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Sample records for 3d echocardiographic evaluation

  1. Detailed Evaluation of Five 3D Speckle Tracking Algorithms Using Synthetic Echocardiographic Recordings.

    PubMed

    Alessandrini, Martino; Heyde, Brecht; Queiros, Sandro; Cygan, Szymon; Zontak, Maria; Somphone, Oudom; Bernard, Olivier; Sermesant, Maxime; Delingette, Herve; Barbosa, Daniel; De Craene, Mathieu; ODonnell, Matthew; Dhooge, Jan

    2016-08-01

    A plethora of techniques for cardiac deformation imaging with 3D ultrasound, typically referred to as 3D speckle tracking techniques, are available from academia and industry. Although the benefits of single methods over alternative ones have been reported in separate publications, the intrinsic differences in the data and definitions used makes it hard to compare the relative performance of different solutions. To address this issue, we have recently proposed a framework to simulate realistic 3D echocardiographic recordings and used it to generate a common set of ground-truth data for 3D speckle tracking algorithms, which was made available online. The aim of this study was therefore to use the newly developed database to contrast non-commercial speckle tracking solutions from research groups with leading expertise in the field. The five techniques involved cover the most representative families of existing approaches, namely block-matching, radio-frequency tracking, optical flow and elastic image registration. The techniques were contrasted in terms of tracking and strain accuracy. The feasibility of the obtained strain measurements to diagnose pathology was also tested for ischemia and dyssynchrony.

  2. Automated segmentation and geometrical modeling of the tricuspid aortic valve in 3D echocardiographic images.

    PubMed

    Pouch, Alison M; Wang, Hongzhi; Takabe, Manabu; Jackson, Benjamin M; Sehgal, Chandra M; Gorman, Joseph H; Gorman, Robert C; Yushkevich, Paul A

    2013-01-01

    The aortic valve has been described with variable anatomical definitions, and the consistency of 2D manual measurement of valve dimensions in medical image data has been questionable. Given the importance of image-based morphological assessment in the diagnosis and surgical treatment of aortic valve disease, there is considerable need to develop a standardized framework for 3D valve segmentation and shape representation. Towards this goal, this work integrates template-based medial modeling and multi-atlas label fusion techniques to automatically delineate and quantitatively describe aortic leaflet geometry in 3D echocardiographic (3DE) images, a challenging task that has been explored only to a limited extent. The method makes use of expert knowledge of aortic leaflet image appearance, generates segmentations with consistent topology, and establishes a shape-based coordinate system on the aortic leaflets that enables standardized automated measurements. In this study, the algorithm is evaluated on 11 3DE images of normal human aortic leaflets acquired at mid systole. The clinical relevance of the method is its ability to capture leaflet geometry in 3DE image data with minimal user interaction while producing consistent measurements of 3D aortic leaflet geometry.

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  5. 3D Xplane Echocardiographic Technique for Validation of Mitral Leaflet Separation to Assess Severity of Mitral Stenosis.

    PubMed

    Gokhroo, Rajendra K; Ranwa, Bhanwar L; Kishor, Kamal; Priti, Kumari; Avinash, Ananthraj; Gupta, Sajal; Bisht, Devendra

    2016-06-01

    Determining the severity of mitral stenosis (MS) is important for both prognostic and therapeutic implications. Mitral valve area (MVA) calculation techniques have more limitations. Mitral leaflet separation (MLS) is a precise and operator friendly alternative to planimetry. In contrast to previous researchers, we have used a novel 3D Xplane technique to validate MLS for assessing the severity of MS. 3D Xplane is superior for validation of MLS due to simultaneous real time acquisition of MLS in parasternal long-axis view and corresponding MVA by planimetry in parsternal short-axis view. It was a prospective observational single center study. A total of 174 patients with MS were evaluated for MVA estimation by various echocardiographic modalities. Maximum leaflet separation and corresponding planimetered MVA were measured using novel 3D Xplane technique. With 3D Xplane technique, there was strong positive correlation between planimetered MVA and MLS (R = 0.925, P < 0.001), irrespective of coexisting MR (R = 0.886, P < 0.001) or AF (R = 0.912, P < 0.001). Receiver operating characteristic curves of MLS demonstrated AUC for mild and severe MS to be 0.966 and 0.995, respectively. MLS less than 8.62 mm predicted severe MS with 95.5% sensitivity and 94.7% specificity and MLS more than 12.23 mm predicted mild MS with 93.2% sensitivity and 91.4% specificity. In our study, a strong correlation between planimetered MVA and MLS was found using 3D Xplane technique. 3D Xplane thus validates and standardizes MLS by excluding errors due to temporal and spatial variations which are important limitations of 2D echocardiography. © 2016, Wiley Periodicals, Inc.

  6. Reproducibility of a novel echocardiographic 3D automated software for the assessment of mitral valve anatomy.

    PubMed

    Aquila, Iolanda; González, Ariana; Fernández-Golfín, Covadonga; Rincón, Luis Miguel; Casas, Eduardo; García, Ana; Hinojar, Rocio; Jiménez-Nacher, José Julio; Zamorano, José Luis

    2016-05-17

    3D transesophageal echocardiography (TEE) is superior to 2D TEE in quantitative anatomic evaluation of the mitral valve (MV) but it shows limitations regarding automatic quantification. Here, we tested the inter-/intra-observer reproducibility of a novel full-automated software in the evaluation of MV anatomy compared to manual 3D assessment. Thirty-six out of 61 screened patients referred to our Cardiac Imaging Unit for TEE were retrospectively included. 3D TEE analysis was performed both manually and with the automated software by two independent operators. Mitral annular area, intercommissural distance, anterior leaflet length and posterior leaflet length were assessed. A significant correlation between both methods was found for all variables: intercommissural diameter (r = 0.84, p < 0.01), mitral annular area (r = 0.94, p > 0, 01), anterior leaflet length (r = 0.83, p < 0.01) and posterior leaflet length (r = 0.67, p < 0.01). Interobserver variability assessed by the intraclass correlation coefficient was superior for the automatic software: intercommisural distance 0.997 vs. 0.76; mitral annular area 0.957 vs. 0.858; anterior leaflet length 0.963 vs. 0.734 and posterior leaflet length 0.936 vs. 0.838. Intraobserver variability was good for both methods with a better level of agreement with the automatic software. The novel 3D automated software is reproducible in MV anatomy assessment. The incorporation of this new tool in clinical MV assessment may improve patient selection and outcomes for MV interventions as well as patient diagnosis and prognosis stratification. Yet, high-quality 3D images are indispensable.

  7. 3D echocardiographic reference ranges for normal left ventricular volumes and strain: results from the EACVI NORRE study.

    PubMed

    Bernard, Anne; Addetia, Karima; Dulgheru, Raluca; Caballero, Luis; Sugimoto, Tadafumi; Akhaladze, Natela; Athanassopoulos, George D; Barone, Daniele; Baroni, Monica; Cardim, Nuno; Hagendorff, Andreas; Hristova, Krasimira; Ilardi, Federica; Lopez, Teresa; de la Morena, Gonzalo; Popescu, Bogdan A; Penicka, Martin; Ozyigit, Tolga; David Rodrigo Carbonero, Jose; van de Veire, Nico; Stephan Von Bardeleben, Ralph; Vinereanu, Dragos; Luis Zamorano, Jose; Martinez, Christophe; Magne, Julien; Cosyns, Bernard; Donal, Erwan; Habib, Gilbert; Badano, Luigi P; Lang, Roberto M; Lancellotti, Patrizio

    2017-04-01

    To obtain the normal ranges for 3D echocardiography (3DE) measurement of left ventricular (LV) volumes, function, and strain from a large group of healthy volunteers. A total of 440 (mean age: 45 ± 13 years) out of the 734 healthy subjects enrolled at 22 collaborating institutions of the Normal Reference Ranges for Echocardiography (NORRE) study had good-quality 3DE data sets that have been analysed with a vendor-independent software package allowing homogeneous measurements regardless of the echocardiographic machine used to acquire the data sets. Upper limits of LV end-diastolic and end-systolic volumes were larger in men (97 and 42 mL/m2) than in women (82 and 35 mL/m2; P < 0.0001). Conversely, lower limits of LV ejection fraction were higher in women than in men (51% vs. 50%; P < 0.01). Similarly, all strain components were higher in women than in men. Lower range was -18.6% in men and -19.5% in women for 3D longitudinal strain, -27.0% and -27.6% for 3D circumferential strain, -33.2% and -34.4% for 3D tangential strain and 38.8% and 40.7% for 3D radial strain, respectively. LV volumes decreased with age in both genders (P < 0.0001), whereas LV ejection fraction increased with age only in men. Among 3DE LV strain components, the only one, which did not change with age was longitudinal strain. The NORRE study provides applicable 3D echocardiographic reference ranges for LV function assessment. Our data highlight the importance of age- and gender-specific reference values for both LV volumes and strain.

  8. Correlation based 3-D segmentation of the left ventricle in pediatric echocardiographic images using radio-frequency data.

    PubMed

    Nillesen, Maartje M; Lopata, Richard G P; Huisman, H J; Thijssen, Johan M; Kapusta, Livia; de Korte, Chris L

    2011-09-01

    Clinical diagnosis of heart disease might be substantially supported by automated segmentation of the endocardial surface in three-dimensional (3-D) echographic images. Because of the poor echogenicity contrast between blood and myocardial tissue in some regions and the inherent speckle noise, automated analysis of these images is challenging. A priori knowledge on the shape of the heart cannot always be relied on, e.g., in children with congenital heart disease, segmentation should be based on the echo features solely. The objective of this study was to investigate the merit of using temporal cross-correlation of radio-frequency (RF) data for automated segmentation of 3-D echocardiographic images. Maximum temporal cross-correlation (MCC) values were determined locally from the RF-data using an iterative 3-D technique. MCC values as well as a combination of MCC values and adaptive filtered, demodulated RF-data were used as an additional, external force in a deformable model approach to segment the endocardial surface and were tested against manually segmented surfaces. Results on 3-D full volume images (Philips, iE33) of 10 healthy children demonstrate that MCC values derived from the RF signal yield a useful parameter to distinguish between blood and myocardium in regions with low echogenicity contrast and incorporation of MCC improves the segmentation results significantly. Further investigation of the MCC over the whole cardiac cycle is required to exploit the full benefit of it for automated segmentation.

  9. Incremental value of 3-D transesophageal echocardiographic imaging of the mitral valve.

    PubMed

    Jain, Sonia; Malouf, Joseph F

    2014-01-01

    Transesophageal echocardiography provides excellent visualization of the posteriorly located mitral valve. Over the last decade, 3-dimensional transesophageal echocardiography (3D TEE) has emerged as an exciting imaging modality, particularly of the mitral valve. The current generation matrix array technology allows the operator to perform 2D and 3D imaging with a single transducer. 3D TEE affords the unique ability to view the mitral valve and its surrounding structures "en face" in real time (RT), and provide contextual anatomical guidance during surgical and transcatheter interventions. Additionally, offline quantification has made significant contributions to our mechanistic understanding of the normal and diseased mitral valve, and alterations induced by therapeutic intervention such as surgical repair. This review will address recent advances in the incremental role of 3D TEE in mitral valve imaging.

  10. Echocardiographic Evaluation of the Right Heart

    PubMed Central

    Markley, Roshanak R; Potfay, Jonathan; Paulsen, Walter; Jovin, Ion S

    2016-01-01

    The appropriate use of echocardiography may reduce the need for invasive diagnostic cardiac procedures. The right side of the heart has recently gained interest among cardiologists as it became clear that abnormalities of the right heart morphology and function are associated with increased morbidity and mortality. Echocardiography is easy to perform, relatively cheap, readily available and do not pose the risk of ionizing radiation. Conventional 2D and, more recently, 3D echocardiography provides pertinent anatomic and physiologic information about the right side of the heart. Because of the advantages and simplicity of echocardiography it continues to be an excellent tool for evaluating the structure and function of the right side of the heart. This review outlines the uses of echocardiography in evaluating the right heart structure and function. PMID:27721944

  11. Segmentation of the Aortic Valve Apparatus in 3D Echocardiographic Images: Deformable Modeling of a Branching Medial Structure.

    PubMed

    Pouch, Alison M; Tian, Sijie; Takabe, Manabu; Wang, Hongzhi; Yuan, Jiefu; Cheung, Albert T; Jackson, Benjamin M; Gorman, Joseph H; Gorman, Robert C; Yushkevich, Paul A

    2015-01-01

    3D echocardiographic (3DE) imaging is a useful tool for assessing the complex geometry of the aortic valve apparatus. Segmentation of this structure in 3DE images is a challenging task that benefits from shape-guided deformable modeling methods, which enable inter-subject statistical shape comparison. Prior work demonstrates the efficacy of using continuous medial representation (cm-rep) as a shape descriptor for valve leaflets. However, its application to the entire aortic valve apparatus is limited since the structure has a branching medial geometry that cannot be explicitly parameterized in the original cm-rep framework. In this work, we show that the aortic valve apparatus can be accurately segmented using a new branching medial modeling paradigm. The segmentation method achieves a mean boundary displacement of 0.6 ± 0.1 mm (approximately one voxel) relative to manual segmentation on 11 3DE images of normal open aortic valves. This study demonstrates a promising approach for quantitative 3DE analysis of aortic valve morphology.

  12. Segmentation of the Aortic Valve Apparatus in 3D Echocardiographic Images: Deformable Modeling of a Branching Medial Structure

    PubMed Central

    Pouch, Alison M.; Tian, Sijie; Takabe, Manabu; Wang, Hongzhi; Yuan, Jiefu; Cheung, Albert T.; Jackson, Benjamin M.; Gorman, Joseph H.; Gorman, Robert C.; Yushkevich, Paul A.

    2015-01-01

    3D echocardiographic (3DE) imaging is a useful tool for assessing the complex geometry of the aortic valve apparatus. Segmentation of this structure in 3DE images is a challenging task that benefits from shape-guided deformable modeling methods, which enable inter-subject statistical shape comparison. Prior work demonstrates the efficacy of using continuous medial representation (cm-rep) as a shape descriptor for valve leaflets. However, its application to the entire aortic valve apparatus is limited since the structure has a branching medial geometry that cannot be explicitly parameterized in the original cm-rep framework. In this work, we show that the aortic valve apparatus can be accurately segmented using a new branching medial modeling paradigm. The segmentation method achieves a mean boundary displacement of 0.6 ± 0.1 mm (approximately one voxel) relative to manual segmentation on 11 3DE images of normal open aortic valves. This study demonstrates a promising approach for quantitative 3DE analysis of aortic valve morphology. PMID:26247062

  13. The Value of 3D Printing Models of Left Atrial Appendage Using Real-Time 3D Transesophageal Echocardiographic Data in Left Atrial Appendage Occlusion: Applications toward an Era of Truly Personalized Medicine.

    PubMed

    Liu, Peng; Liu, Rijing; Zhang, Yan; Liu, Yingfeng; Tang, Xiaoming; Cheng, Yanzhen

    2016-01-01

    The objective of this study was to assess the clinical feasibility of generating 3D printing models of left atrial appendage (LAA) using real-time 3D transesophageal echocardiogram (TEE) data for preoperative reference of LAA occlusion. Percutaneous LAA occlusion can effectively prevent patients with atrial fibrillation from stroke. However, the anatomical structure of LAA is so complicated that adequate information of its structure is essential for successful LAA occlusion. Emerging 3D printing technology has the demonstrated potential to structure more accurately than conventional imaging modalities by creating tangible patient-specific models. Typically, 3D printing data sets are acquired from CT and MRI, which may involve intravenous contrast, sedation, and ionizing radiation. It has been reported that 3D models of LAA were successfully created by the data acquired from CT. However, 3D printing of the LAA using real-time 3D TEE data has not yet been explored. Acquisition of 3D transesophageal echocardiographic data from 8 patients with atrial fibrillation was performed using the Philips EPIQ7 ultrasound system. Raw echocardiographic image data were opened in Philips QLAB and converted to 'Cartesian DICOM' format and imported into Mimics® software to create 3D models of LAA, which were printed using a rubber-like material. The printed 3D models were then used for preoperative reference and procedural simulation in LAA occlusion. We successfully printed LAAs of 8 patients. Each LAA costs approximately CNY 800-1,000 and the total process takes 16-17 h. Seven of the 8 Watchman devices predicted by preprocedural 2D TEE images were of the same sizes as those placed in the real operation. Interestingly, 3D printing models were highly reflective of the shape and size of LAAs, and all device sizes predicted by the 3D printing model were fully consistent with those placed in the real operation. Also, the 3D printed model could predict operating difficulty and the

  14. Evaluating scatterometry 3D capabilities for EUV

    NASA Astrophysics Data System (ADS)

    Li, Jie; Kritsun, Oleg; Dasari, Prasad; Volkman, Catherine; Wallow, Tom; Hu, Jiangtao

    2013-04-01

    Optical critical dimension (OCD) metrology using scatterometry has been demonstrated to be a viable solution for fast and non-destructive in-line process control and monitoring. As extreme ultraviolet lithography (EUVL) is more widely adopted to fabricate smaller and smaller patterns for electronic devices, scatterometry faces new challenges due to several reasons. For 14nm node and beyond, the feature size is nearly an order of magnitude smaller than the shortest wavelength used in scatterometry. In addition, thinner resist layer is used in EUVL compared with conventional lithography, which leads to reduced measurement sensitivity. Despite these difficulties, tolerance has reduced for smaller feature size. In this work we evaluate 3D capability of scatterometry for EUV process using spectroscopic ellipsometry (SE). Three types of structures, contact holes, tip-to-tip, and tip-to-edge, are studied to test CD and end-gap metrology capabilities. The wafer is processed with focus and exposure matrix. Good correlations to CD-SEM results are achieved and good dynamic precision is obtained for all the key parameters. In addition, the fit to process provides an independent method to evaluate data quality from different metrology tools such as OCD and CDSEM. We demonstrate 3D capabilities of scatterometry OCD metrology for EUVL using spectroscopic ellipsometry, which provides valuable in-line metrology for CD and end-gap control in electronic circuit fabrications.

  15. Echocardiographic evaluation of aorto-iliac occlusive disease.

    PubMed

    Styczynski, Grzegorz; Szmigielski, Cezary; Kaczynska, Anna; Leszczynski, Jerzy; Rosinski, Grzegorz; Kuch-Wocial, Agnieszka

    2012-08-01

    Several studies demonstrated feasibility of visual assessment of the common femoral artery Doppler waveform, in an indirect evaluation of aorto-iliac segment stenosis. Patients with cardiac diseases referred for echocardiography often have coexistent arterial pathology. Since many of them are potential candidates for endovascular procedures, we decided to study, whether echocardiography can be useful for detection of aorto-iliac occlusive disease. We evaluated 92 patients with abdominal aortic aneurysm or peripheral artery occlusive disease, referred from the vascular surgery department for cardiac evaluation before surgery. At the end of an echocardiographic examination, evaluation of flow in the distal external iliac arteries with an echocardiographic probe was performed. The Doppler waveform was classified into normal--with early diastolic flow reversal or abnormal--without early diastolic flow reversal. Echocardiographic results were compared in a blinded fashion with reports from computed tomography angiography. Overall there were 58 iliac segments with significant (≥70%) area stenosis or occlusion and 126 iliac segments without significant disease on computed tomography angiography. Abnormal Doppler waveform was found in 56 out of 58 abnormal iliac segments-sensitivity 97%, and normal waveform was found in 106 out of 126 normal iliac segments-specificity 84%. Positive predictive value of abnormal Doppler waveform for significant iliac disease was 74%, and negative predicting value was 98%. Detection of significant stenoses in aorto-iliac segments is feasible with echocardiography. Further studies are necessary to evaluate its potential utility in a population of patients with cardiac disease referred for echocardiographic study.

  16. Echocardiographic Evaluation of Pericardial Effusion and Cardiac Tamponade

    PubMed Central

    Pérez-Casares, Alejandro; Cesar, Sergi; Brunet-Garcia, Laia; Sanchez-de-Toledo, Joan

    2017-01-01

    Pericardial effusion (PEff) is defined by an increase in the physiological amount of fluid within the pericardial space. It can appear following different medical conditions, mainly related to inflammation and cardiac surgery. Cardiac tamponade is a critical condition that occurs after sudden and/or excessive accumulation of fluid in the pericardial space that restricts appropriate filling of the cardiac chambers disturbing normal hemodynamics and ultimately causing hypotension and cardiac arrest. It is, therefore, a life-threatening condition that must be diagnosed as soon as possible for correct treatment and management. Echocardiographic evaluation of PEff is paramount for timely and appropriate diagnosis and management. A structured echocardiographic approach including two-dimensional, M-mode, and Doppler echocardiographic evaluation assessing (i) quantity and quality of pericardial fluid, (ii) collapse of cardiac chambers, (iii) respiratory variation of the ventricular diameters, (iv) inferior vena cava collapsibility, and (v) flow patterns in atrioventricular valves should give the bedside clinician the necessary information to appropriately manage PEff. Here, we review these key echocardiographic signs that will ensure an appropriate assessment of a patient with PEff and/or cardiac tamponade. PMID:28484689

  17. Evaluation of right ventricular volume and function by 2D and 3D echocardiography compared to MRI.

    PubMed

    Kjaergaard, Jesper; Petersen, Claus Leth; Kjaer, Andreas; Schaadt, Bente Krogsgaard; Oh, Jae K; Hassager, Christian

    2006-12-01

    Radionuclide techniques, and recently MRI, have been used for clinical evaluation of right ventricular (RV) volumes function (RVEF) and volumes; but with the introduction of 3D echocardiography, new echocardiographic possibilities for RV evaluation independent of geometrical assumptions have emerged. This study compared classic and new echocardiographic and radionuclide estimates, including gated blood pool single-photon emission computed tomography (SPECT) of RV size and function to RV volumes, and ejection fraction (RVEF) measured by magnetic resonance imaging (MRI). Thirty-four subjects with (a) prior inferior ST-elevation myocardial infarction (n=17), (b) a history of pulmonary embolism and persistent dyspnea (n=7) or (c) normal subjects (n=10) had 2D and 3D echocardiography, SPECT and MRI within 24h. End-diastolic volume and peak tricuspid regurgitation velocity were increased in patients with a history of pulmonary embolism compared to healthy subjects, 130+/-26 ml vs. 94+/-26 ml, P<0.05, and 3.3+/-1.1m/s vs. 2.3+/-0.3m/s, P<0.05, respectively, whereas no differences in RVEF were seen in the three groups. Echocardiographic as well as SPECT estimates of RV volume showed significant correlation to RV volumes by MRI. Tricuspid annular plane systolic excursion (TAPSE) had the better correlation to RVEF by MRI, r=0.48, P<0.01; whereas 3D echocardiography had a correlation of 0.42, P<0.05. Compared to MRI, 3D echocardiography underestimated RVEF by 5.9%, 95% limits of agreement 1.6-10.2%. 3D echocardiographic estimates of RV size and RVEF show only moderate correlation to MRI measures of these parameters, and simple 2D echocardiographic estimates of RV size and function show similar correlations. For routine clinical purposes the simple TAPSE may be preferred over 3D and SPECT techniques for RVEF estimation.

  18. [Echocardiographic evaluation of HIV-positive subjects].

    PubMed

    Minardi, G; Di Segni, M; Boccardi, L; Pucci, E; Giovannini, E

    1991-03-01

    The purpose of the study was to assess the prevalence and the type of cardiac abnormalities in patients with HIV infection. Echocardiographic examination (M-mode, two-dimensional and Doppler) was performed in 51 patients (40 male, 11 female), whose mean age was 29 +/- 10 years; 48 of them (94%) were intravenous drug addicts, 3 (6%) homosexuals. Diagnosis was AIDS in 19 (37%) patients, AIDS related complex in 19 (37%) and asymptomatic infection in 13 (26%). Echocardiography was normal in 13 subjects. Pericardial effusion was found in 19 patients (in 8 of them, this was the only cardiac abnormality). Valve vegetations were found in 16 patients (3 of them had pericardial effusion, 5 had ventricular dilatation or wall motion abnormalities, 1 had both pericardial and myocardial impairment). Myocardial dysfunction was found in 18 patients: 11 had left ventricular dilatation (5 with wall hypokinesia), 1 had right ventricular enlargement, 1 had biventricular dilatation and 5 had only wall motion abnormalities (diffuse or localized). During the follow-up 9 patients died: 8 had AIDS, 1 was asymptomatic. Eight subjects died during hospitalization (none because of cardiac causes) and one at home for sudden unexplained death. Echocardiography had displayed myocardial dysfunction in 6 of them, thickened pericardium in 1 and was normal in 2. Pathologic examination (performed in 8 subjects) showed cardiac enlargement in 3 subjects, thickened pericardium in 2 and valve vegetation in 1. One subject had histopathologic diagnosis of myocarditis and 7 had non specific histologic abnormalities. The study shows a cardiac involvement in 75% of HIV infected patients: 35% had myocardial dysfunction, 37% pericardial disease, 31% infective endocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. A Pipeline for the Generation of Realistic 3D Synthetic Echocardiographic Sequences: Methodology and Open-access Database.

    PubMed

    Alessandrini, Martino; De Craene, Mathieu; Bernard, Olivier; Giffard-Roisin, Sophie; Allain, Pascal; Weese, Juergen; Saloux, Eric; Delingette, Herve; Sermesant, Maxime; D'hooge, Jan

    2015-01-27

    Quantification of cardiac deformation and strain with 3D ultrasound takes considerable research efforts. Nevertheless, a widespread use of these techniques in clinical practice is still held back due to the lack of a solid verification process to quantify and compare performance. In this context, the use of fully synthetic sequences has become an established tool for initial in silico evaluation. Nevertheless, the realism of existing simulation techniques is still too limited to represent reliable benchmarking data. Moreover, the fact that different centers typically make use of in-house developed simulation pipelines makes a fair comparison difficult. In this context, this paper introduces a novel pipeline for the generation of synthetic 3D cardiac ultrasound image sequences. State-of-the art solutions in the fields of electromechanical modeling and ultrasound simulation are combined within an original framework that exploits a real ultrasound recording to learn and simulate realistic speckle textures. The simulated images show typical artifacts that make motion tracking in ultrasound challenging. The ground-truth displacement field is available voxelwise and is fully controlled by the electromechanical model. By progressively modifying mechanical and ultrasound parameters, the sensitivity of 3D strain algorithms to pathology and image properties can be evaluated. The proposed pipeline is used to generate an initial library of 8 sequences including healthy and pathological cases, which is made freely accessible to the research community via our project web-page..

  20. Reconstruction of the descending thoracic aorta by multiview compounding of 3-D transesophageal echocardiographic aortic data sets for improved examination and quantification of atheroma burden.

    PubMed

    Carminati, Maria Chiara; Piazzese, Concetta; Weinert, Lynn; Tsang, Wendy; Tamborini, Gloria; Pepi, Mauro; Lang, Roberto Miguel; Caiani, Enrico Gianluca

    2015-05-01

    A robust and efficient approach to reconstruction of the descending thoracic aorta from contiguous 3-D transesophageal echocardiographic (TEE) images is proposed. An ad hoc image acquisition protocol was designed to acquire ordered and partially overlapped 3-D TEE data sets, followed by dedicated image processing to align and fuse all acquired data sets. Alignment strategy implemented pairwise rigid registration guided by a priori knowledge, and it was validated using artificially misaligned images. Image fusion was finally performed to enable visualization and analysis of extended field-of-view of the acquired aorta. The application of different fusion techniques was also investigated. The method was applied to a population of 17 consecutive patients. Qualitative and quantitative results supported the feasibility and accuracy of the proposed approach. In a clinical scenario, its application could allow the quantitative assessment of aortic plaque burden in the descending thoracic aorta from 3-D TEE images.

  1. Acute Beneficial Hemodynamic Effects of a Novel 3D-Echocardiographic Optimization Protocol in Cardiac Resynchronization Therapy

    PubMed Central

    Hauck, Simon; Lesevic, Hasema; Barthel, Petra; Michalk, Fabian; Hoppe, Katharina; Hausleiter, Jörg; Kolb, Christof

    2012-01-01

    Background Post-implantation therapies to optimize cardiac resynchronization therapy (CRT) focus on adjustments of the atrio-ventricular (AV) delay and ventricular-to-ventricular (VV) interval. However, there is little consensus on how to achieve best resynchronization with these parameters. The aim of this study was to examine a novel combination of doppler echocardiography (DE) and three-dimensional echocardiography (3DE) for individualized optimization of device based AV delays and VV intervals compared to empiric programming. Methods 25 recipients of CRT (male: 56%, mean age: 67 years) were included in this study. Ejection fraction (EF), the primary outcome parameter, and left ventricular (LV) dimensions were evaluated by 3DE before CRT (baseline), after AV delay optimization while pacing the ventricles simultaneously (empiric VV interval programming) and after individualized VV interval optimization. For AV delay optimization aortic velocity time integral (AoVTI) was examined in eight different AV delays, and the AV delay with the highest AoVTI was programmed. For individualized VV interval optimization 3DE full-volume datasets of the left ventricle were obtained and analyzed to derive a systolic dyssynchrony index (SDI), calculated from the dispersion of time to minimal regional volume for all 16 LV segments. Consecutively, SDI was evaluated in six different VV intervals (including LV or right ventricular preactivation), and the VV interval with the lowest SDI was programmed (individualized optimization). Results EF increased from baseline 23±7% to 30±8 (p<0.001) after AV delay optimization and to 32±8% (p<0.05) after individualized optimization with an associated decrease of end-systolic volume from a baseline of 138±60 ml to 115±42 ml (p<0.001). Moreover, individualized optimization significantly reduced SDI from a baseline of 14.3±5.5% to 6.1±2.6% (p<0.001). Conclusions Compared with empiric programming of biventricular pacemakers, individualized

  2. Echocardiographic Evaluation of Patent Ductus Arteriosus in Preterm Infants

    PubMed Central

    Arlettaz, Romaine

    2017-01-01

    Patent ductus arteriosus (PDA) is part of the typical morbidity profile of the preterm infant, with a high incidence of 80–90% in extremely low birth weight infants born before 26 weeks of gestation. Whereas spontaneous closure of the ductus arteriosus (DA) is likely in term infants, it is less so in preterm ones. PDA is associated with increased mortality and various comorbidities including cardiac failure, need for respiratory support, bronchopulmonary dysplasia, pulmonary or intracranial hemorrhage, and necrotizing enterocolitis; however, there is no proven causality between these morbidities and the presence of DA. Thus, the indication to close PDA remains highly controversial. This paper focuses on echocardiographic evaluation of PDA in the preterm infant and particularly on the echocardiographic signs of hemodynamic significance. PMID:28680875

  3. Feasibility of rapid and automated importation of 3D echocardiographic left ventricular (LV) geometry into a finite element (FEM) analysis model

    PubMed Central

    Verhey, Janko F; Nathan, Nadia S

    2004-01-01

    Background Finite element method (FEM) analysis for intraoperative modeling of the left ventricle (LV) is presently not possible. Since 3D structural data of the LV is now obtainable using standard transesophageal echocardiography (TEE) devices intraoperatively, the present study describes a method to transfer this data into a commercially available FEM analysis system: ABAQUS©. Methods In this prospective study TomTec LV Analysis TEE© Software was used for semi-automatic endocardial border detection, reconstruction, and volume-rendering of the clinical 3D echocardiographic data. A newly developed software program MVCP FemCoGen©, written in Delphi, reformats the TomTec file structures in five patients for use in ABAQUS and allows visualization of regional deformation of the LV. Results This study demonstrates that a fully automated importation of 3D TEE data into FEM modeling is feasible and can be efficiently accomplished in the operating room. Conclusion For complete intraoperative 3D LV finite element analysis, three input elements are necessary: 1. time-gaited, reality-based structural information, 2. continuous LV pressure and 3. instantaneous tissue elastance. The first of these elements is now available using the methods presented herein. PMID:15473901

  4. Semi-automated segmentation and quantification of mitral annulus and leaflets from transesophageal 3-D echocardiographic images.

    PubMed

    Sotaquira, Miguel; Pepi, Mauro; Fusini, Laura; Maffessanti, Francesco; Lang, Roberto M; Caiani, Enrico G

    2015-01-01

    Quantification of three-dimensional (3-D) morphology of the mitral valve (MV) using real-time 3-D transesophageal echocardiography (RT3-D TEE) has proved to be a valuable tool for the assessment of MV pathologies, but of limited use in clinical practice because it relies on user-intensive approaches. This study presents a new algorithm for the segmentation and morphologic quantification of the mitral annulus (MA) and mitral leaflets (ML) in closed valve configuration from RT3-D TEE volumes. Following initialization, the MA and the ML and the coaptation line (CL) are automatically obtained in 3-D. Validation with manual tracings was performed on 33 patients, resulting in segmentation errors in the order of 0.7 mm and 0.6 mm for the MA and ML segmentation, in addition to good intra- and inter-observer reproducibility (coefficients of variation below 12% and 15%, respectively). The ability of the algorithm to assess different MV pathologies as well as repaired valves with implanted annular rings was also explored. The reported performance of the proposed fast, semi-automated MA and ML quantification makes it promising for future applications in clinical settings such as the operating room, where obtaining results in short time is important. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. Metric Evaluation Pipeline for 3d Modeling of Urban Scenes

    NASA Astrophysics Data System (ADS)

    Bosch, M.; Leichtman, A.; Chilcott, D.; Goldberg, H.; Brown, M.

    2017-05-01

    Publicly available benchmark data and metric evaluation approaches have been instrumental in enabling research to advance state of the art methods for remote sensing applications in urban 3D modeling. Most publicly available benchmark datasets have consisted of high resolution airborne imagery and lidar suitable for 3D modeling on a relatively modest scale. To enable research in larger scale 3D mapping, we have recently released a public benchmark dataset with multi-view commercial satellite imagery and metrics to compare 3D point clouds with lidar ground truth. We now define a more complete metric evaluation pipeline developed as publicly available open source software to assess semantically labeled 3D models of complex urban scenes derived from multi-view commercial satellite imagery. Evaluation metrics in our pipeline include horizontal and vertical accuracy and completeness, volumetric completeness and correctness, perceptual quality, and model simplicity. Sources of ground truth include airborne lidar and overhead imagery, and we demonstrate a semi-automated process for producing accurate ground truth shape files to characterize building footprints. We validate our current metric evaluation pipeline using 3D models produced using open source multi-view stereo methods. Data and software is made publicly available to enable further research and planned benchmarking activities.

  6. Performance Evaluation of 3d Modeling Software for Uav Photogrammetry

    NASA Astrophysics Data System (ADS)

    Yanagi, H.; Chikatsu, H.

    2016-06-01

    UAV (Unmanned Aerial Vehicle) photogrammetry, which combines UAV and freely available internet-based 3D modeling software, is widely used as a low-cost and user-friendly photogrammetry technique in the fields such as remote sensing and geosciences. In UAV photogrammetry, only the platform used in conventional aerial photogrammetry is changed. Consequently, 3D modeling software contributes significantly to its expansion. However, the algorithms of the 3D modelling software are black box algorithms. As a result, only a few studies have been able to evaluate their accuracy using 3D coordinate check points. With this motive, Smart3DCapture and Pix4Dmapper were downloaded from the Internet and commercial software PhotoScan was also employed; investigations were performed in this paper using check points and images obtained from UAV.

  7. Evaluation of viewing experiences induced by curved 3D display

    NASA Astrophysics Data System (ADS)

    Mun, Sungchul; Park, Min-Chul; Yano, Sumio

    2015-05-01

    As advanced display technology has been developed, much attention has been given to flexible panels. On top of that, with the momentum of the 3D era, stereoscopic 3D technique has been combined with the curved displays. However, despite the increased needs for 3D function in the curved displays, comparisons between curved and flat panel displays with 3D views have rarely been tested. Most of the previous studies have investigated their basic ergonomic aspects such as viewing posture and distance with only 2D views. It has generally been known that curved displays are more effective in enhancing involvement in specific content stories because field of views and distance from the eyes of viewers to both edges of the screen are more natural in curved displays than in flat panel ones. For flat panel displays, ocular torsions may occur when viewers try to move their eyes from the center to the edges of the screen to continuously capture rapidly moving 3D objects. This is due in part to differences in viewing distances from the center of the screen to eyes of viewers and from the edges of the screen to the eyes. Thus, this study compared S3D viewing experiences induced by a curved display with those of a flat panel display by evaluating significant subjective and objective measures.

  8. An Evaluative Review of Simulated Dynamic Smart 3d Objects

    NASA Astrophysics Data System (ADS)

    Romeijn, H.; Sheth, F.; Pettit, C. J.

    2012-07-01

    Three-dimensional (3D) modelling of plants can be an asset for creating agricultural based visualisation products. The continuum of 3D plants models ranges from static to dynamic objects, also known as smart 3D objects. There is an increasing requirement for smarter simulated 3D objects that are attributed mathematically and/or from biological inputs. A systematic approach to plant simulation offers significant advantages to applications in agricultural research, particularly in simulating plant behaviour and the influences of external environmental factors. This approach of 3D plant object visualisation is primarily evident from the visualisation of plants using photographed billboarded images, to more advanced procedural models that come closer to simulating realistic virtual plants. However, few programs model physical reactions of plants to external factors and even fewer are able to grow plants based on mathematical and/or biological parameters. In this paper, we undertake an evaluation of plant-based object simulation programs currently available, with a focus upon the components and techniques involved in producing these objects. Through an analytical review process we consider the strengths and weaknesses of several program packages, the features and use of these programs and the possible opportunities in deploying these for creating smart 3D plant-based objects to support agricultural research and natural resource management. In creating smart 3D objects the model needs to be informed by both plant physiology and phenology. Expert knowledge will frame the parameters and procedures that will attribute the object and allow the simulation of dynamic virtual plants. Ultimately, biologically smart 3D virtual plants that react to changes within an environment could be an effective medium to visually represent landscapes and communicate land management scenarios and practices to planners and decision-makers.

  9. Echocardiographic agreement in the diagnostic evaluation for infective endocarditis.

    PubMed

    Lauridsen, Trine Kiilerich; Selton-Suty, Christine; Tong, Steven; Afonso, Luis; Cecchi, Enrico; Park, Lawrence; Yow, Eric; Barnhart, Huiman X; Paré, Carlos; Samad, Zainab; Levine, Donald; Peterson, Gail; Stancoven, Amy Butler; Johansson, Magnus Carl; Dickerman, Stuart; Tamin, Syahidah; Habib, Gilbert; Douglas, Pamela S; Bruun, Niels Eske; Crowley, Anna Lisa

    2016-07-01

    Echocardiography is essential for the diagnosis and management of infective endocarditis (IE). However, the reproducibility for the echocardiographic assessment of variables relevant to IE is unknown. Objectives of this study were: (1) To define the reproducibility for IE echocardiographic variables and (2) to describe a methodology for assessing quality in an observational cohort containing site-interpreted data. IE reproducibility was assessed on a subset of echocardiograms from subjects enrolled in the International Collaboration on Endocarditis registry. Specific echocardiographic case report forms were used. Intra-observer agreement was assessed from six site readers on ten randomly selected echocardiograms. Inter-observer agreement between sites and an echocardiography core laboratory was assessed on a separate random sample of 110 echocardiograms. Agreement was determined using intraclass correlation (ICC), coverage probability (CP), and limits of agreement for continuous variables and kappa statistics (κweighted) and CP for categorical variables. Intra-observer agreement for LVEF was excellent [ICC = 0.93 ± 0.1 and all pairwise differences for LVEF (CP) were within 10 %]. For IE categorical echocardiographic variables, intra-observer agreement was best for aortic abscess (κweighted = 1.0, CP = 1.0 for all readers). Highest inter-observer agreement for IE categorical echocardiographic variables was obtained for vegetation location (κweighted = 0.95; 95 % CI 0.92-0.99) and lowest agreement was found for vegetation mobility (κweighted = 0.69; 95 % CI 0.62-0.86). Moderate to excellent intra- and inter-observer agreement is observed for echocardiographic variables in the diagnostic assessment of IE. A pragmatic approach for determining echocardiographic data reproducibility in a large, multicentre, site interpreted observational cohort is feasible.

  10. Fully automatic segmentation of the mitral leaflets in 3D transesophageal echocardiographic images using multi-atlas joint label fusion and deformable medial modeling.

    PubMed

    Pouch, A M; Wang, H; Takabe, M; Jackson, B M; Gorman, J H; Gorman, R C; Yushkevich, P A; Sehgal, C M

    2014-01-01

    Comprehensive visual and quantitative analysis of in vivo human mitral valve morphology is central to the diagnosis and surgical treatment of mitral valve disease. Real-time 3D transesophageal echocardiography (3D TEE) is a practical, highly informative imaging modality for examining the mitral valve in a clinical setting. To facilitate visual and quantitative 3D TEE image analysis, we describe a fully automated method for segmenting the mitral leaflets in 3D TEE image data. The algorithm integrates complementary probabilistic segmentation and shape modeling techniques (multi-atlas joint label fusion and deformable modeling with continuous medial representation) to automatically generate 3D geometric models of the mitral leaflets from 3D TEE image data. These models are unique in that they establish a shape-based coordinate system on the valves of different subjects and represent the leaflets volumetrically, as structures with locally varying thickness. In this work, expert image analysis is the gold standard for evaluating automatic segmentation. Without any user interaction, we demonstrate that the automatic segmentation method accurately captures patient-specific leaflet geometry at both systole and diastole in 3D TEE data acquired from a mixed population of subjects with normal valve morphology and mitral valve disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Objective breast symmetry evaluation using 3-D surface imaging.

    PubMed

    Eder, Maximilian; Waldenfels, Fee V; Swobodnik, Alexandra; Klöppel, Markus; Pape, Ann-Kathrin; Schuster, Tibor; Raith, Stefan; Kitzler, Elena; Papadopulos, Nikolaos A; Machens, Hans-Günther; Kovacs, Laszlo

    2012-04-01

    This study develops an objective breast symmetry evaluation using 3-D surface imaging (Konica-Minolta V910(®) scanner) by superimposing the mirrored left breast over the right and objectively determining the mean 3-D contour difference between the 2 breast surfaces. 3 observers analyzed the evaluation protocol precision using 2 dummy models (n = 60), 10 test subjects (n = 300), clinically tested it on 30 patients (n = 900) and compared it to established 2-D measurements on 23 breast reconstructive patients using the BCCT.core software (n = 690). Mean 3-D evaluation precision, expressed as the coefficient of variation (VC), was 3.54 ± 0.18 for all human subjects without significant intra- and inter-observer differences (p > 0.05). The 3-D breast symmetry evaluation is observer independent, significantly more precise (p < 0.001) than the BCCT.core software (VC = 6.92 ± 0.88) and may play a part in an objective surgical outcome analysis after incorporation into clinical practice.

  12. Echocardiographic evaluation of aged male cross country skiers.

    PubMed

    Grimsmo, J; Grundvold, I; Maehlum, S; Arnesen, H

    2011-06-01

    The aim of this echocardiographic study was to evaluate the effects of long-term endurance training on cardiac structure and function in three different age groups of 48 healthy middle-aged and old former or still active male cross country skiers (23 in age group I: age 58.6 ± 2.2 years; 21 in age group II: age 74.9 ± 2.2 years; four in age group III: age 89.5 ± 1.9 years). The two oldest age groups were combined and compared with age group I. No significant differences in left atrial or ventricular dimensions between these two age groups were found. A high proportion of enlarged left atrial dimensions were found among all subjects with 80% exceeding the upper reference limit of 40 mm in diameter (LADs) and 94% exceeding the upper reference limit of 20 cm(2) in area (LAAs). Mean values for LADs (mm) and LAAs (cm(2) ) were: group I: 41.9 ± 4.7 and 24.7 ± 3.3; group II: 43.5 ± 4.8 and 25.2 ± 3.7; group III: 44.5 ± 4.7 and 25.8 ± 3.7. Left ventricular diastolic diameter exceeded the upper reference limits of >54 mm in 20 subjects among all. The groups had preserved systolic and age-related diastolic function.

  13. Evaluation of reproducibility and reliability of 3D soft tissue analysis using 3D stereophotogrammetry.

    PubMed

    Plooij, J M; Swennen, G R J; Rangel, F A; Maal, T J J; Schutyser, F A C; Bronkhorst, E M; Kuijpers-Jagtman, A M; Bergé, S J

    2009-03-01

    In 3D photographs the bony structures are neither available nor palpable, therefore, the bone-related landmarks, such as the soft tissue gonion, need to be redefined. The purpose of this study was to determine the reproducibility and reliability of 49 soft tissue landmarks, including newly defined 3D bone-related soft tissue landmarks with the use of 3D stereophotogrammetric images. Two observers carried out soft-tissue analysis on 3D photographs twice for 20 patients. A reference frame and 49 landmarks were identified on each 3D photograph. Paired Student's t-test was used to test the reproducibility and Pearson's correlation coefficient to determine the reliability of the landmark identification. Intra- and interobserver reproducibility of the landmarks were high. The study showed a high reliability coefficient for intraobserver (0.97 (0.90 - 0.99)) and interobserver reliability (0.94 (0.69 - 0.99)). Identification of the landmarks in the midline was more precise than identification of the paired landmarks. In conclusion, the redefinition of bone-related soft tissue 3D landmarks in combination with the 3D photograph reference system resulted in an accurate and reliable 3D photograph based soft tissue analysis. This shows that hard tissue data are not needed to perform accurate soft tissue analysis.

  14. Echocardiographic findings in a contemporary Afro-Caribbean Population referred for evaluation of unexplained syncope.

    PubMed

    Martin, T C; Bains, B K; Aslam, P A

    2008-09-01

    Echocardiographic findings were reviewed for 106 patients (mean age 41.3 +/- 23.0 years, range 3 to 90 years, 61% female) referred for evaluation of unexplained syncope. Abnormal echocardiographic findings were seen in 36/106 (34%) patients, of which 12/106 (11%) may have an abnormality that contributed to symptoms. Abnormal echocardiographic findings (64 vs 6%, p < 0.01) and those possibly causing syncope (22 vs 0%, p < 0.05) were significantly more likely in the oldest tercile of patients compared with the youngest. No patient less than 35 years old had a possibly diagnostic abnormality.

  15. 3D painting documentation: evaluation of conservation conditions with 3D imaging and ranging techniques

    NASA Astrophysics Data System (ADS)

    Abate, D.; Menna, F.; Remondino, F.; Gattari, M. G.

    2014-06-01

    The monitoring of paintings, both on canvas and wooden support, is a crucial issue for the preservation and conservation of this kind of artworks. Many environmental factors (e.g. humidity, temperature, illumination, etc.), as well as bad conservation practices (e.g. wrong restorations, inappropriate locations, etc.), can compromise the material conditions over time and deteriorate an artwork. The article presents an on-going project realized by a multidisciplinary team composed by the ENEA UTICT 3D GraphLab, the 3D Optical Metrology Unit of the Bruno Kessler Foundation and the Soprintendenza per i Beni Storico Artistici ed Etnoantropologici of Bologna (Italy). The goal of the project is the multi-temporal 3D documentation and monitoring of paintings - at the moment in bad conservation's situation - and the provision of some metrics to quantify the deformations and damages.

  16. Echocardiographic evaluation of external iliac artery Doppler waveform in patients with coronary artery disease.

    PubMed

    Styczynski, Grzegorz; Szmigielski, Cezary; Kaczynska, Anna; Kuch-Wocial, Agnieszka

    2014-04-01

    Visual interpretation of the Doppler waveform in the common femoral or distal external iliac artery (EIA) was reported to be useful in screening for proximal peripheral artery occlusive disease (PAOD) in patients with lower limb ischemia. Commonly patients with coronary artery disease (CAD) referred for echocardiography have coexistent arterial pathology. Therefore, we decided to study whether echocardiographic evaluation of the distal EIA flow can be useful for detection of PAOD in patients with CAD. We studied 150 consecutive patients (pts) with CAD referred for echocardiography. At the end of an echocardiographic examination, evaluation of the flow in the distal EIA with an echocardiographic probe was performed. The Doppler waveform was classified as normal-with early diastolic flow reversal or abnormal-without early diastolic flow reversal. Echocardiographic findings were compared in a blinded fashion with the results of the ankle brachial index measurements (ABI). Based on the ABI ≤ 0.9, peripheral artery disease was diagnosed in 54 pts (36%) and abnormal external iliac Doppler waveform was found in 27 pts (18%). Sensitivity of abnormal external iliac Doppler waveform in predicting PAOD was 48%, specificity 99%, positive predictive value (PPV) 96%, and negative predictive value 77%. Peripheral arterial occlusive disease is common in patients with CAD referred for echocardiographic study. Echocardiographic assessment of distal EIA Doppler waveform has low sensitivity, but high specificity and high PPV in the diagnosis of peripheral arterial occlusive disease.

  17. Subjective evaluation of a 3D videoconferencing system

    NASA Astrophysics Data System (ADS)

    Rizek, Hadi; Brunnström, Kjell; Wang, Kun; Andrén, Börje; Johanson, Mathias

    2014-03-01

    A shortcoming of traditional videoconferencing systems is that they present the user with a flat, two-dimensional image of the remote participants. Recent advances in autostereoscopic display technology now make it possible to develop video conferencing systems supporting true binocular depth perception. In this paper, we present a subjective evaluation of a prototype multiview autostereoscopic video conferencing system and suggest a number of possible improvements based on the results. Whereas methods for subjective evaluation of traditional 2D videoconferencing systems are well established, the introduction of 3D requires an extension of the test procedures to assess the quality of depth perception. For this purpose, two depth-based test tasks have been designed and experiments have been conducted with test subjects comparing the 3D system to a conventional 2D video conferencing system. The outcome of the experiments show that the perception of depth is significantly improved in the 3D system, but the overall quality of experience is higher in the 2D system.

  18. Prospective comparison of 3D FIESTA versus fat-suppressed 3D SPGR MRI in evaluating knee cartilage lesions.

    PubMed

    Li, X; Yu, C; Wu, H; Daniel, K; Hu, D; Xia, L; Pan, C; Xu, A; Hu, J; Wang, L; Peng, W; Li, F

    2009-10-01

    To prospectively compare the accuracy of three-dimensional fast imaging employing steady-state acquisition (3D FIESTA) sequences with that of fat-suppressed three-dimensional spoiled gradient-recalled (3D SPGR) in the diagnosis of knee articular cartilage lesions, using arthroscopy as the reference standard. Fifty-eight knees in 54 patients (age range 21-82 years; mean 36 years) were prospectively evaluated by using sagittal 3D FIESTA and sagittal fat-suppressed 3D SPGR sequences. Articular cartilage lesions were graded on MRI and during arthroscopy with a modified Noyes scoring system. Sensitivity, specificity, and accuracy were assessed. Interobserver agreement was determined with kappa statistics. The performance of 3D FIESTA sequences (sensitivity, specificity, and accuracy were 80, 94, and 92%, respectively, for reader 1 and 76, 94, and 90%, respectively, for reader 2) was similar to that of fat-suppressed 3D SPGR sequences (sensitivity, specificity, and accuracy were 82, 92, and 90%, respectively, for reader 1 and 82, 90, and 88%, respectively, for reader 2) in the detection of knee articular cartilage lesions. The interobserver agreement varied from fair to good to excellent (kappa values from 0.43-0.83). 3D FIESTA has good diagnostic performance, comparable with fat-suppressed 3D SPGR in evaluating knee cartilage lesions, and it can be incorporated into routine knee MRI protocols due to the short acquisition time.

  19. Evaluating lubricant performance by 3D profilometry of wear scars

    NASA Astrophysics Data System (ADS)

    Georgescu, C.; Deleanu, L.; Pirvu, C.

    2016-08-01

    Due to improvement in analysing surface texture and optical instruments for investigating the texture surface, the authors propose to evaluate the lubricant performance by analysing the change in several 3D parameters in comparison to an analysis on 2D profile. All the surface of the wear scar generated on the four ball machine is investigated and the conclusion is that from the tribological point of view, the 3D parameters reflect better the surface quality evolution after testing. Investigation was done on the wear scars generated on the three fixed balls, for five lubricants: a non-additivated transmission mineral oil (T90), two grades of rapeseed oil (coarse degummed and refined) and two grades of soybean oil (coarse and degummed).

  20. 3-d volumetric evaluation of human mandibular growth.

    PubMed

    Reynolds, Mathew; Reynolds, Michael; Adeeb, Samer; El-Bialy, Tarek

    2011-01-01

    Bone growth is a complex process that is controlled by a multitude of mechanisms that are not fully understood.Most of the current methods employed to measure the growth of bones focus on either studying cadaveric bones from different individuals of different ages, or successive two-dimensional (2D) radiographs. Both techniques have their known limitations. The purpose of this study was to explore a technique for quantifying the three dimensional (3D) growth of an adolescent human mandible over the period of one year utilizing cone beam computed tomography (CBCT) scans taken for regular orthodontic records. Three -dimensional virtual models were created from the CBCT data using mainstream medical imaging software. A comparison between computer-generated surface meshes of successive 3-D virtual models illustrates the magnitude of relative mandible growth. The results of this work are in agreement with previously reported data from human cadaveric studies and implantable marker studies. The presented method provides a new relatively simple basis (utilizing commercially available software) to visualize and evaluate individualized 3D (mandibular) growth in vivo.

  1. 3-D Volumetric Evaluation of Human Mandibular Growth

    PubMed Central

    Reynolds, Mathew; Reynolds, Michael; Adeeb, Samer; El-Bialy, Tarek

    2011-01-01

    Bone growth is a complex process that is controlled by a multitude of mechanisms that are not fully understood.Most of the current methods employed to measure the growth of bones focus on either studying cadaveric bones from different individuals of different ages, or successive two-dimensional (2D) radiographs. Both techniques have their known limitations. The purpose of this study was to explore a technique for quantifying the three dimensional (3D) growth of an adolescent human mandible over the period of one year utilizing cone beam computed tomography (CBCT) scans taken for regular orthodontic records. Three -dimensional virtual models were created from the CBCT data using mainstream medical imaging software. A comparison between computer-generated surface meshes of successive 3-D virtual models illustrates the magnitude of relative mandible growth. The results of this work are in agreement with previously reported data from human cadaveric studies and implantable marker studies. The presented method provides a new relatively simple basis (utilizing commercially available software) to visualize and evaluate individualized 3D (mandibular) growth in vivo. PMID:22046201

  2. Evaluation of the monocular depth cue in 3D displays.

    PubMed

    Kim, Sung-Kyu; Kim, Dong-Wook; Kwon, Yong Moo; Son, Jung-Young

    2008-12-22

    Binocular disparity and monocular depth information are the principal functions of ideal 3D displays. 3D display systems such as stereoscopic or multi-view, super multi-view (SMV), and multi-focus (MF) displays were considered for the testing of the satisfaction level with the monocular accommodation of three different depths of 3D object points. The numerical simulation and experimental results show that the MF 3D display gives a monocular depth cue. In addition, the experimental results of the monocular MF 3D display show clear monocular focus on four different depths. Therefore, we can apply the MF 3D display to monocular 3D displays.

  3. Evaluating stereoacuity with 3D shutter glasses technology.

    PubMed

    Wu, Huang; Jin, Han; Sun, Ying; Wang, Yang; Ge, Min; Chen, Yang; Chi, Yunfeng

    2016-04-26

    To determine the stereoacuity threshold with a 3D laptop equipped with 3D shutter glasses, and to evaluate the effect of different shape and size of test symbols and different type of disparities to stereoacuity. Thirty subjects with a visual acuity in each eye of at least 0 logMAR and a stereoacuity of at least 32 arcsec (as assessed in Fly Stereo Acuity Test) were recruited. Three target symbols-tumbling "E", tumbling "C", and "□"-were displayed, each with six different sizes representing a visual acuity ranging from 0.5 to 0 logMAR when tested at 4.1 m, and with both crossed and uncrossed disparities. Two test systems were designed - fixed distance of 4.1 m and one for variable distance. The former has disparities ranging from 10 to 1000 arcsec. Each subject completed 36 trials to investigate the effect of different symbol sizes and shapes, and disparity types on stereoacuity. In the variable distance system, each subject was tested 12 times for the same purposes, both proximally and distally (the point where the 3D effect just appears and where it just disappears respectively), and the mean value was calculated from the mean proximal and distal distances. No significant difference was found among the groups in the fixed distance test system (Kruskal-Wallis test; Chi-square = 29.844, P = 0.715). Similarly, no significant difference was found in the variable distance system (Kruskal-Wallis test; proximal: Chi-square = 5.687, P = 0.338; distal: Chi-square = 5.898, P = 0.316; mean: Chi-square = 6.152, P = 0.292). Evaluating stereoacuity using this measurement system was convenient and effective. Changes in target shape and size and disparity types had no significant effect on stereoacuity. It would be helpful to choose optimal targets according to different purposes using computer-assisted 3D measurements.

  4. Robotic 3D vision solder joint verification system evaluation

    SciTech Connect

    Trent, M.A.

    1992-02-01

    A comparative performance evaluation was conducted between a proprietary inspection system using intelligent 3D vision and manual visual inspection of solder joints. The purpose was to assess the compatibility and correlation of the automated system with current visual inspection criteria. The results indicated that the automated system was more accurate (> 90%) than visual inspection (60--70%) in locating and/or categorizing solder joint defects. In addition, the automated system can offer significant capabilities to characterize and monitor a soldering process by measuring physical attributes, such as solder joint volumes and wetting angles, which are not available through manual visual inspection. A more in-depth evaluation of this technology is recommended.

  5. Evaluation of vision training using 3D play game

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Ho; Kwon, Soon-Chul; Son, Kwang-Chul; Lee, Seung-Hyun

    2015-03-01

    The present study aimed to examine the effect of the vision training, which is a benefit of watching 3D video images (3D video shooting game in this study), focusing on its accommodative facility and vergence facility. Both facilities, which are the scales used to measure human visual performance, are very important factors for man in leading comfortable and easy life. This study was conducted on 30 participants in their 20s through 30s (19 males and 11 females at 24.53 ± 2.94 years), who can watch 3D video images and play 3D game. Their accommodative and vergence facility were measured before and after they watched 2D and 3D game. It turned out that their accommodative facility improved after they played both 2D and 3D games and more improved right after they played 3D game than 2D game. Likewise, their vergence facility was proved to improve after they played both 2D and 3D games and more improved soon after they played 3D game than 2D game. In addition, it was demonstrated that their accommodative facility improved to greater extent than their vergence facility. While studies have been so far conducted on the adverse effects of 3D contents, from the perspective of human factor, on the imbalance of visual accommodation and convergence, the present study is expected to broaden the applicable scope of 3D contents by utilizing the visual benefit of 3D contents for vision training.

  6. Dynamic quantitative echocardiographic evaluation of mitral regurgitation in the operating department.

    PubMed

    Gisbert, Alejandro; Soulière, Vicky; Denault, André Y; Bouchard, Denis; Couture, Pierre; Pellerin, Michel; Carrier, Michel; Levesque, Sylvie; Ducharme, Anique; Basmadjian, Arsène J

    2006-02-01

    Hemodynamic modifications induced by general anesthesia could lead to underestimation of mitral regurgitation (MR) severity in the operating department and potentially serious consequences. The intraoperative severity of MR was prospectively compared with the preoperative baseline evaluation using dynamic quantitative transesophageal echocardiography in 25 patients who were stable with MR 2/4 or greater undergoing coronary bypass, mitral valve operation, or both. Significant changes in the severity of MR using transesophageal echocardiographic criteria occurred after the induction of general anesthesia and with phenylephrine. Quantitative transesophageal echocardiographic evaluation of MR using effective orifice area and vena contracta, and the use of phenylephrine challenge, were useful to avoid underestimating MR severity in the operating department.

  7. ETeach3D: Designing a 3D Virtual Environment for Evaluating the Digital Competence of Preservice Teachers

    ERIC Educational Resources Information Center

    Esteve-Mon, Francesc M.; Cela-Ranilla, Jose María; Gisbert-Cervera, Mercè

    2016-01-01

    The acquisition of teacher digital competence is a key aspect in the initial training of teachers. However, most existing evaluation instruments do not provide sufficient evidence of this teaching competence. In this study, we describe the design and development process of a three-dimensional (3D) virtual environment for evaluating the teacher…

  8. ETeach3D: Designing a 3D Virtual Environment for Evaluating the Digital Competence of Preservice Teachers

    ERIC Educational Resources Information Center

    Esteve-Mon, Francesc M.; Cela-Ranilla, Jose María; Gisbert-Cervera, Mercè

    2016-01-01

    The acquisition of teacher digital competence is a key aspect in the initial training of teachers. However, most existing evaluation instruments do not provide sufficient evidence of this teaching competence. In this study, we describe the design and development process of a three-dimensional (3D) virtual environment for evaluating the teacher…

  9. Performance evaluation and clinical applications of 3D plenoptic cameras

    NASA Astrophysics Data System (ADS)

    Decker, Ryan; Shademan, Azad; Opfermann, Justin; Leonard, Simon; Kim, Peter C. W.; Krieger, Axel

    2015-06-01

    The observation and 3D quantification of arbitrary scenes using optical imaging systems is challenging, but increasingly necessary in many fields. This paper provides a technical basis for the application of plenoptic cameras in medical and medical robotics applications, and rigorously evaluates camera integration and performance in the clinical setting. It discusses plenoptic camera calibration and setup, assesses plenoptic imaging in a clinically relevant context, and in the context of other quantitative imaging technologies. We report the methods used for camera calibration, precision and accuracy results in an ideal and simulated surgical setting. Afterwards, we report performance during a surgical task. Test results showed the average precision of the plenoptic camera to be 0.90mm, increasing to 1.37mm for tissue across the calibrated FOV. The ideal accuracy was 1.14mm. The camera showed submillimeter error during a simulated surgical task.

  10. Evaluation of Kinect 3D Sensor for Healthcare Imaging.

    PubMed

    Pöhlmann, Stefanie T L; Harkness, Elaine F; Taylor, Christopher J; Astley, Susan M

    2016-01-01

    Microsoft Kinect is a three-dimensional (3D) sensor originally designed for gaming that has received growing interest as a cost-effective and safe device for healthcare imaging. Recent applications of Kinect in health monitoring, screening, rehabilitation, assistance systems, and intervention support are reviewed here. The suitability of available technologies for healthcare imaging applications is assessed. The performance of Kinect I, based on structured light technology, is compared with that of the more recent Kinect II, which uses time-of-flight measurement, under conditions relevant to healthcare applications. The accuracy, precision, and resolution of 3D images generated with Kinect I and Kinect II are evaluated using flat cardboard models representing different skin colors (pale, medium, and dark) at distances ranging from 0.5 to 1.2 m and measurement angles of up to 75°. Both sensors demonstrated high accuracy (majority of measurements <2 mm) and precision (mean point to plane error <2 mm) at an average resolution of at least 390 points per cm(2). Kinect I is capable of imaging at shorter measurement distances, but Kinect II enables structures angled at over 60° to be evaluated. Kinect II showed significantly higher precision and Kinect I showed significantly higher resolution (both p < 0.001). The choice of object color can influence measurement range and precision. Although Kinect is not a medical imaging device, both sensor generations show performance adequate for a range of healthcare imaging applications. Kinect I is more appropriate for short-range imaging and Kinect II is more appropriate for imaging highly curved surfaces such as the face or breast.

  11. Feasibility of 3D ultrasound to evaluate upper extremity nerves.

    PubMed

    Girtler, M-T; Krasinski, A; Dejaco, C; Kitzler, H H; Cui, L G; Sherebrin, S; Gardi, L; Chhem, R K; Fenster, A; Romagnoli, C; De Zordo, T

    2013-08-01

    This study investigates the performance of a 3 D Ultrasound (US) system in imaging elbow and wrist nerves. Twenty healthy volunteers with asymptomatic median, ulnar and radial nerves were prospectively investigated. Bilateral 3DUS scans of the elbows and wrists were acquired by using a commercially available US scanner (18 MHz, AplioXG, Toshiba) and stored as a 3 D volume by a dedicated software (CURE, Robarts Research Institute). Retrospectively, qualitative (image quality, atypical nerve location, findings potentially associated with compression neuropathy) and quantitative (cross-sectional area measurements) evaluations were performed. In all 200 nerves 3DUS was feasible (100%). Image quality was insufficient in 13.5% (25 ulnar nerve elbow, 2 radial nerve) and sonomorphology was not assessable in those nerves. Measurement of cross sectional areas was feasible in all nerves (100%). Median cross-sectional area (range) were: median nerve elbow 7 mm2 (6-9), radial nerve 3 mm2 (1-4), ulnar nerve elbow 8 mm2 (5-11), median nerve wrist 8 mm2 (5-10), and ulnar nerve wrist 4 mm2 (2-6). No significant changes in nerve cross-sectional area along each nerve was found. Ulnar nerve subluxation was found in 2 nerves (6.7%). No anconeus epitrochlearis muscle or osteophytes were found. 3DUS is a feasible method for assessing nerves of the upper extremity and has been shown to provide a good overview of the median, ulnar and radial nerve at the elbow and wrist, but is limited for evaluation of the ulnar nerve in the cubital tunnel. This technique enables reliable measurements at different locations along the nerve. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Image performance evaluation of a 3D surgical imaging platform

    NASA Astrophysics Data System (ADS)

    Petrov, Ivailo E.; Nikolov, Hristo N.; Holdsworth, David W.; Drangova, Maria

    2011-03-01

    The O-arm (Medtronic Inc.) is a multi-dimensional surgical imaging platform. The purpose of this study was to perform a quantitative evaluation of the imaging performance of the O-arm in an effort to understand its potential for future nonorthopedic applications. Performance of the reconstructed 3D images was evaluated, using a custom-built phantom, in terms of resolution, linearity, uniformity and geometrical accuracy. Both the standard (SD, 13 s) and high definition (HD, 26 s) modes were evaluated, with the imaging parameters set to image the head (120 kVp, 100 mAs and 150 mAs, respectively). For quantitative noise characterization, the images were converted to Hounsfield units (HU) off-line. Measurement of the modulation transfer function revealed a limiting resolution (at 10% level) of 1.0 mm-1 in the axial dimension. Image noise varied between 15 and 19 HU for the HD and SD modes, respectively. Image intensities varied linearly over the measured range, up to 1300 HU. Geometric accuracy was maintained in all three dimensions over the field of view. The present study has evaluated the performance characteristics of the O-arm, and demonstrates feasibility for use in interventional applications and quantitative imaging tasks outside those currently targeted by the manufacturer. Further improvements to the reconstruction algorithms may further enhance performance for lower-contrast applications.

  13. Echocardiographic evaluation of ventricular function in children with pulmonary hypertension.

    PubMed

    Vorhies, Erika E; Gajarski, Robert J; Yu, Sunkyung; Donohue, Janet E; Fifer, Carlen G

    2014-06-01

    Although described in adults, it remains unclear whether ventricular dysfunction exists in pediatric patients with pulmonary hypertension (PHN). The goal of this study was to identify differences in echocardiographic indices of ventricular function among pediatric PHN patients. From 2009 to 2011, pediatric PHN patients with normal intracardiac anatomy and age-matched controls (1:3 ratio) were enrolled in this retrospective case-control study. Diagnosis of PHN was based on tricuspid regurgitation velocity or septal position estimating right-ventricular (RV) pressure >50 % systemic. Measures of RV and left ventricular systolic and diastolic function, including tissue Doppler imaging (TDI) of the mitral annulus (MA) and tricuspid annulus (TA), were compared. Enrollees included 25 PHN patients and 75 age-matched controls (mean age 7.5 years [range 1 day to 19 years]). Parameters of RV systolic and diastolic function were worse in PHN patients. Compared with controls, PHN patients had significantly decreased tricuspid valve inflow ratio, decreased TA TDI early diastolic velocities, decreased systolic velocities, increased tricuspid E/E' ratio (all p < 0.01) and increased myocardial performance index. In an age-stratified analysis, TDI measures in PHN patients <1 year of age were similar to controls, whereas differences in TA TDI velocities and MA TDI velocities were noted in patients ≥1 year of age. Abnormalities in Doppler echocardiographic indices of ventricular systolic and diastolic function were identified in pediatric PHN patients and were more prominent with older age. These indices are promising for serial noninvasive monitoring of disease severity, but further correlation with catheterization-derived measures is needed.

  14. [Longitudinal echocardiographic evaluation in children with thalassemia major].

    PubMed

    Balducci, G; Barbanente, C; Di Lecce, A; Schettini, F

    1984-01-01

    We report the results of a longitudinal echocardiographic survey on 15 children with thalassemia major, who had received multiple transfusions. The average interval between the two examinations was 2.9 +/- 0.7 years. At the second examination the mean hemoglobin (Hb) level for the group was higher because of the increased number of transfusions. During the same period of time the chelating treatment with desferrioxamine was administered subcutaneously instead of intramuscularly. The following echocardiographic parameters have been measured: left ventricular dimension, diastolic (LVDd); left ventricular dimension, systolic (LVDs); septal thickness, diastolic (STd); free wall, diastolic (FWd); left atrial dimension (LAD); aortic root (AoR); fractional shortening (FA); velocity of circumferential shortening (VCF). At the first examination 6 patients had abnormal values of LVDd, STd and AoR; 10 subjects had increased LAD; the mean Hb levels of the patients with abnormal STd and LAD was significantly lower than in normals (p less than 0.05 and less than 0.01 respectively). At the second examination 8 patients had abnormal LVDd values and 7 had increased LAD. Only the patients with increased LVDd had lower Hb values. Patients with increased LAD had received more transfusions. The following functional parameters were found to be decreased at the second study: FA (29 +/- 3.3 vs 32.6 +/- 7; p less than 0.05); VCF (1.16 +/- 0.25 vs 0.99 +/- 0.14; p less than 0.05). From the results it appears that the change of treatment improved some parameters (STd, AoR, LAD), but was unable to arrest the deterioration of the LV contractile efficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. [Evaluation of Motion Sickness Induced by 3D Video Clips].

    PubMed

    Matsuura, Yasuyuki; Takada, Hiroki

    2016-01-01

    The use of stereoscopic images has been spreading rapidly. Nowadays, stereoscopic movies are nothing new to people. Stereoscopic systems date back to 280 A.D. when Euclid first recognized the concept of depth perception by humans. Despite the increase in the production of three-dimensional (3D) display products and many studies on stereoscopic vision, the effect of stereoscopic vision on the human body has been insufficiently understood. However, symptoms such as eye fatigue and 3D sickness have been the concerns when viewing 3D films for a prolonged period of time; therefore, it is important to consider the safety of viewing virtual 3D contents as a contribution to society. It is generally explained to the public that accommodation and convergence are mismatched during stereoscopic vision and that this is the main reason for the visual fatigue and visually induced motion sickness (VIMS) during 3D viewing. We have devised a method to simultaneously measure lens accommodation and convergence. We used this simultaneous measurement device to characterize 3D vision. Fixation distance was compared between accommodation and convergence during the viewing of 3D films with repeated measurements. Time courses of these fixation distances and their distributions were compared in subjects who viewed 2D and 3D video clips. The results indicated that after 90 s of continuously viewing 3D images, the accommodative power does not correspond to the distance of convergence. In this paper, remarks on methods to measure the severity of motion sickness induced by viewing 3D films are also given. From the epidemiological viewpoint, it is useful to obtain novel knowledge for reduction and/or prevention of VIMS. We should accumulate empirical data on motion sickness, which may contribute to the development of relevant fields in science and technology.

  16. Accuracy evaluation of 3D lidar data from small UAV

    NASA Astrophysics Data System (ADS)

    Tulldahl, H. M.; Bissmarck, Fredrik; Larsson, Hâkan; Grönwall, Christina; Tolt, Gustav

    2015-10-01

    A UAV (Unmanned Aerial Vehicle) with an integrated lidar can be an efficient system for collection of high-resolution and accurate three-dimensional (3D) data. In this paper we evaluate the accuracy of a system consisting of a lidar sensor on a small UAV. High geometric accuracy in the produced point cloud is a fundamental qualification for detection and recognition of objects in a single-flight dataset as well as for change detection using two or several data collections over the same scene. Our work presented here has two purposes: first to relate the point cloud accuracy to data processing parameters and second, to examine the influence on accuracy from the UAV platform parameters. In our work, the accuracy is numerically quantified as local surface smoothness on planar surfaces, and as distance and relative height accuracy using data from a terrestrial laser scanner as reference. The UAV lidar system used is the Velodyne HDL-32E lidar on a multirotor UAV with a total weight of 7 kg. For processing of data into a geographically referenced point cloud, positioning and orientation of the lidar sensor is based on inertial navigation system (INS) data combined with lidar data. The combination of INS and lidar data is achieved in a dynamic calibration process that minimizes the navigation errors in six degrees of freedom, namely the errors of the absolute position (x, y, z) and the orientation (pitch, roll, yaw) measured by GPS/INS. Our results show that low-cost and light-weight MEMS based (microelectromechanical systems) INS equipment with a dynamic calibration process can obtain significantly improved accuracy compared to processing based solely on INS data.

  17. 3dRNAscore: a distance and torsion angle dependent evaluation function of 3D RNA structures

    PubMed Central

    Wang, Jian; Zhao, Yunjie; Zhu, Chunyan; Xiao, Yi

    2015-01-01

    Model evaluation is a necessary step for better prediction and design of 3D RNA structures. For proteins, this has been widely studied and the knowledge-based statistical potential has been proved to be one of effective ways to solve this problem. Currently, a few knowledge-based statistical potentials have also been proposed to evaluate predicted models of RNA tertiary structures. The benchmark tests showed that they can identify the native structures effectively but further improvements are needed to identify near-native structures and those with non-canonical base pairs. Here, we present a novel knowledge-based potential, 3dRNAscore, which combines distance-dependent and dihedral-dependent energies. The benchmarks on different testing datasets all show that 3dRNAscore are more efficient than existing evaluation methods in recognizing native state from a pool of near-native states of RNAs as well as in ranking near-native states of RNA models. PMID:25712091

  18. Evaluation of 3D Printer Accuracy in Producing Fractal Structure.

    PubMed

    Kikegawa, Kana; Takamatsu, Kyuuichirou; Kawakami, Masaru; Furukawa, Hidemitsu; Mayama, Hiroyuki; Nonomura, Yoshimune

    2017-01-01

    Hierarchical structures, also known as fractal structures, exhibit advantageous material properties, such as water- and oil-repellency as well as other useful optical characteristics, owing to its self-similarity. Various methods have been developed for producing hierarchical geometrical structures. Recently, fractal structures have been manufactured using a 3D printing technique that involves computer-aided design data. In this study, we confirmed the accuracy of geometrical structures when Koch curve-like fractal structures with zero to three generations were printed using a 3D printer. The fractal dimension was analyzed using a box-counting method. This analysis indicated that the fractal dimension of the third generation hierarchical structure was approximately the same as that of the ideal Koch curve. These findings demonstrate that the design and production of fractal structures can be controlled using a 3D printer. Although the interior angle deviated from the ideal value, the side length could be precisely controlled.

  19. Echocardiographic evaluation of left ventricular diastolic function in cats: Hemodynamic determinants and pattern recognition.

    PubMed

    Schober, Karsten E; Chetboul, Valérie

    2015-12-01

    Left ventricular (LV) diastolic dysfunction is highly prevalent in cats and is a functional hallmark of feline cardiomyopathy. The majority of cats with hypertrophic, restrictive, and dilated cardiomyopathy have echocardiographic evidence of abnormal LV filling, even during the occult (preclinical) phase. Moderate and severe diastolic dysfunction is an indicator of advanced myocardial disease, is associated with clinical signs including exercise intolerance and congestive heart failure, affects outcome, and influences therapeutic decisions. Therefore, identification and quantification of LV diastolic dysfunction are clinically important. Surrogate measures of diastolic function determined by transthoracic two-dimensional, M-mode, and Doppler echocardiographic (DE) methods have been used widely for such purpose. Major functional characteristics of LV diastole, including global function, relaxation and untwist, chamber compliance, filling volume, and the resultant filling pressures can be semi-quantified by echocardiographic methods, and variables retrieved from transmitral flow, pulmonary vein flow, and tissue Doppler recordings are most frequently used. Although there is still a critical lack of well-designed studies in the field, knowledge has steadily accumulated over the past 20 years, reference ranges of diastolic echocardiographic variables have been determined, epidemiological studies have been conducted, and new treatments of diastolic dysfunction in cats have been evaluated. This report will give the reader a summary of the current status in the field of feline diastology with focus on the noninvasive diagnostic methods and interpretation of echocardiographic surrogate measures of LV diastolic function. Lastly, a grading system using a composite of left atrial size and various DE variables potentially useful in the functional classification of LV diastole in cats is introduced.

  20. Visual fatigue evaluation based on depth in 3D videos

    NASA Astrophysics Data System (ADS)

    Wang, Feng-jiao; Sang, Xin-zhu; Liu, Yangdong; Shi, Guo-zhong; Xu, Da-xiong

    2013-08-01

    In recent years, 3D technology has become an emerging industry. However, visual fatigue always impedes the development of 3D technology. In this paper we propose some factors affecting human perception of depth as new quality metrics. These factors are from three aspects of 3D video--spatial characteristics, temporal characteristics and scene movement characteristics. They play important roles for the viewer's visual perception. If there are many objects with a certain velocity and the scene changes fast, viewers will feel uncomfortable. In this paper, we propose a new algorithm to calculate the weight values of these factors and analyses their effect on visual fatigue.MSE (Mean Square Error) of different blocks is taken into consideration from the frame and inter-frame for 3D stereoscopic videos. The depth frame is divided into a number of blocks. There are overlapped and sharing pixels (at half of the block) in the horizontal and vertical direction. Ignoring edge information of objects in the image can be avoided. Then the distribution of all these data is indicated by kurtosis with regard of regions which human eye may mainly gaze at. Weight values can be gotten by the normalized kurtosis. When the method is used for individual depth, spatial variation can be achieved. When we use it in different frames between current and previous one, we can get temporal variation and scene movement variation. Three factors above are linearly combined, so we can get objective assessment value of 3D videos directly. The coefficients of three factors can be estimated based on the liner regression. At last, the experimental results show that the proposed method exhibits high correlation with subjective quality assessment results.

  1. 3D Evaluation of Palatal Rugae in Identical Twins

    PubMed Central

    2017-01-01

    The study of identical twins can point out potential limitations in biometrics and forensic odontology. This case report presents three-dimensional (3D) palatal rugae analysis in monozygotic twins utilizing digital models obtained directly by scanning the maxillary dental arch with the iTero® intraoral digital scanner. The results show that the rugae patterns contain related but not identical features between the pair of identical twins. Dental study models taken on a regular basis for diagnosis and treatment planning in dentistry include the palatal rugae, which could be valuable to forensics in identical twin identification cases. PMID:28611927

  2. 3D Evaluation of Palatal Rugae in Identical Twins.

    PubMed

    Taneva, Emiliya; Evans, Carla; Viana, Grace

    2017-01-01

    The study of identical twins can point out potential limitations in biometrics and forensic odontology. This case report presents three-dimensional (3D) palatal rugae analysis in monozygotic twins utilizing digital models obtained directly by scanning the maxillary dental arch with the iTero® intraoral digital scanner. The results show that the rugae patterns contain related but not identical features between the pair of identical twins. Dental study models taken on a regular basis for diagnosis and treatment planning in dentistry include the palatal rugae, which could be valuable to forensics in identical twin identification cases.

  3. Does the routine echocardiographic exam have a role in the detection and evaluation of cholelithiasis and gallbladder wall thickening?

    PubMed

    Daly, David D; El-Shurafa, Haytham; Nanda, Navin C; Dumaswala, Bhavin; Dumaswala, Komal; Kumar, Nilay; Mutluer, Ferit Onur

    2012-09-01

    Cholelithiasis is a very common disease in the United States. Most cases remain asymptomatic but a fraction of these patients can develop serious complications such as cholecystitis which may lead to gallbladder perforation and gallbladder cancer which is much less common. Here, we present three cases of cholelithiasis where transthoracic echocardiography was performed routinely. In each case, echocardiography detected cholelithiasis which prompted three-dimensional (3D) echocardiographic evaluation. Three-dimensional echocardiography allowed for more comprehensive examination of the gallbladder shape, size, and wall thickening and the measurement and composition of the stones in three dimensions, measurement of stone volumes, and minimized shadowing produced by stone calcifications. These cases suggest that routine echocardiography has value in detecting gallstones and that 3D echocardiography has incremental value over two-dimensional echocardiography due to pyramidal data sets which allow sequential slicing through the gallbladder and full gallbladder examination without a technologist who is trained in gallbladder imaging. These pyramidal data sets can be further viewed and cropped by a radiologist specialized in abdominal ultrasound. © 2012, Wiley Periodicals, Inc.

  4. Fisheye Lenses for 3d Modeling: Evaluations and Considerations

    NASA Astrophysics Data System (ADS)

    Barazzetti, L.; Previtali, M.; Roncoroni, F.

    2017-02-01

    Fisheye lenses are becoming more popular in complete image-based modelling projects of small and narrow spaces. The growing interest in fisheye lenses is confirmed by the availability of different commercial software incorporating a fisheye camera model. Such software are now able to carry out the steps of the image processing pipeline in a fully automated way, from camera calibration and orientation to dense matching, surface generation, and orthophoto production. This paper highlights the advantages (and disadvantages) of fisheye lenses when used for 3D modelling projects through different commercial software. The goal is not only a comparison of commercial software, but also an analysis of the additional issues that arise when a fisheye lens is used for 3D modelling. Results confirm that a fisheye lens is suitable for accurate metric documentation, especially when limited space is available. On the other hand, additional issues where found during the camera calibration/image orientation step as well as the texture generation and orthophoto production phases, for which particular attention is required.

  5. Evaluation of 3-D graphics software: A case study

    NASA Technical Reports Server (NTRS)

    Lores, M. E.; Chasen, S. H.; Garner, J. M.

    1984-01-01

    An efficient 3-D geometry graphics software package which is suitable for advanced design studies was developed. The advanced design system is called GRADE--Graphics for Advanced Design. Efficiency and ease of use are gained by sacrificing flexibility in surface representation. The immediate options were either to continue development of GRADE or to acquire a commercially available system which would replace or complement GRADE. Test cases which would reveal the ability of each system to satisfy the requirements were developed. A scoring method which adequately captured the relative capabilities of the three systems was presented. While more complex multi-attribute decision methods could be used, the selected method provides all the needed information without being so complex that it is difficult to understand. If the value factors are modestly perturbed, system Z is a clear winner based on its overall capabilities. System Z is superior in two vital areas: surfacing and ease of interface with application programs.

  6. Computerized geometric evaluation of angio- and echocardiographic images.

    PubMed

    Onnasch, D G

    1985-08-01

    Since the first comprehensive computerized videometric systems for quantitative assessment of the dynamic morphology and function of the heart have been developed, angiocardiographic image generation and computer aided evaluation have improved considerably. As a second method for morphological imaging echocardiography is also established in cardiology, so that videometry branched off into angio- and echocardiometry. In this paper, the common aspects of both methods are discussed concerning manual outlining and computerized contour representation, additional storage of anatomical landmarks labelled by digits and letters, and list-directed automated evaluation of data. It allows standard graphical documentations including comparisons of global volumetric and functional results for individual patients as well as versatile research orientated evaluations of oblique semi-axes, sectorial areas, wall thicknesses, shape parameters, spatial orientation and derived global and regional functional parameters for patient groups. As an example wall thickness measured from echographic long and short axis views and from angiographic projections are compared.

  7. Doppler echocardiographic parameters of evaluation of left ventricular systolic function.

    PubMed

    Drăgulescu, S I; Roşu, D; Abazid, J; Ionac, A

    1993-01-01

    The authors suggest a new method using Doppler echocardiography for the evaluation of cardiac performance. Doppler echocardiography permits the calculation of left ventricular (LV) ejection force (according to Newton's second law of motion). The ejection force was calculated in 36 patients with heart failure subgrouped into 3 groups based on ejection fraction (EF) (> 60%; 41-60%; < 40%) compared to 11 normal subjects. The LV ejection force showed a good linear correlation with LV ejection fraction (r = 0.86). Data of the study suggest that the LV ejection force is a valuable and accurate index for the assessment of cardiac performance, especially in early stages of disease.

  8. Echocardiographic evaluation of clinically healthy Florida manatees (Trichechus manatus latirostris).

    PubMed

    Gerlach, Trevor J; Estrada, Amara H; Sosa, Ivan S; Powell, Melanie; Maisenbacher, Herbert W; de Wit, Martine; Ball, Ray L; Walsh, Michael T

    2013-06-01

    Antemortem studies pertaining to the manatee cardiovascular and cardiopulmonary systems are limited despite reports of cardiac disease in postmortem specimens. The objective of this project was to develop a technique for echocardiography in the Florida manatee (Trichechus manatus latirostris). Because of their unique anatomy, a ventral approach was employed by use of an echocardiography table designed specifically for this study. Fourteen clinically healthy, free-ranging and captive Florida manatees underwent echocardiography between the fall of 2011 and winter of 2012. Eight females and six males of various age categories were included in the study. Clear visualization of all valves and chambers was accomplished, and length and width measurements of the left atrium, peak aortic flow velocity, and ejection fraction percentage were calculated in most animals. Abnormalities observed during the study included atrioventricular regurgitation and severe right-atrial enlargement. Based on the results of this study, echocardiography in the Florida manatee is possible, which has both clinical and research implications in larger epidemiologic studies evaluating diseases of the cardiopulmonary and cardiovascular systems.

  9. Cardiac performance in cats after administration of xylazine or xylazine and glycopyrrolate: echocardiographic evaluations.

    PubMed

    Dunkle, N; Moise, N S; Scarlett-Kranz, J; Short, C E

    1986-10-01

    Cardiac performance was evaluated in 9 healthy cats sedated with xylazine. Each cat was evaluated echocardiographically before and after the administration of xylazine or xylazine and glycopyrrolate. Each cat was echocardiographically evaluated during manual restraint only (control value), after IM administration of 0.55 mg of xylazine/kg of body weight, after IM administration of 2.2 mg of xylazine/kg, and after IM administration of 0.011 mg of glycopyrrolate/kg followed 10 minutes later by IM administration of 2.2 mg of xylazine/kg. Echocardiographic indices of cardiac performance (fractional shortening, left ventricular wall amplitude, aortic amplitude, mitral valve E point septal separation) indicated a significant decrease (P less than 0.05) in the left ventricular function and heart rate after the small (0.55 mg/kg) and large (2.2 mg/kg) dosages of xylazine. With the administration of glycopyrrolate, the bradycardia was minimized, but cardiac performance was not improved. After administration of glycopyrrolate, cardiac performance decreased, but the decrease was not significant when compared with the ventricular performance of the cats after administration of the large dosage of xylazine. Compared with control values, the reduction in left ventricular function values associated with administration of xylazine or xylazine and glycopyrrolate was independent of the heart rate. Therefore, the alpha-2 adrenergic agonist xylazine has a marked depressive effect on cardiac performance in the cat, and premedication with glycopyrrolate may not completely alleviate the undesirable bradycardia, but may actually be detrimental to the cardiovascular system.

  10. Evaluation of field development plans using 3-D reservoir modelling

    SciTech Connect

    Seifert, D.; Lewis, J.J.M.; Newbery, J.D.H.

    1997-08-01

    Three-dimensional reservoir modelling has become an accepted tool in reservoir description and is used for various purposes, such as reservoir performance prediction or integration and visualisation of data. In this case study, a small Northern North Sea turbiditic reservoir was to be developed with a line drive strategy utilising a series of horizontal producer and injector pairs, oriented north-south. This development plan was to be evaluated and the expected outcome of the wells was to be assessed and risked. Detailed analyses of core, well log and analogue data has led to the development of two geological {open_quotes}end member{close_quotes} scenarios. Both scenarios have been stochastically modelled using the Sequential Indicator Simulation method. The resulting equiprobable realisations have been subjected to detailed statistical well placement optimisation techniques. Based upon bivariate statistical evaluation of more than 1000 numerical well trajectories for each of the two scenarios, it was found that the wells inclinations and lengths had a great impact on the wells success, whereas the azimuth was found to have only a minor impact. After integration of the above results, the actual well paths were redesigned to meet external drilling constraints, resulting in substantial reductions in drilling time and costs.

  11. Echocardiographic evaluation of female centrifuge subjects for chronic changes in cardiac function.

    PubMed

    Albery, W B

    1999-06-01

    High sustained G exposure as experienced in flying high performance aircraft can affect cardiac function. Numerous studies, mostly on male pilots, have evaluated the chronic effects of exposure to high G. To date, none of these studies has revealed significant positive findings in cardiac function as a result of long-term high G exposure. A longitudinal study was conducted on six female centrifuge panel members who did not have a history of significant high +Gz exposure. Baseline echocardiographic studies were conducted prior to any +Gz exposure on the Dynamic Environment Simulator (DES) centrifuge. The echocardiograms were repeated after each panel member completed approximately 100 3-min high G (up to 9 G) exposures over the period of 7 mo. These follow-up echos were performed after all six subjects had been exposed to at least 6 h (cumulative) of sustained acceleration > 3 G. The women were protected with the COMBAT EDGE positive pressure breathing G protection ensemble. Each subject served as her own control. All studies were evaluated independently by a cardiologist who was blinded to the order in which the echos were performed. Although complete echocardiographic studies were performed, only the parameters identified as significant in prior studies were evaluated. No significant differences were found between the initial and follow-up echo parameters. We found no significant differences in cardiac function after at least 6 and up to 17 h (cumulative) of exposure to G > 3 in women. These subjects will be monitored during a longitudinal study throughout their centrifuge subject career.

  12. Evaluation of stereoscopic 3D displays for image analysis tasks

    NASA Astrophysics Data System (ADS)

    Peinsipp-Byma, E.; Rehfeld, N.; Eck, R.

    2009-02-01

    In many application domains the analysis of aerial or satellite images plays an important role. The use of stereoscopic display technologies can enhance the image analyst's ability to detect or to identify certain objects of interest, which results in a higher performance. Changing image acquisition from analog to digital techniques entailed the change of stereoscopic visualisation techniques. Recently different kinds of digital stereoscopic display techniques with affordable prices have appeared on the market. At Fraunhofer IITB usability tests were carried out to find out (1) with which kind of these commercially available stereoscopic display techniques image analysts achieve the best performance and (2) which of these techniques achieve a high acceptance. First, image analysts were interviewed to define typical image analysis tasks which were expected to be solved with a higher performance using stereoscopic display techniques. Next, observer experiments were carried out whereby image analysts had to solve defined tasks with different visualization techniques. Based on the experimental results (performance parameters and qualitative subjective evaluations of the used display techniques) two of the examined stereoscopic display technologies were found to be very good and appropriate.

  13. Evaluation of right ventricular function performed by 3D-echocardiography in scleroderma patients.

    PubMed

    Pigatto, E; Peluso, D; Zanatta, E; Polito, P; Miatton, P; Bourji, K; Badano, L P; Punzi, L; Cozzi, F

    2015-03-31

    The impairment of the right ventricle (RV) in systemic sclerosis (SSc) is usually related to pulmonary arterial hypertension (PAH). New echocardiographic techniques, such as 3-dimensional echocardiography (3DE) and 2-dimensional speckle tracking (2DSTE), allow an accurate evaluation of the RV function. The aim of this study was to evaluate the RV function using 3DE and 2DSTE in SSc patients with no history of heart disease and no PAH. Forty-five SSc patients, 42 females and 3 males, 28 with limited cutaneous SSc (lcSSc) and 17 with diffuse cutaneous SSc (dcSSc), were studied. Forty-three age- and gender-matched healthy subjects were enrolled as controls. All of them underwent a 3DE and 2DSTE ecocardiographic evaluation of the RV function. Systolic pulmonary arterial pressure (sPAP) and total pulmonary vascular resistance (tPVR) were also estimated by power doppler. RV echocardiographic parameters were compared in the different subsets of SSc patients. A statistical analysis was performed by t-test, ANOVA and multiple logistic regression. RV areas in 2DSTE and volumes in 3DE were higher and RV function parameters were reduced in SSc patients compared with controls. Also sPAP and tVPR were higher, but they did not reach pathological values. Echocardiographic alterations were more pronounced in patients with lcSSc. 3DE and 2DSTE echocardiography allowed us to detect morphological and functional alterations of the RV in a group of SSc patients with no clinical signs of heart disease and no PAH. These patients had significantly higher sPAP and tPVR than healthy controls without reporting values compatible with PAH. These data suggest that RV alterations are related to a pressure overload rather than to an intrinsic myocardial involvement in SSc.

  14. Evaluation of the Radiation Susceptibility of a 3D NAND Flash Memory

    NASA Technical Reports Server (NTRS)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Seidleck, Christina; Kim, Hak; Phan, Anthony; LaBel, Kenneth

    2017-01-01

    We evaluated the heavy ion and proton-induced single-event effects (SEE) for a 3D NAND flash. The 3D NAND showed similar single-event upset (SEU) sensitivity to a planar NAND of similar density and performance in the multiple-cell level (MLC) storage mode. However, the single-level-cell (SLC) storage mode of the 3D NAND showed significantly reduced SEU susceptibility. Additionally, the 3D NAND showed less MBU susceptibility than the planar NAND, with reduced number of upset bits per byte and reduced cross sections overall. However, the 3D architecture exhibited angular sensitivities for both base and face angles, reflecting the anisotropic nature of the SEU vulnerability in space. Furthermore, the SEU cross section decreased with increasing fluence for both the 3D NAND and the latest generation planar NAND, indicating a variable upset rate for a space mission. These unique characteristics introduce complexity to traditional ground irradiation test procedures.

  15. Comparison of post-contrast 3D-T1-MPRAGE, 3D-T1-SPACE and 3D-T2-FLAIR MR images in evaluation of meningeal abnormalities at 3-T MRI.

    PubMed

    Jeevanandham, Balaji; Kalyanpur, Tejas; Gupta, Prashant; Cherian, Mathew

    2017-06-01

    This study was to assess the usefulness of newer three-dimensional (3D)-T1 sampling perfection with application optimized contrast using different flip-angle evolutions (SPACE) and 3D-T2 fluid-attenuated inversion recovery (FLAIR) sequences in evaluation of meningeal abnormalities. 78 patients who presented with high suspicion of meningeal abnormalities were evaluated using post-contrast 3D-T2-FLAIR, 3D-T1 magnetization-prepared rapid gradient-echo (MPRAGE) and 3D-T1-SPACE sequences. The images were evaluated independently by two radiologists for cortical gyral, sulcal space, basal cisterns and dural enhancement. The diagnoses were confirmed by further investigations including histopathology. Post-contrast 3D-T1-SPACE and 3D-T2-FLAIR images yielded significantly more information than MPRAGE images (p < 0.05 for both SPACE and FLAIR images) in detection of meningeal abnormalities. SPACE images best demonstrated abnormalities in dural and sulcal spaces, whereas FLAIR was useful for basal cisterns enhancement. Both SPACE and FLAIR performed equally well in detection of gyral enhancement. In all 10 patients, where both SPACE and T2-FLAIR images failed to demonstrate any abnormality, further analysis was also negative. The 3D-T1-SPACE sequence best demonstrated abnormalities in dural and sulcal spaces, whereas FLAIR was useful for abnormalities in basal cisterns. Both SPACE and FLAIR performed holds good for detection of gyral enhancement. Post-contrast SPACE and FLAIR sequences are superior to the MPRAGE sequence for evaluation of meningeal abnormalities and when used in combination have the maximum sensitivity for leptomeningeal abnormalities. The negative-predictive value is nearly 100%, where no leptomeningeal abnormality was detected on these sequences. Advances in knowledge: Post-contrast 3D-T1-SPACE and 3D-T2-FLAIR images are more useful than 3D-T1-MPRAGE images in evaluation of meningeal abnormalities.

  16. [Echocardiographic evaluation of the athlete's heart: from morphological adaptations to myocardial function].

    PubMed

    D'Andrea, Antonello; Galderisi, Maurizio; Sciomer, Susanna; Nistri, Stefano; Agricola, Eustachio; Ballo, Piercarlo; Buralli, Simona; D'Errico, Arcangelo; Losi, Maria Angela; Mele, Donato; Mondillo, Sergio

    2009-08-01

    The definition of the athlete's heart includes the mechanisms of cardiac adaptation to training, characterized by the increase of internal chamber dimensions, ventricular wall thickness, and atrial chambers. The morphology of the athlete's heart is intermediate between concentric and eccentric left ventricular hypertrophy (LVH), in relation to the large prevalence of mixed sports activities and training protocols (including both aerobic and anaerobic exercise). Echocardiography is the tool of choice for the assessment of the athlete's heart and also for the differentiation of physiologic and pathologic LVH (hypertrophic cardiomyopathy and LVH due to arterial hypertension). The initial echocardiographic approach includes the quantitative analysis of the left ventricle, in order to calculate left ventricular mass, left ventricular mass index and relative wall thickness for diagnosing concentric or eccentric LVH. Tissue Doppler (pulsed or color modality) and strain rate imaging (Doppler or two-dimensional modality) may give additional information to the standard indices of systolic function. Diastolic function can be evaluated not only by standard Doppler transmitral inflow measurements but also using pulsed tissue Doppler, which may allow to distinguish the athlete's LVH from diastolic impairment of hypertensive patients or hypertrophic cardiomyopathy by the simple determination of myocardial early diastolic velocity. Also the morphological and functional features of the left atrium and of the right ventricle can be assessed in the athlete's heart by combining standard echocardiography with new echocardiographic technologies.

  17. Framework for quantitative evaluation of 3D vessel segmentation approaches using vascular phantoms in conjunction with 3D landmark localization and registration

    NASA Astrophysics Data System (ADS)

    Wörz, Stefan; Hoegen, Philipp; Liao, Wei; Müller-Eschner, Matthias; Kauczor, Hans-Ulrich; von Tengg-Kobligk, Hendrik; Rohr, Karl

    2016-03-01

    We introduce a framework for quantitative evaluation of 3D vessel segmentation approaches using vascular phantoms. Phantoms are designed using a CAD system and created with a 3D printer, and comprise realistic shapes including branches and pathologies such as abdominal aortic aneurysms (AAA). To transfer ground truth information to the 3D image coordinate system, we use a landmark-based registration scheme utilizing fiducial markers integrated in the phantom design. For accurate 3D localization of the markers we developed a novel 3D parametric intensity model that is directly fitted to the markers in the images. We also performed a quantitative evaluation of different vessel segmentation approaches for a phantom of an AAA.

  18. Real-time rendering method and performance evaluation of composable 3D lenses for interactive VR.

    PubMed

    Borst, Christoph W; Tiesel, Jan-Phillip; Best, Christopher M

    2010-01-01

    We present and evaluate a new approach for real-time rendering of composable 3D lenses for polygonal scenes. Such lenses, usually called "volumetric lenses," are an extension of 2D Magic Lenses to 3D volumes in which effects are applied to scene elements. Although the composition of 2D lenses is well known, 3D composition was long considered infeasible due to both geometric and semantic complexity. Nonetheless, for a scene with multiple interactive 3D lenses, the problem of intersecting lenses must be considered. Intersecting 3D lenses in meaningful ways supports new interfaces such as hierarchical 3D windows, 3D lenses for managing and composing visualization options, or interactive shader development by direct manipulation of lenses providing component effects. Our 3D volumetric lens approach differs from other approaches and is one of the first to address efficient composition of multiple lenses. It is well-suited to head-tracked VR environments because it requires no view-dependent generation of major data structures, allowing caching and reuse of full or partial results. A Composite Shader Factory module composes shader programs for rendering composite visual styles and geometry of intersection regions. Geometry is handled by Boolean combinations of region tests in fragment shaders, which allows both convex and nonconvex CSG volumes for lens shape. Efficiency is further addressed by a Region Analyzer module and by broad-phase culling. Finally, we consider the handling of order effects for composed 3D lenses.

  19. An evaluation of cine-mode 3D portal image dosimetry for Volumetric Modulated Arc Therapy

    NASA Astrophysics Data System (ADS)

    Ansbacher, W.; Swift, C.-L.; Greer, P. B.

    2010-11-01

    We investigated cine-mode portal imaging on a Varian Trilogy accelerator and found that the linearity and other dosimetric properties are sufficient for 3D dose reconstruction as used in patient-specific quality assurance for VMAT (RapidArc) treatments. We also evaluated the gantry angle label in the portal image file header as a surrogate for the true imaged angle. The precision is only just adequate for the 3D evaluation method chosen, as discrepancies of 2° were observed.

  20. Engineering EMT using 3D micro-scaffold to promote hepatic functions for drug hepatotoxicity evaluation.

    PubMed

    Wang, Jingyu; Chen, Fengling; Liu, Longwei; Qi, Chunxiao; Wang, Bingjie; Yan, Xiaojun; Huang, Chenyu; Hou, Wei; Zhang, Michael Q; Chen, Yang; Du, Yanan

    2016-06-01

    Accompanied by decreased hepatic functions, epithelial-mesenchymal transition (EMT) was observed in two dimensional (2D) cultured hepatocytes with elongated morphology, loss of polarity and weakened cell-cell interaction, while upgrading to 3D culture has been considered as significant improvement of its 2D counterpart for hepatocyte maintenance. Here we hypothesize that 3D culture enhances hepatic functions through regulating the EMT status. Biomaterial-engineered EMT was achieved by culturing HepaRG as 3D spheroids (SP-3D) or 3D stretched cells (ST-3D) in non-adherent and adherent micro-scaffold respectively. In SP-3D, constrained EMT of HepaRG, a hepatic stem cell line, as represented by increased epithelial markers and decreased mesenchymal markers, was echoed by improved hepatic functions. To investigate the relationship between EMT status and hepatic functions, time-series RNA-Seq and gene network analysis were used for comparing different cell culture models, which identified histone deacetylases (HDACs) as key mediating factors. Protein analysis confirmed that high HDAC activity was correlated with high expression of Cadherin-1 (CDH1) and hepatic function genes, which were decreased upon HDAC inhibitor treatment in SP-3D, suggesting HDACs may play positive role in regulating EMT and hepatic functions. To illustrate the application of 3D micro-scaffold culture in drug safety evaluation, hepatotoxicity and metabolism assays of two hepatotoxins (i.e. N-acetyl-p-aminophenol and Doxorubicin) were performed and SP-3D showed more biomimetic toxicity response, indicating regulation of EMT as a vital consideration in designing 3D hepatocyte culture configuration.

  1. On Fundamental Evaluation Using Uav Imagery and 3d Modeling Software

    NASA Astrophysics Data System (ADS)

    Nakano, K.; Suzuki, H.; Tamino, T.; Chikatsu, H.

    2016-06-01

    Unmanned aerial vehicles (UAVs), which have been widely used in recent years, can acquire high-resolution images with resolutions in millimeters; such images cannot be acquired with manned aircrafts. Moreover, it has become possible to obtain a surface reconstruction of a realistic 3D model using high-overlap images and 3D modeling software such as Context capture, Pix4Dmapper, Photoscan based on computer vision technology such as structure from motion and multi-view stereo. 3D modeling software has many applications. However, most of them seem to not have obtained appropriate accuracy control in accordance with the knowledge of photogrammetry and/or computer vision. Therefore, we performed flight tests in a test field using an UAV equipped with a gimbal stabilizer and consumer grade digital camera. Our UAV is a hexacopter and can fly according to the waypoints for autonomous flight and can record flight logs. We acquired images from different altitudes such as 10 m, 20 m, and 30 m. We obtained 3D reconstruction results of orthoimages, point clouds, and textured TIN models for accuracy evaluation in some cases with different image scale conditions using 3D modeling software. Moreover, the accuracy aspect was evaluated for different units of input image—course unit and flight unit. This paper describes the fundamental accuracy evaluation for 3D modeling using UAV imagery and 3D modeling software from the viewpoint of close-range photogrammetry.

  2. Evaluating 3D Printed Biomaterials as Scaffolds for Vascularized Bone Tissue Engineering

    PubMed Central

    Wang, Martha O.; Vorwald, Charlotte E.; Dreher, Maureen L.; Mott, Eric J.; Cheng, Ming-Huei; Cinar, Ali; Mehdizadeh, Hamidreza; Somo, Sami; Dean, David; Brey, Eric M.; Fisher, John P.

    2015-01-01

    The recent proliferation of three dimensional (3D) printing technologies has allowed the exploration of increasing complex designs, and, furthermore, the consideration of 3D printed constructs for biological applications. However, there is an unmet need for a consistent set of tools for the design and evaluation of these biological 3D printed constructs, particularly as they relate to engineered tissues. For example, identifying the most advantageous construct parameters for the rapid vascularization of an engineered tissue - a critical parameter in regenerative medicine - is difficult without a common group of measures. We demonstrate here a toolbox to design, characterize, and evaluate 3D printed scaffolds for vascularized tissue regenerative medicine. Our toolbox (1) identifies the range of design specifications using a modular design, (2) nondestructively compares the 3D printed scaffolds to the design, (3) evaluates biocompatibility and mechanical properties, and (4) predicts host vessel integration. As a case study, we designed, fabricated, and evaluated polymer scaffolds using a poly(propylene fumarate) based resin. Our work highlights the potential for these tools to be combined as a consistent methodology for the evaluation of porous 3D printed constructs for regenerative medicine. PMID:25387454

  3. Evaluation of 3D cognitive fatigue using heart-brain synchronization.

    PubMed

    Park, Sangin; Won, Myoung Ju; Lee, Eui Chul; Mun, Sungchul; Park, Min-Chul; Whang, Mincheol

    2015-08-01

    The purpose of this study was to identify an evaluation method for 3D cognitive fatigue based on a heart-brain synchronization phenomenon known as the heartbeat evoked potential (HEP). Thirty undergraduate students (15 females) watched a video in both 2D and 3D for an hour. Because visual fatigue is related to cognitive load, the HEP was used as an indicator of communication between the heart and the brain and therefore of cognitive function; responses were compared after 2D and 3D viewing. At the standard EEG sites F3 and F4, the alpha activity of the first and second HEP components was significantly increased after 3D video viewing relative to 2D. This increase likely indicates that sensory input from 3D video requires heavy computation by the brain, stimulating heart activity. The conclusion is that the first and second HEP components are significant parameters that can quantitatively evaluate 3D visual fatigue. Further work is needed to uncover the cause of 3D visual fatigue.

  4. Comprehensive evaluation of latest 2D/3D monitors and comparison to a custom-built 3D mirror-based display in laparoscopic surgery

    NASA Astrophysics Data System (ADS)

    Wilhelm, Dirk; Reiser, Silvano; Kohn, Nils; Witte, Michael; Leiner, Ulrich; Mühlbach, Lothar; Ruschin, Detlef; Reiner, Wolfgang; Feussner, Hubertus

    2014-03-01

    Though theoretically superior, 3D video systems did not yet achieve a breakthrough in laparoscopic surgery. Furthermore, visual alterations, such as eye strain, diplopia and blur have been associated with the use of stereoscopic systems. Advancements in display and endoscope technology motivated a re-evaluation of such findings. A randomized study on 48 test subjects was conducted to investigate whether surgeons can benefit from using most current 3D visualization systems. Three different 3D systems, a glasses-based 3D monitor, an autostereoscopic display and a mirror-based theoretically ideal 3D display were compared to a state-of-the-art 2D HD system. The test subjects split into a novice and an expert surgeon group, which high experience in laparoscopic procedures. Each of them had to conduct a well comparable laparoscopic suturing task. Multiple performance parameters like task completion time and the precision of stitching were measured and compared. Electromagnetic tracking provided information on the instruments path length, movement velocity and economy. The NASA task load index was used to assess the mental work load. Subjective ratings were added to assess usability, comfort and image quality of each display. Almost all performance parameters were superior for the 3D glasses-based display as compared to the 2D and the autostereoscopic one, but were often significantly exceeded by the mirror-based 3D display. Subjects performed the task at average 20% faster and with a higher precision. Work-load parameters did not show significant differences. Experienced and non-experienced laparoscopists profited equally from 3D. The 3D mirror system gave clear evidence for additional potential of 3D visualization systems with higher resolution and motion parallax presentation.

  5. Bi-Luminal Mitral Valve: Incidence, Clinical Features, Associated Anomaly and Echocardiographic Evaluation

    PubMed Central

    Sinha, Santosh Kumar; Mishra, Vikas; Singh, Karandeep; Asif, Mohammad; Sachan, Mohit; Kumar, Ashutosh; Jha, Mukesh Jitendra; Khanra, Dibbendhu; Singh, Avinash Kumar; Singh, Shravan; Razi, Mahamdula; Thakur, Ramesh; Pandey, Umeshwar; Varma, Chandra Mohan

    2016-01-01

    Objective The aim of the study was to know the incidence, clinical features, associated anomaly and echocardiographic evaluation of bi-luminal mitral valve (also known as double orifice mitral valve or DOMV) in patients with suspected mitral valve disease, continous murmur or left-to-right shunt. Methods Twenty-eight patients with DOMV were diagnosed by transthoracic echocardiography (TTE) in a retrospective review of 52,256 echocardiographic studies in 45,898 patients performed between 2000 and 2015. Results The mean age was 20.1 years (15 - 34 years) with female preponderance (M/F: 1:1.8). Dyspnea and diastolic murmur were the most common symptoms found in 19 (67.8%) and 19 (67.8%) of patients, respectively. Normal sinus rhythm was the most common electrocardiographic finding. Twenty-five (89%) patients had complete bridge, while three (11%) had incomplete bridge type of DOMV. Twenty-one (75%) had severe mitral stenosis (MS) including severe tricuspid regurgitation (n = 13, 61%), ventricular septal defect (VSD, n = 3, 14%), complete endocardial cushion defect (ECD, n = 3, 14%), and mild to moderate mitral regurgitation (MR) (n = 2, 11%), moderate MS and moderate MR were found in four (16%) patients among complete bridge type of DOMV, while all patients with incomplete bridge type had severe MS and patent ductus arteriosus (PDA) as associated lesions. Overall, 24 (85%) had severe and four (15%) had moderate MS. Conclusions DOMV as a cause of symptomatic mitral valve disease was seen in young and middle-aged patients with estimated incidence of 0.06%. Dyspnea and diastolic murmur were the most common symptoms. Mostly, it was an isolated anomaly but in majority, associated with VSD, complete ECD and PDA. TTE examination is a reliable and sufficient means of diagnosing DOMV and determining its type. PMID:27829956

  6. Relevance of echocardiographic evaluation of right ventricular function in patients undergoing cardiac resynchronization therapy.

    PubMed

    Scuteri, Lea; Rordorf, Roberto; Marsan, Nina Ajmone; Landolina, Maurizio; Magrini, Giulia; Klersy, Catherine; Frattini, Folco; Petracci, Barbara; Vicentini, Alessandro; Campana, Carlo; Tavazzi, Luigi; Ghio, Stefano

    2009-08-01

    Right ventricular (RV) dysfunction is a marker of poor prognosis in heart failure (HF) patients. It is still unclear whether RV function might influence response to cardiac resynchronization therapy (CRT). Forty-four consecutive patients with HF, large QRS, and either intraventricular or interventricular dyssynchrony underwent echocardiographic evaluation before, 1 month after, and 6 months after CRT. Response to CRT was considered in case of significant LV reverse remodeling, defined as the occurrence of LV end-systolic volume (LVESV) reduction > or =15% at 6 months. All echocardiographic indexes of baseline RV function and dimensions were significantly more impaired in nonresponders versus responders to CRT: tricuspid annular plane systolic excursion (TAPSE 15 +/- 4 mm vs 20 +/- 5 mm, P = 0.001), RV systolic pulmonary artery pressure (RVSP 39 +/- 14 mmHg vs 27 +/- 8 mmHg, P = 0.02), RV end-diastolic area (RVEDA 23 +/- 6 cm(2) vs 16 +/- 3 cm(2) P < 0.001), RV end-systolic area (RVESA 16 +/- 6 cm(2) vs 8 +/- 2 cm(2), P = 0.001), and RV fractional area change (30 +/- 12% vs 48 +/- 8%, P < 0.001). All the indexes of RV function significantly correlated with the percentage of LVESV reduction after CRT. Severe RV dysfunction was defined as TAPSE < or =14 mm and the population was stratified into two groups based on baseline TAPSE < or = or > 14 mm. As compared to those with high TAPSE (n = 30), patients with low TAPSE (n = 14) were less likely to show LV reverse remodeling after CRT (76% vs 14%, P < 0.001). Our study suggests that RV function significantly affects response to CRT. Poor LV reverse remodeling occurs after CRT in patients with HF having severe RV dysfunction at baseline.

  7. Evaluation of Model Recognition for Grammar-Based Automatic 3d Building Model Reconstruction

    NASA Astrophysics Data System (ADS)

    Yu, Qian; Helmholz, Petra; Belton, David

    2016-06-01

    In recent years, 3D city models are in high demand by many public and private organisations, and the steadily growing capacity in both quality and quantity are increasing demand. The quality evaluation of these 3D models is a relevant issue both from the scientific and practical points of view. In this paper, we present a method for the quality evaluation of 3D building models which are reconstructed automatically from terrestrial laser scanning (TLS) data based on an attributed building grammar. The entire evaluation process has been performed in all the three dimensions in terms of completeness and correctness of the reconstruction. Six quality measures are introduced to apply on four datasets of reconstructed building models in order to describe the quality of the automatic reconstruction, and also are assessed on their validity from the evaluation point of view.

  8. Embodied collaboration support system for 3D shape evaluation in virtual space

    NASA Astrophysics Data System (ADS)

    Okubo, Masashi; Watanabe, Tomio

    2005-12-01

    Collaboration mainly consists of two tasks; one is each partner's task that is performed by the individual, the other is communication with each other. Both of them are very important objectives for all the collaboration support system. In this paper, a collaboration support system for 3D shape evaluation in virtual space is proposed on the basis of both studies in 3D shape evaluation and communication support in virtual space. The proposed system provides the two viewpoints for each task. One is the viewpoint of back side of user's own avatar for the smooth communication. The other is that of avatar's eye for 3D shape evaluation. Switching the viewpoints satisfies the task conditions for 3D shape evaluation and communication. The system basically consists of PC, HMD and magnetic sensors, and users can share the embodied interaction by observing interaction between their avatars in virtual space. However, the HMD and magnetic sensors, which are put on the users, would restrict the nonverbal communication. Then, we have tried to compensate the loss of nodding of partner's avatar by introducing the speech-driven embodied interactive actor InterActor. Sensory evaluation by paired comparison of 3D shapes in the collaborative situation in virtual space and in real space and the questionnaire are performed. The result demonstrates the effectiveness of InterActor's nodding in the collaborative situation.

  9. Mobile 3D quality of experience evaluation: a hybrid data collection and analysis approach

    NASA Astrophysics Data System (ADS)

    Utriainen, Timo; Häyrynen, Jyrki; Jumisko-Pyykkö, Satu; Boev, Atanas; Gotchev, Atanas; Hannuksela, Miska M.

    2011-02-01

    The paper presents a hybrid approach to study the user's experienced quality of 3D visual content on mobile autostereoscopic displays. It combines extensive subjective tests with collection and objective analysis of eye-tracked data. 3D cues which are significant for mobiles are simulated in the generated 3D test content. The methodology for conducting subjective quality evaluation includes hybrid data-collection of quantitative quality preferences, qualitative impressions, and binocular eye-tracking. We present early results of the subjective tests along with eye movement reaction times, areas of interest and heatmaps obtained from raw eye-tracked data after statistical analysis. The study contributes to the question what is important to be visualized on portable auto-stereoscopic displays and how to maintain and visually enhance the quality of 3D content for such displays.

  10. Tricuspid regurgitation following left-sided valve surgery: echocardiographic evaluation and optimal timing of surgical treatment.

    PubMed

    Izumi, Chisato

    2015-03-01

    Severe tricuspid regurgitation may often appear and progress late after left-sided valve surgery without left-sided valve dysfunction, significant left heart failure, and pulmonary hypertension. The clinical features, echocardiographic evaluation, treatment, and prognosis of this disease entity have been discussed, but data is limited compared with left-sided valve diseases. Tricuspid annular dilatation associated with atrial fibrillation and right ventricular dysfunction strongly relate to development of isolated tricuspid regurgitation late after left-sided valve surgery. Three-dimensional evaluation may be useful in evaluating tricuspid valve anatomy in more detail. Better prognosis in patients undergoing surgical treatment for severe isolated tricuspid regurgitation than those who were treated medically has been reported; however, the timing of isolated tricuspid valve surgery is often too late. Right ventricular function is a key word for determining the timing of isolated tricuspid valve surgery; however, it is difficult to evaluate by conventional echocardiography. One of the serious issues in the future will be how to accurately evaluate right ventricular function.

  11. "Gold standard" data for evaluation and comparison of 3D/2D registration methods.

    PubMed

    Tomazevic, Dejan; Likar, Bostjan; Pernus, Franjo

    2004-01-01

    Evaluation and comparison of registration techniques for image-guided surgery is an important problem that has received little attention in the literature. In this paper we address the challenging problem of generating reliable "gold standard" data for use in evaluating the accuracy of 3D/2D registrations. We have devised a cadaveric lumbar spine phantom with fiducial markers and established highly accurate correspondences between 3D CT and MR images and 18 2D X-ray images. The expected target registration errors for target points on the pedicles are less than 0.26 mm for CT-to-X-ray registration and less than 0.42 mm for MR-to-X-ray registration. As such, the "gold standard" data, which has been made publicly available on the Internet (http://lit.fe.uni-lj.si/Downloads/downloads.asp), is useful for evaluation and comparison of 3D/2D image registration methods.

  12. 3D Printed Surgical Instruments Evaluated by a Simulated Crew of a Mars Mission.

    PubMed

    Wong, Julielynn Y; Pfahnl, Andreas C

    2016-09-01

    The first space-based fused deposition modeling (FDM) 3D printer became operational in 2014. This study evaluated whether Mars simulation crewmembers of the Hawai'i Space Exploration Analog and Simulation (HI-SEAS) II mission with no prior surgical experience could utilize acrylonitrile butadiene styrene (ABS) thermoplastic surgical instruments FDM 3D printed on Earth to complete simulated surgical tasks. This study sought to examine the feasibility of using 3D printed surgical tools when the primary crew medical officer is incapacitated and the back-up crew medical officer must conduct a surgical procedure during a simulated extended space mission. During a 4 mo duration ground-based analog mission, five simulation crewmembers with no prior surgical experience completed 16 timed sets of simulated prepping, draping, incising, and suturing tasks to evaluate the relative speed of using four ABS thermoplastic instruments printed on Earth compared to conventional instruments. All four simulated surgical tasks were successfully performed using 3D printed instruments by Mars simulation crewmembers with no prior surgical experience. There was no substantial difference in time to completion of simulated tasks with control vs. 3D printed sponge stick, towel clamp, scalpel handle, and toothed forceps. These limited findings support further investigation into the creation of an onboard digital catalog of validated 3D printable surgical instrument design files to support autonomous, crew-administered healthcare on Mars missions. Future work could include addressing sterility, biocompatibility, and having astronaut crew medical officers test a wider range of surgical instruments printed in microgravity during actual surgical procedures. Wong JY, Pfahnl AC. 3D printed surgical instruments evaluated by a simulated crew of a Mars mission. Aerosp Med Hum Perform. 2016; 87(9):806-810.

  13. Laboratory and in-flight experiments to evaluate 3-D audio display technology

    NASA Technical Reports Server (NTRS)

    Ericson, Mark; Mckinley, Richard; Kibbe, Marion; Francis, Daniel

    1994-01-01

    Laboratory and in-flight experiments were conducted to evaluate 3-D audio display technology for cockpit applications. A 3-D audio display generator was developed which digitally encodes naturally occurring direction information onto any audio signal and presents the binaural sound over headphones. The acoustic image is stabilized for head movement by use of an electromagnetic head-tracking device. In the laboratory, a 3-D audio display generator was used to spatially separate competing speech messages to improve the intelligibility of each message. Up to a 25 percent improvement in intelligibility was measured for spatially separated speech at high ambient noise levels (115 dB SPL). During the in-flight experiments, pilots reported that spatial separation of speech communications provided a noticeable improvement in intelligibility. The use of 3-D audio for target acquisition was also investigated. In the laboratory, 3-D audio enabled the acquisition of visual targets in about two seconds average response time at 17 degrees accuracy. During the in-flight experiments, pilots correctly identified ground targets 50, 75, and 100 percent of the time at separation angles of 12, 20, and 35 degrees, respectively. In general, pilot performance in the field with the 3-D audio display generator was as expected, based on data from laboratory experiments.

  14. Development of a three-dimensional hand model using 3D stereophotogrammetry: Evaluation of landmark reproducibility.

    PubMed

    Hoevenaren, Inge A; Maal, Thomas J J; Krikken, E; de Haan, A F J; Bergé, S J; Ulrich, D J O

    2015-05-01

    Using three-dimensional (3D) photography, exact images of the human body can be produced. Over the last few years, this technique is mainly being developed in the field of maxillofacial reconstructive surgery, creating fusion images with computed tomography (CT) data for accurate planning and prediction of treatment outcome. However, in hand surgery, 3D photography is not yet being used in clinical settings. The aim of this study was to develop a valid method for imaging the hand using 3D stereophotogrammetry. The reproducibility of 30 soft tissue landmarks was determined using 3D stereophotogrammetric images. Analysis was performed by two observers on 20 3D photographs. Reproducibility and reliability of the landmark identification were determined using statistical analysis. The intra- and interobserver reproducibility of the landmarks were high. This study showed a high reliability coefficient for intraobserver (1.00) and interobserver reliability (0.99). Identification of the landmarks on the palmar aspect of individual fingers was more precise than the identification of landmarks of the thumb. This study shows that 3D photography can safely produce accurate and reproducible images of the hand, which makes the technique a reliable method for soft tissue analysis. 3D images can be a helpful tool in pre- and postoperative evaluation of reconstructive trauma surgery, in aesthetic surgery of the hand, and for educational purposes. The use in everyday practice of hand surgery and the concept of fusing 3D photography images with radiologic images of the interior hand structures needs to be further explored. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  15. Study of objective evaluation indicators of 3D visual fatigue based on RDS related tasks

    NASA Astrophysics Data System (ADS)

    Huang, Yi; Liu, Yue; Zou, Bochao; Wang, Yongtian; Cheng, Dewen

    2015-03-01

    Three dimensional (3D) displays have witnessed rapid progress in recent years because of its highly realistic sensation and sense of presence to humanist users. However, the comfort issues of 3D display are often reported and thus restrict its wide applications. In order to study the objective evaluation indicators associated with 3D visual fatigue, an experiment is designed in which subjects are required to accomplish a task realized with random dot stereogram (RDS). The aim of designing the task is to induce 3D visual fatigue of subjects and exclude the impacts of monocular depth cues. The visual acuity, critical flicker frequency (CFF), reaction time and correct rate of subjects during the experiment are recorded and analyzed. Correlation of the experimental data with the subjective evaluation scores is studied to find which indicator is closely related to 3D visual fatigue. Analysis of the experimental data shows that the trends of the correct rate are in line with the result of subjective evaluation.

  16. A neural network based 3D/3D image registration quality evaluator for the head-and-neck patient setup in the absence of a ground truth

    SciTech Connect

    Wu Jian; Murphy, Martin J.

    2010-11-15

    Purpose: To develop a neural network based registration quality evaluator (RQE) that can identify unsuccessful 3D/3D image registrations for the head-and-neck patient setup in radiotherapy. Methods: A two-layer feed-forward neural network was used as a RQE to classify 3D/3D rigid registration solutions as successful or unsuccessful based on the features of the similarity surface near the point-of-solution. The supervised training and test data sets were generated by rigidly registering daily cone-beam CTs to the treatment planning fan-beam CTs of six patients with head-and-neck tumors. Two different similarity metrics (mutual information and mean-squared intensity difference) and two different types of image content (entire image versus bony landmarks) were used. The best solution for each registration pair was selected from 50 optimizing attempts that differed only by the initial transformation parameters. The distance from each individual solution to the best solution in the normalized parametrical space was compared to a user-defined error threshold to determine whether that solution was successful or not. The supervised training was then used to train the RQE. The performance of the RQE was evaluated using the test data set that consisted of registration results that were not used in training. Results: The RQE constructed using the mutual information had very good performance when tested using the test data sets, yielding the sensitivity, the specificity, the positive predictive value, and the negative predictive value in the ranges of 0.960-1.000, 0.993-1.000, 0.983-1.000, and 0.909-1.000, respectively. Adding a RQE into a conventional 3D/3D image registration system incurs only about 10%-20% increase of the overall processing time. Conclusions: The authors' patient study has demonstrated very good performance of the proposed RQE when used with the mutual information in identifying unsuccessful 3D/3D registrations for daily patient setup. The classifier had

  17. Use of 2.5-D and 3-D technology to evaluate control room upgrades

    SciTech Connect

    Hanes, L. F.; Naser, J.

    2006-07-01

    This paper describes an Electric Power Research Inst. (EPRI) study in which 2.5-D and 3-D visualization technology was applied to evaluate the design of a nuclear power plant control room upgrade. The study involved converting 3-D CAD flies of a planned upgrade into a photo-realistic appearing virtual model, and evaluating the value and usefulness of the model. Nuclear utility and EPRI evaluators viewed and interacted with the control room virtual model with both 2.5-D and 3-D representations. They identified how control room and similar virtual models may be used by utilities for design and evaluation purposes; assessed potential economic and other benefits; and identified limitations, potential problems, and other issues regarding use of visualization technology for this and similar applications. In addition, the Halden CREATE (Control Room Engineering Advanced Tool-kit Environment) Verification Tool was applied to evaluate features of the virtual model against US NRC NUREG 0700 Revision 2 human factors engineering guidelines (NUREG 0700) [1]. The study results are very favorable for applying 2.5-D visualization technology to support upgrading nuclear power plant control rooms and other plant facilities. Results, however, show that today's 3-D immersive viewing systems are difficult to justify based on cost, availability and value of information provided for this application. (authors)

  18. Two-dimensional echocardiographic evaluation of ventricular asynergy induced by dipyridamole: correlation with thallium scanning

    SciTech Connect

    Ferrara, N.; Bonaduce, D.; Leosco, D.; Longobardi, G.; Abete, P.; Morgano, G.; Salvatore, M.; Rengo, F.

    1986-09-01

    Myocardial asynergies detected by two-dimensional echocardiography during intravenous administration of Dipyridamole (0.75 mg/kg) were evaluated in 54 patients referred for angiographic evaluation of chest pain. Technically adequate two-dimensional echocardiograms suitable for analysis were recorded in 42 of 54 (77.7%) patients studied. Thallium-201 myocardial perfusion scintigraphy, during dipyridamole test was performed in the same patients. Thirty of the 42 patients studied showed significant coronary narrowing at cardiac catheterization. Dipyridamole-induced wall motion abnormalities and myocardial perfusion defects were detected, respectively, in 19 (63.3%) and 21 (70%) of 30 patients with significant coronary artery disease. Wall by wall comparison of the distribution of dipyridamole-induced echocardiographic asynergy with reversible thallium-201 (/sup 201/Tl) perfusion defects demonstrated complete correlation in 42 segments examined. Three segments with perfusion defects at thallium scanning did not show asynergy during the test while two segments showing wall motion abnormalities during dipyridamole infusion did not manifest perfusion defects. Our study demonstrates that two-dimensional echocardiography during dipyridamole testing is useful in detecting patients with coronary artery disease. Furthermore, ventricular asynergies detected during the test show a high correspondence with site of myocardial perfusion defects at thallium scanning.

  19. Evaluation of an improved algorithm for producing realistic 3D breast software phantoms: application for mammography.

    PubMed

    Bliznakova, K; Suryanarayanan, S; Karellas, A; Pallikarakis, N

    2010-11-01

    This work presents an improved algorithm for the generation of 3D breast software phantoms and its evaluation for mammography. The improved methodology has evolved from a previously presented 3D noncompressed breast modeling method used for the creation of breast models of different size, shape, and composition. The breast phantom is composed of breast surface, duct system and terminal ductal lobular units, Cooper's ligaments, lymphatic and blood vessel systems, pectoral muscle, skin, 3D mammographic background texture, and breast abnormalities. The key improvement is the development of a new algorithm for 3D mammographic texture generation. Simulated images of the enhanced 3D breast model without lesions were produced by simulating mammographic image acquisition and were evaluated subjectively and quantitatively. For evaluation purposes, a database with regions of interest taken from simulated and real mammograms was created. Four experienced radiologists participated in a visual subjective evaluation trial, as they judged the quality of the simulated mammograms, using the new algorithm compared to mammograms, obtained with the old modeling approach. In addition, extensive quantitative evaluation included power spectral analysis and calculation of fractal dimension, skewness, and kurtosis of simulated and real mammograms from the database. The results from the subjective evaluation strongly suggest that the new methodology for mammographic breast texture creates improved breast models compared to the old approach. Calculated parameters on simulated images such as beta exponent deducted from the power law spectral analysis and fractal dimension are similar to those calculated on real mammograms. The results for the kurtosis and skewness are also in good coincidence with those calculated from clinical images. Comparison with similar calculations published in the literature showed good agreement in the majority of cases. The improved methodology generated breast

  20. Evaluation of low-dose limits in 3D-2D rigid registration for surgical guidance

    NASA Astrophysics Data System (ADS)

    Uneri, A.; Wang, A. S.; Otake, Y.; Kleinszig, G.; Vogt, S.; Khanna, A. J.; Gallia, G. L.; Gokaslan, Z. L.; Siewerdsen, J. H.

    2014-09-01

    An algorithm for intensity-based 3D-2D registration of CT and C-arm fluoroscopy is evaluated for use in surgical guidance, specifically considering the low-dose limits of the fluoroscopic x-ray projections. The registration method is based on a framework using the covariance matrix adaptation evolution strategy (CMA-ES) to identify the 3D patient pose that maximizes the gradient information similarity metric. Registration performance was evaluated in an anthropomorphic head phantom emulating intracranial neurosurgery, using target registration error (TRE) to characterize accuracy and robustness in terms of 95% confidence upper bound in comparison to that of an infrared surgical tracking system. Three clinical scenarios were considered: (1) single-view image + guidance, wherein a single x-ray projection is used for visualization and 3D-2D guidance; (2) dual-view image + guidance, wherein one projection is acquired for visualization, combined with a second (lower-dose) projection acquired at a different C-arm angle for 3D-2D guidance; and (3) dual-view guidance, wherein both projections are acquired at low dose for the purpose of 3D-2D guidance alone (not visualization). In each case, registration accuracy was evaluated as a function of the entrance surface dose associated with the projection view(s). Results indicate that images acquired at a dose as low as 4 μGy (approximately one-tenth the dose of a typical fluoroscopic frame) were sufficient to provide TRE comparable or superior to that of conventional surgical tracking, allowing 3D-2D guidance at a level of dose that is at most 10% greater than conventional fluoroscopy (scenario #2) and potentially reducing the dose to approximately 20% of the level in a conventional fluoroscopically guided procedure (scenario #3).

  1. Evaluation of low-dose limits in 3D-2D rigid registration for surgical guidance.

    PubMed

    Uneri, A; Wang, A S; Otake, Y; Kleinszig, G; Vogt, S; Khanna, A J; Gallia, G L; Gokaslan, Z L; Siewerdsen, J H

    2014-09-21

    An algorithm for intensity-based 3D-2D registration of CT and C-arm fluoroscopy is evaluated for use in surgical guidance, specifically considering the low-dose limits of the fluoroscopic x-ray projections. The registration method is based on a framework using the covariance matrix adaptation evolution strategy (CMA-ES) to identify the 3D patient pose that maximizes the gradient information similarity metric. Registration performance was evaluated in an anthropomorphic head phantom emulating intracranial neurosurgery, using target registration error (TRE) to characterize accuracy and robustness in terms of 95% confidence upper bound in comparison to that of an infrared surgical tracking system. Three clinical scenarios were considered: (1) single-view image+guidance, wherein a single x-ray projection is used for visualization and 3D-2D guidance; (2) dual-view image+guidance, wherein one projection is acquired for visualization, combined with a second (lower-dose) projection acquired at a different C-arm angle for 3D-2D guidance; and (3) dual-view guidance, wherein both projections are acquired at low dose for the purpose of 3D-2D guidance alone (not visualization). In each case, registration accuracy was evaluated as a function of the entrance surface dose associated with the projection view(s). Results indicate that images acquired at a dose as low as 4 μGy (approximately one-tenth the dose of a typical fluoroscopic frame) were sufficient to provide TRE comparable or superior to that of conventional surgical tracking, allowing 3D-2D guidance at a level of dose that is at most 10% greater than conventional fluoroscopy (scenario #2) and potentially reducing the dose to approximately 20% of the level in a conventional fluoroscopically guided procedure (scenario #3).

  2. An Interactive 3D Virtual Anatomy Puzzle for Learning and Simulation - Initial Demonstration and Evaluation.

    PubMed

    Messier, Erik; Wilcox, Jascha; Dawson-Elli, Alexander; Diaz, Gabriel; Linte, Cristian A

    2016-01-01

    To inspire young students (grades 6-12) to become medical practitioners and biomedical engineers, it is necessary to expose them to key concepts of the field in a way that is both exciting and informative. Recent advances in medical image acquisition, manipulation, processing, visualization, and display have revolutionized the approach in which the human body and internal anatomy can be seen and studied. It is now possible to collect 3D, 4D, and 5D medical images of patient specific data, and display that data to the end user using consumer level 3D stereoscopic display technology. Despite such advancements, traditional 2D modes of content presentation such as textbooks and slides are still the standard didactic equipment used to teach young students anatomy. More sophisticated methods of display can help to elucidate the complex 3D relationships between structures that are so often missed when viewing only 2D media, and can instill in students an appreciation for the interconnection between medicine and technology. Here we describe the design, implementation, and preliminary evaluation of a 3D virtual anatomy puzzle dedicated to helping users learn the anatomy of various organs and systems by manipulating 3D virtual data. The puzzle currently comprises several components of the human anatomy and can be easily extended to include additional organs and systems. The 3D virtual anatomy puzzle game was implemented and piloted using three display paradigms - a traditional 2D monitor, a 3D TV with active shutter glass, and the DK2 version Oculus Rift, as well as two different user interaction devices - a space mouse and traditional keyboard controls.

  3. Evaluation of Home Delivery of Lectures Utilizing 3D Virtual Space Infrastructure

    ERIC Educational Resources Information Center

    Nishide, Ryo; Shima, Ryoichi; Araie, Hiromu; Ueshima, Shinichi

    2007-01-01

    Evaluation experiments have been essential in exploring home delivery of lectures for which users can experience campus lifestyle and distant learning through 3D virtual space. This paper discusses the necessity of virtual space for distant learners by examining the effects of virtual space. The authors have pursued the possibility of…

  4. Evaluation of Home Delivery of Lectures Utilizing 3D Virtual Space Infrastructure

    ERIC Educational Resources Information Center

    Nishide, Ryo; Shima, Ryoichi; Araie, Hiromu; Ueshima, Shinichi

    2007-01-01

    Evaluation experiments have been essential in exploring home delivery of lectures for which users can experience campus lifestyle and distant learning through 3D virtual space. This paper discusses the necessity of virtual space for distant learners by examining the effects of virtual space. The authors have pursued the possibility of…

  5. 3D-QSAR-Assisted Design, Synthesis, and Evaluation of Novobiocin Analogues

    PubMed Central

    2012-01-01

    Hsp90 is an attractive therapeutic target for the treatment of cancer. Extensive structural modifications to novobiocin, the first Hsp90 C-terminal inhibitor discovered, have produced a library of novobiocin analogues and revealed some structure–activity relationships. On the basis of the most potent novobiocin analogues generated from prior studies, a three-dimensional quantitative structure–activity (3D QSAR) model was built. In addition, a new set of novobiocin analogues containing various structural features supported by the 3D QSAR model were synthesized and evaluated against two breast cancer cell lines. Several new inhibitors produced antiproliferative activity at midnanomolar concentrations, which results through Hsp90 inhibition. PMID:23606927

  6. Soft Tissue Stability around Single Implants Inserted to Replace Maxillary Lateral Incisors: A 3D Evaluation

    PubMed Central

    Mangano, F. G.; Picciocchi, G.; Park, K. B.

    2016-01-01

    Purpose. To evaluate the soft tissue stability around single implants inserted to replace maxillary lateral incisors, using an innovative 3D method. Methods. We have used reverse-engineering software for the superimposition of 3D surface models of the dentogingival structures, obtained from intraoral scans of the same patients taken at the delivery of the final crown (S1) and 2 years later (S2). The assessment of soft tissues changes was performed via calculation of the Euclidean surface distances between the 3D models, after the superimposition of S2 on S1; colour maps were used for quantification of changes. Results. Twenty patients (8 males, 12 females) were selected, 10 with a failing/nonrestorable lateral incisor (test group: immediate placement in postextraction socket) and 10 with a missing lateral incisor (control group: conventional placement in healed ridge). Each patient received one immediately loaded implant (Anyridge®, Megagen, Gyeongbuk, South Korea). The superimposition of the 3D surface models taken at different times (S2 over S1) revealed a mean (±SD) reduction of 0.057 mm (±0.025) and 0.037 mm (±0.020) for test and control patients, respectively. This difference was not statistically significant (p = 0.069). Conclusions. The superimposition of the 3D surface models revealed an excellent peri-implant soft tissue stability in both groups of patients, with minimal changes registered along time. PMID:27298621

  7. On the evaluation of photogrammetric methods for dense 3D surface reconstruction in a metrological context

    NASA Astrophysics Data System (ADS)

    Toschi, I.; Capra, A.; De Luca, L.; Beraldin, J.-A.; Cournoyer, L.

    2014-05-01

    This paper discusses a methodology to evaluate the accuracy of recently developed image-based 3D modelling techniques. So far, the emergence of these novel methods has not been supported by the definition of an internationally recognized standard which is fundamental for user confidence and market growth. In order to provide an element of reflection and solution to the different communities involved in 3D imaging, a promising approach is presented in this paper for the assessment of both metric quality and limitations of an open-source suite of tools (Apero/MicMac), developed for the extraction of dense 3D point clouds from a set of unordered 2D images. The proposed procedural workflow is performed within a metrological context, through inter-comparisons with "reference" data acquired with two hemispherical laser scanners, one total station, and one laser tracker. The methodology is applied to two case studies, designed in order to analyse the software performances in dealing with both outdoor and environmentally controlled conditions, i.e. the main entrance of Cathédrale de la Major (Marseille, France) and a custom-made scene located at National Research Council of Canada 3D imaging Metrology Laboratory (Ottawa). Comparative data and accuracy evidence produced for both tests allow the study of some key factors affecting 3D model accuracy.

  8. Soft Tissue Stability around Single Implants Inserted to Replace Maxillary Lateral Incisors: A 3D Evaluation.

    PubMed

    Mangano, F G; Luongo, F; Picciocchi, G; Mortellaro, C; Park, K B; Mangano, C

    2016-01-01

    Purpose. To evaluate the soft tissue stability around single implants inserted to replace maxillary lateral incisors, using an innovative 3D method. Methods. We have used reverse-engineering software for the superimposition of 3D surface models of the dentogingival structures, obtained from intraoral scans of the same patients taken at the delivery of the final crown (S1) and 2 years later (S2). The assessment of soft tissues changes was performed via calculation of the Euclidean surface distances between the 3D models, after the superimposition of S2 on S1; colour maps were used for quantification of changes. Results. Twenty patients (8 males, 12 females) were selected, 10 with a failing/nonrestorable lateral incisor (test group: immediate placement in postextraction socket) and 10 with a missing lateral incisor (control group: conventional placement in healed ridge). Each patient received one immediately loaded implant (Anyridge®, Megagen, Gyeongbuk, South Korea). The superimposition of the 3D surface models taken at different times (S2 over S1) revealed a mean (±SD) reduction of 0.057 mm (±0.025) and 0.037 mm (±0.020) for test and control patients, respectively. This difference was not statistically significant (p = 0.069). Conclusions. The superimposition of the 3D surface models revealed an excellent peri-implant soft tissue stability in both groups of patients, with minimal changes registered along time.

  9. Two-alternative forced-choice evaluation of 3D CT angiograms

    NASA Astrophysics Data System (ADS)

    Habets, Damiaan F.; Chapman, Brian E.; Fox, Allan J.; Hyde, Derek E.; Holdsworth, David W.

    2001-06-01

    This study describes the development and evaluation of an appropriate methodology to study observer performance when comparing 2D and 3D angiographic techniques. 3D-CT angiograms were obtained from patients with cerebral aneurysms or occlusive carotid artery disease and perspective rendering of this 3D data was performed to produce maximum intensity projections (MIP) at view angles identical to digital subtraction angiography (DSA) images. Two-alternative-forced-choice methodology (2AFC) was then used to determine the percent correct (Pc), which is equivalent to the area Az under the receiver-operating characteristic (RTOC) curve. In a comparison of CRA MIP images and DSA images of the intracranial vasculature, the average value of Pc was 0.90+/- 0.03. Perspective reprojection produces digitally reconstructed radiographs (DRRs) with image quality that is nearly equivalent to conventional DSA, with the additional clinical advantage of providing digitally reconstructed images at an unlimited number of viewing angles.

  10. Jet length/velocity ratio: a new index for echocardiographic evaluation of chronic aortic regurgitation.

    PubMed

    Güvenç, Tolga Sinan; Karaçimen, Denizhan; Erer, Hatice Betül; İlhan, Erkan; Sayar, Nurten; Karakuş, Gültekin; Çekirdekçi, Elif; Eren, Mehmet

    2015-01-01

    Management of aortic regurgitation depends on the assessment for severity. Echocardiography remains as the most widely available tool for evaluation of aortic regurgitation. In this manuscript, we describe a novel parameter, jet length/velocity ratio, for the diagnosis of severe aortic regurgitation. A total of 30 patients with aortic regurgitation were included to this study. Severity of aortic regurgitation was assessed with an aortic regurgitation index incorporating five echocardiographic parameters. Jet length/velocity ratio is calculated as the ratio of maximum jet penetrance to mean velocity of regurgitant flow. Jet length/velocity ratio was significantly higher in patients with severe aortic regurgitation (2.03 ± 0.53) compared to patients with less than severe aortic regurgitation (1.24 ± 0.32, P < 0.001). Correlation of jet length/velocity ratio with aortic regurgitation index was very good (r(2) = 0.86) and correlation coefficient was higher for jet length/velocity ratio compared to vena contracta, jet width/LVOT ratio and pressure half time. For a cutoff value of 1.61, jet length/velocity ratio had a sensitivity of 92% and specificity of 88%, with an AUC value of 0.955. Jet length/velocity ratio is a novel parameter that can be used to assess severity of chronic aortic regurgitation. Main limitation for usage of this novel parameter is jet impringement to left ventricular wall. © 2014, Wiley Periodicals, Inc.

  11. 3D evaluation of palatal rugae for human identification using digital study models

    PubMed Central

    Taneva, Emilia D.; Johnson, Andrew; Viana, Grace; Evans, Carla A.

    2015-01-01

    Background: While there is literature suggesting that the palatal rugae could be used for human identification, most of these studies use two-dimensional (2D) approach. Aim: The aims of this study were to evaluate palatal ruga patterns using three-dimensional (3D) digital models; compare the most clinically relevant digital model conversion techniques for identification of the palatal rugae; develop a protocol for overlay registration; determine changes in palatal ruga individual patterns through time; and investigate the efficiency and accuracy of 3D matching processes between different individuals’ patterns. Material and Methods: Five cross sections in the anteroposterior dimension and four cross sections in the transverse dimension were computed which generated 18 2D variables. In addition, 13 3D variables were defined: The posterior point of incisive papilla (IP), and the most medial and lateral end points of the palatal rugae (R1MR, R1ML, R1LR, R1LL, R2MR, R2ML, R2LR, R2LL, R3MR, R3ML, R3LR, and R3LL). The deviation magnitude for each variable was statistically analyzed in this study. Five different data sets with the same 31 landmarks were evaluated in this study. Results: The results demonstrated that 2D images and linear measurements in the anteroposterior and transverse dimensions were not sufficient for comparing different digital model conversion techniques using the palatal rugae. 3D digital models proved to be a highly effective tool in evaluating different palatal ruga patterns. The 3D landmarks showed no statistically significant mean differences over time or as a result of orthodontic treatment. No statistically significant mean differences were found between different digital model conversion techniques, that is, between OrthoCAD™ and Ortho Insight 3D™, and between Ortho Insight 3D™ and the iTero® scans, when using 12 3D palatal rugae landmarks for comparison. Conclusion: Although 12 palatal 3D landmarks could be used for human

  12. Evaluation of 3D printing materials for fabrication of a novel multi-functional 3D thyroid phantom for medical dosimetry and image quality

    NASA Astrophysics Data System (ADS)

    Alssabbagh, Moayyad; Tajuddin, Abd Aziz; Abdulmanap, Mahayuddin; Zainon, Rafidah

    2017-06-01

    Recently, the three-dimensional printer has started to be utilized strongly in medical industries. In the human body, many parts or organs can be printed from 3D images to meet accurate organ geometries. In this study, five common 3D printing materials were evaluated in terms of their elementary composition and the mass attenuation coefficients. The online version of XCOM photon cross-section database was used to obtain the attenuation values of each material. The results were compared with the attenuation values of the thyroid listed in the International Commission on Radiation Units and Measurements - ICRU 44. Two original thyroid models (hollow-inside and solid-inside) were designed from scratch to be used in nuclear medicine, diagnostic radiology and radiotherapy for dosimetry and image quality purposes. Both designs have three holes for installation of radiation dosimeters. The hollow-inside model has more two holes in the top for injection the radioactive materials. The attenuation properties of the Polylactic Acid (PLA) material showed a very good match with the thyroid tissue, which it was selected to 3D print the phantom using open source RepRap, Prusa i3 3D printer. The scintigraphy images show that the phantom simulates a real healthy thyroid gland and thus it can be used for image quality purposes. The measured CT numbers of the PA material after the 3D printing show a close match with the human thyroid CT numbers. Furthermore, the phantom shows a good accommodation of the TLD dosimeters inside the holes. The 3D fabricated thyroid phantom simulates the real shape of the human thyroid gland with a changeable geometrical shape-size feature to fit different age groups. By using 3D printing technology, the time required to fabricate the 3D phantom was considerably shortened compared to the longer conventional methods, where it took only 30 min to print out the model. The 3D printing material used in this study is commercially available and cost

  13. Human neuron-astrocyte 3D co-culture-based assay for evaluation of neuroprotective compounds.

    PubMed

    Terrasso, Ana Paula; Silva, Ana Carina; Filipe, Augusto; Pedroso, Pedro; Ferreira, Ana Lúcia; Alves, Paula Marques; Brito, Catarina

    Central nervous system drug development has registered high attrition rates, mainly due to the lack of efficacy of drug candidates, highlighting the low reliability of the models used in early-stage drug development and the need for new in vitro human cell-based models and assays to accurately identify and validate drug candidates. 3D human cell models can include different tissue cell types and represent the spatiotemporal context of the original tissue (co-cultures), allowing the establishment of biologically-relevant cell-cell and cell-extracellular matrix interactions. Nevertheless, exploitation of these 3D models for neuroprotection assessment has been limited due to the lack of data to validate such 3D co-culture approaches. In this work we combined a 3D human neuron-astrocyte co-culture with a cell viability endpoint for the implementation of a novel in vitro neuroprotection assay, over an oxidative insult. Neuroprotection assay robustness and specificity, and the applicability of Presto Blue, MTT and CytoTox-Glo viability assays to the 3D co-culture were evaluated. Presto Blue was the adequate endpoint as it is non-destructive and is a simpler and reliable assay. Semi-automation of the cell viability endpoint was performed, indicating that the assay setup is amenable to be transferred to automated screening platforms. Finally, the neuroprotection assay setup was applied to a series of 36 test compounds and several candidates with higher neuroprotective effect than the positive control, Idebenone, were identified. The robustness and simplicity of the implemented neuroprotection assay with the cell viability endpoint enables the use of more complex and reliable 3D in vitro cell models to identify and validate drug candidates. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Evaluation of Fully 3-D Emission Mammotomography With a Compact Cadmium Zinc Telluride Detector

    PubMed Central

    Tornai, Martin P.; McKinley, Randolph L.; Bowsher, James E.

    2015-01-01

    A compact, dedicated cadmium zinc telluride (CZT) gamma camera coupled with a fully three-dimensional (3-D) acquisition system may serve as a secondary diagnostic tool for volumetric molecular imaging of breast cancers, particularly in cases when mammographic findings are inconclusive. The developed emission mammotomography system comprises a medium field-of-view, quantized CZT detector and 3-D positioning gantry. The intrinsic energy resolution, sensitivity and spatial resolution of the detector are evaluated with Tc-99m (140 keV) filled flood sources, capillary line sources, and a 3-D frequency-resolution phantom. To mimic realistic human pendant, uncompressed breast imaging, two different phantom shapes of an average sized breast, and three different lesion diameters are imaged to evaluate the system for 3-D mammotomography. Acquisition orbits not possible with conventional emission, or transmission, systems are designed to optimize the viewable breast volume while improving sampling of the breast and anterior chest wall. Complications in camera positioning about the patient necessitate a compromise in these two orbit design criteria. Image quality is evaluated with signal-to-noise ratios and contrasts of the lesions, both with and without additional torso phantom background. Reconstructed results indicate that 3-D mammotomography, incorporating a compact CZT detector, is a promising, dedicated breast imaging technique for visualization of tumors <1 cm in diameter. Additionally, there are no outstanding trajectories that consistently yield optimized quantitative lesion imaging parameters. Qualitatively, imaging breasts with realistic torso backgrounds (out-of-field activity) substantially alters image characteristics and breast morphology unless orbits which improve sampling are utilized. In practice, the sampling requirement may be less strict than initially anticipated. PMID:16011316

  15. Performance evaluation of 2D fingerprint and 3D shape similarity methods in virtual screening.

    PubMed

    Hu, Guoping; Kuang, Guanglin; Xiao, Wen; Li, Weihua; Liu, Guixia; Tang, Yun

    2012-05-25

    Virtual screening (VS) can be accomplished in either ligand- or structure-based methods. In recent times, an increasing number of 2D fingerprint and 3D shape similarity methods have been used in ligand-based VS. To evaluate the performance of these ligand-based methods, retrospective VS was performed on a tailored directory of useful decoys (DUD). The VS performances of 14 2D fingerprints and four 3D shape similarity methods were compared. The results revealed that 2D fingerprints ECFP_2 and FCFP_4 yielded better performance than the 3D Phase Shape methods. These ligand-based methods were also compared with structure-based methods, such as Glide docking and Prime molecular mechanics generalized Born surface area rescoring, which demonstrated that both 2D fingerprint and 3D shape similarity methods could yield higher enrichment during early retrieval of active compounds. The results demonstrated the superiority of ligand-based methods over the docking-based screening in terms of both speed and hit enrichment. Therefore, considering ligand-based methods first in any VS workflow would be a wise option.

  16. Myocardial oxygen supply/demand ratio in aortic stenosis: hemodynamic and echocardiographic evaluation of patients with and without angina pectoris.

    PubMed

    Nadell, R; DePace, N L; Ren, J F; Hakki, A H; Iskandrian, A S; Morganroth, J

    1983-08-01

    Angina pectoris is a common symptom in patients with aortic stenosis without coronary artery disease. To investigate the correlates of angina pectoris, echocardiographic and hemodynamic data from 44 patients with aortic stenosis and no coronary artery disease (mean age 56 +/- 10 years) were analyzed. Twenty-three patients had no angina pectoris and 21 patients had angina pectoris. The ratio of the diastolic pressure-time index (area between the aortic and left ventricular pressure curves during diastole) to the systolic pressure-time index (area under the left ventricular pressure curve during systole), an index of the oxygen supply/demand ratio, was not different in patients with or without angina pectoris. There were no differences between patients with and without angina pectoris in echocardiographically determined wall thickness, chamber size, systolic and diastolic wall stress and left ventricular mass; in electrocardiographically defined voltage; and in hemodynamically defined aortic valve area, transaortic gradient and stroke work index. Thus, echocardiographic and hemodynamic measurements at rest are not significantly different in the presence or absence of angina pectoris in patients with aortic stenosis. Dynamic data appear to be essential for evaluation of the mechanisms of angina pectoris in patients with aortic stenosis.

  17. Evaluation Model for Pavement Surface Distress on 3d Point Clouds from Mobile Mapping System

    NASA Astrophysics Data System (ADS)

    Aoki, K.; Yamamoto, K.; Shimamura, H.

    2012-07-01

    This paper proposes a methodology to evaluate the pavement surface distress for maintenance planning of road pavement using 3D point clouds from Mobile Mapping System (MMS). The issue on maintenance planning of road pavement requires scheduled rehabilitation activities for damaged pavement sections to keep high level of services. The importance of this performance-based infrastructure asset management on actual inspection data is globally recognized. Inspection methodology of road pavement surface, a semi-automatic measurement system utilizing inspection vehicles for measuring surface deterioration indexes, such as cracking, rutting and IRI, have already been introduced and capable of continuously archiving the pavement performance data. However, any scheduled inspection using automatic measurement vehicle needs much cost according to the instruments' specification or inspection interval. Therefore, implementation of road maintenance work, especially for the local government, is difficult considering costeffectiveness. Based on this background, in this research, the methodologies for a simplified evaluation for pavement surface and assessment of damaged pavement section are proposed using 3D point clouds data to build urban 3D modelling. The simplified evaluation results of road surface were able to provide useful information for road administrator to find out the pavement section for a detailed examination and for an immediate repair work. In particular, the regularity of enumeration of 3D point clouds was evaluated using Chow-test and F-test model by extracting the section where the structural change of a coordinate value was remarkably achieved. Finally, the validity of the current methodology was investigated by conducting a case study dealing with the actual inspection data of the local roads.

  18. Evaluation of an improved algorithm for producing realistic 3D breast software phantoms: Application for mammography

    PubMed Central

    Bliznakova, K.; Suryanarayanan, S.; Karellas, A.; Pallikarakis, N.

    2010-01-01

    Purpose: This work presents an improved algorithm for the generation of 3D breast software phantoms and its evaluation for mammography. Methods: The improved methodology has evolved from a previously presented 3D noncompressed breast modeling method used for the creation of breast models of different size, shape, and composition. The breast phantom is composed of breast surface, duct system and terminal ductal lobular units, Cooper’s ligaments, lymphatic and blood vessel systems, pectoral muscle, skin, 3D mammographic background texture, and breast abnormalities. The key improvement is the development of a new algorithm for 3D mammographic texture generation. Simulated images of the enhanced 3D breast model without lesions were produced by simulating mammographic image acquisition and were evaluated subjectively and quantitatively. For evaluation purposes, a database with regions of interest taken from simulated and real mammograms was created. Four experienced radiologists participated in a visual subjective evaluation trial, as they judged the quality of the simulated mammograms, using the new algorithm compared to mammograms, obtained with the old modeling approach. In addition, extensive quantitative evaluation included power spectral analysis and calculation of fractal dimension, skewness, and kurtosis of simulated and real mammograms from the database. Results: The results from the subjective evaluation strongly suggest that the new methodology for mammographic breast texture creates improved breast models compared to the old approach. Calculated parameters on simulated images such as β exponent deducted from the power law spectral analysis and fractal dimension are similar to those calculated on real mammograms. The results for the kurtosis and skewness are also in good coincidence with those calculated from clinical images. Comparison with similar calculations published in the literature showed good agreement in the majority of cases. Conclusions: The

  19. Evaluation of an improved algorithm for producing realistic 3D breast software phantoms: Application for mammography

    SciTech Connect

    Bliznakova, K.; Suryanarayanan, S.; Karellas, A.; Pallikarakis, N.

    2010-11-15

    Purpose: This work presents an improved algorithm for the generation of 3D breast software phantoms and its evaluation for mammography. Methods: The improved methodology has evolved from a previously presented 3D noncompressed breast modeling method used for the creation of breast models of different size, shape, and composition. The breast phantom is composed of breast surface, duct system and terminal ductal lobular units, Cooper's ligaments, lymphatic and blood vessel systems, pectoral muscle, skin, 3D mammographic background texture, and breast abnormalities. The key improvement is the development of a new algorithm for 3D mammographic texture generation. Simulated images of the enhanced 3D breast model without lesions were produced by simulating mammographic image acquisition and were evaluated subjectively and quantitatively. For evaluation purposes, a database with regions of interest taken from simulated and real mammograms was created. Four experienced radiologists participated in a visual subjective evaluation trial, as they judged the quality of the simulated mammograms, using the new algorithm compared to mammograms, obtained with the old modeling approach. In addition, extensive quantitative evaluation included power spectral analysis and calculation of fractal dimension, skewness, and kurtosis of simulated and real mammograms from the database. Results: The results from the subjective evaluation strongly suggest that the new methodology for mammographic breast texture creates improved breast models compared to the old approach. Calculated parameters on simulated images such as {beta} exponent deducted from the power law spectral analysis and fractal dimension are similar to those calculated on real mammograms. The results for the kurtosis and skewness are also in good coincidence with those calculated from clinical images. Comparison with similar calculations published in the literature showed good agreement in the majority of cases. Conclusions: The

  20. Echocardiographic evaluation of left ventricular filling pressure in heart transplant recipients.

    PubMed

    Broch, Kaspar; Al-Ani, Ahmed; Gude, Einar; Gullestad, Lars; Aakhus, Svend

    2014-12-01

    Diastolic dysfunction is a major cause of morbidity in heart transplant recipients. A reliable, non-invasive marker of left ventricular (LV) filling pressure would simplify follow-up in these patients. We aimed to test the validity of echocardiographic indices of LV filling pressure in a contemporary population of heart transplant recipients. Eighty-three patients were examined by right-sided heart catheterisation and echocardiography one year after heart transplantation. We explored the association between echocardiographic parameters of LV filling pressure and invasively measured pulmonary capillary wedge pressure (PCWP). Peak early mitral flow velocity divided by septal early mitral relaxation velocity (E/e'(septal)) was the echocardiographic parameter that best correlated with PCWP (r = 0.47; p < 0.001). At a cut-off value of 22, E/e'(septal) could identify patients with a PCWP above 12 mm Hg with a sensitivity of 56% and a specificity of 95%. The E/e' index was moderately associated with LV filling pressure in heart transplant recipients. Echocardiographic parameters of diastolic function should be interpreted with caution when estimating left ventricular filling pressures in this population.

  1. Subjective evaluation of mobile 3D video content: depth range versus compression artifacts

    NASA Astrophysics Data System (ADS)

    Jumisko-Pyykkö, Satu; Haustola, Tomi; Boev, Atanas; Gotchev, Atanas

    2011-02-01

    Mobile 3D television is a new form of media experience, which combines the freedom of mobility with the greater realism of presenting visual scenes in 3D. Achieving this combination is a challenging task as greater viewing experience has to be achieved with the limited resources of the mobile delivery channel such as limited bandwidth and power constrained handheld player. This challenge sets need for tight optimization of the overall mobile 3DTV system. Presence of depth and compression artifacts in the played 3D video are two major factors that influence viewer's subjective quality of experience and satisfaction. The primary goal of this study has been to examine the influence of varying depth and compression artifacts on the subjective quality of experience for mobile 3D video content. In addition, the influence of the studied variables on simulator sickness symptoms has been studied and vocabulary-based descriptive quality of experience has been conducted for a sub-set of variables in order to understand the perceptual characteristics in detail. In the experiment, 30 participants have evaluated the overall quality of different 3D video contents with varying depth ranges and compressed with varying quantization parameters. The test video content has been presented on a portable autostereoscopic LCD display with horizontal double density pixel arrangement. The results of the psychometric study indicate that compression artifacts are a dominant factor determining the quality of experience compared to varying depth range. More specifically, contents with strong compression has been rejected by the viewers and deemed unacceptable. The results of descriptive study confirm the dominance of visible spatial artifacts along the added value of depth for artifact-free content. The level of visual discomfort has been determined as not offending.

  2. Evaluation of precision and accuracy assessment of different 3-D surface imaging systems for biomedical purposes.

    PubMed

    Eder, Maximilian; Brockmann, Gernot; Zimmermann, Alexander; Papadopoulos, Moschos A; Schwenzer-Zimmerer, Katja; Zeilhofer, Hans Florian; Sader, Robert; Papadopulos, Nikolaos A; Kovacs, Laszlo

    2013-04-01

    Three-dimensional (3-D) surface imaging has gained clinical acceptance, especially in the field of cranio-maxillo-facial and plastic, reconstructive, and aesthetic surgery. Six scanners based on different scanning principles (Minolta Vivid 910®, Polhemus FastSCAN™, GFM PRIMOS®, GFM TopoCAM®, Steinbichler Comet® Vario Zoom 250, 3dMD DSP 400®) were used to measure five sheep skulls of different sizes. In three areas with varying anatomical complexity (areas, 1 = high; 2 = moderate; 3 = low), 56 distances between 20 landmarks are defined on each skull. Manual measurement (MM), coordinate machine measurements (CMM) and computer tomography (CT) measurements were used to define a reference method for further precision and accuracy evaluation of different 3-D scanning systems. MM showed high correlation to CMM and CT measurements (both r = 0.987; p < 0.001) and served as the reference method. TopoCAM®, Comet® and Vivid 910® showed highest measurement precision over all areas of complexity; Vivid 910®, the Comet® and the DSP 400® demonstrated highest accuracy over all areas with Vivid 910® being most accurate in areas 1 and 3, and the DSP 400® most accurate in area 2. In accordance to the measured distance length, most 3-D devices present higher measurement precision and accuracy for large distances and lower degrees of precision and accuracy for short distances. In general, higher degrees of complexity are associated with lower 3-D assessment accuracy, suggesting that for optimal results, different types of scanners should be applied to specific clinical applications and medical problems according to their special construction designs and characteristics.

  3. Optimization of 3D Poisson-Nernst-Planck model for fast evaluation of diverse protein channels.

    PubMed

    Dyrka, Witold; Bartuzel, Maciej M; Kotulska, Malgorzata

    2013-10-01

    We show the accuracy and applicability of our fast algorithmic implementation of a three-dimensional Poisson-Nernst-Planck (3D-PNP) flow model for characterizing different protein channels. Due to its high computational efficiency, our model can predict the full current-voltage characteristics of a channel within minutes, based on the experimental 3D structure of the channel or its computational model structure. Compared with other methods, such as Brownian dynamics, which currently needs a few weeks of the computational time, or even much more demanding molecular dynamics modeling, 3D-PNP is the only available method for a function-based evaluation of very numerous tentative structural channel models. Flow model tests of our algorithm and its optimal parametrization are provided for five native channels whose experimental structures are available in the protein data bank (PDB) in an open conductive state, and whose experimental current-voltage characteristics have been published. The channels represent very different geometric and structural properties, which makes it the widest test to date of the accuracy of 3D-PNP on real channels. We test whether the channel conductance, rectification, and charge selectivity obtained from the flow model, could be sufficiently sensitive to single-point mutations, related to unsignificant changes in the channel structure. Our results show that the classical 3D-PNP model, under proper parametrization, is able to achieve a qualitative agreement with experimental data for a majority of the tested characteristics and channels, including channels with narrow and irregular conductivity pores. We propose that although the standard PNP model cannot provide insight into complex physical phenomena due to its intrinsic limitations, its semiquantitative agreement is achievable for rectification and selectivity at a level sufficient for the bioinformatical purpose of selecting the best structural models with a great advantage of a very short

  4. A comprehensive evaluation of the PRESAGE/optical-CT 3D dosimetry system

    SciTech Connect

    Sakhalkar, H. S.; Adamovics, J.; Ibbott, G.; Oldham, M.

    2009-01-15

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H and N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1x3 cm{sup 2}) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to {approx}2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in

  5. A comprehensive evaluation of the PRESAGE/optical-CT 3D dosimetry system.

    PubMed

    Sakhalkar, H S; Adamovics, J; Ibbott, G; Oldham, M

    2009-01-01

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H&N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1 x 3 cm2) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to approximately 2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in

  6. Two-dimensional evaluation of 3D needled Cf/SiC composite fiber bundle surface

    NASA Astrophysics Data System (ADS)

    Wei, Jinhua; Lin, Bin; Cao, Xiaoyan; Zhang, Xiaofeng; Fang, Sheng

    2015-11-01

    The variations of fiber bundle surface microstructure have direct influence on the material performance, especially the friction and wear properties. Therefore, fiber bundle is the smallest evaluation unit of Cf/SiC composite surface. However, due to the anisotropy and inhomogeneity of Cf/SiC composite, it is difficult to evaluate the surface characteristics. Researchers think that two-dimensional evaluation is not suitable for the composites surface assessment any more because of its complex composition and varied surface structure. In this paper, a novel method is introduced for the evaluation of 3D needled Cf/SiC composite fiber bundle surface. On the level of Cf/SiC composite fiber bundle surface, two-dimensional evaluation method is adopted, with which the fiber bundle surface quality can be quantitatively evaluated by the two-dimensional surface roughness Ra. As long as the extracted surface profiles averagely distributed on Cf/SiC composite fiber bundle surface, with appropriate sampling length and sampling number, the mean value of Ra can estimate the whole surface roughness, thus reflecting the roughness degree of surface accurately. This study not only benefits the detection of 3D needled Cf/SiC composite fiber bundle surface quality, and lays a foundation on the evaluation of material functional features in further. And it corresponds to the convenient application in engineering practice.

  7. A theoretical framework for 3D LADAR ATR problem definition and performance evaluation

    NASA Astrophysics Data System (ADS)

    DelMarco, Stephen; Sobel, Erik; Douglas, Joel

    2005-05-01

    LADAR imagery provides the capability to represent high resolution detail of 3D surface geometry of complex targets. In previous work we exploited this capability for automatic target recognition (ATR) by developing matching algorithms for performing surface matching of 3D LADAR point clouds with highly-detailed target CAD models. A central challenge in evaluating ATR performance is characterizing the degree of problem difficulty. One of the most important factors is the inherent similarity of target signatures. We've developed a flexible approach to target taxonomy based on 3D shape which includes a classification framework for defining the target recognition problem and evaluating ATR algorithm performance. The target model taxonomy consists of a hierarchical, tree-structured target classification scheme in which different levels of the tree correspond to different degrees of target classification difficulty. Each node in the tree corresponds to a collection of target models forming a target category. Target categories near the tree root represent large and very general target classes, exhibiting large interclass distance. Targets in these categories are easily separated. Target categories near the tree bottom represent very specific target classes with small interclass distance. These targets are difficult to separate. In this paper we focus on creation of optimal categories. We develop approaches for optimal aggregation of target model types into categories which provide for improved classification performance. We generate numerical results using match scores derived from matching highly-detailed CAD models of civilian ground vehicles.

  8. Evaluating the performance of close-range 3D active vision systems for industrial design applications

    NASA Astrophysics Data System (ADS)

    Beraldin, J.-Angelo; Gaiani, Marco

    2004-12-01

    In recent years, active three-dimensional (3D) active vision systems or range cameras for short have come out of research laboratories to find niche markets in application fields as diverse as industrial design, automotive manufacturing, geomatics, space exploration and cultural heritage to name a few. Many publications address different issues link to 3D sensing and processing but currently these technologies pose a number of challenges to many recent users, i.e., "what are they, how good are they and how do they compare?". The need to understand, test and integrate those range cameras with other technologies, e.g. photogrammetry, CAD, etc. is driven by the quest for optimal resolution, accuracy, speed and cost. Before investing, users want to be certain that a given range camera satisfy their operational requirements. The understanding of the basic theory and best practices associated with those cameras are in fact fundamental to fulfilling the requirements listed above in an optimal way. This paper addresses the evaluation of active 3D range cameras as part of a study to better understand and select one or a number of them to fulfill the needs of industrial design applications. In particular, object material and surface features effect, calibration and performance evaluation are discussed. Results are given for six different range cameras for close range applications.

  9. Evaluating the performance of close-range 3D active vision systems for industrial design applications

    NASA Astrophysics Data System (ADS)

    Beraldin, J.-Angelo; Gaiani, Marco

    2005-01-01

    In recent years, active three-dimensional (3D) active vision systems or range cameras for short have come out of research laboratories to find niche markets in application fields as diverse as industrial design, automotive manufacturing, geomatics, space exploration and cultural heritage to name a few. Many publications address different issues link to 3D sensing and processing but currently these technologies pose a number of challenges to many recent users, i.e., "what are they, how good are they and how do they compare?". The need to understand, test and integrate those range cameras with other technologies, e.g. photogrammetry, CAD, etc. is driven by the quest for optimal resolution, accuracy, speed and cost. Before investing, users want to be certain that a given range camera satisfy their operational requirements. The understanding of the basic theory and best practices associated with those cameras are in fact fundamental to fulfilling the requirements listed above in an optimal way. This paper addresses the evaluation of active 3D range cameras as part of a study to better understand and select one or a number of them to fulfill the needs of industrial design applications. In particular, object material and surface features effect, calibration and performance evaluation are discussed. Results are given for six different range cameras for close range applications.

  10. Registration of 3D ultrasound computer tomography and MRI for evaluation of tissue correspondences

    NASA Astrophysics Data System (ADS)

    Hopp, T.; Dapp, R.; Zapf, M.; Kretzek, E.; Gemmeke, H.; Ruiter, N. V.

    2015-03-01

    3D Ultrasound Computer Tomography (USCT) is a new imaging method for breast cancer diagnosis. In the current state of development it is essential to correlate USCT with a known imaging modality like MRI to evaluate how different tissue types are depicted. Due to different imaging conditions, e.g. with the breast subject to buoyancy in USCT, a direct correlation is demanding. We present a 3D image registration method to reduce positioning differences and allow direct side-by-side comparison of USCT and MRI volumes. It is based on a two-step approach including a buoyancy simulation with a biomechanical model and free form deformations using cubic B-Splines for a surface refinement. Simulation parameters are optimized patient-specifically in a simulated annealing scheme. The method was evaluated with in-vivo datasets resulting in an average registration error below 5mm. Correlating tissue structures can thereby be located in the same or nearby slices in both modalities and three-dimensional non-linear deformations due to the buoyancy are reduced. Image fusion of MRI volumes and USCT sound speed volumes was performed for intuitive display. By applying the registration to data of our first in-vivo study with the KIT 3D USCT, we could correlate several tissue structures in MRI and USCT images and learn how connective tissue, carcinomas and breast implants observed in the MRI are depicted in the USCT imaging modes.

  11. Supply-demand 3D dynamic model in water resources evaluation: taking Lebanon as an example

    NASA Astrophysics Data System (ADS)

    Fang, Hong; Hou, Zhimin

    2017-05-01

    In this paper, supply-demand 3D dynamic model is adopted to create a measurement of a region’s capacity to provide available water to meet the needs of its population. First of all, we draw a diagram between supply and demand. Then taking the main dynamic factors into account, we establish an index to evaluate the balance of supply and demand. The three dimension vector reflects the scarcity of industrial, agricultural and residential water. Lebanon is chosen as the object of case study, and we do quantitative analysis of its current situation. After data collecting and processing, we calculate the 3D vector in 2012, which reveals that agriculture is susceptible to water scarcity. Water resources of Lebanon are “physical rich” but “economic scarcity” according to the correlation chart and other statistical analysis.

  12. Ex vivo evaluation of new 2D and 3D dental radiographic technology for detecting caries

    PubMed Central

    Tyndall, Donald; Mol, André; Everett, Eric T; Bangdiwala, Ananta

    2016-01-01

    Objectives: Proximal dental caries remains a prevalent disease with only modest detection rates by current diagnostic systems. Many new systems are available without controlled validation of diagnostic efficacy. The objective of this study was to evaluate the diagnostic efficacy of three potentially promising new imaging systems. Methods: This study evaluated the caries detection efficacy of Schick 33 (Sirona Dental, Salzburg, Austria) intraoral digital detector images employing an advanced sharpening filter, Planmeca ProMax® (Planmeca Inc., Helsinki, Finland) extraoral “panoramic bitewing” images and Sirona Orthophos XG3D (Sirona Dental) CBCT images with advanced artefact reduction. Conventional photostimulable phosphor images served as the control modality. An ex vivo study design using extracted human teeth, ten expert observers and micro-CT ground truth was employed. Results: Receiver operating characteristic analysis indicated similar diagnostic efficacy of all systems (ANOVA p > 0.05). The sensitivity of the Schick 33 images (0.48) was significantly lower than the other modalities (0.53–0.62). The specificity of the Planmeca images (0.86) was significantly lower than Schick 33 (0.96) and XG3D (0.97). The XG3D showed significantly better cavitation detection sensitivity (0.62) than the other modalities (0.48–0.57). Conclusions: The Schick 33 images demonstrated reduced caries sensitivity, whereas the Planmeca panoramic bitewing images demonstrated reduced specificity. XG3D with artefact reduction demonstrated elevated sensitivity and specificity for caries detection, improved depth accuracy and substantially improved cavitation detection. Care must be taken to recognize potential false-positive caries lesions with Planmeca panoramic bitewing images. Use of CBCT for caries detection must be carefully balanced with the presence of metal artefacts, time commitment, financial cost and radiation dose. PMID:26670605

  13. Evaluation of 3D multi-contrast joint intra- and extracranial vessel wall cardiovascular magnetic resonance.

    PubMed

    Zhou, Zechen; Li, Rui; Zhao, Xihai; He, Le; Wang, Xiaole; Wang, Jinnan; Balu, Niranjan; Yuan, Chun

    2015-05-27

    Multi-contrast vessel wall cardiovascular magnetic resonance (CMR) has demonstrated its capability for atherosclerotic plaque morphology measurement and component characterization in different vasculatures. However, limited coverage and partial volume effect with conventional two-dimensional (2D) techniques might cause lesion underestimation. The aim of this work is to evaluate the performance in a) blood suppression and b) vessel wall delineation of three-dimensional (3D) multi-contrast joint intra- and extracranial vessel wall imaging at 3T. Three multi-contrast 3D black blood (BB) sequences with T1, T2 and heavy T1 weighting and a custom designed 36-channel neurovascular coil covering the entire intra- and extracranial vasculature have been used and investigated in this study. Two healthy subjects were recruited for sequence parameter optimization and twenty-five patients were consecutively scanned for image quality and blood suppression assessment. Qualitative image scores of vessel wall delineation as well as quantitative Signal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR) were evaluated at five typical locations ranging from common carotid arteries to middle cerebral arteries. The 3D multi-contrast images acquired within 15mins allowed the vessel wall visualization with 0.8 mm isotropic spatial resolution covering intra- and extracranial segments. Quantitative wall and lumen SNR measurements for each sequence showed effective blood suppression at all selected locations (P < 0.0001). Although the wall-lumen CNR varied across measured locations, each sequence provided good or adequate image quality in both intra- and extracranial segments. The proposed 3D multi-contrast vessel wall technique provides isotropic resolution and time efficient solution for joint intra- and extracranial vessel wall CMR.

  14. Treatment envelope evaluation in transcranial magnetic resonance-guided focused ultrasound utilizing 3D MR thermometry

    PubMed Central

    2014-01-01

    Background Current clinical targets for transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) are all located close to the geometric center of the skull convexity, which minimizes challenges related to focusing the ultrasound through the skull bone. Non-central targets will have to be reached to treat a wider variety of neurological disorders and solid tumors. Treatment envelope studies utilizing two-dimensional (2D) magnetic resonance (MR) thermometry have previously been performed to determine the regions in which therapeutic levels of FUS can currently be delivered. Since 2D MR thermometry was used, very limited information about unintended heating in near-field tissue/bone interfaces could be deduced. Methods In this paper, we present a proof-of-concept treatment envelope study with three-dimensional (3D) MR thermometry monitoring of FUS heatings performed in a phantom and a lamb model. While the moderate-sized transducer used was not designed for transcranial geometries, the 3D temperature maps enable monitoring of the entire sonication field of view, including both the focal spot and near-field tissue/bone interfaces, for full characterization of all heating that may occur. 3D MR thermometry is achieved by a combination of k-space subsampling and a previously described temporally constrained reconstruction method. Results We present two different types of treatment envelopes. The first is based only on the focal spot heating—the type that can be derived from 2D MR thermometry. The second type is based on the relative near-field heating and is calculated as the ratio between the focal spot heating and the near-field heating. This utilizes the full 3D MR thermometry data achieved in this study. Conclusions It is shown that 3D MR thermometry can be used to improve the safety assessment in treatment envelope evaluations. Using a non-optimal transducer, it is shown that some regions where therapeutic levels of FUS can be delivered, as suggested by

  15. Positioning evaluation of corrective osteotomy for the malunited radius: 3-D CT versus 2-D radiographs.

    PubMed

    Vroemen, Joy C; Dobbe, Johannes G G; Strackee, Simon D; Streekstra, Geert J

    2013-02-01

    The authors retrospectively investigated the postoperative position of the distal radius after a corrective osteotomy using 2-dimensional (2-D) and 3-dimensional (3-D) imaging techniques to determine whether malposition correlates with clinical outcome. Twenty-five patients who underwent a corrective osteotomy were available for follow-up. The residual positioning errors of the distal end were determined retrospectively using standard 2-D radiographs and 3-D computed tomography evaluations based on a scan of both forearms, with the contralateral healthy radius serving as reference. For 3-D analysis, use of an anatomical coordinate system for each reference bone allowed the authors to express the residual malalignment parameters in displacements (Δx, Δy, Δz) and rotations (Δφx, Δφy, Δφz) for aligning the affected bone in a standardized way with the corresponding reference bone. The authors investigated possible correlations between malalignment parameters and clinical outcome using patients' questionnaires. Two-dimensional radiographic evaluation showed a radial inclination of 24.9°±6.8°, a palmar tilt of 4.5°±8.6°, and an ulnar variance of 0.8±1.7 mm. With 3-D analysis, residual displacements were 2.6±3 (Δx), 2.4±3 (Δy), and -2.2±4 (Δz) mm. Residual rotations were -6.2°±10° (Δφx), 0.3°±7° (Δφy), and -5.1°±10° (Δφz). The large standard deviation is indicative of persistent malalignment in individual cases. Statistically significant correlations were found between 3-D rotational deficits and clinical outcome but not between 2-D evaluation parameters. Considerable residual malalignments and statistically significant correlations between malalignment parameters and clinical outcome confirm the need for better positioning techniques.

  16. Evaluation of Fish Passage at Whitewater Parks Using 2D and 3D Hydraulic Modeling

    NASA Astrophysics Data System (ADS)

    Hardee, T.; Nelson, P. A.; Kondratieff, M.; Bledsoe, B. P.

    2016-12-01

    In-stream whitewater parks (WWPs) are increasingly popular recreational amenities that typically create waves by constricting flow through a chute to increase velocities and form a hydraulic jump. However, the hydraulic conditions these structures create can limit longitudinal habitat connectivity and potentially inhibit upstream fish migration, especially of native fishes. An improved understanding of the fundamental hydraulic processes and potential environmental effects of whitewater parks is needed to inform management decisions about Recreational In-Channel Diversions (RICDs). Here, we use hydraulic models to compute a continuous and spatially explicit description of velocity and depth along potential fish swimming paths in the flow field, and the ensemble of potential paths are compared to fish swimming performance data to predict fish passage via logistic regression analysis. While 3d models have been shown to accurately predict trout movement through WWP structures, 2d methods can provide a more cost-effective and manager-friendly approach to assessing the effects of similar hydraulic structures on fish passage when 3d analysis in not feasible. Here, we use 2d models to examine the hydraulics in several WWP structures on the North Fork of the St. Vrain River at Lyons, Colorado, and we compare these model results to fish passage predictions from a 3d model. Our analysis establishes a foundation for a practical, transferable and physically-rigorous 2d modeling approach for mechanistically evaluating the effects of hydraulic structures on fish passage.

  17. Mining 3D Patterns from Gene Expression Temporal Data: A New Tricluster Evaluation Measure

    PubMed Central

    2014-01-01

    Microarrays have revolutionized biotechnological research. The analysis of new data generated represents a computational challenge due to the characteristics of these data. Clustering techniques are applied to create groups of genes that exhibit a similar behavior. Biclustering emerges as a valuable tool for microarray data analysis since it relaxes the constraints for grouping, allowing genes to be evaluated only under a subset of the conditions. However, if a third dimension appears in the data, triclustering is the appropriate tool for the analysis. This occurs in longitudinal experiments in which the genes are evaluated under conditions at several time points. All clustering, biclustering, and triclustering techniques guide their search for solutions by a measure that evaluates the quality of clusters. We present an evaluation measure for triclusters called Mean Square Residue 3D. This measure is based on the classic biclustering measure Mean Square Residue. Mean Square Residue 3D has been applied to both synthetic and real data and it has proved to be capable of extracting groups of genes with homogeneous patterns in subsets of conditions and times, and these groups have shown a high correlation level and they are also related to their functional annotations extracted from the Gene Ontology project. PMID:25143987

  18. In vitro evaluation of curcumin effects on breast adenocarcinoma 2D and 3D cell cultures.

    PubMed

    Abuelba, Hussam; Cotrutz, Carmen Elena; Stoica, Bogdan Alexandru; Stoica, Laura; Olinici, DoiniŢa; Petreuş, Tudor

    2015-01-01

    Breast adenocarcinoma cell line MDA-MB-231, even if it expresses low levels of E-cadherin, still readily form multicellular aggregates of cells, namely spheroids. Curcumin is a diarylheptanoid antitumoral drug while it significantly inhibits cell migration, invasion, and colony formation in vitro and reduces tumor growth and liver metastasis in vivo. Curcumin photoactivation may enhance antiapoptotic role against cancer cells. To evaluate the effect of low curcumin concentrations, ranged from 1.9 to 15 μM, with and without photoactivation, using a manufactured 670 nm LED-matrix. A secondary aim was to evaluate the ideal method to produce easy-to-use tumor cell spheroids, comparing two low adherence plate supports. Breast adenocarcinoma cell line MDA-MB-231 were cultured according to 2D monolayer and 3D spheroid models then submitted to normal and photoactivated curcumin in micromolar concentrations. MTT assay was used to evaluate cell viability following curcumin application on cells. On 2D cell cultures, curcumin inhibits cell tumor development and proliferation at concentrations of 15 μM, with a viability of 65.7% at 48 hours incubation time. A decreased viability up to 25% for a concentration of 15 μM was recorded following photoactivation and cytotoxic action on breast cancer tumor cell line continued at concentrations of 7.5 and 3.75 μM. Curcumin photoactivation increases pro-apoptotic effects in both 2D and 3D tumor cell culture models and also responsiveness to curcumin is slightly reduced in spheroid-like structures. Thus, 3D tumor cell culture systems appear to be the ideal environment for in vitro assays regarding anticancer drug effects on cell viability.

  19. [Atrial filling fraction predicts left ventricular systolic function after myocardial infarction: pre-discharge echocardiographic evaluation].

    PubMed

    Galderisi, M; Fakher, A; Petrocelli, A; Alfieri, A; Garofalo, M; de Divitiis, O

    1995-10-01

    Aim of the study was to examine the relation between Doppler-derived indices of left ventricular diastolic and systolic function early after myocardial infarction. Fifty-three patients (31 males, 22 females) recovering from acute myocardial infarction underwent predischarge Doppler echocardiographic examination. Patients with age > 70 years, previous myocardial infarction, more than mild mitral and aortic regurgitation, mitral and aortic stenosis were excluded. Twenty-two healthy subjects (13 males; 9 females) free of coronary risk factors were selected as the control group. Both end-diastolic and end-systolic volumes and ejection fraction were measured by two-dimensional echocardiography. Pulsed Doppler was used to evaluate mitral inflow and left ventricular outflow velocity patterns. The following indices were measured: peak velocity of early (E) and late (A) flows, ratio of E/A peak velocities, ratio of early to late time velocity integrals, atrial filling fraction (time velocity integral A / time velocity integral of flow during total diastole) and deceleration time of E wave for mitral inflow; peak and time-velocity integral for left ventricular outflow. Stroke volume and cardiac output were obtained by pulsed Doppler using the left ventricular outflow method. The two groups were comparable for age, with blood pressure (p < 0.05) and heart rate (p < 0.01) reduced in myocardial infarction patients. Both end-diastolic and end-systolic volumes were significantly higher (both p < 0.0001) and ejection fraction (p < 0.0001) lower after myocardial infarction. Also stroke volume and cardiac output (both p < 0.0001) were reduced in myocardial infarction patients. No significant difference in Doppler indices of diastolic function was observed between the two groups, except for shortened deceleration time (p < 0.0001) in myocardial infarction patients. Multilinear regression analyses were performed separately into the two groups to identify determinants of left

  20. Evaluation of interlaminar shear of laminate by 3D digital holography

    NASA Astrophysics Data System (ADS)

    Mayssa, Karray; Christophe, Poilane; Mohamed, Gargouri; Pascal, Picart

    2017-05-01

    In this paper, we propose a three-color holographic interferometer devoted to the 3D displacement field analysis of a composite material. The method in applied to analyze cracks during a short beam shear test. The tested materials are a glass/epoxy composite, a flax/carbon/epoxy composite and a flax/epoxy composite. Such an evaluation provides a pertinent parameter to detect premature cracks in the structure, long before it becomes visible on the real time stress/strain curve, or with a classical microscope. Moreover, the mechanical proprieties of flax/carbon/epoxy composite and flax/epoxy composite are compared.

  1. EEG based evaluation of stereoscopic 3D displays for viewer discomfort.

    PubMed

    Malik, Aamir Saeed; Khairuddin, Raja Nur Hamizah Raja; Amin, Hafeez Ullah; Smith, Mark Llewellyn; Kamel, Nidal; Abdullah, Jafri Malin; Fawzy, Samar Mohammad; Shim, Seongo

    2015-03-11

    Consumer preference is rapidly changing from 2D to 3D movies due to the sensational effects of 3D scenes, like those in Avatar and The Hobbit. Two 3D viewing technologies are available: active shutter glasses and passive polarized glasses. However, there are consistent reports of discomfort while viewing in 3D mode where the discomfort may refer to dizziness, headaches, nausea or simply not being able to see in 3D continuously. In this paper, we propose a theory that 3D technology which projects the two images (required for 3D perception) alternatively, cannot provide true 3D visual experience while the 3D technology projecting the two images simultaneously is closest to the human visual system for depth perception. Then we validate our theory by conducting experiments with 40 subjects and analyzing the EEG results of viewing 3D movie clips with passive polarized glasses while the images are projected simultaneously compared to 2D viewing. In addition, subjective feedback of the subjects was also collected and analyzed. A higher theta and alpha band absolute power is observed across various areas including the occipital lobe for 3D viewing. We also found that the complexity of the signal, e.g. variations in EEG samples over time, increases in 3D as compared to 2D. Various results conclude that working memory, as well as, attention is increased in 3D viewing because of the processing of more data in 3D as compared to 2D. From subjective feedback analysis, 75% of subjects felt comfortable with 3D passive polarized while 25% preferred 3D active shutter technology. We conclude that 3D passive polarized technology provides more comfortable visualization than 3D active shutter technology. Overall, 3D viewing is more attractive than 2D due to stereopsis which may cause of high attention and involvement of working memory manipulations.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  3. Evaluation of surface roughness of the bracket slot floor--a 3D perspective study.

    PubMed

    Agarwal, Chetankumar O; Vakil, Ketan K; Mahamuni, Avinash; Tekale, Pawankumar Dnyandeo; Gayake, Prasad V; Vakil, Jeegar K

    2016-01-01

    An important constituent of an orthodontic appliance is orthodontic brackets. It is either the bracket or the archwire that slides through the bracket slot, during sliding mechanics. Overcoming the friction between the two surfaces demands an important consideration in an appliance design. The present study investigated the surface roughness of four different commercially available stainless steel brackets. All tests were carried out to analyse quantitatively the morphological surface of the bracket slot floor with the help of scanning electron microscope (SEM) machine and to qualitatively analyse the average surface roughness (Sa) of the bracket slot floor with the help of a three-dimensional (3D) non-contact optical surface profilometer machine. The SEM microphotographs were evaluated with the help of visual analogue scale, the surface roughness for group A = 0-very rough surface, group C = 1--rough surface, group B = 2--smooth surface, and group D = 3-very smooth surface. Surface roughness evaluation with the 3D non-contact optical surface profilometer machine was highest for group A, followed by group C, group B and group D. Groups B and D provided smooth surface roughness; however, group D had the very smooth surface with values 0.74 and 0.75 for mesial and distal slots, respectively. Evaluation of surface roughness of the bracket slot floor with both SEM and profilometer machine led to the conclusion that the average surface roughness was highest for group A, followed by group C, group B and group D.

  4. 3D-DIR for early differential diagnostic and prognostic evaluation of NMO

    PubMed Central

    Wang, Yanbing; Yan, Hong; Ding, Qixing; Mao, Cunhua; Shen, Yelong; Wang, Guangbin

    2016-01-01

    Neuromyelitis optica (NMO) is an acute or subacute lesion of demyelinating disease involving the optic nerve and spinal cord, and imaging techniques and their effects have been the focus of investigations. The aim of the present study was to examine the value of three-dimensional double inversion recovery (3D-DIR) in the early differential diagnostic and prognostic evaluation of NMO. Forty-eight patients with suspicious NMO were included into the study and underwent a combination of serum NMO-IgG quantitative detection and 3D-DIR examination. Forty cases (83.3%) of the suspicious cases were confirmed with NMO. The average time from onset to definite diagnosis was 3.5±0.6 days. The brain showed high T2W and fluid-attenuated inversion recovery (FLAIR) signals, involving 5.8±1.2 sites on average, distributed in the peripheral lateral ventricle, medulla, cerebral white matter, the third ventricle, peripheral aqueduct of sylvius, pons and diencephalon. The average T2W signal strength was 2.73±0.12. The signal intensity of DIR was significantly higher than that of T2W and FLAIR, and the difference was statistically significant. The optic nerve and chiasma showed a high FLAIR signal, with an average signal intensity of 2.13±0.14. The spinal cord showed swelling, necrosis and cavity lesion, involving the gray and white matter of the central site, transversely, with an average lesion length of 4.7±0.6 centrum. The relative signal intensity of DIR was significantly higher than that of T2W and FLAIR. Following treatment, the signal intensity of the brain, optic nerve, optic chiasma and spinal cord decreased significantly (P<0.05). In conclusion, 3D-DIR has great application value in the early differential diagnostic and prognostic evaluation of NMO. PMID:27588068

  5. Evaluation of PC-ISO for customized, 3D printed, gynecologic 192Ir HDR brachytherapy applicators.

    PubMed

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-01

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. PACS number: none.

  6. Evaluation of PC-ISO for customized, 3D Printed, gynecologic 192-Ir HDR brachytherapy applicators.

    PubMed

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-08

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. 

  7. Some Experiences in 3D Laser Scanning for Assisting Restoration and Evaluating Damage in Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Fuentes, L. M.; Finat, Javier; Fernández-Martin, J. J.; Martínez, J.; SanJose, J. I.

    The recent incorporation of laser devices provides advanced tools for assisting the conservation and restoration of Cultural Heritage. It is necessary to have as complete as possible understanding of the object state before evaluating or defining the reach of the restoration process. Thus, a special effort is devoted to surveying, measuring and generating a high-resolution 3D model prior to restoration planning. This work presents results of several experiments performed on damaged pieces for evaluation purposes in Cultural Heritage. Some software tools are applied for carving-work analysis, conservation-state monitoring, and simulation of weathering processes for evaluating temporal changes. In all cases considered, a high resolution information capture has been performed with a laser scanner, the Minolta 910. Our approach is flexible enough to be adapted to other kinds of pieces or Cultural Heritage artefacts, in order to provide an assessment for intervention planning in conservation and restoration tasks.

  8. The Performance Evaluation of Multi-Image 3d Reconstruction Software with Different Sensors

    NASA Astrophysics Data System (ADS)

    Mousavi, V.; Khosravi, M.; Ahmadi, M.; Noori, N.; Naveh, A. Hosseini; Varshosaz, M.

    2015-12-01

    Today, multi-image 3D reconstruction is an active research field and generating three dimensional model of the objects is one the most discussed issues in Photogrammetry and Computer Vision that can be accomplished using range-based or image-based methods. Very accurate and dense point clouds generated by range-based methods such as structured light systems and laser scanners has introduced them as reliable tools in the industry. Image-based 3D digitization methodologies offer the option of reconstructing an object by a set of unordered images that depict it from different viewpoints. As their hardware requirements are narrowed down to a digital camera and a computer system, they compose an attractive 3D digitization approach, consequently, although range-based methods are generally very accurate, image-based methods are low-cost and can be easily used by non-professional users. One of the factors affecting the accuracy of the obtained model in image-based methods is the software and algorithm used to generate three dimensional model. These algorithms are provided in the form of commercial software, open source and web-based services. Another important factor in the accuracy of the obtained model is the type of sensor used. Due to availability of mobile sensors to the public, popularity of professional sensors and the advent of stereo sensors, a comparison of these three sensors plays an effective role in evaluating and finding the optimized method to generate three-dimensional models. Lots of research has been accomplished to identify a suitable software and algorithm to achieve an accurate and complete model, however little attention is paid to the type of sensors used and its effects on the quality of the final model. The purpose of this paper is deliberation and the introduction of an appropriate combination of a sensor and software to provide a complete model with the highest accuracy. To do this, different software, used in previous studies, were compared and

  9. Development of a patient-specific 3D dose evaluation program for QA in radiation therapy

    NASA Astrophysics Data System (ADS)

    Lee, Suk; Chang, Kyung Hwan; Cao, Yuan Jie; Shim, Jang Bo; Yang, Dae Sik; Park, Young Je; Yoon, Won Sup; Kim, Chul Yong

    2015-03-01

    We present preliminary results for a 3-dimensional dose evaluation software system ( P DRESS, patient-specific 3-dimensional dose real evaluation system). Scanned computed tomography (CT) images obtained by using dosimetry were transferred to the radiation treatment planning system (ECLIPSE, VARIAN, Palo Alto, CA) where the intensity modulated radiation therapy (IMRT) nasopharynx plan was designed. We used a 10 MV photon beam (CLiX, VARIAN, Palo Alto, CA) to deliver the nasopharynx treatment plan. After irradiation, the TENOMAG dosimeter was scanned using a VISTA ™ scanner. The scanned data were reconstructed using VistaRecon software to obtain a 3D dose distribution of the optical density. An optical-CT scanner was used to readout the dose distribution in the gel dosimeter. Moreover, we developed the P DRESS by using Flatform, which were developed by our group, to display the 3D dose distribution by loading the DICOM RT data which are exported from the radiotherapy treatment plan (RTP) and the optical-CT reconstructed VFF file, into the independent P DRESS with an ioniz ation chamber and EBT film was used to compare the dose distribution calculated from the RTP with that measured by using a gel dosimeter. The agreement between the normalized EBT, the gel dosimeter and RTP data was evaluated using both qualitative and quantitative methods, such as the isodose distribution, dose difference, point value, and profile. The profiles showed good agreement between the RTP data and the gel dosimeter data, and the precision of the dose distribution was within ±3%. The results from this study showed significantly discrepancies between the dose distribution calculated from the treatment plan and the dose distribution measured by a TENOMAG gel and by scanning with an optical CT scanner. The 3D dose evaluation software system ( P DRESS, patient specific dose real evaluation system), which were developed in this study evaluates the accuracies of the three-dimensional dose

  10. Evaluation of helper-dependent canine adenovirus vectors in a 3D human CNS model.

    PubMed

    Simão, D; Pinto, C; Fernandes, P; Peddie, C J; Piersanti, S; Collinson, L M; Salinas, S; Saggio, I; Schiavo, G; Kremer, E J; Brito, C; Alves, P M

    2016-01-01

    Gene therapy is a promising approach with enormous potential for treatment of neurodegenerative disorders. Viral vectors derived from canine adenovirus type 2 (CAV-2) present attractive features for gene delivery strategies in the human brain, by preferentially transducing neurons, are capable of efficient axonal transport to afferent brain structures, have a 30-kb cloning capacity and have low innate and induced immunogenicity in preclinical tests. For clinical translation, in-depth preclinical evaluation of efficacy and safety in a human setting is primordial. Stem cell-derived human neural cells have a great potential as complementary tools by bridging the gap between animal models, which often diverge considerably from human phenotype, and clinical trials. Herein, we explore helper-dependent CAV-2 (hd-CAV-2) efficacy and safety for gene delivery in a human stem cell-derived 3D neural in vitro model. Assessment of hd-CAV-2 vector efficacy was performed at different multiplicities of infection, by evaluating transgene expression and impact on cell viability, ultrastructural cellular organization and neuronal gene expression. Under optimized conditions, hd-CAV-2 transduction led to stable long-term transgene expression with minimal toxicity. hd-CAV-2 preferentially transduced neurons, whereas human adenovirus type 5 (HAdV5) showed increased tropism toward glial cells. This work demonstrates, in a physiologically relevant 3D model, that hd-CAV-2 vectors are efficient tools for gene delivery to human neurons, with stable long-term transgene expression and minimal cytotoxicity.

  11. TH-C-19A-05: Evaluation of a New Reusable 3D Dosimeter

    SciTech Connect

    Juang, T; Adamovics, J; Oldham, M

    2014-06-15

    Purpose: PRESAGE is a radiochromic plastic which has demonstrated strong potential for high resolution single-use 3D dosimetry. This study evaluates a new PRESAGE formulation (Presage-RU) in which the radiochromic response is reversible (the dosimeter optically clears after irradiation), enabling the potential for reusability. Methods: Presage-RU dose response and optical-clearing rates were evaluated in both small volume dosimeters (1×1×4.5cm) and a larger cylindrical dosimeter (8cm diameter, 4.5cm length). All dosimeters were allowed to fully optically clear in dark, room temperature conditions between irradiations. Dose response was determined by irradiating small volume samples from 0–8.0Gy and measuring change in optical density. The cylindrical dosimeter was irradiated with a simple 4-field box plan (parallel opposed pairs of 4cm×4cm AP-PA beams and 2cm×4cm lateral beams) to 20Gy. High resolution 3D dosimetry was achieved utilizing optical-CT readout. Readings were tracked up to 14 days to characterize optical clearing. Results: Initial irradiation yielded a response of 0.0119△OD/(Gy*cm) while two subsequent reirradiations yielded a lower but consistent response of 0.0087△OD/(Gy*cm). Strong linearity of dose response was observed for all irradiations. In the large cylindrical dosimeter, the integral dose within the high dose region exhibited an exponential decay in signal over time (halflife= 23.9 hours), with the dosimeter effectively cleared (0.04% of the initial signal) after 10 days. Subsequent irradiation resulted in 19.5% lower initial signal but demonstrated that the exponential clearing rate remained consistent. Results of additional subsequent irradiations will also be presented. Conclusion: This work introduces a new re-usable radiochromic dosimeter (Presage-RU) compatible with high resolution (sub-millimeter) 3D dosimetry. Sensitivity of the initial radiation was observed to be slightly higher than subsequent irradiations, but the

  12. MAL Daylight Photodynamic Therapy for Actinic Keratosis: Clinical and Imaging Evaluation by 3D Camera.

    PubMed

    Cantisani, Carmen; Paolino, Giovanni; Pellacani, Giovanni; Didona, Dario; Scarno, Marco; Faina, Valentina; Gobello, Tommaso; Calvieri, Stefano

    2016-07-11

    Non-melanoma skin cancer is the most common skin cancer with an incidence that varies widely worldwide. Among them, actinic keratosis (AK), considered by some authors as in situ squamous cell carcinoma (SCC), are the most common and reflect an abnormal multistep skin cell development due to the chronic ultraviolet (UV) light exposure. No ideal treatment exists, but the potential risk of their development in a more invasive form requires prompt treatment. As patients usually present with multiple AK on fields of actinic damage, there is a need for effective, safe, simple and short treatments which allow the treatment of large areas. To achieve this, daylight photodynamic therapy (DL-PDT) is an innovative treatment for multiple mild actinic keratosis, well tolerated by patients. Patients allocated to the PDT unit, affected by multiple mild-moderate and severe actinic keratosis on sun-exposed areas treated with DL-PDT, were clinically evaluated at baseline and every three months with an Antera 3D, Miravex(©) camera. Clinical and 3D images were performed at each clinical check almost every three months. In this retrospective study, 331 patients (56.7% male, 43.3% female) were treated with DL-PDT. We observed a full clearance in more than two-thirds of patients with one or two treatments. Different responses depend on the number of lesions and on their severity; for patients with 1-3 lesions and with grade I or II AK, a full clearance was reached in 85% of cases with a maximum of two treatments. DL-PDT in general improved skin tone and erased sun damage. Evaluating each Antera 3D images, hemoglobin concentration and pigmentation, a skin color and tone improvement in 310 patients was observed. DL-PDT appears as a promising, effective, simple, tolerable and practical treatment for actinic damage associated with AK, and even treatment of large areas can be with little or no pain. The 3D imaging allowed for quantifying in real time the aesthetic benefits of DL

  13. MAL Daylight Photodynamic Therapy for Actinic Keratosis: Clinical and Imaging Evaluation by 3D Camera

    PubMed Central

    Cantisani, Carmen; Paolino, Giovanni; Pellacani, Giovanni; Didona, Dario; Scarno, Marco; Faina, Valentina; Gobello, Tommaso; Calvieri, Stefano

    2016-01-01

    Non-melanoma skin cancer is the most common skin cancer with an incidence that varies widely worldwide. Among them, actinic keratosis (AK), considered by some authors as in situ squamous cell carcinoma (SCC), are the most common and reflect an abnormal multistep skin cell development due to the chronic ultraviolet (UV) light exposure. No ideal treatment exists, but the potential risk of their development in a more invasive form requires prompt treatment. As patients usually present with multiple AK on fields of actinic damage, there is a need for effective, safe, simple and short treatments which allow the treatment of large areas. To achieve this, daylight photodynamic therapy (DL-PDT) is an innovative treatment for multiple mild actinic keratosis, well tolerated by patients. Patients allocated to the PDT unit, affected by multiple mild−moderate and severe actinic keratosis on sun-exposed areas treated with DL-PDT, were clinically evaluated at baseline and every three months with an Antera 3D, Miravex© camera. Clinical and 3D images were performed at each clinical check almost every three months. In this retrospective study, 331 patients (56.7% male, 43.3% female) were treated with DL-PDT. We observed a full clearance in more than two-thirds of patients with one or two treatments. Different responses depend on the number of lesions and on their severity; for patients with 1–3 lesions and with grade I or II AK, a full clearance was reached in 85% of cases with a maximum of two treatments. DL-PDT in general improved skin tone and erased sun damage. Evaluating each Antera 3D images, hemoglobin concentration and pigmentation, a skin color and tone improvement in 310 patients was observed. DL-PDT appears as a promising, effective, simple, tolerable and practical treatment for actinic damage associated with AK, and even treatment of large areas can be with little or no pain. The 3D imaging allowed for quantifying in real time the aesthetic benefits of DL

  14. Three-dimensional echocardiographic quantitative evaluation of left ventricular diastolic function using analysis of chamber volume and myocardial deformation.

    PubMed

    Yodwut, Chattanong; Lang, Roberto M; Weinert, Lynn; Ahmad, Homaa; Mor-Avi, Victor

    2013-02-01

    Currently, no real-time three-dimensional echocardiographic (RT3DE) indices are recommended by the official guidelines for the assessment of diastolic dysfunction (DD). We hypothesized that recent developments in RT3DE imaging technology that allow dynamic quantification of both left ventricular (LV) volume and 3D myocardial deformation, could be utilized to objectively assess DD. Transthoracic RT3DE datasets were acquired (Philips iE33, X5 transducer, frame rate 19 ± 4) in 76 subjects, including 20 normal controls (NL), 16 mild DD, 20 moderate DD and 20 severe DD (grade 1, 2 and 3, respectively, using ASE guideline). Images were analyzed using prototype software (TomTec) that performs 3D speckle tracking to generate time curves of LV volume and segmental myocardial strain. Indices of diastolic LV function were calculated: volume at 25, 50 and 75 % of filling duration (FD) in percent of end-diastolic volume (volume index, LVVi), and rapid filling volume (RFV) fraction. Temporal indices included: FD in % of RR, and rapid filling duration (RFD) in % of FD. Additionally, longitudinal, radial and circumferential strains at 25, 50 and 75 % of FD were calculated. Inter-groups differences were tested using ANOVA. LVVi and RFV fraction showed a biphasic pattern with the severity of DD characterized by an initial decrease (grade 1), a pseudo-normalization (grade 2), and then an increase above normal (grade 3). FD progressively decreased with severity of DD. RFD was significantly increased in all 3 groups compared to NL. After normalization by peak systolic values, all three strain components showed a linear pattern with the severity of DD, suggesting potential clinical usefulness. This is the first study to show that current RT3DE technology allows combined quantitative analysis of LV volume and 3D myocardial strain, which is sensitive enough to demonstrate differences in myocardial relaxation in patients with different degrees of DD.

  15. Evaluation of passive polarized stereoscopic 3D display for visual & mental fatigues.

    PubMed

    Amin, Hafeez Ullah; Malik, Aamir Saeed; Mumtaz, Wajid; Badruddin, Nasreen; Kamel, Nidal

    2015-01-01

    Visual and mental fatigues induced by active shutter stereoscopic 3D (S3D) display have been reported using event-related brain potentials (ERP). An important question, that is whether such effects (visual & mental fatigues) can be found in passive polarized S3D display, is answered here. Sixty-eight healthy participants are divided into 2D and S3D groups and subjected to an oddball paradigm after being exposed to S3D videos with passive polarized display or 2D display. The age and fluid intelligence ability of the participants are controlled between the groups. ERP results do not show any significant differences between S3D and 2D groups to find the aftereffects of S3D in terms of visual and mental fatigues. Hence, we conclude that passive polarized S3D display technology may not induce visual and/or mental fatigue which may increase the cognitive load and suppress the ERP components.

  16. Design and Performance Evaluation on Ultra-Wideband Time-Of-Arrival 3D Tracking System

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Dusl, John

    2012-01-01

    A three-dimensional (3D) Ultra-Wideband (UWB) Time--of-Arrival (TOA) tracking system has been studied at NASA Johnson Space Center (JSC) to provide the tracking capability inside the International Space Station (ISS) modules for various applications. One of applications is to locate and report the location where crew experienced possible high level of carbon-dioxide and felt upset. In order to accurately locate those places in a multipath intensive environment like ISS modules, it requires a robust real-time location system (RTLS) which can provide the required accuracy and update rate. A 3D UWB TOA tracking system with two-way ranging has been proposed and studied. The designed system will be tested in the Wireless Habitat Testbed which simulates the ISS module environment. In this presentation, we discuss the 3D TOA tracking algorithm and the performance evaluation based on different tracking baseline configurations. The simulation results show that two configurations of the tracking baseline are feasible. With 100 picoseconds standard deviation (STD) of TOA estimates, the average tracking error 0.2392 feet (about 7 centimeters) can be achieved for configuration Twisted Rectangle while the average tracking error 0.9183 feet (about 28 centimeters) can be achieved for configuration Slightly-Twisted Top Rectangle . The tracking accuracy can be further improved with the improvement of the STD of TOA estimates. With 10 picoseconds STD of TOA estimates, the average tracking error 0.0239 feet (less than 1 centimeter) can be achieved for configuration "Twisted Rectangle".

  17. Evaluation of feature-based 3-d registration of probabilistic volumetric scenes

    NASA Astrophysics Data System (ADS)

    Restrepo, Maria I.; Ulusoy, Ali O.; Mundy, Joseph L.

    2014-12-01

    Automatic estimation of the world surfaces from aerial images has seen much attention and progress in recent years. Among current modeling technologies, probabilistic volumetric models (PVMs) have evolved as an alternative representation that can learn geometry and appearance in a dense and probabilistic manner. Recent progress, in terms of storage and speed, achieved in the area of volumetric modeling, opens the opportunity to develop new frameworks that make use of the PVM to pursue the ultimate goal of creating an entire map of the earth, where one can reason about the semantics and dynamics of the 3-d world. Aligning 3-d models collected at different time-instances constitutes an important step for successful fusion of large spatio-temporal information. This paper evaluates how effectively probabilistic volumetric models can be aligned using robust feature-matching techniques, while considering different scenarios that reflect the kind of variability observed across aerial video collections from different time instances. More precisely, this work investigates variability in terms of discretization, resolution and sampling density, errors in the camera orientation, and changes in illumination and geographic characteristics. All results are given for large-scale, outdoor sites. In order to facilitate the comparison of the registration performance of PVMs to that of other 3-d reconstruction techniques, the registration pipeline is also carried out using Patch-based Multi-View Stereo (PMVS) algorithm. Registration performance is similar for scenes that have favorable geometry and the appearance characteristics necessary for high quality reconstruction. In scenes containing trees, such as a park, or many buildings, such as a city center, registration performance is significantly more accurate when using the PVM.

  18. Evaluation of a 3D serious game for advanced life support retraining.

    PubMed

    Buttussi, Fabio; Pellis, Tommaso; Cabas Vidani, Alberto; Pausler, Daniele; Carchietti, Elio; Chittaro, Luca

    2013-09-01

    Advanced life support (ALS) knowledge and skills decrease in as little as three months, but only a few ALS providers actually attend retraining courses. We assess the effectiveness of a 3D serious game as a new tool for frequent ALS retraining. We developed a 3D serious game for scenario-based ALS retraining. The serious game, called EMSAVE, was designed to promote self-correction while playing. We organized a retraining course in which 40 ALS providers played two cardiac arrest scenarios with EMSAVE and took a test with 38 multiple-choice questions before and after playing. We administered the same test again 3 months later to evaluate retention. Participants also rated EMSAVE and the overall retraining experience. After using EMSAVE, the number of correct answers per participant increased by 4.8 (95%CI +3.4, +6.2, p<0.001) and all but one participant improved. After 3 months, despite an expected decrease in ALS knowledge and skills (-1.9 correct answers, 95%CI -0.6, -3.3, p<0.01), there was a significant retention benefit (+2.9 correct answers per participant, 95%CI +1.5, +4.2, p<0.001). Moreover, all but one participant regarded EMSAVE as a valuable tool to refresh ALS knowledge and skills, and 85% of participants were also willing to devote 1h/month to retrain with the serious game. A 3D serious game for scenario-based retraining proved effective to retrain in ALS and supported retention of acquired knowledge and skills at 3 months. EMSAVE also positively engaged and motivated participants. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  19. Evaluation of Full Reynolds Stress Turbulence Models in FUN3D

    NASA Technical Reports Server (NTRS)

    Dudek, Julianne C.; Carlson, Jan-Renee

    2017-01-01

    Full seven-equation Reynolds stress turbulence models are a relatively new and promising tool for todays aerospace technology challenges. This paper uses two stress-omega full Reynolds stress models to evaluate challenging flows including shock-wave boundary layer interactions, separation and mixing layers. The Wilcox and the SSG/LRR full second-moment Reynolds stress models have been implemented into the FUN3D (Fully Unstructured Navier-Stokes Three Dimensional) unstructured Navier-Stokes code and are evaluated for four problems: a transonic two-dimensional diffuser, a supersonic axisymmetric compression corner, a compressible planar shear layer, and a subsonic axisymmetric jet. Simulation results are compared with experimental data and results using the more commonly used Spalart-Allmaras (SA) one-equation and the Menter Shear Stress Transport (SST-V) two-equation turbulence models.

  20. Evaluation of 3D printing and its potential impact on biotechnology and the chemical sciences.

    PubMed

    Gross, Bethany C; Erkal, Jayda L; Lockwood, Sarah Y; Chen, Chengpeng; Spence, Dana M

    2014-04-01

    Nearing 30 years since its introduction, 3D printing technology is set to revolutionize research and teaching laboratories. This feature encompasses the history of 3D printing, reviews various printing methods, and presents current applications. The authors offer an appraisal of the future direction and impact this technology will have on laboratory settings as 3D printers become more accessible.

  1. A novel time dependent gamma evaluation function for dynamic 2D and 3D dose distributions.

    PubMed

    Podesta, Mark; Persoon, Lucas C G G; Verhaegen, Frank

    2014-10-21

    Modern external beam radiotherapy requires detailed verification and quality assurance so that confidence can be placed on both the delivery of a single treatment fraction and on the consistency of delivery throughout the treatment course. To verify dose distributions, a comparison between prediction and measurement must be made. Comparisons between two dose distributions are commonly performed using a Gamma evaluation which is a calculation of two quantities on a pixel by pixel basis; the dose difference, and the distance to agreement. By providing acceptance criteria (e.g. 3%, 3 mm), the function will find the most appropriate match within its two degrees of freedom. For complex dynamic treatments such as IMRT or VMAT it is important to verify the dose delivery in a time dependent manner and so a gamma evaluation that includes a degree of freedom in the time domain via a third parameter, time to agreement, is presented here. A C++ (mex) based gamma function was created that could be run on either CPU and GPU computing platforms that would allow a degree of freedom in the time domain. Simple test cases were created in both 2D and 3D comprising of simple geometrical shapes with well-defined boundaries varying over time. Changes of varying magnitude in either space or time were introduced and repeated gamma analyses were performed varying the criteria. A clinical VMAT case was also included, artificial air bubbles of varying size were introduced to a patient geometry, along with shifts of varying magnitude in treatment time. For all test cases where errors in distance, dose or time were introduced, the time dependent gamma evaluation could accurately highlight the errors.The time dependent gamma function presented here allows time to be included as a degree of freedom in gamma evaluations. The function allows for 2D and 3D data sets which are varying over time to be compared using appropriate criteria without penalising minor offsets of subsequent radiation fields

  2. A novel time dependent gamma evaluation function for dynamic 2D and 3D dose distributions

    NASA Astrophysics Data System (ADS)

    Podesta, Mark; CGG Persoon, Lucas; Verhaegen, Frank

    2014-10-01

    Modern external beam radiotherapy requires detailed verification and quality assurance so that confidence can be placed on both the delivery of a single treatment fraction and on the consistency of delivery throughout the treatment course. To verify dose distributions, a comparison between prediction and measurement must be made. Comparisons between two dose distributions are commonly performed using a Gamma evaluation which is a calculation of two quantities on a pixel by pixel basis; the dose difference, and the distance to agreement. By providing acceptance criteria (e.g. 3%, 3 mm), the function will find the most appropriate match within its two degrees of freedom. For complex dynamic treatments such as IMRT or VMAT it is important to verify the dose delivery in a time dependent manner and so a gamma evaluation that includes a degree of freedom in the time domain via a third parameter, time to agreement, is presented here. A C++ (mex) based gamma function was created that could be run on either CPU and GPU computing platforms that would allow a degree of freedom in the time domain. Simple test cases were created in both 2D and 3D comprising of simple geometrical shapes with well-defined boundaries varying over time. Changes of varying magnitude in either space or time were introduced and repeated gamma analyses were performed varying the criteria. A clinical VMAT case was also included, artificial air bubbles of varying size were introduced to a patient geometry, along with shifts of varying magnitude in treatment time. For all test cases where errors in distance, dose or time were introduced, the time dependent gamma evaluation could accurately highlight the errors. The time dependent gamma function presented here allows time to be included as a degree of freedom in gamma evaluations. The function allows for 2D and 3D data sets which are varying over time to be compared using appropriate criteria without penalising minor offsets of subsequent radiation

  3. Echocardiographic evaluation of the cardiovascular effects of short-duration spaceflight

    NASA Technical Reports Server (NTRS)

    Mulvagh, Sharon L.; Charles, John B.; Riddle, Jeanne M.; Rehbein, Tracy L.; Bungo, Michael W.

    1991-01-01

    Results are presented of echocardiographic investigations and hemodynamic measurements performed on 24 astronauts before and after short-duration (4-5 days) spaceflight, including data on the heart rate, blood pressure, and cardiac volumes. Cardiovascular changes which were found to occur after 4-5 day long spaceflight included decreased the left ventricular end-diastolic volume and the stroke volume indices, with a compensatory increased heart rate and the cardiac output being maintained; in addition, altered total peripheral vascular resistance was found to occur, with an apparent reduction in the ability to augment the peripheral vascular tone upon assuming the standing position. These cardiovascular characteristics normalized within 48 hrs of landing.

  4. Transesophageal echocardiographic evaluation of baboons during microgravity induced by parabolic flight

    NASA Technical Reports Server (NTRS)

    Vernalis, Marina N.; Latham, Ricky D.; Fanton, John W.; Geffney, F. Andrew

    1993-01-01

    Transthoracic echocardiography (TTE) is a feasible method to noninvasively examine cardiac anatomy during parabolic flight. However, transducer placement on the chest wall is very difficult to maintain during transition to microgravity. In addition, TTE requires the use of low frequency transponders which limit resolution. Transesophical echocardiography (TEE) is an established imaging technique which obtains echocardiographic information from the esophagus. It is a safe procedure and provides higher quality images of cardiac structure than obtained with TTE. This study is designed to determine whether TEE was feasible to perform during parabolic flight and to determine whether acute central volume responses occur in acute transition to zero gravity by direct visualization of the cardiac chambers.

  5. Echocardiographic Evaluation of Left Atrial Mechanics: Function, History, Novel Techniques, Advantages, and Pitfalls

    PubMed Central

    Littwitz, Henning; Dworrak, Birgit; Garg, Pankaj; Zhu, Meihua; Sahn, David J.; Horlitz, Marc

    2015-01-01

    Left atrial (LA) functional analysis has an established role in assessing left ventricular diastolic function. The current standard echocardiographic parameters used to study left ventricular diastolic function include pulsed-wave Doppler mitral inflow analysis, tissue Doppler imaging measurements, and LA dimension estimation. However, the above-mentioned parameters do not directly quantify LA performance. Deformation studies using strain and strain-rate imaging to assess LA function were validated in previous research, but this technique is not currently used in routine clinical practice. This review discusses the history, importance, and pitfalls of strain technology for the analysis of LA mechanics. PMID:26236735

  6. Evaluation and application of 3D lung warping and registration model using HRCT images

    NASA Astrophysics Data System (ADS)

    Fan, Li; Chen, Chang W.; Reinhardt, Joseph M.; Hoffman, Eric A.

    2001-05-01

    Image-based study of structure-function relationships is a challenging problem in that the structure or region of interest may vary in position and shape on images captured over time. Such variation may be caused by the change in body posture or the motion of breathing and heart beating. Therefore, the structure or region of interest should be registered before any further regional study can be carried out. In this paper, we propose a novel approach to study the structure-function relationship of ventilation using a previously developed 3D lung warping and registration model. First, we evaluate the effectiveness of the lung warping and registration model using a set of criteria, including apparent lung motion patterns and ground truths. Then, we study the ventilation by integrating the warping model with air content calibration. The warping model is applied to three CT lung data sets, obtained under volume control of FRC, 40% and 75% vital capacity (VC). Dense displacement fields are obtained to represent deformation between different lung volume steps. For any specific region of interest, we first register it between images over time using the dense displacement, and then estimate the corresponding regional inspired air content. Assessments include change of regional volume during inspiration, change of regional air content, and the distribution of regional ventilation. This is the first time that 3D warping of lung images is applied to assess clinically significant pulmonary functions.

  7. Evaluation of a 3D diamond detector for medical radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Kanxheri, K.; Servoli, L.; Oh, A.; Munoz Sanchez, F.; Forcolin, G. T.; Murphy, S. A.; Aitkenhead, A.; Moore, C. J.; Morozzi, A.; Passeri, D.; Bellini, M.; Corsi, C.; Lagomarsino, S.; Sciortino, S.

    2017-01-01

    Synthetic diamond has several properties that are particularly suited to applications in medical radiation dosimetry. It is tissue equivalent, not toxic and shows a high resistance to radiation damage, low leakage current and stability of response. It is an electrical insulator, robust and realizable in small size; due to these features there are several examples of diamond devices, mainly planar single-crystalline chemical vapor depositation (sCVD) diamond, used for relative dose measurement in photon beams. Thanks to a new emerging technology, diamond devices with 3-dimensional structures are produced by using laser pulses to create graphitic paths in the diamond bulk. The necessary bias voltage to operate such detector decreases considerably while the signal response and radiation resistance increase. In order to evaluate the suitability of this new technology for measuring the dose delivered by radiotherapy beams in oncology a 3D polycrystalline (pCVD) diamond detector designed for single charged particle detection has been tested and the photon beam profile has been studied. The good linearity and high sensitivity to the dose observed in the 3D diamond, opens the way to the possibility of realizing a finely segmented device with the potential for dose distribution measurement in a single exposure for small field dosimetry that nowadays is still extremely challenging.

  8. 3D Microfluidic model for evaluating immunotherapy efficacy by tracking dendritic cell behaviour toward tumor cells.

    PubMed

    Parlato, Stefania; De Ninno, Adele; Molfetta, Rosa; Toschi, Elena; Salerno, Debora; Mencattini, Arianna; Romagnoli, Giulia; Fragale, Alessandra; Roccazzello, Lorenzo; Buoncervello, Maria; Canini, Irene; Bentivegna, Enrico; Falchi, Mario; Bertani, Francesca Romana; Gerardino, Annamaria; Martinelli, Eugenio; Natale, Corrado; Paolini, Rossella; Businaro, Luca; Gabriele, Lucia

    2017-04-24

    Immunotherapy efficacy relies on the crosstalk within the tumor microenvironment between cancer and dendritic cells (DCs) resulting in the induction of a potent and effective antitumor response. DCs have the specific role of recognizing cancer cells, taking up tumor antigens (Ags) and then migrating to lymph nodes for Ag (cross)-presentation to naïve T cells. Interferon-α-conditioned DCs (IFN-DCs) exhibit marked phagocytic activity and the special ability of inducing Ag-specific T-cell response. Here, we have developed a novel microfluidic platform recreating tightly interconnected cancer and immune systems with specific 3D environmental properties, for tracking human DC behaviour toward tumor cells. By combining our microfluidic platform with advanced microscopy and a revised cell tracking analysis algorithm, it was possible to evaluate the guided efficient motion of IFN-DCs toward drug-treated cancer cells and the succeeding phagocytosis events. Overall, this platform allowed the dissection of IFN-DC-cancer cell interactions within 3D tumor spaces, with the discovery of major underlying factors such as CXCR4 involvement and underscored its potential as an innovative tool to assess the efficacy of immunotherapeutic approaches.

  9. The Evaluation of Steam Generator Level Measurement Model for OPR1000 Using RETRAN-3D

    SciTech Connect

    Doo Yong Lee; Soon Joon Hong; Byung Chul Lee; Heok Soon Lim

    2006-07-01

    Steam generator level measurement is important factor for plant transient analyses using best estimate thermal hydraulic computer codes since the value of steam generator level is used for steam generator level control system and plant protection system. Because steam generator is in the saturation condition which includes steam and liquid together and is the place that heat exchange occurs from primary side to secondary side, computer codes are hard to calculate steam generator level realistically without appropriate level measurement model. In this paper, we prepare the steam generator models using RETRAN-3D that include geometry models, full range feedwater control system and five types of steam generator level measurement model. Five types of steam generator level measurement model consist of level measurement model using elevation difference in downcomer, 1D level measurement model using fluid mass, 1D level measurement model using fluid volume, 2D level measurement model using power and fluid mass, and 2D level measurement model using power and fluid volume. And we perform the evaluation of the capability of each steam generator level measurement model by simulating the real plant transient condition, the title is 'Reactor Trip by The Failure of The Deaerator Level Control Card of Ulchin Unit 3'. The comparison results between real plant data and RETRAN-3D analyses for each steam generator level measurement model show that 2D level measurement model using power and fluid mass or fluid volume has more realistic prediction capability compared with other level measurement models. (authors)

  10. Temporal bone MRI with 3D-FIESTA in the evaluation of facial and audiovestibular dysfunction.

    PubMed

    Cavusoglu, M; Cılız, D S; Duran, S; Ozsoy, A; Elverici, E; Karaoglanoglu, R; Sakman, B

    2016-09-01

    To evaluate the clinical usefulness of magnetic resonance imaging (MRI) of the temporal bone using three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences in patients with facial and audiovestibular dysfunction. We retrospectively reviewed the MR images of 1263 patients who presented with hearing loss (n=429), peripheral facial palsy (n=96), tinnitus (n=341) or vertigo (n=397). There were 605 men and 658 women, with a mean age of 46.97±16.95 (SD) years (range: 2-83 years). Positive MRI findings that were responsible for clinical manifestations in individual patients were categorized according to the anatomic sites and etiologies of the lesions. Positive MRI findings possibly responsible for clinical manifestations were found in 232/1263 (18.37%) patients, including 86/429 (20.05%) patients with hearing loss, 21/96 (21.88%) patients with facial palsy, 62/341 (18.18%) patients with tinnitus, and 63/397 (15.87%) patients with vertigo. Although the use of MRI of the temporal bone using 3D-FIESTA shows positive findings in only 18.37% of patients, it provides important information in those with facial and audiovestibular dysfunction. However, for patients with normal MRI of the temporal bone, other etiological factors should be investigated in order to clarify or elucidate the cause of clinical manifestations. Copyright © 2015 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  11. Quantitative evaluation of 3D dosimetry for stereotactic volumetric-modulated arc delivery using COMPASS.

    PubMed

    Vikraman, Subramani; Manigandan, Durai; Karrthick, Karukkupalayam Palaniappan; Sambasivaselli, Raju; Senniandavar, Vellaingiri; Ramu, Mahendran; Rajesh, Thiyagarajan; Lutz, Muller; Muthukumaran, Manavalan; Karthikeyan, Nithyanantham; Tejinder, Kataria

    2014-01-07

    The purpose of this study was to evaluate quantitatively the patient-specific 3D dosimetry tool COMPASS with 2D array MatriXX detector for stereotactic volumetric-modulated arc delivery. Twenty-five patients CT images and RT structures from different sites (brain, head & neck, thorax, abdomen, and spine) were taken from CyberKnife Multiplan planning system for this study. All these patients underwent radical stereotactic treatment in CyberKnife. For each patient, linac based volumetric-modulated arc therapy (VMAT) stereotactic plans were generated in Monaco TPS v3.1 using Elekta Beam Modulator MLC. Dose prescription was in the range of 5-20 Gy per fraction. Target prescription and critical organ constraints were tried to match the delivered treatment plans. Each plan quality was analyzed using conformity index (CI), conformity number (CN), gradient Index (GI), target coverage (TC), and dose to 95% of volume (D95). Monaco Monte Carlo (MC)-calculated treatment plan delivery accuracy was quantitatively evaluated with COMPASS-calculated (CCA) dose and COMPASS indirectly measured (CME) dose based on dose-volume histogram metrics. In order to ascertain the potential of COMPASS 3D dosimetry for stereotactic plan delivery, 2D fluence verification was performed with MatriXX using MultiCube phantom. Routine quality assurance of absolute point dose verification was performed to check the overall delivery accuracy. Quantitative analyses of dose delivery verification were compared with pass and fail criteria of 3 mm and 3% distance to agreement and dose differences. Gamma passing rate was compared with 2D fluence verification from MatriXX with MultiCube. Comparison of COMPASS reconstructed dose from measured fluence and COMPASS computed dose has shown a very good agreement with TPS calculated dose. Each plan was evaluated based on dose volume parameters for target volumes such as dose at 95% of volume (D95) and average dose. For critical organs dose at 20% of volume (D20

  12. Evaluation of single photon and Geiger mode Lidar for the 3D Elevation Program

    USGS Publications Warehouse

    Stoker, Jason M.; Abdullah, Qassim; Nayegandhi, Amar; Winehouse, Jayna

    2016-01-01

    Data acquired by Harris Corporation’s (Melbourne, FL, USA) Geiger-mode IntelliEarth™ sensor and Sigma Space Corporation’s (Lanham-Seabrook, MD, USA) Single Photon HRQLS sensor were evaluated and compared to accepted 3D Elevation Program (3DEP) data and survey ground control to assess the suitability of these new technologies for the 3DEP. While not able to collect data currently to meet USGS lidar base specification, this is partially due to the fact that the specification was written for linear-mode systems specifically. With little effort on part of the manufacturers of the new lidar systems and the USGS Lidar specifications team, data from these systems could soon serve the 3DEP program and its users. Many of the shortcomings noted in this study have been reported to have been corrected or improved upon in the next generation sensors.

  13. Fabrication and evaluation of novel rabbit model cardiovascular simulator with 3D printer

    NASA Astrophysics Data System (ADS)

    Jang, Min; Lee, Min-Woo; Seo, See-Yoon; Shin, Sang-Hoon

    2017-03-01

    Simulators allow researchers to study the hemodynamics of the cardiovascular system in a reproducible way without using complicated equations. Previous simulators focused on heart functions. However, a detailed model of the vessels is required to replicate the pulse wave of the arterial system. A computer simulation was used to simplify the arterial branch because producing every small artery is neither possible nor necessary. A 3D-printed zig was used to make a hand-made arterial tree. The simulator that was developed was evaluated by comparing its results to in-vivo data, in terms of the hemodynamic parameters (waveform, augmentation index, impedance, etc.) that were measured at three points: the ascending aorta, the thoracic aorta, and the brachiocephalic artery. The results from the simulator showed good agreement with the in-vivo data. Therefore, this simulator can be used as a research tool for the cardiovascular study of animal models, specifically rabbits.

  14. Evaluation of Full Reynolds Stress Turbulence Models in FUN3D

    NASA Technical Reports Server (NTRS)

    Dudek, Julianne C.; Carlson, Jan-Renee

    2017-01-01

    Full seven-equation Reynolds stress turbulence models are promising tools for today’s aerospace technology challenges. This paper examines two such models for computing challenging turbulent flows including shock-wave boundary layer interactions, separation and mixing layers. The Wilcox and the SSG/LRR full second-moment Reynolds stress models have been implemented into the FUN3D (Fully Unstructured Navier-Stokes Three Dimensional) unstructured Navier-Stokes code and were evaluated for four problems: a transonic two-dimensional diffuser, a supersonic axisymmetric compression corner, a compressible planar shear layer, and a subsonic axisymmetric jet. Simulation results are compared with experimental data and results computed using the more commonly used Spalart-Allmaras (SA) one-equation and the Menter Shear Stress Transport (SST-V) two-equation turbulence models.

  15. 3D-Mössbauer spectroscopic microscope for mc-Si solar cell evaluation

    NASA Astrophysics Data System (ADS)

    Ino, Y.; Soejima, H.; Hayakawa, K.; Yukihira, K.; Tanaka, K.; Fujita, H.; Watanabe, T.; Ogai, K.; Moriguchi, K.; Harada, Y.; Yoshida, Y.

    2016-12-01

    A 3D-Mössbauer Spectroscopic Microscope is developed to evaluate Fe impurities in multi-crystalline Si solar cells, which combines the Mössbauer spectroscopic microscope with a scanning electron microscope (SEM), an electron beam induced current (EBIC), an electron backscatter diffraction (EBSD), and an electron energy analyzer (HV-CSA). In addition, a new moving-coil-actuator with a liner encoder of 100 nm-resolution is incorporated for the operations with both a constant velocity and a constant acceleration mode successfully with the same precision as that obtained by the conventional transducers. Furthermore, a new multi-capillary X-ray lens is designed to achieve a γ-ray spot size less than 100 μm in diameter. The new microscope provides us to investigate the space correlation between Fe impurities and the lattice defects such as grain boundaries in multi-crystalline Si solar cells.

  16. Evaluation and comparison of current biopsy needle localization and tracking methods using 3D ultrasound.

    PubMed

    Zhao, Yue; Shen, Yi; Bernard, Adeline; Cachard, Christian; Liebgott, Hervé

    2017-01-01

    This article compares four different biopsy needle localization algorithms in both 3D and 4D situations to evaluate their accuracy and execution time. The localization algorithms were: Principle component analysis (PCA), random Hough transform (RHT), parallel integral projection (PIP) and ROI-RK (ROI based RANSAC and Kalman filter). To enhance the contrast of the biopsy needle and background tissue, a line filtering pre-processing step was implemented. To make the PCA, RHT and PIP algorithms comparable with the ROI-RK method, a region of interest (ROI) strategy was added. Simulated and ex-vivo data were used to evaluate the performance of the different biopsy needle localization algorithms. The resolutions of the sectorial and cylindrical volumes were 0.3mm×0.4mm×0.6mmand0.1mm×0.1mm×0.2mm (axial×lateral×azimuthal) respectively. In so far as the simulation and experimental results show, the ROI-RK method successfully located and tracked the biopsy needle in both 3D and 4D situations. The tip localization error was within 1.5mm and the axis accuracy was within 1.6mm. To the best of our knowledge, considering both localization accuracy and execution time, the ROI-RK was the most stable and time-saving method. Normally, accuracy comes at the expense of time. However, the ROI-RK method was able to locate the biopsy needle with high accuracy in real time, which makes it a promising method for clinical applications.

  17. Microvascular transplants in head and neck reconstruction: 3D evaluation of volume loss.

    PubMed

    Bittermann, Gido; Thönissen, Philipp; Poxleitner, Philipp; Zimmerer, Ruediger; Vach, Kirstin; Metzger, Marc C

    2015-10-01

    Despite oversized latissimus dorsi free flap reconstruction in the head and neck area, esthetic and functional problems continue to exist due to the well-known occurrence of transplant shrinkage. The purpose of this study was to acquire an estimation of the volume and time of the shrinkage process. The assessment of volume loss was performed using a 3D evaluation of two postoperative CT scans. A retrospective review was conducted on all latissimus dorsi free flap reconstructions performed between 2004 and 2013. Inclusion criteria for the assessment were: resection of an oral carcinoma and microsurgical defect coverage with latissimus dorsi free flap; a first postoperative CT (CT1) performed between 3 weeks and a maximum of 3 months after reconstruction surgery; and an additional CT scan (CT2) performed at least one year postoperatively. The exclusion criterion was surgical intervention in the local area between the acquisition of CT1 and CT2. The effect of adjuvant radiation therapy was considered. Volume determination of the transplant was carried out in CT1 and CT2 by manual segmentation of the graft. Fifteen patients were recruited. 3D evaluation showed an average volume loss of 34.4%. In the consideration of postoperative radiotherapy the volume reduction was 39.2% in patients with radiotherapy and 31.3% in patients without radiotherapy. The reconstruction flap volume required for overcorrection of the surgical defect was investigated. This study indicates that a volume loss of more than 30% could be expected one or more years after latissimus dorsi free flap reconstruction. Clinical trial number DRKS00007534. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  18. Evaluation of helper-dependent canine adenovirus vectors in a 3D human CNS model

    PubMed Central

    Simão, Daniel; Pinto, Catarina; Fernandes, Paulo; Peddie, Christopher J.; Piersanti, Stefania; Collinson, Lucy M.; Salinas, Sara; Saggio, Isabella; Schiavo, Giampietro; Kremer, Eric J.; Brito, Catarina; Alves, Paula M.

    2017-01-01

    Gene therapy is a promising approach with enormous potential for treatment of neurodegenerative disorders. Viral vectors derived from canine adenovirus type 2 (CAV-2) present attractive features for gene delivery strategies in the human brain, by preferentially transducing neurons, are capable of efficient axonal transport to afferent brain structures, have a 30-kb cloning capacity and have low innate and induced immunogenicity in pre-clinical tests. For clinical translation, in-depth pre-clinical evaluation of efficacy and safety in a human setting is primordial. Stem cell-derived human neural cells have a great potential as complementary tools by bridging the gap between animal models, which often diverge considerably from human phenotype, and clinical trials. Herein, we explore helper-dependent CAV-2 (hd-CAV-2) efficacy and safety for gene delivery in a human stem cell-derived 3D neural in vitro model. Assessment of hd-CAV-2 vector efficacy was performed at different multiplicities of infection, by evaluating transgene expression and impact on cell viability, ultrastructural cellular organization and neuronal gene expression. Under optimized conditions, hd-CAV-2 transduction led to stable long-term transgene expression with minimal toxicity. hd-CAV-2 preferentially transduced neurons, while human adenovirus type 5 (HAdV5) showed increased tropism towards glial cells. This work demonstrates, in a physiologically relevant 3D model, that hd-CAV-2 vectors are efficient tools for gene delivery to human neurons, with stable long-term transgene expression and minimal cytotoxicity. PMID:26181626

  19. CAVAREV—an open platform for evaluating 3D and 4D cardiac vasculature reconstruction

    NASA Astrophysics Data System (ADS)

    Rohkohl, Christopher; Lauritsch, Günter; Keil, Andreas; Hornegger, Joachim

    2010-05-01

    The 3D reconstruction of cardiac vasculature, e.g. the coronary arteries, using C-arm CT (rotational angiography) is an active and challenging field of research. There are numerous publications on different reconstruction techniques. However, there is still a lack of comparability of achieved results for several reasons: foremost, datasets used in publications are not open to public and thus experiments are not reproducible by other researchers. Further, the results highly depend on the vasculature motion, i.e. cardiac and breathing motion patterns which are also not comparable across publications. We aim to close this gap by providing an open platform, called Cavarev (CArdiac VAsculature Reconstruction EValuation). It features two simulated dynamic projection datasets based on the 4D XCAT phantom with contrasted coronary arteries which was derived from patient data. In the first dataset, the vasculature undergoes a continuous periodic motion. The second dataset contains aperiodic heart motion by including additional breathing motion. The geometry calibration and acquisition protocol were obtained from a real-world C-arm system. For qualitative evaluation of the reconstruction results, the correlation of the morphology is used. Two segmentation-based quality measures are introduced which allow us to assess the 3D and 4D reconstruction quality. They are based on the spatial overlap of the vasculature reconstruction with the ground truth. The measures enable a comprehensive analysis and comparison of reconstruction results independent from the utilized reconstruction algorithm. An online platform (www.cavarev.com) is provided where the datasets can be downloaded, researchers can manage and publish algorithm results and download a reference C++ and Matlab implementation.

  20. Plaque characterization in ex vivo MRI evaluated by dense 3D correspondence with histology

    NASA Astrophysics Data System (ADS)

    van Engelen, Arna; de Bruijne, Marleen; Klein, Stefan; Verhagen, Hence; Groen, Harald; Wentzel, Jolanda; van der Lugt, Aad; Niessen, Wiro

    2011-03-01

    Automatic quantification of carotid artery plaque composition is important in the development of methods that distinguish vulnerable from stable plaques. MRI has shown to be capable of imaging different components noninvasively. We present a new plaque classification method which uses 3D registration of histology data with ex vivo MRI data, using non-rigid registration, both for training and evaluation. This is more objective than previously presented methods, as it eliminates selection bias that is introduced when 2D MRI slices are manually matched to histological slices before evaluation. Histological slices of human atherosclerotic plaques were manually segmented into necrotic core, fibrous tissue and calcification. Classification of these three components was voxelwise evaluated. As features the intensity, gradient magnitude and Laplacian in four MRI sequences after different degrees of Gaussian smoothing, and the distances to the lumen and the outer vessel wall, were used. Performance of linear and quadratic discriminant classifiers for different combinations of features was evaluated. Best accuracy (72.5 +/- 7.7%) was reached with the linear classifier when all features were used. Although this was only a minor improvement to the accuracy of a classifier that only included the intensities and distance features (71.6 +/- 7.9%), the difference was statistically significant (paired t-test, p<0.05). Good sensitivity and specificity for calcification was reached (83% and 95% respectively), however, differentiation between fibrous (sensitivity 85%, specificity 60%) and necrotic tissue (sensitivity 49%, specificity 89%) was more difficult.

  1. 3D fitting accuracy evaluation of CAD/CAM copings - comparison with spacer design settings.

    PubMed

    Boitelle, Philippe; Tapie, Laurent; Mawussi, Bernardin; Fromentin, Olivier

    2016-01-01

    The accuracy of computer-aided design/computer- aided manufacturing (CAD/CAM) systems is linked to their technical characteristics and reliability for manufacturing the restoration designed. The aim of this study was to compare the accuracy of fit of zirconia copings manufactured with different CAD/CAM systems and their capacity to conform to pre-established spacer design settings. Sixty zirconia copings were manufactured by three CAD/CAM systems, with their spacers set as recommended by their manufacturer on occlusal, axial, and marginal surfaces. The 3D triple-scan optical technique was used to obtain a fit mapping and to analyze the marginal and axial accuracy of fit. The reliability of the 3D measurement method was estimated using intraclass correlation and repeatability coefficients. The preparation coping interface width results were statistically analyzed using non-parametric analysis (Kruskal-Wallis, one-way ANOVA, and Wilcoxon signedrank tests) (P < 0.05). The repeatability coefficient was 6, 8, and 15 μm for axial, marginal, and occlusal interface width measurements, respectively. For the three systems tested, no differences were found in the marginal area of the copings studied, with a mean fitting accuracy ranging from 54.3 to 66.6 μm interface width. Statistically significant differences between groups were observed for the fitting accuracy measured in axial and occlusal areas. With the spacers set in the different areas, mean fit measurements of the zirconia copings were significantly larger, with an increased fit width ranging from 30 to 73 μm. The three CAD/CAM systems evaluated allowed similar marginal accuracy but failed to reproduce the pre-established spacer parameters, with larger spacing showing throughout.

  2. Evaluation of a Gait Assessment Module Using 3D Motion Capture Technology

    PubMed Central

    Baskwill, Amanda J.; Belli, Patricia; Kelleher, Leila

    2017-01-01

    Background Gait analysis is the study of human locomotion. In massage therapy, this observation is part of an assessment process that informs treatment planning. Massage therapy students must apply the theory of gait assessment to simulated patients. At Humber College, the gait assessment module traditionally consists of a textbook reading and a three-hour, in-class session in which students perform gait assessment on each other. In 2015, Humber College acquired a three-dimensional motion capture system. Purpose The purpose was to evaluate the use of 3D motion capture in a gait assessment module compared to the traditional gait assessment module. Participants Semester 2 massage therapy students who were enrolled in Massage Theory 2 (n = 38). Research Design Quasi-experimental, wait-list comparison study. Intervention The intervention group participated in an in-class session with a Qualisys motion capture system. Main Outcome Measure(s) The outcomes included knowledge and application of gait assessment theory as measured by quizzes, and students’ satisfaction as measured through a questionnaire. Results There were no statistically significant differences in baseline and post-module knowledge between both groups (pre-module: p = .46; post-module: p = .63). There was also no difference between groups on the final application question (p = .13). The intervention group enjoyed the in-class session because they could visualize the content, whereas the comparison group enjoyed the interactivity of the session. The intervention group recommended adding the assessment of gait on their classmates to their experience. Both groups noted more time was needed for the gait assessment module. Conclusions Based on the results of this study, it is recommended that the gait assessment module combine both the traditional in-class session and the 3D motion capture system. PMID:28293329

  3. Evaluation of a Gait Assessment Module Using 3D Motion Capture Technology.

    PubMed

    Baskwill, Amanda J; Belli, Patricia; Kelleher, Leila

    2017-03-01

    Gait analysis is the study of human locomotion. In massage therapy, this observation is part of an assessment process that informs treatment planning. Massage therapy students must apply the theory of gait assessment to simulated patients. At Humber College, the gait assessment module traditionally consists of a textbook reading and a three-hour, in-class session in which students perform gait assessment on each other. In 2015, Humber College acquired a three-dimensional motion capture system. The purpose was to evaluate the use of 3D motion capture in a gait assessment module compared to the traditional gait assessment module. Semester 2 massage therapy students who were enrolled in Massage Theory 2 (n = 38). Quasi-experimental, wait-list comparison study. The intervention group participated in an in-class session with a Qualisys motion capture system. The outcomes included knowledge and application of gait assessment theory as measured by quizzes, and students' satisfaction as measured through a questionnaire. There were no statistically significant differences in baseline and post-module knowledge between both groups (pre-module: p = .46; post-module: p = .63). There was also no difference between groups on the final application question (p = .13). The intervention group enjoyed the in-class session because they could visualize the content, whereas the comparison group enjoyed the interactivity of the session. The intervention group recommended adding the assessment of gait on their classmates to their experience. Both groups noted more time was needed for the gait assessment module. Based on the results of this study, it is recommended that the gait assessment module combine both the traditional in-class session and the 3D motion capture system.

  4. Evaluation of Fetal Thyroid with 3D Gradient Echo T1-weighted MR Imaging.

    PubMed

    Fujii, Shinya; Nagaishi, Junichi; Mukuda, Naoko; Kaneda, Sachi; Inoue, Chie; Fukunaga, Takeru; Ogawa, Toshihide

    2017-07-10

    The characteristics of fetal thyroid on magnetic resonance (MR) imaging, including normal thyroid and disorders other than goiter have not been fully evaluated. Our aim was to assess fetal thyroid using three dimensional (3D) gradient echo (GRE) T1-weighted MR imaging and to examine the usefulness of this modality. The study included 27 3D GRE T1-weighted images from 26 fetuses. The largest possible region of interest (ROI) within the thyroid at the slice level depicting the thyroid was manually defined and three circular ROIs on neck muscle were manually defined on the image slices showing the highest signal intensity (SI) of the thyroid. Maximum and mean thyroid-to-muscle SI ratios (SIRs) were then calculated as SIR = maximum or mean thyroid SI/muscle SI. The thyroid could not be identified in two cases. Fetal thyroid function was normal in 17 cases, and there were 7 cases of hypothyroidism (6 transient and 1 thyroid dysgenesis). There was no linear relationship between mean and maximum SIR and gestational age. The mean and maximum SIR in the cases of normal fetal thyroid were 1.85 ± 0.20 and 2.61 ± 0.39, and the mean and maximum SIR in fetal hypothyroidism were 1.58 ± 0.20 and 2.13 ± 0.37. Mean (P = 0.0088) and maximum (P = 0.0221) SIR values were significantly different between euthyroid and hypothyroid fetuses. Thyroid SIR measurement provided useful information regarding fetal thyroid function.

  5. CCTV Coverage Index Based on Surveillance Resolution and Its Evaluation Using 3D Spatial Analysis.

    PubMed

    Choi, Kyoungah; Lee, Impyeong

    2015-09-16

    We propose a novel approach to evaluating how effectively a closed circuit television (CCTV) system can monitor a targeted area. With 3D models of the target area and the camera parameters of the CCTV system, the approach produces surveillance coverage index, which is newly defined in this study as a quantitative measure for surveillance performance. This index indicates the proportion of the space being monitored with a sufficient resolution to the entire space of the target area. It is determined by computing surveillance resolution at every position and orientation, which indicates how closely a specific object can be monitored with a CCTV system. We present full mathematical derivation for the resolution, which depends on the location and orientation of the object as well as the geometric model of a camera. With the proposed approach, we quantitatively evaluated the surveillance coverage of a CCTV system in an underground parking area. Our evaluation process provided various quantitative-analysis results, compelling us to examine the design of the CCTV system prior to its installation and understand the surveillance capability of an existing CCTV system.

  6. CCTV Coverage Index Based on Surveillance Resolution and Its Evaluation Using 3D Spatial Analysis

    PubMed Central

    Choi, Kyoungah; Lee, Impyeong

    2015-01-01

    We propose a novel approach to evaluating how effectively a closed circuit television (CCTV) system can monitor a targeted area. With 3D models of the target area and the camera parameters of the CCTV system, the approach produces surveillance coverage index, which is newly defined in this study as a quantitative measure for surveillance performance. This index indicates the proportion of the space being monitored with a sufficient resolution to the entire space of the target area. It is determined by computing surveillance resolution at every position and orientation, which indicates how closely a specific object can be monitored with a CCTV system. We present full mathematical derivation for the resolution, which depends on the location and orientation of the object as well as the geometric model of a camera. With the proposed approach, we quantitatively evaluated the surveillance coverage of a CCTV system in an underground parking area. Our evaluation process provided various quantitative-analysis results, compelling us to examine the design of the CCTV system prior to its installation and understand the surveillance capability of an existing CCTV system. PMID:26389909

  7. Evaluating the accuracy of orthophotos and 3D models from UAV photogrammetry

    NASA Astrophysics Data System (ADS)

    Julge, Kalev; Ellmann, Artu

    2015-04-01

    Rapid development of unmanned aerial vehicles (UAV) in recent years has made their use for various applications more feasible. This contribution evaluates the accuracy and quality of different UAV remote sensing products (i.e. orthorectified image, point cloud and 3D model). Two different autonomous fixed wing UAV systems were used to collect the aerial photographs. One is a mass-produced commercial UAV system, the other is a similar state-of-the-art UAV system. Three different study areas with varying sizes and characteristics (including urban areas, forests, fields, etc.) were surveyed. The UAV point clouds, 3D models and orthophotos were generated with three different commercial and free-ware software. The performance of each of these was evaluated. The effect of flying height on the accuracy of the results was explored, as well as the optimum number and placement of ground control points. Also the achieved results, when the only georeferencing data originates from the UAV system's on-board GNSS and inertial measurement unit, are investigated. Problems regarding the alignment of certain types of aerial photos (e.g. captured over forested areas) are discussed. The quality and accuracy of UAV photogrammetry products are evaluated by comparing them with control measurements made with GNSS-measurements on the ground, as well as high-resolution airborne laser scanning data and other available orthophotos (e.g. those acquired for large scale national mapping). Vertical comparisons are made on surfaces that have remained unchanged in all campaigns, e.g. paved roads. Planar comparisons are performed by control surveys of objects that are clearly identifiable on orthophotos. The statistics of these differences are used to evaluate the accuracy of UAV remote sensing. Some recommendations are given on how to conduct UAV mapping campaigns cost-effectively and with minimal time-consumption while still ensuring the quality and accuracy of the UAV data products. Also the

  8. 3D/4D sonographic evaluation of amniotic band syndrome in early pregnancy: a supplement to 2D ultrasound.

    PubMed

    Hata, Toshiyuki; Tanaka, Hirokazu; Noguchi, Junko

    2011-06-01

    We present two cases of amniotic band syndrome diagnosed using two-dimensional (2D) ultrasound with three-dimensional (3D)/four-dimensional (4D) ultrasound in early pregnancy. In Case 1, at 13 weeks' gestation, multiple amniotic bands, acrania, the absence of fingers and amputation of the toes bilaterally were clearly shown using transvaginal 3D/4D ultrasound. In Case 2, at 15 weeks' gestation, several amniotic bands, acrania and a cleft lip were depicted with transabdominal 3D/4D ultrasound. The spatial relationship between the amniotic bands and the fetus was clearly visualized and easily discernible by 3D/4D ultrasound. The parents and families could readily understand the fetal conditions and undergo counseling; they then choose the option of termination of pregnancy. 3D/4D ultrasound has the potential to be a supplement to conventional 2D ultrasound in evaluating amniotic band syndrome.

  9. Diastolic heart failure: restrictive cardiomyopathy, constrictive pericarditis, and cardiac tamponade: clinical and echocardiographic evaluation.

    PubMed

    Asher, Craig R; Klein, Allan L

    2002-01-01

    An understanding of the basic principles of diastolic function is important in order to recognize diseases that may result in diastolic dysfunction and diastolic heart failure. Although uncommon, restrictive cardiomyopathy, constrictive pericarditis, and cardiac tamponade are among the disorders that may affect primarily diastolic function with preservation of systolic function. Diastolic heart failure may manifest with chronic nonspecific symptoms or may present with acute hemodynamic compromise. Echocardiography plays a vital role in the diagnosis of diastolic dysfunction and differentiation of these disease processes. It also provides a basis for clinical decisions regarding management and surgical referral. This review summarizes the clinical features, pathophysiology, and hemodynamic and echocardiographic signs of restrictive cardiomyopathy, constrictive pericarditis, and cardiac tamponade.

  10. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    PubMed Central

    Pereira, N F; Sitek, A

    2011-01-01

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated. PMID:20736496

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-01-01

    Background. Over time, the striae rubra develop into striae alba that appear white, flat, and depressed. It is very important to determine the optimum striae management. In order to evaluate the effectiveness of these therapies, objective measurement tools are necessary. Objective. The aim of this study is to evaluate if ultrasonography and PRIMOS can be used to obtain an objective assessment of stretch marks type and stage; furthermore, we aim to apply these techniques to evaluate the efficacy of a topical treatment. Methods. 20 volunteers were enrolled with a two-month study. A marketed cosmetic product was used as the active over one body area. The controlateral area with stretch marks was treated with a "placebo" formulation without active, as a control. The instrumental evaluation was carried out at the beginning of the trial (baseline values or t(0)), after 1 month (t(1)), and at the end of the study (t(2)). Results. PRIMOS was able to measure and document striae distensae maturation; furthermore, ultrasound imaging permitted to visualize and diagnose the striae. Statistical analysis of skin roughness demonstrated a statistically significant reduction of Rp value only in a treated group. In fact, the Rp value represented a maximum peak height in the area selected. These results demonstrated that after two months of treatment only the striae rubra can be treated successfully. Conclusions. This work demonstrated that the 22MHz ultrasound can diagnose stretch marks; PRIMOS device can detect and measure striae distensae type and maturation. Furthermore, the high-frequency ultrasound and the 3D image device, described in this work, can be successfully employed in order to evaluate the efficacy of a topical treatment.

  13. An Evaluation of 3D Woven Orthogonal Composites' Potential in the Automotive Supply Chain

    NASA Astrophysics Data System (ADS)

    Taylor, Dalia

    The automotive supply chain and its management can be a very complex process and comprises a long dynamic and complex network that consists of four primary segments: original equipment manufacturers (OEMs), first tier suppliers, sub tiers suppliers, and infrastructure suppliers. During the analysis of the current automotive industry it was identified that textile industry importance is considerable increasing as a part of the global automotive supply chain, because textile products are used for interior, exterior and even suspension parts and components. Automotive industry has an increasing demand for higher quality exterior panels with better functional properties and reduced weight. One of the main potentials for this demand is based on the three-dimensional woven composites technology innovations which can replace an existing technology. The new role of the textile industry could make important changes in the automotive supply chain industry, such as: changes in the size of the supply chain, the time to the market and the position of textile industry in the automotive supply chain structure. 3D composite materials from high performance fibers, such as glass and carbon, have been used for automotive applications in a limited way due to the low production rate and the lack of research and development. This research will contribute to the understanding of textile composites in transportation and the textile parameters that affect the performance characteristics of these materials. The research examines the performance characteristics of lighter and stronger 3D woven fabric composites made from fiberglass with the aim to improve fuel efficiency by reducing the total vehicle weight while maintaining safety standards. The performance characteristics of the 3D woven fabric composite can be designed by changing different construction parameters, such as picks density, pick roving linear density, arrangements of warp and z-yarns, and the number of warp and picks layers

  14. 3D-2D registration of cerebral angiograms: a method and evaluation on clinical images.

    PubMed

    Mitrovic, Uroš; Špiclin, Žiga; Likar, Boštjan; Pernuš, Franjo

    2013-08-01

    Endovascular image-guided interventions (EIGI) involve navigation of a catheter through the vasculature followed by application of treatment at the site of anomaly using live 2D projection images for guidance. 3D images acquired prior to EIGI are used to quantify the vascular anomaly and plan the intervention. If fused with the information of live 2D images they can also facilitate navigation and treatment. For this purpose 3D-2D image registration is required. Although several 3D-2D registration methods for EIGI achieve registration accuracy below 1 mm, their clinical application is still limited by insufficient robustness or reliability. In this paper, we propose a 3D-2D registration method based on matching a 3D vasculature model to intensity gradients of live 2D images. To objectively validate 3D-2D registration methods, we acquired a clinical image database of 10 patients undergoing cerebral EIGI and established "gold standard" registrations by aligning fiducial markers in 3D and 2D images. The proposed method had mean registration accuracy below 0.65 mm, which was comparable to tested state-of-the-art methods, and execution time below 1 s. With the highest rate of successful registrations and the highest capture range the proposed method was the most robust and thus a good candidate for application in EIGI.

  15. Accuracy of 3D white light scanning of abutment teeth impressions: evaluation of trueness and precision

    PubMed Central

    Jeon, Jin-Hun; Kim, Hae-Young; Kim, Ji-Hwan

    2014-01-01

    PURPOSE This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. MATERIALS AND METHODS To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05). RESULTS Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (P<.001). Trueness discrepancies for teeth types were 6.2 µm, 11.2 µm, and 21.8 µm, respectively, indicating the poorest trueness for the molar (P=.007). CONCLUSION In respect to accuracy the molar showed the largest discrepancies compared with the canine and premolar. Digitizing of dental impressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall. PMID:25551007

  16. Accuracy of 3D white light scanning of abutment teeth impressions: evaluation of trueness and precision.

    PubMed

    Jeon, Jin-Hun; Kim, Hae-Young; Kim, Ji-Hwan; Kim, Woong-Chul

    2014-12-01

    This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05). Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (P<.001). Trueness discrepancies for teeth types were 6.2 µm, 11.2 µm, and 21.8 µm, respectively, indicating the poorest trueness for the molar (P=.007). In respect to accuracy the molar showed the largest discrepancies compared with the canine and premolar. Digitizing of dental impressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall.

  17. Evaluation of axial and lateral modal superposition for general 3D drilling riser analysis

    SciTech Connect

    Burgdorf, O. Jr.

    1996-12-31

    A 3D partially non-linear transient fully-coupled riser analysis method is evaluated which uses modal superposition of independently extracted lateral and axial modes. Many lateral modes are combined with a lesser number axial modes to minimize adverse time step requirements typically induced by axial flexibility in direct time integration of beam-column elements. The reduced computer time option enables much faster parametric analysis of hang-off, as well as other connected drilling environments normally examined. Axial-lateral coupling is explicitly enforced and, resonance fidelity is preserved when excitation is near or coincident with axial natural periods. Reasonable correlation is shown with envelopes of test case dynamic responses published by API. Applicability of the method is limited by linearity assumptions indigenous to modal representation of dynamic deflections relative to a mean deflected shape. Sensitivities of incipient buckling during hang-off to axial damping and stiffness are described for an example 6,000 ft. deep composite drilling riser system.

  18. Preparation and Evaluation of Gelatin-Chitosan-Nanobioglass 3D Porous Scaffold for Bone Tissue Engineering

    PubMed Central

    Maji, Kanchan; Dasgupta, Sudip; Pramanik, Krishna; Bissoyi, Akalabya

    2016-01-01

    The aim of the present study was to prepare and characterize bioglass-natural biopolymer based composite scaffold and evaluate its bone regeneration ability. Bioactive glass nanoparticles (58S) in the size range of 20–30 nm were synthesized using sol-gel method. Porous scaffolds with varying bioglass composition from 10 to 30 wt% in chitosan, gelatin matrix were fabricated using the method of freeze drying of its slurry at 40 wt% solids loading. Samples were cross-linked with glutaraldehyde to obtain interconnected porous 3D microstructure with improved mechanical strength. The prepared scaffolds exhibited >80% porosity with a mean pore size range between 100 and 300 microns. Scaffold containing 30 wt% bioglass (GCB 30) showed a maximum compressive strength of 2.2 ± 0.1 MPa. Swelling and degradation studies showed that the scaffold had excellent properties of hydrophilicity and biodegradability. GCB 30 scaffold was shown to be noncytotoxic and supported mesenchymal stem cell attachment, proliferation, and differentiation as indicated by MTT assay and RUNX-2 expression. Higher cellular activity was observed in GCB 30 scaffold as compared to GCB 0 scaffold suggesting the fact that 58S bioglass nanoparticles addition into the scaffold promoted better cell adhesion, proliferation, and differentiation. Thus, the study showed that the developed composite scaffolds are potential candidates for regenerating damaged bone tissue. PMID:26884764

  19. 3D dynamic model of healthy and pathologic arteries for ultrasound technique evaluation.

    PubMed

    Balocco, Simone; Basset, Olivier; Azencot, Jacques; Tortoli, Piero; Cachard, Christian

    2008-12-01

    A 3D model reproducing the biomechanical behavior of human blood vessels is presented. The model, based on a multilayer geometry composed of right generalized cylinders, enables the representation of different vessel morphologies, including bifurcations, either healthy or affected by stenoses. Using a finite element approach, blood flow is simulated by considering a dynamic displacement of the scatterers (erythrocytes), while arterial pulsation due to the hydraulic pressure is taken into account through a fluid-structure interaction based on a wall model. Each region is acoustically characterized using FIELD II software, which produces the radio frequency echo signals corresponding to echographic scans. Three acoustic physiological phantoms of carotid arteries surrounded by elastic tissue are presented to illustrate the model's capability. The first corresponds to a healthy blood vessel, the second includes a 50% stenosis, and the third represents a carotid bifurcation. Examples of M mode, B mode and color Doppler images derived from these phantoms are shown. Two examples of M-mode image segmentation and the identification of the atherosclerotic plaque boundaries on Doppler color images are reported. The model could be used as a tool for the preliminary evaluation of ultrasound signal processing and visualization techniques.

  20. Performance evaluation of laser line scanner for in-process inspection of 3D geometries

    NASA Astrophysics Data System (ADS)

    Zhou, Sen; Xu, Jian; Tao, Lei; Yan, Yu

    2016-09-01

    Non-contact measurement techniques using laser scanning have the power to deliver tremendous benefits to most notably manufacturing, and have the advantage of high speed and high detail output. However, a major obstacle to their widespread adoption in more complex on-line producing environments is their geometric constraints and low accuracy compared to the contact-based counterparts. The work presented in this paper introduces a performance evaluation test of laser line scanning for in-process inspection of 3D geometries. Some straightforward test methods that use a designed artifact are proposed. First, one work aims to experimentally investigate the location accuracy of knee point or corner point of edge features using a commercial laser stripe scanner, which is common in mechanical parts. Another work experimentally investigates the formation of outliers that may be usually promoted by reflective surfaces around surrounding area of corner point, and these outliers are characterized with large measurement errors, which significantly deteriorate the quality of the scanned point cloud data. Scanning path planning and outlier filter design are respectively discussed.

  1. Evaluation of Bogie Frame Safety of Shanghai Metro Line 1 by 3D FEM Analysis

    NASA Astrophysics Data System (ADS)

    Xiongyao, Xie; Guolong, Jin; Rulu, Wang

    2010-05-01

    The vehicle bogies of Shanghai metro line 1 began to crack just in the third year after the trains operated. More than 50 cracks occurred in the succeeding six year during the train operation. This paper evaluated the safety of the motorized bogies. First, the loading conditions imposed on the vehicle structure were calculated based on the measured data in service of the train, and compared with the original design load. Then, this paper calculated simulated the stress of the vehicle bogie by 3D FEM, and presented the distribution of every stress concentration point in Goodman fatigue diagram. The computational locations of the strength less than the safety are agreed with where cracks have happened. Finally, this paper calculated the fatigue life of the motor bracket of the bogie through S-N curve based on revised Miner theory. In conclusion, this paper think that the bogie cracks of Shanghai metro line 1 are contributed by the overburden fatigue load, and ignoring the lateral vibration load in the design of the vehicle bogie is the important cause that bogie cracks occurred far earlier than in the designed time.

  2. Evaluating Dense 3d Reconstruction Software Packages for Oblique Monitoring of Crop Canopy Surface

    NASA Astrophysics Data System (ADS)

    Brocks, S.; Bareth, G.

    2016-06-01

    Crop Surface Models (CSMs) are 2.5D raster surfaces representing absolute plant canopy height. Using multiple CMSs generated from data acquired at multiple time steps, a crop surface monitoring is enabled. This makes it possible to monitor crop growth over time and can be used for monitoring in-field crop growth variability which is useful in the context of high-throughput phenotyping. This study aims to evaluate several software packages for dense 3D reconstruction from multiple overlapping RGB images on field and plot-scale. A summer barley field experiment located at the Campus Klein-Altendorf of University of Bonn was observed by acquiring stereo images from an oblique angle using consumer-grade smart cameras. Two such cameras were mounted at an elevation of 10 m and acquired images for a period of two months during the growing period of 2014. The field experiment consisted of nine barley cultivars that were cultivated in multiple repetitions and nitrogen treatments. Manual plant height measurements were carried out at four dates during the observation period. The software packages Agisoft PhotoScan, VisualSfM with CMVS/PMVS2 and SURE are investigated. The point clouds are georeferenced through a set of ground control points. Where adequate results are reached, a statistical analysis is performed.

  3. Foot roll-over evaluation based on 3D dynamic foot scan.

    PubMed

    Samson, William; Van Hamme, Angèle; Sanchez, Stéphane; Chèze, Laurence; Van Sint Jan, Serge; Feipel, Véronique

    2014-01-01

    Foot roll-over is commonly analyzed to evaluate gait pathologies. The current study utilized a dynamic foot scanner (DFS) to analyze foot roll-over. The right feet of ten healthy subjects were assessed during gait trials with a DFS system integrated into a walkway. A foot sole picture was computed by vertically projecting points from the 3D foot shape which were lower than a threshold height of 15 mm. A 'height' value of these projected points was determined; corresponding to the initial vertical coordinates prior to projection. Similar to pedobarographic analysis, the foot sole picture was segmented into anatomical regions of interest (ROIs) to process mean height (average of height data by ROI) and projected surface (area of the projected foot sole by ROI). Results showed that these variables evolved differently to plantar pressure data previously reported in the literature, mainly due to the specificity of each physical quantity (millimeters vs Pascals). Compared to plantar pressure data arising from surface contact by the foot, the current method takes into account the whole plantar aspect of the foot, including the parts that do not make contact with the support surface. The current approach using height data could contribute to a better understanding of specific aspects of foot motion during walking, such as plantar arch height and the windlass mechanism. Results of this study show the underlying method is reliable. Further investigation is required to validate the DFS measurements within a clinical context, prior to implementation into clinical practice.

  4. Evaluation of hydrocephalus patients with 3D-SPACE technique using variant FA mode at 3T.

    PubMed

    Algin, Oktay

    2017-09-26

    The major advantages of three-dimensional sampling perfection with application optimized contrasts using different flip-angle evolution (3D-SPACE) technique are its high resistance to artifacts that occurs as a result of radiofrequency or static field, the ability of providing images with sub-millimeter voxel size which allows obtaining reformatted images in any plane due to isotropic three-dimensional data with lower specific absorption rate values. That is crucial during examination of cerebrospinal-fluid containing complex structures, and the acquisition time, which is approximately 5 min for scanning of entire cranium. Recent data revealed that T2-weighted (T2W) 3D-SPACE with variant flip-angle mode (VFAM) imaging allows fast and accurate evaluation of the hydrocephalus patients during both pre- and post-operative period for monitoring the treatment. For a better assessment of these patients; radiologists and neurosurgeons should be aware of the details and implications regarding to the 3D-SPACE technique, and they should follow the updates in this field. There could be a misconception about the difference between T2W-VFAM and routine heavily T2W 3D-SPACE images. T2W 3D-SPACE with VFAM imaging is only a subtype of 3D-SPACE technique. In this review, we described the details of T2W 3D-SPACE with VFAM imaging and comprehensively reviewed its recent applications.

  5. A pair-conformation-dependent scoring function for evaluating 3D RNA-protein complex structures

    PubMed Central

    Li, Haotian; Huang, Yangyu

    2017-01-01

    Computational prediction of RNA-protein complex 3D structures includes two basic steps: one is sampling possible structures and another is scoring the sampled structures to pick out the correct one. At present, constructing accurate scoring functions is still not well solved and the performances of the scoring functions usually depend on used benchmarks. Here we propose a pair-conformation-dependent scoring function, 3dRPC-Score, for 3D RNA-protein complex structure prediction by considering the nucleotide-residue pairs having the same energy if their conformations are similar, instead of the distance-only dependence of the most existing scoring functions. Benchmarking shows that 3dRPC-Score has a consistent performance in three test sets. PMID:28358834

  6. A pair-conformation-dependent scoring function for evaluating 3D RNA-protein complex structures.

    PubMed

    Li, Haotian; Huang, Yangyu; Xiao, Yi

    2017-01-01

    Computational prediction of RNA-protein complex 3D structures includes two basic steps: one is sampling possible structures and another is scoring the sampled structures to pick out the correct one. At present, constructing accurate scoring functions is still not well solved and the performances of the scoring functions usually depend on used benchmarks. Here we propose a pair-conformation-dependent scoring function, 3dRPC-Score, for 3D RNA-protein complex structure prediction by considering the nucleotide-residue pairs having the same energy if their conformations are similar, instead of the distance-only dependence of the most existing scoring functions. Benchmarking shows that 3dRPC-Score has a consistent performance in three test sets.

  7. Evaluation of endoscopic entire 3D image acquisition of the digestive tract using a stereo endoscope

    NASA Astrophysics Data System (ADS)

    Yoshimoto, Kayo; Watabe, Kenji; Fujinaga, Tetsuji; Iijima, Hideki; Tsujii, Masahiko; Takahashi, Hideya; Takehara, Tetsuo; Yamada, Kenji

    2017-02-01

    Because the view angle of the endoscope is narrow, it is difficult to get the whole image of the digestive tract at once. If there are more than two lesions in the digestive tract, it is hard to understand the 3D positional relationship among the lesions. Virtual endoscopy using CT is a present standard method to get the whole view of the digestive tract. Because the virtual endoscopy is designed to detect the irregularity of the surface, it cannot detect lesions that lack irregularity including early cancer. In this study, we propose a method of endoscopic entire 3D image acquisition of the digestive tract using a stereo endoscope. The method is as follows: 1) capture sequential images of the digestive tract by moving the endoscope, 2) reconstruct 3D surface pattern for each frame by stereo images, 3) estimate the position of the endoscope by image analysis, 4) reconstitute the entire image of the digestive tract by combining the 3D surface pattern. To confirm the validity of this method, we experimented with a straight tube inside of which circles were allocated at equal distance of 20 mm. We captured sequential images and the reconstituted image of the tube revealed that the distance between each circle was 20.2 +/- 0.3 mm (n=7). The results suggest that this method of endoscopic entire 3D image acquisition may help us understand 3D positional relationship among the lesions such as early esophageal cancer that cannot be detected by virtual endoscopy using CT.

  8. Floor Probe/Contamination Monitor (NE Model FLP3D) Test and Evaluation Report

    SciTech Connect

    Shourbaji, A.A.

    2003-06-27

    A floor contamination monitor model FLP3D manufactured by Saint-Gobain Crystals and Detectors UK Ltd. was tested at Oak Ridge National Laboratory. The purpose of the test is to evaluate the monitor's performance as a mobile instrument capable of detecting alpha and/or beta contamination that may exist on a flat surface such as a floor. The monitor consists of a large area scintillation probe (600 cm{sup 2}) and a rate meter mounted on heavy-duty wheels with a 22 mm separation between the monitored surface and the probe. Performance was evaluated under normal and severe environmental conditions in terms of temperature and humidity variations, and exposure to RF and magnetic fields. Sensitivity measurements were also made to determine the probe's efficiency for detecting alpha and beta contamination. The overall performance of the floor monitor is considered satisfactory under the various environmental conditions with no major problems observed. The monitor is approximately 50% efficiency for {sup 90}Sr/{sup 90}Y with the source placed in contact with the detector's protective grille (0 mm) and at a distance of 22 mm. However, in its present physical configuration, the floor monitor is inefficient in detecting alpha contamination due to the 22 mm separation between the surface to be monitored and the detector's surface. The alpha detection efficiency can be enhanced to a reasonable vale by redesigning the brackets holding the heavy-duty wheels to reduce the height between the surface to be monitored and the surface of the probe to a few millimeters. For use at ORNL, this change is recommended.

  9. Echocardiographic evaluation of the effects of dexmedetomidine on cardiac function during total intravenous anaesthesia.

    PubMed

    Lee, S H; Choi, Y S; Hong, G R; Oh, Y J

    2015-09-01

    The purpose of this study was to investigate the effects of dexmedetomidine on biventricular systolic and diastolic function using transoesophageal echocardiography. Cardiac function was assessed in 30 healthy patients who received total intravenous anaesthesia with propofol and remifentanil. The echocardiographic examinations were performed just before and 20, 40 and 60 min after dexmedetomidine or saline administration. Patients who received dexmedetomidine, compared with saline after 20 min, had a lower mean (SD) heart rate (56.7 (5.2) vs. 67.1 (7.1) beats.min(-1) ), higher systolic blood pressure (125.7 (18.9) vs. 109 (7.9) mmHg), and lower cardiac output (2.9 (0.5) vs. 3.7 (1.0) l.min(-1) ), respectively (all p < 0.05). In contrast, no changes were observed in biventricular systolic and diastolic indices in either group, and there were no inter-group differences at any time point. Dexmedetomidine, as an adjuvant to total intravenous anaesthesia, does not impair biventricular systolic and diastolic function in healthy patients, but decreases cardiac output by reducing heart rate.

  10. Evaluation of the 3d Urban Modelling Capabilities in Geographical Information Systems

    NASA Astrophysics Data System (ADS)

    Dogru, A. O.; Seker, D. Z.

    2010-12-01

    Geographical Information System (GIS) Technology, which provides successful solutions to basic spatial problems, is currently widely used in 3 dimensional (3D) modeling of physical reality with its developing visualization tools. The modeling of large and complicated phenomenon is a challenging problem in terms of computer graphics currently in use. However, it is possible to visualize that phenomenon in 3D by using computer systems. 3D models are used in developing computer games, military training, urban planning, tourism and etc. The use of 3D models for planning and management of urban areas is very popular issue of city administrations. In this context, 3D City models are produced and used for various purposes. However the requirements of the models vary depending on the type and scope of the application. While a high level visualization, where photorealistic visualization techniques are widely used, is required for touristy and recreational purposes, an abstract visualization of the physical reality is generally sufficient for the communication of the thematic information. The visual variables, which are the principle components of cartographic visualization, such as: color, shape, pattern, orientation, size, position, and saturation are used for communicating the thematic information. These kinds of 3D city models are called as abstract models. Standardization of technologies used for 3D modeling is now available by the use of CityGML. CityGML implements several novel concepts to support interoperability, consistency and functionality. For example it supports different Levels-of-Detail (LoD), which may arise from independent data collection processes and are used for efficient visualization and efficient data analysis. In one CityGML data set, the same object may be represented in different LoD simultaneously, enabling the analysis and visualization of the same object with regard to different degrees of resolution. Furthermore, two CityGML data sets

  11. 3-D visualisation and interpretation of seismic attributes extracted from large 3-D seismic datasets: Subregional and prospect evaluation, deepwater Nigeria

    SciTech Connect

    Sola, M.; Haakon Nordby, L.; Dailey, D.V.; Duncan, E.A.

    1996-12-31

    High resolution 3-D visualization of horizon interpretation and seismic attributes from large 3-D seismic surveys in deepwater Nigeria has greatly enhanced the exploration team`s ability to quickly recognize prospective segments of subregional and prospect specific scale areas. Integrated workstation generated structure, isopach and extracted horizon consistent, interval and windowed attributes are particularly useful in illustrating the complex structural and stratigraphical prospectivity of deepwater Nigeria. Large 3-D seismic volumes acquired over 750 square kilometers can be manipulated within the visualization system with attribute tracking capability that allows for real time data interrogation and interpretation. As in classical seismic stratigraphic studies, pattern recognition is fundamental to effective depositions facies interpretation and reservoir model construction. The 3-D perspective enhances the data interpretation through clear representation of relative scale, spatial distribution and magnitude of attributes. In deepwater Nigeria, many prospective traps rely on an interplay between syndepositional structure and slope turbidite depositional systems. Reservoir systems in many prospects appear to be dominated by unconfined to moderately focused slope feeder channel facies. These units have spatially complex facies architecture with feeder channel axes separated by extensive interchannel areas. Structural culminations generally have a history of initial compressional folding with late in extensional collapse and accommodation faulting. The resulting complex trap configurations often have stacked reservoirs over intervals as thick as 1500 meters. Exploration, appraisal and development scenarios in these settings can be optimized by taking full advantage of integrating high resolution 3-D visualization and seismic workstation interpretation.

  12. 3-D visualisation and interpretation of seismic attributes extracted from large 3-D seismic datasets: Subregional and prospect evaluation, deepwater Nigeria

    SciTech Connect

    Sola, M.; Haakon Nordby, L.; Dailey, D.V.; Duncan, E.A. )

    1996-01-01

    High resolution 3-D visualization of horizon interpretation and seismic attributes from large 3-D seismic surveys in deepwater Nigeria has greatly enhanced the exploration team's ability to quickly recognize prospective segments of subregional and prospect specific scale areas. Integrated workstation generated structure, isopach and extracted horizon consistent, interval and windowed attributes are particularly useful in illustrating the complex structural and stratigraphical prospectivity of deepwater Nigeria. Large 3-D seismic volumes acquired over 750 square kilometers can be manipulated within the visualization system with attribute tracking capability that allows for real time data interrogation and interpretation. As in classical seismic stratigraphic studies, pattern recognition is fundamental to effective depositions facies interpretation and reservoir model construction. The 3-D perspective enhances the data interpretation through clear representation of relative scale, spatial distribution and magnitude of attributes. In deepwater Nigeria, many prospective traps rely on an interplay between syndepositional structure and slope turbidite depositional systems. Reservoir systems in many prospects appear to be dominated by unconfined to moderately focused slope feeder channel facies. These units have spatially complex facies architecture with feeder channel axes separated by extensive interchannel areas. Structural culminations generally have a history of initial compressional folding with late in extensional collapse and accommodation faulting. The resulting complex trap configurations often have stacked reservoirs over intervals as thick as 1500 meters. Exploration, appraisal and development scenarios in these settings can be optimized by taking full advantage of integrating high resolution 3-D visualization and seismic workstation interpretation.

  13. Influences of 3D PET scanner components on increased scatter evaluated by a Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Hirano, Yoshiyuki; Koshino, Kazuhiro; Iida, Hidehiro

    2017-05-01

    Monte Carlo simulation is widely applied to evaluate the performance of three-dimensional positron emission tomography (3D-PET). For accurate scatter simulations, all components that generate scatter need to be taken into account. The aim of this work was to identify the components that influence scatter. The simulated geometries of a PET scanner were: a precisely reproduced configuration including all of the components; a configuration with the bed, the tunnel and shields; a configuration with the bed and shields; and the simplest geometry with only the bed. We measured and simulated the scatter fraction using two different set-ups: (1) as prescribed by NEMA-NU 2007 and (2) a similar set-up but with a shorter line source, so that all activity was contained only inside the field-of-view (FOV), in order to reduce influences of components outside the FOV. The scatter fractions for the two experimental set-ups were, respectively, 45% and 38%. Regarding the geometrical configurations, the former two configurations gave simulation results in good agreement with the experimental results, but simulation results of the simplest geometry were significantly different at the edge of the FOV. From the simulation of the precise configuration, the object (scatter phantom) was the source of more than 90% of the scatter. This was also confirmed by visualization of photon trajectories. Then, the bed and the tunnel were mainly the sources of the rest of the scatter. From the simulation results, we concluded that the precise construction was not needed; the shields, the tunnel, the bed and the object were sufficient for accurate scatter simulations.

  14. Use and Evaluation of 3D GeoWall Visualizations in Undergraduate Space Science Classes

    NASA Astrophysics Data System (ADS)

    Turner, N. E.; Hamed, K. M.; Lopez, R. E.; Mitchell, E. J.; Gray, C. L.; Corralez, D. S.; Robinson, C. A.; Soderlund, K. M.

    2005-12-01

    One persistent difficulty many astronomy students face is the lack of 3- dimensional mental model of the systems being studied, in particular the Sun-Earth-Moon system. Students without such a mental model can have a very hard time conceptualizing the geometric relationships that cause, for example, the cycle of lunar phases or the pattern of seasons. The GeoWall is a recently developed and affordable projection mechanism for three-dimensional stereo visualization which is becoming a popular tool in classrooms and research labs for use in geology classes, but as yet very little work has been done involving the GeoWall for astronomy classes. We present results from a large study involving over 1000 students of varied backgrounds: some students were tested at the University of Texas at El Paso, a large public university on the US-Mexico border and other students were from the Florida Institute of Technology, a small, private, technical school in Melbourne Florida. We wrote a lecture tutorial-style lab to go along with a GeoWall 3D visual of the Earth-Moon system and tested the students before and after with several diagnostics. Students were given pre and post tests using the Lunar Phase Concept Inventory (LPCI) as well as a separate evaluation written specifically for this project. We found the lab useful for both populations of students, but not equally effective for all. We discuss reactions from the students and their improvement, as well as whether the students are able to correctly assess the usefullness of the project for their own learning.

  15. Evaluation of Jumping and Creeping Regularization Approaches Applied to 3D Seismic Tomography

    NASA Astrophysics Data System (ADS)

    Liu, M.; Ramachandran, K.

    2011-12-01

    are evaluated on a synthetic 3-D true model obtained from a large scale experiment. The evaluation is performed for jumping and creeping approaches for various levels of smoothing constraints, and initial models. The final models are compared against the true models to compute residual distance between the models. Horizontal and vertical roughness in the final models are computed and compared with the true model roughness. Correlation between the true and final models is computed to evaluate the similarities of spatial patterns in the models. The study is also used to show that average 1-D models derived from the final models are very close, indicating that this will be an optimal approach to construct 1-D starting models.

  16. Echocardiographic evaluation of cardiac functions in newborns of mildly preeclamptic pregnant women within postnatal 24-48 hours.

    PubMed

    Mutlu, Kadir; Karadas, Ulas; Yozgat, Yilmaz; Meşe, Timur; Demirol, Mustafa; Coban, Senay; Karadeniz, Cem; Özdemir, Rahmi; Orbatu, Dilek; Karaarslan, Utku; Tavli, Vedide

    2017-06-20

    The aim of this study is to detect preeclampsia-related cardiac dysfunction within 24-48 hours of delivery in newborns born from preeclamptic mothers. Forty newborns from mildly preeclamptic mothers formed the study group and the control group was formed by 40 healthy newborns. Cardiac function for the groups were evaluated using conventional echocardiography and myocardial performance index (MPI) within the first 24-48 hours of their lifetime and the results of both groups were compared. A significant difference between the groups was observed especially in the PW Doppler MPI measurements (the left ventricle MPI 0.37 ± 0.09 and 0.26 ± 0.11, p < .001; the right ventricle MPI 0.29 ± 0.08 and 0.26 ± 0.07, p < .035) for the control group and the study group. Elongation in the left and right ventricle MPI was detected to be more significant in terms of comparing systolic and diastolic functions to determine preeclampsia-related cardiac injury in newborns from preeclamptic mothers within the first 24-48 hours of their lifetime. Impact statement Today, the methods which may detect cardiac injury earlier than conventional echocardiographic methods are used for evaluating cardiac functions. Among them, myocardial performance index (MPI) measurement with PW Doppler is the most common ones. While studies are available in the literature evaluating foetal cardiac functions with MPI in foetuses of preeclamptic women, studies evaluating cardiac functions with MPI index within the first 24-48 hours in postnatal period are not available. This is the first study to detect cardiac injury by measuring cardiac functions of the newborns of preeclamptic babies using conventional echocardiography (EF, SF, mitral and tricuspid E/A) and myocardial performance index within the first 24-48 hours of life and compare these values with those of a control group composed of healthy newborns with similar demographic characteristics. According to the results of the

  17. ECHOCARDIOGRAPHIC EVALUATION OF THE EFFECTS OF STEM CELL THERAPY ON PERFUSION AND FUNCTION IN ISCHEMIC CARDIOMYOPATHY

    PubMed Central

    Inaba, Yoichi; Davidson, Brian P.; Kim, Sajeevani; Liu, Ya Ni; Packwood, William; Belcik, Todd; Xie, Aris; Lindner, Jonathan R.

    2013-01-01

    BACKGROUND Small animal models of ischemic left ventricular (LV) dysfunction are important for the pre-clinical optimization of stem cell therapy. We hypothesized that temporal changes in LV function and regional perfusion after cell therapy can be assessed in mice using echocardiographic imaging. METHODS Wild-type mice (n=25) were studied 7 and 28 days after permanent ligation of the left anterior descending artery. Animals were randomized to receive closed-chest ultrasound-guided intramyocardial delivery of saline (n=13) or 5×105 multipotential adult progenitor cells (MAPC) (n=12) at day 7. Left ventricular end-diastolic (LVEDV) and end-systolic (LVESV) volume, left ventricular ejection fraction (LVEF), and stroke volume were measured by high-frequency echocardiography. Multiplanar assessment of perfusion and defect area size were made by myocardial contrast echocardiography (MCE). RESULTS Between day 7 and 28, MAPC-treated animals had a 40–50% reduction in defect size (p<0.001) and a 20–30% increase in total perfusion (p<0.01). Perfusion did not change in non-treated controls. Both LVEDV and LVESV increased between day 7 and 28 in both groups, however LVESV increased to a lesser degree in MAPC-treated versus control mice (+4.2±7.9 vs +19.2±22.0 μL, p<0.05). LVEF increased in the MAPC-treated mice and decreased in control mice (+3.0±4.3 vs −5.6±5.9 %, p<0.01). There was a significant linear relation between the change in LVEF and the change in either defect area size or total perfusion. CONCLUSIONS High-frequency echocardiography and MCE in murine models of ischemic LV dysfunction can be used to assess the response to stem cell therapy and to characterize the relationship between spatial flow, ventricular function and ventricular remodeling. PMID:24315764

  18. SYDESCO: a laser-video scanner for 3D scoliosis evaluations.

    PubMed

    Treuillet, S; Lucas, Y; Crepin, G; Peuchot, B; Pichaud, J C

    2002-01-01

    SYDESCO is a new 3D vision system developed for trunk surface topography. This structured light surface scanner uses the principle of triangulation-based range sensing to infer 3D shape. The complete trunk acquisition is fast (2 seconds). The accuracy of the metric data is ensured by a subpixel image detection and a calibration process, which rectifies image deformations. A preliminary study presents results on 50 children in a gymnastics school. These children, aged between eight to sixteen years, are particularly exposed to spinal deformities. An asymmetry index is calculated from the 3D data to detect the pathologic cases. These results have been compared to an independent medical diagnosis. The system results have been confirmed for 72,1% of the patients.

  19. 3-D FDTD simulation of shear waves for evaluation of complex modulus imaging.

    PubMed

    Orescanin, Marko; Wang, Yue; Insana, Michael

    2011-02-01

    The Navier equation describing shear wave propagation in 3-D viscoelastic media is solved numerically with a finite differences time domain (FDTD) method. Solutions are formed in terms of transverse scatterer velocity waves and then verified via comparison to measured wave fields in heterogeneous hydrogel phantoms. The numerical algorithm is used as a tool to study the effects on complex shear modulus estimation from wave propagation in heterogeneous viscoelastic media. We used an algebraic Helmholtz inversion (AHI) technique to solve for the complex shear modulus from simulated and experimental velocity data acquired in 2-D and 3-D. Although 3-D velocity estimates are required in general, there are object geometries for which 2-D inversions provide accurate estimations of the material properties. Through simulations and experiments, we explored artifacts generated in elastic and dynamic-viscous shear modulus images related to the shear wavelength and average viscosity.

  20. Evaluation of 3D printed materials used to print WR10 horn antennas

    NASA Astrophysics Data System (ADS)

    Köhler, Elof; Rahiminejad, Sofia; Enoksson, Peter

    2016-10-01

    A WR10 waveguide horn antenna is 3D printed with three different materials. The antennas are printed on a fusion deposition modeling delta 3D printer built in house at Chalmers University of Technology. The different plastic materials used are an electrically conductive Acrylonitrile butadiene styrene (ABS), a thermally conductive polylactic acid containing 35% copper, and a tough Amphora polymer containing at least 20% carbon fiber. The antennas are all printed with a 0.25 mm nozzle and 100 μm layer thickness and the software settings are tuned to give maximum quality for each material. The three 3D printed horn antennas are compared when it comes to cost, time and material properties.

  1. 3D range-modulator for scanned particle therapy: development, Monte Carlo simulations and experimental evaluation

    NASA Astrophysics Data System (ADS)

    Simeonov, Yuri; Weber, Uli; Penchev, Petar; Printz Ringbæk, Toke; Schuy, Christoph; Brons, Stephan; Engenhart-Cabillic, Rita; Bliedtner, Jens; Zink, Klemens

    2017-09-01

    The purpose of this work was to design and manufacture a 3D range-modulator for scanned particle therapy. The modulator is intended to create a highly conformal dose distribution with only one fixed energy, simultaneously reducing considerably the treatment time. As a proof of concept, a 3D range-modulator was developed for a spherical target volume with a diameter of 5 cm, placed at a depth of 25 cm in a water phantom. It consists of a large number of thin pins with a well-defined shape and different lengths to modulate the necessary shift of the Bragg peak. The 3D range-modulator was manufactured with a rapid prototyping technique. The FLUKA Monte Carlo package was used to simulate the modulating effect of the 3D range-modulator and the resulting dose distribution. For that purpose, a special user routine was implemented to handle its complex geometrical contour. Additionally, FLUKA was extended with the capability of intensity modulated scanning. To validate the simulation results, dose measurements were carried out at the Heidelberg Ion Beam Therapy Center with a 400.41 MeV/u 12C beam. The high resolution dosimetric measurements show a good agreement between simulated and measured dose distributions. Irradiation of the monoenergetic raster plan took 3 s, which is approximately 20 times shorter than a comparable plan with 16 different energies. The combination of only one energy and a 3D range-modulator leads to a tremendous decrease in irradiation time. ‘Interplay effects’, typical for moving targets and pencil beam scanning, can be immensely reduced or disappear completely, making the delivery of a homogeneous dose to moving targets more reliable. Combining high dose conformity, very good homogeneity and extremely short irradiation times, the 3D range-modulator is considered to become a clinically applicable method for very fast treatment of lung tumours.

  2. Evaluation of internal fit of interim crown fabricated with CAD/CAM milling and 3D printing system

    PubMed Central

    2017-01-01

    PURPOSE This study is to evaluate the internal fit of the crown manufactured by CAD/CAM milling method and 3D printing method. MATERIALS AND METHODS The master model was fabricated with stainless steel by using CNC machine and the work model was created from the vinyl-polysiloxane impression. After scanning the working model, the design software is used to design the crown. The saved STL file is used on the CAD/CAM milling method and two types of 3D printing method to produce 10 interim crowns per group. Internal discrepancy measurement uses the silicon replica method and the measured data are analyzed with One-way ANOVA to verify the statistic significance. RESULTS The discrepancy means (standard deviation) of the 3 groups are 171.6 (97.4) µm for the crown manufactured by the milling system and 149.1 (65.9) and 91.1 (36.4) µm, respectively, for the crowns manufactured with the two types of 3D printing system. There was a statistically significant difference and the 3D printing system group showed more outstanding value than the milling system group. CONCLUSION The marginal and internal fit of the interim restoration has more outstanding 3D printing method than the CAD/CAM milling method. Therefore, the 3D printing method is considered as applicable for not only the interim restoration production, but also in the dental prosthesis production with a higher level of completion. PMID:28874993

  3. Evaluation of internal fit of interim crown fabricated with CAD/CAM milling and 3D printing system.

    PubMed

    Lee, Wan-Sun; Lee, Du-Hyeong; Lee, Kyu-Bok

    2017-08-01

    This study is to evaluate the internal fit of the crown manufactured by CAD/CAM milling method and 3D printing method. The master model was fabricated with stainless steel by using CNC machine and the work model was created from the vinyl-polysiloxane impression. After scanning the working model, the design software is used to design the crown. The saved STL file is used on the CAD/CAM milling method and two types of 3D printing method to produce 10 interim crowns per group. Internal discrepancy measurement uses the silicon replica method and the measured data are analyzed with One-way ANOVA to verify the statistic significance. The discrepancy means (standard deviation) of the 3 groups are 171.6 (97.4) µm for the crown manufactured by the milling system and 149.1 (65.9) and 91.1 (36.4) µm, respectively, for the crowns manufactured with the two types of 3D printing system. There was a statistically significant difference and the 3D printing system group showed more outstanding value than the milling system group. The marginal and internal fit of the interim restoration has more outstanding 3D printing method than the CAD/CAM milling method. Therefore, the 3D printing method is considered as applicable for not only the interim restoration production, but also in the dental prosthesis production with a higher level of completion.

  4. Evaluation by quantitative image analysis of anticancer drug activity on multicellular spheroids grown in 3D matrices

    PubMed Central

    Gomes, Aurélie; Russo, Adrien; Vidal, Guillaume; Demange, Elise; Pannetier, Pauline; Souguir, Zied; Lagarde, Jean-Michel; Ducommun, Bernard; Lobjois, Valérie

    2016-01-01

    Pharmacological evaluation of anticancer drugs using 3D in vitro models provides invaluable information for predicting in vivo activity. Artificial matrices are currently available that scale up and increase the power of such 3D models. The aim of the present study was to propose an efficient and robust imaging and analysis pipeline to assess with quantitative parameters the efficacy of a particular cytotoxic drug. HCT116 colorectal adenocarcinoma tumor cell multispheres were grown in a 3D physiological hyaluronic acid matrix. 3D microscopy was performed with structured illumination, whereas image processing and feature extraction were performed with custom analysis tools. This procedure makes it possible to automatically detect spheres in a large volume of matrix in 96-well plates. It was used to evaluate drug efficacy in HCT116 spheres treated with different concentrations of topotecan, a DNA topoisomerase inhibitor. Following automatic detection and quantification, changes in cluster size distribution with a topotecan concentration-dependent increase of small clusters according to drug cytotoxicity were observed. Quantitative image analysis is thus an effective means to evaluate and quantify the cytotoxic and cytostatic activities of anticancer drugs on 3D multicellular models grown in a physiological matrix. PMID:28105152

  5. Adaptive quality assurance of the product development process of additive manufacturing with modern 3D data evaluation methods

    NASA Astrophysics Data System (ADS)

    Kroll, Julia; Botta, Sabine; Breuninger, Jannis; Verl, Alexander

    2013-03-01

    In this paper, the possibilities of modern 3D data evaluation for metrology and quality assurance are presented for the special application of the plastic laser sinter process, especially the Additive Manufacturing process. We use the advantages of computer tomography and of the 3D focus variation at all stages of a production process for an increased quality of the resulting products. With the CT and the 3D focus variation the modern quality assurance and metrology have state of the art instruments that allow non-destructive, complete and accurate measuring of parts. Therefore, these metrological methods can be used in many stages of the product development process for non-destructive quality control. In this work, studies and evaluation of 3D data and the conclusions for relevant quality criteria are presented. Additionally, new developments and implementations for adapting the evaluation results for quality prediction, comparison and for correction are described to show how an adequate process control can be achieved with the help of modern 3D metrology techniques. The focus is on the optimization of laser sintering components with regard to their quality requirements so that the functionality during production can be guaranteed and quantified.

  6. 3D-2D registration in mobile radiographs: algorithm development and preliminary clinical evaluation

    NASA Astrophysics Data System (ADS)

    Otake, Yoshito; Wang, Adam S.; Uneri, Ali; Kleinszig, Gerhard; Vogt, Sebastian; Aygun, Nafi; Lo, Sheng-fu L.; Wolinsky, Jean-Paul; Gokaslan, Ziya L.; Siewerdsen, Jeffrey H.

    2015-03-01

    An image-based 3D-2D registration method is presented using radiographs acquired in the uncalibrated, unconstrained geometry of mobile radiography. The approach extends a previous method for six degree-of-freedom (DOF) registration in C-arm fluoroscopy (namely ‘LevelCheck’) to solve the 9-DOF estimate of geometry in which the position of the source and detector are unconstrained. The method was implemented using a gradient correlation similarity metric and stochastic derivative-free optimization on a GPU. Development and evaluation were conducted in three steps. First, simulation studies were performed that involved a CT scan of an anthropomorphic body phantom and 1000 randomly generated digitally reconstructed radiographs in posterior-anterior and lateral views. A median projection distance error (PDE) of 0.007 mm was achieved with 9-DOF registration compared to 0.767 mm for 6-DOF. Second, cadaver studies were conducted using mobile radiographs acquired in three anatomical regions (thorax, abdomen and pelvis) and three levels of source-detector distance (~800, ~1000 and ~1200 mm). The 9-DOF method achieved a median PDE of 0.49 mm (compared to 2.53 mm for the 6-DOF method) and demonstrated robustness in the unconstrained imaging geometry. Finally, a retrospective clinical study was conducted with intraoperative radiographs of the spine exhibiting real anatomical deformation and image content mismatch (e.g. interventional devices in the radiograph that were not in the CT), demonstrating a PDE = 1.1 mm for the 9-DOF approach. Average computation time was 48.5 s, involving 687 701 function evaluations on average, compared to 18.2 s for the 6-DOF method. Despite the greater computational load, the 9-DOF method may offer a valuable tool for target localization (e.g. decision support in level counting) as well as safety and quality assurance checks at the conclusion of a procedure (e.g. overlay of planning data on the radiograph for verification of

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

    PubMed

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

    2016-07-01

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

  8. 3-D Intestinal Scaffolds for Evaluating the Therapeutic Potential of Probiotics

    PubMed Central

    2015-01-01

    Biomimetic in vitro intestinal models are becoming useful tools for studying host–microbial interactions. In the past, these models have typically been limited to simple cultures on 2-D scaffolds or Transwell inserts, but it is widely understood that epithelial cells cultured in 3-D environments exhibit different phenotypes that are more reflective of native tissue, and that different microbial species will preferentially adhere to select locations along the intestinal villi. We used a synthetic 3-D tissue scaffold with villous features that could support the coculture of epithelial cell types with select bacterial populations. Our end goal was to establish microbial niches along the crypt–villus axis in order to mimic the natural microenvironment of the small intestine, which could potentially provide new insights into microbe-induced intestinal disorders, as well as enabling targeted probiotic therapies. We recreated the surface topography of the small intestine by fabricating a biodegradable and biocompatible villous scaffold using poly lactic-glycolic acid to enable the culture of Caco-2 with differentiation along the crypt–villus axis in a similar manner to native intestines. This was then used as a platform to mimic the adhesion and invasion profiles of both Salmonella and Pseudomonas, and assess the therapeutic potential of Lactobacillus and commensal Escherichia coli in a 3-D setting. We found that, in a 3-D environment, Lactobacillus is more successful at displacing pathogens, whereas Nissle is more effective at inhibiting pathogen adhesion. PMID:24798584

  9. Cranial Base Superimposition for 3D Evaluation of Soft Tissue Changes

    PubMed Central

    Cevidanes, Lucia H.C.; Motta, Alexandre; Proffit, William R.; Ackerman, James L.; Styner, Martin

    2009-01-01

    The recent emphasis on soft tissues as the limiting factor in treatment and on soft tissue relationships in establishing the goals of treatment has made 3D analysis of soft tissues more important in diagnosis and treatment planning. It is equally important to be able to detect changes in the facial soft tissues produced by growth and/or treatment. This requires structures of reference for superimposition, and a way to display the changes with quantitative information. This paper outlines a technique for quantifying facial soft tissue changes as viewed in CBCT data, using fully-automated voxel-wise registration of the cranial base surface. The assessment of change of soft tissues is done via calculation of the Euclidean surface distances between the 3D models. Color maps are used for visual assessment of the location and quantification of changes. This methodology allows a detailed examination of soft tissue changes with growth and/or treatment. Because of the lack of stable references with 3D photogrammetry, 3D photography and laser scanning, soft tissue changes cannot be accurately quantified by these methods. PMID:20381752

  10. A Small-Scale 3D Imaging Platform for Algorithm Performance Evaluation

    DTIC Science & Technology

    2007-06-01

    object tracking systems can imitate the 3D depth perception experienced in human vision by using the binocular disparity between the left and right...television, security monitoring, medical endoscopy, modern astronomy and video conferencing applications [4]. The newly discovered technology demonstrated

  11. Evaluation of the systematic error in using 3D dose calculation in scanning beam proton therapy for lung cancer.

    PubMed

    Li, Heng; Liu, Wei; Park, Peter; Matney, Jason; Liao, Zhongxing; Chang, Joe; Zhang, Xiaodong; Li, Yupeng; Zhu, Ronald X

    2014-09-08

    The objective of this study was to evaluate and understand the systematic error between the planned three-dimensional (3D) dose and the delivered dose to patient in scanning beam proton therapy for lung tumors. Single-field and multifield optimized scanning beam proton therapy plans were generated for ten patients with stage II-III lung cancer with a mix of tumor motion and size. 3D doses in CT datasets for different respiratory phases and the time-weighted average CT, as well as the four-dimensional (4D) doses were computed for both plans. The 3D and 4D dose differences for the targets and different organs at risk were compared using dose-volume histogram (DVH) and voxel-based techniques, and correlated with the extent of tumor motion. The gross tumor volume (GTV) dose was maintained in all 3D and 4D doses, using the internal GTV override technique. The DVH and voxel-based techniques are highly correlated. The mean dose error and the standard deviation of dose error for all target volumes were both less than 1.5% for all but one patient. However, the point dose difference between the 3D and 4D doses was up to 6% for the GTV and greater than 10% for the clinical and planning target volumes. Changes in the 4D and 3D doses were not correlated with tumor motion. The planning technique (single-field or multifield optimized) did not affect the observed systematic error. In conclusion, the dose error in 3D dose calculation varies from patient to patient and does not correlate with lung tumor motion. Therefore, patient-specific evaluation of the 4D dose is important for scanning beam proton therapy for lung tumors.

  12. Evaluating the utility of 3D TRUS image information in guiding intra-procedure registration for motion compensation

    NASA Astrophysics Data System (ADS)

    De Silva, Tharindu; Cool, Derek W.; Romagnoli, Cesare; Fenster, Aaron; Ward, Aaron D.

    2014-03-01

    In targeted 3D transrectal ultrasound (TRUS)-guided biopsy, patient and prostate movement during the procedure can cause target misalignments that hinder accurate sampling of pre-planned suspicious tissue locations. Multiple solutions have been proposed for motion compensation via registration of intra-procedural TRUS images to a baseline 3D TRUS image acquired at the beginning of the biopsy procedure. While 2D TRUS images are widely used for intra-procedural guidance, some solutions utilize richer intra-procedural images such as bi- or multi-planar TRUS or 3D TRUS, acquired by specialized probes. In this work, we measured the impact of such richer intra-procedural imaging on motion compensation accuracy, to evaluate the tradeoff between cost and complexity of intra-procedural imaging versus improved motion compensation. We acquired baseline and intra-procedural 3D TRUS images from 29 patients at standard sextant-template biopsy locations. We used the planes extracted from the 3D intra-procedural scans to simulate 2D and 3D information available in different clinically relevant scenarios for registration. The registration accuracy was evaluated by calculating the target registration error (TRE) using manually identified homologous fiducial markers (micro-calcifications). Our results indicate that TRE improves gradually when the number of intra-procedural imaging planes used in registration is increased. Full 3D TRUS information helps the registration algorithm to robustly converge to more accurate solutions. These results can also inform the design of a fail-safe workflow during motion compensation in a system using a tracked 2D TRUS probe, by prescribing rotational acquisitions that can be performed quickly and easily by the physician immediately prior to needle targeting.

  13. The RNA 3D Motif Atlas: Computational methods for extraction, organization and evaluation of RNA motifs.

    PubMed

    Parlea, Lorena G; Sweeney, Blake A; Hosseini-Asanjan, Maryam; Zirbel, Craig L; Leontis, Neocles B

    2016-07-01

    RNA 3D motifs occupy places in structured RNA molecules that correspond to the hairpin, internal and multi-helix junction "loops" of their secondary structure representations. As many as 40% of the nucleotides of an RNA molecule can belong to these structural elements, which are distinct from the regular double helical regions formed by contiguous AU, GC, and GU Watson-Crick basepairs. With the large number of atomic- or near atomic-resolution 3D structures appearing in a steady stream in the PDB/NDB structure databases, the automated identification, extraction, comparison, clustering and visualization of these structural elements presents an opportunity to enhance RNA science. Three broad applications are: (1) identification of modular, autonomous structural units for RNA nanotechnology, nanobiology and synthetic biology applications; (2) bioinformatic analysis to improve RNA 3D structure prediction from sequence; and (3) creation of searchable databases for exploring the binding specificities, structural flexibility, and dynamics of these RNA elements. In this contribution, we review methods developed for computational extraction of hairpin and internal loop motifs from a non-redundant set of high-quality RNA 3D structures. We provide a statistical summary of the extracted hairpin and internal loop motifs in the most recent version of the RNA 3D Motif Atlas. We also explore the reliability and accuracy of the extraction process by examining its performance in clustering recurrent motifs from homologous ribosomal RNA (rRNA) structures. We conclude with a summary of remaining challenges, especially with regard to extraction of multi-helix junction motifs. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Electrical impedance tomography in 3D using two electrode planes: characterization and evaluation.

    PubMed

    Wagenaar, Justin; Adler, Andy

    2016-06-01

    Electrical impedance tomography (EIT) uses body surface electrical stimulation and measurements to create conductivity images; it shows promise as a non-invasive technology to monitor the distribution of lung ventilation. Most applications of EIT have placed electrodes in a 2D ring around the thorax, and thus produced 2D cross-sectional images. These images are unable to distinguish out-of-plane contributions, or to image volumetric effects. Volumetric EIT can be calculated using multiple electrode planes and a 3D reconstruction algorithm. However, while 3D reconstruction algorithms are available, little has been done to understand the performance of 3D EIT in terms of the measurement configurations available. The goal of this paper is to characterize the phantom and in vivo performance of 3D EIT with two electrode planes. First, phantom measurements are used to measure the reconstruction characteristics of seven stimulation and measurement configurations. Measurements were then performed on eight healthy volunteers as a function of body posture, postures, and with various electrode configurations. Phantom results indicate that 3D EIT using two rings of electrodes provides reasonable resolution in the electrode plane but low vertical resolution. For volunteers, functional EIT images are created from inhalation curve features to analyze the effect of posture (standing, sitting, supine and decline) on regional lung behaviour. An ability to detect vertical changes in lung volume distribution was shown for two electrode configurations. Based on tank and volunteer results, we recommend the use of the 'square' stimulation and measurement pattern for two electrode plane EIT.

  15. Transesophageal echocardiographic evaluation of baboons during microgravity induced by parabolic flight.

    PubMed

    Vernalis, M N; Latham, R D; Fanton, J W; Gaffney, F A

    1993-01-01

    The central cardiovascular responses to transient microgravity are not well understood. Theoretically, entrance into microgravity results in the loss of the hydrostatic pressure head and an increase in central venous pressure (CVP) as a consequence of augmented venous return. However, controversy exists regarding the time course and magnitude of cephalad blood volume shifts and its relationship to central atrial filling pressures. On the June 1991 STS 40 shuttle mission, pre-launch echocardiograms suggested changes in cardiac dimensions occurred while the astronauts were in the supine, feet-up position. Furthermore, a CVP line in an astronaut (n=1) demonstrated an unexpected abrupt decrease in CVP during orbital insertion. In April 1991, our laboratory performed Doppler echocardiography in 6 normal human volunteers during parabolic flight. Increases in right ventricular velocities reflecting a central shift of blood volume was demonstrated in subjects examined in the sitting position. However, test subjects examined in the horizontal positions had no significant rise in Doppler velocities. In addition, Latham et al noted variable central cardiovascular responses in chronically instrumented baboons during early microgravity. Transthoracic echocardiography (TTE) is a feasible method to noninvasively examine cardiac anatomy during parabolic flight. However, transducer placement on the chest wall is very difficult to maintain during transition to microgravity. In addition, TTE requires the use of low frequency transducers (2.5 MHz) which limits resolution. Transesophageal echocardiography (TEE) is an established imaging technique which obtains echocardiographic information from the esophagus. It is a safe procedure and provides higher quality images of cardiac structures than obtained with TTE. Since there are no interposed structures between the esophagus and the heart, higher frequency transducers can be used and resolution is enhanced. With TEE, a flexible

  16. Using Geometry-Based Metrics as Part of Fitness-for-Purpose Evaluations of 3D City Models

    NASA Astrophysics Data System (ADS)

    Wong, K.; Ellul, C.

    2016-10-01

    Three-dimensional geospatial information is being increasingly used in a range of tasks beyond visualisation. 3D datasets, however, are often being produced without exact specifications and at mixed levels of geometric complexity. This leads to variations within the models' geometric and semantic complexity as well as the degree of deviation from the corresponding real world objects. Existing descriptors and measures of 3D data such as CityGML's level of detail are perhaps only partially sufficient in communicating data quality and fitness-for-purpose. This study investigates whether alternative, automated, geometry-based metrics describing the variation of complexity within 3D datasets could provide additional relevant information as part of a process of fitness-for-purpose evaluation. The metrics include: mean vertex/edge/face counts per building; vertex/face ratio; minimum 2D footprint area and; minimum feature length. Each metric was tested on six 3D city models from international locations. The results show that geometry-based metrics can provide additional information on 3D city models as part of fitness-for-purpose evaluations. The metrics, while they cannot be used in isolation, may provide a complement to enhance existing data descriptors if backed up with local knowledge, where possible.

  17. Application and Evaluation of Interactive 3D PDF for Presenting and Sharing Planning Results for Liver Surgery in Clinical Routine

    PubMed Central

    Newe, Axel; Becker, Linda; Schenk, Andrea

    2014-01-01

    Background & Objectives The Portable Document Format (PDF) is the de-facto standard for the exchange of electronic documents. It is platform-independent, suitable for the exchange of medical data, and allows for the embedding of three-dimensional (3D) surface mesh models. In this article, we present the first clinical routine application of interactive 3D surface mesh models which have been integrated into PDF files for the presentation and the exchange of Computer Assisted Surgery Planning (CASP) results in liver surgery. We aimed to prove the feasibility of applying 3D PDF in medical reporting and investigated the user experience with this new technology. Methods We developed an interactive 3D PDF report document format and implemented a software tool to create these reports automatically. After more than 1000 liver CASP cases that have been reported in clinical routine using our 3D PDF report, an international user survey was carried out online to evaluate the user experience. Results Our solution enables the user to interactively explore the anatomical configuration and to have different analyses and various resection proposals displayed within a 3D PDF document covering only a single page that acts more like a software application than like a typical PDF file (“PDF App”). The new 3D PDF report offers many advantages over the previous solutions. According to the results of the online survey, the users have assessed the pragmatic quality (functionality, usability, perspicuity, efficiency) as well as the hedonic quality (attractiveness, novelty) very positively. Conclusion The usage of 3D PDF for reporting and sharing CASP results is feasible and well accepted by the target audience. Using interactive PDF with embedded 3D models is an enabler for presenting and exchanging complex medical information in an easy and platform-independent way. Medical staff as well as patients can benefit from the possibilities provided by 3D PDF. Our results open the door for a

  18. Application and evaluation of interactive 3D PDF for presenting and sharing planning results for liver surgery in clinical routine.

    PubMed

    Newe, Axel; Becker, Linda; Schenk, Andrea

    2014-01-01

    The Portable Document Format (PDF) is the de-facto standard for the exchange of electronic documents. It is platform-independent, suitable for the exchange of medical data, and allows for the embedding of three-dimensional (3D) surface mesh models. In this article, we present the first clinical routine application of interactive 3D surface mesh models which have been integrated into PDF files for the presentation and the exchange of Computer Assisted Surgery Planning (CASP) results in liver surgery. We aimed to prove the feasibility of applying 3D PDF in medical reporting and investigated the user experience with this new technology. We developed an interactive 3D PDF report document format and implemented a software tool to create these reports automatically. After more than 1000 liver CASP cases that have been reported in clinical routine using our 3D PDF report, an international user survey was carried out online to evaluate the user experience. Our solution enables the user to interactively explore the anatomical configuration and to have different analyses and various resection proposals displayed within a 3D PDF document covering only a single page that acts more like a software application than like a typical PDF file ("PDF App"). The new 3D PDF report offers many advantages over the previous solutions. According to the results of the online survey, the users have assessed the pragmatic quality (functionality, usability, perspicuity, efficiency) as well as the hedonic quality (attractiveness, novelty) very positively. The usage of 3D PDF for reporting and sharing CASP results is feasible and well accepted by the target audience. Using interactive PDF with embedded 3D models is an enabler for presenting and exchanging complex medical information in an easy and platform-independent way. Medical staff as well as patients can benefit from the possibilities provided by 3D PDF. Our results open the door for a wider use of this new technology, since the basic idea

  19. Performance evaluation of 3D vision-based semi-autonomous control method for assistive robotic manipulator.

    PubMed

    Ka, Hyun W; Chung, Cheng-Shiu; Ding, Dan; James, Khara; Cooper, Rory

    2017-03-22

    We developed a 3D vision-based semi-autonomous control interface for assistive robotic manipulators. It was implemented based on one of the most popular commercially available assistive robotic manipulator combined with a low-cost depth-sensing camera mounted on the robot base. To perform a manipulation task with the 3D vision-based semi-autonomous control interface, a user starts operating with a manual control method available to him/her. When detecting objects within a set range, the control interface automatically stops the robot, and provides the user with possible manipulation options through audible text output, based on the detected object characteristics. Then, the system waits until the user states a voice command. Once the user command is given, the control interface drives the robot autonomously until the given command is completed. In the empirical evaluations conducted with human subjects from two different groups, it was shown that the semi-autonomous control can be used as an alternative control method to enable individuals with impaired motor control to more efficiently operate the robot arms by facilitating their fine motion control. The advantage of semi-autonomous control was not so obvious for the simple tasks. But, for the relatively complex real-life tasks, the 3D vision-based semi-autonomous control showed significantly faster performance. Implications for Rehabilitation A 3D vision-based semi-autonomous control interface will improve clinical practice by providing an alternative control method that is less demanding physically as well cognitively. A 3D vision-based semi-autonomous control provides the user with task specific intelligent semiautonomous manipulation assistances. A 3D vision-based semi-autonomous control gives the user the feeling that he or she is still in control at any moment. A 3D vision-based semi-autonomous control is compatible with different types of new and existing manual control methods for ARMs.

  20. Evaluation of Low-Cost Terrestrial Photogrammetry for 3d Reconstruction of Complex Buildings

    NASA Astrophysics Data System (ADS)

    Altman, S.; Xiao, W.; Grayson, B.

    2017-09-01

    Terrestrial photogrammetry is an accessible method of 3D digital modelling, and can be done with low-cost consumer grade equipment. Globally there are many undocumented buildings, particularly in the developing world, that could benefit from 3D modelling for documentation, redesign or restoration. Areas with buildings at risk of destruction by natural disaster or war could especially benefit. This study considers a range of variables that affect the quality of photogrammetric results. Different point clouds of the same building are produced with different variables, and they are systematically tested to see how the output was affected. This is done by geometrically comparing them to a laser scanned point cloud of the same building. It finally considers how best results can be achieved for different applications, how to mitigate negative effects, and the limits of this technique.

  1. Immunocompetent 3D model of human upper airway for disease modeling and in vitro drug evaluation.

    PubMed

    Harrington, Helen; Cato, Paul; Salazar, Fabian; Wilkinson, Malcolm; Knox, Alan; Haycock, John W; Rose, Felicity; Aylott, Jon W; Ghaemmaghami, Amir M

    2014-07-07

    The development of more complex in vitro models for the assessment of novel drugs and chemicals is needed because of the limited biological relevance of animal models to humans as well as ethical considerations. Although some human-cell-based assays exist, they are usually 2D, consist of single cell type, and have limited cellular and functional representation of the native tissue. In this study, we have used biomimetic porous electrospun scaffolds to develop an immunocompetent 3D model of the human respiratory tract comprised of three key cell types present in upper airway epithelium. The three cell types, namely, epithelial cells (providing a physical barrier), fibroblasts (extracellular matrix production), and dendritic cells (immune sensing), were initially grown on individual scaffolds and then assembled into the 3D multicell tissue model. The epithelial layer was cultured at the air-liquid interface for up to four weeks, leading to formation of a functional barrier as evidenced by an increase in transepithelial electrical resistance (TEER) and tight junction formation. The response of epithelial cells to allergen exposure was monitored by quantifying changes in TEER readings and by assessment of cellular tight junctions using immunostaining. It was found that epithelial cells cocultured with fibroblasts formed a functional epithelial barrier at a quicker rate than single cultures of epithelial cells and that the recovery from allergen exposure was also more rapid. Also, our data show that dendritic cells within this model remain viable and responsive to external stimulation as evidenced by their migration within the 3D construct in response to allergen challenge. This model provides an easy to assemble and physiologically relevant 3D model of human airway epithelium that can be used for studies aiming at better understanding lung biology, the cross-talk between immune cells, and airborne allergens and pathogens as well as drug delivery.

  2. Effectiveness Evaluation of Force Protection Training Using Computer-Based Instruction and X3d Simulation

    DTIC Science & Technology

    2007-09-01

    to growing operational constraints accelerated by the Global War on Terror, the United States Navy is looking for alternative methods of training to...accomplished efficiently and effectively, saving the U.S. Navy time and resources while maintaining a high state of readiness. The goal of this thesis is...COMPUTER-BASED INSTRUCTION AND X3D SIMULATION Wilfredo Cruzbaez Lieutenant, United States Navy B.A., Norfolk State University, 2001 Submitted in

  3. Development and Evaluation of 2-D and 3-D Exocentric Synthetic Vision Navigation Display Concepts for Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Kramer, Lynda J.; Arthur, J. J., III; Bailey, Randall E.; Sweeters, Jason L.

    2005-01-01

    NASA's Synthetic Vision Systems (SVS) project is developing technologies with practical applications that will help to eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. The paper describes experimental evaluation of a multi-mode 3-D exocentric synthetic vision navigation display concept for commercial aircraft. Experimental results evinced the situation awareness benefits of 2-D and 3-D exocentric synthetic vision displays over traditional 2-D co-planar navigation and vertical situation displays. Conclusions and future research directions are discussed.

  4. 3D Silicon Microstructures: A New Tool for Evaluating Biological Aggressiveness of Tumor Cells.

    PubMed

    Mazzini, Giuliano; Carpignano, Francesca; Surdo, Salvatore; Aredia, Francesca; Panini, Nicolò; Torchio, Martina; Erba, Eugenio; Danova, Marco; Scovassi, Anna Ivana; Barillaro, Giuseppe; Merlo, Sabina

    2015-10-01

    In this work, silicon micromachined structures (SMS), consisting of arrays of 3- μ m-thick silicon walls separated by 50- μm-deep, 5- μ m-wide gaps, were applied to investigate the behavior of eight tumor cell lines, with different origins and biological aggressiveness, in a three-dimensional (3D) microenvironment. Several cell culture experiments were performed on 3D-SMS and cells grown on silicon were stained for fluorescence microscopy analyses. Most of the tumor cell lines recognized in the literature as highly aggressive (OVCAR-5, A375, MDA-MB-231, and RPMI-7951) exhibited a great ability to enter and colonize the narrow deep gaps of the SMS, whereas less aggressive cell lines (OVCAR-3, Capan-1, MCF7, and NCI-H2126) demonstrated less penetration capability and tended to remain on top of the SMS. Quantitative image analyses of several fluorescence microscopy fields of silicon samples were performed for automatic cell recognition and count, in order to quantify the fraction of cells inside the gaps, with respect to the total number of cells in the examined field. Our results show that higher fractions of cells in the gaps are obtained with more aggressive cell lines, thus supporting in a quantitative way the observation that the behavior of tumor cells on the 3D-SMS depends on their aggressiveness level.

  5. Evaluating analytical ionization quenching correction models for 3D liquid organic scintillator detector

    NASA Astrophysics Data System (ADS)

    Alsanea, F.; Beddar, S.

    2017-05-01

    Proton therapy offers dosimetric advantage over conventional photon therapy due to the finite range of the proton beam, which improves dose conformity. However, one of the main challenges of proton beam therapy is verification of the complex treatment plans delivered to a patient. Thus, 3D measurements are needed to verify the complex dose distribution. A 3D organic scintillator detector is capable of such measurements. However, organic scintillators exhibit a non-linear relation to the ionization density called ionization quenching. The ionization quenching phenomenon in organic scintillators must be accounted for to obtain accurate dose measurements. We investigated the energy deposition by secondary electrons (EDSE) model to explain ionization quenching in 3D liquid organic scintillator when exposed to proton beams. The EDSE model was applied to volumetric scintillation measurement of proton pencil beam with energies of 85.6, 100.9, 144.9 and 161.9 MeV. The quenching parameter in EDSE model ρq was determined by plotting the total light output vs the initial energy of the ion. The results were compared to the Birks semi-empirical formula of scintillation light emission.

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

    PubMed

    Hata, Toshiyuki; Tanaka, Hirokazu; Noguchi, Junko

    2012-03-01

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

  7. A procedure for the evaluation of 2D radiographic texture analysis to assess 3D bone micro-architecture

    NASA Astrophysics Data System (ADS)

    Apostol, Lian; Peyrin, Francoise; Yot, Sophie; Basset, Olivier; Odet, Christophe; Tabary, Joachim; Dinten, Jean-Marc; Boller, Elodie; Boudousq, Vincent; Kotzki, Pierre-Olivier

    2004-05-01

    Although the diagnosis of osteoporosis is mainly based on Dual X-ray Absorptiometry, it has been shown that trabecular bone micro-architecture is also an important factor in regards of fracture risk, which can be efficiently assessed in vitro using three-dimensional x-ray microtomography (μCT). In vivo, techniques based on high-resolution s-ray radiography associated to texture analysis have been proposed to investigate bone micro-architecture, but their relevance for giving pertinent 3D information is unclear. The purpose of this work was to develop a method for evaluating the relationships betweeen 3D micro-architecture and 2D texture parameters, and optimizing the conditions for radiographic imaging. Bone sample images taken from cortical to cortical were acquired using 3D-synchrotron x-ray μCT at the ESRF. The 3D digital imagees were further used for two purposes: 1) quantification of three-dimensional bone micro-architecture, 2) simulation of realistic x-ray radiographs under different acquisition conditions. Texture analysis was then applied to these 2D radiographs using a large variety of methods (co-occurence, spectrum, fractal...). First results of the statistical analysis between 2D and 3D parameters allowed identfying the most relevant 2D texture parameters.

  8. Alterations of filopodia by near infrared photoimmunotherapy: evaluation with 3D low-coherent quantitative phase microscopy

    PubMed Central

    Nakamura, Yuko; Nagaya, Tadanobu; Sato, Kazuhide; Harada, Toshiko; Okuyama, Shuhei; Choyke, Peter L.; Yamauchi, Toyohiko; Kobayashi, Hisataka

    2016-01-01

    Filopodia are highly organized cellular membrane structures that facilitate intercellular communication. Near infrared photoimmunotherapy (NIR-PIT) is a newly developed cancer treatment that causes necrotic cell death. Three-dimensional low-coherent quantitative phase microscopy (3D LC-QPM) is based on a newly established low-coherent interference microscope designed to obtain serial topographic images of the cellular membrane. Herein, we report rapid involution of filopodia after NIR-PIT using 3D LC-QPM. For 3T3/HER2 cells, the number of filopodia decreased immediately after treatment with significant differences. Volume and relative height of 3T3/HER2 cells increased immediately after NIR light exposure, but significant differences were not observed. Thus, disappearance of filopodia, evaluated by 3D LC-QPM, is an early indicator of cell membrane damage after NIR-PIT. PMID:27446702

  9. Early detection of liver fibrosis in rats using 3-D ultrasound Nakagami imaging: a feasibility evaluation.

    PubMed

    Ho, Ming-Chih; Tsui, Po-Hsiang; Lee, Yu-Hsin; Chen, Yung-Sheng; Chen, Chiung-Nien; Lin, Jen-Jen; Chang, Chien-Cheng

    2014-09-01

    We investigated the feasibility of using 3-D ultrasound Nakagami imaging to detect the early stages of liver fibrosis in rats. Fibrosis was induced in livers of rats (n = 60) by intraperitoneal injection of 0.5% dimethylnitrosamine (DMN). Group 1 was the control group, and rats in groups 2-6 received DMN injections for 1-5 weeks, respectively. Each rat was sacrificed to perform 3-D ultrasound scanning of the liver in vitro using a single-element transducer of 6.5 MHz. The 3-D raw data acquired at a sampling rate of 50 MHz were used to construct 3-D Nakagami images. The liver specimen was further used for histologic analysis with hematoxylin and eosin and Masson staining to score the degree of liver fibrosis. The results indicate that the Metavir scores of the hematoxylin and eosin-stained sections in Groups 1-4 were 0 (defined as early liver fibrosis in this study), and those in groups 5 and 6 ranged from 1 to 2 and 2 to 3, respectively. To quantify the degree of early liver fibrosis, the histologic sections with Masson stain were analyzed to calculate the number of fiber-related blue pixels. The number of blue pixels increased from (2.36 ± 0.79) × 10(4) (group 1) to (7.68 ± 2.62) × 10(4) (group 4) after DMN injections for 3 weeks, indicating that early stages of liver fibrosis were successfully induced in rats. The Nakagami parameter increased from 0.36 ± 0.02 (group 1) to 0.55 ± 0.03 (group 4), with increasing numbers of blue pixels in the Masson-stained sections (p-value < 0.05, t-test). We concluded that 3-D Nakagami imaging has potential in the early detection of liver fibrosis in rats and may serve as an image-based pathologic model to visually track fibrosis formation and growth.

  10. Quantitative evaluation of an automatic segmentation method for 3D reconstruction of intervertebral scoliotic disks from MR images.

    PubMed

    Claudia, Chevrefils; Farida, Cheriet; Guy, Grimard; Marie-Claude, Miron; Carl-Eric, Aubin

    2012-08-02

    For some scoliotic patients the spinal instrumentation is inevitable. Among these patients, those with stiff curvature will need thoracoscopic disk resection. The removal of the intervertebral disk with only thoracoscopic images is a tedious and challenging task for the surgeon. With computer aided surgery and 3D visualisation of the interverterbral disk during surgery, surgeons will have access to additional information such as the remaining disk tissue or the distance of surgical tools from critical anatomical structures like the aorta or spinal canal. We hypothesized that automatically extracting 3D information of the intervertebral disk from MR images would aid the surgeons to evaluate the remaining disk and would add a security factor to the patient during thoracoscopic disk resection. This paper presents a quantitative evaluation of an automatic segmentation method for 3D reconstruction of intervertebral scoliotic disks from MR images. The automatic segmentation method is based on the watershed technique and morphological operators. The 3D Dice Similarity Coefficient (DSC) is the main statistical metric used to validate the automatically detected preoperative disk volumes. The automatic detections of intervertebral disks of real clinical MR images are compared to manual segmentation done by clinicians. Results show that depending on the type of MR acquisition sequence, the 3D DSC can be as high as 0.79 (±0.04). These 3D results are also supported by a 2D quantitative evaluation as well as by robustness and variability evaluations. The mean discrepancy (in 2D) between the manual and automatic segmentations for regions around the spinal canal is of 1.8 (±0.8) mm. The robustness study shows that among the five factors evaluated, only the type of MRI acquisition sequence can affect the segmentation results. Finally, the variability of the automatic segmentation method is lower than the variability associated with manual segmentation performed by different

  11. Quantitative evaluation of an automatic segmentation method for 3D reconstruction of intervertebral scoliotic disks from MR images

    PubMed Central

    2012-01-01

    Background For some scoliotic patients the spinal instrumentation is inevitable. Among these patients, those with stiff curvature will need thoracoscopic disk resection. The removal of the intervertebral disk with only thoracoscopic images is a tedious and challenging task for the surgeon. With computer aided surgery and 3D visualisation of the interverterbral disk during surgery, surgeons will have access to additional information such as the remaining disk tissue or the distance of surgical tools from critical anatomical structures like the aorta or spinal canal. We hypothesized that automatically extracting 3D information of the intervertebral disk from MR images would aid the surgeons to evaluate the remaining disk and would add a security factor to the patient during thoracoscopic disk resection. Methods This paper presents a quantitative evaluation of an automatic segmentation method for 3D reconstruction of intervertebral scoliotic disks from MR images. The automatic segmentation method is based on the watershed technique and morphological operators. The 3D Dice Similarity Coefficient (DSC) is the main statistical metric used to validate the automatically detected preoperative disk volumes. The automatic detections of intervertebral disks of real clinical MR images are compared to manual segmentation done by clinicians. Results Results show that depending on the type of MR acquisition sequence, the 3D DSC can be as high as 0.79 (±0.04). These 3D results are also supported by a 2D quantitative evaluation as well as by robustness and variability evaluations. The mean discrepancy (in 2D) between the manual and automatic segmentations for regions around the spinal canal is of 1.8 (±0.8) mm. The robustness study shows that among the five factors evaluated, only the type of MRI acquisition sequence can affect the segmentation results. Finally, the variability of the automatic segmentation method is lower than the variability associated with manual segmentation

  12. A global 3-D CTM evaluation of black carbon in the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    He, C.; Li, Q. B.; Liou, K. N.; Zhang, J.; Qi, L.; Mao, Y.; Gao, M.; Lu, Z.; Streets, D. G.; Zhang, Q.; Sarin, M. M.; Ram, K.

    2014-07-01

    We systematically evaluate the black carbon (BC) simulations for 2006 over the Tibetan Plateau by a global 3-D chemical transport model (CTM) (GEOS-Chem) driven by GEOS-5 assimilated meteorological fields, using in situ measurements of BC in surface air, BC in snow, and BC absorption aerosol optical depth (AAOD). Using improved anthropogenic BC emission inventories for Asia that account for rapid technology renewal and energy consumption growth (Zhang et al., 2009; Lu et al., 2011) and improved global biomass burning emission inventories that account for small fires (van der Werf et al., 2010; Randerson et al., 2012), we find that model results of both BC in surface air and in snow are statistically in good agreement with observations (biases < 15%) away from urban centers. Model results capture the seasonal variations of the surface BC concentrations at rural sites in the Indo-Gangetic Plain, but the observed elevated values in winter are absent. Modeled surface-BC concentrations are within a factor of 2 of the observations at remote sites. Part of the discrepancy is explained by the deficiencies of the meteorological fields over the complex Tibetan terrain. We find that BC concentrations in snow computed from modeled BC deposition and GEOS-5 precipitation are spatiotemporally consistent with observations (r = 0.85). The computed BC concentrations in snow are a factor of 2-4 higher than the observations at several Himalayan sites because of excessive BC deposition. The BC concentrations in snow are biased low by a factor of 2 in the central plateau, which we attribute to the absence of snow aging in the CTM and strong local emissions unaccounted for in the emission inventories. Modeled BC AAOD is more than a factor of 2 lower than observations at most sites, particularly to the northwest of the plateau and along the southern slopes of the Himalayas in winter and spring, which is attributable in large part to underestimated emissions and the assumption of external

  13. In vivo 3D neuroanatomical evaluation of periprostatic nerve plexus with 3T-MR Diffusion Tensor Imaging.

    PubMed

    Panebianco, Valeria; Barchetti, Flavio; Sciarra, Alessandro; Marcantonio, Andrea; Zini, Chiara; Salciccia, Stefano; Collettini, Federico; Gentile, Vincenzo; Hamm, Bernard; Catalano, Carlo

    2013-10-01

    To evaluate if Diffusion Tensor Imaging technique (DTI) can improve the visualization of periprostatic nerve fibers describing the location and distribution of entire neurovascular plexus around the prostate in patients who are candidates for prostatectomy. Magnetic Resonance Imaging (MRI), including a 2D T2-weighted FSE sequence in 3 planes, 3D T2-weighted and DTI using 16 gradient directions and b=0 and 1000, was performed on 36 patients. Three out of 36 patients were excluded from the analysis due to poor image quality (blurring N=2, artifact N=1). The study was approved by local ethics committee and all patients gave an informed consent. Images were evaluated by two radiologists with different experience in MRI. DTI images were analyzed qualitatively using dedicated software. Also 2D and 3D T2 images were independently considered. 3D-DTI allowed description of the entire plexus of the periprostatic nerve fibers in all directions, while 2D and 3D T2 morphological sequences depicted part of the fibers, in a plane by plane analysis of fiber courses. DTI demonstrated in all patients the dispersion of nerve fibers around the prostate on both sides including the significant percentage present in the anterior and anterolateral sectors. DTI offers optimal representation of the widely distributed periprostatic plexus. If validated, it may help guide nerve-sparing radical prostatectomy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Accuracy of real-time 3D echocardiography in the evaluation of functional anatomy of mitral regurgitation.

    PubMed

    Agricola, Eustachio; Oppizzi, Michele; Pisani, Matteo; Maisano, Francesco; Margonato, Alberto

    2008-07-21

    To evaluate the feasibility of mitral valve (MV) reconstruction protocol by real-time 3D echocardiography (RT3DE) in the assessment mitral regurgitant (MR) lesions, and to determine the accuracy of RT3DE compared with transthoracic (TTE) and transesophageal (TEE) echocardiographies using surgical findings as gold standard. Sixty-three consecutive patients (mean age 61.7+/-12.5 years, 35 men and 28 women) with severe organic MR were enrolled. Data were acquired in zoom and in full-volume modes from apical and/or parasternal windows. A volume rendered en-face view of MV and five serial longitudinal cut planes were reconstructed to visualize all segments of both leaflets. The feasibility of RT3D reconstruction was 94%. Compared with surgical diagnosis, the accuracy of RT3D was 91% for aetiology, 92% for mechanisms, 94% for prolapse, 88% for flail and 94% for defect location. Diagnostic accuracy was significant higher for RT3D than TTE for all end points except for flail lesion and similar to TEE but inferior to this for flail lesion. The accuracy, sensitivity and specificity were higher in patients with good-excellent than those with poor image quality regarding aetiology, mechanisms and defect location (all p=0.0001). RT3D imaging of MV is feasible and accurate in defining aetiology, mechanism and defect location in patients with MR and has incremental diagnostic value if TTE is inconclusive and similar diagnostic value of TEE except for flail lesion. RT3D, at least in patients with good acoustic window, may obviate the need for subsequent TEE and/or can be considered a complementary technique to study MV in patients with MR.

  15. Evaluation of the Kinect™ sensor for 3-D kinematic measurement in the workplace.

    PubMed

    Dutta, Tilak

    2012-07-01

    Recording posture and movement is important for determining risk of musculoskeletal injury in the workplace, but existing motion capture systems are not suited for field work. Estimates of the 3-D relative positions of four 0.10 m cubes from the Kinect were compared to estimates from a Vicon motion capture system to determine whether the hardware sensing components were sensitive enough to be used as a portable 3-D motion capture system for workplace ergonomic assessments. The root-mean-squared errors (SD) were 0.0065 m (0.0048 m), 0.0109 m (0.0059 m), 0.0057 m (0.0042 m) in the x, y and z directions (with x axis to the right, y axis away from the sensor and z axis upwards). These data were collected over a range of 1.0-3.0m from the device covering a field of view of 54.0 degrees horizontally and 39.1 degrees vertically. Requirements for software, hardware and subject preparation were also considered to determine the usability of the Kinect in the field.

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  17. Development and evaluation of a 3D model observer with nonlinear spatiotemporal contrast sensitivity

    NASA Astrophysics Data System (ADS)

    Avanaki, Ali R. N.; Espig, Kathryn S.; Maidment, Andrew D. A.; Marchessoux, Cedric; Bakic, Predrag R.; Kimpe, Tom R. L.

    2014-03-01

    We investigate improvements to our 3D model observer with the goal of better matching human observer performance as a function of viewing distance, effective contrast, maximum luminance, and browsing speed. Two nonlinear methods of applying the human contrast sensitivity function (CSF) to a 3D model observer are proposed, namely the Probability Map (PM) and Monte Carlo (MC) methods. In the PM method, the visibility probability for each frequency component of the image stack, p, is calculated taking into account Barten's spatiotemporal CSF, the component modulation, and the human psychometric function. The probability p is considered to be equal to the perceived amplitude of the frequency component and thus can be used by a traditional model observer (e.g., LG-msCHO) in the space-time domain. In the MC method, each component is randomly kept with probability p or discarded with 1-p. The amplitude of the retained components is normalized to unity. The methods were tested using DBT stacks of an anthropomorphic breast phantom processed in a comprehensive simulation pipeline. Our experiments indicate that both the PM and MC methods yield results that match human observer performance better than the linear filtering method as a function of viewing distance, effective contrast, maximum luminance, and browsing speed.

  18. Mechanical evaluation of gradient electrospun scaffolds with 3D printed ring reinforcements for tracheal defect repair.

    PubMed

    Ott, Lindsey M; Zabel, Taylor A; Walker, Natalie K; Farris, Ashley L; Chakroff, Jason T; Ohst, Devan G; Johnson, Jed K; Gehrke, Steven H; Weatherly, Robert A; Detamore, Michael S

    2016-04-21

    Tracheal stenosis can become a fatal condition, and current treatments include augmentation of the airway with autologous tissue. A tissue-engineered approach would not require a donor source, while providing an implant that meets both surgeons' and patients' needs. A fibrous, polymeric scaffold organized in gradient bilayers of polycaprolactone (PCL) and poly-lactic-co-glycolic acid (PLGA) with 3D printed structural ring supports, inspired by the native trachea rings, could meet this need. The purpose of the current study was to characterize the tracheal scaffolds with mechanical testing models to determine the design most suitable for maintaining a patent airway. Degradation over 12 weeks revealed that scaffolds with the 3D printed rings had superior properties in tensile and radial compression, with at least a three fold improvement and 8.5-fold improvement, respectively, relative to the other scaffold groups. The ringed scaffolds produced tensile moduli, radial compressive forces, and burst pressures similar to or exceeding physiological forces and native tissue data. Scaffolds with a thicker PCL component had better suture retention and tube flattening recovery properties, with the monolayer of PCL (PCL-only group) exhibiting a 2.3-fold increase in suture retention strength (SRS). Tracheal scaffolds with ring reinforcements have improved mechanical properties, while the fibrous component increased porosity and cell infiltration potential. These scaffolds may be used to treat various trachea defects (patch or circumferential) and have the potential to be employed in other tissue engineering applications.

  19. Accuracy Evaluation of a 3D Ultrasound-guided Biopsy System.

    PubMed

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

    2013-03-14

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

  20. [3D evaluation model for drug hepatotoxicity testing on HepG2 cells and its application in drug safety evaluation].

    PubMed

    Li, Dan-Dan; Tang, Xiang-Lin; Tan, Hong-Ling; Liang, Qian-de; Wang, Yu-Guang; Ma, Zeng-Chun; Xiao, Cheng-Rong; Gao, Yue

    2016-04-01

    3D in vitro toxicity testing model was developed by magnetic levitation method for culture of the human hepatoma cell line HepG2 and applied to evaluate the drug hepatotoxicity. After formation of stable 3D structure for HepG2 cells, their glycogen storage capacity under 2D and 3D culture conditions were detected by immunohistochemistry technology, and the mRNA expression levels of phase Ⅰ and Ⅱ drug metabolism enzymes, drug transporters, nuclear receptors and liver-specific marker albumin(ALB) were compared between 2D and 3D culture conditions by using RT-PCR method. Immunohistochemistry results showed that HepG2 cells had abundant glycogen storage capacity under 3D culture conditions, which was similar to human liver tissues. The mRNA expression levels of major drug metabolism enzymes, drug transporters, nuclear receptors and ALB in HepG2 cells under 3D culture conditions were up-regulated as compared with 2D culture conditions. For drug hepatotoxicity evaluation, the typical hepatotoxic drug acetaminophen(APAP), and most reported drugs Polygonum multiflorum Thunb.(Chinese name He-shou-wu) and Psoraleae corylifolia L.(Chinese name Bu-gu-zhi) were selected for single dose and repeated dose(7 d) exposure. In the repeated dose exposure test, 3D HepG2 cells showed higher sensitivity. This established 3D HepG2 cells model with magnetic levitation 3D culture techniques was more close to the human liver tissues both in morphology and functions, so it was a better 3D hepatotoxicity evaluation model. Copyright© by the Chinese Pharmaceutical Association.

  1. EOS 2D/3D X-ray imaging system: a systematic review and economic evaluation.

    PubMed

    McKenna, C; Wade, R; Faria, R; Yang, H; Stirk, L; Gummerson, N; Sculpher, M; Woolacott, N

    2012-01-01

    EOS is a biplane X-ray imaging system manufactured by EOS Imaging (formerly Biospace Med, Paris, France). It uses slot-scanning technology to produce a high-quality image with less irradiation than standard imaging techniques. To determine the clinical effectiveness and cost-effectiveness of EOS two-dimensional (2D)/three-dimensional (3D) X-ray imaging system for the evaluation and monitoring of scoliosis and other relevant orthopaedic conditions. For the systematic review of EOS, electronic databases (MEDLINE, Allied and Complementary Medicine Database, BIOSIS Previews, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, EMBASE, Health Management Information Consortium, Inspec, ISI Science Citation Index and PASCAL), clinical trials registries and the manufacturer's website were searched from 1993 to November 2010. A systematic review of studies comparing EOS with standard X-ray [film, computed radiography (CR) or digital radiography] in any orthopaedic condition was performed. A narrative synthesis was undertaken. A decision-analytic model was developed to assess the cost-effectiveness of EOS in the relevant indications compared with standard X-ray and incorporated the clinical effectiveness of EOS and the adverse effects of radiation. The model incorporated a lifetime horizon to estimate outcomes in terms of quality-adjusted life-years (QALYs) and costs from the perspective of the NHS. Three studies met the inclusion criteria for the review. Two studies compared EOS with film X-ray and one study compared EOS with CR. The three included studies were small and of limited quality. One study used an earlier version of the technology, the Charpak system. Both studies comparing EOS with film X-ray found image quality to be comparable or better with EOS overall. Radiation dose was considerably lower with EOS: ratio of means for posteroanterior spine was 5.2 (13.1 for the study using the Charpak system); ratio of means for the lateral spine

  2. Evaluation of simulation-based scatter correction for 3-D PET cardiac imaging

    SciTech Connect

    Watson, C.C.; Newport, D.; Casey, M.E.; Kemp, R.A. de; Beanlands, R.S.; Schmand, M. |

    1997-02-01

    Quantitative imaging of the human thorax poses one of the most difficult challenges for three-dimensional (3-D) (septaless) positron emission tomography (PET), due to the strong attenuation of the annihilation radiation and the large contribution of scattered photons to the data. In [{sup 18}F] fluorodeoxyglucose (FDG) studies of the heart with the patient`s arms in the field of view, the contribution of scattered events can exceed 50% of the total detected coincidences. Accurate correction for this scatter component is necessary for meaningful quantitative image analysis and tracer kinetic modeling. For this reason, the authors have implemented a single-scatter simulation technique for scatter correction in positron volume imaging. In this paper they describe this algorithm and present scatter correction results from human and chest phantom studies.

  3. Biological Evaluation and 3D-QSAR Studies of Curcumin Analogues as Aldehyde Dehydrogenase 1 Inhibitors

    PubMed Central

    Wang, Hui; Du, Zhiyun; Zhang, Changyuan; Tang, Zhikai; He, Yan; Zhang, Qiuyan; Zhao, Jun; Zheng, Xi

    2014-01-01

    Aldehyde dehydrogenase 1 (ALDH1) is reported as a biomarker for identifying some cancer stem cells, and down-regulation or inhibition of the enzyme can be effective in anti-drug resistance and a potent therapeutic for some tumours. In this paper, the inhibitory activity, mechanism mode, molecular docking and 3D-QSAR (three-dimensional quantitative structure activity relationship) of curcumin analogues (CAs) against ALDH1 were studied. Results demonstrated that curcumin and CAs possessed potent inhibitory activity against ALDH1, and the CAs compound with ortho di-hydroxyl groups showed the most potent inhibitory activity. This study indicates that CAs may represent a new class of ALDH1 inhibitor. PMID:24840575

  4. Evaluation of 3D displacement components by combining DSCM with ESPI

    NASA Astrophysics Data System (ADS)

    Sun, Ping; Shi, Kai; Sun, Mingyong; Sun, Haibin

    2016-11-01

    A method for three-dimensional (3-D) deformation measurement is presented by combining Digital Speckle Correlation Method (DSCM) with Electronic Speckle Pattern Interferometry (ESPI). The combination is completed based on a typical ESPI system, in which the reference light is controlled to turn on or shut down. The in-plane displacement components are obtained by using DSCM when the reference light is shut. A phase shifting ESPI is formed when the reference light is used, which can be used for the measurement of the out-plane displacement component. A typical three-point-bending experiment is completed. Experiment results show that the three displacement components can be obtained by the combination effectively.

  5. Evaluation of Effective Material Parameters of CNT-reinforced Composites via 3D BEM

    SciTech Connect

    De Araujo, Francisco Celio

    2008-01-01

    In recent years, carbon nanotubes (CNTs) have been widely employed to build advanced composites. In this work, a Boundary Element Method (BEM) is applied to 3D representative volume elements (RVEs) to estimate mechanical properties of CNT-based composites. To model the thin-walled nanotubes, special integration procedures for calculating nearly-strongly-singular integrals have been developed. The generic BE substructuring algorithm allows modeling complex CNT-reinforced polymers, containing any number of nanotubes of any shape (straight or curved). The subregion-by-subregion strategy, based on Krylov solvers, makes the independent generation, assembly, and storage of the many parts of the complete BE model possible. Thus, significant memory and CPU-time reductions are achieved in avoiding working with an explicit global system of equations. Further CPU-time reduction is obtained by employing a matrix-copy option for repeated subregions. Several applications will illustrate the ability of this algorithm to analyze CNT-based composites.

  6. Proposal of a taste evaluating method of the sponge cake by using 3D range sensor

    NASA Astrophysics Data System (ADS)

    Kato, Kunihito; Yamamoto, Kazuhiko; Ogawa, Noriko

    2002-10-01

    Nowadays, the image processing techniques are while applying to the food industry in many situations. The most of these researches are applications for the quality control in plants, and there are hardly any cases of measuring the 'taste'. We are developing the measuring system of the deliciousness by using the image sensing. In this paper, we propose the estimation method of the deliciousness of a sponge cake. Considering about the deliciousness of the sponge cake, if the size of the bubbles on the surface is small and the number of them is large, then it is defined that the deliciousness of the sponge cake is better in the field of the food science. We proposed a method of detection bubbles in the surface of the sectional sponge cake automatically by using 3-D image processing. By the statistical information of these detected bubbles based on the food science, the deliciousness is estimated.

  7. Development and Evaluation of Roadside/Obstacle Detection Method Using 3D Scanned Data Processing

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hiroshi; Ishii, Yoshinori; Yamazaki, Katsuyuki

    In this paper, we have reported the development of a snowblower support system which can safely navigate snowblowers, even during a whiteout, with the combination of a very accurate GPS system, so called RTK-GPS, and a unique and highly accurate map of roadsides and obstacles on roads. Particularly emphasized new techniques in this paper are ways to detect accurate geographical positions of roadsides and obstacles by utilizing and analyzing 3D laser scanned data, whose data has become available in recent days. The experiment has shown that the map created by the methods and RTK-GPS can sufficiently navigate snowblowers, whereby a secure and pleasant social environment can be archived in snow areas of Japan. In addition, proposed methods are expected to be useful for other systems such as a quick development of a highly accurate road map, a safely navigation of a wheeled chair, and so on.

  8. 3D Observation and Evaluation of Induced Damaged Zones in Anisotropic Media

    NASA Astrophysics Data System (ADS)

    Nasseri, M.; Rezanezhad, F.; Young, R.

    2009-05-01

    Rift zones, sites for dyke intrusion and supporting roof of a mine under tension, production enhancement and stimulation of hydrocarbon and geothermal reservoirs are good examples to study the nature of interaction of propagating tensile fractures with pre-existing preferably oriented sets of geological structures. Such interactions cause anisotropy in transport and mechanical properties in rocks, eventually affecting the post strength, post-frictional and hydro-geological properties of resultant rock masses. In present study 3D micro CT images are used to understand the relationship between the test crack path propagation and structure of caused damage zones, with microstructural fabric orientation in a granite tested for fracture toughness under mode I along specific directions. X-ray CT scanning images were obtained on a volume of Barre granite when the test cracks were forced to propagate parallel (case 1) and perpendicular (case 2) to the preferably oriented microstructural fabric. These images were binarized to mineral grains and induced cracks by means of a neighborhood-based standard deviation thresholding algorithm. 3D objects counter algorithm was applied on these images to identify and compare the physical properties such as crack induced porosity, induced crack density, generated total surface area and contribution of individual mineral grains within the damaged zones in case 1 and 2 scenarios. Results showed that measured induced crack porosity for case 1 is more than ten times than that of case 2 which further justifies the reason for the fracture toughness in case 1 being almost twice of that of case 2. The type and structure of damage zones in these cases were found geometrically different. This study, linked with observations in field scale helps in better understanding of fracture propagation and its application to stability of underground openings, control of rock fragmentation, prediction of transport properties with divers flow regimes and

  9. Multimodal, 3D pathology-mimicking bladder phantom for evaluation of cystoscopic technologies (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Smith, Gennifer T.; Lurie, Kristen L.; Zlatev, Dimitar V.; Liao, Joseph C.; Ellerbee, Audrey K.

    2016-02-01

    Optical coherence tomography (OCT) and blue light cystoscopy (BLC) have shown significant potential as complementary technologies to traditional white light cystoscopy (WLC) for early bladder cancer detection. Three-dimensional (3D) organ-mimicking phantoms provide realistic imaging environments for testing new technology designs, the diagnostic potential of systems, and novel image processing algorithms prior to validation in real tissue. Importantly, the phantom should mimic features of healthy and diseased tissue as they appear under WLC, BLC, and OCT, which are sensitive to tissue color and structure, fluorescent contrast, and optical scattering of subsurface layers, respectively. We present a phantom posing the hollow shape of the bladder and fabricated using a combination of 3D-printing and spray-coating with Dragon Skin (DS) (Smooth-On Inc.), a highly elastic polymer to mimic the layered structure of the bladder. Optical scattering of DS was tuned by addition of titanium dioxide, resulting in scattering coefficients sufficient to cover the human bladder range (0.49 to 2.0 mm^-1). Mucosal vasculature and tissue coloration were mimicked with elastic cord and red dye, respectively. Urethral access was provided through a small hole excised from the base of the phantom. Inserted features of bladder pathology included altered tissue color (WLC), fluorescence emission (BLC), and variations in layered structure (OCT). The phantom surface and underlying material were assessed on the basis of elasticity, optical scattering, layer thicknesses, and qualitative image appearance. WLC, BLC, and OCT images of normal and cancerous features in the phantom qualitatively matched corresponding images from human bladders.

  10. Clinical Evaluation of a 3-D Automatic Annotation Method for Breast Ultrasound Imaging.

    PubMed

    Jiang, Wei-Wei; Li, Cheng; Li, An-Hua; Zheng, Yong-Ping

    2016-04-01

    The routine clinical breast ultrasound annotation method is limited by the time it consumes, inconsistency, inaccuracy and incomplete notation. A novel 3-D automatic annotation method for breast ultrasound imaging has been developed that uses a spatial sensor to track and record conventional B-mode scanning so as to provide more objective annotation. The aim of the study described here was to test the feasibility of the automatic annotation method in clinical breast ultrasound scanning. An ultrasound scanning procedure using the new method was established. The new method and the conventional manual annotation method were compared in 46 breast cancer patients (49 ± 12 y). The time used for scanning a patient was recorded and compared for the two methods. Intra-observer and inter-observer experiments were performed, and intra-class correlation coefficients (ICCs) were calculated to analyze system reproducibility. The results revealed that the new annotation method had an average scanning time 36 s (42.9%) less than that of the conventional method. There were high correlations between the results of the two annotation methods (r = 0.933, p < 0.0001 for distance; r = 0.995, p < 0.0001 for radial angle). Intra-observer and inter-observer reproducibility was excellent, with all ICCs > 0.92. The results indicated that the 3-D automatic annotation method is reliable for clinical breast ultrasound scanning and can greatly reduce scanning time. Although large-scale clinical studies are still needed, this work verified that the new annotation method has potential to be a valuable tool in breast ultrasound examination.

  11. The effect of smiling on facial asymmetry in adults: a 3D evaluation.

    PubMed

    Darby, Laura J; Millett, Declan T; Kelly, Niamh; McIntyre, Grant T; Cronin, Michael S

    2015-11-01

    Mild resting facial asymmetry exists in clinically symmetrical faces, but the effect of smiling on the magnitude of overall facial asymmetry in adults has not been assessed. The aim of the present study was to use stereophotogrammetry to quantify the effect of smiling on overall facial asymmetry in Caucasian adults who presented with Class I incisor relationships and no history of orthodontic treatment. Twenty male and 20 female Caucasians aged 1 8-30 years with no history of orthodontic treatment, a clinically symmetrical face and a Class I incisor relationship had 3D stereophotogrammetric images captured at rest and on natural and maximal smile (T1). The images were repeated 2-4 weeks later (T2) to assess expression reproducibility. Overall facial asymmetry scores were produced from 27 landmarks using partial Ordinary Procrustes Analysis (OPA) and assessed by an Analysis of Covariance (ANCOVA) model. A random sample of the images was re-examined two months later to calculate intraobserver landmark reproducibility. Mean landmark error was low (0.41 ± 0.07 mm). Mean overall facial asymmetry scores were not significantly gender different (p = 0.5300); therefore, the male and female data were pooled. Mean overall facial asymmetry scores for maximal (0.91 ± 0.16) and natural smile (0.88 ± 0.18) were higher than at rest (0.80 ± 0.17) (p < 0.0001) and were reproducible across (T1-T2) sessions (p = 0.3204). Overall 3D facial asymmetry scores for the sampled Caucasian adults with clinically symmetrical faces increased in magnitude from rest to natural and to maximal smile. Clinicians should assess overall facial asymmetry at rest and on natural and maximal smile at baseline, during treatment and as part of a core outcome assessment, particularly for cases with unilateral posterior crossbite, unilateral cleft lip and palate or skeletal asymmetry.

  12. Evaluation of labor-related pelvic floor changes 3 months after delivery: a 3D transperineal ultrasound study.

    PubMed

    Aydın, Serdar; Aydın, Çağrı Arıoğlu

    2015-12-01

    The levator hiatus and puborectalis muscle play a critical role in supporting the pelvic organs. Vaginal birth is known to be the main etiological factor for development of levator defects. The aim of this study was to define and evaluate changes in the levator ani immediately and at 3 months after delivery with 3D transperineal ultrasonography. Of 92 eligible primiparous women who delivered vaginally, 84 were examined within 36 h of delivery (early evaluation) and 3 months after delivery (late evaluation) with 3D transperineal ultrasonography. 3D volumes were evaluated in the supine position after voiding. Levator biometry, levator defect and loss of tenting were determined in the axial plane. The levator defect rate was significantly higher at the early evaluation (71.4 %) than at the late evaluation (39.6 %; p < 0.0001). Levator thickness and transverse hiatal diameters on resting and during maximal Valsalva maneuver were greater at the late evaluation than at the early evaluation. Anteroposterior hiatal dimension, hiatal area on resting and maximal during the Valsalva maneuver were greater at the early evaluation than at the late evaluation. Head circumference and the length of the first stage of labor were associated with levator defects. Changes in the levator hiatus could be transitional or persist over time. There were significant changes in levator hiatus measurements, levator thickness, levator defect incidence and loss of tenting rate between early postpartum and late postpartum. The head circumference of the fetus and the length of the first stage of labor are the shared and consistent factors that can be associated with pelvic floor trauma.

  13. Evaluation of 3D-human skin equivalents for assessment of human dermal absorption of some brominated flame retardants.

    PubMed

    Abdallah, Mohamed Abou-Elwafa; Pawar, Gopal; Harrad, Stuart

    2015-11-01

    Ethical and technical difficulties inherent to studies in human tissues are impeding assessment of the dermal bioavailability of brominated flame retardants (BFRs). This is further complicated by increasing restrictions on the use of animals in toxicity testing, and the uncertainties associated with extrapolating data from animal studies to humans due to inter-species variations. To overcome these difficulties, we evaluate 3D-human skin equivalents (3D-HSE) as a novel in vitro alternative to human and animal testing for assessment of dermal absorption of BFRs. The percutaneous penetration of hexabromocyclododecanes (HBCD) and tetrabromobisphenol-A (TBBP-A) through two commercially available 3D-HSE models was studied and compared to data obtained for human ex vivo skin according to a standard protocol. No statistically significant differences were observed between the results obtained using 3D-HSE and human ex vivo skin at two exposure levels. The absorbed dose was low (less than 7%) and was significantly correlated with log Kow of the tested BFR. Permeability coefficient values showed increasing dermal resistance to the penetration of γ-HBCD>β-HBCD>α-HBCD>TBBPA. The estimated long lag times (>30 min) suggests that frequent hand washing may reduce human exposure to HBCDs and TBBPA via dermal contact.

  14. Retrospective evaluation of the incidence and prognostic significance of spontaneous echocardiographic contrast in relation to cardiac disease and congestive heart failure in cats: 725 cases (2006-2011).

    PubMed

    Peck, Courtney M; Nielsen, Lindsey K; Quinn, Rebecca L; Laste, Nancy J; Price, Lori Lyn

    2016-09-01

    To determine whether the presence of spontaneous echocardiographic contrast (SEC) in cats with cardiomyopathy is associated with increased mortality. To establish whether specific types of cardiomyopathy are more often associated with SEC in an attempt to provide a risk-stratification scheme for cats with increased risk of thromboembolic events. Retrospective study 2006-2011. Tertiary referral and teaching hospital. Seven hundred twenty-five client-owned cats undergoing echocardiographic evaluation. Patient characteristics, including age, breed, clinical signs, type of cardiovascular disease, presence of SEC, and survival time were recorded. Thyroxine, HCT, and blood pressure were recorded when available. Among cats diagnosed with cardiac abnormalities based on echocardiographic findings, those with SEC were at significantly increased risk of death as compared to those without SEC. Cats with dilated cardiomyopathy, unclassified cardiomyopathy, and hypertrophic cardiomyopathy were significantly more likely to have SEC compared to cats with other types of cardiac disease. Cats with cardiomyopathy and SEC have an increased risk of death compared to cats without SEC, although other previously identified factors such as the presence of congestive heart failure and increased left atrium to aorta ratio remain important determinants of mortality. Cats with hypertrophic cardiomyopathy, unclassified cardiomyopathy, and dilated cardiomyopathy may benefit from anticoagulant therapy due to the increased risk of SEC in these subpopulations. © Veterinary Emergency and Critical Care Society 2016.

  15. Intralaboratory and interlaboratory evaluation of the EpiDerm 3D human reconstructed skin micronucleus (RSMN) assay.

    PubMed

    Hu, Ting; Kaluzhny, Yulia; Mun, Greg C; Barnett, Brenda; Karetsky, Viktor; Wilt, Nathan; Klausner, Mitchell; Curren, Rodger D; Aardema, Marilyn J

    2009-03-17

    A novel in vitro human reconstructed skin micronucleus (RSMN) assay has been developed using the EpiDerm 3D human skin model [R. D. Curren, G. C. Mun, D. P. Gibson, and M. J. Aardema, Development of a method for assessing micronucleus induction in a 3D human skin model EpiDerm, Mutat. Res. 607 (2006) 192-204]. The RSMN assay has potential use in genotoxicity assessments as a replacement for in vivo genotoxicity assays that will be banned starting in 2009 according to the EU 7th Amendment to the Cosmetics Directive. Utilizing EpiDerm tissues reconstructed with cells from four different donors, intralaboratory and interlaboratory reproducibility of the RSMN assay were examined. Seven chemicals were evaluated in three laboratories using a standard protocol. Each chemical was evaluated in at least two laboratories and in EpiDerm tissues from at least two different donors. Three model genotoxins, mitomycin C (MMC), vinblastine sulfate (VB) and methyl methanesulfonate (MMS) induced significant, dose-related increases in cytotoxicity and MN induction in EpiDerm tissues. Conversely, four dermal non-carcinogens, 4-nitrophenol (4-NP), trichloroethylene (TCE), 2-ethyl-1,3-hexanediol (EHD), and 1,2-epoxydodecane (EDD) were negative in the RSMN assay. Results between tissues reconstructed from different donors were comparable. These results indicate the RSMN assay using the EpiDerm 3D human skin model is a promising new in vitro genotoxicity assay that allows evaluation of chromosome damage following "in vivo-like" dermal exposures.

  16. Evaluation of Echocardiographic Epicardial Fat Thickness as a Sign of Cardiovascular Risk in Positive Exercise Test Patients

    PubMed Central

    Katlandur, Hüseyin; Ulucan, Şeref; Özdil, Hüseyin; Keser, Ahmet; Kaya, Zeynettin; Özbek, Kerem; Ülgen, M. Sıddık

    2016-01-01

    Background The association between epicardial fat thickness (EFT) and positive exercise test results for the diagnosis of coronary artery diseases (CAD) has yet to be evaluated. This study assessed the predictive value of EFT for CAD on the angiographs of patients with positive exercise tests. Methods A total of 91 subjects were chosen consecutively from stable angina pectoris patients who were referred for coronary angiography due to a positive exercise test result. The EFT measures were obtained by echocardiographic parasternal long-axis views on the free wall of the right ventricle at end-systole of three cardiac cycles. Gensini scores were calculated by a conventional coronary angiography technique using a calculation method previously defined. Results Receiver operator characteristic (ROC) curve analysis revealed a 0.65 cm (95% confidence interval: 0.628, 0.832, p < 0.001) area under the curve with 74.3% sensitivity and 62.3% specificity at the cut-off value of EFT for the prediction of critical coronary artery stenosis. Following ROC curve analysis, two groups were defined according to EFT cut-off value (groups 1 and 2). The severe coronary stenosis ratio was significantly higher in group 2 compared to group 1 (31.9 % vs. 11%, p < 0.001) and Gensini scores were significantly higher in group 2 (6.3 ± 13.3 vs. 16.5 ± 17.9; p < 0.001). There was no significant correlation between Gensini scores and EFT in group 1 (r = 0.093, p = 0.549), but there was a strong significant correlation in group 2 (r = 0.730, p < 0.001). Linear multivariate regression analysis revealed that EFT (> 0.65 cm) was the only independent risk factor for critical coronary artery stenosis (β = 0.451, p < 0.001). Conclusions EFT was significantly correlated with the severity and prevalence of coronary artery disease in positive exercise test patients. PMID:27899855

  17. Echocardiographic B-mode evaluation of the right heart in older people: The ActiFE Study.

    PubMed

    Laszlo, Roman; Baumann, Tobias; Konz, Hannah; Dallmeier, Dhayana; Klenk, Jochen; Denkinger, Michael; Koenig, Wolfgang; Rothenbacher, Dietrich; Steinacker, Juergen Michael

    2016-01-01

    Right heart B-mode echocardiography reference values have been predominantly obtained in younger age cohorts (<65years). Aims of the study were to describe and evaluate the feasibility of right heart B-mode echocardiography in a large geriatric cohort and to analyze standard parameters in defined subgroups with or without any evidence for structural cardiac disease. ActiFE-Ulm study is a population-based cohort study including a sample of people≥65years old living in the region of Ulm, Germany. Echocardiography including right heart parameters was performed within a cardiovascular follow-up of 688 subjects. Non-obtainability of right heart B-mode data was rather not a consequence of accompanying cardiac diseases or risk factors but of a more obese body composition. Mean values of right heart measurements of our subpopulation of subjects without evidence for structural cardiac disease were continuously higher than those of the guidelines (e.g. mean right ventricular end diastolic area 23.5±5.6cm(2) (males), 20.3±5.0cm(2) (females)). On an individual basis, guideline-suggested abnormality thresholds were also often exceeded, whereas this situation occurred more often in male than in female subjects. Methodically, right heart B-mode echocardiography in older subjects is challenging. Our results suggest an ageing-associated right heart enlargement. Utilization of published right heart reference values in older adults seems to be problematic and in clinical practice, they always have to be interpreted within the clinical and functional context and in relation to other right heart echocardiographic parameters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Evaluation of 3D Inverse Code Using Rotor 67 as Test Case

    NASA Technical Reports Server (NTRS)

    Dang, T.

    1998-01-01

    A design modification of Rotor 67 is carried out with a full 3D inverse method. The blade camber surface is modified to produce a prescribed pressure loading distribution, with the blade tangential thickness distribution and the blade stacking line at midchord kept the same as the original Rotor 67 design. Because of the inviscid-flow assumption used in the current version of the method, Rotor 67 geometry is modified for use at a design point different from the original design value. A parametric study with the prescribed pressure loading distribution yields the following results. In the subsonic section, smooth pressure loading shapes generally produce blades with well-behaved blade surface pressure distributions. In the supersonic section, the study shows that the strength and position of the passage shock correlate with the characteristics of the blade pressure loading shape. In general, "smooth" prescribed blade pressure loading distributions generate blade designs with reverse cambers which have the effect of weakening the passage shock.

  19. Automated 3-D Printed Arrays to Evaluate Genotoxic Chemistry: E-Cigarettes and Water Samples.

    PubMed

    Kadimisetty, Karteek; Malla, Spundana; Rusling, James F

    2017-05-26

    A novel, automated, low cost, three-dimensional (3-D) printed microfluidic array was developed to detect DNA damage from metabolites of chemicals in environmental samples. The electrochemiluminescent (ECL) detection platform incorporates layer-by-layer (LbL) assembled films of microsomal enzymes, DNA and an ECL-emitting ruthenium metallopolymer in ∼10 nm deep microwells. Liquid samples are introduced into the array, metabolized by the human enzymes, products react with DNA if possible, and DNA damage is detected by ECL with a camera. Measurements of relative DNA damage by the array assess the genotoxic potential of the samples. The array analyzes three samples simultaneously in 5 min. Measurement of cigarette and e-cigarette smoke extracts and polluted water samples was used to establish proof of concept. Potentially genotoxic reactions from e-cigarette vapor similar to smoke from conventional cigarettes were demonstrated. Untreated wastewater showed a high genotoxic potential compared to negligible values for treated wastewater from a pollution control treatment plant. Reactivity of chemicals known to produce high rates of metabolite-related DNA damage were measured, and array results for environmental samples were expressed in terms of equivalent responses from these standards to assess severity of possible DNA damage. Genotoxic assessment of wastewater samples during processing also highlighted future on-site monitoring applications.

  20. Evaluation of 3D modality-independent elastography for breast imaging: a simulation study

    NASA Astrophysics Data System (ADS)

    Ou, J. J.; Ong, R. E.; Yankeelov, T. E.; Miga, M. I.

    2008-01-01

    This paper reports on the development and preliminary testing of a three-dimensional implementation of an inverse problem technique for extracting soft-tissue elasticity information via non-rigid model-based image registration. The modality-independent elastography (MIE) algorithm adjusts the elastic properties of a biomechanical model to achieve maximal similarity between images acquired under different states of static loading. A series of simulation experiments with clinical image sets of human breasts were performed to test the ability of the method to identify and characterize a radiographically occult stiff lesion. Because boundary conditions are a critical input to the algorithm, a comparison of three methods for semi-automated surface point correspondence was conducted in the context of systematic and randomized noise processes. The results illustrate that 3D MIE was able to successfully reconstruct elasticity images using data obtained from both magnetic resonance and x-ray computed tomography systems. The lesion was localized correctly in all cases and its relative elasticity found to be reasonably close to the true values (3.5% with the use of spatial priors and 11.6% without). In addition, the inaccuracies of surface registration performed with thin-plate spline interpolation did not exceed empiric thresholds of unacceptable boundary condition error.

  1. Experimental evaluation of ultrasound-guided 3D needle steering in biological tissue.

    PubMed

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

    2014-11-01

    In this paper, we present a system capable of automatically steering bevel tip flexible needles under ultrasound guidance toward stationary and moving targets in gelatin phantoms and biological tissue while avoiding stationary and moving obstacles. We use three-dimensional (3D) ultrasound to track the needle tip during the procedure. Our system uses a fast sampling-based path planner to compute and periodically update a feasible path to the target that avoids obstacles. We then use a novel control algorithm to steer the needle along the path in a manner that reduces the number of needle rotations, thus reducing tissue damage. We present experimental results for needle insertion procedures for both stationary and moving targets and obstacles for up to 90 mm of needle insertion. We obtained a mean targeting error of [Formula: see text] and [Formula: see text] mm in gelatin-based phantom and biological tissue, respectively. The achieved submillimeter accuracy suggests that our approach is sufficient to target the smallest lesions ([Formula: see text] 2 mm) that can be detected using state-of-the-art ultrasound imaging systems.

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

    PubMed Central

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

    2014-01-01

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

  3. Accuracy and Robustness Improvements of Echocardiographic Particle Image Velocimetry for Routine Clinical Cardiac Evaluation

    NASA Astrophysics Data System (ADS)

    Meyers, Brett; Vlachos, Pavlos; Charonko, John; Giarra, Matthew; Goergen, Craig

    2015-11-01

    Echo Particle Image Velocimetry (echoPIV) is a recent development in flow visualization that provides improved spatial resolution with high temporal resolution in cardiac flow measurement. Despite increased interest a limited number of published echoPIV studies are clinical, demonstrating that the method is not broadly accepted within the medical community. This is due to the fact that use of contrast agents are typically reserved for subjects whose initial evaluation produced very low quality recordings. Thus high background noise and low contrast levels characterize most scans, which hinders echoPIV from producing accurate measurements. To achieve clinical acceptance it is necessary to develop processing strategies that improve accuracy and robustness. We hypothesize that using a short-time moving window ensemble (MWE) correlation can improve echoPIV flow measurements on low image quality clinical scans. To explore the potential of the short-time MWE correlation, evaluation of artificial ultrasound images was performed. Subsequently, a clinical cohort of patients with diastolic dysfunction was evaluated. Qualitative and quantitative comparisons between echoPIV measurements and Color M-mode scans were carried out to assess the improvements delivered by the proposed methodology.

  4. Dual-projection 3D-2D registration for surgical guidance: preclinical evaluation of performance and minimum angular separation

    NASA Astrophysics Data System (ADS)

    Uneri, A.; Otake, Y.; Wang, A. S.; Kleinszig, G.; Vogt, S.; Gallia, G. L.; Rigamonti, D.; Wolinsky, J.-P.; Gokaslan, Ziya L.; Khanna, A. J.; Siewerdsen, J. H.

    2014-03-01

    An algorithm for 3D-2D registration of CT and x-ray projections has been developed using dual projection views to provide 3D localization with accuracy exceeding that of conventional tracking systems. The registration framework employs a normalized gradient information (NGI) similarity metric and covariance matrix adaptation evolution strategy (CMAES) to solve for the patient pose in 6 degrees of freedom. Registration performance was evaluated in anthropomorphic head and chest phantoms, as well as a human torso cadaver, using C-arm projection views acquired at angular separations (Δ𝜃) ranging 0-178°. Registration accuracy was assessed in terms target registration error (TRE) and compared to that of an electromagnetic tracker. Studies evaluated the influence of C-arm magnification, x-ray dose, and preoperative CT slice thickness on registration accuracy and the minimum angular separation required to achieve TRE ~2 mm. The results indicate that Δ𝜃 as small as 10-20° is adequate to achieve TRE <2 mm with 95% confidence, comparable or superior to that of commercial trackers. The method allows direct registration of preoperative CT and planning data to intraoperative fluoroscopy, providing 3D localization free from conventional limitations associated with external fiducial markers, stereotactic frames, trackers, and manual registration. The studies support potential application to percutaneous spine procedures and intracranial neurosurgery.

  5. Evaluation of hybrid polymers for high-precision manufacturing of 3D optical interconnects by two-photon absorption lithography

    NASA Astrophysics Data System (ADS)

    Schleunitz, A.; Klein, J. J.; Krupp, A.; Stender, B.; Houbertz, R.; Gruetzner, G.

    2017-02-01

    The fabrication of optical interconnects has been widely investigated for the generation of optical circuit boards. Twophoton absorption (TPA) lithography (or high-precision 3D printing) as an innovative production method for direct manufacture of individual 3D photonic structures gains more and more attention when optical polymers are employed. In this regard, we have evaluated novel ORMOCER-based hybrid polymers tailored for the manufacture of optical waveguides by means of high-precision 3D printing. In order to facilitate future industrial implementation, the processability was evaluated and the optical performance of embedded waveguides was assessed. The results illustrate that hybrid polymers are not only viable consumables for industrial manufacture of polymeric micro-optics using generic processes such as UV molding. They also are potential candidates to fabricate optical waveguide systems down to the chip level where TPA-based emerging manufacturing techniques are engaged. Hence, it is shown that hybrid polymers continue to meet the increasing expectations of dynamically growing markets of micro-optics and optical interconnects due to the flexibility of the employed polymer material concept.

  6. Aldose reductase inhibitors for diabetic complications: Receptor induced atom-based 3D-QSAR analysis, synthesis and biological evaluation.

    PubMed

    Vyas, Bhawna; Singh, Manjinder; Kaur, Maninder; Bahia, Malkeet Singh; Jaggi, Amteshwar Singh; Silakari, Om; Singh, Baldev

    2015-06-01

    Herein, atom-based 3D-QSAR analysis was performed using receptor-guided alignment of 46 flavonoid inhibitors of aldose reductase (ALR2) enzyme. 3D-QSAR models were generated in PHASE programme, and the best model corresponding to PLS factor four (QSAR4), was selected based on different statistical parameters (i.e., Rtrain(2), 0.96; Qtest(2) 0.81; SD, 0.26). The contour plots of different structural properties generated from the selected model were utilized for the designing of five new congener molecules. These designed molecules were duly synthesized, and evaluated for their in vitro ALR2 inhibitory activity that resulted in the micromolar (IC50<22μM) activity of all molecules. Thus, the newly designed molecules having ALR inhibitory potential could be employed for the management of diabetic complications.

  7. An evaluation of 3D head pose estimation using the Microsoft Kinect v2.

    PubMed

    Darby, John; Sánchez, María B; Butler, Penelope B; Loram, Ian D

    2016-07-01

    The Kinect v2 sensor supports real-time non-invasive 3D head pose estimation. Because the sensor is small, widely available and relatively cheap it has great potential as a tool for groups interested in measuring head posture. In this paper we compare the Kinect's head pose estimates with a marker-based record of ground truth in order to establish its accuracy. During movement of the head and neck alone (with static torso), we find average errors in absolute yaw, pitch and roll angles of 2.0±1.2°, 7.3±3.2° and 2.6±0.7°, and in rotations relative to the rest pose of 1.4±0.5°, 2.1±0.4° and 2.0±0.8°. Larger head rotations where it becomes difficult to see facial features can cause estimation to fail (10.2±6.1% of all poses in our static torso range of motion tests) but we found no significant changes in performance with the participant standing further away from Kinect - additionally enabling full-body pose estimation - or without performing face shape calibration, something which is not always possible for younger or disabled participants. Where facial features remain visible, the sensor has applications in the non-invasive assessment of postural control, e.g. during a programme of physical therapy. In particular, a multi-Kinect setup covering the full range of head (and body) movement would appear to be a promising way forward. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Evaluation of the Accuracy, Reliability, and Reproducibility of Two Different 3D Face-Scanning Systems.

    PubMed

    Ye, Hongqiang; Lv, Longwei; Liu, Yunsong; Liu, Yushu; Zhou, Yongsheng

    2016-01-01

    To compare the accuracy, reliability, and reproducibility of a structured light scanning system and a stereophotogrammetry scanning system on human faces. A total of 10 healthy volunteers were included in this study. After marking of facial anatomy points, their faces were scanned by a structured light scanning system and a stereophotogrammetry system, and three-dimensional (3D) images were reconstructed with corresponding software. For each volunteer, scanning was performed twice after calibration. Linear measurements were calculated and compared for the two scanning techniques with direct caliper measurements. Absolute errors (AE), absolute percentage errors (APE), and intraclass correlation coefficients (ICC) were chosen as indices to determine the accuracy, reliability, and reproducibility of the two systems. There was no statistically significant difference among the three measuring techniques (.891 < P < .999). Both scanning systems demonstrated high accuracy (AE = 0.58 ± 0.37 mm and APE = 1.11 ± 0.73% for the structured light system; AE = 0.62 ± 0.39 mm and APE 1.17 ± 0.71% for the stereophotogrammetry system). The two systems demonstrated extremely high reliability compared to caliper measurement (0.982 < ICC < 0.998 for the structured light system; 0.984 < ICC < 0.999 for the stereophotogrammetry system). In addition, high reproducibility was observed with the two systems (0.981 < ICC < 0.999 for the structured light system; 0.984 < ICC < 1.000 for the stereophotogrammetry system). When applied in scanning and measuring human faces, the structured light scanning system and stereophotogrammetry scanning system both demonstrated high accuracy, reliability, and reproducibility.

  9. Technical Note: Immunohistochemical evaluation of mouse brain irradiation targeting accuracy with 3D-printed immobilization device

    SciTech Connect

    Zarghami, Niloufar Jensen, Michael D.; Talluri, Srikanth; Dick, Frederick A.; Foster, Paula J.; Chambers, Ann F.; Wong, Eugene

    2015-11-15

    Purpose: Small animal immobilization devices facilitate positioning of animals for reproducible imaging and accurate focal radiation therapy. In this study, the authors demonstrate the use of three-dimensional (3D) printing technology to fabricate a custom-designed mouse head restraint. The authors evaluate the accuracy of this device for the purpose of mouse brain irradiation. Methods: A mouse head holder was designed for a microCT couch using CAD software and printed in an acrylic based material. Ten mice received half-brain radiation while positioned in the 3D-printed head holder. Animal placement was achieved using on-board image guidance and computerized asymmetric collimators. To evaluate the precision of beam localization for half-brain irradiation, mice were sacrificed approximately 30 min after treatment and brain sections were stained for γ-H2AX, a marker for DNA breaks. The distance and angle of the γ-H2AX radiation beam border to longitudinal fissure were measured on histological samples. Animals were monitored for any possible trauma from the device. Results: Visualization of the radiation beam on ex vivo brain sections with γ-H2AX immunohistochemical staining showed a sharp radiation field within the tissue. Measurements showed a mean irradiation targeting error of 0.14 ± 0.09 mm (standard deviation). Rotation between the beam axis and mouse head was 1.2° ± 1.0° (standard deviation). The immobilization device was easily adjusted to accommodate different sizes of mice. No signs of trauma to the mice were observed from the use of tooth block and ear bars. Conclusions: The authors designed and built a novel 3D-printed mouse head holder with many desired features for accurate and reproducible radiation targeting. The 3D printing technology was found to be practical and economical for producing a small animal imaging and radiation restraint device and allows for customization for study specific needs.

  10. One-step reconstruction with a 3D-printed, biomechanically evaluated custom implant after complex pelvic tumor resection.

    PubMed

    Wong, K C; Kumta, S M; Geel, N V; Demol, J

    2015-01-01

    Resection of a pelvic tumor is challenging because of its complex three-dimensional (3D) anatomy and deep-seated location with nearby vital structures. The resection is technically demanding if a custom implant is used for reconstruction of the bone defect as the surgeon needs to ensure the resection margin is sufficiently wide and the orientation of intended resection planes must match that of the custom implant. We describe a novel workflow of performing a partial acetabular resection in a patient with pelvic chondrosarcoma and reconstruction with a custom pelvic implant in a one-step operation. A multi-planar bone resection was virtually planned. A computer-aided design implant that both matched the bone defect and biomechanically evaluated was prefabricated with 3D printing technology. The 3D-printed patient-specific instruments (PSIs) were used to reproduce the same planned resection. The histology of the tumor specimen showed a clear resection margin. The errors of the achieved resection and implant position were deviating (1-4 mm) from the planned. The patient could walk unaided with a good hip function. No tumor recurrence and implant loosening were noted at 11 months after surgery. The use of this novel CT-based method for surgical planning, the engineering software for implant design and validation, together with 3D printing technology for implant and PSI fabrication makes it possible to generate a personalized, biomechanically evaluated implant for accurate reconstruction after a pelvic tumor resection in a one-step operation. Further study in a larger population is needed to assess the clinical efficacy of the workflow in complex bone tumor surgery.

  11. Echocardiographic evaluation of mitral stenosis using diastolic posterior left ventricular wall motion.

    PubMed

    Wise, J R

    1980-05-01

    The slope of the posterior left ventricular wall motion in diastole (LVDS) was determined by echocardiography in 25 normal subjects and 21 patients with mitral stenosis. Patients with mitral stenosis had reduced LVDS that was related to the degree of mitral stenosis determined by calculated mitral valve area (r = 0.92). The mitral valve area correlated more closely with the LVDS than with the left atrial emptying index derived from the posterior aortic wall motion. Three patients with mitral stenosis had an increased LVDS after mitral valvotomy or mitral valve replacement. One patient with a stenotic mitral valve prosthesis had reduced LVDS. The results of this study suggest that analysis of the LVDS would be useful in predicting the severity of mitral stenosis and may be beneficial in evaluating patients with suspected prosthetic mitral valve malfunction.

  12. Evaluation of an electromagnetic 3D navigation system to facilitate endovascular tasks: a feasibility study.

    PubMed

    Sidhu, R; Weir-McCall, J; Cochennec, F; Riga, C; DiMarco, A; Bicknell, C D

    2012-01-01

    We describe a novel approach to arterial cannulation using the StealthStation(®) Guidance System (Medtronic, USA). This uses electromagnetic technology to track the guidewire, displaying a 3D image of the vessel and guidewire. The study was performed on a 'bench top' simulation model called the Cannulation Suite comprising of a silicone aortic arch model and simulated fluoroscopy. The accuracy of the StealthStation(®) was assessed. 16 participants of varying experience in performing endovascular procedures (novices: 6 participants, ≤5 procedures performed; intermediate: 5 participants, 6-50 procedures performed; experts: 5 participants, >50 procedures performed) underwent a standardised training session in cannulating the left subclavian artery on the model with the conventional method (i.e. with fluoroscopy) and with the StealthStation(®). Each participant was then assessed on cannulating the left subclavian artery using the conventional method and with the StealthStation(®). Performance was video-recorded. The subjects then completed a structured questionnaire assessing the StealthStation(®). The StealthStation(®) was accurate to less than 1 mm [mean (SD) target registration error 0.56 mm (0.91)]. Every participant was able to complete the cannulation task with a significantly lower use of fluoroscopy with the navigation system compared with the conventional method [median 0 s (IQR 0-2) vs median 14 s (IQR 10-19), respectively; p = <0.001]. There was no significant difference between the StealthStation(®) and conventional method for: total procedure time [median 17 s (IQR 9-53) vs median 21 s (IQR 11-32), respectively; p=0.53]; total guidewire hits to the vessel wall [median 0 (IQR 0-1) vs median 0 (IQR 0-1), respectively; p=0.86]; catheter hits to the vessel wall [median 0.5 (IQR 0-2) vs median 0.5 (IQR 0-1), respectively; p=0.13]; and cannulation performance on the global rating scale [median score, 39/40 (IQR 28-39) vs 38/40 (IQR 33-40), respectively

  13. Evaluation of 3D Ground Penetrating Radar Efficiency for Abandoned Tailings Pond Internal Structure Analysis and Risk Assessment

    NASA Astrophysics Data System (ADS)

    Cortada, Unai; Martínez, Julián; Hidalgo, Mª Carmen; Rey, Javier

    2017-04-01

    Evaluation of 3D Ground Penetrating Radar Efficiency for Abandoned Tailings Pond Internal Structure Analysis and Risk Assessment Abandoned tailings ponds constitute a severe environmental problem in old Pb mining districts due to their high contents in metallic and semi-metallic elements. In most of the cases, there is a lack of information about the construction procedures and the previous environmental situation, which hinders the environmental risk evaluation. In these cases, Ground Penetrating Radar (GPR) could be an interesting technique to analyze the internal structure of the tailings ponds and detect vulnerable zones for leaching processes. Consequently, the GPR could help in the abandoned tailings ponds environmental risk assessment. In this study, a GPR 3D campaign was carried out with a 250 MHz frequency antenna in order to evaluate the efficiency of this technique in both the analysis of internal structures and the environmental risk assessment. Subsequently, 2D and 3D models were undertaken to represent graphically the obtained results. The studied tailings pond is located in the Guadiel river bank, a water course draining the mining district of Linares, Spain. The dam is 150 m length and 80 m width. The GPR 3D was done in a selected area near the central part of the pond. The analyzed grid was 25x50 m and the spacing of the slides was 1 m. The study revealed that the contact between the tailings and the substratum is located at 2.5 m. No intermediate layer was found, which means that the tailings pond was heightened on the fluvial terrace without any insulation system. Inside the first meter of the pond, a cross stratification was identified. The orientation of those laminations changed with the depth, which means that the stockpiling was performed from the different sides of the tailings pond. Furthermore, the direction of these stratifications is slightly concentric to the middle of the dam which could be associated with a central drainage system

  14. Generation and evaluation of 3D digital casts of maxillary defects based on multisource data registration: A pilot clinical study.

    PubMed

    Ye, Hongqiang; Ma, Qijun; Hou, Yuezhong; Li, Man; Zhou, Yongsheng

    2017-04-25

    Digital techniques are not clinically applied for 1-piece maxillary prostheses containing an obturator and removable partial denture retained by the remaining teeth because of the difficulty in obtaining sufficiently accurate 3-dimensional (3D) images. The purpose of this pilot clinical study was to generate 3D digital casts of maxillary defects, including the defective region and the maxillary dentition, based on multisource data registration and to evaluate their effectiveness. Twelve participants with maxillary defects were selected. The maxillofacial region was scanned with spiral computer tomography (CT), and the maxillary arch and palate were scanned using an intraoral optical scanner. The 3D images from the CT and intraoral scanner were registered and merged to form a 3D digital cast of the maxillary defect containing the anatomic structures needed for the maxillary prosthesis. This included the defect cavity, maxillary dentition, and palate. Traditional silicone impressions were also made, and stone casts were poured. The accuracy of the digital cast in comparison with that of the stone cast was evaluated by measuring the distance between 4 anatomic landmarks. Differences and consistencies were assessed using paired Student t tests and the intraclass correlation coefficient (ICC). In 3 participants, physical resin casts were produced by rapid prototyping from digital casts. Based on the resin casts, maxillary prostheses were fabricated by using conventional methods and then evaluated in the participants to assess the clinical applicability of the digital casts. Digital casts of the maxillary defects were generated and contained all the anatomic details needed for the maxillary prosthesis. Comparing the digital and stone casts, a paired Student t test indicated that differences in the linear distances between landmarks were not statistically significant (P>.05). High ICC values (0.977 to 0.998) for the interlandmark distances further indicated the high

  15. Evaluation of 3D-CRT, IMRT and VMAT radiotherapy plans for left breast cancer based on clinical dosimetric study.

    PubMed

    Liu, Haiyun; Chen, Xinde; He, Zhijian; Li, Jun

    2016-12-01

    This paper aims to compare dosimetric differences based on three types of radiotherapy plans for postoperative left breast cancer. In particular, based on a clinical dosimetric study, the three-dimensional conformal radiotherapy (3D-CRT), intensity- modulated radiation therapy (IMRT) and VMAT plans were implemented on 15 cases of postoperative patients with left breast cancer with prescription doses of 5000cGy. Dose volume histogram (DVH) was used to analyze each evaluation index of clinical target volume (CTV) and organs at risk (OARs). Except for homogeneous index (HI), D2, each CTV evaluation index of 3D-CRT plan was inferior to IMRT and VMAT plans (P<0.05). Compared with the VMAT plans, IMRT has a statistical significance only in Dmean, V95 (P<0.05). On the contrary, Dmean pertaining to the VMAT plan is much closer to the prescription dose with a V95 coverage rate as high as 97.44%. For the infected lung, V5, V10 of 3D-CRT were the lowest (P<0.05), while V20, V30 were the highest (P<0.05) among the three types of plans. Here, the V5, V10 of infected lung were slightly higher (P<0.05) for the VMAT and IMRT plans. Each evaluation index of the contralateral lung and heart in 3D-CRT was the lowest (P<0.05). D1 of contralateral breast was lower in both IMRT and VMAT plans, which were 1770.89±121.16cGy and 1839.92±92.77cGy, respectively. While D1 of the spinal cord in IMRT and VMAT plans was higher, which were 1990.12±61.52cGy and 1927.38±43.67cGy, respectively. When the radiation dose of 500-1500cGy was delivered to the normal tissues, 3D-CRT significantly shows the lowest volume, VMAT is relatively higher. Monitor Units (MU) and treatment time (T) of VMAT were the least, only 49.33% and 55.86% of those of IMRT. The three types of plans can meet the clinical dosimetry demands of postoperative radiotherapy for left breast cancer. The target of IMRT and VMAT plans has a better conformity, and the VMAT plan takes the advantages of less MU and treatment time

  16. Echocardiographic evaluation of cardiac dyssynchrony in patients with congestive heart failure.

    PubMed

    Qin, Chuan; Zhang, Li; Zhang, Zi-Ming; Wang, Bin; Ye, Zhou; Wang, Yong; Nanda, Navin C; Xie, Ming-Xing

    2016-06-01

    The present study investigated the application of echocardiography to evaluation of cardiac dyssynchrony in patients with congestive heart failure (CHF). A total of 348 consecutive CHF patients who were admitted for cardiac resynchronization (CRT) and presented with low ejection fraction (EF) and wide QRS duration were enrolled in this study, along with 388 healthy individuals. Dyssynchrony was assessed based on filling time ratio (FT/RR), left ventricular pre-ejection delay (PED), interventricular mechanical delay (IVMD), longitudinal opposing wall delay (LOWD) and radial septal to posterior wall delay (RSPWD). Response to CRT was defined as a ≥15% increase in EF. The results showed that FT/RR was decreased while PED, IVMD, LOWD and RSPWD were increased in the CHF group compared with the control group (P<0.01). In the CHF group, FT/RR was negatively correlated with the QRS duration, LV end-diastolic diameter (LVESd), LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) (P<0.01), but positively with the LVEF (P<0.01). Additionally, PED, IVMD, LOWD and RSPWD were positively correlated with the QRS duration, LVESd, LVEDV and LVESV (P<0.01), but negatively with the LVEF (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of LVEF. FT/RR decreased successively from the LVEF-1 group to the LVEF-2 group to the LVEF-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of QRS duration, and FT/RR decreased successively in a sequence from the QRS-1 group to the QRS-2 group to the QRS-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). Speckle tracking radial dyssynchrony ≥130 ms was predictive of an EF response in patients in QRS-1 group (78% sensitivity, 83% specificity), those in QRS-2 group (83% sensitivity, 77% specificity) and in QRS-3 group (89

  17. Noninvasive Doppler echocardiographic evaluation of shunt flow dynamics of the ductus arteriosus.

    PubMed

    Hiraishi, S; Horiguchi, Y; Misawa, H; Oguchi, K; Kadoi, N; Fujino, N; Yashiro, K

    1987-06-01

    The pulsed Doppler technique was used to record the flow velocity patterns in the ductus arteriosus and the pulmonary artery in 26 patients with either isolated or complicated patent ductus arteriosus (PDA). In all patients, abnormal Doppler signals indicating left-to-right (L-R) or right-to-left shunt flow or both could be obtained at the site of the ductus arteriosus. These Doppler flow patterns determined within the ductus coincided with the direction of ductal flow seen on the contrast two-dimensional echocardiogram. No Doppler signals of shunt flow were demonstrated in any of 42 control subjects. The peak, mean, and diastolic velocities of the L-R shunt flow within the ductus were measured from the ductal flow velocity profiles. With the Doppler-derived measurements of the mean and diastolic velocities, patients with normal pulmonary arterial pressure and those with evidence of pulmonary hypertension could be correctly identified. In addition, the mean velocity of the diastolic antegrade flow portion obtained from the proximal left pulmonary artery, which was related to ductal L-R shunting, was measured in 16 patients with isolated PDA. This Doppler flow determinant showed a good linear correlation with the L-R shunt ratio determined by Fick's method (r = .88, p less than .01). Our technique permits the noninvasive evaluation of shunt flow dynamics in patients with PDA.

  18. Application of 3D scanned imaging methodology for volume, surface area, and envelope density evaluation of densified biomass.

    PubMed

    Igathinathane, C; Davis, J D; Purswell, J L; Columbus, E P

    2010-06-01

    Measurement of volume, surface area, and density is an essential for quantifying, evaluating, and designing the biomass densification, storage, and transport operations. Acquiring accurate and repeated measurements of these parameters for hygroscopic densified biomass are not straightforward and only a few methods are available. A 3D laser scanner was used as a measurement device and the 3D images were analyzed using image processing software. The validity of the method was verified using reference objects of known geometry and the accuracy obtained was in excess of 98%. Cotton gin trash briquettes, switchgrass pellets, switchgrass cubes, hardwood pellets, and softwood chips were tested. Most accurate results of the volume and surface area required the highest possible resolution of the scanner, which increased the total scan-process times, and image file size. Physical property determination using the 3D scanning and image analysis is highly repeatable (coefficient of variation <0.3%), non-invasive, accurate, and alternative methodology. The various limitations and merits of the developed method were also enumerated.

  19. Evaluation of Stratospheric Transport in New 3D Models Using the Global Modeling Initiative Grading Criteria

    NASA Technical Reports Server (NTRS)

    Strahan, Susan E.; Douglass, Anne R.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The Global Modeling Initiative (GMI) Team developed objective criteria for model evaluation in order to identify the best representation of the stratosphere. This work created a method to quantitatively and objectively discriminate between different models. In the original GMI study, 3 different meteorological data sets were used to run an offline chemistry and transport model (CTM). Observationally-based grading criteria were derived and applied to these simulations and various aspects of stratospheric transport were evaluated; grades were assigned. Here we report on the application of the GMI evaluation criteria to CTM simulations integrated with a new assimilated wind data set and a new general circulation model (GCM) wind data set. The Finite Volume Community Climate Model (FV-CCM) is a new GCM developed at Goddard which uses the NCAR CCM physics and the Lin and Rood advection scheme. The FV-Data Assimilation System (FV-DAS) is a new data assimilation system which uses the FV-CCM as its core model. One year CTM simulations of 2.5 degrees longitude by 2 degrees latitude resolution were run for each wind data set. We present the evaluation of temperature and annual transport cycles in the lower and middle stratosphere in the two new CTM simulations. We include an evaluation of high latitude transport which was not part of the original GMI criteria. Grades for the new simulations will be compared with those assigned during the original GMT evaluations and areas of improvement will be identified.

  20. Evaluation of Stratospheric Transport in New 3D Models Using the Global Modeling Initiative Grading Criteria

    NASA Technical Reports Server (NTRS)

    Strahan, Susan E.; Douglass, Anne R.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The Global Modeling Initiative (GMI) Team developed objective criteria for model evaluation in order to identify the best representation of the stratosphere. This work created a method to quantitatively and objectively discriminate between different models. In the original GMI study, 3 different meteorological data sets were used to run an offline chemistry and transport model (CTM). Observationally-based grading criteria were derived and applied to these simulations and various aspects of stratospheric transport were evaluated; grades were assigned. Here we report on the application of the GMI evaluation criteria to CTM simulations integrated with a new assimilated wind data set and a new general circulation model (GCM) wind data set. The Finite Volume Community Climate Model (FV-CCM) is a new GCM developed at Goddard which uses the NCAR CCM physics and the Lin and Rood advection scheme. The FV-Data Assimilation System (FV-DAS) is a new data assimilation system which uses the FV-CCM as its core model. One year CTM simulations of 2.5 degrees longitude by 2 degrees latitude resolution were run for each wind data set. We present the evaluation of temperature and annual transport cycles in the lower and middle stratosphere in the two new CTM simulations. We include an evaluation of high latitude transport which was not part of the original GMI criteria. Grades for the new simulations will be compared with those assigned during the original GMT evaluations and areas of improvement will be identified.

  1. Evaluating the Potential of Rtk-Uav for Automatic Point Cloud Generation in 3d Rapid Mapping

    NASA Astrophysics Data System (ADS)

    Fazeli, H.; Samadzadegan, F.; Dadrasjavan, F.

    2016-06-01

    During disaster and emergency situations, 3D geospatial data can provide essential information for decision support systems. The utilization of geospatial data using digital surface models as a basic reference is mandatory to provide accurate quick emergency response in so called rapid mapping activities. The recipe between accuracy requirements and time restriction is considered critical in this situations. UAVs as alternative platforms for 3D point cloud acquisition offer potentials because of their flexibility and practicability combined with low cost implementations. Moreover, the high resolution data collected from UAV platforms have the capabilities to provide a quick overview of the disaster area. The target of this paper is to experiment and to evaluate a low-cost system for generation of point clouds using imagery collected from a low altitude small autonomous UAV equipped with customized single frequency RTK module. The customized multi-rotor platform is used in this study. Moreover, electronic hardware is used to simplify user interaction with the UAV as RTK-GPS/Camera synchronization, and beside the synchronization, lever arm calibration is done. The platform is equipped with a Sony NEX-5N, 16.1-megapixel camera as imaging sensor. The lens attached to camera is ZEISS optics, prime lens with F1.8 maximum aperture and 24 mm focal length to deliver outstanding images. All necessary calibrations are performed and flight is implemented over the area of interest at flight height of 120 m above the ground level resulted in 2.38 cm GSD. Earlier to image acquisition, 12 signalized GCPs and 20 check points were distributed in the study area and measured with dualfrequency GPS via RTK technique with horizontal accuracy of σ = 1.5 cm and vertical accuracy of σ = 2.3 cm. results of direct georeferencing are compared to these points and experimental results show that decimeter accuracy level for 3D points cloud with proposed system is achievable, that is suitable

  2. Echocardiographic Evaluation of Changes in Cardiac Hemodynamics and Loading Conditions after Transthoracic Minimally Invasive Device Closure of Atrial Septal Defect

    PubMed Central

    Cao, Hua; Zhang, Gui-Can; Chen, Liang-Wan; Hu, Yun-Nan

    2015-01-01

    -procedure, left ventricular ejection fraction had not changed significantly, but at 3 months and at 1 year post-procedure, left ejection fraction had increased significantly compared with the preoperative data (P<0.05). Conclusion Echocardiographic evaluation has demonstrated that cardiac hemodynamics and loading conditions improved significantly after transthoracic minimally invasive device closure of atrial septal defects. PMID:26147594

  3. Evaluation of the Use of Existing RELAP5-3D Models to Represent the Actinide Burner Test Reactor

    SciTech Connect

    C. B. Davis

    2007-02-01

    The RELAP5-3D code is being considered as a thermal-hydraulic system code to support the development of the sodium-cooled Actinide Burner Test Reactor as part of Global Nuclear Energy Partnership. An evaluation was performed to determine whether the control system could be used to simulate the effects of non-convective mechanisms of heat transport in the fluid that are not currently represented with internal code models, including axial and radial heat conduction in the fluid and subchannel mixing. The evaluation also determined the relative importance of axial and radial heat conduction and fluid mixing on peak cladding temperature for a wide range of steady conditions and during a representative loss-of-flow transient. The evaluation was performed using a RELAP5-3D model of a subassembly in the Experimental Breeder Reactor-II, which was used as a surrogate for the Actinide Burner Test Reactor. An evaluation was also performed to determine if the existing centrifugal pump model could be used to simulate the performance of electromagnetic pumps.

  4. Bone apposition to laminin-1 coated implants: histologic and 3D evaluation.

    PubMed

    Bougas, K; Jimbo, R; Vandeweghe, S; Hayashi, M; Bryington, M; Kozai, Y; Schwartz-Filho, H O; Tovar, N; Adolfsson, E; Ono, D; Coelho, P G; Wennerberg, A

    2013-05-01

    Laminin-1 has been reported as one of the factors responsible for the nucleation of calcium phosphates and, in vitro, has been reported to selectively recruit osteoprogenitors. This article focused on its in vivo effects, and evaluated the effect of laminin-1 local application on osseointegration. Polished cylindrical hydroxyapatite implants were coated with laminin-1 (test) and the bone responses in the rabbit tibiae after 2 and 4 weeks were evaluated and compared to the non-coated implants (control). Before the samples were processed for histological sectioning, they were three-dimensionally analysed with micro computed tomography (μCT). Both evaluation methods were analysed with regards to bone area around the implant and bone to implant contact. From the histologic observation, new bone formation around the laminin-1 coated implant at 2 weeks seemed to have increased the amount of supporting bone around the implant, however, at 4 weeks, the two groups presented no notable differences. The two-dimensional and three-dimensional morphometric evaluation revealed that both histologic and three-dimensional analysis showed some tendency in favour of the test group implants, however there was no statistical significance between the test and control group results. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  5. Thoracic cage plasticity in prepubertal New Zealand white rabbits submitted to T1-T12 dorsal arthrodesis: computed tomography evaluation, echocardiographic assessment and cardio-pulmonary measurements.

    PubMed

    Canavese, Federico; Dimeglio, Alain; Stebel, Marco; Galeotti, Marco; Canavese, Bartolomeo; Cavalli, Fabio

    2013-05-01

    We aimed to describe the morphological changes in the thoracic cage and spinal column induced in New Zealand White (NZW) prepubertal rabbits subjected to dorsal arthrodesis and observed at skeletal maturity by computed tomography (CT) scans. This was done to evaluate the plasticity of the thoracic cage of rabbits with non-deformed spine, by highlighting its modifications after spinal arthrodesis. Emogas data analysis, echocardiographic assessment and cardio-pulmonary measurements completed the evaluation. Surgery was performed in 16 female rabbits, 6 weeks old. Nine were subjected to T1-T12 dorsal arthrodesis, while seven were sham-operated. Surgery involved the implant of two C-shaped stainless steel bars and heterologous bone graft. CT scans were performed before surgery, 2, 6 and 12 months after surgery. One week after the last CT scan, echocardiographic and emogas evaluations were performed. Chest depth (8%), thoracic kyphosis (ThK) (23%), dorsal and ventral length of the thoracic spine (11%) and sternal length (7%) were significantly reduced in operated compared to sham-operated rabbits. Mean values ± standard deviation (SD) of PaCO2, PaO2 and sO2 were not significantly different. Mean values ± SD of echocardiographic measurements were not significantly different between the two groups of rabbits, except for thickness of the interventricular septum in systole, contractile capacity of the left ventricle and ejection fraction. T1-T12 dorsal arthrodesis in prepubertal NZW rabbits with non-deformed spine induced changes of the thoracic cage morphology. However, those changes are source of cardio-pulmonary complications not severe enough to reproduce a clinical picture comparable to thoracic insufficiency syndrome in humans.

  6. Evaluation of Full Reynolds Stress Turbulence Models in FUN3D

    NASA Technical Reports Server (NTRS)

    Dudek, Julianne C.; Carlson, Jan-Renee

    2017-01-01

    Full seven-equation Reynolds stress turbulence models are a relatively new and promising tool for todays aerospace technology challenges. This paper uses two stress-omega full Reynolds stress models to evaluate challenging flows including shock-wave boundary layer interactions, separation and mixing layers. The Wilcox and the SSGLRR full second-moment Reynolds stress models are evaluated for four problems: a transonic two-dimensional diffuser, a supersonic axisymmetric compression corner, a compressible planar shear layer, and a subsonic axisymmetric jet. Simulation results are compared with experimental data and results using the more commonly used Spalart-Allmaras (SA) one-equation and the Menter Shear Stress Transport (SST) two-equation models.

  7. Sensors for 3D Imaging: Metric Evaluation and Calibration of a CCD/CMOS Time-of-Flight Camera.

    PubMed

    Chiabrando, Filiberto; Chiabrando, Roberto; Piatti, Dario; Rinaudo, Fulvio

    2009-01-01

    3D imaging with Time-of-Flight (ToF) cameras is a promising recent technique which allows 3D point clouds to be acquired at video frame rates. However, the distance measurements of these devices are often affected by some systematic errors which decrease the quality of the acquired data. In order to evaluate these errors, some experimental tests on a CCD/CMOS ToF camera sensor, the SwissRanger (SR)-4000 camera, were performed and reported in this paper. In particular, two main aspects are treated: the calibration of the distance measurements of the SR-4000 camera, which deals with evaluation of the camera warm up time period, the distance measurement error evaluation and a study of the influence on distance measurements of the camera orientation with respect to the observed object; the second aspect concerns the photogrammetric calibration of the amplitude images delivered by the camera using a purpose-built multi-resolution field made of high contrast targets.

  8. VCM automated 3-D measurement system: theory, application, and performance evaluation

    NASA Astrophysics Data System (ADS)

    El-Hakim, Sabry F.; Pizzi, Nicolino J.; Westmore, David B.

    1992-03-01

    The vision-based coordinate measurement (VCM) automated measurement system has been under development at the National Research Council Canada for several years. The system, which is a multicamera passive system, combines the principles of stereo vision, photogrammetry, knowledge-based techniques, and object-oriented design to provide precise coordinate and dimension measurements of parts for applications such as those found in the aerospace and automobile industries. The system may also be used for tracking or positioning of parts and digitization of targeted objects. Description of the system, the techniques employed for calibration, CAD-based feature extraction and measurement, and performance evaluation are presented.

  9. Segmentation and quantitative evaluation of brain MRI data with a multiphase 3D implicit deformable model

    NASA Astrophysics Data System (ADS)

    Angelini, Elsa D.; Song, Ting; Mensh, Brett D.; Laine, Andrew

    2004-05-01

    Segmentation of three-dimensional anatomical brain images into tissue classes has applications in both clinical and research settings. This paper presents the implementation and quantitative evaluation of a four-phase three-dimensional active contour implemented with a level set framework for automated segmentation of brain MRIs. The segmentation algorithm performs an optimal partitioning of three-dimensional data based on homogeneity measures that naturally evolves to the extraction of different tissue types in the brain. Random seed initialization was used to speed up numerical computation and avoid the need for a priori information. This random initialization ensures robustness of the method to variation of user expertise, biased a priori information and errors in input information that could be influenced by variations in image quality. Experimentation on three MRI brain data sets showed that an optimal partitioning successfully labeled regions that accurately identified white matter, gray matter and cerebrospinal fluid in the ventricles. Quantitative evaluation of the segmentation was performed with comparison to manually labeled data and computed false positive and false negative assignments of voxels for the three organs. We report high accuracy for the two comparison cases. These results demonstrate the efficiency and flexibility of this segmentation framework to perform the challenging task of automatically extracting brain tissue volume contours.

  10. Analytical and experimental evaluation of a 3-D hypersonic fixed-geometry, swept, mixed compression inlet

    NASA Technical Reports Server (NTRS)

    Agnone, Anthony M.

    1987-01-01

    The performance of a fixed-geometry, swept, mixed compression hypersonic inlet is presented. The experimental evaluation was conducted for a Mach number of 6.0 and for several angles of attack. The measured surface pressures and pitot pressure surveys at the inlet throat are compared to computations using a three-dimensional Euler code and an integral boundary layer theory. Unique features of the intake design, including the boundary layer control, insure a high inlet performance. The experimental data show the inlet has a high mass averaged total pressure recovery, a high mass capture and nearly uniform flow diffusion. The swept inlet exhibits excellent starting characteristics, and high flow stability at angle of attack.

  11. 3-D THERMAL EVALUATIONS FOR a FUELED EXPERIMENT in the ADVANCED TEST REACTOR

    SciTech Connect

    Ambrosek, R.G.; Chang, G.S.; Utterbeck, D.J.

    2004-10-06

    The DOE Advanced Fuel Cycle Initiative and Generation IV reactor programs are developing new fuel types for use in the current Light Water Reactors and future advanced reactor concepts. The Advanced Gas Reactor program is planning to test fuel to be used in the Next Generation Nuclear Plant (NGNP) nuclear reactor. Preliminary information for assessing performance of the fuel will be obtained from irradiations performed in the Advanced Test Reactor large ''B'' experimental facility. A test configuration has been identified for demonstrating fuel types typical of gas cooled reactors or fast reactors that may play a role in closing the fuel cycle or increasing efficiency via high temperature operation Plans are to have 6 capsules, each containing 12 compacts, for the test configuration. Each capsule will have its own temperature control system. Passing a helium-neon gas through the void regions between the fuel compacts and the graphite carrier and between the graphite carrier and the capsule wall will control temperature. This design with three compacts per axial level was evaluated for thermal performance to ascertain the temperature distributions in the capsule and test specimens with heating rates that encompass the range of initial heat generation rates.

  12. 3-D Thermal Evaluations for a Fueled Experiment in the Advanced Test Reactor

    SciTech Connect

    Richard Ambrosek; Gray Chang; Debra Utterbeck

    2004-10-01

    The DOE Advanced Fuel Cycle Initiative and Generation IV reactor programs are developing new fuel types for use in the current Light Water Reactors and future advanced reactor concepts. The Advanced Gas Reactor program is planning to test fuel to be used in the Next Generation Nuclear Plant (NGNP) nuclear reactor. Preliminary information for assessing performance of the fuel will be obtained from irradiations performed in the Advanced Test Reactor large “B” experimental facility. A test configurations has been identified for demonstrating fuel types typical of gas cooled reactors or fast reactors that may play a role in closing the fuel cycle or increasing efficiency via high temperature operation Plans are to have 6 capsules, each containing 12 compacts, for the test configuration. Each capsule will have its own temperature control system. Passing a helium-neon gas through the void regions between the fuel compacts and the graphite carrier and between the graphite carrier and the capsule wall will control temperature. This design with three compacts per axial level was evaluated for thermal performance to ascertain the temperature distributions in the capsule and test specimens with heating rates that encompass the range of initial heat generation rates.

  13. Development and Evaluation of a UAV-Photogrammetry System for Precise 3D Environmental Modeling

    PubMed Central

    Shahbazi, Mozhdeh; Sohn, Gunho; Théau, Jérôme; Menard, Patrick

    2015-01-01

    The specific requirements of UAV-photogrammetry necessitate particular solutions for system development, which have mostly been ignored or not assessed adequately in recent studies. Accordingly, this paper presents the methodological and experimental aspects of correctly implementing a UAV-photogrammetry system. The hardware of the system consists of an electric-powered helicopter, a high-resolution digital camera and an inertial navigation system. The software of the system includes the in-house programs specifically designed for camera calibration, platform calibration, system integration, on-board data acquisition, flight planning and on-the-job self-calibration. The detailed features of the system are discussed, and solutions are proposed in order to enhance the system and its photogrammetric outputs. The developed system is extensively tested for precise modeling of the challenging environment of an open-pit gravel mine. The accuracy of the results is evaluated under various mapping conditions, including direct georeferencing and indirect georeferencing with different numbers, distributions and types of ground control points. Additionally, the effects of imaging configuration and network stability on modeling accuracy are assessed. The experiments demonstrated that 1.55 m horizontal and 3.16 m vertical absolute modeling accuracy could be achieved via direct geo-referencing, which was improved to 0.4 cm and 1.7 cm after indirect geo-referencing. PMID:26528976

  14. Performance evaluation of medical LCD displays using 3D channelized Hotelling observers

    NASA Astrophysics Data System (ADS)

    Platiša, Ljiljana; Marchessoux, Cédric; Goossens, Bart; Philips, Wilfried

    2011-03-01

    High performance of the radiologists in the task of image lesion detection is crucial for successful medical practice. One relevant factor in clinical image reading is the quality of the medical display. With the current trends of stack-mode liquid crystal displays (LCDs), the slow temporal response of the display plays a significant role in image quality assurance. In this paper, we report on the experimental study performed to evaluate the quality of a novel LCD with advanced temporal response compensation, and compare it to an existing state-of-the-art display of the same category but with no temporal response compensation. The data in the study comprise clinical digital tomosynthesis images of the breast with added simulated mass lesions. The detectability for the two displays is estimated using the recent multi-slice channelized Hotelling observer (msCHO) model which is especially designed for multi-slice image data. Our results suggest that the novel LCD allows higher detectability than the existing one. Moreover, the msCHO results are used to advise on the parameters for the follow up image reading study with real medical doctors as observers. Finally, the main findings of the msCHO study were confirmed by a human reader study (details to be published in a separate paper).

  15. Development and Evaluation of a UAV-Photogrammetry System for Precise 3D Environmental Modeling.

    PubMed

    Shahbazi, Mozhdeh; Sohn, Gunho; Théau, Jérôme; Menard, Patrick

    2015-10-30

    The specific requirements of UAV-photogrammetry necessitate particular solutions for system development, which have mostly been ignored or not assessed adequately in recent studies. Accordingly, this paper presents the methodological and experimental aspects of correctly implementing a UAV-photogrammetry system. The hardware of the system consists of an electric-powered helicopter, a high-resolution digital camera and an inertial navigation system. The software of the system includes the in-house programs specifically designed for camera calibration, platform calibration, system integration, on-board data acquisition, flight planning and on-the-job self-calibration. The detailed features of the system are discussed, and solutions are proposed in order to enhance the system and its photogrammetric outputs. The developed system is extensively tested for precise modeling of the challenging environment of an open-pit gravel mine. The accuracy of the results is evaluated under various mapping conditions, including direct georeferencing and indirect georeferencing with different numbers, distributions and types of ground control points. Additionally, the effects of imaging configuration and network stability on modeling accuracy are assessed. The experiments demonstrated that 1.55 m horizontal and 3.16 m vertical absolute modeling accuracy could be achieved via direct geo-referencing, which was improved to 0.4 cm and 1.7 cm after indirect geo-referencing.

  16. Comparative evaluation of 3D virtual ligand screening methods: impact of the molecular alignment on enrichment.

    PubMed

    Giganti, David; Guillemain, Hélène; Spadoni, Jean-Louis; Nilges, Michael; Zagury, Jean-François; Montes, Matthieu

    2010-06-28

    In the early stage of drug discovery programs, when the structure of a complex involving a target and a small molecule is available, structure-based virtual ligand screening methods are generally preferred. However, ligand-based strategies like shape-similarity search methods can also be applied. Shape-similarity search methods consist in exploring a pseudo-binding-site derived from the known small molecule used as a reference. Several of these methods use conformational sampling algorithms which are also shared by corresponding docking methods: for example Surflex-dock/Surflex-sim, FlexX/FlexS, ICM, and OMEGA-FRED/OMEGA-ROCS. Using 11 systems issued from the challenging "own" subsets of the Directory of Useful Decoys (DUD-own), we evaluated and compared the performance of the above-cited programs in terms of molecular alignment accuracy, enrichment in active compounds, and enrichment in different chemotypes (scaffold-hopping). Since molecular alignment is a crucial aspect of performance for the different methods, we have assessed its impact on enrichment. We have also illustrated the paradox of retrieving active compounds with good scores even if they are inaccurately positioned. Finally, we have highlighted possible positive aspects of using shape-based approaches in drug-discovery protocols when the structure of the target in complex with a small molecule is known.

  17. Micro-computed tomography image-based evaluation of 3D anisotropy degree of polymer scaffolds.

    PubMed

    Pérez-Ramírez, Ursula; López-Orive, Jesús Javier; Arana, Estanislao; Salmerón-Sánchez, Manuel; Moratal, David

    2015-01-01

    Anisotropy is one of the most meaningful determinants of biomechanical behaviour. This study employs micro-computed tomography (μCT) and image techniques for analysing the anisotropy of regenerative medicine polymer scaffolds. For this purpose, three three-dimensional anisotropy evaluation image methods were used: ellipsoid of inertia (EI), mean intercept length (MIL) and tensor scale (t-scale). These were applied to three patterns (a sphere, a cube and a right prism) and to two polymer scaffold topologies (cylindrical orthogonal pore mesh and spherical pores). For the patterns, the three methods provided good results. Regarding the scaffolds, EI mistook both topologies (0.0158, [-0.5683; 0.6001]; mean difference and 95% confidence interval), and MIL showed no significant differences (0.3509, [0.0656; 0.6362]). T-scale is the preferable method because it gave the best capability (0.3441, [0.1779; 0.5102]) to differentiate both topologies. This methodology results in the development of non-destructive tools to engineer biomimetic scaffolds, incorporating anisotropy as a fundamental property to be mimicked from the original tissue and permitting its assessment by means of μCT image analysis.

  18. Browsing Through Closed Books: Evaluation of Preprocessing Methods for Page Extraction of a 3-D CT Book Volume

    NASA Astrophysics Data System (ADS)

    Stromer, D.; Christlein, V.; Schön, T.; Holub, W.; Maier, A.

    2017-09-01

    It is often the case that a document can not be opened, page-turned or touched anymore due to damages caused by aging processes, moisture or fire. To counter this, special imaging systems can be used. One of our earlier work revealed that a common 3-D X-ray micro-CT scanner is well suited for imaging and reconstructing historical documents written with iron gall ink – an ink consisting of metallic particles. We acquired a volume of a self-made book without opening or page-turning with a single 3-D scan. However, when investigating the reconstructed volume, we faced the problem of a proper automatic extraction of single pages within the volume in an acceptable time without losing information of the writings. Within this work, we evaluate different appropriate pre-processing methods with respect to computation time and accuracy which are decisive for a proper extraction of book pages from the reconstructed X-ray volume and the subsequent ink identification. The different methods were tested for an extreme case with low resolution, noisy input data and wavy pages. Finally, we present results of the page extraction after applying the evaluated methods.

  19. Formability evaluation for hot-rolled HB780 steel sheet based on 3-D non-quadratic yield function

    NASA Astrophysics Data System (ADS)

    Kim, Wonjae; Koh, Youngwoo; Kim, Hyunki; Chung, Youn-Il; Lee, Myoung-Gyu; Chung, Kwansoo

    2017-05-01

    A common practice to evaluate formability in the typical sheet metal forming process is to measure hardening behavior and a forming limit diagram as separate material properties, and perform numerical forming simulations utilizing various yield functions. The measured forming limit diagram is applied as the failure criterion. However, the performance of material properties such as hardening behavior and yield functions in predicting strain localization in the simple tension and forming limit diagram tests is seldom validated before their application to forming simulation. In this study, a new numerical formability evaluation procedure was proposed, in which not only hardening behavior but also measured forming limit data were employed in characterizing the input data for the hardening behavior and the yield function. Besides, strain localization was directly monitored to determine failure without employing any forming limit criterion. The new procedure was applied for rather thick advanced high strength hot-rolled steel sheet so that 3-D continuum elements were utilized along with 3-D non-quadratic Hosford and quadratic Hill yield functions.

  20. Dosimetric Evaluation of Intensity Modulated Radiotherapy and 4-Field 3-D Conformal Radiotherapy in Prostate Cancer Treatment

    PubMed Central

    Uysal, Bora; Beyzadeoğlu, Murat; Sager, Ömer; Dinçoğlan, Ferrat; Demiral, Selçuk; Gamsız, Hakan; Sürenkök, Serdar; Oysul, Kaan

    2013-01-01

    Objective: The purpose of this dosimetric study is the targeted dose homogeneity and critical organ dose comparison of 7-field Intensity Modulated Radiotherapy (IMRT) and 3-D 4-field conformal radiotherapy. Study Design: Cross sectional study. Material and Methods: Twenty patients with low and moderate risk prostate cancer treated at Gülhane Military Medical School Radiation Oncology Department between January 2009 and December 2009 are included in this study. Two seperate dosimetric plans both for 7-field IMRT and 3D-CRT have been generated for each patient to comparatively evaluate the dosimetric status of both techniques and all the patients received 7-field IMRT. Results: Dose-comparative evaluation of two techniques revealed the superiority of IMRT technique with statistically significantly lower femoral head doses along with reduced critical organ dose-volume parameters of bladder V60 (the volume receiving 60 Gy) and rectal V40 (the volume receiving 40 Gy) and V60. Conclusion: It can be concluded that IMRT is an effective definitive management tool for prostate cancer with improved critical organ sparing and excellent dose homogenization in target organs of prostate and seminal vesicles. PMID:25207069

  1. Evaluation of a combined pre-processing and H.264-compression scheme for 3D integral images

    NASA Astrophysics Data System (ADS)

    Olsson, Roger; Sjöström, Mårten; Xu, Youzhi

    2007-01-01

    To provide sufficient 3D-depth fidelity, integral imaging (II) requires an increase in spatial resolution of several orders of magnitude from today's 2D images. We have recently proposed a pre-processing and compression scheme for still II-frames based on forming a pseudo video sequence (PVS) from sub images (SI), which is later coded using the H.264/MPEG-4 AVC video coding standard. The scheme has shown good performance on a set of reference images. In this paper we first investigate and present how five different ways to select the SIs when forming the PVS affect the schemes compression efficiency. We also study how the II-frame structure relates to the performance of a PVS coding scheme. Finally we examine the nature of the coding artifacts which are specific to the evaluated PVS-schemes. We can conclude that for all except the most complex reference image, all evaluated SI selection orders significantly outperforms JPEG 2000 where compression ratios of up to 342:1, while still keeping PSNR > 30 dB, is achieved. We can also confirm that when selecting PVS-scheme, the scheme which results in a higher PVS-picture resolution should be preferred to maximize compression efficiency. Our study of the coded II-frames also indicates that the SI-based PVS, contrary to other PVS schemes, tends to distribute its coding artifacts more homogenously over all 3D-scene depths.

  2. Evaluation of 3D-Printed Polycaprolactone Scaffolds Coated with Freeze-Dried Platelet-Rich Plasma for Bone Regeneration

    PubMed Central

    Li, Junda; Chen, Meilin; Wei, Xiaoying; Hao, Yishan; Wang, Jinming

    2017-01-01

    Three-dimensional printing is one of the most promising techniques for the manufacturing of scaffolds for bone tissue engineering. However, a pure scaffold is limited by its biological properties. Platelet-rich plasma (PRP) has been shown to have the potential to improve the osteogenic effect. In this study, we improved the biological properties of scaffolds by coating 3D-printed polycaprolactone (PCL) scaffolds with freeze-dried and traditionally prepared PRP, and we evaluated these scaffolds through in vitro and in vivo experiments. In vitro, we evaluated the interaction between dental pulp stem cells (DPSCs) and the scaffolds by measuring cell proliferation, alkaline phosphatase (ALP) activity, and osteogenic differentiation. The results showed that freeze-dried PRP significantly enhanced ALP activity and the mRNA expression levels of osteogenic genes (ALP, RUNX2 (runt-related gene-2), OCN (osteocalcin), OPN (osteopontin)) of DPSCs (p < 0.05). In vivo, 5 mm calvarial defects were created, and the PRP-PCL scaffolds were implanted. The data showed that compared with traditional PRP-PCL scaffolds or bare PCL scaffolds, the freeze-dried PRP-PCL scaffolds induced significantly greater bone formation (p < 0.05). All these data suggest that coating 3D-printed PCL scaffolds with freeze-dried PRP can promote greater osteogenic differentiation of DPSCs and induce more bone formation, which may have great potential in future clinical applications. PMID:28773189

  3. Evaluation and validation methods for intersubject nonrigid 3D image registration of the human brain

    NASA Astrophysics Data System (ADS)

    Guo, Ting; Starreveld, Yves P.; Peters, Terry M.

    2005-04-01

    This work presents methodologies for assessing the accuracy of non-rigid intersubject registration algorithms from both qualitative and quantitative perspectives. The first method was based on a set of 43 anatomical landmarks. MRI brain images of 12 subjects were non-rigidly registered to the standard MRI dataset. The "gold-standard" coordinates of the 43 landmarks in the target were estimated by averaging their coordinates after 6 tagging sessions. The Euclidean distance between each landmark of a subject after warping to the reference space and the homologous "gold-standard" landmark on the reference image was considered as the registration error. Another method based on visual inspection software displaying the spatial change of colour-coded spheres, before and after warping, was also developed to evaluate the performance of the non-rigid warping algorithms within the homogeneous regions in the deep-brain. Our methods were exemplified by assessing and comparing the accuracy of two intersubject non-rigid registration approaches, AtamaiWarp and ANIMAL algorithms. From the first method, the average registration error was 1.04mm +/- 0.65mm for AtamaiWarp, and 1.59mm +/- 1.47mm for ANIMAL. With maximum registration errors of 2.78mm and 3.90mm respectively, AtamaiWarp and ANIMAL located 58% and 35% landmarks respectively with registration errors less than 1mm. A paired t-test showed that the differences in registration error between AtamaiWarp and ANIMAL were significant (P < 0.002) demonstrating that AtamaiWarp, in addition to being over 60 times faster than ANIMAL, also provides more accurate results. From the second method, both algorithms treated the interior of homogeneous regions in an appropriate manner.

  4. 3-D volumetric MRI evaluation of the placenta in fetuses with complex congenital heart disease

    PubMed Central

    Andescavage, Nickie; Yarish, Alexa; Donofrio, Mary; Bulas, Dorothy; Evangelou, Iordanis; Vezina, Gilbert; McCarter, Robert; DuPlessis, Adre; Limperopoulos, Catherine

    2015-01-01

    Introduction Placental insufficiency remains a common cause of perinatal mortality and neurodevelopmental morbidity. Congenital heart disease (CHD) in the fetus and its relationship to placental function is unknown. This study explores placental health and its relationship to neonatal outcomes by comparing placental volumes in healthy pregnancies and pregnancies complicated by CHD using in vivo three-dimensional MRI studies. Methods In a prospective observational study, pregnant women greater than 18 weeks gestation with normal pregnancies or pregnancies complicated by CHD were recruited and underwent fetal MR imaging. The placenta was manually outlined and the volume was calculated in cm3. Brain volume was also calculated and clinical data were also collected. Relationships, including interactive effects, between placental and fetal growth, including brain growth, were evaluated using longitudinal multiple linear regression analysis. Results 135 women underwent fetal MRI between 18 and 39 weeks gestation (mean 31.6 ± 4.4). Placental volume increased exponentially with gestational age (p=0.041). Placental volume was positively associated with birth weight (p <0.001) and increased more steeply with birth weight in CHD-affected fetuses (p=0.046). Total brain and cerebral volumes were smaller in the CHD group (p<0.001), but brainstem volume (p<0.001) was larger. Placental volumes were not associated with brain volumes. Discussion Impaired placental growth in CHD is associated with gestational age and birth weight at delivery. Abnormalities in placental development may contribute to the significant morbidity in this high-risk population. Assessment of placental volume by MRI allows for in vivo assessments of placental development. PMID:26190037

  5. 3-D volumetric MRI evaluation of the placenta in fetuses with complex congenital heart disease.

    PubMed

    Andescavage, Nickie; Yarish, Alexa; Donofrio, Mary; Bulas, Dorothy; Evangelou, Iordanis; Vezina, Gilbert; McCarter, Robert; duPlessis, Adre; Limperopoulos, Catherine

    2015-09-01

    Placental insufficiency remains a common cause of perinatal mortality and neurodevelopmental morbidity. Congenital heart disease (CHD) in the fetus and its relationship to placental function is unknown. This study explores placental health and its relationship to neonatal outcomes by comparing placental volumes in healthy pregnancies and pregnancies complicated by CHD using in vivo three-dimensional MRI studies. In a prospective observational study, pregnant women greater than 18 weeks gestation with normal pregnancies or pregnancies complicated by CHD were recruited and underwent fetal MR imaging. The placenta was manually outlined and the volume was calculated in cm(3). Brain volume was also calculated and clinical data were also collected. Relationships, including interactive effects, between placental and fetal growth, including brain growth, were evaluated using longitudinal multiple linear regression analysis. 135 women underwent fetal MRI between 18 and 39 weeks gestation (mean 31.6 ± 4.4). Placental volume increased exponentially with gestational age (p = 0.041). Placental volume was positively associated with birth weight (p < 0.001) and increased more steeply with birth weight in CHD-affected fetuses (p = 0.046). Total brain and cerebral volumes were smaller in the CHD group (p < 0.001), but brainstem volume (p < 0.001) was larger. Placental volumes were not associated with brain volumes. Impaired placental growth in CHD is associated with gestational age and birth weight at delivery. Abnormalities in placental development may contribute to the significant morbidity in this high-risk population. Assessment of placental volume by MRI allows for in vivo assessments of placental development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Fabrication and evaluation of electrohydrodynamic jet 3D printed polycaprolactone/chitosan cell carriers using human embryonic stem cell-derived fibroblasts.

    PubMed

    Wu, Yang; Sriram, Gopu; Fawzy, Amr S; Fuh, Jerry Yh; Rosa, Vinicius; Cao, Tong; Wong, Yoke San

    2016-08-01

    Biological function of adherent cells depends on the cell-cell and cell-matrix interactions in three-dimensional space. To understand the behavior of cells in 3D environment and their interactions with neighboring cells and matrix requires 3D culture systems. Here, we present a novel 3D cell carrier scaffold that provides an environment for routine 3D cell growth in vitro We have developed thin, mechanically stable electrohydrodynamic jet (E-jet) 3D printed polycaprolactone and polycaprolactone/Chitosan macroporous scaffolds with precise fiber orientation for basic 3D cell culture application. We have evaluated the application of this technology by growing human embryonic stem cell-derived fibroblasts within these 3D scaffolds. Assessment of cell viability and proliferation of cells seeded on polycaprolactone and polycaprolactone/Chitosan 3D-scaffolds show that the human embryonic stem cell-derived fibroblasts could adhere and proliferate on the scaffolds over time. Further, using confocal microscopy we demonstrate the ability to use fluorescence-labelled cells that could be microscopically monitored in real-time. Hence, these 3D printed polycaprolactone and polycaprolactone/Chitosan scaffolds could be used as a cell carrier for in vitro 3D cell culture-, bioreactor- and tissue engineering-related applications in the future.

  7. Combining 3D human in vitro methods for a 3Rs evaluation of novel titanium surfaces in orthopaedic applications

    PubMed Central

    Stevenson, G.; Rehman, S.; Draper, E.; Hernández‐Nava, E.; Hunt, J.

    2016-01-01

    ABSTRACT In this study, we report on a group of complementary human osteoblast in vitro test methods for the preclinical evaluation of 3D porous titanium surfaces. The surfaces were prepared by additive manufacturing (electron beam melting [EBM]) and plasma spraying, allowing the creation of complex lattice surface geometries. Physical properties of the surfaces were characterized by SEM and profilometry and 3D in vitro cell culture using human osteoblasts. Primary human osteoblast cells were found to elicit greater differences between titanium sample surfaces than an MG63 osteoblast‐like cell line, particularly in terms of cell survival. Surface morphology was associated with higher osteoblast metabolic activity and mineralization on rougher titanium plasma spray coated surfaces than smoother surfaces. Differences in osteoblast survival and metabolic activity on titanium lattice structures were also found, despite analogous surface morphology at the cellular level. 3D confocal microscopy identified osteoblast organization within complex titanium surface geometries, adhesion, spreading, and alignment to the biomaterial strut geometries. Mineralized nodule formation throughout the lattice structures was also observed, and indicative of early markers of bone in‐growth on such materials. Testing methods such as those presented are not traditionally considered by medical device manufacturers, but we suggest have value as an increasingly vital tool in efficiently translating pre‐clinical studies, especially in balance with current regulatory practice, commercial demands, the 3Rs, and the relative merits of in vitro and in vivo studies. Biotechnol. Bioeng. 2016;113: 1586–1599. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. PMID:26702609

  8. Novel 3-D cell culture system for in vitro evaluation of anticancer drugs under anchorage-independent conditions.

    PubMed

    Aihara, Ayako; Abe, Natsuki; Saruhashi, Koichiro; Kanaki, Tatsuro; Nishino, Taito

    2016-12-01

    Anticancer drug discovery efforts have used 2-D cell-based assay models, which fail to forecast in vivo efficacy and result in a lower success rate of clinical approval. Recent 3-D cell culture models are expected to bridge the gap between 2-D and in vivo models. However, 3-D cell culture methods that are available for practical anticancer drug screening have not yet been fully attained. In this study, we screened several polymers for their ability to suspend cells or cell spheroids homogeneously in a liquid medium without changing the viscosity behavior, and identified gellan gum (FP001), as the most potent polymer. FP001 promoted cell dispersion in the medium and improved the proliferation of a wide range of cancer cell lines under low attachment conditions by inhibiting the formation of large-sized spheroids. In addition, cancer cells cultured with FP001-containing medium were more susceptible to inhibitors of epidermal growth factor (EGF) signaling than those cultured under attachment conditions. We also showed that ligands of the EGF receptor family clearly enhance proliferation of SKOV3 ovarian carcinoma cells under anchorage-independent conditions with FP001. Consistent with this result, the cells grown with FP001 showed higher EGF receptor content compared with cells cultured under attachment conditions. In conclusion, we developed a novel 3-D cell culture system that is available for high throughput screening of anticancer agents, and is suitable for evaluation of molecular-targeted anticancer drugs. Three-dimensional cell culture using FP001 will be of value in the development of useful technologies for anticancer drug discovery.

  9. Combining 3D human in vitro methods for a 3Rs evaluation of novel titanium surfaces in orthopaedic applications.

    PubMed

    Stevenson, G; Rehman, S; Draper, E; Hernández-Nava, E; Hunt, J; Haycock, J W

    2016-07-01

    In this study, we report on a group of complementary human osteoblast in vitro test methods for the preclinical evaluation of 3D porous titanium surfaces. The surfaces were prepared by additive manufacturing (electron beam melting [EBM]) and plasma spraying, allowing the creation of complex lattice surface geometries. Physical properties of the surfaces were characterized by SEM and profilometry and 3D in vitro cell culture using human osteoblasts. Primary human osteoblast cells were found to elicit greater differences between titanium sample surfaces than an MG63 osteoblast-like cell line, particularly in terms of cell survival. Surface morphology was associated with higher osteoblast metabolic activity and mineralization on rougher titanium plasma spray coated surfaces than smoother surfaces. Differences in osteoblast survival and metabolic activity on titanium lattice structures were also found, despite analogous surface morphology at the cellular level. 3D confocal microscopy identified osteoblast organization within complex titanium surface geometries, adhesion, spreading, and alignment to the biomaterial strut geometries. Mineralized nodule formation throughout the lattice structures was also observed, and indicative of early markers of bone in-growth on such materials. Testing methods such as those presented are not traditionally considered by medical device manufacturers, but we suggest have value as an increasingly vital tool in efficiently translating pre-clinical studies, especially in balance with current regulatory practice, commercial demands, the 3Rs, and the relative merits of in vitro and in vivo studies. Biotechnol. Bioeng. 2016;113: 1586-1599. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

  10. Configuration and Evaluation of a Dual-Doppler 3-D Wind Field System

    NASA Technical Reports Server (NTRS)

    Crawford, Winifred C.

    2014-01-01

    Current LSP, GSDO, and SLS space vehicle operations are halted when wind speeds from specific directions exceed defined thresholds and when lightning is a threat. Strong winds and lightning are difficult parameters for the 45th Weather Squadron (45 WS) to forecast, yet are important in the protection of customer vehicle operations and the personnel that conduct them. A display of the low-level horizontal wind field to reveal areas of high winds or convergence would be a valuable tool for forecasters in assessing the timing of high winds, or convection initiation and subsequent lightning occurrence. This is especially important for areas where no weather observation platforms exist. Developing a dual-Doppler radar capability would provide such a display to assist forecasters in predicting high winds and convection initiation. The wind fields can also be used to initialize a local mesoscale numerical weather prediction model to help improve the model forecast winds, convection initiation, and other phenomena. The 45 WS and NWS MLB tasked the Applied Meteorology Unit (AMU) to develop a dual- Doppler wind field display using data from the 45th Space Wing radar, known as the Weather Surveillance Radar (WSR), NWS MLB Weather Surveillance Radar 1988 Doppler (KMLB), and the Orlando International Airport Terminal Doppler Weather Radar (KMCO). They also stipulated that the software used should be freely available. The AMU evaluated two software packages and, with concurrence from NWS MLB and the 45 WS, chose the Warning Decision Support System-Integrated Information (WDSS-II). The AMU collected data from two significant weather cases: a tornadic event on 14 April 2013 and a severe wind and hail event on 12 February 2014. For the 14 April case, the data were from WSR and KMLB. For the 12 February case, the data were from KMCO and KMLB. The AMU installed WDSS-II on a Linux PC, then processed and quality controlled the radar data for display and analysis using WDSS-II tools

  11. Research and Teaching: Methods for Creating and Evaluating 3D Tactile Images to Teach STEM Courses to the Visually Impaired

    ERIC Educational Resources Information Center

    Hasper, Eric; Windhorst, Rogier; Hedgpeth, Terri; Van Tuyl, Leanne; Gonzales, Ashleigh; Martinez, Britta; Yu, Hongyu; Farkas, Zolton; Baluch, Debra P.

    2015-01-01

    Project 3D IMAGINE or 3D Image Arrays to Graphically Implement New Education is a pilot study that researches the effectiveness of incorporating 3D tactile images, which are critical for learning science, technology, engineering, and mathematics, into entry-level lab courses. The focus of this project is to increase the participation and…

  12. Research and Teaching: Methods for Creating and Evaluating 3D Tactile Images to Teach STEM Courses to the Visually Impaired

    ERIC Educational Resources Information Center

    Hasper, Eric; Windhorst, Rogier; Hedgpeth, Terri; Van Tuyl, Leanne; Gonzales, Ashleigh; Martinez, Britta; Yu, Hongyu; Farkas, Zolton; Baluch, Debra P.

    2015-01-01

    Project 3D IMAGINE or 3D Image Arrays to Graphically Implement New Education is a pilot study that researches the effectiveness of incorporating 3D tactile images, which are critical for learning science, technology, engineering, and mathematics, into entry-level lab courses. The focus of this project is to increase the participation and…

  13. Extraction of 3D Femur Neck Trabecular Bone Architecture from Clinical CT Images in Osteoporotic Evaluation: a Novel Framework.

    PubMed

    Sapthagirivasan, V; Anburajan, M; Janarthanam, S

    2015-08-01

    The early detection of osteoporosis risk enhances the lifespan and quality of life of an individual. A reasonable in-vivo assessment of trabecular bone strength at the proximal femur helps to evaluate the fracture risk and henceforth, to understand the associated structural dynamics on occurrence of osteoporosis. The main aim of our study was to develop a framework to automatically determine the trabecular bone strength from clinical femur CT images and thereby to estimate its correlation with BMD. All the 50 studied south Indian female subjects aged 30 to 80 years underwent CT and DXA measurements at right femur region. Initially, the original CT slices were intensified and active contour model was utilised for the extraction of the neck region. After processing through a novel process called trabecular enrichment approach (TEA), the three dimensional (3D) trabecular features were extracted. The extracted 3D trabecular features, such as volume fraction (VF), solidity of delta points (SDP) and boundness, demonstrated a significant correlation with femoral neck bone mineral density (r = 0.551, r = 0.432, r = 0.552 respectively) at p < 0.001. The higher area under the curve values of the extracted features (VF: 85.3 %; 95CI: 68.2-100 %, SDP: 82.1 %; 95CI: 65.1-98.9 % and boundness: 90.4 %; 95CI: 78.7-100 %) were observed. The findings suggest that the proposed framework with TEA method would be useful for spotting women vulnerable to osteoporotic risk.

  14. Failure Progress of 3D Reinforced GFRP Laminate during Static Bending, Evaluated by Means of Acoustic Emission and Vibrations Analysis

    PubMed Central

    Koziol, Mateusz; Figlus, Tomasz

    2015-01-01

    The work aimed to assess the failure progress in a glass fiber-reinforced polymer laminate with a 3D-woven and (as a comparison) plain-woven reinforcement, during static bending, using acoustic emission signals. The innovative method of the separation of the signal coming from the fiber fracture and the one coming from the matrix fracture with the use of the acoustic event’s energy as a criterion was applied. The failure progress during static bending was alternatively analyzed by evaluation of the vibration signal. It gave a possibility to validate the results of the acoustic emission. Acoustic emission, as well as vibration signal analysis proved to be good and effective tools for the registration of failure effects in composite laminates. Vibration analysis is more complicated methodologically, yet it is more precise. The failure progress of the 3D laminate is “safer” and more beneficial than that of the plain-woven laminate. It exhibits less rapid load capacity drops and a higher fiber effort contribution at the moment of the main laminate failure. PMID:28793743

  15. Applying and validating the RANS-3D flow-solver for evaluating a subsonic serpentine diffuser geometry

    NASA Technical Reports Server (NTRS)

    Fletcher, Michael J.; Won, Mark J.; Cosentino, Gary B.; Te, Alexander

    1993-01-01

    Subsonic inlet ducts for advanced, high-performance aircraft are evolving towards complex three-dimensional shapes for reasons of overall integration and weight. These factors lead to diffuser geometries that may sacrifice inlet performance, unless careful attention to design details and boundary layer management techniques are employed. The ability of viscous computational fluid dynamic (CFD) analysis of such geometries to aid the aircraft configurator in this complex design problem is herein examined. The RANS-3D Reynolds-Averaged Navier-Stokes solver is applied to model the complex flowfield occurring in a representative diffuser geometry and the solutions are compared to experimental results from a static test of the inlet duct. The computational results are shown to compare very favorably with experimental results over a range of mass flow rates, including those involving large amounts of separation in the diffuser. In addition, a novel grid topology is presented, and two turbulence models are evaluated in this study as part of the RANS-3D code.

  16. Quantitative Evaluation of Tissue Surface Adaption of CAD-Designed and 3D Printed Wax Pattern of Maxillary Complete Denture

    PubMed Central

    Chen, Hu; Wang, Han; Lv, Peijun; Wang, Yong; Sun, Yuchun

    2015-01-01

    Objective. To quantitatively evaluate the tissue surface adaption of a maxillary complete denture wax pattern produced by CAD and 3DP. Methods. A standard edentulous maxilla plaster cast model was used, for which a wax pattern of complete denture was designed using CAD software developed in our previous study and printed using a 3D wax printer, while another wax pattern was manufactured by the traditional manual method. The cast model and the two wax patterns were scanned in the 3D scanner as “DataModel,” “DataWaxRP,” and “DataWaxManual.” After setting each wax pattern on the plaster cast, the whole model was scanned for registration. After registration, the deviations of tissue surface between “DataModel” and “DataWaxRP” and between “DataModel” and “DataWaxManual” were measured. The data was analyzed by paired t-test. Results. For both wax patterns produced by the CAD&RP method and the manual method, scanning data of tissue surface and cast surface showed a good fit in the majority. No statistically significant (P > 0.05) difference was observed between the CAD&RP method and the manual method. Conclusions. Wax pattern of maxillary complete denture produced by the CAD&3DP method is comparable with traditional manual method in the adaption to the edentulous cast model. PMID:26583108

  17. Evaluation of 3D pre-treatment verification for volumetric modulated arc therapy plan in head region

    NASA Astrophysics Data System (ADS)

    Ruangchan, S.; Oonsiri, S.; Suriyapee, S.

    2016-03-01

    The development of pre-treatment QA tools contributes to the three dimension (3D) dose verification using the calculation software with the measured planar dose distribution. This research is aimed to evaluate the Sun Nuclear 3DVH software with Thermo luminescence dosimeter (TLD) measurement. The two VMAT patient plans (2.5 arcs) of 6 MV photons with different PTV locations were transferred to the Rando phantom images. The PTV of the first plan located in homogeneous area and vice versa in the second plan. For treatment planning process, the Rando phantom images were employed in optimization and calculation with the PTV, brain stem, lens and TLD position contouring. The verification plans were created, transferred to the ArcCHECK for measurement and calculated the 3D dose using 3DVH software. The range of the percent dose differences in both PTV and organ at risk (OAR) between TLD and 3DVH software of the first and the second plans were -2.09 to 3.87% and -1.39 to 6.88%, respectively. The mean percent dose differences for the PTV were 1.62% and 3.93% for the first and the second plans, respectively. In conclusion, the 3DVH software results show good agreement with TLD when the tumor located in the homogeneous area.

  18. Echocardiographic Evaluation of Coronary Abnormalities and Cardiac Function in a Murine Model of Kawasaki Disease Using High-frequency Ultrasound.

    PubMed

    Zhang, Xin-Xin; Du, Zhong-Dong; Wen, Shang-Guan; Sun, Xiu-Ping

    2017-06-20

    Murine model of coronary arterial inflammation has been widely accepted as an animal model of and used in Kawasaki disease (KD). This study sought to evaluate the developmental changes of coronary arteries and cardiac function in a murine model of KD with a high-frequency ultrasound system and to provide evidence for the preparation of the model of KD. Lactobacillus casei cell wall extract was prepared and injected into C57BL/6 mice intraperitoneally (i.p.) to induce KD. A total of 120 mice were grouped into three groups. The intravenous immunoglobulin (IVIG) treatment group was i.p. injected with IVIG (2 g/kg), while the KD model and normal control groups were i.p. injected with 0.5 ml of phosphate buffered solution on day 5. All high-resolution echocardiography detection of mouse heart was performed by the same senior technician. Animal echocardiography was performed by measuring the coronary artery dimensions and cardiac function on days 0, 7, 14, 28, and 56 (high-resolution small animal ultrasound [Vevo770 pattern; VisualSonic, Canada] with broadband probe [RMVTM707B; frequency, 30 mHz; depth of focus, 1.2 cm]) which were measured and analyzed with Vevo770 software. Pathological studies revealed focal inflammatory infiltrate asymmetrically distributed around the coronary artery trunk in the KD model group. Echocardiographic study including coronary dimension and cardiac function measurements was successfully performed in all subjects. The KD model and IVIG treatment groups showed left coronary artery dilation on days 7, 14, 28, and 56. The diameter of left coronary artery in the KD model group (0.53 ± 0.09 mm; 0.36 ± 0.07 mm; 0.34 ± 0.05 mm; 0.34 ± 0.04 mm) was significantly larger than those of IVIG treatment group (0.22 ± 0.02 mm; 0.28 ± 0.03 mm; 0.26 ± 0.03 mm; 0.27 ± 0.05 mm; 0.26 ± 0.03 mm; all P < 0.01) and the normal control group (0.21 ± 0.02 mm; 0.22 ± 0.03 mm; 0.22 ± 0.02 mm; 0.23 ± 0.02 mm; 0.27 ± 0.04 mm; all P< 0.01) on days 7, 14, 28

  19. Evaluation of RSA set-up from a clinical biplane fluoroscopy system for 3D joint kinematic analysis

    PubMed Central

    BONANZINGA, TOMMASO; SIGNORELLI, CECILIA; BONTEMPI, MARCO; RUSSO, ALESSANDRO; ZAFFAGNINI, STEFANO; MARCACCI, MAURILIO; BRAGONZONI, LAURA

    2016-01-01

    Purpose dinamic roentgen stereophotogrammetric analysis (RSA), a technique currently based only on customized radiographic equipment, has been shown to be a very accurate method for detecting three-dimensional (3D) joint motion. The aim of the present work was to evaluate the applicability of an innovative RSA set-up for in vivo knee kinematic analysis, using a biplane fluoroscopic image system. To this end, the Authors describe the set-up as well as a possible protocol for clinical knee joint evaluation. The accuracy of the kinematic measurements is assessed. Methods the Authors evaluated the accuracy of 3D kinematic analysis of the knee in a new RSA set-up, based on a commercial biplane fluoroscopy system integrated into the clinical environment. The study was organized in three main phases: an in vitro test under static conditions, an in vitro test under dynamic conditions reproducing a flexion-extension range of motion (ROM), and an in vivo analysis of the flexion-extension ROM. For each test, the following were calculated, as an indication of the tracking accuracy: mean, minimum, maximum values and standard deviation of the error of rigid body fitting. Results in terms of rigid body fitting, in vivo test errors were found to be 0.10±0.05 mm. Phantom tests in static and kinematic conditions showed precision levels, for translations and rotations, of below 0.1 mm/0.2° and below 0.5 mm/0.3° respectively for all directions. Conclusions the results of this study suggest that kinematic RSA can be successfully performed using a standard clinical biplane fluoroscopy system for the acquisition of slow movements of the lower limb. Clinical relevance a kinematic RSA set-up using a clinical biplane fluoroscopy system is potentially applicable and provides a useful method for obtaining better characterization of joint biomechanics. PMID:27602352

  20. Evaluating integration of inland bathymetry in the U.S. Geological Survey 3D Elevation Program, 2014

    USGS Publications Warehouse

    Miller-Corbett, Cynthia

    2016-09-01

    Inland bathymetry survey collections, survey data types, features, sources, availability, and the effort required to integrate inland bathymetric data into the U.S. Geological Survey 3D Elevation Program are assessed to help determine the feasibility of integrating three-dimensional water feature elevation data into The National Map. Available data from wading, acoustic, light detection and ranging, and combined technique surveys are provided by the U.S. Geological Survey, National Oceanic and Atmospheric Administration, U.S. Army Corps of Engineers, and other sources. Inland bathymetric data accessed through Web-hosted resources or contacts provide useful baseline parameters for evaluating survey types and techniques used for collection and processing, and serve as a basis for comparing survey methods and the quality of results. Historically, boat-mounted acoustic surveys have provided most inland bathymetry data. Light detection and ranging techniques that are beneficial in areas hard to reach by boat, that can collect dense data in shallow water to provide comprehensive coverage, and that can be cost effective for surveying large areas with good water clarity are becoming more common; however, optimal conditions and techniques for collecting and processing light detection and ranging inland bathymetry surveys are not yet well defined.Assessment of site condition parameters important for understanding inland bathymetry survey issues and results, and an evaluation of existing inland bathymetry survey coverage are proposed as steps to develop criteria for implementing a useful and successful inland bathymetry survey plan in the 3D Elevation Program. These survey parameters would also serve as input for an inland bathymetry survey data baseline. Integration and interpolation techniques are important factors to consider in developing a robust plan; however, available survey data are usually in a triangulated irregular network format or other format compatible with

  1. A wellness platform for stereoscopic 3D video systems using EEG-based visual discomfort evaluation technology.

    PubMed

    Kang, Min-Koo; Cho, Hohyun; Park, Han-Mu; Jun, Sung Chan; Yoon, Kuk-Jin

    2017-07-01

    Recent advances in three-dimensional (3D) video technology have extended the range of our experience while providing various 3D applications to our everyday life. Nevertheless, the so-called visual discomfort (VD) problem inevitably degrades the quality of experience in stereoscopic 3D (S3D) displays. Meanwhile, electroencephalography (EEG) has been regarded as one of the most promising brain imaging modalities in the field of cognitive neuroscience. In an effort to facilitate comfort with S3D displays, we propose a new wellness platform using EEG. We first reveal features in EEG signals that are applicable to practical S3D video systems as an index for VD perception. We then develop a framework that can automatically determine severe perception of VD based on the EEG features during S3D video viewing by capitalizing on machine-learning-based braincomputer interface technology. The proposed platform can cooperate with advanced S3D video systems whose stereo baseline is adjustable. Thus, the optimal S3D content can be reconstructed according to a viewer's sensation of VD. Applications of the proposed platform to various S3D industries are suggested, and further technical challenges are discussed for follow-up research.

  2. Evaluation of a 3D local multiresolution algorithm for the correction of partial volume effects in positron emission tomography.

    PubMed

    Le Pogam, Adrien; Hatt, Mathieu; Descourt, Patrice; Boussion, Nicolas; Tsoumpas, Charalampos; Turkheimer, Federico E; Prunier-Aesch, Caroline; Baulieu, Jean-Louis; Guilloteau, Denis; Visvikis, Dimitris

    2011-09-01

    Partial volume effects (PVEs) are consequences of the limited spatial resolution in emission tomography leading to underestimation of uptake in tissues of size similar to the point spread function (PSF) of the scanner as well as activity spillover between adjacent structures. Among PVE correction methodologies, a voxel-wise mutual multiresolution analysis (MMA) was recently introduced. MMA is based on the extraction and transformation of high resolution details from an anatomical image (MR/CT) and their subsequent incorporation into a low-resolution PET image using wavelet decompositions. Although this method allows creating PVE corrected images, it is based on a 2D global correlation model, which may introduce artifacts in regions where no significant correlation exists between anatomical and functional details. A new model was designed to overcome these two issues (2D only and global correlation) using a 3D wavelet decomposition process combined with a local analysis. The algorithm was evaluated on synthetic, simulated and patient images, and its performance was compared to the original approach as well as the geometric transfer matrix (GTM) method. Quantitative performance was similar to the 2D global model and GTM in correlated cases. In cases where mismatches between anatomical and functional information were present, the new model outperformed the 2D global approach, avoiding artifacts and significantly improving quality of the corrected images and their quantitative accuracy. A new 3D local model was proposed for a voxel-wise PVE correction based on the original mutual multiresolution analysis approach. Its evaluation demonstrated an improved and more robust qualitative and quantitative accuracy compared to the original MMA methodology, particularly in the absence of full correlation between anatomical and functional information.

  3. Evaluation of a 3D local multiresolution algorithm for the correction of partial volume effects in positron emission tomography

    PubMed Central

    Le Pogam, Adrien; Hatt, Mathieu; Descourt, Patrice; Boussion, Nicolas; Tsoumpas, Charalampos; Turkheimer, Federico E.; Prunier-Aesch, Caroline; Baulieu, Jean-Louis; Guilloteau, Denis; Visvikis, Dimitris

    2011-01-01

    Purpose Partial volume effects (PVE) are consequences of the limited spatial resolution in emission tomography leading to under-estimation of uptake in tissues of size similar to the point spread function (PSF) of the scanner as well as activity spillover between adjacent structures. Among PVE correction methodologies, a voxel-wise mutual multi-resolution analysis (MMA) was recently introduced. MMA is based on the extraction and transformation of high resolution details from an anatomical image (MR/CT) and their subsequent incorporation into a low resolution PET image using wavelet decompositions. Although this method allows creating PVE corrected images, it is based on a 2D global correlation model which may introduce artefacts in regions where no significant correlation exists between anatomical and functional details. Methods A new model was designed to overcome these two issues (2D only and global correlation) using a 3D wavelet decomposition process combined with a local analysis. The algorithm was evaluated on synthetic, simulated and patient images, and its performance was compared to the original approach as well as the geometric transfer matrix (GTM) method. Results Quantitative performance was similar to the 2D global model and GTM in correlated cases. In cases where mismatches between anatomical and functional information were present the new model outperformed the 2D global approach, avoiding artefacts and significantly improving quality of the corrected images and their quantitative accuracy. Conclusions A new 3D local model was proposed for a voxel-wise PVE correction based on the original mutual multi-resolution analysis approach. Its evaluation demonstrated an improved and more robust qualitative and quantitative accuracy compared to the original MMA methodology, particularly in the absence of full correlation between anatomical and functional information. PMID:21978037

  4. Evaluation of the Accuracy of a 3D Surface Imaging System for Patient Setup in Head and Neck Cancer Radiotherapy

    SciTech Connect

    Gopan, Olga; Wu Qiuwen

    2012-10-01

    Purpose: To evaluate the accuracy of three-dimensional (3D) surface imaging system (AlignRT) registration algorithms for head-and-neck cancer patient setup during radiotherapy. Methods and Materials: Eleven patients, each undergoing six repeated weekly helical computed tomography (CT) scans during treatment course (total 77 CTs including planning CT), were included in the study. Patient surface images used in AlignRT registration were not captured by the 3D cameras; instead, they were derived from skin contours from these CTs, thereby eliminating issues with immobilization masks. The results from surface registrations in AlignRT based on CT skin contours were compared to those based on bony anatomy registrations in Pinnacle{sup 3}, which was considered the gold standard. Both rigid and nonrigid types of setup errors were analyzed, and the effect of tumor shrinkage was investigated. Results: The maximum registration errors in AlignRT were 0.2 Degree-Sign for rotations and 0.7 mm for translations in all directions. The rigid alignment accuracy in the head region when applied to actual patient data was 1.1 Degree-Sign , 0.8 Degree-Sign , and 2.2 Degree-Sign in rotation and 4.5, 2.7, and 2.4 mm in translation along the vertical, longitudinal, and lateral axes at 90% confidence level. The accuracy was affected by the patient's weight loss during treatment course, which was patient specific. Selectively choosing surface regions improved registration accuracy. The discrepancy for nonrigid registration was much larger at 1.9 Degree-Sign , 2.4 Degree-Sign , and 4.5 Degree-Sign and 10.1, 11.9, and 6.9 mm at 90% confidence level. Conclusions: The 3D surface imaging system is capable of detecting rigid setup errors with good accuracy for head-and-neck cancer. Further investigations are needed to improve the accuracy in detecting nonrigid setup errors.

  5. Prospective trial of breast MRI versus 2D and 3D ultrasound for evaluation of response to neoadjuvant chemotherapy.

    PubMed

    Lee, Marie Catherine; Gonzalez, Segundo Jaime; Lin, Huiyi; Zhao, Xiuhua; Kiluk, John V; Laronga, Christine; Mooney, Blaise

    2015-09-01

    Preoperative imaging to assess response to neoadjuvant chemotherapy in breast cancer is routine but no single imaging modality is standard of practice. Our hypothesis is that ultrasound (US) is comparable to magnetic resonance imaging (MRI) in the prediction of residual disease. A single-institution, Institutional Review Board-approved prospective trial of primary invasive ductal breast cancer patients receiving neoadjuvant chemotherapy enrolled women from 2008 to 2012. Two-dimensional (2D) and three-dimensional (3D) US, as well as MRI images of pre- and post-neoadjuvant tumors were obtained. Skin involvement or inadequate images were excluded. Residual tumor on imaging was compared with surgical pathology. Differences of tumor volume on imaging and pathology were compared using the non-parametric Wilcoxon signed-rank test. US to MRI agreement was determined by the kappa coefficient. Tumor volumes in estrogen receptor (ER), progesterone receptor (PR), and Her2neu subgroups were compared using the Kruskal-Wallis test. ER/PR staining <5 % was considered negative; Her2neu status was determined by in situ hybridization. Forty-two patients were enrolled in the study; 39 had evaluable post-treatment data. Four patients were Her2neu positive, and 17 (46 %) patients had triple-negative tumors. Among 11 (28 %) patients with pathologic complete response (pCR), US correctly predicted pCR in six (54.5 %) patients compared with eight (72.7 %) patients when MRI was used. This is a substantial agreement between US and MRI in predicting pCR (kappa = 0.62). There was no difference between 2D and 3D US modalities. For the 39 patients, US and MRI had no significant difference in volume estimation of pathology, even stratified by receptor status. The estimation of residual breast tumor volume by US and MRI achieves similar results, including prediction of pCR.

  6. IMRT vs. 3D Noncoplanar Treatment Plans for Maxillary Sinus Tumors: A New Tool for Quantitative Evaluation

    SciTech Connect

    Levin, Daphne Menhel, Janna; Alezra, Dror; Pfeffer, Raphael

    2008-01-01

    We compared 9-field, equispaced intensity modulated radiation therapy (IMRT), 4- to 5-field, directionally optimized IMRT, and 3-dimensional (3D) noncoplanar planning approaches for tumors of the maxillary sinus. Ten patients were planned retrospectively to compare the different treatment techniques. Prescription doses were 60 to 70 Gy. Critical structures contoured included optic nerves and chiasm, lacrimal glands, lenses, and retinas. As an aid for plan assessment, we introduced a new tool: Critical Organ Scoring Index (COSI), which allows quantitative evaluation of the tradeoffs between target coverage and critical organ sparing. This index was compared with other, commonly used conformity indices. For a reliable assessment of both tumor coverage and dose to critical organs in the different planning techniques, we introduced a 2D, graphical representation of COSI vs. conformity index (CI). Dose-volume histograms and mean, maximum, and minimum organ doses were also compared. IMRT plans delivered lower doses to ipsilateral structures, but were unable to spare them. 3D plans delivered less dose to contralateral structures, and were more homogeneous, as well. Both IMRT approaches gave similar results. In cases where choice of optimal plan was difficult, the novel 2D COSI-CI representation gave an accurate picture of the tradeoffs between target coverage and organ sparing, even in cases where other conformity indices failed. Due to their unique anatomy, maxillary sinus tumors may benefit more from a noncoplanar approach than from IMRT. The new graphical representation proposed is a quick, visual, reliable tool, which may facilitate the physician's choice of best treatment plan for a given patient.

  7. Tibial component considerations in bicruciate-retaining total knee arthroplasty: A 3D MRI evaluation of proximal tibial anatomy.

    PubMed

    Saxena, Vishal; Anari, Jason B; Ruutiainen, Alexander T; Voleti, Pramod B; Stephenson, Jason W; Lee, Gwo-Chin

    2016-08-01

    Restoration of normal anatomy and proper ligament balance are theoretical prerequisites for reproducing physiological kinematics with bicruciate-retaining total knee arthroplasty (TKA). The purpose of this study was to use a 3D MRI technique to evaluate the topography of the proximal tibia and outline considerations in tibial component design for bicruciate-retaining TKA. We identified 100 consecutive patients (50 males and 50 females) between ages 20 and 40 years with knee MRIs without arthritis, dysplasia, ACL tears, or prior knee surgery. A novel 3D MRI protocol coordinating axial, coronal, and sagittal images was used to measure: 1) medial and lateral posterior tibial slopes; 2) medial and lateral coronal slopes; and 3) distance from the anterior tibia to the ACL footprint. There was no overall difference in medial and lateral posterior tibial slopes (5.5° (95% CI 5.0 to 6.0°) vs. 5.4° (95% CI 4.8 to 6.0°), respectively (p=0.80)), but 41 patients had side-to-side differences greater than 3°. The medial coronal slope was greater than the lateral coronal slope (4.6° (95% CI 4.0 to 5.1°) vs. 3.3° (95% CI 2.9 to 3.7°), respectively (p<0.0001)). Females had less clearance between the anterior tibia and ACL footprint than males (10.8mm (95% CI 10.4 to 11.2mm) vs. 13.0mm (95% CI 12.5 to 13.5mm), respectively (p<0.0001)). Due to highly variable proximal tibial topography, a monoblock bicruciate-retaining tibial baseplate may not reproduce normal anatomy in all patients. Level IV - Anatomic research study. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Evaluation of sub-voxel registration accuracy between MRI and 3D MR spectroscopy of the brain

    NASA Astrophysics Data System (ADS)

    Rousseau, Francois; Maudsley, Andrew; Ebel, Andreas; Darkazanli, Ammar; Weber, Patrice; Sivasankaran, Krishnakumar; Yu, Yingjian; Studholme, Colin

    2005-04-01

    The implementation of Magnetic Resonance Spectroscopic Imaging (MRSI) for diagnostic imaging benefits from close integration of the lower-spatial resolution MRSI information with information from high-resolution structural MRI. Since patients can commonly move between acquisitions, it is necessary to account for possible mis-registration between the datasets arising from differences in patient positioning. In this paper we evaluate the use of 4 common multi-modality registration criteria to recover alignment between high resolution structural MRI and 3D MRSI data of the brain with sub-voxel accuracy. We explore the use of alternative MRSI water reference images to provide different types of structural information for the alignment process. The alignment accuracy was evaluated using both synthetically created MRSI and MRI data and a set of carefully collected subject image data with known ground truth spatial transformation between image volumes. The final accuracy and precision of estimates were assessed using multiple random starts of the registration algorithm. Sub voxel accuracy was found by all four similarity criteria with normalized mutual information providing the lowest target registration error for the 7 subject images. This effort supports the ongoing development of a database of brain metabolite distributions in normal subjects, which will be used in the evaluation of metabolic changes in neurological diseases.

  9. A zero-footprint 3D visualization system utilizing mobile display technology for timely evaluation of stroke patients

    NASA Astrophysics Data System (ADS)

    Park, Young Woo; Guo, Bing; Mogensen, Monique; Wang, Kevin; Law, Meng; Liu, Brent

    2010-03-01

    When a patient is accepted in the emergency room suspected of stroke, time is of the utmost importance. The infarct brain area suffers irreparable damage as soon as three hours after the onset of stroke symptoms. A CT scan is one of standard first line of investigations with imaging and is crucial to identify and properly triage stroke cases. The availability of an expert Radiologist in the emergency environment to diagnose the stroke patient in a timely manner only increases the challenges within the clinical workflow. Therefore, a truly zero-footprint web-based system with powerful advanced visualization tools for volumetric imaging including 2D. MIP/MPR, 3D display can greatly facilitate this dynamic clinical workflow for stroke patients. Together with mobile technology, the proper visualization tools can be delivered at the point of decision anywhere and anytime. We will present a small pilot project to evaluate the use of mobile technologies using devices such as iPhones in evaluating stroke patients. The results of the evaluation as well as any challenges in setting up the system will also be discussed.

  10. Ventricular-arterial uncoupling in heart failure with preserved ejection fraction after myocardial infarction in dogs - invasive versus echocardiographic evaluation.

    PubMed

    Mathieu, Myrielle; El Oumeiri, Bachar; Touihri, Karim; Hadad, Ielham; Mahmoudabady, Maryam; Thoma, Philippe; Metens, Thierry; Bartunek, Jozef; Heyndrickx, Guy R; Brimioulle, Serge; Naeije, Robert; Mc Entee, Kathleen

    2010-06-29

    Heart failure with preserved left ventricular ejection fraction and abnormal diastolic function is commonly observed after recovery from an acute myocardial infarction. The aim of this study was to investigate the physiopathology of heart failure with preserved ejection fraction in a model of healed myocardial infarction in dogs. Echocardiography, levels of neurohormones and conductance catheter measurements of left ventricular pressure-volume relationships were obtained in 17 beagle dogs 2 months after a coronary artery ligation, and in 6 controls. Healed myocardial infarction was associated with preserved echocardiographic left ventricular ejection fraction (0.57 +/- 0.01, mean +/- SEM) and altered Doppler mitral indices of diastolic function. NT-proBNP was increased, aldosterone was decreased, and norepinephrine was unchanged. Invasive measurements showed a markedly decreased end-systolic elastance (2.1 +/- 0.2 vs 6.1 +/- 0.8, mmHg/ml, p < 0.001) and end-systolic elastance to effective arterial elastance ratio (0.6 +/- 0.1 vs 1.4 +/- 0.2, p < 0.001), with altered active relaxation (dP/dtmin -1992 +/- 71 vs -2821 +/- 305, mmHg/s, p < 0.01) but preserved left ventricular capacitance (70 +/- 6 vs 61 +/- 3, ml at 20 mmHg, p = NS) and stiffness constant. Among echocardiographic variables, the wall motion score index was the most reliable indicator of cardiac contractility while E', E/A and E'/A' were correlated to dP/dtmin. In the canine model of healed myocardial infarction induced by coronary ligation, heart failure is essentially characterized by an altered contractility with left ventricular-arterial uncoupling despite vascular compensation rather than by abnormal diastolic function.

  11. Ventricular-arterial uncoupling in heart failure with preserved ejection fraction after myocardial infarction in dogs - invasive versus echocardiographic evaluation

    PubMed Central

    2010-01-01

    Background Heart failure with preserved left ventricular ejection fraction and abnormal diastolic function is commonly observed after recovery from an acute myocardial infarction. The aim of this study was to investigate the physiopathology of heart failure with preserved ejection fraction in a model of healed myocardial infarction in dogs. Methods Echocardiography, levels of neurohormones and conductance catheter measurements of left ventricular pressure-volume relationships were obtained in 17 beagle dogs 2 months after a coronary artery ligation, and in 6 controls. Results Healed myocardial infarction was associated with preserved echocardiographic left ventricular ejection fraction (0.57 ± 0.01, mean ± SEM) and altered Doppler mitral indices of diastolic function. NT-proBNP was increased, aldosterone was decreased, and norepinephrine was unchanged. Invasive measurements showed a markedly decreased end-systolic elastance (2.1 ± 0.2 vs 6.1 ± 0.8, mmHg/ml, p < 0.001) and end-systolic elastance to effective arterial elastance ratio (0.6 ± 0.1 vs 1.4 ± 0.2, p < 0.001), with altered active relaxation (dP/dtmin -1992 ± 71 vs -2821 ± 305, mmHg/s, p < 0.01) but preserved left ventricular capacitance (70 ± 6 vs 61 ± 3, ml at 20 mmHg, p = NS) and stiffness constant. Among echocardiographic variables, the wall motion score index was the most reliable indicator of cardiac contractility while E', E/A and E'/A' were correlated to dP/dtmin. Conclusions In the canine model of healed myocardial infarction induced by coronary ligation, heart failure is essentially characterized by an altered contractility with left ventricular-arterial uncoupling despite vascular compensation rather than by abnormal diastolic function PMID:20587034

  12. Targeted Echocardiographic Screening for Latent Rheumatic Heart Disease in Northern Uganda: Evaluating Familial Risk Following Identification of an Index Case

    PubMed Central

    Aliku, Twalib; Sable, Craig; Scheel, Amy; Tompsett, Alison; Lwabi, Peter; Okello, Emmy; McCarter, Robert; Summar, Marshall; Beaton, Andrea

    2016-01-01

    Background Echocardiographic screening for detection of latent RHD has shown potential as a strategy to decrease the burden of disease. However, further research is needed to determine optimal implementation strategies. RHD results from a complex interplay between environment and host susceptibility. Family members share both and relatives of children with latent RHD may represent a high-risk group. The objective of this study was to use echocardiographic family screening to determine the relative risk of RHD among first-degree relatives of children with latent RHD compared to the risk in first-degree relatives of healthy peers. Methodology/Principal Findings Previous school-based screening data were used to identify RHD positive children and RHD negative peers. All first-degree relatives ≥ 5 years were invited for echocardiography screening (2012 World Heart Federation Criteria). Sixty RHD positive cases (30 borderline/30 definite RHD) and 67 RHD negative cases were recruited. A total of 455/667 (68%) family members were screened. Definite RHD was more common in childhood siblings of RHD positive compared to RHD negative (p = 0.05). Children with any RHD were 4.5 times as likely to have a sibling with definite RHD, a risk that increased to 5.6 times when considering only cases with definite RHD. Mothers of RHD positive and RHD negative cases had an unexpectedly high rate of latent RHD (9.3%). Conclusions/Significance Siblings of RHD positive cases with RHD are more likely to have definite RHD and the relative risk is highest if the index case has definite RHD. Future screening programs should consider implementation of sibling screening following detection of an RHD positive child. Larger screening studies of adults are needed, as data on prevalence of latent RHD outside of childhood are sparse. Future studies should prioritize implementation research to answer questions of how RHD screening can best be integrated into existing healthcare structures, ensuring

  13. Three-dimensional echocardiographic virtual endoscopy for the diagnosis of congenital heart disease in children.

    PubMed

    Xue, Haihong; Sun, Kun; Yu, Jianguo; Chen, Binjin; Chen, Guozhen; Hong, Wenjing; Yao, Liping; Wu, Lanping

    2010-12-01

    Virtual endoscopy (VE) is a new post-processing method that uses volumetric data sets to simulate the tracks of a "conventional" flexible endoscope. However, almost all studies of this method have involved virtual visualizations of the cardiovascular structures applied to computed tomography (CT) and magnetic resonance (MR) datasets. This paper introduces a novel visualization method called the "three-dimensional echocardiographic intracardiac endoscopic simulation system (3DE IESS)", which uses 3D echocardiographic images in a virtual reality (VR) environment to diagnose congenital heart disease. The aim of this study was to analyze the feasibility of VE in the evaluation of congenital heart disease in children and its accuracy compared with 2DE. Three experienced pediatric cardiologists blinded to the patients' diagnoses separately reviewed 40 two-dimensional echocardiographic (2DE) datasets and 40 corresponding VE datasets and judged whether abnormal intracardiac anatomy was present in terms of a five-point scale (1 = definitely absent; 2 = probably absent; 3 = cannot be determined; 4 = probably present; and 5 = definitely present). Compared with clinical diagnosis, the diagnostic accuracy of VE was 98.7% for ASD, 92.4% for VSD, 92.6% for TOF, and 94% for DORV, respectively. Diagnostic accuracy of VE was significantly higher than that of 2DE for TOF and DORV except for ASD and VSD. The receiver operating characteristic (ROC) curve for VE was closer to the optimal performance point than was the ROC curve for 2DE. The area under the ROC curve was 0.96 for VE and 0.93 for 2DE. Kappa values (range, 0.73-0.79) for VE and 2DE indicated substantial agreement. 3D echocardiographic VE can enhance our understanding of intracardiac structures and facilitate the evaluation of congenital heart disease.

  14. Three-dimensional echocardiographic virtual endoscopy for the diagnosis of congenital heart disease in children

    PubMed Central

    Xue, Haihong; Yu, Jianguo; Chen, Binjin; Chen, Guozhen; Hong, Wenjing; Yao, Liping; Wu, Lanping

    2010-01-01

    Virtual endoscopy (VE) is a new post-processing method that uses volumetric data sets to simulate the tracks of a “conventional” flexible endoscope. However, almost all studies of this method have involved virtual visualizations of the cardiovascular structures applied to computed tomography (CT) and magnetic resonance (MR) datasets. This paper introduces a novel visualization method called the “three-dimensional echocardiographic intracardiac endoscopic simulation system (3DE IESS)”, which uses 3D echocardiographic images in a virtual reality (VR) environment to diagnose congenital heart disease. The aim of this study was to analyze the feasibility of VE in the evaluation of congenital heart disease in children and its accuracy compared with 2DE. Three experienced pediatric cardiologists blinded to the patients’ diagnoses separately reviewed 40 two-dimensional echocardiographic (2DE) datasets and 40 corresponding VE datasets and judged whether abnormal intracardiac anatomy was present in terms of a five-point scale (1 = definitely absent; 2 = probably absent; 3 = cannot be determined; 4 = probably present; and 5 = definitely present). Compared with clinical diagnosis, the diagnostic accuracy of VE was 98.7% for ASD, 92.4% for VSD, 92.6% for TOF, and 94% for DORV, respectively. Diagnostic accuracy of VE was significantly higher than that of 2DE for TOF and DORV except for ASD and VSD. The receiver operating characteristic (ROC) curve for VE was closer to the optimal performance point than was the ROC curve for 2DE. The area under the ROC curve was 0.96 for VE and 0.93 for 2DE. Kappa values (range, 0.73–0.79) for VE and 2DE indicated substantial agreement. 3D echocardiographic VE can enhance our understanding of intracardiac structures and facilitate the evaluation of congenital heart disease. PMID:20535561

  15. Evaluation of the Effectiveness of 3D Vascular Stereoscopic Models in Anatomy Instruction for First Year Medical Students

    ERIC Educational Resources Information Center

    Cui, Dongmei; Wilson, Timothy D.; Rockhold, Robin W.; Lehman, Michael N.; Lynch, James C.

    2017-01-01

    The head and neck region is one of the most complex areas featured in the medical gross anatomy curriculum. The effectiveness of using three-dimensional (3D) models to teach anatomy is a topic of much discussion in medical education research. However, the use of 3D stereoscopic models of the head and neck circulation in anatomy education has not…

  16. Evaluation of the Effectiveness of 3D Vascular Stereoscopic Models in Anatomy Instruction for First Year Medical Students

    ERIC Educational Resources Information Center

    Cui, Dongmei; Wilson, Timothy D.; Rockhold, Robin W.; Lehman, Michael N.; Lynch, James C.

    2017-01-01

    The head and neck region is one of the most complex areas featured in the medical gross anatomy curriculum. The effectiveness of using three-dimensional (3D) models to teach anatomy is a topic of much discussion in medical education research. However, the use of 3D stereoscopic models of the head and neck circulation in anatomy education has not…

  17. Digital three-dimensional photogrammetry: evaluation of anthropometric precision and accuracy using a Genex 3D camera system.

    PubMed

    Weinberg, Seth M; Scott, Nicole M; Neiswanger, Katherine; Brandon, Carla A; Marazita, Mary L

    2004-09-01

    To determine the precision and accuracy of facial anthropometric measurements obtained through digital three-dimensional (3D) photogrammetry. Nineteen standard craniofacial measurements were repeatedly obtained on 20 subjects by two independent observers, using calipers and 3D photos (obtained with a Genex 3D camera system), both with and without facial landmarks labeled. Four different precision estimates were then calculated and compared statistically across techniques. In addition, mean measurements from 3D photos were compared statistically with those from direct anthropometry. In terms of measurement precision, the 3D photos were clearly better than direct anthropometry. In almost all cases, the 3D photo with landmarks labeled had the highest overall precision. In addition, labeling landmarks prior to taking measurements improved precision, regardless of method. Good congruence was observed between means derived from the 3D photos and direct anthropometry. Statistically significant differences were noted for seven measurements; however, the magnitude of these differences was often clinically insignificant (< 2 mm). Digital 3D photogrammetry with the Genex camera system is sufficiently precise and accurate for the anthropometric needs of most medical and craniofacial research designs.

  18. An imaging-based platform for high-content, quantitative evaluation of therapeutic response in 3D tumour models

    NASA Astrophysics Data System (ADS)

    Celli, Jonathan P.; Rizvi, Imran; Blanden, Adam R.; Massodi, Iqbal; Glidden, Michael D.; Pogue, Brian W.; Hasan, Tayyaba

    2014-01-01

    While it is increasingly recognized that three-dimensional (3D) cell culture models recapitulate drug responses of human cancers with more fidelity than monolayer cultures, a lack of quantitative analysis methods limit their implementation for reliable and routine assessment of emerging therapies. Here, we introduce an approach based on computational analysis of fluorescence image data to provide high-content readouts of dose-dependent cytotoxicity, growth inhibition, treatment-induced architectural changes and size-dependent response in 3D tumour models. We demonstrate this approach in adherent 3D ovarian and pancreatic multiwell extracellular matrix tumour overlays subjected to a panel of clinically relevant cytotoxic modalities and appropriately designed controls for reliable quantification of fluorescence signal. This streamlined methodology reads out the high density of information embedded in 3D culture systems, while maintaining a level of speed and efficiency traditionally achieved with global colorimetric reporters in order to facilitate broader implementation of 3D tumour models in therapeutic screening.

  19. An imaging-based platform for high-content, quantitative evaluation of therapeutic response in 3D tumour models.

    PubMed

    Celli, Jonathan P; Rizvi, Imran; Blanden, Adam R; Massodi, Iqbal; Glidden, Michael D; Pogue, Brian W; Hasan, Tayyaba

    2014-01-17

    While it is increasingly recognized that three-dimensional (3D) cell culture models recapitulate drug responses of human cancers with more fidelity than monolayer cultures, a lack of quantitative analysis methods limit their implementation for reliable and routine assessment of emerging therapies. Here, we introduce an approach based on computational analysis of fluorescence image data to provide high-content readouts of dose-dependent cytotoxicity, growth inhibition, treatment-induced architectural changes and size-dependent response in 3D tumour models. We demonstrate this approach in adherent 3D ovarian and pancreatic multiwell extracellular matrix tumour overlays subjected to a panel of clinically relevant cytotoxic modalities and appropriately designed controls for reliable quantification of fluorescence signal. This streamlined methodology reads out the high density of information embedded in 3D culture systems, while maintaining a level of speed and efficiency traditionally achieved with global colorimetric reporters in order to facilitate broader implementation of 3D tumour models in therapeutic screening.

  20. CoroEval: a multi-platform, multi-modality tool for the evaluation of 3D coronary vessel reconstructions

    NASA Astrophysics Data System (ADS)

    Schwemmer, C.; Forman, C.; Wetzl, J.; Maier, A.; Hornegger, J.

    2014-09-01

    We present a software, called CoroEval, for the evaluation of 3D coronary vessel reconstructions from clinical data. It runs on multiple operating systems and is designed to be independent of the imaging modality used. At this point, its purpose is the comparison of reconstruction algorithms or acquisition protocols, not the clinical diagnosis. Implemented metrics are vessel sharpness and diameter. All measurements are taken from the raw intensity data to be independent of display windowing functions. The user can either import a vessel centreline segmentation from other software, or perform a manual segmentation in CoroEval. An automated segmentation correction algorithm is provided to improve non-perfect centrelines. With default settings, measurements are taken at 1 mm intervals along the vessel centreline and from 10 different angles at each measurement point. This allows for outlier detection and noise-robust measurements without the burden and subjectivity a manual measurement process would incur. Graphical measurement results can be directly exported to vector or bitmap graphics for integration into scientific publications. Centreline and lumen segmentations can be exported as point clouds and in various mesh formats. We evaluated the diameter measurement process using three phantom datasets. An average deviation of 0.03 ± 0.03 mm was found. The software is available in binary and source code form at http://www5.cs.fau.de/CoroEval/.

  1. An intelligent recovery progress evaluation system for ACL reconstructed subjects using integrated 3-D kinematics and EMG features.

    PubMed

    Malik, Owais A; Senanayake, S M N Arosha; Zaheer, Dansih

    2015-03-01

    An intelligent recovery evaluation system is presented for objective assessment and performance monitoring of anterior cruciate ligament reconstructed (ACL-R) subjects. The system acquires 3-D kinematics of tibiofemoral joint and electromyography (EMG) data from surrounding muscles during various ambulatory and balance testing activities through wireless body-mounted inertial and EMG sensors, respectively. An integrated feature set is generated based on different features extracted from data collected for each activity. The fuzzy clustering and adaptive neuro-fuzzy inference techniques are applied to these integrated feature sets in order to provide different recovery progress assessment indicators (e.g., current stage of recovery, percentage of recovery progress as compared to healthy group, etc.) for ACL-R subjects. The system was trained and tested on data collected from a group of healthy and ACL-R subjects. For recovery stage identification, the average testing accuracy of the system was found above 95% (95-99%) for ambulatory activities and above 80% (80-84%) for balance testing activities. The overall recovery evaluation performed by the proposed system was found consistent with the assessment made by the physiotherapists using standard subjective/objective scores. The validated system can potentially be used as a decision supporting tool by physiatrists, physiotherapists, and clinicians for quantitative rehabilitation analysis of ACL-R subjects in conjunction with the existing recovery monitoring systems.

  2. 3D photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Carson, Jeffrey J. L.; Roumeliotis, Michael; Chaudhary, Govind; Stodilka, Robert Z.; Anastasio, Mark A.

    2010-06-01

    Our group has concentrated on development of a 3D photoacoustic imaging system for biomedical imaging research. The technology employs a sparse parallel detection scheme and specialized reconstruction software to obtain 3D optical images using a single laser pulse. With the technology we have been able to capture 3D movies of translating point targets and rotating line targets. The current limitation of our 3D photoacoustic imaging approach is its inability ability to reconstruct complex objects in the field of view. This is primarily due to the relatively small number of projections used to reconstruct objects. However, in many photoacoustic imaging situations, only a few objects may be present in the field of view and these objects may have very high contrast compared to background. That is, the objects have sparse properties. Therefore, our work had two objectives: (i) to utilize mathematical tools to evaluate 3D photoacoustic imaging performance, and (ii) to test image reconstruction algorithms that prefer sparseness in the reconstructed images. Our approach was to utilize singular value decomposition techniques to study the imaging operator of the system and evaluate the complexity of objects that could potentially be reconstructed. We also compared the performance of two image reconstruction algorithms (algebraic reconstruction and l1-norm techniques) at reconstructing objects of increasing sparseness. We observed that for a 15-element detection scheme, the number of measureable singular vectors representative of the imaging operator was consistent with the demonstrated ability to reconstruct point and line targets in the field of view. We also observed that the l1-norm reconstruction technique, which is known to prefer sparseness in reconstructed images, was superior to the algebraic reconstruction technique. Based on these findings, we concluded (i) that singular value decomposition of the imaging operator provides valuable insight into the capabilities of

  3. Gadolinium enhanced 3D proton density driven equilibrium MR imaging in the evaluation of cisternal tumor and associated structures: comparison with balanced fast-field-echo sequence.

    PubMed

    Ahn, Sung Jun; Yoo, Mi Ri; Suh, Sang Hyun; Lee, Seung-Koo; Lee, Kyu Sung; Son, Eun Jin; Chung, Tae-Sub

    2014-01-01

    Although Gadolinium enhanced bFFE is commonly used to evaluate cisternal tumors, banding artifact may interrupt interpretation and adjacent nerve and vessels differentiation is known to be difficult. We analyzed the qualities of Gd enhanced 3D PDDE in the evaluation of cisternal tumors, comparing with bFFE. Forty five cisternal tumors (33 schwannoma and 12 meningioma) on both bFFE and PDDE were retrospectively reviewed. For quantitative analysis, contrast ratios of CSF to tumor and tumor to parenchyma (CRC/T and CRT/P) on both sequences were compared by paired t-test. For qualitative analysis, the readers gauged the qualities of the two MR sequences with respect to the degree of demarcating cisternal structures (tumor, basilar artery, AICA, trigeminal nerve, facial nerve and vestibulocochlear nerve). In quantitative analysis, CRC/T and CRT/P on 3D PDDE was significantly lower than that of 3D bFFE (p < 0.01). In qualitative analysis, basilar artery, AICA, facial nerve and vestibulocochlear nerves were significantly better demarcated on 3D PDDE than on bFFE (p < 0.01). The degree of demarcation of tumor on 3D PDDE was not significantly different with that on 3D bFFE (p = 0.13). Although the contrast between tumor and the surrounding structures are reduced, Gd enhanced 3D PDDE provides better demarcation of cranial nerves and major vessels adjacent to cisternal tumors than Gd enhanced bFFE.

  4. Evaluation of static pressure drops and PM10 and TSP emissions for modified 1D-3D cyclones

    SciTech Connect

    Holt, G.A.; Baker, R.V.; Hughs, S.E.

    1999-12-01

    Five modifications of a standard 1D3D cyclone were tested and compared against the standard 1D3D design in the areas of particulate emissions and static pressure drop across the cyclone. The modifications to the 1D3D design included a 2D2D inlet, a 2D2D air outlet, a D/3 trash exit, an expansion chamber with a D/3 trash exit, and a tapered air outlet duct. The 1D3D modifications that exhibited a significant improvement in reducing both PM10 and total suspended particulate (TSP) emissions were the designs with the 2D2D inlet and air exhaust combined with either the conical D/3 tail cone or the expansion chamber. In reference to the standard 1D3D cyclone, the average reduction in PM10 emissions was 24 to 29% with a 29 to 35% reduction observed in TSP emissions. The modifications with the tapered air outlets did not show any significant improvements in controlling PM10 emissions. However, the modification with the tapered air outlet/expansion chamber combination exhibited statistical significance in reducing TSP emissions by 18% compared to the 1D3D cyclone. All modifications tested exhibited lower static pressure drops than the standard 1D3D.

  5. BIOMEDICAL - MEDICAL (ECHOCARDIOGRAPH) - JSC

    NASA Image and Video Library

    1987-03-12

    S87-28936 (March 1987) --- The Spacelab Life Sciences-1 (SLS-1) echocardiograph, installed in a science module rack, displays the image of a human heart. One of the objectives on SLS-1 is the investigation of the effects of microgravity on heart size and function.

  6. 3D computed tomographic evaluation of the upper airway space of patients undergoing mandibular distraction osteogenesis for micrognathia.

    PubMed

    Bianchi, A; Betti, E; Badiali, G; Ricotta, F; Marchetti, C; Tarsitano, A

    2015-10-01

    Mandibular distraction osteogenesis (MDO) is currently an accepted method of treatment for patients requiring reconstruction of hypoplastic mandibles. To date one of the unsolved problems is how to assess the quantitative increase of mandible length needed to achieve a significant change in the volume of the posterior airway space (PAS) in children with mandibular micrognathia following distraction osteogenesis. The purpose of this study is to present quantitative volumetric evaluation of PAS in young patients having distraction osteogenesis for micrognathia using 3D-CT data sets and compare it with pre-operative situation. In this observational retrospective study, we report our experience in five consecutive patients who underwent MDO in an attempt to relieve severe upper airway obstruction. Each patient was evaluated before treatment (T0) and at the end of distraction procedure (T1) with computer tomography (CT) in axial, coronal, and sagittal planes and three-dimensional CT of the facial bones and upper airway. Using parameters to extract only data within anatomic constraints, a digital set of the edited upper airway volume was obtained. The volume determination was used for volumetric qualification of upper airway. The computed tomographic digital data were used to evaluate the upper airway volumes both pre-distraction and post-distraction. The mean length of distraction was 23 mm. Quantitative assessment of upper airway volume before and after distraction demonstrated increased volumes ranging from 84% to 3,087% with a mean of 536%. In conclusion, our study seems to show that DO can significantly increase the volume of the PAS in patients with upper airway obstruction following micrognathia, by an average of 5 times. Furthermore, the worse is the starting volume, the greater the increase in PAS to equal distraction.

  7. A 3D reconstruction method of the body envelope from biplanar X-rays: Evaluation of its accuracy and reliability.

    PubMed

    Nérot, Agathe; Choisne, Julie; Amabile, Célia; Travert, Christophe; Pillet, Hélène; Wang, Xuguang; Skalli, Wafa

    2015-12-16

    The aim of this study was to propose a novel method for reconstructing the external body envelope from the low dose biplanar X-rays of a person. The 3D body envelope was obtained by deforming a template to match the surface profiles in two X-rays images in three successive steps: global morphing to adopt the position of a person and scale the template׳s body segments, followed by a gross deformation and a fine deformation using two sets of pre-defined control points. To evaluate the method, a biplanar X-ray acquisition was obtained from head to foot for 12 volunteers in a standing posture. Up to 172 radio-opaque skin markers were attached to the body surface and used as reference positions. Each envelope was reconstructed three times by three operators. Results showed a bias lower than 7mm and a confidence interval (95%) of reproducibility lower than 6mm for all body parts, comparable to other existing methods matching a template onto stereographic photographs. The proposed method offers the possibility of reconstructing body shape in addition to the skeleton using a low dose biplanar X-rays system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Evaluation of cell-surface interaction using a 3D spheroid cell culture model on artificial extracellular matrices.

    PubMed

    Metzger, Wolfgang; Rother, Sandra; Pohlemann, Tim; Möller, Stephanie; Schnabelrauch, Matthias; Hintze, Vera; Scharnweber, Dieter

    2017-04-01

    Since decades, cell-surface interactions are studied in 2D cell culture approaches, but cells organized in 3D (spheroids) reflect the normal situation of cells in tissues much better due to intense cell-cell-contacts. Accordingly, this study aimed to prove, if spheroids could be used to study cell-surface interaction. Spheroids consisting of fibroblasts and/or osteoblasts were seeded on artificial extracellular matrices. Here, non-sulfated hyaluronan as a biological relevant compound of the extracellular matrix was chemically sulfated to different extents and co-fibrillised with collagen. The changes of the spheroid diameters and the migration distance of outgrown cells after seeding on the matrices were used as parameters to evaluate cell-surface interaction quantitatively. Fibroblast-based spheroids reacted in the initial phase of adhesion with different spheroid sizes on the contact with the matrices. In contrast, the reaction of osteoblasts was more pronounced at later time points exhibiting a decrease of the size of the spheroids with increasing sulfation degree of the matrix. The migration of the cells was impaired by increasing sulfation degree, which might be caused by an increased expression of focal adhesion relevant proteins. In summary, spheroids can be used in cell-surface interaction studies and additional analytical tools could be implemented. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. 3D evaluation of the lingual fracture line after a bilateral sagittal split osteotomy of the mandible.

    PubMed

    Plooij, J M; Naphausen, M T P; Maal, T J J; Xi, T; Rangel, F A; Swennnen, G; de Koning, M; Borstlap, W A; Bergé, S J

    2009-12-01

    The purpose of this prospective observational study was to evaluate whether cone beam CT (CBCT) is a useful tool for analyzing the fracture line in a bilateral sagittal split osteotomy (BSSO). The patient group consisted of 40 consecutive patients (9 males and 31 females) with a mandibular hypoplasia who underwent a BSSO advancement (Hunsuck modification; n=80 splits) between September 2006 and July 2008. The mean age at the time of surgery was 34 years (range 17-61 years). A newly developed lingual split scale was used to categorize the path of the fracture line on the lingual side of the ramus based on one-day postoperative data sets reconstructed from CBCT data. Although all splits (n=80) were performed according to the standardized protocol, only 51% of the fracture lines run according to the Hunsuck's description, whereas 33% ran through the mandibular canal and 16% split otherwise. The split pattern was influenced by the length of the medial osteotomy (p=0.01). In conclusion, 3D imaging is a useful tool for analyzing the surgical outcome of a BSSO and has the potential to provide substantial data on the position of the proximal segments as a result of the lingual fracture line.

  10. Genotoxicity of quinolones: substituents contribution and transformation products QSAR evaluation using 2D and 3D models.

    PubMed

    Li, Min; Wei, Dongbin; Zhao, Huimin; Du, Yuguo

    2014-01-01

    The genotoxicity of 21 quinolones antibiotics was determined using SOS/umu assay. Some quinolones exhibited high genotoxicity, and the chemical substituent on quinolone ring significantly affected genotoxicity. To establish the relationship between genotoxicity and substituent, a 2D-QSAR model based on quantum chemical parameters was developed. Calculation suggested that both steric and electrostatic properties were correlated well with genotoxicity. Furthermore, the specific effect on three key active sites (1-, 7- and 8-positions) of quinolone ring was investigated using a 3D-QSAR (comparative molecular field analysis, CoMFA) method. From our modeling, the genotoxicity increased when substituents had: (1) big volume and/or positive charge at 1-position; (2) negative charge at 7-position; and (3) small volume and/or negative charge at 8-position. The developed QSAR models were applicable to estimate genotoxicity of quinolones antibiotics and their transformation products. It is noted that some of the transformation products exhibited higher genotoxicity comparing to their precursor (e.g., ciprofloxacin). This study provided an alternative way to understand the molecule genotoxicity of quinolones derivatives, as well as to evaluate their potential environmental risks.

  11. Evaluation of corrective reconstruction methods using a 3D cardiac-torso phantom and bull's-eye plots

    SciTech Connect

    Zhao, X.D.; Tsui, B.M.W.; Gregoriou, G.K.; Lalush, D.S.; Li, J. ); Eisner, R.L. . Dept. of Radiology)

    1994-12-01

    The goal of the investigation was to study the effectiveness of the corrective reconstruction methods in cardiac SPECT using a realistic phantom and to qualitatively and quantitatively evaluate the reconstructed images using bull's-eye plots. A 3D mathematical phantom which realistically models the anatomical structures of the cardiac-torso region of patients was used. The phantom allows simulation of both the attenuation distribution and the uptake of radiopharmaceuticals in different organs. Also, the phantom can be easily modified to simulate different genders and variations in patient anatomy. Two-dimensional projection data were generated from the phantom and included the effects of attenuation and detector response blurring. The reconstruction methods used in the study included the conventional filtered backprojection (FBP) with no attenuation compensation, and the first-order Chang algorithm, an iterative filtered backprojection algorithm (IFBP), the weighted least square conjugate gradient algorithm and the ML-EM algorithm with non-uniform attenuation compensation. The transaxial reconstructed images were rearranged into short-axis slices from which bull's-eye plots of the count density distribution in the myocardium were generated.

  12. Microfluidic 3D bone tissue model for high-throughput evaluation of wound-healing and infection-preventing biomaterials.

    PubMed

    Lee, Joung-Hyun; Gu, Yexin; Wang, Hongjun; Lee, Woo Y

    2012-02-01

    We report the use of a microfluidic 3D bone tissue model, as a high-throughput means of evaluating the efficacy of biomaterials aimed at accelerating orthopaedic implant-related wound-healing while preventing bacterial infection. As an example of such biomaterials, inkjet-printed micropatterns were prepared to contain antibiotic and biphasic calcium phosphate (BCP) nanoparticles dispersed in a poly(D,L-lactic-co-glycolic) acid matrix. The micropatterns were integrated with a microfluidic device consisting of eight culture chambers. The micropatterns immediately and completely killed Staphylococcus epidermidis upon inoculation, and enhanced the calcified extracellular matrix production of osteoblasts. Without antibiotic elution, bacteria rapidly proliferated to result in an acidic microenvironment which was detrimental to osteoblasts. These results were used to demonstrate the tissue model's potential in: (i) significantly reducing the number of biomaterial samples and culture experiments required to assess in vitro efficacy for wound-healing and infection prevention and (ii) in situ monitoring of dynamic interactions of biomaterials with bacteria as wells as with tissue cells simultaneously.

  13. Long-range atmospheric transport of polycyclic aromatic hydrocarbons: a global 3-D model analysis including evaluation of Arctic sources.

    PubMed

    Friedman, Carey L; Selin, Noelle E

    2012-09-04

    We use the global 3-D chemical transport model GEOS-Chem to simulate long-range atmospheric transport of polycyclic aromatic hydrocarbons (PAHs). To evaluate the model's ability to simulate PAHs with different volatilities, we conduct analyses for phenanthrene (PHE), pyrene (PYR), and benzo[a]pyrene (BaP). GEOS-Chem captures observed seasonal trends with no statistically significant difference between simulated and measured mean annual concentrations. GEOS-Chem also captures variability in observed concentrations at nonurban sites (r = 0.64, 0.72, and 0.74, for PHE, PYR, and BaP). Sensitivity simulations suggest snow/ice scavenging is important for gas-phase PAHs, and on-particle oxidation and temperature-dependency of gas-particle partitioning have greater effects on transport than irreversible partitioning or increased particle concentrations. GEOS-Chem estimates mean atmospheric lifetimes of <1 day for all three PAHs. Though corresponding half-lives are lower than the 2-day screening criterion for international policy action, we simulate concentrations at the high-Arctic station of Spitsbergen within four times observed concentrations with strong correlation (r = 0.70, 0.68, and 0.70 for PHE, PYR, and BaP). European and Russian emissions combined account for ~80% of episodic high-concentration events at Spitsbergen.

  14. Evaluation of the respiratory motion influence in the 3D dose distribution of IMRT breast radiation therapy treatments

    NASA Astrophysics Data System (ADS)

    Lizar, J. C.; Santos, L. F.; Brandão, F. C.; Volpato, K. C.; Guimarães, F. S.; Pavoni, J. F.

    2017-05-01

    This study aims to evaluate the motion influence in the tridimensional dose distribution due to respiratory for IMRT breast planning technique. To simulate the breathing movement an oscillating platform was used. To simulate the breast, MAGIC-f phantoms were used. CT images of a static phantom were obtained and the IMRT treatment was planned based on them. One phantom was irradiated static in the platform and two other phantoms were irradiated while oscillating in the platform with amplitudes of 0.34 cm and 1.22 cm, the fourth phantom was used as reference in the MRI acquisition. The percentage of points approved in the 3D global gamma analyses (3%/3mm) when comparing the dose distribution of the static phantom with the oscillating ones was 91% for the 0.34cm amplitude and 62% for the 1.22 cm amplitude. Considering this result, the differences found in the dosimetric analyses for the oscillating amplitude of 0.34cm could be considered acceptable in a real treatment. The isodose distribution analyses showed a decrease of dose in the anterior breast region and an increase of dose on the posterior breast region, being these differences most pronounced for large amplitude motion.

  15. CAD/CAM-designed 3D-printed electroanalytical cell for the evaluation of nanostructured gas-diffusion electrodes.

    PubMed

    Chervin, Christopher N; Parker, Joseph F; Nelson, Eric S; Rolison, Debra R; Long, Jeffrey W

    2016-04-29

    The ability to effectively screen and validate gas-diffusion electrodes is critical to the development of next-generation metal-air batteries and regenerative fuel cells. The limiting electrode in a classic two-terminal device such as a battery or fuel cell is difficult to discern without an internal reference electrode, but the flooded electrolyte characteristic of three-electrode electroanalytical cells negates the prime function of an air electrode-a void volume freely accessible to gases. The nanostructured catalysts that drive the energy-conversion reactions (e.g., oxygen reduction and evolution in the air electrode of metal-air batteries) are best evaluated in the electrode structure as-used in the practical device. We have designed, 3D-printed, and characterized an air-breathing, thermodynamically referenced electroanalytical cell that allows us to mimic the Janus arrangement of the gas-diffusion electrode in a metal-air cell: one face freely exposed to gases, the other wetted by electrolyte.

  16. CAD/CAM-designed 3D-printed electroanalytical cell for the evaluation of nanostructured gas-diffusion electrodes

    NASA Astrophysics Data System (ADS)

    Chervin, Christopher N.; Parker, Joseph F.; Nelson, Eric S.; Rolison, Debra R.; Long, Jeffrey W.

    2016-04-01

    The ability to effectively screen and validate gas-diffusion electrodes is critical to the development of next-generation metal-air batteries and regenerative fuel cells. The limiting electrode in a classic two-terminal device such as a battery or fuel cell is difficult to discern without an internal reference electrode, but the flooded electrolyte characteristic of three-electrode electroanalytical cells negates the prime function of an air electrode—a void volume freely accessible to gases. The nanostructured catalysts that drive the energy-conversion reactions (e.g., oxygen reduction and evolution in the air electrode of metal-air batteries) are best evaluated in the electrode structure as-used in the practical device. We have designed, 3D-printed, and characterized an air-breathing, thermodynamically referenced electroanalytical cell that allows us to mimic the Janus arrangement of the gas-diffusion electrode in a metal-air cell: one face freely exposed to gases, the other wetted by electrolyte.

  17. 3D Volumetric Evaluation of Lipiodol Retention in HCC after Chemoembolization: A Quantitative Comparison between CBCT and MDCT

    PubMed Central

    Wang, Zhijun; Lin, MingDe; Lesage, David; Chen, Rongxin; Chapiro, Julius; Gu, Tara; Tacher, Vania; Duran, Rafael; Geschwind, Jean-François

    2014-01-01

    Rationale and Objectives To evaluate the capability of cone-beam computed tomography (CBCT) acquired immediately after transcatheter arterial chemoembolization (TACE) in determining Lipiodol retention quantitatively and volumetrically when compared to 1-day post-procedure unenhanced MDCT. Materials and methods From June to December, 2012, fifteen patients met the inclusion criteria of unresectable hepatocellular carcinoma (HCC) that was treated with conventional TACE (cTACE), and had intra-procedural CBCT and 1-day post-TACE MDCT. Four patients were excluded because the Lipiodol was diffuse throughout the entire liver or Lipiodol deposition was not clear on both CBCT and MDCT. Eleven patients with a total of 31 target lesions were included in the analysis. A quantitative and 3D software was used to assess complete, localized and diffuse lipiodol deposition. Tumor volume, Lipiodol volume in the tumor, % Lipiodol retention, and Lipiodol enhancement in Hounsfield Unit (HU) were calculated and compared between CBCT and MDCT using two-tailed student’s t-test and Bland-Altman plots. Results The mean value of tumor volume, Lipiodol deposited regions, calculated average % Lipiodol retention, and HU value of CBCT were not significantly different from those of MDCT (tumor volume: 9.37±11.35cm3 vs. 9.34±11.44cm3, P=0.991; Lipiodol volume: 7.84±9.34cm3 vs. 7.84±9.60 cm3, P=0.998; % Lipiodol retention: 89.3%±14.7% vs. 90.2% ± 14.9%, P=0.811; HU value: 307.7±160.1 HU vs. 257.2±120.0 HU, P=0.139). Bland-Altman plots showed only minimal difference and high agreement when comparing CBCT to MDCT. Conclusion CBCT has a similar capability, intraprocedurally, to assess Lipiodol deposition in 3D for patients with HCC treated with cTACE when compared to MDCT. PMID:24507426

  18. Simulation-Based Evaluation of Light Posts and Street Signs as 3-D Geolocation Targets in SAR Images

    NASA Astrophysics Data System (ADS)

    Auer, S.; Balss, U.

    2017-05-01

    The assignment of phase center positions (in 2D or 3D) derived from SAR data to physical object is challenging for many man-made structures such as buildings or bridges. In contrast, light poles and traffic signs are promising targets for tasks based on 3-D geolocation as they often show a prominent and spatially isolated appearance. For a detailed understanding of the nature of both targets, this paper presents results of a dedicated simulation case study, which is based on ray tracing methods (simulator RaySAR). For the first time, the appearance of the targets is analyzed in 2D (image plane) and 3D space (world coordinates of scene model) and reflecting surfaces are identified for related dominant image pixels. The case studies confirms the crucial impact of spatial resolution in the context of light poles and traffic signs and the appropriateness of light poles as target for 3-D geolocation in case of horizontal ground surfaces beneath.

  19. Evaluating the Use of Cleft Lip and Palate 3D-Printed Models as a Teaching Aid.

    PubMed

    AlAli, Ahmad B; Griffin, Michelle F; Calonge, Wenceslao M; Butler, Peter E

    2017-08-28

    Visualization tools are essential for effective medical education, to aid students understanding of complex anatomical systems. Three dimensional (3D) printed models are showing a wide-reaching potential in the field of medical education, to aid the interpretation of 2D imaging. This study investigates the use of 3D-printed models in educational seminars on cleft lip and palate, by comparing integrated "hands-on" student seminars, with 2D presentation seminar methods. Cleft lip and palate models were manufactured using 3D-printing technology at the medical school. Sixty-seven students from two medical schools participated in the study. The students were randomly allocated to 2 groups. Knowledge was compared between the groups using a multiple-choice question test before and after the teaching intervention. Group 1 was the control group with a PowerPoint presentation-based educational seminar and group 2 was the test group, with the same PowerPoint presentation, but with the addition of a physical demonstration using 3D-printed models of unilateral and bilateral cleft lips and palate. The level of knowledge gained was established using a preseminar and postseminar assessment, in 2 different institutions, where the addition of the 3D-printed model resulted in a significant improvement in the mean percentage of knowledge gained (44.65% test group; 32.16%; control group; p = 0.038). Student experience was assessed using a postseminar survey, where students felt the 3D-printed model significantly improved the learning experience (p = 0.005) and their visualization (p = 0.001). This study highlights the benefits of the use of 3D-printed models as visualization tools in medical education and the potential of 3D-printing technology to become a standard and effective tool in the interpretation of 2D imaging. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  20. Novel, fast and efficient image-based 3D modeling method and its application in fracture risk evaluation.

    PubMed

    Li, Dan; Xiao, Zhitao; Wang, Gang; Zhao, Guoqing

    2014-06-01

    Constructing models based on computed tomography images for finite element analysis (FEA) is challenging under pathological conditions. In the present study, an innovative method was introduced that uses Siemens syngo(®) 3D software for processing models and Mimics software for further modeling. Compared with the slice-by-slice traditional manual margin discrimination, the new 3D modeling method utilizes automatic tissue margin determination and 3D cutting using syngo software. The modeling morphologies of the two methods were similar; however, the 3D modeling method was 8-10 times faster than the traditional method, particularly in cases with osteoporosis and osteophytes. A comparative FEA study of the lumbar spines of young and elderly patients, on the basis of the models constructed by the 3D modeling method, showed peak stress elevation in the vertebrae of elderly patients. Stress distribution was homogeneous in the entire vertebrae of young individuals. By contrast, stress redistribution in the vertebrae of the elderly was concentrated in the anterior cortex of the vertebrae, which explains the high fracture risk mechanism in elderly individuals. In summary, the new 3D modeling method is highly efficient, accurate and faster than traditional methods. The method also allows reliable FEA in pathological cases with osteoporosis and osteophytes.

  1. Novel, fast and efficient image-based 3D modeling method and its application in fracture risk evaluation

    PubMed Central

    LI, DAN; XIAO, ZHITAO; WANG, GANG; ZHAO, GUOQING

    2014-01-01

    Constructing models based on computed tomography images for finite element analysis (FEA) is challenging under pathological conditions. In the present study, an innovative method was introduced that uses Siemens syngo® 3D software for processing models and Mimics software for further modeling. Compared with the slice-by-slice traditional manual margin discrimination, the new 3D modeling method utilizes automatic tissue margin determination and 3D cutting using syngo software. The modeling morphologies of the two methods were similar; however, the 3D modeling method was 8–10 times faster than the traditional method, particularly in cases with osteoporosis and osteophytes. A comparative FEA study of the lumbar spines of young and elderly patients, on the basis of the models constructed by the 3D modeling method, showed peak stress elevation in the vertebrae of elderly patients. Stress distribution was homogeneous in the entire vertebrae of young individuals. By contrast, stress redistribution in the vertebrae of the elderly was concentrated in the anterior cortex of the vertebrae, which explains the high fracture risk mechanism in elderly individuals. In summary, the new 3D modeling method is highly efficient, accurate and faster than traditional methods. The method also allows reliable FEA in pathological cases with osteoporosis and osteophytes. PMID:24926348

  2. [HRV-Spectral analysis of Pain, by 3D Evaluation and by Balance Index in the Pain Rehabilitation Field].

    PubMed

    Goto, Yukio

    2015-07-01

    Pain signaling is achieved by electrical impulses in the body; however, some electrical abnormalities can cause pain in the body without generating any visible symptoms. This phenomenon is sensed by the brain and a signal that may affect cardiac rhythms is immediately transmitted to the heart. To evaluate heart rate variability (HRV), the balance correction between an increase and decrease of heart rate was recorded in real time. Using a special method for spectral-analysis of the HRV, techniques for analyzing the essence of pain were developed, namely, the 'Balance index' and the '3D spectrum evaluation method'. Using these techniques, an alpha wave-like factor or a beta wave-like reaction can be obtained, and the nature and strength of pain can be displayed as spectral zones, as in a rainbow. The balance reaction can be shown by analyzing data in the frequency band using a 1/f-like spectral-analysis method. Additionally, emotional reactions can be detected using a 'Balance index' that can demonstrate imbalance responding to the pain. The mental state of the subject can also be inferred because this technique is adapted from the 1/f fluctuation theory related to the best balanced 1/f-sound wave in nature that comforts the human mind, similar to music (artificial sound wave). In this study, the variety and intensity of pain were determined from the frequency band resulting from the 1/f-spectral analysis of HRV fluctuation. These techniques could explain several situations related to medication or anesthesia and can be helpful in preventative treatment and/or explaining the differences in the effectiveness of various techniques for the rehabilitation of chronic pain.

  3. Long-term evaluation of patients with apical hypertrophic cardiomyopathy. Correlation between quantitative echocardiographic assessment of apical hypertrophy and clinical-electrocardiographic findings.

    PubMed

    Moro, E; D'Angelo, G; Nicolosi, G L; Mimo, R; Zanuttini, D

    1995-02-01

    Apical hypertrophic cardiomyopathy (AHCM) is characterized by primary hypertrophy localized exclusively in the apex of the left ventricle. Previous studies have indicated that AHCM results in a unique combination of cross-sectional echocardiographic (CSE) and ECG findings ('giant' T wave inversion and high R wave voltage in the precordial leads). The aims of this study were: (1) to assess the degree of AHCM in a quantitative fashion (2) to evaluate the possible relationship between apical hypertrophy, quantitatively determined, and ECG findings in patients with AHCM (3) to verify the changes in echocardiographic and ECG parameters over time (4) to define the relationship between the severity of AHCM and the clinical course of such patients. Eleven selected patients with AHCM were studied for an average 6 year follow-up period; there were seven men and four women (age from 18 to 62 years, mean 49). Apical hypertrophy was assessed quantitatively by determining the muscle cross-sectional area in the apical region, which was considered an index of myocardial mass. From the end-diastolic apical four chamber view, endocardial and epicardial contours were digitized in order to obtain the total muscle cross-sectional area of the left ventricle. The walls of the left ventricle were then divided into three regions (basal, intermediate, apical). The final value of each cross-sectional muscle area was obtained from the mean measurements of four independent and blinded observers. In AHCM the apical muscle cross-sectional area (AMA) ranged from 10.3 to 17.9 cm2, mean 13.2 +/- 2.6 cm2.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Effects of exercise training on systo-diastolic ventricular dysfunction in patients with hypertension: an echocardiographic study with tissue velocity and strain imaging evaluation.

    PubMed

    Leggio, Massimo; Mazza, Andrea; Cruciani, Giancarlo; Sgorbini, Luca; Pugliese, Marco; Bendini, Maria Grazia; Severi, Paolo; Jesi, Anna Patrizia

    2014-07-01

    There is a lack of detailed data regarding the effect of exercise training in pharmacologically treated hypertensive patients. Therefore, the aim of this study was to evaluate the effects of exercise training on left and right ventricular morphologic and functional parameters by means of conventional echocardiography and sensitive new echocardiographic techniques including tissue Doppler velocity and strain imaging, that were performed in pharmacologically treated hypertensive patients at baseline and at the end of a specific exercise training protocol for primary prevention of cardiovascular disease. We selected 116 pharmacologically treated hypertensive patients who completed the exercise training protocol. All patients underwent a clinical history and examination; transthoracic echocardiography and exercise testing were performed at baseline and at the end of the exercise training protocol. Conventional echocardiography revealed a mild degree of diastolic dysfunction without significant differences or variations from baseline to the end of the exercise training protocol. In contrast, tissue Doppler velocity and strain imaging measurements demonstrated and highlighted the positive influence of exercise training: for both left and right ventricle myocardial early peak diastolic velocities (Em), the ratio of myocardial early-late peak diastolic velocity (Em/Am), myocardial peak systolic velocities (Sm) and peak strain and strain rate values significantly increased at the end of the exercise training protocol, suggesting a relationship between exercise capacity and both left and right ventricular systo-diastolic function. Our study, by means of newer more sensitive echocardiographic techniques, clearly demonstrated the positive impact of exercise training on both left and right ventricular systo-diastolic function, in terms of adjunctive subclinical improvement, in pharmacologically treated hypertensive patients.

  5. A Fuzzy-Based Fusion Method of Multimodal Sensor-Based Measurements for the Quantitative Evaluation of Eye Fatigue on 3D Displays.

    PubMed

    Bang, Jae Won; Choi, Jong-Suk; Heo, Hwan; Park, Kang Ryoung

    2015-05-07

    With the rapid increase of 3-dimensional (3D) content, considerable research related to the 3D human factor has been undertaken for quantitatively evaluating visual discomfort, including eye fatigue and dizziness, caused by viewing 3D content. Various modalities such as electroencephalograms (EEGs), biomedical signals, and eye responses have been investigated. However, the majority of the previous research has analyzed each modality separately to measure user eye fatigue. This cannot guarantee the credibility of the resulting eye fatigue evaluations. Therefore, we propose a new method for quantitatively evaluating eye fatigue related to 3D content by combining multimodal measurements. This research is novel for the following four reasons: first, for the evaluation of eye fatigue with high credibility on 3D displays, a fuzzy-based fusion method (FBFM) is proposed based on the multimodalities of EEG signals, eye blinking rate (BR), facial temperature (FT), and subjective evaluation (SE); second, to measure a more accurate variation of eye fatigue (before and after watching a 3D display), we obtain the quality scores of EEG signals, eye BR, FT and SE; third, for combining the values of the four modalities we obtain the optimal weights of the EEG signals BR, FT and SE using a fuzzy system based on quality scores; fourth, the quantitative level of the variation of eye fatigue is finally obtained using the weighted sum of the values measured by the four modalities. Experimental results confirm that the effectiveness of the proposed FBFM is greater than other conventional multimodal measurements. Moreover, the credibility of the variations of the eye fatigue using the FBFM before and after watching the 3D display is proven using a t-test and descriptive statistical analysis using effect size.

  6. A Fuzzy-Based Fusion Method of Multimodal Sensor-Based Measurements for the Quantitative Evaluation of Eye Fatigue on 3D Displays

    PubMed Central

    Bang, Jae Won; Choi, Jong-Suk; Heo, Hwan; Park, Kang Ryoung

    2015-01-01

    With the rapid increase of 3-dimensional (3D) content, considerable research related to the 3D human factor has been undertaken for quantitatively evaluating visual discomfort, including eye fatigue and dizziness, caused by viewing 3D content. Various modalities such as electroencephalograms (EEGs), biomedical signals, and eye responses have been investigated. However, the majority of the previous research has analyzed each modality separately to measure user eye fatigue. This cannot guarantee the credibility of the resulting eye fatigue evaluations. Therefore, we propose a new method for quantitatively evaluating eye fatigue related to 3D content by combining multimodal measurements. This research is novel for the following four reasons: first, for the evaluation of eye fatigue with high credibility on 3D displays, a fuzzy-based fusion method (FBFM) is proposed based on the multimodalities of EEG signals, eye blinking rate (BR), facial temperature (FT), and subjective evaluation (SE); second, to measure a more accurate variation of eye fatigue (before and after watching a 3D display), we obtain the quality scores of EEG signals, eye BR, FT and SE; third, for combining the values of the four modalities we obtain the optimal weights of the EEG signals BR, FT and SE using a fuzzy system based on quality scores; fourth, the quantitative level of the variation of eye fatigue is finally obtained using the weighted sum of the values measured by the four modalities. Experimental results confirm that the effectiveness of the proposed FBFM is greater than other conventional multimodal measurements. Moreover, the credibility of the variations of the eye fatigue using the FBFM before and after watching the 3D display is proven using a t-test and descriptive statistical analysis using effect size. PMID:25961382

  7. Evaluation of the effectiveness of 3D vascular stereoscopic models in anatomy instruction for first year medical students.

    PubMed

    Cui, Dongmei; Wilson, Timothy D; Rockhold, Robin W; Lehman, Michael N; Lynch, James C

    2017-01-01

    The head and neck region is one of the most complex areas featured in the medical gross anatomy curriculum. The effectiveness of using three-dimensional (3D) models to teach anatomy is a topic of much discussion in medical education research. However, the use of 3D stereoscopic models of the head and neck circulation in anatomy education has not been previously studied in detail. This study investigated whether 3D stereoscopic models created from computed tomographic angiography (CTA) data were efficacious teaching tools for the head and neck vascular anatomy. The test subjects were first year medical students at the University of Mississippi Medical Center. The assessment tools included: anatomy knowledge tests (prelearning session knowledge test and postlearning session knowledge test), mental rotation tests (spatial ability; presession MRT and postsession MRT), and a satisfaction survey. Results were analyzed using a Wilcoxon rank-sum test and linear regression analysis. A total of 39 first year medical students participated in the study. The results indicated that all students who were exposed to the stereoscopic 3D vascular models in 3D learning sessions increased their ability to correctly identify the head and neck vascular anatomy. Most importantly, for students with low-spatial ability, 3D learning sessions improved postsession knowledge scores to a level comparable to that demonstrated by students with high-spatial ability indicating that the use of 3D stereoscopic models may be particularly valuable to these students with low-spatial ability. Anat Sci Educ 10: 34-45. © 2016 American Association of Anatomists.

  8. A 3D microfluidic model for preclinical evaluation of TCR-engineered T cells against solid tumors.

    PubMed

    Pavesi, Andrea; Tan, Anthony T; Koh, Sarene; Chia, Adeline; Colombo, Marta; Antonecchia, Emanuele; Miccolis, Carlo; Ceccarello, Erica; Adriani, Giulia; Raimondi, Manuela T; Kamm, Roger D; Bertoletti, Antonio

    2017-06-15

    The tumor microenvironment imposes physical and functional constraints on the antitumor efficacy of adoptive T cell immunotherapy. Preclinical testing of different T cell preparations can help in the selection of efficient immune therapies, but in vivo models are expensive and cumbersome to develop, while classical in vitro 2D models cannot recapitulate the spatiotemporal dynamics experienced by T cells targeting cancer. Here, we describe an easily customizable 3D model, in which the tumor microenvironment conditions are modulated and the functionality of different T cell preparations is tested. We incorporate human cancer hepatocytes as a single cell or as tumor cell aggregates in a 3D collagen gel region of a microfluidic device. Human T cells engineered to express tumor-specific T cell receptors (TCR-T cells) are then added in adjacent channels. The TCR-T cells' ability to migrate and kill the tumor target and the profile of soluble factors were investigated under conditions of varying oxygen levels and in the presence of inflammatory cytokines. We show that only the 3D model detects the effect that oxygen levels and the inflammatory environment impose on engineered TCR-T cell function, and we also used the 3D microdevice to analyze the TCR-T cell efficacy in an immunosuppressive scenario. Hence, we show that our microdevice platform enables us to decipher the factors that can alter T cell function in 3D and can serve as a preclinical assay to tailor the most efficient immunotherapy configuration for a specific therapeutic goal.

  9. Evaluation of AN Integrated Gis-Based Crime Analysis & 3d Modelling for Izmir-Konak Municipality

    NASA Astrophysics Data System (ADS)

    Tarhan, C.; Deniz, D.

    2011-08-01

    GIS integrated 3D modelling is crucial for the city planning and design processes because urban modelling is a tool used in virtual environments, and provides convenience to work. Although, the creation and display of 3D city models for large regions is difficult it is vital for planning and designing safer cities, as well as public places. Today, crime is a significant problem in Turkey. When it was compared by years of crime rates, population growth and urbanization rate, an increasing more than in parallel has been observed. This paper aims to discuss GIS integrated 3D modelling affects in urban planning and design, explaining Turkish planning processes with GIS and 3D modelling. To do that, it presents a case study for Izmir Konak Municipality about GIS integrated crime analysis and 3D models of the crime scenes. Izmir crime records has been obtained from Izmir Police Department belonging to 2003-2004 and 2005 (D. Deniz, 2007) are used for districts' crime map. In the light of these data, the highest rate crime district, Konak, is analyzed between 2001 and 2005 data.

  10. Evaluation of accuracy of 3D reconstruction images using multi-detector CT and cone-beam CT

    PubMed Central

    Kim, Mija; YI, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul

    2012-01-01

    Purpose This study was performed to determine the accuracy of linear measurements on three-dimensional (3D) images using multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). Materials and Methods MDCT and CBCT were performed using 24 dry skulls. Twenty-one measurements were taken on the dry skulls using digital caliper. Both types of CT data were imported into OnDemand software and identification of landmarks on the 3D surface rendering images and calculation of linear measurements were performed. Reproducibility of the measurements was assessed using repeated measures ANOVA and ICC, and the measurements were statistically compared using a Student t-test. Results All assessments under the direct measurement and image-based measurements on the 3D CT surface rendering images using MDCT and CBCT showed no statistically difference under the ICC examination. The measurements showed no differences between the direct measurements of dry skull and the image-based measurements on the 3D CT surface rendering images (P>.05). Conclusion Three-dimensional reconstructed surface rendering images using MDCT and CBCT would be appropriate for 3D measurements. PMID:22474645

  11. Evaluation of Methods for Coregistration and Fusion of Rpas-Based 3d Point Clouds and Thermal Infrared Images

    NASA Astrophysics Data System (ADS)

    Hoegner, L.; Tuttas, S.; Xu, Y.; Eder, K.; Stilla, U.

    2016-06-01

    This paper discusses the automatic coregistration and fusion of 3d point clouds generated from aerial image sequences and corresponding thermal infrared (TIR) images. Both RGB and TIR images have been taken from a RPAS platform with a predefined flight path where every RGB image has a corresponding TIR image taken from the same position and with the same orientation with respect to the accuracy of the RPAS system and the inertial measurement unit. To remove remaining differences in the exterior orientation, different strategies for coregistering RGB and TIR images are discussed: (i) coregistration based on 2D line segments for every single TIR image and the corresponding RGB image. This method implies a mainly planar scene to avoid mismatches; (ii) coregistration of both the dense 3D point clouds from RGB images and from TIR images by coregistering 2D image projections of both point clouds; (iii) coregistration based on 2D line segments in every single TIR image and 3D line segments extracted from intersections of planes fitted in the segmented dense 3D point cloud; (iv) coregistration of both the dense 3D point clouds from RGB images and from TIR images using both ICP and an adapted version based on corresponding segmented planes; (v) coregistration of both image sets based on point features. The quality is measured by comparing the differences of the back projection of homologous points in both corrected RGB and TIR images.

  12. The influence of the IMRT QA set-up error on the 2D and 3D gamma evaluation method as obtained by using Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Kim, Kyeong-Hyeon; Kim, Dong-Su; Kim, Tae-Ho; Kang, Seong-Hee; Cho, Min-Seok; Suh, Tae Suk

    2015-11-01

    The phantom-alignment error is one of the factors affecting delivery quality assurance (QA) accuracy in intensity-modulated radiation therapy (IMRT). Accordingly, a possibility of inadequate use of spatial information in gamma evaluation may exist for patient-specific IMRT QA. The influence of the phantom-alignment error on gamma evaluation can be demonstrated experimentally by using the gamma passing rate and the gamma value. However, such experimental methods have a limitation regarding the intrinsic verification of the influence of the phantom set-up error because experimentally measuring the phantom-alignment error accurately is impossible. To overcome this limitation, we aimed to verify the effect of the phantom set-up error within the gamma evaluation formula by using a Monte Carlo simulation. Artificial phantom set-up errors were simulated, and the concept of the true point (TP) was used to represent the actual coordinates of the measurement point for the mathematical modeling of these effects on the gamma. Using dose distributions acquired from the Monte Carlo simulation, performed gamma evaluations in 2D and 3D. The results of the gamma evaluations and the dose difference at the TP were classified to verify the degrees of dose reflection at the TP. The 2D and the 3D gamma errors were defined by comparing gamma values between the case of the imposed phantom set-up error and the TP in order to investigate the effect of the set-up error on the gamma value. According to the results for gamma errors, the 3D gamma evaluation reflected the dose at the TP better than the 2D one. Moreover, the gamma passing rates were higher for 3D than for 2D, as is widely known. Thus, the 3D gamma evaluation can increase the precision of patient-specific IMRT QA by applying stringent acceptance criteria and setting a reasonable action level for the 3D gamma passing rate.

  13. Physico-Chemical, In Vitro, and In Vivo Evaluation of a 3D Unidirectional Porous Hydroxyapatite Scaffold for Bone Regeneration

    PubMed Central

    Tanaka, Manabu; Haniu, Hisao; Kamanaka, Takayuki; Takizawa, Takashi; Sobajima, Atsushi; Yoshida, Kazushige; Aoki, Kaoru; Okamoto, Masanori; Kato, Hiroyuki; Saito, Naoto

    2017-01-01

    The unidirectional porous hydroxyapatite HAp (UDPHAp) is a scaffold with continuous communicated pore structure in the axial direction. We evaluated and compared the ability of the UDPHAp as a three-dimensional (3D) bone tissue engineering scaffold to the interconnected calcium porous HAp ceramic (IP-CHA). To achieve this, we evaluated in vitro the compressive strength, controlled rhBMP-2 release behavior, adherent cell morphology, cell adhesion manner, and cell attachment of UDPHAp. As a further in vivo experiment, UDPHAp and IP-CHA with rhBMP-2 were transplanted into mouse calvarial defects to evaluate their bone-forming ability. The Results demonstrated that the maximum compressive strengths of the UDPHAp was 7.89 ± 1.23 MPa and higher than that of IP-CHA (1.92 ± 0.53 MPa) (p = 0.0039). However, the breaking energies were similar (8.99 ± 2.72 vs. 13.95 ± 5.69 mJ, p = 0.055). The UDPHAp released rhBMP-2 more gradually in vivo. Cells on the UDPHAp adhered tightly to the surface, which had grown deeply into the scaffolds. A significant increase in cell number on the UDPHAp was observed compared to the IP-CHA on day 8 (102,479 ± 34,391 vs. 32,372 ± 29,061 estimated cells per scaffold, p = 0.0495). In a mouse calvarial defect model, the percentages of new bone area (mature bone + trabecular bone) in the 2x field were 2.514% ± 1.224% for the IP-CHA group and 7.045% ± 2.055% for the UDPHAp group, and the percentage was significantly higher in the UDPHAp group (p = 0.0209). While maintaining the same strength as the IP-CHA, the UDPHAp with 84% porosity showed a high cell number, high cell invasiveness, and excellent bone formation. We believe the UDPHAp is an excellent material that can be applied to bone regenerative medicine. PMID:28772390

  14. Performance evaluation of 3D polystyrene 96-well plates with human neural stem cells in a calcium assay.

    PubMed

    Lai, Yinzhi; Kisaalita, William S

    2012-08-01

    In this study, we have generated a high-throughput screening (HTS)-compatible 3D cell culture platform by chemically "welding" polystyrene scaffolds into standard 2D polystyrene 96-well plates. The variability of scaffolds was minimized by introducing automation into the fabrication process. The fabricated 3D cell culture plates were compared with several commercially available 3D cell culture platforms with light and scanning electron microscopy. Voltage-gated calcium channel functionality was used to access the Z' factors of all plates, including a 2D standard plate control. It was found that with the No-Wash Fluo-4 calcium assay and neural progenitor cells, all plates display acceptable Z' factors for use in HTS. The plates with "welded" polystyrene scaffolds have several advantages, such as being versatile and economical, and are ready to use off the shelf. These characteristics are especially desired in HTS preclinical drug discovery applications.

  15. Proximal pulmonary vein stenosis detection in pediatric patients: value of multiplanar and 3-D VR imaging evaluation.

    PubMed

    Lee, Edward Y; Jenkins, Kathy J; Muneeb, Muhammad; Marshall, Audrey C; Tracy, Donald A; Zurakowski, David; Boiselle, Phillip M

    2013-08-01

    One of the important benefits of using multidetector computed tomography (MDCT) is its capability to generate high-quality two-dimensional (2-D) multiplanar (MPR) and three-dimensional (3-D) images from volumetric and isotropic axial CT data. However, to the best of our knowledge, no results have been published on the potential diagnostic role of multiplanar and 3-D volume-rendered (VR) images in detecting pulmonary vein stenosis, a condition in which MDCT has recently assumed a role as the initial noninvasive imaging modality of choice. The purpose of this study was to compare diagnostic accuracy and interpretation time of axial, multiplanar and 3-D VR images for detection of proximal pulmonary vein stenosis in children, and to assess the potential added diagnostic value of multiplanar and 3-D VR images. We used our hospital information system to identify all consecutive children (< 18 years of age) with proximal pulmonary vein stenosis who had both a thoracic MDCT angiography study and a catheter-based conventional angiography within 2 months from June 2005 to February 2012. Two experienced pediatric radiologists independently reviewed each MDCT study for the presence of proximal pulmonary vein stenosis defined as ≥ 50% of luminal narrowing on axial, multiplanar and 3-D VR images. Final diagnosis was confirmed by angiographic findings. Diagnostic accuracy was compared using the z-test. Confidence level of diagnosis (scale 1-5, 5 = highest), perceived added diagnostic value (scale 1-5, 5 = highest), and interpretation time of multiplanar or 3-D VR images were compared using paired t-tests. Interobserver agreement was measured using the chance-corrected kappa coefficient. The final study population consisted of 28 children (15 boys and 13 girls; mean age: 5.2 months). Diagnostic accuracy based on 116 individual pulmonary veins for detection of proximal pulmonary vein stenosis was 72.4% (84 of 116) for axial MDCT images, 77.5% (90 of 116 cases) for

  16. Evaluation of two 3D virtual computer reconstructions for comparison of cleft lip and palate to normal fetal microanatomy.

    PubMed

    Landes, Constantin A; Weichert, Frank; Geis, Philipp; Helga, Fritsch; Wagner, Mathias

    2006-03-01

    Cleft lip and palate reconstructive surgery requires thorough knowledge of normal and pathological labial, palatal, and velopharyngeal anatomy. This study compared two software algorithms and their 3D virtual anatomical reconstruction because exact 3D micromorphological reconstruction may improve learning, reveal spatial relationships, and provide data for mathematical modeling. Transverse and frontal serial sections of the midface of 18 fetal specimens (11th to 32nd gestational week) were used for two manual segmentation approaches. The first manual segmentation approach used bitmap images and either Windows-based or Mac-based SURFdriver commercial software that allowed manual contour matching, surface generation with average slice thickness, 3D triangulation, and real-time interactive virtual 3D reconstruction viewing. The second manual segmentation approach used tagged image format and platform-independent prototypical SeViSe software developed by one of the authors (F.W.). Distended or compressed structures were dynamically transformed. Registration was automatic but allowed manual correction, such as individual section thickness, surface generation, and interactive virtual 3D real-time viewing. SURFdriver permitted intuitive segmentation, easy manual offset correction, and the reconstruction showed complex spatial relationships in real time. However, frequent software crashes and erroneous landmarks appearing "out of the blue," requiring manual correction, were tedious. Individual section thickness, defined smoothing, and unlimited structure number could not be integrated. The reconstruction remained underdimensioned and not sufficiently accurate for this study's reconstruction problem. SeViSe permitted unlimited structure number, late addition of extra sections, and quantified smoothing and individual slice thickness; however, SeViSe required more elaborate work-up compared to SURFdriver, yet detailed and exact 3D reconstructions were created.

  17. 3D joint inversion using seismic data and marine controlled-source electromagnetic data for evaluating gas hydrate concentrations

    NASA Astrophysics Data System (ADS)

    Kim, B.; Byun, J.; Seol, S. J.; Jeong, S.; Chung, Y.; Kwon, T.

    2015-12-01

    For many decades, gas hydrates have been received great attention as a potential source of natural gas. Therefore, the detailed information of structures of buried gas hydrates and their concentrations are prerequisite for the production for the gas hydrate as a reliable source of alternate energy. Recently, for this reason, a lot of gas hydrate assessment methods have been proposed by many researchers. However, it is still necessary to establish as new method for the further improvement of the accuracy of the 3D gas hydrate distribution. In this study, we present a 3D joint inversion method that provides superior quantitative information of gas hydrate distributions using 3D seismic data obtained by ocean-bottom cable (OBC) and marine controlled-source electromagnetic (CSEM) data. To verify our inversion method, we first built the general 3D gas hydrate model containing vertical methane-flow pathways. With the described model, we generated synthetic 3D OBC data and marine CSEM data using finite element modeling algorithms, respectively. In the joint inversion process, to obtain the high-resolution volumetric P-wave velocity structure, we applied the 3D full waveform inversion algorithm to the acquired OBC data. After that, the obtained P-wave velocity model is used as the structure constraint to compute cross-gradients with the updated resistivity model in the EM inversion process. Finally, petrophysical relations were applied to estimate volumetric gas hydrate concentrations. The proposed joint inversion process makes possible to obtain more precise quantitative gas hydrate assessment than inversion processes using only seismic or EM data. This technique can be helpful for accurate decision-making in gas hydrate development as well as in their production monitoring.

  18. Echocardiographic Evaluation of Hemodynamic Changes in Left-Sided Heart Valves in Pregnant Women With Valvular Heart Disease.

    PubMed

    Samiei, Niloufar; Amirsardari, Mandana; Rezaei, Yousef; Parsaee, Mozhgan; Kashfi, Fahimeh; Hantoosh Zadeh, Sedigheh; Beikmohamadi, Somayeh; Fouladi, Masoumeh; Hosseini, Saeid; Peighambari, Mohammad Mehdi; Mohebbi, Ahmad

    2016-10-01

    Physiologic changes during pregnancy can deteriorate or improve patients' hemodynamic status in the setting of valvular heart disease. There are sparse data regarding the effect of pregnancy on valve hemodynamics in normal pregnant women with known valvular heart disease. In a prospective study from July 2014 to January 2016, a total of 52 normal pregnant women who had mitral stenosis, aortic stenosis, or a history of mitral valve or aortic valve replacements were assessed. All patients underwent echocardiographic examinations and hemodynamic parameters were measured for both the mitral valve and aortic valve at first, second, and third trimesters. The parameters included mean gradient, peak gradient, mean gradient/heart rate, peak gradient/heart rate, pressure halftime, dimensionless velocity index, and valve area. Although most hemodynamic parameters (i.e., mean gradient, peak gradient, mean gradient/heart rate, and peak gradient/heart rate) increased approximately 50% from first to second trimester and first to third trimester (p <0.05) but those remained stable at third compared with second trimester (p >0.05). The ratio of changes between trimesters for valve area and dimensionless velocity index were comparable. No clinical decompensations were observed except for 3 and 7 cases of deterioration to functional class II at second and third trimesters, respectively. In conclusion, during a full-term and uncomplicated pregnancy, mitral and aortic valve gradients increase without significant changes in valve area that are more marked between the second and first trimester than between the third and second trimester. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Why Do We Need to Use Three-Dimensional (3D) Fourier Transform (FT) Analysis to Evaluate a High-Performance Transmission Electron Microscope (TEM)?

    PubMed

    Ishizuka, Kazuo; Kimoto, Koji

    2016-10-01

    The resolution of high-resolution transmission electron microscopes (TEM) has been improved down to subangstrom levels by correcting the spherical aberration (Cs) of the objective lens, and the information limit is thus determined mainly by partial temporal coherence. As a traditional Young's fringe test does not reveal the true information limit for an ultra-high-resolution electron microscope, new methods to evaluate temporal coherence have been proposed based on a tilted-beam diffractogram. However, the diffractogram analysis cannot be applied when the nonlinear contribution becomes significant. Therefore, we have proposed a method based on the three-dimensional (3D) Fourier transform (FT) of through-focus TEM images, and evaluated the performance of some Cs-corrected TEMs at lower voltages. In this report, we generalize the 3D FT analysis and derive the 3D transmission cross-coefficient. The profound difference of the 3D FT analysis from the diffractogram analysis is its capability to extract linear image information from the image intensity, and further to evaluate two linear image contributions separately on the Ewald sphere envelopes. Therefore, contrary to the diffractogram analysis the 3D FT analysis can work with a strong scattering object. This is the necessary condition if we want to directly observe the linear image transfer down to a few tens of picometer.

  20. Formulation of Aminosilica Adsorbents into 3D-Printed Monoliths and Evaluation of Their CO2 Capture Performance.

    PubMed

    Thakkar, Harshul; Eastman, Stephen; Al-Mamoori, Ahmed; Hajari, Amit; Rownaghi, Ali A; Rezaei, Fateme

    2017-03-01

    Amine-based materials have represented themselves as a promising class of CO2 adsorbents; however, their large-scale implementation requires their formulation into suitable structures. In this study, we report formulation of aminosilica adsorbents into monolithic structures through a three-dimensional (3D) printing technique. In particular, 3D-printed monoliths were fabricated using presynthesized silica-supported tetraethylenepentamine (TEPA) and poly(ethylenimine) (PEI) adsorbents using three different approaches. In addition, a 3D-printed bare silica monolith was prepared and post-functionalized with 3-aminopropyltrimethoxysilane (APS). Characterization of the obtained monoliths indicated that aminosilica materials retained their characteristics after being extruded into 3D-printed configurations. Adsorptive performance of amine-based structured adsorbents was also investigated in CO2 capture. Our results indicated that aminosilica materials retain their structural, physical, and chemical properties in the monoliths. In addition, the aminosilica monoliths exhibited adsorptive characteristics comparable to their corresponding powders. This work highlights the importance of adsorbent materials formulations into practical contactors such as monoliths, as the scalabale technology platform, that could facilitate rapid deployment of adsorption-based CO2 capture processes on commercial scales.

  1. Using 3-D OFEM for movement correction and quantitative evaluation in dynamic cardiac NH3 PET images

    NASA Astrophysics Data System (ADS)

    Lin, Hong-Dun; Yang, Bang-Hung; Chen, Chih-Hao; Wu, Liang-Chih; Liu, Ren-Shyan; Chung, Being-Tau; Lin, Kang-Ping

    2005-04-01

    Various forms of cardiac pathology, such as myocardial ischemia and infarction, can be characterized with 13NH3-PET images. In clinical situation, polar map (bullseye image), which derived by combining images from multiple planes (designated by the circle around the myocardium in the above images), so that information of the entire myocardium can be displayed in a single image for diagnosis. However, image artifact problem always arises from body movement or breathing motion in image acquisition period and results in indefinite myocardium disorder region shown in bullseye image. In this study, a 3-D motion and movement correction method is developed to solve the image artifact problem to improve the accuracy of diagnostic bullseye image. The proposed method is based on 3-D optical flow estimation method (OFEM) and cooperates with the particular dynamic imaging protocol, which snaps serial PET images (5 frames) in later half imaging period. The 3-D OFEM assigns to each image point in the visual 3-D flow velocity field, which associates with the non-rigid motion of the time-varying brightness of a sequence of images. It presents vectors of corresponding images position between frames for motion correction. To validate the performance of proposed method, 10 normal and 20 abnormal whole-body dynamic PET imaging studies were applied, and the results show that the bullseye images, which generated by corrected images, present clear and definite tissue region for clinical diagnosis.

  2. Magnitude subtraction vs. complex subtraction in dynamic contrast-enhanced 3D-MR angiography: basic experiments and clinical evaluation.

    PubMed

    Naganawa, S; Ito, T; Iwayama, E; Fukatsu, H; Ishiguchi, T; Ishigaki, T; Ichinose, N

    1999-11-01

    Magnitude subtraction and complex subtraction in dynamic contrast-enhanced three-dimensional magnetic resonance (3D-MR) angiography were compared using a phantom and 23 human subjects. In phantom studies, complex subtraction showed far better performance than magnitude subtraction, especially for longer echo times, with thicker slices, and without fat suppression. With complex subtraction, non-fat-suppressed studies showed contrast-to-noise ratios comparable to those in fat-suppressed studies. In human subjects, complex subtraction was superior to magnitude subtraction in 9 subjects, but comparable to magnitude subtraction in 14 subjects. There were no cases in which magnitude subtraction was superior to complex subtraction. Although the differences observed in human studies when complex subtraction was applied with thinner slices, shorter echo times, and the fat-suppression technique were not as pronounced as those seen in phantom studies, complex subtraction should be performed in dynamic contrast-enhanced 3D-MR angiography because there are no drawbacks in complex subtraction. Further research is necessary to assess the feasibility of dynamic contrast-enhanced 3D-MR angiography without fat suppression in human subjects using complex subtraction, as suggested by the results of phantom studies. If it is found to be feasible, dynamic contrast-enhanced 3D-MR angiography without fat suppression using complex subtraction may prove to be a robust technique that eliminates the need for shimming and can reduce the acquisition time. J. Magn. Reson. Imaging 1999;10:813-820.

  3. Development, Validation, and Evaluation of Literacy 3D: A Package Supporting Tier 1 Preschool Literacy Instruction Implementation and Intervention

    ERIC Educational Resources Information Center

    Greenwood, Charles R.; Abbott, Mary; Beecher, Constance; Atwater, Jane; Petersen, Sarah

    2017-01-01

    Increasingly, prekindergarten programs with literacy outcome goals are seeking to implement evidence-based practices to improve results. Such efforts require instructional intervention strategies to engage children as well as strategies to support teacher implementation. Reported is the iterative development of Literacy 3D, an enhanced support…

  4. Dimensional evaluation of patient-specific 3D printing using calcium phosphate cement for craniofacial bone reconstruction.

    PubMed

    Bertol, Liciane Sabadin; Schabbach, Rodrigo; Dos Santos, Luís Alberto Loureiro

    2016-12-01

    The 3D printing process is highlighted nowadays as a possibility to generate individual parts with complex geometries. Moreover, the development of 3D printing hardware, software and parameters permits the manufacture of parts that can be not only used as prototypes, but are also made from materials that are suitable for implantation. In this way, this study investigates the process involved in the production of patient-specific craniofacial implants using calcium phosphate cement, and its dimensional accuracy. The implants were previously generated in a computer-aided design environment based on the patient's tomographic data. The fabrication of the implants was carried out in a commercial 3D powder printing system using alfa-tricalcium phosphate powder and an aqueous solution of Na2HPO4 as a binder. The fit of the 3D printed implants was measured by three-dimensional laser scanning and by checking the right adjustment to the patient's anatomical biomodel. The printed parts presented a good degree of fitting and accuracy.

  5. A 3D microfluidic model for preclinical evaluation of TCR-engineered T cells against solid tumors

    PubMed Central

    Tan, Anthony T.; Koh, Sarene; Chia, Adeline; Colombo, Marta; Antonecchia, Emanuele; Miccolis, Carlo; Raimondi, Manuela T.; Kamm, Roger D.

    2017-01-01

    The tumor microenvironment imposes physical and functional constraints on the antitumor efficacy of adoptive T cell immunotherapy. Preclinical testing of different T cell preparations can help in the selection of efficient immune therapies, but in vivo models are expensive and cumbersome to develop, while classical in vitro 2D models cannot recapitulate the spatiotemporal dynamics experienced by T cells targeting cancer. Here, we describe an easily customizable 3D model, in which the tumor microenvironment conditions are modulated and the functionality of different T cell preparations is tested. We incorporate human cancer hepatocytes as a single cell or as tumor cell aggregates in a 3D collagen gel region of a microfluidic device. Human T cells engineered to express tumor-specific T cell receptors (TCR–T cells) are then added in adjacent channels. The TCR–T cells’ ability to migrate and kill the tumor target and the profile of soluble factors were investigated under conditions of varying oxygen levels and in the presence of inflammatory cytokines. We show that only the 3D model detects the effect that oxygen levels and the inflammatory environment impose on engineered TCR–T cell function, and we also used the 3D microdevice to analyze the TCR–T cell efficacy in an immunosuppressive scenario. Hence, we show that our microdevice platform enables us to decipher the factors that can alter T cell function in 3D and can serve as a preclinical assay to tailor the most efficient immunotherapy configuration for a specific therapeutic goal. PMID:28614795

  6. Europeana and 3D

    NASA Astrophysics Data System (ADS)

    Pletinckx, D.

    2011-09-01

    The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  7. 3D-FIESTA MR images are useful in the evaluation of the endoscopic expanded endonasal approach for midline skull-base lesions.

    PubMed

    Xie, Tao; Zhang, Xiao-Biao; Yun, Hong; Hu, Fan; Yu, Yong; Gu, Ye

    2011-01-01

    The endoscopic expanded endonasal approach (EEA) has been reported in literature as a useful tool to treat sellar, parasellar, suprasellar, and clival lesions. The endoscope permits a panoramic view rather than a narrow microscopic view, and this approach can reach the lesion without brain retraction and with minimal neurovascular manipulation. However, because of the narrow corridor, the preoperative evaluation of the lesions should be of high priority. 3D fast-imaging employing steady-state acquisition (3D-FIESTA) or constructive interference in steady state (CISS) MR imaging provides high spatial resolution in the small structures within the cisterns. Therefore, this technique may be useful for better preoperative planning in detecting optic nerve, oculomotor nerve, chiasma, infundibulum, pituitary stalk, and small vessels in sellar region. Here we used the 3D-FIESTA MR images to evaluate EEA for seven midline skull-base lesions. Our report showed that, when EEA was used to treat midline skull-base lesions, 3D-FIESTA MR images were valuable in the assessment of vital structures in and around the tumor-involved midline skull-base region. 3D-FIESTA MR images can help in making a better preoperative planning, locating the intraoperative structures, and reducing the surgical risks. Otherwise, this approach is helpful for the craniopharyngioma classification based on EEA.

  8. Comparison of FSE T2W and 3D FIESTA sequences in the evaluation of posterior fossa cranial nerves with MR cisternography.

    PubMed

    Hatipoğlu, Hatice Gül; Durakoğlugil, Tuğba; Ciliz, Deniz; Yüksel, Enis

    2007-06-01

    The aim of this study was to compare 3D fast imaging with steady state acquisition (3D FIESTA) to fast spin echo T2-weighted (FSE T2W) MRI sequences in the imaging of cisternal parts of cranial nerves V-XII. We retrospectively evaluated the temporal MRI sequences of 50 patients (F:M ratio, 27:23; mean age, 44.5 +/- 15.9 years) who were admitted to our hospital with vertigo, tinnitus, and hearing loss. In all, we evaluated 800 nerves. Two radiologists, working independently, divided the imaging findings into 3 groups: 0 (not visualized), 1 (partially visualized), and 2 (completely visualized). The rate of visualization of these cranial nerves with FSE T2W and 3D FIESTA sequences, respectively, (partially and completely visualized) were as follows: nerve V (100% and 100%); nerve VI (43% and 98%); nerve VII (100% and 100%); nerve VIII (100% and 100%); nerve IX-XI complex (67% and 100%); nerve XII (2% and 91%). 3D FIESTA sequences are superior to FSE T2W sequences in the imaging of cisternal parts of the posterior fossa nerves. 3D FIESTA sequences may be used for obtaining high-resolution MR cisternography images.

  9. Design and evaluation of the variable-angle slant-hole collimator for 3D molecular breast imaging

    NASA Astrophysics Data System (ADS)

    Gopan, Olga

    Purpose: The purpose of this work is to develop an improved method for 3D molecular imaging of the breast using limited angle SPECT. Methods: The proposed method uses a variable-angle slant-hole (VASH) collimator. Rather than rotate the camera around the breast, the VASH collimator allows limited angle, tomographic acquisition while the detector remains stationary and flush against the compression paddle. This design minimizes object-to-detector distance for high spatial resolution. Theoretical analysis is presented of VASH spatial resolution and sensitivity, including depth-of-interaction (DOI) effects and magnification. The theory is compared with Monte Carlo simulation results for a point source, a breast phantom including a compression paddle and a realistically segmented breast phantom with an inhomogeneous background uptake. A channelized Hotelling observer is applied to the evaluation of VASH using a lesion detection task, and the standard areaunder- the-curve (AUC) metric is obtained. Experimental results are presented using a proof-of-concept VASH collimator constructed of brass and used to image a low energy, Am-241 source. Results: The theoretical model of the VASH system showed good agreement with Monte Carlo simulations based on spatial resolution, including DOI effects, and sensitivity. The DOI effect resulted in roughly a 2 mm loss in spatial resolution only in depth dimension; in the other two dimensions the spatial resolution was not affected by DOI. In terms of contrast-to-noise ratio (CNR) and AUC, VASH outperformed a parallel hole SPECT approach. In terms of CNR, VASH outperformed a planar approach when the background inhomogeneity level was greater than 20% and in discerning two overlapping lesions. The difference in VASH and planar AUCs was not statistically significant. The reconstructed images from the proof-of-concept VASH collimator demonstrated the expected image blur in the depth dimension due to limited projection angle effects

  10. Evaluation of a 3-D interactive tooth atlas by dental students in dental anatomy and endodontics courses.

    PubMed

    Wright, Edward F; Hendricson, William D

    2010-02-01

    Advances in information and communication technology continually offer innovations to assist faculty in their efforts to help students learn new information or develop new skills. However, faculty members are often hesitant to incorporate these innovations into their courses out of fear that these new methods may not provide the anticipated outcomes. Hence, students are often the subjects of educational trials to evaluate curriculum innovations by comparing a new teaching/learning method to traditional lecture-based instruction. The most typical finding is that students can learn equally well by either method. However, two questions that have not been studied extensively in dental education are whether dental students will actually use computer-based educational resources made available to them and whether students perceive these materials to provide a value-added learning experience. Accordingly, the goals of this study were to determine whether first-year dental students (D1), second-year dental students (D2), and third-year dental students (D3) would 1) use an interactive tooth atlas, available on a DVD, as a study aid and 2) perceive that the atlas provided sufficient value-added benefit for their dental anatomy (D1), preclinical laboratory endodontics (D2), and clinical endodontics (D3) courses to recommend adding it to their school's comprehensive electronic resources. A low percentage of the students (14 percent; 40/289) voluntarily downloaded the atlas from a DVD to their laptops prior to the addition of incentives in the form of atlas-related examination questions. Even after incentives were added, only 43 percent of the students (126/289) downloaded the DVD. After using the atlas, students responded to the statement "Using the 3D Interactive Tooth Atlas was beneficial for me" on a 0 to 10 scale with 0 representing strongly disagree, 5 representing unsure, and 10 representing strongly agree. The mean rankings were 5.34 for D1s, 6.79 for D2s, and 7.28 for D

  11. Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

    PubMed Central

    Khoh-Reiter, Su; Jessen, Bart A

    2009-01-01

    Background Benzalkonium chloride (BAC) is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D) corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC) and olopatadine (0.01% BAC) was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T) cell cultures, expression levels (mRNA and protein) of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year) in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC) and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC contained in ophthalmic

  12. Application of 3D Printing in a Case of Osteogenesis Imperfecta for Patient Education, Anatomic Understanding, Preoperative Planning, and Intraoperative Evaluation.

    PubMed

    Eisenmenger, Laura B; Wiggins, Richard H; Fults, Daniel W; Huo, Eugene J

    2017-08-17

    The techniques and applications of three-dimensional (3D) printing have progressed at a fast pace. In the last 10 years, there has been significant progress in applying this technology to medical applications. We present a case of osteogenesis imperfecta in which treatment was aided by prospectively utilizing patient-specific, anatomically accurate 3D prints of the calvaria. The patient-specific, anatomically accurate 3D prints were used in the clinic and in the operating room to augment patient education, improve surgical decision making, and enhance preoperative planning. A 41-year-old woman with osteogenesis imperfecta and an extensive neurosurgical history presented for cranioplasty revision. Computed tomography (CT) data obtained as part of routine preoperative imaging was processed into a 3D model. The 3D patient-specific models were used in the clinic for patient education and in the operating room for preoperative visualization, planning, and intraoperative evaluation of anatomy. The patient reported the 3D models improved her understanding and comfort with the planned surgery when compared with discussing the procedure with the neurosurgeon or viewing the CT images with a neuroradiologist. The neurosurgeon reported an improved understanding of the patient's anatomy and potential cause of patient symptoms as well as improved preoperative planning compared with viewing the CT imaging alone. The neurosurgeon also reported an improvement in the planned surgical approach with a better intraoperative visualization and confirmation of the regions of planned calvarial resection. The use of patient-specific, anatomically accurate 3D prints may improve patient education, surgeon understanding and visualization, preoperative decision making, and intraoperative management. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Evaluation of grades 3 and 4 chondromalacia of the knee using T2*-weighted 3D gradient-echo articular cartilage imaging.

    PubMed

    Murphy, B J

    2001-06-01

    To determine the accuracy of T2*-weighted three-dimensional (3D) gradient-echo articular cartilage imaging in the identification of grades 3 and 4 chondromalacia of the knee. A retrospective evaluation of 80 patients who underwent both arthroscopic and MRI evaluation was performed. The 3D images were interpreted by one observer without knowledge of the surgical results. The medial and lateral femoral condyles, the medial and lateral tibial plateau, the patellar cartilage and trochlear groove were evaluated. MR cartilage images were considered positive if focal reduction of cartilage thickness was present (grade 3 chondromalacia) or if complete loss of cartilage was present (grade 4 chondromalacia). Comparison of the 3D MR results with the arthroscopic findings was performed. Eighty patients were included in the study group. A total of 480 articular cartilage sites were evaluated with MRI and arthroscopy. Results of MR identification of grades 3 and 4 chondromalacia, all sites combined, were: sensitivity 83%, specificity 97%, false negative rate 17%, false positive rate 3%, positive predictive value 87%, negative predictive value 95%, overall accuracy 93%. The results demonstrate that T2*-weighted 3D gradient-echo articular cartilage imaging can identify grades 3 and 4 chondromalacia of the knee.

  14. Evaluation of the 3D Finite Element Method Using a Tantalum Rod for Osteonecrosis of the Femoral Head

    PubMed Central

    Shi, Jingsheng; Chen, Jie; Wu, Jianguo; Chen, Feiyan; Huang, Gangyong; Wang, Zhan; Zhao, Guanglei; Wei, Yibing; Wang, Siqun

    2014-01-01

    Background The aim of this study was to contrast the collapse values of the postoperative weight-bearing areas of different tantalum rod implant positions, fibula implantation, and core decompression model and to investigate the advantages and disadvantages of tantalum rod implantation in different ranges of osteonecrosis in comparison with other methods. Material/Methods The 3D finite element method was used to establish the 3D finite element model of normal upper femur, 3D finite element model after tantalum rod implantation into different positions of the upper femur in different osteonecrosis ranges, and other 3D finite element models for simulating fibula implant and core decompression. Results The collapse values in the weight-bearing area of the femoral head of the tantalum rod implant model inside the osteonecrosis area, implant model in the middle of the osteonecrosis area, fibula implant model, and shortening implant model exhibited no statistically significant differences (p>0.05) when the osteonecrosis range was small (60°). The stress values on the artificial bone surface for the tantalum rod implant model inside the osteonecrosis area and the shortening implant model exhibited statistical significance (p<0.01). Conclusions Tantalum rod implantation into the osteonecrosis area can reduce the collapse values in the weight-bearing area when osteonecrosis of the femoral head (ONFH) was in a certain range, thereby obtaining better clinical effects. When ONFH was in a large range (120°), the tantalum rod implantation inside the osteonecrosis area, shortening implant or fibula implant can reduce the collapse values of the femoral head, as assessed by other methods. PMID:25479830

  15. Evaluation of the 3D finite element method using a tantalum rod for osteonecrosis of the femoral head.

    PubMed

    Shi, Jingsheng; Chen, Jie; Wu, Jianguo; Chen, Feiyan; Huang, Guangyong; Wang, Zhan; Zhao, Guanglei; Wei, Yibing; Wang, Siqun

    2014-12-06

    The aim of this study was to contrast the collapse values of the postoperative weight-bearing areas of different tantalum rod implant positions, fibula implantation, and core decompression model and to investigate the advantages and disadvantages of tantalum rod implantation in different ranges of osteonecrosis in comparison with other methods. The 3D finite element method was used to establish the 3D finite element model of normal upper femur, 3D finite element model after tantalum rod implantation into different positions of the upper femur in different osteonecrosis ranges, and other 3D finite element models for simulating fibula implant and core decompression. The collapse values in the weight-bearing area of the femoral head of the tantalum rod implant model inside the osteonecrosis area, implant model in the middle of the osteonecrosis area, fibula implant model, and shortening implant model exhibited no statistically significant differences (p>0.05) when the osteonecrosis range was small (60°). The stress values on the artificial bone surface for the tantalum rod implant model inside the osteonecrosis area and the shortening implant model exhibited statistical significance (p<0.01). Tantalum rod implantation into the osteonecrosis area can reduce the collapse values in the weight-bearing area when osteonecrosis of the femoral head (ONFH) was in a certain range, thereby obtaining better clinical effects. When ONFH was in a large range (120°), the tantalum rod implantation inside the osteonecrosis area, shortening implant or fibula implant can reduce the collapse values of the femoral head, as assessed by other methods.

  16. Cell-laden 3D bioprinting hydrogel matrix depending on different compositions for soft tissue engineering: Characterization and evaluation.

    PubMed

    Park, Jisun; Lee, Sang Jin; Chung, Solchan; Lee, Jun Hee; Kim, Wan Doo; Lee, Jae Young; Park, Su A

    2017-02-01

    Cell-printing techniques that can construct three-dimensional (3D) structures with biocompatible materials and cells are of great interest for various biomedical applications, such as tissue engineering and drug-screening studies. For successful cell-printing with cells, bioinks are critical for both the processability of printing and the viability of printed cells. However, the influence of composition on 3D bio-printing with cells has not been well explored. In this study, we investigated different compositions of alginate bioinks by varying the concentrations of high molecular weight alginate (High Alg) and low molecular weight alginate (Low Alg). Bioinks of 3wt% alginate containing High Alg alone or a 1:2 (Low Alg:High Alg) composite allowed for the construction of 3D scaffolds with good processability and shapes. Cell-printing with fibroblasts and in vitro culture studies revealed good viability and growth of the printed cells after up to 7days of culture. Bioinks prepared with High and Low Alg at a 2:1 ratio exhibited better cell growth compared with those of other compositions. This study progresses the design and applications of alginate-based bioinks for cell-printing platforms in soft tissue engineering. Copyright © 2016. Published by Elsevier B.V.

  17. Evaluation of synovium-derived mesenchymal stem cells and 3D printed nanocomposite scaffolds for tissue engineering.

    PubMed

    Pan, Jian-Feng; Li, Shuo; Guo, Chang-An; Xu, Du-Liang; Zhang, Feng; Yan, Zuo-Qin; Mo, Xiu-Mei

    2015-08-01

    Stem cells and scaffolds play a very important role in tissue engineering. Here, we isolated synovium-derived mesenchymal stem cells (SMSCs) from synovial membrane tissue and characterized stem-cell properties. Gelatin nanoparticles (NP) were prepared using a two-step desolvation method and then pre-mixed into different host matrix (silk fibroin (SF), gelatin (Gel), or SF-Gel mixture) to generate various 3D printed nanocomposite scaffolds (NP/SF, NP/SF-Gel, NP/Gel-1, and NP/Gel-2). The microstructure was examined by scanning electron microscopy. Biocompatibility assessment was performed through CCK-8 assay by coculturing with SMSCs at 1, 3, 7 and 14 days. According to the results, SMSCs are similar to other MSCs in their surface epitope expression, which are negative for CD45 and positive for CD44, CD90, and CD105. After incubation in lineage-specific medium, SMSCs could differentiate into chondrocytes, osteocytes and adipocytes. 3D printed nanocomposite scaffolds exhibited a good biocompatibility in the process of coculturing with SMSCs and had no negative effect on cell behavior. The study provides a strategy to obtain SMSCs and fabricate 3D printed nanocomposite scaffolds, the combination of which could be used for practical applications in tissue engineering.

  18. Evaluation of synovium-derived mesenchymal stem cells and 3D printed nanocomposite scaffolds for tissue engineering

    NASA Astrophysics Data System (ADS)

    Pan, Jian-Feng; Li, Shuo; Guo, Chang-An; Xu, Du-Liang; Zhang, Feng; Yan, Zuo-Qin; Mo, Xiu-Mei

    2015-08-01

    Stem cells and scaffolds play a very important role in tissue engineering. Here, we isolated synovium-derived mesenchymal stem cells (SMSCs) from synovial membrane tissue and characterized stem-cell properties. Gelatin nanoparticles (NP) were prepared using a two-step desolvation method and then pre-mixed into different host matrix (silk fibroin (SF), gelatin (Gel), or SF-Gel mixture) to generate various 3D printed nanocomposite scaffolds (NP/SF, NP/SF-Gel, NP/Gel-1, and NP/Gel-2). The microstructure was examined by scanning electron microscopy. Biocompatibility assessment was performed through CCK-8 assay by coculturing with SMSCs at 1, 3, 7 and 14 days. According to the results, SMSCs are similar to other MSCs in their surface epitope expression, which are negative for CD45 and positive for CD44, CD90, and CD105. After incubation in lineage-specific medium, SMSCs could differentiate into chondrocytes, osteocytes and adipocytes. 3D printed nanocomposite scaffolds exhibited a good biocompatibility in the process of coculturing with SMSCs and had no negative effect on cell behavior. The study provides a strategy to obtain SMSCs and fabricate 3D printed nanocomposite scaffolds, the combination of which could be used for practical applications in tissue engineering.

  19. Evaluation of synovium-derived mesenchymal stem cells and 3D printed nanocomposite scaffolds for tissue engineering

    PubMed Central

    Pan, Jian-Feng; Li, Shuo; Guo, Chang-An; Xu, Du-Liang; Zhang, Feng; Yan, Zuo-Qin; Mo, Xiu-Mei

    2015-01-01

    Stem cells and scaffolds play a very important role in tissue engineering. Here, we isolated synovium-derived mesenchymal stem cells (SMSCs) from synovial membrane tissue and characterized stem-cell properties. Gelatin nanoparticles (NP) were prepared using a two-step desolvation method and then pre-mixed into different host matrix (silk fibroin (SF), gelatin (Gel), or SF–Gel mixture) to generate various 3D printed nanocomposite scaffolds (NP/SF, NP/SF–Gel, NP/Gel-1, and NP/Gel-2). The microstructure was examined by scanning electron microscopy. Biocompatibility assessment was performed through CCK-8 assay by coculturing with SMSCs at 1, 3, 7 and 14 days. According to the results, SMSCs are similar to other MSCs in their surface epitope expression, which are negative for CD45 and positive for CD44, CD90, and CD105. After incubation in lineage-specific medium, SMSCs could differentiate into chondrocytes, osteocytes and adipocytes. 3D printed nanocomposite scaffolds exhibited a good biocompatibility in the process of coculturing with SMSCs and had no negative effect on cell behavior. The study provides a strategy to obtain SMSCs and fabricate 3D printed nanocomposite scaffolds, the combination of which could be used for practical applications in tissue engineering. PMID:27877821

  20. A 3d-3d appetizer

    NASA Astrophysics Data System (ADS)

    Pei, Du; Ye, Ke

    2016-11-01

    We test the 3d-3d correspondence for theories that are labeled by Lens spaces. We find a full agreement between the index of the 3d N=2 "Lens space theory" T [ L( p, 1)] and the partition function of complex Chern-Simons theory on L( p, 1). In particular, for p = 1, we show how the familiar S 3 partition function of Chern-Simons theory arises from the index of a free theory. For large p, we find that the index of T[ L( p, 1)] becomes a constant independent of p. In addition, we study T[ L( p, 1)] on the squashed three-sphere S b 3 . This enables us to see clearly, at the level of partition function, to what extent G ℂ complex Chern-Simons theory can be thought of as two copies of Chern-Simons theory with compact gauge group G.

  1. Evaluation of similarity measures for use in the intensity-based rigid 2D-3D registration for patient positioning in radiotherapy

    SciTech Connect

    Wu Jian; Kim, Minho; Peters, Jorg; Chung, Heeteak; Samant, Sanjiv S.

    2009-12-15

    Purpose: Rigid 2D-3D registration is an alternative to 3D-3D registration for cases where largely bony anatomy can be used for patient positioning in external beam radiation therapy. In this article, the authors evaluated seven similarity measures for use in the intensity-based rigid 2D-3D registration using a variation in Skerl's similarity measure evaluation protocol. Methods: The seven similarity measures are partitioned intensity uniformity, normalized mutual information (NMI), normalized cross correlation (NCC), entropy of the difference image, pattern intensity (PI), gradient correlation (GC), and gradient difference (GD). In contrast to traditional evaluation methods that rely on visual inspection or registration outcomes, the similarity measure evaluation protocol probes the transform parameter space and computes a number of similarity measure properties, which is objective and optimization method independent. The variation in protocol offers an improved property in the quantification of the capture range. The authors used this protocol to investigate the effects of the downsampling ratio, the region of interest, and the method of the digitally reconstructed radiograph (DRR) calculation [i.e., the incremental ray-tracing method implemented on a central processing unit (CPU) or the 3D texture rendering method implemented on a graphics processing unit (GPU)] on the performance of the similarity measures. The studies were carried out using both the kilovoltage (kV) and the megavoltage (MV) images of an anthropomorphic cranial phantom and the MV images of a head-and-neck cancer patient. Results: Both the phantom and the patient studies showed the 2D-3D registration using the GPU-based DRR calculation yielded better robustness, while providing similar accuracy compared to the CPU-based calculation. The phantom study using kV imaging suggested that NCC has the best accuracy and robustness, but its slow function value change near the global maximum requires a