to capture the wash-in) and continued until washout. A microvascular staining technique based on stable (non-radioactive) isotope-labeled microspheres (Biophysics Assay Laboratory Inc, Worcester, MA) was used to quantify the degree of perfusion in each kidney (the reference standard). Ligating a surgically exposed branch of the renal arteries induced lower perfusion rates. This was followed by additional contrast-enhanced imaging and microsphere injections to measure post-ligation perfusion. Slice data were extracted from the 3D ultrasound volumes and used to generate time-intensity curves off-line in the regions corresponding to the tissue samples used for microvascular staining. The mid-line plane was also selected from the 3D volume (as a quasi-2D image) and compared to the 3D imaging modes. Perfusion was estimated from the initial slope of the fractional blood volume uptake (for both HI and SHI) and compared to the reference standard using linear regression analysis. Results Both 3D HI and SHI were able to provide visualization of flow and, thus, perfusion in the kidneys. However, SHI provided near complete tissue

  18. Two- and three-dimensional ultrasound imaging to facilitate detection and targeting of taut bands in myofascial pain syndrome.

    PubMed

    Shankar, Hariharan; Reddy, Sapna

    2012-07-01

    Ultrasound imaging has gained acceptance in pain management interventions. Features of myofascial pain syndrome have been explored using ultrasound imaging and elastography. There is a paucity of reports showing the benefit clinically. This report provides three-dimensional features of taut bands and highlights the advantages of using two-dimensional ultrasound imaging to improve targeting of taut bands in deeper locations. Fifty-eight-year-old man with pain and decreased range of motion of the right shoulder was referred for further management of pain above the scapula after having failed conservative management for myofascial pain syndrome. Three-dimensional ultrasound images provided evidence of aberrancy in the architecture of the muscle fascicles around the taut bands compared to the adjacent normal muscle tissue during serial sectioning of the accrued image. On two-dimensional ultrasound imaging over the palpated taut band, areas of hyperechogenicity were visualized in the trapezius and supraspinatus muscles. Subsequently, the patient received ultrasound-guided real-time lidocaine injections to the trigger points with successful resolution of symptoms. This is a successful demonstration of utility of ultrasound imaging of taut bands in the management of myofascial pain syndrome. Utility of this imaging modality in myofascial pain syndrome requires further clinical validation. Wiley Periodicals, Inc.

  19. Three-dimensional geometrical changes of the human tibialis anterior muscle and its central aponeurosis measured with three-dimensional ultrasound during isometric contractions

    PubMed Central

    Cresswell, Andrew G.; Lichtwark, Glen A.

    2016-01-01

    Background. Muscles not only shorten during contraction to perform mechanical work, but they also bulge radially because of the isovolumetric constraint on muscle fibres. Muscle bulging may have important implications for muscle performance, however quantifying three-dimensional (3D) muscle shape changes in human muscle is problematic because of difficulties with sustaining contractions for the duration of an in vivo scan. Although two-dimensional ultrasound imaging is useful for measuring local muscle deformations, assumptions must be made about global muscle shape changes, which could lead to errors in fully understanding the mechanical behaviour of muscle and its surrounding connective tissues, such as aponeurosis. Therefore, the aims of this investigation were (a) to determine the intra-session reliability of a novel 3D ultrasound (3DUS) imaging method for measuring in vivo human muscle and aponeurosis deformations and (b) to examine how contraction intensity influences in vivo human muscle and aponeurosis strains during isometric contractions. Methods. Participants (n = 12) were seated in a reclined position with their left knee extended and ankle at 90° and performed isometric dorsiflexion contractions up to 50% of maximal voluntary contraction. 3DUS scans of the tibialis anterior (TA) muscle belly were performed during the contractions and at rest to assess muscle volume, muscle length, muscle cross-sectional area, muscle thickness and width, fascicle length and pennation angle, and central aponeurosis width and length. The 3DUS scan involved synchronous B-mode ultrasound imaging and 3D motion capture of the position and orientation of the ultrasound transducer, while successive cross-sectional slices were captured by sweeping the transducer along the muscle. Results. 3DUS was shown to be highly reliable across measures of muscle volume, muscle length, fascicle length and central aponeurosis length (ICC ≥ 0.98, CV < 1%). The TA remained isovolumetric

  20. Predictive factors for recurrence of cryptoglandular fistulae characterized by preoperative three-dimensional endoanal ultrasound.

    PubMed

    Visscher, A P; Schuur, D; Slooff, R A E; Meijerink, W J H J; Deen-Molenaar, C B H; Felt-Bersma, R J F

    2016-05-01

    Precise information regarding the location of an anal fistula and its relationship to adjacent structures is necessary for selecting the best surgical strategy. Retrospective and cross-sectional studies were performed to determine predictive factors for recurrence of anal fistula from preoperative examination by three-dimensional endoanal ultrasound (3D-EAUS). Patients in our tertiary centre and in a private centre specialized in proctology undergoing preoperative 3D-EAUS for cryptoglandular anal fistulae between 2002 and 2012 were included. A questionnaire was sent in September 2013 to assess the patient's condition with regard to recurrence. Variables checked for association with recurrence were gender, type of centre, previous fistula surgery, secondary track formation and classification of the fistula. There were 143 patients of whom 96 had a low fistula treated by fistulotomy, 28 a high fistula treated by fistulectomy and 19 a high fistula treated by fistulectomy combined with a mucosal advancement flap. The median duration of follow-up was 26 (2-118) months. The fistula recurred in 40 (27%) patients. Independent risk factors included the presence of secondary track formation [hazard ratio 2.4 (95% CI 1.2-51), P = 0.016] and previous fistula surgery [hazard ratio 1.2 (95% CI 1.0-4.6), P = 0.041]. Agreement between the 3D-EAUS examination and the evaluation under anaesthesia regarding the site of the internal opening, classification of the fistula and the presence of secondary tracks was 97%, 98% and 78%. The identification of secondary tracks by preoperative 3D-EAUS examination was the strongest independent risk factor for recurrence. This stresses the importance of preoperative 3D-EAUS in mapping the pathological anatomy of the fistula and a thorough search for secondary track formation during surgery. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

  1. Three-dimensional power Doppler ultrasound in cervical carcinoma: monitoring treatment response to radiotherapy.

    PubMed

    Huang, Y-F; Cheng, Y-M; Wu, Y-P; Chen, H H W; Hsu, K-F; Wu, Y-H; Chou, C-Y

    2013-07-01

    To investigate, using three-dimensional power Doppler ultrasound (3D-PDU), alterations in cervical intratumoral vascularization during and after radiotherapy. Between 2004 and 2009 we enrolled into the study 37 patients with FIGO Stages IB1-IIB cervical carcinoma who were undergoing radiotherapy. Serial 3D-PDU scans were performed during treatment, providing ultrasonographic measurement of tumor size, vascularization index, flow index and vascularization flow index, as well as monthly for 3 months post-treatment and tri-monthly thereafter, until vascularity was undetectable on two consecutive occasions. Physical examination, cervical cytology and serum marker evaluation were performed every 3-6 months for the first 5 years following treatment. Patients evaluated after a 2-year tumor-free interval and those with clinically assessed positive findings at follow-up underwent 3D-PDU to detect possible local disease. A total of 329 3D-PDU scans were performed in the 37 women. Cervical tumors and intratumoral vascularization disappeared within 3 months following radiotherapy, except in one patient with persistent disease. Nine patients had disease relapse, in four of whom the recurrence was local. In three of these four, there was recurrence of tumor and vascularization after a complete response. At follow-up, 3D-PDU detected local disease with 75.0% sensitivity and 98.5% specificity, while serum markers detected local disease among 34 patients with squamous cell carcinoma with 20.0% sensitivity and 77.3% specificity. Compared with serum markers in cervical squamous cell carcinoma, 3D-PDU has higher sensitivity and specificity for detecting local recurrence or persistence in cervical carcinoma. Thus, 3D-PDU combined with clinical assessment may be a new and safe method for monitoring radiotherapy treatment response and detecting local recurrence. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

  2. Vascularization of Three-Dimensional Collagen Hydrogels Using Ultrasound Standing Wave Fields

    PubMed Central

    Garvin, Kelley A.; Dalecki, Diane; Hocking, Denise C.

    2011-01-01

    The successful fabrication of large, three-dimensional (3D) tissues and organs in vitro requires the rapid development of a vascular network to maintain cell viability and tissue function. In this study, we utilized an application of ultrasound standing wave field (USWF) technology to vascularize 3D, collagen-based hydrogels in vitro. Acoustic radiation forces associated with USWF were used to non-invasively organize human endothelial cells into distinct, multicellular planar bands within 3D collagen gels. The formation and maturation of capillary-like endothelial cell sprouts was monitored over time and compared to sham-exposed collagen constructs which were characterized by a homogeneous cell distribution. USWF10 induced cell banding accelerated the formation and elongation of capillary-like sprouts, promoted collagen fiber alignment, and resulted in the maturation of endothelial cell sprouts into lumen-containing, anastomosing networks found throughout the entire volume of the collagen gel. USWF-induced endothelial cell networks contained large, arteriole-sized lumen areas that branched into smaller, capillary-sized structures indicating the development of vascular tree-like networks. In contrast, sprout formation was delayed in sham-exposed collagen gels, and endothelial cell networks were absent from sham gel centers and failed to develop into the vascular tree-like structures found in USWF-exposed constructs. Our results demonstrate that USWF technology leads to rapid and extensive vascularization of 3D collagen-based engineered tissue and therefore, provides a new strategy to vascularize engineered tissues in vitro. PMID:21924816

  3. Texture analysis of carotid artery atherosclerosis from three-dimensional ultrasound images.

    PubMed

    Awad, Joseph; Krasinski, Adam; Parraga, Grace; Fenster, Aaron

    2010-04-01

    To quantitatively evaluate local carotid arterial statin effects in 3D US images using multiclassifier image texture analysis tools. Texture analysis tools were used to evaluate the effect of 80 mg atorvastatin administered daily to patients with carotid stenosis compared to those treated with placebo. Using three-dimensional carotid ultrasound images, 270 texture features from seven texture techniques were extracted from manually segmented carotid arteries based on the intima-media boundary [vessel wall (VW)]. Individual texture features were compared to the previously determined changes in VW volume (VWV) using the distance between classes, the Wilcoxon rank sum test, and accuracy of the classifiers. Texture features that resulted in maximal classification accuracy from each texture technique were selected using Pudil's sequential floating forward selection (SFFS) as a method of ranking each technique. Finally, SFFS-selected texture features from all texture techniques were used in combination with 24 classifier fusion techniques to improve classification accuracy. Using the measurement of change in VWV, the distance between classes (DBC), Wilcoxon rank sum (WRS) p-value, and median accuracy measures (ACC) were 0.3798, 0.076, and 54.50%, respectively. Texture features improved the detection of statin-related changes using DBC to 0.5199, using WRS to 0.002, and ACC to 63.87%, respectively. The texture techniques that most differentiated between atorvastatin and placebo classes were Fourier power spectrum and Laws texture energy measures. The average classification accuracy between atorvastatin and placebo classes was improved from 57.22 +/- 12.11% using VWV to 97.87 +/- 3.93% using specific texture features. Furthermore, the use of specific texture features resulted in the average area under the receiver-operator characteristic curve (AUC) a value of 0.9988 +/- 0.0069 compared to 0.617 +/- 0.15 using carotid VWV. Based on DBC, WRS, ACC, and AUC texture features

  4. Is curved three-dimensional ultrasound reconstruction needed to assess the warped pelvic floor plane?

    PubMed

    Youssef, A; Cavalera, M; Pacella, G; Salsi, G; Morganelli, G; Montaguti, E; Cataneo, I; Pilu, G; Rizzo, N

    2016-09-19

    Caudal distension of the female pelvic floor is common and results in perineal descent and a caudally curved levator hiatus (warping). Image reconstruction of the pelvic floor using currently available ultrasound techniques involves a linear approach (flat-plane reconstruction). We aimed to evaluate the feasibility, reproducibility and potential usefulness of a new three-dimensional (3D) technique capable of reconstructing a curved plane of the levator hiatus. Primiparous women were recruited to undergo a 3D/four-dimensional transperineal ultrasound examination 3-6 months after delivery. Levator ani muscle warping was evaluated on Valsalva maneuver by measuring the distance between the plane extending from the pubic rami to the anorectal angle and the plane of minimal hiatal dimensions on the coronal plane. Warping distance was used to reconstruct a curved plane of the levator hiatus using the curved OmniView volume contrast imaging (VCI) technique (C-OV). Intra- and interobserver reproducibility of the C-OV technique were assessed, as was intermethod agreement between the C-OV technique and the linear OmniView-VCI (L-OV) technique, for the measurement of levator hiatal area on Valsalva maneuver. Measurement of the levator hiatal area using C-OV was feasible in all 84 women recruited. The warping distance ranged from -3.5 to 9.7 mm, confirming that the 1-2-cm slice thickness traditionally used for linear reconstruction was adequate for proper assessment of levator hiatal area in our population. C-OV showed excellent intra- and interobserver reproducibility, as well as excellent agreement with the L-OV technique for measuring levator hiatal area. No systematic difference was demonstrated in any of the reproducibility studies performed. 3D reconstruction of the warped levator hiatal plane is feasible and highly reproducible. In our population, reconstruction of a curved plane to correct for levator hiatal warping did not offer any benefit over the traditionally

  5. Comparison of two- and three-dimensional transvaginal ultrasound in the visualisation of intrauterine devices.

    PubMed

    Kerr, N K; Dunham, R; Wolstenhulme, S; Wilson, J

    2014-08-01

    The aims of the study were to evaluate whether three-dimensional transvaginal ultrasound (3D TV US) is superior to two-dimensional transvaginal ultrasound (2D TV US) at visualising intrauterine devices and determining their position. This prospective study included 52 participants with an intrauterine device fitted, who underwent 2D TV US and 3D TV US. 2D TV US and 3D-reconstructed coronal images were reviewed by two gynaecological radiologists to assess ease of visualisation and position of the intrauterine devices. Statistical analysis was performed using Wilcoxon signed-rank, McNemar and Chi-squared tests. The inter-observer agreement was measured using Cohen's Kappa. Intrauterine device visualisation scores were significantly higher with 2D TV US compared with 3D TV US (Radiologist 1 p = <0.001, Radiologist 2 p = 0.007). A significant number of T-arms appeared to perforate into the adjacent myometrium on the 3D-reconstructed coronal image, but were normal on the 2D images (Radiologist 1 p = <0.001, Radiologist 2 p = 0.008). Radiologist 1 found 19 perforated T-arms on 3D TV US compared with four on 2D TV US. Radiologist 2 found 13 perforated T-arms on 3D TV US compared with five on 2D TV US. Both radiologists agreed on the positions of the intrauterine devices substantially with 3D TV US (Kappa = 0.69) and moderately with 2D TV US (Kappa = 0.55). The 3D TV US did not visualise an intrauterine device better than 2D TV US. The 3D-reconstructed coronal image of the uterus can reliably display cases of T-arm perforation into the adjacent myometrium, which could be missed on 2D TV US images. The 3D TV US should be used in addition to 2D TV US in all cases where an intrauterine device is under evaluation.

  6. Comparison of two- and three-dimensional transvaginal ultrasound in the visualisation of intrauterine devices

    PubMed Central

    Dunham, R; Wolstenhulme, S; Wilson, J

    2014-01-01

    The aims of the study were to evaluate whether three-dimensional transvaginal ultrasound (3D TV US) is superior to two-dimensional transvaginal ultrasound (2D TV US) at visualising intrauterine devices and determining their position. This prospective study included 52 participants with an intrauterine device fitted, who underwent 2D TV US and 3D TV US. 2D TV US and 3D-reconstructed coronal images were reviewed by two gynaecological radiologists to assess ease of visualisation and position of the intrauterine devices. Statistical analysis was performed using Wilcoxon signed-rank, McNemar and Chi-squared tests. The inter-observer agreement was measured using Cohen’s Kappa. Intrauterine device visualisation scores were significantly higher with 2D TV US compared with 3D TV US (Radiologist 1 p = <0.001, Radiologist 2 p = 0.007). A significant number of T-arms appeared to perforate into the adjacent myometrium on the 3D-reconstructed coronal image, but were normal on the 2D images (Radiologist 1 p = <0.001, Radiologist 2 p = 0.008). Radiologist 1 found 19 perforated T-arms on 3D TV US compared with four on 2D TV US. Radiologist 2 found 13 perforated T-arms on 3D TV US compared with five on 2D TV US. Both radiologists agreed on the positions of the intrauterine devices substantially with 3D TV US (Kappa = 0.69) and moderately with 2D TV US (Kappa = 0.55). The 3D TV US did not visualise an intrauterine device better than 2D TV US. The 3D-reconstructed coronal image of the uterus can reliably display cases of T-arm perforation into the adjacent myometrium, which could be missed on 2D TV US images. The 3D TV US should be used in addition to 2D TV US in all cases where an intrauterine device is under evaluation. PMID:27433211

  7. Real-time optoacoustic imaging of breast cancer using an interleaved two laser imaging system coregistered with ultrasound

    NASA Astrophysics Data System (ADS)

    Ermilov, Sergey A.; Fronheiser, Matthew P.; Nadvoretsky, Vyacheslav; Brecht, Hans-Peter; Su, Richard; Conjusteau, André; Mehta, Ketan; Otto, Pamela; Oraevsky, Alexander A.

    2010-02-01

    We present results from a clinical case study on imaging breast cancer using a real-time interleaved two laser optoacoustic imaging system co-registered with ultrasound. The present version of Laser Optoacoustic Ultrasonic Imaging System (LOUIS) utilizes a commercial linear ultrasonic transducer array, which has been modified to include two parallel rectangular optical bundles, to operate in both ultrasonic (US) and optoacoustic (OA) modes. In OA mode, the images from two optical wavelengths (755 nm and 1064 nm) that provide opposite contrasts for optical absorption of oxygenated vs deoxygenated blood can be displayed simultaneously at a maximum rate of 20 Hz. The real-time aspect of the system permits probe manipulations that can assist in the detection of the lesion. The results show the ability of LOUIS to co-register regions of high absorption seen in OA images with US images collected at the same location with the dual modality probe. The dual wavelength results demonstrate that LOUIS can potentially provide breast cancer diagnostics based on different intensities of OA images of the lesion obtained at 755 nm and 1064 nm. We also present new data processing based on deconvolution of the LOUIS impulse response that helps recover original optoacoustic pressure profiles. Finally, we demonstrate the image analysis tool that provides automatic detection of the tumor boundary and quantitative metrics of the optoacoustic image quality. Using a blood vessel phantom submerged in a tissue-like milky background solution we show that the image contrast is minimally affected by the phantom distance from the LOUIS probe until about 60-65 mm. We suggest using the image contrast for quantitative assessment of an OA image of a breast lesion, as a part of the breast cancer diagnostics procedure.

  8. Photoacoustic radar phase-filtered spatial resolution and co-registered ultrasound image enhancement for tumor detection

    PubMed Central

    Dovlo, Edem; Lashkari, Bahman; Mandelis, Andreas; Shi, Wei; Liu, Fei-Fei

    2015-01-01

    Co-registered ultrasound (US) and frequency-domain photoacoustic radar (FD-PAR) imaging is reported for the first time in this paper. The merits of ultrasound and cross-correlation (radar) frequency-domain photoacoustic imaging are leveraged for accurate tumor detection. Commercial US imagers possess sophisticated, optimized software for rapid image acquisition that could dramatically speed-up PA imaging. The PAR image generated from the amplitude of the cross-correlation between detected and input signals was filtered by the standard deviation (SD) of the phase of the correlation signal, resulting in strong improvement of image spatial resolution, signal-to-noise ratio (SNR) and contrast. Application of phase-mediated image improvement is illustrated by imaging a cancer cell-injected mouse. A 14–15 dB SNR gain was recorded for the phase-filtered image compared to the amplitude and phase independently, while ~340 μm spatial resolution was seen for the phase PAR image compared to ~840 μm for the amplitude image. PMID:25798321

  9. Photoacoustic radar phase-filtered spatial resolution and co-registered ultrasound image enhancement for tumor detection.

    PubMed

    Dovlo, Edem; Lashkari, Bahman; Mandelis, Andreas; Shi, Wei; Liu, Fei-Fei

    2015-03-01

    Co-registered ultrasound (US) and frequency-domain photoacoustic radar (FD-PAR) imaging is reported for the first time in this paper. The merits of ultrasound and cross-correlation (radar) frequency-domain photoacoustic imaging are leveraged for accurate tumor detection. Commercial US imagers possess sophisticated, optimized software for rapid image acquisition that could dramatically speed-up PA imaging. The PAR image generated from the amplitude of the cross-correlation between detected and input signals was filtered by the standard deviation (SD) of the phase of the correlation signal, resulting in strong improvement of image spatial resolution, signal-to-noise ratio (SNR) and contrast. Application of phase-mediated image improvement is illustrated by imaging a cancer cell-injected mouse. A 14-15 dB SNR gain was recorded for the phase-filtered image compared to the amplitude and phase independently, while ~340 μm spatial resolution was seen for the phase PAR image compared to ~840 μm for the amplitude image.

  10. Co-registered Frequency-Domain Photoacoustic Radar and Ultrasound System for Subsurface Imaging in Turbid Media

    NASA Astrophysics Data System (ADS)

    Dovlo, Edem; Lashkari, Bahman; Mandelis, Andreas

    2016-03-01

    Frequency-domain photoacoustic radar (FD-PAR) imaging of absorbers in turbid media and their comparison and/or validation as well as co-registration with their corresponding ultrasound (US) images are demonstrated in this paper. Also presented are the FD-PAR tomography and the effects of reducing the number of scan lines (or angles) on image quality, resolution, and contrast. The FD-PAR modality uses intensity-modulated (coded) continuous wave laser sources driven by frequency-swept (chirp) waveforms. The spatial cross-correlation function between the PA response and the reference signal used for laser source modulation produces the reconstructed image. Live animal testing is demonstrated, and images of comparable signal-to-noise ratio, contrast, and spatial resolution were obtained. Various image improvement techniques to further reduce absorber spread and artifacts in the images such as normalization, filtering, and amplification were also investigated. The co-registered image produced from the combined US and PA images provides more information than both images independently. The significance of this work lies in the fact that achieving PA imaging functionality on a commercial ultrasound instrument could accelerate its clinical acceptance and use. This work is aimed at functional PA imaging of small animals in vivo.

  11. Coregistered photoacoustic and ultrasound tomography of healthy and inflamed human interphalangeal joints

    NASA Astrophysics Data System (ADS)

    van Es, Peter; Vlieg, Redmar C.; Biswas, Samir K.; Hondebrink, Erwin; van Hespen, Johan C. G.; Moens, Hein B. J.; Steenbergen, Wiendelt; Manohar, Srirang

    2015-07-01

    Photoacoustic (PA) or optoacoustic (OA) imaging combines the high (blood) contrast to light with the high-resolution of ultrasound. The method can visualize vascularization deep inside tissue. Of late there is interest in PA imaging of synovial joints which are expected to be associated with increased vascularization in the event of rheumatoid arthritis (RA). We here describe our approach in investigating the application of the PA technique in arthritis. We are developing a CT-geometry version PA finger imager, intended for early clinical assessment of the method. The imager uses two curved array ultrasound detectors each with 64 elements with central frequencies 1.5 and 7.5 MHz respectively, stacked above each other. Both cover approximately 180 degrees of the circle. Illumination is provided with a multiple of optical fiber bundles coupled to a laser-OPO system. Ultrasound imaging is also possible with the system, since the curved arrays are each provided with 12 or 8 ultrasound pulsers. We have investigated systematically imaging of finger vasculature in healthy volunteers using an earlier laboratory prototype. In this paper we present finger imaging results of a patient diagnosed with rheumatoid arthritis.

  12. Three-dimensional Ultrasound Molecular Imaging of Angiogenesis in Colon Cancer using a Clinical Matrix Array Ultrasound Transducer

    PubMed Central

    Wang, Huaijun; Kaneko, Osamu F.; Tian, Lu; Hristov, Dimitre; Willmann, Jürgen K.

    2015-01-01

    Objectives We sought to assess the feasibility and reproducibility of three-dimensional (3D) ultrasound molecular imaging (USMI) of vascular endothelial growth factor receptor 2 (VEGFR2) expression in tumor angiogenesis using a clinical matrix array transducer and a clinical grade VEGFR2-targeted contrast agent in a murine model of human colon cancer. Materials and Methods Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice with human colon cancer xenografts (n=33) were imaged with a clinical ultrasound system and transducer (Philips iU22; X6-1) following intravenous injection of either clinical grade VEGFR2-targeted microbubbles (MBVEGFR2) or non-targeted control microbubbles (MBControl). Nineteen mice were scanned twice to assess imaging reproducibility. Fourteen mice were scanned both before and 24h after treatment with either bevacizumab (n=7) or saline only (n=7). 3D USMI datasets were retrospectively reconstructed into multiple consecutive 1-mm thick USMI data sets to simulate 2D imaging. Vascular VEGFR2 expression was assessed ex vivo using immunofluorescence. Results 3D USMI was highly reproducible using both MBVEGFR2 and MBControl (ICC=0.83). VEGFR2-targeted USMI signal significantly (P=0.02) decreased by 57% following anti-angiogenic treatment compared to the control group, which correlated well with ex vivo VEGFR2 expression on immunofluorescence (rho=0.93, P=0.003). If only central 1-mm tumor planes were analyzed to assess anti-angiogenic treatment response, the USMI signal change was significantly (P=0.006) overestimated by an average of 27% (range, 2–73%) compared to 3D USMI. Conclusions 3D USMI is feasible and highly reproducible and allows accurate assessment and monitoring of VEGFR2 expression in tumor angiogenesis in a murine model of human colon cancer. PMID:25575176

  13. Three-dimensional ultrasound of carotid atherosclerosis: semiautomated segmentation using a level set-based method.

    PubMed

    Ukwatta, E; Awad, J; Ward, A D; Buchanan, D; Samarabandu, J; Parraga, G; Fenster, A

    2011-05-01

    Three-dimensional ultrasound (3D US) of the carotid artery provides measurements of arterial wall and plaque [vessel wall volume (VWV)] that are complementary to the one-dimensional measurement of the carotid artery intima-media thickness. 3D US VWV requires an observer to delineate the media-adventitia boundary (MAB) and lumen-intima boundary (LIB) of the carotid artery. The main purpose of this work was to develop and evaluate a semiautomated segmentation algorithm for delineating the MAB and LIB of the carotid artery from 3D US images. To segment the MAB and LIB, the authors used a level set method and combined several low-level image cues with high-level domain knowledge and limited user interaction. First, the operator initialized the algorithm by choosing anchor points on the boundaries, identified in the images. The MAB was segmented using local region- and edge-based energies and an energy that encourages the boundary to pass through anchor points from the preprocessed images. For the LIB segmentation, the authors used local and global region-based energies, the anchor point-based energy, as well as a constraint promoting a boundary separation between the MAB and LIB. The data set consisted of 231 2D images (11 2D images per each of 21 subjects) extracted from 3D US images. The image slices were segmented five times each by a single observer using the algorithm and the manual method. Volume-based, region-based, and boundary distance-based metrics were used to evaluate accuracy. Moreover, repeated measures analysis was used to evaluate precision. The algorithm yielded an absolute VWV difference of 5.0% +/- 4.3% with a segmentation bias of -0.9% +/- 6.6%. For the MAB and LIB segmentations, the method gave absolute volume differences of 2.5% +/- 1.8% and 5.6% +/- 3.0%, Dice coefficients of 95.4% +/- 1.6% and 93.1% +/- 3.1%, mean absolute distances of 0.2 +/- 0.1 and 0.2 +/- 0.1 mm, and maximum absolute distances of 0.6 +/- 0.3 and 0.7 +/- 0.6 mm, respectively

  14. Effects of growth on geometry of gastrocnemius muscle in children: a three-dimensional ultrasound analysis

    PubMed Central

    Bénard, Menno R; Harlaar, Jaap; Becher, Jules G; Huijing, Peter A; Jaspers, Richard T

    2011-01-01

    During development, muscle growth is usually finely adapted to meet functional demands in daily activities. However, how muscle geometry changes in typically developing children and how these changes are related to functional and mechanical properties is largely unknown. In rodents, longitudinal growth of the pennate m. gastrocnemius medialis (GM) has been shown to occur mainly by an increase in physiological cross-sectional area and less by an increase in fibre length. Therefore, we aimed to: (i) determine how geometry of GM changes in healthy children between the ages of 5 and 12 years, (ii) test whether GM geometry in these children is affected by gender, (iii) compare normalized growth of GM geometry in children with that in rats at similar normalized ages, and (iv) investigate how GM geometry in children relates to range of motion of angular foot movement at a given moment. Thirty children (16 females, 14 males) participated in the study. Moment-angle data were collected over a range of angles by rotating the foot from plantar flexion to dorsal flexion at standardized moments. GM geometry in the mid-longitudinal plane was measured using three-dimensional ultrasound imaging. This geometry was compared with that of GM geometry in rats. During growth from 5 to 12 years of age, the mean neutral footplate angle (0 Nm) occurred at −5° (SD 7°) and was not a function of age. Measured at standardized moments (4 Nm), footplate angles towards plantar flexion and dorsal flexion decreased by 25 and 40%, respectively. In both rats and children, GM muscle length increased proportionally with tibia length. In children, the length component of the physiological cross-sectional area and fascicle length increased by 7 and 5% per year, respectively. Fascicle angle did not change over the age range measured. In children, the Achilles tendon length increased by 6% per year. GM geometry was not affected by gender. We conclude that, whereas the length of GM in rat develops mainly

  15. Manual planimetric measurement of carotid plaque volume using three-dimensional ultrasound imaging

    SciTech Connect

    Landry, Anthony; Ainsworth, Craig; Blake, Chris; Spence, J. David; Fenster, Aaron

    2007-04-15

    We investigated the utility of three manual planimetric methods to quantify carotid plaque volume. A single observer measured 15 individual plaques from 15 three-dimensional (3D) ultrasound (3D US) images of patients ten times each using three different planimetric approaches. Individual plaque volumes were measured (range: 32.6-597.1 mm{sup 3}) using a standard planimetric approach (M1) whereby a plaque end was identified and sequential contours were measured. The same plaques were measured using a second approach (M2), whereby plaque ends were first identified and the 3D US image of the plaque was then subdivided into equal intervals. A third method (M3) was used to measure total plaque burden (range: 165.1-1080.0 mm{sup 3}) in a region ({+-}1.5 cm) relative to the carotid bifurcation. M1 systematically underestimated individual plaque volume compared to M2 (V{sub 2}=V{sub 1}+14.0 mm{sup 3}, r=0.99, p=0.006) due to a difference in the mean plaque length measured. Coefficients of variance (CV) for M1 and M2 decrease with increasing plaque volume, with M2 results less than M1. Root mean square difference between experimental and theoretical CV for M2 was 3.2%. The standard deviation in the identification of the transverse location of the carotid bifurcation was 0.56 mm. CVs for plaque burden measured using M3 ranged from 1.2% to 7.6% and were less than CVs determined for individual plaque volumes of the same volume. The utility of M3 was demonstrated by measuring carotid plaque burden and volume change over a period of 3 months in three patients. In conclusion, M2 was determined to be a more superior measurement technique than M1 to measure individual plaque volume. Furthermore, we demonstrated the utility of M3 to quantify regional plaque burden and to quantify change in plaque volume.

  16. Effects of growth on geometry of gastrocnemius muscle in children: a three-dimensional ultrasound analysis.

    PubMed

    Bénard, Menno R; Harlaar, Jaap; Becher, Jules G; Huijing, Peter A; Jaspers, Richard T

    2011-09-01

    During development, muscle growth is usually finely adapted to meet functional demands in daily activities. However, how muscle geometry changes in typically developing children and how these changes are related to functional and mechanical properties is largely unknown. In rodents, longitudinal growth of the pennate m. gastrocnemius medialis (GM) has been shown to occur mainly by an increase in physiological cross-sectional area and less by an increase in fibre length. Therefore, we aimed to: (i) determine how geometry of GM changes in healthy children between the ages of 5 and 12 years, (ii) test whether GM geometry in these children is affected by gender, (iii) compare normalized growth of GM geometry in children with that in rats at similar normalized ages, and (iv) investigate how GM geometry in children relates to range of motion of angular foot movement at a given moment. Thirty children (16 females, 14 males) participated in the study. Moment-angle data were collected over a range of angles by rotating the foot from plantar flexion to dorsal flexion at standardized moments. GM geometry in the mid-longitudinal plane was measured using three-dimensional ultrasound imaging. This geometry was compared with that of GM geometry in rats. During growth from 5 to 12 years of age, the mean neutral footplate angle (0 Nm) occurred at -5° (SD 7°) and was not a function of age. Measured at standardized moments (4 Nm), footplate angles towards plantar flexion and dorsal flexion decreased by 25 and 40%, respectively. In both rats and children, GM muscle length increased proportionally with tibia length. In children, the length component of the physiological cross-sectional area and fascicle length increased by 7 and 5% per year, respectively. Fascicle angle did not change over the age range measured. In children, the Achilles tendon length increased by 6% per year. GM geometry was not affected by gender. We conclude that, whereas the length of GM in rat develops mainly

  17. Assessment of the uterus with three-dimensional ultrasound in women undergoing ART.

    PubMed

    Saravelos, Sotirios H; Jayaprakasan, Kannamannadiar; Ojha, Kamal; Li, Tin-Chiu

    2017-03-01

    A detailed assessment of the uterus forms a pivotal part of the ART treatment process. The emergence of three-dimensional ultrasound (3D US) has provided clinicians with a highly powerful tool in this respect. Assessments with 3D US range from the reconstruction of anatomical planes elusive to conventional US, to the objective measurement of anatomical volumes and vascularization parameters. However, despite the ever increasing number of publications emerging in the literature, the question of which aspects of 3D US are of most clinical value remains a topic of debate. The objective of this review is to dissect which aspects of the 3D US assessment of the uterus are supported by a strong level of evidence to date, and should therefore be incorporated into current routine clinical practice. We conducted a systematic search of the PubMed database up to May 2016, using a combination of text words and Medical Subject Headings (MeSH) pertaining to the 3D US assessment of the uterus. All articles published in the English language were screened to ascertain relevance to women of reproductive age; further citations were retrieved through manual reference list searching. A multitude of predominantly observational studies were identified, which concerned a vast variety of 3D US uterine assessments. All articles unequivocally praised the non-invasive, cost-effective, highly acceptable and objective nature of 3D US. Studies regarding the value of assessing the endometrial volume and vascularization prior to embryo transfer appeared conflicting and inconsistent. Studies regarding the imaging of uterine pathology and identification of intratubal and intrauterine devices consistently reported high rates of diagnostic accuracy. A recent RCT did not show an improvement in clinical outcomes when comparing 3D versus 2D US during embryo transfer. However, preliminary studies suggested that 3D US is superior in determining the site of implantation, particularly in ambiguous cases such

  18. Real-time co-registered ultrasound and photoacoustic imaging system based on FPGA and DSP architecture

    NASA Astrophysics Data System (ADS)

    Alqasemi, Umar; Li, Hai; Aguirre, Andres; Zhu, Quing

    2011-03-01

    Co-registering ultrasound (US) and photoacoustic (PA) imaging is a logical extension to conventional ultrasound because both modalities provide complementary information of tumor morphology, tumor vasculature and hypoxia for cancer detection and characterization. In addition, both modalities are capable of providing real-time images for clinical applications. In this paper, a Field Programmable Gate Array (FPGA) and Digital Signal Processor (DSP) module-based real-time US/PA imaging system is presented. The system provides real-time US/PA data acquisition and image display for up to 5 fps* using the currently implemented DSP board. It can be upgraded to 15 fps, which is the maximum pulse repetition rate of the used laser, by implementing an advanced DSP module. Additionally, the photoacoustic RF data for each frame is saved for further off-line processing. The system frontend consists of eight 16-channel modules made of commercial and customized circuits. Each 16-channel module consists of two commercial 8-channel receiving circuitry boards and one FPGA board from Analog Devices. Each receiving board contains an IC† that combines. 8-channel low-noise amplifiers, variable-gain amplifiers, anti-aliasing filters, and ADC's‡ in a single chip with sampling frequency of 40MHz. The FPGA board captures the LVDSξ Double Data Rate (DDR) digital output of the receiving board and performs data conditioning and subbeamforming. A customized 16-channel transmission circuitry is connected to the two receiving boards for US pulseecho (PE) mode data acquisition. A DSP module uses External Memory Interface (EMIF) to interface with the eight 16-channel modules through a customized adaptor board. The DSP transfers either sub-beamformed data (US pulse-echo mode or PAI imaging mode) or raw data from FPGA boards to its DDR-2 memory through the EMIF link, then it performs additional processing, after that, it transfer the data to the PC** for further image processing. The PC code

  19. Ultrasound directed self-assembly of three-dimensional user-specified patterns of particles in a fluid medium

    NASA Astrophysics Data System (ADS)

    Prisbrey, M.; Greenhall, J.; Guevara Vasquez, F.; Raeymaekers, B.

    2017-01-01

    We use ultrasound directed self-assembly to organize particles dispersed in a fluid medium into a three-dimensional (3D) user-specified pattern. The technique employs ultrasound transducers that line the boundary of a fluid reservoir to create a standing ultrasound wave field. The acoustic radiation force associated with the wave field drives particles dispersed in the fluid medium into organized patterns, assuming that the particles are much smaller than the wavelength and do not interact with each other. We have theoretically derived a direct solution method to calculate the ultrasound transducer operating parameters that are required to assemble a user-specified 3D pattern of particles in a fluid reservoir of arbitrary geometry. We formulate the direct solution method as a constrained optimization problem that reduces to eigendecomposition. We experimentally validate the solution method by assembling 3D patterns of carbon nanoparticles in a water reservoir and observe good quantitative agreement between theory and experiment. Additionally, we demonstrate the versatility of the solution method by simulating ultrasound directed self-assembly of complex 3D patterns of particles. The method works for any 3D simple, closed fluid reservoir geometry in combination with any arrangement of ultrasound transducers and enables employing ultrasound directed self-assembly in a myriad of engineering applications, including biomedical and materials fabrication processes.

  20. Method for aortic wall strain measurement with three-dimensional ultrasound speckle tracking and fitted finite element analysis.

    PubMed

    Karatolios, Konstantinos; Wittek, Andreas; Nwe, Thet Htar; Bihari, Peter; Shelke, Amit; Josef, Dennis; Schmitz-Rixen, Thomas; Geks, Josef; Maisch, Bernhard; Blase, Christopher; Moosdorf, Rainer; Vogt, Sebastian

    2013-11-01

    Aortic wall strains are indicators of biomechanical changes of the aorta due to aging or progressing pathologies such as aortic aneurysm. We investigated the potential of time-resolved three-dimensional ultrasonography coupled with speckle-tracking algorithms and finite element analysis as a novel method for noninvasive in vivo assessment of aortic wall strain. Three-dimensional volume datasets of 6 subjects without cardiovascular risk factors and 2 abdominal aortic aneurysms were acquired with a commercial real time three-dimensional echocardiography system. Longitudinal and circumferential strains were computed offline with high spatial resolution using a customized commercial speckle-tracking software and finite element analysis. Indices for spatial heterogeneity and systolic dyssynchrony were determined for healthy abdominal aortas and abdominal aneurysms. All examined aortic wall segments exhibited considerable heterogenous in-plane strain distributions. Higher spatial resolution of strain imaging resulted in the detection of significantly higher local peak strains (p ≤ 0.01). In comparison with healthy abdominal aortas, aneurysms showed reduced mean strains and increased spatial heterogeneity and more pronounced temporal dyssynchrony as well as delayed systole. Three-dimensional ultrasound speckle tracking enables the analysis of spatially highly resolved strain fields of the aortic wall and offers the potential to detect local aortic wall motion deformations and abnormalities. These data allow the definition of new indices by which the different biomechanical properties of healthy aortas and aortic aneurysms can be characterized. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Preterm neonatal lateral ventricle volume from three-dimensional ultrasound is not strongly correlated to two-dimensional ultrasound measurements.

    PubMed

    Kishimoto, Jessica; de Ribaupierre, Sandrine; Salehi, Fateme; Romano, Walter; Lee, David S C; Fenster, Aaron

    2016-10-01

    The aim of this study is to compare longitudinal two-dimensional (2-D) and three-dimensional (3-D) ultrasound (US) estimates of ventricle size in preterm neonates with posthemorrhagic ventricular dilatation (PHVD) using quantitative measurements of the lateral ventricles. Cranial 2-D US and 3-D US images were acquired from neonatal patients with diagnosed PHVD within 10 min of each other one to two times per week and analyzed offline. Ventricle index, anterior horn width, third ventricle width, and thalamo-occipital distance were measured on the 2-D images and ventricle volume (VV) was measured from 3-D US images. Changes in the measurements between successive image sets were also recorded. No strong correlations were found between VV and 2-D US measurements ([Formula: see text] between 0.69 and 0.36). Additionally, weak correlations were found between changes in 2-D US measurements and 3-D US VV ([Formula: see text] between 0.13 and 0.02). A trend was found between increasing 2-D US measurements and 3-D US-based VV, but this was not the case when comparing changes between 3-D US VV and 2-D US measurements. If 3-D US-based VV provides a more accurate estimate of ventricle size than 2-D US measurements, moderate-weak correlations with 3-D US suggest that monitoring preterm patients with PHVD using 2-D US measurements alone might not accurately represent whether the ventricles are progressively dilating. A volumetric measure (3-D US or MRI) could be used instead to more accurately represent changes.

  2. Imaging of sebaceous glands of human skin by three-dimensional ultrasound microscopy and its relation to elasticity.

    PubMed

    Kumagai, Kazutoshi; Koike, Hideyuki; Kudo, Yukina; Nagaoka, Ryo; Kubo, Kiyono; Kobayashi, Kazuto; Saijo, Yoshifumi

    2011-01-01

    High frequency ultrasound imaging has realized high resolution in vivo imaging of the biological tissues at a microscopic level. Human skin structure, especially sebaceous glands at the deep part of the dermis, was observed by three-dimensional ultrasound microscopy with the central frequency of 120 MHz. The visco-elasticity and surface sebum level of the observed region were measured by established testing devices. Both sebaceous glands density and surface sebum level were higher in cheek than those in forearm. The viscosity of forearm was lower than that of cheek. These results suggest that sebaceous glands may act as cushions of the skin besides their classical role of secreting sebum and some hormones. High frequency ultrasound imaging contributes to the evaluation of human skin aging.

  3. The fetal larynx and pharynx: structure and development on two- and three-dimensional ultrasound.

    PubMed

    Liberty, G; Boldes, R; Shen, O; Shaul, C; Cohen, S M; Yagel, S

    2013-08-01

    To present a systematic approach for evaluating the fetal pharynx and larynx based on two- and three-dimensional ultrasound (2D-US and 3D-US) modalities, describing the sonographic appearance and function of the fetal upper respiratory tract and measuring the anatomical components of the pharynx and larynx. Gravidae presenting from the late first trimester to mid-gestation for routine booked examinations with structurally normal singleton fetuses of confirmed gestational age were enrolled. Transabdominal 2D-US was performed for anatomical and functional evaluation of the pharynx and larynx. Color Doppler was used to show fluid motion in the target area. 3D-US (Voluson® E6 with RAB-4-8-D transducer) scans of the fetal neck were acquired during fetal quiescence and in the absence of movements of the pharynx and larynx. Multiplanar reconstruction (MPR) in post-processing allowed adjustment of the volume to obtain the coronal plane. After a learning period to understand the sonographic anatomy of the target area, we measured the pharynx width and height, the upper, middle and lower larynx width and the larynx height. Render mode was applied for spatial evaluation of the target area. We developed a new methodological approach for structured evaluation of the fetal pharynx and larynx based on five spatial planes: posterior and anterior coronal planes and high, mid and low axial planes. We examined 582 fetuses during the second trimester of pregnancy; target anatomy was imaged successfully in 218 patients at 11-24 gestational weeks. Acquisition added approximately 1 min to examination time. Rates of successful visualization and measurements increased significantly as pregnancy progressed, being 23% (46/194) at 11-13 weeks, 29% (69/240) at 14-16 weeks, 35% (18/51) at 17-19 weeks and 88% (85/97) at 20-24 weeks (P < 0.01). Pharynx components identified were: the sphenoid bone, pterygoid processes, constrictor muscles, piriform recesses and uvula. Larynx components

  4. Design and test of a PC-based portable three-dimensional ultrasound software system Ultra3D.

    PubMed

    Xu, X George; Hum Na, Yong; Zhang, Tiantian

    2008-02-01

    Currently, portable ultrasound units lack three-dimensional (3D) image display, limiting their potential usefulness especially under remote and hostile operating environments where information must be intuitive and objective. A freehand 3D image processing and visualization software package, Ultra3D, has been developed and tested, especially to work with a miniaturized linear-array transducer probe that is connected to a laptop PC. This paper presents the software design and method to integrate Ultra3D into Terason's miniaturized SmartProbe for freehand 3D ultrasound imaging. Since images generated by Ultra3D are in a digital imaging and communications in medicine (DICOM) format, data sharing with others is easy.

  5. Elasticity-based three dimensional ultrasound real-time volume rendering

    NASA Astrophysics Data System (ADS)

    Boctor, Emad M.; Matinfar, Mohammad; Ahmad, Omar; Rivaz, Hassan; Choti, Michael; Taylor, Russell H.

    2009-02-01

    Volumetric ultrasound imaging has not gained wide recognition, despite the availability of real-time 3D ultrasound scanners and the anticipated potential of 3D ultrasound imaging in diagnostic and interventional radiology. Their use, however, has been hindered by the lack of real-time visualization methods that are capable of producing high quality 3D rendering of the target/surface of interest. Volume rendering is a known visualization method, which can display clear surfaces out of the acquired volumetric data, and has an increasing number of applications utilizing CT and MRI data. The key element of any volume rendering pipeline is the ability to classify the target/surface of interest by setting an appropriate opacity function. Practical and successful real-time 3D ultrasound volume rendering can be achieved in Obstetrics and Angio applications where setting these opacity functions can be done rapidly, and reliably. Unfortunately, 3D ultrasound volume rendering of soft tissues is a challenging task due to the presence of significant amount of noise and speckle. Recently, several research groups have shown the feasibility of producing 3D elasticity volume from two consecutive 3D ultrasound scans. This report describes a novel volume rendering pipeline utilizing elasticity information. The basic idea is to compute B-mode voxel opacity from the rapidly calculated strain values, which can also be mixed with conventional gradient based opacity function. We have implemented the volume renderer using GPU unit, which gives an update rate of 40 volume/sec.

  6. Three-dimensional volume off-line analysis as compared to real-time ultrasound for assessing adnexal masses.

    PubMed

    Alcázar, Juan Luis; Iturra, Alberto; Sedda, Federica; Aubá, María; Ajossa, Silvia; Guerriero, Stefano; Jurado, Matías

    2012-03-01

    To assess the agreement between three-dimensional volume off-line analysis as compared to real-time ultrasound for assessing adnexal masses. Ninety-nine non-consecutive women diagnosed as having an adnexal mass were assessed by transvaginal power Doppler ultrasound. One single examiner performed all ultrasound examinations. Based on the examiner's subjective evaluation using gray scale and Doppler ultrasound findings a presumptive diagnosis (benign or malignant) was provided after real-time ultrasound was performed. Once real-time was done a 3D volume of the adnexal mass was acquired and stored by this examiner. Two examiners, unaware of the real-time ultrasound results, evaluated the 3D volumes using multiplanar display and virtual navigation and also had to provide a presumptive diagnosis (benign or malignant). These two examiners, like the first one, had information about patient's age, menopausal status and complaints. All women underwent surgery or were followed-up until cyst resolution. Histologic diagnosis was used as gold standard. Cysts that resolved spontaneously were considered as benign for analytical purposes. The Kappa index was used to assess the agreement between real time ultrasound and 3D volume analysis. Sensitivity and specificity of both methods were calculated and compared using McNemar test. Forty-one masses were malignant and 58 were benign. Agreement between real-time ultrasound and 3D volume analysis was good for both off-line examiners (Kappa index: 0.82, 95% CI: 0.70-0.93 and 0.78, 95% CI: 0.65-0.90). Sensitivities for real-time ultrasound and 3D volume analyses were 100%, 93% and 90%, respectively (p>0.05). Specificities for real-time ultrasound and 3D volume analyses were 91%, 84% and 86%, respectively (p>0.05). Off-line 3D volume analysis may be a useful method for assessing adnexal masses, showing a good agreement with real-time ultrasound and having a similar diagnostic performance. Copyright © 2011 Elsevier Ireland Ltd. All

  7. Developing High-Frequency Quantitative Ultrasound Techniques to Characterize Three-Dimensional Engineered Tissues

    NASA Astrophysics Data System (ADS)

    Mercado, Karla Patricia E.

    Tissue engineering holds great promise for the repair or replacement of native tissues and organs. Further advancements in the fabrication of functional engineered tissues are partly dependent on developing new and improved technologies to monitor the properties of engineered tissues volumetrically, quantitatively, noninvasively, and nondestructively over time. Currently, engineered tissues are evaluated during fabrication using histology, biochemical assays, and direct mechanical tests. However, these techniques destroy tissue samples and, therefore, lack the capability for real-time, longitudinal monitoring. The research reported in this thesis developed nondestructive, noninvasive approaches to characterize the structural, biological, and mechanical properties of 3-D engineered tissues using high-frequency quantitative ultrasound and elastography technologies. A quantitative ultrasound technique, using a system-independent parameter known as the integrated backscatter coefficient (IBC), was employed to visualize and quantify structural properties of engineered tissues. Specifically, the IBC was demonstrated to estimate cell concentration and quantitatively detect differences in the microstructure of 3-D collagen hydrogels. Additionally, the feasibility of an ultrasound elastography technique called Single Tracking Location Acoustic Radiation Force Impulse (STL-ARFI) imaging was demonstrated for estimating the shear moduli of 3-D engineered tissues. High-frequency ultrasound techniques can be easily integrated into sterile environments necessary for tissue engineering. Furthermore, these high-frequency quantitative ultrasound techniques can enable noninvasive, volumetric characterization of the structural, biological, and mechanical properties of engineered tissues during fabrication and post-implantation.

  8. Clinical benefits of combined diagnostic three-dimensional digital breast tomosynthesis and ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Varjonen, Mari; Pamilo, Martti; Raulisto, Leena

    2005-04-01

    Our goal is to evaluate diagnostic digital breast tomosynthesis and ultrasound imaging clinical value in detecting and diagnosing early stage breast cancers. Determine if fusion imaging would decrease the number of biopsies and reduce further patient workup otherwise required to establish a definitive diagnosis. This paper presents the clinical results based on the study conducted at Helsinki University Central Hospital. Presentation demonstrates clinical dual modality images and results. Tomosynthesis of amorphous selenium based full field digital mammography system will be also presented. Forty asymptomatic women enrolled in the study based on prior identification of suspicious findings on screening mammograms where the possibility of breast cancer could not be excluded. Abnormal screening mammogram findings included tumor-like densities, parenchymal asymmetries and architectural distortions. Eight women were operated and 32 were not referred for surgery. Those cases, which were operated, three lesions represented ductal carcinoma in situ, two ductal carcinomas, one atypical ductal hyperplasia, one fibroadenoma and one radial scar. The 32 not operated cases revealed to be benign or superimposition of normal parenchymal breast tissue. The cases were returned to biennial screening. Ultrasound did not show clearly any lesions, but using tomosynthesis and ultrasound together we were able to analyze and locate the lesions exactly. Special tomosynthesis improves overall lesion detection and analysis. The value of tomosynthesis and ultrasound fusion imaging will be to provide additional clinical information in order to improve decision making accuracy to either confirm or exclude a suspected abnormality and in particular detect small breast cancers.

  9. Quantification of Right and Left Ventricular Function With Real-Time Three-Dimensional Ultrasound

    DTIC Science & Technology

    2007-11-02

    But it is very delicate to increase the maximum number of iterations in every case since the septum wall that separates the two cavities very often...as the medial axis as developed by Pizer and Stetten [12]. V. CONCLUSION Quantification of RV and LV volumes with 2D ultrasound transducers is...the American Society of Echocardiography, vol. 14, pp. 275-284, 2001. [12] G. D. Stetten and S. M. Pizer, “ Medial -node models to identify and

  10. High-Frequency Focused Water-Coupled Ultrasound Used for Three-Dimensional Surface Depression Profiling

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    To interface with other solids, many surfaces are engineered via methods such as plating, coating, and machining to produce a functional surface ensuring successful end products. In addition, subsurface properties such as hardness, residual stress, deformation, chemical composition, and microstructure are often linked to surface characteristics. Surface topography, therefore, contains the signatures of the surface and possibly links to volumetric properties, and as a result serves as a vital link between surface design, manufacturing, and performance. Hence, surface topography can be used to diagnose, monitor, and control fabrication methods. At the NASA Glenn Research Center, the measurement of surface topography is important in developing high-temperature structural materials and for profiling the surface changes of materials during microgravity combustion experiments. A prior study demonstrated that focused air-coupled ultrasound at 1 MHz could profile surfaces with a 25-m depth resolution and a 400-m lateral resolution over a 1.4-mm depth range. In this work, we address the question of whether higher frequency focused water-coupled ultrasound can improve on these specifications. To this end, we employed 10- and 25-MHz focused ultrasonic transducers in the water-coupled mode. The surface profile results seen in this investigation for 25-MHz water-coupled ultrasound, in comparison to those for 1-MHz air-coupled ultrasound, represent an 8 times improvement in depth resolution (3 vs. 25 m seen in practice), an improvement of at least 2 times in lateral resolution (180 vs. 400 m calculated and observed in practice), and an improvement in vertical depth range of 4 times (calculated).

  11. Registration of three-dimensional compound ultrasound scans of the breast for refraction and motion correction.

    PubMed

    Moskalik, A; Carson, P L; Meyer, C R; Fowlkes, J B; Rubin, J M; Roubidoux, M A

    1995-01-01

    Use of multiple look directions, that is, compound imaging, has been shown previously to increase detection of specular reflectors and averaging of speckle noise in gray-scale images, often at the expense of spatial resolution and other misregistration errors. In color flow imaging, additional view angles can fill in vessels missed due to Doppler angle dropout and increase quantitative and visual Doppler accuracy by triangulation or a simple peak-frequency-shift combination algorithm. Image registration and unwarping throughout multiple three-dimensional (3D) volume sets should correct for many refraction artifacts, motion between and during compounded image sets and even, possibly, positioning errors between image sets, acquired months apart, to display growth of abnormalities. The registration described here does not provide sufficient accuracy for formation of enhanced coherent apertures, but shows promise in some cases to provide superior compound images and possibly comparisons of current and prior studies. In this study, the breast is stabilized by mild compression between a flat plate and a scanning membrane. Registration and unwarping is performed retrospectively on two separate volumetric data sets by defining pairs of corresponding points and, in some cases, line and plane segments. Three-dimensional linear affine transforms are performed using identified points, lines and planes. 3D nonlinear warped transforms are also possible given adequate numbers of identifiable points. More than two data sets are registered by selecting one as the standard, and registering the remainder to match. The most appropriate algorithm, such as averaging or maximum amplitude, may be used to combine the data sets for display. Significant success has been achieved in compound display of a test object and of the breast in vivo, even when there was relative motion or warping between image sets. In pulse-echo imaging, homologous feature registration for compounding appears to

  12. Assessment of murine colorectal cancer by micro-ultrasound using three dimensional reconstruction and non-linear contrast imaging

    PubMed Central

    Freeling, Jessica L; Rezvani, Khosrow

    2016-01-01

    The relatively low success rates of current colorectal cancer (CRC) therapies have led investigators to search for more specific treatments. Vertebrate models of colorectal cancer are essential tools for the verification of new therapeutic avenues such as gene therapy. The evaluation of colorectal cancer in mouse models has been limited due to the lack of an accurate quantitative and longitudinal noninvasive method. This work introduces a method of three-dimensional micro-ultrasound reconstruction and microbubble administration for the comprehensive and longitudinal evaluation of CRC progression. This approach enabled quantification of both tumor volume and relative vascularity using a well-established inducible murine model of colon carcinogenesis. This inducible model recapitulated the adenocarcinoma sequence that occurs in human CRC allowing systematic in situ evaluation of the ultrasound technique. The administration of intravenous microbubbles facilitated enhancement of colon vascular contrast and quantification of relative vascularity of the mid and distal colon of the mouse in three dimensions. In addition, two-dimensional imaging in the sagittal orientation of the colon using Non-Linear Contrast Mode enabled calculation of relative blood volume and perfusion as the microbubbles entered the colon microvasculature. Quantitative results provided by the outlined protocol represent a noninvasive tool that can more accurately define CRC development and progression. This ultrasound technique will allow the practical and economical longitudinal study of murine CRC in both basic and preclinical studies. PMID:28053998

  13. Effect of complex wavelet transform filter on thyroid tumor classification in three-dimensional ultrasound.

    PubMed

    Acharya, U Rajendra; Sree, S Vinitha; Swapna, G; Gupta, Savita; Molinari, Filippo; Garberoglio, R; Witkowska, Agnieszka; Suri, Jasjit S

    2013-03-01

    Ultrasonography has great potential in differentiating malignant thyroid nodules from the benign ones. However, visual interpretation is limited by interobserver variability, and further, the speckle distribution poses a challenge during the classification process. This article thus presents an automated system for tumor classification in three-dimensional contrast-enhanced ultrasonography data sets. The system first processes the contrast-enhanced ultrasonography images using complex wavelet transform-based filter to mitigate the effect of speckle noise. The higher order spectra features are then extracted and used as input for training and testing a fuzzy classifier. In the off-line training system, higher order spectra features are extracted from a set of images known as the training images. These higher order spectra features along with the clinically assigned ground truth are used to train the classifier and obtain an estimate of the classifier or training parameters. The ground truth tells the class label of the image (i.e. whether the image belongs to a benign or malignant nodule). During the online testing phase, the estimated classifier parameters are applied on the higher order spectra features that are extracted from the testing images to predict their class labels. The predicted class labels are compared with their corresponding original ground truth to evaluate the performance of the classifier. Without utilizing the complex wavelet transform filter, the fuzzy classifier demonstrated an accuracy of 91.6%, while utilizing the complex wavelet transform filter, the accuracy significantly boosted to 99.1%.

  14. Image analysis of placental issues using three-dimensional ultrasound and color power Doppler based on Support Vector Machine

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Xu, Diyun; Liu, Jianguo

    2009-10-01

    With the development of medical science, three-dimensional ultrasound and color power Doppler tomography shooting placenta is widely used. To determine whether the fetus's development is abnormal or not is mainly through the analysis of the capillary's distribution of the obtained images which are shot by the Doppler scanner. In this classification process, we will adopt Support Vector Machine classifier. SVM achieves substantial improvements over the statistical learning methods and behaves robustly over a variety of different learning tasks. Furthermore, it is fully automatic, eliminating the need for manual parameter tuning and can solve the small sample problem wonderfully well. So SVM classifier is valid and reliable in the identification of placentas and is more accurate with the lower error rate.

  15. Three-dimensional power Doppler ultrasound diagnosis and laparoscopic management of a pregancy in a previous cesarean scar.

    PubMed

    Wang, Chin-Jung; Yuen, Leung-To; Yen, Chih-Feng; Lee, Chyi-Long; Soong, Yung-Kuei

    2004-12-01

    An ectopic pregnancy developing in a previous Cesarean section scar is a rare event, and there is still a lack of information concerning the adequacy of management strategies. So far, no modality can guarantee the integrity of the uterus. We report the case of a 29-year-old woman with three Cesarean deliveries who was transferred to our hospital with a diagnosis of cervical pregnancy. Transvaginal three-dimensional power Doppler ultrasound revealed a well-encapsulated bulging mass displacing anteriorly over the lower anterior uterine wall sounding with an irregular course and branching vessels. The diagnosis of pregnancy in a previous Cesarean scar was made. Laparoscopic ligation of bilateral uterine arteries followed by excision of the ectopic pregnant mass was undertaken, and the patient's uterus was successfully preserved. Conservative management with the laparoscopic approach may be a safe and effective alternative to hysterectomy in patients with a pregnacy in a previous Cesarean scar.

  16. Visualization of Microvessels in Skin by Three-Dimensional Ultrasound Microscope

    NASA Astrophysics Data System (ADS)

    Saijo, Y.; Kobayashi, K.; Hozumi, N.; Tanaka, A.; Sakai, S.

    A non-invasive imaging technique capable of visualizing microvessels through epidermis to subdermis has been strongly desired. A PVDF ultrasonic transducer with the central frequency of 100 MHz and the focal length of 3.2 mm was mechanically scanned over the objects by two linear servo motors controlled by a personal computer. A microvessel model was made of a tungsten wire with a diameter of 100-microns and placed in the water tank. The microvessel model was clearly visualized by 3D ultrasound microscope. In cases of skin imaging, conventional echo gel was used as the coupling medium between transducer and skin surface. In vivo 3D skin morphology was also clearly visualized. In dermis, a microvessel may be shown as small, round, lucent echo areas continuously observed in the serial sections. 3D structure of hair-follicle was also visualized from the skin surface to the bud of hair-follicle in dermis. The 3D ultrasound microscope noninvasively provides important information on the distribution of microvessels in skin.

  17. Automatic three-dimensional reconstruction and characterization of articular cartilage from high-resolution ultrasound acquisitions.

    PubMed

    Lefebvre, F; Graillat, N; Cherin, E; Berger, G; Saïed, A

    1998-11-01

    Three-dimensional (3D) high-resolution ultrasonography has proved to be useful for in vitro assessment of cartilage remodeling due to osteoarthritis. The diagnosis is performed by computation of the mean thickness of the cartilage, which reveals hypertrophy or thinning, and by 3D reconstruction of the data, which provides essential information about the size, extent, and localization of the lesion. In both cases, preliminary segmention of the cartilage is necessary. This article proposes an algorithm for automatic segmentation of the cartilage from 3D ultrasonic acquisitions of the rat patella, which includes the detection of the cartilage surface and the cartilage/bone interface. The method was designed on the assumption of regularity and smoothness of the interfaces. The use of a global threshold was sufficient to separate the patella area from the background. The cartilage/bone interface was detected by selection of regions of interest (ROIs) encompassing the interface, followed by the detection of the interface within these ROIs using the graph theory. The method was applied to 162 samples. The detection accuracy was judged to be very good or good in 99% of the cases for the cartilage surface and in 86% of the cases for the cartilage/bone interface. The mean cartilage thickness value in the central part of the patella obtained from the automatic detection method was compared to that obtained manually. The coefficient of correlation between the two measurements was 0.92. These results show that our method is reliable. Thus, fast processing of a large number of acquisitions and a more complete analysis of the cartilage surface become possible.

  18. Differential strain patterns of the human Achilles tendon determined in vivo with freehand three-dimensional ultrasound imaging.

    PubMed

    Farris, Dominic James; Trewartha, Grant; McGuigan, M Polly; Lichtwark, Glen A

    2013-02-15

    The human Achilles tendon (AT) has often been considered to act as a single elastic structure in series with the muscles of the triceps surae. As such it has been commonly modelled as a Hookean spring of uniform stiffness. However, the free AT and the proximal AT have distinctly different structures that lend themselves to different elastic properties. This study aimed to use three-dimensional freehand ultrasound imaging to determine whether the proximal AT and the free AT exhibit different elastic behaviour during sub-maximal, fixed-end contractions of the triceps surae. Six male and five female participants (mean ± s.d. age=27 ± 5 years) performed fixed position contractions of the plantar-flexors on an isokinetic dynamometer at 50% of their maximum voluntary contraction in this position. Freehand three-dimensional ultrasound imaging was used to reconstruct the free-tendon and proximal AT at rest and during contraction. The free-tendon exhibited significantly (P=0.03) greater longitudinal strain (5.2 ± 1.7%) than the proximal AT (2.6 ± 2.0%). The lesser longitudinal strain of the proximal AT was linked to the fact that it exhibited considerable transverse (orthogonal to the longitudinal direction) strains (5.0 ± 4%). The transverse strain of the proximal AT is likely due to the triceps surae muscles bulging upon contraction, and thus the level of bulging may influence the elastic behaviour of the proximal AT. This might have implications for the understanding of triceps surae muscle-tendon interaction during locomotion, tendon injury mechanics and previous measurements of AT elastic properties.

  19. A new semi-automated method for fetal volume measurements with three-dimensional ultrasound: preliminary results.

    PubMed

    Smeets, Nicol A C; Dvinskikh, Natallia A; Winkens, Bjorn; Oei, S Guid

    2012-08-01

    Complications in pregnancy are suggested to be the result of intrauterine conditions in the first trimester of pregnancy. Three-dimensional ultrasound volume measurements might give more information, compared with two-dimensional measurements. Commonly available methods for volume measurements are not suited for daily practice. This is a report of preliminary results of a promising, more practical semi-automated method for volume calculations with three-dimensional ultrasound. Volume datasets of 16 objects (10.2-41.5 cm(3) ) were obtained. Euclidean shortening flow and Perona and Malik were used as image enhancement techniques. The image gradient was calculated. The points of interest were detected by the iso-intensity and the edge-detection technique. Volume measurements with Volume Computer-aided AnaLysis (VOCAL) are used as a reference. A volume dataset of a first trimester fetus was acquired to test this method in vivo. The mathematical calculations with iso-intensity (Perona and Malik: average= -1.57 cm(3) , SD=4.05; and Euclidean shortening flow: average= -1.38 cm(3) , SD=2.47) showed results comparable with the VOCAL method (average= +1.28 cm(3) , SD=2.07). We also succeeded in detecting all voxels in the whole contour of a 12-week fetus. Mathematical volume calculations are possible with the semi-automated method. We were able to apply this new method on a first trimester fetus. This new method is promising for future use in the daily practice. © 2012 John Wiley & Sons, Ltd.

  20. Volume reconstruction of freehand three-dimensional ultrasound using median filters.

    PubMed

    Huang, Qing-Hua; Zheng, Yong-Ping

    2008-07-01

    This paper aims to apply median filters for reducing interpolation error and improving the quality of 3D images in a freehand 3D ultrasound (US) system. Freehand 3D US imaging has been playing an important role in obtaining the entire 3D impression of tissues and organs. Reconstructing a sequence of irregularly located 2D US images (B-scans) into a 3D data set is one of the key procedures for visualization and data analysis. In this study, we investigated the feasibility of using median filters for the reconstruction of 3D images in a freehand 3D US system. The B-scans were collected using a 7.5 MHz ultrasound probe. Four algorithms including the standard median (SM), Gaussian weighted median (GWM) and two types of distance-weighted median (DWM) filters were proposed to filter noises and compute voxel intensities. Qualitative and quantitative comparisons were made among the results of different methods based on the image set captured in freehand from the forearm of a healthy subject. A leave-one-out approach was used to demonstrate the performance of the median filters for predicting the removed B-scan pixels. Compared with the voxel nearest-neighbourhood (VNN) and distance-weighted (DW) interpolation methods, the four median filters reduced the interpolation error by 8.0-24.0% and 1.2-21.8%, respectively, when 1/4 to 5 B-scans was removed from the raw B-scan sequence. In summary, the median filters can improve the quality of volume reconstruction by reducing the interpolation errors and facilitate the following image analyses in clinical applications.

  1. Dynamic Three-Dimensional Ultrasound to Evaluate Scapular Movement Among Manual Wheelchair Users and Healthy Controls

    PubMed Central

    Lin, Yen-Sheng; Koontz, Alicia M.; Boninger, Michael L.

    2015-01-01

    Background: A large percentage of individuals with spinal cord injury (SCI) report shoulder pain that can limit independence and quality of life. The pain is likely related to the demands placed on the shoulder by transfers and propulsion. Shoulder pathology has been linked to altered scapular mechanics; however, current methods to evaluate scapular movement are invasive, require ionizing radiation, are subject to skin-based motion artifacts, or require static postures. Objective: To investigate the feasibility of applying 3-dimensional ultrasound methods, previously used to look at scapular position in static postures, to evaluate dynamic scapular movement. Method: This study evaluated the feasibility of the novel application of a method combining 2-dimensional ultrasound and a motion capture system to determine 3-dimensional scapular position during dynamic arm elevation in the scapular plane with and without loading. Results: Incremental increases in scapular rotations were noted for extracted angles of 30°, 45°, 60°, and 75° of humeral elevation. Group differences were evaluated between a group of 16 manual wheelchair users (MWUs) and a group of age- and gender-matched able-bodied controls. MWUs had greater scapular external rotation and baseline pathology on clinical exam. MWUs also had greater anterior tilting, with this difference further accentuated during loading. The relationship between demographics and scapular positioning was also investigated, revealing that increased age, pathology on clinical exam, years since injury, and body mass index were correlated with scapular rotations associated with impingement (internal rotation, downward rotation, and anterior tilting). Conclusion: Individuals with SCI, as well as other populations who are susceptible to shoulder pathology, may benefit from the application of this imaging modality to quantitatively evaluate scapular positioning and effectively target therapeutic interventions. PMID:26689695

  2. Usefulness of three-dimensionally guided assessment of mitral stenosis using matrix-array ultrasound.

    PubMed

    Sebag, Igal A; Morgan, John G; Handschumacher, Mark D; Marshall, Jane E; Nesta, Francesca; Hung, Judy; Picard, Michael H; Levine, Robert A

    2005-10-15

    Two-dimensional (2-D) planimetry is limited by the technical demands, time, and observer variability required to locate the minimal orifice area, limiting the confident clinical reporting of mitral valve area (MVA). In 27 consecutive patients, MVA was determined independently by 2 observers using the conventional 2-D method and a new 3-D-guided method. Using a matrix-array probe, the valve was visualized in a long-axis view and a cursor steered to intersect the leaflet tips and provide a perpendicular short-axis plane viewed side-by-side. Two-dimensional and 3-D-guided methods allowed planimetry in 24 patients. Consistent with better orifice localization, 3-D guidance eliminated the overestimation of internal orifice diameters in the planimetered short-axis view relative to the limiting diameter defined by the long-axis view (for 3-D guidance, 0.73 +/- 0.20 vs 0.73 +/- 0.21 cm, p = 0.98, vs 0.90 +/- 0.27 cm in the 2-D short-axis view, p <0.01). Accordingly, mean values for the smallest orifice area by 3-D guidance were less than by 2-D imaging (1.4 +/- 0.5 vs 1.5 +/- 0.5 cm(2), p <0.01), changing the clinical severity classification in 11 of 24 patients (46%). The 2-D method also overestimated MVA relative to 3-D guidance compared with Doppler pressure halftime and (n = 6) Gorlin areas. Phantom studies verified no differences in resolution for the 2 acquisition modes. Three-dimensional guidance reduced intraobserver variability from 9.8% to 3.8% (SEE 0.14 to 0.06 cm(2), p <0.01) and interobserver variability from 10.6% to 6.1% (SEE 0.15 to 0.09 cm(2), p <0.02). In conclusion, matrix-array technology provides a feasible and highly reproducible direct 3-D-guided method for measuring the limiting mitral orifice area.

  3. Three-dimensional ultrasound-guided robotic needle placement: an experimental evaluation

    PubMed Central

    Boctor, Emad M.; Choti, Michael A.; Burdette, Everette C.; Webster III, Robert J.

    2014-01-01

    Background Clinical use of image-guided needle placement robots has lagged behind laboratory-demonstrated robotic capability. Bridging this gap requires reliable and easy-to-use robotic systems. Methods Our system for image-guided needle placement requires only simple, low-cost components and minimal, entirely off-line calibration. It rapidly aligns needles to planned entry paths using 3D ultrasound (US) reconstructed from freehand 2D scans. We compare system accuracy against clinical standard manual needle placement. Results The US-guided robotic system is significantly more accurate than single manual insertions. When several manual withdrawals and reinsertions are allowed, accuracy becomes equivalent. In ex vivo experiments, robotic repeatability was 1.56 mm, compared to 3.19 and 4.63 mm for two sets of manual insertions. In an in vivo experiment with heartbeat and respiratory effects, robotic system accuracy was 5.5 mm. Conclusions A 3D US-guided robot can eliminate error bias and reduce invasiveness (the number of insertions required) compared to manual needle insertion. Remaining future challenges include target motion compensation. PMID:18433079

  4. Three-Dimensional Strains in Human Posterior Sclera Using Ultrasound Speckle Tracking

    PubMed Central

    Pavlatos, Elias; Perez, Benjamin Cruz; Morris, Hugh J.; Chen, Hong; Palko, Joel R.; Pan, Xueliang; Weber, Paul A.; Hart, Richard T.; Liu, Jun

    2016-01-01

    Intraocular pressure (IOP) induced strains in the peripapillary sclera may play a role in glaucoma progression. Using inflation testing and ultrasound speckle tracking, the 3D strains in the peripapillary sclera were measured in nine human donor globes. Our results showed that the peripapillary sclera experienced through-thickness compression and meridional stretch during inflation, while minimal circumferential dilation was observed when IOP was increased from 10 to 19 mmHg. The maximum shear was primarily oriented in the through-thickness, meridional cross sections and had a magnitude slightly larger than the first principal strain. The tissue volume had minimal overall change, confirming near-incompressibility of the sclera. Substantial strain heterogeneity was present in the peripapillary region, with local high strain areas likely corresponding to structural heterogeneity caused by traversing blood vessels. These 3D strain characteristics provide new insights into the biomechanical responses of the peripapillary sclera during physiological increases of IOP. Future studies are needed to confirm these findings and investigate the role of these biomechanical characteristics in ocular diseases. PMID:26632258

  5. Three-dimensional modeling of the dynamics of therapeutic ultrasound contrast agents.

    PubMed

    Hsiao, Chao-Tsung; Lu, Xiaozhen; Chahine, Georges

    2010-12-01

    A 3-D thick-shell contrast agent dynamics model was developed by coupling a finite volume Navier-Stokes solver and a potential boundary element method flow solver to simulate the dynamics of thick-shelled contrast agents subjected to pressure waves. The 3-D model was validated using a spherical thick-shell model validated by experimental observations. We then used this model to study shell break-up during nonspherical deformations resulting from multiple contrast agent interaction or the presence of a nearby solid wall. Our simulations indicate that the thick viscous shell resists the contrast agent from forming a re-entrant jet, as normally observed for an air bubble oscillating near a solid wall. Instead, the shell thickness varies significantly from location to location during the dynamics, and this could lead to shell break-up caused by local shell thinning and stretching. Copyright © 2010 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  6. Volume measurement variability in three-dimensional high-frequency ultrasound images of murine liver metastases.

    PubMed

    Wirtzfeld, L A; Graham, K C; Groom, A C; Macdonald, I C; Chambers, A F; Fenster, A; Lacefield, J C

    2006-05-21

    The identification and quantification of tumour volume measurement variability is imperative for proper study design of longitudinal non-invasive imaging of pre-clinical mouse models of cancer. Measurement variability will dictate the minimum detectable volume change, which in turn influences the scheduling of imaging sessions and the interpretation of observed changes in tumour volume. In this paper, variability is quantified for tumour volume measurements from 3D high-frequency ultrasound images of murine liver metastases. Experimental B16F1 liver metastases were analysed in different size ranges including less than 1 mm3, 1-4 mm3, 4-8 mm3 and 8-70 mm3. The intra- and inter-observer repeatability was high over a large range of tumour volumes, but the coefficients of variation (COV) varied over the volume ranges. The minimum and maximum intra-observer COV were 4% and 14% for the 1-4 mm3 and <1 mm3 tumours, respectively. For tumour volumes measured by segmenting parallel planes, the maximum inter-slice distance that maintained acceptable measurement variability increased from 100 to 600 microm as tumour volume increased. Comparison of free breathing versus ventilated animals demonstrated that respiratory motion did not significantly change the measured volume. These results enable design of more efficient imaging studies by using the measured variability to estimate the time required to observe a significant change in tumour volume.

  7. A theoretical framework to three-dimensional ultrasound reconstruction from irregularly sampled data.

    PubMed

    San José-Estépar, Raúl; Martín-Fernández, Marcos; Caballero-Martínez, P Pablo; Alberola-López, Carlos; Ruiz-Alzola, Juan

    2003-02-01

    Several techniques have been described in the literature in recent years for the reconstruction of a regular volume out of a series of ultrasound (US) slices with arbitrary orientations, typically scanned by means of US freehand systems. However, a systematic approach to such a problem is still missing. This paper focuses on proposing a theoretical framework for the 3-D US volume reconstruction problem. We introduce a statistical method for the construction and trimming of the sampling grid where the reconstruction will be carried out. The results using in vivo US data demonstrate that the computed reconstruction grid that encloses the region-of-interest (ROI) is smaller than those obtained from other reconstruction methods in those cases where the scanning trajectory deviates from a pure straight line. In addition, an adaptive Gaussian interpolation technique is studied and compared with well-known interpolation methods that have been applied to the reconstruction problem in the past. We find that the proposed method numerically outperforms former proposals in several control studies; subjective visual results also support this conclusion and highlight some potential deficiencies of methods previously proposed.

  8. Three-Dimensional Transcranial Ultrasound Imaging of Microbubble Clouds Using a Sparse Hemispherical Array

    PubMed Central

    O'Reilly, Meaghan A.; Jones, Ryan M.; Hynynen, Kullervo

    2014-01-01

    There is an increasing interest in bubble-mediated focused ultrasound (FUS) interventions in the brain. However, current technology lacks the ability to spatially monitor the interaction of the microbubbles with the applied acoustic field, something which is critical for safe clinical translation of these treatments. Passive acoustic mapping could offer a means for spatially monitoring microbubble emissions that relate to bubble activity and associated bioeffects. In this study a hemispherical receiver array was integrated within an existing transcranial therapy array to create a device capable of both delivering therapy and monitoring the process via passive imaging of bubble clouds. A 128-element receiver array was constructed and characterized for varying bubble concentrations and source spacings. Initial in vivo feasibility testing was performed. The system was found to be capable of monitoring bubble emissions down to single bubble events through an ex vivo human skull. The lateral resolution of the system was found to be between 1.25-2 mm and the axial resolution between 2-3.5 mm, comparable to the resolution of MRI-based temperature monitoring during thermal FUS treatments in the brain. The results of initial in vivo experiments show that bubble activity can be mapped starting at pressure levels below the threshold for Blood-Brain barrier disruption. This study presents a feasible solution for imaging bubble activity during cavitation-mediated FUS treatments in the brain. PMID:24658252

  9. Needle path planning and steering in a three-dimensional non-static environment using two-dimensional ultrasound images

    PubMed Central

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

    2015-01-01

    Needle insertion is commonly performed in minimally invasive medical procedures such as biopsy and radiation cancer treatment. During such procedures, accurate needle tip placement is critical for correct diagnosis or successful treatment. Accurate placement of the needle tip inside tissue is challenging, especially when the target moves and anatomical obstacles must be avoided. We develop a needle steering system capable of autonomously and accurately guiding a steerable needle using two-dimensional (2D) ultrasound images. The needle is steered to a moving target while avoiding moving obstacles in a three-dimensional (3D) non-static environment. Using a 2D ultrasound imaging device, our system accurately tracks the needle tip motion in 3D space in order to estimate the tip pose. The needle tip pose is used by a rapidly exploring random tree-based motion planner to compute a feasible needle path to the target. The motion planner is sufficiently fast such that replanning can be performed repeatedly in a closed-loop manner. This enables the system to correct for perturbations in needle motion, and movement in obstacle and target locations. Our needle steering experiments in a soft-tissue phantom achieves maximum targeting errors of 0.86 ± 0.35 mm (without obstacles) and 2.16 ± 0.88 mm (with a moving obstacle). PMID:26279600

  10. Needle path planning and steering in a three-dimensional non-static environment using two-dimensional ultrasound images.

    PubMed

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

    2014-09-01

    Needle insertion is commonly performed in minimally invasive medical procedures such as biopsy and radiation cancer treatment. During such procedures, accurate needle tip placement is critical for correct diagnosis or successful treatment. Accurate placement of the needle tip inside tissue is challenging, especially when the target moves and anatomical obstacles must be avoided. We develop a needle steering system capable of autonomously and accurately guiding a steerable needle using two-dimensional (2D) ultrasound images. The needle is steered to a moving target while avoiding moving obstacles in a three-dimensional (3D) non-static environment. Using a 2D ultrasound imaging device, our system accurately tracks the needle tip motion in 3D space in order to estimate the tip pose. The needle tip pose is used by a rapidly exploring random tree-based motion planner to compute a feasible needle path to the target. The motion planner is sufficiently fast such that replanning can be performed repeatedly in a closed-loop manner. This enables the system to correct for perturbations in needle motion, and movement in obstacle and target locations. Our needle steering experiments in a soft-tissue phantom achieves maximum targeting errors of 0.86 ± 0.35 mm (without obstacles) and 2.16 ± 0.88 mm (with a moving obstacle).

  11. Three-dimensional carotid ultrasound segmentation variability dependence on signal difference and boundary orientation.

    PubMed

    Chiu, Bernard; Krasinski, Adam; Spence, J David; Parraga, Grace; Fenster, Aaron

    2010-01-01

    Quantitative measurements of the progression (or regression) of carotid plaque burden are important in monitoring patients and evaluating new treatment options. We previously developed a quantitative metric to analyze changes in carotid plaque morphology from 3-D ultrasound (US) on a point-by-point basis. This method requires multiple segmentations of the arterial wall and lumen boundaries to obtain the local standard deviation (SD) of vessel-wall-plus-plaque thickness (VWT) so that t-tests could be used to determine whether a change in VWT is statistically significant. However, the requirement for multiple segmentations makes clinical trials laborious and time-consuming. Therefore, this study was designed to establish the relationship between local segmentation SD and local signal difference on the arterial wall and lumen boundaries. We propose metrics to quantify segmentation SD and signal difference on a point-by-point basis, and studied whether the signal difference at arterial wall or lumen boundaries could be used to predict local segmentation SD. The ability to predict the local segmentation SD could eliminate the need of repeated segmentations of a 2-D transverse image to obtain the local segmentation standard deviation, thereby making clinical trials less laborious and saving time. Six subjects involved in this study were associated with different degrees of atherosclerosis: three carotid stenosis subjects with mean plaque area >3 cm(2) and >60% carotid stenosis were involved in a clinical study evaluating the effect of atorvastatin, a cholesterol-lowering and plaque-stabilizing drug; and three subjects with carotid plaque area >0.5 cm(2) were subjects with moderate atherosclerosis. Our results suggest that when local signal difference is higher than 8 greyscale value (GSV), the local segmentation SD stabilizes at 0.05 mm and is thus predictable. This information provides a target value of local signal difference on the arterial boundaries that should be

  12. Three-dimensional transvaginal tomographic ultrasound imaging for cervical cancer staging.

    PubMed

    Han, Xue-Song; Ning, Chun-Ping; Sun, Li-Tao; Li, Xiao-Ying; Peng, Yan-Qing; Dang, Mei-Zheng

    2015-09-01

    The objective of this study was to investigate the feasibility of using 3-D transvaginal tomographic ultrasound imaging (TUI) to stage patients with cervical carcinoma. Eighty women with cervical cancer who underwent transvaginal TUI examinations were enrolled. In all patients, cancer was confirmed pre-operatively by pathologic examination. Staging on the basis of clinical features, ultrasonography and magnetic resonance imaging was performed according to the International Federation of Gynecology and Obstetrics (FIGO) staging system. Clinical, TUI and magnetic resonance imaging staging was compared with that based on histology. Depth of invasion into the stroma was measured by TUI in 52 cases and compared with pathologic results. An interclass correlation coefficient was used to analyze reproducibility. In total, all 80 patients underwent surgical treatment. The accuracy of pre-operative staging, compared with histologic findings, was 92.50% for TUI, 82.50% for magnetic resonance imaging and 78.75% for clinical examination. The mean depth of lesions as measured with TUI was 12.5 ± 6.2 mm (range: 3.5-40.0 mm), and that measured on histology was 10.5 ± 8.0 mm (range: 3.0-40.0 mm). The interclass correlation coefficient of the two methods was 0.933 (95% confidence interval: 0.887-0.961). Pre-operative TUI is promising as a method for pre-operative staging of cervical carcinomas. TUI can also reliably assess lesion depth. Copyright © 2015. Published by Elsevier Inc.

  13. Quantitative Three-Dimensional Ultrasound Analysis of Tongue Protrusion, Grooving and Symmetry: Data from 12 Normal Speakers and a Partial Glossectomee

    ERIC Educational Resources Information Center

    Bressmann, Tim; Thind, Parveen; Uy, Catherine; Bollig, Carmen; Gilbert, Ralph W.; Irish, Jonathan C.

    2005-01-01

    The functional determinants for a good speech outcome after a partial tongue resection and reconstruction are not well established. The purpose of the present study was to assess the protrusion, grooving and symmetry of the tongue during sustained speech sound production using three-dimensional ultrasound. The participants were twelve normal…

  14. Quantitative Three-Dimensional Ultrasound Analysis of Tongue Protrusion, Grooving and Symmetry: Data from 12 Normal Speakers and a Partial Glossectomee

    ERIC Educational Resources Information Center

    Bressmann, Tim; Thind, Parveen; Uy, Catherine; Bollig, Carmen; Gilbert, Ralph W.; Irish, Jonathan C.

    2005-01-01

    The functional determinants for a good speech outcome after a partial tongue resection and reconstruction are not well established. The purpose of the present study was to assess the protrusion, grooving and symmetry of the tongue during sustained speech sound production using three-dimensional ultrasound. The participants were twelve normal…

  15. A clinical validation study for the feasibility and reliability of three-dimensional ultrasound-ultrasound automatic image registration.

    PubMed

    Su, Zhongzhen; Li, Kai; Xu, Erjiao; Wu, Lili; Wang, Xiaoli; Li, Liujun; Wang, Jue; Lin, Peijie; Chen, Yinan; Zhang, Yuan; Li, Junbo; Dufour, Cecile; Mory, Benoit; Zheng, Rongqin

    2015-01-01

    The purpose of our study was to assess the feasibility and reliability of 3D ultrasound-ultrasound (US-US) automatic registration-based analysis of the hepatic vessel tree (VT) (3D VT-based automatic registration) in clinical applications. A total of 70 pairs of 3D ultrasound data were acquired from the livers of 10 healthy volunteers enrolled in the study. An automatic registration method was applied to the acquired volumetric data pairs, and anatomic landmarks were picked by an experienced sonographer as 'ground truth'. The influences of respiration phase, subject posture, and liver lobe on data acquisition and scan volumetric angle on the registration accuracy and robustness were investigated. The registration time, success rate, median registration error distance, and sonographer's subjective feedback were assessed. The time required for the 3D VT-based automatic registration was approximately 15∼20 s. Overall, the success rate for the hepatic vessel-based registration was 71% (50/70), and the median registration error distance was 1.72 mm (0.57∼4.71 mm). When the influential factors were well controlled, the optimal registration accuracy (median registration error distance = 1.22 mm) could be obtained with an excellent success rate of 100% (10/10). According to the subjective assessment of the sonographer, over 90% (45/50) of the automatic registration results were not inferior to the ground truth. Among them, 42% (21/50) were superior to the fusion results from the ground truth. The results suggest that the 3D VT-based automatic registration is feasible and reliable and has potential for guidance and evaluation of intraoperative ablation of hepatocellular carcinoma.

  16. Evaluation of a three-dimensional ultrasound localisation system incorporating probe pressure correction for use in partial breast irradiation.

    PubMed

    Harris, E J; Symonds-Taylor, R; Treece, G M; Gee, A H; Prager, R W; Brabants, P; Evans, P M

    2009-10-01

    This work evaluates a three-dimensional (3D) freehand ultrasound-based localisation system with new probe pressure correction for use in partial breast irradiation. Accuracy and precision of absolute position measurement was measured as a function of imaging depth (ID), object depth, scanning direction and time using a water phantom containing crossed wires. To quantify the improvement in accuracy due to pressure correction, 3D scans of a breast phantom containing ball bearings were obtained with and without pressure. Ball bearing displacements were then measured with and without pressure correction. Using a single scan direction (for all imaging depths), the mean error was <1.3 mm, with the exception of the wires at 68.5 mm imaged with an ID of 85 mm, which gave a mean error of -2.3 mm. Precision was greater than 1 mm for any single scan direction. For multiple scan directions, precision was within 1.7 mm. Probe pressure corrections of between 0 mm and 2.2 mm have been observed for pressure displacements of 1.1 mm to 4.2 mm. Overall, anteroposterior position measurement accuracy increased from 2.2 mm to 1.6 mm and to 1.4 mm for the two opposing scanning directions. Precision is comparable to that reported for other commercially available ultrasound localisation systems, provided that 3D image acquisition is performed in the same scan direction. The existing temporal calibration is imperfect and a "per installation" calibration would further improve the accuracy and precision. Probe pressure correction was shown to improve the accuracy and will be useful for the localisation of the excision cavity in partial breast radiotherapy.

  17. Prediction of abortion using three-dimensional ultrasound volumetry of the gestational sac and the amniotic sac in threatened abortion.

    PubMed

    Odeh, Marwan; Ophir, Ella; Grinin, Vitaly; Tendler, Rene; Kais, Mohamad; Bornstein, Jacob

    2012-09-01

    To determine whether gestational sac volume (GSV) or amniotic sac volume (ASV) and/or the difference between them can predict abortion in women with first-trimester threatened abortion. Ninety patients between 6 and 12 weeks of gestation presenting with vaginal bleeding were studied. Seventy-six delivered after 24 weeks of gestation (group A) and 14 aborted before 20 weeks of gestation (group B). All patients had a singleton viable pregnancy demonstrated by transvaginal ultrasound. Gestational sac and amniotic sac volumes were measured in all the patients using three-dimensional transvaginal ultrasound with Virtual Organ Computer-aided Analysis software, and the gestational sac volume - amniotic sac volume (GSV - ASV) was calculated. The groups did not differ in terms of age, parity, number of previous abortions, or term deliveries. The GSV (group A: mean 32.0 ± 27.7 cm(3) ; group B: 26.7 ± 29.1 cm(3) ) and the ASV (group A: 21.1 ± 25.5 cm(3) ; group B: 20.6 ± 26.0 cm(3) ) were not statistically different, while the GSV - ASV was significantly smaller in group B (aborting before week 20) (group A: 10.9 ± 10.9 cm(3) ; group B: 6.1 ± 8.6 cm(3) ; p < 0.05). Using receiver operator curves, the area under the curve for predicting normal pregnancy outcome of the GSV - ASV measurement was 0.654. When the GSV - ASV was 1.8 cm(3) or less, abortion was predicted with 84% sensitivity and 43% specificity. The measurement of the GSV and the ASV are not good predictors of abortion in patients with first-trimester vaginal bleeding, whereas the use of the GSV - ASV may be helpful in predicting the outcome of pregnancy. Copyright © 2012 Wiley Periodicals, Inc.

  18. Incorporating texture features in a computer-aided breast lesion diagnosis system for automated three-dimensional breast ultrasound

    PubMed Central

    Liu, Haixia; Tan, Tao; van Zelst, Jan; Mann, Ritse; Karssemeijer, Nico; Platel, Bram

    2014-01-01

    Abstract. We investigated the benefits of incorporating texture features into an existing computer-aided diagnosis (CAD) system for classifying benign and malignant lesions in automated three-dimensional breast ultrasound images. The existing system takes into account 11 different features, describing different lesion properties; however, it does not include texture features. In this work, we expand the system by including texture features based on local binary patterns, gray level co-occurrence matrices, and Gabor filters computed from each lesion to be diagnosed. To deal with the resulting large number of features, we proposed a combination of feature-oriented classifiers combining each group of texture features into a single likelihood, resulting in three additional features used for the final classification. The classification was performed using support vector machine classifiers, and the evaluation was done with 10-fold cross validation on a dataset containing 424 lesions (239 benign and 185 malignant lesions). We compared the classification performance of the CAD system with and without texture features. The area under the receiver operating characteristic curve increased from 0.90 to 0.91 after adding texture features (p<0.001). PMID:26158036

  19. Distributed three-dimensional simulation of B-mode ultrasound imaging using a first-order k-space method.

    PubMed

    Daoud, Mohammad I; Lacefield, James C

    2009-09-07

    Computational modeling is an important tool in ultrasound imaging research, but realistic three-dimensional (3D) simulations can exceed the capabilities of serial computers. This paper uses a 3D simulator based on a k-space method that incorporates relaxation absorption and nonreflecting boundary conditions. The simulator, which runs on computer clusters, computes the propagation of a single wavefront. In this paper, an allocation algorithm is introduced to assign each scan line to a group of nodes and use multiple groups to compute independent lines concurrently. The computational complexity required for realistic simulations is analyzed using example calculations of ultrasonic propagation and attenuation in the 30-50 MHz band. Parallel efficiency for B-mode imaging simulations is evaluated for various numbers of scan lines and cluster nodes. An aperture-projection technique is introduced to simulate imaging with a focused transducer using reduced computation grids. This technique is employed to synthesize B-mode images that show realistic 3D refraction artifacts. Parallel computing using 20 nodes to compute groups of ten scan lines concurrently reduced the execution time for each image to 18.6 h, compared to a serial execution time of 357.5 h. The results demonstrate that fully 3D imaging simulations are practical using contemporary computing technology.

  20. [Development of software for three-dimensional reconstruction and automatic quantification of intravascular ultrasound images. Initial experience].

    PubMed

    Sanz, Roberto; Bodí, Vicente; Sanchís, Juan; Moratal, David; Núñez, Julio; Palau, Patricia; García, Diego; Rieta, José J; Sanchís, Juan M; Chorro, Francisco J; Llácer, Angel

    2006-09-01

    Quantification of intravascular ultrasound (IVUS) images is essential in ischemic heart disease and interventional cardiology. Manual analysis is very slow and expensive. We describe an automated computerized method of analysis that requires only minimal initial input from a specialist. This study was carried out by interventional cardiologists and biomedical engineers working in close collaboration. We developed software in which it was necessary only to identify the media-adventitia boundary in a few images taken from the whole sequence. A three-dimensional reconstruction was then generated from each sequence, from which measurements of areas and volumes could be derived automatically. In total, 2300 randomly selected images from video sequences of 11 patients were analyzed. Results obtained using the proposed method differed only minimally from those obtained with the manual method: for vessel area measurements, the variability was 0.08 (0.07) (mean absolute error [standard deviation] normalized to the actual value; this corresponds to an error of 0.08 mm(2) per mm(2) of vessel area); for lumen area, 0.11 (0.11) (normalized), and for plaque volume, 0.5 (0.3) (normalized). Regions with severe lesions (<4 mm(2)) were correctly identified in more than 90% of cases. Specialist time needed for each reconstruction was 10 (8) minutes (vs 60 [10] minutes for manual analysis; P< .0001). The computerized method used dramatically reduced the time and effort needed for IVUS sequence analysis, and the automated measurements obtained were very promising.

  1. The effect of ultrasound stimulation on the cytoskeletal organization of chondrocytes seeded in three-dimensional matrices.

    PubMed

    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 three-dimensional (3D) scaffolds was evaluated. Chondrocytes seeded on 3D chitosan matrices were exposed to LIDUS at 5.0 MHz (approx. 15 kPa, 51 s, 4 applications/day) in order to study the organization of actin, tubulin and vimentin. The results showed that actin presented a punctate cytosolic distribution and tubulin presented a quasiparallel 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 Rho-activated kinase (ROCK) inhibitor (Y27632). The gene expression of ROCK-I, a key element in the formation of stress fibers and mDia1, was significantly upregulated 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 punctate actin upon US stimulation was accompanied by the upregulation of the RhoA/ROCK pathway.

  2. Incorporating texture features in a computer-aided breast lesion diagnosis system for automated three-dimensional breast ultrasound.

    PubMed

    Liu, Haixia; Tan, Tao; van Zelst, Jan; Mann, Ritse; Karssemeijer, Nico; Platel, Bram

    2014-07-01

    We investigated the benefits of incorporating texture features into an existing computer-aided diagnosis (CAD) system for classifying benign and malignant lesions in automated three-dimensional breast ultrasound images. The existing system takes into account 11 different features, describing different lesion properties; however, it does not include texture features. In this work, we expand the system by including texture features based on local binary patterns, gray level co-occurrence matrices, and Gabor filters computed from each lesion to be diagnosed. To deal with the resulting large number of features, we proposed a combination of feature-oriented classifiers combining each group of texture features into a single likelihood, resulting in three additional features used for the final classification. The classification was performed using support vector machine classifiers, and the evaluation was done with 10-fold cross validation on a dataset containing 424 lesions (239 benign and 185 malignant lesions). We compared the classification performance of the CAD system with and without texture features. The area under the receiver operating characteristic curve increased from 0.90 to 0.91 after adding texture features ([Formula: see text]).

  3. Intra-cycle variation of the uterine cavity indentation assessed with three-dimensional ultrasound in natural and stimulated cycles.

    PubMed

    Saravelos, Sotirios H; Li, Tin-Chiu

    2016-05-01

    The recent ESHRE-ESGE classification for female genital anomalies attempts to promote objectivity in diagnosis of normal and septate uteri. The aim of this study was to ascertain whether the uterine cavity indentation - the characteristic feature of septate uteri - varies significantly throughout the cycle. Seventy consecutive women underwent three-dimensional ultrasound twice: 35 during the proliferative and luteal phase of a natural cycle, and 35 during the first and final day of a stimulated cycle. Endometrial thickness, interostial distance, cavity indentation and percentage of cavity indentation were all assessed in accordance with the ESHRE-ESGE consensus on diagnosis of female genital anomalies. Overall, throughout both cycles, there was a significant increase in endometrial thickness (from 4.6 mm to 10.2 mm; P < 0.001) and interostial distance (from 30.1 mm to 35.1 mm; P < 0.001), which was associated with a significant reduction in the percentage of cavity indentation (from 30.3% to 15.0%; P < 0.001). Between the first and second assessment, 3/70 (4.3%) patients had a change in diagnosis from septate to normal uterus, although this did not reach statistical significance. This observation of a significant intra-cycle variation of the uterine cavity indentation has important implications for both clinical practice and research.

  4. Three-dimensional ultrasound of the pelvic floor 2 days after first delivery: influence of constitutional and obstetric factors.

    PubMed

    Falkert, A; Endress, E; Weigl, M; Seelbach-Göbel, B

    2010-05-01

    Morphological changes of the pelvic floor during pregnancy and delivery can be visualized by three-dimensional (3D) perineal ultrasound. The aim of this study was to compare biometric measurements of the levator ani muscle according to maternal constitutional factors, delivery mode and size of the baby immediately after the first delivery. In this prospective observational study, 130 primiparae were recruited (all of them Caucasians with singleton pregnancy and cephalic presentation). A 3D perineal ultrasound scan was performed on the second day after delivery with standardized settings. Volumes were obtained at rest and on Valsalva maneuver, and biometric measurements of the levator hiatus were determined in the axial plane. Different obstetric and constitutional parameters were obtained from our clinical files. All biometric measurements of the levator hiatus were significantly greater in the vaginal delivery group than in the Cesarean section group (P < 0.001), whereas subgroup analysis within the vaginal (spontaneous vs. operative vaginal) and Cesarean (primary vs. secondary) delivery groups did not show statistically significant differences. There was no demonstrable influence of maternal constitutional factors (age, body mass index (BMI)) or different obstetric parameters (length of second stage of labor, episiotomy, maternal injuries) on levator hiatus size postpartum, even in subgroups that delivered vaginally. Women with de novo postpartum stress incontinence showed a significantly higher mean levator hiatus transverse diameter and larger hiatal area on Valsalva maneuver (P < 0.05). There was also a positive but very weak correlation between the newborn's head circumference and hiatal dimensions at Valsalva maneuver (P < 0.05). Pelvic floor imaging by 3D ultrasound is easily accessible even on the first days after delivery and can provide useful information on morphological changes of the levator ani muscle. In our study, women with vaginal or operative

  5. Intra- and inter-observer variability of uterine measurements with three-dimensional ultrasound and implications for clinical practice.

    PubMed

    Saravelos, Sotirios H; Li, Tin-Chiu

    2015-10-01

    Despite the emergence of new classifications, the best way to measure and differentiate between the most common congenital uterine anomalies remains debatable. The aim of this study was to test the intra- and inter-observer variability of the different three-dimensional ultrasound (3DUS) uterine measurements described to date. Twenty consecutive women underwent 3DUS in a standardized manner. Two observers analysed each volume three times to assess the interostial distance, indentation distance, indentation angle, percentage of indentation, fundal wall thickness, and lateral wall thickness. Intra- and inter-class correlation coefficients (intra- and inter-CC), limits of agreement (LOA) and repeatability coefficients were estimated. For observers 1 and 2, the intra-observer reproducibility was the lowest for the left lateral wall thickness (intra-CC 0.91 [LOA -6.54 to 7.10] and 0.58 [LOA -6.58 to 6.94], respectively) and right lateral wall thickness (intra-CC 0.92 [LOA -5.68 to 4.74] and 0.56 [LOA -6.79 to 5.59], respectively). The inter-observer reproducibility was also the lowest for both these measurements (inter-CC 0.74 [LOA -4.01 to 6.09] and 0.72 [LOA -3.33 to 5.83], respectively). The remaining measurements showed high levels of intra- and inter-observer reproducibility (intra- and inter-CC ≥0.95). It is evident that not all uterine measurements are equally reproducible on 3DUS. Copyright © 2015 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  6. Functional morphology of anal sphincter complex unveiled by high definition anal manometery and three dimensional ultrasound imaging.

    PubMed

    Raizada, V; Bhargava, V; Karsten, A; Mittal, R K

    2011-11-01

    Anal sphincter complex consists of anatomically overlapping internal anal sphincter (IAS), external anal sphincter (EAS) and puborectalis muscle (PRM). We determined the functional morphology of anal sphincter muscles using high definition anal manometery (HDAM), three dimensional (3D)-ultrasound (US) and Magnetic resonance (MR) imaging. We studied 15 nulliparous women. High definition anal manometery probe equipped with 256 pressure transducers was used to measure the anal canal pressures at rest and squeeze. Lengths of IAS, PRM, and EAS were determined from the 3D-US images and superimposed on the HDAM plots. Movements of anorectal angle with squeeze were determined from the dynamic MR images. High definition anal manometery plots reveal that anal canal pressures are highly asymmetric in the axial and circumferential direction. Anal canal length determined by the 3D-US images is slightly smaller than that measured by HDAM. The EAS (1.9 ± 0.5 cm long) and PRM (1.7 ± 0.4 cm long) surround distal and proximal parts of the anal canal, respectively. With voluntary contraction, anal canal pressures increase in the proximal (PRM) and distal (EAS zone) parts of anal canal. Posterior peak pressure in the anal canal moves cranially in relation to the anterior peak pressure, with squeeze. Similar to the movement of peak posterior pressure, MR images show cranial movement of anorectal angle with squeeze. Our study proves that the PRM is responsible for the closure of the cranial part of anal canal. HDAM, in addition to measuring constrictor function can also record the elevator function of levator ani/pelvic floor muscles. © 2011 Blackwell Publishing Ltd.

  7. Three-dimensional nonrigid landmark-based magnetic resonance to transrectal ultrasound registration for image-guided prostate biopsy.

    PubMed

    Sun, Yue; Qiu, Wu; Yuan, Jing; Romagnoli, Cesare; Fenster, Aaron

    2015-04-01

    Registration of three-dimensional (3-D) magnetic resonance (MR) to 3-D transrectal ultrasound (TRUS) prostate images is an important step in the planning and guidance of 3-D TRUS guided prostate biopsy. In order to accurately and efficiently perform the registration, a nonrigid landmark-based registration method is required to account for the different deformations of the prostate when using these two modalities. We describe a nonrigid landmark-based method for registration of 3-D TRUS to MR prostate images. The landmark-based registration method first makes use of an initial rigid registration of 3-D MR to 3-D TRUS images using six manually placed approximately corresponding landmarks in each image. Following manual initialization, the two prostate surfaces are segmented from 3-D MR and TRUS images and then nonrigidly registered using the following steps: (1) rotationally reslicing corresponding segmented prostate surfaces from both 3-D MR and TRUS images around a specified axis, (2) an approach to find point correspondences on the surfaces of the segmented surfaces, and (3) deformation of the surface of the prostate in the MR image to match the surface of the prostate in the 3-D TRUS image and the interior using a thin-plate spline algorithm. The registration accuracy was evaluated using 17 patient prostate MR and 3-D TRUS images by measuring the target registration error (TRE). Experimental results showed that the proposed method yielded an overall mean TRE of [Formula: see text] for the rigid registration and [Formula: see text] for the nonrigid registration, which is favorably comparable to a clinical requirement for an error of less than 2.5 mm. A landmark-based nonrigid 3-D MR-TRUS registration approach is proposed, which takes into account the correspondences on the prostate surface, inside the prostate, as well as the centroid of the prostate. Experimental results indicate that the proposed method yields clinically sufficient accuracy.

  8. Clinical utility of contrast-enhanced three-dimensional ultrasound imaging with Sonazoid: findings on hepatocellular carcinoma lesions.

    PubMed

    Luo, Wen; Numata, Kazushi; Morimoto, Manabu; Nozaki, Akito; Nagano, Yasuhiko; Sugimori, Kazuya; Zhou, Xiaodong; Tanaka, Katsuaki

    2009-12-01

    We investigated clinical utility of contrast-enhanced three-dimensional ultrasound (CE 3D US) imaging with contrast medium Sonazoid for demonstrating characteristic enhancement of hepatocellular carcinoma (HCC). Among 115 focal liver tumors undergoing CE 3D US imaging, 70 HCCs confirmed with contrast-enhanced multi-detector computed tomography, contrast-enhanced magnetic resonance imaging or histopathologic examination were retrospectively analyzed. CE 3D US imaging was performed using Autosweep 3D scan functionality in the early, middle and late phase, after bolus injection of 0.2 ml Sonazoid. The CE 3D tomographic images reconstructed in parallel slices and sonographic angiogram images were independently reviewed by two reviewers. Kappa values were used to assess inter-reviewers' agreement. TUI images showed most of HCCs were detected with intratumoral vessels and early tumor enhancement in the early phase, expressed homogenous or heterogeneous tumor enhancement in the middle phase, and became hypoechoic or isoechoic in the late phase. The kappa values in the early, middle and late phase for inter-reviewer agreements regarding the characteristic enhancement of tumors were 0.817, 0.774, and 0.785. In addition, TUI images demonstrated satellite foci and tortuous tumor vessels in three orthogonal planes. Sonographic angiogram reconstructed by different rendering modes showed the vessels and tumor stain in spatial view. The spatial configuration of anatomic structures was revealed on basis of both TUI and sonographic angiogram images. CE 3D US imaging, with spatial visualization, is clinically useful to exhibit the characteristic enhancement of HCC tumors objectively.

  9. Impact of three-dimensional endoanal ultrasound on the outcome of anal fistula surgery: a prospective cohort study.

    PubMed

    Ding, J-H; Bi, L-X; Zhao, K; Feng, Y-Y; Zhu, J; Zhang, B; Yin, S-H; Zhao, Y-J

    2015-12-01

    The aim of the study was to evaluate the impact of three-dimensional endoanal ultrasound (3D-EAUS) on postoperative outcome in patients with anal fistula. This prospective study compared clinical and functional outcomes of patients with and without preoperative 3D-EAUS examination 1 year after anal fistula surgery. Patients were prospectively followed and evaluated by a standardized protocol including physical examination, the Wexner Incontinence Score (WIS) and anorectal manometry, at baseline and 1 year after surgery. A total of 196 patients were enrolled. There were no significant differences in demographic and operative parameters, except for operation time, between the two groups. At 1 year follow-up, the overall recurrence rates were 8.8% (9/102) in the 3D-EAUS group and 13.8% (13/94) in the examination under anaesthesia (EUA) group. In the subgroup of patients with complex fistulae, the recurrence rate was numerically lower in the 3D-EAUS group (12.8% vs 22.5%; P = 0.26). The WIS in the EUA group significantly worsened (0.35 ± 0.94 vs 1.07 ± 1.59; P = 0.003) with a decreased the number of fully continent patients (82.5% vs 55%; P = 0.008) while neither the WIS nor the proportion of fully continent patients changed in the 3D-EAUS group. Fewer patients in the 3D-EAUS group developed incontinence postoperatively (6.7% vs 33.3%; P = 0.012) and they had better maximum resting pressure and maximum squeeze pressure than the EUA group. Preoperative use of 3D-EAUS had a favourable impact on the outcome of surgical treatment for anal fistulae, especially in those with complex anal fistula. It should be routinely used in the clinical setting. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

  10. Role of three-dimensional endoanal ultrasound in assessing the anal sphincter morphology of female patients with chronic proctalgia.

    PubMed

    Xue, Ya-Hong; Ding, Shu-Qing; Ding, Yi-Jiang; Pan, Li-Qun

    2017-06-07

    To assess the role of three-dimensional endoanal ultrasound (3D-EAUS) for morphological assessment of the anal sphincter of female patients with chronic proctalgia (CP). In this unmatched case control study, 30 consecutive female patients with CP and 25 normal women (control group) were enrolled. 3D-EAUS was performed in all subjects. Thickness and length of internal anal sphincter (IAS), thickness of puborectalis muscle (PR), length of the external anal sphincter (EAS) plus PR, and puborectalis angle were measured and compared between the two groups. Patients with CP had significantly shorter IAS length and greater PR thickness, as compared to those in normal individuals (26.28 ± 3.59 mm vs 28.87 ± 4.84 mm, P < 0.05 and 9.67 ± 1.57 mm vs 8.85 ± 0.97 mm, P < 0.05, respectively). No significant between-group differences were observed with respect to IAS thickness and the EAS plus PR length (P > 0.05). Puborectalis angle in the CP group was significantly decreased, both in resting (88.23° ± 1.81° vs 89.94° ± 2.07° in control group, P < 0.05) and straining (88.47° ± 3.32° vs 90.72° ± 1.87° in control group, P < 0.05) phases, which suggest the presence of paradoxical contraction of PR in patients with CP. In the CP group, no significant difference in puborectalis angle was observed between the resting and straining phases (88.23° ± 1.81° vs 88.47° ± 3.32° respectively, P > 0.05). The association of greater PR thickness and paradoxical contraction of PR with CP suggest their potential value as markers of CP.

  11. Transperineal three-dimensional ultrasound imaging for detection of anatomic defects in the anal sphincter complex muscles.

    PubMed

    Weinstein, Milena M; Pretorius, Dolores H; Jung, Sung-Ai; Nager, Charles W; Mittal, Ravinder K

    2009-02-01

    Three-dimensional ultrasound (3D-US) imaging is a powerful tool to visualize various components of the anal sphincter complex, that is, the internal anal sphincter (IAS), the external anal sphincter (EAS), and the puborectalis muscle (PRM). Our goal was to determine the reliability of the 3D-US imaging technique in detecting morphologic defects in the IAS, EAS, and PRM. Transperineal 3D-US images were obtained in 3 groups of women: nulliparous (n = 13), asymptomatic parous (n = 20), and patients with fecal incontinence (FI) (n = 25). The IAS and EAS were assessed to determine the craniocaudal length of defects and were scored as follows: 0 = normal, 1 = less than 25%, 2 = 25% to 50%, 3 = 50% to 75%, and 4 = greater than 75%. The 2 PRM hemislings were scored separately as follows: 0 = normal, 1 = less than 50% abnormal, and 2 = greater than 50% length abnormal. Subjects were grouped according to the score as follows: normal (score 0), minor abnormality (scores of 1 and 2), and major abnormality (scores of 3 and 4). Three observers performed the scoring. The 3D-US allowed detailed evaluation of the IAS, EAS, and PRM. The inter-rater reliability for detecting the defects ranged between 0.80 and 0.95. Nullipara women did not show any significant defect but the defects were quite common in asymptomatic parous and FI patients. The prevalence of defects was greater in the FI patients as compared with the asymptomatic parous women. 3D-US yields reliable assessment of morphologic defects in the anal sphincter complex muscles.

  12. Comparison between three-dimensional angiographic reconstruction and intravascular ultrasound: imaging of the left main coronary artery.

    PubMed

    Spoon, Daniel B; Rubinshtein, Ronen; Psaltis, Peter J; Sandhu, Gupreet S; Lennon, Ryan; Rihal, Charanjit S; Lerman, Amir

    2013-06-01

    The purpose of this study was to evaluate the left main (LM) coronary artery anatomy using three-dimensional (3D) quantitative coronary angiography (QCA) software as compared to intravascular ultrasound (IVUS). Percutaneous intervention of the LM coronary artery is becoming more common in selected patients with LM coronary artery disease (CAD). Quantification of LM CAD by conventional angiography can be difficult. IVUS is considered the gold standard to evaluate LM anatomy and severity of CAD but entails additional steps, catheters, and expertise. Our objective was to compare a novel quantitative angiographic analysis system with IVUS for LM anatomy. Fifty five patients underwent both coronary angiography and IVUS of the LM. LM measurements were analyzed with 3D QCA (IC-PRO, Paieon, Israel) software using IVUS as the reference standard. The measurements included proximal, middle, distal minimal luminal diameter (MLD) and area. Additionally, lesion MLD, minimal luminal area were recorded by both systems. Bland-Altman plots were used to investigate agreement between the two imaging systems. Of the 55 patients in our cohort, average age was 66 ± 11 years (25% female). By Bland-Altman analysis there was very good agreement between 3D QCA and IVUS for measures of MLD and minimal lumen area (MLA). However, there was poor concordance in the estimation of plaque burden between the two methods. Our data demonstrate that 3D QCA software has fair agreement when compared with IVUS for imaging of LM MLD and MLA. These results suggest that 3D QCA could potentially be helpful to guide intervention of the LM. Copyright © 2012 Wiley Periodicals, Inc.

  13. An Assessment of Fetal Cerebral and Hepatic Perfusion in Normal Pregnancy and Pre-Eclampsia Using Three-Dimensional Ultrasound

    PubMed Central

    Addley, Susan; Ali, Amanda

    2017-01-01

    Background Pre-eclampsia and placental causes of intrauterine growth restriction (IUGR) are part of the same spectrum of disorders. In IUGR, there is preferential shunting of blood to the fetal brain at the expense of other organs. We wanted to demonstrate that this also occurs in pre-eclampsia using three dimensional (3D) ultrasound. The 3D indices of perfusion are: flow index (FI), vascular index (VI) and vascularisation flow index (VFI) which reflect tissue vascularity and flow intensity. Methods Fourteen normal pregnant women and 14 with diagnosed pre-eclampsia were recruited. Scanning was conducted by 2 observers using a Voluson E8 machine. Perfusion was measured at a pre-defined position within the fetal brain and fetal liver. The power Doppler signals were quantified using the ‘histogram facility’ to generate 3 indices of vascularity: FI, VI and VFI. The unpaired t-test was used to compare differences between groups. The hypothesis was that fetal brain FI, VI and VFI would be similar between women with normal pregnancy and women with pre-eclampsia, but measurements would be reduced in the fetal liver in women with pre-eclampsia. Results Maternal characteristics of age, body mass index and gestation were not different between groups. The depth of insonnation did not differ between groups. Fetal cerebral perfusion was not different between women with a normal pregnancy compared to women with pre-eclampsia. The mean (SD) for FI was 22.4 (5.7) vs. 21.1 (4.3) respectively (p=0.49). For VI, the mean (SD) was as 64.7 (40.4) vs. 79.1 (27.4) respectively (p=0.28). For VFI, the mean (SD) was 14.8 (10.3) vs. 16.1 (5.5) respectively (p = 0.66). Fetal hepatic perfusion was not different between women with a normal pregnancy compared to women with pre-eclampsia. The mean (SD) for FI was 34.4 (19.9) vs. 27.8 (11.0) respectively (p = 0.28). For VI, mean (SD) was 67.6 (36.0) vs. 87.3 (25.8) respectively (p=0.11). For VFI, the mean (SD) was 19.6 (11.6) vs. 23.1 (10

  14. A three dimensional model of an ultrasound contrast agent gas bubble and its mechanical effects on microvessels

    PubMed Central

    Hosseinkhah, N.; Hynynen, K.

    2012-01-01

    Ultrasound contrast agents inside a microvessel, when driven by ultrasound, oscillate and induce mechanical stresses on the vessel wall. These mechanical stresses can produce beneficial therapeutic effects but also induce vessel rupture if the stresses are too high. Therefore, it is important to use sufficiently low pressure amplitudes to avoid rupturing the vessels while still inducing the desired therapeutic effects. In this work, we developed a comprehensive three dimensional model of a confined microbubble inside a vessel while considering the bubble shell properties, blood viscosity, vessel wall curvature and the mechanical properties of the vessel wall. Two bubble models with the assumption of a spherical symmetric bubble and a simple asymmetrical bubble were simulated. This work was validated with previous experimental results and enabled us to evaluate the microbubbles’ behaviour and the resulting mechanical stresses induced on the vessel walls. In this study the fluid shear and circumferential stresses were evaluated as indicators of the mechanical stresses. The effects of acoustical parameters, vessel viscoelasticity and rigidity, vessel/bubble size and off-center bubbles on bubble behaviour and stresses on the vessel were investigated. The fluid shear and circumferential stresses acting on the vessel varied with time and location. As the frequency changed, the microbubble oscillated with the highest amplitude at its resonance frequency which was different from the resonance frequency of an unbound bubble. The bubble resonance frequency increased as the rigidity of a flexible vessel increased. The fluid shear and circumferential stresses peaked at frequencies above the bubble’s resonance frequency. The more rigid the vessels were, the more damped the bubble oscillations. The synergistic effect of acoustic frequency and vessel elasticity had also been investigated, since the circumferential stress showed either an increasing trend or a decreasing one

  15. Evaluation of two-dimensional and three-dimensional ultrasound in the assessment of thyroid volume of the Indo-Pacific bottlenose dolphin (Tursiops aduncus).

    PubMed

    Kot, Brian C W; Ying, Michael T C; Brook, Fiona M; Kinoshita, Reimi E

    2012-03-01

    The assessment of thyroid volume plays an indispensable role in the diagnosis and management of different thyroid diseases. The present study evaluates the accuracy of dolphin thyroid volume measurement as determined by four two-dimensional (2D) ultrasound methods (A-D), with a standard of reference using three-dimensional (3D) ultrasound. The measurement accuracy for different recognized thyroid configuration is also evaluated. Inter- and intraoperator variability of the measurement methods was determined. Thyroid ultrasound examinations were conducted in 16 apparently healthy Indo-Pacific bottlenose dolphins (Tursiops aduncus) with 2D and 3D ultrasound under identical scanning conditions. All 2D ultrasound measurement methods yielded high accuracies (79.9-81.3%) when compared with the 3D ultrasound measurement, and had high measurement reproducibility (77.6-86.2%) and repeatability (78.1-99.7%). For 2D ultrasound measurements, Methods A and B were more accurate and reliable than Methods C and D, regardless of thyroid configuration. Ultrasound is useful in the measurement of thyroid volume in bottlenose dolphins. For the first time, a reliable ultrasound scanning protocol for measuring dolphin thyroid volume was developed, which provides a means to establish a normative reference for the diagnosis of thyroid pathologies and to monitor the thyroid volume during the course of treatment in living dolphins. Key words: 3D ultrasound, Indo-Pacific bottlenose dolphin, thyroid volume measurement, Tursiops aduncus.

  16. Assessment of visual quality and spatial accuracy of fast anisotropic diffusion and scan conversion algorithms for real-time three-dimensional spherical ultrasound

    NASA Astrophysics Data System (ADS)

    Duan, Qi; Angelini, Elsa D.; Laine, Andrew

    2004-04-01

    Three-dimensional ultrasound machines based on matrix phased-array transducers are gaining predominance for real-time dynamic screening in cardiac and obstetric practice. These transducers array acquire three-dimensional data in spherical coordinates along lines tiled in azimuth and elevation angles at incremental depth. This study aims at evaluating fast filtering and scan conversion algorithms applied in the spherical domain prior to visualization into Cartesian coordinates for visual quality and spatial measurement accuracy. Fast 3d scan conversion algorithms were implemented and with different order interpolation kernels. Downsizing and smoothing of sampling artifacts were integrated in the scan conversion process. In addition, a denoising scheme for spherical coordinate data with 3d anisotropic diffusion was implemented and applied prior to scan conversion to improve image quality. Reconstruction results under different parameter settings, such as different interpolation kernels, scaling factor, smoothing options, and denoising, are reported. Image quality was evaluated on several data sets via visual inspections and measurements of cylinder objects dimensions. Error measurements of the cylinder's radius, reported in this paper, show that the proposed fast scan conversion algorithm can correctly reconstruct three-dimensional ultrasound in Cartesian coordinates under tuned parameter settings. Denoising via three-dimensional anisotropic diffusion was able to greatly improve the quality of resampled data without affecting the accuracy of spatial information after the modification of the introduction of a variable gradient threshold parameter.

  17. Sirenomelia: a review on embryogenic enviromental theories, novel three-dimensional ultrasound imaging and first trimester diagnosis in a case of mosaic 69,XXX/46,XX fetus.

    PubMed

    Tonni, Gabriele; Gabriele, Tonni; Grisolia, Gianpaolo; Gianpaolo, Grisolia

    2013-07-01

    Sirenomelia is caused by atrophy of the lower extremities that is commonly associated with gastrointestinal and urogenital malformations. Embryogenic environmental theories and systematic review of the literature are reported. Genetic basis of the condition has been demonstrated in the animal model. In humans, association with de novo balanced translocation has only recently been documented. A case of triploidy mosaic fetus with sirenomelia and posterior fossa anomaly diagnosed at first trimester using novel three-dimensional ultrasound imaging techniques is presented.

  18. Three-dimensional ultrasound image-guided robotic system for accurate microwave coagulation of malignant liver tumours.

    PubMed

    Xu, Jing; Jia, Zhen-zhong; Song, Zhang-jun; Yang, Xiang-dong; Chen, Ken; Liang, Ping

    2010-09-01

    The further application of conventional ultrasound (US) image-guided microwave (MW) ablation of liver cancer is often limited by two-dimensional (2D) imaging, inaccurate needle placement and the resulting skill requirement. The three-dimensional (3D) image-guided robotic-assisted system provides an appealing alternative option, enabling the physician to perform consistent, accurate therapy with improved treatment effectiveness. Our robotic system is constructed by integrating an imaging module, a needle-driven robot, a MW thermal field simulation module, and surgical navigation software in a practical and user-friendly manner. The robot executes precise needle placement based on the 3D model reconstructed from freehand-tracked 2D B-scans. A qualitative slice guidance method for fine registration is introduced to reduce the placement error caused by target motion. By incorporating the 3D MW specific absorption rate (SAR) model into the heat transfer equation, the MW thermal field simulation module determines the MW power level and the coagulation time for improved ablation therapy. Two types of wrists are developed for the robot: a 'remote centre of motion' (RCM) wrist and a non-RCM wrist, which is preferred in real applications. The needle placement accuracies were < 3 mm for both wrists in the mechanical phantom experiment. The target accuracy for the robot with the RCM wrist was improved to 1.6 +/- 1.0 mm when real-time 2D US feedback was used in the artificial-tissue phantom experiment. By using the slice guidance method, the robot with the non-RCM wrist achieved accuracy of 1.8 +/- 0.9 mm in the ex vivo experiment; even target motion was introduced. In the thermal field experiment, a 5.6% relative mean error was observed between the experimental coagulated neurosis volume and the simulation result. The proposed robotic system holds promise to enhance the clinical performance of percutaneous MW ablation of malignant liver tumours. Copyright 2010 John Wiley

  19. Three-dimensional nonrigid landmark-based magnetic resonance to transrectal ultrasound registration for image-guided prostate biopsy

    PubMed Central

    Sun, Yue; Qiu, Wu; Yuan, Jing; Romagnoli, Cesare; Fenster, Aaron

    2015-01-01

    Abstract. Registration of three-dimensional (3-D) magnetic resonance (MR) to 3-D transrectal ultrasound (TRUS) prostate images is an important step in the planning and guidance of 3-D TRUS guided prostate biopsy. In order to accurately and efficiently perform the registration, a nonrigid landmark-based registration method is required to account for the different deformations of the prostate when using these two modalities. We describe a nonrigid landmark-based method for registration of 3-D TRUS to MR prostate images. The landmark-based registration method first makes use of an initial rigid registration of 3-D MR to 3-D TRUS images using six manually placed approximately corresponding landmarks in each image. Following manual initialization, the two prostate surfaces are segmented from 3-D MR and TRUS images and then nonrigidly registered using the following steps: (1) rotationally reslicing corresponding segmented prostate surfaces from both 3-D MR and TRUS images around a specified axis, (2) an approach to find point correspondences on the surfaces of the segmented surfaces, and (3) deformation of the surface of the prostate in the MR image to match the surface of the prostate in the 3-D TRUS image and the interior using a thin-plate spline algorithm. The registration accuracy was evaluated using 17 patient prostate MR and 3-D TRUS images by measuring the target registration error (TRE). Experimental results showed that the proposed method yielded an overall mean TRE of 3.50±1.34  mm for the rigid registration and 2.24±0.71  mm for the nonrigid registration, which is favorably comparable to a clinical requirement for an error of less than 2.5 mm. A landmark-based nonrigid 3-D MR-TRUS registration approach is proposed, which takes into account the correspondences on the prostate surface, inside the prostate, as well as the centroid of the prostate. Experimental results indicate that the proposed method yields clinically sufficient accuracy. PMID

  20. Level of agreement between three-dimensional volumetric ultrasound and real-time conventional ultrasound in the assessment of synovitis, tenosynovitis and erosions in rheumatoid arthritis patients.

    PubMed

    Acebes, Carlos; McKay, Neil; Ciechomska, Anna; Alcorn, Nicola; Harvie, John P; Robson, Barbara; Groenendijk, Nico; McDonald, Moira; Wilson, Alison; Garrido, Jesus

    2017-02-01

    The aim of the study was to assess agreement between three-dimensional volumetric ultrasound (3D US) performed by inexperienced staff and real-time conventional ultrasound (2D US) performed by experienced rheumatologists in detecting and scoring rheumatoid arthritis (RA) lesions. Thirty-one RA patients underwent examination of seven joints by 2D and 3D US for synovitis and tenosynovitis in B and PD modes and erosions in B mode. A global score for synovitis and global counts for synovitis, tenosynovitis and erosions were also calculated for every patient. Agreement between 2D and 3D US was analysed for counts and scores at the patient level with the intraclass correlation coefficient (ICC) and for counts at the joint level with Cohen's kappa coefficient. B-mode synovitis was detected at a median of five joints in each patient, frequently in wrists and hand joints but less frequently in foot joints. PD-mode synovitis, tenosynovitis and erosions were detected less frequently. All ICCs for agreement between 2D and 3D US findings were significant. All kappa coefficients were significant for B- and PD-mode synovitis and for erosions (except PIP3), while those for tenosynovitis were only significant for MCP2 (B and PD modes) and PIP2 (B mode). Although the 3D US volumes were acquired by inexperienced operators, agreement between 2D and 3D US was acceptable in detecting and scoring synovitis. A higher level of agreement was attained for patient-level global scores and counts than for individual joints.

  1. Spatial-temporal three-dimensional ultrasound plane-by-plane active cavitation mapping for high-intensity focused ultrasound in free field and pulsatile flow.

    PubMed

    Ding, Ting; Hu, Hong; Bai, Chen; Guo, Shifang; Yang, Miao; Wang, Supin; Wan, Mingxi

    2016-07-01

    Cavitation plays important roles in almost all high-intensity focused ultrasound (HIFU) applications. However, current two-dimensional (2D) cavitation mapping could only provide cavitation activity in one plane. This study proposed a three-dimensional (3D) ultrasound plane-by-plane active cavitation mapping (3D-UPACM) for HIFU in free field and pulsatile flow. The acquisition of channel-domain raw radio-frequency (RF) data in 3D space was performed by sequential plane-by-plane 2D ultrafast active cavitation mapping. Between two adjacent unit locations, there was a waiting time to make cavitation nuclei distribution of the liquid back to the original state. The 3D cavitation map equivalent to the one detected at one time and over the entire volume could be reconstructed by Marching Cube algorithm. Minimum variance (MV) adaptive beamforming was combined with coherence factor (CF) weighting (MVCF) or compressive sensing (CS) method (MVCS) to process the raw RF data for improved beamforming or more rapid data processing. The feasibility of 3D-UPACM was demonstrated in tap-water and a phantom vessel with pulsatile flow. The time interval between temporal evolutions of cavitation bubble cloud could be several microseconds. MVCF beamformer had a signal-to-noise ratio (SNR) at 14.17dB higher, lateral and axial resolution at 2.88times and 1.88times, respectively, which were compared with those of B-mode active cavitation mapping. MVCS beamformer had only 14.94% time penalty of that of MVCF beamformer. This 3D-UPACM technique employs the linear array of a current ultrasound diagnosis system rather than a 2D array transducer to decrease the cost of the instrument. Moreover, although the application is limited by the requirement for a gassy fluid medium or a constant supply of new cavitation nuclei that allows replenishment of nuclei between HIFU exposures, this technique may exhibit a useful tool in 3D cavitation mapping for HIFU with high speed, precision and resolution

  2. Agreement of two-dimensional and three-dimensional transvaginal ultrasound with magnetic resonance imaging in assessment of parametrial infiltration in cervical cancer.

    PubMed

    Chiappa, V; Di Legge, A; Valentini, A L; Gui, B; Miccò, M; Ludovisi, M; Giansiracusa, C; Testa, A C; Valentin, L

    2015-04-01

    To compare two-dimensional (2D) and three-dimensional (3D) transvaginal ultrasound with magnetic resonance imaging (MRI) as the gold standard in assessment of parametrial infiltration of cervical cancer and to determine if all parts of the cervix are equally assessable with ultrasound. Patients with macroscopically evident and histologically confirmed cervical cancer were staged using International Federation of Gynecology and Obstetrics (FIGO) criteria and underwent MRI and 2D and 3D ultrasound examination before treatment. When assessing parametrial infiltration with 3D ultrasound and MRI, the cervix was (virtually) divided into three cylinders (cranial, middle and caudal) of equal size and each cylinder was then divided into six sectors in a clockwise manner following a consensus between radiologists and ultrasound examiners. The presence and the extent of parametrial invasion were recorded for each sector. Results of 2D ultrasound, 3D ultrasound and MRI were compared and reported in terms of percentage agreement and kappa value. A total of 29 consecutive patients were included in the study. The percentage agreement between 2D ultrasound and MRI in assessing parametrial infiltration (yes or no) was 76% (kappa, 0.459) and that between 3D ultrasound and MRI was 79% (kappa, 0.508). The results of 2D ultrasound showed the following agreement with those of MRI: 90% for the ventral parametrium (kappa, 0.720), 72% for the right lateral parametrium (kappa, 0.494), 69% for the left lateral parametrium (kappa, 0.412) and 58.5% for the dorsal parametrium (kappa, 0.017). The results of 3D ultrasound showed the following agreement with those of MRI: 62.5% for the ventral parametrium (kappa, 0.176), 81% for the right lateral parametrium (kappa, 0.595), 70% for the left lateral parametrium (kappa, 0.326) and 52% for the dorsal parametrium (kappa, 0.132). The best agreement between 3D ultrasound and MRI was for the middle cervical cylinder (76%; kappa, 0.438) and the poorest

  3. Prenatal ultrasound and MRI Diagnosis of Jeune syndrome type I (asphyxiating thoracic dystrophy) with histology and post-mortem three-dimensional CT confirmation.

    PubMed

    Tonni, Gabriele; Panteghini, Marco; Bonasoni, Mariapaola; Pattacini, Pierpaolo; Ventura, Alessandro

    2013-04-01

    Asphyxiating thoracic dystrophy (ATD) also known as Jeune syndrome is a rare autosomal recessive multisystem disorder with an incidence estimated in 1:100.000-130.000 live births. Associated findings may include hepatic fibrosis and renal cysts. A prenatal ultrasound and MRI diagnosis performed in the early second-trimester of pregnancy is reported together with DNA analysis. Post-mortem diagnostic investigations such as radiograph and three-dimensional CT scan and histology have been useful in the final diagnosis of this rare skeletal dysplasia.

  4. Prenatal three-dimensional ultrasound and magnetic resonance imaging evaluation of a fetal oral tumor in preparation for the ex-utero intrapartum treatment (EXIT) procedure.

    PubMed

    Shih, J C; Hsu, W C; Chou, H C; Peng, S S; Chen, L K; Chang, Y L; Hsieh, F J

    2005-01-01

    Recent attempts at predelivery management of obstructed fetal airways have focused on the EXIT (ex-utero intrapartum treatment) procedure, which allows sufficient time to secure the fetal airway through preservation of uteroplacental gas exchange. We report a fetus with an exophytic oral tumor noted at 34 weeks of gestation. In this case, three-dimensional (3D) ultrasound allowed a complete and interactive evaluation of the tumor and related facial anatomy, and confirmed that access to the fetal airway was unlikely during delivery. Fetal magnetic resonance imaging (MRI) further demonstrated that the tumor originated in the nasopharynx and obstructed the upper airway. Both imaging results led to a final decision to offer an EXIT procedure for the neonate. At 36 weeks' gestation, a successful EXIT procedure was performed to reduce the risk of respiratory distress immediately after birth. This report highlights the value of 3D ultrasound and MRI as essential prerequisites for optimization of the triage process in selecting EXIT candidates.

  5. Design and Production of an Articulating Needle Guide for Ultrasound-Guided Needle Block Manufactured With a Three-Dimensional Printer: Technical Communication.

    PubMed

    Bigeleisen, Paul E

    2017-05-15

    Needle guides may allow the practitioner to align the needle with the probe when ultrasound-guided nerve block is performed. The author's goal was to design and fabricate an inexpensive ($1.90), disposable, needle guide that could articulate over a range from 85 degrees to 0 degrees with a three-dimension printer. Three-dimensional representations of an L50, L25, and C 60 ultrasound probe (Sono Site, Bothell, WA) were created using a laser scanner. Computer-aided design software (Solid Works, Waltham, MA) was used to design a needle bracket and needle guide to attach to these probes. A three-dimensional printer was used to fabricate the needle bracket and guide with acrylonitrile polybutadiene polystyrene. An echogenic needle was held in plane with the needle guide. The author performed a supraclavicular block in a morbidly obese patient. The needle was easily visualized. Similar guides that are commercially available cost as much as $400. A knowledge of computer-aided design is necessary for this work.

  6. A three-dimensional, extended field of view ultrasound method for estimating large strain mechanical properties of the cervix during pregnancy

    PubMed Central

    House, Michael; Feltovich, Helen; Hall, Timothy J; Stack, Trevor; Patel, Atur; Socrate, Simona

    2015-01-01

    Cervical shortening and cervical insufficiency contribute to a significant number of preterm births. However, the deformation mechanisms that control how the cervix changes its shape from long and closed to short and dilated are not clear. Investigation of the biomechanical problem is limited by 1) lack of thorough characterization of the three-dimensional anatomical changes associated with cervical deformation and 2) difficulty measuring cervical tissue properties in vivo. The objective of the present study was to explore the feasibility of using three-dimensional ultrasound and fundal pressure to obtain anatomically accurate numerical models of large-strain cervical deformation during pregnancy and enable non-invasive assessment of cervical tissue compliance. Healthy subjects (n=6) and one subject with acute cervical insufficiency in the midtrimester were studied. Extended field of view ultrasound images were obtained of the entire uterus and cervix. These images aided construction of anatomically accurate numerical models. Cervical loading was achieved with fundal pressure, which was quantified with a vaginal pressure catheter. In one subject, the anatomical response to fundal pressure was matched by a model-based simulation of the deformation response, thereby deriving the corresponding cervical mechanical properties and showing the feasibility of non-invasive assessment of compliance. The results of this pilot study demonstrate the feasibility of a biomechanical modeling framework for estimating cervical mechanical properties in vivo. An improved understanding of cervical biomechanical function will clarify the pathophysiology of cervical shortening. PMID:22655487

  7. Visualization and quantitation of fetal movements by real-time three-dimensional ultrasound with live xPlane imaging in the first trimester of pregnancy.

    PubMed

    Lu, Ye; Yang, Taizhu; Luo, Hong; Deng, Feng; Cai, Qianyun; Sun, Weiwei; Song, Hao

    2016-10-31

    To prove whether real-time three-dimensional (3D) ultrasound with live xPlane imaging is better in observing fetal movements than standard ultrasound imaging. 50 healthy women with singleton pregnancies (22-43 years old) at 11 to 14 weeks of gestation underwent real-time 3D ultrasound examination with live xPlane imaging from July 2014 to February 2015. The incidence and frequency of 10 fetal movement patterns in 10 minutes were evaluated, including general movements (GMs), isolated arm movements, isolated leg movements, hiccup, stretching, breathing, startle, jaw opening, isolated head retroflexion, and isolated head anteflexion. The correlation between gestational age and frequency of each fetal movement pattern was analyzed. GM had the highest incidence (100%), followed by startle (84%) and isolated arm movements (68%). Their median frequency was 5 (IQR 3-6), 5 (IQR 1.75-11.5), and 1 (IQR 0-2), respectively. GM (Z=5.875, P<0.001) and startle (Z=5.302, P<0.001) had significantly higher frequency than isolated arm movements. The other 7 fetal movement patterns had much lower incidence and frequency. The frequency of GM was positively correlated with gestational age (r=0.360, P=0.010). Real-time 3D ultrasound with live x Plane imaging was shown to be a feasible tool for observing fetal movements.

  8. Visualization and quantitation of fetal movements by real-time three-dimensional ultrasound with live xPlane imaging in the first trimester of pregnancy

    PubMed Central

    Lu, Ye; Yang, Taizhu; Luo, Hong; Deng, Feng; Cai, Qianyun; Sun, Weiwei; Song, Hao

    2016-01-01

    Aim To prove whether real-time three-dimensional (3D) ultrasound with live xPlane imaging is better in observing fetal movements than standard ultrasound imaging. Methods 50 healthy women with singleton pregnancies (22-43 years old) at 11 to 14 weeks of gestation underwent real-time 3D ultrasound examination with live xPlane imaging from July 2014 to February 2015. The incidence and frequency of 10 fetal movement patterns in 10 minutes were evaluated, including general movements (GMs), isolated arm movements, isolated leg movements, hiccup, stretching, breathing, startle, jaw opening, isolated head retroflexion, and isolated head anteflexion. The correlation between gestational age and frequency of each fetal movement pattern was analyzed. Results GM had the highest incidence (100%), followed by startle (84%) and isolated arm movements (68%). Their median frequency was 5 (IQR 3-6), 5 (IQR 1.75-11.5), and 1 (IQR 0-2), respectively. GM (Z = 5.875, P < 0.001) and startle (Z = 5.302, P < 0.001) had significantly higher frequency than isolated arm movements. The other 7 fetal movement patterns had much lower incidence and frequency. The frequency of GM was positively correlated with gestational age (r = 0.360, P = 0.010). Conclusion Real-time 3D ultrasound with live x Plane imaging was shown to be a feasible tool for observing fetal movements. PMID:27815938

  9. Image reconstruction and system optimization for three-dimensional speed of sound tomography using laser-induced ultrasound

    NASA Astrophysics Data System (ADS)

    Anis, Fatima; Su, Richard; Nadvoretsky, Vyacheslav V.; Conjusteau, André; Ermilov, Sergey A.; Oraevsky, Alexander A.; Anastasio, Mark A.

    2013-03-01

    We developed the first prototype of dual-modality imager combining optoacoustic tomography (OAT) and laser ultrasound tomography (UST) using computer models followed by experimental validation. The system designed for preclinical biomedical research can concurrently yield images depicting both the absorbed optical energy density and acoustic properties (speed of sound) of an object. In our design of the UST imager, we seek to replace conventional electrical generation of ultrasound waves by laser-induced ultrasound (LU). While earlier studies yielded encouraging results [Manohar, et al., Appl. Phys. Lett, 131911, 2007], they were limited to two-dimensional (2D) geometries. In this work, we conduct computer-simulation studies to investigate different designs for the 3D LU UST imager. The number and location of the laser ultrasound emitters, which are constrained to reside on the cylindrical surface opposite to the arc of detectors, are optimized. In addition to the system parameters, an iterative image reconstruction algorithm was optimized. We demonstrate that high quality volumetric maps of the speed of sound can be reconstructed when only 32 emitters and 128 receiving transducers are employed to record time-of-flight data at 360 tomographic view angles. The implications of the proposed system for small animal and breast-cancer imaging are discussed.

  10. The use of an online three-dimensional model improves performance in ultrasound scanning of the spine: a randomized trial.

    PubMed

    Niazi, Ahtsham U; Tait, Gordon; Carvalho, Jose C A; Chan, Vincent W

    2013-05-01

    The use of ultrasound for neuraxial blockade is a new application of technology that is rapidly becoming accepted as a standard of care. This new skill has shown to improve success, but it is a challenge to teach. To assist with teaching the use of ultrasound in regional anesthesia of the lumbar spine, we have developed an interactive educational model ( http://pie.med.utoronto.ca/vspine or http://www.usra.ca/vspine.php ). In this study, we aimed to determine whether use of this model for a two-week period would improve the performance of novice operators in determining defined landmarks during real-time ultrasound imaging of the lumbar spine. We evaluated the educational benefit of the ultrasound module by randomly assigning 16 postgraduate first-year (PGY1) anesthesia residents to either a control group with password-protected access to only the lumbar anatomy module or to an intervention group with access to the complete module. All residents had access to the module for two weeks following a full-day workshop that is part of the university teaching program which consists of a didactic lecture on ultrasound-facilitated neuraxial anesthesia, mentored teaching on cadaveric spine dissections, and hands-on ultrasound scanning of live models. At the end of the two weeks, the performance of the residents was evaluated using a 12-item task-specific checklist while carrying out a scout scan on a live model. The control group had a median score of 5.5 (25(th) percentile: 4, 75(th) percentile: 18), while the intervention group had a median score of 11.5 (25(th) percentile: 8, 75(th) percentile: 12) in the task-specific checklist, with a significant difference of 6 (confidence interval 1.5 to 10.5) between groups (P = 0.021). Our results show superior performance by the residents who had access to both components of the module, indicating that access to the interactive ultrasound spine module improves knowledge and skills prior to clinical care.

  11. Impact of mode of delivery on levator morphology: a prospective observational study with three-dimensional ultrasound early in the postpartum period.

    PubMed

    Albrich, S B; Laterza, R M; Skala, C; Salvatore, S; Koelbl, H; Naumann, G

    2012-01-01

    To evaluate morphology and integrity of the levator ani muscle (LAM) with three-dimensional ultrasound early in the postpartum period. Prospective cross-sectional observational study. University hospital in Germany. Women after vaginal delivery and caesarean section with no previous vaginal delivery. Three-dimensional perineal ultrasound was performed between 48 and 72 hours postpartum. The axial plane at the level of minimal hiatal dimension and tomographic ultrasound imaging were used to determine LAM biometry and defect. Primary outcome was to compare hiatal dimensions and levator defect following vaginal delivery or caesarean section. For secondary outcomes, we evaluated the role of caesarean section in protecting levator integrity, and the possible involvement of the first stage of labour in LAM changes. In all, 157 women participated: 81 (51.6%) following vaginal delivery (70 spontaneous and 11 operative deliveries) and 76 (48.4%) following caesarean section (55 elective and 21 emergency caesarean sections). All biometric indices of the levator were higher after vaginal delivery (P<0.001), except for LAM thickness. LAM defects were found to be significantly associated with vaginal delivery, with relative risk 7.5 (P<0.001). Following vaginal delivery, 32 (39.5%) levator defects were found: 27 (38.5%) after spontaneous delivery and five (45.4%) after operative delivery. Four (5.2%) women had a levator defect following emergency caesarean section. Vaginal delivery modifies and damages the LAM: the risk of levator defect after vaginal delivery is more than seven times higher than after caesarean section. Despite this, emergency caesarean section seems to have no complete preventive effect on LAM trauma. © 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.

  12. The feasibility of using 5D CNS software in obtaining standard fetal head measurements from volumes acquired by three-dimensional ultrasonography: comparison with two-dimensional ultrasound.

    PubMed

    Rizzo, Giuseppe; Aiello, Elisa; Pietrolucci, Maria Elena; Arduini, Domenico

    2016-01-01

    To evaluate the performance of a new software (5D CNS) developed to automatically recognize the axial planes of the fetal brain from three-dimensional volumes and to obtain the basic standard biometric measurements. The accuracy, reproducibility, and time required for analysis of 5D CNS were compared with that of two-dimensional (2D) ultrasound. This was a prospective study of 120 uncomplicated singleton pregnancies undergoing routine second trimester examination. For every pregnancy standard biometric measurements including biparietal diameter, head circumference, distal lateral ventricle width, transverse cerebellar diameter and cisterna magna width were obtained using 2D ultrasound and three-dimensional (3D) ultrasound with 5D CNS software. Reliability and agreement of the two techniques were evaluated using intraclass correlation coefficients (ICCs) and proportionate Bland-Altman plots were constructed. The time necessary to complete the measurements with either technique was compared and intraobserver and interobserver agreements of measurements calculated. In 118/120 (98.3%), 5D CNS successfully reconstructed the axial diagnostic planes and calculated all the basic biometric head and brain measurements. The agreement between the two techniques was high for all the measurements considered (all ICCS > 0.920). The time necessary to measure the biometric variables considered was significantly shorter with 5D CNS (54 versus 115 s, p < 0.0001) than with 2D ultrasonography. No significant differences were found in 5D CNS repeated measurements obtained either by the same observer or by two independent observers. 5D CNS software allows us to obtain reliable biometric measurements of the fetal brain and to reduce the examination time. Its application may improve work-flow efficiency in ultrasonographic practices.

  13. Thermoacoustic range verification using a clinical ultrasound array provides perfectly co-registered overlay of the Bragg peak onto an ultrasound image.

    PubMed

    Patch, S K; Kireeff Covo, M; Jackson, A; Qadadha, Y M; Campbell, K S; Albright, R A; Bloemhard, P; Donoghue, A P; Siero, C R; Gimpel, T L; Small, S M; Ninemire, B F; Johnson, M B; Phair, L

    2016-08-07

    The potential of particle therapy due to focused dose deposition in the Bragg peak has not yet been fully realized due to inaccuracies in range verification. The purpose of this work was to correlate the Bragg peak location with target structure, by overlaying the location of the Bragg peak onto a standard ultrasound image. Pulsed delivery of 50 MeV protons was accomplished by a fast chopper installed between the ion source and the cyclotron inflector. The chopper limited the train of bunches so that 2 Gy were delivered in [Formula: see text]. The ion pulse generated thermoacoustic pulses that were detected by a cardiac ultrasound array, which also produced a grayscale ultrasound image. A filtered backprojection algorithm focused the received signal to the Bragg peak location with perfect co-registration to the ultrasound images. Data was collected in a room temperature water bath and gelatin phantom with a cavity designed to mimic the intestine, in which gas pockets can displace the Bragg peak. Phantom experiments performed with the cavity both empty and filled with olive oil confirmed that displacement of the Bragg peak due to anatomical change could be detected. Thermoacoustic range measurements in the waterbath agreed with Monte Carlo simulation within 1.2 mm. In the phantom, thermoacoustic range estimates and first-order range estimates from CT images agreed to within 1.5 mm.

  14. Thermoacoustic range verification using a clinical ultrasound array provides perfectly co-registered overlay of the Bragg peak onto an ultrasound image

    NASA Astrophysics Data System (ADS)

    Patch, S. K.; Kireeff Covo, M.; Jackson, A.; Qadadha, Y. M.; Campbell, K. S.; Albright, R. A.; Bloemhard, P.; Donoghue, A. P.; Siero, C. R.; Gimpel, T. L.; Small, S. M.; Ninemire, B. F.; Johnson, M. B.; Phair, L.

    2016-08-01

    The potential of particle therapy due to focused dose deposition in the Bragg peak has not yet been fully realized due to inaccuracies in range verification. The purpose of this work was to correlate the Bragg peak location with target structure, by overlaying the location of the Bragg peak onto a standard ultrasound image. Pulsed delivery of 50 MeV protons was accomplished by a fast chopper installed between the ion source and the cyclotron inflector. The chopper limited the train of bunches so that 2 Gy were delivered in 2 μ \\text{s} . The ion pulse generated thermoacoustic pulses that were detected by a cardiac ultrasound array, which also produced a grayscale ultrasound image. A filtered backprojection algorithm focused the received signal to the Bragg peak location with perfect co-registration to the ultrasound images. Data was collected in a room temperature water bath and gelatin phantom with a cavity designed to mimic the intestine, in which gas pockets can displace the Bragg peak. Phantom experiments performed with the cavity both empty and filled with olive oil confirmed that displacement of the Bragg peak due to anatomical change could be detected. Thermoacoustic range measurements in the waterbath agreed with Monte Carlo simulation within 1.2 mm. In the phantom, thermoacoustic range estimates and first-order range estimates from CT images agreed to within 1.5 mm.

  15. Postpartum two- and three-dimensional ultrasound evaluation of anal sphincter complex in women with obstetric anal sphincter injury.

    PubMed

    Ros, C; Martínez-Franco, E; Wozniak, M M; Cassado, J; Santoro, G A; Elías, N; López, M; Palacio, M; Wieczorek, A P; Espuña-Pons, M

    2017-04-01

    To compare the sensitivity and specificity of two- (2D) and three- (3D) dimensional transperineal ultrasound (TPUS) and 3D endovaginal ultrasound (EVUS) with the gold standard 3D endoanal ultrasound (EAUS) in detecting residual defects after primary repair of obstetric anal sphincter injuries (OASIS). External (EAS) and internal (IAS) anal sphincters were evaluated by the four ultrasound modalities in women with repaired OASIS. 2D-TPUS was evaluated in real-time, whereas 3D-TPUS, 3D-EVUS and 3D-EAUS volumes were evaluated offline by six blinded readers. The presence/absence of any tear in EAS or IAS was recorded and defects were scored according to the Starck system. Sensitivity, specificity and predictive values were calculated, using 3D-EAUS as reference standard. Inter- and intraobserver analyses were performed for all 3D imaging modalities. Association between patients' symptoms (Wexner score) and ultrasound findings (Starck score) was calculated. Images from 55 patients were analyzed. Compared with findings on 3D-EAUS, the agreement for EAS evaluation was poor for 3D-EVUS (κ = 0.01), fair for 2D-TPUS (κ = 0.30) and good for 3D-TPUS (κ = 0.73). The agreement for IAS evaluation was moderate for both 3D-EVUS (κ = 0.41) and 2D-TPUS (κ = 0.52) and good for 3D-TPUS (κ = 0.66). Good intraobserver (3D-EAUS, κ = 0.73; 3D-TPUS, κ = 0.78) and interobserver (3D-EAUS, κ = 0.68; 3D-TPUS, κ = 0.60) agreement was reported. Significant association between Starck and Wexner scores was found only for 3D-EAUS (Spearman's rho = 0.277, P = 0.04). 2D-TPUS and 3D-EVUS are not accurate modalities for the assessment of anal sphincters after repair of OASIS. 3D-TPUS shows good agreement with the gold standard 3D-EAUS and a high sensitivity in detecting residual defects. It, thus, has potential as a screening tool after primary repair of OASIS. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG

  16. Three-dimensional noninvasive ultrasound Joule heat tomography based on the acousto-electric effect using unipolar pulses: a simulation study.

    PubMed

    Yang, Renhuan; Li, Xu; Song, Aiguo; He, Bin; Yan, Ruqiang

    2012-11-21

    Electrical properties of biological tissues are highly sensitive to their physiological and pathological status. Thus it is of importance to image electrical properties of biological tissues. However, spatial resolution of conventional electrical impedance tomography (EIT) is generally poor. Recently, hybrid imaging modalities combining electric conductivity contrast and ultrasonic resolution based on the acousto-electric effect has attracted considerable attention. In this study, we propose a novel three-dimensional (3D) noninvasive ultrasound Joule heat tomography (UJHT) approach based on the acousto-electric effect using unipolar ultrasound pulses. As the Joule heat density distribution is highly dependent on the conductivity distribution, an accurate and high-resolution mapping of the Joule heat density distribution is expected to give important information that is closely related to the conductivity contrast. The advantages of the proposed ultrasound Joule heat tomography using unipolar pulses include its simple inverse solution, better performance than UJHT using common bipolar pulses and its independence of a priori knowledge of the conductivity distribution of the imaging object. Computer simulation results show that using the proposed method, it is feasible to perform a high spatial resolution Joule heat imaging in an inhomogeneous conductive media. Application of this technique on tumor scanning is also investigated by a series of computer simulations.

  17. Three-dimensional printing (3DP) of neonatal head phantom for ultrasound: thermocouple embedding and simulation of bone.

    PubMed

    Gatto, Matteo; Memoli, Gianluca; Shaw, Adam; Sadhoo, Neelaksh; Gelat, Pierre; Harris, Russell A

    2012-09-01

    A neonatal head phantom, comprising of an ellipsoidal geometry and including a circular aperture for simulating the fontanel was designed and fabricated, in order to allow an objective assessment of thermal rise in tissues during trans-cranial ultrasonic scanning of pre-term neonates. The precise position of a series of thermocouples was determined on the basis of finite-element analysis, which identified crucial target points for the thermal monitoring within the phantom geometry. Three-Dimensional Printing (3DP) was employed for the manufacture of the skull phantom, which was subsequently filled with dedicated brain-mimic material. A novel 3DP material combination was found to be able to mimic the acoustic properties of neonatal skull bone. Similarly, variations of a standard recipe for tissue mimic were examined, until one was found to mimic the brain of an infant. A specific strategy was successfully pursued to embed a thermocouple within the 3DP skull phantom during the manufacturing process. An in-process machine vision system was used to assess the correct position of the deposited thermocouple inside the fabricated skull phantom. An external silicone-made skin-like covering completed the phantom and was manufactured through a Direct Rapid Tooling (DRT) technique. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

  18. Three-dimensional versus two-dimensional ultrasound for assessing levonorgestrel intrauterine device location: A pilot study.

    PubMed

    Andrade, Carla Maria Araujo; Araujo Júnior, Edward; Torloni, Maria Regina; Moron, Antonio Fernandes; Guazzelli, Cristina Aparecida Falbo

    2016-02-01

    To compare the rates of success of two-dimensional (2D) and three-dimensional (3D) sonographic (US) examinations in locating and adequately visualizing levonorgestrel intrauterine devices (IUDs) and to explore factors associated with the unsuccessful viewing on 2D US. Transvaginal 2D and 3D US examinations were performed on all patients 1 month after insertion of levonorgestrel IUDs. The devices were considered adequately visualized on 2D US if both the vertical (shadow, upper and lower extremities) and the horizontal (two echogenic lines) shafts were identified. 3D volumes were also captured to assess the location of levonorgestrel IUDs on 3D US. Thirty women were included. The rates of adequate device visualization were 40% on 2D US (95% confidence interval [CI], 24.6; 57.7) and 100% on 3D US (95% CI, 88.6; 100.0). The device was not adequately visualized in all six women who had a retroflexed uterus, but it was adequately visualized in 12 of the 24 women (50%) who had a nonretroflexed uterus (95% CI, -68.6; -6.8). We found that 3D US is better than 2D US for locating and adequately visualizing levonorgestrel IUDs. Other well-designed studies with adequate power should be conducted to confirm this finding. © 2015 Wiley Periodicals, Inc.

  19. Application of ultrasound-aided method for the synthesis of CdS-incorporated three-dimensional TiO2 photocatalysts with enhanced performance.

    PubMed

    Lee, Joon Yeob; Jo, Wan-Kuen

    2017-03-01

    In this study, an ultrasound-aided hydrothermal-impregnation method was used to synthesize three-dimensional (3D) urchin-like CdS-TiO2 nanostructures (UCTs) with variable CdS content. The photocatalytic efficiencies (for degrading limonene and toluene vapor) of UCTs synthesized using the ultrasound-aided process were greater than those of UCTs fabricated without ultrasound treatment. In addition, the photocatalytic efficiencies of ultrasound-treated UCTs were greater than those of zero-dimensional ultrasound-treated CdS-TiO2 particles, which, in turn, were greater than those of untreated 3D TiO2. These results indicate that ultrasonication is an amicable process for the synthesis of UCTs with high photocatalytic activity. The enhanced activity of ultrasound-treated photocatalysts is ascribed to the greater charge carrier efficiency, adsorption capacity, and light absorption efficiency of these materials. The photocatalytic efficiencies of ultrasound-treated UCTs increased as the CdS loading was increased from 0.1% to 0.3%, gradually dropping as the loading was further increased to 3.0%, which indicated the existence of an optimum CdS loading. UCT photocatalytic efficiencies depended on the input concentration of target pollutants, relative humidity, and air flow rate. The photocatalytic efficiency for the decomposition of limonene mixed with 2-propanol was lower than that for limonene alone, likely due to the radical scavenging properties of 2-propanol. However, the photocatalytic degradation efficiency of the latter alcohol was not changed upon admixture. Toluene exhibited the same behavior. The mineralization ratios of both target compounds were lower than their decomposition ratios, indicating formation of byproducts due to incomplete oxidation. In addition to CO, three organic compounds were observed as photocatalytic decomposition byproducts of limonene (acetic acid, limonene oxide, and methacrolein) and toluene (benzene, benzaldehyde, and p-xylene). UCTs

  20. Coronary artery calcification is inversely related to body morphology in patients with significant coronary artery disease: a three-dimensional intravascular ultrasound study.

    PubMed

    Dangas, George D; Maehara, Akiko; Evrard, Solene M; Sartori, Samantha; Li, Jennifer R; Chirumamilla, Amala P; Nomura-Kitabayashi, Aya; Gukathasan, Nilusha; Hassanin, Ahmed; Baber, Usman; Fahy, Martin; Fuster, Valentin; Mintz, Gary S; Kovacic, Jason C

    2014-02-01

    Emerging data have indicated unexpected complexity in the regulation of vascular and bone calcification. In particular, several recent studies have challenged the concept of a universally positive relationship between body morphology [weight, height, body mass index (BMI), body surface area (BSA)] and the extent of vascular calcification. We sought to clarify these discrepancies and investigated the relationship between index lesion coronary artery calcification (CAC) and body morphology in patients undergoing percutaneous coronary intervention (PCI) using three-dimensional intravascular ultrasound (IVUS). We analysed CAC in patients who underwent PCI with pre-intervention IVUS imaging. The main outcome measure was the calcium index (CalcIndex); a three-dimensional IVUS-derived measure of total calcification per obstructive coronary lesion. A total of 346 patients (65.3 ± 10.6 years; 29.5% females) underwent PCI with IVUS-based CAC assessment. CalcIndex was categorized as zero-low (0-0.1399; n = 152) or intermediate-high (0.1400-1.2541; n = 194). All measures of body morphology were lower in patients with intermediate-high CalcIndex (height, P = 0.024; weight, P = 0.008; BMI, P = 0.064; BSA, P = 0.005). In adjusted multivariable models, weight and BSA were independent inverse predictors of intermediate-high CalcIndex [weight: odds ratio (OR) 0.986, P = 0.017; BSA: OR 0.323, P = 0.012] while CalcIndex also trended towards an inverse association with both height (P = 0.068) and BMI (P = 0.064). These independent inverse associations were consistent across multiple clinical subgroups, including stratification by age, race, gender, diabetes, and renal impairment. Using three-dimensional IVUS to assess vascular calcification, these data confirm an independent, inverse relationship between body size and index lesion CAC in patients with obstructive coronary artery disease.

  1. Coronary artery calcification is inversely related to body morphology in patients with significant coronary artery disease: a three-dimensional intravascular ultrasound study

    PubMed Central

    Dangas, George D.; Maehara, Akiko; Evrard, Solene M.; Sartori, Samantha; Li, Jennifer R.; Chirumamilla, Amala P.; Nomura-Kitabayashi, Aya; Gukathasan, Nilusha; Hassanin, Ahmed; Baber, Usman; Fahy, Martin; Fuster, Valentin; Mintz, Gary S.; Kovacic, Jason C.

    2014-01-01

    Aims Emerging data have indicated unexpected complexity in the regulation of vascular and bone calcification. In particular, several recent studies have challenged the concept of a universally positive relationship between body morphology [weight, height, body mass index (BMI), body surface area (BSA)] and the extent of vascular calcification. We sought to clarify these discrepancies and investigated the relationship between index lesion coronary artery calcification (CAC) and body morphology in patients undergoing percutaneous coronary intervention (PCI) using three-dimensional intravascular ultrasound (IVUS). Methods and results We analysed CAC in patients who underwent PCI with pre-intervention IVUS imaging. The main outcome measure was the calcium index (CalcIndex); a three-dimensional IVUS-derived measure of total calcification per obstructive coronary lesion. A total of 346 patients (65.3 ± 10.6 years; 29.5% females) underwent PCI with IVUS-based CAC assessment. CalcIndex was categorized as zero–low (0–0.1399; n = 152) or intermediate–high (0.1400–1.2541; n = 194). All measures of body morphology were lower in patients with intermediate–high CalcIndex (height, P = 0.024; weight, P = 0.008; BMI, P = 0.064; BSA, P = 0.005). In adjusted multivariable models, weight and BSA were independent inverse predictors of intermediate–high CalcIndex [weight: odds ratio (OR) 0.986, P = 0.017; BSA: OR 0.323, P = 0.012] while CalcIndex also trended towards an inverse association with both height (P = 0.068) and BMI (P = 0.064). These independent inverse associations were consistent across multiple clinical subgroups, including stratification by age, race, gender, diabetes, and renal impairment. Conclusion Using three-dimensional IVUS to assess vascular calcification, these data confirm an independent, inverse relationship between body size and index lesion CAC in patients with obstructive coronary artery disease. PMID:23904334

  2. Morphometric analysis in three-dimensional intracoronary ultrasound: an in vitro and in vivo study performed with a novel system for the contour detection of lumen and plaque.

    PubMed

    von Birgelen, C; Di Mario, C; Li, W; Schuurbiers, J C; Slager, C J; de Feyter, P J; Roelandt, J R; Serruys, P W

    1996-09-01

    Currently, automated systems for quantitative analysis by intracoronary ultrasound (ICUS) are restricted to the detection of the lumen. The aim of this study was to determine the accuracy and reproducibility of a new semiautomated contour detection method, providing off-line identification of the intimal leading edge and external contour of the vessel in three-dimensional ICUS. The system allows cross-sectional and volumetric quantification of lumen and of plaque. It applies a minimum-cost algorithm and the concept that edge points derived from previously detected longitudinal contours guide and facilitate the contour detection in the cross-sectional images. A tubular phantom with segments of various luminal dimensions was examined in vitro during five catheter pull-backs (1 mm/sec), and subsequently 20 diseased human coronary arteries were studied in vivo with 2.9F 30 MHz mechanical ultrasound catheters (200 images per 20 mm segment). The ICUS measurements of phantom lumen area and volume revealed a high correlation with the true phantom areas and volumes (r = 0.99); relative mean differences were -0.65% to 3.86% for the areas and 0.25% to 1.72% for the volumes of the various segments. Intraob-server and interobserver comparisons showed high correlations (r = 0.95 to 0.98 for area and r = 0.99 for volume) and small mean relative differences (-0.87% to 1.08%), with SD of lumen, plaque, and total vessel measurements not exceeding 7.28%, 10.81%, and 4.44% (area) and 2.66%, 2.81%, and 0.67% (volume), respectively. Thus the proposed analysis system provided accurate measurements of phantom dimensions and can be used to perform highly reproducible area and volume measurements in three-dimensional ICUS in vivo.

  3. To assess the reparative ability of differentiated mesenchymal stem cells in a rat critical size bone repair defect model using high frequency co-registered photoacoustic/ultrasound imaging and micro computed tomography

    NASA Astrophysics Data System (ADS)

    Zafar, Haroon; Gaynard, Sean; O'Flatharta, Cathal; Doroshenkova, Tatiana; Devine, Declan; Sharif, Faisal; Barry, Frank; Hayes, Jessica; Murphy, Mary; Leahy, Martin J.

    2016-03-01

    Stem cell based treatments hold great potential and promise to address many unmet clinical needs. The importance of non-invasive imaging techniques to monitor transplanted stem cells qualitatively and quantitatively is crucial. The objective of this study was to create a critical size bone defect in the rat femur and then assess the ability of the differentiated mesenchymal stem cells (MSCs) to repair the defect using high frequency co-registered photoacoustic(PA)/ultrasound(US) imaging and micro computed tomography (μCT) over an 8 week period. Combined PA and US imaging was performed using 256 elements, 21 MHz frequency linear-array transducer combined with multichannel collecting system. In vivo 3D PA and US images of the defect bone in the rat femur were acquired after 4 and 8 weeks of the surgery. 3D co-registered structural such as microvasculature and the functional images such as total concentration of haemoglobin (HbT) and the haemoglobin oxygen saturation (sO2) were obtained using PA and US imaging. Bone formation was assessed after 4 and 8 weeks of the surgery by μCT. High frequency linear-array based coregistered PA/US imaging has been found promising in terms of non-invasiveness, sensitivity, adaptability, high spatial and temporal resolution at sufficient depths for the assessment of the reparative ability of MSCs in a rat critical size bone repair defect model.

  4. Agreement and reliability of pelvic floor measurements during rest and on maximum Valsalva maneuver using three-dimensional translabial ultrasound and virtual reality imaging.

    PubMed

    Speksnijder, L; Oom, D M J; Koning, A H J; Biesmeijer, C S; Steegers, E A P; Steensma, A B

    2016-08-01

    Imaging of the levator ani hiatus provides valuable information for the diagnosis and follow-up of patients with pelvic organ prolapse (POP). This study compared measurements of levator ani hiatal volume during rest and on maximum Valsalva, obtained using conventional three-dimensional (3D) translabial ultrasound and virtual reality imaging. Our objectives were to establish their agreement and reliability, and their relationship with prolapse symptoms and POP quantification (POP-Q) stage. One hundred women with an intact levator ani were selected from our tertiary clinic database. Information on clinical symptoms were obtained using standardized questionnaires. Ultrasound datasets were analyzed using a rendered volume with a slice thickness of 1.5 cm, at the level of minimal hiatal dimensions, during rest and on maximum Valsalva. The levator area (in cm(2) ) was measured and multiplied by 1.5 to obtain the levator ani hiatal volume (in cm(3) ) on conventional 3D ultrasound. Levator ani hiatal volume (in cm(3) ) was measured semi-automatically by virtual reality imaging using a segmentation algorithm. Twenty patients were chosen randomly to analyze intra- and interobserver agreement. The mean difference between levator hiatal volume measurements on 3D ultrasound and by virtual reality was 1.52 cm(3) (95% CI, 1.00-2.04 cm(3) ) at rest and 1.16 cm(3) (95% CI, 0.56-1.76 cm(3) ) during maximum Valsalva (P < 0.001). Both intra- and interobserver intraclass correlation coefficients were ≥ 0.96 for conventional 3D ultrasound and > 0.99 for virtual reality. Patients with prolapse symptoms or POP-Q Stage ≥ 2 had significantly larger hiatal measurements than those without symptoms or POP-Q Stage < 2. Levator ani hiatal volume at rest and on maximum Valsalva is significantly smaller when using virtual reality compared with conventional 3D ultrasound; however, this difference does not seem clinically important. Copyright © 2015 ISUOG. Published by

  5. A Robotic Ultrasound Scanner for Automatic Vessel Tracking and Three-Dimensional Reconstruction of B-Mode Images.

    PubMed

    Merouche, Samir; Allard, Louise; Montagnon, Emmanuel; Soulez, Gilles; Bigras, Pascal; Cloutier, Guy

    2016-01-01

    Locating and evaluating the length and severity of a stenosis is very important for planning adequate treatment of peripheral arterial disease (PAD). Conventional ultrasound (US) examination cannot provide maps of entire lower limb arteries in 3-D. We propose a prototype 3D-US robotic system with B-mode images, which is nonionizing, noninvasive, and is able to track and reconstruct a continuous segment of the lower limb arterial tree between the groin and the knee. From an initialized cross-sectional view of the vessel, automatic tracking was conducted followed by 3D-US reconstructions evaluated using Hausdorff distance, cross-sectional area, and stenosis severity in comparison with 3-D reconstructions with computed tomography angiography (CTA). A mean Hausdorff distance of 0.97 ± 0.46 mm was found in vitro for 3D-US compared with 3D-CTA vessel representations. To evaluate the stenosis severity in vitro, 3D-US reconstructions gave errors of 3%-6% when compared with designed dimensions of the phantom, which are comparable to 3D-CTA reconstructions, with 4%-13% errors. The in vivo system's feasibility to reconstruct a normal femoral artery segment of a volunteer was also investigated. These results encourage further ergonomic developments to increase the robot's capacity to represent lower limb vessels in the clinical context.

  6. [Differential diagnostic value of real-time tissue elastography and three dimensional ultrasound imaging in breast lumps].

    PubMed

    Li, M H; Liu, Y; Liu, L S; Li, P X; Chen, Q

    2016-05-24

    To investigate the real-time tissue elastography and 3D contrast-enhanced ultrasonography(CEUS) in breast lumps differential diagnostic value. A total of 126 patients (180 lumps) with breast mass were retrospectively analyzed from December 2012 to December 2014 in Tumor Hospital Affiliated To Xinjiang Medical University.All patients were divided into three groups by using stratified random method.Each group was detected by real-time tissue elastography, 3D CEUS and two joint inspection.Each group of 42 cases (60 lumps) was confirmed by the pathological results as gold standard.Diagnostic sensitivity, specificity and coincidence rate of different methods were compared. The benign masses of ultrasound contrast showed the punctate, linear and nodular enhancement, and the border of enhancement was smooth.The malignant tumors were mainly dominated by uneven and high enhancement. There was no statistical difference in sensitivity, specificity and coincidence rate between elastography group and 3D CEUS group (64.7% vs 73.5%, 69.2% vs 76.9%, 66.7% vs 75.0%, all P>0.05). The sensitivity, specificity and coincidence rate of two joint inspection group were higher than those of elastography group and 3D CEUS group, the differences were statistically significant (97.1%, 92.3% and 98.3% , all P<0.05). 3D CEUS combined with real-time tissue elastography is of high value in the diagnosis of breast masses.

  7. Three-dimensional electrode displacement elastography using the Siemens C7F2 fourSight four-dimensional ultrasound transducer.

    PubMed

    Bharat, Shyam; Fisher, Ted G; Varghese, Tomy; Hall, Timothy J; Jiang, Jingfeng; Madsen, Ernest L; Zagzebski, James A; Lee, Fred T

    2008-08-01

    Because ablation therapy alters the elastic modulus of tissues, emerging strain imaging methods may enable clinicians for the first time to have readily available, cost-effective, real-time guidance to identify the location and boundaries of thermal lesions. Electrode displacement elastography is a method of strain imaging tailored specifically to ultrasound-guided electrode-based ablative therapies (e.g., radio-frequency ablation). Here tissue deformation is achieved by applying minute perturbations to the unconstrained end of the treatment electrode, resulting in localized motion around the end of the electrode embedded in tissue. In this article, we present a method for three-dimensional (3D) elastographic reconstruction from volumetric data acquired using the C7F2 fourSight four-dimensional ultrasound transducer, provided by Siemens Medical Solutions USA, Inc. (Issaquah, WA, USA). Lesion reconstruction is demonstrated for a spherical inclusion centered in a tissue-mimicking phantom, which simulates a thermal lesion embedded in a normal tissue background. Elastographic reconstruction is also performed for a thermal lesion created in vitro in canine liver using radio-frequency ablation. Postprocessing is done on the acquired raw radio-frequency data to form surface-rendered 3D elastograms of the inclusion. Elastographic volume estimates of the inclusion compare reasonably well with the actual known inclusion volume, with 3D electrode displacement elastography slightly underestimating the true inclusion volume.

  8. 2pBAb5. Validation of three-dimensional strain tracking by volumetric ultrasound image correlation in a pubovisceral muscle model.

    PubMed

    Nagle, Anna S; Nageswaren, Ashok R; Haridas, Balakrishna; Mast, T D

    2013-06-02

    Little is understood about the biomechanical changes leading to pelvic floor disorders such as stress urinary incontinence. In order to measure regional biomechanical properties of the pelvic floor muscles in vivo, a three dimensional (3D) strain tracking technique employing correlation of volumetric ultrasound images has been implemented. In this technique, local 3D displacements are determined as a function of applied stress and then converted to strain maps. To validate this approach, an in vitro model of the pubovisceral muscle, with a hemispherical indenter emulating the downward stress caused by intra-abdominal pressure, was constructed. Volumetric B-scan images were recorded as a function of indenter displacement while muscle strain was measured independently by a sonomicrometry system (Sonometrics). Local strains were computed by ultrasound image correlation and compared with sonomicrometry-measured strains to assess strain tracking accuracy. Image correlation by maximizing an exponential likelihood function was found more reliable than the Pearson correlation coefficient. Strain accuracy was dependent on sizes of the subvolumes used for image correlation, relative to characteristic speckle length scales of the images. Decorrelation of echo signals was mapped as a function of indenter displacement and local tissue orientation. Strain measurement accuracy was weakly related to local echo decorrelation.

  9. Three dimensional level set based semiautomatic segmentation of atherosclerotic carotid artery wall volume using 3D ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Murad; AlMuhanna, Khalid; Zhao, Limin; Lal, Brajesh K.; Sikdar, Siddhartha

    2014-03-01

    3D segmentation of carotid plaque from ultrasound (US) images is challenging due to image artifacts and poor boundary definition. Semiautomatic segmentation algorithms for calculating vessel wall volume (VWV) have been proposed for the common carotid artery (CCA) but they have not been applied on plaques in the internal carotid artery (ICA). In this work, we describe a 3D segmentation algorithm that is robust to shadowing and missing boundaries. Our algorithm uses distance regularized level set method with edge and region based energy to segment the adventitial wall boundary (AWB) and lumen-intima boundary (LIB) of plaques in the CCA, ICA and external carotid artery (ECA). The algorithm is initialized by manually placing points on the boundary of a subset of transverse slices with an interslice distance of 4mm. We propose a novel user defined stopping surface based energy to prevent leaking of evolving surface across poorly defined boundaries. Validation was performed against manual segmentation using 3D US volumes acquired from five asymptomatic patients with carotid stenosis using a linear 4D probe. A pseudo gold-standard boundary was formed from manual segmentation by three observers. The Dice similarity coefficient (DSC), Hausdor distance (HD) and modified HD (MHD) were used to compare the algorithm results against the pseudo gold-standard on 1205 cross sectional slices of 5 3D US image sets. The algorithm showed good agreement with the pseudo gold standard boundary with mean DSC of 93.3% (AWB) and 89.82% (LIB); mean MHD of 0.34 mm (AWB) and 0.24 mm (LIB); mean HD of 1.27 mm (AWB) and 0.72 mm (LIB). The proposed 3D semiautomatic segmentation is the first step towards full characterization of 3D plaque progression and longitudinal monitoring.

  10. Agreement between two- and three-dimensional transperineal ultrasound methods in assessing fetal head descent in the first stage of labor.

    PubMed

    Torkildsen, E A; Salvesen, K Å; Eggebø, T M

    2012-03-01

    To study intraobserver repeatability and intermethod agreement between two- (2D) and three-dimensional (3D) transperineal ultrasound methods in assessing fetal head descent during the first stage of labor. Fetal head descent was measured with transperineal ultrasound as the fetal head-perineum distance and the angle of progression in 106 primiparous women with prolonged first stage of labor. A single obstetrician performed all the scans, and another obstetrician analyzed the acquired 2D images and 3D volumes, blinded to clinical assessments and labor outcome. Intraobserver repeatability and intermethod agreement between 2D and 3D methods were analyzed. The repeatability coefficient was ± 4.1 mm in 2D acquisitions and ± 1.7 mm in 3D acquisitions of fetal head-perineum distance. The intraclass correlation coefficients (ICC) were 0.94 for 2D and 0.99 for 3D measurements. The angle of progression repeatability coefficients were ± 6.7° using 2D and ± 5.7° using 3D ultrasound and ICCs were 0.91 and 0.94, respectively. The intermethod ICC for fetal head-perineum distance in 2D vs 3D acquisitions was 0.95 and for angle of progression it was 0.93; the intermethod 95% limits of agreement were - 5.8 mm to + 7.2 mm and - 8.9° to + 13.7°, respectively. Cohen's kappa for 2D vs 3D acquisitions was 0.85 using 40 mm as a cut-off level for fetal head-perineum distance and 0.79 using 110° as cut-off level for angle of progression. For one ultrasound operator the intraobserver repeatability and agreement between 2D and 3D ultrasound methods in prolonged first stage of labor were good. Given that 2D methods are simpler to learn and can be analyzed quickly online, 2D equipment might therefore be preferred in the labor room. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

  11. Sphenofrontal distance on three-dimensional ultrasound in euploid and trisomy-21 fetuses at 16-24 weeks' gestation.

    PubMed

    Cossellu, G; Persico, N; D'Ambrosi, F; Carbone, F; Fabietti, I; Boito, S; Farronato, G; Fedele, L; Nicolaides, K H

    2016-08-01

    To compare the distance between the sphenoid and frontal bones on three-dimensional (3D) ultrasound in euploid and trisomy-21 fetuses at 16-24 weeks' gestation. We acquired 3D volumes of the fetal profile from 80 normal and 30 trisomy-21 fetuses at 16-24 weeks' gestation. We used the multiplanar mode to obtain the mid-sagittal plane and measured the sphenofrontal distance as the shortest distance between the most anterior edge of the sphenoid bone and the lowest edge of the frontal bone. In normal fetuses, the sphenofrontal distance increased linearly with gestational age, from 15.1 mm at 16 weeks to 18.2 mm at 24 weeks. In fetuses with trisomy 21, the mean sphenofrontal distance delta value was significantly smaller than in normal cases (-3.447 mm (95% CI, -5.684 to -1.211 mm); P < 0.01). The sphenofrontal distance was below the 5(th) and 1(st) percentiles of the normal range in 29 (96.7%) and 27 (90.0%) trisomy-21 fetuses, respectively. The sphenofrontal distance is shorter at 16-24 weeks' gestation in fetuses with trisomy 21 than in normal fetuses. A reduction in the growth of the anterior cranial base contributes to the mid-facial hypoplasia observed in fetuses with trisomy 21. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

  12. Results of a comparative analysis of magnetic resonance imaging-targeted versus three-dimensional transrectal ultrasound prostate biopsies: Size does matter.

    PubMed

    Peltier, Alexandre; Aoun, Fouad; Albisinni, Simone; Marcelis, Quentin; Ledinh, Dam; Paesmans, Marianne; Lemort, Marc; van Velthoven, Roland

    2016-06-01

    The aim of this study was to compare the detection rate of clinically significant disease in magnetic resonance imaging (MRI)-targeted biopsies versus three-dimensional transrectal ultrasound (3D TRUS)-guided biopsies according to prostate size. The study compared 120 consecutive biopsy-naïve men who underwent 3D TRUS-guided systematic biopsy to 120 consecutive men who underwent MRI-targeted biopsy. Stratifications based on tertiles were used for assessing interactions between prostate volume and rates of detection of significant cancer. Older age, higher prostate-specific antigen level, lower prostate volume, increased number of cores and MRI-targeted biopsy were independent predictors of prostate cancer detection in the entire cohort on logistic regression. Clinically significant cancer detection rates were significantly higher in the MRI-targeted group than in the 3D TRUS-guided biopsy group (48.7% vs 29.4%, p = 0.002). When stratified according to prostate volume, these rates were significantly higher only in the third tertile group (volume > 50 cm(3)) for MRI-targeted biopsy compared to 3D TRUS-guided biopsy (56% vs 22%, p = 0.003). MRI-targeted biopsies increased the detection rate of clinically significant prostate cancer only in patients with enlarged prostates compared to the 3D TRUS.

  13. Off-site evaluation of three-dimensional ultrasound for the diagnosis of thyroid nodules: comparison with two-dimensional ultrasound.

    PubMed

    Kim, Soo Chin; Kim, Ji-Hoon; Choi, Seung Hong; Yun, Tae Jin; Wi, Jae Yeon; Kim, Sun Ah; Sun, Hye Young; Ryoo, Inseon; Park, Sun-Won; Sohn, Chul-Ho

    2016-10-01

    We compared the diagnostic performance of off-site evaluation between prospectively obtained 3D and 2D ultrasound for thyroid nodules. 3D and 2D ultrasonographies were preoperatively obtained from 85 consecutive patients (mean age, 51 years; age range, 28-83 years) who were referred for a total thyroidectomy. Three radiologists independently evaluated 3D and 2D images of 91 pathologically confirmed thyroid nodules (30 benign and 61 malignant nodules) for nodule characterization. Diagnostic performance, interobserver agreement and time for scanning were compared between 3D and 2D. 3D had significantly higher sensitivities than 2D for predicting malignancy (78.7 % vs. 61.2 %, P < 0.01) and extrathyroidal extension (66.7 % vs. 46.4 %, P = 0.03) in malignancy. In terms of specificities, there were no statistically significant differences between 2D and 3D for predicting malignancy (78.4 % vs. 74.8 %, P = 1.00) and extrathyroidal extension (63.6 % vs. 57.6 %, P = 0.46). With respect to interobserver agreement, 3D showed moderate agreement (κ = 0.53) for predicting extrathyroidal extension in malignancy compared with 2D ultrasound, which showed fair agreement (κ = 0.37). 3D saved time (30 ± 56.52 s) for scanning compared with 2D. For off-site evaluation, 3D US is more useful for diagnosis of thyroid nodules than 2D US. • 3D had higher sensitivity than 2D for predicting malignancy and extrathyroidal extension. • 3D showed better agreement for predicting extrathyroidal extension in malignancy than 2D. • 3D thyroid ultrasound saved time for scanning compared with 2D. • For off-site evaluation of thyroid nodules, 3D is more useful than 2D.

  14. Three-dimensional Contrast-enhanced Ultrasound in Response Assessment for Breast Cancer: A Comparison with Dynamic Contrast-enhanced Magnetic Resonance Imaging and Pathology

    PubMed Central

    Jia, Wan-Ru; Tang, Lei; Wang, Deng-Bin; Chai, Wei-Min; Fei, Xiao-Chun; He, Jian-Rong; Chen, Man; Wang, Wen-Ping

    2016-01-01

    To compare the capabilities of three-dimensional contrast enhanced ultrasound (3D-CEUS) and dynamic contrast-enhanced magnetic resonance (DCE-MRI) in predicting the response to neoadjuvant chemotherapy (NAC) among breast cancer patients, 48 patients with unilateral breast cancer were recruited for 3D-CEUS and DCE-MRI examinations both before and after NAC; pathology was used to validate the results. This study was approved by the institutional review board, and written informed consent was obtained from each patient. Imaging feature changes and pathological vascularity response, including microvessel density (MVD) and vascular endothelial growth factor (VEGF), were calculated. Pathological complete response (pCR) and major histological response (MHR) were used as references. The 3D-CEUS score, DCE-MRI score, MVD and VEGF significantly decreased (P < 0.0001) after NAC. The correlations between Δ3D-CEUS and ΔDCE-MRI with pCR (r = 0.649, P < 0.0001; r = 0.639, P < 0.0001) and MHR (r = 0.863, P < 0.0001; r = 0.836, P < 0.0001) were significant. All scores showed significant differences between the pCR and non-pCR groups with folder changes of 0.1, 0.1, 2.4, and 2.3, respectively (P = 0.0001, <0.0001, <0.0001 and <0.0001). In conclusion, 3D-CEUS is effective in assessing the response of breast cancer patients undergoing NAC. PMID:27652518

  15. A novel way of visualizing the ductal and aortic arches by real-time three-dimensional ultrasound with live xPlane imaging.

    PubMed

    Xiong, Y; Chen, M; Chan, L W; Ting, Y H; Fung, T Y; Leung, T Y; Lau, T K

    2012-03-01

    To describe a novel method of visualizing the ductal and aortic arches by real-time three-dimensional echocardiography with live xPlane imaging. Live xPlane imaging was used to display the ductal- and aortic-arch views in 107 women with singleton pregnancies, including seven cases with suspected congenital heart defects (CHDs). The three vessels and trachea (3VT) view was obtained in such an orientation that either the pulmonary artery or the aorta was parallel to the direction of the ultrasound beam. The xPlane reference line was then placed across the targeted vessel, which in a normal case would provide an image of the corresponding arch view as a dual-image display. Once the 3VT view had been obtained, live xPlane imaging showed the aortic and ductal arches in all 100 normal cases. In seven cases with suspected CHD, the 3VT view was abnormal in five cases and normal in the other two. However, the ductal-arch view demonstrated by live xPlane imaging was abnormal in five cases of conotruncal anomalies and normal in two cases in which conotruncal anomalies were excluded. CHDs were confirmed at autopsy following termination of pregnancy in five cases and on postnatal echocardiography in one case. The heart was found postnatally to be normal in one case of suspected CHD; in this case live xPlane imaging showed that the observed abnormal 3VT view was caused by a tortuous course of the thoracic aorta associated with an abnormal diaphragm. Live xPlane imaging is a novel and relatively simple method of visualizing the ductal- and aortic-arch views, and may potentially be a useful tool in the screening of fetal conotruncal and aortic-arch anomalies. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

  16. Tissue ablation after 120W greenlight laser vaporization and bipolar plasma vaporization of the prostate: a comparison using transrectal three-dimensional ultrasound volumetry

    NASA Astrophysics Data System (ADS)

    Kranzbühler, Benedikt; Gross, Oliver; Fankhauser, Christian D.; Hefermehl, Lukas J.; Poyet, Cédric; Largo, Remo; Müntener, Michael; Seifert, Hans-Helge; Zimmermann, Matthias; Sulser, Tullio; Müller, Alexander; Hermanns, Thomas

    2012-02-01

    Introduction and objectives: Greenlight laser vaporization (LV) of the prostate is characterized by simultaneous vaporization and coagulation of prostatic tissue resulting in tissue ablation together with excellent hemostasis during the procedure. It has been reported that bipolar plasma vaporization (BPV) of the prostate might be an alternative for LV. So far, it has not been shown that BPV is as effective as LV in terms of tissue ablation or hemostasis. We performed transrectal three-dimensional ultrasound investigations to compare the efficiency of tissue ablation between LV and BPV. Methods: Between 11.2009 and 5.2011, 50 patients underwent pure BPV in our institution. These patients were matched with regard to the pre-operative prostate volume to 50 LV patients from our existing 3D-volumetry-database. Transrectal 3D ultrasound and planimetric volumetry of the prostate were performed pre-operatively, after catheter removal, 6 weeks and 6 months. Results: Median pre-operative prostate volume was not significantly different between the two groups (45.3ml vs. 45.4ml; p=1.0). After catheter removal, median absolute volume reduction (BPV 12.4ml, LV 6.55ml) as well as relative volume reduction (27.8% vs. 16.4%) were significantly higher in the BPV group (p<0.001). After six weeks (42.9% vs. 33.3%) and six months (47.2% vs. 39.7%), relative volume reduction remained significantly higher in the BPV group (p<0.001). Absolute volume reduction was non-significantly higher in the BPV group after six weeks (18.4ml, 13.8ml; p=0.051) and six months (20.8ml, 18ml; p=0.3). Clinical outcome parameters improved significantly in both groups without relevant differences between the groups. Conclusions: Both vaporization techniques result in efficient tissue ablation with initial prostatic swelling. BPV seems to be superior due to a higher relative volume reduction. This difference had no clinical impact after a follow-up of 6M.

  17. Ovarian size and vascularization as assessed by three-dimensional grayscale and power Doppler ultrasound in asymptomatic women 20-39 years old using combined oral contraceptives.

    PubMed

    Jokubkiene, Ligita; Sladkevicius, Povilas; Valentin, Lil

    2012-09-01

    The aim of this study is to estimate ovarian volume, number and volume of antral follicles, and ovarian power Doppler vascular indices as assessed by three-dimensional (3D) transvaginal grayscale and power Doppler ultrasound in women using combined oral contraceptives (COC). Two hundred thirteen gynecologically asymptomatic women 20-39 years old using COC were examined with transvaginal 3D grayscale and power Doppler ultrasound on cycle day 4-8 (first cycle day is first day of withdrawal bleeding). We used a Voluson E8 ultrasound system with a 6-12-MHz transvaginal transducer. Ovarian volume, number and volume of antral follicles ≥2 mm, vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated using the virtual organ computer-aided analysis (VOCAL™) and sonography-based automated volume calculation (SonoAVC™) software. Results are described separately for women with follicles 2.0-10.0 mm and for those with at least one follicle >10.0 mm for two age groups: 20-29 years (n=166) and 30-39 years (n=47). Results are also compared between women on monophasic (n=151) and triphasic (n=59) COC, and between women using COC with older (n=110) and newer (n=100) progestins and different doses of estrogen. One hundred eighty-nine (89%) women had follicles 2.0-10.0 mm, and 24 (11%) had follicle(s) >10.0 mm. The proportion of women with follicle(s) >10.0 mm did not differ between women with different types of COC. In women with follicles 2.0-10.0 mm, the right ovary was larger (mean difference 0.5 cm(3) [95% confidence interval 0.22-0.82]) and contained more follicles (mean difference 1.5 [0.52-2.56]) than the left one in the age group 20-29 years. The same differences between the right and left ovary were seen in women 30-39 years old, but they were not statistically significant. In both ovaries, the number of antral follicles 2.0-10.0 mm [median (range)] was significantly higher in women 20-29 than in those 30-39 years old [11 (2

  18. Three dimensional strained semiconductors

    DOEpatents

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  19. Three-dimensional contrast enhanced ultrasound score and dynamic contrast-enhanced magnetic resonance imaging score in evaluating breast tumor angiogenesis: correlation with biological factors.

    PubMed

    Jia, Wan-Ru; Chai, Wei-Min; Tang, Lei; Wang, Yi; Fei, Xiao-Chun; Han, Bao-San; Chen, Man

    2014-07-01

    To explore the clinical value of three-dimensional contrast enhanced ultrasound (3D-CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) score systems in evaluating breast tumor angiogenesis by comparing their diagnostic efficacy and correlation with biological factors. 3D-CEUS was performed in 183 patients with breast tumors by Esaote Mylab90 with SonoVue (Bracco, Italy), DCE-MRI was performed on a dedicated breast magnetic resonance imaging (DBMRI) system (Aurora Dedicated Breast MRI Systems, USA) with a dedicated breast coil. 3D-CEUS and DCE-MRI score systems were created based on tumor perfusion and vascular characteristics. Microvessel density (MVD), vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP-2, MMP-9) expression were measured by immunohistochemistry. Pathological results showed 35 benign and 148 malignant breast tumors. MVD (P=0.000, r=0.76), VEGF (P=0.000, r=0.55), MMP-2 (P=0.000, r=0.39) and MMP-9 (P=0.000, r=0.41) expression were all significantly different between benignity and malignancy. Regarding 3D-CEUS 4 points as cutoff value, the sensitivity, specificity and accuracy were 85.1%, 94.3% and 86.9%, respectively, and correlated well with MVD (P=0.000, r=0.50), VEGF (P=0.000, r=0.50), MMP-2 (P=0.000, r=0.50) and MMP-9 (P=0.000, r=0.66). Taking DCE-MRI 5 points as cutoff value, the sensitivity, specificity and accuracy were 86.5%, 94.3% and 88.0%, respectively and also correlated well with MVD (P=0.000, r=0.52), VEGF (P=0.000, r=0.44), MMP-2 (P=0.000, r=0.42) and MMP-9 (P=0.000, r=0.35). 3D-CEUS score system displays inspiring diagnostic performance and good agreement with DCE-MRI scoring. Moreover, both score systems correlate well with MVD, VEGF, MMP-2 and MMP-9 expression, and thus have great potentials in tumor angiogenesis evaluation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Accuracy of Ultrasound-Based (BAT) Prostate-Repositioning: A Three-Dimensional On-Line Fiducial-Based Assessment With Cone-Beam Computed Tomography

    SciTech Connect

    Boda-Heggemann, Judit Koehler, Frederick Marc; Kuepper, Beate; Wolff, Dirk; Wertz, Hansjoerg; Mai, Sabine; Hesser, Juergen; Lohr, Frank; Wenz, Frederik

    2008-03-15

    Purpose: To assess the accuracy of ultrasound-based repositioning (BAT) before prostate radiation with fiducial-based three-dimensional matching with cone-beam computed tomography (CBCT). Patients and Methods: Fifty-four positionings in 8 patients with {sup 125}I seeds/intraprostatic calcifications as fiducials were evaluated. Patients were initially positioned according to skin marks and after this according to bony structures based on CBCT. Prostate position correction was then performed with BAT. Residual error after repositioning based on skin marks, bony anatomy, and BAT was estimated by a second CBCT based on user-independent automatic fiducial registration. Results: Overall mean value (MV {+-} SD) residual error after BAT based on fiducial registration by CBCT was 0.7 {+-} 1.7 mm in x (group systematic error [M] = 0.5 mm; SD of systematic error [{sigma}] = 0.8 mm; SD of random error [{sigma}] = 1.4 mm), 0.9 {+-} 3.3 mm in y (M = 0.5 mm, {sigma} = 2.2 mm, {sigma} = 2.8 mm), and -1.7 {+-} 3.4 mm in z (M = -1.7 mm, {sigma} = 2.3 mm, {sigma} = 3.0 mm) directions, whereas residual error relative to positioning based on skin marks was 2.1 {+-} 4.6 mm in x (M = 2.6 mm, {sigma} = 3.3 mm, {sigma} = 3.9 mm), -4.8 {+-} 8.5 mm in y (M = -4.4 mm, {sigma} = 3.7 mm, {sigma} = 6.7 mm), and -5.2 {+-} 3.6 mm in z (M = -4.8 mm, {sigma} = 1.7 mm, {sigma} = 3.5mm) directions and relative to positioning based on bony anatomy was 0 {+-} 1.8 mm in x (M = 0.2 mm, {sigma} = 0.9 mm, {sigma} = 1.1 mm), -3.5 {+-} 6.8 mm in y (M = -3.0 mm, {sigma} = 1.8 mm, {sigma} = 3.7 mm), and -1.9 {+-} 5.2 mm in z (M = -2.0 mm, {sigma} = 1.3 mm, {sigma} = 4.0 mm) directions. Conclusions: BAT improved the daily repositioning accuracy over skin marks or even bony anatomy. The results obtained with BAT are within the precision of extracranial stereotactic procedures and represent values that can be achieved with several users with different education levels. If sonographic visibility is insufficient

  1. A CT-ultrasound-coregistered augmented reality enhanced image-guided surgery system and its preliminary study on brain-shift estimation

    NASA Astrophysics Data System (ADS)

    Huang, C. H.; Hsieh, C. H.; Lee, J. D.; Huang, W. C.; Lee, S. T.; Wu, C. T.; Sun, Y. N.; Wu, Y. T.

    2012-08-01

    With the combined view on the physical space and the medical imaging data, augmented reality (AR) visualization can provide perceptive advantages during image-guided surgery (IGS). However, the imaging data are usually captured before surgery and might be different from the up-to-date one due to natural shift of soft tissues. This study presents an AR-enhanced IGS system which is capable to correct the movement of soft tissues from the pre-operative CT images by using intra-operative ultrasound images. First, with reconstructing 2-D free-hand ultrasound images to 3-D volume data, the system applies a Mutual-Information based registration algorithm to estimate the deformation between pre-operative and intra-operative ultrasound images. The estimated deformation transform describes the movement of soft tissues and is then applied to the pre-operative CT images which provide high-resolution anatomical information. As a result, the system thus displays the fusion of the corrected CT images or the real-time 2-D ultrasound images with the patient in the physical space through a head mounted display device, providing an immersive augmented-reality environment. For the performance validation of the proposed system, a brain phantom was utilized to simulate brain-shift scenario. Experimental results reveal that when the shift of an artificial tumor is from 5mm ~ 12mm, the correction rates can be improved from 32% ~ 45% to 87% ~ 95% by using the proposed system.

  2. Three-dimensional photoacoustic and ultrasonic endoscopic imaging of two rabbit esophagi

    NASA Astrophysics Data System (ADS)

    Yang, Joon-Mo; Favazza, Christopher P.; Yao, Junjie; Chen, Ruimin; Zhou, Qifa; Shung, K. K.; Wang, Lihong V.

    2015-03-01

    The addition of photoacoustic endoscopy to conventional endoscopic ultrasound offers imaging capabilities that may improve diagnosis and clinical care of gastrointestinal tract diseases. In this study, using a 3.8-mm diameter dual-mode photoacoustic and ultrasonic endoscopic probe, we investigated photoacoustic and ultrasonic image features of rabbit esophagi. Specifically, we performed ex vivo imaging of intact rabbit esophagi and correlated the acquired images with histology. Without motion artifact-based limitations, we were able to utilize the full resolving power of the endoscopic device and acquire the first three-dimensional vasculature map of the esophagus and mediastinum, along with coregistered tissue density information. Here, we present the experimental results and discuss potential clinical applications of the technique.

  3. Detection of the subendometrial vascularization flow index by three-dimensional ultrasound may be useful for predicting the pregnancy rate for patients undergoing in vitro fertilization-embryo transfer.

    PubMed

    Wu, Hsien-Ming; Chiang, Chi-Hsin; Huang, Hong-Yuan; Chao, An-Shine; Wang, Hsin-Shih; Soong, Yung-Kuei

    2003-03-01

    To obtain quantitative data on endometrial volume and subendometrial blood flow by three-dimensional ultrasound clue to endometrial receptivity. A prospective, nonrandomized clinical study. One tertiary center for assisted reproduction. Fifty-four patients aged <38 years with normal basal serum FSH level experiencing their first IVF cycle, whose uteri were morphologically normal as confirmed by 3-dimensional (3-D) ultrasound, were studied. Ultrasound evaluation was performed for all patients with 3-D facility by a single operator on the day of hCG administration. Ultrasonographic parameters and conception rates. Subendometrial vascularization flow index (VFI) in predicting the pregnancy rate of IVF was superior to that using vascularization index, flow index, or endometrial volume in the receiver operating characteristics curve analysis. The best prediction rate was achieved by a VFI cutoff value of >0.24. The detection of subendometrial blood flow by 3-D power Doppler ultrasound may be a useful ultrasound parameter in the prediction of pregnancy rate of IVF, especially subendometrial VFI.

  4. Cleft of the secondary palate without cleft lip diagnosed with three-dimensional ultrasound and magnetic resonance imaging in a fetus with Fryns' syndrome.

    PubMed

    Benacerraf, B R; Sadow, P M; Barnewolt, C E; Estroff, J A; Benson, C

    2006-05-01

    We present a case of Fryns' syndrome diagnosed prenatally using three-dimensional (3D) ultrasonography and magnetic resonance imaging (MRI). A cleft of the soft palate was diagnosed using 3D thick-slice ultrasonography. Other sonographic findings included a right diaphragmatic hernia, enlarged echogenic kidneys and severe polyhydramnios. The detection of the cleft palate was instrumental in suggesting the diagnosis of Fryns' syndrome in a fetus which also had a diaphragmatic hernia. These findings were also demonstrated with prenatal MRI. The technique of imaging the soft palate en face using a thick-slice technique is presented.

  5. Enhancement of Cell Ingrowth, Proliferation, and Early Differentiation in a Three-Dimensional Silicon Carbide Scaffold Using Low-Intensity Pulsed Ultrasound

    PubMed Central

    Lin, Liangjun

    2015-01-01

    Concerns over the use of autografts or allografts have necessitated the development of biomaterials for bone regeneration. Various studies have been performed to optimize the cultivation of osteogenic cells using osteoconductive porous scaffolds. The aim of this study was to evaluate the osteogenic efficiency of bone cell ingrowth, proliferation, and early differentiation in a silicon carbide (SiC) porous ceramic scaffold promoted with low-intensity pulsed ultrasound. MC3T3-E1 mouse preosteoblasts were seeded onto scaffolds and cultured for 4 and 7 days with daily of 20-min ultrasound treatment. The cells were evaluated for cell attachment, morphology, viability, ingrowth depth, volumetric proliferation, and early differentiation. After 4 and 7 days of culture and ultrasound exposure, the cell density was higher in the ultrasound-treated group compared with the sham-treated group on SiC scaffolds. The cell ingrowth depths inside the SiC scaffolds were 149.2±27.3 μm at 1 day, 310.1±12.6 μm for the ultrasound-treated group and 248.0±19.7 μm for the sham control at 4 days, and 359.6±18.5 μm for the ultrasound-treated group and 280.0±17.7 μm for the sham control at 7 days. They were significantly increased, that is, 25% (p=0.0029) and 28% (p=0.0008) increase, respectively, with ultrasound radiation force as compared with those in sham control at 4 and 7 days postseeding. The dsDNA contents were 583.5±19.1 ng/scaffold at 1 day, 2749.9±99.9 ng/scaffold for the ultrasound-treated group and 2514.9±114.7 ng/scaffold for the sham control at 4 days, and 3582.3±325.3 ng/scaffold for the ultrasound-treated group and 2825.7±134.3 ng/scaffold for the sham control at 7 days. There was a significant difference in the dsDNA content between the ultrasound- and sham-treated groups at 4 and 7 days. The ultrasound-treated group with the SiC construct showed a 9% (p=0.00029) and 27% (p=0.00017) increase in the average dsDNA content at 4 and 7 days over

  6. Enhancement of cell ingrowth, proliferation, and early differentiation in a three-dimensional silicon carbide scaffold using low-intensity pulsed ultrasound.

    PubMed

    Wu, Lin; Lin, Liangjun; Qin, Yi-Xian

    2015-01-01

    Concerns over the use of autografts or allografts have necessitated the development of biomaterials for bone regeneration. Various studies have been performed to optimize the cultivation of osteogenic cells using osteoconductive porous scaffolds. The aim of this study was to evaluate the osteogenic efficiency of bone cell ingrowth, proliferation, and early differentiation in a silicon carbide (SiC) porous ceramic scaffold promoted with low-intensity pulsed ultrasound. MC3T3-E1 mouse preosteoblasts were seeded onto scaffolds and cultured for 4 and 7 days with daily of 20-min ultrasound treatment. The cells were evaluated for cell attachment, morphology, viability, ingrowth depth, volumetric proliferation, and early differentiation. After 4 and 7 days of culture and ultrasound exposure, the cell density was higher in the ultrasound-treated group compared with the sham-treated group on SiC scaffolds. The cell ingrowth depths inside the SiC scaffolds were 149.2±27.3 μm at 1 day, 310.1±12.6 μm for the ultrasound-treated group and 248.0±19.7 μm for the sham control at 4 days, and 359.6±18.5 μm for the ultrasound-treated group and 280.0±17.7 μm for the sham control at 7 days. They were significantly increased, that is, 25% (p=0.0029) and 28% (p=0.0008) increase, respectively, with ultrasound radiation force as compared with those in sham control at 4 and 7 days postseeding. The dsDNA contents were 583.5±19.1 ng/scaffold at 1 day, 2749.9±99.9 ng/scaffold for the ultrasound-treated group and 2514.9±114.7 ng/scaffold for the sham control at 4 days, and 3582.3±325.3 ng/scaffold for the ultrasound-treated group and 2825.7±134.3 ng/scaffold for the sham control at 7 days. There was a significant difference in the dsDNA content between the ultrasound- and sham-treated groups at 4 and 7 days. The ultrasound-treated group with the SiC construct showed a 9% (p=0.00029) and 27% (p=0.00017) increase in the average dsDNA content at 4 and 7 days over

  7. Three-dimensional nanomagnetism

    DOE PAGES

    Fernandez-Pacheco, Amalio; Streubel, Robert; Fruchart, Olivier; ...

    2017-06-09

    Magnetic nanostructures are being developed for use in many aspects of our daily life, spanning areas such as data storage, sensing and biomedicine. Whereas patterned nanomagnets are traditionally two-dimensional planar structures, recent work is expanding nanomagnetism into three dimensions; a move triggered by the advance of unconventional synthesis methods and the discovery of new magnetic effects. In three-dimensional nanomagnets more complex magnetic configurations become possible, many with unprecedented properties. Here we review the creation of these structures and their implications for the emergence of new physics, the development of instrumentation and computational methods, and exploitation in numerous applications.

  8. Three dimensional quantum chromodynamics

    NASA Astrophysics Data System (ADS)

    Ferretti, G.; Rajeev, S. G.; Yang, Z.

    1992-02-01

    The subject of this talk is the study of the low energy behavior of three (2+1) dimensional Quantum Chromodynamics. We show the existence of a phase where parity is unbroken and the flavor group U(2n) is broken into a subgroup U(n)×U(n). We derive the low energy effective action for the theory and show that it has solitonic excitations with Fermi statistic, to be identified with the three dimensional ``baryon''. Finally, we study the current algebra for this effective action and we find a co-homologically nontrivial generalization of Kac-Moody algebras to three dimension.

  9. Three-dimensional metamaterials

    SciTech Connect

    Burckel, David Bruce

    2012-06-12

    A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.

  10. Three-dimensional nanomagnetism

    NASA Astrophysics Data System (ADS)

    Fernández-Pacheco, Amalio; Streubel, Robert; Fruchart, Olivier; Hertel, Riccardo; Fischer, Peter; Cowburn, Russell P.

    2017-06-01

    Magnetic nanostructures are being developed for use in many aspects of our daily life, spanning areas such as data storage, sensing and biomedicine. Whereas patterned nanomagnets are traditionally two-dimensional planar structures, recent work is expanding nanomagnetism into three dimensions; a move triggered by the advance of unconventional synthesis methods and the discovery of new magnetic effects. In three-dimensional nanomagnets more complex magnetic configurations become possible, many with unprecedented properties. Here we review the creation of these structures and their implications for the emergence of new physics, the development of instrumentation and computational methods, and exploitation in numerous applications.

  11. Three Dimensional Dirac Semimetals

    NASA Astrophysics Data System (ADS)

    Zaheer, Saad

    2014-03-01

    Dirac points on the Fermi surface of two dimensional graphene are responsible for its unique electronic behavior. One can ask whether any three dimensional materials support similar pseudorelativistic physics in their bulk electronic spectra. This possibility has been investigated theoretically and is now supported by two successful experimental demonstrations reported during the last year. In this talk, I will summarize the various ways in which Dirac semimetals can be realized in three dimensions with primary focus on a specific theory developed on the basis of representations of crystal spacegroups. A three dimensional Dirac (Weyl) semimetal can appear in the presence (absence) of inversion symmetry by tuning parameters to the phase boundary separating a bulk insulating and a topological insulating phase. More generally, we find that specific rules governing crystal symmetry representations of electrons with spin lead to robust Dirac points at high symmetry points in the Brillouin zone. Combining these rules with microscopic considerations identifies six candidate Dirac semimetals. Another method towards engineering Dirac semimetals involves combining crystal symmetry and band inversion. Several candidate materials have been proposed utilizing this mechanism and one of the candidates has been successfully demonstrated as a Dirac semimetal in two independent experiments. Work carried out in collaboration with: Julia A. Steinberg, Steve M. Young, J.C.Y. Teo, C.L. Kane, E.J. Mele and Andrew M. Rappe.

  12. Evaluation of three-dimensional temperature distributions produced by a low-frequency transcranial focused ultrasound system within ex vivo human skulls.

    PubMed

    McDannold, Nathan; Park, Eun-Joo; Mei, Chang-Sheng; Zadicario, Eyal; Jolesz, Ferenc

    2010-09-01

    Transcranial MR-guided focused ultrasound (TcMRgFUS) provides a potential noninvasive alternative to surgical resection and for other treatments for brain disorders. Use of low-frequency ultrasound provides several advantages for TcMRgFUS, but is potentially limited by reflection and standing wave effects that may cause secondary hotspots within the skull cavity. The purpose of this work was to use volumetric magnetic resonance temperature imaging (MRTI) and ex vivo human skulls filled with tissue-mimicking phantom material to search for heating distant from the focal point that may occur during sonication with a TcMRgFUS system as a result of reflections or standing wave effects. Heating during 120-s sonications was monitored within the entire skull volume for 12 different locations in two different skulls. The setup used a hemispheric array operating at 220 kHz. Multiple sonications were delivered at each location while varying the MRTI slice positions to provide full coverage of the skull cavity. An automated routine was used evaluate the MRTI to detect voxel regions that appeared to be heated by ultrasound. No secondary hotspots with a temperature rise of 15% or more of the focal heating were found. The MRTI noise level prevented the identification of possible hotspots with a lower temperature rise. These results suggest that significant secondary heating by this TcMRgFUS system at points distant from the focal point are not common.

  13. New Technology-Large-Area Three- Dimensional Surface Profiling Using Only Focused Air-Coupled Ultrasound-Given 1999 R&D 100 Award

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Kautz, Harold E.; Abel, Phillip B.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    2000-01-01

    Surface topography, which significantly affects the performance of many industrial components, is normally measured with diamond-tip profilometry over small areas or with optical scattering methods over larger areas. To develop air-coupled surface profilometry, the NASA Glenn Research Center at Lewis Field initiated a Space Act Agreement with Sonix, Inc., through two Glenn programs, the Advanced High Temperature Engine Materials Program (HITEMP) and COMMTECH. The work resulted in quantitative surface topography profiles obtained using only high-frequency, focused ultrasonic pulses in air. The method is nondestructive, noninvasive, and noncontact, and it does not require light-reflective surfaces. Air surface profiling may be desirable when diamond-tip or laserbased methods are impractical, such as over large areas, when a significant depth range is required, or for curved surfaces. When the configuration is optimized, the method is reasonably rapid and all the quantitative analysis facilities are online, including two- and three-dimensional visualization, extreme value filtering (for faulty data), and leveling.

  14. Three dimensional interactive display

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2005-01-01

    A three-dimensional (3-D) interactive display and method of forming the same, includes a transparent capaciflector (TC) camera formed on a transparent shield layer on the screen surface. A first dielectric layer is formed on the shield layer. A first wire layer is formed on the first dielectric layer. A second dielectric layer is formed on the first wire layer. A second wire layer is formed on the second dielectric layer. Wires on the first wire layer and second wire layer are grouped into groups of parallel wires with a turnaround at one end of each group and a sensor pad at the opposite end. An operational amplifier is connected to each of the sensor pads and the shield pad biases the pads and receives a signal from connected sensor pads in response to intrusion of a probe. The signal is proportional to probe location with respect to the monitor screen.

  15. Three-dimensional transcranial ultrasound imaging with bilateral phase aberration correction of multiple isoplanatic patches: A pilot human study with microbubble contrast enhancement

    PubMed Central

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

    2013-01-01

    With stroke currently the second-leading cause of death globally, and 87% of all strokes classified as ischemic, the development of a fast, accessible, cost-effective approach for imaging occlusive stroke could have a significant impact on healthcare outcomes and costs. While clinical examination and standard CT alone do not provide adequate information for understanding the complex temporal events that occur during an ischemic stroke, ultrasound imaging is well-suited to the task of examining blood flow dynamics in real-time and may allow for localization of a clot. A prototype bilateral 3D ultrasound imaging system utilizing two matrix array probes on either side of the head allows for correction of skull-induced aberration throughout two entire phased array imaging volumes. We investigated the feasibility of applying this custom correction technique in 5 healthy volunteers with Definity® microbubble contrast enhancement. Subjects were scanned simultaneously via both temporal acoustic windows in 3D color flow mode. The number of color flow voxels above a common threshold increased due to aberration correction in 5/5 subjects, with a mean increase of 33.9%. The percentage of large arteries visualized in 3D color Doppler imaging increased from 46% without aberration correction to 60% with aberration correction. PMID:24239360

  16. Three-Dimensional Complex Variables

    NASA Technical Reports Server (NTRS)

    Martin, E. Dale

    1988-01-01

    Report presents new theory of analytic functions of three-dimensional complex variables. While three-dimensional system subject to more limitations and more difficult to use than the two-dimensional system, useful in analysis of three-dimensional fluid flows, electrostatic potentials, and other phenomena involving harmonic functions.

  17. Backward-mode multiwavelength photoacoustic scanner using a planar Fabry-Perot polymer film ultrasound sensor for high-resolution three-dimensional imaging of biological tissues.

    PubMed

    Zhang, Edward; Laufer, Jan; Beard, Paul

    2008-02-01

    A multiwavelength backward-mode planar photoacoustic scanner for 3D imaging of soft tissues to depths of several millimeters with a spatial resolution in the tens to hundreds of micrometers range is described. The system comprises a tunable optical parametric oscillator laser system that provides nanosecond laser pulses between 600 and 1200 nm for generating the photoacoustic signals and an optical ultrasound mapping system based upon a Fabry-Perot polymer film sensor for detecting them. The system enables photoacoustic signals to be mapped in 2D over a 50 mm diameter aperture in steps of 10 microm with an optically defined element size of 64 microm. Two sensors were used, one with a 22 microm thick polymer film spacer and the other with a 38 mum thick spacer providing -3 dB acoustic bandwidths of 39 and 22 MHz, respectively. The measured noise equivalent pressure of the 38 microm sensor was 0.21 kPa over a 20 MHz measurement bandwidth. The instrument line-spread function (LSF) was measured as a function of position and the minimum lateral and vertical LSFs found to be 38 and 15 microm, respectively. To demonstrate the ability of the system to provide high-resolution 3D images, a range of absorbing objects were imaged. Among these was a blood vessel phantom that comprised a network of blood filled tubes of diameters ranging from 62 to 300 microm immersed in an optically scattering liquid. In addition, to demonstrate the applicability of the system to spectroscopic imaging, a phantom comprising tubes filled with dyes of different spectral characteristics was imaged at a range of wavelengths. It is considered that this type of instrument may provide a practicable alternative to piezoelectric-based photoacoustic systems for high-resolution structural and functional imaging of the skin microvasculature and other superficial structures.

  18. Corneal ablation depth readout of the MEL 80 excimer laser compared to Artemis three-dimensional very high-frequency digital ultrasound stromal measurements.

    PubMed

    Reinstein, Dan Z; Archer, Timothy J; Gobbe, Marine

    2010-12-01

    To evaluate the accuracy of the ablation depth readout for the MEL 80 excimer laser (Carl Zeiss Meditec). Artemis 1 very high-frequency digital ultrasound measurements were obtained before and at least 3 months after LASIK in 121 eyes (65 patients). The Artemis-measured ablation depth was calculated as the maximum difference in stromal thickness before and after treatment. Laser in situ keratomileusis was performed using the MEL 80 excimer laser and the Hansatome microkeratome (Bausch & Lomb). The Aberration Smart Ablation profile was used in 56 eyes and the Tissue Saving Ablation profile was used in 65 eyes. All ablations were centered on the corneal vertex. Comparative statistics and linear regression analysis were performed between the laser readout ablation depth and Artemis-measured ablation depth. The mean maximum myopic meridian was -6.66±2.40 diopters (D) (range: -1.50 to -10.00 D) for Aberration Smart Ablation-treated eyes and -6.50±2.56 D (range: -1.34 to -11.50 D) for Tissue Saving Ablation-treated eyes. The MEL 80 readout was found to overestimate the Artemis-measured ablation depth by 20±12 μm for Aberration Smart Ablation and by 21±12 μm for Tissue Saving Ablation profiles. The accuracy of ablation depth measurement was improved by using the Artemis stromal thickness profile measurements before and after surgery to exclude epithelial changes. The MEL 80 readout was found to overestimate the achieved ablation depth. The linear regression equations could be used by MEL 80 users to adjust the ablation depth for predicted residual stromal thickness calculations without increasing the risk of ectasia due to excessive keratectomy depth as long as a suitable flap thickness bias is included. Copyright 2010, SLACK Incorporated.

  19. Three dimensional Dirac semimetals

    NASA Astrophysics Data System (ADS)

    Zaheer, Saad

    We extend the physics of graphene to three dimensional systems by showing that Dirac points can exist on the Fermi surface of realistic materials in three dimensions. Many of the exotic electronic properties of graphene can be ascribed to the pseudorelativistic behavior of its charge carriers due to two dimensional Dirac points on the Fermi surface. We show that certain nonsymmorphic spacegroups exhibit Dirac points among the irreducible representations of the appropriate little group at high symmetry points on the surface of the Brillouin zone. We provide a list of all Brillouin zone momenta in the 230 spacegroups that can host Dirac points. We describe microscopic considerations necessary to design materials in one of the candidate spacegroups such that the Dirac point appears at the Fermi energy without any additional non-Dirac-like Fermi pockets. We use density functional theory based methods to propose six new Dirac semimetals: BiO 2 and SbO2 in the beta-cristobalite lattice (spacegroup 227), and BiCaSiO4, BiMgSiO4, BiAlInO 4, and BiZnSiO4 in the distorted spinels lattice (spacegroup 74). Additionally we derive effective Dirac Hamiltonians given group representative operators as well as tight binding models incorporating spin-orbit coupling. Finally we study the Fermi surface of zincblende (spacegroup 216) HgTe which is effectively point-like at Gamma in the Brillouin zone and exhibits accidental degeneracies along a threefold rotation axis. Whereas compressive strain gaps the band structure into a topological insulator, tensile strain shifts the accidental degeneracies away from Gamma and enlarges the Fermi surface. States on the Fermi surface exhibit nontrivial spin texture marked by winding of spins around the threefold rotation axis and by spin vortices indicating a change in the winding number. This is confirmed by microscopic calculations performed in tensile strained HgTe and Hg0.5Zn 0.5 Te as well as k.p theory. We conclude with a summary of recent

  20. Lenticule thickness readout for small incision lenticule extraction compared to artemis three-dimensional very high-frequency digital ultrasound stromal measurements.

    PubMed

    Reinstein, Dan Z; Archer, Timothy J; Gobbe, Marine

    2014-05-01

    To evaluate the accuracy of the lenticule thickness readout for small incision lenticule extraction (SMILE) with the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Artemis very high-frequency digital ultrasound (ArcScan, Inc., Morrison, CO) measurements were obtained before and 3 months after SMILE in 70 eyes of 37 patients. The Artemis measured lenticule thickness was calculated as the maximum difference in stromal thickness before and after treatment. Comparative statistics and linear regression analysis were performed between the VisuMax readout lenticule thickness and Artemis measured maximum stromal change. Central epithelial thickness was measured and a similar analysis was performed using corneal thickness. Variability of the data were compared to ablation depths for a matched group of eyes from a previously published LASIK population treated with the MEL80 excimer laser (Carl Zeiss Meditec). The mean maximum myopic meridian treated was -7.81 ± 2.33 diopters (range: -2.25 to -12.50 diopters). On average, the VisuMax readout lenticule depth was 8.2 ± 8.0 μm thicker (range: -8 to +29 μm) than the Artemis measured stromal change (P < .001). On average, central epithelial thickness was 15.0 ± 5.2 μm thicker (range: 5 to 30 μm) after the procedure. The VisuMax readout lenticule thickness was 23.2 ± 10.9 μm thicker (range: +5 to +49 μm) than the Artemis measured corneal thickness change. The R(2) of 0.868 for the SMILE group was higher than 0.738 for the LASIK group (P = .015). The accuracy of SMILE lenticule thickness was found to be higher than actual measured stromal thickness change; however, predictability for SMILE lenticule thickness appeared higher than predictability for excimer laser ablation depth. The VisuMax readout lenticule depth was found to be 8 μm thicker than the achieved stromal change. This can be partly explained by alignment errors between preoperative and postoperative scans. However, this appears to show some

  1. Three-dimensional echocardiographic technology.

    PubMed

    Salgo, Ivan S

    2007-05-01

    This article addresses the current state of the art of technology in three-dimensional echocardiography as it applies to transducer design, beam forming, display, and quantification. Because three-dimensional echocardiography encompasses many technical and clinical areas, this article reviews its strengths and limitations and concludes with an analysis of what to use when.

  2. Three-Dimensional Photo Structures

    ERIC Educational Resources Information Center

    Vieth, Ken

    2006-01-01

    People influence lives in many ways. Through the author's desire to encourage high school students to reflect on the influential people in their lives, he developed this three-dimensional project in which they create a celebratory three-dimensional structure that shares their impressions of themselves and those who have influenced them. This…

  3. Three-dimensional marginal separation

    NASA Technical Reports Server (NTRS)

    Duck, Peter W.

    1988-01-01

    The three dimensional marginal separation of a boundary layer along a line of symmetry is considered. The key equation governing the displacement function is derived, and found to be a nonlinear integral equation in two space variables. This is solved iteratively using a pseudo-spectral approach, based partly in double Fourier space, and partly in physical space. Qualitatively, the results are similar to previously reported two dimensional results (which are also computed to test the accuracy of the numerical scheme); however quantitatively the three dimensional results are much different.

  4. Three dimensional colorimetric assay assemblies

    SciTech Connect

    Charych, D.; Reichart, A.

    2000-06-27

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  5. Three dimensional colorimetric assay assemblies

    DOEpatents

    Charych, Deborah; Reichart, Anke

    2000-01-01

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  6. Three-Dimensional Lissajous Figures.

    ERIC Educational Resources Information Center

    D'Mura, John M.

    1989-01-01

    Described is a mechanically driven device for generating three-dimensional harmonic space figures with different frequencies and phase angles on the X, Y, and Z axes. Discussed are apparatus, viewing stereo pairs, equations of motion, and using space figures in classroom. (YP)

  7. Three-dimensional stellarator codes

    PubMed Central

    Garabedian, P. R.

    2002-01-01

    Three-dimensional computer codes have been used to develop quasisymmetric stellarators with modular coils that are promising candidates for a magnetic fusion reactor. The mathematics of plasma confinement raises serious questions about the numerical calculations. Convergence studies have been performed to assess the best configurations. Comparisons with recent data from large stellarator experiments serve to validate the theory. PMID:12140367

  8. Creating Three-Dimensional Scenes

    ERIC Educational Resources Information Center

    Krumpe, Norm

    2005-01-01

    Persistence of Vision Raytracer (POV-Ray), a free computer program for creating photo-realistic, three-dimensional scenes and a link for Mathematica users interested in generating POV-Ray files from within Mathematica, is discussed. POV-Ray has great potential in secondary mathematics classrooms and helps in strengthening students' visualization…

  9. Three-Dimensional Lissajous Figures.

    ERIC Educational Resources Information Center

    D'Mura, John M.

    1989-01-01

    Described is a mechanically driven device for generating three-dimensional harmonic space figures with different frequencies and phase angles on the X, Y, and Z axes. Discussed are apparatus, viewing stereo pairs, equations of motion, and using space figures in classroom. (YP)

  10. Creating Three-Dimensional Scenes

    ERIC Educational Resources Information Center

    Krumpe, Norm

    2005-01-01

    Persistence of Vision Raytracer (POV-Ray), a free computer program for creating photo-realistic, three-dimensional scenes and a link for Mathematica users interested in generating POV-Ray files from within Mathematica, is discussed. POV-Ray has great potential in secondary mathematics classrooms and helps in strengthening students' visualization…

  11. Three-dimensional perspective visualization

    NASA Technical Reports Server (NTRS)

    Hussey, Kevin

    1991-01-01

    It was demonstrated that image processing computer graphic techniques can provide an effective means of physiographic analysis of remotely sensed regions through the use of three-dimensional perspective rendering. THe methods used to simulate and animate three-dimensional surfaces from two-dimensional imagery and digital elevation models are explained. A brief historic look at JPL's efforts in this field and several examples of animations, illustrating the evolution of these techniques from 1985, are shown. JPL's current research in this area is discussed along with examples of technology transfer and potential commercial application. The software is part of the VICAR (Video Image Communication and Retrieval) image processing system which was developed at the Multimission Image Processing Laboratory of JPL.

  12. Facial three-dimensional morphometry.

    PubMed

    Ferrario, V F; Sforza, C; Poggio, C E; Serrao, G

    1996-01-01

    Three-dimensional facial morphometry was investigated in a sample of 40 men and 40 women, with a new noninvasive computerized method. Subjects ranged in age between 19 and 32 years, had sound dentitions, and no craniocervical disorders. For each subject, 16 cutaneous facial landmarks were automatically collected by a system consisting of two infrared camera coupled device (CCD) cameras, real time hardware for the recognition of markers, and software for the three-dimensional reconstruction of landmarks' x, y, z coordinates. From these landmarks, 15 linear and 10 angular measurements, and four linear distance ratios were computed and averaged for sex. For all angular values, both samples showed a narrow variability and no significant gender differences were demonstrated. Conversely, all the linear measurements were significantly higher in men than in women. The highest intersample variability was observed for the measurements of facial height (prevalent vertical dimension), and the lowest for the measurements of facial depth (prevalent horizontal dimension). The proportions of upper and lower face height relative to the anterior face height showed a significant sex difference. Mean values were in good agreement with literature data collected with traditional methods. The described method allowed the direct and noninvasive calculation of three-dimensional linear and angular measurements that would be usefully applied in clinics as a supplement to the classic x-ray cephalometric analyses.

  13. Quasicrystalline three-dimensional foams

    NASA Astrophysics Data System (ADS)

    Cox, S. J.; Graner, F.; Mosseri, R.; Sadoc, J.-F.

    2017-03-01

    We present a numerical study of quasiperiodic foams, in which the bubbles are generated as duals of quasiperiodic Frank–Kasper phases. These foams are investigated as potential candidates to the celebrated Kelvin problem for the partition of three-dimensional space with equal volume bubbles and minimal surface area. Interestingly, one of the computed structures falls close to (but still slightly above) the best known Weaire–Phelan periodic candidate. In addition we find a correlation between the normalized bubble surface area and the root mean squared deviation of the number of faces, giving an additional clue to understanding the main geometrical ingredients driving the Kelvin problem.

  14. Three-dimensional light bullets

    NASA Astrophysics Data System (ADS)

    Minardi, S.; Eilenberger, F.; Kartashov, Y. V.; Szameit, A.; Röpke, U.; Kobelke, J.; Schuster, K.; Bartelt, H.; Nolte, S.; Torner, L.; Lederer, F.; Tünnermann, A.; Pertsch, T.

    2012-02-01

    Three dimensional Light Bullets (3D-LBs) are the most symmetric solitary waves, being nonlinear optical wavepackets propagating without diffraction nor dispersion. Since their theoretical prediction, 3D-LB's have constituted a challenge in nonlinear science, due to the impossibility to avoid catastrophic collapse in conventional homogeneous nonlinear media. We have recently observed stable 3D-LBs in media with periodically modulated transverse refractive index profile. We found that higher order linear and nonlinear effects force the 3D-LBs to evolve along their propagation path and eventually decay. The evolution and decay mechanism entails spatiotemporal effects, which under certain conditions, leads to superluminally propagating wavepackets.

  15. Automated coregistered imaging using a hand-held probe-based optical imager

    NASA Astrophysics Data System (ADS)

    Regalado, Steven; Erickson, Sarah J.; Zhu, Banghe; Ge, Jiajia; Godavarty, Anuradha

    2010-02-01

    Near-infrared optical imaging holds a promise as a noninvasive technology toward cancer diagnostics and other tissue imaging applications. In recent years, hand-held based imagers are of great interest toward the clinical translation of the technology. However hand-held imagers developed to date are typically designed to obtain surface images and not tomography information due to lack of coregistration facilities. Herein, a recently developed hand-held probe-based optical imager in our Optical Imaging Laboratory has been implemented with novel coregistration facilities toward real-time and tomographic imaging of tissue phantoms. Continuous-wave fluorescence-enhanced optical imaging studies were performed using an intensified charge coupled device camera based imaging system in order to demonstrate the feasibility of automated coregistered imaging of flat phantom surfaces, using a flexible probe that can also contour to curvatures. Three-dimensional fluorescence tomographic reconstructions were also demonstrated using coregistered frequency-domain measurements obtained using the hand-held based optical imager. It was also observed from preliminary studies on cubical phantoms that multiple coregistered scans differentiated deeper targets (˜3 cm) from artifacts that were not feasible from a single coregistered scan, demonstrating the possibility of improved target depth detectability in the future.

  16. Three-dimensional vortex methods

    SciTech Connect

    Greengard, C.A.

    1984-08-01

    Three-dimensional vortex methods for the computation of incompressible fluid flow are presented from a unified point of view. Reformulations of the filament method and of the method of Beale and Majda show them to be very similar algorithms; in both of them, the vorticity is evaluated by a discretization of the spatial derivative of the flow map. The fact that the filament method, the one which is most often used in practice, can be formulated as a version of the Beale and Majda algorithm in a curved coordinate system is used to give a convergence theorem for the filament method. The method of Anderson is also discussed, in which vorticity is evaluated by the exact differentiation of the approximate velocity field. It is shown that, in the inviscid version of this algorithm, each approximate vector of vorticity remains tangent to a material curve moving with the computed flow, with magnitude proportional to the stretching of this vortex line. This remains true even when time discretization is taken into account. It is explained that the expanding core vortex method converges to a system of equations different from the Navier-Stokes equations. Computations with the filament method of the inviscid interaction of two vortex rings are reported, both with single filaments in each ring and with a fully three-dimensional discretization of vorticity. The dependence on parameters is discussed, and convergence of the computed solutions is observed. 36 references, 4 figures.

  17. Three-dimensional canine heart model for cardiac elastography

    PubMed Central

    Chen, Hao; Varghese, Tomy

    2010-01-01

    Purpose: A three-dimensional finite element analysis based canine heart model is introduced that would enable the assessment of cardiac function. Methods: The three-dimensional canine heart model is based on the cardiac deformation and motion model obtained from the Cardiac Mechanics Research Group at UCSD. The canine heart model is incorporated into ultrasound simulation programs previously developed in the laboratory, enabling the generation of simulated ultrasound radiofrequency data to evaluate algorithms for cardiac elastography. The authors utilize a two-dimensional multilevel hybrid method to estimate local displacements and strain from the simulated cardiac radiofrequency data. Results: Tissue displacements and strains estimated along both the axial and lateral directions (with respect to the ultrasound scan plane) are compared to the actual scatterer movement obtained using the canine heart model. Simulation and strain estimation algorithms combined with the three-dimensional canine heart model provide high resolution displacement and strain curves for improved analysis of cardiac function. The use of principal component analysis along parasternal cardiac short axis views is also presented. Conclusions: A 3D cardiac deformation model is proposed for evaluating displacement tracking and strain estimation algorithms for cardiac strain imaging. Validation of the model is shown using ultrasound simulations to generate axial and lateral displacement and strain curves that are similar to the actual axial and lateral displacement and strain curves. PMID:21158300

  18. Three-dimensional aromatic networks.

    PubMed

    Toyota, Shinji; Iwanaga, Tetsuo

    2014-01-01

    Three-dimensional (3D) networks consisting of aromatic units and linkers are reviewed from various aspects. To understand principles for the construction of such compounds, we generalize the roles of building units, the synthetic approaches, and the classification of networks. As fundamental compounds, cyclophanes with large aromatic units and aromatic macrocycles with linear acetylene linkers are highlighted in terms of transannular interactions between aromatic units, conformational preference, and resolution of chiral derivatives. Polycyclic cage compounds are constructed from building units by linkages via covalent bonds, metal-coordination bonds, or hydrogen bonds. Large cage networks often include a wide range of guest species in their cavity to afford novel inclusion compounds. Topological isomers consisting of two or more macrocycles are formed by cyclization of preorganized species. Some complicated topological networks are constructed by self-assembly of simple building units.

  19. Three-dimensional display technologies.

    PubMed

    Geng, Jason

    2013-01-01

    The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain's power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies.

  20. Three-dimensional coil inductor

    DOEpatents

    Bernhardt, Anthony F.; Malba, Vincent

    2002-01-01

    A three-dimensional coil inductor is disclosed. The inductor includes a substrate; a set of lower electrically conductive traces positioned on the substrate; a core placed over the lower traces; a set of side electrically conductive traces laid on the core and the lower traces; and a set of upper electrically conductive traces attached to the side traces so as to form the inductor. Fabrication of the inductor includes the steps of forming a set of lower traces on a substrate; positioning a core over the lower traces; forming a set of side traces on the core; connecting the side traces to the lower traces; forming a set of upper traces on the core; and connecting the upper traces to the side traces so as to form a coil structure.

  1. Three-dimensional vortex methods

    NASA Astrophysics Data System (ADS)

    Greengard, C. A.

    1984-08-01

    Reformulations of the filament method and of the method of Beale and Majda show them to be very similar algorithms. The method of Anderson in which vorticity is evaluated by the exact differentiation of the approximate velocity field is discussed. It is shown that, in the inviscid version of this algorithm, each approximate vector of vorticity remains tangent to a material curve moving with the computed flow, with magnitude proportional to the stretching of this vortex line. It is explained that the expanding core vortex method converges to a system of equations different from the Navier-Stokes equations. Computations with the filament method of the inviscid interaction of two vortex rings are reported, both with single filaments in each ring and with a fully three-dimensional discretization of vorticity. The dependence on parameters is discussed, and convergence of the computed solutions is observed.

  2. Three-dimensional colloidal lithography.

    PubMed

    Nagai, Hironori; Poteet, Austen; Zhang, Xu A; Chang, Chih-Hao

    2017-03-24

    Light interactions with colloidal particles can generate a variety of complex three-dimensional (3D) intensity patterns, which can be utilized for nanolithography. The study of particle-light interactions can add more types of intensity patterns by manipulating key factors. Here we investigate a novel 3D nanolithography technique using colloidal particles under two-beam coherent illuminations. The fabricated 3D nanostructures are hollow, nested within periodic structures, and possess multiple chamber geometry. The effects of incident angles and particle size on the fabricated nanostructures were examined. The relative phase shift between particle position and interference pattern is identified as another significant parameter influencing the resultant nanostructures. A numerical model has been developed to show the evolution of nanostructure geometry with phase shifts, and experimental studies confirm the simulation results. Through the introduction of single colloidal particles, the fabrication capability of Lloyd's mirror interference can now be extended to fabrication of 3D nanostructure with complex shell geometry. The fabricated hollow nanostructures with grating background could find potential applications in the area of photonics, drug delivery, and nanofluidics.

  3. Three-dimensional colloidal lithography

    NASA Astrophysics Data System (ADS)

    Nagai, Hironori; Poteet, Austen; Zhang, Xu A.; Chang, Chih-Hao

    2017-03-01

    Light interactions with colloidal particles can generate a variety of complex three-dimensional (3D) intensity patterns, which can be utilized for nanolithography. The study of particle-light interactions can add more types of intensity patterns by manipulating key factors. Here we investigate a novel 3D nanolithography technique using colloidal particles under two-beam coherent illuminations. The fabricated 3D nanostructures are hollow, nested within periodic structures, and possess multiple chamber geometry. The effects of incident angles and particle size on the fabricated nanostructures were examined. The relative phase shift between particle position and interference pattern is identified as another significant parameter influencing the resultant nanostructures. A numerical model has been developed to show the evolution of nanostructure geometry with phase shifts, and experimental studies confirm the simulation results. Through the introduction of single colloidal particles, the fabrication capability of Lloyd’s mirror interference can now be extended to fabrication of 3D nanostructure with complex shell geometry. The fabricated hollow nanostructures with grating background could find potential applications in the area of photonics, drug delivery, and nanofluidics.

  4. Three-dimensional display technologies

    PubMed Central

    Geng, Jason

    2014-01-01

    The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain’s power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies. PMID:25530827

  5. Three-dimensional laser microvision.

    PubMed

    Shimotahira, H; Iizuka, K; Chu, S C; Wah, C; Costen, F; Yoshikuni, Y

    2001-04-10

    A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 mum; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 mum.

  6. Three-Dimensional Laser Microvision

    NASA Astrophysics Data System (ADS)

    Shimotahira, Hiroshi; Iizuka, Keigo; Chu, Sun-Chun; Wah, Christopher; Costen, Furnie; Yoshikuni, Yuzo

    2001-04-01

    A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 m; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 m.

  7. Three dimensional magnetic abacus memory

    PubMed Central

    Zhang, ShiLei; Zhang, JingYan; Baker, Alexander A.; Wang, ShouGuo; Yu, GuangHua; Hesjedal, Thorsten

    2014-01-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme. It is inspired by the idea of second quantisation, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered ‘quantised' Hall voltage, each representing a count of the spin-up and spin-down layers in the stack. This new memory system further allows for both flexible scaling of the system and fast communication among cells. The magnetic abacus provides a promising approach for future nonvolatile 3D magnetic random access memory. PMID:25146338

  8. Live three-dimensional echocardiography: imaging principles and clinical application.

    PubMed

    Wang, Xin-Fang; Deng, You-Bin; Nanda, Navin C; Deng, Jing; Miller, Andrew P; Xie, Ming-Xing

    2003-10-01

    Live three-dimensional echocardiography (L3DE) is an important breakthrough in the field of medical ultrasound. It will provide a great potential tool for clinical diagnosis and treatment. In this article, the authors first review the bottlenecks in 3D cardiac imaging and the technical principles of L3DE that have been used to overcome some of these problems. We then discuss the scanning methods, clinical usefulness, and the future of L3DE, drawing on our experiences in examining 124 human patients and in conducting animal verification studies with a live 3D ultrasound system.

  9. Ultrasound guided spine needle insertion

    NASA Astrophysics Data System (ADS)

    Chen, Elvis C. S.; Mousavi, Parvin; Gill, Sean; Fichtinger, Gabor; Abolmaesumi, Purang

    2010-02-01

    An ultrasound (US) guided, CT augmented, spine needle insertion navigational system is introduced. The system consists of an electromagnetic (EM) sensor, an US machine, and a preoperative CT volume of the patient anatomy. Three-dimensional (3D) US volume is reconstructed intraoperatively from a set of two-dimensional (2D) freehand US slices, and is coregistered with the preoperative CT. This allows the preoperative CT volume to be used in the intraoperative clinical coordinate. The spatial relationship between the patient anatomy, surgical tools, and the US transducer are tracked using the EM sensor, and are displayed with respect to the CT volume. The pose of the US transducer is used to interpolate the CT volume, providing the physician with a 2D "x-ray vision" to guide the needle insertion. Many of the system software components are GPU-accelerated, allowing real-time performance of the guidance system in a clinical setting.

  10. [Three-dimensional printing and oral medicine].

    PubMed

    Hu, M

    2017-04-09

    After 30 years of development, three-dimensional printing technology has made great progress, and the model and surgical guide have been clinically applied. The three-dimensional printing of titanium and other metal prosthesis and dental crown after adequate research will be applied clinically, and three-dimensional bioprinting and related biological materials need further study. Three-dimensional printing provides opportunities for the development of oral medicine, which will change the way of clinical work, teaching and research. The dentists should integrate multi-disciplinary knowledge and understand the essence of new technology to meet the challenges of the era of digital medicine.

  11. Three dimensional identification card and applications

    NASA Astrophysics Data System (ADS)

    Zhou, Changhe; Wang, Shaoqing; Li, Chao; Li, Hao; Liu, Zhao

    2016-10-01

    Three dimensional Identification Card, with its three-dimensional personal image displayed and stored for personal identification, is supposed be the advanced version of the present two-dimensional identification card in the future [1]. Three dimensional Identification Card means that there are three-dimensional optical techniques are used, the personal image on ID card is displayed to be three-dimensional, so we can see three dimensional personal face. The ID card also stores the three-dimensional face information in its inside electronics chip, which might be recorded by using two-channel cameras, and it can be displayed in computer as three-dimensional images for personal identification. Three-dimensional ID card might be one interesting direction to update the present two-dimensional card in the future. Three-dimension ID card might be widely used in airport custom, entrance of hotel, school, university, as passport for on-line banking, registration of on-line game, etc...

  12. Three-dimensional map construction.

    PubMed

    Jenks, G F; Brown, D A

    1966-11-18

    Three-dimensional maps are useful tools which have been neglected for some time. They shouldbe more commonly used, and familiarity with the techniques discussed in this article should dispel any qualms anyone might ve about needing artistic talent to nstruct them. The saving in time esulting from the use of an anamorphoser provides a further incentive. The anamorphoser transformations discussed above were all prepared by using straight slits, oriented at right angles to each other and placed so that all planes of the elements were parallel to each other. It is possible to vary these conditions in an infinite number of ways and thereby produce nonparallel tranceformations. Some of these variations are illustrated in Fig. 10. All the illustrations in Fig. 10 are transformations of the planimetric weather map shown in Fig. 8A. The variations used for the maps of Fig. 10 are as follows. (A) All planes parallel, with a curved rear slit; (B) all planes parallel, with curved slits front and rear; ( C) all planes parallel, with S-shaped rear slit; (D) all planes parallel, with an undulating rear slit; (E) all planes parallel, with curved front and undulating rear slit; (F) plane of the original rotated on the horizontal axis-both slits curved; (G) plane of the original rotated on thevertical axis- both slits curved; (H) plane of the original rotated on the horizontal axis -both slits straight. These are only a few of the many transformations which can be made with an anamorphoser, butthey do point toward some interesting possibilities. For example, it appears that maps based onone projection might be altered to satisfy the coordinates of a completely different projection. Note, for example, the change of parallels from concave to convex curves (Figs. 8A and 10A) and the change from converging meridians to diverging meridians (Figs. 8A and l0G). Similarly, the grids of maps B, F, and H of Fig. 10 approximate projections which are quite different from the original. Other

  13. Normal and abnormal images of intrauterine devices: Role of three-dimensional sonography.

    PubMed

    Graupera, Betlem; Hereter, Lourdes; Pascual, M Angela; Fernández-Cid, María; Urbina, Carla; Di Paola, Rossana; Pedrero, Cristina

    2012-09-01

    The purpose of this pictorial essay is to describe the diagnostic value of two-dimensional ultrasound (2DUS) and the additional information that three-dimensional ultrasound (3DUS) provides in the assessment of location, type and complications of IUDs. Copyright © 2012 Wiley Periodicals, Inc.

  14. Three-dimensional gravity and string ghosts

    SciTech Connect

    Carlip, S. ); Kogan, I.I. )

    1991-12-23

    It is known that much of the structure of string theory can be derived from three-dimensional topological field theory and gravity. We show here that, at least for simple topologies, the string diffeomorphism ghosts can also be explained in terms of three-dimensional physics.

  15. Three Dimensional Illustrating--Three-Dimensional Vision and Deception of Sensibility

    ERIC Educational Resources Information Center

    Szállassy, Noémi; Gánóczy, Anita; Kriska, György

    2009-01-01

    The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena…

  16. Microlaser-based three-dimensional display

    NASA Astrophysics Data System (ADS)

    Takeuchi, Eric B.; Bergstedt, Robert; Hargis, David E.; Higley, Paul D.

    1999-08-01

    Three dimensional (3D) displays are critical for viewing complex multi-dimensional information and for viewing representations of the three dimensional real world. A teaming arrangement between Laser Power Corporation (LPC) and Specialty Devices, Inc. (SDI) has led to the feasibility demonstration of a directly-viewed three dimensional volumetric display. LPC has developed red, green, and blue (RGB) diode pumped solid state microlaser display technology for use as a high resolution, high brightness display engine for the three dimensional display. Concurrently, SDI has developed a unique technology for viewing high resolution three dimensional volumetric images without external viewing aids (eye wear). When coupled to LPC's display engine, the resultant all solid state three dimensional display presets a true, physical three dimensionality which is directly viewable from all angles by multiple viewers without additional viewing equipment (eye wear). The resultant volumetric display will further enable applications such as the 'virtual sandbox,' visualization of radar and sonar data, air traffic control, remote surgery and diagnostics, and CAD workstations.

  17. Three-dimensional laser window formation

    NASA Technical Reports Server (NTRS)

    Verhoff, Vincent G.

    1992-01-01

    The NASA Lewis Research Center has developed and implemented a unique process for forming flawless three-dimensional laser windows. These windows represent a major part of specialized, nonintrusive laser data acquisition systems used in a variety of compressor and turbine research test facilities. This report discusses in detail the aspects of three-dimensional laser window formation. It focuses on the unique methodology and the peculiarities associated with the formation of these windows. Included in this discussion are the design criteria, bonding mediums, and evaluation testing for three-dimensional laser windows.

  18. Three-dimensional velocity measurements using LDA

    NASA Astrophysics Data System (ADS)

    Buchhave, Preben

    The design requirements for and development of an LDA that measures the three components of the fluid velocity vector are described. The problems encountered in LDA measurements in highly turbulent flows, multivariate response, velocity bias, spatial resolution, temporal resolution, and dynamic range, are discussed. The use of the fringe and/or the reference beam methods to measure the three velocity components, and the use of color, frequency shift, and polarization to separate three velocity projections are examined. Consideration is given to the coordinate transformation, the presentation of three-dimensional LDA data, and the possibility of three-dimensional bias correction. Procedures for conducting three-dimensional LDA measurements are proposed.

  19. Three-dimensional neurosonography - a novel field in fetal medicine.

    PubMed

    Lipa, Michał; Pooh, Ritsuko Kimata; Wielgoś, Mirosław

    2017-01-01

    Neurosonography is a promising technique for prenatal diagnosis, combining features of ultrasound imaging with fetal neurology. The brain is a three-dimensional structure, therefore observing brain structure in the three basic planes (sagittal, coronal and axial) is mandatory. The anterior fontanelle and sagittal suture may serve as acoustic ultrasound windows in the transvaginal brain scan, allowing to obtain high-resolution neuroimages of the intracranial structures. Furthermore, three-dimensional (3D) ultrasound combined with the transvaginal brain approach provides detailed and sophisticated neuroimages. Three orthogonal planes of the brain, tomographic ultrasound imaging (TUI) and other off-line approaches (e.g. volume contrast imaging (VCI) or HDlive silhouette imaging) may be obtained from a single 3D dataset. 3D Doppler ultrasound enables visualization of the intracerebral vascularity, allowing to obtain more precise information on cerebral perfusion. Various abnormal brain conditions, including ventriculomegaly, agenesis of the corpus callosum, posterior fossa abnormalities and others, can be well-demonstrated. Due to high rates of the associated anomalies and uncertain prognosis, any suspicion of CNS abnormalities shall imply detailed ultrasonographic evaluation of the fetal anatomy to exclude the associated anomalies. Despite a growing number of neuroimaging modalities, prenatal counselling remains a challenge as prediction of brain functionality and the neurological prognosis often remain uncertain. New investigations on the relations between various migration disorders and gene mutations, as well as recent clinical research on the relations between neuroimaging detection of local migration disorders using sophisticated imaging technologies and the postnatal neurological prognosis will contribute to the development of maternal-fetal medicine as well as pediatric neurology.

  20. Three Dimensional Optic Tissue Culture and Process

    NASA Technical Reports Server (NTRS)

    OConnor, Kim C. (Inventor); Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); Aten, Laurie A. (Inventor); Francis, Karen M. (Inventor); Caldwell, Delmar R. (Inventor); Prewett, Tacey L. (Inventor); Fitzgerald, Wendy S. (Inventor)

    1999-01-01

    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioireactor at low shear conditions. The tissue forms as normal, functional tissue grows with tissue organization and extracellular matrix formation.

  1. Three dimensional optic tissue culture and process

    NASA Technical Reports Server (NTRS)

    Spaulding, Glenn F. (Inventor); Prewett, Tacey L. (Inventor); Goodwin, Thomas J. (Inventor); Francis, Karen M. (Inventor); Cardwell, Delmar R. (Inventor); Oconnor, Kim (Inventor); Fitzgerald, Wendy S. (Inventor); Aten, Laurie A. (Inventor)

    1994-01-01

    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix.

  2. Device fabrication: Three-dimensional printed electronics

    NASA Astrophysics Data System (ADS)

    Lewis, Jennifer A.; Ahn, Bok Y.

    2015-02-01

    Can three-dimensional printing enable the mass customization of electronic devices? A study that exploits this method to create light-emitting diodes based on 'quantum dots' provides a step towards this goal.

  3. Three-dimensional printing of surgical anatomy.

    PubMed

    Powers, Mary K; Lee, Benjamin R; Silberstein, Jonathan

    2016-05-01

    Over the past decade, three-dimensional printing for the medical field has been expanding rapidly throughout all of medicine. This manuscript reviews the current and potential applications for three-dimensional printing, including education, presurgical planning, surgical simulation, bioprinting, and printed surgical equipment. Three-dimensional printing has proved most relevant in the fields of craniofacial, plastic, orthopedics, and especially, urologic surgery. This review focuses on several examples of how three-dimensional printing can be utilized, with emphasis on renal models for renal cell carcinoma, ureteral stents, and staghorn calculus. From an education standpoint, both patients and residents can benefit from the use of three-dimensional printed models, and even skilled surgeons report better understanding of complex procedures by using printed models. Three-dimensional printing in the field of medicine is growing quickly, and will soon be incorporated into the way residents are taught and patients are educated. For surgical simulation in a variety of disease processes, this will be particularly useful for urologic surgery.

  4. Three-dimensional motion measurements using feature tracking.

    PubMed

    Kuo, Johnny; von Ramm, Olaf T

    2008-04-01

    Feature tracking was developed to efficiently compute motion measurements from volumetric ultrasound images. Prior studies have demonstrated the motion magnitude accuracy and computation speed of feature tracking. However, the previous feature tracking implementations were limited by performance of their calculations in rectilinear coordinates. Also, the previous feature tracking approaches did not fully explore the three dimensional (3- D) nature of volumetric image analysis or utilize the 3-D directional information from the tracking calculations. This study presents an improved feature tracking method which achieves further computation speed gains by performing all calculations in the native spherical coordinates of the 3-D ultrasound image. The novel method utilizes a statistical analysis of tracked directions of motion to achieve better rejection of false tracking matches. Results from in vitro tracking of a speckle target show that the new feature tracking method is significantly faster than correlation search and can accurately determine target motion magnitude and 3-D direction.

  5. Three-dimensional separation and reattachment

    NASA Technical Reports Server (NTRS)

    Peake, D. J.; Tobak, M.

    1982-01-01

    The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be construed as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.

  6. Topology of three-dimensional separated flows

    NASA Technical Reports Server (NTRS)

    Tobak, M.; Peake, D. J.

    1981-01-01

    Based on the hypothesis that patterns of skin-friction lines and external streamlines reflect the properties of continuous vector fields, topology rules define a small number of singular points (nodes, saddle points, and foci) that characterize the patterns on the surface and on particular projections of the flow (e.g., the crossflow plane). The restricted number of singular points and the rules that they obey are considered as an organizing principle whose finite number of elements can be combined in various ways to connect together the properties common to all steady three dimensional viscous flows. Introduction of a distinction between local and global properties of the flow resolves an ambiguity in the proper definition of a three dimensional separated flow. Adoption of the notions of topological structure, structural stability, and bifurcation provides a framework to describe how three dimensional separated flows originate and succeed each other as the relevant parameters of the problem are varied.

  7. Three-dimensional separation and reattachment

    NASA Technical Reports Server (NTRS)

    Peake, D. J.; Tobak, M.

    1982-01-01

    The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be constrained as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.

  8. Vision in our three-dimensional world.

    PubMed

    Parker, Andrew J

    2016-06-19

    Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices.This article is part of the themed issue 'Vision in our three-dimensional world'. © 2016 The Author(s).

  9. Vision in our three-dimensional world

    PubMed Central

    2016-01-01

    Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269595

  10. Three dimensional boundary conditions in supersonic flow

    NASA Technical Reports Server (NTRS)

    Rudman, S.; Marconi, F.

    1981-01-01

    A theoretical analysis of the flow pattern at a solid surface in three dimensional supersonic flow is presented. The additional information necessary to overcome the nonuniqueness associated with the body tangency condition in three dimensions was developed. The analysis is based on the fact that three dimensional waves propagate locally exactly as they do in axisymmetric flow when viewed in the osculating plane to the streamline. The supersonic flow over an infinite swept corner is examined by both the classical solution and the three dimensional solution in the osculating plane and the results are shown to be identical. A simple numerical algorithm is proposed which accounts for the three wave surfaces that interact at a solid boundary.

  11. Three-dimensional stability of vortex arrays

    NASA Astrophysics Data System (ADS)

    Robinson, A. C.; Saffman, P. G.

    1982-12-01

    The stability to three-dimensional disturbances of three classical steady vortex configurations in an incompressible inviscid fluid is studied in the limit of small vortex cross-sectional area and long axial disturbance wavelength. The configurations examined are the single infinite vortex row, the Karman vortex street of staggered vortices and the symmetric vortex street. It is shown that the single row is most unstable to a two-dimensional disturbance, while the Karman vortex street is most unstable to a three-dimensional disturbance over a significant range of street spacing ratios. The symmetric vortex street is found to be most unstable to three-dimensional or two-dimensional symmetric disturbances depending on the spacing ratio of the street. Short remarks are made concerning the relevance of the calculations to the observed instabilities in free shear layer, wake and boundary-layer type flows.

  12. Fabrication of three dimensional microstructure fiber

    NASA Astrophysics Data System (ADS)

    Luo, Ying; Ma, Jie; Chen, Zhe; Lu, Huihui; Zhong, Yongchun

    2015-05-01

    A method of fabricating three dimensional (3D) microstructured fiber is presented. Polystyrene (PS) microspheres were coated around the surface of a micro-fiber through isothermal heating evaporation induced self-assembly method. Scanning electron microscopy (SEM) image shows that the colloidal crystal has continuous, uniform, and well-ordered face-centered cubic (FCC) structure, with [111] crystallographic direction normal to the surface of micro-fiber. This micro-fiber with three-dimensional photonic crystals structure is very useful in the applications of micro-fiber sensors or filters.

  13. Three-dimensional topological insulators and bosonization

    NASA Astrophysics Data System (ADS)

    Cappelli, Andrea; Randellini, Enrico; Sisti, Jacopo

    2017-05-01

    Massless excitations at the surface of three-dimensional time-reversal invariant topological insulators possess both fermionic and bosonic descriptions, originating from band theory and hydrodynamic BF theory, respectively. We analyze the corresponding field theories of the Dirac fermion and compactified boson and compute their partition functions on the three-dimensional torus geometry. We then find some non-dynamic exact properties of bosonization in (2+1) dimensions, regarding fermion parity and spin sectors. Using these results, we extend the Fu-Kane-Mele stability argument to fractional topological insulators in three dimensions.

  14. Three-dimensional displays and stereo vision.

    PubMed

    Westheimer, Gerald

    2011-08-07

    Procedures for three-dimensional image reconstruction that are based on the optical and neural apparatus of human stereoscopic vision have to be designed to work in conjunction with it. The principal methods of implementing stereo displays are described. Properties of the human visual system are outlined as they relate to depth discrimination capabilities and achieving optimal performance in stereo tasks. The concept of depth rendition is introduced to define the change in the parameters of three-dimensional configurations for cases in which the physical disposition of the stereo camera with respect to the viewed object differs from that of the observer's eyes.

  15. Three-dimensional crack closure behavior

    NASA Technical Reports Server (NTRS)

    Dawicke, D. S.; Grandt, A. F., Jr.; Newman, J. C., Jr.

    1990-01-01

    A crack closure measurement technique involving fatigue striations was used to produce a three-dimensional crack opening load profile for 2024-T351 aluminum alloy. The crack opening load profile, determined through the specimen thickness, was compared with crack opening load measurements made with strain gages and displacement gages. The results of this study indicate that a significant three-dimensional variation in crack closure behavior occurs in the alloy examined. An understanding of this phehomenon is important in understanding crack growth behavior, predicting crack shape changes, and interpreting 'standard' crack closure measurement techniques.

  16. Three-dimensional stochastic vortex flows

    NASA Astrophysics Data System (ADS)

    Esposito, R.; Pulvirenti, M.

    1989-08-01

    It is well known that the dynamics of point vortices approximate, under suitable limits, the two-dimensional Euler flow for an ideal fluid. To find particle models for three-dimensional flows is a more intricate problem. A stochastic version of the algorithm introduced by Beale amd Maida (1982) for simulating the behavior of a three-dimensional Euler flow is introduced here, and convergence to the Navier-Stokes (NS) flow in R exp 3 is shown. The result is based on a stochastic Lagrangian picture of the NS equations.

  17. Three-dimensional magnetic bubble memory system

    NASA Technical Reports Server (NTRS)

    Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor)

    1994-01-01

    A compact memory uses magnetic bubble technology for providing data storage. A three-dimensional arrangement, in the form of stacks of magnetic bubble layers, is used to achieve high volumetric storage density. Output tracks are used within each layer to allow data to be accessed uniquely and unambiguously. Storage can be achieved using either current access or field access magnetic bubble technology. Optical sensing via the Faraday effect is used to detect data. Optical sensing facilitates the accessing of data from within the three-dimensional package and lends itself to parallel operation for supporting high data rates and vector and parallel processing.

  18. Three-dimensional chiral photonic superlattices.

    PubMed

    Thiel, M; Fischer, H; von Freymann, G; Wegener, M

    2010-01-15

    We investigate three-dimensional photonic superlattices composed of polymeric helices in various spatial checkerboard-like arrangements. Depending on the relative phase shift and handedness of the chiral building blocks, different circular-dichroism resonances appear or are suppressed. Samples corresponding to four different configurations are fabricated by direct laser writing. The measured optical transmittance spectra are in good agreement with numerical calculations.

  19. Three-dimensional RF structure calculations

    NASA Astrophysics Data System (ADS)

    Cooper, R. K.; Browman, M. J.; Weiland, T.

    1989-04-01

    The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described.

  20. Three-dimensional rf structure calculations

    SciTech Connect

    Cooper, R.K.; Browman, M.J.; Weiland, T.

    1988-01-01

    The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described. 13 refs., 14 figs.

  1. Growing Three-Dimensional Cocultures Of Cells

    NASA Technical Reports Server (NTRS)

    Wolf, David A.; Goodwin, Thomas J.

    1995-01-01

    Laboratory process provides environmental conditions favoring simultaneous growth of cocultures of mammalian cells of more than one type. Cultures become three-dimensional tissuelike assemblies serving as organoid models of differentiation of cells. Process used, for example, to study growth of human colon cancers, starting from mixtures of normal colonic fibroblasts and partially differentiated colon adenocarcinoma cells.

  2. Spectral tomography of three-dimensional objects

    SciTech Connect

    Bulygin, F.V.; Levin, G.G.

    1995-12-01

    Spectral tomography is a new field in optical tomography concerned with studies of the internal space-spectral structure of polychromatic objects. In this paper, methods for obtaining projections spectral structure of three-dimensional objects and algorithms for its reconstruction are proposed and described. The results of the spectral-tomography reconstruction of the object structure are presented. 6 refs., 4 figs.

  3. Three-Dimensional Printing Surgical Applications.

    PubMed

    AlAli, Ahmad B; Griffin, Michelle F; Butler, Peter E

    2015-01-01

    Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice.

  4. Three dimensional reconnection in astrophysical plasmas

    NASA Technical Reports Server (NTRS)

    Spicer, D. S.

    1990-01-01

    Theoretical issues related to three-dimensional reconnection and its application to the space and astrophysical environment are reviewed. Consideration is given to the meaning of reconnection in three dimensions, the way in which periodic and nonperiodic magnetic topologies alter the physics of reconnections, and the effects of chaotic magnetic fields on the reconnection process.

  5. [Three Dimensional Display in Nuclear Medicine].

    PubMed

    Teraoka, Satomi; Souma, Tsutomu

    2015-01-01

    Imaging techniques to obtain a tomographic image in nuclear medicine such as PET and SPECT are widely used. It is necessary to interpreting all of the tomographic images obtained in order to accurately evaluate the individual lesion, whereas three dimensional display is often useful in order to overview and evaluate the feature of the entire lesion or disease such as the position, size and abnormal pattern. In Japan, the use of three dimensional image analysis workstation with an application of the co-registration and image fusion between the functional images such as PET or SPECT and anatomical images such as CT or MRI has been generalized. In addition, multimodality imaging system such as a PET/CT and SPECT/CT has been widespread. Therefore, it is expected to improve the diagnostic accuracy using three dimensionally image fusion to functional images with poor anatomical information. In this commentary, as an example of a three dimensional display that are commonly used in nuclear medicine examination in Japan, brain regions, cardiac region and bone and tumor region will be introduced separately.

  6. Three Dimensional Display Of Meteorological Scientific Data

    NASA Astrophysics Data System (ADS)

    Grotch, Stanley L.

    1988-01-01

    Even a cursory reading of any daily newspaper shows that we are in the midst of a dramatic revolution in computer graphics. Virtually every day some new piece of hardware or software is announced, adding to the tools available to the working scientist. Three dimensional graphics form a significant part of this revolution having become virtually commonplace in advertising and on television.

  7. Three-dimensional colorimetric assay assemblies

    DOEpatents

    Charych, Deborah; Reichert, Anke

    2001-01-01

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flue virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  8. Three-Dimensional Pointers for Stereoscopic Projection.

    ERIC Educational Resources Information Center

    Hayman, H. J. G.

    1984-01-01

    Because class size often limits student opportunity to handle individual models, teachers use stereoscopic projections to demonstrate structural features. Describes three-dimensional pointers for use with different projection systems so teachers can indicate a particular atom or bond to entire classes, avoiding the perspective problems inherent in…

  9. Growing Three-Dimensional Cocultures Of Cells

    NASA Technical Reports Server (NTRS)

    Wolf, David A.; Goodwin, Thomas J.

    1995-01-01

    Laboratory process provides environmental conditions favoring simultaneous growth of cocultures of mammalian cells of more than one type. Cultures become three-dimensional tissuelike assemblies serving as organoid models of differentiation of cells. Process used, for example, to study growth of human colon cancers, starting from mixtures of normal colonic fibroblasts and partially differentiated colon adenocarcinoma cells.

  10. Three-dimensional implicit lambda methods

    NASA Technical Reports Server (NTRS)

    Napolitano, M.; Dadone, A.

    1983-01-01

    This paper derives the three dimensional lambda-formulation equations for a general orthogonal curvilinear coordinate system and provides various block-explicit and block-implicit methods for solving them, numerically. Three model problems, characterized by subsonic, supersonic and transonic flow conditions, are used to assess the reliability and compare the efficiency of the proposed methods.

  11. Three-Dimensional Visualization of Particle Tracks.

    ERIC Educational Resources Information Center

    Julian, Glenn M.

    1993-01-01

    Suggests ways to bring home to the introductory physics student some of the excitement of recent discoveries in particle physics. Describes particle detectors and encourages the use of the Standard Model along with real images of particle tracks to determine three-dimensional views of tracks. (MVL)

  12. Three-Dimensional Printing Surgical Applications

    PubMed Central

    Griffin, Michelle F.; Butler, Peter E.

    2015-01-01

    Introduction: Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. Objective: To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Methods: Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Discussion: Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Conclusion: Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice. PMID:26301002

  13. Three-dimensional sonography in prenatal diagnosis: a luxury or a necessity?

    PubMed

    Kurjak, A; Hafner, T; Kos, M; Kupesic, S; Stanojevic, M

    2000-01-01

    Three-dimensional sonography revolutionized ultrasound imaging with its capacity to depict an unlimited number of planes in which the object of interest can be displayed. The addition of numerous modalities of image rendering promotes three-dimensional sonography to the top of the spectrum of diagnostic imaging in obstetrics and gynecology. The aim of this article is to present our experience in 3-D sonography during the second and third trimester of pregnancy and to give a comparative review of literature. 247 patients in gestational age ranging from 12 to 40 weeks of gestation were examined over a three year period. The majority of patients entered the study because fetal anomaly was suspected at two-dimensional sonography. Some patients were sent on to three-dimensional sonography because it was not possible to depict clearly normal fetal anatomy by two dimensional sonography. Out of 170 fetal anomalies three-dimensional sonographic analysis failed in only three cases. In all three anomaly was accompanied with severe oligohydramnios. Main advantages of three-dimensional ultrasound in perinatal medicine and antenatal diagnosis include scanning in the coronal plane, improved assessment of complex anatomic structures, surface analysis of minor defects, volumetric measuring of organs, "plastic" transparent imaging of fetal skeleton, spatial presentation of blood flow arborization and, finally, storage of scanned volumes and images. It is our decided opinion that three-dimensional sonography has gained a valuable place in prenatal diagnosis, becoming a necessity for every modern perinatal unit.

  14. Three-dimensional patterning methods and related devices

    SciTech Connect

    Putnam, Morgan C.; Kelzenberg, Michael D.; Atwater, Harry A.; Boettcher, Shannon W.; Lewis, Nathan S.; Spurgeon, Joshua M.; Turner-Evans, Daniel B.; Warren, Emily L.

    2016-12-27

    Three-dimensional patterning methods of a three-dimensional microstructure, such as a semiconductor wire array, are described, in conjunction with etching and/or deposition steps to pattern the three-dimensional microstructure.

  15. 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 ...

  16. In vivo three-dimensional spectroscopic photoacoustic imaging for monitoring nanoparticle delivery

    PubMed Central

    Kim, Seungsoo; Chen, Yun-Sheng; Luke, Geoffrey P.; Emelianov, Stanislav Y.

    2011-01-01

    Abstract In vivo monitoring of nanoparticle delivery is essential to better understand cellular and molecular interactions of nanoparticles with tissue and to better plan nanoparticle-mediated therapies. We developed a three-dimensional ultrasound and photoacoustic (PA) imaging system and a spectroscopic PA imaging algorithm to identify and quantify the presence of nanoparticles and other tissue constituents. Using the developed system and approach, three-dimensional in vivo imaging of a mouse with tumor was performed before and after intravenous injection of gold nanorods. The developed spectroscopic PA imaging algorithm estimated distribution of nanoparticle as well as oxygen saturation of blood. Moreover, silver staining of excised tumor tissue confirmed nanoparticle deposition, and showed good correlation with spectroscopic PA images. The results of our study suggest that three-dimensional ultrasound-guided spectroscopic PA imaging can monitor nanoparticle delivery in vivo. PMID:21991546

  17. Co-registered spectral photoacoustic tomography and ultrasonography of breast cancer

    NASA Astrophysics Data System (ADS)

    Ke, Haixin; Erpelding, Todd N.; Garcia-Uribe, Alejandro; Jacobs, Eileen; Holley, Susan; Monsees, Barbara; Wang, Lihong V.

    2014-03-01

    Many breast cancer patients receive neoadjuvant treatment to reduce tumor size and enable breast conserving therapy. Most imaging methods used to monitor response to neoadjuvant chemotherapy or hormone therapy depend on overall gross tumor morphology and size measurements, which may not be sensitive or specific, despite tumor response on a cellular level. A more sensitive and specific method of detecting response to therapy might allow earlier adjustments in treatment, and thus result in better outcomes while avoiding unnecessary morbidity. We developed an imaging system that combines spectral photoacoustic tomography and ultrasonography to predict breast neoadjuvant therapeutic response based on blood volume and blood oxygenation contrast. The system consists of a tunable dye laser pumped by a Nd:YAG laser, a commercial ultrasound imaging system (Philips iU22), and a multichannel data acquisition system which displays co-registered photoacoustic and ultrasound images in real time. Early studies demonstrate functional imaging capabilities, such as oxygen saturation and total concentration of hemoglobin, in addition to ultrasonography of tumor morphology. Further study is needed to determine if the co-registered photoacoustic tomography and ultrasonography system may provide an accurate tool to assess treatment efficacy by monitoring tumor response in vivo.

  18. Three Dimensional Particle Tracking in Superfluid Helium

    NASA Astrophysics Data System (ADS)

    Megson, Peter

    2016-11-01

    Superfluid helium is a macroscopic quantum state which exhibits exotic physical properties, such as flow without friction and ballistic heat transport. Superfluid flow is irrotational except about line-like topological phase defects with quantized circulation, known as quatized vortices. The presence of these vortices and their dynamics is the dominating factor of turbulence in superfluid flows. One commonly studied regime of superfluid turbulence is thermal counterflow, where a local heat flux drives the formation and growth of a tangle of vortices. This talk will present experimental studies of counterflow turbulence performed using a multi-camera three-dimensional imaging apparatus with micron-sized ice tracer particles as well as fluorescent nanoparticles. In particular, we will discuss the measurement of three-dimensional velocties and their autocorrelations. Additionally, we are developing new techniques for optical studies of bulk superfluid helium, with particular focus on characterizing tracer particles and particle dispersal mechanisms. Funding from NSF DMR-1407472.

  19. Three-dimensional trabecular alignment model.

    PubMed

    Bono, Eric S; Smolinski, Patrick; Casagranda, Al; Xu, Junde

    2003-04-01

    Trabecular alignment theory has been used to quantify Wolff's Law of bone remodeling. A three-dimensional finite element scheme was developed to analyze the bone remodeling phenomenon. The mathematical model proposed by Mullender et al. and later modified by Smith et al. was adopted to simulate the surface-based trabecular resorption and formation processes. Enhancements incorporated into the previous model include: mapping into three-dimensions, controlling the remodeling signal's passage through marrow, controlling the finite distance the signal may pass through the bone matrix, and including non-bone material in the finite element model. After the model is explained and thoroughly studied, three-dimensional implant surface geometries are simulated.

  20. Analysis of three-dimensional transonic compressors

    NASA Technical Reports Server (NTRS)

    Bourgeade, A.

    1984-01-01

    A method for computing the three-dimensional transonic flow around the blades of a compressor or of a propeller is given. The method is based on the use of the velocity potential, on the hypothesis that the flow is inviscid, irrotational and isentropic. The equation of the potential is solved in a transformed space such that the surface of the blade is mapped into a plane where the periodicity is implicit. This equation is in a nonconservative form and is solved with the help of a finite difference method using artificial time. A computer code is provided and some sample results are given in order to demonstrate the influence of three-dimensional effects and the blade's rotation.

  1. Three dimensional fabrication at small size scales

    PubMed Central

    Leong, Timothy G.; Zarafshar, Aasiyeh M.; Gracias, David H.

    2010-01-01

    Despite the fact that we live in a three-dimensional (3D) world and macroscale engineering is 3D, conventional sub-mm scale engineering is inherently two-dimensional (2D). New fabrication and patterning strategies are needed to enable truly three-dimensionally-engineered structures at small size scales. Here, we review strategies that have been developed over the last two decades that seek to enable such millimeter to nanoscale 3D fabrication and patterning. A focus of this review is the strategy of self-assembly, specifically in a biologically inspired, more deterministic form known as self-folding. Self-folding methods can leverage the strengths of lithography to enable the construction of precisely patterned 3D structures and “smart” components. This self-assembling approach is compared with other 3D fabrication paradigms, and its advantages and disadvantages are discussed. PMID:20349446

  2. Three-dimensional imaging modalities in endodontics.

    PubMed

    Mao, Teresa; Neelakantan, Prasanna

    2014-09-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

  3. Three-dimensional imaging modalities in endodontics

    PubMed Central

    Mao, Teresa

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome. PMID:25279337

  4. Arching in three-dimensional clogging

    NASA Astrophysics Data System (ADS)

    Török, János; Lévay, Sára; Szabó, Balázs; Somfai, Ellák; Wegner, Sandra; Stannarius, Ralf; Börzsönyi, Tamás

    2017-06-01

    Arching in dry granular material is a long established concept, however it remains still an open question how three-dimensional orifices clog. We investigate by means of numerical simulations and experimental data how the outflow creates a blocked configuration of particles. We define the concave surface of the clogged dome by two independent methods (geometric and density based). The average shape of the cupola for spheres is almost a hemisphere but individual samples have large holes in the structure indicating a blocked state composed of two-dimensional force chains rather than three-dimensional objects. The force chain structure justifies this assumption. For long particles the clogged configurations display large variations, and in certain cases the empty region reaches a height of 5 hole diameters. These structures involve vertical walls consisting of horizontally placed stable stacking of particles.

  5. Three-dimensional effects on airfoils

    NASA Technical Reports Server (NTRS)

    Chevallier, J. P.

    1983-01-01

    The effects of boundary layer flows along the walls of wind tunnels were studied to validate the transfer of two dimensional calculations to three dimensional transonic flowfield calculations. Results from trials in various wind tunnels were examind to determine the effects of the wall boundary flow on the control surfaces of an airfoil. Models sliding along a groove in the wall of a channel at sub- and transonic speeds were examined, with the finding that with either nonuniformities in the groove, or even if the channel walls are uniform, the lateral boundary layer can cause variations in the central flow region or alter the onset of shock at the transition point. Models for the effects in both turbulence and in the absence of turbulence are formulated, and it is noted that the characteristics of individual wind tunnels must be studied to quantify any existing three dimensional effects.

  6. Three dimensional digital imaging of environmental data

    SciTech Connect

    Nichols, R.L.; Eddy, C.A.

    1991-06-14

    The Environmental Sciences Section (ESS) of the Savannah River Laboratory has recently acquired the computer hardware (Silicon Graphics Personal Iris Workstations) and software (Dynamic Graphics, Interactive Surface and Volume Modeling) to perform three dimensional analysis of hydrogeologic data. Three dimensional digital imaging of environmental data is a powerful technique that can be used to incorporate field, analytical, and modeling results from geologic, hydrologic, ecologic, and chemical studies into a comprehensive model for visualization and interpretation. This report covers the contamination of four different sites of the Savannah River Plant. Each section of this report has a computer graphic display of the concentration of contamination in the groundwater and/or sediments of each site.

  7. Real time three dimensional sensing system

    DOEpatents

    Gordon, Steven J.

    1996-01-01

    The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane.

  8. Real time three dimensional sensing system

    DOEpatents

    Gordon, S.J.

    1996-12-31

    The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane. 7 figs.

  9. Bootstrapping the Three Dimensional Supersymmetric Ising Model.

    PubMed

    Bobev, Nikolay; El-Showk, Sheer; Mazáč, Dalimil; Paulos, Miguel F

    2015-07-31

    We implement the conformal bootstrap program for three dimensional conformal field theories with N=2 supersymmetry and find universal constraints on the spectrum of operator dimensions in these theories. By studying the bounds on the dimension of the first scalar appearing in the operator product expansion of a chiral and an antichiral primary, we find a kink at the expected location of the critical three dimensional N=2 Wess-Zumino model, which can be thought of as a supersymmetric analog of the critical Ising model. Focusing on this kink, we determine, to high accuracy, the low-lying spectrum of operator dimensions of the theory, as well as the stress-tensor two-point function. We find that the latter is in an excellent agreement with an exact computation.

  10. Simulation of complex three-dimensional flows

    NASA Technical Reports Server (NTRS)

    Diewert, G. S.; Rothmund, H. J.; Nakahashi, K.

    1985-01-01

    The concept of splitting is used extensively to simulate complex three dimensional flows on modern computer architectures. Used in all aspects, from initial grid generation to the determination of the final converged solution, splitting is used to enhance code vectorization, to permit solution driven grid adaption and grid enrichment, to permit the use of concurrent processing, and to enhance data flow through hierarchal memory systems. Three examples are used to illustrate these concepts to complex three dimensional flow fields: (1) interactive flow over a bump; (2) supersonic flow past a blunt based conical afterbody at incidence to a free stream and containing a centered propulsive jet; and (3) supersonic flow past a sharp leading edge delta wing at incidence to the free stream.

  11. Three dimensional contact/impact methodology

    SciTech Connect

    Kulak, R.F.

    1987-01-01

    The simulation of three-dimensional interface mechanics between reactor components and structures during static contact or dynamic impact is necessary to realistically evaluate their structural integrity to off-normal loads. In our studies of postulated core energy release events, we have found that significant structure-structure interactions occur in some reactor vessel head closure designs and that fluid-structure interactions occur within the reactor vessel. Other examples in which three-dimensional interface mechanics play an important role are: (1) impact response of shipping casks containing spent fuel, (2) whipping pipe impact on reinforced concrete panels or pipe-to-pipe impact after a pipe break, (3) aircraft crash on secondary containment structures, (4) missiles generated by turbine failures or tornados, and (5) drops of heavy components due to lifting accidents. The above is a partial list of reactor safety problems that require adequate treatment of interface mechanics and are discussed in this paper.

  12. Three-dimensional bio-printing.

    PubMed

    Gu, Qi; Hao, Jie; Lu, YangJie; Wang, Liu; Wallace, Gordon G; Zhou, Qi

    2015-05-01

    Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at the exploratory stage. This review summarize the development of 3D bio-printing and its potential in medical applications, as well as discussing the current challenges faced by 3D bio-printing.

  13. Three-dimensional metallic boron nitride.

    PubMed

    Zhang, Shunhong; Wang, Qian; Kawazoe, Yoshiyuki; Jena, Puru

    2013-12-04

    Boron nitride (BN) and carbon are chemical analogues of each other and share similar structures such as one-dimensional nanotubes, two-dimensional nanosheets characterized by sp(2) bonding, and three-dimensional diamond structures characterized by sp(3) bonding. However, unlike carbon which can be metallic in one, two, and three dimensions, BN is an insulator, irrespective of its structure and dimensionality. On the basis of state-of-the-art theoretical calculations, we propose a tetragonal phase of BN which is both dynamically stable and metallic. Analysis of its band structure, density of states, and electron localization function confirms the origin of the metallic behavior to be due to the delocalized B 2p electrons. The metallicity exhibited in the studied three-dimensional BN structures can lead to materials beyond conventional ceramics as well as to materials with potential for applications in electronic devices.

  14. Three-dimensional magnetic field annihilation

    NASA Astrophysics Data System (ADS)

    Jardine, M.; Allen, H. R.; Grundy, R. E.

    1993-11-01

    We present a family of three-dimensional nonlinear solutions for magnetic field annihilation in a current sheet, including the effects of resistivity and viscosity. The different members of the family are characterized by the imposed vorticity of the flow that brings the field lines together. Since in a three- dimensional flow the vorticity can be increased by the stretching of vortex lines (an effect that is absent in two dimensions), we find some striking differences to our previous two-dimensional analysis. In both the two-dimensional and three-dimensional analyses, above a certain critical imposed vorticity omegacrit, the flow breaks up into cells with current sheet is completely altered. In the two-dimensional analysis, omegacrit is a steeply increasing function of the viscous Reynolds number R, whereas in the three-dimensional case, it quickly asymptotes to only omegacrit = 2v0/L where v0 and L are the characteristic velocity and length scale of the flow, respectively. The width of the current sheet, which depends on the speed at which field lines are carried into it, also responds differently to an increase in R. In two dimensions, the current sheet narrows for all vorticities, but three dimensions, it narrows when the imposed vorticity is negative and widens when it is positive. Also we find that the current density within the current sheet varies as the nature of the flow is changed, rather than being constant as in the the two-dimensional case. Finally, we find that there is a minimum value of the plasma beta betamin below which the plasma pressure is negative. For the nonsheared (neutral current sheet) case, betamin increases rapidly with the magnetic Reynolds number Rm such that this type of annihilation is only possible for a high-beta plasma. For a sheared magnetic field, however, betamin is much lower, making this type of annihilation more relevant to the sonar corona.

  15. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA; York, Jeremy [Bothell, WA

    2009-06-30

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  16. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.

    2006-09-26

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may e transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  17. Three-Dimensional Dispaly Of Document Set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.

    2003-06-24

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  18. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA

    2001-10-02

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  19. Method and apparatus for three dimensional braiding

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    1997-01-01

    A machine for three-dimensional braiding of fibers is provided in which carrier members travel on a curved, segmented and movable braiding surface. The carrier members are capable of independent, self-propelled motion along the braiding surface. Carrier member position on the braiding surface is controlled and monitored by computer. Also disclosed is a yarn take-up device capable of maintaining tension in the braiding fiber.

  20. Method and apparatus for three dimensional braiding

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    1995-01-01

    A machine for three-dimensional braiding of fibers is provided in which carrier members travel on a curved, segmented and movable braiding surface. The carrier members are capable of independent, self-propelled motion along the braiding surface. Carrier member position on the braiding surface is controlled and monitored by computer. Also disclosed is a yarn take-up device capable of maintaining tension in the braiding fiber.

  1. Three dimensional boundary layers in internal flows

    NASA Technical Reports Server (NTRS)

    Bodonyi, R. J.

    1987-01-01

    A numerical study of the effects of viscous-inviscid interactions in three-dimensional duct flows is presented. In particular interacting flows for which the oncoming flow is not fully-developed were considered. In this case there is a thin boundary layer still present upstream of the surface distortion, as opposed to the fully-developed pipe flow situation wherein the flow is viscous across the cross section.

  2. Three-dimensional accelerating electromagnetic waves.

    PubMed

    Bandres, Miguel A; Alonso, Miguel A; Kaminer, Ido; Segev, Mordechai

    2013-06-17

    We present a general theory of three-dimensional non-paraxial spatially-accelerating waves of the Maxwell equations. These waves constitute a two-dimensional structure exhibiting shape-invariant propagation along semicircular trajectories. We provide classification and characterization of possible shapes of such beams, expressed through the angular spectra of parabolic, oblate and prolate spheroidal fields. Our results facilitate the design of accelerating beams with novel structures, broadening scope and potential applications of accelerating beams.

  3. Three Dimensional Inverse Synthetic Aperture Radar Imaging

    DTIC Science & Technology

    1995-12-01

    to upsample the projection data in order to get sufficient image quality. Working within these memory constraints, three-dimensional images were... metallic film on the windscreen in order to block reflections from the cockpit. Photographs and scale drawings of the model are shown in Figures 11 and...as well as spurious responses in the final image. Theoretically, sufficient resolution should have been available without upsampling the original data

  4. Three-dimensional simulation of vortex breakdown

    NASA Technical Reports Server (NTRS)

    Kuruvila, G.; Salas, M. D.

    1990-01-01

    The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state.

  5. Three-Dimensional Shallow Water Acoustics

    DTIC Science & Technology

    2014-09-30

    sound can occur and produce significant three-dimensional (3-D) sound propagation effects. The long-term goals of this project are targeted on...efficient and accurate 3D acoustics models for studying underwater sound propagation in complex ocean environments. The ultimate scientific...objective is to study the underlying physics of the 3-D sound propagation effects caused jointly by physical oceanographic processes and geological features

  6. Lossless compression for three-dimensional images

    NASA Astrophysics Data System (ADS)

    Tang, Xiaoli; Pearlman, William A.

    2004-01-01

    We investigate and compare the performance of several three-dimensional (3D) embedded wavelet algorithms on lossless 3D image compression. The algorithms are Asymmetric Tree Three-Dimensional Set Partitioning In Hierarchical Trees (AT-3DSPIHT), Three-Dimensional Set Partitioned Embedded bloCK (3D-SPECK), Three-Dimensional Context-Based Embedded Zerotrees of Wavelet coefficients (3D-CB-EZW), and JPEG2000 Part II for multi-component images. Two kinds of images are investigated in our study -- 8-bit CT and MR medical images and 16-bit AVIRIS hyperspectral images. First, the performances by using different size of coding units are compared. It shows that increasing the size of coding unit improves the performance somewhat. Second, the performances by using different integer wavelet transforms are compared for AT-3DSPIHT, 3D-SPECK and 3D-CB-EZW. None of the considered filters always performs the best for all data sets and algorithms. At last, we compare the different lossless compression algorithms by applying integer wavelet transform on the entire image volumes. For 8-bit medical image volumes, AT-3DSPIHT performs the best almost all the time, achieving average of 12% decreases in file size compared with JPEG2000 multi-component, the second performer. For 16-bit hyperspectral images, AT-3DSPIHT always performs the best, yielding average 5.8% and 8.9% decreases in file size compared with 3D-SPECK and JPEG2000 multi-component, respectively. Two 2D compression algorithms, JPEG2000 and UNIX zip, are also included for reference, and all 3D algorithms perform much better than 2D algorithms.

  7. Mineralized Three-Dimensional Bone Constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2013-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  8. Three-Dimensional Ocean Noise Modeling

    DTIC Science & Technology

    2015-03-01

    particular attention paid to the case of Gaussian canyon . The solution to the three-dimensional wave equation in Cartesian co-ordinates can be written...in terms of a modal decomposition, carried out in the vertical and across- canyon horizontal directions. Work Completed 1. Nx2D and 3D Noise PE...azimuth in the Hudson Canyon [Figure 2). Additionally, the PE-reciprocity noise model was used to estimate the size, speed and distance from the

  9. Three-dimensional motor schema based navigation

    NASA Technical Reports Server (NTRS)

    Arkin, Ronald C.

    1989-01-01

    Reactive schema-based navigation is possible in space domains by extending the methods developed for ground-based navigation found within the Autonomous Robot Architecture (AuRA). Reformulation of two dimensional motor schemas for three dimensional applications is a straightforward process. The manifold advantages of schema-based control persist, including modular development, amenability to distributed processing, and responsiveness to environmental sensing. Simulation results show the feasibility of this methodology for space docking operations in a cluttered work area.

  10. Three-dimensional ballistocardiography in weightlessness

    NASA Technical Reports Server (NTRS)

    Scano, A.

    1981-01-01

    An experiment is described the aim of which is to record a three dimensional ballistocardiogram under the condition of weightlessness and to compare it with tracings recorded on the same subject on the ground as a means of clarifying the meaning of ballistocardiogram waves in different physiological and perphaps pathological conditions. Another purpose is to investigate cardiovascular and possibly fluid adaptations to weightlessness from data collected almost simultaneously on the same subjects during the other cardiovascular during the other cardiovascular and metabolic experiments.

  11. Three-dimensional adjustment of trilateration data

    NASA Technical Reports Server (NTRS)

    Sung, L.-Y.; Jackson, D. D.

    1985-01-01

    The three-dimensional locations of the monuments in the USGS Hollister trilateration network were adjusted to fit line length observations observed in 1977, using a Bayesian approach, and incorporating prior elevation estimates as data in the adjustment procedure. No significant discrepancies in the measured line lengths were found, but significant elevation adjustments (up to 1.85 m) were needed to fit the length data.

  12. Three-Dimensional (3D) Distribution

    DTIC Science & Technology

    2009-03-11

    witnessed by ongoing efforts in both Afghanistan and Iraq , must turn distribution challenges into opportunities by mastering Three-Dimensional (3D...sustainment. 5 Joint Logistics Functions •Supply •Services •Maintenance •Transportation • Health Service Support •General Engineering Joint Personnel...Maintenance •Transportation • Health Service Support •Explosive Ordinance Disposal •Human Resource Support •Legal Support •Religious Support •Financial

  13. Three-Dimensional Printing in Orthopedic Surgery.

    PubMed

    Eltorai, Adam E M; Nguyen, Eric; Daniels, Alan H

    2015-11-01

    Three-dimensional (3D) printing is emerging as a clinically promising technology for rapid prototyping of surgically implantable products. With this commercially available technology, computed tomography or magnetic resonance images can be used to create graspable objects from 3D reconstructed images. Models can enhance patients' understanding of their pathology and surgeon preoperative planning. Customized implants and casts can be made to match an individual's anatomy. This review outlines 3D printing, its current applications in orthopedics, and promising future directions.

  14. Real Imagery as a Three Dimensional Display

    DTIC Science & Technology

    1991-12-01

    under two categories--stereoscopic and autostereoscopic displays. The difference between these two displays is that autostereoscopic displays do not...require the use of special viewing glasses whereas stereoscopic displays do. In order to place a minimum incumbrance on the viewer, the autostereoscopic ...fooled into believing that the scene is three dimensional. This is accomplished even though the second view that normally comes with an autostereoscopic

  15. Mineralized three-dimensional bone constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2011-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  16. Multiparallel Three-Dimensional Optical Microscopy

    NASA Technical Reports Server (NTRS)

    Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel

    2010-01-01

    Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.

  17. Three-dimensional deformation of orthodontic brackets

    PubMed Central

    Melenka, Garrett W; Nobes, David S; Major, Paul W

    2013-01-01

    Braces are used by orthodontists to correct the misalignment of teeth in the mouth. Archwire rotation is a particular procedure used to correct tooth inclination. Wire rotation can result in deformation to the orthodontic brackets, and an orthodontic torque simulator has been designed to examine this wire–bracket interaction. An optical technique has been employed to measure the deformation due to size and geometric constraints of the orthodontic brackets. Images of orthodontic brackets are collected using a stereo microscope and two charge-coupled device cameras, and deformation of orthodontic brackets is measured using a three-dimensional digital image correlation technique. The three-dimensional deformation of orthodontic brackets will be evaluated. The repeatability of the three-dimensional digital image correlation measurement method was evaluated by performing 30 archwire rotation tests using the same bracket and archwire. Finally, five Damon 3MX and five In-Ovation R self-ligating brackets will be compared using this technique to demonstrate the effect of archwire rotation on bracket design. PMID:23762201

  18. Three-dimensional printing of the retina

    PubMed Central

    Lorber, Barbara; Hsiao, Wen-Kai; Martin, Keith R.

    2016-01-01

    Purpose of review Biological three-dimensional printing has received a lot of media attention over recent years with advances made in printing cellular structures, including skin and heart tissue for transplantation. Although limitations exist in creating functioning organs with this method, the hope has been raised that creating a functional retina to cure blindness is within reach. The present review provides an update on the advances made toward this goal. Recent findings It has recently been shown that two types of retinal cells, retinal ganglion cells and glial cells, can be successfully printed using a piezoelectric inkjet printer. Importantly, the cells remained viable and did not change certain phenotypic features as a result of the printing process. In addition, recent advances in the creation of complex and viable three-dimensional cellular structures have been made. Summary Some first promising steps toward the creation of a functional retina have been taken. It now needs to be investigated whether recent findings can be extended to other cells of the retina, including those derived from human tissue, and if a complex and viable retinal structure can be created through three-dimensional printing. PMID:27045545

  19. Three-dimensional printing of the retina.

    PubMed

    Lorber, Barbara; Hsiao, Wen-Kai; Martin, Keith R

    2016-05-01

    Biological three-dimensional printing has received a lot of media attention over recent years with advances made in printing cellular structures, including skin and heart tissue for transplantation. Although limitations exist in creating functioning organs with this method, the hope has been raised that creating a functional retina to cure blindness is within reach. The present review provides an update on the advances made toward this goal. It has recently been shown that two types of retinal cells, retinal ganglion cells and glial cells, can be successfully printed using a piezoelectric inkjet printer. Importantly, the cells remained viable and did not change certain phenotypic features as a result of the printing process. In addition, recent advances in the creation of complex and viable three-dimensional cellular structures have been made. Some first promising steps toward the creation of a functional retina have been taken. It now needs to be investigated whether recent findings can be extended to other cells of the retina, including those derived from human tissue, and if a complex and viable retinal structure can be created through three-dimensional printing.

  20. Three-Dimensional Imaging. Chapter 10

    NASA Technical Reports Server (NTRS)

    Kelso, R. M.; Delo, C.

    1999-01-01

    This chapter is concerned with three-dimensional imaging of fluid flows. Although relatively young, this field of research has already yielded an enormous range of techniques. These vary widely in cost and complexity, with the cheapest light sheet systems being within the budgets of most laboratories, and the most expensive Magnetic Resonance Imaging systems available to a select few. Taking the view that the most likely systems to be developed are those using light sheets, the authors will relate their knowledge and experience of such systems. Other systems will be described briefly and references provided. Flows are inherently three-dimensional in structure; even those generated around nominally 2-D surface geometry. It is becoming increasingly apparent to scientists and engineers that the three-dimensionalities, both large and small scale, are important in terms of overall flow structure and species, momentum, and energy transport. Furthermore, we are accustomed to seeing the world in three dimensions, so it is natural that we should wish to view, measure and interpret flows in three-dimensions. Unfortunately, 3-D images do not lend themselves to convenient presentation on the printed page, and this task is one of the challenges facing us.

  1. Three-Dimensional Audio Client Library

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A.

    2005-01-01

    The Three-Dimensional Audio Client Library (3DAudio library) is a group of software routines written to facilitate development of both stand-alone (audio only) and immersive virtual-reality application programs that utilize three-dimensional audio displays. The library is intended to enable the development of three-dimensional audio client application programs by use of a code base common to multiple audio server computers. The 3DAudio library calls vendor-specific audio client libraries and currently supports the AuSIM Gold-Server and Lake Huron audio servers. 3DAudio library routines contain common functions for (1) initiation and termination of a client/audio server session, (2) configuration-file input, (3) positioning functions, (4) coordinate transformations, (5) audio transport functions, (6) rendering functions, (7) debugging functions, and (8) event-list-sequencing functions. The 3DAudio software is written in the C++ programming language and currently operates under the Linux, IRIX, and Windows operating systems.

  2. Reconfigurable, braced, three-dimensional DNA nanostructures.

    PubMed

    Goodman, Russell P; Heilemann, Mike; Doose, Sören; Erben, Christoph M; Kapanidis, Achillefs N; Turberfield, Andrew J

    2008-02-01

    DNA nanotechnology makes use of the exquisite self-recognition of DNA in order to build on a molecular scale. Although static structures may find applications in structural biology and computer science, many applications in nanomedicine and nanorobotics require the additional capacity for controlled three-dimensional movement. DNA architectures can span three dimensions and DNA devices are capable of movement, but active control of well-defined three-dimensional structures has not been achieved. We demonstrate the operation of reconfigurable DNA tetrahedra whose shapes change precisely and reversibly in response to specific molecular signals. Shape changes are confirmed by gel electrophoresis and by bulk and single-molecule Förster resonance energy transfer measurements. DNA tetrahedra are natural building blocks for three-dimensional construction; they may be synthesized rapidly with high yield of a single stereoisomer, and their triangulated architecture conveys structural stability. The introduction of shape-changing structural modules opens new avenues for the manipulation of matter on the nanometre scale.

  3. Teaching and Assessing Three-Dimensional M

    NASA Astrophysics Data System (ADS)

    Bateman, Robert C., Jr.; Booth, Deborah; Sirochman, Rudy; Richardson, Jane; Richardson, David

    2002-05-01

    Structural concepts such as the exact arrangement of a protein in three dimensions are crucial to almost every aspect of biology and chemistry, yet most of us have not been educated in three-dimensional literacy and all of us need a great deal of help in order to perceive and to communicate structural information successfully. It is in the undergraduate biochemistry course where students learn most concepts of molecular structure pertinent to living systems. We are addressing the issue of three-dimensional structural literacy by having undergraduate students construct kinemages, which are plain text scripts derived from Protein Data Bank coordinate files that can be viewed with the program MAGE. These annotated, interactive, three-dimensional illustrations are designed to develop a molecular story and allow exploration in the world of that story. In the process, students become familiar with the structure-based scientific literature and the Protein Data Bank. Our assessment to date has shown that students perceive kinemage authorship to be more helpful in understanding protein structure than simply viewing prepared kinemages. In addition, students perceived kinemage authorship as being beneficial to their career and a significant motivation to learn biochemistry.

  4. Three-Dimensional Imaging. Chapter 10

    NASA Technical Reports Server (NTRS)

    Kelso, R. M.; Delo, C.

    1999-01-01

    This chapter is concerned with three-dimensional imaging of fluid flows. Although relatively young, this field of research has already yielded an enormous range of techniques. These vary widely in cost and complexity, with the cheapest light sheet systems being within the budgets of most laboratories, and the most expensive Magnetic Resonance Imaging systems available to a select few. Taking the view that the most likely systems to be developed are those using light sheets, the authors will relate their knowledge and experience of such systems. Other systems will be described briefly and references provided. Flows are inherently three-dimensional in structure; even those generated around nominally 2-D surface geometry. It is becoming increasingly apparent to scientists and engineers that the three-dimensionalities, both large and small scale, are important in terms of overall flow structure and species, momentum, and energy transport. Furthermore, we are accustomed to seeing the world in three dimensions, so it is natural that we should wish to view, measure and interpret flows in three-dimensions. Unfortunately, 3-D images do not lend themselves to convenient presentation on the printed page, and this task is one of the challenges facing us.

  5. Volumetric Three-Dimensional Display Systems

    NASA Astrophysics Data System (ADS)

    Blundell, Barry G.; Schwarz, Adam J.

    2000-03-01

    A comprehensive study of approaches to three-dimensional visualization by volumetric display systems This groundbreaking volume provides an unbiased and in-depth discussion on a broad range of volumetric three-dimensional display systems. It examines the history, development, design, and future of these displays, and considers their potential for application to key areas in which visualization plays a major role. Drawing substantially on material that was previously unpublished or available only in patent form, the authors establish the first comprehensive technical and mathematical formalization of the field, and examine a number of different volumetric architectures. System level design strategies are presented, from which proposals for the next generation of high-definition predictable volumetric systems are developed. To ensure that researchers will benefit from work already completed, they provide: * Descriptions of several recent volumetric display systems prepared from material supplied by the teams that created them * An abstract volumetric display system design paradigm * An historical summary of 90 years of development in volumetric display system technology * An assessment of the strengths and weaknesses of many of the systems proposed to date * A unified presentation of the underlying principles of volumetric display systems * A comprehensive bibliography Beautifully supplemented with 17 color plates that illustrate volumetric images and prototype displays, Volumetric Three-Dimensional Display Systems is an indispensable resource for professionals in imaging systems development, scientific visualization, medical imaging, computer graphics, aerospace, military planning, and CAD/CAE.

  6. General Ultrasound Imaging

    MedlinePlus

    ... blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ...

  7. Three-dimensional stereo by photometric ratios

    SciTech Connect

    Wolff, L.B.; Angelopoulou, E.

    1994-11-01

    We present a methodology for corresponding a dense set of points on an object surface from photometric values for three-dimensional stereo computation of depth. The methodology utilizes multiple stereo pairs of images, with each stereo pair being taken of the identical scene but under different illumination. With just two stereo pairs of images taken under two different illumination conditions, a stereo pair of ratio images can be produced, one for the ratio of left-hand images and one for the ratio of right-hand images. We demonstrate how the photometric ratios composing these images can be used for accurate correspondence of object points. Object points having the same photometric ratio with respect to two different illumination conditions constitute a well-defined equivalence class of physical constraints defined by local surface orientation relative to illumination conditions. We formally show that for diffuse reflection the photometric ratio is invariant to varying camera characteristics, surface albedo, and viewpoint and that therefore the same photometric ratio in both images of a stereo pair implies the same equivalence class of physical constraints. The correspondence of photometric ratios along epipolar lines in a stereo pair of images under different illumination conditions is a correspondence of equivalent physical constraints, and the determination of depth from stereo can be performed. Whereas illumination planning is required, our photometric-based stereo methodology does not require knowledge of illumination conditions in the actual computation of three-dimensional depth and is applicable to perspective views. This technique extends the stereo determination of three-dimensional depth to smooth featureless surfaces without the use of precisely calibrated lighting. We demonstrate experimental depth maps from a dense set of points on smooth objects of known ground-truth shape, determined to within 1% depth accuracy.

  8. Three-dimensional relativistic electromagnetic subcycle solitons.

    PubMed

    Esirkepov, Timur; Nishihara, Katsunobu; Bulanov, Sergei V; Pegoraro, Francesco

    2002-12-30

    Three-dimensional (3D) relativistic electromagnetic subcycle solitons were observed in 3D particle-in-cell simulations of an intense short-laser-pulse propagation in an underdense plasma. Their structure resembles that of an oscillating electric dipole with a poloidal electric field and a toroidal magnetic field that oscillate in phase with the electron density with frequency below the Langmuir frequency. On the ion time scale, the soliton undergoes a Coulomb explosion of its core, resulting in ion acceleration, and then evolves into a slowly expanding quasineutral cavity.

  9. Three-dimensional echocardiography in valve disease

    PubMed Central

    COLOMBO, CHIARA; TAMBORINI, GLORIA; PEPI, MAURO; ALIMENTO, MARINA; FIORENTINI, CESARE

    2007-01-01

    This review covers the role of three-dimensional (3D) echocardiography in the diagnosis of heart valve disease. Several factors have contributed to the evolution of this technique, which is currently a simple and routine method: rapid evolution in probe and computer technologies, demonstration that 3D data sets allowed more complete and accurate evaluation of cardiac structures, emerging clinical experience indicating the strong potential particularly in valve diseases, volume and function of the two ventricle measurements and several other fields. This report will review current and future applications of 3D echocardiography in mitral, aortic and tricuspid valve diseases underlying both qualitative (morphologic) and quantitative advantages of this technique. PMID:21977273

  10. Three-dimensional echocardiography in valve disease.

    PubMed

    Colombo, Chiara; Tamborini, Gloria; Pepi, Mauro; Alimento, Marina; Fiorentini, Cesare

    2007-01-01

    This review covers the role of three-dimensional (3D) echocardiography in the diagnosis of heart valve disease. Several factors have contributed to the evolution of this technique, which is currently a simple and routine method: rapid evolution in probe and computer technologies, demonstration that 3D data sets allowed more complete and accurate evaluation of cardiac structures, emerging clinical experience indicating the strong potential particularly in valve diseases, volume and function of the two ventricle measurements and several other fields. This report will review current and future applications of 3D echocardiography in mitral, aortic and tricuspid valve diseases underlying both qualitative (morphologic) and quantitative advantages of this technique.

  11. The Three-Dimensional Structure of Mimivirus

    PubMed Central

    Klose, Thomas; Kuznetsov, Yurii G.; Xiao, Chuan; Sun, Siyang; McPherson, Alexander; Rossmann, Michael G.

    2010-01-01

    Mimivirus, the prototypic member of the new family of Mimiviridae, is the largest virus known to date. Progress has been made recently in determining the three-dimensional structure of the 0.75-μm diameter virion using cryo-electron microscopy and atomic force microscopy. These showed that the virus is composed of an outer layer of dense fibers surrounding an icosahedrally shaped capsid and an internal membrane sac enveloping the genomic material of the virus. Additionally, a unique starfish-like structure at one of the fivefold vertices, required by the virus for infecting its host, has been defined in more detail. PMID:20551678

  12. Electrode With Porous Three-Dimensional Support

    DOEpatents

    Bernard, Patrick; Dauchier, Jean-Michel; Simonneau, Olivier

    1999-07-27

    Electrode including a paste containing particles of electrochemically active material and a conductive support consisting of a three-dimensional porous material comprising strands delimiting contiguous pores communicating via passages, characterized in that the average width L in .mu.m of said passages is related to the average diameter .O slashed. in .mu.m of said particles by the following equation, in which W and Y are dimensionless coefficients: wherein W=0.16 Y=1.69 X=202.4 .mu.m and Z=80 .mu.m

  13. Three-dimensional ultrasonic colloidal crystals

    NASA Astrophysics Data System (ADS)

    Caleap, Mihai; Drinkwater, Bruce W.

    2016-05-01

    Colloidal assembly represents a powerful method for the fabrication of functional materials. In this article, we describe how acoustic radiation forces can guide the assembly of colloidal particles into structures that serve as microscopic elements in novel acoustic metadevices or act as phononic crystals. Using a simple three-dimensional orthogonal system, we show that a diversity of colloidal structures with orthorhombic symmetry can be assembled with megahertz-frequency (MHz) standing pressure waves. These structures allow rapid tuning of acoustic properties and provide a new platform for dynamic metamaterial applications.

  14. Three-dimensional flow about penguin wings

    NASA Astrophysics Data System (ADS)

    Noca, Flavio; Sudki, Bassem; Lauria, Michel

    2012-11-01

    Penguins, contrary to airborne birds, do not need to compensate for gravity. Yet, the kinematics of their wings is highly three-dimensional and seems exceedingly complex for plain swimming. Is such kinematics the result of an evolutionary optimization or is it just a forced adaptation of an airborne flying apparatus to underwater swimming? Some answers will be provided based on flow dynamics around robotic penguin wings. Updates will also be presented on the development of a novel robotic arm intended to simulate penguin swimming and enable novel propulsion devices.

  15. Sculptra: the new three-dimensional filler.

    PubMed

    Sherman, Richard N

    2006-10-01

    Sculptra, the synthetic injectable poly-l-lactic acid (PLLA), is a revolutionary three-dimensional filler lasting 18 to 24 months. This unique volumizing agent is best used to globally restore volume to the lower two thirds of the face in patients who have lipoatrophy. Sculptra is a biocompatible, biodegradable, and nonimmunogenic derivative of the alpha-hydroxy-acid family. The size and the slow degradation kinetics of PLLA microparticles act as a stimulus for collagen production, providing lasting volume enhancement in lipoatrophy patients.

  16. High resolution three-dimensional doping profiler

    DOEpatents

    Thundat, Thomas G.; Warmack, Robert J.

    1999-01-01

    A semiconductor doping profiler provides a Schottky contact at one surface and an ohmic contact at the other. While the two contacts are coupled to a power source, thereby establishing an electrical bias in the semiconductor, a localized light source illuminates the semiconductor to induce a photocurrent. The photocurrent changes in accordance with the doping characteristics of the semiconductor in the illuminated region. By changing the voltage of the power source the depth of the depletion layer can be varied to provide a three dimensional view of the local properties of the semiconductor.

  17. Three-dimensional simulations of burning thermals

    NASA Astrophysics Data System (ADS)

    Aspden, Andy; Bell, John; Woosley, Stan

    2010-11-01

    Flame ignition in type Ia supernovae (SNe Ia) leads to isolated bubbles of burning buoyant fluid. As a bubble rises due to gravity, it becomes deformed by shear instabilities and transitions to a turbulent buoyant vortex ring. Morton, Taylor and Turner (1956) introduced the entrainment assumption, which can be applied to inert thermals. In this study, we use the entrainment assumption, suitably modified to account for burning, to predict the late-time asymptotic behaviour of these turbulent buoyant vortex rings in SNe Ia. The theory is validated against three- dimensional simulations with adaptive mesh refinement at effective resolutions up to 4096^3.

  18. Three-dimensional photoacoustic imaging of breast tissue phantoms

    NASA Astrophysics Data System (ADS)

    Manohar, Srirang; Kharine, Alexei; Steenbergen, Wiendelt; van Leeuwen, Ton G.

    2004-07-01

    A laboratory prototype of a time-resolved photoacoustic mammograph, based on a parallel plate geometry is presented. Light is delivered from a Q-switched Nd:YAG laser using fiber-optic bundles which can be mechanically scanned across the surface of a phantom. The ultrasound signals produced by the photoacoustic effect are measured in a transmission mode, using a large-area ultrasound detector matrix. Signals from the matrix are acquired using fast digitizers. Various performance studies of the system are presented. A breast phantom of dimensions (150x120x60)mm was created based on poly(vinyl alcohol) (PVA) gel, which can be imparted with the average optical scattering properties of breast tissue by a simple process of freezing and thawing of an aqueous poly(vinyl alcohol) solution. The acoustic properties are also found to match those of breast tissue. Such a photoacoustic breast phantom was embedded with several tumour-simulating inhomogeneities. These inserts were also based on poly(vinyl alcohol) gels, appropriately dyed at the time of formation, to possess various optical absorption coefficients, between 2 and 7 times that of the background. Using the signals collected from regions-of-interest (ROI) in the volume of the phantom, three-dimensional images were obtained using a modified delay-and-sum beamforming algorithm. The results indicate that photoacoustics, as embodied in this instrument, has a potential for detecting tumours in the breast.

  19. In-lab three-dimensional printing

    PubMed Central

    Partridge, Roland; Conlisk, Noel; Davies, Jamie A.

    2012-01-01

    The development of the microscope in 1590 by Zacharias Janssenby and Hans Lippershey gave the world a new way of visualizing details of morphogenesis and development. More recent improvements in this technology including confocal microscopy, scanning electron microscopy (SEM) and optical projection tomography (OPT) have enhanced the quality of the resultant image. These technologies also allow a representation to be made of a developing tissue’s three-dimensional (3-D) form. With all these techniques however, the image is delivered on a flat two-dimensional (2-D) screen. 3-D printing represents an exciting potential to reproduce the image not simply on a flat screen, but in a physical, palpable three-dimensional structure. Here we explore the scope that this holds for exploring and interacting with the structure of a developing organ in an entirely novel way. As well as being useful for visualization, 3-D printers are capable of rapidly and cost-effectively producing custom-made structures for use within the laboratory. We here describe the advantages of producing hardware for a tissue culture system using an inexpensive in-lab printer. PMID:22652907

  20. Three dimensional quantum geometry and deformed symmetry

    NASA Astrophysics Data System (ADS)

    Joung, E.; Mourad, J.; Noui, K.

    2009-05-01

    We study a three dimensional noncommutative space emerging in the context of three dimensional Euclidean quantum gravity. Our starting point is the assumption that the isometry group is deformed to the Drinfeld double D(SU(2)). We generalize to the deformed case the construction of E3 as the quotient of its isometry group ISU(2) by SU(2). We show that the algebra of functions on E3 becomes the noncommutative algebra of SU(2) distributions, C(SU(2))∗, endowed with the convolution product. This construction gives the action of ISU(2) on the algebra and allows the determination of plane waves and coordinate functions. In particular, we show the following: (i) plane waves have bounded momenta; (ii) to a given momentum are associated several SU(2) elements leading to an effective description of ϕ ɛC(SU(2))∗ in terms of several physical scalar fields on E3; (iii) their product leads to a deformed addition rule of momenta consistent with the bound on the spectrum. We generalize to the noncommutative setting the "local" action for a scalar field. Finally, we obtain, using harmonic analysis, another useful description of the algebra as the direct sum of the algebra of matrices. The algebra of matrices inherits the action of ISU(2): rotations leave the order of the matrices invariant, whereas translations change the order in a way we explicitly determine.

  1. Three-dimensional image signals: processing methods

    NASA Astrophysics Data System (ADS)

    Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

    2010-11-01

    Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

  2. Three-dimensional terahertz wave imaging.

    PubMed

    Zhang, X-C

    2004-02-15

    Pulsed terahertz (THz) wave sensing and imaging is a coherent measurement technology. Like radar, based on the phase and amplitude of the THz pulse at each frequency, THz waves provide temporal and spectroscopic information that allows us to develop various three-dimensional (3D) terahertz tomographic imaging modalities. The 3D THz tomographic imaging methods we investigated include THz time-of-flight tomography, THz computed tomography (CT) and THz binary lens tomography. THz time-of-flight uses the THz pulses as a probe beam to temporally mark the target, and then constructs a 3D image of the target using the THz waves scattered by the target. THz CT is based on geometrical optics and inspired from X-ray CT. THz binary lens tomography uses the frequency-dependent focal-length property of binary lenses to obtain tomographic images of an object. Three-dimensional THz imaging has potential in such applications as non-destructive inspection. The interaction between a coherent THz pulse and an object provides rich information about the object under study; therefore, 3D THz imaging can be used to inspect or characterize dielectric and semiconductor objects. For example, 3D THz imaging has been used to detect and identify the defects inside a Space Shuttle insulation tile.

  3. Three-dimensional turbopump flowfield analysis

    NASA Technical Reports Server (NTRS)

    Sharma, O. P.; Belford, K. A.; Ni, R. H.

    1992-01-01

    A program was conducted to develop a flow prediction method applicable to rocket turbopumps. The complex nature of a flowfield in turbopumps is described and examples of flowfields are discussed to illustrate that physics based models and analytical calculation procedures based on computational fluid dynamics (CFD) are needed to develop reliable design procedures for turbopumps. A CFD code developed at NASA ARC was used as the base code. The turbulence model and boundary conditions in the base code were modified, respectively, to: (1) compute transitional flows and account for extra rates of strain, e.g., rotation; and (2) compute surface heat transfer coefficients and allow computation through multistage turbomachines. Benchmark quality data from two and three-dimensional cascades were used to verify the code. The predictive capabilities of the present CFD code were demonstrated by computing the flow through a radial impeller and a multistage axial flow turbine. Results of the program indicate that the present code operated in a two-dimensional mode is a cost effective alternative to full three-dimensional calculations, and that it permits realistic predictions of unsteady loadings and losses for multistage machines.

  4. Three-dimensional singular points in aerodynamics

    NASA Technical Reports Server (NTRS)

    Unal, Aynur

    1988-01-01

    When three-dimensional separation occurs on a body immersed in a flow governed by the incompressible Navier-Stokes equations, the geometrical surfaces formed by the three vector fields (velocity, vorticity and the skin-friction) and a scalar field (pressure) become interrelated through topological maps containing their respective singular points and extremal points. A mathematically consistent description of these singular points becomes inevitable when we want to study the geometry of the separation. A separated stream surface requires, for example, the existence of a saddle-type singular point on the skin-friction surface. This singular point is actually, in the proper language of mathematics, a saddle of index two. The index is a measure of the dimension of the outset (set leaving the singular point). Hence, when a saddle of index two is specified, a two dimensional surface that becomes separated from the osculating plane of the saddle is implied. The three-dimensional singular point is interpreted mathematically and the most common aerodynamical singular points are discussed through this perspective.

  5. Nanowired three-dimensional cardiac patches

    NASA Astrophysics Data System (ADS)

    Dvir, Tal; Timko, Brian P.; Brigham, Mark D.; Naik, Shreesh R.; Karajanagi, Sandeep S.; Levy, Oren; Jin, Hongwei; Parker, Kevin K.; Langer, Robert; Kohane, Daniel S.

    2011-11-01

    Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds. These biomaterials, which are usually made of either biological polymers such as alginate or synthetic polymers such as poly(lactic acid) (PLA), help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches.

  6. Three-dimensional head anthropometric analysis

    NASA Astrophysics Data System (ADS)

    Enciso, Reyes; Shaw, Alex M.; Neumann, Ulrich; Mah, James

    2003-05-01

    Currently, two-dimensional photographs are most commonly used to facilitate visualization, assessment and treatment of facial abnormalities in craniofacial care but are subject to errors because of perspective, projection, lack metric and 3-dimensional information. One can find in the literature a variety of methods to generate 3-dimensional facial images such as laser scans, stereo-photogrammetry, infrared imaging and even CT however each of these methods contain inherent limitations and as such no systems are in common clinical use. In this paper we will focus on development of indirect 3-dimensional landmark location and measurement of facial soft-tissue with light-based techniques. In this paper we will statistically evaluate and validate a current three-dimensional image-based face modeling technique using a plaster head model. We will also develop computer graphics tools for indirect anthropometric measurements in a three-dimensional head model (or polygonal mesh) including linear distances currently used in anthropometry. The measurements will be tested against a validated 3-dimensional digitizer (MicroScribe 3DX).

  7. Three-dimensional fluorescence lifetime tomography

    SciTech Connect

    Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

    2005-04-01

    Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores.

  8. Long pathlength, three-dimensional absorbance microchip.

    PubMed

    Collins, Greg E; Lu, Qin; Pereira, Nicholas; Wu, Peter

    2007-04-15

    A long pathlength, three-dimensional U-type flow cell was microfabricated and evaluated for improved absorbance detection on a glass microdevice. A small diameter hole (75mum) was laser etched in a thin glass substrate whose thickness (100mum) defined much of the pathlength of the cell. This substrate was thermally bonded and sandwiched between two different glass substrates. The top substrate contained a typical injection cross and separation microchannel. Projecting out of the plane of the separation device was a 126mum pathlength flow cell as defined by the laser etched hole and the attached microchannels. The flow cell was connected to a microchannel on the bottom substrate that led to a waste reservoir. The planar, flat windows on the top and bottom of this device made light introduction and collection a simple matter using a light emitting diode (LED) and microscope objective. The experimentally obtained detection limit for rhodamine B was determined to be 0.95muM, which is nearly identical to the theoretical limit calculated by Beer's Law. A separation of three fluorescent dyes was performed, and direct comparisons were made between the transmittance changes through the narrow pathlength separation microchannel and the adjacent long pathlength, three-dimensional U-type flow cell.

  9. Two component-three dimensional catalysis

    DOEpatents

    Schwartz, Michael; White, James H.; Sammells, Anthony F.

    2002-01-01

    This invention relates to catalytic reactor membranes having a gas-impermeable membrane for transport of oxygen anions. The membrane has an oxidation surface and a reduction surface. The membrane is coated on its oxidation surface with an adherent catalyst layer and is optionally coated on its reduction surface with a catalyst that promotes reduction of an oxygen-containing species (e.g., O.sub.2, NO.sub.2, SO.sub.2, etc.) to generate oxygen anions on the membrane. The reactor has an oxidation zone and a reduction zone separated by the membrane. A component of an oxygen containing gas in the reduction zone is reduced at the membrane and a reduced species in a reactant gas in the oxidation zone of the reactor is oxidized. The reactor optionally contains a three-dimensional catalyst in the oxidation zone. The adherent catalyst layer and the three-dimensional catalyst are selected to promote a desired oxidation reaction, particularly a partial oxidation of a hydrocarbon.

  10. Three dimensional force balance of asymmetric droplets

    NASA Astrophysics Data System (ADS)

    Kim, Yeseul; Lim, Su Jin; Cho, Kun; Weon, Byung Mook

    2016-11-01

    An equilibrium contact angle of a droplet is determined by a horizontal force balance among vapor, liquid, and solid, which is known as Young's law. Conventional wetting law is valid only for axis-symmetric droplets, whereas real droplets are often asymmetric. Here we show that three-dimensional geometry must be considered for a force balance for asymmetric droplets. By visualizing asymmetric droplets placed on a free-standing membrane in air with X-ray microscopy, we are able to identify that force balances in one side and in other side control pinning behaviors during evaporation of droplets. We find that X-ray microscopy is powerful for realizing the three-dimensional force balance, which would be essential in interpretation and manipulation of wetting, spreading, and drying dynamics for asymmetric droplets. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2016R1D1A1B01007133).

  11. Three-dimensional television: a broadcaster's perspective

    NASA Astrophysics Data System (ADS)

    Jolly, S. J. E.; Armstrong, M.; Salmon, R. A.

    2009-02-01

    The recent resurgence of interest in the stereoscopic cinema and the increasing availability to the consumer of stereoscopic televisions and computer displays are leading broadcasters to consider, once again, the feasibility of stereoscopic broadcasting. High Definition Television is now widely deployed, and the R&D departments of broadcasters and consumer electronics manufacturers are starting to plan future enhancements to the experience of television. Improving the perception of depth via stereoscopy is a strong candidate technology. In this paper we will consider the challenges associated with the production, transmission and display of different forms of "three-dimensional" television. We will explore options available to a broadcaster wishing to start a 3D service using the technologies available at the present time, and consider how they could be improved to enable many more television programmes to be recorded and transmitted in a 3D-compatible form, paying particular attention to scenarios such as live broadcasting, where the workflows developed for the stereoscopic cinema are inapplicable. We will also consider the opportunities available for broadcasters to reach audiences with "three-dimensional" content via other media in the near future: for example, distributing content via the existing stereoscopic cinema network, or over the Internet to owners of stereoscopic computer displays.

  12. Three-dimensional method for determination of amniotic fluid volume in intrauterine pockets.

    PubMed

    Grover, J; Mentakis, E A; Ross, M G

    1997-12-01

    Although current ultrasound techniques provide a linear (amniotic fluid index; AFI) or two-dimensional area index of amniotic fluid (AF), these indices have limited correlation with actual AF volume. We sought to quantify the three-dimensional volume of ultrasound-identified AF pockets, as assessed by the AFI and two-dimensional area methods. The BVI 2500 (Bladder Volume Instrument 2500; Diagnostic Ultrasound Corp., Redmond, WA) has been used to quantify the volume of residual urine in the bladder. INSTRUMENT AND METHOD: The BVI 2500 (Diagnostic Ultrasound Corp.) ultrasound uses a rotating 2-MHz transducer, computer-defined fluid interface, and computer integration of 12 cross-sectional images to calculate three-dimensional fluid volume. After providing written informed consent, 14 term pregnant patients (36-42 weeks) were evaluated using the BVI 2500 and an Ultramark 8 sector scan (Advanced Technology Laboratory, Bothell, WA). The largest vertical fluid pocket in each quadrant of the abdomen was identified with the sector scan, and vertical and horizontal measurements for AFI and two-dimensional area were recorded. Simultaneous AF volume measurements of each pocket were performed three times with the bladder volume instrument, and maximum values were used. Three-dimensional volume, two-dimensional area, and AFI values were compared by correlation analysis, with P < or = .05 considered statistically significant. Among all patients, the average (+/- standard deviation) AFI was 7.6 +/- 4.1 (range 1.5-16.4) cm, and the average two-dimensional area was 30.9 +/- 21.1 (range 4.3-81.3) cm2. This corresponded to an average three-dimensional volume of 215 +/- 134 (range 23-497) cm3. Three-dimensional volume correlated highly with both AFI (r = 0.9; P < .001) and two-dimensional area (r = 0.86; P < .001). One AFI centimeter was equivalent to a volume of 30 cm3. There are highly significant linear correlations of three-dimensional amniotic fluid volumes with AFI and two

  13. Clinical feasibility study of combined opto-acoustic and ultrasonic imaging modality providing coregistered functional and anatomical maps of breast tumors

    NASA Astrophysics Data System (ADS)

    Zalev, Jason; Clingman, Bryan; Smith, Remie J.; Herzog, Don; Miller, Tom; Stavros, A. Thomas; Ermilov, Sergey; Conjusteau, André; Tsyboulski, Dmitri; Oraevsky, Alexander A.; Kist, Kenneth; Dornbluth, N. C.; Otto, Pamela

    2013-03-01

    We report on findings from the clinical feasibility study of the ImagioTM. Breast Imaging System, which acquires two-dimensional opto-acoustic (OA) images co-registered with conventional ultrasound using a specialized duplex hand-held probe. Dual-wavelength opto-acoustic technology is used to generate parametric maps based upon total hemoglobin and its oxygen saturation in breast tissues. This may provide functional diagnostic information pertaining to tumor metabolism and microvasculature, which is complementary to morphological information obtained with conventional gray-scale ultrasound. We present co-registered opto-acoustic and ultrasonic images of malignant and benign tumors from a recent clinical feasibility study. The clinical results illustrate that the technology may have the capability to improve the efficacy of breast tumor diagnosis. In doing so, it may have the potential to reduce biopsies and to characterize cancers that were not seen well with conventional gray-scale ultrasound alone.

  14. Diagnostic value of three-dimensional transcranial contrast duplex sonography.

    PubMed

    Delcker, A; Turowski, B

    1997-07-01

    This study evaluated intracranial cerebral arteries using a new data acquisition system for transcranial three-dimensional (3D) ultrasonography with and without an echo contrast agent, with confirmation by cerebral angiography. Ten patients, studied with diagnostic cerebral angiography, were examined without knowledge of the angiographic results. Data acquisition through the transtemporal acoustic window was performed using a magnetic sensor system to track the spatial orientation of the ultrasound probe while scanning the volume of interest. A color transcranial duplex system with a power Doppler mode was used, and 3D data sets were acquired before and after the injection of transpulmonary-stable ultrasound contrast medium. Ipsilateral to the transducer, the anterior cerebral artery (ACA) in 90%, middle cerebral artery (MCA) in 60%, all three or more branches of the MCA in 60%, posterior cerebral artery (PCA) in 60%, and posterior communicating artery (PCoA) in 60% were successfully imaged without the echo contrast agent. With the contrast agent, the ACA, MCA, three or more branches of the MCA, PCA, and PCoA were visible in 100%. The anterior communicating artery was visualized in 40% without contrast enhancement and in 90% with contrast enhancement. Contralateral to the transducer, the ACA (60%), MCA (30%), all three or more branches of the MCA (10%), PCA (20%), and PCoA (20%) were successfully imaged without contrast. Contrast enhancement improved the imaging success rate for the ACA (90%), MCA (80%), three or more branches of the MCA (80%), PCA (100%), and PCoA (100%). A transpulmonary-stable ultrasound contrast agent used in combination with 3D transcranial duplex ultrasonography can significantly improve the success rate for transcranial color duplex imaging of intracranial arteries.

  15. Functional three-dimensional sonographic study of the postpartum uterus.

    PubMed

    Wataganara, Tuangsit; Phithakwatchara, Nisarat; Komoltri, Chulaluk; Tantisirin, Pornpen; Pooliam, Julaporn; Titapant, Vitaya

    2015-01-01

    To demonstrate sequential changes of the postpartum uterus using two- and three-dimensional (2D and 3D) ultrasounds and Doppler studies. Eighty-one women who delivered a singleton at term were recruited for this prospective longitudinal study. Manual and ultrasound examinations of the uterus were performed for seven consecutive weeks. Sequential changes in size of the uterus, endometrial thickness and appearances and Doppler indices of the uterine and arcuate arteries were analyzed. Complete follow ups were achieved in 71 women who had an uncomplicated postpartum course. 2D and 3D ultrasound estimations of uterine volume are highly correlated with each other (r > 0.7), but not manual estimations (r < 0.3). Data generated from 497 3D observations demonstrated rapid involution of the uterus in the first two weeks after delivery. Breastfeeding and parity did not affect uterine involution (r < 0.2). Resistance index (RI) of the uterine artery started to elevate at four weeks after delivery (r > 0.7). RI of the arcuate artery was not significantly changed during the study period (r < 0.2). Uterine involution was independent from progressive thinning of the endometrium and elevation of uterine artery RI. (r < 0.1 and 0.2, respectively). Longitudinal sonographic study showed independent physiologic reversals of uterine volume, endometrium and vascular supply in the first seven weeks following vaginal delivery. Standardization of measurement techniques is essential to apply this information for an early detection of postpartum uterine complications.

  16. Magneto Transport in Three Dimensional Carbon Nanostructures

    NASA Astrophysics Data System (ADS)

    Datta, Timir; Wang, Lei; Jaroszynski, Jan; Yin, Ming; Alameri, Dheyaa

    Electrical properties of self-assembled three dimensional nanostructures are interesting topic. Here we report temperature dependence of magneto transport in such carbon nanostructures with periodic spherical voids. Specimens with different void diameters in the temperature range from 200 mK to 20 K were studied. Above 2 K, magnetoresistance, MR = [R(B) - R(0)] / R(0), crosses over from quadratic to a linear dependence with the increase of magnetic field [Wang et al., APL 2015; DOI:10.1063/1.4926606]. We observe MR to be non-saturating even up to 18 Tesla. Furthermore, MR demonstrates universality because all experimental data can be collapsed on to a single curve, as a universal function of B/T. Below 2 K, magnetoresistance saturates with increasing field. Quantum Hall like steps are also observed in this low temperature regime. Remarkably, MR of our sample displays orientation independence, an attractive feature for technological applications.

  17. Three-dimensional hologram display system

    NASA Technical Reports Server (NTRS)

    Mintz, Frederick (Inventor); Chao, Tien-Hsin (Inventor); Bryant, Nevin (Inventor); Tsou, Peter (Inventor)

    2009-01-01

    The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.

  18. Three-dimensional elastic lidar winds

    SciTech Connect

    Buttler, W.T.

    1996-07-01

    Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three- dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain following winds in the Rio Grande valley.

  19. Quantum interferometry with three-dimensional geometry

    PubMed Central

    Spagnolo, Nicolò; Aparo, Lorenzo; Vitelli, Chiara; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto; Mataloni, Paolo; Sciarrino, Fabio

    2012-01-01

    Quantum interferometry uses quantum resources to improve phase estimation with respect to classical methods. Here we propose and theoretically investigate a new quantum interferometric scheme based on three-dimensional waveguide devices. These can be implemented by femtosecond laser waveguide writing, recently adopted for quantum applications. In particular, multiarm interferometers include “tritter” and “quarter” as basic elements, corresponding to the generalization of a beam splitter to a 3- and 4-port splitter, respectively. By injecting Fock states in the input ports of such interferometers, fringe patterns characterized by nonclassical visibilities are expected. This enables outperforming the quantum Fisher information obtained with classical fields in phase estimation. We also discuss the possibility of achieving the simultaneous estimation of more than one optical phase. This approach is expected to open new perspectives to quantum enhanced sensing and metrology performed in integrated photonics. PMID:23181189

  20. Quantum interferometry with three-dimensional geometry.

    PubMed

    Spagnolo, Nicolò; Aparo, Lorenzo; Vitelli, Chiara; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto; Mataloni, Paolo; Sciarrino, Fabio

    2012-01-01

    Quantum interferometry uses quantum resources to improve phase estimation with respect to classical methods. Here we propose and theoretically investigate a new quantum interferometric scheme based on three-dimensional waveguide devices. These can be implemented by femtosecond laser waveguide writing, recently adopted for quantum applications. In particular, multiarm interferometers include "tritter" and "quarter" as basic elements, corresponding to the generalization of a beam splitter to a 3- and 4-port splitter, respectively. By injecting Fock states in the input ports of such interferometers, fringe patterns characterized by nonclassical visibilities are expected. This enables outperforming the quantum Fisher information obtained with classical fields in phase estimation. We also discuss the possibility of achieving the simultaneous estimation of more than one optical phase. This approach is expected to open new perspectives to quantum enhanced sensing and metrology performed in integrated photonics.

  1. Three-dimensional printing physiology laboratory technology

    PubMed Central

    Sulkin, Matthew S.; Widder, Emily; Shao, Connie; Holzem, Katherine M.; Gloschat, Christopher; Gutbrod, Sarah R.

    2013-01-01

    Since its inception in 19th-century Germany, the physiology laboratory has been a complex and expensive research enterprise involving experts in various fields of science and engineering. Physiology research has been critically dependent on cutting-edge technological support of mechanical, electrical, optical, and more recently computer engineers. Evolution of modern experimental equipment is constrained by lack of direct communication between the physiological community and industry producing this equipment. Fortunately, recent advances in open source technologies, including three-dimensional printing, open source hardware and software, present an exciting opportunity to bring the design and development of research instrumentation to the end user, i.e., life scientists. Here we provide an overview on how to develop customized, cost-effective experimental equipment for physiology laboratories. PMID:24043254

  2. Three-dimensional printing physiology laboratory technology.

    PubMed

    Sulkin, Matthew S; Widder, Emily; Shao, Connie; Holzem, Katherine M; Gloschat, Christopher; Gutbrod, Sarah R; Efimov, Igor R

    2013-12-01

    Since its inception in 19th-century Germany, the physiology laboratory has been a complex and expensive research enterprise involving experts in various fields of science and engineering. Physiology research has been critically dependent on cutting-edge technological support of mechanical, electrical, optical, and more recently computer engineers. Evolution of modern experimental equipment is constrained by lack of direct communication between the physiological community and industry producing this equipment. Fortunately, recent advances in open source technologies, including three-dimensional printing, open source hardware and software, present an exciting opportunity to bring the design and development of research instrumentation to the end user, i.e., life scientists. Here we provide an overview on how to develop customized, cost-effective experimental equipment for physiology laboratories.

  3. Towards microscale electrohydrodynamic three-dimensional printing

    NASA Astrophysics Data System (ADS)

    He, Jiankang; Xu, Fangyuan; Cao, Yi; Liu, Yaxiong; Li, Dichen

    2016-02-01

    It is challenging for the existing three-dimensional (3D) printing techniques to fabricate high-resolution 3D microstructures with low costs and high efficiency. In this work we present a solvent-based electrohydrodynamic 3D printing technique that allows fabrication of microscale structures like single walls, crossed walls, lattice and concentric circles. Process parameters were optimized to deposit tiny 3D patterns with a wall width smaller than 10 μm and a high aspect ratio of about 60. Tight bonding among neighbour layers could be achieved with a smooth lateral surface. In comparison with the existing microscale 3D printing techniques, the presented method is low-cost, highly efficient and applicable to multiple polymers. It is envisioned that this simple microscale 3D printing strategy might provide an alternative and innovative way for application in MEMS, biosensor and flexible electronics.

  4. Three dimensional polymer waveguide using hybrid lithography.

    PubMed

    Wang, Huanran; Liu, Yu; Jiang, Minghui; Chen, Changming; Wang, Xibin; Wang, Fei; Zhang, Daming; Yi, Yunji

    2015-10-01

    A three dimensional polymer waveguide with taper structure was demonstrated and fabricated by a reliable and effective hybrid lithography. The hybrid lithography consists of lithography to fabricate a polymer waveguide and gray scale lithography to fabricate a polymer taper structure. Laser ablation and shadow aluminum evaporation were designed for gray scale lithography. The length of the gray scale region ranging from 20 to 400 μm could be controlled by the laser power, the ablation speed, and the aluminum thickness. The slope angle was determined by the length of the gray scale region and the thickness of the photoresist. The waveguide taper structure could be transferred to the lower layer by the etching method. The taper structure can be used for integration of the waveguide with different dimensions.

  5. Three-Dimensional Gear Crack Propagation Studies

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Sane, Ashok D.; Drago, Raymond J.; Wawrzynek, Paul A.

    1998-01-01

    Three-dimensional crack growth simulation was performed on a split-tooth gear design using boundary element modeling and linear elastic fracture mechanics. Initial cracks in the fillet of the teeth produced stress intensity factors of greater magnitude (and thus, greater crack growth rates) than those in the root or groove areas of the teeth. Crack growth simulation was performed on a case study to evaluate crack propagation paths. Tooth fracture was predicted from the crack growth simulation for an initial crack in the tooth fillet region. Tooth loads on the uncracked mesh of the split-tooth design were up to five times greater than those on the cracked mesh if equal deflections of the cracked and uncracked teeth were considered. Predicted crack shapes as well as crack propagation life are presented based on calculated stress intensity factors, mixed-mode crack propagation trajectory theories, and fatigue crack growth theories.

  6. Three-dimensional modular electronic interconnection system

    NASA Technical Reports Server (NTRS)

    Bolotin, Gary S. (Inventor); Cardone, John (Inventor)

    2001-01-01

    A three-dimensional connection system uses a plurality of printed wiring boards with connectors completely around the printed wiring boards, and connected by an elastomeric interface connector. The device includes internal space to allow room for circuitry. The device is formed by stacking an electronics module, an elastomeric interface board on the electronics module such that the interface board's exterior makes electrical connection with the connectors around the perimeter of the interface board, but the internal portion is open to allow room for the electrical devices on the printed wiring board. A plurality of these devices are stacked between a top stiffener and a bottom device, and held into place by alignment elements.

  7. Three-dimensional tori and Arnold tongues.

    PubMed

    Sekikawa, Munehisa; Inaba, Naohiko; Kamiyama, Kyohei; Aihara, Kazuyuki

    2014-03-01

    This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.

  8. The Three-Dimensional EIT Wave

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Biesecker, D. A.; Gilbert, H. R.; Lawrence, G. R.; Ofman, L.; Wu, S. T.; Warmuth, A.; Fisher, Richard R. (Technical Monitor)

    2002-01-01

    An EIT wave is an impulsive disturbance which has been observed in the EUV, Soft X-ray and white light corona, with corresponding observations in the chromosphere. The effects of these disturbances can be observed across the entire solar disk of the Sun, and throughout the inner heliosphere as well. However, the picture is not complete; observations alone do not establish a complete understanding of the nature of this three-dimensional phenomenon. A number of associated phenomena have been documented, though in most cases causality has not determined. Additionally, it is unclear which factors govern the impulse's ability to affect regions of the corona and heliosphere. We discuss the various observations and the models which provided links between the associated phenomena.

  9. Simplification of three-dimensional density maps.

    PubMed

    Natarajan, Vijay; Edelsbrunner, Herbert

    2004-01-01

    We consider scientific data sets that describe density functions over three-dimensional geometric domains. Such data sets are often large and coarsened representations are needed for visualization and analysis. Assuming a tetrahedral mesh representation, we construct such representations with a simplification algorithm that combines three goals: the approximation of the function, the preservation of the mesh topology, and the improvement of the mesh quality. The third goal is achieved with a novel extension of the well-known quadric error metric. We perform a number of computational experiments to understand the effect of mesh quality improvement on the density map approximation. In addition, we study the effect of geometric simplification on the topological features of the function by monitoring its critical points.

  10. THE THREE DIMENSIONAL THERMAL HYDRAULIC CODE BAGIRA.

    SciTech Connect

    KALINICHENKO,S.D.; KOHUT,P.; KROSHILIN,A.E.; KROSHILIN,V.E.; SMIRNOV,A.V.

    2003-05-04

    BAGIRA - a thermal-hydraulic program complex was primarily developed for using it in nuclear power plant simulator models, but is also used as a best-estimate analytical tool for modeling two-phase mixture flows. The code models allow consideration of phase transients and the treatment of the hydrodynamic behavior of boiling and pressurized water reactor circuits. It provides the capability to explicitly model three-dimensional flow regimes in various regions of the primary and secondary circuits such as, the mixing regions, circular downcomer, pressurizer, reactor core, main primary loops, the steam generators, the separator-reheaters. In addition, it is coupled to a severe-accident module allowing the analysis of core degradation and fuel damage behavior. Section II will present the theoretical basis for development and selected results are presented in Section III. The primary use for the code complex is to realistically model reactor core behavior in power plant simulators providing enhanced training tools for plant operators.

  11. Scaffolding for Three-Dimensional Embryonic Vasculogenesis

    NASA Astrophysics Data System (ADS)

    Kraehenbuehl, Thomas P.; Aday, Sezin; Ferreira, Lino S.

    Biomaterial scaffolds have great potential to support efficient vascular differentiation of embryonic stem cells. Vascular cell fate-specific biochemical and biophysical cues have been identified and incorporated into three-dimensional (3D) biomaterials to efficiently direct embryonic vasculogenesis. The resulting vascular-like tissue can be used for regenerative medicine applications, further elucidation of biophysical and biochemical cues governing vasculogenesis, and drug discovery. In this chapter, we give an overview on the following: (1) developmental cues for directed differentiation of human embryonic stem cells (hESCs) into vascular cells, (2) 3D vascular differentiation in embryoid bodies (EBs), (3) preparation of 3D scaffolds for the vascular differentiation of hESCs, and (4) the most significant studies combining scaffolding and hESCs for development of vascular-like tissue.

  12. Versatile three-dimensional cryogenic micropositioning device

    NASA Astrophysics Data System (ADS)

    Heil, J.; Böhm, A.; Primke, M.; Wyder, P.

    1996-01-01

    A simple design for a mechanically driven three-dimensional cryogenic micropositioner is presented. The design is based on a parallelogram structure constructed from leaf springs and wires. Actuation is achieved by the elastic deformation of the parallelogram by screws. Positions within a volume of roughly (2 mm)3 are attainable. The precision and reproducibility of positioning are in the μm-range. The deviations from linearity are smaller than 10% for the whole working range and the deviation from orthogonality is smaller than 3°. Calibration measurements performed on a Cu-mesh with a lattice constant of 60 μm are presented. In an experiment investigating the ballistic transport of carriers in the semimetal Bi, two such devices are used. The first one is used as a scanning unit for an optical fiber and the second one is used as micropositioner for a Cu point contact.

  13. Multiscale modeling of three-dimensional genome

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Wolynes, Peter

    The genome, the blueprint of life, contains nearly all the information needed to build and maintain an entire organism. A comprehensive understanding of the genome is of paramount interest to human health and will advance progress in many areas, including life sciences, medicine, and biotechnology. The overarching goal of my research is to understand the structure-dynamics-function relationships of the human genome. In this talk, I will be presenting our efforts in moving towards that goal, with a particular emphasis on studying the three-dimensional organization, the structure of the genome with multi-scale approaches. Specifically, I will discuss the reconstruction of genome structures at both interphase and metaphase by making use of data from chromosome conformation capture experiments. Computationally modeling of chromatin fiber at atomistic level from first principles will also be presented as our effort for studying the genome structure from bottom up.

  14. Automatic three-dimensional underground mine mapping

    SciTech Connect

    Huber, D.F.; Vandapel, N.

    2006-01-15

    For several years, our research group has been developing methods for automated modeling of three-dimensional environments. In September 2002, we were given the opportunity to demonstrate our mapping capability in an underground coal mine. The opportunity arose as a result of the Quecreek mine accident, in which an inaccurate map caused miners to breach an abandoned, water-filled mine, trapping them for several days. Our field test illustrates the feasibility and potential of high-resolution 3D mapping of an underground coal mine using a cart-mounted 3D laser scanner In this paper we present our experimental setup, the automatic 3D modeling method used, and the results of the field test.

  15. Three-dimensional tori and Arnold tongues

    SciTech Connect

    Sekikawa, Munehisa; Inaba, Naohiko; Kamiyama, Kyohei; Aihara, Kazuyuki

    2014-03-15

    This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.

  16. AAOGlimpse: Three-dimensional Data Viewer

    NASA Astrophysics Data System (ADS)

    Shortridge, Keith

    2011-10-01

    AAOGlimpse is an experimental display program that uses OpenGL to display FITS data (and even JPEG images) as 3D surfaces that can be rotated and viewed from different angles, all in real-time. It is WCS-compliant and designed to handle three-dimensional data. Each plane in a data cube is surfaced in the same way, and the program allows the user to travel through a cube by 'peeling off' successive planes, or to look into a cube by suppressing the display of data below a given cutoff value. It can blink images and can superimpose images and contour maps from different sources using their world coordinate data. A limited socket interface allows communication with other programs.

  17. Three-dimensional context regulation of metastasis.

    PubMed

    Erler, Janine T; Weaver, Valerie M

    2009-01-01

    Tumor progression ensues within a three-dimensional microenvironment that consists of cellular and non-cellular components. The extracellular matrix (ECM) and hypoxia are two non-cellular components that potently influence metastasis. ECM remodeling and collagen cross-linking stiffen the tissue stroma to promote transformation, tumor growth, motility and invasion, enhance cancer cell survival, enable metastatic dissemination, and facilitate the establishment of tumor cells at distant sites. Matrix degradation can additionally promote malignant progression and metastasis. Tumor hypoxia is functionally linked to altered stromal-epithelial interactions. Hypoxia additionally induces the expression of pro-migratory, survival and invasion genes, and up-regulates expression of ECM components and modifying enzymes, to enhance tumor progression and metastasis. Synergistic interactions between matrix remodeling and tumor hypoxia influence common mechanisms that maximize tumor progression and cooperate to drive metastasis. Thus, clarifying the molecular pathways by which ECM remodeling and tumor hypoxia intersect to promote tumor progression should identify novel therapeutic targets.

  18. Three dimensional carbon-nanotube polymers.

    PubMed

    Zhao, Zhisheng; Xu, Bo; Wang, Li-Min; Zhou, Xiang-Feng; He, Julong; Liu, Zhongyuan; Wang, Hui-Tian; Tian, Yongjun

    2011-09-27

    Eight fascinating sp(2)- and sp(3)-hybridized carbon allotropes have been uncovered using a newly developed ab initio particle-swarm optimization methodology for crystal structure prediction. These crystalline allotropes can be viewed respectively as three-dimensional (3D) polymers of (4,0), (5,0), (7,0), (8,0), (9,0), (3,3), (4,4), and (6,6) carbon nanotubes, termed 3D-(n, 0) or 3D-(n, n) carbons. The ground-state energy calculations show that the carbons all have lower energies than C(60) fullerene, and some are energetically more stable than the van der Waals packing configurations of their nanotube parents. Owing to their unique configurations, they have distinctive electronic properties, high Young's moduli, high tensile strength, ultrahigh hardness, good ductility, and low density, and may be potentially applied to a variety of needs.

  19. Three-dimensional cultured glioma cell lines

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Marley, Garry M. (Inventor)

    1991-01-01

    Three-dimensional glioma spheroids were produced in vitro with size and histological differentiation previously unattained. The spheroids were grown in liquid media suspension in a Johnson Space Center (JSC) Rotating Wall Bioreactor without using support matrices such as microcarrier beads. Spheroid volumes of greater than 3.5 cu mm and diameters of 2.5 mm were achieved with a viable external layer or rim of proliferating cells, a transitional layer beneath the external layer with histological differentiation, and a degenerative central region with a hypoxic necrotic core. Cell debris was evident in the degenerative central region. The necrotics centers of some of the spheroids had hyaline droplets. Granular bodies were detected predominantly in the necrotic center.

  20. Localized shear generates three-dimensional transport

    NASA Astrophysics Data System (ADS)

    Smith, Lachlan D.; Rudman, Murray; Lester, Daniel R.; Metcalfe, Guy

    2017-04-01

    Understanding the mechanisms that control three-dimensional (3D) fluid transport is central to many processes, including mixing, chemical reaction, and biological activity. Here a novel mechanism for 3D transport is uncovered where fluid particles are kicked between streamlines near a localized shear, which occurs in many flows and materials. This results in 3D transport similar to Resonance Induced Dispersion (RID); however, this new mechanism is more rapid and mutually incompatible with RID. We explore its governing impact with both an abstract 2-action flow and a model fluid flow. We show that transitions from one-dimensional (1D) to two-dimensional (2D) and 2D to 3D transport occur based on the relative magnitudes of streamline jumps in two transverse directions.

  1. Three-Dimensional Reflectance Traction Microscopy

    PubMed Central

    Jones, Christopher A. R.; Groves, Nicholas Scott; Sun, Bo

    2016-01-01

    Cells in three-dimensional (3D) environments exhibit very different biochemical and biophysical phenotypes compared to the behavior of cells in two-dimensional (2D) environments. As an important biomechanical measurement, 2D traction force microscopy can not be directly extended into 3D cases. In order to quantitatively characterize the contraction field, we have developed 3D reflectance traction microscopy which combines confocal reflection imaging and partial volume correlation postprocessing. We have measured the deformation field of collagen gel under controlled mechanical stress. We have also characterized the deformation field generated by invasive breast cancer cells of different morphologies in 3D collagen matrix. In contrast to employ dispersed tracing particles or fluorescently-tagged matrix proteins, our methods provide a label-free, computationally effective strategy to study the cell mechanics in native 3D extracellular matrix. PMID:27304456

  2. Three-dimensional image contrast using biospeckle

    NASA Astrophysics Data System (ADS)

    Godinho, Robson Pierangeli; Braga, Roberto A., Jr.

    2010-09-01

    The biospeckle laser (BSL) has been applied in many areas of knowledge and a variety of approaches has been presented to address the best results in biological and non-biological samples, in fast or slow activities, or else in defined flow of materials or in random activities. The methodologies accounted in the literature consider the apparatus used in the image assembling and the way the collected data is processed. The image processing steps presents in turn a variety of procedures with first or second order statistics analysis, and as well with different sizes of data collected. One way to access the biospeckle in defined flow, such as in capillary blood flow in alive animals, was the adoption of the image contrast technique which uses only one image from the illuminated sample. That approach presents some problems related to the resolution of the image, which is reduced during the image contrast processing. In order to help the visualization of the low resolution image formed by the contrast technique, this work presents the three-dimensional procedure as a reliable alternative to enhance the final image. The work based on a parallel processing, with the generation of a virtual map of amplitudes, and maintaining the quasi-online characteristic of the contrast technique. Therefore, it was possible to generate in the same display the observed material, the image contrast result and in addiction the three-dimensional image with adjustable options of rotation. The platform also offers to the user the possibility to access the 3D image offline.

  3. Three-dimensional analysis of facial morphology.

    PubMed

    Liu, Yun; Kau, Chung How; Talbert, Leslie; Pan, Feng

    2014-09-01

    The objectives of this study were to evaluate sexual dimorphism for facial features within Chinese and African American populations and to compare the facial morphology by sex between these 2 populations. Three-dimensional facial images were acquired by using the portable 3dMDface System, which captured 189 subjects from 2 population groups of Chinese (n = 72) and African American (n = 117). Each population was categorized into male and female groups for evaluation. All subjects in the groups were aged between 18 and 30 years and had no apparent facial anomalies. A total of 23 anthropometric landmarks were identified on the three-dimensional faces of each subject. Twenty-one measurements in 4 regions, including 19 distances and 2 angles, were not only calculated but also compared within and between the Chinese and African American populations. The Student's t-test was used to analyze each data set obtained within each subgroup. Distinct facial differences were presented between the examined subgroups. When comparing the sex differences of facial morphology in the Chinese population, significant differences were noted in 71.43% of the parameters calculated, and the same proportion was found in the African American group. The facial morphologic differences between the Chinese and African American populations were evaluated by sex. The proportion of significant differences in the parameters calculated was 90.48% for females and 95.24% for males between the 2 populations. The African American population had a more convex profile and greater face width than those of the Chinese population. Sexual dimorphism for facial features was presented in both the Chinese and African American populations. In addition, there were significant differences in facial morphology between these 2 populations.

  4. Integration of 3D intraoperative ultrasound for enhanced neuronavigation

    NASA Astrophysics Data System (ADS)

    Paulsen, Keith D.; Ji, Songbai; Hartov, Alex; Fan, Xiaoyao; Roberts, David W.

    2012-03-01

    True three-dimensional (3D) volumetric ultrasound (US) acquisitions stand to benefit intraoperative neuronavigation on multiple fronts. While traditional two-dimensional (2D) US and its tracked, hand-swept version have been recognized for many years to advantage significantly image-guided neurosurgery, especially when coregistered with preoperative MR scans, its unregulated and incomplete sampling of the surgical volume of interest have limited certain intraoperative uses of the information that are overcome through direct volume acquisition (i.e., through 2D scan-head transducer arrays). In this paper, we illustrate several of these advantages, including image-based intraoperative registration (and reregistration) and automated, volumetric displacement mapping for intraoperative image updating. These applications of 3D US are enabled by algorithmic advances in US image calibration, and volume rasterization and interpolation for multi-acquisition synthesis that will also be highlighted. We expect to demonstrate that coregistered 3D US is well worth incorporating into the standard neurosurgical navigational environment relative to traditional tracked, hand-swept 2D US.

  5. Prenatal diagnosis of ectopia cordis at 10 weeks of gestation using two-dimensional and three-dimensional ultrasonography.

    PubMed

    Liang, R I; Huang, S E; Chang, F M

    1997-08-01

    We report here the earliest prenatal diagnosis to date of a case of ectopia cordis using both two-dimensional and three-dimensional ultrasound at 10 weeks of gestation. Both two-dimensional and three-dimensional ultrasound clearly revealed a thoracoabdominal ectopia cordis and an omphalocele. Histopathological examination confirmed the prenatal ultrasonic findings. In addition to an ectopia cordis, a supraumbilical hepato-omphalocele, absence of a pericardium and an anterior diaphragmatic defect were seen, although there was a normal sternum. These pathological findings, suggested that our case was a variant of pentalogy of Cantrell.

  6. Primary and Secondary Three Dimensional Microbatteries

    NASA Astrophysics Data System (ADS)

    Cirigliano, Nicolas

    Today's MEMS devices are limited more so by the batteries that supply their power than the fabrication methods used to build them. Thick battery electrodes are capable of providing adequate energy, but long and tortuous diffusion pathways lead to low power capabilities. On the other hand, thin film batteries can operate at significant current densities but require large surface areas to supply practical energy. This dilemma can be solved by either developing new high capacity materials or by engineering new battery designs that decouple power and energy. Three dimensional batteries redesign traditional configurations to create nonplanar interfaces between battery components. This can be done by introducing hierarchical structures into the electrode shape. Designs such as these provide a maximum surface area over which chemical reactions can occur. Furthermore, by maintaining small feature sizes, ion diffusion and electronic transport distances can remain minimal. Manipulating these properties ensures fast kinetics that are required for high power situations. Energy density is maximized by layering material in the vertical direction, thus ensuring a minimal footprint area. Three dimensional carbon electrodes are fabricated using basic MEMS techniques. A silicon mold is anisotropically etched to produce channels of a predetermined diameter. The channels are then filled using an infiltration technique with electrode slurry. Once dried, the mold is attached to a current collector and etched using a XeF2 process. Electrodes of varying feature sizes have been fabricated using this method with aspect ratios ranging from 3.5:1 to 7:1. 3D carbon electrodes are shown to obtain capacities over 8 mAh/cm2 at 0.1 mA/cm2, or nearly 700% higher than planar carbon electrodes. When assembled with a planar cathode, the battery cell produced an average discharge capacity of 40 J/cm 2 at a current density of 0.2 mA/cm2. This places the energy density values slightly less than thick

  7. Development of three-dimensional nanoengineered architectures

    NASA Astrophysics Data System (ADS)

    Matsuura, Naomi

    2003-10-01

    Nanostructured arrays with feature sizes <100 nm are desirable for a wide variety of applications in the fields of optics and electronics. One limitation of traditional lithographic methods is that such small feature sizes are difficult to cost-effectively pattern at high throughputs. Consequently, it is very important to develop novel strategies for rapidly fabricating three-dimensional nanostructured arrays. True engineering of nanoscale architectures also requires the ability to control the material composition and the structural arrangement which, until now, has been limited. This thesis demonstrates two new high-throughput methods of three-dimensional nanostructured synthesis. These techniques yield large-area, array-type nanostructures with 2D and 3D periodicities, with feature sizes <100 nm. Specifically, 2D periodic air-hole arrays and 3D periodic ferroelectric inverse opal films are fabricated. In the first part of the thesis, 2D periodic, nanoporous arrays were fabricated for the first time using conventional, broad-beam ion implantation of heavy ions through self-organized, nanochannel alumina (NCA) templates. The significant features of this technique are that minimum feature sizes of ˜40 nm are achievable in a parallel process over a large area (˜cm 2) using a non-material specific process, with successful nanoscale patterning achieved in both single crystal InP and SrTiO3. In addition, this work represents the first study of the selective etch character of amorphous SrTiO3. The nanoengineering of complex profiles, including membrane structures, is also demonstrated using this novel technique. In the second part of the thesis, the first fabrication of 3D periodic, ferroelectric, BaTiO3 inverse opals, and a simple, adjustable process for the fabrication of large, high-quality, inverse opal ferroelectric films are reported. Highly ordered, ferroelectric, Pb-doped Ba0.7Sr 0.3TiO3 (BST) inverse opal films were fabricated by spin-coating a sol

  8. Flow Fields Over Unsteady Three Dimensional Dunes

    NASA Astrophysics Data System (ADS)

    Hardy, R. J.; Reesink, A.; Parsons, D. R.; Ashworth, P. J.; Best, J.

    2013-12-01

    The flow field over dunes has been extensively measured in laboratory conditions and there is general understanding on the nature of the flow over dunes formed under equilibrium flow conditions. However, fluvial systems typically experience unsteady flow and therefore the sediment-water interface is constantly responding and reorganizing to these unsteady flows, over a range of both spatial and temporal scales. This is primarily through adjustment of bed forms (including ripples, dunes and bar forms) which then subsequently alter the flow field. This paper investigates, through the application of a numerical model, the influence of these roughness elements on the overall flow and the increase in flow resistance. A series of experiments were undertaken in a flume, 16m long and 2m wide, where a fine sand (D50 of 239μm) mobile bed was water worked under a range of unsteady hydraulic conditions to generate a series of quasi-equilibrium three dimensional bed forms. During the experiments flow was measured with acoustic Doppler velocimeters, (aDv's). On four occasions the flume was drained and the bed topography measured with terrestrial LiDAR to create digital elevation models. This data provide the necessary boundary conditions and validation data for a Large Eddy Simulation (LES) model, which provided a three dimensional time dependent prediction of flow over the four static beds. The numerical predicted flow is analyzed through a series of approaches, and included: i) standard Reynolds decomposition to the flow fields; ii) Eulerian coherent structure detection methods based on the invariants of the velocity gradient tensor; iii) Lagrangian coherent structure identification methods based upon direct Lyapunov exponents (DLE). The results show that superimposed bed forms can cause changes in the nature of the classical separated flow region in particularly the number of locations where vortices are shed and the point of flow reattachment, which may be important for

  9. Understanding three-dimensional damage envelopes

    NASA Astrophysics Data System (ADS)

    Browning, John; Harland, Sophie; Meredith, Philip; Healy, David; Mitchell, Tom

    2017-04-01

    Microcrack damage leading to failure in rocks evolves in response to differential loading. This loading is often visualized in a two-dimensional stress space through the use of Mohr-Coulomb diagrams. The vast majority of experimental studies investigate damage evolution and rock failure using conventional triaxial stress states (σ1 > σ2 = σ3) in which the results can be easily represented in a Mohr-Coulomb plot. However, in nature the stress state is in general truly triaxial (σ1 > σ2 > σ3) and as such comprises a 3D stress state potentially leading to more complexity. By monitoring acoustic wave velocities and acoustic emissions we have shown that damage is generated in multiple orientations depending on the loading directions and hence principal stress directions. Furthermore, crack growth is shown to be a function of differential stress regardless of the mean stress. As such, new cracks can form due to a decrease in the minimum principal stress, which reduces mean stress but increases the differential stress. Although the size of individual cracks is not affected by the intermediate principal stress it has been shown that the σ2 plays a key role in suppressing the total amount of crack growth and concentrates this damage in a single plane. Hence, the differential stress at which rocks fail (i.e. the rock strength) will be significantly increased under true triaxial stress conditions than under the much more commonly applied condition of conventional triaxial stress. Through a series of cyclic loading tests we investigated the Kaiser effect, we show that while individual stress states are important, the stress path by which this stress state is reached is equally important. Whether or not a stress state has been 'visited' before is also vitally important in determining and understanding damage envelopes. Finally, we show that damage evolution can be anisotropic and must be considered as a three-dimensional problem. It is unclear how damage envelopes

  10. Nanoscale three-dimensional single particle tracking

    NASA Astrophysics Data System (ADS)

    Dupont, Aurélie; Lamb, Don C.

    2011-11-01

    Single particle tracking (SPT) in biological systems is a quickly growing field. Many new technologies are being developed providing new tracking capabilities, which also lead to higher demands and expectations for SPT. Following a single biomolecule as it performs its function provides quantitative mechanistic information that cannot be obtained in classical ensemble methods. From the 3D trajectory, information is available over the diffusional behavior of the particle and precise position information can also be used to elucidate interactions of the tracked particle with its surroundings. Thus, three-dimensional (3D) SPT is a very valuable tool for investigating cellular processes. This review presents recent progress in 3D SPT, from image-based techniques toward more sophisticated feedback approaches. We focus mainly on the feedback technique known as orbital tracking. We present here a modified version of the original orbital tracking in which the intensities from two z-planes are simultaneously measured allowing a concomitant wide-field imaging. The system can track single particles with a precision down to 5 nm in the x-y plane and 7 nm in the axial direction. The capabilities of the system are demonstrated using single virus tracing to follow the infection pathway of Prototype Foamy Virus in living cells.Single particle tracking (SPT) in biological systems is a quickly growing field. Many new technologies are being developed providing new tracking capabilities, which also lead to higher demands and expectations for SPT. Following a single biomolecule as it performs its function provides quantitative mechanistic information that cannot be obtained in classical ensemble methods. From the 3D trajectory, information is available over the diffusional behavior of the particle and precise position information can also be used to elucidate interactions of the tracked particle with its surroundings. Thus, three-dimensional (3D) SPT is a very valuable tool for

  11. Area MT Encodes Three-Dimensional Motion

    PubMed Central

    Huk, Alexander C.; Cormack, Lawrence K.; Kohn, Adam

    2014-01-01

    We use visual information to determine our dynamic relationship with other objects in a three-dimensional (3D) world. Despite decades of work on visual motion processing, it remains unclear how 3D directions—trajectories that include motion toward or away from the observer—are represented and processed in visual cortex. Area MT is heavily implicated in processing visual motion and depth, yet previous work has found little evidence for 3D direction sensitivity per se. Here we use a rich ensemble of binocular motion stimuli to reveal that most neurons in area MT of the anesthetized macaque encode 3D motion information. This tuning for 3D motion arises from multiple mechanisms, including different motion preferences in the two eyes and a nonlinear interaction of these signals when both eyes are stimulated. Using a novel method for functional binocular alignment, we were able to rule out contributions of static disparity tuning to the 3D motion tuning we observed. We propose that a primary function of MT is to encode 3D motion, critical for judging the movement of objects in dynamic real-world environments. PMID:25411482

  12. Two and three dimensional magnetotelluric inversion

    SciTech Connect

    Booker, J.

    1993-01-01

    Electrical conductivity depends on properties such as the presence of ionic fluids in interconnected pores that are difficult to sense with other remote sensing techniques. Thus improved imaging of underground electrical structure has wide practical importance in exploring for groundwater, mineral and geothermal resources, and in assessing the diffusion of fluids in oil fields and waste sites. Because the electromagnetic inverse problem is fundamentally multi-dimensional, most imaging algorithms saturate available computer power long before they can deal with the complete data set. We have developed an algorithm to directly invert large multi-dimensional data sets that is orders of magnitude faster than competing methods. We have proven that a two-dimensional (2D) version of the algorithm is highly effective for real data and have made substantial progress towards a three-dimensional (3D) version. We are proposing to cure identified shortcomings and substantially expand the utility of the existing 2D program, overcome identified difficulties with extending our method to three-dimensions (3D) and embark on an investigation of related EM imaging techniques which may have the potential for even further increasing resolution.

  13. Three-dimensional simulations of fracture dissolution

    NASA Astrophysics Data System (ADS)

    Starchenko, Vitaliy; Marra, Cameron J.; Ladd, Anthony J. C.

    2016-09-01

    Numerical studies of fracture dissolution are frequently based on two-dimensional models, where the fracture geometry is represented by an aperture field h(x,y). However, it is known that such models can break down when the spatial variations in aperture are rapid or large in amplitude; for example, in a rough fracture or when instabilities in the dissolution front develop into pronounced channels (or wormholes). Here we report a finite-volume implementation of a three-dimensional reactive transport model using the OpenFOAM® toolkit. Extensions to the OpenFOAM source code have been developed which displace and then relax the mesh in response to variations in the surface concentration; up to 100-fold increases in fracture aperture are possible without remeshing. Our code has simulated field-scale fractures with physical dimensions of about 10 m. We report simulations of smooth fractures, with small, well-controlled perturbations in fracture aperture introduced at the inlet. This allows for systematic convergence studies and for detailed comparisons with results from a two-dimensional model. Initially, the fracture aperture develops similarly in both models, but as local inhomogeneities develop the results start to diverge. We investigate numerically the onset of instabilities in the dissolution of fractures with small random variations in the initial aperture field. Our results show that elliptical cross sections, which are characteristic of karstic conduits, can develop very rapidly, on time scales of 10-20 years in calcite rocks.

  14. Three-dimensional Diffusive Strip Method

    NASA Astrophysics Data System (ADS)

    Martinez-Ruiz, Daniel; Meunier, Patrice; Duchemin, Laurent; Villermaux, Emmanuel

    2016-11-01

    The Diffusive Strip Method (DSM) is a near-exact numerical method developed for mixing computations at large Péclet number in two-dimensions. The method consists in following stretched material lines to compute a-posteriori the resulting scalar field is extended here to three-dimensional flows, following surfaces. We describe its 3D peculiarities, and show how it applies to a simple Taylor-Couette configuration with non-rotating boundary conditions at the top end, bottom and outer cylinder. This flow produces an elaborate, although controlled, steady 3D flow which relies on the Ekman pumping arising from the rotation of the inner cylinder is both studied experimentally, and numerically modeled. A recurrent two-cells structure appears formed by stream tubes shaped as nested tori. A scalar blob in the flow experiences a Lagrangian oscillating dynamics with stretchings and compressions, driving the mixing process, and yielding both rapidly-mixed and nearly pure-diffusive regions. A triangulated-surface method is developed to calculate the blob elongation and scalar concentration PDFs through a single variable computation along the advected blob surface, capturing the rich evolution observed in the experiments.

  15. Three-dimensional adaptive soft phononic crystals

    NASA Astrophysics Data System (ADS)

    Babaee, Sahab; Wang, Pai; Bertoldi, Katia

    2015-06-01

    We report a new class of three-dimensional (3D) adaptive phononic crystals whose dynamic response is controlled by mechanical deformation. Using finite element analysis, we demonstrate that the bandgaps of the proposed 3D structure can be fully tuned by the externally applied deformation. In fact, our numerical results indicate that the system acts as a reversible phononic switch: a moderate level of applied strain (i.e., -0.16) is sufficient to completely suppress the bandgap, and upon the release of applied strain, the deformed structure recovers its original shape, which can operate with a sizable bandgap under dynamic loading. In addition, we investigate how material damping significantly affects the propagation of elastic waves in the proposed 3D soft phononic crystal. We believe that our results pave the way for the design of a new class of soft, adaptive, and re-configurable 3D phononic crystals, whose bandgaps can be easily tuned and switched on/off by controlling the applied deformation.

  16. Three-Dimensional Optical Coherence Tomography

    NASA Technical Reports Server (NTRS)

    Gutin, Mikhail; Wang, Xu-Ming; Gutin, Olga

    2009-01-01

    Three-dimensional (3D) optical coherence tomography (OCT) is an advanced method of noninvasive infrared imaging of tissues in depth. Heretofore, commercial OCT systems for 3D imaging have been designed principally for external ophthalmological examination. As explained below, such systems have been based on a one-dimensional OCT principle, and in the operation of such a system, 3D imaging is accomplished partly by means of a combination of electronic scanning along the optical (Z) axis and mechanical scanning along the two axes (X and Y) orthogonal to the optical axis. In 3D OCT, 3D imaging involves a form of electronic scanning (without mechanical scanning) along all three axes. Consequently, the need for mechanical adjustment is minimal and the mechanism used to position the OCT probe can be correspondingly more compact. A 3D OCT system also includes a probe of improved design and utilizes advanced signal- processing techniques. Improvements in performance over prior OCT systems include finer resolution, greater speed, and greater depth of field.

  17. Three dimensional imaging with randomly distributed sensors.

    PubMed

    DaneshPanah, Mehdi; Javidi, Bahram; Watson, Edward A

    2008-04-28

    As a promising three dimensional passive imaging modality, Integral Imaging (II) has been investigated widely within the research community. In virtually all of such investigations, there is an implicit assumption that the collection of elemental images lie on a simple geometric surface (e.g. flat, concave, etc), also known as pickup surface. In this paper, we present a generalized framework for 3D II with arbitrary pickup surface geometry and randomly distributed sensor configuration. In particular, we will study the case of Synthetic Aperture Integral Imaging (SAII) with random location of cameras in space, while all cameras have parallel optical axes but different distances from the 3D scene. We assume that the sensors are randomly distributed in 3D volume of pick up space. For 3D reconstruction, a finite number of sensors with known coordinates are randomly selected from within this volume. The mathematical framework for 3D scene reconstruction is developed based on an affine transform representation of imaging under geometrical optics regime. We demonstrate the feasibility of the methods proposed here by experimental results. To the best of our knowledge, this is the first report on 3D imaging using randomly distributed sensors.

  18. Generation of three-dimensional medical thermograms.

    PubMed

    Chan, F H; So, A T; Lam, F K

    1996-01-01

    To visualise non-invasively human organs in their true form and shape has intrigued mankind for centuries. Three-dimensional (3D) imaging is one recent development that has brought us closer to fulfilling the age-old quest of non-invasive visualisation so that diagnoses by doctors can be efficiently enhanced. Nowadays, 3D CT and MRI images have been very popular. Thermography is an important medical imaging technique that displays the temperature distribution on the surface of a human organ and it has been proved to be significant in offering a unique physiological reflection of pathology that may confirm or enhance the anatomic findings of other diagnostic imaging modalities. It is the only imaging modality that can evaluate pain whereas plain radiographs, CT and MRI, etc. can only depict structural anatomic abnormalities that may not always coincide with patients' clinical complaints. It is against this background that 3D thermograms have been developed. A set of comprehensive calibration procedures for the 3-camera system have been designed based on different models for the optical and infrared cameras. The accuracy of the results is high enough to produce 3D thermograms that can be used to correlate with the 3D images from other medical imaging modalities. One important achievement of the system is that the resultant 3D images are absolutely dimensioned and hence, it is particularly favourable for fully autonomous applications with robots. The system can also provide an overall picture of both the structural abnormalities and nervous responses of patients.

  19. Three dimensional characterization and archiving system

    SciTech Connect

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1995-12-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. Chemical analysis plays a vital role throughout the process of decontamination. Before clean-up operations can begin the site must be characterized with respect to the type and concentration of contaminants, and detailed site mapping must clarify areas of both high and low risk. During remediation activities chemical analysis provides a means to measure progress and to adjust clean-up strategy. Once the clean-up process has been completed the results of chemical analysis will verify that the site is in compliance with federal and local regulations.

  20. Three dimensional characterization and archiving system

    SciTech Connect

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1995-10-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. The 3D-ICAS system robotically conveys a multisensor probe near the surface to be inspected. The sensor position and orientation are monitored and controlled by Coherent laser radar (CLR) tracking. The ICAS fills the need for high speed automated organic analysis by means of gas chromatography-mass spectrometry sensors, and also by radionuclide sensors which combines alpha, beta, and gamma counting.

  1. Three-dimensional laser velocimeter simultaneity detector

    NASA Technical Reports Server (NTRS)

    Brown, James L. (Inventor)

    1990-01-01

    A three-dimensional laser Doppler velocimeter has laser optics for a first channel positioned to create a probe volume in space, and laser optics and for second and third channels, respectively, positioned to create entirely overlapping probe volumes in space. The probe volumes and overlap partially in space. The photodetector is positioned to receive light scattered by a particle present in the probe volume, while photodetectors and are positioned to receive light scattered by a particle present in the probe volume. The photodetector for the first channel is directly connected to provide a first channel analog signal to frequency measuring circuits. The first channel is therefore a primary channel for the system. Photodetectors and are respectively connected through a second channel analog signal attenuator to frequency measuring circuits and through a third channel analog signal attenuator to frequency measuring circuits. The second and third channels are secondary channels, with the second and third channels analog signal attenuators and controlled by the first channel measurement burst signal on line. The second and third channels analog signal attenuators and attenuate the second and third channels analog signals only when the measurement burst signal is false.

  2. Three-Dimensional Printed Graphene Foams.

    PubMed

    Sha, Junwei; Li, Yilun; Villegas Salvatierra, Rodrigo; Wang, Tuo; Dong, Pei; Ji, Yongsung; Lee, Seoung-Ki; Zhang, Chenhao; Zhang, Jibo; Smith, Robert H; Ajayan, Pulickel M; Lou, Jun; Zhao, Naiqin; Tour, James M

    2017-07-25

    An automated metal powder three-dimensional (3D) printing method for in situ synthesis of free-standing 3D graphene foams (GFs) was successfully modeled by manually placing a mixture of Ni and sucrose onto a platform and then using a commercial CO2 laser to convert the Ni/sucrose mixture into 3D GFs. The sucrose acted as the solid carbon source for graphene, and the sintered Ni metal acted as the catalyst and template for graphene growth. This simple and efficient method combines powder metallurgy templating with 3D printing techniques and enables direct in situ 3D printing of GFs with no high-temperature furnace or lengthy growth process required. The 3D printed GFs show high-porosity (∼99.3%), low-density (∼0.015g cm(-3)), high-quality, and multilayered graphene features. The GFs have an electrical conductivity of ∼8.7 S cm(-1), a remarkable storage modulus of ∼11 kPa, and a high damping capacity of ∼0.06. These excellent physical properties of 3D printed GFs indicate potential applications in fields requiring rapid design and manufacturing of 3D carbon materials, for example, energy storage devices, damping materials, and sound absorption.

  3. Three-dimensional modelling of Venus photochemistry

    NASA Astrophysics Data System (ADS)

    Stolzenbach, Aurélien; Lefèvre, Franck; Lebonnois, Sébastien; Määttänen, Anni; Bekki, Slimane

    2014-05-01

    We have developed a new code of the Venus atmospheric chemistry based on our photochemical model already in use for Mars (e.g., Lefèvre et al., J. Geophys. Res., 2004). For Venus, the code also includes a parameterized treatment of cloud microphysics that computes the composition of sulphuric acid droplets and their number density based on a given droplet size distribution in altitude. We coupled this photochemical-microphysical package to the LMD general circulation model of Venus (Lebonnois et al., J. Geophys. Res., 2010) with a sedimentation module recently added. We will describe preliminary results obtained with this first three-dimensional model of the Venus photochemistry. The space and time distribution of key chemical species as well as the modelled clouds characteristics will be detailed and compared to observations performed from Venus Express and from the Earth (e.g. Knollenberg and Hunten, J. Geophys. Res., 1980 ; Wilquet et al., J. Geophys. Res., 2009 ; Sandor et al., Icarus, 2012).

  4. Three-Dimensional Modelling of Venus Photochemistry

    NASA Astrophysics Data System (ADS)

    Stolzenbach, A.; Lefèvre, F.; Lebonnois, S.; Maattanen, A. E.; Bekki, S.

    2015-12-01

    We have developed a new code of the Venus atmospheric chemistry based on our photochemical model already in use for Mars (e.g., Lefèvre et al., J. Geophys. Res., 2004). For Venus, the code also includes a parameterized treatment of cloud microphysics that computes the composition of sulphuric acid droplets and their number density based on a given droplet size distribution in altitude and latitude. We coupled this photochemical-microphysical package to the LMD general circulation model of Venus (Lebonnois et al., J. Geophys. Res., 2010) with a sedimentation module that takes into account the parametrized droplet size distribution. We will describe the results obtained with this first three-dimensional model of the Venus photochemistry. The space and time distribution of key chemical species as well as the modelled clouds characteristics will be detailed and compared to observations performed from Venus Express and from the Earth (e.g. Knollenberg and Hunten, J. Geophys. Res., 1980 ; Wilquet et al., J. Geophys. Res., 2009 ; Sandor et al., Icarus, 2012 ; Mahieux et al., PSS, 2014 ; Marcq et al., 2015, PSS).

  5. Three-dimensional landing zone ladar

    NASA Astrophysics Data System (ADS)

    Savage, James; Goodrich, Shawn; Burns, H. N.

    2016-05-01

    Three-Dimensional Landing Zone (3D-LZ) refers to a series of Air Force Research Laboratory (AFRL) programs to develop high-resolution, imaging ladar to address helicopter approach and landing in degraded visual environments with emphasis on brownout; cable warning and obstacle avoidance; and controlled flight into terrain. Initial efforts adapted ladar systems built for munition seekers, and success led to a the 3D-LZ Joint Capability Technology Demonstration (JCTD) , a 27-month program to develop and demonstrate a ladar subsystem that could be housed with the AN/AAQ-29 FLIR turret flown on US Air Force Combat Search and Rescue (CSAR) HH-60G Pave Hawk helicopters. Following the JCTD flight demonstration, further development focused on reducing size, weight, and power while continuing to refine the real-time geo-referencing, dust rejection, obstacle and cable avoidance, and Helicopter Terrain Awareness and Warning (HTAWS) capability demonstrated under the JCTD. This paper summarizes significant ladar technology development milestones to date, individual LADAR technologies within 3D-LZ, and results of the flight testing.

  6. Three-dimensional visualization for large models

    NASA Astrophysics Data System (ADS)

    Roth, Michael W.

    2001-09-01

    High-resolution (0.3-1 m) digital-elevation data is widely available from commercial sources. Whereas the production of two-dimensional (2D) mapping products from such data is standard practice, the visualization of such three-dimensional (3D) data has been problematic. The basis for this problem is the same as that for the large-model problem in computer graphics-- large amounts of geometry are difficult for current rendering algorithms and hardware. This paper describes a cost-effective solution to this problem that has two parts. First is the employment of the latest in cost-effective 3D chips and video boards that have recently emerged. The second part is the employment of quad-tree data structures for efficient data storage and retrieval during rendering. The result is the capability for real-time display of large (over tens of millions of samples) digital elevation models on modest PC-based systems. This paper shows several demonstrations of this approach using airborne lidar data. The implication of this work is a paradigm shift for geo-spatial information systems--3D data can now be as easy to use as 2D data.

  7. Three-dimensional transverse vibration of microtubules

    NASA Astrophysics Data System (ADS)

    Li, Si; Wang, Chengyuan; Nithiarasu, Perumal

    2017-06-01

    A three-dimensional (3D) transverse vibration was reported based on the molecular structural mechanics model for microtubules (MTs), where the bending axis of the cross section rotates in an anticlockwise direction and the adjacent half-waves oscillate in different planes. Herein, efforts were invested to capturing the physics behind the observed phenomenon and identifying the important factors that influence the rotation angle between two adjacent half waves. A close correlation was confirmed between the rotation of the oscillation planes and the helical structures of the MTs, showing that the 3D mode is a result of the helicity found in the MTs. Subsequently, the wave length-dependence and the boundary condition effects were also investigated for the 3D transverse vibration of the MTs. In addition, the vibration frequency was found to remain the same in the presence or absence of the bending axis rotation. This infers that the unique vibration mode is merely due to the bending axis rotation of the cross section, but no significant torsion occurs for the MTs.

  8. A three-dimensional human walking model

    NASA Astrophysics Data System (ADS)

    Yang, Q. S.; Qin, J. W.; Law, S. S.

    2015-11-01

    A three-dimensional human bipedal walking model with compliant legs is presented in this paper. The legs are modeled with time-variant dampers, and the model is able to characterize the gait pattern of an individual using a minimal set of parameters. Feedback control, for both the forward and lateral movements, is implemented to regulate the walking performance of the pedestrian. The model provides an improvement over classic invert pendulum models. Numerical studies were undertaken to investigate the effects of leg stiffness and attack angle. Simulation results show that when walking at a given speed, increasing the leg stiffness with a constant attack angle results in a longer step length, a higher step frequency, a faster walking speed and an increase in both the peak vertical and lateral ground reaction forces. Increasing the attack angle with a constant leg stiffness results in a higher step frequency, a decrease in the step length, an increase in the total energy of the system and a decrease in both the peak vertical and lateral ground reaction forces.

  9. Three dimensional characterization and archiving system

    SciTech Connect

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1996-04-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D and D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D and D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. The 3D-ICAS system robotically conveys a multisensor probe near the surfaces to be inspected. The sensor position and orientation are monitored and controlled using coherent laser radar (CLR) tracking. The CLR also provides 3D facility maps which establish a 3D world view within which the robotic sensor system can operate.

  10. PLOT3D- DRAWING THREE DIMENSIONAL SURFACES

    NASA Technical Reports Server (NTRS)

    Canright, R. B.

    1994-01-01

    PLOT3D is a package of programs to draw three-dimensional surfaces of the form z = f(x,y). The function f and the boundary values for x and y are the input to PLOT3D. The surface thus defined may be drawn after arbitrary rotations. However, it is designed to draw only functions in rectangular coordinates expressed explicitly in the above form. It cannot, for example, draw a sphere. Output is by off-line incremental plotter or online microfilm recorder. This package, unlike other packages, will plot any function of the form z = f(x,y) and portrays continuous and bounded functions of two independent variables. With curve fitting; however, it can draw experimental data and pictures which cannot be expressed in the above form. The method used is division into a uniform rectangular grid of the given x and y ranges. The values of the supplied function at the grid points (x, y) are calculated and stored; this defines the surface. The surface is portrayed by connecting successive (y,z) points with straight-line segments for each x value on the grid and, in turn, connecting successive (x,z) points for each fixed y value on the grid. These lines are then projected by parallel projection onto the fixed yz-plane for plotting. This program has been implemented on the IBM 360/67 with on-line CDC microfilm recorder.

  11. Three-dimensional planning in craniomaxillofacial surgery

    PubMed Central

    Rubio-Palau, Josep; Prieto-Gundin, Alejandra; Cazalla, Asteria Albert; Serrano, Miguel Bejarano; Fructuoso, Gemma Garcia; Ferrandis, Francisco Parri; Baró, Alejandro Rivera

    2016-01-01

    Introduction: Three-dimensional (3D) planning in oral and maxillofacial surgery has become a standard in the planification of a variety of conditions such as dental implants and orthognathic surgery. By using custom-made cutting and positioning guides, the virtual surgery is exported to the operating room, increasing precision and improving results. Materials and Methods: We present our experience in the treatment of craniofacial deformities with 3D planning. Software to plan the different procedures has been selected for each case, depending on the procedure (Nobel Clinician, Kodak 3DS, Simplant O&O, Dolphin 3D, Timeus, Mimics and 3-Matic). The treatment protocol is exposed step by step from virtual planning, design, and printing of the cutting and positioning guides to patients’ outcomes. Conclusions: 3D planning reduces the surgical time and allows predicting possible difficulties and complications. On the other hand, it increases preoperative planning time and needs a learning curve. The only drawback is the cost of the procedure. At present, the additional preoperative work can be justified because of surgical time reduction and more predictable results. In the future, the cost and time investment will be reduced. 3D planning is here to stay. It is already a fact in craniofacial surgery and the investment is completely justified by the risk reduction and precise results. PMID:28299272

  12. Lattice theory of three-dimensional cracks

    NASA Technical Reports Server (NTRS)

    Esterling, D. M.

    1976-01-01

    The problem of the stability of a three-dimensional crack is analyzed within a lattice-statics approximation. The consequence of introducing a jog into the crack face as well as the effects of various nonlinear-force laws are studied. The phenomenon of lattice trapping (upper and lower bounds on the applied stress for an equilibrium crack of given length) is again obtained. It is possible to obtain some physical insight into which aspects of the force law are critical for crack stability. In particular, the inadequacy of a thermodynamic approach - which relates the critical stress to a surface energy corresponding to the area under the cohesive-force-vs-displacement curve - is demonstrated. Surface energy is a global property of the cohesive-force law. Crack stability is sensitive to much more refined aspects of the cohesive-force law. Crack healing is sensitive to the long-range portion of the cohesive force. Crack expansion is sensitive to the position of the maximum in the cohesive-force relation.

  13. Three dimensional, multi-chip module

    SciTech Connect

    Bernhardt, A.F.; Petersen, R.W.

    1992-12-31

    The present invention relates to integrated circuit packaging technology, and particularly to three dimensional packages involving high density stacks of integrated circuits. A plurality of multi-chip modules are stacked and bonded around the perimeter by sold-bump bonds to adjacent modules on, for instance, three sides of the perimeter. The fourth side can be used for coolant distribution, for more interconnect structures, or other features, depending on particular design considerations of the chip set. The multi-chip modules comprise a circuit board, having a planarized interconnect structure formed on a first major surface, and integrated circuit chips bonded to the planarized interconnect surface. Around the periphery of each circuit board, long, narrow ``dummy chips`` are bonded to the finished circuit board to form a perimeter wall. The wall is higher than any of the chips on the circuit board, so that the flat back surface of the board above will only touch the perimeter wall. Module-to-module interconnect is laser-patterned on the sides of the boards and over the perimeter wall in the same way and at the same time that chip to board interconnect may be laser-patterned.

  14. Tip selection in three-dimensional dendrites

    NASA Astrophysics Data System (ADS)

    Foster, M. R.; Tanveer, S.

    2004-11-01

    Dendrites are well-known to have a fully three-dimensional structure, often with four equally-spaced fins emanating from the steady parabolic tip, the pattern for which has now a good theoretical foundation.(McFadden, Coriell & Sekerka, J. Crys. Growth) 208 (2000) The four fins are of course related to four-fold crystalline anisotropy of quite small magnitude. We follow Tanveer(Tanveer, S. Phys. Rev. A) 40 (1989) in carefully exploring the matching of the inner solution in the neighborhood of the singularity nearest the real line to the small-surface-energy regular perturbation expansion, in order to obtain the (selected) tip radius and the amplitude of the fin. We consider the case for which the anisotropy parameter, α, is much larger than a dimensionless capillary length to the 4/7 power. We confirm what was already found in a slightly different parameter range(Ben Amar & Brener, Phys. Rev. Lett.) 71 (1993)--that the inner equation is essentially that of the two-dimensional case, with azimuthally-dependent parameters. We compare our results with those of Ben Amar & Brener.

  15. FRET Imaging in Three-dimensional Hydrogels

    PubMed Central

    Taboas, Juan M.

    2016-01-01

    Imaging of Förster resonance energy transfer (FRET) is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly employ two-dimensional (2D) culture, which does not mimic the three-dimensional (3D) cellular microenvironment. A method to perform quenched emission FRET imaging using conventional widefield epifluorescence microscopy of cells within a 3D hydrogel environment is presented. Here an analysis method for ratiometric FRET probes that yields linear ratios over the probe activation range is described. Measurement of intracellular cyclic adenosine monophosphate (cAMP) levels is demonstrated in chondrocytes under forskolin stimulation using a probe for EPAC1 activation (ICUE1) and the ability to detect differences in cAMP signaling dependent on hydrogel material type, herein a photocrosslinking hydrogel (PC-gel, polyethylene glycol dimethacrylate) and a thermoresponsive hydrogel (TR-gel). Compared with 2D FRET methods, this method requires little additional work. Laboratories already utilizing FRET imaging in 2D can easily adopt this method to perform cellular studies in a 3D microenvironment. It can further be applied to high throughput drug screening in engineered 3D microtissues. Additionally, it is compatible with other forms of FRET imaging, such as anisotropy measurement and fluorescence lifetime imaging (FLIM), and with advanced microscopy platforms using confocal, pulsed, or modulated illumination. PMID:27500354

  16. Three-dimensional Printing in the Intestine.

    PubMed

    Wengerter, Brian C; Emre, Gulus; Park, Jea Young; Geibel, John

    2016-08-01

    Intestinal transplantation remains a life-saving option for patients with severe intestinal failure. With the advent of advanced tissue engineering techniques, great strides have been made toward manufacturing replacement tissues and organs, including the intestine, which aim to avoid transplant-related complications. The current paradigm is to seed a biocompatible support material (scaffold) with a desired cell population to generate viable replacement tissue. Although this technique has now been extended by the three-dimensional (3D) printing of geometrically complex scaffolds, the overall approach is hindered by relatively slow turnover and negative effects of residual scaffold material, which affects final clinical outcome. Methods recently developed for scaffold-free 3D bioprinting may overcome such obstacles and should allow for rapid manufacture and deployment of "bioprinted organs." Much work remains before 3D bioprinted tissues can enter clinical use. In this brief review we examine the present state and future perspectives of this nascent technology before full clinical implementation. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

  17. Three Dimensional Characterization of the Mundrabilla Meteorite

    NASA Technical Reports Server (NTRS)

    Gillies, Donald C.; Engel, H. Peter; Carpenter, P. K.

    2003-01-01

    The differentiated meteorite, Mundrabilla, exhibits a rare structure of primary kamacite/taenite, and at least 25 volume % of sulfide (troilite and daubreelite). The structure has been investigated in three dimensions using the technique of gamma-ray computed tomography (CT) with a radioactive (60)Co isotope as the source of the flux. Using CT, a 50 kg slab with dimensions 12.6 x 8.2 x approx. 70 cm has been sectioned at 1 mm intervals over 50 cm length, and the three dimensional structure is at present being evaluated. These data revealed, in addition to the metallic and troilite-rich phases, the presence and distribution of graphite-rich cones (up to 5 cm long), and small (1-2 mm), low density particles. The graphite cones are readily visible on the surfaces of many of the sections of Mundrabilla, while the smaller phases have a density (determined from CT) of approximately 2.9 g/cc, and are assumed to be silicate inclusions. CT spatial resolution is not adequate to elucidate the shapes of these particles. One can only state that they show no directionality and are equiaxed.

  18. Three-dimensional imaging in craniofacial surgery.

    PubMed

    Zonneveld, F W; Lobregt, S; van der Meulen, J C; Vaandrager, J M

    1989-01-01

    Over the past decade, three-dimensional (3-D) imaging has been developed to such a stage of perfection and to such a level of interactive selective imaging of specific anatomic and pathologic structures that craniofacial surgeons can now use this technique effectively in the planning of complicated reconstructive surgery. In addition, modeling techniques have been devised that can be used in surgical simulation and in the manufacture of implants and prosthetic devices. The technical aspects of 3-D imaging are discussed in relation to their applications in craniofacial surgery, and reference is made to the literature describing these techniques in full detail. The results are illustrated with cases that the authors have processed by means of: (a) a clinical research program that was developed on a general purpose computer which provided full flexibility in changing and improving the reconstruction algorithms (Lobregt algorithms and DEC VAX 750 computer), (b) a system under development (Pixar PICS 2000), and (c) a commercial system (Cemax 1500X). Finally, a number of emerging techniques are discussed such as surgical stimulation (electronic sculpting), and trends such as multimodality imaging.

  19. Three Dimensional Characterization of the Mundrabilla Meteorite

    NASA Technical Reports Server (NTRS)

    Gillies, Donald C.; Engel, H. Peter; Carpenter, P. K.

    2003-01-01

    The differentiated meteorite, Mundrabilla, exhibits a rare structure of primary kamacite/taenite, and at least 25 volume % of sulfide (troilite and daubreelite). The structure has been investigated in three dimensions using the technique of gamma-ray computed tomography (CT) with a radioactive (60)Co isotope as the source of the flux. Using CT, a 50 kg slab with dimensions 12.6 x 8.2 x approx. 70 cm has been sectioned at 1 mm intervals over 50 cm length, and the three dimensional structure is at present being evaluated. These data revealed, in addition to the metallic and troilite-rich phases, the presence and distribution of graphite-rich cones (up to 5 cm long), and small (1-2 mm), low density particles. The graphite cones are readily visible on the surfaces of many of the sections of Mundrabilla, while the smaller phases have a density (determined from CT) of approximately 2.9 g/cc, and are assumed to be silicate inclusions. CT spatial resolution is not adequate to elucidate the shapes of these particles. One can only state that they show no directionality and are equiaxed.

  20. Three-dimensional modeling of tsunami waves

    SciTech Connect

    Mader, C.L.

    1985-01-01

    Two- and three-dimensional, time-dependent, nonlinear, incompressible, viscous flow calculations of realistic models of tsunami wave formation and run up have been performed using the Los Alamos-developed SOLA-3D code. The results of the SOLA calculations are compared with shallow-water, long-wave calculations for the same problems using the SWAN code. Tsunami wave formation by a continental slope subsidence has been examined using the two numerical models. The SOLA waves were slower than the SWAN waves and the interaction with the shoreline was more complicated for the SOLA waves. In the SOLA calculation, the first wave was generated by the cavity being filled along the shoreline close to the source of motion. The second wave was generated by the cavity being filled from the deep water end. The two waves interacted along the shoreline resulting in the second wave being the largest wave with a velocity greater than the first wave. The second wave overtook the first wave at later times and greater distances from the source. In the SWAN calculation, the second wave was smaller than the first wave. 6 refs.

  1. a Three-Dimensional Orbit for Capella

    NASA Astrophysics Data System (ADS)

    Branham, Richard L.

    2008-09-01

    Semidefinite programming is applied to 169 interferometric observations of Capella, made between 1919 and 1999, and 221 double-line radial velocities, obtained between 1896 and 1991, to calculate a three-dimensional orbit. The data are reduced with the robust L 1 criterion. The orbit is nearly circular, eccentricity of 0.00508, with a semimajor axis of 0farcs056 and period of 104.039 days. The mass of the primary is calculated to be 3.049 M sun, that of the secondary 2.569 M sun, and the parallax of the system is calculated to be 74.85 mas. Another orbit is calculated, but using only the best data, Mark III interferometric observations, and Coralie radial velocities. Although the mean errors for this orbit are considerably smaller, reasons are given for preferring the orbit calculated from all of the data as opposed to only the best data: the residuals are more random, the parallax agrees better with van Leeuwen's re-reduction of the Hipparcos parallax, and the Shannon uncertainty is lower.

  2. Magnetophotonic response of three-dimensional opals.

    PubMed

    Caicedo, José Manuel; Pascu, Oana; López-García, Martín; Canalejas, Víctor; Blanco, Alvaro; López, Cefe; Fontcuberta, Josep; Roig, Anna; Herranz, Gervasi

    2011-04-26

    Three-dimensional magnetophotonic crystals (3D-MPCs) are being postulated as appropriate platforms to tailor the magneto-optical spectral response of magnetic materials and to incorporate this functionality in a new generation of optical devices. By infiltrating self-assembled inverse opal structures with monodisperse nickel nanoparticles we have fabricated 3D-MPCs that show a sizable enhancement of the magneto-optical signal at frequencies around the stop-band edges of the photonic crystals. We have established a proper methodology to disentangle the intrinsic magneto-optical spectra from the nonmagnetic optical activity of the 3D-MPCs. The results of the optical and magneto-optical characterization are consistent with a homogeneous magnetic infiltration of the opal structure that gives rise to both a red-shift of the optical bandgap and a modification of the magneto-optical spectral response due to photonic bandgap effects. The results of our investigation demonstrate the potential of 3D-MPCs fabricated following the approach outlined here and offer opportunities to adapt the magneto-optical spectral response at optical frequencies by appropriate design of the opal structure or magnetic field strength.

  3. Three-dimensional context regulation of metastasis

    PubMed Central

    Erler, Janine T.; Weaver, Valerie M.

    2009-01-01

    Tumor progression ensues within a three-dimensional microenvironment that consists of cellular and non-cellular components. The extracellular matrix (ECM) and hypoxia are two non-cellular components that potently influence metastasis. ECM remodeling and collagen cross-linking stiffen the tissue stroma to promote transformation, tumor growth, motility and invasion, enhance cancer cell survival, enable metastatic dissemination, and facilitate the establishment of tumor cells at distant sites. Matrix degradation can additionally promote malignant progression and metastasis. Tumor hypoxia is functionally linked to altered stromal-epithelial interactions. Hypoxia additionally induces the expression of pro-migratory, survival and invasion genes, and up-regulates expression of ECM components and modifying enzymes, to enhance tumor progression and metastasis. Synergistic interactions between matrix remodeling and tumor hypoxia influence common mechanisms that maximize tumor progression and cooperate to drive metastasis. Thus, clarifying the molecular pathways by which ECM remodeling and tumor hypoxia intersect to promote tumor progression should identify novel therapeutic targets. PMID:18814043

  4. Three-dimensional laparoscopy: Principles and practice.

    PubMed

    Sinha, Rakesh Y; Raje, Shweta R; Rao, Gayatri A

    2017-01-01

    The largest challenge for laparoscopic surgeons is the eye-hand coordination within a three-dimensional (3D) scene observed on a 2D display. The 2D view on flat screen laparoscopy is cerebrally intensive. The loss of binocular vision on a 2D display causes visual misperceptions, mainly loss of depth perception and adds to the surgeon's fatigue. This compromises the safety of laparoscopy. The 3D high-definition view with great depth perception and tactile feedback makes laparoscopic surgery more acceptable, safe and cost-effective. It improves surgical precision and hand-eye coordination, conventional and all straight stick instruments can be used, capital expenditure is less and recurring cost and annual maintenance cost are less. In this article, we have discussed the physics of 3D laparoscopy, principles of depth perception, and the different kinds of 3D systems available for laparoscopy. We have also discussed our experience of using 3D laparoscopy in over 2000 surgeries in the last 4 years.

  5. Three-dimensional charge coupled device

    DOEpatents

    Conder, Alan D.; Young, Bruce K. F.

    1999-01-01

    A monolithic three dimensional charged coupled device (3D-CCD) which utilizes the entire bulk of the semiconductor for charge generation, storage, and transfer. The 3D-CCD provides a vast improvement of current CCD architectures that use only the surface of the semiconductor substrate. The 3D-CCD is capable of developing a strong E-field throughout the depth of the semiconductor by using deep (buried) parallel (bulk) electrodes in the substrate material. Using backside illumination, the 3D-CCD architecture enables a single device to image photon energies from the visible, to the ultra-violet and soft x-ray, and out to higher energy x-rays of 30 keV and beyond. The buried or bulk electrodes are electrically connected to the surface electrodes, and an E-field parallel to the surface is established with the pixel in which the bulk electrodes are located. This E-field attracts charge to the bulk electrodes independent of depth and confines it within the pixel in which it is generated. Charge diffusion is greatly reduced because the E-field is strong due to the proximity of the bulk electrodes.

  6. Three-Dimensional Imaging of Viral Infections.

    PubMed

    Risco, Cristina; de Castro, Isabel Fernández; Sanz-Sánchez, Laura; Narayan, Kedar; Grandinetti, Giovanna; Subramaniam, Sriram

    2014-11-01

    Three-dimensional (3D) imaging technologies are beginning to have significant impact in the field of virology, as they are helping us understand how viruses take control of cells. In this article we review several methodologies for 3D imaging of cells and show how these technologies are contributing to the study of viral infections and the characterization of specialized structures formed in virus-infected cells. We include 3D reconstruction by transmission electron microscopy (TEM) using serial sections, electron tomography, and focused ion beam scanning electron microscopy (FIB-SEM). We summarize from these methods selected contributions to our understanding of viral entry, replication, morphogenesis, egress and propagation, and changes in the spatial architecture of virus-infected cells. In combination with live-cell imaging, correlative microscopy, and new techniques for molecular mapping in situ, the availability of these methods for 3D imaging is expected to provide deeper insights into understanding the structural and dynamic aspects of viral infection.

  7. Three-dimensional instability of isolated vortices

    NASA Astrophysics Data System (ADS)

    Gallaire, F.; Chomaz, J.-M.

    2003-08-01

    We study the three-dimensional stability of the family of vortices introduced by Carton and McWilliams [Mesoscale/Synoptic Coherent Structures in Geophysical Turbulence, edited by Nikhoul and Jamart (Elsevier, New York, 1989)] describing isolated vortices. For these vortices, the circulation vanishes outside their core over a distance depending on a single parameter, the steepness α. We proceed to the direct numerical simulation of the linear impulse response to obtain both temporal and spatio-temporal instability results. In the temporal instability framework, growth rates are calculated as a function of the axial wavenumber k and the azimuthal wavenumber m. The stability analysis is performed at a Reynolds number of Re=667. It is shown that the most unstable mode is the axisymmetric mode m=0, regardless of the steepness parameter in the investigated range. When the steepness α is increased the band of unstable azimuthal modes widens, i.e., larger m are destabilized. The study of the spatio-temporal spreading of the wave packet shows that the m=2 mode is always the fastest traveling mode, for all studied values of the steepness parameter.

  8. Globographic visualisation of three dimensional joint angles.

    PubMed

    Baker, Richard

    2011-07-07

    Three different methods for describing three dimensional joint angles are commonly used in biomechanics. The joint coordinate system and Cardan/Euler angles are conceptually quite different but are known to represent the same underlying mathematics. More recently the globographic method has been suggested as an alternative and this has proved particularly attractive for the shoulder joint. All three methods can be implemented in a number of ways leading to a choice of angle definitions. Very recently Rab has demonstrated that the globographic method is equivalent to one implementation of the joint coordinate system. This paper presents a rigorous analysis of the three different methods and proves their mathematical equivalence. The well known sequence dependence of Cardan/Euler is presented as equivalent to configuration dependence of the joint coordinate system and orientation dependence of globographic angles. The precise definition of different angle sets can be easily visualised using the globographic method using analogues of longitude, latitude and surface bearings with which most users will already be familiar. The method implicitly requires one axis of the moving segment to be identified as its principal axis and this can be extremely useful in helping define the most appropriate angle set to describe the orientation of any particular joint. Using this technique different angle sets are considered to be most appropriate for different joints and examples of this for the hip, knee, ankle, pelvis and axial skeleton are outlined.

  9. Contrast-Enhanced Three Dimensional Ultrasonography supporting HIFU treatment of Small Liver Cancer

    NASA Astrophysics Data System (ADS)

    Ohto, Masao; Fukuda, Hiroyuki; Ito, Ryu; Shinohara, Yasushi; Sakamoto, Akio; Karasawa, Eii

    2009-04-01

    HIFU was carried out in the 12 patients with small hepatocellular carcinoma (small HCC) as a extracorporeal ablation therapy, and clinical availability was studied from the results. In carrying out the HIFU therapy, contrast enhanced (CE) three dimensional (3D) ultrasound imaging played an important role to clarify the tumor nature , to monitor the sonication procedure and to assess the tumor ablation and was almost indispensable for the treatment. All the patient had no serious side effects and they are all alive with no local tumor progression for 3 to 14 months after the treatment. Ultrasound supporting HIFU therapy could be usefully available for the treatment of small HCC.

  10. Three-dimensional ultrasonic Nakagami imaging for tissue characterization

    NASA Astrophysics Data System (ADS)

    Tsui, Po-Hsiang; Hsu, Cheng-Wei; Ho, Ming-Chih; Chen, Yung-Sheng; Lin, Jen-Jen; Chang, Chien-Cheng; Chu, Chin-Chou

    2010-10-01

    The two-dimensional (2D) Nakagami image complements the ultrasound B-scan image when attempting to visualize the scatterer properties of tissues. The resolution of the Nakagami image is lower than that of the B-scan image, since the former is produced by processing the raw envelope data using a 2D sliding window with side lengths typically corresponding to three times the pulse length of the incident ultrasound. This paper proposes using three-dimensional (3D) Nakagami imaging for improving the resolution of the obtained Nakagami image and providing more complete information of scatterers for a better tissue characterization. The 3D Nakagami image is based on a voxel array composed of the Nakagami parameters constructed using a 3D sliding cube to process the 3D backscattered raw data. Experiments on phantoms with different scatterer concentrations were carried out to determine the optimal size of the sliding cube for a stable estimation of the Nakagami parameter. Tissue measurements on rat livers without and with fibrosis formation were further used to explore the practical feasibility of 3D Nakagami imaging. The results indicated that the side length of the cube used to construct the 3D Nakagami image must be at least two times the pulse length, which improved the resolution for each Nakagami image frame in the 3D Nakagami image. The results further demonstrated that the 3D Nakagami image is better than the conventional 2D Nakagami image for complementing the B-scan in detecting spatial variations in the scatterer concentration and classifying normal and fibrotic livers. This study suggests that 3D Nakagami imaging has the potential to become a new 3D quantitative imaging approach.

  11. Three-dimensional ultrasonic Nakagami imaging for tissue characterization.

    PubMed

    Tsui, Po-Hsiang; Hsu, Cheng-Wei; Ho, Ming-Chih; Chen, Yung-Sheng; Lin, Jen-Jen; Chang, Chien-Cheng; Chu, Chin-Chou

    2010-10-07

    The two-dimensional (2D) Nakagami image complements the ultrasound B-scan image when attempting to visualize the scatterer properties of tissues. The resolution of the Nakagami image is lower than that of the B-scan image, since the former is produced by processing the raw envelope data using a 2D sliding window with side lengths typically corresponding to three times the pulse length of the incident ultrasound. This paper proposes using three-dimensional (3D) Nakagami imaging for improving the resolution of the obtained Nakagami image and providing more complete information of scatterers for a better tissue characterization. The 3D Nakagami image is based on a voxel array composed of the Nakagami parameters constructed using a 3D sliding cube to process the 3D backscattered raw data. Experiments on phantoms with different scatterer concentrations were carried out to determine the optimal size of the sliding cube for a stable estimation of the Nakagami parameter. Tissue measurements on rat livers without and with fibrosis formation were further used to explore the practical feasibility of 3D Nakagami imaging. The results indicated that the side length of the cube used to construct the 3D Nakagami image must be at least two times the pulse length, which improved the resolution for each Nakagami image frame in the 3D Nakagami image. The results further demonstrated that the 3D Nakagami image is better than the conventional 2D Nakagami image for complementing the B-scan in detecting spatial variations in the scatterer concentration and classifying normal and fibrotic livers. This study suggests that 3D Nakagami imaging has the potential to become a new 3D quantitative imaging approach.

  12. Three-Dimensional Frame Buffers For Interactive Analysis Of Three-Dimensional Data

    NASA Astrophysics Data System (ADS)

    Hunter, Gregory M.

    1986-02-01

    Two-dimensional data such as photos, x-rays, various types of satellite images, sonar, radar, seismic plots, etc., in many cases must be analyzed using frame buffers for purposes of medical diagnoses, crop estimates, mineral exploration, and so forth. In many cases the same types of sensors used to gather such samples in two dimensions can gather 3D data for even more effective analysis. Just as 2D arrays of data can be analyzed using frame buffers, three-dimensional data can be analyzed using SOLIDS-BUFFER memories. Image processors deal with samples from two-dimensional arrays and are based on frame buffers. The SOLIDS PROCESSOR system deals with samples from a three-dimensional volume, or solid, and is based on a 3D frame buffer. This paper focuses upon the SOLIDS-BUFFER system as used in the INSIGHT SOLIDS-PROCESSOR system from Phoenix Data Systems.

  13. RADIAL STELLAR PULSATION AND THREE-DIMENSIONAL CONVECTION. IV. FULL AMPLITUDE THREE-DIMENSIONAL SOLUTIONS

    SciTech Connect

    Geroux, Christopher M.; Deupree, Robert G.

    2015-02-10

    Three-dimensional hydrodynamic simulations of full amplitude RR Lyrae stars have been computed for several models across the instability strip. The three-dimensional nature of the calculations allows convection to be treated without reference to a phenomenological approach such as the local mixing length theory. Specifically, the time-dependent interaction of large-scale eddies and radial pulsation is controlled by conservation laws, while the effects of smaller convective eddies are simulated by an eddy viscosity model. The light amplitudes for these calculations are quite similar to those of our previous two-dimensional calculations in the middle of the instability strip, but somewhat lower near the red edge, the fundamental blue edge, and for the one first overtone model we computed. The time-dependent interaction between the radial pulsation and the convective energy transport is essentially the same in three dimensions as it is in two dimensions. There are some differences between the light curves of the two- and three-dimensional simulations, particularly during decreasing light. Reasons for the differences, both numerical and physical, are explored.

  14. Identifying ultrasonic scattering sites from three-dimensional impedance maps

    NASA Astrophysics Data System (ADS)

    Mamou, Jonathan; Oelze, Michael L.; O'Brien, William D.; Zachary, James F.

    2005-01-01

    Ultrasonic backscattered signals contain frequency-dependent information that is usually discarded to produce conventional B-mode images. It is hypothesized that parametrization of the quantitative ultrasound frequency-dependent information (i.e., estimating scatterer size and acoustic concentration) may be related to discrete scattering anatomic structures in tissues. Thus, an estimation technique is proposed to extract scatterer size and acoustic concentration from the power spectrum derived from a three-dimensional impedance map (3DZM) of a tissue volume. The 3DZM can be viewed as a computational phantom and is produced from a 3D histologic data set. The 3D histologic data set is constructed from tissue sections that have been appropriately stained to highlight specific tissue features. These tissue features are assigned acoustic impedance values to yield a 3DZM. From the power spectrum, scatterer size and acoustic concentration estimates were obtained by optimization. The 3DZM technique was validated by simulations that showed relative errors of less than 3% for all estimated parameters. Estimates using the 3DZM technique were obtained and compared against published ultrasonically derived estimates for two mammary tumors, a rat fibroadenoma and a 4T1 mouse mammary carcinoma. For both tumors, the relative difference between ultrasonic and 3DZM estimates was less than 10% for the average scatterer size. .

  15. Applicability of three-dimensional imaging techniques in fetal medicine*

    PubMed Central

    Werner Júnior, Heron; dos Santos, Jorge Lopes; Belmonte, Simone; Ribeiro, Gerson; Daltro, Pedro; Gasparetto, Emerson Leandro; Marchiori, Edson

    2016-01-01

    Objective To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. PMID:27818540

  16. Three-dimensional volume analysis of vasculature in engineered tissues

    NASA Astrophysics Data System (ADS)

    YousefHussien, Mohammed; Garvin, Kelley; Dalecki, Diane; Saber, Eli; Helguera, María.

    2013-01-01

    Three-dimensional textural and volumetric image analysis holds great potential in understanding the image data produced by multi-photon microscopy. In this paper, an algorithm that quantitatively analyzes the texture and the morphology of vasculature in engineered tissues is proposed. The investigated 3D artificial tissues consist of Human Umbilical Vein Endothelial Cells (HUVEC) embedded in collagen exposed to two regimes of ultrasound standing wave fields under different pressure conditions. Textural features were evaluated using the normalized Gray-Scale Cooccurrence Matrix (GLCM) combined with Gray-Level Run Length Matrix (GLRLM) analysis. To minimize error resulting from any possible volume rotation and to provide a comprehensive textural analysis, an averaged version of nine GLCM and GLRLM orientations is used. To evaluate volumetric features, an automatic threshold using the gray level mean value is utilized. Results show that our analysis is able to differentiate among the exposed samples, due to morphological changes induced by the standing wave fields. Furthermore, we demonstrate that providing more textural parameters than what is currently being reported in the literature, enhances the quantitative understanding of the heterogeneity of artificial tissues.

  17. Antenatal Three-Dimensional Printing of Aberrant Facial Anatomy

    PubMed Central

    VanKoevering, Kyle K.; Morrison, Robert J.; Prabhu, Sanjay P.; Torres, Maria F. Ladino; Mychaliska, George B.; Treadwell, Marjorie C.; Hollister, Scott J.

    2015-01-01

    Congenital airway obstruction poses a life-threatening challenge to the newborn. We present the first case of three-dimensional (3D) modeling and 3D printing of complex fetal maxillofacial anatomy after prenatal ultrasound indicated potential upper airway obstruction from a midline mass of the maxilla. Using fetal MRI and patient-specific computer-aided modeling, the craniofacial anatomy of the fetus was manufactured using a 3D printer. This model demonstrated the mass to be isolated to the upper lip and maxilla, suggesting the oral airway to be patent. The decision was made to deliver the infant without a planned ex utero intrapartum treatment procedure. The neonate was born with a protuberant cleft lip and palate deformity, without airway obstruction, as predicted by the patient-specific model. The delivery was uneventful, and the child was discharged without need for airway intervention. This case demonstrates that 3D modeling may improve prenatal evaluation of complex patient-specific fetal anatomy and facilitate the multidisciplinary approach to perinatal management of complex airway anomalies. PMID:26438708

  18. Antenatal Three-Dimensional Printing of Aberrant Facial Anatomy.

    PubMed

    VanKoevering, Kyle K; Morrison, Robert J; Prabhu, Sanjay P; Torres, Maria F Ladino; Mychaliska, George B; Treadwell, Marjorie C; Hollister, Scott J; Green, Glenn E

    2015-11-01

    Congenital airway obstruction poses a life-threatening challenge to the newborn. We present the first case of three-dimensional (3D) modeling and 3D printing of complex fetal maxillofacial anatomy after prenatal ultrasound indicated potential upper airway obstruction from a midline mass of the maxilla. Using fetal MRI and patient-specific computer-aided modeling, the craniofacial anatomy of the fetus was manufactured using a 3D printer. This model demonstrated the mass to be isolated to the upper lip and maxilla, suggesting the oral airway to be patent. The decision was made to deliver the infant without a planned ex utero intrapartum treatment procedure. The neonate was born with a protuberant cleft lip and palate deformity, without airway obstruction, as predicted by the patient-specific model. The delivery was uneventful, and the child was discharged without need for airway intervention. This case demonstrates that 3D modeling may improve prenatal evaluation of complex patient-specific fetal anatomy and facilitate the multidisciplinary approach to perinatal management of complex airway anomalies.

  19. Three-dimensional photoacoustic endoscopic imaging of the rabbit esophagus.

    PubMed

    Yang, Joon Mo; Favazza, Christopher; Yao, Junjie; Chen, Ruimin; Zhou, Qifa; Shung, K Kirk; Wang, Lihong V

    2015-01-01

    We report photoacoustic and ultrasonic endoscopic images of two intact rabbit esophagi. To investigate the esophageal lumen structure and microvasculature, we performed in vivo and ex vivo imaging studies using a 3.8-mm diameter photoacoustic endoscope and correlated the images with histology. Several interesting anatomic structures were newly found in both the in vivo and ex vivo images, which demonstrates the potential clinical utility of this endoscopic imaging modality. In the ex vivo imaging experiment, we acquired high-resolution motion-artifact-free three-dimensional photoacoustic images of the vasculatures distributed in the walls of the esophagi and extending to the neighboring mediastinal regions. Blood vessels with apparent diameters as small as 190 μm were resolved. Moreover, by taking advantage of the dual-mode high-resolution photoacoustic and ultrasound endoscopy, we could better identify and characterize the anatomic structures of the esophageal lumen, such as the mucosal and submucosal layers in the esophageal wall, and an esophageal branch of the thoracic aorta. In this paper, we present the first photoacoustic images showing the vasculature of a vertebrate esophagus and discuss the potential clinical applications and future development of photoacoustic endoscopy.

  20. Three-dimensional ultrathin planar lenses by acoustic metamaterials.

    PubMed

    Li, Yong; Yu, Gaokun; Liang, Bin; Zou, Xinye; Li, Guangyun; Cheng, Su; Cheng, Jianchun

    2014-10-30

    Acoustic lenses find applications in various areas ranging from ultrasound imaging to nondestructive testing. A compact-size and high-efficient planar acoustic lens is crucial to achieving miniaturization and integration, and should have deep implication for the acoustic field. However its realization remains challenging due to the trade-off between high refractive-index and impedance-mismatch. Here we have designed and experimentally realized the first ultrathin planar acoustic lens capable of steering the convergence of acoustic waves in three-dimensional space. A theoretical approach is developed to analytically describe the proposed metamaterial with hybrid labyrinthine units, which reveals the mechanism of coexistence of high refractive index and well-matched impedance. A hyperbolic gradient-index lens design is fabricated and characterized, which can enhance the acoustic energy by 15 dB at the focal point with very high transmission efficiency. Remarkably, the thickness of the lens is only approximately 1/6 of the operating wavelength. The lens can work within a certain frequency band for which the ratio between the bandwidth and the center frequency reaches 0.74. By tailoring the structure of the metamaterials, one can further reduce the thickness of the lens or even realize other acoustic functionalities, opening new opportunity for manipulation of low-frequency sounds with versatile potential.

  1. Three-dimensional kinematics of wheelchair propulsion.

    PubMed

    Rao, S S; Bontrager, E L; Gronley, J K; Newsam, C J; Perry, J

    1996-09-01

    A three-dimensional (3-D) biomechanical model was used to determine upper extremity kinematics of 16 male subjects with low-level paraplegia while performing wheelchair propulsion (WCP). A six-camera VICON motion analysis system was used to acquire the coordinate data of ten anatomic markers. Joint axes for the wrist and elbow were defined along with the planes of motion for the upper arm (humerus) and trunk. The group's mean and standard deviation profiles were graphed for eight of the nine rotations measured during WCP. Variability in the intercycle and intersubject movement patterns were calculated using the root mean square standard deviation (RMS sigma) and the coefficient of variation (CV). Motion pattern similarities were quantified using the coefficient of multiple correlation (CMC). The intercycle (Nc > or = 6) motion patterns of individual subjects were highly consistent, similar, and repeatable during WCP. This was confirmed by low CVc values (3-31%), high CMCc values (0.724-0.996) and RMS sigma c values below 3.2 degrees. For the group, mean values of the propulsion velocity, cadence, and propulsion cycle duration were 89.7 m/min, 66.1 pushes/min, and 0.96 s, respectively. Humeral plane and rotation showed large excursions (76.1-81.6 degrees), while trunk lean and forearm carrying angle displayed relatively small ranges of motion (5.5-10.9 degrees). The intersubject (N3 = 16) motion patterns were less similar compared to individual intercycle patterns. This was evidenced by higher CVc values (12-128%) and lower CMC3 values (0.418-0.935). Intersubject humeral patterns were the most consistent while trunk lean was the least consistent. Intersubject root mean square standard deviations (RMS sigma c) were more than three times the corresponding intercycle values for all nine rotations.

  2. Three-dimensional topological insulator based nanospaser

    NASA Astrophysics Data System (ADS)

    Paudel, Hari P.; Apalkov, Vadym; Stockman, Mark I.

    2016-04-01

    After the discovery of the spaser (surface plasmon amplification by stimulated emission of radiation), first proposed by Bergman and Stockman in 2003, it has become possible to deliver optical energy beyond the diffraction limit and generate an intense source of an optical field. The spaser is a nanoplasmonic counterpart of a laser. One of the major advantages of the spaser is its size: A spaser is a truly nanoscopic device whose size can be made smaller than the skin depth of a material to a size as small as the nonlocality radius (˜1 nm). Recently, an electrically pumped graphene based nanospaser has been proposed that operates in the midinfrared region and utilizes a nanopatch of graphene as a source of plasmons and a quantum-well cascade as its gain medium. Here we propose an optically pumped nanospaser based on three-dimensional topological insulator (3D TI) materials, such as Bi2Se3 , that operates at an energy close to the bulk band-gap energy ˜0.3 eV and uses the surface as a source for plasmons and its bulk as a gain medium. Population inversion is obtained in the bulk and the radiative energy of the exciton recombination is transferred to the surface plasmons of the same material to stimulate spasing action. This is truly a nanoscale spaser as it utilizes the same material for dual purposes. We show theoretically the possibility of achieving spasing with a 3D TI. As the spaser operates in the midinfrared spectral region, it can be a useful device for a number of applications, such as nanoscopy, nanolithography, nanospectroscopy, and semiclassical information processing.

  3. Three-dimensional Spontaneous Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Beresnyak, Andrey

    2017-01-01

    Magnetic reconnection is best known from observations of the Sun where it causes solar flares. Observations estimate the reconnection rate as a small, but non-negligible fraction of the Alfvén speed, so-called fast reconnection. Until recently, the prevailing pictures of reconnection were either of resistivity or plasma microscopic effects, which was contradictory to the observed rates. Alternative pictures were either of reconnection due to the stochasticity of magnetic field lines in turbulence or the tearing instability of the thin current sheet. In this paper we simulate long-term three-dimensional nonlinear evolution of a thin, planar current sheet subject to a fast oblique tearing instability using direct numerical simulations of resistive-viscous magnetohydrodynamics. The late-time evolution resembles generic turbulence with a ‑5/3 power spectrum and scale-dependent anisotropy, so we conclude that the tearing-driven reconnection becomes turbulent reconnection. The turbulence is local in scale, so microscopic diffusivity should not affect large-scale quantities. This is confirmed by convergence of the reconnection rate toward ∼ 0.015{v}{{A}} with increasing Lundquist number. In this spontaneous reconnection, with mean field and without driving, the dissipation rate per unit area also converges to ∼ 0.006ρ {v}{{A}}3, and the dimensionless constants 0.015 and 0.006 are governed only by self-driven nonlinear dynamics of the sheared magnetic field. Remarkably, this also means that a thin current sheet has a universal fluid resistance depending only on its length to width ratio and to {v}{{A}}/c.

  4. Remote Dynamic Three-Dimensional Scene Reconstruction

    PubMed Central

    Yang, You; Liu, Qiong; Ji, Rongrong; Gao, Yue

    2013-01-01

    Remote dynamic three-dimensional (3D) scene reconstruction renders the motion structure of a 3D scene remotely by means of both the color video and the corresponding depth maps. It has shown a great potential for telepresence applications like remote monitoring and remote medical imaging. Under this circumstance, video-rate and high resolution are two crucial characteristics for building a good depth map, which however mutually contradict during the depth sensor capturing. Therefore, recent works prefer to only transmit the high-resolution color video to the terminal side, and subsequently the scene depth is reconstructed by estimating the motion vectors from the video, typically using the propagation based methods towards a video-rate depth reconstruction. However, in most of the remote transmission systems, only the compressed color video stream is available. As a result, color video restored from the streams has quality losses, and thus the extracted motion vectors are inaccurate for depth reconstruction. In this paper, we propose a precise and robust scheme for dynamic 3D scene reconstruction by using the compressed color video stream and their inaccurate motion vectors. Our method rectifies the inaccurate motion vectors by analyzing and compensating their quality losses, motion vector absence in spatial prediction, and dislocation in near-boundary region. This rectification ensures the depth maps can be compensated in both video-rate and high resolution at the terminal side towards reducing the system consumption on both the compression and transmission. Our experiments validate that the proposed scheme is robust for depth map and dynamic scene reconstruction on long propagation distance, even with high compression ratio, outperforming the benchmark approaches with at least 3.3950 dB quality gains for remote applications. PMID:23667417

  5. Three-dimensional, dynamic meteorology of Titan

    NASA Astrophysics Data System (ADS)

    Mitchell, J.; Adamkovics, M.; Caballero, R.; Turtle, E. P.; Arias, T.; Sayanagi, K. M.

    2011-12-01

    Titan exhibits an active weather cycle involving methane. Because of low insolation and a stabilizing antigreenhouse effect [McKay et al. 1989], moist convection on Titan cannot be maintained purely through surface evaporative fluxes, indicating that moisture convergence provided by large-scale modes of circulation is important for convective cloud formation [e.g., Mitchell et al. 2006; Barth & Rafkin 2010]. Recent Cassini Imaging Science Subsystem (ISS) images of Titan have revealed large-scale clouds with an interesting array of morphologies and characteristics. Most strikingly, an arrow-shaped cloud oriented eastward was observed at the equator on 27 September 2010 [Turtle et al. 2011a], followed by observations of surface wetting which gradually diminished over several months [Turtle et al. 2011b]. We demonstrate a process for the physical interpretation of individual observed storms and their aggregate effect on surface erosion through a combined analysis of cloud observations and simulations [Mitchell et al. in press]. We show that planetary-scale Kelvin waves naturally arising in a new, three-dimensional version of our Titan general circulation model (GCM) robustly organize convection into chevron-shaped storms at Titan's equator during the current season, as observed. The phasing of this mode with another, much slower one causes a 20-fold increase in precipitation rates over the average, each producing up to several centimeters of precipitation over 1000-km-scale regions, with important implications for observed fluvial features [Langhans et al. 2011]. Our initial results indicate an essential role for planetary-scale atmospheric waves in organizing Titan's methane weather. I will discuss prospects for extending our analysis to other Titan observations.

  6. [Three-dimensional reconstruction of heart valves].

    PubMed

    Flachskampf, F A; Kühl, H; Franke, A; Frielingsdorf, J; Klues, H; Krebs, W; Hanrath, P

    1995-08-01

    The reconstruction of three-dimensional data sets from two-dimensional echocardiographic images offers several fundamental advantages: 1. more complete data than present in the few standard 2D-view; 2. off-line generation of any desired plane, cut, or perspective after the data set has been acquired; 3. access to quantitative parameters like surface areas (e.g., of valve leaflets or portions of leaflets), volumes, and others, without geometric assumptions. The mitral valve has been the focus of several studies using various techniques of reconstruction of transthoracic or transesophageal images. These studies have shown the mitral annulus to be a non-planar, "saddle-shaped" structure, with an average distance of highest to lowest points of 14 mm in normals. This recognition of mitral annular non-planarity has led to a more stringent echocardiographic definition of mitral valve prolapse. Further studies have shown systolic shrinkage of mitral annular area by about 30% and systolic apico-basal translation of the annulus by approximately 1 cm in normals. In patients with dilated cardiomyopathy, the annulus is flattened, and both cyclic change in annular area and apico-basal translation are significantly reduced. 3D-studies of the left ventricular outflow tract in hypertrophic obstructive cardiomyopathy allow measurement of outflow tract and leaflet surface areas and dynamic spatial visualization of systolic anterior motion of the anterior mitral leaflet. Automated techniques to reconstruct the full grey value data set from a high number of parallel or rotational transesophageal planes allow impressive visualization of normal and diseased mitral and aortic valves or valve prostheses, with special emphasis on generating "surgical" views and perspectives, which cannot be obtained by conventional tomographic imaging.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. A three-dimensional model of vasculogenesis.

    PubMed

    Valarmathi, Mani T; Davis, Jeffrey M; Yost, Michael J; Goodwin, Richard L; Potts, Jay D

    2009-02-01

    Postnatal bone marrow contains various subpopulations of resident and circulating stem cells (HSCs, BMSCs/MSCs) and progenitor cells (MAPCs, EPCs) that are capable of differentiating into one or more of the cellular components of the vascular bed in vitro as well as contribute to postnatal neo-vascularization in vivo. When rat BMSCs were seeded onto a three-dimensional (3-D) tubular scaffold engineered from topographically aligned type I collagen fibers and cultured either in vasculogenic or non-vasculogenic media for 7, 14, 21 or 28 days, the maturation and co-differentiation into endothelial and/or smooth muscle cell lineages were observed. Phenotypic induction of these substrate-grown cells was assayed at transcript level by real-time PCR and at protein level by confocal microscopy. In the present study, the observed upregulation of transcripts coding for vascular phenotypic markers is reminiscent of an in vivo expression pattern. Immunolocalization of vasculogenic lineage-associated markers revealed typical expression patterns of vascular endothelial and smooth muscle cells. These endothelial cells exhibited high metabolism of acetylated low-density lipoprotein. In addition to the induced monolayers of endothelial cells, the presence of numerous microvascular capillary-like structures was observed throughout the construct. At the level of scanning electron microscopy, smooth-walled cylindrical tube-like structures with smooth muscle cells and/or pericytes attached to its surface were elucidated. Our 3-D culture system not only induces the maturation and differentiation of BMSCs into vascular cell lineages but also supports microvessel morphogenesis. Thus, this unique in vitro model provides an excellent platform to study the temporal and spatial regulation of postnatal de novo vasculogenesis, as well as attack the lingering limit in developing engineered tissues, that is perfusion.

  8. Three-dimensional ring current decay model

    NASA Technical Reports Server (NTRS)

    Fok, Mei-Ching; Moore, Thomas E.; Kozyra, Janet U.; Ho, George C.; Hamilton, Douglas C.

    1995-01-01

    This work is an extension of a previous ring current decay model. In the previous work, a two-dimensional kinetic model was constructed to study the temporal variations of the equatorially mirroring ring current ions, considering charge exchange and Coulomb drag losses along drift paths in a magnetic dipole field. In this work, particles with arbitrary pitch angle are considered. By bounce averaging the kinetic equation of the phase space density, information along magnetic field lines can be inferred from the equator. The three-dimensional model is used to simulate the recovery phase of a model great magnetic storm, similar to that which occurred in early February 1986. The initial distribution of ring current ions (at the minimum Dst) is extrapolated to all local times from AMPTE/CCE spacecraft observations on the dawnside and duskside of the inner magnetosphere spanning the L value range L = 2.25 to 6.75. Observations by AMPTE/CCE of ring current distributions over subsequent orbits during the storm recovery phase are compared to model outputs. In general, the calculated ion fluxes are consistent with observations, except for H(+) fluxes at tens of keV, which are always overestimated. A newly invented visualization idea, designated as a chromogram, is used to display the spatial and energy dependence of the ring current ion differential flux. Important features of storm time ring current, such as day-night asymmetry during injection and drift hole on the dayside at low energies (less than 10 keV), are manifested in the chromogram representation. The pitch angle distribution is well fit by the function, J(sub o)(1 + Ay(sup n)), where y is sine of the equatorial pitch angle. The evolution of the index n is a combined effect of charge exchange loss and particle drift. At low energies (less than 30 keV), both drift dispersion and charge exchange are important in determining n.

  9. Ultrasound

    MedlinePlus Videos and Cool Tools

    ... baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two-dimensional image of the baby while inside the mother's uterus. The sound waves bounce off solid structures in the body ...

  10. Ultrasound

    MedlinePlus

    ... called multiples) To screen for birth defects, like spina bifida or heart defects . Screening means seeing if your ... example, if the ultrasound shows your baby has spina bifida, she may be treated in the womb before ...

  11. Ultrasound

    MedlinePlus

    ... a pregnant woman and assess her fetus Diagnose gallbladder disease Evaluate flow in blood vessels Guide a ... For some ultrasound exams, such as of the gallbladder, your doctor may ask that you not eat ...

  12. Three-dimensional carbon nanotube based photovoltaics

    NASA Astrophysics Data System (ADS)

    Flicker, Jack

    2011-12-01

    Photovoltaic (PV) cells with a three dimensional (3D) morphology are an exciting new research thrust with promise to create cheaper, more efficient solar cells. This work introduces a new type of 3D PV device based on carbon nanotube (CNT) arrays. These arrays are paired with the thin film heterojunction, CdTe/CdS, to form a complete 3D carbon nanotube PV device (3DCNTPV). Marriage of a complicated 3D structure with production methods traditionally used for planar CdTe solar cell is challenging. This work examines the problems associated with processing these types of cells and systematically alters production methods of the semiconductor layers and electrodes to increase the short circuit current (Isc), eliminate parasitic shunts, and increase the open circuit voltage (Voc). The main benefit of 3D solar cell is the ability to utilize multiple photon interactions with the solar cell surface. The three dimensionality allows photons to interact multiple times with the photoactive material, which increases the absorption and the overall power output over what is possible with a two dimensional (2D) morphology. To quantify the increased power output arising from these multiple photon interactions, a new absorption efficiency term, eta3D, is introduced. The theoretical basis behind this new term and how it relates to the absorption efficiency of a planar cell, eta 2D, is derived. A unique model for the average number of multiple photon impingements, Gamma, is proposed based on three categories of 3D morphology: an infinite trench, an enclosed box, and an array of towers. The derivation of eta3D and Gamma for these 3D PV devices gives a complete picture of the enhanced power output over 2D cells based on CNT array height, pitch, radius, and shape. This theory is validated by monte carlo simulations and experiment. This new type of 3D PV devices has been shown to work experimentally. The first 3DCNTPV cells created posses Isc values of 0.085 to 17.872mA/cm2 and Voc values

  13. Numerical investigations in three-dimensional internal flows

    NASA Technical Reports Server (NTRS)

    Rose, William C.

    1991-01-01

    The present study is a preliminary investigation into the behavior of the flow within a 28 degree total geometric turning angle hypothetical Mach 10 inlet as calculated with the full three-dimensional Navier-Stokes equations. Comparison between the two-dimensional and three-dimensional solutions have been made. The overall compression is not significantly different between the two-dimensional and center plane three dimensional solutions. Approximately one-half to two-thirds of the inlet flow at the exit of the inlet behave nominally two-dimensionally. On the other hand, flow field non-uniformities in the three-dimensional solution indicate the potential significance of the sidewall boundary layer flows ingested into the inlet. The tailoring of the geometry at the inlet shoulder and on the cowl obtained in the two-dimensional parametric design study have also proved to be effective at controlling the boundary layer behavior in the three-dimensional code. The three-dimensional inlet solution remained started indicating that the two-dimensional design had a sufficient margin to allow for three-dimensional flow field effects. Although confidence is being gained in the use of SCRAM3D (three-dimensional full Navier-Stokes code) as applied to similar flow fields, the actual effects of the three-dimensional flow fields associated with sidewalls and wind tunnel installations can require verification with ground-based experiments.

  14. Developing three-dimensional display technologies

    NASA Astrophysics Data System (ADS)

    Dallas, William J.; Roehrig, Hans; Allen, Daniel J.

    2008-08-01

    Stereo, multi-perspective, and volumetric display technologies have made several recent gains. We are seeing increased availability of such systems for entertainment, both in theaters and for the home. The concurrent advent of medical imaging modalities that deliver very large data sets such as, spiral CT, high-field MRI, and 3-D ultrasound, makes renewed assessment of 3-D display of medical images attractive. We concentrate on autostereographic displays, those that are viewed without viewing aids such as special eye-glasses or goggles. We begin with a very brief review of a few stereo-display, multi-perspective, and volumetric display technologies. We focus our attention primarily on the integral display (ID) and the computer-generated hologram (CGH). We will examine the boost that ID has gotten from the availability of flat-panel displays with very high pixel counts. We also discuss some recent advances in CGH's included the emergence of rewritable holographic materials. We also look at one, undeveloped 3-D display technology: the Correlelogram.

  15. Advanced Three-Dimensional Display System

    NASA Technical Reports Server (NTRS)

    Geng, Jason

    2005-01-01

    A desktop-scale, computer-controlled display system, initially developed for NASA and now known as the VolumeViewer(TradeMark), generates three-dimensional (3D) images of 3D objects in a display volume. This system differs fundamentally from stereoscopic and holographic display systems: The images generated by this system are truly 3D in that they can be viewed from almost any angle, without the aid of special eyeglasses. It is possible to walk around the system while gazing at its display volume to see a displayed object from a changing perspective, and multiple observers standing at different positions around the display can view the object simultaneously from their individual perspectives, as though the displayed object were a real 3D object. At the time of writing this article, only partial information on the design and principle of operation of the system was available. It is known that the system includes a high-speed, silicon-backplane, ferroelectric-liquid-crystal spatial light modulator (SLM), multiple high-power lasers for projecting images in multiple colors, a rotating helix that serves as a moving screen for displaying voxels [volume cells or volume elements, in analogy to pixels (picture cells or picture elements) in two-dimensional (2D) images], and a host computer. The rotating helix and its motor drive are the only moving parts. Under control by the host computer, a stream of 2D image patterns is generated on the SLM and projected through optics onto the surface of the rotating helix. The system utilizes a parallel pixel/voxel-addressing scheme: All the pixels of the 2D pattern on the SLM are addressed simultaneously by laser beams. This parallel addressing scheme overcomes the difficulty of achieving both high resolution and a high frame rate in a raster scanning or serial addressing scheme. It has been reported that the structure of the system is simple and easy to build, that the optical design and alignment are not difficult, and that the

  16. Three-Dimensional Gear Crack Propagation Studied

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.

    1999-01-01

    Gears used in current helicopters and turboprops are designed for light weight, high margins of safety, and high reliability. However, unexpected gear failures may occur even with adequate tooth design. To design an extremely safe system, the designer must ask and address the question, "What happens when a failure occurs?" With gear-tooth bending fatigue, tooth or rim fractures may occur. A crack that propagates through a rim will be catastrophic, leading to disengagement of the rotor or propeller, loss of an aircraft, and possible fatalities. This failure mode should be avoided. A crack that propagates through a tooth may or may not be catastrophic, depending on the design and operating conditions. Also, early warning of this failure mode may be possible because of advances in modern diagnostic systems. One concept proposed to address bending fatigue fracture from a safety aspect is a splittooth gear design. The prime objective of this design would be to control crack propagation in a desired direction such that at least half of the tooth would remain operational should a bending failure occur. A study at the NASA Lewis Research Center analytically validated the crack-propagation failsafe characteristics of a split-tooth gear. It used a specially developed three-dimensional crack analysis program that was based on boundary element modeling and principles of linear elastic fracture mechanics. Crack shapes as well as the crack-propagation life were predicted on the basis of the calculated stress intensity factors, mixed-mode crack-propagation trajectory theories, and fatigue crack-growth theories. The preceding figures show the effect of the location of initial cracks on crack propagation. Initial cracks in the fillet of the teeth produced stress intensity factors of greater magnitude (and thus, greater crack growth rates) than those in the root or groove areas of the teeth. Crack growth was simulated in a case study to evaluate crack-propagation paths. Tooth

  17. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view to the southeast, from between the cloud layers and over the north center of the region. The tall white clouds in the lower cloud deck are probably much like large terrestrial thunderclouds. They may be regions where atmospheric water powers vertical convection over large horizontal distances.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756 nm. This model is overly simplistic, but is based on

  18. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view to the northeast, from between the cloud layers and above the streaks in the lower cloud leading towards the hotspot. The upper haze layer has some features that match the lower cloud, such as the bright streak in the foreground of the frame. These are probably thick clouds that span several tens of vertical kilometers.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756 nm. This model is overly

  19. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view to the west, from between the cloud layers and over the patchy white clouds to the east of the hotspot. This is probably an area where moist convection is occurring over large horizontal distances, similar to the atmosphere over the equatorial ocean on Earth. The clouds are high and thick, and are observed to change rapidly over short time scales.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756

  20. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view from the southwest looking northeast, from an altitude just above the high haze layer. The streaks in the lower cloud leading towards the hotspot are visible. The upper haze layer is mostly flat, with notable small peaks that can be matched with features in the lower cloud. In reality, these areas may represent a continuous vertical cloud column.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756