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.

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

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.

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.

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

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.

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.

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.

Mesh three-dimensional arm orthosis with built-in ultrasound physiotherapy system

NASA Astrophysics Data System (ADS)

Kashapova, R. M.; Kashapov, R. N.; Kashapova, R. S.

2017-09-01

The possibility of using the built-in ultrasound physiotherapy system of the hand orthosis is explored in the work. The individual mesh orthosis from nylon 12 was manufactured by the 3D prototyping method on the installation of selective laser sintering SLS SPro 60HD. The applied technology of three-dimensional scanning made it possible to obtain a model of the patient’s hand and on the basis of it to build a virtual model of the mesh frame. In the course of the research, the developed system of ultrasound exposure was installed on the orthosis and its tests were carried out. As a result, the acceleration of the healing process and the reduction in the time of wearing orthosis were found.

First trimester diagnosis of parapagus diprosopus dibrachius dipus twins with cranirachischisis totalis by three-dimensional ultrasound.

PubMed

Ülker, Kahraman; Akyer, Şahika P; Temur, İsmail; Tan, Temel; Karaca, Mehmet; Adıgüzel, Esat; Gül, Abdülaziz

2012-02-01

Parapagus (laterally fused), diprosopus (two faces), dibrachius (two upper extremities), dipus (two lower extremities) conjoined twinning is extremely rare. The coexistence of anencephaly with a contiguous spinal defect (craniorachischisis totalis) makes the present case one of the rarest of the published cases. In our case, it was difficult to make the final diagnosis by two-dimensional abdominal and vaginal ultrasound. Three-dimensional ultrasound was helpful for final diagnosis and post-abortal examination confirmed the prenatal ultrasound diagnosis. The heart, diaphragm, liver and perineum were all united. Fine dissection of the heart showed four vessels arising from the ventricles and a membranous type ventricular septal defect. © 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.

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.

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.

Quantitative evaluation of the fetal cerebellar vermis using the median view on three-dimensional ultrasound.

PubMed

Zhao, Dan; Liu, Wei; Cai, Ailu; Li, Jingyu; Chen, Lizhu; Wang, Bing

2013-02-01

The purpose of this study was to investigate the effectiveness for quantitative evaluation of cerebellar vermis using three-dimensional (3D) ultrasound and to establish a nomogram for Chinese fetal vermis measurements during gestation. Sonographic examinations were performed in normal fetuses and in cases suspected of the diagnosis of vermian rotation. 3D median planes were obtained with both OMNIVIEW and tomographic ultrasound imaging. Measurements of the cerebellar vermis were highly correlated between two-dimensional and 3D median planes. The diameter of the cerebellar vermis follows growth approximately predicted by the quadratic regression equation. The normal vermis was almost parallel to the brain stem, with the average angle degree to be <2° in normal fetuses. The average angle degree of the 9 cases of vermian rotation was >5°. Three-dimensional median planes are obtained more easily than two-dimensional ones, and allow accurate measurements of the cerebellar vermis. The 3D approach may enable rapid assessment of fetal cerebral anatomy in standard examination. Measurements of cerebellar vermis may provide a quantitative index for prenatal diagnosis of posterior fossa malformations. © 2012 John Wiley & Sons, Ltd.

Recognizing ovarian cancer from co-registered ultrasound and photoacoustic images

NASA Astrophysics Data System (ADS)

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

2013-03-01

Unique features in co-registered ultrasound and photoacoustic images of ex vivo ovarian tissue are introduced, along with the hypotheses of how these features may relate to the physiology of tumors. The images are compressed with wavelet transform, after which the mean Radon transform of the photoacoustic image is computed and fitted with a Gaussian function to find the centroid of the suspicious area for shift-invariant recognition process. In the next step, 24 features are extracted from a training set of images by several methods; including features from the Fourier domain, image statistics, and the outputs of different composite filters constructed from the joint frequency response of different cancerous images. The features were chosen from more than 400 training images obtained from 33 ex vivo ovaries of 24 patients, and used to train a support vector machine (SVM) structure. The SVM classifier was able to exclusively separate the cancerous from the non-cancerous cases with 100% sensitivity and specificity. At the end, the classifier was 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 cancerous case is sufficient to consider the ovary as malignant, then the SVM classifier achieves 100% sensitivity and 87.88% specificity.

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

In vitro three-dimensional aortic vasculature modeling based on sensor fusion between intravascular ultrasound and magnetic tracker.

PubMed

Shi, Chaoyang; Tercero, Carlos; Ikeda, Seiichi; Ooe, Katsutoshi; Fukuda, Toshio; Komori, Kimihiro; Yamamoto, Kiyohito

2012-09-01

It is desirable to reduce aortic stent graft installation time and the amount of contrast media used for this process. Guidance with augmented reality can achieve this by facilitating alignment of the stent graft with the renal and mesenteric arteries. For this purpose, a sensor fusion is proposed between intravascular ultrasound (IVUS) and magnetic trackers to construct three-dimensional virtual reality models of the blood vessels, as well as improvements to the gradient vector flow snake for boundary detection in ultrasound images. In vitro vasculature imaging experiments were done with hybrid probe and silicone models of the vasculature. The dispersion of samples for the magnetic tracker in the hybrid probe increased less than 1 mm when the IVUS was activated. Three-dimensional models of the descending thoracic aorta, with cross-section radius average error of 0.94 mm, were built from the data fusion. The development of this technology will enable reduction in the amount of contrast media required for in vivo and real-time three-dimensional blood vessel imaging. Copyright © 2012 John Wiley & Sons, Ltd.

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.

The use of three-dimensional ultrasound does not improve training in fetal biometric measurements.

PubMed

Chan, Lin W; Ting, Yuen H; Lao, Terence T; Chau, Macy M C; Fung, Tak Y; Leung, Tak Y; Sahota, Daljit S; Lau, Tze K

2011-09-01

To investigate whether three-dimensional (3D) technology offers any advantage over two-dimensional (2D) ultrasound in fetal biometric measurement training. Ten midwives with no hands-on experience in ultrasound were randomized to receive training on 2D or 3D ultrasound fetal biometry assessment. Midwives were taught how to obtain fetal biometric measurements (biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL)) by a trainer. Subsequently, each midwife measured the parameters on another 10 fetuses. The same set of measurements was repeated by the trainer. The percentage deviation between the midwives' and the trainer's measurements was determined and compared between training groups. Time required for completion was recorded. Frozen images were reviewed by another sonographer to assess the image quality using a standardized scoring system. The median time for the complete set of measurements was significantly shorter in the 2D than in 3D group (13.4 min versus 17.8 min, P = 0.03). The mean percentage deviations did not reach statistical significance between the two groups except for FL (3.83% in 2D group versus 2.23% in 3D group (P = 0.046)). There were no significant differences in the quality scores. This study showed that the only demonstrable advantage of 3D ultrasound was a slightly more accurate measurement of FL, at the expense of a significantly longer time required.

Prenatal diagnosis of parapagus diprosopus dibrachius dipus twins with spina bifida in the first trimester using two- and three-dimensional ultrasound.

PubMed

Yang, Pei-Yin; Wu, Ching-Hua; Yeh, Guang-Perng; Hsieh, Charles Tsung-Che

2015-12-01

Here, we report a case of parapagus diprosopus twins with spina bifida diagnosed in the first trimester of pregnancy using two-dimensional (2D) and three-dimensional (3D) ultrasound. A 28-year-old Taiwanese woman, gravid 1, para 0, visited our hospital due to an abnormal fetal head shape discovered by 2D ultrasound at 11-weeks gestation. Parapagus diprosopus twins with spina bifida were diagnosed after ultrasound examination. The characteristics of parapagus diprosopus twins are more illustrative in 3D ultrasound than in 2D ultrasound. After counseling, termination of pregnancy was chosen by the couple. Although necropsy was declined, the gross appearance and radiograph of the abortus confirmed our diagnosis. With the help of 3D ultrasound, we made an early and definitive diagnosis of conjoined twins. Copyright © 2015. Published by Elsevier B.V.

Three-dimensional ultrasound features of the polycystic ovary in Chinese women.

PubMed

Lam, P; Raine-Fenning, N; Cheung, L; Haines, C

2009-08-01

To quantify the three-dimensional (3D) ultrasound characteristics of ovaries in Chinese women with polycystic ovarian syndrome (PCOS) and to compare these with previous data on a Caucasian cohort with PCOS. 3D pelvic ultrasound was performed in 40 Chinese women with PCOS and 40 controls. Ovarian volume, stromal volume and echogenicity, and antral follicle count (AFC) were measured and ovarian blood flow was quantified using both 3D power Doppler and two-dimensional (2D) pulsed wave Doppler. These data were compared with previously published data on a Caucasian cohort with PCOS. Compared with controls, women with PCOS had a higher AFC (median (range), 15 (11-30) vs. 5.5 (1-10) per ovary, P < 0.01), ovarian volume (12.32 (8.10-16.16) mL vs. 5.64 (2.62-8.81) mL, P < 0.01) and stromal volume (9.74 (6.44-13.56) mL vs. 4.07 (1.52-6.67) mL, P < 0.01) but were comparable in stromal echogenicity and ovarian blood flow as measured by 3D power Doppler or 2D pulsed wave Doppler indices. However, in comparison with a previously reported Caucasian cohort with PCOS, the ovaries of Chinese women with PCOS had a significantly smaller stromal volume (median (range), 9.74 (6.44-13.56) mL vs. 10.79 (5.65-17.12) mL, P < 0.05), were less echogenic as reflected in a lower mean gray value (22.43 (13.13-35.50) vs. 32.36 (19.35-53.71), P < 0.01), and had reduced ovarian blood flow as reflected in a lower flow index (30.19 (23.32-44.88) vs. 33.54 (21.88-51.65), P < 0.05). Based on 3D ultrasound measurements, Chinese women with PCOS have an increased stromal volume compared with controls. However, their stromal volume, echogenicity and vascularity is significantly lower than that in Caucasian women with PCOS. The possible etiology for these differences is discussed.

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.

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

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

Freehand three-dimensional ultrasound imaging of carotid artery using motion tracking technology.

PubMed

Chung, Shao-Wen; Shih, Cho-Chiang; Huang, Chih-Chung

2017-02-01

Ultrasound imaging has been extensively used for determining the severity of carotid atherosclerotic stenosis. In particular, the morphological characterization of carotid plaques can be performed for risk stratification of patients. However, using 2D ultrasound imaging for detecting morphological changes in plaques has several limitations. Due to the scan was performed on a single longitudinal cross-section, the selected 2D image is difficult to represent the entire morphology and volume of plaque and vessel lumen. In addition, the precise positions of 2D ultrasound images highly depend on the radiologists' experience, it makes the serial long-term exams of anti-atherosclerotic therapies are difficult to relocate the same corresponding planes by using 2D B-mode images. This has led to the recent development of three-dimensional (3D) ultrasound imaging, which offers improved visualization and quantification of complex morphologies of carotid plaques. In the present study, a freehand 3D ultrasound imaging technique based on optical motion tracking technology is proposed. Unlike other optical tracking systems, the marker is a small rigid body that is attached to the ultrasound probe and is tracked by eight high-performance digital cameras. The probe positions in 3D space coordinates are then calibrated at spatial and temporal resolutions of 10μm and 0.01s, respectively. The image segmentation procedure involves Otsu's and the active contour model algorithms and accurately detects the contours of the carotid arteries. The proposed imaging technique was verified using normal artery and atherosclerotic stenosis phantoms. Human experiments involving freehand scanning of the carotid artery of a volunteer were also performed. The results indicated that compared with manual segmentation, the lowest percentage errors of the proposed segmentation procedure were 7.8% and 9.1% for the external and internal carotid arteries, respectively. Finally, the effect of handshaking was

Three-dimensional ultrasound for prenatal assessment of conjoined twins: additional advantages?

PubMed

Wataganara, Tuangsit; Ruangvutilert, Pornpimol; Sunsaneevithayakul, Prasert; Russameecharoen, Kusol; Nawapun, Katika; Phithakwatchara, Nisarat

2017-08-28

Conjoined twins are a rare, but serious, complication of monozygotic twins. Early prenatal diagnosis of conjoined twins is increasingly made with transvaginal ultrasound and color Doppler studies. Most prenatally diagnosed conjoined twins are terminated due to the high perinatal mortality, but advancement in pediatric surgery has allowed for successful postnatal separation in a small number of cases, and some parents may consider this option over termination of pregnancy. It is important to get a detailed prenatal ultrasound for the site and extent of fusion for an accurate categorization. Three-dimensional ultrasound (3DUS) provides images that can facilitate counselling for the parents. Additional information that impacts on diagnosis, prognostication, and perinatal management of conjoined twins could be obtained from selective use of 3DUS, particularly those with atypical fetal union. Most of the proposed additional benefits of 3DUS are based on case reports. Magnetic resonance imaging (MRI) has been increasingly used for the purpose of identifying intricate organ sharing. Because of the rarity of this condition, and the heterogeneity of fetal fusion, added benefits of either 3DUS or MRI for prenatal diagnosis and perinatal management of conjoined twins have not been demonstrated by well-conducted clinical trials. This article aims to review clinical application of various 3DUS display modes in prenatal assessment of conjoined twins, focusing on their potential additional benefits, risks and misuses. 3DUS may help detecting additional findings that are not possible with 2DUS, but, it has not been scientifically shown to improve the survival rate of the twins or reduce maternal morbidity.

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.

Sonothrombolysis of Intra-Catheter Aged Venous Thrombi Using Microbubble Enhancement and Guided Three Dimensional Ultrasound Pulses

PubMed Central

Kutty, Shelby; Xie, Feng; Gao, Shunji; Drvol, Lucas K; Lof, John; Fletcher, Scott E; Radio, Stanley J; Danford, David A; Hammel, James M; Porter, Thomas R

2010-01-01

Central venous and arterial catheters are a major source of thrombo-embolic disease in children. We hypothesized that guided high mechanical index (MI) impulses from diagnostic three-dimensional (3D) ultrasound during an intravenous microbubble infusion could dissolve these thrombi. An in vitro system simulating intra-catheter thrombi was created and then treated with guided high MI impulses from 3D ultrasound, utilizing low MI microbubble sensitive imaging pulse sequence schemes to detect the microbubbles (Perflutren Lipid Microsphere, Definity®, Lantheus). Ten aged thrombi over 24 hours old were tested using 3D ultrasound coupled with a continuous diluted microbubble infusion (Group A), and ten with 3D ultrasound alone (Group B). Mean thrombus age was 28.6 hours (range 26.6–30.3). Groups A exhibited a 55 ± 19 % reduction in venous thrombus size, compared to 31±10 % for Group B (p=0.008). Feasibility testing was performed in 4 pigs, establishing a model to further investigate the efficacy. Sonothrombolysis of aged intra-catheter venous thrombi can be achieved with commercially available microbubbles and guided high MI ultrasound from a diagnostic 3D transducer. PMID:20696549

Minimal invasive complete excision of benign breast tumors using a three-dimensional ultrasound-guided mammotome vacuum device.

PubMed

Baez, E; Huber, A; Vetter, M; Hackelöer, B-J

2003-03-01

The aim of this study was to evaluate the use of three-dimensional (3D) ultrasonography in the complete excision of benign breast tumors using ultrasound-guided vacuum-assisted core-needle biopsy (Mammotome). A protocol for the management of benign breast tumors is proposed. Twenty consecutive patients with sonographically benign breast lesions underwent 3D ultrasound-guided mammotome biopsy under local anesthesia. The indication for surgical biopsy was a solid lesion with benign characteristics on both two-dimensional (2D) and 3D ultrasound imaging, increasing in size over time or causing pain or irritation. Preoperatively, the size of the lesion was assessed using 2D and 3D volumetry. During vacuum biopsy the needle was visualized sonographically in all three dimensions, including the coronal plane. Excisional biopsy was considered complete when no residual tumor tissue could be seen sonographically. Ultrasonographic follow-up examinations were performed on the following day and 3-6 months later to assess residual tissue and scarring. All lesions were histologically benign. Follow-up examinations revealed complete excision of all lesions of < 1.5 mL in volume as assessed by 3D volumetry. 3D ultrasonographic volume assessment was more accurate than 2D using the ellipsoid formula or assessment of the maximum diameter for the prediction of complete excision of the tumor. No bleeding or infections occurred postoperatively and no scarring was seen ultrasonographically on follow-up examinations. Ultrasound-guided vacuum-assisted biopsy allows complete excision of benign breast lesions that are ultrasound offers the advantage of better preoperative demonstration of the lesions' margins, resulting in better assessment of volumetry, improved intraoperative needle location and perioperative

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

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

PubMed

Mercado, Karla P; Helguera, María; Hocking, Denise C; Dalecki, Diane

2015-07-01

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.

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.

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.

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.

Three-dimensional Visualization of Ultrasound Backscatter Statistics by Window-modulated Compounding Nakagami Imaging.

PubMed

Zhou, Zhuhuang; Wu, Shuicai; Lin, Man-Yen; Fang, Jui; Liu, Hao-Li; Tsui, Po-Hsiang

2018-05-01

In this study, the window-modulated compounding (WMC) technique was integrated into three-dimensional (3D) ultrasound Nakagami imaging for improving the spatial visualization of backscatter statistics. A 3D WMC Nakagami image was produced by summing and averaging a number of 3D Nakagami images (number of frames denoted as N) formed using sliding cubes with varying side lengths ranging from 1 to N times the transducer pulse. To evaluate the performance of the proposed 3D WMC Nakagami imaging method, agar phantoms with scatterer concentrations ranging from 2 to 64 scatterers/mm 3 were made, and six stages of fatty liver (zero, one, two, four, six, and eight weeks) were induced in rats by methionine-choline-deficient diets (three rats for each stage, total n = 18). A mechanical scanning system with a 5-MHz focused single-element transducer was used for ultrasound radiofrequency data acquisition. The experimental results showed that 3D WMC Nakagami imaging was able to characterize different scatterer concentrations. Backscatter statistics were visualized with various numbers of frames; N = 5 reduced the estimation error of 3D WMC Nakagami imaging in visualizing the backscatter statistics. Compared with conventional 3D Nakagami imaging, 3D WMC Nakagami imaging improved the image smoothness without significant image resolution degradation, and it can thus be used for describing different stages of fatty liver in rats.

Diagnostic utility of three-dimensional power Doppler ultrasound for postmenopausal bleeding.

PubMed

Kim, Ari; Lee, Ji Young; Chun, Sungwook; Kim, Heung Yeol

2015-06-01

We evaluated the role of three-dimensional power Doppler ultrasound (3D PD-US) to detect endometrial lesions in women with postmenopausal endometrial bleeding. In this prospective observational study, from January 2009 to November 2012, we recruited 225 postmenopausal women with postmenopausal uterine bleeding who met the study criteria. Women who had hematologic disease, chronic medical diseases, or nonuterine pelvic diseases were excluded. Prior to endometrial biopsy, the patients underwent a baseline transvaginal ultrasound screening. The vascular indices and endometrial volumes were calculated with 3D PD-US and compared with the endometrial histopathology. Among the endometrial histopathologic findings of 174 women, atrophic endometrium was the most common finding (30.5%). Endometrial malignancy was confirmed in 28 cases (16.1%), and endometrial hyperplasia was diagnosed in 17 cases (9.8%). The prevalence of endometrial cancer was high in patients who had endometrial thickness >9.5 mm (p < 0.001) and volume greater than 4.05 mL (p < 0.001). For the endometrial carcinoma only, the cutoff values of vascular index, flow index, and vascular flow index for predicting malignancy were 13.070, 12.610, and 3.764, respectively. For endometrial hyperplasia, endometrial thickness and vascular flow index were significant findings. Endometrial vasculature and volume can be obtained using 3D PD-US. The diagnostic usefulness of 3D PD-US for endometrial diseases is promising in women with postmenopausal endometrial bleeding. Copyright © 2015. Published by Elsevier B.V.

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…

Fundamental Study on One-Dimensional-Array Medical Ultrasound Probe with Piezoelectric Polycrystalline Film by Hydrothermal Method: Experimental Fabrication of One-Dimensional-Array Ultrasound Probe

NASA Astrophysics Data System (ADS)

Endo, Akito; Kawashima, Norimichi; Takeuchi, Shinichi; Ishikawa, Mutsuo; Kurosawa, Minoru Kuribayashi

2007-07-01

We deposited a lead zirconate titanete (PZT) polycrystalline film on a titanium substrate by the hydrothermal method and fabricated a transducer using the PZT film for use as an ultrasound probe. A 10 MHz miniature one-dimensional-array medical ultrasound probe containing the PZT film was developed. After sputtering titanium on the surface of a hydroxyapatite substrate, the titanium film on the substrate was etched by the photolithography to form a one-dimensional titanium film electrode array. We could thus fabricate a miniature one-dimensional-array ultrasound probe by the hydrothermal method. Transmitted ultrasound pulses from a 10 MHz commercial ultrasound probe were received by the newly fabricated one-dimensional-array ultrasound probe. The fabrication process of the probe and the results of experiments on receiving waveforms were reported in this paper.

Fast integrated intravascular photoacoustic/ultrasound catheter

NASA Astrophysics Data System (ADS)

Choi, Changhoon; Cho, Seunghee; Kim, Taehoon; Park, Sungjo; Park, Hyoeun; Kim, Jinmoo; Lee, Seunghoon; Kang, Yeonsu; Jang, Kiyuk; Kim, Chulhong

2016-03-01

In cardiology, a vulnerable plaque is considered to be a key subject because it is strongly related to atherosclerosis and acute myocardial infarction. Because conventional intravascular imaging devices exhibit several limitations with regard to vulnerable plaque detection, the need for an effective lipid imaging modality has been continuously suggested. Photoacoustic (PA) imaging is a medical imaging technique with a high level of ultrasound (US) resolution and strong optical contrast. In this study, we successfully developed an integrated intravascular photoacoustic/ultrasound (IV-PAUS) imaging system with a catheter diameter of 1.2 mm for lipid-rich atherosclerosis imaging. An Nd:YAG pulsed laser with an excitation wavelength of 1064 nm was utilized. IV-PAUS offers 5-mm depth penetration and axial and lateral PA imaging resolutions of 94 μm and 203 μm, respectively, as determined by imaging a 6-μm carbon fiber. We initially obtained 3-dimensional (3D) co-registered PA/US images of metal stents. Subsequently, we successfully obtained 3D coregistered PA/US ex vivo images using an iliac artery from a rabbit atherosclerosis model. Accordingly, lipid-rich plaques were sufficiently differentiated from normal tissue in the ex vivo experiment. We validated these findings histologically to confirm the lipid content.

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

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.

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.

Comparison of translabial three-dimensional ultrasound with magnetic resonance imaging for measurement of levator hiatal biometry at rest.

PubMed

Vergeldt, T F M; Notten, K J B; Stoker, J; Fütterer, J J; Beets-Tan, R G; Vliegen, R F A; Schweitzer, K J; Mulder, F E M; van Kuijk, S M J; Roovers, J P W R; Kluivers, K B; Weemhoff, M

2016-05-01

To compare translabial three-dimensional (3D) ultrasound with magnetic resonance imaging (MRI) for the measurement of levator hiatal biometry at rest in women with pelvic organ prolapse, and to determine the interobserver reliability between two independent observers for ultrasound and MRI measurements. Data were derived from a multicenter prospective cohort study in which women scheduled for conventional anterior colporrhaphy underwent translabial 3D ultrasound and MRI prior to surgery. Intraclass correlation coefficients (ICCs) were calculated to estimate interobserver reliability between two independent observers and determine the agreement between ultrasound and MRI measurements. Bland-Altman plots were created to assess the agreement between ultrasound and MRI measurements. Data from 139 women from nine hospitals were included in the study. The interobserver reliability of ultrasound assessment at rest, during Valsalva maneuver and during contraction and of MRI assessment at rest were moderate or good. The agreement between ultrasound and MRI for the measurement of levator hiatal biometry at rest was moderate, with ICCs of 0.52 (95%CI, 0.32-0.66) for levator hiatal area, 0.44 (95%CI, 0.21-0.60) for anteroposterior diameter and 0.44 (95%CI, 0.22-0.60) for transverse diameter. Levator hiatal biometry measurements were statistically significantly larger on MRI than on translabial 3D ultrasound. The agreement between translabial 3D ultrasound and MRI for measurement of the levator hiatus at rest in women with pelvic organ prolapse was only moderate. The results of translabial 3D ultrasound and MRI should therefore not be used interchangeably in daily practice or in clinical research. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Reliability of Achilles Tendon Moment Arm Measured In Vivo Using Freehand Three-Dimensional Ultrasound.

PubMed

Obst, Steven J; Barber, Lee; Miller, Ashton; Barrett, Rod S

2017-08-01

This study investigated reliability of freehand three-dimensional ultrasound (3DUS) measurement of in vivo human Achilles tendon (AT) moment arm. Sixteen healthy adults were scanned on 2 separate occasions by a single investigator. 3DUS scans were performed over the free AT, medial malleolus, and lateral malleolus with the ankle passively positioned in maximal dorsiflexion, mid dorsiflexion, neutral, mid plantar flexion and maximal plantar flexion. 3D reconstructions of the AT, medial malleolus, and lateral malleolus were created from manual segmentation of the ultrasound images and used to geometrically determine the AT moment arm using both a straight (straight AT MA ) and curved (curved AT MA ) tendon line-of-action. Both methods were reliable within- and between-session (intra-class correlation coefficients > 0.92; coefficient of variation < 2.5 %) and revealed that AT moment arm increased by ∼ 7 mm from maximal dorsiflexion (∼ 41mm) to maximal plantar flexion (∼ 48 mm). Failing to account for tendon curvature led to a small overestimation (< 2 mm) of AT moment arm that was most pronounced in ankle plantar flexion, but was less than the minimal detectable change of the method and could be disregarded.

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.

Use of translabial three-dimensional power Doppler ultrasound for cervical assessment before labor induction.

PubMed

Esin, Sertac; Yirci, Bulent; Yalvac, Serdar; Kandemir, Omer

2017-07-26

To compare translabial three-dimensional (3D) power Doppler ultrasound with Bishop score and transvaginal ultrasound measurements for cervical assessment before induction of labor with dinoprostone or cervical ripening balloon. Translabial cervical volume and length, vascularization indices and transvaginal cervical length were measured. Results were compared among women who had vaginal delivery at 24 h or less and more than 24 h after the insertion of the dinoprostone vaginal insert or cervical ripening balloon and among women who had vaginal delivery and cesarean delivery for failure to go into labor or failure to progress. There was no correlation between the time to delivery after a ripening agent was applied and translabial cervical volume, translabial cervical length, vascularization index (VI), flow index (FI), vascularization flow index (VFI), transvaginal cervical length and Bishop scores. The ultrasonographic measurements were no different among women who had vaginal delivery at 24 h or less and more than 24 h and among women who had vaginal delivery and cesarean delivery for failure to go into labor or failure to progress. In this study, we failed to demonstrate the superiority of translabial 3D ultrasonography over Bishop score and transvaginal ultrasonography for predicting the success of induction of labor.

Magnetic resonance imaging and three-dimensional ultrasound of carotid atherosclerosis: mapping regional differences.

PubMed

Krasinski, Adam; Chiu, Bernard; Fenster, Aaron; Parraga, Grace

2009-04-01

To evaluate differences in carotid atherosclerosis measured using magnetic resonance imaging (MRI) and three-dimensional ultrasound (3DUS). Ten subject volunteers underwent carotid 3DUS and MRI (multislice black blood fast spin echo, T1-weighted contrast, double inversion recovery, 0.5 mm in-plane resolution, 2 mm slice, 3.0 T) within 1 hour. 3DUS and MR images were manually segmented by two observers providing vessel wall and lumen contours for quantification of vessel wall volume (VWV) and generation of carotid thickness maps. MRI VWV (1040 +/- 210 mm(3)) and 3DUS VWV (540 +/- 110 mm(3)) were significantly different (P < 0.0001). When normalized for the estimated adventitia volume, mean MRI VWV decreased 240 +/- 50 mm(3) and was significantly different from 3DUS VWV (P < 0.001). Two-dimensional carotid maps showed qualitative evidence of regional differences in the plaque and vessel wall thickness between MR and 3DUS in all subjects. Power Doppler US confirmed that heterogeneity in the common carotid artery in all patients resulted from apparent flow disturbances, not atherosclerotic plaque. MRI and 3DUS VWV were significantly different and carotid maps showed homogeneous thickness differences and heterogeneity in specific regions of interest identified as MR flow artifacts in the common carotid artery.

Three-dimensional mid-air acoustic manipulation by ultrasonic phased arrays.

PubMed

Ochiai, Yoichi; Hoshi, Takayuki; Rekimoto, Jun

2014-01-01

The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that expanded-polystyrene particles of 0.6 mm, 1 mm, and 2 mm in diameter could be manipulated by our proposed method.

Assessment of pelvic floor by three-dimensional-ultrasound in primiparous women according to delivery mode: initial experience from a single reference service in Brazil.

PubMed

Araujo Júnior, Edward; de Freitas, Rogério Caixeta Moraes; Di Bella, Zsuzsanna Ilona Katalin de Jármy; Alexandre, Sandra Maria; Nakamura, Mary Uchiyama; Nardozza, Luciano Marcondes Machado; Moron, Antonio Fernandes

2013-03-01

To evaluate changes to the pelvic floor of primiparous women with different delivery modes, using three-dimensional ultrasound. A prospective cross-sectional study on 35 primiparae divided into groups according to the delivery mode: elective cesarean delivery (n=10), vaginal delivery (n=16), and forceps delivery (n=9). Three-dimensional ultrasound on the pelvic floor was performed on the second postpartum day with the patient in a resting position. A convex volumetric transducer (RAB4-8L) was used, in contact with the large labia, with the patient in the gynecological position. Biometric measurements of the urogenital hiatus were taken in the axial plane on images in the rendering mode, in order to assess the area, anteroposterior and transverse diameters, average thickness, and avulsion of the levator ani muscle. Differences between groups were evaluated by determining the mean differences and their respective 95% confidence intervals. The proportions of levator ani muscle avulsion were compared between elective cesarean section and vaginal birth using Fisher's exact test. The mean areas of the urogenital hiatus in the cases of vaginal and forceps deliveries were 17.0 and 20.1 cm(2), respectively, versus 12.4 cm(2) in the Control Group (elective cesarean). Avulsion of the levator ani muscle was observed in women who underwent vaginal delivery (3/25), however there was no statistically significant difference between cesarean section and vaginal delivery groups (p=0.5). Transperineal three-dimensional ultrasound was useful for assessing the pelvic floor of primiparous women, by allowing pelvic morphological changes to be differentiated according to the delivery mode.

Left ventricular volume estimation in cardiac three-dimensional ultrasound: a semiautomatic border detection approach.

PubMed

van Stralen, Marijn; Bosch, Johan G; Voormolen, Marco M; van Burken, Gerard; Krenning, Boudewijn J; van Geuns, Robert-Jan M; Lancée, Charles T; de Jong, Nico; Reiber, Johan H C

2005-10-01

We propose a semiautomatic endocardial border detection method for three-dimensional (3D) time series of cardiac ultrasound (US) data based on pattern matching and dynamic programming, operating on two-dimensional (2D) slices of the 3D plus time data, for the estimation of full cycle left ventricular volume, with minimal user interaction. The presented method is generally applicable to 3D US data and evaluated on data acquired with the Fast Rotating Ultrasound (FRU-) Transducer, developed by Erasmus Medical Center (Rotterdam, the Netherlands), a conventional phased-array transducer, rotating at very high speed around its image axis. The detection is based on endocardial edge pattern matching using dynamic programming, which is constrained by a 3D plus time shape model. It is applied to an automatically selected subset of 2D images of the original data set, for typically 10 equidistant rotation angles and 16 cardiac phases (160 images). Initialization requires the drawing of four contours per patient manually. We evaluated this method on 14 patients against MRI end-diastole and end-systole volumes. Initialization requires the drawing of four contours per patient manually. We evaluated this method on 14 patients against MRI end-diastolic (ED) and end-systolic (ES) volumes. The semiautomatic border detection approach shows good correlations with MRI ED/ES volumes (r = 0.938) and low interobserver variability (y = 1.005x - 16.7, r = 0.943) over full-cycle volume estimations. It shows a high consistency in tracking the user-defined initial borders over space and time. We show that the ease of the acquisition using the FRU-transducer and the semiautomatic endocardial border detection method together can provide a way to quickly estimate the left ventricular volume over the full cardiac cycle using little user interaction.

Agreement and reliability of pelvic floor measurements during contraction using three-dimensional pelvic floor ultrasound and virtual reality.

PubMed

Speksnijder, L; Rousian, M; Steegers, E A P; Van Der Spek, P J; Koning, A H J; Steensma, A B

2012-07-01

Virtual reality is a novel method of visualizing ultrasound data with the perception of depth and offers possibilities for measuring non-planar structures. The levator ani hiatus has both convex and concave aspects. The aim of this study was to compare levator ani hiatus volume measurements obtained with conventional three-dimensional (3D) ultrasound and with a virtual reality measurement technique and to establish their reliability and agreement. 100 symptomatic patients visiting a tertiary pelvic floor clinic with a normal intact levator ani muscle diagnosed on translabial ultrasound were selected. Datasets were analyzed using a rendered volume with a slice thickness of 1.5 cm at the level of minimal hiatal dimensions during contraction. The levator area (in cm(2)) was measured and multiplied by 1.5 to get the levator ani hiatus volume in conventional 3D ultrasound (in cm(3)). Levator ani hiatus volume measurements were then measured semi-automatically in virtual reality (cm(3) ) using a segmentation algorithm. An intra- and interobserver analysis of reliability and agreement was performed in 20 randomly chosen patients. The mean difference between levator ani hiatus volume measurements performed using conventional 3D ultrasound and virtual reality was 0.10 (95% CI, - 0.15 to 0.35) cm(3). The intraclass correlation coefficient (ICC) comparing conventional 3D ultrasound with virtual reality measurements was > 0.96. Intra- and interobserver ICCs for conventional 3D ultrasound measurements were > 0.94 and for virtual reality measurements were > 0.97, indicating good reliability for both. Levator ani hiatus volume measurements performed using virtual reality were reliable and the results were similar to those obtained with conventional 3D ultrasonography. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

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.

Assessment of placental volume and vascularization at 11-14 weeks of gestation in a Taiwanese population using three-dimensional power Doppler ultrasound.

PubMed

Wang, Hsing-I; Yang, Ming-Jie; Wang, Peng-Hui; Wu, Yi-Cheng; Chen, Chih-Yao

2014-12-01

The placental volume and vascular indices are crucial in helping doctors to evaluate early fetal growth and development. Inadequate placental volume or vascularity might indicate poor fetal growth or gestational complications. This study aimed to evaluate the placental volume and vascular indices during the period of 11-14 weeks of gestation in a Taiwanese population. From June 2006 to September 2009, three-dimensional power Doppler ultrasound was performed in 222 normal pregnancies from 11-14 weeks of gestation. Power Doppler ultrasound was applied to the placenta and the placental volume was obtained by a rotational technique (VOCAL). The three-dimensional power histogram was used to assess the placental vascular indices, including the mean gray value, the vascularization index, the flow index, and the vascularization flow index. The placental vascular indices were then plotted against gestational age (GA) and placental volume. Our results showed that the linear regression equation for placental volume using gestational week as the independent variable was placental volume = 18.852 × GA - 180.89 (r = 0.481, p < 0.05). All the placental vascular indices showed a constant distribution throughout the period 11-14 weeks of gestation. A tendency for a reduction in the placental mean gray value with gestational week was observed, but without statistical significance. All the placental vascular indices estimated by three-dimensional power Doppler ultrasonography showed a constant distribution throughout gestation. Copyright © 2014. Published by Elsevier Taiwan.

Value of Quantitative Three-dimensional Doppler Ultrasound in the Differentiation of Benign and Malignant Thyroid Nodules.

PubMed

Li, Wen-Bo; Zhang, Bo; Jiang, Yu-Xin; Zhu, Qing-Li; Zhang, Qing; Sun, Jian

2015-06-01

To investigate the role of quantitative three-dimensional (3D) power Doppler ultrasound in differentiating malignant and benign thyroid nodule. A total of 92 lesions in 86 patients were preoperatively examined using 3D power Doppler ultrasound. The Virtual Organ Computer-aided Analysis(VOCAL)-imaging program was used to analyze the stored volume ultrasound. The differences in the mean gray value (MG), vascularization index (VI), flow index(FI), and vascularization flow index (VFI) were compared between benign and malignant lesions. The MG of the malignant thyroid nodules was significantly lower than that of the benign ones (28.27±7.21 vs. 32.89±8.73,P=0.007). The benign nodules had significantly higher VI,FI,and VFI than the malignant nodules [VI:(40.43±26.55)% vs. (26.87±23.06)%,P=0.011;FI:41.03±7.19 vs. 37.51±7.17,P=0.022;VFI:18.23±14.60 vs. 11.47±12.47, P=0.009]. Also,76.5% (39/51) of the malignant nodules and 92.7% (38/41) of the benign nodules had higher VIs in the shell of the lesion than that of the whole lesion,and 80.4%(41/51) of the malignant nodules and 95.1% (39/41) of the benign nodules had higher FIs in the shell of the lesion than that of the whole lesion. Quantitative 3D power Doppler ultrasound provides a useful tool in distinguishing benign and malignant thyroid nodules. The malignant thyroid nodules have lower echoes than the benign nodules, wherese the benign nodules have larger blood flow than the malignant nodules.

Three-Dimensional Mid-Air Acoustic Manipulation by Ultrasonic Phased Arrays

PubMed Central

Ochiai, Yoichi; Hoshi, Takayuki; Rekimoto, Jun

2014-01-01

The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that expanded-polystyrene particles of 0.6 mm, 1 mm, and 2 mm in diameter could be manipulated by our proposed method. PMID:24849371

Preliminary evaluation of foetal liver volume by three-dimensional ultrasound in women with gestational diabetes mellitus.

PubMed

İlhan, Gülşah; Gültekin, Hüseyin; Kubat, Ayça; Gokmen Karasu, Ayse Filiz; Güngör, Emre Sinan; Zebitay, Galip Ali; Verit Atmaca, Fatma Ferda

2018-03-19

The aim of the study was to assess the standard foetal biometric measurements and foetal liver volume (FLV) in pregnancies complicated by gestational diabetes mellitus (GDM) at the time of GDM screening and to compare the results with foetuses in normal pregnancies. Ninety-seven pregnant women with normal singleton uncomplicated pregnancies between 24 and 28 weeks of gestation were allocated into GDM (+) (n: 33) and GDM (-) (n: 64) groups based on their 75 g oral glucose tolerance test results. Foetal biometric measurements and FLV measurements of the groups were compared. Although there were no significant differences in the standard biometric measurements between the two groups, FLV was significantly higher in the women with GDM (p < .01). The ROC analysis implied that with a cut-off value of FLV of 32.72 cm 3 for GDM prediction, the sensitivity was 78.8% and specificity was 56.3%. We suggest that FLV measurements during the second-trimester ultrasound scanning may be a tool for the prediction of GDM in the obstetric population. Impact statement What is already known on this subject? GDM is an important pregnancy disease, because of its possible foetal and maternal complications. Besides the standard biometric measurements, some other foetal body dimensions such as the anterior abdominal wall thickness, skinfold thickness, adipose tissue thickness, Wharton's jelly thickness, foetal liver length and foetal liver volume (FLV) have been evaluated as ultrasound parameters of glycaemic control. While the evaluation of foetal liver dimensions has a role in identifying foetal growth acceleration, previous studies addressed patients with insulin-dependent diabetes mellitus rather than gestational diabetes mellitus, utilised two-dimensional ultrasound and did not argue the diagnostic value of these findings. What do the results of this study add? In our study, besides the standard biometric measurements, the FLV measurements were evaluated by a three-dimensional

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.

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.

Detection of intracavitary uterine pathology using offline analysis of three-dimensional ultrasound volumes: interobserver agreement and diagnostic accuracy.

PubMed

Van den Bosch, T; Valentin, L; Van Schoubroeck, D; Luts, J; Bignardi, T; Condous, G; Epstein, E; Leone, F P; Testa, A C; Van Huffel, S; Bourne, T; Timmerman, D

2012-10-01

To estimate the diagnostic accuracy and interobserver agreement in predicting intracavitary uterine pathology at offline analysis of three-dimensional (3D) ultrasound volumes of the uterus. 3D volumes (unenhanced ultrasound and gel infusion sonography with and without power Doppler, i.e. four volumes per patient) of 75 women presenting with abnormal uterine bleeding at a 'bleeding clinic' were assessed offline by six examiners. The sonologists were asked to provide a tentative diagnosis. A histological diagnosis was obtained by hysteroscopy with biopsy or operative hysteroscopy. Proliferative, secretory or atrophic endometrium was classified as 'normal' histology; endometrial polyps, intracavitary myomas, endometrial hyperplasia and endometrial cancer were classified as 'abnormal' histology. The diagnostic accuracy of the six sonologists with regard to normal/abnormal histology and interobserver agreement were estimated. Intracavitary pathology was diagnosed at histology in 39% of patients. Agreement between the ultrasound diagnosis and the histological diagnosis (normal vs abnormal) ranged from 67 to 83% for the six sonologists. In 45% of cases all six examiners agreed with regard to the presence/absence of intracavitary pathology. The percentage agreement between any two examiners ranged from 65 to 91% (Cohen's κ, 0.31-0.81). The Schouten κ for all six examiners was 0.51 (95% CI, 0.40-0.62), while the highest Schouten κ for any three examiners was 0.69. When analyzing stored 3D ultrasound volumes, agreement between sonologists with regard to classifying the endometrium/uterine cavity as normal or abnormal as well as the diagnostic accuracy varied substantially. Possible actions to improve interobserver agreement and diagnostic accuracy include optimization of image quality and the use of a consistent technique for analyzing the 3D volumes. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

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

Real-time 3-dimensional contrast-enhanced ultrasound in detecting hemorrhage of blunt renal trauma.

PubMed

Xu, Rui-Xue; Li, Ye-Kuo; Li, Ting; Wang, Sha-Sha; Yuan, Gui-Zhong; Zhou, Qun-Fang; Zheng, Hai-Rong; Yan, Fei

2013-10-01

The objective of this study is to evaluate the diagnostic value of real-time 3-dimensional contrast-enhanced ultrasound in the hemorrhage of blunt renal trauma. Eighteen healthy New Zealand white rabbits were randomly divided into 3 groups. Blunt renal trauma was performed on each group by using minitype striker. Ultrasonography, color Doppler flow imaging, and contrast-enhanced 2-dimensional and real-time 3-dimensional ultrasound were applied before and after the strike. The time to shock and blood pressure were subjected to statistical analysis. Then, a comparative study of ultrasound and pathology was carried out. All the struck kidneys were traumatic. In the ultrasonography, free fluid was found under the renal capsule. In the color Doppler flow imaging, active hemorrhage was not identified. In 2-dimensional contrast-enhanced ultrasound, active hemorrhage of the damaged kidney was characterized. Real-time 3-dimensional contrast-enhanced ultrasound showed a real-time and stereoscopic ongoing bleeding of the injured kidney. The wider the hemorrhage area in 4-dimensional contrast-enhanced ultrasound was, the faster the blood pressure decreased. Real-time 3-dimensional contrast-enhanced ultrasound is a promising noninvasive tool for stereoscopically and vividly detecting ongoing hemorrhage of blunt renal trauma in real time. © 2013.

Application of Combined Two-Dimensional and Three-Dimensional Transvaginal Contrast Enhanced Ultrasound in the Diagnosis of Endometrial Carcinoma

PubMed Central

Zhou, Hui-li; Xiang, Hong; Duan, Li; Shahai, Gulinaer; Liu, Hui; Li, Xiang-hong; Mou, Rui-xue

2015-01-01

Objective. The goal of this study was to explore the clinical value of combining two-dimensional (2D) and three-dimensional (3D) transvaginal contrast-enhanced ultrasounds (CEUS) in diagnosis of endometrial carcinoma (EC). Methods. In this prospective diagnostic study, transvaginal 2D and 3D CEUS were performed on 68 patients with suspected EC, and the results of the obtained 2D-CEUS and 3D-CEUS images were compared with the gold standard for statistical analysis. Results. 2D-CEUS benign endometrial lesions showed the normal uterine perfusion phase while EC cases showed early arrival and early washout of the contrast agent and nonuniform enhancement. The 3D-CEUS images differed in central blood vessel manifestation, blood vessel shape, and vascular pattern between benign and malignant endometrial lesions (P < 0.05). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of transvaginal 2D-CEUS and 2D-CEUS combined with 3D-CEUS for diagnosis of benign and malignant endometrial lesions were 76.9%, 73.8%, 64.5%, 83.8%, and 75.0% and 84.6%, 83.3%, 75.9%, 89.7%, and 83.8%, respectively. Conclusion. 3D-CEUS is a useful supplement to 2D-CEUS and can clearly reveal the angioarchitecture spatial relationships between vessels and depth of myometrial invasion in EC. The combined use of 2D and 3D-CEUS can offer direct, accurate, and comprehensive diagnosis of early EC. PMID:26090396

Three-dimensional holographic display of ultrasound computed tomograms

NASA Astrophysics Data System (ADS)

Andre, Michael P.; Janee, Helmar S.; Ysrael, Mariana Z.; Hodler, Jeurg; Olson, Linda K.; Leopold, George R.; Schulz, Raymond

1997-05-01

Breast ultrasound is a valuable adjunct to mammography but is limited by a very small field of view, particularly with high-resolution transducers necessary for breast diagnosis. We have been developing an ultrasound system based on a diffraction tomography method that provides slices through the breast on a large 20-cm diameter circular field of view. Eight to fifteen images are typically produced in sequential coronal planes from the nipple to the chest wall with either 0.25 or 0.5 mm pixels. As a means to simplify the interpretation of this large set of images, we report experience with 3D life-sized displays of the entire breast of human volunteers using a digital holographic technique. The compound 3D holographic images are produced from the digital image matrix, recorded on 14 X 17 inch transparency and projected on a special white-light viewbox. Holographic visualization of the entire breast has proved to be the preferred method for 3D display of ultrasound computed tomography images. It provides a unique perspective on breast anatomy and may prove useful for biopsy guidance and surgical planning.

Using Flow Characteristics in Three-Dimensional Power Doppler Ultrasound Imaging to Predict Complete Responses in Patients Undergoing Neoadjuvant Chemotherapy.

PubMed

Shia, Wei-Chung; Huang, Yu-Len; Wu, Hwa-Koon; Chen, Dar-Ren

2017-05-01

Strategies are needed for the identification of a poor response to treatment and determination of appropriate chemotherapy strategies for patients in the early stages of neoadjuvant chemotherapy for breast cancer. We hypothesize that power Doppler ultrasound imaging can provide useful information on predicting response to neoadjuvant chemotherapy. The solid directional flow of vessels in breast tumors was used as a marker of pathologic complete responses (pCR) in patients undergoing neoadjuvant chemotherapy. Thirty-one breast cancer patients who received neoadjuvant chemotherapy and had tumors of 2 to 5 cm were recruited. Three-dimensional power Doppler ultrasound with high-definition flow imaging technology was used to acquire the indices of tumor blood flow/volume, and the chemotherapy response prediction was established, followed by support vector machine classification. The accuracy of pCR prediction before the first chemotherapy treatment was 83.87% (area under the ROC curve [AUC] = 0.6957). After the second chemotherapy treatment, the accuracy of was 87.9% (AUC = 0.756). Trend analysis showed that good and poor responders exhibited different trends in vascular flow during chemotherapy. This preliminary study demonstrates the feasibility of using the vascular flow in breast tumors to predict chemotherapeutic efficacy. © 2017 by the American Institute of Ultrasound in Medicine.

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.

Three-Dimensional Endoanal Ultrasound Features of the Anal Sphincter in Asian Primigravidae.

PubMed

Wickramasinghe, Dakshitha Praneeth; Senaratne, Supun; Senanayake, Hemantha; Samarasekera, Dharmabandu Nandadeva

2018-04-17

The normal parameters of 3-dimensional endoanal ultrasound (3DEAUS) of the anal sphincter have not been reported for primigravidae or pregnant women at present. 3DEAUS parameters in Asian primigravidae were assessed in this study. We analyzed 3DEAUS data of 101 consecutives Asian primigravidae, assessed in the early third trimester. The assessment was performed with a rigid ultrasonic probe (Olympus ® RU 12M-R1 probe and EU-ME1 ultrasound system (Olympus Corp., Shinjuku, Japan). The Wilcoxon signed-rank test was used to detect the differences in pressure in different quadrants. The participants had a mean age of 24.7 (standard deviation [SD], 5.1) years. The Cleveland Clinic Incontinence Score was normal in all participants. The anal sphincter complex had 3 characteristic segments that were identifiable: upper, middle and lower. The puborectalis muscle was identified as a striated "V"-shaped sling, and its mean thickness was 7.44 (SD, 1.41) mm. The mean thickness of internal (IAS) and external (EAS) sphincters at the mid-sphincter level were 1.78 (SD, 0.59) and 5.49 (SD, 1.21) mm, respectively. The EAS measured 6.02 (SD, 1.07) mm at the lower sphincter level. The statistically significant differences seen in the in quadrants were: the IAS was thicker anteriorly (Z = -2.642; P = .008), the EAS at both midsphincter level (Z = -3.70; P < .001) and lower sphincter level (Z = -7.712; P < .001) was thicker posteriorly, and the IAS was thicker at the 9 o'clock position (Z = -2.081; P = .037). Good symmetry at all 3 levels was seen in the EAS (including the puborectalis muscle). Normal values of 3DEAUS for primigravidae have been identified and may serve as reference values for other laboratories. © 2018 by the American Institute of Ultrasound in Medicine.

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.

Three-dimensional multispectral optoacoustic mesoscopy reveals melanin and blood oxygenation in human skin in vivo.

PubMed

Schwarz, Mathias; Buehler, Andreas; Aguirre, Juan; Ntziachristos, Vasilis

2016-01-01

Optical imaging plays a major role in disease detection in dermatology. However, current optical methods are limited by lack of three-dimensional detection of pathophysiological parameters within skin. It was recently shown that single-wavelength optoacoustic (photoacoustic) mesoscopy resolves skin morphology, i.e. melanin and blood vessels within epidermis and dermis. In this work we employed illumination at multiple wavelengths for enabling three-dimensional multispectral optoacoustic mesoscopy (MSOM) of natural chromophores in human skin in vivo operating at 15-125 MHz. We employ a per-pulse tunable laser to inherently co-register spectral datasets, and reveal previously undisclosed insights of melanin, and blood oxygenation in human skin. We further reveal broadband absorption spectra of specific skin compartments. We discuss the potential of MSOM for label-free visualization of physiological biomarkers in skin in vivo. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

FPGA-Based Reconfigurable Processor for Ultrafast Interlaced Ultrasound and Photoacoustic Imaging

PubMed Central

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

2016-01-01

In this paper, we report, to the best of our knowledge, a unique field-programmable gate array (FPGA)-based reconfigurable processor for real-time interlaced co-registered ultrasound and photoacoustic imaging and its application in imaging tumor dynamic response. The FPGA is used to control, acquire, store, delay-and-sum, and transfer the data for real-time co-registered imaging. The FPGA controls the ultrasound transmission and ultrasound and photoacoustic data acquisition process of a customized 16-channel module that contains all of the necessary analog and digital circuits. The 16-channel module is one of multiple modules plugged into a motherboard; their beamformed outputs are made available for a digital signal processor (DSP) to access using an external memory interface (EMIF). The FPGA performs a key role through ultrafast reconfiguration and adaptation of its structure to allow real-time switching between the two imaging modes, including transmission control, laser synchronization, internal memory structure, beamforming, and EMIF structure and memory size. It performs another role by parallel accessing of internal memories and multi-thread processing to reduce the transfer of data and the processing load on the DSP. Furthermore, because the laser will be pulsing even during ultrasound pulse-echo acquisition, the FPGA ensures that the laser pulses are far enough from the pulse-echo acquisitions by appropriate time-division multiplexing (TDM). A co-registered ultrasound and photoacoustic imaging system consisting of four FPGA modules (64-channels) is constructed, and its performance is demonstrated using phantom targets and in vivo mouse tumor models. PMID:22828830

FPGA-based reconfigurable processor for ultrafast interlaced ultrasound and photoacoustic imaging.

PubMed

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

2012-07-01

In this paper, we report, to the best of our knowledge, a unique field-programmable gate array (FPGA)-based reconfigurable processor for real-time interlaced co-registered ultrasound and photoacoustic imaging and its application in imaging tumor dynamic response. The FPGA is used to control, acquire, store, delay-and-sum, and transfer the data for real-time co-registered imaging. The FPGA controls the ultrasound transmission and ultrasound and photoacoustic data acquisition process of a customized 16-channel module that contains all of the necessary analog and digital circuits. The 16-channel module is one of multiple modules plugged into a motherboard; their beamformed outputs are made available for a digital signal processor (DSP) to access using an external memory interface (EMIF). The FPGA performs a key role through ultrafast reconfiguration and adaptation of its structure to allow real-time switching between the two imaging modes, including transmission control, laser synchronization, internal memory structure, beamforming, and EMIF structure and memory size. It performs another role by parallel accessing of internal memories and multi-thread processing to reduce the transfer of data and the processing load on the DSP. Furthermore, because the laser will be pulsing even during ultrasound pulse-echo acquisition, the FPGA ensures that the laser pulses are far enough from the pulse-echo acquisitions by appropriate time-division multiplexing (TDM). A co-registered ultrasound and photoacoustic imaging system consisting of four FPGA modules (64-channels) is constructed, and its performance is demonstrated using phantom targets and in vivo mouse tumor models.

[Real-time three-dimensional (4D) ultrasound-guided prostatic biopsies on a phantom. Comparative study versus 2D guidance].

PubMed

Long, Jean-Alexandre; Daanen, Vincent; Moreau-Gaudry, Alexandre; Troccaz, Jocelyne; Rambeaud, Jean-Jacques; Descotes, Jean-Luc

2007-11-01

The objective of this study was to determine the added value of real-time three-dimensional (4D) ultrasound guidance of prostatic biopsies on a prostate phantom in terms of the precision of guidance and distribution. A prostate phantom was constructed. A real-time 3D ultrasonograph connected to a transrectal 5.9 MHz volumic transducer was used. Fourteen operators performed 336 biopsies with 2D guidance then 4D guidance according to a 12-biopsy protocol. Biopsy tracts were modelled by segmentation in a 3D ultrasound volume. Specific software allowed visualization of biopsy tracts in the reference prostate and evaluated the zone biopsied. A comparative study was performed to determine the added value of 4D guidance compared to 2D guidance by evaluating the precision of entry points and target points. The distribution was evaluated by measuring the volume investigated and by a redundancy ratio of the biopsy points. The precision of the biopsy protocol was significantly improved by 4D guidance (p = 0.037). No increase of the biopsy volume and no improvement of the distribution of biopsies were observed with 4D compared to 2D guidance. The real-time 3D ultrasound-guided prostate biopsy technique on a phantom model appears to improve the precision and reproducibility of a biopsy protocol, but the distribution of biopsies does not appear to be improved.

Three-dimensional features on oscillating microbubbles streaming flows

NASA Astrophysics Data System (ADS)

Rossi, Massimiliano; Marin, Alvaro G.; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.

2013-11-01

Ultrasound-driven oscillating micro-bubbles have been used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting and manipulation of microparticles. A common configuration consists in side-bubbles, created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration results in bubbles with a semi-cylindrical shape that creates a streaming flow generally considered quasi two-dimensional. However, recent experiments performed with three-dimensional velocimetry methods have shown how microparticles can present significant three-dimensional trajectories, especially in regions close to the bubble interface. Several reasons will be discussed such as boundary effects of the bottom/top wall, deformation of the bubble interface leading to more complex vibrational modes, or bubble-particle interactions. In the present investigation, precise measurements of particle trajectories close to the bubble interface will be performed by means of 3D Astigmatic Particle Tracking Velocimetry. The results will allow us to characterize quantitatively the three-dimensional features of the streaming flow and to estimate its implications in practical applications as particle trapping, sorting or mixing.

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.

Human placental vasculature imaging using an LED-based photoacoustic/ultrasound imaging system

NASA Astrophysics Data System (ADS)

Maneas, Efthymios; Xia, Wenfeng; Kuniyil Ajith Singh, Mithun; Sato, Naoto; Agano, Toshitaka; Ourselin, Sebastien; West, Simeon J.; David, Anna L.; Vercauteren, Tom; Desjardins, Adrien E.

2018-02-01

Minimally invasive fetal interventions, such as those used for therapy of twin-to-twin transfusion syndrome (TTTS), require accurate image guidance to optimise patient outcomes. Currently, TTTS can be treated fetoscopically by identifying anastomosing vessels on the chorionic (fetal) placental surface, and then performing photocoagulation. Incomplete photocoagulation increases the risk of procedure failure. Photoacoustic imaging can provide contrast for both haemoglobin concentration and oxygenation, and in this study, it was hypothesised that it can resolve chorionic placental vessels. We imaged a term human placenta that was collected after caesarean section delivery using a photoacoustic/ultrasound system (AcousticX) that included light emitting diode (LED) arrays for excitation light and a linear-array ultrasound imaging probe. Two-dimensional (2D) co-registered photoacoustic and B-mode pulse-echo ultrasound images were acquired and displayed in real-time. Translation of the imaging probe enabled 3D imaging. This feasibility study demonstrated that photoacoustic imaging can be used to visualise chorionic placental vasculature, and that it has strong potential to guide minimally invasive fetal interventions.

Using an ultrasound elasticity microscope to map three-dimensional strain in a porcine cornea.

PubMed

Hollman, Kyle W; Shtein, Roni M; Tripathy, Sakya; Kim, Kang

2013-08-01

An ultrasound elasticity microscope was used to map 3-D strain volume in an ex vivo porcine cornea to illustrate its ability to measure the mechanical properties of this tissue. Mechanical properties of the cornea play an important role in its function and, therefore, also in ophthalmic diseases such as kerataconus and corneal ectasia. The ultrasound elasticity microscope combines a tightly focused high-frequency transducer with confocal scanning to produce high-quality speckle over the entire volume of tissue. This system and the analysis were able to generate volume maps of compressional strain in all three directions for porcine corneal tissue, more information than any previous study has reported. Strain volume maps indicated features of the cornea and mechanical behavior as expected. These results constitute a step toward better understanding of corneal mechanics and better treatment of corneal diseases. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

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

[Efficacy and problems of bladder volume measurement using portable three dimensional ultrasound scanning device--in particular, on measuring bladder volume lower than 100ml].

PubMed

Oh-Oka, Hitoshi; Nose, Ryuichiro

2005-09-01

Using a portable three dimensional ultrasound scanning device (The Bladder Scan BVI6100, Diagnostic Ultrasound Corporation), we examined measured values of bladder volume, especially focusing on volume lower than 100 ml. A total of 100 patients (male: 66, female: 34) were enrolled in the study. We made a comparison study between the measured value (the average of three measurements of bladder urine volume after a trial in male and female modes) using BVI6100, and the actual measured value of the sample obtained by urethral catheterization in each patient. We examined the factors which could increase the error rate. We also introduced the effective techniques to reduce measurement errors. The actual measured values in all patients correlated well with the average value of three measurements after a trial in a male mode of the BVI6100. The correlation coefficient was 0.887, the error rate was--4.6 +/- 24.5%, and the average coefficient of variation was 15.2. It was observed that the measurement result using the BVI6100 is influenced by patient side factors (extracted edges between bladder wall and urine, thickened bladder wall, irregular bladder wall, flattened rate of bladder, mistaking prostate for bladder in male, mistaking bladder for uterus in a female mode, etc.) or examiner side factors (angle between BVI and abdominal wall, compatibility between abdominal wall and ultrasound probe, controlling deflection while using probe, etc). When appropriate patients are chosen and proper measurement is performed, BVI6100 provides significantly higher accuracy in determining bladder volume, compared with existing abdominal ultrasound methods. BVI6100 is a convenient and extremely effective device also for the measurement of bladder urine over 100 ml.

Direct Regularization From Co-Registered Contrast MRI Improves Image Quality of MRI-Guided Near-Infrared Spectral Tomography of Breast Lesions.

PubMed

Zhang, Limin; Jiang, Shudong; Zhao, Yan; Feng, Jinchao; Pogue, Brian W; Paulsen, Keith D

2018-05-01

An approach using direct regularization from co-registered dynamic contrast enhanced magnetic reson- ance images was used to reconstruct near-infrared spectral tomography patient images, which does not need image segmentation. 20 patients with mammography/ultrasound confirmed breast abnormalities were involved in this paper, and the resulting images indicated that tumor total hemoglobin concentration contrast differentiated malignant from benign cases (p-value = 0.021). The approach prod- uced reconstructed images, which significantly reduced surface artifacts near the source-detector locations (p-value = 4.16e-6).

Three-dimensional diffuse optical mammography with ultrasound localization in a human subject

NASA Astrophysics Data System (ADS)

Holboke, Monica J.; Tromberg, Bruce J.; Li, Xingde; Shah, Natasha; Fishkin, Joshua B.; Kidney, D.; Butler, J.; Chance, Britton; Yodh, Arjun G.

2000-04-01

We describe an approach that combines clinical ultrasound and photon migration techniques to enhance the sensitivity and information content of diffuse optical tomography. Measurements were performed on a postmenopausal woman with a single 1.8 X 0.9 cm malignant ductal carcinoma in situ approximately 7.4 mm beneath the skin surface (UCI IRB protocol 95-563). The ultrasound-derived information about tumor geometry enabled us to segment the breast tissue into tumor and background regions. Optical data was obtained with a multifrequency, multiwavelength hand-held frequency-domain photon migration backscattering probe. The optical properties of the tumor and background were then computed using the ultrasound-derived geometrical constraints. An iterative perturbative approach, using parallel processing, provided quantitative information about scattering and absorption simultaneously with the ability to incorporate and resolve complex boundary conditions and geometries. A three to four fold increase in the tumor absorption coefficient and nearly 50% reduction in scattering coefficient relative to background was observed ((lambda) equals 674, 782, 803, and 849 nm). Calculations of the mean physiological parameters reveal fourfold greater tumor total hemoglobin concentration [Hbtot] than normal breast (67 (mu) M vs 16 (mu) M) and tumor hemoglobin oxygen saturation (SOx) values of 63% (vs 73% and 68% in the region surrounding the tumor and the opposite normal tissue, respectively). Comparison of semi-infinite to heterogeneous models shows superior tumor/background contrast for the latter in both absorption and scattering. Sensitivity studies assessing the impact of tumor size and refractive index assumptions, as well as scan direction, demonstrate modest effects on recovered properties.

Three-dimensional vs. two-dimensional shear-wave elastography of the testes - preliminary study on a healthy collective.

PubMed

Marcon, J; Trottmann, M; Rübenthaler, J; D'Anastasi, M; Stief, C G; Reiser, M F; Clevert, D A

2016-01-01

Shear wave elastography (SWE) and its derivative Supersonic Shear Imaging (SSI) are newer techniques for the determination of tissue elasticity by measuring the velocity of generated shear waves (SWV), which correlates positively with tissue stiffness.The techniques are integrated into many modern ultrasound systems and have been examined in the evaluation of viscoelastic properties of different organ systems. Two-dimensional shear wave elastography (2D SWE) of the testes has been found to be a useful tool in recent studies which included the determination of standard values in healthy volunteers. Three-dimensional shear wave elastography (3D SWE) is the latest development in elastography and is made possible by generation of a multiplanar three-dimensional map via volumetric acquisition with a special ultrasound transducer. This technique allows the assessment of tissue elasticity in a three-dimensional, fully accessible organ map.The aim of this preliminary study was to both evaluate the feasibility of 3D SWE and to compare 2D and 3D SWE standard values in the testes of healthy subjects. We examined the testes of healthy male volunteers (n = 32) with a mean age of 51.06±17.75 years (range 25-77 years) by B-mode ultrasound, 2D and 3D SWE techniques in September of 2016. Volunteers with a history of testicular pathologies were excluded. For all imaging procedures the SL15-4 linear transducer (bandwidth 4-15 MHz) as well as the SLV16-4 volumetric probe (bandwidth 4-16 MHz) of the Aixplorer® ultrasound device (SuperSonic Imagine, Aix-en-Provence, France) were used. Seven regions of interest (ROI, Q-Box®) within the testes were evaluated for SWV using both procedures. SWV values were described in m/s. Results were statistically evaluated using univariateanalysis. Mean SWV values were 1.05 m/s for the 2D SWE and 1.12 m/s for the 3D SWE.Comparisons of local areas delivered no statistically significant differences (p = 0.11 to p = 0.66), except for

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.

Differentiation of benign from malignant solid breast masses: comparison of two-dimensional and three-dimensional shear-wave elastography.

PubMed

Lee, Su Hyun; Chang, Jung Min; Kim, Won Hwa; Bae, Min Sun; Cho, Nariya; Yi, Ann; Koo, Hye Ryoung; Kim, Seung Ja; Kim, Jin You; Moon, Woo Kyung

2013-04-01

To prospectively compare the diagnostic performances of two-dimensional (2D) and three-dimensional (3D) shear-wave elastography (SWE) for differentiating benign from malignant breast masses. B-mode ultrasound and SWE were performed for 134 consecutive women with 144 breast masses before biopsy. Quantitative elasticity values (maximum and mean elasticity in the stiffest portion of mass, Emax and Emean; lesion-to-fat elasticity ratio, Erat) were measured with both 2D and 3D SWE. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity of B-mode, 2D, 3D SWE and combined data of B-mode and SWE were compared. Sixty-seven of the 144 breast masses (47 %) were malignant. Overall, higher elasticity values of 3D SWE than 2D SWE were noted for both benign and malignant masses. The AUC for 2D and 3D SWE were not significantly different: Emean, 0.938 vs 0.928; Emax, 0.939 vs 0.930; Erat, 0.907 vs 0.871. Either 2D or 3D SWE significantly improved the specificity of B-mode ultrasound from 29.9 % (23 of 77) up to 71.4 % (55 of 77) and 63.6 % (49 of 77) without a significant change in sensitivity. Two-dimensional and 3D SWE performed equally in distinguishing benign from malignant masses and both techniques improved the specificity of B-mode ultrasound.

Concordance of Gleason grading with three-dimensional ultrasound systematic biopsy and biopsy core pre-embedding.

PubMed

van der Aa, Anouk A M A; Mannaerts, Christophe K; van der Linden, Hans; Gayet, Maudy; Schrier, Bart Ph; Mischi, Massimo; Beerlage, Harrie P; Wijkstra, Hessel

2018-02-01

To determine the value of a three-dimensional (3D) greyscale transrectal ultrasound (TRUS)-guided prostate biopsy system and biopsy core pre-embedding method on concordance between Gleason scores of needle biopsies and radical prostatectomy (RP) specimens. Retrospective analysis of prostate biopsies and subsequent RP for PCa in the Jeroen Bosch Hospital, the Netherlands, from 2007 to 2016. Two cohorts were analysed: conventional 2D TRUS-guided biopsies and RP (2007-2013, n = 266) versus 3D TRUS-guided biopsies with pre-embedding (2013-2016, n = 129). The impact of 3D TRUS-guidance with pre-embedding on Gleason score (GS) concordance between biopsy and RP was evaluated using the κ-coefficient. Predictors of biopsy GS 6 upgrading were assessed using logistic regression models. Gleason concordance was comparable between the two cohorts with a κ = 0.44 for the 3D cohort, compared to κ = 0.42 for the 2D cohort. 3D TRUS-guidance with pre-embedding, did not significantly affect the risk of biopsy GS 6 upgrading in univariate and multivariate analysis. 3D TRUS-guidance with biopsy core pre-embedding did not improve Gleason concordance. Improved detection techniques are needed for recognition of low-grade disease upgrading.

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

PubMed Central

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

2014-01-01

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. PMID:24900165

Three-dimensional endoanal ultrasound is accurate and reproducible in determining type and height of anal fistulas.

PubMed

Kołodziejczak, M; Santoro, G A; Obcowska, A; Lorenc, Z; Mańczak, M; Sudoł-Szopińska, I

2017-04-01

Surgical treatment of high anal fistulas is associated with the potential risk of faecal incontinence and recurrence. The primary aim of this study was to determine the accuracy of three-dimensional endoanal ultrasound (3D-EAUS) in the assessment of height and type of anal fistulas, compared to the intra-operative findings (gold standard). The secondary aim was to evaluate the inter-observer reproducibility of 3D-EAUS. The study design was a prospective analysis of retrospective data. 299 patients (202 men), mean age 45.3 years, who underwent surgery for anal fistulas, were included. All patients were preoperatively assessed by 3D-EAUS. Two readers independently reviewed the volumes to determine the type and height of fistulas. Sensitivity, specificity, positive and negative predictive values, proportion of agreements and Cohen's kappa coefficient (κ) were calculated for both examiners. Ultrasound findings were compared with intra-operative data (reference standard), evaluated blindly by the surgeons. At surgery, 201 (67%) were transsphincteric, 49 (16%) suprasphincteric, 47 (16%) intersphincteric and two (1%) extrasphincteric fistulas. Intra-operatively, 177 (59%) were low and 122 (41%) high fistulas. The overall accuracy of 3D-EAUS was 91% for fistula type (271/299 fistulas: 97% transsphincteric, 100% intersphincteric, 57% suprasphincteric, 0% extrasphincteric) and 92% for fistula height (275/299 fistulas: 80% high and 100% low). Both readers reported very good agreement with surgery in the assessment of fistula type (proportion of agreement 0.88, κ = 0.89) and height (proportion of agreement 0.90, κ = 0.91). 3D-EAUS is an accurate and reproducible modality for the assessment of type and height of anal fistulas. Colorectal Disease © 2016 The Association of Coloproctology of Great Britain and Ireland.

Ultrasound-mediated microbubble enhancement of radiation therapy studied using three-dimensional high-frequency power Doppler ultrasound.

PubMed

Kwok, Sheldon J J; El Kaffas, Ahmed; Lai, Priscilla; Al Mahrouki, Azza; Lee, Justin; Iradji, Sara; Tran, William Tyler; Giles, Anoja; Czarnota, Gregory J

2013-11-01

Tumor responses to high-dose (>8 Gy) radiation therapy are tightly connected to endothelial cell death. In the study described here, we investigated whether ultrasound-activated microbubbles can locally enhance tumor response to radiation treatments of 2 and 8 Gy by mechanically perturbing the endothelial lining of tumors. We evaluated vascular changes resulting from combined microbubble and radiation treatments using high-frequency 3-D power Doppler ultrasound in a breast cancer xenograft model. We compared treatment effects and monitored vasculature damage 3 hours, 24 hours and 7 days after treatment delivery. Mice treated with 2 Gy radiation and ultrasound-activated microbubbles exhibited a decrease in vascular index to 48 ± 10% at 24 hours, whereas vascular indices of mice treated with 2 Gy radiation alone or microbubbles alone were relatively unchanged at 95 ± 14% and 78 ± 14%, respectively. These results suggest that ultrasound-activated microbubbles enhance the effects of 2 Gy radiation through a synergistic mechanism, resulting in alterations of tumor blood flow. This novel therapy may potentiate lower radiation doses to preferentially target endothelial cells, thus reducing effects on neighboring normal tissue and increasing the efficacy of cancer treatments. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

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.

Diagnosis of fetal syndromes by three- and four-dimensional ultrasound: is there any improvement?

PubMed

Barišić, Lara Spalldi; Stanojević, Milan; Kurjak, Asim; Porović, Selma; Gaber, Ghalia

2017-08-28

With all of our present knowledge, high technology diagnostic equipment, electronic databases and other available supporting resources, detection of fetal syndromes is still a challenge for healthcare providers in prenatal as well as in the postnatal period. Prenatal diagnosis of fetal syndromes is not straightforward, and it is a difficult puzzle that needs to be assembled and solved. Detection of one anomaly should always raise a suspicion of the existence of more anomalies, and can be a trigger to investigate further and raise awareness of possible syndromes. Highly specialized software systems for three- and four-dimensional ultrasound (3D/4D US) enabled detailed depiction of fetal anatomy and assessment of the dynamics of fetal structural and functional development in real time. With recent advances in 3D/4D US technology, antenatal diagnosis of fetal anomalies and syndromes shifted from the 2nd to the 1st trimester of pregnancy. It is questionable what can and should be done after the prenatal diagnosis of fetal syndrome. The 3D and 4D US techniques improved detection accuracy of fetal abnormalities and syndromes from early pregnancy onwards. It is not easy to make prenatal diagnosis of fetal syndromes, so tools which help like online integrated databases are needed to increase diagnostic precision. The aim of this paper is to present the possibilities of different US techniques in the detection of some fetal syndromes prenatally.

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

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…

Ultrasound imaging of the anal sphincter complex: a review

PubMed Central

Abdool, Z; Sultan, A H; Thakar, R

2012-01-01

Endoanal ultrasound is now regarded as the gold standard for evaluating anal sphincter pathology in the investigation of anal incontinence. The advent of three-dimensional ultrasound has further improved our understanding of the two-dimensional technique. Endoanal ultrasound requires specialised equipment and its relative invasiveness has prompted clinicians to explore alternative imaging techniques. Transvaginal and transperineal ultrasound have been recently evaluated as alternative imaging modalities. However, the need for technique standardisation, validation and reporting is of paramount importance. We conducted a MEDLINE search (1950 to February 2010) and critically reviewed studies using the three imaging techniques in evaluating anal sphincter integrity. PMID:22374273

Three-dimensional ultrasound imaging and measurement of nasal bone length, prenasal thickness and frontomaxillary facial angle in normal second- and third-trimester fetuses.

PubMed

Vos, F I; De Jong-Pleij, E A P; Ribbert, L S M; Tromp, E; Bilardo, C M

2012-06-01

To assess the feasibility of nasal bone length (NBL), prenasal thickness (PT) and frontomaxillary facial (FMF) angle measurements performed on the same three-dimensional (3D) multiplanar-corrected profile view in healthy second- and third-trimester fetuses, to create reference ranges and to review published measurement techniques. 3D volumes of 219 healthy second- and third-trimester fetuses were retrospectively analyzed. The quality of images and measurability of the markers were assessed with 5-point and 3-point scoring systems, respectively. Measurements of NBL (with care to exclude the frontal bone), PT and FMF were obtained in the exact mid-sagittal plane. Reference ranges were constructed based on measurements from images with high-quality (4 or 5 points) and high measurability (2 or 3 points) scores and compared with those in the most relevant published literature. A high-quality score was assigned to 111 images. Among these, a high measurability score was significantly more often achieved for NBL (98.2%) and PT (97.3%) than for the FMF angle (26.1%) (P < 0.001). Both NBL (NBL = - 6.927 + (0.83 × GA) - (0.01 × GA(2))) and PT (PT = (0.212 × GA) - 0.873) (where GA = gestational age) showed growth with gestation, with less pronounced growth for NBL after 28 weeks. Our reference range for the NBL showed a systematically smaller length than those in other two-dimensional (2D) ultrasound-based publications. The FMF angle measurements that we obtained did not show a significant change with GA. NBL and PT are easily measured using 3D ultrasound whereas FMF angle measurement is more challenging. When it is measured in the exact mid-sagittal plane and care is taken to exclude the frontal bone, measurements of the NBL are systematically smaller than those in previous 2D ultrasound-based publications. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

Stretchable ultrasonic transducer arrays for three-dimensional imaging on complex surfaces

PubMed Central

Zhu, Xuan; Li, Xiaoshi; Chen, Zeyu; Chen, Yimu; Lei, Yusheng; Li, Yang; Nomoto, Akihiro; Zhou, Qifa; di Scalea, Francesco Lanza

2018-01-01

Ultrasonic imaging has been implemented as a powerful tool for noninvasive subsurface inspections of both structural and biological media. Current ultrasound probes are rigid and bulky and cannot readily image through nonplanar three-dimensional (3D) surfaces. However, imaging through these complicated surfaces is vital because stress concentrations at geometrical discontinuities render these surfaces highly prone to defects. This study reports a stretchable ultrasound probe that can conform to and detect nonplanar complex surfaces. The probe consists of a 10 × 10 array of piezoelectric transducers that exploit an “island-bridge” layout with multilayer electrodes, encapsulated by thin and compliant silicone elastomers. The stretchable probe shows excellent electromechanical coupling, minimal cross-talk, and more than 50% stretchability. Its performance is demonstrated by reconstructing defects in 3D space with high spatial resolution through flat, concave, and convex surfaces. The results hold great implications for applications of ultrasound that require imaging through complex surfaces. PMID:29740603

Reliability of pelvic floor measurements on three- and four-dimensional ultrasound during and after first pregnancy: implications for training.

PubMed

van Veelen, G A; Schweitzer, K J; van der Vaart, C H

2013-11-01

To evaluate the reliability of measurements of the levator hiatus and levator-urethra gap (LUG) using three/four-dimensional (3D/4D) transperineal ultrasound in women during their first pregnancy and 6 months postpartum, and to assess the learning process for these measurements. An inexperienced observer was taught to perform measurements of the levator hiatus and LUG by an experienced observer. After training, 3D/4D ultrasound volume datasets of 40 women in the first trimester were analyzed by these two observers. Another training session then took place and both observers repeated the analyses of the same volume datasets. Finally, analyses of 40 volume datasets of the women 6 months postpartum were performed by both observers. Intra- and interobserver reliability were determined by intraclass correlation coefficients (ICC) with 95% CIs. For levator hiatal measurements, in the women during their first pregnancy the interobserver reliability was substantial to almost perfect after both the first and second training session (ICC, 0.62-0.83 and 0.71-0.89, respectively, for anteroposterior diameter, transverse diameter and area at rest, on contraction and on Valsalva) and the intraobserver reliability was substantial to almost perfect for both observers. For these measurements performed once the women had delivered, interobserver reliability was moderate to almost perfect. For LUG measurements performed during pregnancy, interobserver reliability was slight to moderate after the first training session (ICC, 0.14-0.54), but improved after the second training session (ICC, 0.38-0.71), and intraobserver reliability was moderate to substantial for the experienced observer and slight to moderate for the inexperienced observer. For these measurements performed when the women had delivered, interobserver reliability was fair to moderate. The levator hiatus and LUG can be measured reliably using 3D/4D ultrasound in primigravid and primiparous women. The technique to measure

Real-time two-dimensional temperature imaging using ultrasound.

PubMed

Liu, Dalong; Ebbini, Emad S

2009-01-01

We present a system for real-time 2D imaging of temperature change in tissue media using pulse-echo ultrasound. The frontend of the system is a SonixRP ultrasound scanner with a research interface giving us the capability of controlling the beam sequence and accessing radio frequency (RF) data in real-time. The beamformed RF data is streamlined to the backend of the system, where the data is processed using a two-dimensional temperature estimation algorithm running in the graphics processing unit (GPU). The estimated temperature is displayed in real-time providing feedback that can be used for real-time control of the heating source. Currently we have verified our system with elastography tissue mimicking phantom and in vitro porcine heart tissue, excellent repeatability and sensitivity were demonstrated.

Three-dimensional sheaf of ultrasound planes reconstruction (SOUPR) of ablated volumes.

PubMed

Ingle, Atul; Varghese, Tomy

2014-08-01

This paper presents an algorithm for 3-D reconstruction of tumor ablations using ultrasound shear wave imaging with electrode vibration elastography. Radio-frequency 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 3-D 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 six imaging planes suggesting that the method is suited for parsimonious data acquisitions with very few sparsely chosen imaging planes.

Interlaced photoacoustic and ultrasound imaging system with real-time coregistration for ovarian tissue characterization

NASA Astrophysics Data System (ADS)

Alqasemi, Umar; Li, Hai; Yuan, Guangqian; Kumavor, Patrick; Zanganeh, Saeid; Zhu, Quing

2014-07-01

Coregistered ultrasound (US) and photoacoustic imaging are emerging techniques for mapping the echogenic anatomical structure of tissue and its corresponding optical absorption. We report a 128-channel imaging system with real-time coregistration of the two modalities, which provides up to 15 coregistered frames per second limited by the laser pulse repetition rate. In addition, the system integrates a compact transvaginal imaging probe with a custom-designed fiber optic assembly for in vivo detection and characterization of human ovarian tissue. We present the coregistered US and photoacoustic imaging system structure, the optimal design of the PC interfacing software, and the reconfigurable field programmable gate array operation and optimization. Phantom experiments of system lateral resolution and axial sensitivity evaluation, examples of the real-time scanning of a tumor-bearing mouse, and ex vivo human ovaries studies are demonstrated.

Three-dimensional imaging of the brain cavities in human embryos.

PubMed

Blaas, H G; Eik-Nes, S H; Kiserud, T; Berg, S; Angelsen, B; Olstad, B

1995-04-01

A system for high-resolution three-dimensional imaging of small structures has been developed, based on the Vingmed CFM-800 annular array sector scanner with a 7.5-MHz transducer attached to a PC-based TomTec Echo-Scan unit. A stepper motor rotates the transducer 180 degrees and the complete three-dimensional scan consists of 132 two-dimensional images, video-grabbed and scan-converted into a regular volumetric data set by the TomTec unit. Three normal pregnancies with embryos of gestational age 7, 9 and 10 weeks received a transvaginal examination with special attention to the embryonic/fetal brain. In all three cases, it was possible to obtain high-resolution images of the brain cavities. At 7 weeks, both hemispheres and their connection to the third ventricle were delineated. The isthmus rhombencephali could be visualized. At 9 weeks, the continuous development of the brain cavities could be followed and at 11 weeks the dominating size of the hemispheres could be depicted. It is concluded that present ultrasound technology has reached a stage where structures of only a few millimeters can be imaged in vivo in three-dimensions with a quality that resembles the plaster figures used in embryonic laboratories. The method can become an important tool in future embryological research and also in the detection of early developmental disorders of the embryo.

Development of a system for acquiring, reconstructing, and visualizing three-dimensional ultrasonic angiograms

NASA Astrophysics Data System (ADS)

Edwards, Warren S.; Ritchie, Cameron J.; Kim, Yongmin; Mack, Laurence A.

1995-04-01

We have developed a three-dimensional (3D) imaging system using power Doppler (PD) ultrasound (US). This system can be used for visualizing and analyzing the vascular anatomy of parenchymal organs. To create the 3D PD images, we acquired a series of two-dimensional PD images from a commercial US scanner and recorded the position and orientation of each image using a 3D magnetic position sensor. Three-dimensional volumes were reconstructed using specially designed software and then volume rendered for display. We assessed the feasibility and geometric accuracy of our system with various flow phantoms. The system was then tested on a volunteer by scanning a transplanted kidney. The reconstructed volumes of the flow phantom contained less than 1 mm of geometric distortion and the 3D images of the transplanted kidney depicted the segmental, arcuate, and interlobar vessels.

Imaging Performance of Quantitative Transmission Ultrasound

PubMed Central

Lenox, Mark W.; Wiskin, James; Lewis, Matthew A.; Darrouzet, Stephen; Borup, David; Hsieh, Scott

2015-01-01

Quantitative Transmission Ultrasound (QTUS) is a tomographic transmission ultrasound modality that is capable of generating 3D speed-of-sound maps of objects in the field of view. It performs this measurement by propagating a plane wave through the medium from a transmitter on one side of a water tank to a high resolution receiver on the opposite side. This information is then used via inverse scattering to compute a speed map. In addition, the presence of reflection transducers allows the creation of a high resolution, spatially compounded reflection map that is natively coregistered to the speed map. A prototype QTUS system was evaluated for measurement and geometric accuracy as well as for the ability to correctly determine speed of sound. PMID:26604918

Measurement of thrombus resolution using three-dimensional ultrasound assessment of deep vein thrombosis volume.

PubMed

Zhao, Limin; Prior, Steven J; Kampmann, Meghan; Sorkin, John D; Caldwell, Kevin; Braganza, Melita; McEvoy, Sue; Lal, Brajesh K

2014-04-01

Current imaging techniques are limited in their ability to quantify thrombus burden, progression, resolution, and organization over time in patients with acute deep vein thrombosis (DVT). These assessments are critical measures of therapeutic success when thrombolytic or thrombectomy treatment protocols are utilized for DVT. We evaluated the reliability of a new, commercially available method of acquiring and analyzing three-dimensional (3D) ultrasound images of DVTs that measures thrombus volume and echogenicity. We studied 25 consecutive hospital in-patients (18 male, seven female; age range, 37-87 years) with a first episode of acute DVT. Treatment decisions were not influenced by the study protocol. Scanning was performed independently by two sonographers, then the first sonographer repeated the scan. A combination of routine imaging in grayscale, color-flow, and power-Doppler modes (2D transducer) along with volumetric imaging (3D transducer) was performed. Patients underwent imaging at baseline and on one or more follow-up days 7, 14, 21 and 30. Image-processing software loaded on the ultrasound machine was used to obtain thrombus volume and echogenicity measurements. Thrombus volume was reliably determined by our protocol. The median volume of thrombus at baseline was 0.4 cm(3). Mean inter- and intraobserver differences in volume measurements were 0.006 ± 0.26 cm(3) and -0.12 ± 0.29 cm(3) (mean ± standard deviation). Thrombus resolved over time at a rate of -0.042 ± 0.01 cm(3)/day (P < .003). The median echogenicity of thrombus at baseline expressed as the grayscale median value was 59. There was a trend for thrombus organization (measured as echogenicity) to increase with time, +0.36 ± 0.23 grayscale median units/day (P < .13). Adjustment for the use of anticoagulation, gender of subject, or location of DVT in the upper vs lower extremity did not alter the relationship between time and volume or time and echogenicity. We describe a 3D

Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fehm, Thomas Felix; Razansky, Daniel, E-mail: dr@tum.de; Faculty of Medicine, Technische Universität München, Munich

2014-10-27

Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an opticalmore » absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.« less

Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

NASA Astrophysics Data System (ADS)

Fehm, Thomas Felix; Deán-Ben, Xosé Luís; Razansky, Daniel

2014-10-01

Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

Identification of muscle necrosis in the mdx mouse model of Duchenne muscular dystrophy using three-dimensional optical coherence tomography

NASA Astrophysics Data System (ADS)

Klyen, Blake R.; Shavlakadze, Thea; Radley-Crabb, Hannah G.; Grounds, Miranda D.; Sampson, David D.

2011-07-01

Three-dimensional optical coherence tomography (3D-OCT) was used to image the structure and pathology of skeletal muscle tissue from the treadmill-exercised mdx mouse model of human Duchenne muscular dystrophy. Optical coherence tomography (OCT) images of excised muscle samples were compared with co-registered hematoxylin and eosin-stained and Evans blue dye fluorescence histology. We show, for the first time, structural 3D-OCT images of skeletal muscle dystropathology well correlated with co-located histology. OCT could identify morphological features of interest and necrotic lesions within the muscle tissue samples based on intrinsic optical contrast. These findings demonstrate the utility of 3D-OCT for the evaluation of small-animal skeletal muscle morphology and pathology, particularly for studies of mouse models of muscular dystrophy.

Feasibility of wall stress analysis of abdominal aortic aneurysms using three-dimensional ultrasound.

PubMed

Kok, Annette M; Nguyen, V Lai; Speelman, Lambert; Brands, Peter J; Schurink, Geert-Willem H; van de Vosse, Frans N; Lopata, Richard G P

2015-05-01

Abdominal aortic aneurysms (AAAs) are local dilations that can lead to a fatal hemorrhage when ruptured. Wall stress analysis of AAAs is a novel tool that has proven high potential to improve risk stratification. Currently, wall stress analysis of AAAs is based on computed tomography (CT) and magnetic resonance imaging; however, three-dimensional (3D) ultrasound (US) has great advantages over CT and magnetic resonance imaging in terms of costs, speed, and lack of radiation. In this study, the feasibility of 3D US as input for wall stress analysis is investigated. Second, 3D US-based wall stress analysis was compared with CT-based results. The 3D US and CT data were acquired in 12 patients (diameter, 35-90 mm). US data were segmented manually and compared with automatically acquired CT geometries by calculating the similarity index and Hausdorff distance. Wall stresses were simulated at P = 140 mm Hg and compared between both modalities. The similarity index of US vs CT was 0.75 to 0.91 (n = 12), with a median Hausdorff distance ranging from 4.8 to 13.9 mm, with the higher values found at the proximal and distal sides of the AAA. Wall stresses were in accordance with literature, and a good agreement was found between US- and CT-based median stresses and interquartile stresses, which was confirmed by Bland-Altman and regression analysis (n = 8). Wall stresses based on US were typically higher (+23%), caused by geometric irregularities due to the registration of several 3D volumes and manual segmentation. In future work, an automated US registration and segmentation approach is the essential point of improvement before pursuing large-scale patient studies. This study is a first step toward US-based wall stress analysis, which would be the modality of choice to monitor wall stress development over time because no ionizing radiation and contrast material are involved. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

ANGIOCARE: an automated system for fast three-dimensional coronary reconstruction by integrating angiographic and intracoronary ultrasound data.

PubMed

Bourantas, Christos V; Kalatzis, Fanis G; Papafaklis, Michail I; Fotiadis, Dimitrios I; Tweddel, Ann C; Kourtis, Iraklis C; Katsouras, Christos S; Michalis, Lampros K

2008-08-01

The development of an automated, user-friendly system (ANGIOCARE), for rapid three-dimensional (3D) coronary reconstruction, integrating angiographic and, intracoronary ultrasound (ICUS) data. Biplane angiographic and ICUS sequence images are imported into the system where a prevalidated method is used for coronary reconstruction. This incorporates extraction of the catheter path from two end-diastolic X-ray images and detection of regions of interest (lumen, outer vessel wall) in the ICUS sequence by an automated border detection algorithm. The detected borders are placed perpendicular to the catheter path and established algorithms used to estimate their absolute orientation. The resulting 3D object is imported into an advanced visualization module with which the operator can interact, examine plaque distribution (depicted as a color coded map) and assess plaque burden by virtual endoscopy. Data from 19 patients (27 vessels) undergoing biplane angiography and ICUS were examined. The reconstructed vessels were 21.3-80.2 mm long. The mean difference was 0.9 +/- 2.9% between the plaque volumes measured using linear 3D ICUS analysis and the volumes, estimated by taking into account the curvature of the vessel. The time required to reconstruct a luminal narrowing of 25 mm was approximately 10 min. The ANGIOCARE system provides rapid coronary reconstruction allowing the operator accurately to estimate the length of the lesion and determine plaque distribution and volume. (c) 2008 Wiley-Liss, Inc.

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.

[Two- and three-dimensional power Doppler ultrasound in the follow-up of placenta accreta treated conservatively].

PubMed

Roulot, A; Barranger, E; Morel, O; Soyer, P; Héquet, D

2015-02-01

To determinate the potential of 2D and 3D-ultrasound in the follow-up of patients with placenta accreta treated conservatively. Seven patients with placenta accreta treated conservatively during June 2007 and September 2009 were included. The follow-up consisted in clinical examination and 2D/3D-ultrasound once a month. Criteria studied included clinical outcome, echogenicity at 2D-ultrasound, vascularisation at colour Doppler, Mean Grey at 3D-ultrasound and vascularisation, flow and perfusion index. Seven women with invasive placenta (3 placentas accreta and 2 percreta) were studied. The mean follow-up was 228 days [75-369]. Mean delay for complete elimination of residual placenta was 280 days [120-365]. The two main results were: presence of an increased anechogenicpart in residual placenta before complete resorption for all patients; a systematic and concomitant stop of genital haemorrhage and vascularisation at colour Doppler. High degrees of variability in parameters measured at 3D-ultrasound were observed between patients so that correlations with clinical outcome were found. Long and regular follow-up is essential after conservative management but the role of 3D-ultrasound compared to 2D-ultrasound was not demonstrated in this study. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

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...

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).

Oxygen consumption estimation with combined color doppler ultrasound and photoacoustic microscopy: a phantom study

NASA Astrophysics Data System (ADS)

Jiang, Yan; Harrison, Tyler; Forbrich, Alex; Zemp, Roger J.

2011-03-01

The metabolic rate of oxygen consumption (MRO2) quantifies tissue metabolism, which is important for diagnosis of many diseases. For a single vessel model, the MRO2 can be estimated in terms of the mean flow velocity, vessel crosssectional area, total concentration of hemoglobin (CHB), and the difference between the oxygen saturation (sO2) of blood flowing into and out of the tissue region. In this work, we would like to show the feasibility to estimate MRO2 with our combined photoacoustic and high-frequency ultrasound imaging system. This system uses a swept-scan 25-MHz ultrasound transducer with confocal dark-field laser illumination optics. A pulse-sequencer enables ultrasonic and laser pulses to be interlaced so that photoacoustic and Doppler ultrasound images are co-registered. Since the mean flow velocity can be measured by color Doppler ultrasound, the vessel cross-sectional area can be measured by power Doppler or photoacoustic imaging, and multi-wavelength photoacoustic methods can be used to estimate sO2 and CHB, all of these parameters necessary for MRO2 estimation can be provided by our system. Experiments have been performed on flow phantoms to generate co-registered color Doppler and photoacoustic images. To verify the sO2 estimation, two ink samples (red and blue) were mixed in various concentration ratios to mimic different levels of sO2, and the result shows a good match between the calculated concentration ratios and actual values.

Co-registration of ultrasound and frequency-domain photoacoustic radar images and image improvement for tumor detection

NASA Astrophysics Data System (ADS)

Dovlo, Edem; Lashkari, Bahman; Choi, Sung soo Sean; Mandelis, Andreas

2015-03-01

This paper demonstrates the co-registration of ultrasound (US) and frequency domain photoacoustic radar (FD-PAR) images with significant image improvement from applying image normalization, filtering and amplification techniques. Achieving PA imaging functionality on a commercial Ultrasound instrument could accelerate clinical acceptance and use. Experimental results presented demonstrate live animal testing and show enhancements in signal-to-noise ratio (SNR), contrast and spatial resolution. The co-registered image produced from the US and phase PA images, provides more information than both images independently.

Assessment by three-dimensional power Doppler ultrasound of cerebral blood flow perfusion in fetuses with congenital heart disease.

PubMed

Zeng, S; Zhou, J; Peng, Q; Tian, L; Xu, G; Zhao, Y; Wang, T; Zhou, Q

2015-06-01

To use three-dimensional (3D) power Doppler ultrasound to investigate cerebral blood flow perfusion in fetuses with congenital heart disease (CHD). The vascularization index (VI), flow index (FI) and vascularization flow index (VFI) in the total intracranial volume and the main arterial territories (middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA)) were evaluated prospectively and compared in 112 fetuses with CHD and 112 normal fetuses using 3D power Doppler. Correlations between the 3D power Doppler indices and neurodevelopment scores at 12 months of age were assessed in a subset of the CHD group, and values were compared with those of controls. Compared with the controls, the VI, FI and VFI of the total intracranial volume and the three main arteries were significantly higher in fetuses with hypoplastic left heart syndrome and left-sided obstructive lesions (P < 0.001), and the 3D power Doppler values in the ACA territory were significantly higher in fetuses with transposition of the great arteries (P < 0.01). The largest proportional increase in the blood flow perfusion indices in the fetuses with CHD relative to controls was observed in the ACA territory (P < 0.05). Among 41 cases with CHD that underwent testing, the mean Psychomotor Development Index (PDI) and Mental Development Index (MDI) scores were significantly lower than in 94 of the controls that were tested (P < 0.001). Among these CHD cases, total intracranial FI was positively correlated with PDI (r = 0.342, P = 0.029) and MDI (r = 0.339, P = 0.030), and ACA-VI and ACA-VFI were positively correlated with PDI (r = 0.377 and 0.389, P = 0.015 and 0.012, respectively) but were not correlated with MDI (r = 0.243 and 0.203, P = 0.126 and 0.204, respectively). Cerebral blood flow perfusion was increased relative to controls in most fetuses with CHD and was associated with neurodevelopment scores at 12 months

Photoacoustic-guided ultrasound therapy with a dual-mode ultrasound array

NASA Astrophysics Data System (ADS)

Prost, Amaury; Funke, Arik; Tanter, Mickaël; Aubry, Jean-François; Bossy, Emmanuel

2012-06-01

Photoacoustics has recently been proposed as a potential method to guide and/or monitor therapy based on high-intensity focused ultrasound (HIFU). We experimentally demonstrate the creation of a HIFU lesion at the location of an optical absorber, by use of photoacoustic signals emitted by the absorber detected on a dual mode transducer array. To do so, a dedicated ultrasound array intended to both detect photoacoustic waves and emit HIFU with the same elements was used. Such a dual-mode array provides automatically coregistered reference frames for photoacoustic detection and HIFU emission, a highly desired feature for methods involving guidance or monitoring of HIFU by use of photoacoustics. The prototype is first characterized in terms of both photoacoustic and HIFU performances. The probe is then used to perform an idealized scenario of photoacoustic-guided therapy, where photoacoustic signals generated by an absorbing thread embedded in a piece of chicken breast are used to automatically refocus a HIFU beam with a time-reversal mirror and necrose the tissue at the location of the absorber.

Analysis of carotid lumen surface morphology using three-dimensional ultrasound imaging

NASA Astrophysics Data System (ADS)

Chiu, Bernard; Beletsky, Vadim; Spence, J. David; Parraga, Grace; Fenster, Aaron

2009-03-01

Carotid plaque surface irregularity and ulcerations play an important role in the risk of ischemic stroke. Ulcerated or fissured plaque, characterized by irregular surface morphology, exposes thrombogenic materials to the bloodstream, possibly leading to life- or brain-threatening thrombosis and embolization. Therefore, the quantification of plaque surface irregularity is important to identify high-risk plaques that would likely lead to vascular events. Although a number of studies have characterized plaque surface irregularity using subjective classification schemes with two or more categories, only a few have quantified surface irregularity using an objective and continuous quantity, such as Gaussian or mean curvature. In this work, our goal was to use both Gaussian and mean curvatures for identifying ulcers from 3D carotid ultrasound (US) images of human subjects. Before performing experiments using patient data, we verified the numerical accuracy of the surface curvature computation method using discrete spheres and tori with different sampling intervals. We also showed that three ulcers of the vascular phantom with 2 mm, 3 mm and 4 mm diameters were associated with high Gaussian and mean curvatures, and thus, were easily detected. Finally, we demonstrated the application of the proposed method for detecting ulcers on luminal surfaces, which were segmented from the 3D US images acquired for two human subjects.

Non-Contact Optical Ultrasound Concept for Biomedical Imaging

DTIC Science & Technology

2016-11-03

Non -Contact Optical Ultrasound Concept for Biomedical Imaging Robert Haupt1, Charles Wynn1, Jonathan Fincke2, Shawn Zhang2, Brian Anthony2...results. Lastly, we present imaging capabilities using a non -contact laser ultrasound proof-of-concept system. Two and three dimensional time... non -contact, standoff optical ultrasound has the potential to provide a fixed reference measurement capability that minimizes operator variability as

Efficient Segmentation of a Breast in B-Mode Ultrasound Tomography Using Three-Dimensional GrabCut (GC3D)

PubMed Central

Wu, Shibin; Zhuang, Ling; Wei, Xinhua; Sak, Mark; Neb, Duric; Hu, Jiani; Xie, Yaoqin

2017-01-01

As an emerging modality for whole breast imaging, ultrasound tomography (UST), has been adopted for diagnostic purposes. Efficient segmentation of an entire breast in UST images plays an important role in quantitative tissue analysis and cancer diagnosis, while major existing methods suffer from considerable time consumption and intensive user interaction. This paper explores three-dimensional GrabCut (GC3D) for breast isolation in thirty reflection (B-mode) UST volumetric images. The algorithm can be conveniently initialized by localizing points to form a polygon, which covers the potential breast region. Moreover, two other variations of GrabCut and an active contour method were compared. Algorithm performance was evaluated from volume overlap ratios (TO, target overlap; MO, mean overlap; FP, false positive; FN, false negative) and time consumption. Experimental results indicate that GC3D considerably reduced the work load and achieved good performance (TO = 0.84; MO = 0.91; FP = 0.006; FN = 0.16) within an average of 1.2 min per volume. Furthermore, GC3D is not only user friendly, but also robust to various inputs, suggesting its great potential to facilitate clinical applications during whole-breast UST imaging. In the near future, the implemented GC3D can be easily automated to tackle B-mode UST volumetric images acquired from the updated imaging system. PMID:28786946

Real-time Interpolation for True 3-Dimensional Ultrasound Image Volumes

PubMed Central

Ji, Songbai; Roberts, David W.; Hartov, Alex; Paulsen, Keith D.

2013-01-01

We compared trilinear interpolation to voxel nearest neighbor and distance-weighted algorithms for fast and accurate processing of true 3-dimensional ultrasound (3DUS) image volumes. In this study, the computational efficiency and interpolation accuracy of the 3 methods were compared on the basis of a simulated 3DUS image volume, 34 clinical 3DUS image volumes from 5 patients, and 2 experimental phantom image volumes. We show that trilinear interpolation improves interpolation accuracy over both the voxel nearest neighbor and distance-weighted algorithms yet achieves real-time computational performance that is comparable to the voxel nearest neighbor algrorithm (1–2 orders of magnitude faster than the distance-weighted algorithm) as well as the fastest pixel-based algorithms for processing tracked 2-dimensional ultrasound images (0.035 seconds per 2-dimesional cross-sectional image [76,800 pixels interpolated, or 0.46 ms/1000 pixels] and 1.05 seconds per full volume with a 1-mm3 voxel size [4.6 million voxels interpolated, or 0.23 ms/1000 voxels]). On the basis of these results, trilinear interpolation is recommended as a fast and accurate interpolation method for rectilinear sampling of 3DUS image acquisitions, which is required to facilitate subsequent processing and display during operating room procedures such as image-guided neurosurgery. PMID:21266563

Real-time interpolation for true 3-dimensional ultrasound image volumes.

PubMed

Ji, Songbai; Roberts, David W; Hartov, Alex; Paulsen, Keith D

2011-02-01

We compared trilinear interpolation to voxel nearest neighbor and distance-weighted algorithms for fast and accurate processing of true 3-dimensional ultrasound (3DUS) image volumes. In this study, the computational efficiency and interpolation accuracy of the 3 methods were compared on the basis of a simulated 3DUS image volume, 34 clinical 3DUS image volumes from 5 patients, and 2 experimental phantom image volumes. We show that trilinear interpolation improves interpolation accuracy over both the voxel nearest neighbor and distance-weighted algorithms yet achieves real-time computational performance that is comparable to the voxel nearest neighbor algrorithm (1-2 orders of magnitude faster than the distance-weighted algorithm) as well as the fastest pixel-based algorithms for processing tracked 2-dimensional ultrasound images (0.035 seconds per 2-dimesional cross-sectional image [76,800 pixels interpolated, or 0.46 ms/1000 pixels] and 1.05 seconds per full volume with a 1-mm(3) voxel size [4.6 million voxels interpolated, or 0.23 ms/1000 voxels]). On the basis of these results, trilinear interpolation is recommended as a fast and accurate interpolation method for rectilinear sampling of 3DUS image acquisitions, which is required to facilitate subsequent processing and display during operating room procedures such as image-guided neurosurgery.

Five-dimensional ultrasound system for soft tissue visualization.

PubMed

Deshmukh, Nishikant P; Caban, Jesus J; Taylor, Russell H; Hager, Gregory D; Boctor, Emad M

2015-12-01

A five-dimensional ultrasound (US) system is proposed as a real-time pipeline involving fusion of 3D B-mode data with the 3D ultrasound elastography (USE) data as well as visualization of these fused data and a real-time update capability over time for each consecutive scan. 3D B-mode data assist in visualizing the anatomy of the target organ, and 3D elastography data adds strain information. We investigate the feasibility of such a system and show that an end-to-end real-time system, from acquisition to visualization, can be developed. We present a system that consists of (a) a real-time 3D elastography algorithm based on a normalized cross-correlation (NCC) computation on a GPU; (b) real-time 3D B-mode acquisition and network transfer; (c) scan conversion of 3D elastography and B-mode volumes (if acquired by 4D wobbler probe); and (d) visualization software that fuses, visualizes, and updates 3D B-mode and 3D elastography data in real time. We achieved a speed improvement of 4.45-fold for the threaded version of the NCC-based 3D USE versus the non-threaded version. The maximum speed was 79 volumes/s for 3D scan conversion. In a phantom, we validated the dimensions of a 2.2-cm-diameter sphere scan-converted to B-mode volume. Also, we validated the 5D US system visualization transfer function and detected 1- and 2-cm spherical objects (phantom lesion). Finally, we applied the system to a phantom consisting of three lesions to delineate the lesions from the surrounding background regions of the phantom. A 5D US system is achievable with real-time performance. We can distinguish between hard and soft areas in a phantom using the transfer functions.

Modeling Three-Dimensional Flow in Confined Aquifers by Superposition of Both Two- and Three-Dimensional Analytic Functions

NASA Astrophysics Data System (ADS)

Haitjema, Henk M.

1985-10-01

A technique is presented to incorporate three-dimensional flow in a Dupuit-Forchheimer model. The method is based on superposition of approximate analytic solutions to both two- and three-dimensional flow features in a confined aquifer of infinite extent. Three-dimensional solutions are used in the domain of interest, while farfield conditions are represented by two-dimensional solutions. Approximate three- dimensional solutions have been derived for a partially penetrating well and a shallow creek. Each of these solutions satisfies the condition that no flow occurs across the confining layers of the aquifer. Because of this condition, the flow at some distance of a three-dimensional feature becomes nearly horizontal. Consequently, remotely from a three-dimensional feature, its three-dimensional solution is replaced by a corresponding two-dimensional one. The latter solution is trivial as compared to its three-dimensional counterpart, and its use greatly enhances the computational efficiency of the model. As an example, the flow is modeled between a partially penetrating well and a shallow creek that occur in a regional aquifer system.

Biomechanics of the rat vagina during pregnancy and postpartum: a 3-dimensional ultrasound approach.

PubMed

Feola, Andrew; Endo, Masayuki; Deprest, Jan

2014-07-01

The vagina and surrounding structures have been shown to remodel during pregnancy. Our objective was to characterize the biomechanical properties of the vagina in the rodent model in vivo utilizing three-dimensional (3D) ultrasound. The vagina was visualized by ultrasound after distention by increasing pressures throughout pregnancy (15 and 18 days) and after vaginal delivery (7 and 30 days postpartum) of six longitudinally followed rodents. The pelvic floor compliance and vaginal cross-sectional area of the proximal, middle, and distal vagina were compared with those of nulliparous control animals (n = 8). The compliance of the pelvic floor increased 3.5- and 5.4-fold at days 15 and 18 of pregnancy respectively (p < 0.05). The compliance of the pelvic floor decreased 7 days postpartum, and it continued to decrease after vaginal delivery through the 30 day time point. Using 3D ultrasound, we could characterize the remodeling of the vagina throughout pregnancy and after vaginal delivery. We could reconstruct the vaginal wall cross-sectional area and found the distal vaginal wall throughout pregnancy to be distended more than the proximal and middle regions. The observed changes in vaginal area may improve our understanding of which areas are at risk of injury during delivery. Further, 3D ultrasound allowed the determination of the in vivo biomechanical properties of the vagina. This image modality is beneficial for characterizing the in vivo properties of the vagina and surrounding pelvic support longitudinally within an animal.

An ultrasound-guided fluorescence tomography system: design and specification

NASA Astrophysics Data System (ADS)

D'Souza, Alisha V.; Flynn, Brendan P.; Kanick, Stephen C.; Torosean, Sason; Davis, Scott C.; Maytin, Edward V.; Hasan, Tayyaba; Pogue, Brian W.

2013-03-01

An ultrasound-guided fluorescence molecular tomography system is under development for in vivo quantification of Protoporphyrin IX (PpIX) during Aminolevulinic Acid - Photodynamic Therapy (ALA-PDT) of Basal Cell Carcinoma. The system is designed to combine fiber-based spectral sampling of PPIX fluorescence emission with co-registered ultrasound images to quantify local fluorophore concentration. A single white light source is used to provide an estimate of the bulk optical properties of tissue. Optical data is obtained by sequential illumination of a 633nm laser source at 4 linear locations with parallel detection at 5 locations interspersed between the sources. Tissue regions from segmented ultrasound images, optical boundary data, white light-informed optical properties and diffusion theory are used to estimate the fluorophore concentration in these regions. Our system and methods allow interrogation of both superficial and deep tissue locations up to PpIX concentrations of 0.025ug/ml.

Assessment of regional lung functional impairment with co-registered respiratory-gated ventilation/perfusion SPET-CT images: initial experiences.

PubMed

Suga, Kazuyoshi; Yasuhiko, Kawakami; Zaki, Mohammed; Yamashita, Tomio; Seto, Aska; Matsumoto, Tsuneo; Matsunaga, Naofumi

2004-02-01

In this study, respiratory-gated ventilation and perfusion single-photon emission tomography (SPET) were used to define regional functional impairment and to obtain reliable co-registration with computed tomography (CT) images in various lung diseases. Using a triple-headed SPET unit and a physiological synchroniser, gated perfusion SPET was performed in a total of 78 patients with different pulmonary diseases, including metastatic nodules (n = 15); in 34 of these patients, it was performed in combination with gated technetium-99m Technegas SPET. Projection data were acquired using 60 stops over 120 degrees for each detector. Gated end-inspiration and ungated images were reconstructed from 1/8 data centered at peak inspiration for each regular respiratory cycle and full respiratory cycle data, respectively. Gated images were registered with tidal inspiration CT images using automated three-dimensional (3D) registration software. Registration mismatch was assessed by measuring 3D distance of the centroid of the nine selected round perfusion-defective nodules. Gated SPET images were completed within 29 min, and increased the number of visible ventilation and perfusion defects by 9.7% and 17.2%, respectively, as compared with ungated images; furthermore, lesion-to-normal lung contrast was significantly higher on gated SPET images. In the nine round perfusion-defective nodules, gated images yielded a significantly better SPET-CT match compared with ungated images (4.9 +/- 3.1 mm vs 19.0 +/- 9.1 mm, P<0.001). The co-registered SPET-CT images allowed accurate perception of the location and extent of each ventilation/perfusion defect on the underlying CT anatomy, and characterised the pathophysiology of the various diseases. By reducing respiratory motion effects and enhancing perfusion/ventilation defect clarity, gated SPET can provide reliable co-registered images with CT images to accurately characterise regional functional impairment in various lung diseases.

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.

Two-Dimensional Versus Three-Dimensional Conceptualization in Astronomy Education

NASA Astrophysics Data System (ADS)

Reynolds, Michael David

Numerous science conceptual issues are naturally three-dimensional. Classroom presentations are often two -dimensional or at best multidimensional. Several astronomy topics are of this nature, e. g. mechanics of the phases of the moon. Textbooks present this three-dimensional topic in two-dimensions; such is often the case in the classroom. This study was conducted to examine conceptions exhibited by pairs of like-sex 11th grade standard physics students as they modeled the lunar phases. Student pairs, 13 male and 13 female, were randomly selected and assigned. Pairing comes closer to classroom emulation, minimizes needs for direct probes, and pair discussion is more likely to display variety and depth. Four hypotheses were addressed: (1) Participants who model three-dimensionally will more likely achieve a higher explanation score. (2) Students who experienced more earth or physical science exposure will more likely model three-dimensionally. (3) Pairs that exhibit a strong science or mathematics preference will more likely model three-dimensionally. (4) Males will model in three dimensions more than females. Students provided background information, including science course exposure and subject preference. Each pair laid out a 16-card set representing two complete lunar phase changes. The pair was asked to explain why the phases occur. Materials were provided for use, including disks, spheres, paper and pen, and flashlight. Activities were videotaped for later evaluation. Statistics of choice was a correlation determination between course preference and model type and ANOVA for the other hypotheses. It was determined that pairs who modeled three -dimensionally achieved a higher score on their phases mechanics explanation at p <.05 level. Pairs with earth science or physical science exposure, those who prefer science or mathematics, and male participants were not more likely to model three-dimensionally. Possible reasons for lack of significance was small sample

Composite ultrasound imaging apparatus and method

DOEpatents

Morimoto, Alan K.; Bow, Jr., Wallace J.; Strong, David Scott; Dickey, Fred M.

1998-01-01

An imaging apparatus and method for use in presenting composite two dimensional and three dimensional images from individual ultrasonic frames. A cross-sectional reconstruction is applied by using digital ultrasound frames, transducer orientation and a known center. Motion compensation, rank value filtering, noise suppression and tissue classification are utilized to optimize the composite image.

Composite ultrasound imaging apparatus and method

DOEpatents

Morimoto, A.K.; Bow, W.J. Jr.; Strong, D.S.; Dickey, F.M.

1998-09-15

An imaging apparatus and method for use in presenting composite two dimensional and three dimensional images from individual ultrasonic frames. A cross-sectional reconstruction is applied by using digital ultrasound frames, transducer orientation and a known center. Motion compensation, rank value filtering, noise suppression and tissue classification are utilized to optimize the composite image. 37 figs.

The use of computed tomographic three-dimensional reconstructions to develop instructional models for equine pelvic ultrasonography.

PubMed

Whitcomb, Mary Beth; Doval, John; Peters, Jason

2011-01-01

Ultrasonography has gained increased utility to diagnose pelvic fractures in horses; however, internal pelvic contours can be difficult to appreciate from external palpable landmarks. We developed three-dimensional (3D) simulations of the pelvic ultrasonographic examination to assist with translation of pelvic contours into two-dimensional (2D) images. Contiguous 1mm transverse computed tomography (CT) images were acquired through an equine femur and hemipelvis using a single slice helical scanner. 3D surface models were created using a DICOM reader and imported into a 3D modeling and animation program. The bone models were combined with a purchased 3D horse model and the skin made translucent to visualize pelvic surface contours. 3D models of ultrasound transducers were made from reference photos, and a thin sector shape was created to depict the ultrasound beam. Ultrasonographic examinations were simulated by moving transducers on the skin surface and rectally to produce images of pelvic structures. Camera angles were manipulated to best illustrate the transducer-beam-bone interface. Fractures were created in multiple configurations. Animations were exported as QuickTime movie files for use in presentations coupled with corresponding ultrasound videoclips. 3D models provide a link between ultrasonographic technique and image generation by depicting the interaction of the transducer, ultrasound beam, and structure of interest. The horse model was important to facilitate understanding of the location of pelvic structures relative to the skin surface. While CT acquisition time was brief, manipulation within the 3D software program was time intensive. Results were worthwhile from an instructional standpoint based on user feedback. © 2011 Veterinary Radiology & Ultrasound.

Three-dimensional multiexcitation magnetoacoustic tomography with magnetic induction

PubMed Central

Li, Xu; Mariappan, Leo; He, Bin

2010-01-01

Magnetoacoustic tomography with magnetic induction (MAT-MI) is a hybrid imaging modality proposed to image electrical conductivity contrast of biological tissue with high spatial resolution. This modality combines magnetic excitations with ultrasound detection through the Lorentz force based coupling mechanism. However, previous studies have shown that MAT-MI method with single type of magnetic excitation can only reconstruct the conductivity boundaries of a sample. In order to achieve more complete conductivity contrast reconstruction, we proposed a multiexcitation MAT-MI approach. In this approach, multiple magnetic excitations using different coil configurations are applied to the object sequentially and ultrasonic signals corresponding to each excitation are collected for conductivity image reconstruction. In this study, we validate the new multiexcitation MAT-MI method for three-dimensional (3D) conductivity imaging through both computer simulations and phantom experiments. 3D volume data are obtained by utilizing acoustic focusing and cylindrical scanning under each magnetic excitation. It is shown in our simulation and experiment results that with a common ultrasound probe that has limited bandwidth we are able to correctly reconstruct the 3D relative conductivity contrast of the imaging object. As compared to those conductivity boundary images generated by previous single-excitation MAT-MI, the new multiexcitation MAT-MI method provides more complete conductivity contrast reconstruction, and therefore, more valuable information in possible clinical and research applications. PMID:21267084

Transition between quasi-two-dimensional and three-dimensional Rayleigh-Bénard convection in a horizontal magnetic field

NASA Astrophysics Data System (ADS)

Vogt, Tobias; Ishimi, Wataru; Yanagisawa, Takatoshi; Tasaka, Yuji; Sakuraba, Ataru; Eckert, Sven

2018-01-01

Magnetohydrodynamic Rayleigh-Bénard convection was studied experimentally and numerically using a liquid metal inside a box with a square horizontal cross section and an aspect ratio of 5. Applying a sufficiently strong horizontal magnetic field converts the convective motion into a flow pattern of quasi-two-dimensional (quasi-2D) rolls arranged parallel to the magnetic field. The aim of this paper is to provide a detailed description of the flow field, which is often considered as quasi-2D. In this paper, we focus on the transition from a quasi-two-dimensional state toward a three-dimensional flow occurring with decreasing magnetic-field strength. We present systematic flow measurements that were performed by means of ultrasound Doppler velocimetry. The measured data provide insight into the dynamics of the primary convection rolls, the secondary flow induced by Ekman pumping, and they reveal the existence of small vortices that develop around the convection rolls. New flow regimes have been identified by the velocity measurements, which show a pronounced manifestation of three-dimensional flow structures as the ratio Ra /Q increases. The interaction between the primary swirling motion of the convection rolls and the secondary flow becomes increasingly strong. Significant bulging of the convection rolls causes a breakdown of the original recirculation loop driven by Ekman pumping into several smaller cells. The flow measurements are completed by direct numerical simulations. The numerical simulations have proven to be able to qualitatively reproduce the newly discovered flow regimes in the experiment.

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.

Measuring the volume of uterine fibroids using 2- and 3-dimensional ultrasound and comparison with histopathology.

PubMed

Zivković, Nikica; Zivković, Kreiimir; Despot, Albert; Paić, Josip; Zelić, Ana

2012-12-01

The aim of this study was clinical testing of the reliability and usability of three-dimensional (3D) and two-dimensional (2D) ultrasound (US) technology. The ultimate aim and purpose of this study was to establish ultrasound methods, standards and protocols for determining the volume of any gynecologic organ or tumor. The study included 31 women in reproductive age and postmenopause. All patients were examined with a RIC 5-9 3D-endovaginal probe (4.3-7.5 MHz) on a Voluson 730 Pro ultrasound device. The volume of myomas was measured by using the existing 2D and 3D ultrasound methods on the above mentioned device. All patients underwent myomectomy or hysterectomy due to clinically and ultrasonographically diagnosed uterine myomas indicating operative intervention. After the operation, the pathologist determined the volume of removed myomas by measuring them in a gauge bowl containing water, i.e. using Archimedes' principle (lift), serving as the control group with histopathologic diagnosis. A total of 155 myoma volumes were processed on 2D display, 31 myoma volumes were preoperatively measured on 3D display and 31 myoma volumes were measured by the pathologist. The values of US measurements for each US method were expressed as mean value of all measurements of myoma volumes. Statistical processing of the results and Student's t-test for independent samples revealed that the 2nd examined US method (measuring of myoma by using an ellipse and the longer tumor diameter) and 4th examined US method (measuring of myoma by using the longer and shorter tumor diameters together with establishing their mean values) in 2D US technique, as well as the 6th examined US method in 3D US technique showed no significant measurement differences in comparison with control measurement in a gauge bowl containing water (p < 0.05), indicating acceptability of the US methods for verifying tumor volumes. The standard error in determining the volume of myomas by the above US methods varied

Placental three-dimensional power Doppler indices in mid-pregnancy and late pregnancy complicated by gestational diabetes mellitus.

PubMed

Surányi, A; Kozinszky, Z; Molnár, A; Nyári, T; Bitó, T; Pál, A

2013-10-01

The aim of our study was to evaluate placental three-dimensional power Doppler indices in diabetic pregnancies in the second and third trimesters and to compare them with those of the normal controls. Placental vascularization of pregnant women was determined by three-dimensional power Doppler ultrasound technique. The calculated indices included vascularization index (VI), flow index (FI), and vascularization flow index (VFI). Uncomplicated pregnancies (n = 113) were compared with pregnancies complicated by gestational diabetes mellitus (n = 56) and diabetes mellitus (n = 43). The three-dimensional power Doppler indices were not significantly different between the two diabetic subgroups. All the indices in diabetic patients were significantly reduced compared with those in non-diabetic individuals (p < 0.001). Placental three-dimensional power Doppler indices are slightly diminished throughout diabetic pregnancy [regression coefficients: -0.23 (FI), -0.06 (VI), and -0.04 (VFI)] and normal pregnancy [regression coefficients: -0.13 (FI), -0.20 (VI), and -0.11 (VFI)]. The uteroplacental circulation (umbilical and uterine artery) was not correlated significantly to the three-dimensional power Doppler indices. If all placental indices are low during late pregnancy, then the odds of the diabetes are significantly high (adjusted odds ratio: 1.10). A decreased placental vascularization could be an adjunct sonographic marker in the diagnosis of diabetic pregnancy in mid-gestation and late gestation. © 2013 John Wiley & Sons, Ltd.

Medical ultrasound - From inner space to outer space

NASA Technical Reports Server (NTRS)

Rooney, J. A.

1984-01-01

During the last decade, medical ultrasound has rapidly become a widely accepted imaging modality used in many medical specialties. It has the advantages that it is noninvasive, does not use ionizing radiation, is relatively inexpensive and is easy to use. Future trends in ultrasound include expanded areas of use, advanced signal processing and digital image analysis including tissue characterization and three-dimensional reconstructions.

Three-dimensional representation of curved nanowires.

PubMed

Huang, Z; Dikin, D A; Ding, W; Qiao, Y; Chen, X; Fridman, Y; Ruoff, R S

2004-12-01

Nanostructures, such as nanowires, nanotubes and nanocoils, can be described in many cases as quasi one-dimensional curved objects projecting in three-dimensional space. A parallax method to construct the correct three-dimensional geometry of such one-dimensional nanostructures is presented. A series of scanning electron microscope images was acquired at different view angles, thus providing a set of image pairs that were used to generate three-dimensional representations using a matlab program. An error analysis as a function of the view angle between the two images is presented and discussed. As an example application, the importance of knowing the true three-dimensional shape of boron nanowires is demonstrated; without the nanowire's correct length and diameter, mechanical resonance data cannot provide an accurate estimate of Young's modulus.

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.

Three-dimensional microbubble streaming flows

NASA Astrophysics Data System (ADS)

Rallabandi, Bhargav; Marin, Alvaro; Rossi, Massimiliano; Kaehler, Christian; Hilgenfeldt, Sascha

2014-11-01

Streaming due to acoustically excited bubbles has been used successfully for applications such as size-sorting, trapping and focusing of particles, as well as fluid mixing. Many of these applications involve the precise control of particle trajectories, typically achieved using cylindrical bubbles, which establish planar flows. Using astigmatic particle tracking velocimetry (APTV), we show that, while this two-dimensional picture is a useful description of the flow over short times, a systematic three-dimensional flow structure is evident over long time scales. We demonstrate that this long-time three-dimensional fluid motion can be understood through asymptotic theory, superimposing secondary axial flows (induced by boundary conditions at the device walls) onto the two-dimensional description. This leads to a general framework that describes three-dimensional flows in confined microstreaming systems, guiding the design of applications that profit from minimizing or maximizing these effects.

Two-Dimensional Chirality in Three-Dimensional Chemistry.

ERIC Educational Resources Information Center

Wintner, Claude E.

1983-01-01

The concept of two-dimensional chirality is used to enhance students' understanding of three-dimensional stereochemistry. This chirality is used as a key to teaching/understanding such concepts as enaniotropism, diastereotopism, pseudoasymmetry, retention/inversion of configuration, and stereochemical results of addition to double bonds. (JN)

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.

Three-dimensional adult echocardiography: where the hidden dimension helps.

PubMed

Mor-Avi, Victor; Sugeng, Lissa; Lang, Roberto M

2008-05-01

The introduction of three-dimensional (3D) imaging and its evolution from slow and labor-intense off-line reconstruction to real-time volumetric imaging is one of the most significant developments in ultrasound imaging of the heart of the past decade. This imaging modality currently provides valuable clinical information that empowers echocardiography with new levels of confidence in diagnosing heart disease. One major advantage of seeing the additional dimension is the improvement in the accuracy of the evaluation of cardiac chamber volumes by eliminating geometric modeling and the errors caused by foreshortened views. Another benefit of 3D imaging is the realistic views of cardiac valves capable of demonstrating numerous pathologies in a unique, noninvasive manner. This article reviews the major technological developments in 3D echocardiography and some of the recent literature that has provided the scientific basis for its clinical use.

Satisfactory rate of post-processing visualization of fetal cerebral axial, sagittal, and coronal planes from three-dimensional volumes acquired in routine second trimester ultrasound practice by sonographers of peripheral centers.

PubMed

Rizzo, Giuseppe; Pietrolucci, Maria Elena; Capece, Giuseppe; Cimmino, Ernesto; Colosi, Enrico; Ferrentino, Salvatore; Sica, Carmine; Di Meglio, Aniello; Arduini, Domenico

2011-08-01

The aim of this study was to evaluate the feasibility to visualize central nervous system (CNS) diagnostic planes from three-dimensional (3D) brain volumes obtained in ultrasound facilities with no specific experience in fetal neurosonography. Five sonographers prospectively recorded transabdominal 3D CNS volumes starting from an axial approach on 500 consecutive pregnancies at 19-24 weeks of gestation undergoing routine ultrasound examination. Volumes were sent to the referral center (Department of Obstetrics and Gynecology, Università Roma Tor Vergata, Italy) and two independent reviewers with experience in 3D ultrasound assessed their quality in the display of axial, coronal, and sagittal planes. CNS volumes were acquired in 491/500 pregnancies (98.2%). The two reviewers acknowledged the presence of satisfactory images with a visualization rate ranging respectively between 95.1% and 97.14% for axial planes, 73.72% and 87.16% for coronal planes, and 78.41% and 94.29% for sagittal planes. The agreement rate between the two reviewers as expressed by Cohen's kappa coefficient was >0.87 for axial planes, >0.89 for coronal planes, and >0.94 for sagittal planes. The presence of a maternal body mass index >30 alters the probability of achieving satisfactory CNS views, while existence of previous maternal lower abdomen surgery does not affect the quality of the reconstructed planes. CNS volumes acquired by 3D ultrasonography in peripheral centers showed a quality high enough to allow a detailed fetal neurosonogram.

Three-dimensional patterning methods and related devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Putnam, Morgan C.; Kelzenberg, Michael D.; Atwater, Harry A.

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.

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.

Computer-Generated, Three-Dimensional Character Animation.

ERIC Educational Resources Information Center

Van Baerle, Susan Lynn

This master's thesis begins by discussing the differences between 3-D computer animation of solid three-dimensional, or monolithic, objects, and the animation of characters, i.e., collections of movable parts with soft pliable surfaces. Principles from two-dimensional character animation that can be transferred to three-dimensional character…

Computer-generated 3D ultrasound images of the carotid artery

NASA Technical Reports Server (NTRS)

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

1989-01-01

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

Computer-generated 3D ultrasound images of the carotid artery

NASA Astrophysics Data System (ADS)

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

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

A novel ultrasound-guided shoulder arthroscopic surgery

NASA Astrophysics Data System (ADS)

Tyryshkin, K.; Mousavi, P.; Beek, M.; Chen, T.; Pichora, D.; Abolmaesumi, P.

2006-03-01

This paper presents a novel ultrasound-guided computer system for arthroscopic surgery of the shoulder joint. Intraoperatively, the system tracks and displays the surgical instruments, such as arthroscope and arthroscopic burrs, relative to the anatomy of the patient. The purpose of this system is to improve the surgeon's perception of the three-dimensional space within the anatomy of the patient in which the instruments are manipulated and to provide guidance towards the targeted anatomy. Pre-operatively, computed tomography images of the patient are acquired to construct virtual threedimensional surface models of the shoulder bone structure. Intra-operatively, live ultrasound images of pre-selected regions of the shoulder are captured using an ultrasound probe whose three-dimensional position is tracked by an optical camera. These images are used to register the surface model to the anatomy of the patient in the operating room. An initial alignment is obtained by matching at least three points manually selected on the model to their corresponding points identified on the ultrasound images. The registration is then improved with an iterative closest point or a sequential least squares estimation technique. In the present study the registration results of these techniques are compared. After the registration, surgical instruments are displayed relative to the surface model of the patient on a graphical screen visible to the surgeon. Results of laboratory experiments on a shoulder phantom indicate acceptable registration results and sufficiently fast overall system performance to be applicable in the operating room.

Three-Dimensional Ultrasound-Guided Real-Time Midline Epidural Needle Placement with Epiguide: A Prospective Feasibility Study.

PubMed

Beigi, Parmida; Malenfant, Paul; Rasoulian, Abtin; Rohling, Robert; Dube, Alison; Gunka, Vit

2017-01-01

Current 2-D ultrasound technology is unable to perform a midline neuraxial needle insertion under real-time ultrasound guidance using a standard needle and without an assistant. The aim of the work described here was to determine the feasibility of a new technology providing such capability, starting with a study evaluating the selected puncture site. A novel 3-D ultrasound imaging technique was designed using thick-slice rendering in conjunction with a custom needle guide (3DUS + Epiguide). A clinical feasibility study evaluated the ability of 3DUS + Epiguide to identify the epidural needle puncture site for a midline insertion in the lumbar spine. We hypothesized that (i) the puncture site identified by 3DUS + Epiguide was within a 5-mm radius from the site chosen by standard palpation, and (ii) the difference between the two puncture sites was not correlated to the patient characteristics age, weight, height, body mass index and gestational age. The mean (±standard deviation) distances between puncture sites determined by 3DUS + Epiguide and palpation were 3.1 (±1.7) mm and 2.8 (±1.3) mm, for the L2-3 and L3-4 interspaces of 20 patients, respectively. Distances were comparable to intra-observer variability, indicating the potential for a thick-slice rendering of 3-D ultrasound along the Epiguide trajectory to select the puncture site of a midline neuraxial needle insertion. The long-term potential benefits of this system include increased efficiency and use of anesthesia, and a reduction in the frequency and severity of the complications from incorrect needle insertions. Epidural success in the most difficult cases (e.g., the obese) will be the focus of future work. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Three-dimensional biofilm structure quantification.

PubMed

Beyenal, Haluk; Donovan, Conrad; Lewandowski, Zbigniew; Harkin, Gary

2004-12-01

Quantitative parameters describing biofilm physical structure have been extracted from three-dimensional confocal laser scanning microscopy images and used to compare biofilm structures, monitor biofilm development, and quantify environmental factors affecting biofilm structure. Researchers have previously used biovolume, volume to surface ratio, roughness coefficient, and mean and maximum thicknesses to compare biofilm structures. The selection of these parameters is dependent on the availability of software to perform calculations. We believe it is necessary to develop more comprehensive parameters to describe heterogeneous biofilm morphology in three dimensions. This research presents parameters describing three-dimensional biofilm heterogeneity, size, and morphology of biomass calculated from confocal laser scanning microscopy images. This study extends previous work which extracted quantitative parameters regarding morphological features from two-dimensional biofilm images to three-dimensional biofilm images. We describe two types of parameters: (1) textural parameters showing microscale heterogeneity of biofilms and (2) volumetric parameters describing size and morphology of biomass. The three-dimensional features presented are average (ADD) and maximum diffusion distances (MDD), fractal dimension, average run lengths (in X, Y and Z directions), aspect ratio, textural entropy, energy and homogeneity. We discuss the meaning of each parameter and present the calculations in detail. The developed algorithms, including automatic thresholding, are implemented in software as MATLAB programs which will be available at site prior to publication of the paper.

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.

A 63 element 1.75 dimensional ultrasound phased array for the treatment of benign prostatic hyperplasia

PubMed Central

Saleh, Khaldon Y; Smith, Nadine Barrie

2005-01-01

Background Prostate cancer and benign prostatic hyperplasia are very common diseases in older American men, thus having a reliable treatment modality for both diseases is of great importance. The currently used treating options, mainly surgical ones, have numerous complications, which include the many side effects that accompany such procedures, besides the invasive nature of such techniques. Focused ultrasound is a relatively new treating modality that is showing promising results in treating prostate cancer and benign prostatic hyperplasia. Thus this technique is gaining more attention in the past decade as a non-invasive method to treat both diseases. Methods In this paper, the design, construction and evaluation of a 1.75 dimensional ultrasound phased array to be used for treating prostate cancer and benign prostatic hyperplasia is presented. With this array, the position of the focus can be controlled by changing the electrical power and phase to the individual elements for electronically focusing and steering in a three dimensional volume. The array was designed with a maximum steering angle of ± 13.5° in the transverse direction and a maximum depth of penetration of 11 cm, which allows the treatment of large prostates. The transducer piezoelectric ceramic, matching layers and cable impedance have been designed for maximum power transfer to tissue. Results To verify the capability of the transducer for focusing and steering, exposimetry was performed and the results correlated well with the calculated field. Ex vivo experiments using bovine tissue were performed with various lesion sizes and indicated the capability of the transducer to ablate tissue using short sonications. Conclusion A 1.75 dimensional array, that overcame the drawbacks associated with one-dimensional arrays, has been designed, built and successfully tested. Design issues, such as cable and ceramic capacitances, were taken into account when designing this array. The final prototype

3D laser optoacoustic ultrasonic imaging system for preclinical research

NASA Astrophysics Data System (ADS)

Ermilov, Sergey A.; Conjusteau, André; Hernandez, Travis; Su, Richard; Nadvoretskiy, Vyacheslav; Tsyboulski, Dmitri; Anis, Fatima; Anastasio, Mark A.; Oraevsky, Alexander A.

2013-03-01

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 or other type of biomedical research. The system (LOUIS-3DM) combines a multi-wavelength optoacoustic and ultrawide-band laser ultrasound tomographies to obtain coregistered maps of tissue optical absorption and acoustic properties, 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 distribution of optoacoustic contrast agents (carbon nanotubes, metal plasmonic nanoparticles, etc.).

Three-dimensional boundary layers approaching separation

NASA Technical Reports Server (NTRS)

Williams, J. C., III

1976-01-01

The theory of semi-similar solutions of the laminar boundary layer equations is applied to several flows in which the boundary layer approaches a three-dimensional separation line. The solutions obtained are used to deduce the nature of three-dimensional separation. It is shown that in these cases separation is of the "ordinary" type. A solution is also presented for a case in which a vortex is embedded within the three-dimensional boundary layer.

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).

Trading spaces: building three-dimensional nets from two-dimensional tilings

PubMed Central

Castle, Toen; Evans, Myfanwy E.; Hyde, Stephen T.; Ramsden, Stuart; Robins, Vanessa

2012-01-01

We construct some examples of finite and infinite crystalline three-dimensional nets derived from symmetric reticulations of homogeneous two-dimensional spaces: elliptic (S2), Euclidean (E2) and hyperbolic (H2) space. Those reticulations are edges and vertices of simple spherical, planar and hyperbolic tilings. We show that various projections of the simplest symmetric tilings of those spaces into three-dimensional Euclidean space lead to topologically and geometrically complex patterns, including multiple interwoven nets and tangled nets that are otherwise difficult to generate ab initio in three dimensions. PMID:24098839

Validating two-dimensional leadership models on three-dimensionally structured fish schools

PubMed Central

Nagy, Máté; Holbrook, Robert I.; Biro, Dora; Burt de Perera, Theresa

2017-01-01

Identifying leader–follower interactions is crucial for understanding how a group decides where or when to move, and how this information is transferred between members. Although many animal groups have a three-dimensional structure, previous studies investigating leader–follower interactions have often ignored vertical information. This raises the question of whether commonly used two-dimensional leader–follower analyses can be used justifiably on groups that interact in three dimensions. To address this, we quantified the individual movements of banded tetra fish (Astyanax mexicanus) within shoals by computing the three-dimensional trajectories of all individuals using a stereo-camera technique. We used these data firstly to identify and compare leader–follower interactions in two and three dimensions, and secondly to analyse leadership with respect to an individual's spatial position in three dimensions. We show that for 95% of all pairwise interactions leadership identified through two-dimensional analysis matches that identified through three-dimensional analysis, and we reveal that fish attend to the same shoalmates for vertical information as they do for horizontal information. Our results therefore highlight that three-dimensional analyses are not always required to identify leader–follower relationships in species that move freely in three dimensions. We discuss our results in terms of the importance of taking species' sensory capacities into account when studying interaction networks within groups. PMID:28280582

Ultrasound Techniques for Space Applications

NASA Technical Reports Server (NTRS)

Rooney, James A.

1985-01-01

Ultrasound has proven to be a safe non-invasive technique for imaging organs and measuring cardiovascular function. It has unique advantages for application to problems with man in space including evaluation of cardiovascular function both in serial studies and during critical operations. In addition, specialized instrumentation may be capable of detecting the onset of decompression sickness during EVA activities. A spatial location and three-dimensional reconstruction system is being developed to improve the accuracy and reproducibility for serial comparative ultrasound studies of cardiovascular function. The three-dimensional method permits the acquisition of ultrasonic images from many views that can be recombined into a single reconstruction of the heart or vasculature. In addition to conventional imaging and monitoring systems, it is sometimes necessary or desirable to develop instrumentation for special purposes. One example of this type of development is the design of a pulsed-Doppler system to monitor cerebral blood flow during critical operations such as re-entry. A second example is the design of a swept-frequency ultrasound system for the detection of bubbles in the circulatory system and/or soft tissues as an early indication of the onset of decompression sickness during EVA activities. This system exploits the resonant properties of bubbles and can detect both fundamental and second harmonic emissions from the insonified region.

Utility of 3-dimensional ultrasound imaging to evaluate carotid artery stenosis: comparison with magnetic resonance angiography.

PubMed

Igase, Keiji; Kumon, Yoshiaki; Matsubara, Ichiro; Arai, Masamori; Goishi, Junji; Watanabe, Hideaki; Ohnishi, Takanori; Sadamoto, Kazuhiko

2015-01-01

We evaluated the utility of 3-dimensional (3-D) ultrasound imaging for assessment of carotid artery stenosis, as compared with similar assessment via magnetic resonance angiography (MRA). Subjects comprised 58 patients with carotid stenosis who underwent both 3-D ultrasound imaging and MRA. We studied whether abnormal findings detected by ultrasound imaging could be diagnosed using MRA. Ultrasound images were generated using Voluson 730 Expert and Voluson E8. The degree of stenosis was mild in 17, moderate in 16, and severe in 25 patients, according to ultrasound imaging. Stenosis could not be recognized using MRA in 4 of 17 patients diagnosed with mild stenosis using ultrasound imaging. Ultrasound imaging showed ulceration in 13 patients and mobile plaque in 6 patients. When assessing these patients, MRA showed ulceration in only 2 of 13 patients and did not detect mobile plaque in any of these 6 patients. Static 3-D B mode images demonstrated distributions of plaque, ulceration, and mobile plaque, and static 3-D flow images showed flow configuration as a total structure. Real-time 3-D B mode images demonstrated plaque and vessel movement. Carotid artery stenting was not selected for patients diagnosed with ulceration or mobile plaque. Ultrasound imaging was necessary to detect mild stenosis, ulcerated plaque, or mobile plaque in comparison with MRA, and 3-D ultrasound imaging was useful to recognize carotid stenosis and flow pattern as a total structure by static and real-time 3-D demonstration. This information may contribute to surgical planning. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Design and development of an ultrasound calibration phantom and system

NASA Astrophysics Data System (ADS)

Cheng, Alexis; Ackerman, Martin K.; Chirikjian, Gregory S.; Boctor, Emad M.

2014-03-01

Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the ultrasound transducer and the ultrasound image. A phantom or model with known geometry is also required. In this work, we design and test an ultrasound calibration phantom and software. The two main considerations in this work are utilizing our knowledge of ultrasound physics to design the phantom and delivering an easy to use calibration process to the user. We explore the use of a three-dimensional printer to create the phantom in its entirety without need for user assembly. We have also developed software to automatically segment the three-dimensional printed rods from the ultrasound image by leveraging knowledge about the shape and scale of the phantom. In this work, we present preliminary results from using this phantom to perform ultrasound calibration. To test the efficacy of our method, we match the projection of the points segmented from the image to the known model and calculate a sum squared difference between each point for several combinations of motion generation and filtering methods. The best performing combination of motion and filtering techniques had an error of 1.56 mm and a standard deviation of 1.02 mm.

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.

Analysing Normal and Partial Glossectomee Tongues Using Ultrasound

ERIC Educational Resources Information Center

Bressmann, Tim; Uy, Catherine; Irish, Jonathan C.

2005-01-01

The present study aimed at identifying underlying parameters that govern the shape of the tongue. A functional topography of the tongue surface was developed based on three-dimensional ultrasound scans of sustained speech sounds in ten normal subjects. A principal component analysis extracted three components that explained 89.2% of the variance…

HOCUS: The Haskins optically-corrected ultrasound system for measuring speech articulation

NASA Astrophysics Data System (ADS)

Whalen, D. H.; Iskarous, Khalil; Tiede, Mark K.; Ostry, David J.

2004-05-01

The tongue is the most important supralaryngeal articulator for speech, yet, because it is typically out of view, its movements have been difficult to quantify. Here is described a new combination of techniques involving ultrasound in conjunction with an optoelectric motion measurement system (Optotrak). Combining these, the movements of the tongue are imaged and simultaneously corrected for motion of the head and of the ultrasound transceiver. Optotrak's infrared-emitting diodes are placed on the transceiver and the speakers head in order to localize the ultrasound image of the tongue relative to the hard palate. The palate can be imaged with ultrasound by having the ultrasound signal penetrate a water bolus held against the palate by the tongue. This trace is coregistered with the head and potentially with the same talker's sagittal MR image, to provide additional information on the unimaged remainder of the tract. The tongue surface, from the larynx to near the tip, can then be localized in relationship to the hard palate. The result is a fairly complete view of the tongue within the vocal tract at sampling rates appropriate for running speech. A comparison with other imaging vocal tract systems will be presented. [Work supported by NIH Grant DC-02717.

TU-FG-BRB-09: Thermoacoustic Range Verification with Perfect Co-Registered Overlay of Bragg Peak onto Ultrasound Image

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patch, S; Kireeff Covo, M; Jackson, A

Purpose: The potential of particle therapy 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 thermoacoustic localization of the Bragg peak onto an ultrasound image. Methods: Pulsed delivery of 50 MeV protons was accomplished by a fast chopper installed between the ion source and the inflector of the 88″ cyclotron at Lawrence Berkeley National Lab. 2 Gy were delivered in 2 µs by a beam with peak current of 2 µA. Thermoacoustic emissions were detected by a cardiac array andmore » Verasonics V1 ultrasound system, which also generated a grayscale ultrasound image. 1024 thermoacoustic pulses were averaged before filtering and one-way beamforming focused signal onto 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. Experiments were performed with the cavity both empty and filled with olive oil. Results: In the waterbath overlays of the Bragg peak agreed with Monte Carlo simulations to within 800±170 µm. Agreement within 1.3 ± 0.2 mm was achieved in the gelatin phantom, although relative stopping powers were estimated only to first order from CT scans. Protoacoustic signals were detected after travel from the Bragg peak through 29 mm and 65 mm of phantom material when the cavity was empty and full of olive oil, respectively. Conclusion: Protoacoustic range verification is feasible with a commercial clinical ultrasound array, but at doses exceeding the clinical realm. Further optimization of both transducer array and injection line chopper is required to enable range verification within a 2 Gy dose limit, which would enable online adaptive treatment. This work was supported in part by a UWM Intramural Instrumentation Grant and by the Director

Ultrasound Imaging Initiative

DTIC Science & Technology

2003-01-01

texture mapping hardware," IEEE Tranactions on Information Technology in Biomedicine, Submitted. [14] C.R. Castro Pareja , J.M. Jagadeesh and R. Shekhar...modulation in real-time three-dimensional sparse synthetic aperture ultrasound imaging systems "* Carlos R. Castro Pareja , Masters of Science, The Ohio...C.R. Castro Pareja , "An architecture for real-time image registration," M.S. Thesis, The Ohio State University, March 2002. 14. C.R. Castro Pareja , R

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.

Three-dimensional architecture of the whole human soleus muscle in vivo

PubMed Central

Finni, Taija; D’Souza, Arkiev; Eguchi, Junya; Clarke, Elizabeth C.; Herbert, Robert D.

2018-01-01

Background Most data on the architecture of the human soleus muscle have been obtained from cadaveric dissection or two-dimensional ultrasound imaging. We present the first comprehensive, quantitative study on the three-dimensional anatomy of the human soleus muscle in vivo using diffusion tensor imaging (DTI) techniques. Methods We report three-dimensional fascicle lengths, pennation angles, fascicle curvatures, physiological cross-sectional areas and volumes in four compartments of the soleus at ankle joint angles of 69 ± 12° (plantarflexion, short muscle length; average ± SD across subjects) and 108 ± 7° (dorsiflexion, long muscle length) of six healthy young adults. Microdissection and three-dimensional digitisation on two cadaveric muscles corroborated the compartmentalised structure of the soleus, and confirmed the validity of DTI-based muscle fascicle reconstructions. Results The posterior compartments of the soleus comprised 80 ± 5% of the total muscle volume (356 ± 58 cm3). At the short muscle length, the average fascicle length, pennation angle and curvature was 37 ± 8 mm, 31 ± 3° and 17 ± 4 /m, respectively. We did not find differences in fascicle lengths between compartments. However, pennation angles were on average 12° larger (p < 0.01) in the posterior compartments than in the anterior compartments. For every centimetre that the muscle-tendon unit lengthened, fascicle lengths increased by 3.7 ± 0.8 mm, pennation angles decreased by −3.2 ± 0.9° and curvatures decreased by −2.7 ± 0.8 /m. Fascicles in the posterior compartments rotated almost twice as much as in the anterior compartments during passive lengthening. Discussion The homogeneity in fascicle lengths and inhomogeneity in pennation angles of the soleus may indicate a functionally different role for the anterior and posterior compartments. The data and techniques presented here demonstrate how DTI can be used to obtain detailed, quantitative measurements of the

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

PubMed Central

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

2017-01-01

AIM 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). METHODS 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. RESULTS 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). CONCLUSION The association of greater PR thickness and paradoxical contraction of PR with CP suggest their potential value as markers of CP. PMID:28638230

A Review on Real-Time 3D Ultrasound Imaging Technology

PubMed Central

Zeng, Zhaozheng

2017-01-01

Real-time three-dimensional (3D) ultrasound (US) has attracted much more attention in medical researches because it provides interactive feedback to help clinicians acquire high-quality images as well as timely spatial information of the scanned area and hence is necessary in intraoperative ultrasound examinations. Plenty of publications have been declared to complete the real-time or near real-time visualization of 3D ultrasound using volumetric probes or the routinely used two-dimensional (2D) probes. So far, a review on how to design an interactive system with appropriate processing algorithms remains missing, resulting in the lack of systematic understanding of the relevant technology. In this article, previous and the latest work on designing a real-time or near real-time 3D ultrasound imaging system are reviewed. Specifically, the data acquisition techniques, reconstruction algorithms, volume rendering methods, and clinical applications are presented. Moreover, the advantages and disadvantages of state-of-the-art approaches are discussed in detail. PMID:28459067

A Review on Real-Time 3D Ultrasound Imaging Technology.

PubMed

Huang, Qinghua; Zeng, Zhaozheng

2017-01-01

Real-time three-dimensional (3D) ultrasound (US) has attracted much more attention in medical researches because it provides interactive feedback to help clinicians acquire high-quality images as well as timely spatial information of the scanned area and hence is necessary in intraoperative ultrasound examinations. Plenty of publications have been declared to complete the real-time or near real-time visualization of 3D ultrasound using volumetric probes or the routinely used two-dimensional (2D) probes. So far, a review on how to design an interactive system with appropriate processing algorithms remains missing, resulting in the lack of systematic understanding of the relevant technology. In this article, previous and the latest work on designing a real-time or near real-time 3D ultrasound imaging system are reviewed. Specifically, the data acquisition techniques, reconstruction algorithms, volume rendering methods, and clinical applications are presented. Moreover, the advantages and disadvantages of state-of-the-art approaches are discussed in detail.

Development of three-dimensional radiotherapy techniques in breast cancer

NASA Astrophysics Data System (ADS)

Coles, Charlotte E.

Radiotherapy following conservation surgery decreases local relapse and death from breast cancer. Currently, the challenge is to minimise the morbidity caused by this treatment without losing efficacy. Despite many advances in radiation techniques in other sites of the body, the majority of breast cancer patients are still planned and treated using 2-dimensional simple radiotherapy techniques. In addition, breast irradiation currently consumes 30% of the UK's radiotherapy workload. Therefore, any change to more complex treatment should be of proven benefit. The primary objective of this research is to develop and evaluate novel radiotherapy techniques to decrease irradiation of normal structures and improve localisation of the tumour bed. I have developed a forward-planned intensity modulated (IMRT) breast radiotherapy technique, which has shown improved dosimetry results compared to standard breast radiotherapy. Subsequently, I have developed and implemented a phase III randomised controlled breast IMRT trial. This National Cancer Research Network adopted trial will answer an important question regarding the clinical benefit of breast IMRT. It will provide DNA samples linked with high quality clinical outcome data, for a national translational radiogenomics study investigating variation in normal tissue toxicity. Thus, patients with significant late normal tissue side effects despite good dose homogeneity will provide the best model for finding differences due to underlying genetics. I evaluated a novel technique using high definition free-hand 3-dimensional (3D) ultrasound in a phantom study, and the results suggested that this is an accurate and reproducible method for tumour bed localisation. I then compared recognised methods of tumour bed localisation with the 3D ultrasound method in a clinical study. The 3D ultrasound technique appeared to accurately represent the shape and spatial position of the tumour cavity. This tumour bed localisation research

Three-Dimensional Virtual Sonographic Cystoscopy for Detection of Ureterocele in Duplicated Collecting Systems in Children.

PubMed

Nabavizadeh, Behnam; Mozafarpour, Sarah; Hosseini Sharifi, Seyed Hossein; Nabavizadeh, Reza; Abbasioun, Reza; Kajbafzadeh, Abdol-Mohammad

2018-03-01

Ureterocele is a sac-like dilatation of terminal ureter. Precise anatomic delineation is of utmost importance to proceed with the surgical plan, particularly in the ectopic subtype. However, the level of ureterocele extension is not always elucidated by the existing imaging modalities and even by conventional cystoscopy, which is considered as the gold standard for evaluation of ureterocele. This study aims to evaluate the accuracy of three-dimensional virtual sonographic cystoscopy (VSC) in the characterization of ureterocele in duplex collecting systems. Sixteen children with a mean age of 5.1 (standard deviation 1.96) years with transabdominal ultrasonography-proven duplex system and ureterocele were included. They underwent VSC by a single pediatric radiologist. All of them subsequently had conventional cystoscopy, and the results were compared in terms of ureterocele features including anatomy, number, size, location, and extension. Three-dimensional VSC was well tolerated in all cases without any complication. Image quality was suboptimal in 2 of 16 patients. Out of the remaining 14 cases, VSC had a high accuracy in characterization of the ureterocele features (93%). Only the extension of one ureterocele was not precisely detected by VSC. The results of this study suggest three-dimensional sonography as a promising noninvasive diagnostic modality in the evaluation of ectopic ureterocele in children. © 2017 by the American Institute of Ultrasound in Medicine.

Three-dimensional power Doppler ultrasound in the early assessment of response to concurrent chemo-radiotherapy for advanced cervical cancer.

PubMed

Xu, Yan; Zhu, Lijing; Ru, Tong; Wang, Huanhuan; He, Jian; Zhou, Zhengyang; Yang, Xiaofeng

2017-09-01

Background Three-dimensional power Doppler ultrasound (3D-PDU) imaging has been widely applied to the differentiation of benign and malignant cervical lesions; however, its potential value for predicting response to chemo-radiotherapy has not been fully explored. Purpose To investigate the feasibility of 3D-PDU imaging in predicting treatment response in patients receiving concurrent chemo-radiotherapy (CCRT) for advanced cervical cancer. Material and Methods Fifty-two patients with advanced cervical cancer who received CCRT underwent 3D-PDU examinations at four timepoints: pre-therapy (baseline), 1 week and 2 weeks during, as well as immediately post CCRT. Final tumor response was determined by change in tumor size using magnetic resonance imaging (MRI). Cervical tumor volumes and vascular indices were calculated and compared with the clinical outcome. Results Of the 52 patients, 32 patients who completed all four examinations were included in the analyses: 21 were classified as complete response (CR) and 11 as partial response (PR). During the treatment, the CR group showed that 3D vascular indices (VI and VFI) significantly increased at 1 week ( P = 0.028, P = 0.017, respectively) then decreased at 2 weeks and obviously decreased at therapy completion (both P < 0.001), whereas tumors significantly decreased in volume at 2 weeks after therapy initiation ( P < 0.05). However, no significant differences in 3D vascular indices values were seen in the PR group during the treatment course (all P > 0.05). Conclusion Prospective longitudinal 3D-PDU imaging may have potentials in monitoring early therapeutic response to CCRT in patients with cervical cancer.

Experiments on an unsteady, three-dimensional separation

NASA Technical Reports Server (NTRS)

Henk, R. W.; Reynolds, W. C.; Reed, H. L.

1992-01-01

Unsteady, three-dimensional flow separation occurs in a variety of technical situations including turbomachinery and low-speed aircraft. An experimental program at Stanford in unsteady, three-dimensional, pressure-driven laminar separation has investigated the structure and time-scaling of these flows; of particular interest is the development, washout, and control of flow separation. Results reveal that a two-dimensional, laminar boundary layer passes through several stages on its way to a quasi-steady three-dimensional separation. The quasi-steady state of the separation embodies a complex, unsteady, vortical structure.

Pursuing Mirror Image Reconstruction in Unilateral Microtia: Customizing Auricular Framework by Application of Three-Dimensional Imaging and Three-Dimensional Printing.

PubMed

Chen, Hsin-Yu; Ng, Li-Shia; Chang, Chun-Shin; Lu, Ting-Chen; Chen, Ning-Hung; Chen, Zung-Chung

2017-06-01

Advances in three-dimensional imaging and three-dimensional printing technology have expanded the frontier of presurgical design for microtia reconstruction from two-dimensional curved lines to three-dimensional perspectives. This study presents an algorithm for combining three-dimensional surface imaging, computer-assisted design, and three-dimensional printing to create patient-specific auricular frameworks in unilateral microtia reconstruction. Between January of 2015 and January of 2016, six patients with unilateral microtia were enrolled. The average age of the patients was 7.6 years. A three-dimensional image of the patient's head was captured by 3dMDcranial, and virtual sculpture carried out using Geomagic Freeform software and a Touch X Haptic device for fabrication of the auricular template. Each template was tailored according to the patient's unique auricular morphology. The final construct was mirrored onto the defective side and printed out with biocompatible acrylic material. During the surgery, the prefabricated customized template served as a three-dimensional guide for surgical simulation and sculpture of the MEDPOR framework. Average follow-up was 10.3 months. Symmetric and good aesthetic results with regard to auricular shape, projection, and orientation were obtained. One case with severe implant exposure was salvaged with free temporoparietal fascia transfer and skin grafting. The combination of three-dimensional imaging and manufacturing technology with the malleability of MEDPOR has surpassed existing limitations resulting from the use of autologous materials and the ambiguity of two-dimensional planning. This approach allows surgeons to customize the auricular framework in a highly precise and sophisticated manner, taking a big step closer to the goal of mirror-image reconstruction for unilateral microtia patients. Therapeutic, IV.

A New Classification of Three-Dimensional Printing Technologies: Systematic Review of Three-Dimensional Printing for Patient-Specific Craniomaxillofacial Surgery.

PubMed

Jacobs, Carly A; Lin, Alexander Y

2017-05-01

Three-dimensional printing technology has been advancing in surgical applications. This systematic review examines its patient-specific applications in craniomaxillofacial surgery. Terms related to "three-dimensional printing" and "surgery" were searched on PubMed on May 4, 2015; 313 unique articles were returned. Inclusion and exclusion criteria concentrated on patient-specific surgical applications, yielding 141 full-text articles, of which 33 craniomaxillofacial articles were analyzed. Thirty-three articles included 315 patients who underwent three-dimensional printing-assisted operations. The most common modeling software was Mimics, the most common printing software was 3D Systems, the average time to create a printed object was 18.9 hours (range, 1.5 to 96 hours), and the average cost of a printed object was $1353.31 (range, $69.75 to $5500). Surgical procedures were divided among 203 craniofacial patients (205 three-dimensional printing objects) and 112 maxillofacial patients (137 objects). Printing technologies could be classified as contour models, guides, splints, and implants. For craniofacial patients, 173 contour models (84 percent), 13 guides (6 percent), two splints (1 percent), and 17 implants (8 percent) were made. For maxillofacial patients, 41 contour models (30 percent), 48 guides (35 percent), 40 splints (29 percent), and eight implants (6 percent) were made. These distributions were significantly different (p < 0.0001). Four studies compared three-dimensional printing techniques to conventional techniques; two of them found that three-dimensional printing produced improved outcomes. Three-dimensional printing technology in craniomaxillofacial surgery can be classified into contour models (type I), guides (type II), splints (type III), and implants (type IV). These four methods vary in their use between craniofacial and maxillofacial surgery, reflecting their different goals. This understanding may help advance and predict three-dimensional

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

Three-dimensional printing and pediatric liver disease.

PubMed

Alkhouri, Naim; Zein, Nizar N

2016-10-01

Enthusiastic physicians and medical researchers are investigating the role of three-dimensional printing in medicine. The purpose of the current review is to provide a concise summary of the role of three-dimensional printing technology as it relates to the field of pediatric hepatology and liver transplantation. Our group and others have recently demonstrated the feasibility of printing three-dimensional livers with identical anatomical and geometrical landmarks to the native liver to facilitate presurgical planning of complex liver surgeries. Medical educators are exploring the use of three-dimensional printed organs in anatomy classes and surgical residencies. Moreover, mini-livers are being developed by regenerative medicine scientist as a way to test new drugs and, eventually, whole livers will be grown in the laboratory to replace organs with end-stage disease solving the organ shortage problem. From presurgical planning to medical education to ultimately the bioprinting of whole organs for transplantation, three-dimensional printing will change medicine as we know in the next few years.

Three-dimensional ultrasonography measurement of fetal nasal bone length during the midtrimester in Taiwanese women.

PubMed

Yang, Pei-Yin; Wu, Joung-Liang; Yeh, Guang-Perng; Tsung-Che Hsieh, Charles

2012-09-01

To evaluate the normal range of the fetal nasal bone length (NBL) in Taiwanese women using three-dimensional (3D) ultrasound, and compare the NBL of normal fetuses with Down syndrome to determine its significance in screening for trisomy 21. A total of 102 consecutive fetuses and another 7 fetuses with trisomy 21, determined by karyotyping at 15-22 weeks' gestation, were evaluated with 3D ultrasound before amniocentesis at Changhua Christian Hospital between November 2003 and April 2004. The normal range for NBL in the second trimester in the Taiwanese population was investigated, and a linear relationship with gestational age was noted. The NBL increased with advancing gestational age (NBL in cm=0.0264×gestational age in weeks -0.042 (R(2)=0.2416). The median of the biparietal diameter/nasal bone length ratio had a stable value which tended to change minimally between 15 and 22 weeks of gestation. Chromosomally normal fetuses had statistically longer nasal bones than fetuses with Down syndrome (p=0.014). We present a reference range for 3D ultrasound measurement of the fetal NBL. A short nasal bone at 15 to 22 weeks is associated with a high risk of trisomy 21. Copyright © 2012. Published by Elsevier B.V.

The impact of contrast enhanced spectral mammogram (CESM) and three dimensional breast ultrasound (3DUS) on the characterization of the disease extend in cancer patients.

PubMed

Helal, Maha Hussien; Salem, Dorria Saleh; Salaleldin, Lamia Adel; Mansour, Sahar Mahmoud; Alkalaawy, Basma Mohamed; Mokhtar, Nadia Mahmoud

2018-04-11

The main importance of imaging breast cancer is to guide conservative surgeries. In this study we evaluated the role of CESM in correlation with 3D breast ultrasound in characterizing the extension of the intramammary cancer in view of the: (i) the size of the main tumour, (ii) the multiplicity of the breast cancer, and (iii) the peri-tumoral stromal involvement (i.e. free or intra-ductal extension of the cancer). The study is a prospective analysis that included 300 breast masses proved to be malignant. The masses were evaluated for their size, multiplicity and surrounding stromal involvement. Contrast-based mammography performed with low (22-33 kVp) and high (44-49 kVp) energy exposures that were taken after IV injection of contrast agent and followed by bilateral 3D breast ultrasound. Operative data were the gold standard reference. There was no significant difference between the sizes of the included cancers as measured by CESM and 3DUS and that measured at the pathological analysis. CESM showed higher accuracy (32.7%, n = 98) than 3DUS (24.7%, n = 74) in the size agreement within 5% range. CESM was the most accurate modality (94%, n = 282) in detecting tumor multiplicity, followed by traditional sonomammogram (88%, n = 264), then 3D breast US (84%, n = 252). Intra-ductal extension of the breast cancer was best evaluated by the 3DUS with an accuracy value of 98% (n = 294) compared to only 60% (n = 180) by CESM. CESM is a recommend investigation in breast cancer to increase the accuracy of size measurement and the detection of multiple tumors. The addition of 3DUS can enhance the detection of intra-ductal extension. Advances in knowledge: Choice of conservative breast surgery versus mastectomy is still a debate. We used an advanced, contrast-based, application of the mammogram: contrast enhanced spectral mammogram and a non-invasive three-dimensional breast ultrasound in the assessment of the local extension of the breast cancer regarding size, perifocal stromal

A comparative study of two-dimensional and three-dimensional ultrasonography in evaluation of gastric affections in dogs

PubMed Central

Pal, Madan; Singh, Prem; Tayal, Rishi; Dehmiwal, Dinesh; Behl, S. M.; Kumar, Sarvan; Chandolia, R. K

2015-01-01

Aim: The objective of the study was to obtain and compare the two-dimensional (2D) and three-dimensional (3D) ultrasonographic images of pathological conditions of the stomach in dogs in clinical cases. Materials and Methods: In our study, 12 clinical conditions of the stomach were recorded using ultrasonography. The ultrasound machine used for this study was 3D ultrasound machine (Nemio-XG: Toshiba, Japan) having four-dimensional volumetric transducer. Results: Present study was done to compare 2D and 3D ultrasonographic images in different gastric affections in dogs. In case of uremic gastropathy due to inflammatory response, the wall of the stomach was 0.6 cm thick and hyperechoic and gastric folds were also hyperechoic indicative of gastritis. In second, third, and fourth case of gastritis the wall of the stomach was 0.7, 0.6, and 0.55 cm, respectively thick and hyperechoic. In fifth and sixth case of gastritis, inflammatory response due to ingestion of polythene and sand led to gastritis and ultrasonographically, the wall of the stomach was 0.6 cm and 0.7 cm thick, respectively, and hyperechoic. In case of gastric ulcer, ultrasonographically, there was a disruption of gastric mucosal layer. In cases of gastric dilatation, anechoic content indicating fluid was seen in stomach area and due to dilatation boundary of the stomach was not clear and the increase in the lumen of the stomach was observed. In case of foreign body, ultrasonographically the wall of the stomach was 0.55 cm thick and hyperechoic. In the middle of the stomach, multiple hyperechoic shadows of the foreign bodies i.e. leather and bunch of straw of grass were observed. In case of pyloric stenosis ultrasonographically, anechoic lumen of the pylorus surrounded by 0.5 cm hypoechoic thickened muscle. In some cases, 3D ultrasonography was not diagnostic i.e. gastric foreign bodies and gastric dilatation. These conditions were better visualized on the 2D sonogram. Conclusion: The appearance of

[Three-dimensional reconstruction of functional brain images].

PubMed

Inoue, M; Shoji, K; Kojima, H; Hirano, S; Naito, Y; Honjo, I

1999-08-01

We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: 1) routine images by SPM, 2) three-dimensional static images, and 3) three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the

Biodynamic profiling of three-dimensional tissue growth techniques

NASA Astrophysics Data System (ADS)

Sun, Hao; Merrill, Dan; Turek, John; Nolte, David

2016-03-01

Three-dimensional tissue culture presents a more biologically relevant environment in which to perform drug development than conventional two-dimensional cell culture. However, obtaining high-content information from inside three dimensional tissue has presented an obstacle to rapid adoption of 3D tissue culture for pharmaceutical applications. Biodynamic imaging is a high-content three-dimensional optical imaging technology based on low-coherence interferometry and digital holography that uses intracellular dynamics as high-content image contrast. In this paper, we use biodynamic imaging to compare pharmaceutical responses to Taxol of three-dimensional multicellular spheroids grown by three different growth techniques: rotating bioreactor, hanging-drop and plate-grown spheroids. The three growth techniques have systematic variations among tissue cohesiveness and intracellular activity and consequently display different pharmacodynamics under identical drug dose conditions. The in vitro tissue cultures are also compared to ex vivo living biopsies. These results demonstrate that three-dimensional tissue cultures are not equivalent, and that drug-response studies must take into account the growth method.

Three-dimensional ultrasound and magnetic resonance imaging assessment of cervix and vagina in women with uterine malformations.

PubMed

Bermejo, C; Martínez-Ten, P; Recio, M; Ruiz-López, L; Díaz, D; Illescas, T

2014-03-01

To investigate the accuracy of three-dimensional ultrasound (3D-US) with respect to magnetic resonance imaging (MRI), and compared to clinical examination, in the assessment of cervix and vagina in women with uterine malformations. In this prospective study, 16 patients diagnosed with uterine malformation with cervical involvement underwent 3D-US examination. The acquisition of cervical volumes was transvaginal, with four cases repeated in the peri-ovulation period, while vaginal volumes were acquired by transperineal imaging following filling of the vagina with gel. MRI was performed in 13 patients using endovaginal gel. All cases underwent clinical examination, comprising bimanual gynecological examination and speculoscopy. Diagnostic concordance of each of the methods with the gold standard was calculated. 3D-US cervical examinations revealed 12 cases of duplicate cervix, two of complete septate cervix and two of incomplete septate cervix. Images of the cervical canal in the peri-ovulation period were judged subjectively to be better in quality, but did not lead us to change any diagnosis. 3D-US vaginal examinations revealed four cases with a vaginal dividing wall and two with a blind hemivagina. None of the 3D-US findings contradicted the clinical findings of the cervix; however, clinically we observed two cases with vaginal dividing wall that had not been diagnosed with 3D-US. MRI diagnosed nine cases of duplicate cervix, three of complete septate cervix, one of incomplete septate cervix, five of vaginal dividing wall and two of blind hemivagina. One case diagnosed as complete septate cervix was in fact a duplicate cervix on 3D-US and on clinical examination. Compared with the gold standard, both 3D-US and MRI were highly efficient in the diagnosis of anomalies of the cervix and vagina. The overall diagnostic concordance of 3D-US with clinical examination (kappa, 0.84; 95% CI, 0.62-1) was slightly inferior to that of MRI with clinical examination (kappa, 0

Farley Three-Dimensional-Braiding Machine

NASA Technical Reports Server (NTRS)

Farley, Gary L.

1991-01-01

Process and device known as Farley three-dimensional-braiding machine conceived to fabricate dry continuous fiber-reinforced preforms of complex three-dimensional shapes for subsequent processing into composite structures. Robotic fiber supply dispenses yarn as it traverses braiding surface. Combines many attributes of weaving and braiding processes with other attributes and capabilities. Other applications include decorative cloths, rugs, and other domestic textiles. Concept could lead to large variety of fiber layups and to entirely new products as well as new fiber-reinforcing applications.

3-D ultrasound guidance of surgical robotics: a feasibility study.

PubMed

Pua, Eric C; Fronheiser, Matthew P; Noble, Joanna R; Light, Edward D; Wolf, Patrick D; von Allmen, Daniel; Smith, Stephen W

2006-11-01

Laparoscopic ultrasound has seen increased use as a surgical aide in general, gynecological, and urological procedures. The application of real-time, three-dimensional (RT3D) ultrasound to these laparoscopic procedures may increase information available to the surgeon and serve as an additional intraoperative guidance tool. The integration of RT3D with recent advances in robotic surgery also can increase automation and ease of use. In this study, a 1-cm diameter probe for RT3D has been used laparoscopically for in vivo imaging of a canine. The probe, which operates at 5 MHz, was used to image the spleen, liver, and gall bladder as well as to guide surgical instruments. Furthermore, the three-dimensional (3-D) measurement system of the volumetric scanner used with this probe was tested as a guidance mechanism for a robotic linear motion system in order to simulate the feasibility of RT3D/robotic surgery integration. Using images acquired with the 3-D laparoscopic ultrasound device, coordinates were acquired by the scanner and used to direct a robotically controlled needle toward desired in vitro targets as well as targets in a post-mortem canine. The rms error for these measurements was 1.34 mm using optical alignment and 0.76 mm using ultrasound alignment.

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.

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.

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

Real-time catheter localization and visualization using three-dimensional echocardiography

NASA Astrophysics Data System (ADS)

Kozlowski, Pawel; Bandaru, Raja Sekhar; D'hooge, Jan; Samset, Eigil

2017-03-01

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) is increasingly used during minimally invasive cardiac surgeries (MICS). In many cath labs, RT3D-TEE is already one of the requisite tools for image guidance during MICS. However, the visualization of the catheter is not always satisfactory making 3D- TEE challenging to use as the only modality for guidance. We propose a novel technique for better visualization of the catheter along with the cardiac anatomy using TEE alone - exploiting both beamforming and post processing methods. We extended our earlier method called Delay and Standard Deviation (DASD) beamforming to 3D in order to enhance specular reflections. The beam-formed image was further post-processed by the Frangi filter to segment the catheter. Multi-variate visualization techniques enabled us to render both the standard tissue and the DASD beam-formed image on a clinical ultrasound scanner simultaneously. A frame rate of 15 FPS was achieved.

A three-dimensional visualization preoperative treatment planning system for microwave ablation in liver cancer: a simulated experimental study.

PubMed

Liu, Fangyi; Cheng, Zhigang; Han, Zhiyu; Yu, Xiaoling; Yu, Mingan; Liang, Ping

2017-06-01

To evaluate the application value of three-dimensional (3D) visualization preoperative treatment planning system (VPTPS) for microwave ablation (MWA) in liver cancer. The study was a simulated experimental study using the CT imaging data of patients in DICOM format in a model. Three students (who learn to interventional ultrasound for less than 1 year) and three experts (who have more than 5 years of experience in ablation techniques) in MWA performed the preoperative planning for 39 lesions (mean diameter 3.75 ± 1.73 cm) of 32 patients using two-dimensional (2D) image planning method and 3D VPTPS, respectively. The number of planning insertions, planning ablation rate, and damage rate to surrounding structures were compared between2D image planning group and 3D VPTPS group. There were fewer planning insertions, lower ablation rate and higher damage rate to surrounding structures in 2D image planning group than 3D VPTPS group for both students and experts. When using the 2D ultrasound planning method, students could carry out fewer planning insertions and had a lower ablation rate than the experts (p < 0.001). However, there was no significant difference in planning insertions, the ablation rate, and the incidence of damage to the surrounding structures between students and experts using 3D VPTPS. 3DVPTPS enables inexperienced physicians to have similar preoperative planning results to experts, and enhances students' preoperative planning capacity, which may improve the therapeutic efficacy and reduce the complication of MWA.

Dual-Modality PET/Ultrasound imaging of the Prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huber, Jennifer S.; Moses, William W.; Pouliot, Jean

2005-11-11

Functional imaging with positron emission tomography (PET)will detect malignant tumors in the prostate and/or prostate bed, as well as possibly help determine tumor ''aggressiveness''. However, the relative uptake in a prostate tumor can be so great that few other anatomical landmarks are visible in a PET image. Ultrasound imaging with a transrectal probe provides anatomical detail in the prostate region that can be co-registered with the sensitive functional information from the PET imaging. Imaging the prostate with both PET and transrectal ultrasound (TRUS) will help determine the location of any cancer within the prostate region. This dual-modality imaging should helpmore » provide better detection and treatment of prostate cancer. LBNL has built a high performance positron emission tomograph optimized to image the prostate.Compared to a standard whole-body PET camera, our prostate-optimized PET camera has the same sensitivity and resolution, less backgrounds and lower cost. We plan to develop the hardware and software tools needed for a validated dual PET/TRUS prostate imaging system. We also plan to develop dual prostate imaging with PET and external transabdominal ultrasound, in case the TRUS system is too uncomfortable for some patients. We present the design and intended clinical uses for these dual imaging systems.« less

Three-Dimensional Phenomena in Microbubble Acoustic Streaming

NASA Astrophysics Data System (ADS)

Marin, Alvaro; Rossi, Massimiliano; Rallabandi, Bhargav; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.

2015-04-01

Ultrasound-driven oscillating microbubbles are used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting, and manipulation of microparticles. A common configuration consists of side bubbles created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration consists of acoustically excited bubbles with a semicylindrical shape that generate significant streaming flow. Because of the geometry of the channels, such flows are generally considered as quasi-two-dimensional. Similar assumptions are often made in many other microfluidic systems based on flat microchannels. However, in this Letter we show that microparticle trajectories actually present a much richer behavior, with particularly strong out-of-plane dynamics in regions close to the microbubble interface. Using astigmatism particle-tracking velocimetry, we reveal that the apparent planar streamlines are actually projections of a stream surface with a pseudotoroidal shape. We, therefore, show that acoustic streaming cannot generally be assumed as a two-dimensional phenomenon in confined systems. The results have crucial consequences for most of the applications involving acoustic streaming such as particle trapping, sorting, and mixing.

[Bone drilling simulation by three-dimensional imaging].

PubMed

Suto, Y; Furuhata, K; Kojima, T; Kurokawa, T; Kobayashi, M

1989-06-01

The three-dimensional display technique has a wide range of medical applications. Pre-operative planning is one typical application: in orthopedic surgery, three-dimensional image processing has been used very successfully. We have employed this technique in pre-operative planning for orthopedic surgery, and have developed a simulation system for bone-drilling. Positive results were obtained by pre-operative rehearsal; when a region of interest is indicated by means of a mouse on the three-dimensional image displayed on the CRT, the corresponding region appears on the slice image which is displayed simultaneously. Consequently, the status of the bone-drilling is constantly monitored. In developing this system, we have placed emphasis on the quality of the reconstructed three-dimensional images, on fast processing, and on the easy operation of the surgical planning simulation.

Three-dimensional printing of orbital and peri-orbital masses in three dogs and its potential applications in veterinary ophthalmology.

PubMed

Dorbandt, Daniel M; Joslyn, Stephen K; Hamor, Ralph E

2017-01-01

To describe the technique and utility of three-dimensional (3D) printing for orbital and peri-orbital masses and discuss other potential applications for 3D printing. Three dogs with a chronic history of nonpainful exophthalmos. Computed tomography (CT) and subsequent 3D printing of the head was performed on each case. CT confirmed a confined mass, and an ultrasound-guided biopsy was obtained in each circumstance. An orbitotomy was tentatively planned for each case, and a 3D print of each head with the associated globe and mass was created to assist in surgical planning. In case 1, the mass was located in the cranioventral aspect of the right orbit, and the histopathologic diagnosis was adenoma. In case 2, the mass was located within the lateral masseter muscle, ventral to the right orbit between the zygomatic arch and the ramus of the mandible. The histopathologic diagnosis in case 2 was consistent with a lipoma. In case 3, the mass was located in the ventral orbit, and the histopathologic diagnosis was histiocytic cellular infiltrate. Three-dimensional printing in cases with orbital and peri-orbital masses has exceptional potential for improved surgical planning and provides another modality for visualization to help veterinarians, students, and owners understand distribution of disease. Additionally, as the techniques of 3D printing continue to evolve, the potential exists to revolutionize ocular surgery and drug delivery. © 2016 American College of Veterinary Ophthalmologists.

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.

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

Limitations of three-dimensional power Doppler angiography in preoperative evaluation of ovarian tumors.

PubMed

Silvestre, Liliane; Martins, Wellington P; Candido-Dos-Reis, Francisco J

2015-07-29

This study describes the accuracy of three-dimensional power Doppler (3D-PD) angiography as secondary method for differential diagnosis of ovarian tumors. Seventy-five women scheduled for surgical removal of adnexal masses were assessed by transvaginal ultrasound. Ovarian tumors were classified by IOTA simple rules and two three-dimensional blocks were recorded. In a second step analyses, a 4 cm(3) spherical sample was obtained from the highest vascularized solid area of each stored block. Vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) were calculated. The repeatability was assessed by concordance correlation coefficient (CCC) and limits of agreement (LoA), and diagnostic accuracy by area under ROC curve. IOTA simple rules classified 26 cases as benign, nine as inconclusive and 40 as malignant. There were eight false positive and no false negative. Among the masses classified as inconclusive or malignant by IOTA simple rules, the CCCs were 0.91 for VI, 0.70 for FI, and 0.86 for VFI. The areas under ROC curve were 0.82 for VI, 0.67 for FI and 0.81 for VFI. 3D-PD angiography presented considerable intraobserver variability and low accuracy for identifying false positive results of IOTA simple rules.

In vivo imaging of inducible tyrosinase gene expression with an ultrasound array-based photoacoustic system

NASA Astrophysics Data System (ADS)

Harrison, Tyler; Paproski, Robert J.; Zemp, Roger J.

2012-02-01

Tyrosinase, a key enzyme in the production of melanin, has shown promise as a reporter of genetic activity. While green fluorescent protein has been used extensively in this capacity, it is limited in its ability to provide information deep in tissue at a reasonable resolution. As melanin is a strong absorber of light, it is possible to image gene expression using tyrosinase with photoacoustic imaging technologies, resulting in excellent resolutions at multiple-centimeter depths. While our previous work has focused on creating and imaging MCF-7 cells with doxycycline-controlled tyrosinase expression, we have now established the viability of these cells in a murine model. Using an array-based photoacoustic imaging system with 5 MHz center frequency, we capture interleaved ultrasound and photoacoustic images of tyrosinase-expressing MCF-7 tumors both in a tissue mimicking phantom, and in vivo. Images of both the tyrosinase-expressing tumor and a control tumor are presented as both coregistered ultrasound-photoacoustic B-scan images and 3-dimensional photoacoustic volumes created by mechanically scanning the transducer. We find that the tyrosinase-expressing tumor is visible with a signal level 12dB greater than that of the control tumor in vivo. Phantom studies with excised tumors show that the tyrosinase-expressing tumor is visible at depths in excess of 2cm, and have suggested that our imaging system is sensitive to a transfection rate of less than 1%.

Towards three-dimensional optical metamaterials

NASA Astrophysics Data System (ADS)

Tanaka, Takuo; Ishikawa, Atsushi

2017-12-01

Metamaterials have opened up the possibility of unprecedented and fascinating concepts and applications in optics and photonics. Examples include negative refraction, perfect lenses, cloaking, perfect absorbers, and so on. Since these metamaterials are man-made materials composed of sub-wavelength structures, their development strongly depends on the advancement of micro- and nano-fabrication technologies. In particular, the realization of three-dimensional metamaterials is one of the big challenges in this research field. In this review, we describe recent progress in the fabrication technologies for three-dimensional metamaterials, as well as proposed applications.

3D ultrasound imaging in image-guided intervention.

PubMed

Fenster, Aaron; Bax, Jeff; Neshat, Hamid; Cool, Derek; Kakani, Nirmal; Romagnoli, Cesare

2014-01-01

Ultrasound imaging is used extensively in diagnosis and image-guidance for interventions of human diseases. However, conventional 2D ultrasound suffers from limitations since it can only provide 2D images of 3-dimensional structures in the body. Thus, measurement of organ size is variable, and guidance of interventions is limited, as the physician is required to mentally reconstruct the 3-dimensional anatomy using 2D views. Over the past 20 years, a number of 3-dimensional ultrasound imaging approaches have been developed. We have developed an approach that is based on a mechanical mechanism to move any conventional ultrasound transducer while 2D images are collected rapidly and reconstructed into a 3D image. In this presentation, 3D ultrasound imaging approaches will be described for use in image-guided interventions.

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

System for generating two-dimensional masks from a three-dimensional model using topological analysis

DOEpatents

Schiek, Richard [Albuquerque, NM

2006-06-20

A method of generating two-dimensional masks from a three-dimensional model comprises providing a three-dimensional model representing a micro-electro-mechanical structure for manufacture and a description of process mask requirements, reducing the three-dimensional model to a topological description of unique cross sections, and selecting candidate masks from the unique cross sections and the cross section topology. The method further can comprise reconciling the candidate masks based on the process mask requirements description to produce two-dimensional process masks.

Ultrasound internal tattooing.

PubMed

Couture, Olivier; Faivre, Magalie; Pannacci, Nicolas; Babataheri, Avin; Servois, Vincent; Tabeling, Patrick; Tanter, Mickael

2011-02-01

The ability of remotely tagging tissues in a controlled and three-dimensional manner during preoperative imaging could greatly help surgeons to identify targets for resection. The authors' objective is to selectively and noninvasively deposit markers under image guidance for such internal tattooing. This study describes the production of new ultrasound-inducible droplets carrying large payloads of fluorescent markers and the in vivo proof of concept of their remote and controlled deposition via focused ultrasound. The droplets are monodispersed multiple emulsions produced in a microfluidic system, consisting of aqueous fluorescein in perfluorocarbon in water. Their conversion (either by vaporization or cavitation) is performed remotely using a clinical ultrasonic imaging probe. When submitted to 5 MHz imaging pulses, the droplets vaporize in vitro at 1.4 MPa peak-negative pressure and eject their content. After several seconds, a brightly fluorescent spot (0.5 mm diameter) is observed at the focus of the transducer. Experiments in the chorioallantoique membrane of chicken eggs and chicken embryo demonstrate that the spot is stable and is easily seen by naked eye. These ultrasound-inducible multiple emulsions could be used to deliver large amounts of contrast agents, chemotherapy, and genetic materials in vivo using a conventional ultrasound scanner.

Three-dimensional ultrasonic scanning.

PubMed

Fredfeldt, K E; Holm, H H; Pedersen, J F

1984-01-01

Simple experiments which form the basis for a true 3-D demonstration of sectional images are presented and a method for genuine 3-D display of dynamic ultrasound images is described. Eight ultrasound images are recorded with a slightly different angulation of the transducer. The images are extracted from the video signal from a conventional ultrasound scanner and stored in eight digital memories. After recording, each image is displayed on an oscilloscope screen, which is viewed via a fast oscillating mirror. The position of the mirror determines which of the eight images are to be displayed and thereby ensures a correct spatial relationship of the images, resulting in a true 3-D scan presentation.

Three-dimensional instability of standing waves

NASA Astrophysics Data System (ADS)

Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

2003-12-01

We investigate the three-dimensional instability of finite-amplitude standing surface waves under the influence of gravity. The analysis employs the transition matrix (TM) approach and uses a new high-order spectral element (HOSE) method for computation of the nonlinear wave dynamics. HOSE is an extension of the original high-order spectral method (HOS) wherein nonlinear wave wave and wave body interactions are retained up to high order in wave steepness. Instead of global basis functions in HOS, however, HOSE employs spectral elements to allow for complex free-surface geometries and surface-piercing bodies. Exponential convergence of HOS with respect to the total number of spectral modes (for a fixed number of elements) and interaction order is retained in HOSE. In this study, we use TM-HOSE to obtain the stability of general three-dimensional perturbations (on a two-dimensional surface) on two classes of standing waves: plane standing waves in a rectangular tank; and radial/azimuthal standing waves in a circular basin. For plane standing waves, we confirm the known result of two-dimensional side-bandlike instability. In addition, we find a novel three-dimensional instability for base flow of any amplitude. The dominant component of the unstable disturbance is an oblique (standing) wave oriented at an arbitrary angle whose frequency is close to the (nonlinear) frequency of the original standing wave. This finding is confirmed by direct long-time simulations using HOSE which show that the nonlinear evolution leads to classical Fermi Pasta Ulam recurrence. For the circular basin, we find that, beyond a threshold wave steepness, a standing wave (of nonlinear frequency Omega) is unstable to three-dimensional perturbations. The unstable perturbation contains two dominant (standing-wave) components, the sum of whose frequencies is close to 2Omega. From the cases we consider, the critical wave steepness is found to generally decrease/increase with increasing radial

An iterated Laplacian based semi-supervised dimensionality reduction for classification of breast cancer on ultrasound images.

PubMed

Liu, Xiao; Shi, Jun; Zhou, Shichong; Lu, Minhua

2014-01-01

The dimensionality reduction is an important step in ultrasound image based computer-aided diagnosis (CAD) for breast cancer. A newly proposed l2,1 regularized correntropy algorithm for robust feature selection (CRFS) has achieved good performance for noise corrupted data. Therefore, it has the potential to reduce the dimensions of ultrasound image features. However, in clinical practice, the collection of labeled instances is usually expensive and time costing, while it is relatively easy to acquire the unlabeled or undetermined instances. Therefore, the semi-supervised learning is very suitable for clinical CAD. The iterated Laplacian regularization (Iter-LR) is a new regularization method, which has been proved to outperform the traditional graph Laplacian regularization in semi-supervised classification and ranking. In this study, to augment the classification accuracy of the breast ultrasound CAD based on texture feature, we propose an Iter-LR-based semi-supervised CRFS (Iter-LR-CRFS) algorithm, and then apply it to reduce the feature dimensions of ultrasound images for breast CAD. We compared the Iter-LR-CRFS with LR-CRFS, original supervised CRFS, and principal component analysis. The experimental results indicate that the proposed Iter-LR-CRFS significantly outperforms all other algorithms.

Wavelength optimization for in vivo multispectral photoacoustic/ultrasound tomography of hemoglobin oxygenation in ovarian cancer: clinical studies

NASA Astrophysics Data System (ADS)

Salehi, Hassan S.; Li, Hai; Kumavor, Patrick D.; Merkulov, Aleksey; Sanders, Melinda; Brewer, Molly; Zhu, Quing

2015-03-01

In this paper, wavelength selection for multispectral photoacoustic/ultrasound tomography was optimized to obtain accurate images of hemoglobin oxygen saturation (sO2) in vivo. Although wavelengths can be selected by theoretical methods, in practice the accuracy of reconstructed images will be affected by wavelength-specific and system-specific factors such as laser source power and ultrasound transducer sensitivity. By performing photoacoustic spectroscopy of mouse tumor models using 14 different wavelengths between 710 and 840 nm, we were able to identify a wavelength set which most accurately reproduced the results obtained using all 14 wavelengths via selection criteria. In clinical studies, the optimal wavelength set was successfully used to image human ovaries in vivo and noninvasively. Although these results are specific to our co-registered photoacoustic/ultrasound imaging system, the approach we developed can be applied to other functional photoacoustic and optical imaging systems.

Numerical Modeling of Three-Dimensional Confined Flows

NASA Technical Reports Server (NTRS)

Greywall, M. S.

1981-01-01

A three dimensional confined flow model is presented. The flow field is computed by calculating velocity and enthalpy along a set of streamlines. The finite difference equations are obtained by applying conservation principles to streamtubes constructed around the chosen streamlines. With appropriate substitutions for the body force terms, the approach computes three dimensional magnetohydrodynamic channel flows. A listing of a computer code, based on this approach is presented in FORTRAN IV language. The code computes three dimensional compressible viscous flow through a rectangular duct, with the duct cross section specified along the axis.

More About The Farley Three-Dimensional Braider

NASA Technical Reports Server (NTRS)

Farley, Gary L.

1993-01-01

Farley three-dimensional braider, undergoing development, is machine for automatic fabrication of three-dimensional braided structures. Incorporates yarns into structure at arbitrary braid angles to produce complicated shape. Braiding surface includes movable braiding segments containing pivot points, along which yarn carriers travel during braiding process. Yarn carrier travels along sequence of pivot points as braiding segments move. Combined motions position yarns for braiding onto preform. Intended for use in making fiber preforms for fiber/matrix composite parts, such as multiblade propellers. Machine also described in "Farley Three-Dimensional Braiding Machine" (LAR-13911).

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.

A preliminary result of three-dimensional microarray technology to gene analysis with endoscopic ultrasound-guided fine-needle aspiration specimens and pancreatic juices

PubMed Central

2010-01-01

Background Analysis of gene expression and gene mutation may add information to be different from ordinary pathological tissue diagnosis. Since samples obtained endoscopically are very small, it is desired that more sensitive technology is developed for gene analysis. We investigated whether gene expression and gene mutation analysis by newly developed ultra-sensitive three-dimensional (3D) microarray is possible using small amount samples from endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) specimens and pancreatic juices. Methods Small amount samples from 17 EUS-FNA specimens and 16 pancreatic juices were obtained. After nucleic acid extraction, the samples were amplified with labeling and analyzed by the 3D microarray. Results The analyzable rate with the microarray was 46% (6/13) in EUS-FNA specimens of RNAlater® storage, and RNA degradations were observed in all the samples of frozen storage. In pancreatic juices, the analyzable rate was 67% (4/6) in frozen storage samples and 20% (2/10) in RNAlater® storage. EUS-FNA specimens were classified into cancer and non-cancer by gene expression analysis and K-ras codon 12 mutations were also detected using the 3D microarray. Conclusions Gene analysis from small amount samples obtained endoscopically was possible by newly developed 3D microarray technology. High quality RNA from EUS-FNA samples were obtained and remained in good condition only using RNA stabilizer. In contrast, high quality RNA from pancreatic juice samples were obtained only in frozen storage without RNA stabilizer. PMID:20416107

Integrated Aeromechanics with Three-Dimensional Solid-Multibody Structures

NASA Technical Reports Server (NTRS)

Datta, Anubhav; Johnson, Wayne

2014-01-01

A full three-dimensional finite element-multibody structural dynamic solver is coupled to a three-dimensional Reynolds-averaged Navier-Stokes solver for the prediction of integrated aeromechanical stresses and strains on a rotor blade in forward flight. The objective is to lay the foundations of all major pieces of an integrated three-dimensional rotor dynamic analysis - from model construction to aeromechanical solution to stress/strain calculation. The primary focus is on the aeromechanical solution. Two types of three-dimensional CFD/CSD interfaces are constructed for this purpose with an emphasis on resolving errors from geometry mis-match so that initial-stage approximate structural geometries can also be effectively analyzed. A three-dimensional structural model is constructed as an approximation to a UH-60A-like fully articulated rotor. The aerodynamic model is identical to the UH-60A rotor. For preliminary validation measurements from a UH-60A high speed flight is used where CFD coupling is essential to capture the advancing side tip transonic effects. The key conclusion is that an integrated aeromechanical analysis is indeed possible with three-dimensional structural dynamics but requires a careful description of its geometry and discretization of its parts.

Three-Dimensional Messages for Interstellar Communication

NASA Astrophysics Data System (ADS)

Vakoch, Douglas A.

One of the challenges facing independently evolved civilizations separated by interstellar distances is to communicate information unique to one civilization. One commonly proposed solution is to begin with two-dimensional pictorial representations of mathematical concepts and physical objects, in the hope that this will provide a foundation for overcoming linguistic barriers. However, significant aspects of such representations are highly conventional, and may not be readily intelligible to a civilization with different conventions. The process of teaching conventions of representation may be facilitated by the use of three-dimensional representations redundantly encoded in multiple formats (e.g., as both vectors and as rasters). After having illustrated specific conventions for representing mathematical objects in a three-dimensional space, this method can be used to describe a physical environment shared by transmitter and receiver: a three-dimensional space defined by the transmitter--receiver axis, and containing stars within that space. This method can be extended to show three-dimensional representations varying over time. Having clarified conventions for representing objects potentially familiar to both sender and receiver, novel objects can subsequently be depicted. This is illustrated through sequences showing interactions between human beings, which provide information about human behavior and personality. Extensions of this method may allow the communication of such culture-specific features as aesthetic judgments and religious beliefs. Limitations of this approach will be noted, with specific reference to ETI who are not primarily visual.

Co-registered perfusion SPECT/CT: utility for prediction of improved postoperative outcome in lung volume reduction surgery candidates.

PubMed

Takenaka, Daisuke; Ohno, Yoshiharu; Koyama, Hisanobu; Nogami, Munenobu; Onishi, Yumiko; Matsumoto, Keiko; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Sugimura, Kazuro

2010-06-01

To directly compare the capabilities of perfusion scan, SPECT, co-registered SPECT/CT, and quantitatively and qualitatively assessed MDCT (i.e. quantitative CT and qualitative CT) for predicting postoperative clinical outcome for lung volume reduction surgery (LVRS) candidates. Twenty-five consecutive candidates (19 men and six women, age range: 42-72 years) for LVRS underwent preoperative CT and perfusion scan with SPECT. Clinical outcome of LVRS for all subjects was also assessed by determining the difference between pre- and postoperative forced expiratory volume in 1s (FEV(1)) and 6-min walking distance (6MWD). All SPECT examinations were performed on a SPECT scanner, and co-registered to thin-section CT by using commercially available software. On planar imaging, SPECT and SPECT/CT, upper versus lower zone or lobe ratios (U/Ls) were calculated from regional uptakes between upper and lower lung fields in the operated lung. On quantitatively assessed CT, U/L for all subjects was assessed from regional functional lung volumes. On qualitatively assessed CT, planar imaging, SPECT and co-registered SPECT/CT, U/Ls were assessed with a 4-point visual scoring system. To compare capabilities of predicting clinical outcome, each U/L was statistically correlated with the corresponding clinical outcome. Significantly fair or moderate correlations were observed between quantitatively and qualitatively assessed U/Ls obtained with all four methods and clinical outcomes (-0.60Co-registered perfusion SPECT/CT has better correlation with clinical outcome in LVRS candidates than do planar imaging, SPECT or qualitatively assessed CT, and is at least as valid as quantitatively assessed CT. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Motion Detection in Ultrasound Image-Sequences Using Tensor Voting

NASA Astrophysics Data System (ADS)

Inba, Masafumi; Yanagida, Hirotaka; Tamura, Yasutaka

2008-05-01

Motion detection in ultrasound image sequences using tensor voting is described. We have been developing an ultrasound imaging system adopting a combination of coded excitation and synthetic aperture focusing techniques. In our method, frame rate of the system at distance of 150 mm reaches 5000 frame/s. Sparse array and short duration coded ultrasound signals are used for high-speed data acquisition. However, many artifacts appear in the reconstructed image sequences because of the incompleteness of the transmitted code. To reduce the artifacts, we have examined the application of tensor voting to the imaging method which adopts both coded excitation and synthetic aperture techniques. In this study, the basis of applying tensor voting and the motion detection method to ultrasound images is derived. It was confirmed that velocity detection and feature enhancement are possible using tensor voting in the time and space of simulated ultrasound three-dimensional image sequences.

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.

Three-dimensional translabial ultrasound assessment of urethral supports and the urethral sphincter complex in stress urinary incontinence.

PubMed

Cassadó Garriga, Jordi; Pessarrodona Isern, Antoni; Rodríguez Carballeira, Monica; Pallarols Badia, Mar; Moya Del Corral, Manuela; Valls Esteve, Marta; Huguet Galofré, Eva

2017-09-01

The pathophysiological mechanism of incontinence is multifactorial. We evaluated the role of 3D-4D ultrasound in the assessment of the fascial supports of the urethra and the urethral sphincter complex (USC) for diagnosing stress urinary incontinence. Observational case-control study in women with and without stress urinary incontinence attending a urogynecology service and a general gynecology service. All women were interviewed, examined, and classified according to the Pelvic Organ Prolapse Quantification (POP-Q) and underwent a 3D-4D translabial ultrasound. Fascial supports of the urethra were assessed by tomographic ultrasound and were considered to be intact or absent if it was possible to identify them at eight levels on each side, urethral mobility was assessed on maximal Valsalva in sagittal section and the length and volume of the USC at rest and on maximal Valsalva were determined using the Virtual Organ Computer-aided Analysis (VOCAL) program. Variables were compared between continent and incontinent women. A total of 173 women were examined, 78 continent and 95 incontinent. There was a significant difference in urethral mobility between continent and incontinent women (12.82 mm vs. 21.85 mm, P < 0.001), but there was no significant difference in the percentage of supports affected (43.27% vs. 35.94%, P < 0.070). The length of the USC at rest was significantly shorter (P < 0.001) ​​in incontinent patients. Ultrasound evaluation of urethral supports does not discriminate between continent and incontinent women. However, the length of the USC at rest was shorter and urethral mobility was higher in incontinent women. Neurourol. Urodynam. 9999:XX-XX, 2016. © 2016 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Ultrasound simulator-assisted teaching of cardiac anatomy to preclinical anatomy students: A pilot randomized trial of a three-hour learning exposure.

PubMed

Canty, David Jeffrey; Hayes, Jenny A; Story, David Andrew; Royse, Colin Forbes

2015-01-01

Ultrasound simulation allows students to virtually explore internal anatomy by producing accurate, moving, color, three-dimensional rendered slices from any angle or approach leaving the organs and their relationships intact without requirement for consumables. The aim was to determine the feasibility and efficacy of self-directed learning of cardiac anatomy with an ultrasound simulator compared to cadavers and plastic models. After a single cardiac anatomy lecture, fifty university anatomy students participated in a three-hour supervised self-directed learning exposure in groups of five, randomized to an ultrasound simulator or human cadaveric specimens and plastic models. Pre- and post-tests were conducted using pictorial and non-pictorial multiple-choice questions (MCQs). Simulator students completed a survey on their experience. Four simulator and seven cadaver group students did not attend after randomization. Simulator use in groups of five students was feasible and feedback from participants was very positive. Baseline test scores were similar (P = 0.9) between groups. After the learning intervention, there was no difference between groups in change in total test score (P = 0.37), whether they were pictorial (P = 0.6) or non-pictorial (P = 0.21). In both groups there was an increase in total test scores (simulator +19.8 ±12.4%% and cadaver: +16.4% ± 10.2, P < 0.0001), pictorial question scores (+22.9 ±18.0%, 19.7 ±19.3%, P < 0.001) and non-pictorial question scores (+16.7 ±18.2%, +13 ±15.4%, P = 0.002). The ultrasound simulator appears equivalent to human cadaveric prosections for learning cardiac anatomy. © 2014 American Association of Anatomists.

Measurement of ventricular torsion by two-dimensional ultrasound speckle tracking imaging.

PubMed

Notomi, Yuichi; Lysyansky, Peter; Setser, Randolph M; Shiota, Takahiro; Popović, Zoran B; Martin-Miklovic, Maureen G; Weaver, Joan A; Oryszak, Stephanie J; Greenberg, Neil L; White, Richard D; Thomas, James D

2005-06-21

We sought to examine the accuracy/consistency of a novel ultrasound speckle tracking imaging (STI) method for left ventricular torsion (LVtor) measurement in comparison with tagged magnetic resonance imaging (MRI) (a time-domain method similar to STI) and Doppler tissue imaging (DTI) (a velocity-based approach). Left ventricular torsion from helically oriented myofibers is a key parameter of cardiac performance but is difficult to measure. Ultrasound STI is potentially suitable for measurement of angular motion because of its angle-independence. We acquired basal and apical short-axis left ventricular (LV) images in 15 patients to estimate LVtor by STI and compare it with tagged MRI and DTI. Left ventricular torsion was defined as the net difference of LV rotation at the basal and apical planes. For the STI analysis, we used high-frame (104 +/- 12 frames/s) second harmonic two-dimensional images. Data on 13 of 15 patients were usable for STI analysis, and LVtor profile estimated by STI strongly correlated with those by tagged MRI (y = 0.95x + 0.19, r = 0.93, p < 0.0001, analyzed by repeated-measures regression models). The STI torsional velocity profile also correlated well with that by the DTI method (y = 0.79x + 2.4, r = 0.76, p < 0.0001, by repeated-measures regression models) with acceptable bias. The STI estimation of LVtor is concordant with those analyzed by tagged MRI (data derived from tissue displacement) and also showed good agreement with those by DTI (data derived from tissue velocity). Ultrasound STI is a promising new method to assess LV torsional deformation and may make the assessment more available in clinical and research cardiology.

Low-cost Volumetric Ultrasound by Augmentation of 2D Systems: Design and Prototype.

PubMed

Herickhoff, Carl D; Morgan, Matthew R; Broder, Joshua S; Dahl, Jeremy J

2018-01-01

Conventional two-dimensional (2D) ultrasound imaging is a powerful diagnostic tool in the hands of an experienced user, yet 2D ultrasound remains clinically underutilized and inherently incomplete, with output being very operator dependent. Volumetric ultrasound systems can more fully capture a three-dimensional (3D) region of interest, but current 3D systems require specialized transducers, are prohibitively expensive for many clinical departments, and do not register image orientation with respect to the patient; these systems are designed to provide improved workflow rather than operator independence. This work investigates whether it is possible to add volumetric 3D imaging capability to existing 2D ultrasound systems at minimal cost, providing a practical means of reducing operator dependence in ultrasound. In this paper, we present a low-cost method to make 2D ultrasound systems capable of quality volumetric image acquisition: we present the general system design and image acquisition method, including the use of a probe-mounted orientation sensor, a simple probe fixture prototype, and an offline volume reconstruction technique. We demonstrate initial results of the method, implemented using a Verasonics Vantage research scanner.

Shape-based ultrasound tomography using a Born model with application to high intensity focused ultrasound therapy.

PubMed

Ulker Karbeyaz, Başak; Miller, Eric L; Cleveland, Robin O

2008-05-01

A shaped-based ultrasound tomography method is proposed to reconstruct ellipsoidal objects using a linearized scattering model. The method is motivated by the desire to detect the presence of lesions created by high intensity focused ultrasound (HIFU) in applications of cancer therapy. The computational size and limited view nature of the relevant three-dimensional inverse problem renders impractical the use of traditional pixel-based reconstruction methods. However, by employing a shape-based parametrization it is only necessary to estimate a small number of unknowns describing the geometry of the lesion, in this paper assumed to be ellipsoidal. The details of the shape-based nonlinear inversion method are provided. Results obtained from a commercial ultrasound scanner and a tissue phantom containing a HIFU-like lesion demonstrate the feasibility of the approach where a 20 mm x 5 mm x 6 mm ellipsoidal inclusion was detected with an accuracy of around 5%.

Adaptive kernel regression for freehand 3D ultrasound reconstruction

NASA Astrophysics Data System (ADS)

Alshalalfah, Abdel-Latif; Daoud, Mohammad I.; Al-Najar, Mahasen

2017-03-01

Freehand three-dimensional (3D) ultrasound imaging enables low-cost and flexible 3D scanning of arbitrary-shaped organs, where the operator can freely move a two-dimensional (2D) ultrasound probe to acquire a sequence of tracked cross-sectional images of the anatomy. Often, the acquired 2D ultrasound images are irregularly and sparsely distributed in the 3D space. Several 3D reconstruction algorithms have been proposed to synthesize 3D ultrasound volumes based on the acquired 2D images. A challenging task during the reconstruction process is to preserve the texture patterns in the synthesized volume and ensure that all gaps in the volume are correctly filled. This paper presents an adaptive kernel regression algorithm that can effectively reconstruct high-quality freehand 3D ultrasound volumes. The algorithm employs a kernel regression model that enables nonparametric interpolation of the voxel gray-level values. The kernel size of the regression model is adaptively adjusted based on the characteristics of the voxel that is being interpolated. In particular, when the algorithm is employed to interpolate a voxel located in a region with dense ultrasound data samples, the size of the kernel is reduced to preserve the texture patterns. On the other hand, the size of the kernel is increased in areas that include large gaps to enable effective gap filling. The performance of the proposed algorithm was compared with seven previous interpolation approaches by synthesizing freehand 3D ultrasound volumes of a benign breast tumor. The experimental results show that the proposed algorithm outperforms the other interpolation approaches.

Ordered three-dimensional interconnected nanoarchitectures in anodic porous alumina

PubMed Central

Martín, Jaime; Martín-González, Marisol; Fernández, Jose Francisco; Caballero-Calero, Olga

2014-01-01

Three-dimensional nanostructures combine properties of nanoscale materials with the advantages of being macro-sized pieces when the time comes to manipulate, measure their properties, or make a device. However, the amount of compounds with the ability to self-organize in ordered three-dimensional nanostructures is limited. Therefore, template-based fabrication strategies become the key approach towards three-dimensional nanostructures. Here we report the simple fabrication of a template based on anodic aluminum oxide, having a well-defined, ordered, tunable, homogeneous 3D nanotubular network in the sub 100 nm range. The three-dimensional templates are then employed to achieve three-dimensional, ordered nanowire-networks in Bi2Te3 and polystyrene. Lastly, we demonstrate the photonic crystal behavior of both the template and the polystyrene three-dimensional nanostructure. Our approach may establish the foundations for future high-throughput, cheap, photonic materials and devices made of simple commodity plastics, metals, and semiconductors. PMID:25342247

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

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)

Ultrasound assisted three phase partitioning of a fibrinolytic enzyme.

PubMed

Avhad, Devchand N; Niphadkar, Sonali S; Rathod, Virendra K

2014-03-01

The present investigation is aimed at ultrasound assisted three phase partitioning (UATPP) of a fibrinolytic enzyme from Bacillus sphaericus MTCC 3672. Three phase partitioning integrates the concentration and partial purification step of downstream processing of a biomolecule. Three phase system is formed with simultaneous addition of ammonium sulfate to crude broth and followed by t-butanol. UATPP of a fibrinolytic enzyme was studied by varying different process parameters such as ammonium sulfate saturation concentration, pH, broth to t-butanol ratio, temperature, ultrasound frequency, ultrasonication power, and duty cycle. The optimized parameters yielding maximum purity of 16.15-fold of fibrinolytic enzyme with 65% recovery comprised of 80% ammonium sulfate saturation, pH 9, temperature 30 °C, broth to t-butanol ratio 0.5 (v/v), at 25 kHz frequency and 150 W ultrasonication power with 40% duty cycle for 5 min irradiation time. SDS PAGE analysis of partitioned enzyme shows partial purification with a molecular weight in the range of 55-70 kDa. Enhanced mass transfer of UATPP resulted in higher fold purity of fibrinolytic enzyme with reduced time of operation from 1 h to 5 min as compared to conventional TPP. Outcome of our findings highlighted the use of UATPP as an efficient biosepartion technique. Copyright © 2013 Elsevier B.V. All rights reserved.

On the Transition from Two-Dimensional to Three-Dimensional MHD Turbulence

NASA Technical Reports Server (NTRS)

Thess, A.; Zikanov, Oleg

2004-01-01

We report a theoretical investigation of the robustness of two-dimensional inviscid MHD flows at low magnetic Reynolds numbers with respect to three-dimensional perturbations. We analyze three model problems, namely flow in the interior of a triaxial ellipsoid, an unbounded vortex with elliptical streamlines, and a vortex sheet parallel to the magnetic field. We demonstrate that motion perpendicular to the magnetic field with elliptical streamlines becomes unstable with respect to the elliptical instability once the velocity has reached a critical magnitude whose value tends to zero as the eccentricity of the streamlines becomes large. Furthermore, vortex sheets parallel to the magnetic field, which are unstable for any velocity and any magnetic field, are found to emit eddies with vorticity perpendicular to the magnetic field and with an aspect ratio proportional to N(sup 1/2). The results suggest that purely two-dimensional motion without Joule energy dissipation is a singular type of flow which does not represent the asymptotic behaviour of three-dimensional MHD turbulence in the limit of infinitely strong magnetic fields.

Segmentation of real-time three-dimensional ultrasound for quantification of ventricular function: a clinical study on right and left ventricles.

PubMed

Angelini, Elsa D; Homma, Shunichi; Pearson, Gregory; Holmes, Jeffrey W; Laine, Andrew F

2005-09-01

Among screening modalities, echocardiography is the fastest, least expensive and least invasive method for imaging the heart. A new generation of three-dimensional (3-D) ultrasound (US) technology has been developed with real-time 3-D (RT3-D) matrix phased-array transducers. These transducers allow interactive 3-D visualization of cardiac anatomy and fast ventricular volume estimation without tomographic interpolation as required with earlier 3-D US acquisition systems. However, real-time acquisition speed is performed at the cost of decreasing spatial resolution, leading to echocardiographic data with poor definition of anatomical structures and high levels of speckle noise. The poor quality of the US signal has limited the acceptance of RT3-D US technology in clinical practice, despite the wealth of information acquired by this system, far greater than with any other existing echocardiography screening modality. We present, in this work, a clinical study for segmentation of right and left ventricular volumes using RT3-D US. A preprocessing of the volumetric data sets was performed using spatiotemporal brushlet denoising, as presented in previous articles Two deformable-model segmentation methods were implemented in 2-D using a parametric formulation and in 3-D using an implicit formulation with a level set implementation for extraction of endocardial surfaces on denoised RT3-D US data. A complete and rigorous validation of the segmentation methods was carried out for quantification of left and right ventricular volumes and ejection fraction, including comparison of measurements with cardiac magnetic resonance imaging as the reference. Results for volume and ejection fraction measurements report good performance of quantification of cardiac function on RT3-D data compared with magnetic resonance imaging with better performance of semiautomatic segmentation methods than with manual tracing on the US data.

Ultrasound physics and instrumentation for pathologists.

PubMed

Lieu, David

2010-10-01

Interest in pathologist-performed ultrasound-guided fine-needle aspiration is increasing. Educational courses discuss clinical ultrasound and biopsy techniques but not ultrasound physics and instrumentation. To review modern ultrasound physics and instrumentation to help pathologists understand the basis of modern ultrasound. A review of recent literature and textbooks was performed. Ultrasound physics and instrumentation are the foundations of clinical ultrasound. The key physical principle is the piezoelectric effect. When stimulated by an electric current, certain crystals vibrate and produce ultrasound. A hand-held transducer converts electricity into ultrasound, transmits it into tissue, and listens for reflected ultrasound to return. The returning echoes are converted into electrical signals and used to create a 2-dimensional gray-scale image. Scanning at a high frequency improves axial resolution but has low tissue penetration. Electronic focusing moves the long-axis focus to depth of the object of interest and improves lateral resolution. The short-axis focus in 1-dimensional transducers is fixed, which results in poor elevational resolution away from the focal zone. Using multiple foci improves lateral resolution but degrades temporal resolution. The sonographer can adjust the dynamic range to change contrast and bring out subtle masses. Contrast resolution is limited by processing speed, monitor resolution, and gray-scale perception of the human eye. Ultrasound is an evolving field. New technologies include miniaturization, spatial compound imaging, tissue harmonics, and multidimensional transducers. Clinical cytopathologists who understand ultrasound physics, instrumentation, and clinical ultrasound are ready for the challenges of cytopathologist-performed ultrasound-guided fine-needle aspiration and core-needle biopsy in the 21st century.

Guiding tissue regeneration with ultrasound in vitro and in vivo

NASA Astrophysics Data System (ADS)

Dalecki, Diane; Comeau, Eric S.; Raeman, Carol H.; Child, Sally Z.; Hobbs, Laura; Hocking, Denise C.

2015-05-01

Developing new technologies that enable the repair or replacement of injured or diseased tissues is a major focus of regenerative medicine. This paper will discuss three ultrasound technologies under development in our laboratories to guide tissue regeneration both in vitro and in vivo. A critical obstacle in tissue engineering is the need for rapid and effective tissue vascularization strategies. To address this challenge, we are developing acoustic patterning techniques for microvascular tissue engineering. Acoustic radiation forces associated with ultrasound standing wave fields provide a rapid, non-invasive approach to spatially pattern cells in three dimensions without affecting cell viability. Acoustic patterning of endothelial cells leads to the rapid formation of microvascular networks throughout the volumes of three-dimensional hydrogels, and the morphology of the resultant microvessel networks can be controlled by design of the ultrasound field. A second technology under development uses ultrasound to noninvasively control the microstructure of collagen fibers within engineered tissues. The microstructure of extracellular matrix proteins provides signals that direct cell functions critical to tissue regeneration. Thus, controlling collagen microfiber structure with ultrasound provides a noninvasive approach to regulate the mechanical properties of biomaterials and control cellular responses. The third technology employs therapeutic ultrasound to enhance the healing of chronic wounds. Recent studies demonstrate increased granulation tissue thickness and collagen deposition in murine dermal wounds exposed to pulsed ultrasound. In summary, ultrasound technologies offer noninvasive approaches to control cell behaviors and extracellular matrix organization and thus hold great promise to advance tissue regeneration in vitro and in vivo.

Three-Dimensional Photoacoustic Endoscopic Imaging of the Rabbit Esophagus

PubMed Central

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. PMID:25874640

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.

Virtual three-dimensional blackboard: three-dimensional finger tracking with a single camera

NASA Astrophysics Data System (ADS)

Wu, Andrew; Hassan-Shafique, Khurram; Shah, Mubarak; da Vitoria Lobo, N.

2004-01-01

We present a method for three-dimensional (3D) tracking of a human finger from a monocular sequence of images. To recover the third dimension from the two-dimensional images, we use the fact that the motion of the human arm is highly constrained owing to the dependencies between elbow and forearm and the physical constraints on joint angles. We use these anthropometric constraints to derive a 3D trajectory of a gesticulating arm. The system is fully automated and does not require human intervention. The system presented can be used as a visualization tool, as a user-input interface, or as part of some gesture-analysis system in which 3D information is important.

Standards of ultrasound imaging of the adrenal glands

PubMed Central

Jakubowski, Wiesław S.; Dobruch-Sobczak, Katarzyna; Kasperlik-Załuska, Anna A.

2015-01-01

Adrenal glands are paired endocrine glands located over the upper renal poles. Adrenal pathologies have various clinical presentations. They can coexist with the hyperfunction of individual cortical zones or the medulla, insufficiency of the adrenal cortex or retained normal hormonal function. The most common adrenal masses are tumors incidentally detected in imaging examinations (ultrasound, tomography, magnetic resonance imaging), referred to as incidentalomas. They include a range of histopathological entities but cortical adenomas without hormonal hyperfunction are the most common. Each abdominal ultrasound scan of a child or adult should include the assessment of the suprarenal areas. If a previously non-reported, incidental solid focal lesion exceeding 1 cm (incidentaloma) is detected in the suprarenal area, computed tomography or magnetic resonance imaging should be conducted to confirm its presence and for differentiation and the tumor functional status should be determined. Ultrasound imaging is also used to monitor adrenal incidentaloma that is not eligible for a surgery. The paper presents recommendations concerning the performance and assessment of ultrasound examinations of the adrenal glands and their pathological lesions. The article includes new ultrasound techniques, such as tissue harmonic imaging, spatial compound imaging, three-dimensional ultrasound, elastography, contrast-enhanced ultrasound and parametric imaging. The guidelines presented above are consistent with the recommendations of the Polish Ultrasound Society. PMID:26807295

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.

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

Three-dimensional deformation of orthodontic brackets.

PubMed

Melenka, Garrett W; Nobes, David S; Major, Paul W; Carey, Jason P

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.

Inverse energy cascades in three-dimensional turbulence

NASA Technical Reports Server (NTRS)

Hossain, Murshed

1991-01-01

Fully three-dimensional magnetohydrodynamic (MHD) turbulence at large kinetic and low magnetic Reynolds numbers is considered in the presence of a strong uniform magnetic field. It is shown by numerical simulation of a model of MHD that the energy inverse cascades to longer length scales when the interaction parameter is large. While the steady-state dynamics of the driven problem is three-dimensional in character, the behavior has resemblance to two-dimensional hydrodynamics. These results have implications in turbulence theory, MHD power generator, planetary dynamos, and fusion reactor blanket design.

Advancing three-dimensional MEMS by complimentary laser micro manufacturing

NASA Astrophysics Data System (ADS)

Palmer, Jeremy A.; Williams, John D.; Lemp, Tom; Lehecka, Tom M.; Medina, Francisco; Wicker, Ryan B.

2006-01-01

This paper describes improvements that enable engineers to create three-dimensional MEMS in a variety of materials. It also provides a means for selectively adding three-dimensional, high aspect ratio features to pre-existing PMMA micro molds for subsequent LIGA processing. This complimentary method involves in situ construction of three-dimensional micro molds in a stand-alone configuration or directly adjacent to features formed by x-ray lithography. Three-dimensional micro molds are created by micro stereolithography (MSL), an additive rapid prototyping technology. Alternatively, three-dimensional features may be added by direct femtosecond laser micro machining. Parameters for optimal femtosecond laser micro machining of PMMA at 800 nanometers are presented. The technical discussion also includes strategies for enhancements in the context of material selection and post-process surface finish. This approach may lead to practical, cost-effective 3-D MEMS with the surface finish and throughput advantages of x-ray lithography. Accurate three-dimensional metal microstructures are demonstrated. Challenges remain in process planning for micro stereolithography and development of buried features following femtosecond laser micro machining.

Picture perfect: benefits and risk of fetal 3D ultrasound.

PubMed

Wiseman, Claudia S; Kiehl, Ermalynn M

2007-01-01

The purpose of this literature review was to survey available information and research related to routine three-dimensional (3D) ultrasound technology in obstetrics, with an emphasis on current medical uses, safety, and availability issues. Several data bases, including Cochrane, WHO, NIH, CINALH, Blackwell Synergy, ERIC, PubMed, and Medline, were used along with information from Internet search engines. Although fetal 3D ultrasound is used in both medical and commercial settings, recent studies focus on its possible uses rather than the more difficult issues of safety and commercial applications. Professional organizations associated with ultrasound technology support limiting ultrasounds in pregnancy to medically necessary events, whereas commercial venues use "direct to consumer" marketing to promote this technology as a way to "see" the baby before it is born. How safe is routine or frequent use of 3D ultrasound? Further research is needed to address these important questions.

Probe Oscillation Shear Elastography (PROSE): A High Frame-Rate Method for Two-Dimensional Ultrasound Shear Wave Elastography.

PubMed

Mellema, Daniel C; Song, Pengfei; Kinnick, Randall R; Urban, Matthew W; Greenleaf, James F; Manduca, Armando; Chen, Shigao

2016-09-01

Ultrasound shear wave elastography (SWE) utilizes the propagation of induced shear waves to characterize the shear modulus of soft tissue. Many methods rely on an acoustic radiation force (ARF) "push beam" to generate shear waves. However, specialized hardware is required to generate the push beams, and the thermal stress that is placed upon the ultrasound system, transducer, and tissue by the push beams currently limits the frame-rate to about 1 Hz. These constraints have limited the implementation of ARF to high-end clinical systems. This paper presents Probe Oscillation Shear Elastography (PROSE) as an alternative method to measure tissue elasticity. PROSE generates shear waves using a harmonic mechanical vibration of an ultrasound transducer, while simultaneously detecting motion with the same transducer under pulse-echo mode. Motion of the transducer during detection produces a "strain-like" compression artifact that is coupled with the observed shear waves. A novel symmetric sampling scheme is proposed such that pulse-echo detection events are acquired when the ultrasound transducer returns to the same physical position, allowing the shear waves to be decoupled from the compression artifact. Full field-of-view (FOV) two-dimensional (2D) shear wave speed images were obtained by applying a local frequency estimation (LFE) technique, capable of generating a 2D map from a single frame of shear wave motion. The shear wave imaging frame rate of PROSE is comparable to the vibration frequency, which can be an order of magnitude higher than ARF based techniques. PROSE was able to produce smooth and accurate shear wave images from three homogeneous phantoms with different moduli, with an effective frame rate of 300 Hz. An inclusion phantom study showed that increased vibration frequencies improved the accuracy of inclusion imaging, and allowed targets as small as 6.5 mm to be resolved with good contrast (contrast-to-noise ratio ≥ 19 dB) between the target and

Probe Oscillation Shear Elastography (PROSE): A High Frame-Rate Method for Two-Dimensional Ultrasound Shear Wave Elastography

PubMed Central

Mellema, Daniel C.; Song, Pengfei; Kinnick, Randall R.; Urban, Matthew W.; Greenleaf, James F.; Manduca, Armando; Chen, Shigao

2017-01-01

Ultrasound shear wave elastography (SWE) utilizes the propagation of induced shear waves to characterize the shear modulus of soft tissue. Many methods rely on an acoustic radiation force (ARF) “push beam” to generate shear waves. However, specialized hardware is required to generate the push beams, and the thermal stress that is placed upon the ultrasound system, transducer, and tissue by the push beams currently limits the frame-rate to about 1 Hz. These constraints have limited the implementation of ARF to high-end clinical systems. This paper presents Probe Oscillation Shear Elastography (PROSE) as an alternative method to measure tissue elasticity. PROSE generates shear waves using a harmonic mechanical vibration of an ultrasound transducer, while simultaneously detecting motion with the same transducer under pulse-echo mode. Motion of the transducer during detection produces a “strain-like” compression artifact that is coupled with the observed shear waves. A novel symmetric sampling scheme is proposed such that pulse-echo detection events are acquired when the ultrasound transducer returns to the same physical position, allowing the shear waves to be decoupled from the compression artifact. Full field-of-view (FOV) two-dimensional (2D) shear wave speed images were obtained by applying a local frequency estimation (LFE) technique, capable of generating a 2D map from a single frame of shear wave motion. The shear wave imaging frame rate of PROSE is comparable to the vibration frequency, which can be an order of magnitude higher than ARF based techniques. PROSE was able to produce smooth and accurate shear wave images from three homogeneous phantoms with different moduli, with an effective frame rate of 300Hz. An inclusion phantom study showed that increased vibration frequencies improved the accuracy of inclusion imaging, and allowed targets as small as 6.5 mm to be resolved with good contrast (contrast-to-noise ratio ≥19 dB) between the target and

Two-dimensional Shear Wave Elastography on Conventional Ultrasound Scanners with Time Aligned Sequential Tracking (TAST) and Comb-push Ultrasound Shear Elastography (CUSE)

PubMed Central

Song, Pengfei; Macdonald, Michael C.; Behler, Russell H.; Lanning, Justin D.; Wang, Michael H.; Urban, Matthew W.; Manduca, Armando; Zhao, Heng; Callstrom, Matthew R.; Alizad, Azra; Greenleaf, James F.; Chen, Shigao

2014-01-01

Two-dimensional (2D) shear wave elastography presents 2D quantitative shear elasticity maps of tissue, which are clinically useful for both focal lesion detection and diffuse disease diagnosis. Realization of 2D shear wave elastography on conventional ultrasound scanners, however, is challenging due to the low tracking pulse-repetition-frequency (PRF) of these systems. While some clinical and research platforms support software beamforming and plane wave imaging with high PRF, the majority of current clinical ultrasound systems do not have the software beamforming capability, which presents a critical challenge for translating the 2D shear wave elastography technique from laboratory to clinical scanners. To address this challenge, this paper presents a Time Aligned Sequential Tracking (TAST) method for shear wave tracking on conventional ultrasound scanners. TAST takes advantage of the parallel beamforming capability of conventional systems and realizes high PRF shear wave tracking by sequentially firing tracking vectors and aligning shear wave data in the temporal direction. The Comb-push Ultrasound Shear Elastography (CUSE) technique was used to simultaneously produce multiple shear wave sources within the field-of-view (FOV) to enhance shear wave signal-to-noise-ratio (SNR) and facilitate robust reconstructions of 2D elasticity maps. TAST and CUSE were realized on a conventional ultrasound scanner (the General Electric LOGIQ E9). A phantom study showed that the shear wave speed measurements from the LOGIQ E9 were in good agreement to the values measured from other 2D shear wave imaging technologies. An inclusion phantom study showed that the LOGIQ E9 had comparable performance to the Aixplorer (Supersonic Imagine) in terms of bias and precision in measuring different sized inclusions. Finally, in vivo case analysis of a breast with a malignant mass, and a liver from a healthy subject demonstrated the feasibility of using the LOGIQ E9 for in vivo 2D shear wave

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…

Design and evaluation of a 63 element 1.75-dimensional ultrasound phased array for treating benign prostatic hyperplasia

NASA Astrophysics Data System (ADS)

Saleh, Khaldon Y.; Smith, Nadine B.

2003-10-01

Focused ultrasound surgery (FUS) is a clinical method for treating benign prostatic hyperplasia (BPH) in which tissue is noninvasively necrosed by elevating the temperature at the focal point above 60°C using short sonications. With 1.75-dimensional (1.75-D) arrays, the power and phase to the individual elements can be controlled electronically for focusing and steering. This research describes the design, construction and evaluation of a 1.75-D ultrasound phased array to be used in the treatment of benign prostatic hyperplasia. The array was designed with a steering angle of +/-13.5 deg in the transverse direction, and can move the focus in three parallel planes in the longitudinal direction with a relatively large focus size. A piezoelectric ceramic (PZT-8) was used as the material of the transducer and two matching layers were built for maximum acoustic power transmission to tissue. To verify the capability of the transducer for focusing and steering, exposimetry was performed and the results correlated well with the calculated fields. In vivo experiments were performed to verify the capability of the transducer to ablate tissue using short sonications. [Work supported by the Whitaker Foundation and the Department of Defense Congressionally Directed Medical Prostate Cancer Research Program.

Structure of turbulence in three-dimensional boundary layers

NASA Technical Reports Server (NTRS)

Subramanian, Chelakara S.

1993-01-01

This report provides an overview of the three dimensional turbulent boundary layer concepts and of the currently available experimental information for their turbulence modeling. It is found that more reliable turbulence data, especially of the Reynolds stress transport terms, is needed to improve the existing modeling capabilities. An experiment is proposed to study the three dimensional boundary layer formed by a 'sink flow' in a fully developed two dimensional turbulent boundary layer. Also, the mean and turbulence field measurement procedure using a three component laser Doppler velocimeter is described.

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.

The validity of ultrasound estimation of muscle volumes.

PubMed

Infantolino, Benjamin W; Gales, Daniel J; Winter, Samantha L; Challis, John H

2007-08-01

The purpose of this study was to validate ultrasound muscle volume estimation in vivo. To examine validity, vastus lateralis ultrasound images were collected from cadavers before muscle dissection; after dissection, the volumes were determined by hydrostatic weighing. Seven thighs from cadaver specimens were scanned using a 7.5-MHz ultrasound probe (SSD-1000, Aloka, Japan). The perimeter of the vastus lateralis was identified in the ultrasound images and manually digitized. Volumes were then estimated using the Cavalieri principle, by measuring the image areas of sets of parallel two-dimensional slices through the muscles. The muscles were then dissected from the cadavers, and muscle volume was determined via hydrostatic weighing. There was no statistically significant difference between the ultrasound estimation of muscle volume and that estimated using hydrostatic weighing (p > 0.05). The mean percentage error between the two volume estimates was 0.4% +/- 6.9. Three operators all performed four digitizations of all images from one randomly selected muscle; there was no statistical difference between operators or trials and the intraclass correlation was high (>0.8). The results of this study indicate that ultrasound is an accurate method for estimating muscle volumes in vivo.

Three Dimensional Underwater Sound Propagation Over Sloping Bottoms

NASA Astrophysics Data System (ADS)

Glegg, Stewart A. L.; Riley, J. M.

This article reviews the work which has been carried out over the past few years on three dimensional underwater sound propagation over sloping bottoms. When sound propagates across a slope three dimensional effects can cause shadow zones and mode cut off effects to occur, which could not be predicted by a two dimensional model. For many years the theory for this type of propagation over realistic ocean floors, which can support both compressional and shear waves, eluded workers in this field. Recently the complete solution for the acoustic field in a "wedge domain with penetrable boundaries" has been developed, and this has allowed for complete understanding of three dimensional bottom interacting sound propagation. These theories have been verified by a series of laboratory scale experiments and excellent agreement has been obtained. However only one full scale ocean experiment has been carried out on three dimensional, bottom interacting, acoustic propagation. This showed significant horizontal refraction of sound propagating across a continental slope and further verifies the importance of bottom slopes on underwater sound propagation.

Multi-depth fractionated aesthetic ultrasound surgery

NASA Astrophysics Data System (ADS)

Slayton, Michael H.; Lyke, Stephanie; Barthe, Peter G.

2017-03-01

Objective: Aesthetic ultrasound surgery provides the ability to treat at precise, clinically relevant depths with varied lesion size. This represents a major advantage compared to cosmetic laser and RF based energy sources. We present results of pre-clinical and clinical research aimed at establishing the feasibility of three-dimensional fractional deposition of focused ultrasound energy in the first 3mm of skin. Conformal thermal lesions were created in ex-vivo porcine muscle and live human skin in a variety of depths and geometries. Gross pathology demonstrating a three-dimensional pattern of non-intersecting lesions was micro- photographed and characterized in porcine tissue, and followed up to thirty days post treatment in human tissue. Methods: Image/treat transducers from 7.5 to 10 MHz, focal depths of 1 to 3 mm, and energies of 160 to 300 mJ were used to lay down a three-dimensional pattern of non-intersecting thermal lesions in freshly excised porcine muscle tissue. Human skin was treated in vivo at 120 to 360 mJ per lesion. Results were photographed immediately post-treatment and followed up to 30 days. Results: Porcine tissue lesion geometry was measured. Average lesion dimensions approximated by a sphere ranged from 360 micron (±19%) to 520 micron (±23%) varying with the energy settings. Measured depth and distance between the thermal lesions were within ±13% of the focal depth and lesion spacing. In human skin all lesions for all energy settings were completely resolved during the follow-up period. At lower energy settings of 120 mJ and 160 mJ lesions were completely resolved by day 2. Mild erythema and localized swelling were the only transient side effects and resolved within 48 hours or less. Conclusions: In conclusion, skin may be successfully treated in a three-dimensional fractionated manner with predictable and precise deposition of thermal damage. In vivo results demonstrate tolerability and fast resolution with minimal side effects.

Simulation of pseudo-CT images based on deformable image registration of ultrasound images: A proof of concept for transabdominal ultrasound imaging of the prostate during radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meer, Skadi van der; Camps, Saskia M.; Oncology Solutions Department, Philips Research, High Tech Campus 34, Eindhoven 5656 AE

Purpose: Imaging of patient anatomy during treatment is a necessity for position verification and for adaptive radiotherapy based on daily dose recalculation. Ultrasound (US) image guided radiotherapy systems are currently available to collect US images at the simulation stage (US{sub sim}), coregistered with the simulation computed tomography (CT), and during all treatment fractions. The authors hypothesize that a deformation field derived from US-based deformable image registration can be used to create a daily pseudo-CT (CT{sub ps}) image that is more representative of the patients’ geometry during treatment than the CT acquired at simulation stage (CT{sub sim}). Methods: The three prostatemore » patients, considered to evaluate this hypothesis, had coregistered CT and US scans on various days. In particular, two patients had two US–CT datasets each and the third one had five US–CT datasets. Deformation fields were computed between pairs of US images of the same patient and then applied to the corresponding US{sub sim} scan to yield a new deformed CT{sub ps} scan. The original treatment plans were used to recalculate dose distributions in the simulation, deformed and ground truth CT (CT{sub gt}) images to compare dice similarity coefficients, maximum absolute distance, and mean absolute distance on CT delineations and gamma index (γ) evaluations on both the Hounsfield units (HUs) and the dose. Results: In the majority, deformation did improve the results for all three evaluation methods. The change in gamma failure for dose (γ{sub Dose}, 3%, 3 mm) ranged from an improvement of 11.2% in the prostate volume to a deterioration of 1.3% in the prostate and bladder. The change in gamma failure for the CT images (γ{sub CT}, 50 HU, 3 mm) ranged from an improvement of 20.5% in the anus and rectum to a deterioration of 3.2% in the prostate. Conclusions: This new technique may generate CT{sub ps} images that are more representative of the actual patient anatomy

Comparison of thyroid segmentation techniques for 3D ultrasound

NASA Astrophysics Data System (ADS)

Wunderling, T.; Golla, B.; Poudel, P.; Arens, C.; Friebe, M.; Hansen, C.

2017-02-01

The segmentation of the thyroid in ultrasound images is a field of active research. The thyroid is a gland of the endocrine system and regulates several body functions. Measuring the volume of the thyroid is regular practice of diagnosing pathological changes. In this work, we compare three approaches for semi-automatic thyroid segmentation in freehand-tracked three-dimensional ultrasound images. The approaches are based on level set, graph cut and feature classification. For validation, sixteen 3D ultrasound records were created with ground truth segmentations, which we make publicly available. The properties analyzed are the Dice coefficient when compared against the ground truth reference and the effort of required interaction. Our results show that in terms of Dice coefficient, all algorithms perform similarly. For interaction, however, each algorithm has advantages over the other. The graph cut-based approach gives the practitioner direct influence on the final segmentation. Level set and feature classifier require less interaction, but offer less control over the result. All three compared methods show promising results for future work and provide several possible extensions.

Power Doppler flow mapping and four-dimensional ultrasound for evaluating tubal patency compared with laparoscopy.

PubMed

Soliman, Amr A; Shaalan, Waleed; Abdel-Dayem, Tamer; Awad, Elsayed Elbadawy; Elkassar, Yasser; Lüdders, Dörte; Malik, Eduard; Sallam, Hassan N

2015-12-01

To study the accuracy of four-dimensional (4D) ultrasound and power Doppler flow mapping in detecting tubal patency in women with sub-/infertility, and compare it with laparoscopy and chromopertubation. A prospective study. The study was performed in the outpatient clinic and infertility unit of a university hospital. The sonographic team and laparoscopic team were blinded to the results of each other. Women aged younger than 43 years seeking medical advice due to primary or secondary infertility and who planned to have a diagnostic laparoscopy performed, were recruited to the study after signing an informed consent. All of the recruited patients had power Doppler flow mapping and 4D hysterosalpingo-sonography by injecting sterile saline into the fallopian tubes 1 day before surgery. Registering Doppler signals, while using power Doppler, both at the tubal ostia and fimbrial end and the ability to demonstrate the course of the tube especially the isthmus and fimbrial end, while using 4D mode, was considered a patent tube. Out of 50 recruited patients, 33 women had bilateral patent tubes and five had unilateral patent tubes as shown by chromopertubation during diagnostic laparoscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for two-dimensional power Doppler hysterosalpingography were 94.4%, 100%, 100%, 89.2%, and 96.2%, respectively and for 4D ultrasound were 70.4%, 100%, 100%, 70.4%, and 82.6%, respectively. Four-dimensional saline hysterosalpingography has acceptable accuracy in detecting tubal patency, but is surpassed by power Doppler saline hysterosalpingography. Power Doppler saline hysterosalpingography could be incorporated into the routine sub-/infertility workup. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Continuum modeling of three-dimensional truss-like space structures

NASA Technical Reports Server (NTRS)

Nayfeh, A. H.; Hefzy, M. S.

1978-01-01

A mathematical and computational analysis capability has been developed for calculating the effective mechanical properties of three-dimensional periodic truss-like structures. Two models are studied in detail. The first, called the octetruss model, is a three-dimensional extension of a two-dimensional model, and the second is a cubic model. Symmetry considerations are employed as a first step to show that the specific octetruss model has four independent constants and that the cubic model has two. The actual values of these constants are determined by averaging the contributions of each rod element to the overall structure stiffness. The individual rod member contribution to the overall stiffness is obtained by a three-dimensional coordinate transformation. The analysis shows that the effective three-dimensional elastic properties of both models are relatively close to each other.

Power-scaling performance of a three-dimensional tritium betavoltaic diode

NASA Astrophysics Data System (ADS)

Liu, Baojun; Chen, Kevin P.; Kherani, Nazir P.; Zukotynski, Stefan

2009-12-01

Three-dimensional diodes fabricated by electrochemical etching are exposed to tritium gas at pressures from 0.05 to 33 atm at room temperature to examine its power scaling performance. It is shown that the three-dimensional microporous structure overcomes the self-absorption limited saturation of beta flux at high tritium pressures. These results are contrasted against the three-dimensional device powered in one instance by tritium absorbed in the near surface region of the three-dimensional microporous network, and in another by a planar scandium tritide foil. These findings suggest that direct tritium occlusion in the near surface of three-dimensional diode can improve the specific power production.

Value of transperineal ultrasound on the observation of paravaginal support.

PubMed

Dou, Chaoran; Li, Qin; Ying, Tao; Shui, Wen; Yan, Yulin; Luo, Yijia; Wang, Xia

2018-04-01

To explore the feasibility of three-dimensional (3D) transperineal ultrasound on the observation of paravaginal support in nulliparous and postpartum women. Volume datasets were acquired in 50 nulliparous and 100 postpartum women using 3D transperineal ultrasound. Paravaginal supports were observed by studying the vaginal cross-sectional morphology. The extent of paravaginal support in specific level were evaluated by counting out at a 2 mm interval in tomographic ultrasound imaging mode in all subjects. The Mann-Whitney U test were applied to establish comparisons between the two groups. Three representative manifestations of vaginal cross-sectional morphology corresponding to different paravaginal support were presented from the dorsal side to the caudal side, both in nulliparous women and postpartum women. The extent of paravaginal support in middle vagina was 11 slices (range 9-12) in nulliparous women and 7 slices (range 4-10) in postpartum women (P < 0.05). This pilot study confirmed that it was feasible to indirectly study paravaginal support by observing the vaginal cross-sectional morphology using 3D transperineal ultrasound.

Modern cosmology and the origin of our three dimensionality.

PubMed

Woodbury, M A; Woodbury, M F

1998-01-01

We are three dimensional egocentric beings existing within a specific space/time continuum and dimensionality which we assume wrongly is the same for all times and places throughout the entire universe. Physicists name Omnipoint the origin of the universe at Dimension zero, which exploded as a Big Bang of energy proceeding at enormous speed along one dimension which eventually curled up into matter: particles, atoms, molecules and Galaxies which exist in two dimensional space. Finally from matter spread throughout the cosmos evolved life generating eventually the DNA molecules which control the construction of brains complex enough to construct our three dimensional Body Representation from which is extrapolated what we perceive as a 3-D universe. The whole interconnected structures which conjure up our three dimensionality are as fragile as Humpty Dumpty, capable of breaking apart with terrifying effects for the individual patient during a psychotic panic, revealing our three dimensionality to be but "maya", an illusion, which we psychiatrists work at putting back together.

Toward real-time temperature monitoring in fat and aqueous tissue during magnetic resonance-guided high-intensity focused ultrasound using a three-dimensional proton resonance frequency T1 method.

PubMed

Diakite, Mahamadou; Odéen, Henrik; Todd, Nick; Payne, Allison; Parker, Dennis L

2014-07-01

To present a three-dimensional (3D) segmented echoplanar imaging (EPI) pulse sequence implementation that provides simultaneously the proton resonance frequency shift temperature of aqueous tissue and the longitudinal relaxation time (T1 ) of fat during thermal ablation. The hybrid sequence was implemented by combining a 3D segmented flyback EPI sequence, the extended two-point Dixon fat and water separation, and the double flip angle T1 mapping techniques. High-intensity focused ultrasound (HIFU) heating experiments were performed at three different acoustic powers on excised human breast fat embedded in ex vivo porcine muscle. Furthermore, T1 calibrations with temperature in four different excised breast fat samples were performed, yielding an estimate of the average and variation of dT1 /dT across subjects. The water only images were used to mask the complex original data before computing the proton resonance frequency shift. T1 values were calculated from the fat-only images. The relative temperature coefficients were found in five fat tissue samples from different patients and ranged from 1.2% to 2.6%/°C. The results demonstrate the capability of real-time simultaneous temperature mapping in aqueous tissue and T1 mapping in fat during HIFU ablation, providing a potential tool for treatment monitoring in organs with large fat content, such as the breast. Copyright © 2013 Wiley Periodicals, Inc.

Efficient implementation of parallel three-dimensional FFT on clusters of PCs

NASA Astrophysics Data System (ADS)

Takahashi, Daisuke

2003-05-01

In this paper, we propose a high-performance parallel three-dimensional fast Fourier transform (FFT) algorithm on clusters of PCs. The three-dimensional FFT algorithm can be altered into a block three-dimensional FFT algorithm to reduce the number of cache misses. We show that the block three-dimensional FFT algorithm improves performance by utilizing the cache memory effectively. We use the block three-dimensional FFT algorithm to implement the parallel three-dimensional FFT algorithm. We succeeded in obtaining performance of over 1.3 GFLOPS on an 8-node dual Pentium III 1 GHz PC SMP cluster.

Human embryonic growth and development of the cerebellum using 3-dimensional ultrasound and virtual reality.

PubMed

Rousian, M; Groenenberg, I A L; Hop, W C; Koning, A H J; van der Spek, P J; Exalto, N; Steegers, E A P

2013-08-01

The aim of our study was to evaluate the first trimester cerebellar growth and development using 2 different measuring techniques: 3-dimensional (3D) and virtual reality (VR) ultrasound visualization. The cerebellum measurements were related to gestational age (GA) and crown-rump length (CRL). Finally, the reproducibility of both the methods was tested. In a prospective cohort study, we collected 630 first trimester, serially obtained, 3D ultrasound scans of 112 uncomplicated pregnancies between 7 + 0 and 12 + 6 weeks of GA. Only scans with high-quality images of the fossa posterior were selected for the analysis. Measurements were performed offline in the coronal plane using 3D (4D view) and VR (V-Scope) software. The VR enables the observer to use all available dimensions in a data set by visualizing the volume as a "hologram." Total cerebellar diameter, left, and right hemispheric diameter, and thickness were measured using both the techniques. All measurements were performed 3 times and means were used in repeated measurements analysis. After exclusion criteria were applied 177 (28%) 3D data sets were available for further analysis. The median GA was 10 + 0 weeks and the median CRL was 31.4 mm (range: 5.2-79.0 mm). The cerebellar parameters could be measured from 7 gestational weeks onward. The total cerebellar diameter increased from 2.2 mm at 7 weeks of GA to 13.9 mm at 12 weeks of GA using VR and from 2.2 to 13.8 mm using 3D ultrasound. The reproducibility, established in a subset of 35 data sets, resulted in intraclass correlation coefficient values ≥0.98. It can be concluded that cerebellar measurements performed by the 2 methods proved to be reproducible and comparable with each other. However, VR-using all three dimensions-provides a superior method for the visualization of the cerebellum. The constructed reference values can be used to study normal and abnormal cerebellar growth and development.

Depth-enhanced three-dimensional-two-dimensional convertible display based on modified integral imaging.

PubMed

Park, Jae-Hyeung; Kim, Hak-Rin; Kim, Yunhee; Kim, Joohwan; Hong, Jisoo; Lee, Sin-Doo; Lee, Byoungho

2004-12-01

A depth-enhanced three-dimensional-two-dimensional convertible display that uses a polymer-dispersed liquid crystal based on the principle of integral imaging is proposed. In the proposed method, a lens array is located behind a transmission-type display panel to form an array of point-light sources, and a polymer-dispersed liquid crystal is electrically controlled to pass or to scatter light coming from these point-light sources. Therefore, three-dimensional-two-dimensional conversion is accomplished electrically without any mechanical movement. Moreover, the nonimaging structure of the proposed method increases the expressible depth range considerably. We explain the method of operation and present experimental results.

A moving observer in a three-dimensional world

PubMed Central

2016-01-01

For many tasks such as retrieving a previously viewed object, an observer must form a representation of the world at one location and use it at another. A world-based three-dimensional reconstruction of the scene built up from visual information would fulfil this requirement, something computer vision now achieves with great speed and accuracy. However, I argue that it is neither easy nor necessary for the brain to do this. I discuss biologically plausible alternatives, including the possibility of avoiding three-dimensional coordinate frames such as ego-centric and world-based representations. For example, the distance, slant and local shape of surfaces dictate the propensity of visual features to move in the image with respect to one another as the observer's perspective changes (through movement or binocular viewing). Such propensities can be stored without the need for three-dimensional reference frames. The problem of representing a stable scene in the face of continual head and eye movements is an appropriate starting place for understanding the goal of three-dimensional vision, more so, I argue, than the case of a static binocular observer. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269608

Evaluation of three-dimensional virtual perception of garments

NASA Astrophysics Data System (ADS)

Aydoğdu, G.; Yeşilpinar, S.; Erdem, D.

2017-10-01

In recent years, three-dimensional design, dressing and simulation programs came into prominence in the textile industry. By these programs, the need to produce clothing samples for every design in design process has been eliminated. Clothing fit, design, pattern, fabric and accessory details and fabric drape features can be evaluated easily. Also, body size of virtual mannequin can be adjusted so more realistic simulations can be created. Moreover, three-dimensional virtual garment images created by these programs can be used while presenting the product to end-user instead of two-dimensional photograph images. In this study, a survey was carried out to investigate the visual perception of consumers. The survey was conducted for three different garment types, separately. Questions about gender, profession etc. was asked to the participants and expected them to compare real samples and artworks or three-dimensional virtual images of garments. When survey results were analyzed statistically, it is seen that demographic situation of participants does not affect visual perception and three-dimensional virtual garment images reflect the real sample characteristics better than artworks for each garment type. Also, it is reported that there is no perception difference depending on garment type between t-shirt, sweatshirt and tracksuit bottom.

A brief history of ultrasound in rheumatology: where we were.

PubMed

Grassi, Walter; Filippucci, Emilio

2014-01-01

Ultrasonography in the '70s was a well-known and widely used method within several medical specialties but not in rheumatology. Initial development of the field was led by radiologists who mainly investigated the potential of ultrasound in the assessment of large joints. In the late '80s, the first studies supporting the role of ultrasound in the detection of soft tissue changes and bone erosions in the hands of patients with rheumatoid arthritis were published. In the '90s, the dramatic improvement of spatial resolution due to the new generation high frequency probes opened up new avenues for the exploration of otherwise undetectable anatomical details. Ultrasound research during this period was enhanced by the growing use of colour Doppler and power Doppler and by the first prototypes of three dimensional ultrasound. Over the last 10 years, the buzz words in ultrasound research in rheumatology have been standardisation, early diagnosis and therapy monitoring.

Multigrid calculation of three-dimensional turbomachinery flows

NASA Technical Reports Server (NTRS)

Caughey, David A.

1989-01-01

Research was performed in the general area of computational aerodynamics, with particular emphasis on the development of efficient techniques for the solution of the Euler and Navier-Stokes equations for transonic flows through the complex blade passages associated with turbomachines. In particular, multigrid methods were developed, using both explicit and implicit time-stepping schemes as smoothing algorithms. The specific accomplishments of the research have included: (1) the development of an explicit multigrid method to solve the Euler equations for three-dimensional turbomachinery flows based upon the multigrid implementation of Jameson's explicit Runge-Kutta scheme (Jameson 1983); (2) the development of an implicit multigrid scheme for the three-dimensional Euler equations based upon lower-upper factorization; (3) the development of a multigrid scheme using a diagonalized alternating direction implicit (ADI) algorithm; (4) the extension of the diagonalized ADI multigrid method to solve the Euler equations of inviscid flow for three-dimensional turbomachinery flows; and also (5) the extension of the diagonalized ADI multigrid scheme to solve the Reynolds-averaged Navier-Stokes equations for two-dimensional turbomachinery flows.

Three-dimensional shear wave elastography for differentiation of breast lesions: An initial study with quantitative analysis using three orthogonal planes.

PubMed

Wang, Qiao

2018-05-25

To prospectively evaluate the diagnostic performance of three-dimensional (3D) shear wave elastography (SWE) for breast lesions with quantitative stiffness information from transverse, sagittal and coronal planes. Conventional ultrasound (US), two-dimensional (2D)-SWE and 3D-SWE were performed for 122 consecutive patients with 122 breast lesions before biopsy or surgical excision. Maximum elasticity values of Young's modulus (Emax) were recorded on 2D-SWE and three planes of 3D-SWE. Area under the receiver operating characteristic curve (AUC), sensitivity and specificity of US, 2D-SWE and 3D-SWE were evaluated. Two combined sets (i.e., BI-RADS and 2D-SWE; BI-RADS and 3D-SWE) were compared in AUC. Observer consistency was also evaluated. On 3D-SWE, the AUC and sensitivity of sagittal plane were significantly higher than those of transverse and coronal planes (both P < 0.05). Compared with BI-RADS alone, both combined sets had significantly (P < 0.05) higher AUCs and specificities, whereas, the two combined sets showed no significant difference in AUC (P > 0.05). However, the combined set of BI-RADS and sagittal plane of 3D-SWE had significantly higher sensitivity than the combined set of BI-RADS and 2D-SWE. The sagittal plane shows the best diagnostic performance among 3D-SWE. The combination of BI-RADS and 3D-SWE is a useful tool for predicting breast malignant lesions in comparison with BI-RADS alone.

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.

Three-dimensional labeling program for elucidation of the geometric properties of biological particles in three-dimensional space.

PubMed

Nomura, A; Yamazaki, Y; Tsuji, T; Kawasaki, Y; Tanaka, S

1996-09-15

For all biological particles such as cells or cellular organelles, there are three-dimensional coordinates representing the centroid or center of gravity. These coordinates and other numerical parameters such as volume, fluorescence intensity, surface area, and shape are referred to in this paper as geometric properties, which may provide critical information for the clarification of in situ mechanisms of molecular and cellular functions in living organisms. We have established a method for the elucidation of these properties, designated the three-dimensional labeling program (3DLP). Algorithms of 3DLP are so simple that this method can be carried out through the use of software combinations in image analysis on a personal computer. To evaluate 3DLP, it was applied to a 32-cell-stage sea urchin embryo, double stained with FITC for cellular protein of blastomeres and propidium iodide for nuclear DNA. A stack of optical serial section images was obtained by confocal laser scanning microscopy. The method was found effective for determining geometric properties and should prove applicable to the study of many different kinds of biological particles in three-dimensional space.

One-dimensional, two-dimensional, and three-dimensional photonic crystals fabricated with interferometric techniques on ultrafine-grain silver halide emulsions

NASA Astrophysics Data System (ADS)

Ulibarrena, Manuel; Carretero, Luis; Acebal, Pablo; Madrigal, Roque; Blaya, Salvador; Fimia, Antonio

2004-09-01

Holographic techniques have been used for manufacturing multiple band one-dimensional, two-dimensional, and three-dimensional photonic crystals with different configurations, by multiplexing reflection and transmission setups on a single layer of holographic material. The recording material used for storage is an ultra fine grain silver halide emulsion, with an average grain size around 20 nm. The results are a set of photonic crystals with the one-dimensional, two-dimensional, and three-dimensional index modulation structure consisting of silver halide particles embedded in the gelatin layer of the emulsion. The characterisation of the fabricated photonic crystals by measuring their transmission band structures has been done and compared with theoretical calculations.

Three-dimensional boron particle loaded thermal neutron detector

DOEpatents

Nikolic, Rebecca J.; Conway, Adam M.; Graff, Robert T.; Kuntz, Joshua D.; Reinhardt, Catherine; Voss, Lars F.; Cheung, Chin Li; Heineck, Daniel

2014-09-09

Three-dimensional boron particle loaded thermal neutron detectors utilize neutron sensitive conversion materials in the form of nano-powders and micro-sized particles, as opposed to thin films, suspensions, paraffin, etc. More specifically, methods to infiltrate, intersperse and embed the neutron nano-powders to form two-dimensional and/or three-dimensional charge sensitive platforms are specified. The use of nano-powders enables conformal contact with the entire charge-collecting structure regardless of its shape or configuration.

Multispectral photoacoustic imaging of nerves with a clinical ultrasound system

NASA Astrophysics Data System (ADS)

Mari, Jean Martial; West, Simeon; Beard, Paul C.; Desjardins, Adrien E.

2014-03-01

Accurate and efficient identification of nerves is of great importance during many ultrasound-guided clinical procedures, including nerve blocks and prostate biopsies. It can be challenging to visualise nerves with conventional ultrasound imaging, however. One of the challenges is that nerves can have very similar appearances to nearby structures such as tendons. Several recent studies have highlighted the potential of near-infrared optical spectroscopy for differentiating nerves and adjacent tissues, as this modality can be sensitive to optical absorption of lipids that are present in intra- and extra-neural adipose tissue and in the myelin sheaths. These studies were limited to point measurements, however. In this pilot study, a custom photoacoustic system with a clinical ultrasound imaging probe was used to acquire multi-spectral photoacoustic images of nerves and tendons from swine ex vivo, across the wavelength range of 1100 to 1300 nm. Photoacoustic images were processed and overlaid in colour onto co-registered conventional ultrasound images that were acquired with the same imaging probe. A pronounced optical absorption peak centred at 1210 nm was observed in the photoacoustic signals obtained from nerves, and it was absent in those obtained from tendons. This absorption peak, which is consistent with the presence of lipids, provides a novel image contrast mechanism to significantly enhance the visualization of nerves. In particular, image contrast for nerves was up to 5.5 times greater with photoacoustic imaging (0.82 +/- 0.15) than with conventional ultrasound imaging (0.148 +/- 0.002), with a maximum contrast of 0.95 +/- 0.02 obtained in photoacoustic mode. This pilot study demonstrates the potential of photoacoustic imaging to improve clinical outcomes in ultrasound-guided interventions in regional anaesthesia and interventional oncology.

Three-Dimensional Dynamic Bone Histomorphometry

PubMed Central

Slyfield, C.R.; Tkachenko, E.V.; Wilson, D.L.; Hernandez, C.J.

2011-01-01

Dynamic bone histomorphometry is the standard method for measuring bone remodeling at the level of individual events. While dynamic bone histomorphometry is an invaluable tool for understanding osteoporosis and other metabolic bone diseases, the technique’s two-dimensional nature requires the use of stereology and prevents measures of individual remodeling event number and size. Here, we use a novel three-dimensional fluorescence imaging technique to achieve measures of individual resorption cavities and formation events. We perform this three-dimensional histomorphometry approach using a common model of postmenopausal osteoporosis, the ovariectomized rat. The three-dimensional images demonstrate the spatial relationship between resorption cavities and formation events consistent with the hemi-osteonal model of cancellous bone remodeling. Established ovariectomy was associated with significant increases in the number of resorption cavities per unit bone surface (2.38 ± 0.24 mm−2 SHAM v. 3.86 ± 0.35 mm−2 OVX, mean ± SD, p < 0.05) and total volume occupied by cavities per unit bone volume (0.38 ± 0.06% SHAM v. 1.12 ± 0.18% OVX, p < 0.001), but no difference in surface area per resorption cavity, maximum cavity depth, or cavity volume. Additionally, we find that established ovariectomy is associated with increased size of bone formation events due to merging of formation events (23,700 ± 6,890 μm2 SHAM v. 33,300 ± 7,950 μm2 OVX). No differences in mineral apposition rate (determined in 3D) were associated with established ovariectomy. That established estrogen depletion is associated with increased number of remodeling events with only subtle changes in remodeling event size suggests that circulating estrogens may have their primary effect on the origination of new basic multicellular units with relatively little effect on the progression and termination of active remodeling events. PMID:22028195

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.

An Evaluation of Two Internal Surrogates for Determining the Three-Dimensional Position of Peripheral Lung Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spoelstra, Femke; Soernsen de Koste, John R. van; Vincent, Andrew

2009-06-01

Purpose: Both carina and diaphragm positions have been used as surrogates during respiratory-gated radiotherapy. We studied the correlation of both surrogates with three-dimensional (3D) tumor position. Methods and Materials: A total of 59 repeat artifact-free four-dimensional (4D) computed tomography (CT) scans, acquired during uncoached breathing, were identified in 23 patients with Stage I lung cancer. Repeat scans were co-registered to the initial 4D CT scan, and tumor, carina, and ipsilateral diaphragm were manually contoured in all phases of each 4D CT data set. Correlation between positions of carina and diaphragm with 3D tumor position was studied by use of log-likelihoodmore » ratio statistics. Models to predict 3D tumor position from internal surrogates at end inspiration (EI) and end expiration (EE) were developed, and model accuracy was tested by calculating SDs of differences between predicted and actual tumor positions. Results: Motion of both the carina and diaphragm significantly correlated with tumor motion, but log-likelihood ratios indicated that the carina was more predictive for tumor position. When craniocaudal tumor position was predicted by use of craniocaudal carina positions, the SDs of the differences between the predicted and observed positions were 2.2 mm and 2.4 mm at EI and EE, respectively. The corresponding SDs derived with the diaphragm positions were 3.7 mm and 3.9 mm at EI and EE, respectively. Prediction errors in the other directions were comparable. Prediction accuracy was similar at EI and EE. Conclusions: The carina is a better surrogate of 3D tumor position than diaphragm position. Because residual prediction errors were observed in this analysis, additional studies will be performed using audio-coached scans.« less

Investigation of optimal method for inducing harmonic motion in tissue using a linear ultrasound phased array--a simulation study.

PubMed

Heikkilä, Janne; Hynynen, Kullervo

2006-04-01

Many noninvasive ultrasound techniques have been developed to explore mechanical properties of soft tissues. One of these methods, Localized Harmonic Motion Imaging (LHMI), has been proposed to be used for ultrasound surgery monitoring. In LHMI, dynamic ultrasound radiation-force stimulation induces displacements in a target that can be measured using pulse-echo imaging and used to estimate the elastic properties of the target. In this initial, simulation study, the use of a one-dimensional phased array is explored for the induction of the tissue motion. The study compares three different dual-frequency and amplitude-modulated single-frequency methods for the inducing tissue motion. Simulations were computed in a homogeneous soft-tissue volume. The Rayleigh integral was used in the simulations of the ultrasound fields and the tissue displacements were computed using a finite-element method (FEM). The simulations showed that amplitude-modulated sonication using a single frequency produced the largest vibration amplitude of the target tissue. These simulations demonstrate that the properties of the tissue motion are highly dependent on the sonication method and that it is important to consider the full three-dimensional distribution of the ultrasound field for controlling the induction of tissue motion.

Pathogen propagation in cultured three-dimensional tissue mass

NASA Technical Reports Server (NTRS)

Wolf, David A. (Inventor); Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor)

2000-01-01

A process for propagating a pathogen in a three-dimensional tissue mass cultured at microgravity conditions in a culture vessel containing culture media and a culture matrix is provided. The three-dimensional tissue mass is inoculated with a pathogen and pathogen replication in the cells of the tissue mass achieved.

Visualization of Two Dimensional to Three Dimensional Transformations--Exploration through Technology

ERIC Educational Resources Information Center

Costa, G. B.; Gorak, M.; Melendez, B. S.

2006-01-01

A small class of functions is described that easily lend themselves to two-dimensional and three-dimensional visualizations at the basic calculus level. The intended audience is those educators involved in the instruction of elementary calculus. This note is an educational piece that begins with the question: "What happens if a function defined on…

Three-dimensional metamaterials

DOEpatents

Burckel, David Bruce [Albuquerque, NM

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.

Subjective figure reversal in two- and three-dimensional perceptual space.

PubMed

Radilová, J; Radil-Weiss, T

1984-08-01

A permanently illuminated pattern of Mach's truncated pyramid can be perceived according to the experimental instruction given, either as a three-dimensional reversible figure with spontaneously changing convex and concave interpretation (in one experiment), or as a two-dimensional reversible figure-ground pattern (in another experiment). The reversal rate was about twice as slow, without the subjects being aware of it, if it was perceived as a three-dimensional figure compared to the situation when it was perceived as two-dimensional. It may be hypothetized that in the three-dimensional case, the process of perception requires more sequential steps than in the two-dimensional one.

Optimizing random searches on three-dimensional lattices

NASA Astrophysics Data System (ADS)

Yang, Benhao; Yang, Shunkun; Zhang, Jiaquan; Li, Daqing

2018-07-01

Search is a universal behavior related to many types of intelligent individuals. While most studies have focused on search in two or infinite-dimensional space, it is still missing how search can be optimized in three-dimensional space. Here we study random searches on three-dimensional (3d) square lattices with periodic boundary conditions, and explore the optimal search strategy with a power-law step length distribution, p(l) ∼l-μ, known as Lévy flights. We find that compared to random searches on two-dimensional (2d) lattices, the optimal exponent μopt on 3d lattices is relatively smaller in non-destructive case and remains similar in destructive case. We also find μopt decreases as the lattice length in z direction increases under high target density. Our findings may help us to understand the role of spatial dimension in search behaviors.

Geometric actions for three-dimensional gravity

NASA Astrophysics Data System (ADS)

Barnich, G.; González, H. A.; Salgado-Rebolledo, P.

2018-01-01

The solution space of three-dimensional asymptotically anti-de Sitter or flat Einstein gravity is given by the coadjoint representation of two copies of the Virasoro group in the former and the centrally extended BMS3 group in the latter case. Dynamical actions that control these solution spaces are usually constructed by starting from the Chern–Simons formulation and imposing all boundary conditions. In this note, an alternative route is followed. We study in detail how to derive these actions from a group-theoretical viewpoint by constructing geometric actions for each of the coadjoint orbits, including the appropriate Hamiltonians. We briefly sketch relevant generalizations and potential applications beyond three-dimensional gravity.

Three-dimensional displays and stereo vision

PubMed Central

Westheimer, Gerald

2011-01-01

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. PMID:21490023

Hydrofocusing Bioreactor for Three-Dimensional Cell Culture

NASA Technical Reports Server (NTRS)

Gonda, Steve R.; Spaulding, Glenn F.; Tsao, Yow-Min D.; Flechsig, Scott; Jones, Leslie; Soehnge, Holly

2003-01-01

The hydrodynamic focusing bioreactor (HFB) is a bioreactor system designed for three-dimensional cell culture and tissue-engineering investigations on orbiting spacecraft and in laboratories on Earth. The HFB offers a unique hydrofocusing capability that enables the creation of a low-shear culture environment simultaneously with the "herding" of suspended cells, tissue assemblies, and air bubbles. Under development for use in the Biotechnology Facility on the International Space Station, the HFB has successfully grown large three-dimensional, tissuelike assemblies from anchorage-dependent cells and grown suspension hybridoma cells to high densities. The HFB, based on the principle of hydrodynamic focusing, provides the capability to control the movement of air bubbles and removes them from the bioreactor without degrading the low-shear culture environment or the suspended three-dimensional tissue assemblies. The HFB also provides unparalleled control over the locations of cells and tissues within its bioreactor vessel during operation and sampling.

Physics and instrumentation of ultrasound.

PubMed

Lawrence, John P

2007-08-01

A thorough understanding of the physics of ultrasound waves and the instrumentation will provide the user with a better understanding of the capabilities and limitations of ultrasound equipment. The ultrasound machine combines two technologies: image production (M-mode and 2-dimensional imaging) with Doppler assessment (continuous and pulse wave as well as color-flow mapping). These distinct technologies have been combined to provide the examiner with the ability to make accurate and comprehensive diagnoses and guide therapeutic intervention.

Calculation of three-dimensional compressible laminar and turbulent boundary layers. Calculation of three-dimensional compressible boundary layers on arbitrary wings

NASA Technical Reports Server (NTRS)

Cebeci, T.; Kaups, K.; Ramsey, J.; Moser, A.

1975-01-01

A very general method for calculating compressible three-dimensional laminar and turbulent boundary layers on arbitrary wings is described. The method utilizes a nonorthogonal coordinate system for the boundary-layer calculations and includes a geometry package that represents the wing analytically. In the calculations all the geometric parameters of the coordinate system are accounted for. The Reynolds shear-stress terms are modeled by an eddy-viscosity formulation developed by Cebeci. The governing equations are solved by a very efficient two-point finite-difference method used earlier by Keller and Cebeci for two-dimensional flows and later by Cebeci for three-dimensional flows.

Three-dimensionally patterned energy absorptive material and method of fabrication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duoss, Eric; Frank, James M.; Kuntz, Joshua

A three-dimensionally patterned energy absorptive material and fabrication method having multiple layers of patterned filaments extrusion-formed from a curable pre-cursor material and stacked and cured in a three-dimensionally patterned architecture so that the energy absorptive material produced thereby has an engineered bulk property associated with the three-dimensionally patterned architecture.

Multifunctional, three-dimensional tomography for analysis of eletrectrohydrodynamic jetting

NASA Astrophysics Data System (ADS)

Nguyen, Xuan Hung; Gim, Yeonghyeon; Ko, Han Seo

2015-05-01

A three-dimensional optical tomography technique was developed to reconstruct three-dimensional objects using a set of two-dimensional shadowgraphic images and normal gray images. From three high-speed cameras, which were positioned at an offset angle of 45° between each other, number, size, and location of electrohydrodynamic jets with respect to the nozzle position were analyzed using shadowgraphic tomography employing multiplicative algebraic reconstruction technique (MART). Additionally, a flow field inside a cone-shaped liquid (Taylor cone) induced under an electric field was observed using a simultaneous multiplicative algebraic reconstruction technique (SMART), a tomographic method for reconstructing light intensities of particles, combined with three-dimensional cross-correlation. Various velocity fields of circulating flows inside the cone-shaped liquid caused by various physico-chemical properties of liquid were also investigated.

Three-dimensional computational aerodynamics in the 1980's

NASA Technical Reports Server (NTRS)

Lomax, H.

1978-01-01

The future requirements for constructing codes that can be used to compute three-dimensional flows about aerodynamic shapes should be assessed in light of the constraints imposed by future computer architectures and the reality of usable algorithms that can provide practical three-dimensional simulations. On the hardware side, vector processing is inevitable in order to meet the CPU speeds required. To cope with three-dimensional geometries, massive data bases with fetch/store conflicts and transposition problems are inevitable. On the software side, codes must be prepared that: (1) can be adapted to complex geometries, (2) can (at the very least) predict the location of laminar and turbulent boundary layer separation, and (3) will converge rapidly to sufficiently accurate solutions.

A panning DLT procedure for three-dimensional videography.

PubMed

Yu, B; Koh, T J; Hay, J G

1993-06-01

The direct linear transformation (DLT) method [Abdel-Aziz and Karara, APS Symposium on Photogrammetry. American Society of Photogrammetry, Falls Church, VA (1971)] is widely used in biomechanics to obtain three-dimensional space coordinates from film and video records. This method has some major shortcomings when used to analyze events which take place over large areas. To overcome these shortcomings, a three-dimensional data collection method based on the DLT method, and making use of panning cameras, was developed. Several small single control volumes were combined to construct a large total control volume. For each single control volume, a regression equation (calibration equation) is developed to express each of the 11 DLT parameters as a function of camera orientation, so that the DLT parameters can then be estimated from arbitrary camera orientations. Once the DLT parameters are known for at least two cameras, and the associated two-dimensional film or video coordinates of the event are obtained, the desired three-dimensional space coordinates can be computed. In a laboratory test, five single control volumes (in a total control volume of 24.40 x 2.44 x 2.44 m3) were used to test the effect of the position of the single control volume on the accuracy of the computed three dimensional space coordinates. Linear and quadratic calibration equations were used to test the effect of the order of the equation on the accuracy of the computed three dimensional space coordinates. For four of the five single control volumes tested, the mean resultant errors associated with the use of the linear calibration equation were significantly larger than those associated with the use of the quadratic calibration equation. The position of the single control volume had no significant effect on the mean resultant errors in computed three dimensional coordinates when the quadratic calibration equation was used. Under the same data collection conditions, the mean resultant errors in

Geometric reconstruction using tracked ultrasound strain imaging

NASA Astrophysics Data System (ADS)

Pheiffer, Thomas S.; Simpson, Amber L.; Ondrake, Janet E.; Miga, Michael I.

2013-03-01

The accurate identification of tumor margins during neurosurgery is a primary concern for the surgeon in order to maximize resection of malignant tissue while preserving normal function. The use of preoperative imaging for guidance is standard of care, but tumor margins are not always clear even when contrast agents are used, and so margins are often determined intraoperatively by visual and tactile feedback. Ultrasound strain imaging creates a quantitative representation of tissue stiffness which can be used in real-time. The information offered by strain imaging can be placed within a conventional image-guidance workflow by tracking the ultrasound probe and calibrating the image plane, which facilitates interpretation of the data by placing it within a common coordinate space with preoperative imaging. Tumor geometry in strain imaging is then directly comparable to the geometry in preoperative imaging. This paper presents a tracked ultrasound strain imaging system capable of co-registering with preoperative tomograms and also of reconstructing a 3D surface using the border of the strain lesion. In a preliminary study using four phantoms with subsurface tumors, tracked strain imaging was registered to preoperative image volumes and then tumor surfaces were reconstructed using contours extracted from strain image slices. The volumes of the phantom tumors reconstructed from tracked strain imaging were approximately between 1.5 to 2.4 cm3, which was similar to the CT volumes of 1.0 to 2.3 cm3. Future work will be done to robustly characterize the reconstruction accuracy of the system.

Resonance fluorescence based two- and three-dimensional atom localization

NASA Astrophysics Data System (ADS)

Wahab, Abdul; Rahmatullah; Qamar, Sajid

2016-06-01

Two- and three-dimensional atom localization in a two-level atom-field system via resonance fluorescence is suggested. For the two-dimensional localization, the atom interacts with two orthogonal standing-wave fields, whereas for the three-dimensional atom localization, the atom interacts with three orthogonal standing-wave fields. The effect of the detuning and phase shifts associated with the corresponding standing-wave fields is investigated. A precision enhancement in position measurement of the single atom can be noticed via the control of the detuning and phase shifts.

Applications of Ultrasound in the Resection of Brain Tumors

PubMed Central

Sastry, Rahul; Bi, Wenya Linda; Pieper, Steve; Frisken, Sarah; Kapur, Tina; Wells, William; Golby, Alexandra J.

2016-01-01

Neurosurgery makes use of pre-operative imaging to visualize pathology, inform surgical planning, and evaluate the safety of selected approaches. The utility of pre-operative imaging for neuronavigation, however, is diminished by the well characterized phenomenon of brain shift, in which the brain deforms intraoperatively as a result of craniotomy, swelling, gravity, tumor resection, cerebrospinal fluid (CSF) drainage, and many other factors. As such, there is a need for updated intraoperative information that accurately reflects intraoperative conditions. Since 1982, intraoperative ultrasound has allowed neurosurgeons to craft and update operative plans without ionizing radiation exposure or major workflow interruption. Continued evolution of ultrasound technology since its introduction has resulted in superior imaging quality, smaller probes, and more seamless integration with neuronavigation systems. Furthermore, the introduction of related imaging modalities, such as 3-dimensional ultrasound, contrast-enhanced ultrasound, high-frequency ultrasound, and ultrasound elastography have dramatically expanded the options available to the neurosurgeon intraoperatively. In the context of these advances, we review the current state, potential, and challenges of intraoperative ultrasound for brain tumor resection. We begin by evaluating these ultrasound technologies and their relative advantages and disadvantages. We then review three specific applications of these ultrasound technologies to brain tumor resection: (1) intraoperative navigation, (2) assessment of extent of resection, and (3) brain shift monitoring and compensation. We conclude by identifying opportunities for future directions in the development of ultrasound technologies. PMID:27541694

Ultrasound-assisted extraction of three bufadienolides from Chinese medicine ChanSu.

PubMed

Sun, Yinshi; Bi, Jianjie; Zhang, Li; Ye, Baoxing

2012-11-01

In this study, the application of ultrasound-assisted extraction (UAE) method was shown to be more efficient in extracting anti-tumor bufadienolides (bufalin, cinobufagin and resibufogenin) from important animal medicine of ChanSu than the maceration extraction (ME) and soxhlet extraction (SE) method. The effects of ultrasonic variables including extraction solvent, solvent concentration, solvent to solid ratio, ultrasound power, temperature, extraction time and particle size on the yields of three bufadienolides were investigated. The optimum extraction conditions found were: 70% (v/v) methanol solution, solvent to solid ratio of 10ml/g, ultrasound power of 125W, temperature of 20°C, extraction time of 20min and particle size of 60-80 mesh. The extraction yields of bufalin, cinobufagin and resibufogenin were 43.17±0.85, 52.58±1.12, 137.70±2.65mg/g, respectively. In order to achieve a similar yield as UAE, soxhlet extraction required 6h and maceration extraction required much longer time of 18h. The results indicated that UAE is an alternative method for extracting bufadienolides from ChanSu. Copyright © 2012 Elsevier B.V. All rights reserved.

Focused ultrasound thermal therapy system with ultrasound image guidance and temperature measurement feedback.

PubMed

Lin, Kao-Han; Young, Sun-Yi; Hsu, Ming-Chuan; Chan, Hsu; Chen, Yung-Yaw; Lin, Win-Li

2008-01-01

In this study, we developed a focused ultrasound (FUS) thermal therapy system with ultrasound image guidance and thermocouple temperature measurement feedback. Hydraulic position devices and computer-controlled servo motors were used to move the FUS transducer to the desired location with the measurement of actual movement by linear scale. The entire system integrated automatic position devices, FUS transducer, power amplifier, ultrasound image system, and thermocouple temperature measurement into a graphical user interface. For the treatment procedure, a thermocouple was implanted into a targeted treatment region in a tissue-mimicking phantom under ultrasound image guidance, and then the acoustic interference pattern formed by image ultrasound beam and low-power FUS beam was employed as image guidance to move the FUS transducer to have its focal zone coincident with the thermocouple tip. The thermocouple temperature rise was used to determine the sonication duration for a suitable thermal lesion as a high power was turned on and ultrasound image was used to capture the thermal lesion formation. For a multiple lesion formation, the FUS transducer was moved under the acoustic interference guidance to a new location and then it sonicated with the same power level and duration. This system was evaluated and the results showed that it could perform two-dimensional motion control to do a two-dimensional thermal therapy with a small localization error 0.5 mm. Through the user interface, the FUS transducer could be moved to heat the target region with the guidance of ultrasound image and acoustic interference pattern. The preliminary phantom experimental results demonstrated that the system could achieve the desired treatment plan satisfactorily.

Interactive multimedia for prenatal ultrasound training.

PubMed

Lee, W; Ault, H; Kirk, J S; Comstock, C H

1995-01-01

This demonstration project examines the utility of interactive multimedia for prenatal ultrasound training. A laser-disc library was linked to a three-dimensional (3-D) heart model and other computer-based training materials through interactive multimedia. A testing module presented ultrasound anomalies and related questions to house-staff physicians through the image library. Users were asked to evaluate these training materials on the basis of perceived instructional value, question content, subjects covered, graphics interface, and ease of use; users were also asked for their comments. House-staff physicians indicated that they consider interactive multimedia to be a helpful adjunct to their core fetal imaging rotation. During a 9-month period, 16 house-staff physicians correctly diagnosed 78 +/- 4% of unknown cases presented through the testing module. The 3-D heart model was also perceived to be a useful teaching aid for spatial orientation skills. Our findings suggest that interactive multimedia and volume visualization models can be used to supplement traditional prenatal ultrasound training. The system provides a broad exposure to ultrasound anomalies, increases opportunities for postnatal correlation, emphasizes motion video for ultrasound training, encourages development of independent diagnostic ability, and helps physicians understand anatomic orientation. We hypothesize that interactive multimedia-based tutorials provide a better overall training experience for house-staff physicians. However, these supplementary methods will require formal evaluation of effectiveness to better understand their potential educational impact.

Three-dimensional friction measurement during hip simulation.

PubMed

Sonntag, Robert; Braun, Steffen; Al-Salehi, Loay; Reinders, Joern; Mueller, Ulrike; Kretzer, J Philippe

2017-01-01

Wear of total hip replacements has been the focus of many studies. However, frictional effects, such as high loading on intramodular connections or the interface to the bone, as well as friction associated squeaking have recently increased interest about the amount of friction that is generated during daily activities. The aim of this study was thus to establish and validate a three-dimensional friction setup under standardized conditions. A standard hip simulator was modified to allow for high precision measurements of small frictional effects in the hip during three-dimensional hip articulation. The setup was verified by an ideal hydrostatic bearing and validated with a static-load physical pendulum and an extension-flexion rotation with a dynamic load profile. Additionally, a pendulum model was proposed for screening measurement of frictional effects based on the damping behavior of the angular oscillation without the need for any force/moment transducer. Finally, three-dimensional friction measurements have been realized for ceramic-on-polyethylene bearings of three different sizes (28, 36 and 40 mm). A precision of less than 0.2 Nm during three-dimensional friction measurements was reported, while increased frictional torque (resultant as well as taper torque) was measured for larger head diameters. These effects have been confirmed by simple pendulum tests and the theoretical model. A comparison with current literature about friction measurements is presented. This investigation of friction is able to provide more information about a field that has been dominated by the reduction of wear. It should be considered in future pre-clinical testing protocols given by international organizations of standardization.

Three-dimensional cell to tissue development process

NASA Technical Reports Server (NTRS)

Goodwin, Thomas J. (Inventor); Parker, Clayton R. (Inventor)

2008-01-01

An improved three-dimensional cell to tissue development process using a specific time varying electromagnetic force, pulsed, square wave, with minimum fluid shear stress, freedom for 3-dimensional spatial orientation of the suspended particles and localization of particles with differing or similar sedimentation properties in a similar spatial region.

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.

Three-dimensional structural analysis using interactive graphics

NASA Technical Reports Server (NTRS)

Biffle, J.; Sumlin, H. A.

1975-01-01

The application of computer interactive graphics to three-dimensional structural analysis was described, with emphasis on the following aspects: (1) structural analysis, and (2) generation and checking of input data and examination of the large volume of output data (stresses, displacements, velocities, accelerations). Handling of three-dimensional input processing with a special MESH3D computer program was explained. Similarly, a special code PLTZ may be used to perform all the needed tasks for output processing from a finite element code. Examples were illustrated.

Three-dimensional imaging of the craniofacial complex.

PubMed

Nguyen, Can X.; Nissanov, Jonathan; Öztürk, Cengizhan; Nuveen, Michiel J.; Tuncay, Orhan C.

2000-02-01

Orthodontic treatment requires the rearrangement of craniofacial complex elements in three planes of space, but oddly the diagnosis is done with two-dimensional images. Here we report on a three-dimensional (3D) imaging system that employs the stereoimaging method of structured light to capture the facial image. The images can be subsequently integrated with 3D cephalometric tracings derived from lateral and PA films (www.clinorthodres.com/cor-c-070). The accuracy of the reconstruction obtained with this inexpensive system is about 400 µ.

Real-time three-dimensional optical coherence tomography image-guided core-needle biopsy system.

PubMed

Kuo, Wei-Cheng; Kim, Jongsik; Shemonski, Nathan D; Chaney, Eric J; Spillman, Darold R; Boppart, Stephen A

2012-06-01

Advances in optical imaging modalities, such as optical coherence tomography (OCT), enable us to observe tissue microstructure at high resolution and in real time. Currently, core-needle biopsies are guided by external imaging modalities such as ultrasound imaging and x-ray computed tomography (CT) for breast and lung masses, respectively. These image-guided procedures are frequently limited by spatial resolution when using ultrasound imaging, or by temporal resolution (rapid real-time feedback capabilities) when using x-ray CT. One feasible approach is to perform OCT within small gauge needles to optically image tissue microstructure. However, to date, no system or core-needle device has been developed that incorporates both three-dimensional OCT imaging and tissue biopsy within the same needle for true OCT-guided core-needle biopsy. We have developed and demonstrate an integrated core-needle biopsy system that utilizes catheter-based 3-D OCT for real-time image-guidance for target tissue localization, imaging of tissue immediately prior to physical biopsy, and subsequent OCT imaging of the biopsied specimen for immediate assessment at the point-of-care. OCT images of biopsied ex vivo tumor specimens acquired during core-needle placement are correlated with corresponding histology, and computational visualization of arbitrary planes within the 3-D OCT volumes enables feedback on specimen tissue type and biopsy quality. These results demonstrate the potential for using real-time 3-D OCT for needle biopsy guidance by imaging within the needle and tissue during biopsy procedures.

[Ultrasound findings in rhabdomyolysis].

PubMed

Carrillo-Esper, Raúl; Galván-Talamantes, Yazmin; Meza-Ayala, Cynthia Margarita; Cruz-Santana, Julio Alberto; Bonilla-Reséndiz, Luis Ignacio

Rhabdomyolysis is defined as skeletal muscle necrosis. Ultrasound assessment has recently become a useful tool for the diagnosis and monitoring of muscle diseases, including rhabdomyolysis. A case is presented on the ultrasound findings in a patient with rhabdomyolysis. To highlight the importance of ultrasound as an essential part in the diagnosis in rhabdomyolysis, to describe the ultrasound findings, and review the literature. A 30 year-old with post-traumatic rhabdomyolysis of both thighs. Ultrasound was performed using a Philips Sparq model with a high-frequency linear transducer (5-10MHz), in low-dimensional scanning mode (2D), in longitudinal and transverse sections at the level of both thighs. The images obtained showed disorganisation of the orientation of the muscle fibres, ground glass image, thickening of the muscular fascia, and the presence of anechoic areas. Ultrasound is a useful tool in the evaluation of rhabdomyolysis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Automated 3D Ultrasound Image Segmentation to Aid Breast Cancer Image Interpretation

PubMed Central

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

2015-01-01

Segmentation of an ultrasound image into functional tissues is of great importance to clinical diagnosis of breast cancer. However, many studies are found to segment only the mass of interest and not all major tissues. Differences and inconsistencies in ultrasound interpretation call for an automated segmentation method to make results operator-independent. Furthermore, manual segmentation of entire three-dimensional (3D) ultrasound volumes is time-consuming, resource-intensive, and clinically impractical. Here, we propose an automated algorithm to segment 3D ultrasound volumes into three major tissue types: cyst/mass, fatty tissue, and fibro-glandular tissue. To test its efficacy and consistency, the proposed automated method was employed on a database of 21 cases of whole breast ultrasound. Experimental results show that our proposed method not only distinguishes fat and non-fat tissues correctly, but performs well in classifying cyst/mass. Comparison of density assessment between the automated method and manual segmentation demonstrates good consistency with an accuracy of 85.7%. Quantitative comparison of corresponding tissue volumes, which uses overlap ratio, gives an average similarity of 74.54%, consistent with values seen in MRI brain segmentations. Thus, our proposed method exhibits great potential as an automated approach to segment 3D whole breast ultrasound volumes into functionally distinct tissues that may help to correct ultrasound speed of sound aberrations and assist in density based prognosis of breast cancer. PMID:26547117

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

NASA Astrophysics Data System (ADS)

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

2016-04-01

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

Three-dimensional dynamic thermal imaging of structural flaws by dual-band infrared computed tomography

NASA Astrophysics Data System (ADS)

DelGrande, Nancy; Dolan, Kenneth W.; Durbin, Philip F.; Gorvad, Michael R.; Kornblum, B. T.; Perkins, Dwight E.; Schneberk, Daniel J.; Shapiro, Arthur B.

1993-11-01

We discuss three-dimensional dynamic thermal imaging of structural flaws using dual-band infrared (DBIR) computed tomography. Conventional (single-band) thermal imaging is difficult to interpret. It yields imprecise or qualitative information (e.g., when subsurface flaws produce weak heat flow anomalies masked by surface clutter). We use the DBIR imaging technique to clarify interpretation. We capture the time history of surface temperature difference patterns at the epoxy-glue disbond site of a flash-heated lap joint. This type of flawed structure played a significant role in causing damage to the Aloha Aircraft fuselage on the aged Boeing 737 jetliner. The magnitude of surface-temperature differences versus time for 0.1 mm air layer compared to 0.1 mm glue layer, varies from 0.2 to 1.6 degree(s)C, for simultaneously scanned front and back surfaces. The scans are taken every 42 ms from 0 to 8 s after the heat flash. By ratioing 3 - 5 micrometers and 8 - 12 micrometers DBIR images, we located surface temperature patterns from weak heat flow anomalies at the disbond site and remove the emissivity mask from surface paint of roughness variations. Measurements compare well with calculations based on TOPAX3D, a three-dimensional, finite element computer model. We combine infrared, ultrasound and x-ray imaging methods to study heat transfer, bond quality and material differences associated with the lap joint disbond site.

Three-dimensional nano-biointerface as a new platform for guiding cell fate.

PubMed

Liu, Xueli; Wang, Shutao

2014-04-21

Three-dimensional nano-biointerface has been emerging as an important topic for chemistry, nanotechnology, and life sciences in recent years. Understanding the exchanges of materials, signals, and energy at biological interfaces has inspired and helped the serial design of three-dimensional nano-biointerfaces. The intimate interactions between cells and nanostructures bring many novel properties, making three-dimensional nano-biointerfaces a powerful platform to guide cell fate in a controllable and accurate way. These advantages and capabilities endow three-dimensional nano-biointerfaces with an indispensable role in developing advanced biological science and technology. This tutorial review is mainly focused on the recent progress of three-dimensional nano-biointerfaces and highlights the new explorations and unique phenomena of three-dimensional nano-biointerfaces for cell-related fundamental studies and biomedical applications. Some basic bio-inspired principles for the design and creation of three-dimensional nano-biointerfaces are also delivered in this review. Current and further challenges of three-dimensional nano-biointerfaces are finally addressed and proposed.

Three-dimensional separation for interaction of shock waves with turbulent boundary layers

NASA Technical Reports Server (NTRS)

Goldberg, T. J.

1973-01-01

For the interaction of shock waves with turbulent boundary layers, obtained experimental three-dimensional separation results and correlations with earlier two-dimensional and three-dimensional data are presented. It is shown that separation occurs much earlier for turbulent three-dimensional than for two-dimensional flow at hypersonic speeds.

Three dimensional contact/impact methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 crashmore » 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.« less

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.

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.

Three-dimensional organization of dermal fibroblasts by macromass culture.

PubMed

Deshpande, Manisha

2008-01-01

The three-dimensional organization of cells by high-cell-seeding-density culture, termed 'macromass culture', is described. By macromass culture, dermal fibroblasts can be made to organize themselves into a unified three-dimensional form without the aid of a scaffold, and macroscopic constructs, named macromasses, can be made wholly from cells. The sole factor causing three-dimensional organization is culture of cells at high cell seeding density per unit area. No scaffold or extraneous matrix is used for the generation of macromasses; they are of completely cellular origin. No other agents or external influences such as tissue-inducing chemicals, tissue-inducing growth factors, substratum with special properties, rotational culture, centrifugation etc. are employed for macromass formation, and all seeded cells become part of the cohesive construct. These three-dimensional constructs have the potential for use as in vitro tissue analogues, and a possible application for in vitro cytotoxicity testing is demonstrated.

Three-dimensional mapping in the electrophysiological laboratory.

PubMed

Maury, Philippe; Monteil, Benjamin; Marty, Lilian; Duparc, Alexandre; Mondoly, Pierre; Rollin, Anne

2018-06-07

Investigation and catheter ablation of cardiac arrhythmias are currently still based on optimal knowledge of arrhythmia mechanisms in relation to the cardiac anatomy involved, in order to target their crucial components. Currently, most complex arrhythmias are investigated using three-dimensional electroanatomical navigation systems, because these are felt to optimally integrate both the anatomical and electrophysiological features of a given arrhythmia in a given patient. In this article, we review the technical background of available three-dimensional electroanatomical navigation systems, and their potential use in complex ablations. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

[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.

Development and Translation of Hybrid Optoacoustic/Ultrasonic Tomography for Early Breast Cancer Detection

DTIC Science & Technology

2015-09-01

OAT) and laser-induced ultrasound tomography (LUT) to obtain coregistered maps of tissue optical absorption and speed of sound , displayed within the...computed tomography (UST) can provide high-resolution anatomical images of breast lesions based on three complementary acoustic properties (speed-of- sound ...tomography (UST) can provide high-resolution anatomical images of breast lesions based on three complementary acoustic properties (speed-of- sound

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

PubMed

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

2016-02-01

Despite variation in bone geometry, muscle and joint function is often investigated using generic musculoskeletal models. Patient-specific bone geometry can be obtained from computerised tomography, which involves ionising radiation, or magnetic resonance imaging (MRI), which is costly and time consuming. Freehand 3-D ultrasound provides an alternative to obtain bony geometry. The purpose of this study was to determine the accuracy and repeatability of 3-D ultrasound in measuring femoral torsion. Measurements of femoral torsion were performed on 10 healthy adults using MRI and 3-D ultrasound. Measurements of femoral torsion from 3-D ultrasound were, on average, smaller than those from MRI (mean difference = 1.8°; 95% confidence interval: -3.9°, 7.5°). MRI and 3-D ultrasound had Bland and Altman repeatability coefficients of 3.1° and 3.7°, respectively. Accurate measurements of femoral torsion were obtained with 3-D ultrasound offering the potential to acquire patient-specific bone geometry for musculoskeletal modelling. Three-dimensional ultrasound is non-invasive and relatively inexpensive and can be integrated into gait analysis. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Three-dimensional scene reconstruction from a two-dimensional image

NASA Astrophysics Data System (ADS)

Parkins, Franz; Jacobs, Eddie

2017-05-01

We propose and simulate a method of reconstructing a three-dimensional scene from a two-dimensional image for developing and augmenting world models for autonomous navigation. This is an extension of the Perspective-n-Point (PnP) method which uses a sampling of the 3D scene, 2D image point parings, and Random Sampling Consensus (RANSAC) to infer the pose of the object and produce a 3D mesh of the original scene. Using object recognition and segmentation, we simulate the implementation on a scene of 3D objects with an eye to implementation on embeddable hardware. The final solution will be deployed on the NVIDIA Tegra platform.

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.

Three-dimensional friction measurement during hip simulation

PubMed Central

Braun, Steffen; Al-Salehi, Loay; Reinders, Joern; Mueller, Ulrike; Kretzer, J. Philippe

2017-01-01

Objectives Wear of total hip replacements has been the focus of many studies. However, frictional effects, such as high loading on intramodular connections or the interface to the bone, as well as friction associated squeaking have recently increased interest about the amount of friction that is generated during daily activities. The aim of this study was thus to establish and validate a three-dimensional friction setup under standardized conditions. Materials and methods A standard hip simulator was modified to allow for high precision measurements of small frictional effects in the hip during three-dimensional hip articulation. The setup was verified by an ideal hydrostatic bearing and validated with a static-load physical pendulum and an extension-flexion rotation with a dynamic load profile. Additionally, a pendulum model was proposed for screening measurement of frictional effects based on the damping behavior of the angular oscillation without the need for any force/moment transducer. Finally, three-dimensional friction measurements have been realized for ceramic-on-polyethylene bearings of three different sizes (28, 36 and 40 mm). Results A precision of less than 0.2 Nm during three-dimensional friction measurements was reported, while increased frictional torque (resultant as well as taper torque) was measured for larger head diameters. These effects have been confirmed by simple pendulum tests and the theoretical model. A comparison with current literature about friction measurements is presented. Conclusions This investigation of friction is able to provide more information about a field that has been dominated by the reduction of wear. It should be considered in future pre-clinical testing protocols given by international organizations of standardization. PMID:28886102

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.

Augmented Reality Using Transurethral Ultrasound for Laparoscopic Radical Prostatectomy: Preclinical Evaluation.

PubMed

Lanchon, Cecilia; Custillon, Guillaume; Moreau-Gaudry, Alexandre; Descotes, Jean-Luc; Long, Jean-Alexandre; Fiard, Gaelle; Voros, Sandrine

2016-07-01

To guide the surgeon during laparoscopic or robot-assisted radical prostatectomy an innovative laparoscopic/ultrasound fusion platform was developed using a motorized 3-dimensional transurethral ultrasound probe. We present what is to our knowledge the first preclinical evaluation of 3-dimensional prostate visualization using transurethral ultrasound and the preliminary results of this new augmented reality. The transurethral probe and laparoscopic/ultrasound registration were tested on realistic prostate phantoms made of standard polyvinyl chloride. The quality of transurethral ultrasound images and the detection of passive markers placed on the prostate surface were evaluated on 2-dimensional dynamic views and 3-dimensional reconstructions. The feasibility, precision and reproducibility of laparoscopic/transurethral ultrasound registration was then determined using 4, 5, 6 and 7 markers to assess the optimal amount needed. The root mean square error was calculated for each registration and the median root mean square error and IQR were calculated according to the number of markers. The transurethral ultrasound probe was easy to manipulate and the prostatic capsule was well visualized in 2 and 3 dimensions. Passive markers could precisely be localized in the volume. Laparoscopic/transurethral ultrasound registration procedures were performed on 74 phantoms of various sizes and shapes. All were successful. The median root mean square error of 1.1 mm (IQR 0.8-1.4) was significantly associated with the number of landmarks (p = 0.001). The highest accuracy was achieved using 6 markers. However, prostate volume did not affect registration precision. Transurethral ultrasound provided high quality prostate reconstruction and easy marker detection. Laparoscopic/ultrasound registration was successful with acceptable mm precision. Further investigations are necessary to achieve sub mm accuracy and assess feasibility in a human model. Copyright © 2016 American Urological

Three-dimensional cardiac architecture determined by two-photon microtomy

NASA Astrophysics Data System (ADS)

Huang, Hayden; MacGillivray, Catherine; Kwon, Hyuk-Sang; Lammerding, Jan; Robbins, Jeffrey; Lee, Richard T.; So, Peter

2009-07-01

Cardiac architecture is inherently three-dimensional, yet most characterizations rely on two-dimensional histological slices or dissociated cells, which remove the native geometry of the heart. We previously developed a method for labeling intact heart sections without dissociation and imaging large volumes while preserving their three-dimensional structure. We further refine this method to permit quantitative analysis of imaged sections. After data acquisition, these sections are assembled using image-processing tools, and qualitative and quantitative information is extracted. By examining the reconstructed cardiac blocks, one can observe end-to-end adjacent cardiac myocytes (cardiac strands) changing cross-sectional geometries, merging and separating from other strands. Quantitatively, representative cross-sectional areas typically used for determining hypertrophy omit the three-dimensional component; we show that taking orientation into account can significantly alter the analysis. Using fast-Fourier transform analysis, we analyze the gross organization of cardiac strands in three dimensions. By characterizing cardiac structure in three dimensions, we are able to determine that the α crystallin mutation leads to hypertrophy with cross-sectional area increases, but not necessarily via changes in fiber orientation distribution.

The measurement of ultrasound scattering from individual micron-sized objects and its application in single cell scattering.

PubMed

Falou, Omar; Rui, Min; El Kaffas, Ahmed; Kumaradas, J Carl; Kolios, Michael C

2010-08-01

The measurement of the ultrasound backscatter from individual micron-sized objects such as cells is required for various applications such as tissue characterization. However, performing such a measurement remains a challenge. For example, the presence of air bubbles in a suspension of cells during the measurements may lead to the incorrect interpretation of the acoustic signals. This work introduces a technique for measuring the ultrasound backscatter from individual micron-sized objects by combining a microinjection system with a co-registered optical microscope and an ultrasound imaging device. This allowed the measurement of the ultrasound backscatter response from a single object under optical microscope guidance. The optical and ultrasonic data were used to determine the size of the object and to deduce its backscatter responses, respectively. In order to calibrate the system, the backscatter frequency responses from polystyrene microspheres were measured and compared to theoretical predictions. A very good agreement was found between the measured backscatter responses of individual microspheres and theoretical predictions of an elastic sphere. The backscatter responses from single OCI-AML-5 cells were also investigated. It was found that the backscatter responses from AML cells are best modeled using the fluid sphere model. The advantages, limitations, and future applications of the developed technique are discussed.

Three-dimensional confocal microscopy of the living cornea and ocular lens

NASA Astrophysics Data System (ADS)

Masters, Barry R.

1991-07-01

The three-dimensional reconstruction of the optic zone of the cornea and the ocular crystalline lens has been accomplished using confocal microscopy and volume rendering computer techniques. A laser scanning confocal microscope was used in the reflected light mode to obtain the two-dimensional images from the cornea and the ocular lens of a freshly enucleated rabbit eye. The light source was an argon ion laser with a 488 nm wavelength. The microscope objective was a Leitz X25, NA 0.6 water immersion lens. The 400 micron thick cornea was optically sectioned into 133 three micron sections. The semi-transparent cornea and the in-situ ocular lens was visualized as high resolution, high contrast two-dimensional images. The structures observed in the cornea include: superficial epithelial cells and their nuclei, basal epithelial cells and their 'beaded' cell borders, basal lamina, nerve plexus, nerve fibers, nuclei of stromal keratocytes, and endothelial cells. The structures observed in the in- situ ocular lens include: lens capsule, lens epithelial cells, and individual lens fibers. The three-dimensional data sets of the cornea and the ocular lens were reconstructed in the computer using volume rendering techniques. Stereo pairs were also created of the two- dimensional ocular images for visualization. The stack of two-dimensional images was reconstructed into a three-dimensional object using volume rendering techniques. This demonstration of the three-dimensional visualization of the intact, enucleated eye provides an important step toward quantitative three-dimensional morphometry of the eye. The important aspects of three-dimensional reconstruction are discussed.

Numerical simulation of the three-dimensional river antidunes

NASA Astrophysics Data System (ADS)

Iwasaki, T.; Inoue, T.; Onda, S.; Yabe, H.

2017-12-01

This study presents numerical simulations of the formation and development of the three-dimensional river antidunes. We use a Boussinesq type depth-integrated hydrodynamic model to account for the non-hydrostatic pressure effects on the flow field, dissipative feature of the free surface and the bed shear stress distribution. In addition, a non-equilibrium bedload transport model is incorporated into the model to consider the lag effect of the bedload transport on the bedform dynamics. The model is applied to idealized laboratory-scale conditions, i.e., steady water and sediment supplies, uniform sediment and a straight channel with constant slope and channel width, to understand the model performance and applicability. The results show that the model is able to reproduce an upstream-migrating antidunes and associated free surface dynamics. The model also captures the formation of the two dimensional and the three-dimensional antidunes. The antidunes reproduced by the model are somewhat unstable, i.e., the repeated cycle of dissipation and regeneration of antidunes is observed. In addition, as the calculation progresses, the modelled three-dimensional antidunes generally tend to lose their three-dimensionality, i.e., the reduction of the spanwise wavenumber. In the early stage of the calculation, the antidune mode is dominant, whereas, the free bars also develop when the formative condition of bars is satisfied. The numerical results show the coexisting of free bars and antidunes, which are a common evident in flume experiments and field observations.

Two-dimensional grayscale ultrasound and spectral Doppler waveform evaluation of dogs with chronic enteropathies.

PubMed

Gaschen, Lorrie; Kircher, Patrick

2007-08-01

Sonography is an important diagnostic tool to examine the gastrointestinal tract of dogs with chronic diarrhea. Two-dimensional grayscale ultrasound parameters to assess for various enteropathies primarily focus on wall thickness and layering. Mild, generalized thickening of the intestinal wall with maintenance of the wall layering is common in inflammatory bowel disease. Quantitative and semi-quantitative spectral Doppler arterial waveform analysis can be utilized for various enteropathies, including inflammatory bowel disease and food allergies. Dogs with inflammatory bowel disease have inadequate hemodynamic responses during digestion of food. Dogs with food allergies have prolonged vasodilation and lower resistive and pulsatility indices after eating allergen-inducing foods.

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

3D-PDR: Three-dimensional photodissociation region code

NASA Astrophysics Data System (ADS)

Bisbas, T. G.; Bell, T. A.; Viti, S.; Yates, J.; Barlow, M. J.

2018-03-01

3D-PDR is a three-dimensional photodissociation region code written in Fortran. It uses the Sundials package (written in C) to solve the set of ordinary differential equations and it is the successor of the one-dimensional PDR code UCL_PDR (ascl:1303.004). Using the HEALpix ray-tracing scheme (ascl:1107.018), 3D-PDR solves a three-dimensional escape probability routine and evaluates the attenuation of the far-ultraviolet radiation in the PDR and the propagation of FIR/submm emission lines out of the PDR. The code is parallelized (OpenMP) and can be applied to 1D and 3D problems.

Ultrasound-Guided Renal Access for Percutaneous Nephrolithotomy: A Description of Three Novel Ultrasound-Guided Needle Techniques

PubMed Central

Chu, Carissa; Masic, Selma; Usawachintachit, Manint; Hu, Weiguo; Yang, Wenzeng; Stoller, Marshall; Li, Jianxing

2016-01-01

Abstract Ultrasound-guided renal access for percutaneous nephrolithotomy (PCNL) is a safe, effective, and low-cost procedure commonly performed worldwide, but a technique underutilized by urologists in the United States. The purpose of this article is to familiarize the practicing urologist with methods for ultrasound guidance for percutaneous renal access. We discuss two alternative techniques for gaining renal access for PCNL under ultrasound guidance. We also describe a novel technique of using the puncture needle to reposition residual stone fragments to avoid additional tract dilation. With appropriate training, ultrasound-guided renal access for PCNL can lead to reduced radiation exposure, accurate renal access, and excellent stone-free success rates and clinical outcomes. PMID:26414304

Integration of Computed Tomography and Three-Dimensional Echocardiography for Hybrid Three-Dimensional Printing in Congenital Heart Disease.

PubMed

Gosnell, Jordan; Pietila, Todd; Samuel, Bennett P; Kurup, Harikrishnan K N; Haw, Marcus P; Vettukattil, Joseph J

2016-12-01

Three-dimensional (3D) printing is an emerging technology aiding diagnostics, education, and interventional, and surgical planning in congenital heart disease (CHD). Three-dimensional printing has been derived from computed tomography, cardiac magnetic resonance, and 3D echocardiography. However, individually the imaging modalities may not provide adequate visualization of complex CHD. The integration of the strengths of two or more imaging modalities has the potential to enhance visualization of cardiac pathomorphology. We describe the feasibility of hybrid 3D printing from two imaging modalities in a patient with congenitally corrected transposition of the great arteries (L-TGA). Hybrid 3D printing may be useful as an additional tool for cardiologists and cardiothoracic surgeons in planning interventions in children and adults with CHD.

Three-dimensional modeling of the plasma arc in arc welding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, G.; Tsai, H. L.; Hu, J.

2008-11-15

Most previous three-dimensional modeling on gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool dynamics and assumes the two-dimensional axisymmetric Gaussian distributions for plasma arc pressure and heat flux. In this article, a three-dimensional plasma arc model is developed, and the distributions of velocity, pressure, temperature, current density, and magnetic field of the plasma arc are calculated by solving the conservation equations of mass, momentum, and energy, as well as part of the Maxwell's equations. This three-dimensional model can be used to study the nonaxisymmetric plasma arc caused by external perturbations such asmore » an external magnetic field. It also provides more accurate boundary conditions when modeling the weld pool dynamics. The present work lays a foundation for true three-dimensional comprehensive modeling of GTAW and GMAW including the plasma arc, weld pool, and/or electrode.« less

Ultrasound Technologies for the Spatial Patterning of Cells and Extracellular Matrix Proteins and the Vascularization of Engineered Tissue

NASA Astrophysics Data System (ADS)

Garvin, Kelley A.

Technological advancements in the field of tissue engineering could save the lives of thousands of organ transplant patients who die each year while waiting for donor organs. Currently, two of the primary challenges preventing tissue engineers from developing functional replacement tissues and organs are the need to recreate complex cell and extracellular microenvironments and to vascularize the tissue to maintain cell viability and function. Ultrasound is a form of mechanical energy that can noninvasively and nondestructively interact with tissues at the cell and protein level. In this thesis, novel ultrasound-based technologies were developed for the spatial patterning of cells and extracellular matrix proteins and the vascularization of three-dimensional engineered tissue constructs. Acoustic radiation forces associated with ultrasound standing wave fields were utilized to noninvasively control the spatial organization of cells and cell-bound extracellular matrix proteins within collagen-based engineered tissue. Additionally, ultrasound induced thermal mechanisms were exploited to site-specifically pattern various extracellular matrix collagen microstructures within a single engineered tissue construct. Finally, ultrasound standing wave field technology was used to promote the rapid and extensive vascularization of three-dimensional tissue constructs. As such, the ultrasound technologies developed in these studies have the potential to provide the field of tissue engineering with novel strategies to spatially pattern cells and extracellular matrix components and to vascularize engineered tissue, and thus, could advance the fabrication of functional replacement tissues and organs in the field of tissue engineering.

Using Three-Dimensional Interactive Graphics To Teach Equipment Procedures.

ERIC Educational Resources Information Center

Hamel, Cheryl J.; Ryan-Jones, David L.

1997-01-01

Focuses on how three-dimensional graphical and interactive features of computer-based instruction can enhance learning and support human cognition during technical training of equipment procedures. Presents guidelines for using three-dimensional interactive graphics to teach equipment procedures based on studies of the effects of graphics, motion,…

Three dimensional canonical singularity and five dimensional N = 1 SCFT

NASA Astrophysics Data System (ADS)

Xie, Dan; Yau, Shing-Tung

2017-06-01

We conjecture that every three dimensional canonical singularity defines a five dimensional N = 1 SCFT. Flavor symmetry can be found from singularity structure: non-abelian flavor symmetry is read from the singularity type over one dimensional singular locus. The dimension of Coulomb branch is given by the number of compact crepant divisors from a crepant resolution of singularity. The detailed structure of Coulomb branch is described as follows: a) a chamber of Coulomb branch is described by a crepant resolution, and this chamber is given by its Nef cone and the prepotential is computed from triple intersection numbers; b) Crepant resolution is not unique and different resolutions are related by flops; Nef cones from crepant resolutions form a fan which is claimed to be the full Coulomb branch.

Three-dimensional high-resolution ultrasonic imaging of the eye

NASA Astrophysics Data System (ADS)

Silverman, Ronald H.; Lizzi, Frederick L.; Kalisz, Andrew; Coleman, D. J.

2000-04-01

Very high frequency (50 MHz) ultrasound provides spatial resolution on the order of 30 microns axially by 60 microns laterally. Our aim was to reconstruct the three-dimensional anatomy of the eye in the full detail permitted by this fine- scale transducer resolution. We scanned the eyes of human subjects and anesthetized rabbits in a sequence of parallel planes 50 microns apart. Within each scan plane, vectors were also spaced 50 microns apart. Radio-frequency data were digitized at a rate of 250 MHz or higher. A series of spectrum analysis and segmentation algorithms was applied to data acquired in each plane; the outputs of these procedures were used to produce color-coded 3-D representations of the sclera, iris and ciliary processes to enhance 3-D volume rendered presentation. We visualized the radial pattern of individual ciliary processes in humans and rabbits and the geodetic web of supporting connections between the ciliary processes and iris that exist only in the rabbit. By acquiring data such that adjacent vectors and planes are separated by less than the transducer's lateral resolution, we were able to visualize structures, such as the ciliary web, that had not been seen before in-vivo. Our techniques offer the possibility of high- precision imaging and measurement of anterior segment structures. This would be relevant in monitoring of glaucoma, tumors, foreign bodies and other clinical conditions.

A system of three-dimensional complex variables

NASA Technical Reports Server (NTRS)

Martin, E. Dale

1986-01-01

Some results of a new theory of multidimensional complex variables are reported, including analytic functions of a three-dimensional (3-D) complex variable. Three-dimensional complex numbers are defined, including vector properties and rules of multiplication. The necessary conditions for a function of a 3-D variable to be analytic are given and shown to be analogous to the 2-D Cauchy-Riemann equations. A simple example also demonstrates the analogy between the newly defined 3-D complex velocity and 3-D complex potential and the corresponding ordinary complex velocity and complex potential in two dimensions.

Optical lithography of three-dimensional magnetophotonic microdevices

NASA Astrophysics Data System (ADS)

Nguyen, Dam Thuy Trang; Del Guercio, Olivia; Au, Thi Huong; Trinh, Duc Thien; Mai, Nguyen Phuong Thao; Lai, Ngoc Diep

2018-04-01

We have recently demonstrated a simple and low-cost fabrication technique, called low one-photon absorption direct laser writing, to realize desired polymeric microstructures. We present the use of this technique for fabrication of three-dimensional magnetophotonic devices on a photocurable homogeneous nanocomposite consisting of magnetite (Fe3O4) nanoparticles and a commercial SU8 photoresist. The fabricated magnetophotonic microstructures show strong response to an applied external magnetic field. Thus, various three-dimensional submicromechanical magnetophotonic devices, which can be mechanically driven by magnetic force, are designed and created. Potential applications of these devices are also discussed.

Radiative Instabilities in Three-Dimensional Astrophysical Masers

NASA Technical Reports Server (NTRS)

Scappaticci, Gerardo A.; Watson, William D.

1995-01-01

Inherent instabilities in the radiative transfer for astrophysical masers have been recognized and calculated in the linear maser idealization in our previous investigations. The same instabilities are now shown to occur in the more realistic, three-dimensional geometries. Fluctuations in the emergent flux result and may be related to the observed fluctuations in the radiative flux from the 1665 MHz OH masers that have been reported to occur on timescales as short as 1000 s. The time-dependent differential equations of radiative transfer are solved numerically for three-dimensional astrophysical masers. Computations are performed for spherical and elongated (rectangular parallelepiped) geometries.

Three-dimensional analysis of tubular permanent magnet machines

NASA Astrophysics Data System (ADS)

Chai, J.; Wang, J.; Howe, D.

2006-04-01

This paper presents results from a three-dimensional finite element analysis of a tubular permanent magnet machine, and quantifies the influence of the laminated modules from which the stator core is assembled on the flux linkage and thrust force capability as well as on the self- and mutual inductances. The three-dimensional finite element (FE) model accounts for the nonlinear, anisotropic magnetization characteristic of the laminated stator structure, and for the voids which exist between the laminated modules. Predicted results are compared with those deduced from an axisymmetric FE model. It is shown that the emf and thrust force deduced from the three-dimensional model are significantly lower than those which are predicted from an axisymmetric field analysis, primarily as a consequence of the teeth and yoke being more highly saturated due to the presence of the voids in the laminated stator core.

Real-time Three-dimensional Echocardiography: From Diagnosis to Intervention.

PubMed

Orvalho, João S

2017-09-01

Echocardiography is one of the most important diagnostic tools in veterinary cardiology, and one of the greatest recent developments is real-time three-dimensional imaging. Real-time three-dimensional echocardiography is a new ultrasonography modality that provides comprehensive views of the cardiac valves and congenital heart defects. The main advantages of this technique, particularly real-time three-dimensional transesophageal echocardiography, are the ability to visualize the catheters, and balloons or other devices, and the ability to image the structure that is undergoing intervention with unprecedented quality. This technique may become one of the main choices for the guidance of interventional cardiology procedures. Copyright © 2017 Elsevier Inc. All rights reserved.

Three-dimensional spiral CT during arterial portography: comparison of three rendering techniques.

PubMed

Heath, D G; Soyer, P A; Kuszyk, B S; Bliss, D F; Calhoun, P S; Bluemke, D A; Choti, M A; Fishman, E K

1995-07-01

The three most common techniques for three-dimensional reconstruction are surface rendering, maximum-intensity projection (MIP), and volume rendering. Surface-rendering algorithms model objects as collections of geometric primitives that are displayed with surface shading. The MIP algorithm renders an image by selecting the voxel with the maximum intensity signal along a line extended from the viewer's eye through the data volume. Volume-rendering algorithms sum the weighted contributions of all voxels along the line. Each technique has advantages and shortcomings that must be considered during selection of one for a specific clinical problem and during interpretation of the resulting images. With surface rendering, sharp-edged, clear three-dimensional reconstruction can be completed on modest computer systems; however, overlapping structures cannot be visualized and artifacts are a problem. MIP is computationally a fast technique, but it does not allow depiction of overlapping structures, and its images are three-dimensionally ambiguous unless depth cues are provided. Both surface rendering and MIP use less than 10% of the image data. In contrast, volume rendering uses nearly all of the data, allows demonstration of overlapping structures, and engenders few artifacts, but it requires substantially more computer power than the other techniques.

Optimized Hyperthermia Treatment of Prostate Cancer Using a Novel Intracavitary Ultrasound Array

DTIC Science & Technology

2005-01-01

many problems Introduction involved with transducer fabrication. Focused ultrasound surgery ( FUS ) has been shown to give promising results in treating...low frequencies are used) (Hutchinson 1997). With focused ultrasound ( FUS ), tissue is noninvasively necrosed by elevating the temperature at the focal...curved 1.5 dimensional (1.5-D) array that could, but had of a 1.75 dimensional (1.75-D) tapered ultrasound phased array restrictions to the focusing

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

NASA Astrophysics Data System (ADS)

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

2014-03-01

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

Surface representations of two- and three-dimensional fluid flow topology

NASA Technical Reports Server (NTRS)

Helman, James L.; Hesselink, Lambertus

1990-01-01

We discuss our work using critical point analysis to generate representations of the vector field topology of numerical flow data sets. Critical points are located and characterized in a two-dimensional domain, which may be either a two-dimensional flow field or the tangential velocity field near a three-dimensional body. Tangent curves are then integrated out along the principal directions of certain classes of critical points. The points and curves are linked to form a skeleton representing the two-dimensional vector field topology. When generated from the tangential velocity field near a body in a three-dimensional flow, the skeleton includes the critical points and curves which provide a basis for analyzing the three-dimensional structure of the flow separation. The points along the separation curves in the skeleton are used to start tangent curve integrations to generate surfaces representing the topology of the associated flow separations.

Three-dimensional magnetophotonic crystals based on artificial opals

NASA Astrophysics Data System (ADS)

Baryshev, A. V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

2004-06-01

We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties.

Three-Dimensional Images For Robot Vision

NASA Astrophysics Data System (ADS)

McFarland, William D.

1983-12-01

Robots are attracting increased attention in the industrial productivity crisis. As one significant approach for this nation to maintain technological leadership, the need for robot vision has become critical. The "blind" robot, while occupying an economical niche at present is severely limited and job specific, being only one step up from the numerical controlled machines. To successfully satisfy robot vision requirements a three dimensional representation of a real scene must be provided. Several image acquistion techniques are discussed with more emphasis on the laser radar type instruments. The autonomous vehicle is also discussed as a robot form, and the requirements for these applications are considered. The total computer vision system requirement is reviewed with some discussion of the major techniques in the literature for three dimensional scene analysis.

Three-dimensional contrasted visualization of pancreas in rats using clinical MRI and CT scanners.

PubMed

Yin, Ting; Coudyzer, Walter; Peeters, Ronald; Liu, Yewei; Cona, Marlein Miranda; Feng, Yuanbo; Xia, Qian; Yu, Jie; Jiang, Yansheng; Dymarkowski, Steven; Huang, Gang; Chen, Feng; Oyen, Raymond; Ni, Yicheng

2015-01-01

The purpose of this work was to visualize the pancreas in post-mortem rats with local contrast medium infusion by three-dimensional (3D) magnetic resonance imaging (MRI) and computed tomography (CT) using clinical imagers. A total of 16 Sprague Dawley rats of about 300 g were used for the pancreas visualization. Following the baseline imaging, a mixed contrast medium dye called GadoIodo-EB containing optimized concentrations of Gd-DOTA, iomeprol and Evens blue was infused into the distally obstructed common bile duct (CBD) for post-contrast imaging with 3.0 T MRI and 128-slice CT scanners. Images were post-processed with the MeVisLab software package. MRI findings were co-registered with CT scans and validated with histomorphology, with relative contrast ratios quantified. Without contrast enhancement, the pancreas was indiscernible. After infusion of GadoIodo-EB solution, only the pancreatic region became outstandingly visible, as shown by 3D rendering MRI and CT and proven by colored dissection and histological examinations. The measured volume of the pancreas averaged 1.12 ± 0.04 cm(3) after standardization. Relative contrast ratios were 93.28 ± 34.61% and 26.45 ± 5.29% for MRI and CT respectively. We have developed a multifunctional contrast medium dye to help clearly visualize and delineate rat pancreas in situ using clinical MRI and CT scanners. The topographic landmarks thus created with 3D demonstration may help to provide guidelines for the next in vivo pancreatic MRI research in rodents. Copyright © 2015 John Wiley & Sons, Ltd.

Three-dimensional macro-structures of two-dimensional nanomaterials.

PubMed

Shehzad, Khurram; Xu, Yang; Gao, Chao; Duan, Xiangfeng

2016-10-21

If two-dimensional (2D) nanomaterials are ever to be utilized as components of practical, macroscopic devices on a large scale, there is a complementary need to controllably assemble these 2D building blocks into more sophisticated and hierarchical three-dimensional (3D) architectures. Such a capability is key to design and build complex, functional devices with tailored properties. This review provides a comprehensive overview of the various experimental strategies currently used to fabricate the 3D macro-structures of 2D nanomaterials. Additionally, various approaches for the decoration of the 3D macro-structures with organic molecules, polymers, and inorganic materials are reviewed. Finally, we discuss the applications of 3D macro-structures, especially in the areas of energy, environment, sensing, and electronics, and describe the existing challenges and the outlook for this fast emerging field.

Three-dimensional interpretation of TEM soundings

NASA Astrophysics Data System (ADS)

Barsukov, P. O.; Fainberg, E. B.

2013-07-01

We describe the approach to the interpretation of electromagnetic (EM) sounding data which iteratively adjusts the three-dimensional (3D) model of the environment by local one-dimensional (1D) transformations and inversions and reconstructs the geometrical skeleton of the model. The final 3D inversion is carried out with the minimal number of the sought parameters. At each step of the interpretation, the model of the medium is corrected according to the geological information. The practical examples of the suggested method are presented.

Reliability of tunnel angle in ACL reconstruction: two-dimensional versus three-dimensional guide technique.

PubMed

Leiter, Jeff R S; de Korompay, Nevin; Macdonald, Lindsey; McRae, Sheila; Froese, Warren; Macdonald, Peter B

2011-08-01

To compare the reliability of tibial tunnel position and angle produced with a standard ACL guide (two-dimensional guide) or Howell 65° Guide (three-dimensional guide) in the coronal and sagittal planes. In the sagittal plane, the dependent variables were the angle of the tibial tunnel relative to the tibial plateau and the position of the tibial tunnel with respect to the most posterior aspect of the tibia. In the coronal plane, the dependent variables were the angle of the tunnel with respect to the medial joint line of the tibia and the medial and lateral placement of the tibial tunnel relative to the most medial aspect of the tibia. The position and angle of the tibial tunnel in the coronal and sagittal planes were determined from anteroposterior and lateral radiographs, respectively, taken 2-6 months postoperatively. The two-dimensional and three-dimensional guide groups included 28 and 24 sets of radiographs, respectively. Tibial tunnel position was identified, and tunnel angle measurements were completed. Multiple investigators measured the position and angle of the tunnel 3 times, at least 7 days apart. The angle of the tibial tunnel in the coronal plane using a two-dimensional guide (61.3 ± 4.8°) was more horizontal (P < 0.05) than tunnels drilled with a three-dimensional guide (64.7 ± 6.2°). The position of the tibial tunnel in the sagittal plane was more anterior (P < 0.05) in the two-dimensional (41.6 ± 2.5%) guide group compared to the three-dimensional guide group (43.3 ± 2.9%). The Howell Tibial Guide allows for reliable placement of the tibial tunnel in the coronal plane at an angle of 65°. Tibial tunnels were within the anatomical footprint of the ACL with either technique. Future studies should investigate the effects of tibial tunnel angle on knee function and patient quality of life. Case-control retrospective comparative study, Level III.

Three-dimensional imaging technology offers promise in medicine.

PubMed

Karako, Kenji; Wu, Qiong; Gao, Jianjun

2014-04-01

Medical imaging plays an increasingly important role in the diagnosis and treatment of disease. Currently, medical equipment mainly has two-dimensional (2D) imaging systems. Although this conventional imaging largely satisfies clinical requirements, it cannot depict pathologic changes in 3 dimensions. The development of three-dimensional (3D) imaging technology has encouraged advances in medical imaging. Three-dimensional imaging technology offers doctors much more information on a pathology than 2D imaging, thus significantly improving diagnostic capability and the quality of treatment. Moreover, the combination of 3D imaging with augmented reality significantly improves surgical navigation process. The advantages of 3D imaging technology have made it an important component of technological progress in the field of medical imaging.

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.

In vivo photoacoustic and ultrasonic mapping of rat sentinel lymph nodes with a modified commercial ultrasound imaging system

NASA Astrophysics Data System (ADS)

Erpelding, Todd N.; Kim, Chulhong; Pramanik, Manojit; Guo, Zijian; Dean, John; Jankovic, Ladislav; Maslov, Konstantin; Wang, Lihong V.

2010-02-01

Sentinel lymph node biopsy (SLNB) has become the standard method for axillary staging in breast cancer patients, relying on invasive identification of sentinel lymph nodes (SLNs) following injection of blue dye and radioactive tracers. While SLNB achieves a low false negative rate (5-10%), it is an invasive procedure requiring ionizing radiation. As an alternative to SLNB, ultrasound-guided fine needle aspiration biopsy has been tested clinically. However, ultrasound alone is unable to accurately identify which lymph nodes are sentinel. Therefore, a non-ionizing and noninvasive detection method for accurate SLN mapping is needed. In this study, we successfully imaged methylene blue dye accumulation in vivo in rat axillary lymph nodes using a Phillips iU22 ultrasound imaging system adapted for photoacoustic imaging with an Nd:YAG pumped, tunable dye laser. Photoacoustic images of rat SLNs clearly identify methylene blue dye accumulation within minutes following intradermal dye injection and co-registered photoacoustic/ultrasound images illustrate lymph node position relative to surrounding anatomy. To investigate clinical translation, the imaging depth was extended up to 2.5 cm by adding chicken breast tissue on top of the rat skin surface. These results raise confidence that photoacoustic imaging can be used clinically for accurate, noninvasive SLN mapping.

Three-dimensional echocardiographic assessment of the repaired mitral valve.

PubMed

Maslow, Andrew; Mahmood, Feroze; Poppas, Athena; Singh, Arun

2014-02-01

This study examined the geometric changes of the mitral valve (MV) after repair using conventional and three-dimensional echocardiography. Prospective evaluation of consecutive patients undergoing mitral valve repair. Tertiary care university hospital. Fifty consecutive patients scheduled for elective repair of the mitral valve for regurgitant disease. Intraoperative transesophageal echocardiography. Assessments of valve area (MVA) were performed using two-dimensional planimetry (2D-Plan), pressure half-time (PHT), and three-dimensional planimetry (3D-Plan). In addition, the direction of ventricular inflow was assessed from the three-dimensional imaging. Good correlations (r = 0.83) and agreement (-0.08 +/- 0.43 cm(2)) were seen between the MVA measured with 3D-Plan and PHT, and were better than either compared to 2D-Plan. MVAs were smaller after repair of functional disease repaired with an annuloplasty ring. After repair, ventricular inflow was directed toward the lateral ventricular wall. Subgroup analysis showed that the change in inflow angle was not different after repair of functional disease (168 to 171 degrees) as compared to those presenting with degenerative disease (168 to 148 degrees; p<0.0001). Three-dimensional imaging provides caregivers with a unique ability to assess changes in valve function after mitral valve repair. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Intravascular ultrasound in coronary atherosclerosis: a new approach to clinical assessment.

PubMed

Liebson, P R; Klein, L W

1992-06-01

Intravascular ultrasound evaluation of the coronary arteries by means of a selective coronary catheter attached to an ultrasound unit has afforded precise depiction of coronary lumen diameter and area at the level of the catheter tip. The arterial wall at this level can be evaluated for lipid, fibrous tissue, calcification, wall dissections, and intraluminal thrombi. The technique has the advantage over coronary angioscopy and angiography in that it does not require infusions or injections to allow visualization, and it has the ability to depict the inside of the arterial wall. The current disadvantages include the inability to visualize the vessel segments distal to the catheter tip. Three-dimensional reconstruction techniques allow depiction of the segment of the artery traversed by the catheter tip. The use of Doppler ultrasound imaging provides information on coronary flow velocities through coronary obstructions. Intravascular ultrasound images may provide information that complements the coronary arteriogram and may have an impact on patient care and clinical investigation strategies.

Three-dimensional surface reconstruction for industrial computed tomography

NASA Technical Reports Server (NTRS)

Vannier, M. W.; Knapp, R. H.; Gayou, D. E.; Sammon, N. P.; Butterfield, R. L.; Larson, J. W.

1985-01-01

Modern high resolution medical computed tomography (CT) scanners can produce geometrically accurate sectional images of many types of industrial objects. Computer software has been developed to convert serial CT scans into a three-dimensional surface form, suitable for display on the scanner itself. This software, originally developed for imaging the skull, has been adapted for application to industrial CT scanning, where serial CT scans thrrough an object of interest may be reconstructed to demonstrate spatial relationships in three dimensions that cannot be easily understood using the original slices. The methods of three-dimensional reconstruction and solid modeling are reviewed, and reconstruction in three dimensions from CT scans through familiar objects is demonstrated.

A three-dimensional turbulent separated flow and related mesurements

NASA Technical Reports Server (NTRS)

Pierce, F. J.

1985-01-01

The applicability of and the limits on the applicability of 11 near wall similarity laws characterizing three-dimensional turbulent boundary layer flows were determined. A direct force sensing local wall shear stress meter was used in both pressure-driven and shear-driven three-dimensional turbulent boundary layers, together with extensive mean velocity field and wall pressure field data. This resulted in a relatively large number of graphical comparisons of the predictive ability of 10 of these 11 similarity models relative to measured data over a wide range of flow conditions. Documentation of a complex, separated three-dimensional turbulent flow as a standard test case for evaluating the predictive ability of numerical codes solving such flows is presented.

Ultrasound evaluation of cortical brain development in fetuses with intrauterine growth restriction.

PubMed

Businelli, Caterina; de Wit, Charlotte; Visser, Gerard H A; Pistorius, Lourens R

2014-09-10

Abstract Objective: We evaluated the ultrasound appearance of brain volume and cortical development in fetuses with early growth restriction and placental insufficiency. Methods: We examined a cohort of 20 fetuses with severe intrauterine growth restriction (IUGR) and evidence of placental insufficiency by three-dimensional (3D) ultrasound between 24 and 34 weeks. We graded cortical development and measured the supratentorial intracranial volume. The cortical grading and volume were compared to data obtained from a reference population of 28 adequate for gestational age (AGA) fetuses. Results: Ultrasound examinations were performed in 20 fetuses with IUGR. The biometry and brain volume were significantly reduced in IUGR fetuses. There was evidence of accelerated cortical development in IUGR fetuses. Conclusion: This study confirms that the smaller brain volume in IUGR fetuses, with normal or accelerated cortical maturation as previously depicted with postnatal MRI examination, can be demonstrated by prenatal 3D ultrasound.

Three-dimensional analysis of magnetometer array data

NASA Technical Reports Server (NTRS)

Richmond, A. D.; Baumjohann, W.

1984-01-01

A technique is developed for mapping magnetic variation fields in three dimensions using data from an array of magnetometers, based on the theory of optimal linear estimation. The technique is applied to data from the Scandinavian Magnetometer Array. Estimates of the spatial power spectra for the internal and external magnetic variations are derived, which in turn provide estimates of the spatial autocorrelation functions of the three magnetic variation components. Statistical errors involved in mapping the external and internal fields are quantified and displayed over the mapping region. Examples of field mapping and of separation into external and internal components are presented. A comparison between the three-dimensional field separation and a two-dimensional separation from a single chain of stations shows that significant differences can arise in the inferred internal component.

Performance and analysis of a three-dimensional nonorthogonal laser Doppler anemometer

NASA Technical Reports Server (NTRS)

Snyder, P. K.; Orloff, K. L.; Aoyagi, K.

1981-01-01

A three dimensional laser Doppler anemometer with a nonorthogonal third axis coupled by 14 deg was designed and tested. A highly three dimensional flow field of a jet in a crossflow was surveyed to test the three dimensional capability of the instrument. Sample data are presented demonstrating the ability of the 3D LDA to resolve three orthogonal velocity components. Modifications to the optics, signal processing electronics, and data reduction methods are suggested.

Two-dimensional airborne ultrasound real-time linear array scanner--applied to screening for scoliosis.

PubMed

Mauritzson, L; Ilver, J; Benoni, G; Lindström, K; Willner, S

1991-01-01

Diagnostic ultrasound is an established, noninvasive and harmless method for imaging the shape and appearance of organs and other tissues inside the body, and it has been used in many clinical applications for more than three decades. We have now applied some of this well-known technique together with the use of airborne ultrasound in medical applications, to build an equipment for anthropometrical investigation outside the body, e.g., measuring and registration of the shape and form of the human back. This is mostly done for screening purposes of young people in an attempt to find patients developing scoliosis, and in order to circumvent some of the disadvantages with the traditional screening method in this field of medical application.

Computation of three-dimensional shock wave and boundary-layer interactions

NASA Technical Reports Server (NTRS)

Hung, C. M.

1985-01-01

Computations of the impingement of an oblique shock wave on a cylinder and a supersonic flow past a blunt fin mounted on a plate are used to study three dimensional shock wave and boundary layer interaction. In the impingement case, the problem of imposing a planar impinging shock as an outer boundary condition is discussed and the details of particle traces in windward and leeward symmetry planes and near the body surface are presented. In the blunt fin case, differences between two dimensional and three dimensional separation are discussed, and the existence of an unique high speed, low pressure region under the separated spiral vortex core is demonstrated. The accessibility of three dimensional separation is discussed.

Three-Particle Complexes in Two-Dimensional Semiconductors

NASA Astrophysics Data System (ADS)

Ganchev, Bogdan; Drummond, Neil; Aleiner, Igor; Fal'ko, Vladimir

2015-03-01

We evaluate binding energies of trions X±, excitons bound by a donor or acceptor charge XD (A ) , and overcharged acceptors or donors in two-dimensional atomic crystals by mapping the three-body problem in two dimensions onto one particle in a three-dimensional potential treatable by a purposely developed boundary-matching-matrix method. We find that in monolayers of transition metal dichalcogenides the dissociation energy of X± is typically much larger than that of localized exciton complexes, so that trions are more resilient to heating, despite the fact that their recombination line in optics is less redshifted from the exciton line than the line of XD (A ) .

THREE-DIMENSIONAL MODEL FOR HYPERTHERMIA CALCULATIONS

EPA Science Inventory

Realistic three-dimensional models that predict temperature distributions with a high degree of spatial resolution in bodies exposed to electromagnetic (EM) fields are required in the application of hyperthermia for cancer treatment. To ascertain the thermophysiologic response of...

Numerical investigations in three-dimensional internal flows

NASA Technical Reports Server (NTRS)

Rose, William C.

1991-01-01

In previous efforts, a two-dimensional full Navier-Stokes (FNS) code (SCRAM2D) was used in a design process that involved parametric modifications of the inlet geometry to arrive at what appeared to be an optimum inlet flowfield that produced a uniform flow at the exit in a very short distance. In these previous studies, the technologies for determining the contours with a 'man-in-the-loop' approach for both the ramp and cowl of the inlet were demonstrated, and nearly shock-free exiting flowfields were shown to be obtainable. The resulting two-dimensional compression contours were then used with swept sidewalls to form a three-dimensional inlet. Then the three-dimensional Navier-Stokes code (SCRAM3D) was used to investigate the inlet's three-dimensional flow. One of the major difficulties encountered in the previous studies was that associated with the relatively long time required to obtain a solution using even the 2D FNS code in the design process. Since one of the goals of high-speed inlet design is to produce inputs to the overall aircraft design in a timely manner, it was proposed for this year's research to examine 2D and 3D viscous flow solver techniques alternative to the NFS codes used to date. Areas of the inlet particularly identified for code speed up are those associated with the forebody and external flow ramp systems of the inlet. In these areas, parabolized, or space-marched, Navier-Stokes codes were proposed to be investigated for their applicability in the design process developed previously. This report describes the results of an investigation into the use of two other codes for analyzing the forebody and inlet ramp systems of high-speed inlets.

The Evolution of Photography and Three-Dimensional Imaging in Plastic Surgery.

PubMed

Weissler, Jason M; Stern, Carrie S; Schreiber, Jillian E; Amirlak, Bardia; Tepper, Oren M

2017-03-01

Throughout history, the technological advancements of conventional clinical photography in plastic surgery have not only refined the methods available to the plastic surgeon, but have invigorated the profession through technology. The technology of the once traditional two-dimensional photograph has since been revolutionized and refashioned to incorporate novel applications, which have since become the standard in clinical photography. Contrary to traditional standardized two-dimensional photographs, three-dimensional photography provides the surgeon with an invaluable volumetric and morphologic analysis by demonstrating true surface dimensions both preoperatively and postoperatively. Clinical photography has served as one of the fundamental objective means by which plastic surgeons review outcomes; however, the newer three-dimensional technology has been primarily used to enhance the preoperative consultation with surgical simulations. The authors intend to familiarize readers with the notion that three-dimensional photography extends well beyond its marketing application during surgical consultation. For the cosmetic surgeon, as the application of three-dimensional photography continues to mature in facial plastic surgery, it will continue to bypass the dated conventional photographic methods plastic surgeons once relied on. This article reviews a paradigm shift and provides a historical review of the fascinating evolution of photography in plastic surgery by highlighting the clinical utility of three-dimensional photography as an adjunct to plastic and reconstructive surgery practices. As three-dimensional photographic technology continues to evolve, its application in facial plastic surgery will provide an opportunity for a new objective standard in plastic surgery.

Versatile low-Reynolds-number swimmer with three-dimensional maneuverability.

PubMed

Jalali, Mir Abbas; Alam, Mohammad-Reza; Mousavi, SeyyedHossein

2014-11-01

We design and simulate the motion of a swimmer, the Quadroar, with three-dimensional translation and reorientation capabilities in low-Reynolds-number conditions. The Quadroar is composed of an I-shaped frame whose body link is a simple linear actuator and four disks that can rotate about the axes of flange links. The time symmetry is broken by a combination of disk rotations and the one-dimensional expansion or contraction of the body link. The Quadroar propels on forward and transverse straight lines and performs full three-dimensional reorientation maneuvers, which enable it to swim along arbitrary trajectories. We find continuous operation modes that propel the swimmer on planar and three-dimensional periodic and quasiperiodic orbits. Precessing quasiperiodic orbits consist of slow lingering phases with cardioid or multiloop turns followed by directional propulsive phases. Quasiperiodic orbits allow the swimmer to access large parts of its neighboring space without using complex control strategies. We also discuss the feasibility of fabricating a nanoscale Quadroar by photoactive molecular rotors.

Projection-type see-through holographic three-dimensional display

NASA Astrophysics Data System (ADS)

Wakunami, Koki; Hsieh, Po-Yuan; Oi, Ryutaro; Senoh, Takanori; Sasaki, Hisayuki; Ichihashi, Yasuyuki; Okui, Makoto; Huang, Yi-Pai; Yamamoto, Kenji

2016-10-01

Owing to the limited spatio-temporal resolution of display devices, dynamic holographic three-dimensional displays suffer from a critical trade-off between the display size and the visual angle. Here we show a projection-type holographic three-dimensional display, in which a digitally designed holographic optical element and a digital holographic projection technique are combined to increase both factors at the same time. In the experiment, the enlarged holographic image, which is twice as large as the original display device, projected on the screen of the digitally designed holographic optical element was concentrated at the target observation area so as to increase the visual angle, which is six times as large as that for a general holographic display. Because the display size and the visual angle can be designed independently, the proposed system will accelerate the adoption of holographic three-dimensional displays in industrial applications, such as digital signage, in-car head-up displays, smart-glasses and head-mounted displays.

Accurate GM atrophy quantification in MS using lesion-filling with co-registered 2D lesion masks☆

PubMed Central

Popescu, V.; Ran, N.C.G.; Barkhof, F.; Chard, D.T.; Wheeler-Kingshott, C.A.; Vrenken, H.

2014-01-01

Background In multiple sclerosis (MS), brain atrophy quantification is affected by white matter lesions. LEAP and FSL-lesion_filling, replace lesion voxels with white matter intensities; however, they require precise lesion identification on 3DT1-images. Aim To determine whether 2DT2 lesion masks co-registered to 3DT1 images, yield grey and white matter volumes comparable to precise lesion masks. Methods 2DT2 lesion masks were linearly co-registered to 20 3DT1-images of MS patients, with nearest-neighbor (NNI), and tri-linear interpolation. As gold-standard, lesion masks were manually outlined on 3DT1-images. LEAP and FSL-lesion_filling were applied with each lesion mask. Grey (GM) and white matter (WM) volumes were quantified with FSL-FAST, and deep gray matter (DGM) volumes using FSL-FIRST. Volumes were compared between lesion mask types using paired Wilcoxon tests. Results Lesion-filling with gold-standard lesion masks compared to native images reduced GM overestimation by 1.93 mL (p < .001) for LEAP, and 1.21 mL (p = .002) for FSL-lesion_filling. Similar effects were achieved with NNI lesion masks from 2DT2. Global WM underestimation was not significantly influenced. GM and WM volumes from NNI, did not differ significantly from gold-standard. GM segmentation differed between lesion masks in the lesion area, and also elsewhere. Using the gold-standard, FSL-FAST quantified as GM on average 0.4% of the lesion area with LEAP and 24.5% with FSL-lesion_filling. Lesion-filling did not influence DGM volumes from FSL-FIRST. Discussion These results demonstrate that for global GM volumetry, precise lesion masks on 3DT1 images can be replaced by co-registered 2DT2 lesion masks. This makes lesion-filling a feasible method for GM atrophy measurements in MS. PMID:24567908

Three dimensional colorimetric assay assemblies

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

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.

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.

Physics of tissue harmonic imaging by ultrasound

NASA Astrophysics Data System (ADS)

Jing, Yuan

Tissue Harmonic Imaging (THI) is an imaging modality that is currently deployed on diagnostic ultrasound scanners. In THI the amplitude of the ultrasonic pulse that is used to probe the tissue is large enough that the pulse undergoes nonlinear distortion as it propagates into the tissue. One result of the distortion is that as the pulse propagates energy is shifted from the fundamental frequency of the source pulse into its higher harmonics. These harmonics will scatter off objects in the tissue and images formed from the scattered higher harmonics are considered to have superior quality to the images formed from the fundamental frequency. Processes that have been suggested as possibly responsible for the improved imaging in THI include: (1) reduced sensitivity to reverberation, (2) reduced sensitivity to aberration, and (3) reduction in side lobes. By using a combination of controlled experiments and numerical simulations, these three reasons have been investigated. A single element transducer and a clinical ultrasound scanner with a phased array transducer were used to image a commercial tissue-mimicking phantom with calibrated targets. The higher image quality achieved with THI was quantified in terms of spatial resolution and "clutter" signals. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed. A time-domain code for solving the KZK equation was validated with measurements of the acoustic field generated by the single element transducer and the phased array transducer. The code was used to investigate the impact of aberration using tissue-like media with three-dimensional variations in all acoustic properties. The three-dimensional maps of tissue properties were derived from the datasets available through the Visible Female project. The experiments and simulations demonstrated that second harmonic imaging (1) suffers less clutter associated with

Defining Ebstein's malformation using three-dimensional echocardiography.

PubMed

Vettukattil, Joseph J; Bharucha, Tara; Anderson, Robert H

2007-12-01

Ebstein's malformation is difficult to visualise, for both the echocardiographer and the surgeon. The essence of the problem in Ebstein's malformation is the deviation of the hingepoints of the leaflets towards the junctions of the inlet and apical trabecular parts of the right ventricle. Three-dimensional echocardiography offers new insights into the morphology and function of malformed valves, and allows elucidation of all the features. It allows clear visualisation of the valve leaflets, showing the precise morphology of the valve leaflets, the extent of their formation, the level of their attachment, and their degree of coaptation. Visualisation of the mechanism of regurgitation or stenosis is possible, as is more accurate quantification of the regurgitant jet or jets. Subchordal apparatus may be seen more clearly using three-dimensional echocardiography, and their functional anatomy understood. The multiplanar review modality allows examination of the three-dimensional data set even in patients with sub-optimal echocardiographic imaging. Previously, much of this information could only be well-understood at the time of surgery or post mortem, meaning that the majority of the specimens fully examined were at the poorly functioning end of the spectrum. This information is of use in furthering our understanding of this complex lesion as it functions in vivo, and demonstrating which anatomical pathology is significant in producing functional and physiological consequences. It is also of use for the clinician in selecting which patients are amenable to surgical intervention, for either single or biventricular repair, and for the surgeon in planning how to approach the operation. Correlation between three-dimensional echocardiographic findings and surgical findings has already been established, but the effect of this enhanced anatomical knowledge on surgical planning and surgical outcome requires further investigation.

[The three-dimensional simulation of arytenoid cartilage movement].

PubMed

Zhang, Jun; Wang, Xuefeng

2011-08-01

Exploring the characteristics of arytenoid cartilage movement. Using Pro/ENGINEER (Pro/E) software, the cricoid cartilage, arytenoid cartilage and vocal cords were simulated to the three-dimensional reconstruction, by analyzing the trajectory of arytenoid cartilage in the joint surface from the cricoid cartilage and arytenoid cartilage composition. The 3D animation simulation showed the normal movement patterns of the vocal cords and the characteristics of vocal cords movement in occasion of arytenoid cartilage dislocation vividly. The three-dimensional model has clinical significance for arytenoid cartilage movement disorders.

Binary Colloidal Alloy Test-5: Three-Dimensional Melt

NASA Technical Reports Server (NTRS)

Yodh, Arjun G.

2008-01-01

Binary Colloidal Alloy Test - 5: Three-Dimensional Melt (BCAT-5-3DMelt) photographs initially randomized colloidal samples in microgravity to determine their resulting structure over time. BCAT-5-3D-Melt will allow the scientists to capture the kinetics (evolution) of their samples, as well as the final equilibrium state of each sample. BCAT-5-3D-Melt will look at the mechanisms of melting using three-dimensional temperature sensitive colloidal crystals. Results will help scientists develop fundamental physics concepts previously shadowed by the effects of gravity.

High-contrast fast Fourier transform acousto-optical tomography of phantom tissues with a frequency-chirp modulation of the ultrasound.

PubMed

Forget, Benoît-Claude; Ramaz, François; Atlan, Michaël; Selb, Juliette; Boccara, Albert-Claude

2003-03-01

We report new results on acousto-optical tomography in phantom tissues using a frequency chirp modulation and a CCD camera. This technique allows quick recording of three-dimensional images of the optical contrast with a two-dimensional scan of the ultrasound source in a plane perpendicular to the ultrasonic path. The entire optical contrast along the ultrasonic path is concurrently obtained from the capture of a film sequence at a rate of 200 Hz. This technique reduces the acquisition time, and it enhances the axial resolution and thus the contrast, which are usually poor owing to the large volume of interaction of the ultrasound perturbation.

Coulomb disorder in three-dimensional Dirac materials

NASA Astrophysics Data System (ADS)

Skinner, Brian

2015-03-01

In three-dimensional materials with a Dirac spectrum, weak short-ranged disorder is essentially irrelevant near the Dirac point. This is manifestly not the case for Coulomb disorder, where the long-ranged nature of the potential produced by charged impurities implies large fluctuations of the disorder potential even when impurities are sparse, and these fluctuations are screened by the formation of electron/hole puddles. Here I outline a theory of such nonlinear screening of Coulomb disorder in three-dimensional Dirac systems, and present results for the typical magnitude of the disorder potential, the corresponding density of states, and the size and density of electron/hole puddles. The resulting conductivity is also discussed.

High-resolution three-dimensional imaging radar

NASA Technical Reports Server (NTRS)

Cooper, Ken B. (Inventor); Chattopadhyay, Goutam (Inventor); Siegel, Peter H. (Inventor); Dengler, Robert J. (Inventor); Schlecht, Erich T. (Inventor); Mehdi, Imran (Inventor); Skalare, Anders J. (Inventor)

2010-01-01

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz, is disclosed. The active target illumination inherent in radar solves the problem of low signal power and narrow-band detection by using submillimeter heterodyne mixer receivers. A submillimeter imaging radar may use low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform. Three-dimensional images are generated through range information derived for each pixel scanned over a target. A peak finding algorithm may be used in processing for each pixel to differentiate material layers of the target. Improved focusing is achieved through a compensation signal sampled from a point source calibration target and applied to received signals from active targets prior to FFT-based range compression to extract and display high-resolution target images. Such an imaging radar has particular application in detecting concealed weapons or contraband.

Three-dimensional spatially curved local Bessel beams generated by metasurface

NASA Astrophysics Data System (ADS)

Liu, Dawei; Wu, Jiawen; Cheng, Bo; Li, Hongliang

2018-03-01

We propose a reflective metasurface based on an artificial admittance modulation surface to generate three-dimensional spatially curved beams. The phase acquisition utilized to modulate this sinusoidally varying surface admittance combines the enveloping theory of differential geometry and the method for producing two-dimensional Bessel beams. The metasurface is fabricated, and the comparison between the full-wave simulations and experimental results demonstrates good performance of three-dimensional spatially curved beams generated by the metasurface.

Initialization and Simulation of Three-Dimensional Aircraft Wake Vortices

NASA Technical Reports Server (NTRS)

Ash, Robert L.; Zheng, Z. C.

1997-01-01

This paper studies the effects of axial velocity profiles on vortex decay, in order to properly initialize and simulate three-dimensional wake vortex flow. Analytical relationships are obtained based on a single vortex model and computational simulations are performed for a rather practical vortex wake, which show that the single vortex analytical relations can still be applicable at certain streamwise sections of three-dimensional wake vortices.

Characterizing College Science Assessments: The Three-Dimensional Learning Assessment Protocol

PubMed Central

Underwood, Sonia M.; Matz, Rebecca L.; Posey, Lynmarie A.; Carmel, Justin H.; Caballero, Marcos D.; Fata-Hartley, Cori L.; Ebert-May, Diane; Jardeleza, Sarah E.; Cooper, Melanie M.

2016-01-01

Many calls to improve science education in college and university settings have focused on improving instructor pedagogy. Meanwhile, science education at the K-12 level is undergoing significant changes as a result of the emphasis on scientific and engineering practices, crosscutting concepts, and disciplinary core ideas. This framework of “three-dimensional learning” is based on the literature about how people learn science and how we can help students put their knowledge to use. Recently, similar changes are underway in higher education by incorporating three-dimensional learning into college science courses. As these transformations move forward, it will become important to assess three-dimensional learning both to align assessments with the learning environment, and to assess the extent of the transformations. In this paper we introduce the Three-Dimensional Learning Assessment Protocol (3D-LAP), which is designed to characterize and support the development of assessment tasks in biology, chemistry, and physics that align with transformation efforts. We describe the development process used by our interdisciplinary team, discuss the validity and reliability of the protocol, and provide evidence that the protocol can distinguish between assessments that have the potential to elicit evidence of three-dimensional learning and those that do not. PMID:27606671

Characterizing College Science Assessments: The Three-Dimensional Learning Assessment Protocol.

PubMed

Laverty, James T; Underwood, Sonia M; Matz, Rebecca L; Posey, Lynmarie A; Carmel, Justin H; Caballero, Marcos D; Fata-Hartley, Cori L; Ebert-May, Diane; Jardeleza, Sarah E; Cooper, Melanie M

2016-01-01

Many calls to improve science education in college and university settings have focused on improving instructor pedagogy. Meanwhile, science education at the K-12 level is undergoing significant changes as a result of the emphasis on scientific and engineering practices, crosscutting concepts, and disciplinary core ideas. This framework of "three-dimensional learning" is based on the literature about how people learn science and how we can help students put their knowledge to use. Recently, similar changes are underway in higher education by incorporating three-dimensional learning into college science courses. As these transformations move forward, it will become important to assess three-dimensional learning both to align assessments with the learning environment, and to assess the extent of the transformations. In this paper we introduce the Three-Dimensional Learning Assessment Protocol (3D-LAP), which is designed to characterize and support the development of assessment tasks in biology, chemistry, and physics that align with transformation efforts. We describe the development process used by our interdisciplinary team, discuss the validity and reliability of the protocol, and provide evidence that the protocol can distinguish between assessments that have the potential to elicit evidence of three-dimensional learning and those that do not.

A three-dimensional quality-guided phase unwrapping method for MR elastography

NASA Astrophysics Data System (ADS)

Wang, Huifang; Weaver, John B.; Perreard, Irina I.; Doyley, Marvin M.; Paulsen, Keith D.

2011-07-01

Magnetic resonance elastography (MRE) uses accumulated phases that are acquired at multiple, uniformly spaced relative phase offsets, to estimate harmonic motion information. Heavily wrapped phase occurs when the motion is large and unwrapping procedures are necessary to estimate the displacements required by MRE. Two unwrapping methods were developed and compared in this paper. The first method is a sequentially applied approach. The three-dimensional MRE phase image block for each slice was processed by two-dimensional unwrapping followed by a one-dimensional phase unwrapping approach along the phase-offset direction. This unwrapping approach generally works well for low noise data. However, there are still cases where the two-dimensional unwrapping method fails when noise is high. In this case, the baseline of the corrupted regions within an unwrapped image will not be consistent. Instead of separating the two-dimensional and one-dimensional unwrapping in a sequential approach, an interleaved three-dimensional quality-guided unwrapping method was developed to combine both the two-dimensional phase image continuity and one-dimensional harmonic motion information. The quality of one-dimensional harmonic motion unwrapping was used to guide the three-dimensional unwrapping procedures and it resulted in stronger guidance than in the sequential method. In this work, in vivo results generated by the two methods were compared.

Three-dimensional fabric reinforced plastics for cryogenic use

NASA Astrophysics Data System (ADS)

Iwasaki, Y.; Yasuda, J.; Hirokawa, T.; Noma, K.; Nishijima, S.; Okada, T.

Three-dimensional fabric reinforced plastics (3DFRPs) have been developed as insulating and/or structural materials in superconducting magnets. Three-dimensional fabrics were designed with practical applications in fibre composites of 3DFRP. The mechanical properties such as Young's modulus, Poisson's ratio, tensile strength and the compressive strength down to liquid helium temperature were measured. Thermal contraction was also measured. The cryogenic characteristics of 3DFRPs were compared with those of conventional laminates. The newly developed 3DFRPs were found to show satisfactory characteristics not only at room temperature but also at low temperatures.

A Three-Dimensional Atlas of the Honeybee Neck

PubMed Central

Berry, Richard P.; Ibbotson, Michael R.

2010-01-01

Three-dimensional digital atlases are rapidly becoming indispensible in modern biology. We used serial sectioning combined with manual registration and segmentation of images to develop a comprehensive and detailed three-dimensional atlas of the honeybee head-neck system. This interactive atlas includes skeletal structures of the head and prothorax, the neck musculature, and the nervous system. The scope and resolution of the model exceeds atlases previously developed on similar sized animals, and the interactive nature of the model provides a far more accessible means of interpreting and comprehending insect anatomy and neuroanatomy. PMID:20520729

Fully Three-Dimensional Virtual-Reality System

NASA Technical Reports Server (NTRS)

Beckman, Brian C.

1994-01-01

Proposed virtual-reality system presents visual displays to simulate free flight in three-dimensional space. System, virtual space pod, is testbed for control and navigation schemes. Unlike most virtual-reality systems, virtual space pod would not depend for orientation on ground plane, which hinders free flight in three dimensions. Space pod provides comfortable seating, convenient controls, and dynamic virtual-space images for virtual traveler. Controls include buttons plus joysticks with six degrees of freedom.

Three-dimensional accuracy of plastic transfer impression copings for three implant systems.

PubMed

Teo, Juin Wei; Tan, Keson B; Nicholls, Jack I; Wong, Keng Mun; Uy, Joanne

2014-01-01

The purpose of this study was to compare the three-dimensional accuracy of indirect plastic impression copings and direct implant-level impression copings from three implant systems (Nobel Biocare [NB], Biomet 3i [3i], and Straumann [STR]) at three interimplant buccolingual angulations (0, 8, and 15 degrees). Two-implant master models were used to simulate a three-unit implant fixed partial denture. Test models were made from Impregum impressions using direct implant-level impression copings (DR). Abutments were then connected to the master models for impressions using the plastic impression copings (INDR) at three different angulations for a total of 18 test groups (n = 5 in each group). A coordinate measuring machine was used to measure linear distortions, three-dimensional (3D) distortions, angular distortions, and absolute angular distortions between the master and test models. Three-way analysis of variance showed that the implant system had a significant effect on 3D distortions and absolute angular distortions in the x- and y-axes. Interimplant angulation had a significant effect on 3D distortions and absolute angular distortions in the y-axis. Impression technique had a significant effect on absolute angular distortions in the y-axis. With DR, the NB and 3i systems were not significantly different. With INDR, 3i appeared to have less distortion than the other systems. Interimplant angulations did not significantly affect the accuracy of NBDR, 3iINDR, and STRINDR. The accuracy of INDR and DR was comparable at all interimplant angulations for 3i and STR. For NB, INDR was comparable to DR at 0 and 8 degrees but was less accurate at 15 degrees. Three-dimensional accuracy of implant impressions varied with implant system, interimplant angulation, and impression technique.

Life-Size Sculptural Heads: A Lesson in Three-Dimensional Design.

ERIC Educational Resources Information Center

Gamble, Harriet

2003-01-01

Presents a lesson in which students created three-dimensional self-portraits, using papier-mache, clay, and plaster, designed to develop their modeling skills as they learn about art history. Discusses how the students created their sculptures, offering detailed directions on creating the three-dimensional heads. (CMK)

Three-dimensional modeling of tea-shoots using images and models.

PubMed

Wang, Jian; Zeng, Xianyin; Liu, Jianbing

2011-01-01

In this paper, a method for three-dimensional modeling of tea-shoots with images and calculation models is introduced. The process is as follows: the tea shoots are photographed with a camera, color space conversion is conducted, using an improved algorithm that is based on color and regional growth to divide the tea shoots in the images, and the edges of the tea shoots extracted with the help of edge detection; after that, using the divided tea-shoot images, the three-dimensional coordinates of the tea shoots are worked out and the feature parameters extracted, matching and calculation conducted according to the model database, and finally the three-dimensional modeling of tea-shoots is completed. According to the experimental results, this method can avoid a lot of calculations and has better visual effects and, moreover, performs better in recovering the three-dimensional information of the tea shoots, thereby providing a new method for monitoring the growth of and non-destructive testing of tea shoots.

Analysis of eletrectrohydrodynamic jetting using multifunctional and three-dimensional tomography

NASA Astrophysics Data System (ADS)

Ko, Han Seo; Nguyen, Xuan Hung; Lee, Soo-Hong; Kim, Young Hyun

2013-11-01

Three-dimensional optical tomography technique was developed to reconstruct three-dimensional flow fields using a set of two-dimensional shadowgraphic images and normal gray images. From three high speed cameras, which were positioned at an offset angle of 45° relative to one another, number, size and location of electrohydrodynamic jets with respect to the nozzle position were analyzed using shadowgraphic tomography employing a multiplicative algebraic reconstruction technique (MART). Additionally, a flow field inside cone-shaped liquid (Taylor cone) which was induced under electric field was also observed using a simultaneous multiplicative algebraic reconstruction technique (SMART) for reconstructing intensities of particle light and combining with a three-dimensional cross correlation. Various velocity fields of a circulating flow inside the cone-shaped liquid due to different physico-chemical properties of liquid and applied voltages were also investigated. This work supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Korean government (MEST) (No. S-2011-0023457).

Numerical aerodynamic simulation facility. [for flows about three-dimensional configurations

NASA Technical Reports Server (NTRS)

Bailey, F. R.; Hathaway, A. W.

1978-01-01

Critical to the advancement of computational aerodynamics capability is the ability to simulate flows about three-dimensional configurations that contain both compressible and viscous effects, including turbulence and flow separation at high Reynolds numbers. Analyses were conducted of two solution techniques for solving the Reynolds averaged Navier-Stokes equations describing the mean motion of a turbulent flow with certain terms involving the transport of turbulent momentum and energy modeled by auxiliary equations. The first solution technique is an implicit approximate factorization finite-difference scheme applied to three-dimensional flows that avoids the restrictive stability conditions when small grid spacing is used. The approximate factorization reduces the solution process to a sequence of three one-dimensional problems with easily inverted matrices. The second technique is a hybrid explicit/implicit finite-difference scheme which is also factored and applied to three-dimensional flows. Both methods are applicable to problems with highly distorted grids and a variety of boundary conditions and turbulence models.

Ultrasound guidance versus anatomical landmarks for internal jugular vein catheterization.

PubMed

Brass, Patrick; Hellmich, Martin; Kolodziej, Laurentius; Schick, Guido; Smith, Andrew F

2015-01-09

by contacting companies and experts in the field, and we searched trial registers. We reran the search in August 2014. We will deal with identified studies of interest when we update the review. We included randomized and quasi-randomized controlled trials comparing two-dimensional ultrasound or Doppler ultrasound with an anatomical 'landmark' technique during insertion of internal jugular venous catheters in both adults and children. Three review authors independently extracted data on methodological quality, participants, interventions and outcomes of interest using a standardized form. A priori, we aimed to perform subgroup analyses, when possible, for adults and children, and for experienced operators and inexperienced operators. Of 735 identified citations, 35 studies enrolling 5108 participants fulfilled the inclusion criteria. The quality of evidence was very low for most of the outcomes and was moderate at best for four of the outcomes. Most trials had an unclear risk of bias across the six domains, and heterogeneity among the studies was significant.Use of two-dimensional ultrasound reduced the rate of total complications overall by 71% (14 trials, 2406 participants, risk ratio (RR) 0.29, 95% confidence interval (CI) 0.17 to 0.52; P value < 0.0001, I² = 57%), and the number of participants with an inadvertent arterial puncture by 72% (22 trials, 4388 participants, RR 0.28, 95% CI 0.18 to 0.44; P value < 0.00001, I² = 35%). Overall success rates were modestly increased in all groups combined at 12% (23 trials, 4340 participants, RR 1.12, 95% CI 1.08 to 1.17; P value < 0.00001, I² = 85%), and similar benefit was noted across all subgroups. The number of attempts needed for successful cannulation was decreased overall (16 trials, 3302 participants, mean difference (MD) -1.19 attempts, 95% CI -1.45 to -0.92; P value < 0.00001, I² = 96%) and in all subgroups. Use of two-dimensional ultrasound increased the chance of success at the first attempt by 57% (18

Speed of sound and photoacoustic imaging with an optical camera based ultrasound detection system

NASA Astrophysics Data System (ADS)

Nuster, Robert; Paltauf, Guenther

2017-07-01

CCD camera based optical ultrasound detection is a promising alternative approach for high resolution 3D photoacoustic imaging (PAI). To fully exploit its potential and to achieve an image resolution <50 μm, it is necessary to incorporate variations of the speed of sound (SOS) in the image reconstruction algorithm. Hence, in the proposed work the idea and a first implementation are shown how speed of sound imaging can be added to a previously developed camera based PAI setup. The current setup provides SOS-maps with a spatial resolution of 2 mm and an accuracy of the obtained absolute SOS values of about 1%. The proposed dual-modality setup has the potential to provide highly resolved and perfectly co-registered 3D photoacoustic and SOS images.

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)

Three Dimensional Measurements And Display Using A Robot Arm

NASA Astrophysics Data System (ADS)

Swift, Thomas E.

1984-02-01

The purpose of this paper is to describe a project which makes three dimensional measurements of an object using a robot arm. A program was written to determine the X-Y-Z coordinates of the end point of a Minimover-5 robot arm which was interfaced to a TRS-80 Model III microcomputer. This program was used in conjunction with computer graphics subroutines that draw a projected three dimensional object.. The robot arm was direc-ted to touch points on an object and then lines were drawn on the screen of the microcomputer between consecutive points as they were entered. A representation of the entire object is in this way constructed on the screen. The three dimensional graphics subroutines have the ability to rotate the projected object about any of the three axes, and to scale the object to any size. This project has applications in the computer-aided design and manufacturing fields because it can accurately measure the features of an irregularly shaped object.

Three-dimensional laser window formation for industrial application

NASA Technical Reports Server (NTRS)

Verhoff, Vincent G.; Kowalski, David

1993-01-01

The NASA Lewis Research Center has developed and implemented a unique process for forming flawless three-dimensional, compound-curvature laser windows to extreme accuracies. These windows represent an integral component of specialized nonintrusive laser data acquisition systems that are used in a variety of compressor and turbine research testing facilities. These windows are molded to the flow surface profile of turbine and compressor casings and are required to withstand extremely high pressures and temperatures. This method of glass formation could also be used to form compound-curvature mirrors that would require little polishing and for a variety of industrial applications, including research view ports for testing devices and view ports for factory machines with compound-curvature casings. Currently, sodium-alumino-silicate glass is recommended for three-dimensional laser windows because of its high strength due to chemical strengthening and its optical clarity. This paper discusses the main aspects of three-dimensional laser window formation. It focuses on the unique methodology and the peculiarities that are associated with the formation of these windows.

Roots and decompositions of three-dimensional topological objects

NASA Astrophysics Data System (ADS)

Matveev, Sergei V.

2012-06-01

In 1942 M.H.A. Newman formulated and proved a simple lemma of great importance for various fields of mathematics, including algebra and the theory of Gröbner-Shirshov bases. Later it was called the Diamond Lemma, since its key construction was illustrated by a diamond-shaped diagram. In 2005 the author suggested a new version of this lemma suitable for topological applications. This paper gives a survey of results on the existence and uniqueness of prime decompositions of various topological objects: three-dimensional manifolds, knots in thickened surfaces, knotted graphs, three-dimensional orbifolds, and knotted theta-curves in three-dimensional manifolds. As it turned out, all these topological objects admit a prime decomposition, although it is not unique in some cases (for example, in the case of orbifolds). For theta-curves and knots of geometric degree 1 in a thickened torus, the algebraic structure of the corresponding semigroups can be completely described. In both cases the semigroups are quotients of free groups by explicit commutation relations. Bibliography: 33 titles.

Three-Dimensional Printing Using a Photoinitiated Polymer

ERIC Educational Resources Information Center

Muskin, Joseph; Ragusa, Matthew; Gelsthorpe, Thomas

2010-01-01

Printers capable of producing three-dimensional objects are becoming more common. Most of these printers are impractical for use in the chemistry classroom because of the expense incurred in fabricating a print head that must be controlled in three dimensions. We propose a simpler solution to this problem that allows the emerging technology of…

[Three-dimensional computer aided design for individualized post-and-core restoration].

PubMed

Gu, Xiao-yu; Wang, Ya-ping; Wang, Yong; Lü, Pei-jun

2009-10-01

To develop a method of three-dimensional computer aided design (CAD) of post-and-core restoration. Two plaster casts with extracted natural teeth were used in this study. The extracted teeth were prepared and scanned using tomography method to obtain three-dimensional digitalized models. According to the basic rules of post-and-core design, posts, cores and cavity surfaces of the teeth were designed using the tools for processing point clouds, curves and surfaces on the forward engineering software of Tanglong prosthodontic system. Then three-dimensional figures of the final restorations were corrected according to the configurations of anterior teeth, premolars and molars respectively. Computer aided design of 14 post-and-core restorations were finished, and good fitness between the restoration and the three-dimensional digital models were obtained. Appropriate retention forms and enough spaces for the full crown restorations can be obtained through this method. The CAD of three-dimensional figures of the post-and-core restorations can fulfill clinical requirements. Therefore they can be used in computer-aided manufacture (CAM) of post-and-core restorations.

Use of a Volume Navigation Technique for Combining Real-Time Ultrasound and Contrast-Enhanced MRI: Accuracy and Feasibility of a Novel Technique for Locating Breast Lesions.

PubMed

Kucukkaya, Fikret; Aribal, Erkin; Tureli, Derya; Altas, Hilal; Kaya, Handan

2016-01-01

The objective of this study was to evaluate the accuracy of the volume navigation technique for combining real-time ultrasound and contrast-enhanced MRI (CE-MRI) of breast lesions. Thirty-eight women with single breast lesions underwent 3-T MRI. A 3.5-minute CE-MRI sequence was used, as was a flexible body coil. Patients underwent imaging in the supine position, with three markers placed on their breasts. Real-time sonographic images were coregistered to the preloaded breast CE-MRI volume by coupling skin markers, with the use of an electromagnetic transmitter positioned next to the subjects. The transmitter detected the spatial positions of the two electromagnetic sensors mounted on the transducer bracket. After this fusion process in 3D space was completed, divergences in the location of the center of each lesion on CE-MRI and ultrasound images were analyzed. The mean lesion size was 17.4 mm on ultrasound and 17.9 mm on MRI, whereas the mean (± SD) misalignment of the lesion centers on CE-MRI and ultrasound was 3.9 ± 2.5 mm on the x-axis (mediolateral view), 3.6 ± 2.7 mm on the y-axis (anteroposterior view), and 4.3 ± 2.6 mm on the z-axis (craniocaudal view). No lesion had a misalignment greater than 10 mm on any of three axes. The accuracy of volume navigation was independent of patient age and the lesion size, location, and histopathologic findings (p > 0.05). Intermediate lesions, which had a depth of center of 11-20 mm on ultrasound had a mean misalignment of 2.6 ± 1.9 mm, compared with 5.5 ± 2.2 mm for deep lesions, which had a depth of center greater than 20 mm (p = 0.049). The volume navigation technique is an accurate method for coregistration of CE-MRI and sonographic images, enabling lesion localization within a limited volume.

Three-dimensional volume containing multiple two-dimensional information patterns

NASA Astrophysics Data System (ADS)

Nakayama, Hirotaka; Shiraki, Atsushi; Hirayama, Ryuji; Masuda, Nobuyuki; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2013-06-01

We have developed an algorithm for recording multiple gradated two-dimensional projection patterns in a single three-dimensional object. When a single pattern is observed, information from the other patterns can be treated as background noise. The proposed algorithm has two important features: the number of patterns that can be recorded is theoretically infinite and no meaningful information can be seen outside of the projection directions. We confirmed the effectiveness of the proposed algorithm by performing numerical simulations of two laser crystals: an octagonal prism that contained four patterns in four projection directions and a dodecahedron that contained six patterns in six directions. We also fabricated and demonstrated an actual prototype laser crystal from a glass cube engraved by a laser beam. This algorithm has applications in various fields, including media art, digital signage, and encryption technology.

Three Dimensional Modeling of Breaking

DTIC Science & Technology

2005-09-30

Three Dimensional Modeling of Breaking Robert A. Dalrymple Dept of Civil Engineering The Johns Hopkins University 3400 North Charles Street...University,Dept of Civil Engineering,3400 North Charles Street,Baltimore,MD,21218 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING...R.A. Dalrymple, A.J.C. Crespo, and D. Cerquiero, "Uso de la Tecnica SPH para el Estudio de la Interaccion entre Olas y Estructuras," Ingenieria del

Ray tracing a three dimensional scene using a grid

DOEpatents

Wald, Ingo; Ize, Santiago; Parker, Steven G; Knoll, Aaron

2013-02-26

Ray tracing a three-dimensional scene using a grid. One example embodiment is a method for ray tracing a three-dimensional scene using a grid. In this example method, the three-dimensional scene is made up of objects that are spatially partitioned into a plurality of cells that make up the grid. The method includes a first act of computing a bounding frustum of a packet of rays, and a second act of traversing the grid slice by slice along a major traversal axis. Each slice traversal includes a first act of determining one or more cells in the slice that are overlapped by the frustum and a second act of testing the rays in the packet for intersection with any objects at least partially bounded by the one or more cells overlapped by the frustum.

An Energy Model of Place Cell Network in Three Dimensional Space.

PubMed

Wang, Yihong; Xu, Xuying; Wang, Rubin

2018-01-01

Place cells are important elements in the spatial representation system of the brain. A considerable amount of experimental data and classical models are achieved in this area. However, an important question has not been addressed, which is how the three dimensional space is represented by the place cells. This question is preliminarily surveyed by energy coding method in this research. Energy coding method argues that neural information can be expressed by neural energy and it is convenient to model and compute for neural systems due to the global and linearly addable properties of neural energy. Nevertheless, the models of functional neural networks based on energy coding method have not been established. In this work, we construct a place cell network model to represent three dimensional space on an energy level. Then we define the place field and place field center and test the locating performance in three dimensional space. The results imply that the model successfully simulates the basic properties of place cells. The individual place cell obtains unique spatial selectivity. The place fields in three dimensional space vary in size and energy consumption. Furthermore, the locating error is limited to a certain level and the simulated place field agrees to the experimental results. In conclusion, this is an effective model to represent three dimensional space by energy method. The research verifies the energy efficiency principle of the brain during the neural coding for three dimensional spatial information. It is the first step to complete the three dimensional spatial representing system of the brain, and helps us further understand how the energy efficiency principle directs the locating, navigating, and path planning function of the brain.

Estimating oxygen distribution from vasculature in three-dimensional tumour tissue.

PubMed

Grimes, David Robert; Kannan, Pavitra; Warren, Daniel R; Markelc, Bostjan; Bates, Russell; Muschel, Ruth; Partridge, Mike

2016-03-01

Regions of tissue which are well oxygenated respond better to radiotherapy than hypoxic regions by up to a factor of three. If these volumes could be accurately estimated, then it might be possible to selectively boost dose to radio-resistant regions, a concept known as dose-painting. While imaging modalities such as 18F-fluoromisonidazole positron emission tomography (PET) allow identification of hypoxic regions, they are intrinsically limited by the physics of such systems to the millimetre domain, whereas tumour oxygenation is known to vary over a micrometre scale. Mathematical modelling of microscopic tumour oxygen distribution therefore has the potential to complement and enhance macroscopic information derived from PET. In this work, we develop a general method of estimating oxygen distribution in three dimensions from a source vessel map. The method is applied analytically to line sources and quasi-linear idealized line source maps, and also applied to full three-dimensional vessel distributions through a kernel method and compared with oxygen distribution in tumour sections. The model outlined is flexible and stable, and can readily be applied to estimating likely microscopic oxygen distribution from any source geometry. We also investigate the problem of reconstructing three-dimensional oxygen maps from histological and confocal two-dimensional sections, concluding that two-dimensional histological sections are generally inadequate representations of the three-dimensional oxygen distribution. © 2016 The Authors.

Estimating oxygen distribution from vasculature in three-dimensional tumour tissue

PubMed Central

Kannan, Pavitra; Warren, Daniel R.; Markelc, Bostjan; Bates, Russell; Muschel, Ruth; Partridge, Mike

2016-01-01

Regions of tissue which are well oxygenated respond better to radiotherapy than hypoxic regions by up to a factor of three. If these volumes could be accurately estimated, then it might be possible to selectively boost dose to radio-resistant regions, a concept known as dose-painting. While imaging modalities such as 18F-fluoromisonidazole positron emission tomography (PET) allow identification of hypoxic regions, they are intrinsically limited by the physics of such systems to the millimetre domain, whereas tumour oxygenation is known to vary over a micrometre scale. Mathematical modelling of microscopic tumour oxygen distribution therefore has the potential to complement and enhance macroscopic information derived from PET. In this work, we develop a general method of estimating oxygen distribution in three dimensions from a source vessel map. The method is applied analytically to line sources and quasi-linear idealized line source maps, and also applied to full three-dimensional vessel distributions through a kernel method and compared with oxygen distribution in tumour sections. The model outlined is flexible and stable, and can readily be applied to estimating likely microscopic oxygen distribution from any source geometry. We also investigate the problem of reconstructing three-dimensional oxygen maps from histological and confocal two-dimensional sections, concluding that two-dimensional histological sections are generally inadequate representations of the three-dimensional oxygen distribution. PMID:26935806

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

[Application Progress of Three-dimensional Laser Scanning Technology in Medical Surface Mapping].

PubMed

Zhang, Yonghong; Hou, He; Han, Yuchuan; Wang, Ning; Zhang, Ying; Zhu, Xianfeng; Wang, Mingshi

2016-04-01

The booming three-dimensional laser scanning technology can efficiently and effectively get spatial three-dimensional coordinates of the detected object surface and reconstruct the image at high speed,high precision and large capacity of information.Non-radiation,non-contact and the ability of visualization make it increasingly popular in three-dimensional surface medical mapping.This paper reviews the applications and developments of three-dimensional laser scanning technology in medical field,especially in stomatology,plastic surgery and orthopedics.Furthermore,the paper also discusses the application prospects in the future as well as the biomedical engineering problems it would encounter with.

Coherent three-dimensional X-ray cryo-imaging.

PubMed

Robinson, Ian

2015-09-01

The combination of cryogenic sample temperatures with three-dimensional coherent diffractive imaging for the case of whole frozen-hydrated cells is discussed in the light of theoretical predictions of the achievable resolution.

Teaching veterinary obstetrics using three-dimensional animation technology.

PubMed

Scherzer, Jakob; Buchanan, M Flint; Moore, James N; White, Susan L

2010-01-01

In this three-year study, test scores for students taught veterinary obstetrics in a classroom setting with either traditional media (photographs, text, and two-dimensional graphical presentations) were compared with those for students taught by incorporating three-dimensional (3D) media (linear animations and interactive QuickTime Virtual Reality models) into the classroom lectures. Incorporation of the 3D animations and interactive models significantly increased students' scores on essay questions designed to assess their comprehension of the subject matter. This approach to education may help to better prepare students for dealing with obstetrical cases during their final clinical year and after graduation.

Three Dimensional Imaging with Multiple Wavelength Speckle Interferometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernacki, Bruce E.; Cannon, Bret D.; Schiffern, John T.

2014-05-28

We present the design, modeling, construction, and results of a three-dimensional imager based upon multiple-wavelength speckle interferometry. A surface under test is illuminated with tunable laser light in a Michelson interferometer configuration while a speckled image is acquired at each laser frequency step. The resulting hypercube is Fourier transformed in the frequency dimension and the beat frequencies that result map the relative offsets of surface features. Synthetic wavelengths resulting from the laser tuning can probe features ranging from 18 microns to hundreds of millimeters. Three dimensional images will be presented along with modeling results.

Three-dimensional wax patterning of paper fluidic devices.

PubMed

Renault, Christophe; Koehne, Jessica; Ricco, Antonio J; Crooks, Richard M

2014-06-17

In this paper we describe a method for three-dimensional wax patterning of microfluidic paper-based analytical devices (μPADs). The method is rooted in the fundamental details of wax transport in paper and provides a simple way to fabricate complex channel architectures such as hemichannels and fully enclosed channels. We show that three-dimensional μPADs can be fabricated with half as much paper by using hemichannels rather than ordinary open channels. We also provide evidence that fully enclosed channels are efficiently isolated from the exterior environment, decreasing contamination risks, simplifying the handling of the device, and slowing evaporation of solvents.

Estimation of three-dimensional radar tracking using modified extended kalman filter

NASA Astrophysics Data System (ADS)

Aditya, Prima; Apriliani, Erna; Khusnul Arif, Didik; Baihaqi, Komar

2018-03-01

Kalman filter is an estimation method by combining data and mathematical models then developed be extended Kalman filter to handle nonlinear systems. Three-dimensional radar tracking is one of example of nonlinear system. In this paper developed a modification method of extended Kalman filter from the direct decline of the three-dimensional radar tracking case. The development of this filter algorithm can solve the three-dimensional radar measurements in the case proposed in this case the target measured by radar with distance r, azimuth angle θ, and the elevation angle ϕ. Artificial covariance and mean adjusted directly on the three-dimensional radar system. Simulations result show that the proposed formulation is effective in the calculation of nonlinear measurement compared with extended Kalman filter with the value error at 0.77% until 1.15%.

Three-dimensional supersonic flow around double compression ramp with finite span

NASA Astrophysics Data System (ADS)

Lee, H. S.; Lee, J. H.; Park, G.; Park, S. H.; Byun, Y. H.

2017-01-01

Three-dimensional flows of Mach number 3 around a double-compression ramp with finite span have been investigated numerically. Shadowgraph visualisation images obtained in a supersonic wind tunnel are used for comparison. A three-dimensional Reynolds-averaged Navier-Stokes solver was used to obtain steady numerical solutions. Two-dimensional numerical results are also compared. Four different cases were studied: two different second ramp angles of 30° and 45° in configurations with and without sidewalls, respectively. Results showed that there is a leakage of mass and momentum fluxes heading outwards in the spanwise direction for three-dimensional cases without sidewalls. The leakage changed the flow characteristics of the shock-induced boundary layer and resulted in the discrepancy between the experimental data and two-dimensional numerical results. It is found that suppressing the flow leakage by attaching the sidewalls enhances the two-dimensionality of the experimental data for the double-compression ramp flow.

Three-dimensional anthropometry of the adult face.

DOT National Transportation Integrated Search

1978-03-01

This study describes a new three-dimensional anatomical axis system based on four conventional anthropometrical face landmarks. Coincident as a coordinate (orthogonal) axis system, this reference system was developed to provide convenient orientation...

Turbulence in Three Dimensional Simulations of Magnetopause Reconnection

NASA Astrophysics Data System (ADS)

Drake, J. F.; Price, L.; Swisdak, M.; Burch, J. L.; Cassak, P.; Dahlin, J. T.; Ergun, R.

2017-12-01

We present two- and three-dimensional particle-in-cell simulations of the 16 October 2015 MMS magnetopause reconnection event. While the two-dimensional simulation is laminar, turbulence develops at both the x-line and along the magnetic separatrices in the three-dimensional simulation. This turbulence is electromagnetic in nature, is characterized by a wavevector k given by kρ e ˜(m_e/m_i)0.25 with ρ e the electron Larmor radius, and appears to have the ion pressure gradient as its source of free energy. Taken together, these results suggest the instability is a variant of the lower-hybrid drift instability. The turbulence produces electric field fluctuations in the out-of-plane direction (the direction of the reconnection electric field) with an amplitude of around ± 10 mV/m, which is much greater than the reconnection electric field of around 0.1 mV/m. Such large values of the out-of-plane electric field have been identified in the MMS data. The turbulence in the simulation controls the scale lengths of the density profile and current layers in asymmetric reconnection, driving them closer to √ {ρ eρ_i } than the ρ e or de scalings seen in 2D reconnection simulations, where de is the electron inertial length. The turbulence is strong enough to make the magnetic field around the reconnection island chaotic and produces both anomalous resistivity and anomalous viscosity. Each contribute significantly to breaking the frozen-in condition in the electron diffusion region. The crescent-shaped features in velocity space seen both in MMS observations and in two-dimensional simulations survive, even in the turbulent environment of the three-dimensional system. We compare and contrast these results to a three-dimensional simulation of the 8 December 2015 MMS magnetopause reconnection event in which the reconnecting and out-of-plane guide fields are comparable. LHDI is still present in this event, although its appearance is modified by the presence of the guide

Linear stability theory and three-dimensional boundary layer transition

NASA Technical Reports Server (NTRS)

Spall, Robert E.; Malik, Mujeeb R.

1992-01-01

The viewgraphs and discussion of linear stability theory and three dimensional boundary layer transition are provided. The ability to predict, using analytical tools, the location of boundary layer transition over aircraft-type configurations is of great importance to designers interested in laminar flow control (LFC). The e(sup N) method has proven to be fairly effective in predicting, in a consistent manner, the location of the onset of transition for simple geometries in low disturbance environments. This method provides a correlation between the most amplified single normal mode and the experimental location of the onset of transition. Studies indicate that values of N between 8 and 10 correlate well with the onset of transition. For most previous calculations, the mean flows were restricted to two-dimensional or axisymmetric cases, or have employed simple three-dimensional mean flows (e.g., rotating disk, infinite swept wing, or tapered swept wing with straight isobars). Unfortunately, for flows over general wing configurations, and for nearly all flows over fuselage-type bodies at incidence, the analysis of fully three-dimensional flow fields is required. Results obtained for the linear stability of fully three-dimensional boundary layers formed over both wing and fuselage-type geometries, and for both high and low speed flows are discussed. When possible, transition estimates form the e(sup N) method are compared to experimentally determined locations. The stability calculations are made using a modified version of the linear stability code COSAL. Mean flows were computed using both Navier Stokes and boundary-layer codes.

Designing a new three-dimensional periodic cellular auxetic material

NASA Astrophysics Data System (ADS)

Zhou, Yiyi; Chen, Lianmen

2017-07-01

Auxetics are materials showing a negative Poisson’s ratio. Early research found several categories of auxetic materials in the chemical field. Later research identified the fundamental mechanism generating this behavior is rotation; a variety of two-dimensional auxetic material have been generated accordingly. Nevertheless, the successful example of three-dimensional auxetic material is still rare. This paper introduces a new design of three-dimensional periodic cellular auxetic material based on geometrical and mechanical methodology. The projections of the optimized periodic modules in two horizontal directions are geometrically same with auxetic hexahedral poem, so that the optimized periodic material can perform auxetic in both two horizontal directions under vertical compression. Parametric model is simulated to prove the design.

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.

Connecting Geometry and Chemistry: A Three-Step Approach to Three-Dimensional Thinking

ERIC Educational Resources Information Center

Donaghy, Kelley J.; Saxton, Kathleen J.

2012-01-01

A three-step active-learning approach is described to enhance the spatial abilities of general chemistry students with respect to three-dimensional molecular drawing and visualization. These activities are used in a medium-sized lecture hall with approximately 150 students in the first semester of the general chemistry course. The first activity…

Three-quarter view preference for three-dimensional objects in 8-month-old infants.

PubMed

Yamashita, Wakayo; Niimi, Ryosuke; Kanazawa, So; Yamaguchi, Masami K; Yokosawa, Kazuhiko

2014-04-04

This study examined infants' visual perception of three-dimensional common objects. It has been reported that human adults perceive object images in a view-dependent manner: three-quarter views are often preferred to other views, and the sensitivity to object orientation is lower for three-quarter views than for other views. We tested whether such characteristics were observed in 6- to 8-month-old infants by measuring their preferential looking behavior. In Experiment 1 we examined 190- to 240-day-olds' sensitivity to orientation change and in Experiment 2 we examined these infants' preferential looking for the three-quarter view. The 240-day-old infants showed a pattern of results similar to adults for some objects, while the 190-day-old infants did not. The 240-day-old infants' perception of object view is (partly) similar to that of adults. These results suggest that human visual perception of three-dimensional objects develops at 6 to 8 months of age.

Three-dimensional propagation in near-field tomographic X-ray phase retrieval

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruhlandt, Aike, E-mail: aruhlan@gwdg.de; Salditt, Tim

An extension of phase retrieval algorithms for near-field X-ray (propagation) imaging to three dimensions is presented, enhancing the quality of the reconstruction by exploiting previously unused three-dimensional consistency constraints. This paper presents an extension of phase retrieval algorithms for near-field X-ray (propagation) imaging to three dimensions, enhancing the quality of the reconstruction by exploiting previously unused three-dimensional consistency constraints. The approach is based on a novel three-dimensional propagator and is derived for the case of optically weak objects. It can be easily implemented in current phase retrieval architectures, is computationally efficient and reduces the need for restrictive prior assumptions, resultingmore » in superior reconstruction quality.« less

Ultra-wideband three-dimensional optoacoustic tomography.

PubMed

Gateau, Jérôme; Chekkoury, Andrei; Ntziachristos, Vasilis

2013-11-15

Broadband optoacoustic waves generated by biological tissues excited with nanosecond laser pulses carry information corresponding to a wide range of geometrical scales. Typically, the frequency content present in the signals generated during optoacoustic imaging is much larger compared to the frequency band captured by common ultrasonic detectors, the latter typically acting as bandpass filters. To image optical absorption within structures ranging from entire organs to microvasculature in three dimensions, we implemented optoacoustic tomography with two ultrasound linear arrays featuring a center frequency of 6 and 24 MHz, respectively. In the present work, we show that complementary information on anatomical features could be retrieved and provide a better understanding on the localization of structures in the general anatomy by analyzing multi-bandwidth datasets acquired on a freshly excised kidney.

Gravitational lensing by a smoothly variable three-dimensional mass distribution

NASA Technical Reports Server (NTRS)

Lee, Man Hoi; Paczynski, Bohdan

1990-01-01

A smooth three-dimensional mass distribution is approximated by a model with multiple thin screens, with surface mass density varying smoothly on each screen. It is found that 16 screens are sufficient for a good approximation of the three-dimensional distribution of matter. It is also found that in this multiscreen model the distribution of amplifications of single images is dominated by the convergence due to matter within the beam. The shear caused by matter outside the beam has no significant effect. This finding considerably simplifies the modeling of lensing by a smooth three-dimensional mass distribution by effectively reducing the problem to one dimension, as it is sufficient to know the mass distribution along a straight light ray.

Three-dimensional broadband omnidirectional acoustic ground cloak

NASA Astrophysics Data System (ADS)

Zigoneanu, Lucian; Popa, Bogdan-Ioan; Cummer, Steven A.

2014-04-01

The control of sound propagation and reflection has always been the goal of engineers involved in the design of acoustic systems. A recent design approach based on coordinate transformations, which is applicable to many physical systems, together with the development of a new class of engineered materials called metamaterials, has opened the road to the unconstrained control of sound. However, the ideal material parameters prescribed by this methodology are complex and challenging to obtain experimentally, even using metamaterial design approaches. Not surprisingly, experimental demonstration of devices obtained using transformation acoustics is difficult, and has been implemented only in two-dimensional configurations. Here, we demonstrate the design and experimental characterization of an almost perfect three-dimensional, broadband, and, most importantly, omnidirectional acoustic device that renders a region of space three wavelengths in diameter invisible to sound.

Parallel computation of three-dimensional aeroelastic fluid-structure interaction

NASA Astrophysics Data System (ADS)

Sadeghi, Mani

This dissertation presents a numerical method for the parallel computation of aeroelasticity (ParCAE). A flow solver is coupled to a structural solver by use of a fluid-structure interface method. The integration of the three-dimensional unsteady Navier-Stokes equations is performed in the time domain, simultaneously to the integration of a modal three-dimensional structural model. The flow solution is accelerated by using a multigrid method and a parallel multiblock approach. Fluid-structure coupling is achieved by subiteration. A grid-deformation algorithm is developed to interpolate the deformation of the structural boundaries onto the flow grid. The code is formulated to allow application to general, three-dimensional, complex configurations with multiple independent structures. Computational results are presented for various configurations, such as turbomachinery blade rows and aircraft wings. Investigations are performed on vortex-induced vibrations, effects of cascade mistuning on flutter, and cases of nonlinear cascade and wing flutter.

Self-assembled three-dimensional and compressible interdigitated thin-film supercapacitors and batteries

PubMed Central

Nyström, Gustav; Marais, Andrew; Karabulut, Erdem; Wågberg, Lars; Cui, Yi; Hamedi, Mahiar M.

2015-01-01

Traditional thin-film energy-storage devices consist of stacked layers of active films on two-dimensional substrates and do not exploit the third dimension. Fully three-dimensional thin-film devices would allow energy storage in bulk materials with arbitrary form factors and with mechanical properties unique to bulk materials such as compressibility. Here we show three-dimensional energy-storage devices based on layer-by-layer self-assembly of interdigitated thin films on the surface of an open-cell aerogel substrate. We demonstrate a reversibly compressible three-dimensional supercapacitor with carbon nanotube electrodes and a three-dimensional hybrid battery with a copper hexacyanoferrate ion intercalating cathode and a carbon nanotube anode. The three-dimensional supercapacitor shows stable operation over 400 cycles with a capacitance of 25 F g−1 and is fully functional even at compressions up to 75%. Our results demonstrate that layer-by-layer self-assembly inside aerogels is a rapid, precise and scalable route for building high-surface-area 3D thin-film devices. PMID:26021485

Preintervention lesion remodelling affects operative mechanisms of balloon optimised directional coronary atherectomy procedures: a volumetric study with three dimensional intravascular ultrasound

PubMed Central

von Birgelen, C; Mintz, G; de Vrey, E A; Serruys, P; Kimura, T; Nobuyoshi, M; Popma, J; Leon, M; Erbel, R; de Feyter, P J

2000-01-01

AIMS—To classify atherosclerotic coronary lesions on the basis of adequate or inadequate compensatory vascular enlargement, and to examine changes in lumen, plaque, and vessel volumes during balloon optimised directional coronary atherectomy procedures in relation to the state of adaptive remodelling before the intervention.
DESIGN—29 lesion segments in 29 patients were examined with intravascular ultrasound before and after successful balloon optimised directional coronary atherectomy procedures, and a validated volumetric intravascular ultrasound analysis was performed off-line to assess the atherosclerotic lesion remodelling and changes in plaque and vessel volumes that occurred during the intervention. Based on the intravascular ultrasound data, lesions were classified according to whether there was inadequate (group I) or adequate (group II) compensatory enlargement.
RESULTS—There was no significant difference in patient and lesion characteristics between groups I and II (n = 10 and 19), including lesion length and details of the intervention. Quantitative coronary angiographic data were similar for both groups. However, plaque and vessel volumes were significantly smaller in group I than in II. In group I, 9 (4)% (mean (SD)) of the plaque volume was ablated, while in group II 16 (11)% was ablated (p = 0.01). This difference was reflected in a lower lumen volume gain in group I than in group II (46 (18) mm3 v 80 (49) mm3 (p < 0.02)).
CONCLUSIONS—Preintervention lesion remodelling has an impact on the operative mechanisms of balloon optimised directional coronary atherectomy procedures. Plaque ablation was found to be particularly low in lesions with inadequate compensatory vascular enlargement.


Keywords: intravascular ultrasound; ultrasonics; remodelling; coronary artery disease; atherectomy PMID:10648496

The three-dimensional Event-Driven Graphics Environment (3D-EDGE)

NASA Technical Reports Server (NTRS)

Freedman, Jeffrey; Hahn, Roger; Schwartz, David M.

1993-01-01

Stanford Telecom developed the Three-Dimensional Event-Driven Graphics Environment (3D-EDGE) for NASA GSFC's (GSFC) Communications Link Analysis and Simulation System (CLASS). 3D-EDGE consists of a library of object-oriented subroutines which allow engineers with little or no computer graphics experience to programmatically manipulate, render, animate, and access complex three-dimensional objects.

Four-dimensional ultrasound current source density imaging of a dipole field

NASA Astrophysics Data System (ADS)

Wang, Z. H.; Olafsson, R.; Ingram, P.; Li, Q.; Qin, Y.; Witte, R. S.

2011-09-01

Ultrasound current source density imaging (UCSDI) potentially transforms conventional electrical mapping of excitable organs, such as the brain and heart. For this study, we demonstrate volume imaging of a time-varying current field by scanning a focused ultrasound beam and detecting the acoustoelectric (AE) interaction signal. A pair of electrodes produced an alternating current distribution in a special imaging chamber filled with a 0.9% NaCl solution. A pulsed 1 MHz ultrasound beam was scanned near the source and sink, while the AE signal was detected on remote recording electrodes, resulting in time-lapsed volume movies of the alternating current distribution.

Synthesis and identification of three-dimensional faces from image(s) and three-dimensional generic models

NASA Astrophysics Data System (ADS)

Liu, Zexi; Cohen, Fernand

2017-11-01

We describe an approach for synthesizing a three-dimensional (3-D) face structure from an image or images of a human face taken at a priori unknown poses using gender and ethnicity specific 3-D generic models. The synthesis process starts with a generic model, which is personalized as images of the person become available using preselected landmark points that are tessellated to form a high-resolution triangular mesh. From a single image, two of the three coordinates of the model are reconstructed in accordance with the given image of the person, while the third coordinate is sampled from the generic model, and the appearance is made in accordance with the image. With multiple images, all coordinates and appearance are reconstructed in accordance with the observed images. This method allows for accurate pose estimation as well as face identification in 3-D rendering of a difficult two-dimensional (2-D) face recognition problem into a much simpler 3-D surface matching problem. The estimation of the unknown pose is achieved using the Levenberg-Marquardt optimization process. Encouraging experimental results are obtained in a controlled environment with high-resolution images under a good illumination condition, as well as for images taken in an uncontrolled environment under arbitrary illumination with low-resolution cameras.

Optimal eavesdropping in cryptography with three-dimensional quantum states.

PubMed

Bruss, D; Macchiavello, C

2002-03-25

We study optimal eavesdropping in quantum cryptography with three-dimensional systems, and show that this scheme is more secure against symmetric attacks than protocols using two-dimensional states. We generalize the according eavesdropping transformation to arbitrary dimensions, and discuss the connection with optimal quantum cloning.

Statistics of Advective Stretching in Three-dimensional Incompressible Flows

NASA Astrophysics Data System (ADS)

Subramanian, Natarajan; Kellogg, Louise H.; Turcotte, Donald L.

2009-09-01

We present a method to quantify kinematic stretching in incompressible, unsteady, isoviscous, three-dimensional flows. We extend the method of Kellogg and Turcotte (J. Geophys. Res. 95:421-432, 1990) to compute the axial stretching/thinning experienced by infinitesimal ellipsoidal strain markers in arbitrary three-dimensional incompressible flows and discuss the differences between our method and the computation of Finite Time Lyapunov Exponent (FTLE). We use the cellular flow model developed in Solomon and Mezic (Nature 425:376-380, 2003) to study the statistics of stretching in a three-dimensional unsteady cellular flow. We find that the probability density function of the logarithm of normalised cumulative stretching (log S) for a globally chaotic flow, with spatially heterogeneous stretching behavior, is not Gaussian and that the coefficient of variation of the Gaussian distribution does not decrease with time as t^{-1/2} . However, it is observed that stretching becomes exponential log S˜ t and the probability density function of log S becomes Gaussian when the time dependence of the flow and its three-dimensionality are increased to make the stretching behaviour of the flow more spatially uniform. We term these behaviors weak and strong chaotic mixing respectively. We find that for strongly chaotic mixing, the coefficient of variation of the Gaussian distribution decreases with time as t^{-1/2} . This behavior is consistent with a random multiplicative stretching process.

Dynamic three-dimensional display of common congenital cardiac defects from reconstruction of two-dimensional echocardiographic images.

PubMed

Hsieh, K S; Lin, C C; Liu, W S; Chen, F L

1996-01-01

Two-dimensional echocardiography had long been a standard diagnostic modality for congenital heart disease. Further attempts of three-dimensional reconstruction using two-dimensional echocardiographic images to visualize stereotypic structure of cardiac lesions have been successful only recently. So far only very few studies have been done to display three-dimensional anatomy of the heart through two-dimensional image acquisition because such complex procedures were involved. This study introduced a recently developed image acquisition and processing system for dynamic three-dimensional visualization of various congenital cardiac lesions. From December 1994 to April 1995, 35 cases were selected in the Echo Laboratory here from about 3000 Echo examinations completed. Each image was acquired on-line with specially designed high resolution image grazmber with EKG and respiratory gating technique. Off-line image processing using a window-architectured interactive software package includes construction of 2-D ehcocardiographic pixel to 3-D "voxel" with conversion of orthogonal to rotatory axial system, interpolation, extraction of region of interest, segmentation, shading and, finally, 3D rendering. Three-dimensional anatomy of various congenital cardiac defects was shown, including four cases with ventricular septal defects, two cases with atrial septal defects, and two cases with aortic stenosis. Dynamic reconstruction of a "beating heart" is recorded as vedio tape with video interface. The potential application of 3D display of the reconstruction from 2D echocardiographic images for the diagnosis of various congenital heart defects has been shown. The 3D display was able to improve the diagnostic ability of echocardiography, and clear-cut display of the various congenital cardiac defects and vavular stenosis could be demonstrated. Reinforcement of current techniques will expand future application of 3D display of conventional 2D images.

Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schultheis, M.; Zasowski, G.; Allende Prieto, C.

Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmosphericmore » parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.« less

[Zn(INO) 2(DMF)]·DMF: A new three-dimensional supramolecular open framework containing one-dimensional channels

NASA Astrophysics Data System (ADS)

Hong, Jun

2006-02-01

A three-dimensional supramolecular compound, [Zn(INO) 2(DMF)]·DMF (1) (INO=isonicotinic acid N-oxide), has been prepared in the DMF solution at room temperature, and characterized by elemental analysis, TG and single crystal X-ray diffraction. The three-dimensional supramolecular open framework of 1 contains rectangular channels with the dimensions of 9.02×10.15 Å, assembled from one-dimensional helical chains via hydrogen-bonding and π-π stacking interactions. Furthermore, compound 1 shows blue photoluminescence at room temperature.

Prenatal diagnosis of bilateral anophthalmia by 3D "reverse face" view ultrasound and magnetic resonance imaging.

PubMed

Araujo Júnior, Edward; Kawanami, Tatiana Emy; Nardozza, Luciano Marcondes Machado; Milani, Hérbene José Figuinha; Oliveira, Patrícia Soares; Moron, Antonio Fernandes

2012-12-01

Primary anophthalmia is a rare congenital malformation that affects 0.6/10,000 liveborn infants. It is usually associated with central nervous system malformations, aneuploidies, cytomegalovirus infection and mental retardation and it can also be part of genetic conditions such as Fraser, Goltz, Goldenhar, Waardenburg and Lenz syndromes. Neonatal prognosis depends on whether anophthalmia is an isolated malformation, or it is associated with other defects or part of a syndrome. A healthy 43-year-old woman, G4 P3 with three previous healthy children, was referred to our clinic for a routine obstetric ultrasound at 28 weeks' gestation. The fetal eye globes and lenses could not be seen on two-dimensional (2D) ultrasound, which led to the diagnosis of bilateral congenital anophthalmia. No other fetal malformations were detected. At 30 weeks' gestation, a three-dimensional (3D) ultrasound was performed using the rendering mode and "reverse face" view. Using this technique, the absence of both eye globes could be clearly seen through a "slit". 3D-ultrasound allowed the parents to better understand their child's problem and possible postnatal implications. Fetal magnetic resonance imaging (MRI) was also performed, to study the fetal cortex in more detail. This exam revealed right cerebral hemisphere sulci and gyri hypoplasia. At 41 1/7 weeks, she went into spontaneous labor and delivered vaginally a 3525 g male infant with Apgar scores of 9 and 10. Postnatal exams confirmed bilateral congenital anophthalmia. This is the first case report in the literature of prenatal diagnosis of bilateral anophthalmia using 3D "reverse face" view ultrasound and MRI. Copyright © 2012. Published by Elsevier B.V.

Evaluating the intra- and interobserver reliability of three-dimensional ultrasound and power Doppler angiography (3D-PDA) for assessment of placental volume and vascularity in the second trimester of pregnancy.

PubMed

Jones, Nia W; Raine-Fenning, Nick J; Mousa, Hatem A; Bradley, Eileen; Bugg, George J

2011-03-01

Three-dimensional (3-D) power Doppler angiography (3-D-PDA) allows visualisation of Doppler signals within the placenta and their quantification is possible by the generation of vascular indices by the 4-D View software programme. This study aimed to investigate intra- and interobserver reproducibility of 3-D-PDA analysis of stored datasets at varying gestations with the ultimate goal being to develop a tool for predicting placental dysfunction. Women with an uncomplicated, viable singleton pregnancy were scanned at 12, 16 or 20 weeks gestational age groups. 3-D-PDA datasets acquired of the whole placenta were analysed using the VOCAL software processing tool. Each volume was analysed by three observers twice in the A plane. Intra- and interobserver reliability was assessed by intraclass correlation coefficients (ICCs) and Bland Altman plots. At each gestational age group, 20 low risk women were scanned resulting in 60 datasets in total. The ICC demonstrated a high level of measurement reliability at each gestation with intraobserver values >0.90 and interobserver values of >0.6 for the vascular indices. Bland Altman plots also showed high levels of agreement. Systematic bias was seen at 20 weeks in the vascular indices obtained by different observers. This study demonstrates that 3-D-PDA data can be measured reliably by different observers from stored datasets up to 18 weeks gestation. Measurements become less reliable as gestation advances with bias between observers evident at 20 weeks. Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Refraction Correction in 3D Transcranial Ultrasound Imaging

PubMed Central

Lindsey, Brooks D.; Smith, Stephen W.

2014-01-01

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

COMOC: Three dimensional boundary region variant, programmer's manual

NASA Technical Reports Server (NTRS)

Orzechowski, J. A.; Baker, A. J.

1974-01-01

The three-dimensional boundary region variant of the COMOC computer program system solves the partial differential equation system governing certain three-dimensional flows of a viscous, heat conducting, multiple-species, compressible fluid including combustion. The solution is established in physical variables, using a finite element algorithm for the boundary value portion of the problem description in combination with an explicit marching technique for the initial value character. The computational lattice may be arbitrarily nonregular, and boundary condition constraints are readily applied. The theoretical foundation of the algorithm, a detailed description on the construction and operation of the program, and instructions on utilization of the many features of the code are presented.

Fully three-dimensional direct numerical simulation of a plunging breaker

NASA Astrophysics Data System (ADS)

Lubin, Pierre; Vincent, Stéphane; Caltagirone, Jean-Paul; Abadie, Stéphane

2003-07-01

The scope of this paper is to show the results obtained for simulating three-dimensional breaking waves by solving the Navier-Stokes equations in air and water. The interface tracking is achieved by a Lax-Wendroff TVD scheme (Total Variation Diminishing), which is able to handle interface reconnections. We first present the equations and the numerical methods used in this work. We then proceed to the study of a three-dimensional plunging breaking wave, using initial conditions corresponding to unstable periodic sinusoidal waves of large amplitudes. We compare the results obtained for two simulations, a longshore depth perturbation has been introduced in the solution of the flow equations in order to see the transition from a two-dimensional velocity field to a fully three-dimensional one after plunging. Breaking processes including overturning, splash-up and breaking induced vortex-like motion beneath the surface are presented and discussed. To cite this article: P. Lubin et al., C. R. Mecanique 331 (2003).

An adaptive front tracking technique for three-dimensional transient flows

NASA Astrophysics Data System (ADS)

Galaktionov, O. S.; Anderson, P. D.; Peters, G. W. M.; van de Vosse, F. N.

2000-01-01

An adaptive technique, based on both surface stretching and surface curvature analysis for tracking strongly deforming fluid volumes in three-dimensional flows is presented. The efficiency and accuracy of the technique are demonstrated for two- and three-dimensional flow simulations. For the two-dimensional test example, the results are compared with results obtained using a different tracking approach based on the advection of a passive scalar. Although for both techniques roughly the same structures are found, the resolution for the front tracking technique is much higher. In the three-dimensional test example, a spherical blob is tracked in a chaotic mixing flow. For this problem, the accuracy of the adaptive tracking is demonstrated by the volume conservation for the advected blob. Adaptive front tracking is suitable for simulation of the initial stages of fluid mixing, where the interfacial area can grow exponentially with time. The efficiency of the algorithm significantly benefits from parallelization of the code. Copyright

Three-dimensional protonic conductivity in porous organic cage solids.

PubMed

Liu, Ming; Chen, Linjiang; Lewis, Scott; Chong, Samantha Y; Little, Marc A; Hasell, Tom; Aldous, Iain M; Brown, Craig M; Smith, Martin W; Morrison, Carole A; Hardwick, Laurence J; Cooper, Andrew I

2016-09-13

Proton conduction is a fundamental process in biology and in devices such as proton exchange membrane fuel cells. To maximize proton conduction, three-dimensional conduction pathways are preferred over one-dimensional pathways, which prevent conduction in two dimensions. Many crystalline porous solids to date show one-dimensional proton conduction. Here we report porous molecular cages with proton conductivities (up to 10(-3) S cm(-1) at high relative humidity) that compete with extended metal-organic frameworks. The structure of the organic cage imposes a conduction pathway that is necessarily three-dimensional. The cage molecules also promote proton transfer by confining the water molecules while being sufficiently flexible to allow hydrogen bond reorganization. The proton conduction is explained at the molecular level through a combination of proton conductivity measurements, crystallography, molecular simulations and quasi-elastic neutron scattering. These results provide a starting point for high-temperature, anhydrous proton conductors through inclusion of guests other than water in the cage pores.

Three-dimensional protonic conductivity in porous organic cage solids

NASA Astrophysics Data System (ADS)

Liu, Ming; Chen, Linjiang; Lewis, Scott; Chong, Samantha Y.; Little, Marc A.; Hasell, Tom; Aldous, Iain M.; Brown, Craig M.; Smith, Martin W.; Morrison, Carole A.; Hardwick, Laurence J.; Cooper, Andrew I.

2016-09-01

Proton conduction is a fundamental process in biology and in devices such as proton exchange membrane fuel cells. To maximize proton conduction, three-dimensional conduction pathways are preferred over one-dimensional pathways, which prevent conduction in two dimensions. Many crystalline porous solids to date show one-dimensional proton conduction. Here we report porous molecular cages with proton conductivities (up to 10-3 S cm-1 at high relative humidity) that compete with extended metal-organic frameworks. The structure of the organic cage imposes a conduction pathway that is necessarily three-dimensional. The cage molecules also promote proton transfer by confining the water molecules while being sufficiently flexible to allow hydrogen bond reorganization. The proton conduction is explained at the molecular level through a combination of proton conductivity measurements, crystallography, molecular simulations and quasi-elastic neutron scattering. These results provide a starting point for high-temperature, anhydrous proton conductors through inclusion of guests other than water in the cage pores.

Two-Dimensional Numerical Simulations of Ultrasound in Liquids with Gas Bubble Agglomerates: Examples of Bubbly-Liquid-Type Acoustic Metamaterials (BLAMMs)

PubMed Central

Vanhille, Christian

2017-01-01

This work deals with a theoretical analysis about the possibility of using linear and nonlinear acoustic properties to modify ultrasound by adding gas bubbles of determined sizes in a liquid. We use a two-dimensional numerical model to evaluate the effect that one and several monodisperse bubble populations confined in restricted areas of a liquid have on ultrasound by calculating their nonlinear interaction. The filtering of an input ultrasonic pulse performed by a net of bubbly-liquid cells is analyzed. The generation of a low-frequency component from a single cell impinged by a two-frequency harmonic wave is also studied. These effects rely on the particular dispersive character of attenuation and nonlinearity of such bubbly fluids, which can be extremely high near bubble resonance. They allow us to observe how gas bubbles can change acoustic signals. Variations of the bubbly medium parameters induce alterations of the effects undergone by ultrasound. Results suggest that acoustic signals can be manipulated by bubbles. This capacity to achieve the modification and control of sound with oscillating gas bubbles introduces the concept of bubbly-liquid-based acoustic metamaterials (BLAMMs). PMID:28106748

Two-Dimensional Numerical Simulations of Ultrasound in Liquids with Gas Bubble Agglomerates: Examples of Bubbly-Liquid-Type Acoustic Metamaterials (BLAMMs).

PubMed

Vanhille, Christian

2017-01-17

This work deals with a theoretical analysis about the possibility of using linear and nonlinear acoustic properties to modify ultrasound by adding gas bubbles of determined sizes in a liquid. We use a two-dimensional numerical model to evaluate the effect that one and several monodisperse bubble populations confined in restricted areas of a liquid have on ultrasound by calculating their nonlinear interaction. The filtering of an input ultrasonic pulse performed by a net of bubbly-liquid cells is analyzed. The generation of a low-frequency component from a single cell impinged by a two-frequency harmonic wave is also studied. These effects rely on the particular dispersive character of attenuation and nonlinearity of such bubbly fluids, which can be extremely high near bubble resonance. They allow us to observe how gas bubbles can change acoustic signals. Variations of the bubbly medium parameters induce alterations of the effects undergone by ultrasound. Results suggest that acoustic signals can be manipulated by bubbles. This capacity to achieve the modification and control of sound with oscillating gas bubbles introduces the concept of bubbly-liquid-based acoustic metamaterials (BLAMMs).

Parallel processing a three-dimensional free-lagrange code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandell, D.A.; Trease, H.E.

1989-01-01

A three-dimensional, time-dependent free-Lagrange hydrodynamics code has been multitasked and autotasked on a CRAY X-MP/416. The multitasking was done by using the Los Alamos Multitasking Control Library, which is a superset of the CRAY multitasking library. Autotasking is done by using constructs which are only comment cards if the source code is not run through a preprocessor. The three-dimensional algorithm has presented a number of problems that simpler algorithms, such as those for one-dimensional hydrodynamics, did not exhibit. Problems in converting the serial code, originally written for a CRAY-1, to a multitasking code are discussed. Autotasking of a rewritten versionmore » of the code is discussed. Timing results for subroutines and hot spots in the serial code are presented and suggestions for additional tools and debugging aids are given. Theoretical speedup results obtained from Amdahl's law and actual speedup results obtained on a dedicated machine are presented. Suggestions for designing large parallel codes are given.« less