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Sample records for 2d digital radiographic

  1. GPU accelerated generation of digitally reconstructed radiographs for 2-D/3-D image registration.

    PubMed

    Dorgham, Osama M; Laycock, Stephen D; Fisher, Mark H

    2012-09-01

    Recent advances in programming languages for graphics processing units (GPUs) provide developers with a convenient way of implementing applications which can be executed on the CPU and GPU interchangeably. GPUs are becoming relatively cheap, powerful, and widely available hardware components, which can be used to perform intensive calculations. The last decade of hardware performance developments shows that GPU-based computation is progressing significantly faster than CPU-based computation, particularly if one considers the execution of highly parallelisable algorithms. Future predictions illustrate that this trend is likely to continue. In this paper, we introduce a way of accelerating 2-D/3-D image registration by developing a hybrid system which executes on the CPU and utilizes the GPU for parallelizing the generation of digitally reconstructed radiographs (DRRs). Based on the advancements of the GPU over the CPU, it is timely to exploit the benefits of many-core GPU technology by developing algorithms for DRR generation. Although some previous work has investigated the rendering of DRRs using the GPU, this paper investigates approximations which reduce the computational overhead while still maintaining a quality consistent with that needed for 2-D/3-D registration with sufficient accuracy to be clinically acceptable in certain applications of radiation oncology. Furthermore, by comparing implementations of 2-D/3-D registration on the CPU and GPU, we investigate current performance and propose an optimal framework for PC implementations addressing the rigid registration problem. Using this framework, we are able to render DRR images from a 256×256×133 CT volume in ~24 ms using an NVidia GeForce 8800 GTX and in ~2 ms using NVidia GeForce GTX 580. In addition to applications requiring fast automatic patient setup, these levels of performance suggest image-guided radiation therapy at video frame rates is technically feasible using relatively low cost PC

  2. Calcification content quantification by dual-energy x-ray absorptiometry with a 2D digital radiographic detector

    NASA Astrophysics Data System (ADS)

    Dinten, Jean M.; Robert-Coutant, Christine; Darboux, Michel; Gonon, Georges; Bordy, Thomas

    2003-06-01

    In a previous paper (SPIE Medical Imaging 2001), a dual energy method for bone densitometry using a 2D digital radiographic detector has been presented. In this paper, calcium content quantification performance of the approach is precised. The main challenge is to achieve quantification using scatter-corrected dual energy acquisitions. Therefore a scatter estimation approach, based on an expression of scatter as a functional of the primary flux, has been developed. This expression is derived from the Klein and Nishina equation and includes tabulated scatter level values. The calcium quantification performances are validated on two configurations. A first one is issued from criteria developed by the French "Groupe de Recherche et d'Information sur les Osteoporoses." It is based on the use of a phantom made of five 3mm thick PVC sheets in the form of five steps, representing five different bone mineral density values, included in a lucite container filled with water. Additional lucite plates can be put over the phantom. This phantom has been used for evaluation of quantification robustness versus patient thickness and composition variations, and for accuracy evaluation. The second configuration, composed of small calcified objects (representative of lung nodules), is used for evaluating capacities to differentiate calcified from non calcified nodules and to test calcium content quantification performance.

  3. Comparison Of Digital Radiographic Units

    NASA Astrophysics Data System (ADS)

    Wang, Yen

    1986-06-01

    A total PACS will be inevitable for radiology practice within several years. To achieve a total PACS for radiology, a satisfactory digital radiographic unit is required, because approximately 65% of digital data for PACS comes from digital radiographs. There are several possibilities for producing digital radiographs, and 3 - 4 companies have been marketing digital radiographic devices. Some data regarding the digital radiographic units on the market are compared. It will aid in assessing the current status and availability of this aspect of development, as well as providing a summary of further development of digital radiographic technology.

  4. DIGITAL SPALL RADIOGRAPH ANALYSIS SYSTEM

    SciTech Connect

    CURTIS L. HARRIS - LATA

    1990-01-01

    This report describes progress on work to develop a cost effective, rapid response system for measuring Technology Assessment National Laboratory. momentum and kinetic energy of span for the Advanced Center (ATAC) Armor/Anti-Armor (As) program at Los Alamos The system will exploit data contained in two sets of simultaneous co-planar flash radiographs taken along the center line of anticipated span motion. Data contained in each set (which is proportional to the mass and z-number of the span material intersected by the exposing x-ray at each point) is digitized and used to construct a three dimensional model (called the reconstructed span image) that approximates the original span cloud. From the model the mass of span fragments is computed. The two sets of radiographs, separated in time, represent the span configuration at two instants of time. Span fragments from the first instant are matched with those from the second instant to determine velocity. Evaluation of the fidelity of candidate reconstruction algorithms is the highest priority task in. this development program for the obvious reason that the efficacy of the projected span analysis system depends upon the fidelity of the reconstruction techniques.

  5. Digital processing of radiographic images

    NASA Technical Reports Server (NTRS)

    Bond, A. D.; Ramapriyan, H. K.

    1973-01-01

    Some techniques are presented and the software documentation for the digital enhancement of radiographs. Both image handling and image processing operations are considered. The image handling operations dealt with are: (1) conversion of format of data from packed to unpacked and vice versa; (2) automatic extraction of image data arrays; (3) transposition and 90 deg rotations of large data arrays; (4) translation of data arrays for registration; and (5) reduction of the dimensions of data arrays by integral factors. Both the frequency and the spatial domain approaches are presented for the design and implementation of the image processing operation. It is shown that spatial domain recursive implementation of filters is much faster than nonrecursive implementations using fast fourier transforms (FFT) for the cases of interest in this work. The recursive implementation of a class of matched filters for enhancing image signal to noise ratio is described. Test patterns are used to illustrate the filtering operations. The application of the techniques to radiographic images of metallic structures is demonstrated through several examples.

  6. MRI visualisation by digitally reconstructed radiographs

    NASA Astrophysics Data System (ADS)

    Serrurier, Antoine; Bönsch, Andrea; Lau, Robert; Deserno, Thomas M.

    2015-03-01

    Visualising volumetric medical images such as computed tomography and magnetic resonance imaging (MRI) on picture archiving and communication systems (PACS) clients is often achieved by image browsing in sagittal, coronal or axial views or three-dimensional (3D) rendering. This latter technique requires fine thresholding for MRI. On the other hand, computing virtual radiograph images, also referred to as digitally reconstructed radiographs (DRR), provides in a single two-dimensional (2D) image a complete overview of the 3D data. It appears therefore as a powerful alternative for MRI visualisation and preview in PACS. This study describes a method to compute DRR from T1-weighted MRI. After segmentation of the background, a histogram distribution analysis is performed and each foreground MRI voxel is labeled as one of three tissues: cortical bone, also known as principal absorber of the X-rays, muscle and fat. An intensity level is attributed to each voxel according to the Hounsfield scale, linearly related to the X-ray attenuation coefficient. Each DRR pixel is computed as the accumulation of the new intensities of the MRI dataset along the corresponding X-ray. The method has been tested on 16 T1-weighted MRI sets. Anterior-posterior and lateral DRR have been computed with reasonable qualities and avoiding any manual tissue segmentations. This proof-of-concept holds for research application for use in clinical PACS.

  7. Simulated radiographic bone and joint modeling from 3D ankle MRI: feasibility and comparison with radiographs and 2D MRI.

    PubMed

    Nordeck, Shaun M; Koerper, Conrad E; Adler, Aaron; Malhotra, Vidur; Xi, Yin; Liu, George T; Chhabra, Avneesh

    2017-05-01

    The purpose of this work is to simulate radiographs from isotropic 3D MRI data, compare relationship of angle and joint space measurements on simulated radiographs with corresponding 2D MRIs and real radiographs (XR), and compare measurement times among the three modalities. Twenty-four consecutive ankles were included, eight males and 16 females, with a mean age of 46 years. Segmented joint models simulating radiographs were created from 3D MRI data sets. Three readers independently performed blinded angle and joint space measurements on the models, corresponding 2D MRIs, and XRs at two time points. Linear mixed models and the intraclass correlation coefficient (ICC) was ascertained, with p values less than 0.05 considered significant. Simulated radiograph models were successfully created in all cases. Good agreement (ICC > 0.65) was noted among all readers across all modalities and among most measurements. Absolute measurement values differed between modalities. Measurement time was significantly greater (p < 0.05) on 2D versus simulated radiographs for most measurements and on XR versus simulated radiographs (p < 0.05) for nearly half the measurements. Simulated radiographs can be successfully generated from 3D MRI data; however, measurements differ. Good inter-reader and moderate-to-good intra-reader reliability was observed and measurements obtained on simulated radiograph models took significantly less time compared to measurements with 2D and generally less time than XR.

  8. Shaped Charge Jet Flash Radiograph Digitization

    DTIC Science & Technology

    2005-09-01

    radiograph digitization of shaped chare jets provides warhead designers with the data required for empirically based models , as well as the jet...characterization used for comparison with high rate continuum modeling . Reduced digitization results include jet tip velocity, jet accumulated length...using CALCOMP model 9500 digitizing tablet. It has the resolution of 0.25 x 10-3 in., accuracy of ± 0.003 in. and about 6 ft in length. The digitized

  9. 3D–2D registration in mobile radiographs: algorithm development and preliminary clinical evaluation.

    PubMed

    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

    2015-03-07

    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 the surgical product

  10. 3D–2D registration in mobile radiographs: algorithm development and preliminary clinical evaluation

    PubMed Central

    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

    2015-01-01

    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 the surgical

  11. 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

  12. Digital radiographic systems detect boiler tube cracks

    SciTech Connect

    Walker, S.

    2008-06-15

    Boiler water wall leaks have been a major cause of steam plant forced outages. But conventional nondestructive evaluation techniques have a poor track record of detecting corrosion fatigue cracking on the inside surface of the cold side of waterwall tubing. EPRI is performing field trials of a prototype direct-digital radiographic system that promises to be a game changer. 8 figs.

  13. 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.

  14. Temporal stability of digital radiographic detectors.

    PubMed

    Ireland, Timothy A; Irvine, Mike

    2016-03-01

    With the current preference for digital radiographic detectors in modern radiology facilities, there has been increasing demand for baseline technical data for equipment comparison and benchmarking. Key system parameters were monitored in 12 individual digital detectors over a 6 months period following installation, to establish baseline performance fluctuations for current generation indirect digital detectors. Performance criteria monitored included exposure index consistency, detector uniformity, system transfer function, artifact presentation, automatic exposure control reproducibility and dose area product consistency. Two indirect digital detector models were included, with the final set of measurements for each detector taken after routine detector calibrations were completed by technical staff. Suggested performance limits are presented based on observed temporal fluctuations, as well as national and international standards, where applicable.

  15. Cup Implant Planning Based on 2-D/3-D Radiographic Pelvis Reconstruction-First Clinical Results.

    PubMed

    Schumann, Steffen; Sato, Yoshinobu; Nakanishi, Yuki; Yokota, Futoshi; Takao, Masaki; Sugano, Nobuhiko; Zheng, Guoyan

    2015-11-01

    In the following, we will present a newly developed X-ray calibration phantom and its integration for 2-D/3-D pelvis reconstruction and subsequent automatic cup planning. Two different planning strategies were applied and evaluated with clinical data. Two different cup planning methods were investigated: The first planning strategy is based on a combined pelvis and cup statistical atlas. Thereby, the pelvis part of the combined atlas is matched to the reconstructed pelvis model, resulting in an optimized cup planning. The second planning strategy analyzes the morphology of the reconstructed pelvis model to determine the best fitting cup implant. The first planning strategy was compared to 3-D CT-based planning. Digitally reconstructed radiographs of THA patients with differently severe pathologies were used to evaluate the accuracy of predicting the cup size and position. Within a discrepancy of one cup size, the size was correctly identified in 100% of the cases for Crowe type I datasets and in 77.8% of the cases for Crowe type II, III, and IV datasets. The second planning strategy was analyzed with respect to the eventually implanted cup size. In seven patients, the estimated cup diameter was correct within one cup size, while the estimation for the remaining five patients differed by two cup sizes. While both planning strategies showed the same prediction rate with a discrepancy of one cup size (87.5%), the prediction of the exact cup size was increased for the statistical atlas-based strategy (56%) in contrast to the anatomically driven approach (37.5%). The proposed approach demonstrated the clinical validity of using 2-D/3-D reconstruction technique for cup planning.

  16. Segmentation of ribs in digital chest radiographs

    NASA Astrophysics Data System (ADS)

    Cong, Lin; Guo, Wei; Li, Qiang

    2016-03-01

    Ribs and clavicles in posterior-anterior (PA) digital chest radiographs often overlap with lung abnormalities such as nodules, and cause missing of these abnormalities, it is therefore necessary to remove or reduce the ribs in chest radiographs. The purpose of this study was to develop a fully automated algorithm to segment ribs within lung area in digital radiography (DR) for removal of the ribs. The rib segmentation algorithm consists of three steps. Firstly, a radiograph was pre-processed for contrast adjustment and noise removal; second, generalized Hough transform was employed to localize the lower boundary of the ribs. In the third step, a novel bilateral dynamic programming algorithm was used to accurately segment the upper and lower boundaries of ribs simultaneously. The width of the ribs and the smoothness of the rib boundaries were incorporated in the cost function of the bilateral dynamic programming for obtaining consistent results for the upper and lower boundaries. Our database consisted of 93 DR images, including, respectively, 23 and 70 images acquired with a DR system from Shanghai United-Imaging Healthcare Co. and from GE Healthcare Co. The rib localization algorithm achieved a sensitivity of 98.2% with 0.1 false positives per image. The accuracy of the detected ribs was further evaluated subjectively in 3 levels: "1", good; "2", acceptable; "3", poor. The percentages of good, acceptable, and poor segmentation results were 91.1%, 7.2%, and 1.7%, respectively. Our algorithm can obtain good segmentation results for ribs in chest radiography and would be useful for rib reduction in our future study.

  17. 3-D Reconstruction From 2-D Radiographic Images and Its Application to Clinical Veterinary Medicine

    NASA Astrophysics Data System (ADS)

    Hamamoto, Kazuhiko; Sato, Motoyoshi

    3D imaging technique is very important and indispensable in diagnosis. The main stream of the technique is one in which 3D image is reconstructed from a set of slice images, such as X-ray CT and MRI. However, these systems require large space and high costs. On the other hand, a low cost and small size 3D imaging system is needed in clinical veterinary medicine, for example, in the case of diagnosis in X-ray car or pasture area. We propose a novel 3D imaging technique using 2-D X-ray radiographic images. This system can be realized by cheaper system than X-ray CT and enables to get 3D image in X-ray car or portable X-ray equipment. In this paper, a 3D visualization technique from 2-D radiographic images is proposed and several reconstructions are shown. These reconstructions are evaluated by veterinarians.

  18. Automated 2D-3D registration of a radiograph and a cone beam CT using line-segment enhancement

    SciTech Connect

    Munbodh, Reshma; Jaffray, David A.; Moseley, Douglas J.; Chen Zhe; Knisely, Jonathan P.S.; Cathier, Pascal; Duncan, James S.

    2006-05-15

    The objective of this study was to develop a fully automated two-dimensional (2D)-three-dimensional (3D) registration framework to quantify setup deviations in prostate radiation therapy from cone beam CT (CBCT) data and a single AP radiograph. A kilovoltage CBCT image and kilovoltage AP radiograph of an anthropomorphic phantom of the pelvis were acquired at 14 accurately known positions. The shifts in the phantom position were subsequently estimated by registering digitally reconstructed radiographs (DRRs) from the 3D CBCT scan to the AP radiographs through the correlation of enhanced linear image features mainly representing bony ridges. Linear features were enhanced by filtering the images with ''sticks,'' short line segments which are varied in orientation to achieve the maximum projection value at every pixel in the image. The mean (and standard deviations) of the absolute errors in estimating translations along the three orthogonal axes in millimeters were 0.134 (0.096) AP(out-of-plane), 0.021 (0.023) ML and 0.020 (0.020) SI. The corresponding errors for rotations in degrees were 0.011 (0.009) AP, 0.029 (0.016) ML (out-of-plane), and 0.030 (0.028) SI (out-of-plane). Preliminary results with megavoltage patient data have also been reported. The results suggest that it may be possible to enhance anatomic features that are common to DRRs from a CBCT image and a single AP radiography of the pelvis for use in a completely automated and accurate 2D-3D registration framework for setup verification in prostate radiotherapy. This technique is theoretically applicable to other rigid bony structures such as the cranial vault or skull base and piecewise rigid structures such as the spine.

  19. A 2D 3D registration with low dose radiographic system for in vivo kinematic studies.

    PubMed

    Jerbi, T; Burdin, V; Stindel, E; Roux, C

    2011-01-01

    The knowledge of the poses and the positions of the knee bones and prostheses is of a great interest in the orthopedic and biomechanical applications. In this context, we use an ultra low dose bi-planar radiographic system called EOS to acquire two radiographs of the studied bones in each position. In this paper, we develop a new method for 2D 3D registration based on the frequency domain to determine the poses and the positions during quasi static motion analysis for healthy and prosthetic knees. Data of two healthy knees and four knees with unicompartimental prosthesis performing three different poses (full extension, 30° and 60° of flexion) were used in this work. The results we obtained are in concordance with the clinical accuracy and with the accuracy reported in other previous studies.

  20. Digit ratio (2D:4D) in Klinefelter's syndrome.

    PubMed

    Manning, J T; Kilduff, L P; Trivers, R

    2013-01-01

    The ratio of second to fourth digit length (2D:4D) is a correlate of prenatal testosterone. High 2D:4D is associated with low prenatal testosterone, and reduced sensitivity to testosterone. Klinefelter's syndrome (KS; 47 XXY) affects the endocrine system, such that low testosterone levels are found in KS foetuses, new-borns and adults. To date, there are no published data regarding the pattern of 2D:4D in KS males. Here we consider 2D:4D in KS individuals (n = 51), their relatives (16 fathers and 15 mothers) and an unaffected control sample of 153 men and 153 women. Adult KS individuals were taller than their fathers and had shorter fingers than fathers and male controls. Compared with fathers, male controls and mothers, KS males had shorter fingers relative to height. With regard to 2D:4D, KS individuals had higher 2D:4D than fathers (right and left hands), male controls (right and left hands) and mothers (left hands). Among KS males older than 13 years there were 34 individuals currently prescribed testosterone and nine not prescribed. In comparison to the former, the latter individuals had higher right 2D:4D and higher right-left 2D:4D. We conclude that KS males have mean 2D:4D values similar to those found in female population norms. In addition, testosterone supplementation in KS males may be most common for individuals with low right 2D:4D. © 2012 American Society of Andrology and European Academy of Andrology.

  1. Digit ratio (2D:4D) and postoperative pain perception.

    PubMed

    Kasielska-Trojan, Anna; Stabryła, Piotr; Antoszewski, Bogusław

    2017-07-01

    It has not been established whether sex differences in pain perception are influenced by prenatal sex hormones. Digit ratio as an indicator of prenatal hormone exposure can be used as a simple measure of the influence of prenatal hormones on pain sensitivity or perception in adulthood. The aim of this study was to determine a correlation between the 2D:4D ratio and pain perception in the postoperative period after rhinoplasty. A prospective cohort study of 100 patients (50 women of the mean age of 30.74±8.09years and 50 men of the mean age of 30.98±10.86years) who underwent posttraumatic rhinoplasty due to the nose trauma in Plastic, Reconstructive and Aesthetic Surgery Clinic. The following measurements were taken the day before a surgery: body height, waist and hip circumference, II and IV digits' lengths and body weight. All subjects filled in a questionnaire including 0-10-point VAS scales to assess postoperative pain 1h after an operation (AO), 6h AO, 12h AO, 24h AO and 48h AO. Women with low 2D:4D reported significantly more pain 1h after an operation than women with high 2D:4D. Similar correlation was observed for low 2D:4D in women 48h AO. In men, low 2D:4D was associated with lower postoperative pain 12h AO (p=0.029). In conclusion, we showed that low 2D:4D in women was associated with high postoperative pain, and low right 2D:4D in men was associated with low postoperative pain. This may suggest that intrauterine estrogen exposure makes women more resistant to pain. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. High frame-rate digital radiographic videography

    SciTech Connect

    King, N.S.P.; Cverna, F.H.; Albright, K.L.; Jaramillo, S.A.; Yates, G.J.; McDonald, T.E.; Flynn, M.J.; Tashman, S.

    1994-09-01

    High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100-microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

  3. High-frame-rate digital radiographic videography

    NASA Astrophysics Data System (ADS)

    King, Nicholas S. P.; Cverna, Frank H.; Albright, Kevin L.; Jaramillo, Steven A.; Yates, George J.; McDonald, Thomas E.; Flynn, Michael J.; Tashman, Scott

    1994-10-01

    High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100 microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

  4. Digital image processing of cephalometric radiographs: a preliminary report.

    PubMed

    Jackson, P H; Dickson, G C; Birnie, D J

    1985-07-01

    The principles of image capture, image storage and image processing in digital radiology are described. The enhancement of radiographic images using digital image processing techniques and its application to cephalometry is discussed. The results of a pilot study which compared some common cephalometric measurements made from manual point identification with those made by direct digitization of digital radiographic images from video monitors are presented. Although in an early stage of development, the results from the image processing system were comparable with those obtained by traditional methods.

  5. Fraudulent use of digital radiography: methods to detect and protect digital radiographs.

    PubMed

    Calberson, Filip L G; Hommez, Geert M; De Moor, Roeland J

    2008-05-01

    Digital radiography has become an indispensable diagnostic tool in dentistry today. To improve vision and diagnosis, dental x-ray software allows image enhancement (eg, adjusting color, density, sharpness, brightness, or contrast). Exporting digital radiographs to a file format compatible with commercial graphic software increases chances that information can be altered, added, or removed in an unethical manner. Dental radiographs are easily duplicated, stored, or distributed in digital format. It is difficult to guarantee the authenticity of digital images, which is especially important in insurance or juridic cases. Image-enhancement features applied to digital radiographs allow mishandling or potential abuse. This has been illustrated by several recently published studies. A standard authentication procedure for digital radiographs is needed. A number of manipulated radiographic images are presented to show concerns about security, reliability, and the potential for fraud. Antitampering techniques and methods of detecting manipulations in digital medical images are discussed.

  6. Digit ratio (2D:4D), salivary testosterone, and handedness.

    PubMed

    Beaton, Alan A; Rudling, Nick; Kissling, Christian; Taurines, Regine; Thome, Johannes

    2011-03-01

    The length of the index finger relative to that of the ring finger, the 2D:4D ratio, has been taken to be a marker of the amount of testosterone (T) that was present in the foetal environment (Manning, Scutt, Wilson, & Lewis-Jones, 1998). It has also been suggested (Geschwind & Galaburda, 1987) that elevated levels of foetal T are associated with left-handedness and that adult levels of circulating T might relate to foetal levels (Jamison, Meier, & Campbell, 1993). We used multiple regression analyses to investigate whether there is any relationship between either left or right hand 2D:4D ratio and handedness. We also examined whether adult levels of salivary T (or cortisol, used as a control hormone) predict digit ratio and/or handedness. Although the 2D:4D ratio of neither the left nor the right hand was related to handedness, the difference between the digit ratios of the right and left hands, D(R-L), was a significant predictor of handedness and of the performance difference between the hands on a peg-moving task, supporting previous findings (Manning & Peters, 2009; Manning et al., 1998; Manning, Trivers, Thornhill, & Singh, 2000; Stoyanov, Marinov, & Pashalieva, 2009). Adult circulating T levels did not predict the digit ratio of the left or right hand; nor was there a significant relationship between concentrations of salivary T (or cortisol) and either hand preference or asymmetry in manual skill. We suggest that the association between D(R-L) and hand preference arises because D(R-L) is a correlate of sensitivity to T in the developing foetus.

  7. 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.

  8. Determinants Of Acceptability Of Radiographic Images For Archival Digital Storage

    NASA Astrophysics Data System (ADS)

    Markivee, C. R.; Nalesnik, W. J.; Chiang, M. C.; Tio, J. R.; Hall, E. L.

    1983-05-01

    The parameter, quality of radiographic film exposure, was evaluated by computer and 15 human observers for the purpose of determining the feasibility of automatic computer eval-uation of radiographs prior to archival storage. Histograms of digitized knee radiographs were parameterized according to the Pearson technique and the computer was used to grade exposure quality relative to a set of training radiographs evaluated by the readers. There was a significant variation in the assessment of film exposure quality among the different observers. The computer scored 73% for the AP films and 53% for the laterals relative to the general consensus. The discrepancies were explained in terms of differences in anatomy and radiographic technique. The significance of this work is that it demonstrates that a computer can grade films according to a predetermined standard set by the radiologist.

  9. Digital processing of radiographic images from PACS to publishing.

    PubMed

    Christian, M E; Davidson, H C; Wiggins, R H; Berges, G; Cannon, G; Jackson, G; Chapman, B; Harnsberger, H R

    2001-03-01

    Several studies have addressed the implications of filmless radiologic imaging on telemedicine, diagnostic ability, and electronic teaching files. However, many publishers still require authors to submit hard-copy images for publication of articles and textbooks. This study compares the quality digital images directly exported from picture archive and communications systems (PACS) to images digitized from radiographic film. The authors evaluated the quality of publication-grade glossy photographs produced from digital radiographic images using 3 different methods: (1) film images digitized using a desktop scanner and then printed, (2) digital images obtained directly from PACS then printed, and (3) digital images obtained from PACS and processed to improve sharpness prior to printing. Twenty images were printed using each of the 3 different methods and rated for quality by 7 radiologists. The results were analyzed for statistically significant differences among the image sets. Subjective evaluations of the filmless images found them to be of equal or better quality than the digitized images. Direct electronic transfer of PACS images reduces the number of steps involved in creating publication-quality images as well as providing the means to produce high-quality radiographic images in a digital environment.

  10. Imaging With Synthesized 2D Mammography: Differences, Advantages, and Pitfalls Compared With Digital Mammography.

    PubMed

    Zuckerman, Samantha P; Maidment, Andrew D A; Weinstein, Susan P; McDonald, Elizabeth S; Conant, Emily F

    2017-07-01

    Synthesized 2D (s2D) mammography is rapidly replacing digital mammography in breast imaging with digital breast tomosynthesis (DBT) to reduce radiation dose and maintain screening outcomes. We illustrate variations in the appearance of s2D and digital mammograms to aid in implementation of this technology. Despite subjective differences in the appearance of s2D and digital mammograms, early outcomes of screening using s2D mammography and DBT are not inferior to those achieved with digital mammography and DBT. Understanding these variations may aid in implementing this technique and improving patient outcomes.

  11. Correlation of 2D:4D digit ratio and craniofacial shape in prepubertal children.

    PubMed

    Valla, Kalliopy; Halazonetis, Demetrios J

    2014-01-01

    The 2D:4D ratio is sexually dimorphic and is considered a proxy of prenatal androgen levels, or, according to recent evidence, is related to genes involved in ocular and palate development. Our aim was to investigate correlation between the 2D:4D ratio and the shape of the craniofacial skeleton in a population of prepubertal children. We conducted a cross-sectional study in a group of 58 male and 59 female prepubertal children aged 7-12 years. Craniofacial shape was evaluated using 15 skeletal landmarks on lateral cephalometric radiographs and fingers were measured with a computer-assisted procedure that involved tracing the finger outline. Geometric morphometric analysis was applied to the craniofacial landmarks and multivariate regression between digit ratios and craniofacial shape was computed in shape space and form space. The male 2D:4D ratio was smaller than the female ratio (Cohen's d: 0.275 left hand, 0.126 right hand), but the difference was not statistically significant. Craniofacial shape did not show sexual dimorphism, but males were larger than females. No correlation was found between digit ratio and craniofacial shape in prepubertal children, either for the whole sample or for any of the two sex groups. As several factors might be involved in the development and growth of both the craniofacial complex and fingers, the 2D:4D ratio, a putative proxy for fetal sex-hormone levels, is probably unable to impose a measurable effect within the variation of a normal population. Future research needs to examine an adult sample for potential covariation arising after the pubertal growth spurt. Copyright © 2014 Wiley Periodicals, Inc.

  12. 2D-3D registration for brain radiation therapy using a 3D CBCT and a single limited field-of-view 2D kV radiograph

    NASA Astrophysics Data System (ADS)

    Munbodh, R.; Moseley, D. J.

    2014-03-01

    We report results of an intensity-based 2D-3D rigid registration framework for patient positioning and monitoring during brain radiotherapy. We evaluated two intensity-based similarity measures, the Pearson Correlation Coefficient (ICC) and Maximum Likelihood with Gaussian noise (MLG) derived from the statistics of transmission images. A useful image frequency band was identified from the bone-to-no-bone ratio. Validation was performed on gold-standard data consisting of 3D kV CBCT scans and 2D kV radiographs of an anthropomorphic head phantom acquired at 23 different poses with parameter variations along six degrees of freedom. At each pose, a single limited field of view kV radiograph was registered to the reference CBCT. The ground truth was determined from markers affixed to the phantom and visible in the CBCT images. The mean (and standard deviation) of the absolute errors in recovering each of the six transformation parameters along the x, y and z axes for ICC were varphix: 0.08(0.04)°, varphiy: 0.10(0.09)°, varphiz: 0.03(0.03)°, tx: 0.13(0.11) mm, ty: 0.08(0.06) mm and tz: 0.44(0.23) mm. For MLG, the corresponding results were varphix: 0.10(0.04)°, varphiy: 0.10(0.09)°, varphiz: 0.05(0.07)°, tx: 0.11(0.13) mm, ty: 0.05(0.05) mm and tz: 0.44(0.31) mm. It is feasible to accurately estimate all six transformation parameters from a 3D CBCT of the head and a single 2D kV radiograph within an intensity-based registration framework that incorporates the physics of transmission images.

  13. 2-D-3-D frequency registration using a low-dose radiographic system for knee motion estimation.

    PubMed

    Jerbi, Taha; Burdin, Valerie; Leboucher, Julien; Stindel, Eric; Roux, Christian

    2013-03-01

    In this paper, a new method is presented to study the feasibility of the pose and the position estimation of bone structures using a low-dose radiographic system, the entrepreneurial operating system (designed by EOS-Imaging Company). This method is based on a 2-D-3-D registration of EOS bi-planar X-ray images with an EOS 3-D reconstruction. This technique is relevant to such an application thanks to the EOS ability to simultaneously make acquisitions of frontal and sagittal radiographs, and also to produce a 3-D surface reconstruction with its attached software. In this paper, the pose and position of a bone in radiographs is estimated through the link between 3-D and 2-D data. This relationship is established in the frequency domain using the Fourier central slice theorem. To estimate the pose and position of the bone, we define a distance between the 3-D data and the radiographs, and use an iterative optimization approach to converge toward the best estimation. In this paper, we give the mathematical details of the method. We also show the experimental protocol and the results, which validate our approach.

  14. Age estimation based on Kvaal's technique using digital panoramic radiographs

    PubMed Central

    Mittal, Samta; Nagendrareddy, Suma Gundareddy; Sharma, Manisha Lakhanpal; Agnihotri, Poornapragna; Chaudhary, Sunil; Dhillon, Manu

    2016-01-01

    Introduction: Age estimation is important for administrative and ethical reasons and also because of legal consequences. Dental pulp undergoes regression in size with increasing age due to secondary dentin deposition and can be used as a parameter of age estimation even beyond 25 years of age. Kvaal et al. developed a method for chronological age estimation based on the pulp size using periapical dental radiographs. There is a need for testing this method of age estimation in the Indian population using simple tools like digital imaging on living individuals not requiring extraction of teeth. Aims and Objectives: Estimation of the chronological age of subjects by Kvaal's method using digital panoramic radiographs and also testing the validity of regression equations as given by Kvaal et al. Materials and Methods: The study sample included a total of 152 subjects in the age group of 14-60 years. Measurements were performed on the standardized digital panoramic radiographs based on Kvaal's method. Different regression formulae were derived and the age was assessed. The assessed age was then correlated to the actual age of the patient using Student's t-test. Results: No significant difference between the mean of the chronological age and the estimated age was observed. However, the values of the mean age estimated by using regression equations as given previously in the study of Kvaal et al. significantly underestimated the chronological age in the present study sample. Conclusion: The results of the study give an inference for the feasibility of this technique by calculation of regression equations on digital panoramic radiographs. However, it negates the applicability of same regression equations as given by Kvaal et al. on the study population. PMID:27555738

  15. Fully automated calculation of cardiothoracic ratio in digital chest radiographs

    NASA Astrophysics Data System (ADS)

    Cong, Lin; Jiang, Luan; Chen, Gang; Li, Qiang

    2017-03-01

    The calculation of Cardiothoracic Ratio (CTR) in digital chest radiographs would be useful for cardiac anomaly assessment and heart enlargement related disease indication. The purpose of this study was to develop and evaluate a fully automated scheme for calculation of CTR in digital chest radiographs. Our automated method consisted of three steps, i.e., lung region localization, lung segmentation, and CTR calculation. We manually annotated the lung boundary with 84 points in 100 digital chest radiographs, and calculated an average lung model for the subsequent work. Firstly, in order to localize the lung region, generalized Hough transform was employed to identify the upper, lower, and outer boundaries of lung by use of Sobel gradient information. The average lung model was aligned to the localized lung region to obtain the initial lung outline. Secondly, we separately applied dynamic programming method to detect the upper, lower, outer and inner boundaries of lungs, and then linked the four boundaries to segment the lungs. Based on the identified outer boundaries of left lung and right lung, we corrected the center and the declination of the original radiography. Finally, CTR was calculated as a ratio of the transverse diameter of the heart to the internal diameter of the chest, based on the segmented lungs. The preliminary results on 106 digital chest radiographs showed that the proposed method could obtain accurate segmentation of lung based on subjective observation, and achieved sensitivity of 88.9% (40 of 45 abnormalities), and specificity of 100% (i.e. 61 of 61 normal) for the identification of heart enlargements.

  16. 2D:4D Digit Ratio Predicts Delay of Gratification in Preschoolers

    PubMed Central

    Da Silva, Sergio; Moreira, Bruno; Da Costa, Newton

    2014-01-01

    We replicate the Stanford marshmallow experiment with a sample of 141 preschoolers and find a correlation between lack of self-control and 2D:4D digit ratio. Children with low 2D:4D digit ratio are less likely to delay gratification. Low 2D:4D digit ratio may indicate high fetal testosterone. If this hypothesis is true, our finding means high fetal testosterone children are less likely to delay gratification. PMID:25490040

  17. 2D:4D digit ratio predicts delay of gratification in preschoolers.

    PubMed

    Da Silva, Sergio; Moreira, Bruno; Da Costa, Newton

    2014-01-01

    We replicate the Stanford marshmallow experiment with a sample of 141 preschoolers and find a correlation between lack of self-control and 2D:4D digit ratio. Children with low 2D:4D digit ratio are less likely to delay gratification. Low 2D:4D digit ratio may indicate high fetal testosterone. If this hypothesis is true, our finding means high fetal testosterone children are less likely to delay gratification.

  18. Digital correction of computed X-radiographs for coral densitometry

    NASA Astrophysics Data System (ADS)

    Boucher, H.; Duprey, N.; Jiménez, C.

    2011-12-01

    Corals are widely used for environmental and climatic changes assessment as their skeletal growth is influenced by the surrounding environment. Variations in skeletal density are sensitive to environmental variations (water temperature, nutrients concentration etc.). Digitized X-radiographs have been used for coral skeleton density measurements since the 1980s. However, the shape of the X-ray beam emitted during the irradiation process is strongly distorted due to spherical spreading (inverse square law) and heel effect. Consequently, the X-ray intensity intersecting the surface of the sensitive film or the electronic sensor (e.g. PSL plate) is heterogeneous. These heterogeneities are characterized by an asymmetrical concentric pattern of decreasing intensity from the center to the edges of the X-radiographs. It commonly generates an error on density measurements that may reach up to 40%. This is twice as much as the seasonal density variations that are usually found in corals. Until now, extra X-ray images or aluminum standards were used to correct X-radiographs. Such corrective methods may be constraining when working with a high number of coral samples. We present an inexpensive, straightforward, and accurate method to correct strong heterogeneities of X-ray irradiation that affect X-ray images. The method relies on the relation between optical density (OD) and skeletal density; it is non-destructive, and provides high-resolution measurements. Our method was applied to measure density variations on Caribbean reef-building coral Siderastrea siderea from Costa Rica. The basic assumption is that the X-radiograph background, i.e., areas without objects, records the asymmetrical concentric pattern of X-ray intensity. A full image of this pattern was created with a natural neighbor interpolation. The resulting modeled image was then subtracted from the original X-ray image, permitting thus a reliable OD measurement directly on the corrected X-ray image. This Digital

  19. Comparison Between Digital and Synthetic 2D Mammograms in Breast Density Interpretation.

    PubMed

    Alshafeiy, Taghreed I; Wadih, Antoine; Nicholson, Brandi T; Rochman, Carrie M; Peppard, Heather R; Patrie, James T; Harvey, Jennifer A

    2017-07-01

    The purpose of this study was to compare assessments of breast density on synthetic 2D images as compared with digital 2D mammograms. This retrospective study included consecutive women undergoing screening with digital 2D mammography and tomosynthesis during May 2015 with a negative or benign outcome. In separate reading sessions, three radiologists with 5-25 years of clinical experience and 1 year of experience with synthetic 2D mammography read digital 2D and synthetic 2D images and assigned breast density categories according to the 5th edition of BI-RADS. Inter- and intrareader agreement was assessed for each BI-RADS density assessment and combined dense and nondense categories using percent agreement and Cohen kappa coefficient for consensus and all reads. A total of 309 patients met study inclusion criteria. Agreement between consensus BI-RADS density categories assigned for digital and synthetic 2D mammography was 80.3% (95% CI, 75.4-84.5%) with κ = 0.73 (95% CI, 0.66-0.79). For combined dense and nondense categories, agreement reached 91.9% (95% CI, 88.2-94.7%). For consensus readings, similar numbers of patients were shifted between nondense and dense categories (11 and 14, respectively) with the synthetic 2D compared with digital 2D mammography. Interreader differences were apparent; assignment to dense categories was greater with digital 2D mammography for reader 1 (odds ratio [OR], 1.26; p = 0.002), the same for reader 2 (OR, 0.91; p = 0.262), and greater with synthetic 2D mammography for reader 3 (OR, 0.86; p = 0.033). Overall, synthetic 2D mammography is comparable with digital 2D mammography in assessment of breast density, though there is some variability by reader. Practices can readily adopt synthetic 2D mammography without concern that it will affect density assessment and subsequent recommendations for supplemental screening.

  20. Image enhancement of digital periapical radiographs according to diagnostic tasks

    PubMed Central

    Choi, Jin-Woo; Han, Won-Jeong

    2014-01-01

    Purpose This study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Materials and Methods Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. Results There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Conclusion Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task. PMID:24701456

  1. Image enhancement of digital periapical radiographs according to diagnostic tasks.

    PubMed

    Choi, Jin-Woo; Han, Won-Jeong; Kim, Eun-Kyung

    2014-03-01

    This study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  2. Digital breast tomosynthesis image reconstruction using 2D and 3D total variation minimization.

    PubMed

    Ertas, Metin; Yildirim, Isa; Kamasak, Mustafa; Akan, Aydin

    2013-10-31

    Digital breast tomosynthesis (DBT) is an emerging imaging modality which produces three-dimensional radiographic images of breast. DBT reconstructs tomographic images from a limited view angle, thus data acquired from DBT is not sufficient enough to reconstruct an exact image. It was proven that a sparse image from a highly undersampled data can be reconstructed via compressed sensing (CS) techniques. This can be done by minimizing the l1 norm of the gradient of the image which can also be defined as total variation (TV) minimization. In tomosynthesis imaging problem, this idea was utilized by minimizing total variation of image reconstructed by algebraic reconstruction technique (ART). Previous studies have largely addressed 2-dimensional (2D) TV minimization and only few of them have mentioned 3-dimensional (3D) TV minimization. However, quantitative analysis of 2D and 3D TV minimization with ART in DBT imaging has not been studied. In this paper two different DBT image reconstruction algorithms with total variation minimization have been developed and a comprehensive quantitative analysis of these two methods and ART has been carried out: The first method is ART + TV2D where TV is applied to each slice independently. The other method is ART + TV3D in which TV is applied by formulating the minimization problem 3D considering all slices. A 3D phantom which roughly simulates a breast tomosynthesis image was designed to evaluate the performance of the methods both quantitatively and qualitatively in the sense of visual assessment, structural similarity (SSIM), root means square error (RMSE) of a specific layer of interest (LOI) and total error values. Both methods show superior results in reducing out-of-focus slice blur compared to ART. Computer simulations show that ART + TV3D method substantially enhances the reconstructed image with fewer artifacts and smaller error rates than the other two algorithms under the same configuration and parameters and it

  3. Digital breast tomosynthesis image reconstruction using 2D and 3D total variation minimization

    PubMed Central

    2013-01-01

    Background Digital breast tomosynthesis (DBT) is an emerging imaging modality which produces three-dimensional radiographic images of breast. DBT reconstructs tomographic images from a limited view angle, thus data acquired from DBT is not sufficient enough to reconstruct an exact image. It was proven that a sparse image from a highly undersampled data can be reconstructed via compressed sensing (CS) techniques. This can be done by minimizing the l1 norm of the gradient of the image which can also be defined as total variation (TV) minimization. In tomosynthesis imaging problem, this idea was utilized by minimizing total variation of image reconstructed by algebraic reconstruction technique (ART). Previous studies have largely addressed 2-dimensional (2D) TV minimization and only few of them have mentioned 3-dimensional (3D) TV minimization. However, quantitative analysis of 2D and 3D TV minimization with ART in DBT imaging has not been studied. Methods In this paper two different DBT image reconstruction algorithms with total variation minimization have been developed and a comprehensive quantitative analysis of these two methods and ART has been carried out: The first method is ART + TV2D where TV is applied to each slice independently. The other method is ART + TV3D in which TV is applied by formulating the minimization problem 3D considering all slices. Results A 3D phantom which roughly simulates a breast tomosynthesis image was designed to evaluate the performance of the methods both quantitatively and qualitatively in the sense of visual assessment, structural similarity (SSIM), root means square error (RMSE) of a specific layer of interest (LOI) and total error values. Both methods show superior results in reducing out-of-focus slice blur compared to ART. Conclusions Computer simulations show that ART + TV3D method substantially enhances the reconstructed image with fewer artifacts and smaller error rates than the other two algorithms under the same

  4. Fast and accurate automated measurements in digitized stereophotogrammetric radiographs.

    PubMed

    Vrooman, H A; Valstar, E R; Brand, G J; Admiraal, D R; Rozing, P M; Reiber, J H

    1998-05-01

    Until recently, Roentgen Stereophotogrammetric Analysis (RSA) required the manual definition of all markers using a high-resolution measurement table. To automate this tedious and time-consuming process and to eliminate observer variabilities, an analytical software package has been developed and validated for the detection, identification, and matching of markers in RSA radiographs. The digital analysis procedure consisted of the following steps: (1) the detection of markers using a variant of the Hough circle-finder technique; (2) the identification and labeling of the detected markers; (3) the reconstruction of the three-dimensional position of the bone markers and the prosthetic markers; and (4) the computation of micromotion. To assess the influence of film digitization, the measurements obtained from nine phantom radiographs using two different film scanners were compared with the results obtained by manual processing. All markers in the phantom radiographs were automatically detected and correctly labeled. The best results were obtained with a Vidar VXR-12 CCD scanner, for which the measurement errors were comparable to the errors associated with the manual approach. To assess the in vivo reproducibility, 30 patient radiographs were analyzed twice with the manual as well as with the automated procedure. Approximately, 85% of all calibration markers and bone markers were automatically detected and correctly matched. The calibration errors and the rigid-body errors show that the accuracy of the automated procedure is comparable to the accuracy of the manual procedure. The rigid-body errors had comparable mean values for both techniques: 0.05 mm for the tibia and 0.06 mm for the prosthesis. The reproducibility of the automated procedure showed to be slightly better than that of the manual procedure. The maximum errors in the computed translation and rotation of the tibial component were 0.11 mm and 0.24, compared to 0.13 mm and 0.27 for the manual RSA procedure

  5. Relevance of 2D radiographic texture analysis for the assessment of 3D bone micro-architecture

    SciTech Connect

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

    2006-09-15

    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 regard to fracture risk. In vivo, techniques based on high-resolution x-ray radiography associated to texture analysis have been proposed to investigate bone micro-architecture, but their relevance for giving pertinent 3D information is unclear. Thirty-three calcaneus and femoral neck bone samples including the cortical shells (diameter: 14 mm, height: 30-40 mm) were imaged using 3D-synchrotron x-ray micro-CT at the ESRF. The 3D reconstructed images with a cubic voxel size of 15 {mu}m were further used for two purposes: (1) quantification of three-dimensional trabecular bone micro-architecture (2) simulation of realistic x-ray radiographs under different acquisition conditions. The simulated x-ray radiographs were then analyzed using a large variety of texture analysis methods (co-occurrence, spectral density, fractal, morphology, etc.). The range of micro-architecture parameters was in agreement with previous studies and rather large, suggesting that the population was representative. More than 350 texture parameters were tested. A small number of them were selected based on their correlation to micro-architectural morphometric parameters. Using this subset of texture parameters, multiple regression allowed one to predict up to 93% of the variance of micro-architecture parameters using three texture features. 2D texture features predicting 3D micro-architecture parameters other than BV/TV were identified. The methodology proposed for evaluating the relationships between 3D micro-architecture and 2D texture parameters may also be used for optimizing the conditions for radiographic imaging. Further work will include the application of the method to physical radiographs. In the future, this approach could be used in combination with DXA to refine osteoporosis diagnosis.

  6. 42 CFR 37.51 - Interpreting and classifying chest radiographs-digital radiography systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-digital radiography systems. 37.51 Section 37.51 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... of Chest Radiographs § 37.51 Interpreting and classifying chest radiographs—digital radiography systems. (a) For each chest radiograph obtained at an approved facility using a digital radiography...

  7. Inter- and intraobserver variance of Cobb angle measurements with digital radiographs.

    PubMed

    Zmurko, Matthew G; Mooney, James F; Podeszwa, David A; Minster, Glenn J; Mendelow, Michael J; Guirgues, Ashraf

    2003-01-01

    This study compares the intra- and interobserver variance of Cobb angle measurements of primary and secondary curves on digital radiographs versus traditional radiographs. Four orthopaedic surgeons of varying experience measured the Cobb angles from a standard posteroanterior thoracolumbar scoliosis radiograph (25 digital, 25 traditional) on two occasions 2 weeks apart. The intra- and interobserver variances were calculated and compared for major versus minor curves and the digital versus traditional radiographs. There was no statistical difference in the mean error index, the variability in choosing the end vertebra on successive measurements, between the digital and traditional groups. Similarly, there was no significant difference in the intraobserver or interobserver variance between the digital and traditional groups. Digital radiographs are comparable to the use of traditional radiographs for following patients with adolescent idiopathic scoliosis. Furthermore, increasing years of experience appears to result in fewer errors and more consistency using the Cobb method.

  8. Electronic system for digital acquisition of rotational panoramic radiographs

    SciTech Connect

    McDavid, W.D.; Dove, S.B.; Welander, U.; Tronje, G. )

    1991-04-01

    A prototype system for digital panoramic imaging of the maxillofacial complex has been developed. In this system x-ray film is replaced by an electronic sensor that delivers the image information to a computer for storage in digital format. The images, which are similar to conventional panoramic radiographs, are displayed on a high-resolution video monitor and may be stored on optical disk for future use. Hard-copy output is also available. The present prototype system has been installed on an Orthopantomograph model OP10 panoramic x-ray machine is programmed for operation with this machine, but in principle the system can be installed on any such device. The system may be incorporated into the design of future panoramic x-ray systems or may be used to retrofit panoramic x-ray systems now using photographic film to record the radiographic image. Greater sensitivity of electronic sensors should make possible a reduction of x-ray dose to the patient, compared with film-based systems.

  9. Comparison of digital breast tomosynthesis and 2D digital mammography using a hybrid performance test

    NASA Astrophysics Data System (ADS)

    Cockmartin, Lesley; Marshall, Nicholas W.; Van Ongeval, Chantal; Aerts, Gwen; Stalmans, Davina; Zanca, Federica; Shaheen, Eman; De Keyzer, Frederik; Dance, David R.; Young, Kenneth C.; Bosmans, Hilde

    2015-05-01

    This paper introduces a hybrid method for performing detection studies in projection image based modalities, based on image acquisitions of target objects and patients. The method was used to compare 2D mammography and digital breast tomosynthesis (DBT) in terms of the detection performance of spherical densities and microcalcifications. The method starts with the acquisition of spheres of different glandular equivalent densities and microcalcifications of different sizes immersed in a homogeneous breast tissue simulating medium. These target objects are then segmented and the subsequent templates are fused in projection images of patients and processed or reconstructed. This results in hybrid images with true mammographic anatomy and clinically relevant target objects, ready for use in observer studies. The detection study of spherical densities used 108 normal and 178 hybrid 2D and DBT images; 156 normal and 321 hybrid images were used for the microcalcifications. Seven observers scored the presence/absence of the spheres/microcalcifications in a square region via a 5-point confidence rating scale. Detection performance in 2D and DBT was compared via ROC analysis with sub-analyses for the density of the spheres, microcalcification size, breast thickness and z-position. The study was performed on a Siemens Inspiration tomosynthesis system using patient acquisitions with an average age of 58 years and an average breast thickness of 53 mm providing mean glandular doses of 1.06 mGy (2D) and 2.39 mGy (DBT). Study results showed that breast tomosynthesis (AUC = 0.973) outperformed 2D (AUC = 0.831) for the detection of spheres (p  <  0.0001) and this applied for all spherical densities and breast thicknesses. By way of contrast, DBT was worse than 2D for microcalcification detection (AUC2D = 0.974, AUCDBT = 0.838, p  <  0.0001), with significant differences found for all sizes (150-354 µm), for breast thicknesses above 40 mm and for heights

  10. Comparison of digital breast tomosynthesis and 2D digital mammography using a hybrid performance test.

    PubMed

    Cockmartin, Lesley; Marshall, Nicholas W; Van Ongeval, Chantal; Aerts, Gwen; Stalmans, Davina; Zanca, Federica; Shaheen, Eman; De Keyzer, Frederik; Dance, David R; Young, Kenneth C; Bosmans, Hilde

    2015-05-21

    This paper introduces a hybrid method for performing detection studies in projection image based modalities, based on image acquisitions of target objects and patients. The method was used to compare 2D mammography and digital breast tomosynthesis (DBT) in terms of the detection performance of spherical densities and microcalcifications. The method starts with the acquisition of spheres of different glandular equivalent densities and microcalcifications of different sizes immersed in a homogeneous breast tissue simulating medium. These target objects are then segmented and the subsequent templates are fused in projection images of patients and processed or reconstructed. This results in hybrid images with true mammographic anatomy and clinically relevant target objects, ready for use in observer studies. The detection study of spherical densities used 108 normal and 178 hybrid 2D and DBT images; 156 normal and 321 hybrid images were used for the microcalcifications. Seven observers scored the presence/absence of the spheres/microcalcifications in a square region via a 5-point confidence rating scale. Detection performance in 2D and DBT was compared via ROC analysis with sub-analyses for the density of the spheres, microcalcification size, breast thickness and z-position. The study was performed on a Siemens Inspiration tomosynthesis system using patient acquisitions with an average age of 58 years and an average breast thickness of 53 mm providing mean glandular doses of 1.06 mGy (2D) and 2.39 mGy (DBT). Study results showed that breast tomosynthesis (AUC = 0.973) outperformed 2D (AUC = 0.831) for the detection of spheres (p  <  0.0001) and this applied for all spherical densities and breast thicknesses. By way of contrast, DBT was worse than 2D for microcalcification detection (AUC2D = 0.974, AUCDBT = 0.838, p  <  0.0001), with significant differences found for all sizes (150-354 µm), for breast thicknesses above 40 mm and for heights

  11. The digit ratio (2D:4D) in China: A meta-analysis.

    PubMed

    Xu, Yin; Zheng, Yong

    2015-01-01

    To explore the 2D:4D in China (mainland and Taiwan) and to analyze the influences of ethnicity, digit measurement methods, age, and latitude on Chinese 2D:4D. We here conducted a meta-analysis of the results of 28 studies. A total of 112 independent samples and 19,093 participants were included. The sex difference in left 2D:4D only approached significance when outliers were removed (P = 0.078), whereas the right 2D:4D was significantly lower in males compared to females, showing that the magnitude of sex difference was greater for the right hand than for the left hand. No significant differences were found in the 2D:4D between Han and ethnic minorities. The 2D:4D of samples measured using indirect digit measurement tended to be lower than in samples measured using direct digit measurement. Moreover, there were no effects of age and latitude on the 2D:4D in China. We concluded that the sex differences in Chinese 2D:4D are consistent with the results from western studies, and that genetic pool differences rather than latitude-related environmental variables affect the 2D:4D in China. In addition, 2D:4D measurements obtained by different digit measurement techniques should not be combined within one study, or used together in comparative studies. © 2014 Wiley Periodicals, Inc.

  12. Analysis of image quality parameter of conventional and dental radiographic digital images.

    PubMed

    Mayo, P; Ródenas, F; Verdu, G; Campayo, J M; Gallardo, S

    2010-01-01

    The image quality obtained by a radiographic equipment is very useful to characterize the physical properties of the image radiographic chain, in a quality control of the radiographic equipment. In the radiographic technique it is necessary that the evaluation of the image can guarantee the constancy of its quality to carry out a suitable diagnosis. In this work we have designed some radiographic phantoms for different radiographic digital devices, as dental, conventional, equipments with computed radiography (phosphor plate) and direct radiography (sensor) technology. Additionally, we have developed a software to analyse the image obtained by the radiographic equipment with digital processing techniques, as edge detector, morphological operators, statistical test for the detected combinations‥ The design of these phantoms let the evaluation of a wide range of operating conditions of voltage, current and time of the digital equipments. Moreover, the image quality analysis by the automatic software, let study it with objective parameters.

  13. Digit ratio 2D:4D is a possible indicator for androgenetic alopecia in males.

    PubMed

    Unal, Mehmet

    2017-08-29

    Androgenetic alopecia (AGA) is the most common hair loss. The 2D:4D digit ratio refers to the ratio of the length of the second finger to that of the fourth finger and is thought as a marker of prenatal androgen exposure. There are many studies which have examined the relationship between 2D:4D ratio and some other diseases. In this study, we evaluated the relationship between digit ratio 2D:4D and AGA. The study group was composed of a male with AGA and healthy controls. The lengths of patients' second and fourth fingers were measured using a digital caliper with a resolution of 0.01 mm. Finger length was measured on the palmar side of the hand from the basal metacarpophalangeal crease. The 2D:4D ratio was obtained by dividing the length of the second finger by the length of the fourth finger. A total of 99 males who have androgenetic alopecia with a score of grade III or more and 90 controls were included. The mean age of AGA group was 29.72 ± 5.53, and the mean age of control group was 19.63 ± 5.05. The left-hand 2D:4D ratios of AGA group (0.893 ± 0.267) were significantly lower than healthy controls (0.971 ± 0.028). No significant relationships were found between AGA severity, age of onset,and digit ratios. The left-hand digit ratio 2D:4D is lower in AGA patients, and therefore, left-hand digit ratio 2D:4D can be used as an estimation tool for AGA development in future. There is not any correlation between digit ratio and age of onset. Also, there is no correlation between digit ratio 2D:4D and AGA severity. © 2017 Wiley Periodicals, Inc.

  14. Digit ratio (2D:4D) and sprinting speed in boys.

    PubMed

    Manning, J T; Hill, M R

    2009-01-01

    Digit ratio (2D:4D), a putative correlate of prenatal testosterone, has been found to relate to performance in sport and athletics such that low 2D:4D (high prenatal testosterone) correlates with high performance. Speed in endurance races is strongly related to 2D:4D, and may be one factor that underlies the link between sport and 2D:4D, but nothing is known of the relationship between 2D:4D and sprinting speed. Here we show that running times over 50 m were positively correlated with 2D:4D in a sample of 241 boys (i.e. runners with low 2D:4D ran faster than runners with high 2D:4D). The relationship was also found for 50 m split times (at 20, 30, and 40 m) and was independent of age, BMI, and an index of maturity. However, associations between 2D:4D and sprinting speed were much weaker than those reported for endurance running. This suggests that 2D:4D is a relatively weak predictor of strength and a stronger predictor of efficiency in aerobic exercise. We discuss the effect sizes for relationships between 2D:4D and sport and target traits in general, and identify areas of strength and weakness in digit ratio research.

  15. Digital radiographic localization for CT scanning of the larynx

    SciTech Connect

    Silverman, P.M.; Korobkin, M.; Rauch, R.F.

    1983-12-01

    Computed tomography (CT) of the larynx is the preferred method for staging laryngeal carcinoma and assessing the extent of injury from trauma. The standard method of examination consists of 5 mm contiguous scans throughout the larynx in quiet respiration. Scans are performed with the patient supine with the neck slightly extended allowing the long axis of the larynx to be perpendicular to the scanning plane. A complete examination requires scanning from the supraglottic region (level of hyoid bone) to the subglottic region (level of cricoid cartlage). In the authors' experience when this method is used, multiple scans are performed cephalad to the level of interest because no upper limit of the examination is established before transaxial scans are done. We have used the lateral digital radiograph of the neck to identify specific landmarks so that the upper and lower limets of the examination can be established before scanning.

  16. Digit ratio (2D:4D) and hand preference for writing in the BBC Internet Study.

    PubMed

    Manning, J T; Peters, M

    2009-09-01

    The ratio of the length of the second to the fourth digit (2D:4D) may be negatively correlated with prenatal testosterone. Hand preference has been linked with prenatal testosterone and 2D:4D. Here we show that 2D:4D is associated with hand preference for writing in a large internet sample (n>170,000) in which participants self-reported their finger lengths. We replicated a significant association between right 2D:4D and writing hand preference (low right 2D:4D associated with left hand preference) as well as a significant correlation between writing hand preference and the difference between left and right 2D:4D or Dr-l (low Dr-l associated with left hand preference). A new significant correlation between left 2D:4D and writing hand preference was also shown (high left 2D:4D associated with left hand preference). There was a clear interaction between writing hand preference and 2D:4D: The left 2D:4D was significantly larger than the right 2D:4D in male and female left-handed writers, and the right hand 2D:4D was significantly larger than the left hand 2D:4D in male and female right-handed writers.

  17. 42 CFR 37.51 - Interpreting and classifying chest radiographs-digital radiography systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-digital radiography systems. 37.51 Section 37.51 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH..., and Submission of Chest Radiographs § 37.51 Interpreting and classifying chest radiographs—digital radiography systems. (a) For each chest radiograph obtained at an approved facility using a...

  18. Digit ratio (2D:4D) in newborns: influences of prenatal testosterone and maternal environment.

    PubMed

    Ventura, T; Gomes, M C; Pita, A; Neto, M T; Taylor, A

    2013-02-01

    The 2D:4D digit ratio is sexually-dimorphic, probably due to testosterone action through the perinatal period. We characterize the 2D:4D ratio in newborn (NB) infants, in between the pre- and postnatal surges of testosterone, and relate it to the mother's 2D:4D and to testosterone levels in the amniotic fluid (AF). Testosterone was assayed in samples of maternal plasma and AF collected at amniocentesis. Shortly after birth, 106 NBs and their mothers were measured for 2D:4D ratio. NB males had lower mean 2D:4D ratios than females but this dimorphism was significant only for the left hand (males: 0.927; females: 0.950; p=0.004). Mothers who had sons had lower 2D:4D ratios than those who had daughters and the mother's 2D:4D were higher than those of NBs regardless of sex. Both hands of NB females were negatively correlated with AF testosterone and positively correlated with the mother's 2D:4D, but males showed no significant associations. Maternal plasma testosterone also showed a negative weak correlation with NB's digit ratio in both sexes. Sexual dimorphism at birth was only significant for the left hand, in contrast with reports of greater right hand dimorphism, suggesting that postnatal testosterone is determinant for 2D:4D stabilization. The lower 2D:4D ratios in mothers who had sons support claims that hormone levels in parents are influential for determining their children's sex. NB female's digit ratio, but not males', was associated to the level of AF testosterone. The mother's 2D:4D ratios were positively correlated with their daughters' 2D:4D, but the same was not observed for male NBs, suggesting that prenatal testosterone levels in male fetus lead their 2D:4D ratios to stray from their mothers' with high individual variability. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. 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

  20. Detectability of normal anatomy in digital panoramic radiographs.

    PubMed

    Gross, Heidi; Nilsson, Mats; Hellén-Halme, Kristina

    2014-01-01

    The aim of this study was to evaluate the image quality of digital panoramic radiographs and its correlation with the detectability of normal anatomical structures. The effects of image enhancement on the detectability were also studied. A total of 500 panoramic images (DICOM format) obtained with a storage phosphor-based digital system were evaluated. The image quality and the detectability of selected normal anatomical structures were evaluated in all images. Images with inadequate image quality were subjected to enhancement after which the detectability of the structures was re-evaluated. Only 9% of the images were classified as having adequate technical quality. The main sources of poor image quality were that the patient's tongue was not held against the palate and incorrect positioning of the patient. Not holding the tongue against the palate was found to have a negative impact on the detectability of maxillary structures. Of the images with horizontal positioning errors the patient's head was rotated to the left in 81% (70 images). The most effective form of enhancement was a combination of increased contrast and decreased brightness. Images in which the tongue was not held against the palate were partially improved, whereas images with positioning errors remained unaffected by this enhancement. In conclusion, most of the panoramic images showed some technical flaws. The marginal bone level and the maxillary area were the most difficult areas to reproduce. Retakes could be avoided in some cases by using image enhancement. However, this should not be regarded as an option to avoid poor image quality.

  1. Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

    NASA Astrophysics Data System (ADS)

    Fieselmann, Andreas; Steinbrener, Jan; Jerebko, Anna K.; Voigt, Johannes M.; Scholz, Rosemarie; Ritschl, Ludwig; Mertelmeier, Thomas

    2016-03-01

    In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D cone-beam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

  2. Digit ratio (2D:4D) in a Chinese population with schizophrenia.

    PubMed

    Qian, Wenli; Huo, Zhenghao; Lu, Hong; Sheng, Youjing; Geng, Zhi; Ma, Zhanbing

    2016-07-01

    Prenatal gonadal hormones may play a major role in pathogenesis of schizophrenia. It has been reported that second to fourth digit ratio (2D:4D) was influenced by the levels of exposure to prenatal testosterone and estrogen. So, 2D:4D may help to predict the disease susceptibility to schizophrenia. The aim of this study was to investigate the relationship between the digit ratio (2D:4D) and schizophrenia in Chinese population. We recruited 178 schizophrenics (males: 76; females: 102) and 365 controls (males: 218; females: 147) in this study. Photocopies of both hands were collected and left hand, right hand, mean hand and left minus right hand (DL-R) 2D:4D were analyzed. The right and mean hand 2D:4D ratios were significantly higher in schizophrenics compared to that of controls in both males and females. The left hand 2D:4D ratio in female schizophrenics was also significantly higher than in controls. Compared to controls, the DL-R 2D:4D in male schizophrenics was obviously higher. There was a weakly (but not significantly) negative correlation between the mean hand 2D:4D ratio and the age of onset. The 2D:4D ratio may correlate with the schizophrenia in Chinese population, and it may be an indicator of schizophrenia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. A digitally reconstructed radiograph algorithm calculated from first principles

    SciTech Connect

    Staub, David; Murphy, Martin J.

    2013-01-15

    Purpose: To develop an algorithm for computing realistic digitally reconstructed radiographs (DRRs) that match real cone-beam CT (CBCT) projections with no artificial adjustments. Methods: The authors used measured attenuation data from cone-beam CT projection radiographs of different materials to obtain a function to convert CT number to linear attenuation coefficient (LAC). The effects of scatter, beam hardening, and veiling glare were first removed from the attenuation data. Using this conversion function the authors calculated the line integral of LAC through a CT along rays connecting the radiation source and detector pixels with a ray-tracing algorithm, producing raw DRRs. The effects of scatter, beam hardening, and veiling glare were then included in the DRRs through postprocessing. Results: The authors compared actual CBCT projections to DRRs produced with all corrections (scatter, beam hardening, and veiling glare) and to uncorrected DRRs. Algorithm accuracy was assessed through visual comparison of projections and DRRs, pixel intensity comparisons, intensity histogram comparisons, and correlation plots of DRR-to-projection pixel intensities. In general, the fully corrected algorithm provided a small but nontrivial improvement in accuracy over the uncorrected algorithm. The authors also investigated both measurement- and computation-based methods for determining the beam hardening correction, and found the computation-based method to be superior, as it accounted for nonuniform bowtie filter thickness. The authors benchmarked the algorithm for speed and found that it produced DRRs in about 0.35 s for full detector and CT resolution at a ray step-size of 0.5 mm. Conclusions: The authors have demonstrated a DRR algorithm calculated from first principles that accounts for scatter, beam hardening, and veiling glare in order to produce accurate DRRs. The algorithm is computationally efficient, making it a good candidate for iterative CT reconstruction techniques

  4. A digitally reconstructed radiograph algorithm calculated from first principles

    PubMed Central

    Staub, David; Murphy, Martin J.

    2013-01-01

    Purpose: To develop an algorithm for computing realistic digitally reconstructed radiographs (DRRs) that match real cone-beam CT (CBCT) projections with no artificial adjustments. Methods: The authors used measured attenuation data from cone-beam CT projection radiographs of different materials to obtain a function to convert CT number to linear attenuation coefficient (LAC). The effects of scatter, beam hardening, and veiling glare were first removed from the attenuation data. Using this conversion function the authors calculated the line integral of LAC through a CT along rays connecting the radiation source and detector pixels with a ray-tracing algorithm, producing raw DRRs. The effects of scatter, beam hardening, and veiling glare were then included in the DRRs through postprocessing. Results: The authors compared actual CBCT projections to DRRs produced with all corrections (scatter, beam hardening, and veiling glare) and to uncorrected DRRs. Algorithm accuracy was assessed through visual comparison of projections and DRRs, pixel intensity comparisons, intensity histogram comparisons, and correlation plots of DRR-to-projection pixel intensities. In general, the fully corrected algorithm provided a small but nontrivial improvement in accuracy over the uncorrected algorithm. The authors also investigated both measurement- and computation-based methods for determining the beam hardening correction, and found the computation-based method to be superior, as it accounted for nonuniform bowtie filter thickness. The authors benchmarked the algorithm for speed and found that it produced DRRs in about 0.35 s for full detector and CT resolution at a ray step-size of 0.5 mm. Conclusions: The authors have demonstrated a DRR algorithm calculated from first principles that accounts for scatter, beam hardening, and veiling glare in order to produce accurate DRRs. The algorithm is computationally efficient, making it a good candidate for iterative CT reconstruction techniques

  5. Digit ratio (2D:4D) in homosexual and heterosexual men from Austria.

    PubMed

    Voracek, Martin; Manning, John T; Ponocny, Ivo

    2005-06-01

    Neurohormonal theories of sexual orientation emphasize the organizational effects of testosterone on the developing brain. A recent suggestion, that the ratio of the length of the 2nd and 4th digits (2D:4D) is negatively correlated with prenatal testosterone, has led to a number of studies of 2D:4D in homosexual and heterosexual men and women. The results have been mixed. In comparison to heterosexual men, mean 2D:4D in gay men has been reported to be hypermasculinized (lower 2D:4D), hypomasculinized (higher 2D:4D), or to show no significant difference. Here, we report mean 2D:4D in Austrian homosexual and heterosexual men. We found no significant difference between means for homosexual and heterosexual 2D:4D, with values for both falling between 0.96 to 0.97. There are now 6 reports of 2D:4D in heterosexual and homosexual men. Considering Caucasian men, the studies from the United States show low heterosexual mean 2D:4D, and homosexual mean 2D:4D is higher or similar to that of heterosexuals. The European studies show high heterosexual mean 2D:4D, and comparisons with homosexuals reveal the latter to have lower or similar mean 2D:4D to that of heterosexuals. We discuss these results in relation to the suggestion that mean 2D:4D in heterosexual men differs across populations but mean 2D:4D in homosexuals shows less geographical variation (the "uniform mean hypothesis"). It is concluded that more data are required to clarify whether or not there is a 2D:4D effect for sexual orientation in men.

  6. Radiographer.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document, which is designed for use in developing a tech prep competency profile for the occupation of radiographer, lists technical competencies and competency builders for 18 units pertinent to the health technologies cluster in general as well as those specific to the occupation of radiographer. The following skill areas are covered in the…

  7. Digit ratio (2D:4D) and performance in Indian swimmers.

    PubMed

    Sudhakar, H H; Veena, Umesh B; Tejaswi, R Nadig

    2013-01-01

    It has been suggested that achievement in sports is correlated with a putative measure of prenatal testosterone the 2nd to 4th digit ratio (2D:4D). It has been shown that digit ratio (2D:4D) is negatively associated with prenatal testosterone, and it is also negatively associated with ability in sports. This study examined associations between 2D:4D and performance of both male and female National level Indian swimmers. Age matched non-sports personnel formed the control. Lengths of second and fourth digits were measured after scanning both hands and their ratio calculated. Our results show lower 2D:4D values in males compared to females (P < 0.05). Among male, but not female, swimmers had significantly (P < 0.05) lower 2D:4D ratio. Low 2D:4D in male swimmers suggests they are more prenatally programmed via long-lasting extra genital effects of testosterone. 2D:4D ratio could be used to identify young sports personnel who have potential to reach high levels of performance.

  8. Comparison of digit ratio (2D:4D) between Brazilian men with and without prostate cancer.

    PubMed

    Mendes, P H C; Martelli, D R B; de Melo Costa, S; Gonçalves, E; Macedo, C P; Silveira, M F; Martelli Júnior, H

    2016-03-01

    Digit ratio (2D:4D) has been suggested as a proxy biomarker for prenatal androgen activity and has been linked to prostate cancer, as the genes that regulate the formation and differentiation of the fingers are also related to the carcinogenesis of prostate cancer. To investigate the possible correlation between right hand, left hand and right hand minus left hand (DR-L) 2D:4D and prostate cancer of Brazilian subjects by comparing 2D:4D ratios of individuals diagnosed with prostate cancer and individuals without the disease. Also, to inquire the relationship between 2D:4D and severity of prostate cancer through Gleason scores. Digital measurements of the lengths of the index and ring fingers of both hands of patients diagnosed with prostate cancer (PCA group, n=100) and healthy control individuals (n=100) were obtained using a digital vernier caliper. Means of the 2D:4D ratios were compared. Data were analyzed by the Student's t-test for unpaired samples, Mann-Whitney test and Spearman's correlation with a significance level of 5%. The PCA group presented significantly lower right and left 2D:4D (P=0.001 and P=0.002, respectively) in comparison to healthy controls, but DR-L were not significantly different between groups (P=0.589). In addition, digit ratios were not correlated to Gleason score for either hand or in DR-L. 2D:4D seems to be a marker for screening patients for prostate cancer in an admixed population, as males with prostate cancer present lower 2D:4D than healthy subjects. On the other hand, 2D:4D does not appear to be associated with the severity of prostate cancer.

  9. Relationships between digit ratio (2D:4D) and female competitive rowing performance.

    PubMed

    Hull, Melissa J; Schranz, Natasha K; Manning, John T; Tomkinson, Grant R

    2015-01-01

    Digit ratio (2D:4D), a measure of prenatal testosterone exposure, is weakly-to-moderately associated with increased physical performance, although the evidence is far stronger for males than females. To examine the relationship between 2D:4D and measured on-water rowing performance in young females competing at the Australian Rowing Championships. Using an observational, cross-sectional design, female rowers (n = 69, aged 12-30 years) who competed in single sculls events at the Australian Rowing Championships in 2007 and 2008 had numerous physical and digital anthropometric measurements taken, including 2D:4D measurements. Relationships between 2D:4Ds and race times were examined using Pearson's correlations, partial correlations and multiple regression. Partial Least Squares regression analysis determined the strength of the 2D:4D as a predictor of race time relative to 78 body dimensions plus age. Overall, weak to strong positive correlations between 2D:4D and race time were found; that is, females with smaller 2D:4Ds had faster race times than females with larger 2D:4Ds. Relationships were weak to moderate for all females (r = 0.29-0.32), moderate-to-strong for senior rowers (aged ≥20 years; r = 0.42-0.55), and weak for junior rowers (aged <20 years; r = 0.13-0.18), with all relationships persisting following adjustment for age. Partial Least Squares regression analysis showed that 2D:4Ds had high predictive importance relative to other body dimensions. Females with smaller 2D:4Ds rowed substantially faster than females with larger 2D:4Ds, with the 2D:4D possibly linked to underlying characteristics that have been optimized over time resulting in better rowing performance. © 2014 Wiley Periodicals, Inc.

  10. Domain specific relationships of 2D:4D digit ratio in risk perception and risk behavior.

    PubMed

    Kim, Youngjun; Kim, Kyungil; Kim, Tae Hoon

    2014-01-01

    The 2D:4D digit ratio (henceforth, 2D:4D) is accepted as a marker of prenatal testosterone, demonstrating gender differences. The present study reveals that 2D:4D shows not only gender differences but also individual differences in personality and risk-taking behavior. We measured individual participants' 2D:4D, structural personality, and risk-taking attitude scores. The result of the current study replicates the gender difference in 2D:4D in previous researches. However, we found different aspects of the correlations among 2D:4D, personality, and risk-taking attitude. Path analyses indicated that 2D:4D passes through personality factors before reaching the risk-taking attitude, particularly in the financial domain activities of investing and gambling. Also we observed a specific relationship between right-hand 2D:4D and emotionality and between left-hand 2D:4D and agreeableness. Finally, we suggest multiple path models of 2D:4D and personality in risk taking depending on the domain.

  11. [Effect of digital radiography processing parameters on digital chest radiograph for occupational exposed workers].

    PubMed

    Wang, Xiao-hua; Liu, Dong-sheng; Xuan, Xiao; Kang, Han; Yuan, Hui-shu

    2013-05-01

    To investigate the effect of different processing parameters of digital radiography (DR) on the image quality of digital chest radiograph in dust-exposed workers. One hundred and five dust-exposed workers underwent both high-KV radiography and DR to obtain chest radiographs; the image processing parameters were set by the conventional processing method for digital chest radiograph (method A) and the processing method based on the special requirements of occupational diseases (method B). With the high-KV chest radiograph as the reference, the image qualities at 10 anatomic sites of DR image were graded. The images acquired by DR and high-KV radiography were compared, and the DR images acquired by methods A and B were also compared. For method A, the scores at the 10 anatomic sites of DR image were mostly 0 and +1, accounting for over 88%, and the mean score was 0.23 ∼ 0.65, there was a significant difference between the mean score of DR image and the score of high-KV image (P < 0.001). For method B, the scores at the 10 anatomic sites of DR image were mostly 0, accounting for over 65%, and the mean score was -0.01∼ +0.02 except at the pleura and chest wall; there was no significant difference between the mean score of DR image and the score of high-KV image (P > 0.05). There were significant differences in the scores at the 10 anatomic sites between the DR images acquired by methods A and B (P < 0.01). The DR images acquired based on different processing parameters are different. The quality of DR image acquired by the processing method based on the special requirements of occupational diseases is similar to that of high-KV image at the anatomic sites.

  12. Automatic segmentation of bones from digital hand radiographs

    NASA Astrophysics Data System (ADS)

    Liu, Brent J.; Taira, Ricky K.; Shim, Hyeonjoon; Keaton, Patricia

    1995-05-01

    The purpose of this paper is to develop a robust and accurate method that automatically segments phalangeal and epiphyseal bones from digital pediatric hand radiographs exhibiting various stages of growth. The algorithm uses an object-oriented approach comprising several stages beginning with the most general objects to be segmented, such as the outline of the hand from background, and proceeding in a succession of stages to the most specific object, such as a specific phalangeal bone from a digit of the hand. Each stage carries custom operators unique to the needs of that specific stage which will aid in more accurate results. The method is further aided by a knowledge base where all model contours and other information such as age, race, and sex, are stored. Shape models, 1-D wrist profiles, as well as an interpretation tree are used to map model and data contour segments. Shape analysis is performed using an arc-length orientation transform. The method is tested on close to 340 phalangeal and epiphyseal objects to be segmented from 17 cases of pediatric hand images obtained from our clinical PACS. Patient age ranges from 2 - 16 years. A pediatric radiologist preliminarily assessed the results of the object contours and were found to be accurate to within 95% for cases with non-fused bones and to within 85% for cases with fused bones. With accurate and robust results, the method can be applied toward areas such as the determination of bone age, the development of a normal hand atlas, and the characterization of many congenital and acquired growth diseases. Furthermore, this method's architecture can be applied to other image segmentation problems.

  13. Digit ratio (2D:4D) and muscular strength in adolescent boys.

    PubMed

    Tomkinson, Jordan M; Tomkinson, Grant R

    2017-07-08

    Using a cross-sectional design, this study quantified the relationship between the digit ratio (2D:4D) and muscular strength in 57 adolescent boys. 2D:4D was very likely a moderate negative correlate of handgrip strength, even after adjustment for age and body size. This result may reflect the organizational benefits of prenatal testosterone. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Fast calculation of digitally reconstructed radiographs using light fields

    NASA Astrophysics Data System (ADS)

    Russakoff, Daniel B.; Rohlfing, Torsten; Rueckert, Daniel; Shahidi, Ramin; Kim, Daniel; Maurer, Calvin R., Jr.

    2003-05-01

    Calculating digitally reconstructed radiographs (DRRs)is an important step in intensity-based fluoroscopy-to-CT image registration methods. Unfortunately, the standard techniques to generate DRRs involve ray casting and run in time O(n3),where we assume that n is approximately the size (in voxels) of one side of the DRR as well as one side of the CT volume. Because of this, generation of DRRs is typically the rate-limiting step in the execution time of intensity-based fluoroscopy-to-CT registration algorithms. We address this issue by extending light field rendering techniques from the computer graphics community to generate DRRs instead of conventional rendered images. Using light fields allows most of the computation to be performed in a preprocessing step;after this precomputation step, very accurate DRRs can be generated in time O(n2). Using a light field generated from 1,024 DRRs of resolution 256×256, we can create new DRRs that appear visually identical to ones generated by conventional ray casting. Importantly, the DRRs generated using the light field are computed over 300 times faster than DRRs generated using conventional ray casting(50 vs.17,000 ms on a PC with a 2 GHz Intel Pentium 4 processor).

  15. Using 2D: 4D digit ratios to determine motor skills in children.

    PubMed

    Wang, Y; Wang, H-L; Li, Y-H; Zhu, F-L; Li, S-J; Ni, H

    2016-03-01

    In past few decades, there has an outburst of research surrounding second to fourth finger digit ratio (2D:4D) and its relation to prenatal sex steroids including both testosterone and estrogen. In utero, testosterone and estrogen are responsible for the differences in digit ratio between the genders. Recent research has tried to extend past the influence of steroids and look at the potential effect of digit ratios on fine and gross motor skills in children. We compiled the current understanding of the connection between sex hormones and the development of the 2D:4D ratio as well as the effect the ratio has on motor skills. There seems to be a significant positive correlation between 2D:4D digit ratio and precision of fine motor skill. In addition, there is a negative correlation between 2D:4D ratio and speed of fine motor activity. In this review, we will outline the use of 2D:4D ratio as a biomarker for prenatal sex steroids and through that, a proxy marker for fine and gross motor skills.

  16. Digit ratio (2D:4D) and performance in elite rugby players.

    PubMed

    Bennett, M; Manning, J T; Cook, C J; Kilduff, L P

    2010-11-01

    The relative length of the second and fourth digits (2D:4D) is a putative marker for prenatal testosterone. Low 2D:4D has been reported to correlate with high performance in sport in general. Here, for the first time, we examine the relationship between 2D:4D and performance in elite rugby players. The 44 players (28 forwards, 16 backs) were drawn from the Ospreys Rugby Union Club and 44 age-matched controls. The measures of performance comprised age-adjusted number of international performances (caps) for Wales, a comparison of coaches' first-choice League team with others, and the number of tries scored by backs in club matches. Compared with controls, players were larger and had lower 2D:4D for the right and left hand. With regard to number of caps, players with low 2D:4D in their right hand and low right 2D:4D compared with their left (right - left 2D:4D difference) had high numbers of caps. First-choice players did not differ significantly from second-choice players in their 2D:4D but they did have a lower right - left 2D:4D difference than second-choice players. Low right 2D:4D and low right - left 2D:4D difference were significantly linked with large numbers of tries. We conclude that low right 2D:4D and low right - left 2D:4D difference are predictors of high rugby performance.

  17. Heritability of digit ratio (2D:4D) in rhesus macaques (Macaca mulatta).

    PubMed

    Nelson, Emma; Voracek, Martin

    2010-01-01

    The second-to-fourth digit ratio (2D:4D) is a putative biomarker for prenatal androgen effects, which has been widely employed to study androgenic-programming effects on shaping sex-linked traits and behaviours in humans. This approach is now increasingly applied to non-human species. Heritability studies of 2D:4D in both humans and zebra finches indicate substantial genetic contributions to the expression of this trait. This study examines the heritability of 2D:4D in rhesus macaques, based on the resemblance of mother-infant dyads, to see how these compare with human values. Results suggest that familial resemblance in 2D:4D is also strong in rhesus monkeys. Heritability estimates were within the range of estimates from human studies. These preliminary results suggest that the strength of heritability of 2D:4D may generalize across taxa.

  18. Relationships between digit ratio (2D:4D) and basketball performance in Australian men.

    PubMed

    Frick, Nathan A; Hull, Melissa J; Manning, John T; Tomkinson, Grant R

    2017-05-06

    To investigate relationships between the digit ratio (2D:4D) and competitive basketball performance in Australian men. Using an observational cross-sectional design a total of 221 Australian basketball players who competed in the Olympic Games, International Basketball Federation World Championships/Cup, Australian National Basketball League, Central Australian Basketball League or socially had their 2D:4Ds measured. Analysis of variance was used to assess differences in mean 2D:4Ds between men playing at different competitive standards, with relationships between 2D:4Ds and basketball game-related statistics assessed using Pearson's product moment correlations in men playing at a single competitive standard. There were significant differences between competitive standards for the left 2D:4D following Bonferroni correction, but not for the right 2D:4D, with basketballers who achieved higher competitive standards tending to have lower left 2D:4Ds. No important correlations between 2D:4D and basketball game-related statistics were found, with correlations typically negligible. This study indicated that the 2D:4D can discriminate between basketballers competing at different standards, but not between basketballers within a single competitive standard using objective game-related statistics. © 2016 Wiley Periodicals, Inc.

  19. The Relationship Between Digit Ratio (2D:4D) and Sexual Orientation in Men from China.

    PubMed

    Xu, Yin; Zheng, Yong

    2016-04-01

    We examined the relationship between 2D:4D digit ratio and sexual orientation in men from China and analyzed the influences of the components used to assess sexual orientation and the criteria used to classify individuals as homosexual on this relationship. A total of 309 male and 110 female participants took part in a web-based survey. Our results showed that heterosexual men had a significantly lower 2D:4D than heterosexual women and exclusively homosexual men had a significantly higher left 2D:4D than heterosexual men whereas only exclusively homosexual men had a significantly higher right 2D:4D than heterosexual men when sexual orientation was assessed via sexual attraction. The left 2D:4D showed a significant positive correlation with sexual identity, sexual attraction, and sexual behavior, and the right 2D:4D showed a significant positive correlation with sexual attraction. The effect sizes for differences in 2D:4D between homosexual and heterosexual men varied according to criteria used to classify individuals as homosexual and sexual orientation components; the more stringent the criteria (scores closer to the homosexual category), the larger the effect sizes; further, sexual attraction yielded the largest effect size. There were no significant effects of age and latitude on Chinese 2D:4D. This study contributes to the current understanding of the relationship between 2D:4D and male sexual orientation.

  20. Second to fourth digit ratio (2D:4D) and coronary heart disease.

    PubMed

    Lu, Hong; Ma, Zhanbing; Zhao, Junli; Huo, Zhenghao

    2015-07-01

    Sex steroid exposure during human development may influence disease susceptibility. Second to fourth digit ratio (2D:4D) is thought to be a putative biomarker for prenatal hormone level during foetal life. Recently there has been a great deal of interest in 2D:4D and risk of disease in adulthood. We explored the relationship between 2D:4D ratio and coronary heart disease. Photocopies of the two hands of 310 males (controls: 155; patients: 155) were collected at Yin chuan city, in the Ningxia province of China. Left hand, right hand, mean hand and right minus left 2D:4D (Dr-l) were analysed. The mean values of 2D:4D ratio in patients were higher than those of CSIN controls. The patients showed significantly higher 2D:4D (left hand: P < 0.01; right hand, mean hand: P < 0.05) than controls. In patients, 2D:4D (especially left hand 2D:4D) were inversely associated with age at diagnosis (left hand: P < 0.001; right hand, mean hand: P < 0.05). No association between Dr-l and age or age at presentation of disease was observed in the groups. 2D:4D may correlate particularly with risk of coronary heart disease in Chinese men. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Clinical applications of digital 2-D and 3-D radiography for the periodontist.

    PubMed

    Eshraghi, Thomas; McAllister, Nicole; McAllister, Brad

    2012-09-01

    Although there has been rapid development of imaging technology within dentistry, there has been limited evidence-based research documenting the benefits of digital radiography. We searched MEDLINE for relevant studies and review papers demonstrating clinical applications, limitations, and advancements within digital radiography. Two-dimensional (2-D) and 3-D digital radiography has become a powerful diagnostic tool for simple and complex procedures, including implant reconstruction. Recent advancements have reduced radiation exposure, increased resolution, and improved detection capabilities of complementary metal oxide semiconductor (CMOS) and cone-beam computed tomography (CBCT) sensors. The current review summarizes such advances and outlines advanced CBCT implant-planning techniques. While evidence-based research grows, the logistic, diagnostic, and planning improvements of 2-D and 3-D digital radiography are irrefutable with the potential to supplant conventional techniques. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Decreased digit ratio (2D:4D) and gastric cancer in Chinese men.

    PubMed

    Sheng, Youjing; Qian, Wenli; Wang, Lu; Huo, Zhenghao; Lu, Hong; Yu, Haochen; Geng, Zhi; Cheng, Ping

    2016-12-01

    The development of finger length is influenced by the level of hormones during pregnancy in the womb. The relative length of 2nd to 4th digit (2D:4D) is considered as a putative marker for prenatal hormone exposure and may represent an individual susceptibility to certain diseases, particularly those hormone-related cancers (e.g., gastric cancer). The aim of this study is to investigate whether there is a possible relationship between 2D:4D ratio and gastric cancer (GCA) in Chinese men. 94 male patients with GCA and 91 controls were chosen to participate in this study. Photographs of both hands were collected and then the lengths of second and fourth digits of both hands were measured. Left hand, right hand, mean hand, and right minus left hand (∆R-L) 2D:4D ratios were analyzed and compared. In GCA group, 2D:4D ratios were significantly lower (right hand: p<0.01; left hand, mean hand: p<0.001) than controls. No association was observed between 2D:4D ratio and tumor staging (neither in tumor size (T) nor in lymph node involvement (N) or distant metastases (M)). There was also no correlation between 2D:4D ratio and age of onset. Decreased 2D:4D ratio may be an indicator for forecasting the susceptibility to develop GCA. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Radiographic 2D:4D index in females: no relation to anthropometric, behavioural, nutritional, health-related, occupational or fertility variables

    PubMed Central

    Vehmas, Tapio; Solovieva, Svetlana; Leino-Arjas, Päivi

    2006-01-01

    Background The ratio of index finger to ring finger length (2D:4D index) may be an indicator of gonadal hormone exposure, because the differentiation of gonads, fingers and toes is influenced by the same HOXA and HOHD genes. Some previous studies have found significant associations between the 2D:4D index and sexual, psychological or behavioural variables. We studied the usability of the radiographic 2D:4D index as a potential predictor of several features in a large female sample. Methods 271 female dentists and 219 teachers (age 45 – 63 years) had their hands radiographed and their right 2nd and 4th fingers measured from the base of the bony proximal phalanxes to the tip of the distal phalanxes to define the radiographic 2D:4D index. The study subjects were classified into two distinctly separate clusters (by using cluster analysis with the K-means algorithm) in each of the following dimensions: anthropometric (including four items), behavioural (five items), nutritional (five items), health-related (seven items), occupational (Karasek job control and job demand scores) and fertility (four items). Results The radiographic 2D:4D index ranged from 0.845 to 0.981 (mean 0.925, SD 0.021). The intraclass correlation between three radiographers' measurements (31 cases) was 0.971. No differences concerning the 2D:4D index were found between clusters 1 and 2 in any studied dimension, nor did any of the items in clusters have relations with the 2D:4D index when tested separately with bivariate tests. Conclusion Despite the ideal set-up of the measuring possibilities in a relatively large radiographic material the variables currently studied were not dependent on the length of finger bones. It can therefore be questioned whether any real associations between the bony 2D:4D index in adult life and (direct or indirect) hormone dependent effects exist. There may be a publication bias explaining that mostly positive findings have been the previously reported. However, the

  4. Radiographic 2D:4D index in females: no relation to anthropometric, behavioural, nutritional, health-related, occupational or fertility variables.

    PubMed

    Vehmas, Tapio; Solovieva, Svetlana; Leino-Arjas, Päivi

    2006-08-25

    The ratio of index finger to ring finger length (2D:4D index) may be an indicator of gonadal hormone exposure, because the differentiation of gonads, fingers and toes is influenced by the same HOXA and HOHD genes. Some previous studies have found significant associations between the 2D:4D index and sexual, psychological or behavioural variables. We studied the usability of the radiographic 2D:4D index as a potential predictor of several features in a large female sample. 271 female dentists and 219 teachers (age 45 - 63 years) had their hands radiographed and their right 2nd and 4th fingers measured from the base of the bony proximal phalanxes to the tip of the distal phalanxes to define the radiographic 2D:4D index. The study subjects were classified into two distinctly separate clusters (by using cluster analysis with the K-means algorithm) in each of the following dimensions: anthropometric (including four items), behavioural (five items), nutritional (five items), health-related (seven items), occupational (Karasek job control and job demand scores) and fertility (four items). The radiographic 2D:4D index ranged from 0.845 to 0.981 (mean 0.925, SD 0.021). The intraclass correlation between three radiographers' measurements (31 cases) was 0.971. No differences concerning the 2D:4D index were found between clusters 1 and 2 in any studied dimension, nor did any of the items in clusters have relations with the 2D:4D index when tested separately with bivariate tests. Despite the ideal set-up of the measuring possibilities in a relatively large radiographic material the variables currently studied were not dependent on the length of finger bones. It can therefore be questioned whether any real associations between the bony 2D:4D index in adult life and (direct or indirect) hormone dependent effects exist. There may be a publication bias explaining that mostly positive findings have been the previously reported. However, the associations of the 2D:4D index with

  5. Digit ratio (2D:4D) in Chinese women with breast cancer.

    PubMed

    Hong, Lu; Zhan-Bing, Ma; Zhi-Yun, Shi; Xiao-Xia, Song; Jun-Li, Zhao; Zheng-Hao, Huo

    2014-01-01

    Digit ratio, especially second-to-fourth digit ratio (2D:4D) is established in utero and is positively correlated with oestrogen in men and women. It is a putative biomarker for prenatal hormone exposure and may represent an individual predisposition to certain diseases (e.g., breast cancer). The aim of the present study is to investigate whether there is a link between digit ratio (2D:4D) and breast cancer in Chinese populations. The controls we chose were healthy subjects-age and -sex matched to the patients diagnosed with breast cancer. Photocopies of the two hands of 218 women (controls: 109; patients: 109) were collected. Left hand, right hand, mean hand, and right minus left 2D:4D (Dr-l ) were analyzed. The patients with breast cancer presented significantly higher 2D:4D than controls (left: P < 0.01; right: P < 0.05; mean: P < 0.05). The mean values of 2D:4D on the left hand were significantly higher than those on the right hand in the two groups, respectively (controls: P < 0.05; patients: P ≤ 0.01). In patients, there was a significantly negative correlation between 2D:4D (left hand: P < 0.01; right hand, mean: P < 0.05) and the presented age with breast cancer, but no association between Dr-l and age of presented disease. Digit ratio (2D:4D) may correlate with the increased risk of breast cancer. Copyright © 2014 Wiley Periodicals, Inc.

  6. Familial digit ratio (2D:4D) associations in a general population sample from Wales.

    PubMed

    Richards, Gareth; Bellin, Wynford; Davies, William

    2017-09-01

    The relative length of the second and fourth fingers (2D:4D) may be a sex-linked correlate of prenatal androgen exposure. However, the nature of the sex-linkage is controversial, with evidence for both X- and Y-linkage of the 2D:4D phenotype. To examine transgenerational effects relating to sex-linkage. In addition, assortative mating on 2D:4D was considered, as well as associations between 2D:4D and age and sex. A family study was conducted. Parents and offspring completed a demographic questionnaire, and digit ratios were calculated from photocopies of participants' hands. We recruited and phenotyped 585 individuals attending a cultural festival in Wales. 2D:4D information was available for 47 mother-son dyads, 70 mother-daughter dyads, 31 father-son dyads and 30 father-daughter dyads. Correlations between 2D:4D of parents and children, as well as between mothers and fathers were conducted. 2D:4D was also examined in relation to age and sex. There was a sex difference in 2D:4D (males2D:4D, but no significant correlation between mother and son ratios, nor between father and offspring ratios. The overall pattern of correlations (with emphasis on father-son dyads) was not supportive of Y-linkage. There was a positive correlation between 2D:4D and age in children, and a negative correlation between 2D:4D and age in adults, and no evidence of assortative mating. Our data are consistent with the notion of 2D:4D as a sexually-dimorphic, mildly age-sensitive, and transgenerationally-transmitted trait that is more likely to be X- than Y-linked. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. 42 CFR 37.42 - Chest radiograph specifications-digital radiography systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... radiograph specifications—digital radiography systems. (a) Miners must be disrobed from the waist up at the... maximum pixel pitch of 200µm, with a minimum bit depth of 10. Spatial resolution must be at least 2.5 line...

  8. Use of 2D:4D digit ratios to determine sex.

    PubMed

    Barrett, Christopher K; Case, D Troy

    2014-09-01

    Second to fourth digit ratios (2D:4D) are sexually dimorphic in human hands and established by the 13th gestational week. Application of 2D:4D for determining sex in living individuals by Kanchan et al. (Forensic Sci Int, 181, 2008, 53.e1) produced classification rates of 80% for males and 74-78% for females. Few studies have explored the use of 2D:4D for sexing skeletal remains. We test estimated finger lengths, phalanx lengths, and 2D:4D derived from hand bones for determining sex. Maximum phalanx length was collected using a mini-osteometric board from 451 individuals of known age, sex, and ancestry in four skeletal collections. Logistic regression of 2nd and 4th digit finger and phalanx lengths produced classification rates greater than 80%. Digit ratios, however, failed to reach classification rates greater than 59%. Our results support those of Voracek (Forensic Sci Int, 185, 2009, e29) and suggest that 2D:4D may be population-specific and thus inappropriate for universal application as a means of determining sex. © 2014 American Academy of Forensic Sciences.

  9. Digit Ratio (2D:4D) and Handgrip Strength in Hani Ethnicity

    PubMed Central

    Zhao, Dapeng; Yu, Keli; Zhang, Xinghua; Zheng, Lianbin

    2013-01-01

    Introduction The ratio of the length of the second finger to the fourth finger (2D:4D) in humans is considered as a putative marker of prenatal exposure to testosterone, and has been progressively adopted as one useful tool to evaluate the effect of prenatal hormones in some traits such as physical ability. Handgrip strength is one authentic measure of physical ability and is generally used on the anthropological research within an evolutionary viewpoint. Methods Here we present the first evidence on 2D:4D and handgrip strength on adult participants of Hani ethnicity and explore the relationship between digit ratio (2D:4D) and handgrip strength. We examined 2D:4D and handgrip strength of 80 males and 60 females at Bubeng village, in the Yunnan province of China. Results The mean 2D:4D in females was higher than that in males for each hand. Females showed significantly higher 2D:4D than males in the right hand rather than in the left hand. Males displayed significantly higher handgrip strength than females for both hands. Handgrip strength decreased with age for both sexes. A significant negative correlation between 2D:4D and handgrip strength was found in the right hand of males. Conclusion The relationship between 2D:4D and handgrip strength may be attributed to evolutionary drive of sexual selection operating on fetal programming. PMID:24205044

  10. Digit ratio (2D:4D) and handgrip strength in Hani ethnicity.

    PubMed

    Zhao, Dapeng; Yu, Keli; Zhang, Xinghua; Zheng, Lianbin

    2013-01-01

    The ratio of the length of the second finger to the fourth finger (2D:4D) in humans is considered as a putative marker of prenatal exposure to testosterone, and has been progressively adopted as one useful tool to evaluate the effect of prenatal hormones in some traits such as physical ability. Handgrip strength is one authentic measure of physical ability and is generally used on the anthropological research within an evolutionary viewpoint. Here we present the first evidence on 2D:4D and handgrip strength on adult participants of Hani ethnicity and explore the relationship between digit ratio (2D:4D) and handgrip strength. We examined 2D:4D and handgrip strength of 80 males and 60 females at Bubeng village, in the Yunnan province of China. The mean 2D:4D in females was higher than that in males for each hand. Females showed significantly higher 2D:4D than males in the right hand rather than in the left hand. Males displayed significantly higher handgrip strength than females for both hands. Handgrip strength decreased with age for both sexes. A significant negative correlation between 2D:4D and handgrip strength was found in the right hand of males. The relationship between 2D:4D and handgrip strength may be attributed to evolutionary drive of sexual selection operating on fetal programming.

  11. Effects of Cognitive Styles on 2D Drafting and Design Performance in Digital Media

    ERIC Educational Resources Information Center

    Pektas, Sule Tasli

    2010-01-01

    This paper investigates the interactions between design students' cognitive styles, as measured by Riding's Cognitive Styles Analysis, and performance in 2D drafting and design tasks in digital media. An empirical research revealed that Imager students outperformed Verbalisers in both drafting and creativity scores. Wholist-Analytic cognitive…

  12. Effects of Cognitive Styles on 2D Drafting and Design Performance in Digital Media

    ERIC Educational Resources Information Center

    Pektas, Sule Tasli

    2010-01-01

    This paper investigates the interactions between design students' cognitive styles, as measured by Riding's Cognitive Styles Analysis, and performance in 2D drafting and design tasks in digital media. An empirical research revealed that Imager students outperformed Verbalisers in both drafting and creativity scores. Wholist-Analytic cognitive…

  13. Comparison between inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements.

    PubMed

    Scaf, Gulnara; Morihisa, Olívia; Loffredo, Leonor de Castro Monteiro

    2007-12-01

    The advances in digital imaging technology in dentistry have provided an alternative to film-based radiography and have given new options to detect periodontal bone loss. The purpose of this study was to compare inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements. Thirty-five film-based periapical radiographs of patients suffering from moderate to advanced untreated periodontal bone loss associated to lower premolar and molars was selected from the department files, with 40 bone loss areas. The film-based radiographs were digitized with a flatbed scanner with a transparency and radiograph adapter used for transilluminating the radiograph imaging. Digitization was performed at 600 dpi and in gray scale. The images were digitized using Image Tool software by applying image inversion, that is, transformation of radiopaque structures into radiolucent structures and vice-versa. The digital data were saved as JPEG files. The images were displayed on a 15-inch and 24-bit video monitor under reduced room lighting. One calibrated examiner performed all radiographic measurements, three times, from the cementoenamel junction to the most apical extension of the bone loss, in both types of image (inverted and unprocessed). Brightness and contrast were adjusted according to the examiner's individual demand. Intraclass correlation coefficient was used to compare the measurements from both types of images. The means of radiographic measurements, in mm, for inverted and unprocessed digitized imaging were 6.4485 and 6.3790, respectively. The intraclass correlation coefficient was significant (0.99) The inverted and unprocessed digitized radiographic images were reliable and there was no difference in the diagnostic accuracy between these images regarding periodontal bone loss measurements.

  14. COMPARISON BETWEEN INVERTED AND UNPROCESSED DIGITIZED RADIOGRAPHIC IMAGING IN PERIODONTAL BONE LOSS MEASUREMENTS

    PubMed Central

    Scaf, Gulnara; Morihisa, Olívia; Loffredo, Leonor de Castro Monteiro

    2007-01-01

    The advances in digital imaging technology in dentistry have provided an alternative to film-based radiography and have given new options to detect periodontal bone loss. The purpose of this study was to compare inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements. Thirty-five film-based periapical radiographs of patients suffering from moderate to advanced untreated periodontal bone loss associated to lower premolar and molars was selected from the department files, with 40 bone loss areas. The film-based radiographs were digitized with a flatbed scanner with a transparency and radiograph adapter used for transilluminating the radiograph imaging. Digitization was performed at 600 dpi and in gray scale. The images were digitized using Image Tool software by applying image inversion, that is, transformation of radiopaque structures into radiolucent structures and vice-versa. The digital data were saved as JPEG files. The images were displayed on a 15-inch and 24-bit video monitor under reduced room lighting. One calibrated examiner performed all radiographic measurements, three times, from the cementoenamel junction to the most apical extension of the bone loss, in both types of image (inverted and unprocessed). Brightness and contrast were adjusted according to the examiner's individual demand. Intraclass correlation coefficient was used to compare the measurements from both types of images. The means of radiographic measurements, in mm, for inverted and unprocessed digitized imaging were 6.4485 and 6.3790, respectively. The intraclass correlation coefficient was significant (0.99) The inverted and unprocessed digitized radiographic images were reliable and there was no difference in the diagnostic accuracy between these images regarding periodontal bone loss measurements. PMID:19089186

  15. Using breast radiographers' reports as a second opinion for radiologists' readings of microcalcifications in digital mammography.

    PubMed

    Tanaka, R; Takamori, M; Uchiyama, Y; Nishikawa, R M; Shiraishi, J

    2015-03-01

    The aim of this study was to investigate a practical method for incorporating radiographers' reports with radiologists' readings of digital mammograms. This simulation study was conducted using data from a free-response receiver operating characteristic observer study obtained with 75 cases (25 malignant, 25 benign and 25 normal cases) of digital mammograms. Each of the rating scores obtained by six breast radiographers was utilized as a second opinion for four radiologists' readings with the radiographers' reports. A logical "OR" operation with various criteria settings was simulated for deciding an appropriate method to select a radiographer's report in all combinations of radiologists and radiographers. The average figure of merit (FOM) of the radiologists' performances was statistically analysed using a jackknife procedure (JAFROC) to verify the clinical utility of using radiographers' reports. Potential improvement of the average FOM of the radiologists' performances for identifying malignant microcalcifications could be expected when using radiographers' reports as a second opinion. When the threshold value of 2.6 in Breast Imaging-Reporting and Data System (BI-RADS®) assessment was applied to adopt/reject a radiographer's report, FOMs of radiologists' performances were further improved. When using breast radiographers' reports as a second opinion, radiologists' performances potentially improved when reading digital mammograms. It could be anticipated that radiologists' performances were improved further by setting a threshold value on the BI-RADS assessment provided by the radiographers. For the effective use of a radiographer's report as a second opinion, radiographers' rating scores and its criteria setting for adoption/rejection would be necessary.

  16. Digit ratio (2D:4D) is associated with gastric cancer.

    PubMed

    Nicolás Hopp, Renato; de Souza Lima, Nathália Caroline; Filho, José Laurentino; Filho, Marcondes Sena; Lima, Carmen Silvia Passos; Jorge, Jacks

    2013-05-01

    Sex steroid exposure during early human development may influence disease susceptibility. Digit ratio (2D:4D) is a putative marker for prenatal hormone exposure and sensitivity, as well as the action of genes closely related to carcinogenesis. Digit ratio could act as a possible marker for cancer predisposition. The aim of this study is to investigate the possible correlations between right hand, left hand and right minus left (R-L) 2D:4D and gastric cancer (GCA) in men and women and assess the correlations with tumor staging and histological diagnosis. Digital images of the right and left hand palms of patients diagnosed with GCA (n=57, 42 males, 15 females) and age and sex-matched controls (n=59, 41 males, 18 females) were obtained. Means for 2D:4D were compared. Data were analyzed by repeated-measures one-way ANOVA and Student's t-test for finger measurements and group comparisons and Pearson's and Spearman's tests for correlations with tumor staging (α=0.05). GCA group presented significantly higher left 2D:4D, but significantly lower R-L in comparison to healthy controls, particularly so for males. Digit ratio did not correlate to clinical staging or TNM staging. However, low R-L was significantly related to adenocarcinomas. Early developmental conditions, including prenatal testosterone seem to play a role on the malignant transformation of gastric lesions. The 2D:4D pattern found for gastric cancer parallels that earlier described for breast cancer. The findings suggest that 2D:4D could add to the list of etiological factors and be a putative marker for the screening of patients' susceptibility to develop gastric cancer. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Is digit ratio (2D:4D) a reliable pointer to speech laterality?

    PubMed

    Hudson, John M; Hodgson, Jessica C

    2016-03-15

    The relative length of the second and fourth digits (2D:4D ratio) is sexually dimorphic and a retrospective biomarker of prenatal hormonal exposure. Low ratios indicate higher prenatal testosterone (pT) and lower estrogen exposure, whereas the reverse pattern is associated with high ratios. Elevated levels of pT exposure have long been thought to modulate hemispheric specialisation; subsequently many studies use the 2D:4D ratio as a proxy index for pT to examine the effects of prenatal hormonal exposure on lateralised cognitive abilities. Here we used Transcranial Doppler ultrasonography and digit ratio to investigate whether pT has an influence on speech laterality. We tested 34 right and 14 left handed adults. Our results indicate that speech representation is unrelated to digit characteristics and therefore purportedly pT. We discuss these findings in relation to androgen theories of lateralisation.

  18. Radiographic determination of canal length direct digital radiography versus conventional radiography.

    PubMed

    Hedrick, R T; Dove, S B; Peters, D D; McDavid, W D

    1994-07-01

    This research compared the length determination images produced by Trophy and Regam direct digital radiographic systems with conventional E-speed radiographs. Size #15 K files were placed in the canals of 19 teeth of cadaver specimens and radiographed in a geometrically standardized bench device. Three evaluators estimated the length adjustment necessary to position the file at the apex. The mean estimated adjustment lengths were compared with the true, anatomically determined adjustment lengths. Statistical analysis with analysis of variance and the Student-Newman-Keuls test indicated no significant difference between direct digital thermal print images and conventional radiographs (p > 0.10). Length adjustment estimates with conventional radiographs were significantly more accurate than Regam high-resolution computer monitor images (p < 0.01). Additionally, it was determined that length adjustment estimates were significantly more accurate when the file was placed short of the apex (p < 0.001). The clinical relevance of these differences is discussed.

  19. Digit ratio (2D:4D), lateral preferences, and performance in fencing.

    PubMed

    Voracek, Martin; Reimer, Barbara; Ertl, Clara; Dressler, Stefan G

    2006-10-01

    The second to fourth digit ratio (2D:4D) is a sexually dimorphic trait (men tend to have lower values than women) and a likely biomarker for the organizational (permanent) effects of prenatal androgens on the human brain and body. Prenatal testosterone, as reflected by 2D:4D, has many extragenital effects, including its relevance for the formation of an efficient cardiovascular system. Previous research, reviewed here, has therefore investigated possible associations of 2D:4D with sport performance. Several studies found more masculinized digit ratio patterns (low 2D:4D values or a negative right-minus-left difference in 2D:4D) to be related to high performance in running, soccer, and skiing. The present research tested this hypothesis in a sample of 54 tournament fencers, predominantly from Austria. For men, negative right-left differences in 2D:4D corresponded significantly to better current as well as highest national fencing rankings, independent of training intensity and fencing experience. The mean 2D:4D values of these fencers were significantly lower and the proportion of left-handers was elevated relative to the local general population. For the right hand, the ratio was somewhat lower in male sabre fencers than in male epée and foil fencers combined and significantly lower in left-handed compared to right-handed fencers. Although nonsignificant due to low statistical power, effect sizes suggested that crossed versus congruent hand-eye and hand-foot preferences might also be related to fencing performance. The present findings add to the evidence that 2D:4D might be a performance indicator for men across a variety of sports.

  20. Scientometric analysis and bibliography of digit ratio (2D:4D) research, 1998-2008.

    PubMed

    Voracek, Martin; Loibl, Lisa Mariella

    2009-06-01

    A scientometric analysis of modern research on the second-to-fourth digit ratio (2D:4D), a widely studied putative marker for prenatal androgen action, is presented. In early 2009, this literature totalled more than 300 publications and, since its initiation in 1998, has grown at a rate slightly faster than linear. Key findings included evidence of publication bias and citation bias, incomplete coverage and outdatedness of existing reviews, and a dearth of meta-analyses in this field. 2D:4D research clusters noticeably in terms of researchers, institutions, countries, and journals involved. Although 2D:4D is an anthropometric trait, most of the research has been conducted at psychology departments, not anthropology departments. However, 2D:4D research has not been predominantly published in core and specialized journals of psychology, but rather in more broadly scoped journals of the behavioral sciences, biomedical social sciences, and neurosciences. Total citation numbers of 2D:4D papers for the most part were not larger than their citation counts within 2D:4D research, indicating that until now, only a few 2D:4D studies have attained broader interest outside this specific field. Comparative citation analyses show that 2D:4D research presently is commensurate in size and importance to evolutionary psychological jealousy research, but has grown faster than the latter field. In contrast, it is much smaller and has spread more slowly than research about the Implicit Association Test Fifteen conjectures about anticipated trends in 2D:4D research are outlined, appendixed by a first-time bibliography of the entirety of the published 2D:4D literature.

  1. Digital spall radiograph analysis system: Report on simulated three- dimensional digital spall image reconstruction fidelity

    SciTech Connect

    Harris, C.L.

    1990-01-01

    This report describes progress on work to develop a cost effective, rapid response system for measuring momentum and kinetic energy of spall for the Advanced Technology Assessment Center (ATAC) Armor/Anti-Armor (A{sup 3}) program at Los Alamos National Laboratory. The system will exploit data contained in two sets of simultaneous co-planar flash radiographs taken along the center line of anticipated spall motion. Data contained in each set (which is proportional to the mass and z- number of the spall material intersected by the exposing x-ray at each point) is digitized and used to construct a three dimensional model (called the reconstructed spall image) that approximates the original spall cloud. From the model the mass of spall fragments is computed. The two sets of radiographs, separated in time, represent the spall configuration at two instants of time. Spall fragments from the first instant are matched with those from the second instant to determine velocity. Evaluation of the fidelity of candidate reconstruction algorithms is the highest priority task in this development program for the obvious reason that the efficacy of the projected spall analysis system depends upon the fidelity of the reconstruction techniques. The purpose of this document is to report the results of analysis of the fidelity of best reconstruction procedure (for one radiograph set) investigated to date. The reconstruction procedure uses data from four simultaneous radiographs representing two sides and two diagonals of a cube. The procedure makes use of an available space algorithm, two probabilistic devices (a mass placement probability heuristic, and a mass clumping heuristic), and a stochastic procedure for mass that cannot be placed by the algorithm or either of the heuristics. The procedure is fully described in the body of the report.

  2. COMPARISON OF RADIOGRAPHIC MEASUREMENTS OBTAINED WITH CONVENTIONAL AND INDIRECT DIGITAL IMAGING DURING ENDODONTIC TREATMENT

    PubMed Central

    Schmitd, Ligia Buloto; Lima, Tatiana de Castro; Chinellato, Luiz Eduardo Montenegro; Bramante, Clóvis Monteiro; Garcia, Roberto Brandão; de Moraes, Ivaldo Gomes; Bernardineli, Norberti

    2008-01-01

    The aims of this study were to evaluate the quality of indirect digitized radiographic images taken during endodontic procedures and to compare the measurements recorded with this technique to those obtained from conventional radiographs. Two-hundred conventional periapical radiographs taken at the undergraduate Endodontics Clinic of the Dental School of Bauru were digitized. The conventional and indirect digitized images were compared by three examiners as to the quality and accuracy of the measurements recorded during endodontic treatment, in canal length determination, gutta-percha adaptation, lateral condensation and final obturation. The conventional radiographs were observed on a film viewer, surrounded by a dark card, and measured with magnifying glass and a millimeter ruler; the indirect digitized images were evaluated on the Digora® for Windows software, with free utilization of the bright/contrast tool. Unlike the conventional radiographic images, all indirect digitized images were considered as having a high quality. The distance between the filling material and the root apex was 0.117 mm larger, on average, for the Digora® system (p<0.01). The measurements achieved by the investigated radiographic methods were clinically similar and they are thus equivalent. Changes in brightness and contrast of the images using Digora® software improved the diagnosis. PMID:19089211

  3. Association Between Hand Digit Ratio (2D:4D) and Nonsyndromic Orofacial Clefts.

    PubMed

    Mendes, Patrícia Helena Costa; Barbosa, Camila Reis; da Silva, Myriam Thatyana Miranda Esteves; Paranaíba, Lívia Máris Ribeiro; Martelli, Daniela Reis Barbosa; de Barros, Letízia Monteiro; Swerts, Mário Sérgio Oliveira; Silveira, Marise Fagundes; Júnior, Hercílio Martelli

    2017-09-01

    Digit ratio (2D:4D) has been considered to be a marker in studies evaluating an individual's susceptibility to diseases, especially those diseases that show sex differences in their occurrence. We aimed to assess whether 2D:4D ratios are associated with nonsyndromic cleft lip and/or palate (NSCL/P) and verify the existence of a specific pattern of 2D:4D ratio in individuals affected by orofacial clefts.   This was a case-control study.   Digital measurements of index and ring finger lengths of both hands of patients with NSCL/P (n = 54) and age- and gender-matched controls (n = 54) were obtained using a digital vernier caliper. Mean ratios between the second and fourth digits were compared. Data were analyzed by Student's t test and Mann-Whitney test with a significance level of 5%.   No significant difference was found between the mean digit ratios of the right and left hands between the groups for any analysis (P > .05), neither for the whole sample nor for the distributions by type of cleft and by gender.   Although the development of the fingers and the occurrence of NSCL/P can be regulated by the actions of similar genes, our results are not consistent with an association between 2D:4D ratio and this craniofacial deformity. This suggests that intrauterine exposure to fetal androgens, assessed using this marker, is similar between patients with NSCL/P and healthy individuals. We highlight the need for further studies in populations with different ancestries.

  4. Is maternal periconceptional smoking associated with 2D:4D digit ratio in their children?

    PubMed

    Velez, M P; Arbuckle, T E; Monnier, P; Fraser, W D

    2017-05-23

    The 2nd--4th finger ratio (2D:4D) has been proposed as a potential indicator of greater androgen exposure during fetal development. Maternal periconceptional smoking may alter the homeostasis of fetal androgens, which could in turn result in differential development of 2D:4Ds in utero. The aim of the present study was to assess the effect of maternal periconceptional smoking (i.e. 1 year before through the first trimester of pregnancy) on the 2D:4D of children within The Maternal-Infant Research on Environmental Chemicals (MIREC) study. Maternal smoking history was obtained through questionnaires during the first trimester of pregnancy in 2001 women from 10 cities across Canada. The periconceptional smoking prevalence was 12%. A follow-up study was conducted to measure growth and development up to 5 years of age in a subsample of some 800 MIREC children (MIREC-CD Plus), and digital pictures of the ventral surface of both hands were obtained in mothers and children (2-5 years). The 2D:4D was calculated as the ratio of the 2nd and 4th fingers of each hand. Boys had lower mean 2D:4Ds compared with girls in both hands. Age and maternal 2D:4D were strong determinants of the children's 2D:4D, however, the mean 2D:4D did not differ among children whose mothers had smoked during the periconceptional period compared with those who had not, irrespective of sex. In conclusion, we did not find an association between maternal periconceptional smoking and children's 2D:4D, although the smoking prevalence was low.

  5. Finger Counting and (2D:4D) Digit Ratio in Spatial-Numerical Association.

    PubMed

    Fabbri, Marco; Natale, Vincenzo

    2016-01-01

    It is reported that a canonical and cultural finger counting habit influences the spatial-numerical association. The digit ratio (the ratio between the lengths of the index and ring fingers as a putative indicator of prenatal androgen exposure) also plays an effect on space-number representation, reflecting a stronger left-to-right number representation in people with a short index finger and longer ring finger (i.e., 2D:4D ratio). It is unknown whether the finger counting habit and digit ratio have an effect on spatial-numerical association independently from each other or whether they interact with each other. In Study 1, the digit ratio and finger counting mapping were recorded in right handers. The participants performed number-to-position, digit string bisection, and physical line bisection tasks. In the number-to-position task, a finger counting effect was found, as well as a significant interaction between factors. A digit ratio effect was observed in the digit string bisection task. In Study 2, digit ratio and finger counting mapping were recorded in right and left handers. The results showed that the finger counting habit influenced the spatial biases in both numerical tasks. A significant interaction between finger counting and digit ratio was found in both numerical tasks when only the left hand was considered. The results are discussed considering the embodied nature of the spatial-numerical association. © The Author(s) 2015.

  6. Right-left digit ratio (2D:4D) and maximal oxygen uptake.

    PubMed

    Hill, Randy; Simpson, Ben; Millet, Grégoire; Manning, John; Kilduff, Liam

    2012-01-01

    A low digit ratio (2D:4D) and low 2D:4D in the right compared with the left hand (right-left 2D:4D) are thought to be determined by high in utero concentrations of testosterone, and are related to "masculine" traits such as aggression and performance in sports like running and rugby. Low right-left 2D:4D is also related to sensitivity to testosterone as measured by the number of cytosine-adenine-guanine triplet repeats in exon 1 of the androgen receptor gene. Here we show that low right-left 2D:4D is associated with high maximal oxygen uptake (VO2(max)), high velocity at VO2(max), and high maximum lactate concentration in a sample of teenage boys. We suggest that low right-left 2D:4D is linked to performance in some sports because it is a proxy of high sensitivity to prenatal and maybe also circulating testosterone and high VO2(max).

  7. A transputer-based list mode parallel system for digital radiography with 2D silicon detectors

    SciTech Connect

    Conti, M.; Russo, P.; Scarlatella, A. . Dipt. di Scienze Fisiche and INFN); Del Guerra, A. . Dipt. di Fisica and INFN); Mazzeo, A.; Mazzocca, N.; Russo, S. . Dipt. di Informatica e Sistemistica)

    1993-08-01

    The authors believe that a dedicated parallel computer system can represent an effective and flexible approach to the problem of list mode acquisition and reconstruction of digital radiographic images obtained with a double-sided silicon microstrip detector. They present a Transputer-based implementation of a parallel system for the data acquisition and image reconstruction from a silicon crystal with 200[mu]m read-out pitch. They are currently developing a prototype of the system connected to a detector with a 10mm[sup 2] sensitive area.

  8. Hadza hunter-gatherer men do not have more masculine digit ratios (2D:4D).

    PubMed

    Apicella, Coren L; Tobolsky, Victoria A; Marlowe, Frank W; Miller, Kathleen W

    2016-02-01

    The ratio between the length of the second and the length of the fourth digit (2D:4D) is sexually dimorphic such that males of many species possess a lower ratio than females, particularly in the right hand. Still, men and women often exhibit overlapping 2D:4D ranges and the ratio is highly variable between populations. In order to further explore populational variability, we chose to analyze 2D:4D in the Hadza, a population of hunter-gatherers living in Tanzania. Data were collected separately by two researchers over the course of three years (1998, 2001, 2006) from 152 adult participants (male: n = 76, female: n = 76). Independent samples t-tests were used to explore sex differences, paired samples t-tests were used to explore directional effects within each sex, and linear regression and one-way ANOVA were used to test possible age effects. In none of the years, or pooled (n = 152), did we find evidence that adult men have a lower 2D:4D than adult women. If anything, the data suggest that women in this population have a significantly lower right hand 2D:4D than men (P < 0.001, d = 0.57). In contrast, left hand 2D:4D did not exhibit a sex difference (P = 0.862, d = 0.03). These findings challenge the current view that lower 2D:4D in men is a uniform characteristic of our species. Cross-populational variance in 2D:4D may be related to known patterns of hormonal variation resulting from both genetic and environmental mechanisms, though this relationship merits further investigation. © 2015 Wiley Periodicals, Inc.

  9. Digital phase-stepping holographic interferometry in measuring 2-D density fields

    NASA Astrophysics Data System (ADS)

    Lanen, T. A. W. M.; Nebbeling, C.; van Ingen, J. L.

    1990-06-01

    This paper presents a holographic interferometer technique for measuring transparent (2-D or quasi 2-D) density fields. To be able to study the realization of such a field at a certain moment of time, the field is “frozen” on a holographic plate. During the reconstruction of the density field from the hologram the length of the path traversed by the reconstruction beam is diminished in equal steps by applying a computer controlled voltage to a piezo-electric crystal that translates a mirror. Four phase-stepped interferograms resulting from this pathlength variation are digitized and serve as input to an algorithm for computing the phase surface. The method is illustrated by measuring the basically 2-D density field existing around a heated horizontal cylinder in free convection.

  10. Increased ratio of 2nd to 4th digit (2D:4D) in schizophrenia.

    PubMed

    Collinson, Simon Lowes; Lim, Matthew; Chaw, Jia Hui; Verma, Swapna; Sim, Kang; Rapisarda, Attilio; Chong, Siow Ann

    2010-03-30

    Sex differences in the onset, epidemiology, clinical presentation and neuropathology of schizophrenia suggest that sexual dimorphism in brain development may be relevant to pathogenesis. Sex hormones, in particular testosterone, are considered to be crucial in brain development, but few investigations have examined the potential role of prenatal testosterone in schizophrenia. In this study, we examined a retrospective marker of prenatal testosterone release - 2D:4D finger length ratio (2D:4D), the relative length of 2nd to 4th digit, in 64 Asian patients with schizophrenia and 64 sex-matched controls. No significant difference in mean finger lengths was present, however 2D:4D ratio was significantly different between patients and controls. The effect was primarily seen in males consistent with a 'less masculinised' pattern and hypotheses suggesting that schizophrenia may be associated with an abnormality in prenatal circulating testosterone. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  11. Brazilian young dental practitioners' use and acceptance of digital radiographic examinations.

    PubMed

    Rovaris, Karla; de Faria Vasconcelos, Karla; do Nascimento, Eduarda Helena Leandro; Oliveira, Matheus Lima; Freitas, Deborah Queiroz; Haiter-Neto, Francisco

    2016-12-01

    The aim of this study was to investigate the use and acceptance of digital radiographic examinations by Brazilian dental practitioners in daily practice and to evaluate the advances that have occurred over the past 5 years. Dental practitioners enrolled in extension courses at the Piracicaba Dental School, University of Campinas, Brazil, responded to a self-administered questionnaire in the years 2011 and 2015. They were asked about sociodemographic factors and their knowledge and use of digital radiographic examinations. Descriptive analysis was performed, as well as the chi-square and Fisher exact tests, with a significance level of 5% (α=0.05). A total of 181 participants responded to the questionnaire in the years 2011 and 2015. Most of the respondents worked in private practice, had graduated within the last 5 years, and were between 20 and 30 years old. In 2011, 55.6% of respondents reported having ever used digital radiographic examinations, while in 2015 this number increased significantly to 85.4% (p<.0001), out of which 71.4% preferred it to conventional images. Moreover, 21.4% of respondents reported having used digital radiographic examinations for more than 3 years. A significant increase in use of intraoral digital radiography (p=0.0316) was observed in 2015. In both years, image quality and high cost were indicated, respectively, as the main advantage and disadvantage of digital radiographic examinations. This study showed that digital radiology has become more common in Brazil over the past 5 years. Most of the Brazilian dental practitioners evaluated in 2015 used digital radiographic examinations.

  12. Brazilian young dental practitioners' use and acceptance of digital radiographic examinations

    PubMed Central

    de Faria Vasconcelos, Karla; do Nascimento, Eduarda Helena Leandro; Oliveira, Matheus Lima; Freitas, Deborah Queiroz; Haiter-Neto, Francisco

    2016-01-01

    Purpose The aim of this study was to investigate the use and acceptance of digital radiographic examinations by Brazilian dental practitioners in daily practice and to evaluate the advances that have occurred over the past 5 years. Materials and Methods Dental practitioners enrolled in extension courses at the Piracicaba Dental School, University of Campinas, Brazil, responded to a self-administered questionnaire in the years 2011 and 2015. They were asked about sociodemographic factors and their knowledge and use of digital radiographic examinations. Descriptive analysis was performed, as well as the chi-square and Fisher exact tests, with a significance level of 5% (α=0.05). Results A total of 181 participants responded to the questionnaire in the years 2011 and 2015. Most of the respondents worked in private practice, had graduated within the last 5 years, and were between 20 and 30 years old. In 2011, 55.6% of respondents reported having ever used digital radiographic examinations, while in 2015 this number increased significantly to 85.4% (p<.0001), out of which 71.4% preferred it to conventional images. Moreover, 21.4% of respondents reported having used digital radiographic examinations for more than 3 years. A significant increase in use of intraoral digital radiography (p=0.0316) was observed in 2015. In both years, image quality and high cost were indicated, respectively, as the main advantage and disadvantage of digital radiographic examinations. Conclusion This study showed that digital radiology has become more common in Brazil over the past 5 years. Most of the Brazilian dental practitioners evaluated in 2015 used digital radiographic examinations. PMID:28035301

  13. Women with more feminine digit ratio (2D:4D) have higher reproductive success.

    PubMed

    Klimek, Magdalena; Galbarczyk, Andrzej; Nenko, Ilona; Jasienska, Grazyna

    2016-07-01

    Prenatal development has a long-lasting influence on biological condition and health. Second-to-fourth digit ratio (2D:4D) is suggested as an indicator of sex hormone exposure during fetal development, and it is likely that women with a more feminine digit ratio were exposed to higher prenatal estrogen levels. Therefore, we tested if 2D:4D was related to a woman's reproductive characteristics. We studied 319 women aged 46-92, who went through a natural menopause and whose husbands were alive at least until their menopause were studied. Women were recruited at the Mogielica Human Ecology Study Site located in rural Poland. Women with more feminine 2D:4D had a higher number of children (P = 0.002), gave birth to their last child at a later age (P = 0.02), and had a longer reproductive lifespan (P = 0.04) than women with more masculine 2D:4D. Age and number of years of education were included as potential confounders in the analyses. The results indicated that women with more feminine 2D:4D had higher reproductive success. While the exact mechanisms were not known, and the relationship between 2D:4D and adult sex hormone levels was questioned by previous studies, there might be other biological pathways explaining the observed results, that is, via behaviors that were indirectly related to fertility. Am J Phys Anthropol 160:549-553, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. A multiple digital watermarking algorithm based on 1D and 2D chaotic sequences

    NASA Astrophysics Data System (ADS)

    Ji, Zhen; Jiang, Lai; Jin, Jing; Zhang, Jihong

    2003-09-01

    Multiple digital watermarking is attracting more and more researchers because it is more valuable in the practical applications than single watermarking. In this paper, a multiple watermarking algorithm based on 1-D and 2-D chaotic sequences is proposed. The chaotic sequences have the advantages of massive, high security, and weakest correlation. The massive and independent digital watermark signals are generated through 1-D chaotic maps, which are determined by different initial conditions and parameters. The chaotic digital watermark signals effectively resolve the construction of massive watermarks with good performance. The embedding of multiple watermakrs is more complex than the single watermarking scheme. In this paper, each watermark is added to the middle frequency coefficients of wavelet domain randomly by exploiting 2-D chaotic system, so the embedding and extracting of each watermark would not disturb each other. Considering the parameters of 2-D chaotic systsem as the key to embedding procedure can prevent the watermarks to be removed maliciously, therefore the performance of security is better. The capacity of the multiple watermarking is also analyzed in this paper. The experimental results demonstrate that this proposed watermarking algorithm is robust to many common attacks and it is a reliable copyright protection for multiple legal owners.

  15. Wideband aperture array using RF channelizers and massively parallel digital 2D IIR filterbank

    NASA Astrophysics Data System (ADS)

    Sengupta, Arindam; Madanayake, Arjuna; Gómez-García, Roberto; Engeberg, Erik D.

    2014-05-01

    Wideband receive-mode beamforming applications in wireless location, electronically-scanned antennas for radar, RF sensing, microwave imaging and wireless communications require digital aperture arrays that offer a relatively constant far-field beam over several octaves of bandwidth. Several beamforming schemes including the well-known true time-delay and the phased array beamformers have been realized using either finite impulse response (FIR) or fast Fourier transform (FFT) digital filter-sum based techniques. These beamforming algorithms offer the desired selectivity at the cost of a high computational complexity and frequency-dependant far-field array patterns. A novel approach to receiver beamforming is the use of massively parallel 2-D infinite impulse response (IIR) fan filterbanks for the synthesis of relatively frequency independent RF beams at an order of magnitude lower multiplier complexity compared to FFT or FIR filter based conventional algorithms. The 2-D IIR filterbanks demand fast digital processing that can support several octaves of RF bandwidth, fast analog-to-digital converters (ADCs) for RF-to-bits type direct conversion of wideband antenna element signals. Fast digital implementation platforms that can realize high-precision recursive filter structures necessary for real-time beamforming, at RF radio bandwidths, are also desired. We propose a novel technique that combines a passive RF channelizer, multichannel ADC technology, and single-phase massively parallel 2-D IIR digital fan filterbanks, realized at low complexity using FPGA and/or ASIC technology. There exists native support for a larger bandwidth than the maximum clock frequency of the digital implementation technology. We also strive to achieve More-than-Moore throughput by processing a wideband RF signal having content with N-fold (B = N Fclk/2) bandwidth compared to the maximum clock frequency Fclk Hz of the digital VLSI platform under consideration. Such increase in bandwidth is

  16. Common Errors in Digital Panoramic Radiographs of Patients with Mixed Dentition and Patients with Permanent Dentition

    PubMed Central

    Peretz, Benjamin; Gotler, Maya; Kaffe, Israel

    2012-01-01

    Purpose. To compare errors in digital panoramic radiographs of permanent and mixed dentitions. Methods. 143 and 146 digital radiographs of mixed and permanent dentitions were examined. Results. Significantly fewer errors presented in the mixed dentition. Positioning too forward significantly prevalent in the mixed dentition; slumped position and nonpositioning of chin properly were significantly prevailed in the permanent dentition. Blurred or shortened upper incisors were significantly more prevalent in the mixed dentition. Diagnostic ability could be improved by manipulating the brightness or contrast in nearly 45% of all radiographs. In the mixed dentition, tilting the chin down and a slumped position made the lower incisors significantly nondiagnostic. In the permanent dentition, tilting the chin down made the lower incisors to be significantly nondiagnostic. Conclusions. More errors were prevalent in panoramic radiographs of permanent dentitions. Properly positioning the patient is the most important factor in preventing a cascade of errors. PMID:22505905

  17. Comparison of radiographic image quality from four digitization devices as viewed on computer monitors.

    PubMed

    Davidson, H C; Johnston, D J; Christian, M E; Harnsberger, H R

    2001-03-01

    The objective of this study was to compare the quality of radiographic images digitized from commercial-grade and consumer-grade digital cameras and scanners as viewed on computer monitor. Radiographic images were digitized from hardcopy film using a commercial-grade laser scanner, a consumer-grade desktop flatbed scanner, a commercial-grade digital camera, and a consumer-grade digital camera. The quality of images without and with grayscale histogram adjustment was evaluated subjectively by 10 board-certified radiologists. Optical density response was evaluated objectively using a grayscale test pattern. There was no significant difference in subjective quality among images digitized with the commercial scanner, consumer scanner, and commercial camera. The quality of images digitized with the consumer camera was lower than the other 3. Objective tests showed the commercial scanner to have the most linear optical density response. For the purpose of viewing images on a computer monitor, a consumer-grade desktop scanner can produce images of similar quality to those produced by more expensive laser commercial-grade scanners and digital cameras and provides cost-efficient means to digitize radiographic plain films. A consumer-grade camera may not be optimal for use in this setting.

  18. The simulation of 3D microcalcification clusters in 2D digital mammography and breast tomosynthesis

    SciTech Connect

    Shaheen, Eman; Van Ongeval, Chantal; Zanca, Federica; Cockmartin, Lesley; Marshall, Nicholas; Jacobs, Jurgen; Young, Kenneth C.; Dance, David R.; Bosmans, Hilde

    2011-12-15

    Purpose: This work proposes a new method of building 3D models of microcalcification clusters and describes the validation of their realistic appearance when simulated into 2D digital mammograms and into breast tomosynthesis images. Methods: A micro-CT unit was used to scan 23 breast biopsy specimens of microcalcification clusters with malignant and benign characteristics and their 3D reconstructed datasets were segmented to obtain 3D models of microcalcification clusters. These models were then adjusted for the x-ray spectrum used and for the system resolution and simulated into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. Six radiologists were asked to distinguish between 40 real and 40 simulated clusters of microcalcifications in two separate studies on 2D mammography and tomosynthesis datasets. Receiver operating characteristic (ROC) analysis was used to test the ability of each observer to distinguish between simulated and real microcalcification clusters. The kappa statistic was applied to assess how often the individual simulated and real microcalcification clusters had received similar scores (''agreement'') on their realistic appearance in both modalities. This analysis was performed for all readers and for the real and the simulated group of microcalcification clusters separately. ''Poor'' agreement would reflect radiologists' confusion between simulated and real clusters, i.e., lesions not systematically evaluated in both modalities as either simulated or real, and would therefore be interpreted as a success of the present models. Results: The area under the ROC curve, averaged over the observers, was 0.55 (95% confidence interval [0.44, 0.66]) for the 2D study, and 0.46 (95% confidence interval [0.29, 0.64]) for the tomosynthesis study, indicating no statistically significant difference between real and simulated

  19. The simulation of 3D microcalcification clusters in 2D digital mammography and breast tomosynthesis.

    PubMed

    Shaheen, Eman; Van Ongeval, Chantal; Zanca, Federica; Cockmartin, Lesley; Marshall, Nicholas; Jacobs, Jurgen; Young, Kenneth C; R Dance, David; Bosmans, Hilde

    2011-12-01

    This work proposes a new method of building 3D models of microcalcification clusters and describes the validation of their realistic appearance when simulated into 2D digital mammograms and into breast tomosynthesis images. A micro-CT unit was used to scan 23 breast biopsy specimens of microcalcification clusters with malignant and benign characteristics and their 3D reconstructed datasets were segmented to obtain 3D models of microcalcification clusters. These models were then adjusted for the x-ray spectrum used and for the system resolution and simulated into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. Six radiologists were asked to distinguish between 40 real and 40 simulated clusters of microcalcifications in two separate studies on 2D mammography and tomosynthesis datasets. Receiver operating characteristic (ROC) analysis was used to test the ability of each observer to distinguish between simulated and real microcalcification clusters. The kappa statistic was applied to assess how often the individual simulated and real microcalcification clusters had received similar scores ("agreement") on their realistic appearance in both modalities. This analysis was performed for all readers and for the real and the simulated group of microcalcification clusters separately. "Poor" agreement would reflect radiologists' confusion between simulated and real clusters, i.e., lesions not systematically evaluated in both modalities as either simulated or real, and would therefore be interpreted as a success of the present models. The area under the ROC curve, averaged over the observers, was 0.55 (95% confidence interval [0.44, 0.66]) for the 2D study, and 0.46 (95% confidence interval [0.29, 0.64]) for the tomosynthesis study, indicating no statistically significant difference between real and simulated lesions (p > 0.05). Agreement

  20. Readability of cervical spine imaging: digital versus film/screen radiographs.

    PubMed

    Kreipke, D L; Silver, D I; Tarver, R D; Braunstein, E M

    1990-01-01

    In 109 trauma patients, both film/screen and digital lateral cervical spine radiographs were obtained. These films were compared for adequate visualization ("readability") of bone, soft tissue, and airway, and lowest visualized cervical vertebra. With viewbox alone, digital adequately demonstrated bone, soft tissue, and airway more often than film/screen. With a hotlight, there was no significant difference between digital and film/screen in adequately demonstrating bone, but for soft tissue and airway definition, digital was significantly better. There was less interobserver and intraobserver variation on digital than in film/screen. There was no significant difference in lowest vertebra identified.

  1. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data

    NASA Astrophysics Data System (ADS)

    Spiegel, M.; Redel, T.; Struffert, T.; Hornegger, J.; Doerfler, A.

    2011-10-01

    Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.

  2. Efficient rendering of digitally reconstructed radiographs on heterogeneous computing architectures using central slice theorem.

    PubMed

    Abdellah, Marwan; Abdallah, Mohamed; Alzanati, Mohamed; Eldeib, Ayman

    2016-08-01

    Digitally reconstructed radiographs (DRRs) play a significant role in modern clinical radiation therapy. They are used to verify patient alignments during image guided therapies with 2D-3D image registration. The generation of DRRs can be implemented intuitively in O(N3) relying on direct volume rendering (DVR) methods, such as ray marching. This complexity imposes certain limitations on the rendering performance if high quality DRR images are needed. Those DRRs can be alternatively generated in the k-space using the central slice theorem in O(N2logN). Several rendering pipelines have been designed to create the DRRs in the k-space, but they were either limited to specific vendor or entail particular software requirements. We present a high performance implementation of a k-space-based DRR generation pipeline that is executable on various heterogeneous computing architectures using OpenCL. Our implementation generates a DRR for a 5123 CT volume in 6, 2.7 and 0.68 milli-seconds on a commodity CPU, mid-range and high-end GPUs respectively.

  3. Parallel generation of digitally reconstructed radiographs on heterogeneous multi-GPU workstations.

    PubMed

    Abdellah, Marwan; Abdelaziz, Asem; Eslam Ali, E M B S; Abdelaziz, Sherief; Sayed, Abdelrahman; Owis, Mohamed I; Eldeib, Ayman

    2016-08-01

    The growing importance of three-dimensional radiotherapy treatment has been associated with the active presence of advanced computational workflows that can simulate conventional x-ray films from computed tomography (CT) volumetric data to create digitally reconstructed radiographs (DRR). These simulated x-ray images are used to continuously verify the patient alignment in image-guided therapies with 2D-3D image registration. The present DRR rendering pipelines are quite limited to handle huge imaging stacks generated by recent state-of-the-art CT imaging modalities. We present a high performance x-ray rendering pipeline that is capable of generating high quality DRRs from large scale CT volumes. The pipeline is designed to harness the immense computing power of all the heterogeneous computing platforms that are connected to the system relying on OpenCL. Load-balancing optimization is also addressed to equalize the rendering load across the entire system. The performance benchmarks demonstrate the capability of our pipeline to generate high quality DRRs from relatively large CT volumes at interactive frame rates using cost-effective multi-GPU workstations. A 5122 DRR frame can be rendered from 1024 × 2048 × 2048 CT volumes at 85 frames per second.

  4. Radiographical assessment of interphalangeal rotation in the evaluation of equine digital conformation.

    PubMed

    Caudron, I; Grülke, S; Gabriel, A; Serteyn, D

    1997-01-01

    This study is a part of a work to design a radiographical method to objectively define the conformation of an equine digit and to assess the individual appropriate trimming of a horse. Various angles were measured directly from the phalangeal bones. The authors observed that the bone relief of the sesamoid ligament insertions on the proximal phalanx was an essential landmark to determine the phalangeal alignment. The same angles were measured from specific radiographs and made it possible to quantify the rotation imposed to the proximal phalanx. The authors also noticed that the phalangeal rotation had little influence on the radiographic image of articular asymmetry.

  5. Determination of vertical interproximal bone loss topography: correlation between indirect digital radiographic measurement and clinical measurement.

    PubMed

    Esmaeli, Farzad; Shirmohammadi, Adileh; Faramarzie, Masoumeh; Abolfazli, Nader; Rasouli, Hossein; Fallahi, Saied

    2012-06-01

    Diagnosis and accuracy in determining the exact location, extent and configuration of bony defects of the jaw are of utmost importance to determine prognosis, treatment planning and long-term preservation of teeth. If relatively accurate diagnosis can be established by radiography, proper treatment planning prior to treatment procedures will be possible. The aim of the present study was to assess the correlation between indirect digital radiographic measurements and clinical measurements in determining the topography of interproximal bony defects. Twenty interproximal bony defects, preferably in the mandibular and maxillary 5↔5 area were selected and radiographed using the parallel periapical technique. The radiographs were corrected and digitized on a computer using "Linear Measurement" software; then the three parameters of the base of defect (BD), alveolar crest (AC) and cementoenamel junction (CEJ) were determined using a software. Subsequent to radiographic measurements, clinical measurements were carried out meticulously during flap procedures. Then linear measurements were carried out using a periodontal probe to determine the defect depth and its mesiodistal width. Then the amount of correlation between these two measurements was assessed by Pearson's correlation coefficient. The correlation between clinical and radiographic measurements in defect depth determination, in the evaluation of defect angle and in determination of defect width were 88%, 98% and 90%, respectively. Indirect digital radiographic technique can be used to diagnose intra-osseous defects, providing a better opportunity to treat bony defects.

  6. Determination of Vertical Interproximal Bone Loss Topography: Correlation Between Indirect Digital Radiographic Measurement and Clinical Measurement

    PubMed Central

    Esmaeli, Farzad; Shirmohammadi, Adileh; Faramarzie, Masoumeh; Abolfazli, Nader; Rasouli, Hossein; Fallahi, Saied

    2012-01-01

    Background Diagnosis and accuracy in determining the exact location, extent and configuration of bony defects of the jaw are of utmost importance to determine prognosis, treatment planning and long-term preservation of teeth. If relatively accurate diagnosis can be established by radiography, proper treatment planning prior to treatment procedures will be possible. Objectives The aim of the present study was to assess the correlation between indirect digital radiographic measurements and clinical measurements in determining the topography of interproximal bony defects. Patients and Methods Twenty interproximal bony defects, preferably in the mandibular and maxillary 5↔5 area were selected and radiographed using the parallel periapical technique. The radiographs were corrected and digitized on a computer using “Linear Measurement” software; then the three parameters of the base of defect (BD), alveolar crest (AC) and cementoenamel junction (CEJ) were determined using a software. Subsequent to radiographic measurements, clinical measurements were carried out meticulously during flap procedures. Then linear measurements were carried out using a periodontal probe to determine the defect depth and its mesiodistal width. Then the amount of correlation between these two measurements was assessed by Pearson's correlation coefficient. Results The correlation between clinical and radiographic measurements in defect depth determination, in the evaluation of defect angle and in determination of defect width were 88%, 98% and 90%, respectively. Conclusions Indirect digital radiographic technique can be used to diagnose intra-osseous defects, providing a better opportunity to treat bony defects. PMID:23329969

  7. Morphometric Comparison of Clavicle Outlines from 3D Bone Scans and 2D Chest Radiographs: A Short-listing Tool to Assist Radiographic Identification of Human Skeletons

    SciTech Connect

    Stephan, Carl N.; Amidan, Brett G.; Trease, Harold E.; Guyomarch, Pierre; Pulsipher, Trenton C.; Byrd, John E.

    2014-03-01

    This paper describes a computerized clavicle identification system, primarily designed to resolve the identities of unaccounted for US soldiers who fought in the Korean War. Elliptical Fourier analysis is used to quantify the clavicle outline shape from skeletons and postero-anterior antemortem chest radiographs to rank individuals in terms of metric distance. Similar to leading fingerprint identification systems, shortlists of the top matching candidates are extracted for subsequent human visual assessment. Two independent tests of the computerized system using 17 field-recovered skeletons and 409 chest radiographs demonstrate that true positive matches are captured within the top 5% of the sample 75% of the time. These results are outstanding given the eroded state of some field-recovered skeletons and the faintness of the 1950’s photoflurographs. These methods enhance the capability to resolve several hundred cold cases for which little circumstantial information exists and current DNA and dental record technologies cannot be applied.

  8. 2D:4D indicates phimosis risk: A study on digit ratio and early foreskin development.

    PubMed

    Li, Guanjian; Huo, Ying; Sun, Ke; Wang, Xiaodong; Li, Hao; Gao, Le; Ma, Bin

    2016-08-01

    Many researchers have adopted 2D:4D (second to fourth finger length ratio) as a noninvasive retrospective biomarker for prenatal androgen exposure in recent years. It is thought to be related to diverse traits including behavioral phenotypes, disease susceptibility, and development of urogenital system. To examine the relationship between 2D:4D and early foreskin development. We analyzed the digit ratio and foreskin condition in 176 cases (range 0-6years). The boys were divided into four groups according to their ages: group 1, neonates (below 28days, n=13); group 2, infants (1-12months, n=45); group 3, toddlers (1-2years old, n=42); group 4, preschool children (3-6years old, n=76). We measured the lengths of the second and fourth digits of the left and right hands. The foreskin status was classified into 4 types. Type I (phimosis), type II (partial phimosis), type III (adhesion of prepuce), type IV (normal). The phimosis rate was 92.3%, 82.2%, 45.2%, and 38.7% in group 1 to group 4. In contrast, the proportion of normal foreskin increased from 0% in neonates to 13.2% in preschool children. The percentage of higher level of foreskin development shows a downward trend with the increase of digits ratio, and as the age grows, the percentage of normal foreskin cases also increases. These results suggest that a higher R2D:4D (right hand 2D:4D) is a risk factor for phimosis in the early human development. Age is also a significant influence factor of foreskin conditions. Additional research is required to identify pathophysiologic mechanisms and to determine clinical significance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

    SciTech Connect

    Shaheen, Eman De Keyzer, Frederik; Bosmans, Hilde; Ongeval, Chantal Van; Dance, David R.; Young, Kenneth C.

    2014-08-15

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  10. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis.

    PubMed

    Shaheen, Eman; De Keyzer, Frederik; Bosmans, Hilde; Dance, David R; Young, Kenneth C; Van Ongeval, Chantal

    2014-08-01

    This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly suggestive for malignancy (BIRADS 5

  11. Digit ratio (2D:4D) in primary brain tumor patients: A case-control study.

    PubMed

    Bunevicius, Adomas; Tamasauskas, Sarunas; Deltuva, Vytenis Pranas; Tamasauskas, Arimantas; Sliauzys, Albertas; Bunevicius, Robertas

    2016-12-01

    The second-to-fourth digit ratio (2D:4D) reflects prenatal estrogen and testosterone exposure, and is established in utero. Sex steroids are implicated in development and progression of primary brain tumors. To investigate whether there is a link between 2D:4D ratio and primary brain tumors, and age at presentation. Digital images of the right and left palms of 85 primary brain tumor patients (age 56.96±13.68years; 71% women) and 106 (age 54.31±13.68years; 68% women) gender and age matched controls were obtained. The most common brain tumor diagnoses were meningioma (41%), glioblastoma (20%) and pituitary adenoma (16%). Right and left 2D:4D ratios, and right minus left 2D:4D (Dr-l) were compared between patients and controls, and were correlated with age. Right and left 2D:4D ratios were significantly lower in primary brain tumor patients relative to controls (t=-4.28, p<0.001 and t=-3.69, p<0.001, respectively). The Dr-l was not different between brain tumor patients and controls (p=0.27). In meningioma and glioma patients, age at presentation correlated negatively with left 2D:4D ratio (rho=-0.42, p=0.01 and rho=-0.36, p=0.02, respectively) and positively with Dr-l (rho=0.45, p=0.009 and rho=0.65, p=0.04, respectively). Right and left hand 2D:4D ratios are lower in primary brain tumor patients relative to healthy individuals suggesting greater prenatal testosterone and lower prenatal estrogen exposure in brain tumor patients. Greater age at presentation is associated with greater Dr-l and with lower left 2D:4D ratio of meningioma and glioma patients. Due to small sample size our results should be considered preliminary and interpreted with caution. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Digit Ratios (2D:4D) Determined by Computer-Assisted Analysis are More Reliable than Those Using Physical Measurements, Photocopies, and Printed Scans

    PubMed Central

    ALLAWAY, HEATHER C.; BLOSKI, TERRI G.; PIERSON, ROGER A.; LUJAN, MARLA E.

    2010-01-01

    Prenatal androgens influence the second to fourth digit ratio (2D:4D) of hands with men having lower ratios than women. Numerous methods are used to assess 2D:4D including, physical measurements with calipers, and measurements made from photocopies, scanned images, digital photographs, radiographs, and scaled tubes. Although each method appears relatively reliable, agreement upon a gold standard is necessary to better explore the putative effects of prenatal androgens. Our objective was to assess the level of intra and interobserver reliability when evaluating 2D:4D using four techniques: (1) physical measurements, (2) photocopies, (3) printed scanned images, and (4) computer-assisted image analysis. Physical measurements, photocopies, and printed scanned images were measured with Vernier calipers. Scanned images were also measured with computer-based calipers. Measurements were made in 30 men and 30 women at two different time points, by three experienced observers. Intraclass correlation coefficients were used to assess the level of reliability. Intraobserver reliability was best for computer-assisted (0.957), followed by photocopies (0.939), physical measurements (0.925), and printed scans (0.842; P = 0.015). Interobserver reliability was also greatest for computer-assisted (0.892), followed by photocopies (0.858), physical measurements (0.795), and printed scans (0.761; P = 0.001). Mean 2D:4D from physical measurements were higher than all other techniques (P < 0.0001). Digit ratios determined from computer-assisted, physical measurements, and printed scans were more reliable in men than women (P = 0.009, P = 0.017, and P = 0.012, respectively). In summary, 2D:4D determined from computer-assisted analysis yielded the most accurate and consistent measurements among observers. Investigations of 2D:4D should use computer-assisted measurements over alternate methods whenever possible. PMID:19263413

  13. 2D-3D radiograph to cone-beam computed tomography (CBCT) registration for C-arm image-guided robotic surgery.

    PubMed

    Liu, Wen Pei; Otake, Yoshito; Azizian, Mahdi; Wagner, Oliver J; Sorger, Jonathan M; Armand, Mehran; Taylor, Russell H

    2015-08-01

    C-arm radiographs are commonly used for intraoperative image guidance in surgical interventions. Fluoroscopy is a cost-effective real-time modality, although image quality can vary greatly depending on the target anatomy. Cone-beam computed tomography (CBCT) scans are sometimes available, so 2D-3D registration is needed for intra-procedural guidance. C-arm radiographs were registered to CBCT scans and used for 3D localization of peritumor fiducials during a minimally invasive thoracic intervention with a da Vinci Si robot. Intensity-based 2D-3D registration of intraoperative radiographs to CBCT was performed. The feasible range of X-ray projections achievable by a C-arm positioned around a da Vinci Si surgical robot, configured for robotic wedge resection, was determined using phantom models. Experiments were conducted on synthetic phantoms and animals imaged with an OEC 9600 and a Siemens Artis zeego, representing the spectrum of different C-arm systems currently available for clinical use. The image guidance workflow was feasible using either an optically tracked OEC 9600 or a Siemens Artis zeego C-arm, resulting in an angular difference of Δθ:∼ 30°. The two C-arm systems provided TRE mean ≤ 2.5 mm and TRE mean ≤ 2.0 mm, respectively (i.e., comparable to standard clinical intraoperative navigation systems). C-arm 3D localization from dual 2D-3D registered radiographs was feasible and applicable for intraoperative image guidance during da Vinci robotic thoracic interventions using the proposed workflow. Tissue deformation and in vivo experiments are required before clinical evaluation of this system.

  14. Reconstruction of 2D x-ray radiographs at the National Ignition Facility using pinhole tomography (invited)

    SciTech Connect

    Field, J. E. Rygg, J. R.; Barrios, M. A.; Benedetti, L. R.; Döppner, T.; Izumi, N.; Jones, O.; Khan, S. F.; Ma, T.; Nagel, S. R.; Pak, A.; Tommasini, R.; Bradley, D. K.; Town, R. P. J.

    2014-11-15

    Two-dimensional radiographs of imploding fusion capsules are obtained at the National Ignition Facility by projection through a pinhole array onto a time-gated framing camera. Parallax among images in the image array makes it possible to distinguish contributions from the capsule and from the backlighter, permitting correction of backlighter non-uniformities within the capsule radiograph. Furthermore, precise determination of the imaging system geometry and implosion velocity enables combination of multiple images to reduce signal-to-noise and discover new capsule features.

  15. Application of Perona Malik anisotropic diffusion on digital radiographic image

    NASA Astrophysics Data System (ADS)

    Halim, Suhaila Abd; Razak, Rohayu Abdul; Ibrahim, Arsmah; Manurung, Yupiter HP

    2014-07-01

    Perona Malik Anisotropic Diffusion (PMAD) is a very useful and efficient denoising technique if the parameters are properly selected. Overestimating the parameters may cause oversmoothed and underestimating it may leave unfiltered noise. This makes the selection of parameters a crucial process. In this paper the PMAD model is solved using a finite difference scheme The discretized model is evaluated using different diffusion coefficient of exponential and quadratic on defective radiographic images in terms of quality and efficiency. In the application of the PMAD model on image data, a set of defective radiographic images of welding is used as input data. Peak Signal to Noise Ratio (PSNR), Structural Similarity Measure (SSIM) and temporal time are used to evaluate the performance of the model. The implementation of the experiment has been carried out using MATLAB R2009a. In terms of quality, results show that the Quadratic Diffusion Coefficient Function (QDCF) provides better results compared with the Exponential Diffusion Coefficient Function (EDCF). In conclusion, the denoising effect using PMAD model based on finite difference scheme shows able to improve image quality by removing noise in the defective radiographic image.

  16. Application of Perona Malik anisotropic diffusion on digital radiographic image

    SciTech Connect

    Halim, Suhaila Abd; Razak, Rohayu Abdul; Ibrahim, Arsmah; Manurung, Yupiter HP

    2014-07-10

    Perona Malik Anisotropic Diffusion (PMAD) is a very useful and efficient denoising technique if the parameters are properly selected. Overestimating the parameters may cause oversmoothed and underestimating it may leave unfiltered noise. This makes the selection of parameters a crucial process. In this paper the PMAD model is solved using a finite difference scheme The discretized model is evaluated using different diffusion coefficient of exponential and quadratic on defective radiographic images in terms of quality and efficiency. In the application of the PMAD model on image data, a set of defective radiographic images of welding is used as input data. Peak Signal to Noise Ratio (PSNR), Structural Similarity Measure (SSIM) and temporal time are used to evaluate the performance of the model. The implementation of the experiment has been carried out using MATLAB R2009a. In terms of quality, results show that the Quadratic Diffusion Coefficient Function (QDCF) provides better results compared with the Exponential Diffusion Coefficient Function (EDCF). In conclusion, the denoising effect using PMAD model based on finite difference scheme shows able to improve image quality by removing noise in the defective radiographic image.

  17. A comparison of 2D and 3D digital image correlation for a membrane under inflation

    NASA Astrophysics Data System (ADS)

    Murienne, Barbara J.; Nguyen, Thao D.

    2016-02-01

    Three-dimensional (3D) digital image correlation (DIC) is becoming widely used to characterize the behavior of structures undergoing 3D deformations. However, the use of 3D-DIC can be challenging under certain conditions, such as high magnification, and therefore small depth of field, or a highly controlled environment with limited access for two-angled cameras. The purpose of this study is to compare 2D-DIC and 3D-DIC for the same inflation experiment and evaluate whether 2D-DIC can be used when conditions discourage the use of a stereo-vision system. A latex membrane was inflated vertically to 5.41 kPa (reference pressure), then to 7.87 kPa (deformed pressure). A two-camera stereo-vision system acquired top-down images of the membrane, while a single camera system simultaneously recorded images of the membrane in profile. 2D-DIC and 3D-DIC were used to calculate horizontal (in the membrane plane) and vertical (out of the membrane plane) displacements, and meridional strain. Under static conditions, the baseline uncertainty in horizontal displacement and strain were smaller for 3D-DIC than 2D-DIC. However, the opposite was observed for the vertical displacement, for which 2D-DIC had a smaller baseline uncertainty. The baseline absolute error in vertical displacement and strain were similar for both DIC methods, but it was larger for 2D-DIC than 3D-DIC for the horizontal displacement. Under inflation, the variability in the measurements were larger than under static conditions for both DIC methods. 2D-DIC showed a smaller variability in displacements than 3D-DIC, especially for the vertical displacement, but a similar strain uncertainty. The absolute difference in the average displacements and strain between 3D-DIC and 2D-DIC were in the range of the 3D-DIC variability. Those findings suggest that 2D-DIC might be used as an alternative to 3D-DIC to study the inflation response of materials under certain conditions.

  18. A comparison of 2D and 3D digital image correlation for a membrane under inflation.

    PubMed

    Murienne, Barbara J; Nguyen, Thao D

    2016-02-01

    Three-dimensional (3D) digital image correlation (DIC) is becoming widely used to characterize the behavior of structures undergoing 3D deformations. However, the use of 3D-DIC can be challenging under certain conditions, such as high magnification, and therefore small depth of field, or a highly controlled environment with limited access for two-angled cameras. The purpose of this study is to compare 2D-DIC and 3D-DIC for the same inflation experiment and evaluate whether 2D-DIC can be used when conditions discourage the use of a stereo-vision system. A latex membrane was inflated vertically to 5.41 kPa (reference pressure), then to 7.87 kPa (deformed pressure). A two-camera stereo-vision system acquired top-down images of the membrane, while a single camera system simultaneously recorded images of the membrane in profile. 2D-DIC and 3D-DIC were used to calculate horizontal (in the membrane plane) and vertical (out of the membrane plane) displacements, and meridional strain. Under static conditions, the baseline uncertainty in horizontal displacement and strain were smaller for 3D-DIC than 2D-DIC. However, the opposite was observed for the vertical displacement, for which 2D-DIC had a smaller baseline uncertainty. The baseline absolute error in vertical displacement and strain were similar for both DIC methods, but it was larger for 2D-DIC than 3D-DIC for the horizontal displacement. Under inflation, the variability in the measurements were larger than under static conditions for both DIC methods. 2D-DIC showed a smaller variability in displacements than 3D-DIC, especially for the vertical displacement, but a similar strain uncertainty. The absolute difference in the average displacements and strain between 3D-DIC and 2D-DIC were in the range of the 3D-DIC variability. Those findings suggest that 2D-DIC might be used as an alternative to 3D-DIC to study the inflation response of materials under certain conditions.

  19. A comparison of 2D and 3D digital image correlation for a membrane under inflation

    PubMed Central

    Murienne, Barbara J.; Nguyen, Thao D.

    2015-01-01

    Three-dimensional (3D) digital image correlation (DIC) is becoming widely used to characterize the behavior of structures undergoing 3D deformations. However, the use of 3D-DIC can be challenging under certain conditions, such as high magnification, and therefore small depth of field, or a highly controlled environment with limited access for two-angled cameras. The purpose of this study is to compare 2D-DIC and 3D-DIC for the same inflation experiment and evaluate whether 2D-DIC can be used when conditions discourage the use of a stereo-vision system. A latex membrane was inflated vertically to 5.41 kPa (reference pressure), then to 7.87 kPa (deformed pressure). A two-camera stereo-vision system acquired top-down images of the membrane, while a single camera system simultaneously recorded images of the membrane in profile. 2D-DIC and 3D-DIC were used to calculate horizontal (in the membrane plane) and vertical (out of the membrane plane) displacements, and meridional strain. Under static conditions, the baseline uncertainty in horizontal displacement and strain were smaller for 3D-DIC than 2D-DIC. However, the opposite was observed for the vertical displacement, for which 2D-DIC had a smaller baseline uncertainty. The baseline absolute error in vertical displacement and strain were similar for both DIC methods, but it was larger for 2D-DIC than 3D-DIC for the horizontal displacement. Under inflation, the variability in the measurements were larger than under static conditions for both DIC methods. 2D-DIC showed a smaller variability in displacements than 3D-DIC, especially for the vertical displacement, but a similar strain uncertainty. The absolute difference in the average displacements and strain between 3D-DIC and 2D-DIC were in the range of the 3D-DIC variability. Those findings suggest that 2D-DIC might be used as an alternative to 3D-DIC to study the inflation response of materials under certain conditions. PMID:26543296

  20. Prenatal influences on sexual orientation: digit ratio (2D:4D) and number of older siblings.

    PubMed

    Kangassalo, Katariina; Pölkki, Mari; Rantala, Markus J

    2011-10-10

    Prenatal androgen levels are suggested to influence sexual orientation in both sexes. The 2D:4D digit ratio has been found to associate with sexual orientation, but published findings have often been contradictory, which may partly be due to the large ethnic diversity between and within studied populations. In men, number of older brothers has been found to correlate positively with homosexuality. This phenomenon has been explained with a maternal immune reaction, which is provoked only by male fetuses and which gets stronger after each pregnancy. Here we assessed the relationship of sexual orientation to 2D:4D ratios and number of older siblings in Finland, where the population is found to be genetically relatively homogeneous. As in many previous studies, heterosexual men had lower 2D:4D than non-heterosexual men, which supports the notion that non- heterosexual men experience higher androgen levels in utero than population norms. Contrary to previous reports, non-heterosexual women had higher 2D:4D than heterosexual women. Non-heterosexual men had more older brothers and older sisters than heterosexual men. The greater number of older sisters in non-heterosexual men indicates that there are other factors that contribute to the higher birth order of homosexual men than the maternal immunization.

  1. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Approval of radiographic facilities that use digital radiography systems. 37.44 Section 37.44 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... made; the X-ray machine used; and the model, version, and production date of each image...

  2. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Approval of radiographic facilities that use digital radiography systems. 37.44 Section 37.44 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... made; the X-ray machine used; and the model, version, and production date of each image...

  3. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Approval of radiographic facilities that use digital radiography systems. 37.44 Section 37.44 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... machine used; and the model, version, and production date of each image acquisition software program...

  4. [The imaging principles and the structure of the low-dose digital radiographic device].

    PubMed

    Kang, Q Z; Yu, H L; Zhang, H; Zhang, D S; Cao, H D

    2001-03-01

    This article introduced A new type of X-ray radiographic device, which uses MWPC as the low-dose detector with the machinery and computer to reconstruct the X-ray digital images. In this paper, the advantages and the disadvantages of the device are analysed, thus much improvement has been made to make it better and more efficient.

  5. Breast density measurement: 3D cone beam computed tomography (CBCT) images versus 2D digital mammograms

    NASA Astrophysics Data System (ADS)

    Han, Tao; Lai, Chao-Jen; Chen, Lingyun; Liu, Xinming; Shen, Youtao; Zhong, Yuncheng; Ge, Shuaiping; Yi, Ying; Wang, Tianpeng; Yang, Wei T.; Shaw, Chris C.

    2009-02-01

    Breast density has been recognized as one of the major risk factors for breast cancer. However, breast density is currently estimated using mammograms which are intrinsically 2D in nature and cannot accurately represent the real breast anatomy. In this study, a novel technique for measuring breast density based on the segmentation of 3D cone beam CT (CBCT) images was developed and the results were compared to those obtained from 2D digital mammograms. 16 mastectomy breast specimens were imaged with a bench top flat-panel based CBCT system. The reconstructed 3D CT images were corrected for the cupping artifacts and then filtered to reduce the noise level, followed by using threshold-based segmentation to separate the dense tissue from the adipose tissue. For each breast specimen, volumes of the dense tissue structures and the entire breast were computed and used to calculate the volumetric breast density. BI-RADS categories were derived from the measured breast densities and compared with those estimated from conventional digital mammograms. The results show that in 10 of 16 cases the BI-RADS categories derived from the CBCT images were lower than those derived from the mammograms by one category. Thus, breasts considered as dense in mammographic examinations may not be considered as dense with the CBCT images. This result indicates that the relation between breast cancer risk and true (volumetric) breast density needs to be further investigated.

  6. Digit ratios (2D:4D), postnatal testosterone and eye contact in toddlers.

    PubMed

    Saenz, Janet; Alexander, Gerianne M

    2013-09-01

    Previous research has shown an association between eye contact and prenatal testosterone measured in amniocenteses samples. The purpose of this study was to test the association between eye contact and prenatal androgen action measured via second to fourth digit ratios (2D:4D ratios), and to explore the relationship between eye contact and postnatal testosterone levels. Participants included 72 children, between the ages of 18 and 24 months, and their parents. Salivary testosterone levels were obtained when children were 3-months old. At 18-months, 2D:4D ratios were measured and parent-child dyads participated in an 8-min play session that was recorded and later coded for duration and frequency of eye contact. Results indicated that larger 2D:4D ratios (indicative of lower androgen levels) significantly predicted longer duration and more frequency of eye contact, while postnatal testosterone levels were unrelated to eye contact. These novel findings suggest prenatal androgens may influence the emergence of social development. Published by Elsevier B.V.

  7. A Pascal computer program for digitizing lateral cephalometric radiographs.

    PubMed

    Konchak, P A; Koehler, J A

    1985-03-01

    The authors describe a new program for cephalometric analysis which uses a commonly available microprocessor (computer) and digitizing pad to register fifteen commonly identified cephalometric landmarks to produce a meaningful analysis which is printed out for permanent or hard-copy record. Conventional and digitizing errors of cephalometric measurement are reviewed, with a discussion of the advantages of computer-assisted programs. The authors describe a program that uses vectors and vector algebra and the capabilities of the Pascal computer language to determine angular measurements and distances. It is suggested that computer-assisted cephalometric programs will likely be widely used in the near future, providing the orthodontist with a superior method of cephalometric analysis with respect to accuracy and speed of completion.

  8. System For The Digitization, Display And Archiving Of Radiographs: Design And Early Experience

    NASA Astrophysics Data System (ADS)

    Jennings, R. J.; Bruce, M. C.

    1985-06-01

    In this paper we describe a system for the digitization, display, and storage of radiographic images. The system was set up to support a project to assess the clinical impact of matrix size on teleradiology, defined for our purposes as the electronic recording and transmission of radiographs. The system consists of two separate facilities, one for image digitizing and the other for image display, interpretation, and archiving. The image digitizing laboratory uses a solid state scanner interfaced to a dedicated, general-purpose minicomputer. The display facility consists of a general-purpose, multi-user minicomputer with large main memory and disk capacity and a 1280 by 1024 display subsystem with three separate image memories. The two facilities communicate via magnetic tape. This paper documents the characterization of the image data base used for the project, the design and operational features of the two facilities, technical problems encountered in the digitizing and display of radiographs, and some logistical and managerial considerations involved in generating and maintaining a large digital image archive. Since many of the functions of the system we have set up are common to picture archiving and communication systems, we have, where possible, compared the performance of the system we have developed with the requirements that would have to be satisfied by a system intended for clinical use. We leave for future reports the discussion of the conduct of the image reading experiments and the results of those experiments.

  9. Prediction of age and gender using digital radiographic method: A retrospective study

    PubMed Central

    Poongodi, V.; Kanmani, R.; Anandi, M. S.; Krithika, C. L.; Kannan, A.; Raghuram, P. H.

    2015-01-01

    Aim and Objective: To investigate age, sex based on gonial angle, width and breadth of the ramus of the mandible by digital orthopantomograph. Materials and Methods: A total of 200 panoramic radiographic images were selected. The age of the individuals ranged between 4 and 75 years of both the gender - males (113) and females (87) and selected radiographic images were measured using KLONK image measurement software tool with linear, angular measurement. The investigated radiographs were collected from the records of SRM Dental College, Department of Oral Medicine and Radiology. Radiographs with any pathology, facial deformities, if no observation of mental foramen, congenital deformities, magnification, and distortion were excluded. Results: Mean, median, standard deviation, derived to check the first and third quartile, linear regression is used to check age and gender correlation with angle of mandible, height and width of the ramus of mandible. Conclusion: The radiographic method is a simpler and cost-effective method of age identification compared with histological and biochemical methods. Mandible is strongest facial bone after the skull, pelvic bone. It is validatory to predict age and gender by many previous studies. Radiographic and tomographic images have become an essential aid for human identification in forensic dentistry forensic dentists can choose the most appropriate one since the validity of age and gender estimation crucially depends on the method used and its proper application. PMID:26538907

  10. Tolerance limit value of brightness and contrast adjustment on digitized radiographs

    NASA Astrophysics Data System (ADS)

    Utami, S. N.; Kiswanjaya, B.; Syahraini, S. I.; Ustriyana, P.

    2017-08-01

    The aim of this study was to measure the tolerance limit value of brightness and contrast adjustment on digitized radiograph with apical periodontitis and early apical abscess. Brightness and contrast adjustment on 60 periapical radiograph with apical periodontitis and early apical abscess made by 2 observers. Reliabilities tested by Cohen’s Kappa Coefficient and significance tested by wilcoxon test. Tolerance limit value of brightness and contrast adjustment for apical periodontitis is -5 and +5, early apical abscess is -10 and +10, and both is -5 and +5. Brightness and contrast adjustment which not appropriate can alter the evaluation and differential diagnosis of periapical lesion.

  11. Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

    NASA Technical Reports Server (NTRS)

    Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

    1990-01-01

    Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modern video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

  12. Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

    NASA Technical Reports Server (NTRS)

    Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

    1990-01-01

    Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modem video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

  13. Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

    NASA Technical Reports Server (NTRS)

    Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

    1990-01-01

    Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modem video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

  14. Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

    NASA Technical Reports Server (NTRS)

    Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

    1990-01-01

    Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modern video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

  15. Hip2Norm: an object-oriented cross-platform program for 3D analysis of hip joint morphology using 2D pelvic radiographs.

    PubMed

    Zheng, G; Tannast, M; Anderegg, C; Siebenrock, K A; Langlotz, F

    2007-07-01

    We developed an object-oriented cross-platform program to perform three-dimensional (3D) analysis of hip joint morphology using two-dimensional (2D) anteroposterior (AP) pelvic radiographs. Landmarks extracted from 2D AP pelvic radiographs and optionally an additional lateral pelvic X-ray were combined with a cone beam projection model to reconstruct 3D hip joints. Since individual pelvic orientation can vary considerably, a method for standardizing pelvic orientation was implemented to determine the absolute tilt/rotation. The evaluation of anatomically morphologic differences was achieved by reconstructing the projected acetabular rim and the measured hip parameters as if obtained in a standardized neutral orientation. The program had been successfully used to interactively objectify acetabular version in hips with femoro-acetabular impingement or developmental dysplasia. Hip(2)Norm is written in object-oriented programming language C++ using cross-platform software Qt (TrollTech, Oslo, Norway) for graphical user interface (GUI) and is transportable to any platform.

  16. Bone and joint modeling from 3D knee MRI: feasibility and comparison with radiographs and 2D MRI.

    PubMed

    Wadhwa, Vibhor; Malhotra, Vidur; Xi, Yin; Nordeck, Shaun; Coyner, Katherine; Chhabra, Avneesh

    2016-01-01

    The purpose was to evaluate feasibility of bone and joint segmentations from three-dimensional magnetic resonance imaging (3D MRI). Segmented joint models from 3D MRI data set were obtained for 42 patients. Blinded angular and joint space measurements were performed on 3D MRI model, two-dimensional (2D) MRI, and radiography (XR). Medial joint space was similar on both XR and 3D MRI (P=.3). The XR measurements were statistically different but closer to 3D MRI for lateral patellar tilt angle, patellar tendon length, and lateral knee joint space, whereas 2D MRI measurements were closer to XR in terms of trochlear depth, sulcal angle, and patellar length. 3D bone and joint segmentations are feasible from isotropic MRI data sets. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Blood flow determination using recursive processing: a digital radiographic method

    SciTech Connect

    Kruger, R.A.; Bateman, W.; Liu, P.Y.; Nelson, J.A.

    1983-10-01

    Temporal filtration of fluoroscopic video sequences is being used as an alternative to pulsed digital subtraction angiography. Using the same image processing architecture and a slight modification in processing logic a parametric image can be synthesized from such a temporally filtered image sequence in virtual real time, i.e., an image sequence that spans T seconds takes exactly T seconds to process. Off-line computer processing is not required. Initial phantom studies imply that the time to maximum opacification (t/sub max/) can be used to determine absolute and relative blood flow with a high confidence level (r > .989). Phantom and animal examples are presented.

  18. Digit ratio (2D:4D) and handgrip strength are correlated in women (but not in men) in Hui ethnicity.

    PubMed

    Lu, Hong; Shen, Dan; Wang, Lu; Niu, Shibo; Bai, Chunyue; Ma, Zhanbing; Huo, Zhenghao

    2017-06-01

    Digit ratio, especially second-to-fourth digit ratio (2D:4D) is used as a biomarker of prenatal testosterone exposure and was found associated with physical ability, such as handgrip strength (HGS). Recently, this association has been discussed in several ethnic groups. To investigate correlations between 2D:4D and HGS in Chinese population of Ningxia Hui ethnicity. Here we firstly present the evidence on digit ratio and HGS of 346 college students (119 males and 227 females) by collecting photographs and HGS of both hands at Yinchuan city, in the Ningxia province of China. Females have higher mean values of digit ratio than males; significant variances of 3D:5D (left and right: P<0.05), 2D:3D, 3D:4D (left and right: P<0.01) and 2D:4D, 2D:5D (left and right: P<0.001) were found between different sex. Males showed significantly greater HGS than females on both hands. 2D:4D of both hands were significantly negative correlated with HGS in females (but not in males). 2D:4D ratio is negatively correlated with HGS in a Chinese population (especially in females) of Ningxia Hui ethnicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Estimation of percentage breast tissue density: comparison between digital mammography (2D full field digital mammography) and digital breast tomosynthesis according to different BI-RADS categories

    PubMed Central

    Cavagnetto, F; Calabrese, M; Houssami, N

    2013-01-01

    Objective: To compare breast density estimated from two-dimensional full-field digital mammography (2D FFDM) and from digital breast tomosynthesis (DBT) according to different Breast Imaging–Reporting and Data System (BI-RADS) categories, using automated software. Methods: Institutional review board approval and written informed patient consent were obtained. DBT and 2D FFDM were performed in the same patients to allow within-patient comparison. A total of 160 consecutive patients (mean age: 50±14 years; mean body mass index: 22±3) were included to create paired data sets of 40 patients for each BI-RADS category. Automatic software (MedDensity©, developed by Giulio Tagliafico) was used to compare the percentage breast density between DBT and 2D FFDM. The estimated breast percentage density obtained using DBT and 2D FFDM was examined for correlation with the radiologists' visual BI-RADS density classification. Results: The 2D FFDM differed from DBT by 16.0% in BI-RADS Category 1, by 11.9% in Category 2, by 3.5% in Category 3 and by 18.1% in Category 4. These differences were highly significant (p<0.0001). There was a good correlation between the BI-RADS categories and the density evaluated using 2D FFDM and DBT (r=0.56, p<0.01 and r=0.48, p<0.01, respectively). Conclusion: Using DBT, breast density values were lower than those obtained using 2D FFDM, with a non-linear relationship across the BI-RADS categories. These data are relevant for clinical practice and research studies using density in determining the risk. Advances in knowledge: On DBT, breast density values were lower than with 2D FFDM, with a non-linear relationship across the classical BI-RADS categories. PMID:24029631

  20. Single-shot and phase-shifting digital holographic microscopy using a 2-D grating.

    PubMed

    Yang, Taeseok Daniel; Kim, Hyung-Jin; Lee, Kyoung J; Kim, Beop-Min; Choi, Youngwoon

    2016-05-02

    We demonstrate digital holographic microscopy that, while being based on phase-shifting interferometry, is capable of single-shot measurements. A two-dimensional (2-D) diffraction grating placed in a Fourier plane of a standard in-line holographic phase microscope generates multiple copies of a sample image on a camera sensor. The identical image copies are spatially separated with different overall phase shifts according to the diffraction orders. The overall phase shifts are adjusted by controlling the lateral position of the grating. These phase shifts are then set to be multiples of π/2. Interferograms composed of four image copies combined with a parallel reference beam are acquired in a single shot. The interferograms are processed through a phase-shifting algorithm to produce a single complex image. By taking advantage of the higher sampling capacity of the in-line holography, we can increase the imaging information density by a factor of 3 without compromising the imaging acquisition speed.

  1. Interpreting digit ratio (2D:4D)-behavior correlations: 2D:4D sex difference, stability, and behavioral correlates and their replicability in young children.

    PubMed

    Wong, Wang I; Hines, Melissa

    2016-02-01

    The popularity of using the ratio of the second to the fourth digit (2D:4D) to study influences of early androgen exposure on human behavior relies, in part, on a report that the ratio is sex-dimorphic and stable from age 2 years (Manning etal., 1998). However, subsequent research has rarely replicated this finding. Moreover, although 2D:4D has been correlated with many behaviors, these correlations are often inconsistent. Young children's 2D:4D-behavior correlations may be more consistent than those of older individuals, because young children have experienced fewer postnatal influences. To evaluate the usefulness of 2D:4D as a biomarker of prenatal androgen exposure in studies of 2D:4D-behavior correlations, we assessed its sex difference, temporal stability, and behavioral correlates over a 6- to 8-month period in 126, 2- to 3-year-old children, providing a rare same-sample replicability test. We found a moderate sex difference on both hands and high temporal stability. However, between-sex overlap and within-sex variability were also large. Only 3 of 24 correlations with sex-typed behaviors-scores on the Preschool Activities Inventory (PSAI), preference for a boy-typical toy, preference for a girl-typical toy, were significant and in the predicted direction, all of which involved the PSAI, partially confirming findings from another study. Correlation coefficients were larger for behaviors that showed larger sex differences. But, as in older samples, the overall pattern showed inconsistency across time, sex, and hand. Therefore, although sex-dimorphic and stable, 2D:4D-behavior correlations are no more consistent for young children than for older samples. Theoretical and methodological implications are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Real-time Simultaneous DKG and 2D DKG Using High-speed Digital Camera.

    PubMed

    Kang, Duck-Hoon; Wang, Soo-Geun; Park, Hee-June; Lee, Jin-Choon; Jeon, Gye-Rok; Choi, Ill-Sang; Kim, Seon-Jong; Shin, Bum-Joo

    2017-03-01

    For the evaluation of voice disorders, direct observation of vocal cord vibration is important. Among the various methods, laryngeal videostroboscopy (LVS) is widely used, but it was not a true image because it collects images from different cycles. In contrast, high-speed videoendoscopy and videokymography have much higher frame rates and can assess functional and mobility disorders. The purpose of the study is to describe real-time, simultaneous digital kymography (DKG), two-dimensional scanning (2D) DKG, and multi-frame (MF) LVS system using a high-speed digital camera, and identify the efficacy of this system in evaluating vibratory patterns of pathologic voice. The pattern of vocal fold vibration was evaluated in a vocally healthy subject and in subjects with vocal polyp, vocal nodules, vocal cord scar, and vocal cord paralysis. We used both quantitative (left-right phase symmetry, amplitude symmetry index) and qualitative (anterior-posterior phase symmetry) parameters for assessment of vocal fold vibration. Our system could record videos within seconds and required relatively little memory. The speed of replay in the DKG, 2D DKG, MF LVS, and high-speed videoendoscopy was controllable. The number of frame per cycle with MF LVS was almost the same as the fundamental frequency. Our system can provide images of various modalities simultaneously in real time and analyze morphological and functional vibratory patterns. It can be possible to provide a greater level of information for the diagnosis and treatment of vibratory disorders. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  3. A comparative assessment of entrance surface doses in analogue and digital radiography during common radiographic examinations.

    PubMed

    Seo, Deoknam; Jang, Seogoo; Kim, Jungmin; Kim, Jungsu; Sung, Dongwook; Kim, HyunJi; Yoon, Yongsu

    2014-01-01

    Digital radiography is often performed at a higher dose rate than analogue radiography for image acquisition. The authors measured the Entrance Surface Dose (ESD) of analogue and digital radiography techniques for 14 radiographic examinations from randomly selected medical centres in the central district of Korea. It was that the mean ESD of the digital examinations was 2.84 mGy (range, 0.37-6.38 mGy) and that of the analogue examinations was 1.83 mGy (range, 0.38-4.74 mGy), resulting in a 55.25 % higher ESD for digital technique. Although this survey is not completely representative of Korea, findings of this study indicate a need for closer exposure management in digital radiography to minimise patient dose.

  4. Interventional digital tomosynthesis from a standard fluoroscopy system using 2D-3D registration.

    PubMed

    Alhrishy, Mazen; Varnavas, Andreas; Carrell, Tom; King, Andrew; Penney, Graeme

    2015-01-01

    Interventional fluoroscopy provides guidance in a variety of minimally invasive procedures. However, three-dimensional (3D) clinically relevant information is projected onto a two-dimensional (2D) image which can make image interpretation difficult. Moreover, vasculature visualisation requires the use of iodinated contrast media which is nephrotoxic and is the primary cause of renal complications. In this article, we demonstrate how digital tomosynthesis slices can be produced on standard fluoroscopy equipment by registering the preoperative CT volume and the intraoperative fluoroscopy images using 2D-3D image registration. The proposed method automatically reconstructs patient-anatomy-specific slices and removes clutter resulting from bony anatomy. Such slices could provide additional intraoperative information which cannot be provided by the preoperative CT volume alone, such as the deformed aorta position offering improved guidance precision. Image acquisition would fit with interventional clinical work-flow and would not require a high X-ray dose. Experiments are carried out using one phantom and four clinical datasets. Phantom results showed a 3351% contrast-to-noise improvement compared to standard fluoroscopy. Patient results showed our method enabled visualization of clinically relevant features: outline of the aorta, the aortic bifurcation and some aortic calcifications. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. High-accuracy biaxial optical extensometer based on 2D digital image correlation

    NASA Astrophysics Data System (ADS)

    Zhu, Feipeng; Gong, Yan; Bai, Pengxiang; Jiang, Zhencheng; Lei, Dong

    2017-08-01

    In two-dimensional digital image correlation (2D-DIC), the optical axis of the camera must be exactly perpendicular to the object surface to avoid the generation of out-of-plane displacement, which leads to low strain accuracy. In this work, we first studied the strain accuracy of a common optical extensometer when the optical axis of the camera is not perpendicular to the specimen surface. Derivation reveals that even a very small oblique angle θ will introduce a considerable strain error and that an opposite oblique angle θ generates an opposite strain error of the same magnitude. Therefore, taking the strain average of these two optical extensometers can almost entirely eliminate such effect of non-perpendicularity, which has the same form as the optical extensometer realized by dual-reflector imaging. Because the transverse strain of a specimen is less than its axial strain, the measurement of transverse strain requires higher strain-measurement accuracy. With the aid of a self-designed right-angled apparatus, we conveniently extend this 1D extensometer to a 2D situation, which is called the biaxial optical extensometer. Uniaxial tensile tests of a stainless-steel specimen are conducted to evaluate the strain accuracy of the biaxial optical extensometer quantitatively. Experimental results show that the transverse and axial strains obtained using the proposed biaxial extensometer are in good agreement with those obtained using strain gauges and that the proposed extensometer achieves higher strain accuracy compared to the 3D-DIC extensometer.

  6. Overall trends vs. individual trajectories in the second-to-fourth digit (2D:4D) and metacarpal (2M:4M) ratios during puberty and adolescence.

    PubMed

    Králík, Miroslav; Ingrová, Pavlína; Kozieł, Sławomir; Hupková, Adela; Klíma, Ondřej

    2017-04-01

    The second-to-fourth digit ratio (2D:4D ratio) can be assumed a valid indicator of sexual differentiation, provided that it is stable once it develops, or eventual changes remain uniform in a respective cohort throughout ontogenesis. The main goal of this study was to determine whether the metacarpal 2M:4M and the digit 2D:4D ratio change during the period of pubertal/adolescent growth. The metacarpals and digits were measured on radiographs of left hands in the sample of 328 individuals (96 pairs of male and 68 pairs of female twins) from the Wrocław Longitudinal Study of Twins (1967-1983). Five consecutive annual measurements were done for each individual within a 4-year-interval somewhere between 7 and 18 years of age. Age-related changes in both ratios were studied using a set of mixed-effects linear models. Three types of correlation coefficients were used for assessment of stability between repeated measurements at different ages. An overall decrease in the average 2M:4M ratio was observed, attributable to a much larger extent to males than to females. On the contrary, a slight overall increase in the average 2D:4D ratio was observed, attributable to a much larger extent to females than to males. The rank order of the ratios remained highly stable within the monitored period (the correlation coefficient mostly ranged between 0.85 and 0.95). In spite of these findings, we recorded significant intraindividual changes in both ratios. In some individuals the 2D:4D ratio can undergo changes comparable to average sex differences and much higher than average age-related changes. Relatively slight overall changes in digit ratio in puberty and adolescence themselves are not inconsistent with the use of the 2D:4D ratio as an indirect marker of prenatal sexual differentiation. Nevertheless, individual changes in the ratios varied substantially in this study and differed from the average trends. Future studies should focus on the nature of interindividual developmental

  7. Effects of radiographic techniques on the low-contrast detail detectability performance of digital radiography systems.

    PubMed

    Alsleem, Haney; U, Paul; Mong, Kam Shan; Davidson, Robert

    2014-01-01

    the kilovolt peak at the different milliampere second settings essentially did not affect the IQFinv of the different digital radiography systems. Increasing milliampere seconds in all digital imaging systems generally improves detectability performance. However, altering the kilovolt peak setting does not significantly change the IQFinv and detectability of objects in a digital radiograph. Imaging system selection should be based on typical radiographic examinations. Indirect digital radiography systems are better for studies that require higher kilovolt peak, such as large organs, and direct digital radiography is better for studies that require low kilovolt peak, such as small organs and mammography, which is used to examine fine tissue details.

  8. Female digit length ratio (2D:4D) and time-to-pregnancy.

    PubMed

    Vélez, M P; Arbuckle, T E; Monnier, P; Fraser, W D

    2016-09-01

    Is the female 2th- to 4th-finger ratio (2D:4D) associated with fecundity as measured by time-to-pregnancy (TTP)? Our study does not support an association between female 2D:4D and TTP. The 2th- to 4th-finger ratio (2D:4D) has been proposed as a potential indicator of greater androgen exposure during fetal development. Women exposed in utero to unbalanced steroid hormones may have impaired fecundity in the adulthood. Fecundity is often measured by TTP, an epidemiological tool commonly used to assess the impact of environmental factors in human conception. The Maternal-Infant Research on Environmental Chemicals (MIREC) Study is a pregnancy and birth cohort of 2001 women recruited before 14 weeks of gestation in 10 cities across Canada between 2008 and 2011. The present analysis is part of MIREC-CD Plus, a follow-up study in a subsample of some 800 MIREC mothers and their children from 2012 to 2015. TTP and maternal characteristics were collected from questionnaires administered during the first trimester of pregnancy as part of the MIREC study. Digital pictures of the ventral surface of both hands were obtained in the MIREC mothers at the MIREC-CD Plus follow-up study. The 2D:4D was calculated as the ratio of the second and fourth fingers of each hand. The exposure of interest was the 2D:4D of the women categorized by tertiles, or dichotomized as ≥1 (index finger longer than the ring finger) or <1 (ring finger longer than the index finger, implying greater androgen exposure during fetal development). The final sample included 696 mothers. Statistical analyses included discrete-time Cox proportional hazard models, allowing adjustment for potential confounding factors. There was no evidence of diminished/increased fecundability according to the 2D:4D, neither on the right nor on the left hand. In our analysis by tertiles, the smallest 2D:4D (i.e. higher androgen exposure during fetal life) resulted in FORs higher than 1 (i.e. shorter TTP) in both hands, although this

  9. Female digit length ratio (2D:4D) and time-to-pregnancy

    PubMed Central

    Vélez, M.P.; Arbuckle, T.E.; Monnier, P.; Fraser, W.D.

    2016-01-01

    STUDY QUESTION Is the female 2th- to 4th-finger ratio (2D:4D) associated with fecundity as measured by time-to-pregnancy (TTP)? SUMMARY ANSWER Our study does not support an association between female 2D:4D and TTP. WHAT IS KNOWN ALREADY The 2th- to 4th-finger ratio (2D:4D) has been proposed as a potential indicator of greater androgen exposure during fetal development. Women exposed in utero to unbalanced steroid hormones may have impaired fecundity in the adulthood. Fecundity is often measured by TTP, an epidemiological tool commonly used to assess the impact of environmental factors in human conception. STUDY DESIGN, SIZE, DURATION The Maternal-Infant Research on Environmental Chemicals (MIREC) Study is a pregnancy and birth cohort of 2001 women recruited before 14 weeks of gestation in 10 cities across Canada between 2008 and 2011. The present analysis is part of MIREC-CD Plus, a follow-up study in a subsample of some 800 MIREC mothers and their children from 2012 to 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS TTP and maternal characteristics were collected from questionnaires administered during the first trimester of pregnancy as part of the MIREC study. Digital pictures of the ventral surface of both hands were obtained in the MIREC mothers at the MIREC-CD Plus follow-up study. The 2D:4D was calculated as the ratio of the second and fourth fingers of each hand. The exposure of interest was the 2D:4D of the women categorized by tertiles, or dichotomized as ≥1 (index finger longer than the ring finger) or <1 (ring finger longer than the index finger, implying greater androgen exposure during fetal development). The final sample included 696 mothers. Statistical analyses included discrete-time Cox proportional hazard models, allowing adjustment for potential confounding factors. MAIN RESULTS AND THE ROLE OF CHANCE There was no evidence of diminished/increased fecundability according to the 2D:4D, neither on the right nor on the left hand. In our analysis by

  10. Foreground marker controlled watershed on digital radiographic image for weld discontinuity detection

    NASA Astrophysics Data System (ADS)

    Abd Halim, Suhaila; Zahid, Akhma; Abdul Razak, Nurul Syafinaz; Ibrahim, Arsmah; Manurung, Yupiter HP; Jayes, Mohd Idris

    2013-04-01

    Radiography is one of the most common and widely used non-destructive testing (NDT) technique in inspecting weld discontinuity in welded joints. Conventionally, radiography inspector is requires to do the inspection analysis manually on weld discontinuity based on visual characteristics such as location, shape, length and density. The results can be very subjective, time consuming and inconsistent. Hence, semi-automated inspection using digital image processing and segmentation technique can be applied for weld discontinuity detection. The goal of this work is to detect the weld discontinuity on digital radiographic image using Foreground Marker Controlled Watershed. It is usually implemented in image processing because it always generates closed contour for each region in the image. In this paper, image enhancement on radiographic image is aim to remove image noise and improve image contrast. Then, marker controlled watershed with foreground markers is applied on the image to detect the discontinuity. The accuracy of the technique is evaluated using Receiver Operating Characteristic (ROC) curve. The accuracy of the technique has been compared with the ground truth and the result shows that the accuracy is 67% and area under the curve is 0.7134. The application of image processing technique in detecting weld discontinuity is able to assist radiographer to improve the inconsistent results in evaluating the radiographic image.

  11. A comparison of measurement methods and sexual dimorphism for digit ratio (2D:4D) in Han ethnicity.

    PubMed

    Xi, Huanjiu; Li, Ming; Fan, Yingnan; Zhao, Liguang

    2014-02-01

    The digit ratio (2D:4D) is sexually dimorphic and has been considered an indicator of prenatal sex hormone exposure. Previous studies have shown that males tend to have lower 2D to 4D ratio than females, and this sexual dimorphism has been reported across different ethnic groups and different countries. However, digit ratio data are missing from the Han ethnicity in China. Furthermore, most of the previous studies used direct measurement for digit ratio. In this article, we used multiple measurement methods, including the direct measurement and two X-ray measurement methods to examine the trait of 2D:4D in Chinese Han. Our sample consisted of 128 men and 122 women from Liaoning Medical University. They were 18-20 years old. The direct measurement and two types of X-ray measurements of the length of their 2nd and 4th fingers were used separately to calculate digit ratios. Soft tissue thickness of 2D and 4D fingertips were also assessed from the two X-ray methods. The results suggest that (1) sex differences in 2D:4D tend to be stronger in the two X-ray measurements in comparison to the direct measurement; (2) 2D:4D ratios from X-ray measurements tend to be lower than that from the direct measurement; (3) Han ethnicity have a lower mean value of 2D:4D than other ethnic groups; (4) no sex difference in the soft tissue of finger tips. In conclusion, the digit ratio is lower in both men and women in Han, and the sexual dimorphism in digit ratio was stronger with X-ray measurements in comparison to the direct measurement.

  12. Technical Note: Guidelines for the digital computation of 2D and 3D enamel thickness in hominoid teeth.

    PubMed

    Benazzi, Stefano; Panetta, Daniele; Fornai, Cinzia; Toussaint, Michel; Gruppioni, Giorgio; Hublin, Jean-Jacques

    2014-02-01

    The study of enamel thickness has received considerable attention in regard to the taxonomic, phylogenetic and dietary assessment of human and non-human primates. Recent developments based on two-dimensional (2D) and three-dimensional (3D) digital techniques have facilitated accurate analyses, preserving the original object from invasive procedures. Various digital protocols have been proposed. These include several procedures based on manual handling of the virtual models and technical shortcomings, which prevent other scholars from confidently reproducing the entire digital protocol. There is a compelling need for standard, reproducible, and well-tailored protocols for the digital analysis of 2D and 3D dental enamel thickness. In this contribution we provide essential guidelines for the digital computation of 2D and 3D enamel thickness in hominoid molars, premolars, canines and incisors. We modify previous techniques suggested for 2D analysis and we develop a new approach for 3D analysis that can also be applied to premolars and anterior teeth. For each tooth class, the cervical line should be considered as the fundamental morphological feature both to isolate the crown from the root (for 3D analysis) and to define the direction of the cross-sections (for 2D analysis). Copyright © 2013 Wiley Periodicals, Inc.

  13. Radiopacity evaluation of Portland and MTA-based cements by digital radiographic system

    PubMed Central

    BORGES, Alvaro Henrique; PEDRO, Fabio Luiz Miranda; SEMANOFF-SEGUNDO, Alex; MIRANDA, Carlos Eduardo Saraiva; PÉCORA, Jesus Djalma; CRUZ FILHO, Antônio Miranda

    2011-01-01

    Objective The aim of the present study was to evaluate the radiopacity of Portland and MTA-based cements using the Digora TM digital radiographic system. Material and Methods The performed tests followed specification number 57 from the American National Standard Institute/American Dental Association (2000) for endodontic sealing materials. The materials were placed in 5 acrylic plates, especially designed for this experiment, along with a graduated aluminum stepwedge varying from 1 to 10 mm in thickness. The set was radiographed at a 30 cm focus-object distance and with 0.2 s exposure time. After the radiographs were taken, the optical laser readings of radiographs were performed by Digora TM system. Five radiographic density readings were performed for each studied material and for each step of the aluminum scale. Results White ProRoot MTA (155.99±8.04), gray ProRoot MTA (155.96±16.30) and MTA BIO (143.13±16.94) presented higher radiopacity values (p<0.05), while white non-structural Portland (119.76±22.34), gray Portland (109.71±4.90) and white structural Portland (99.59±12.88) presented lower radiopacity values (p<0.05). Conclusions It was concluded that MTA-based cements were the only materials presenting radiopacity within the ANSI/ADA specifications. PMID:21625738

  14. Effective DQE (eDQE) and speed of digital radiographic systems: An experimental methodology

    PubMed Central

    Samei, Ehsan; Ranger, Nicole T.; MacKenzie, Alistair; Honey, Ian D.; Dobbins, James T.; Ravin, Carl E.

    2009-01-01

    Prior studies on performance evaluation of digital radiographic systems have primarily focused on the assessment of the detector performance alone. However, the clinical performance of such systems is also substantially impacted by magnification, focal spot blur, the presence of scattered radiation, and the presence of an antiscatter grid. The purpose of this study is to evaluate an experimental methodology to assess the performance of a digital radiographic system, including those attributes, and to propose a new metric, effective detective quantum efficiency (eDQE), a candidate for defining the efficiency or speed of digital radiographic imaging systems. The study employed a geometric phantom simulating the attenuation and scatter properties of the adult human thorax and a representative indirect flat-panel-based clinical digital radiographic imaging system. The noise power spectrum (NPS) was derived from images of the phantom acquired at three exposure levels spanning the operating range of the clinical system. The modulation transfer function (MTF) was measured using an edge device positioned at the surface of the phantom, facing the x-ray source. Scatter measurements were made using a beam stop technique. The eDQE was then computed from these measurements, along with measures of phantom attenuation and x-ray flux. The MTF results showed notable impact from the focal spot blur, while the NPS depicted a large component of structured noise resulting from use of an antiscatter grid. The eDQE was found to be an order of magnitude lower than the conventional DQE. At 120 kVp, eDQE(0) was in the 8%–9% range, fivefold lower than DQE(0) at the same technique. The eDQE method yielded reproducible estimates of the system performance in a clinically relevant context by quantifying the inherent speed of the system, that is, the actual signal to noise ratio that would be measured under clinical operating conditions. PMID:19746814

  15. Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations

    PubMed Central

    Manning, John; Kilduff, Liam; Cook, Christian; Crewther, Blair; Fink, Bernhard

    2013-01-01

    Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. This ratio is considered to be a biomarker of the balance between fetal testosterone (T) and estrogen (E) in a narrow window of early ontogeny. Evidence for this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits) in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroids in adults are less clear, as many correlational studies of 2D:4D and adult sex steroids have concluded that this association is statistically non-significant. Here, we suggest that in order to understand the link between 2D:4D and sex hormones, one must consider both fetal organizing and adult activating effects of T and E. In particular, we hypothesize that 2D:4D correlates with organizing effects on the endocrine system that moderate activating effects in adulthood. We argue that this is particularly evident in “challenging” conditions such as aggressive and sexual encounters, in which individuals show increased levels of T. We discuss this refinement of the 2D:4D paradigm in relation to the links between 2D:4D and sports performance, and aggression. PMID:24523714

  16. The 2nd to 4th digit ratio (2D:4D) and eating disorder diagnosis in women

    PubMed Central

    Smith, April Rose; Joiner, Thomas

    2010-01-01

    Eating disorders are more common in females than in males and are believed to be caused, in part, by biological and hormonal factors. Digit ratio or 2D:4D (the ratio of the 2nd to the 4th digit) is considered to be a proxy for prenatal testosterone (PT) and prenatal oestrogen (PE) exposure. However, how 2D:4D may be related to type of eating pathology is unknown. The relationship between 2D:4D and eating disorder diagnosis was investigated in recovered and currently eating disordered (n=31) and control (n=99) women. Mean 2D:4D ratio was significantly lower (indicating higher levels of PT and lower levels of PE) in anorexic (AN) compared to bulimic (BN) women, with controls intermediary. In eating disordered women, 2D:4D was positively and significantly related to current weight, lowest weight and current BMI, with strongest associations for right 2D:4D. Among women, low 2D:4D is related to AN and high 2D:4D to BN, suggesting a differential causal influence of prenatal sex hormones on later eating pathology. PMID:21765573

  17. Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations.

    PubMed

    Manning, John; Kilduff, Liam; Cook, Christian; Crewther, Blair; Fink, Bernhard

    2014-01-01

    Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. This ratio is considered to be a biomarker of the balance between fetal testosterone (T) and estrogen (E) in a narrow window of early ontogeny. Evidence for this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits) in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroids in adults are less clear, as many correlational studies of 2D:4D and adult sex steroids have concluded that this association is statistically non-significant. Here, we suggest that in order to understand the link between 2D:4D and sex hormones, one must consider both fetal organizing and adult activating effects of T and E. In particular, we hypothesize that 2D:4D correlates with organizing effects on the endocrine system that moderate activating effects in adulthood. We argue that this is particularly evident in "challenging" conditions such as aggressive and sexual encounters, in which individuals show increased levels of T. We discuss this refinement of the 2D:4D paradigm in relation to the links between 2D:4D and sports performance, and aggression.

  18. [Conventional radiology, digital radiology with photostimulable phosphor, laser digitalization of thoracic radiographic films at the bedside. A comparative study].

    PubMed

    Miceli, M; Stamati, R; Burci, P; Guidarelli, G; Sartoni Galloni, S

    1992-10-01

    The bedside chest images obtained with conventional radiology and with "on line" and "off line" digital modalities were compared to evaluate the respective capabilities in visualizing chest anatomical structures. Seventy patients were submitted to bedside chest examinations with a portable unit; both a conventional film and a digital system (PCR Graphics 1, Philips) with photostimulable phosphor imaging plate were fitted in the radiographic cassette. The former was digitized using an "off line" laser beam unit (FD 2000, Dupont); the latter was subsequently postprocessed by modifying contrast, optical density and spatial frequencies. Thus, 4 different viewing modalities were obtained for each examination: a) conventional radiography; b) standard digital radiography; c) postprocessed digital radiography; d) digitized conventional radiography. Detectability rates of chest anatomical structures were analyzed by 4 independent radiologists on the different images and expressed by a score 1-4. The values were always higher with digital modalities than with the conventional one and the differences were statistically significant (Student's t-test modified by Bonferroni). In particular, the greatest difference was found between c) and a) in retrocardiac lung parenchyma and in skeletal structures, in favour of c). Concerning the comparative adequacy of the various digital modalities, higher detectability rates of chest anatomical structures were obtained with c), but also with b), than with d).

  19. Second to fourth digit ratio (2D:4D) and concentrations of circulating sex hormones in adulthood.

    PubMed

    Muller, David C; Giles, Graham G; Bassett, Julie; Morris, Howard A; Manning, John T; Hopper, John L; English, Dallas R; Severi, Gianluca

    2011-04-27

    The second to fourth digit ratio (2D:4D) is used as a marker of prenatal sex hormone exposure. The objective of this study was to examine whether circulating concentrations of sex hormones and SHBG measured in adulthood was associated with 2D:4D. This analysis was based on a random sample from the Melbourne Collaborative Cohort Study. The sample consisted of of 1036 men and 620 post-menopausal women aged between 39 and 70 at the time of blood draw. Concentrations of circulating sex hormones were measured from plasma collected at baseline (1990-1994), while digit length was measured from hand photocopies taken during a recent follow-up (2003-2009). The outcome measures were circulating concentrations of testosterone, oestradiol, dehydroepiandrosterone sulphate, androstenedione, Sex Hormone Binding Globulin, androstenediol glucoronide for men only and oestrone sulphate for women only. Free testosterone and oestradiol were estimated using standard formulae derived empirically. Predicted geometric mean hormone concentrations (for tertiles of 2D:4D) and conditional correlation coefficients (for continuous 2D:4D) were obtained using mixed effects linear regression models. No strong associations were observed between 2D:4D measures and circulating concentrations of hormones for men or women. For males, right 2D:4D was weakly inversely associated with circulating testosterone (predicted geometric mean testosterone was 15.9 and 15.0 nmol/L for the lowest and highest tertiles of male right 2D:4D respectively (P-trend = 0.04). There was a similar weak association between male right 2D:4D and the ratio of testosterone to oestradiol. These associations were not evident in analyses of continuous 2D:4D. There were no strong associations between any adult circulating concentration of sex hormone or SHGB and 2D:4D. These results contribute to the growing body of evidence indicating that 2D:4D is unrelated to adult sex hormone concentrations.

  20. An algorithm for kilovoltage x-ray dose calculations with applications in kV-CBCT scans and 2D planar projected radiographs

    NASA Astrophysics Data System (ADS)

    Pawlowski, Jason M.; Ding, George X.

    2014-04-01

    A new model-based dose calculation algorithm is presented for kilovoltage x-rays and is tested for the cases of calculating the radiation dose from kilovoltage cone-beam CT (kV-CBCT) and 2D planar projected radiographs. This algorithm calculates the radiation dose to water-like media as the sum of primary and scattered dose components. The scatter dose is calculated by convolution of a newly introduced, empirically parameterized scatter dose kernel with the primary photon fluence. Several approximations are introduced to increase the scatter dose calculation efficiency: (1) the photon energy spectrum is approximated as monoenergetic; (2) density inhomogeneities are accounted for by implementing a global distance scaling factor in the scatter kernel; (3) kernel tilting is ignored. These approximations allow for efficient calculation of the scatter dose convolution with the fast Fourier transform. Monte Carlo simulations were used to obtain the model parameters. The accuracy of using this model-based algorithm was validated by comparing with the Monte Carlo method for calculating dose distributions for real patients resulting from radiotherapy image guidance procedures including volumetric kV-CBCT scans and 2D planar projected radiographs. For all patients studied, mean dose-to-water errors for kV-CBCT are within 0.3% with a maximum standard deviation error of 4.1%. Using a medium-dependent correction method to account for the effects of photoabsorption in bone on the dose distribution, mean dose-to-medium errors for kV-CBCT are within 3.6% for bone and 2.4% for soft tissues. This algorithm offers acceptable accuracy and has the potential to extend the applicability of model-based dose calculation algorithms from megavoltage to kilovoltage photon beams.

  1. Analysis of the Pelvic Functional Orientation in the Sagittal Plane: A Radiographic Study With EOS 2D/3D Technology.

    PubMed

    Loppini, Mattia; Longo, Umile Giuseppe; Ragucci, Pasquala; Trenti, Nicoletta; Balzarini, Luca; Grappiolo, Guido

    2017-03-01

    We investigated the relationship between pelvic incidence (PI) with anterior pelvic plane angle (APPA), pelvic tilt (PT) angle, and sacral slope (SS) in standing and sitting positions to identify the best parameter expressing the pelvic functional orientation in the sagittal plane. We enrolled 109 consecutive patients (M:F = 43:66) eligible for a primary total hip arthroplasty (THA) with an average age of 63.4 years (15-85). EOS 2D/3D radiography was performed in standing and sitting positions before THA to evaluate the functional pelvic orientation. 3D images took into account the patient-specific sagittal balance measuring APPA, PT, SS, and PI. In standing position, functional parameters measured 5° ± 7.1 for APPA, 11° ± 8.3 for PT, 43° ± 8.5 for SS, and 53° ± 10.9 for PI. In sitting position, they were -18° ± 10.4 for APPA, 34° ± 11.8 for PT, 20° ± 12.6 for SS, and 54° ± 10.9 for PI. There was no significant difference between men and women in terms of the functional parameters in both positions. No relationship was found between APPA and PI in both positions. SS correlated with PI in standing (r = 0.66; P < .0001; R(2) = 0.44) and sitting (r = 0.51; P < .0001; R(2) = 0.26). PT correlated with PI in standing (r = 0.65; P < .0001; R(2) = 0.42) and sitting (r = 0.38; P < .0001; R(2) = 0.14). SS shows the highest correlation with functional pelvic tilt. The study suggests that adjustments in acetabular anteversion during primary THA should be based on SS. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Pathologic Outcomes of Architectural Distortion on Digital 2D Versus Tomosynthesis Mammography.

    PubMed

    Bahl, Manisha; Lamb, Leslie R; Lehman, Constance D

    2017-08-23

    The purpose of this study is to compare the risk of malignancy associated with architectural distortion detected on 2D digital mammography (DM) versus digital breast tomosynthesis (DBT). We performed a retrospective review of architectural distortion cases recommended for biopsy from September 2007 to February 2011, the period before DBT integration (hereafter known as the DM group), and from January 2013 to June 2016, the period after DBT integration (hereafter known as the DBT group). Medical records were reviewed for imaging findings and pathology results. Architectural distortion was more commonly detected in the DBT group than the DM group (0.14% [274/202,438 examinations] vs 0.07% [121/166,661 examinations]; p < 0.001). The positive predictive value of architectural distortion for malignancy was significantly lower in the DBT group than the DM group (50.7% [139/274 cases] vs 73.6% [89/121 cases]; p < 0.001). Radial scar was the most common nonmalignant finding in both groups, but it was more common in the DBT group (33.2% [91/274] vs 11.6% [14/121]; p < 0.001). In the DBT group, architectural distortion without correlative findings on ultrasound was less likely to represent malignancy than was architectural distortion with correlative findings on ultrasound (29.2% [31/106] vs 66.5% [105/158]; p < 0.001). Architectural distortion is more commonly detected on DBT than DM and is less likely to represent malignancy on DBT. Architectural distortion on DBT is less likely to represent malignancy if there is no sonographic correlate; however, biopsy is warranted even in the absence of a sonographic correlate, given the nearly 30% risk of malignancy in this setting.

  3. The use of digital periapical radiographs to study the prevalence of alveolar domes

    PubMed Central

    Xambre, Pedro Augusto Oliveira Santos; Valerio, Claudia Scigliano; e Alves Cardoso, Claudia Assunção; Custódio, Antônio Luís Neto

    2016-01-01

    Purpose In the present study, we coined the term 'alveolar dome' and aimed to demonstrate the prevalence of alveolar domes through digital periapical radiographs. Materials and Methods This study examined 800 digital periapical radiographs in regard to the presence of alveolar domes. The periapical radiographs were acquired by a digital system using a photostimulable phosphor (PSP) plate. The χ2 test, with a significance level of 5%, was used to compare the prevalence of alveolar domes in the maxillary posterior teeth and, considering the same teeth, to verify the difference in the prevalence of dome-shaped phenomena between the roots. Results The prevalence of alveolar domes present in the first pre-molars was statistically lower as compared to the other maxillary posterior teeth (p<0.05). No statistically significant difference was observed in the prevalence of alveolar domes between the maxillary first and second molars. Considering the maxillary first and second molars, it was observed that the palatal root presented a lower prevalence of alveolar domes when compared to the distobuccal and mesiobuccal roots (p<0.05). Conclusion The present study coined the term 'alveolar dome', referring to the anatomical projection of the root into the floor of the maxillary sinus. The maxillary first and second molars presented a greater prevalence of alveolar domes, especially in the buccal roots, followed by the third molars and second pre-molars. Although the periapical radiograph is a two-dimensional method, it can provide dentists with the auxiliary information necessary to identify alveolar domes, thus improving diagnosis, planning, and treatment. PMID:27672614

  4. Digit ratio (2D:4D), aggression, and testosterone in men exposed to an aggressive video stimulus.

    PubMed

    Kilduff, Liam P; Hopp, Renato N; Cook, Christian J; Crewther, Blair T; Manning, John T

    2013-10-10

    The relative lengths of the 2(nd) and 4(th) digits (2D:4D) is a negative biomarker for prenatal testosterone, and low 2D:4D may be associated with aggression. However, the evidence for a 2D:4D-aggression association is mixed. Here we test the hypothesis that 2D:4D is robustly linked to aggression in "challenge" situations in which testosterone is increased. Participants were exposed to an aggressive video and a control video. Aggression was measured after each video and salivary free testosterone levels before and after each video. Compared to the control video, the aggressive video was associated with raised aggression responses and a marginally significant increase in testosterone. Left 2D:4D was negatively correlated with aggression after the aggressive video and the strength of the correlation was higher in those participants who showed the greatest increases in testosterone. Left 2D:4D was also negatively correlated to the difference between aggression scores in the aggressive and control conditions. The control video did not influence testosterone concentrations and there were no associations between 2D:4D and aggression. We conclude that 2D:4D moderates the impact of an aggressive stimulus on aggression, such that an increase in testosterone resulting from a "challenge" is associated with a negative correlation between 2D:4D and aggression.

  5. Remapping of digital subtraction angiography on a standard fluoroscopy system using 2D-3D registration

    NASA Astrophysics Data System (ADS)

    Alhrishy, Mazen G.; Varnavas, Andreas; Guyot, Alexis; Carrell, Tom; King, Andrew; Penney, Graeme

    2015-03-01

    Fluoroscopy-guided endovascular interventions are being performing for more and more complex cases with longer screening times. However, X-ray is much better at visualizing interventional devices and dense structures compared to vasculature. To visualise vasculature, angiography screening is essential but requires the use of iodinated contrast medium (ICM) which is nephrotoxic. Acute kidney injury is the main life-threatening complication of ICM. Digital subtraction angiography (DSA) is also often a major contributor to overall patient radiation dose (81% reported). Furthermore, a DSA image is only valid for the current interventional view and not the new view once the C-arm is moved. In this paper, we propose the use of 2D-3D image registration between intraoperative images and the preoperative CT volume to facilitate DSA remapping using a standard fluoroscopy system. This allows repeated ICM-free DSA and has the potential to enable a reduction in ICM usage and radiation dose. Experiments were carried out using 9 clinical datasets. In total, 41 DSA images were remapped. For each dataset, the maximum and averaged remapping accuracy error were calculated and presented. Numerical results showed an overall averaged error of 2.50 mm, with 7 patients scoring averaged errors < 3 mm and 2 patients < 6 mm.

  6. Weld defect detection on digital radiographic image using level set method

    NASA Astrophysics Data System (ADS)

    Halim, Suhaila Abd; Petrus, Bertha Trissan; Ibrahim, Arsmah; Manurung, Yupiter HP; Jayes, Mohd Idris

    2013-09-01

    Segmentation is the most critical task and widely used to obtain useful information in image processing. In this study, Level set based on Chan Vese method is explored and applied to define weld defect on digital radiographic image and its accuracy is evaluated to measure its performance. A set of images with region of interest (ROI) that contain defect are used as input image. The ROI image is pre-processed to improve their quality for better detection. Then, the image is segmented using level set method that is implemented using MATLAB R2009a. The accuracy of the method is evaluated using Receiver Operating Characteristic (ROC). Experimental results show that the method generated an area underneath the ROC of 0.7 in the set of images and the operational point reached corresponds to 0.6 of sensitivity and 0.8 of specificity. The application of segmentation technique such as Chan-Vese level set able to assist radiographer in detecting the defect on digital radiographic image accurately.

  7. An automatic early stage alveolar-bone-resorption evaluation method on digital dental panoramic radiographs

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Katsumata, Akitoshi; Muramatsu, Chisako; Hara, Takeshi; Suzuki, Hiroki; Fujita, Hiroshi

    2014-03-01

    Periodontal disease is a kind of typical dental diseases, which affects many adults. The presence of alveolar bone resorption, which can be observed from dental panoramic radiographs, is one of the most important signs of the progression of periodontal disease. Automatically evaluating alveolar-bone resorption is of important clinic meaning in dental radiology. The purpose of this study was to propose a novel system for automated alveolar-bone-resorption evaluation from digital dental panoramic radiographs for the first time. The proposed system enables visualization and quantitative evaluation of alveolar bone resorption degree surrounding the teeth. It has the following procedures: (1) pre-processing for a test image; (2) detection of tooth root apices with Gabor filter and curve fitting for the root apex line; (3) detection of features related with alveolar bone by using image phase congruency map and template matching and curving fitting for the alveolar line; (4) detection of occlusion line with selected Gabor filter; (5) finally, evaluation of the quantitative alveolar-bone-resorption degree in the area surrounding teeth by simply computing the average ratio of the height of the alveolar bone and the height of the teeth. The proposed scheme was applied to 30 patient cases of digital panoramic radiographs, with alveolar bone resorption of different stages. Our initial trial on these test cases indicates that the quantitative evaluation results are correlated with the alveolar-boneresorption degree, although the performance still needs further improvement. Therefore it has potential clinical practicability.

  8. Elongated styloid process evaluation on digital panoramic radiograph in a North Italian population

    PubMed Central

    Gracco, Antonio; De Stefani, Alberto; Balasso, Paolo; Alessandri-Bonetti, Giulio; Stellini, Edoardo

    2017-01-01

    Background The aim of this study is to evaluate the prevalence of elongated styloid process in digital panoramic radiographs in a North Italian population in relation to age, gender and side. Material and Methods This study was performed as a retrospective analysis on digital panoramic radiographs of 600 (271 males and 329 females) Italian patients between 6 and 87 years old. The styloid process length were measured using the measuring tool of Sidexis Software. It was measured from the point where it left the temporal bone plate to its tip. Styloid processes measuring more than 30 mm were considered elongated. Chi-squared and Fisher tests were used and the test is considered significant if the p-value is lower or equal to 0.05. Results Thirty-three per cent of the patients showed an elongated styloid process. Seventeen per cent were elongated on both right and left side, fifteen point nine per cent were elongated only in one side. Conclusions The prevalence of elongated styloid process was high and a progressive increase of the elongation prevalence was found in older groups. Key words:Elongated styloid process, Eagle’s syndrome, panoramic radiograph. PMID:28298982

  9. Is the Second to Fourth Digit Ratio (2D:4D) a Biomarker of Sex-Steroids Activity?

    PubMed

    de Sanctis, Vincenzo; Soliman, Ashraf T; Elsedfy, Heba; Soliman, Nada; Elalaily, Rania; Di Maio, Salvatore

    2017-06-01

    The second-to-fourth digit ratio (2D:4D) has been used as an indirect method to investigate the putative effects of prenatal exposure to androgens, and has been reported to be smaller in males than in females. This gender difference in digit length ratios has been linked with the in utero balance of androgens to oestrogen. This sexual dimorphism in 2D:4D ratios is apparent by 2 years of age and seems to be established early in life, possibly by the 14th week of gestation. Digits in females attain their maximum length at about 2.2 years (dextral subjects) or 5.1 years (sinistral subjects) earlier than those in males and increase slightly with age. It has also been reported that the 2D:4D ratio is correlated negatively with prenatal testosterone levels. This tentative theory is partially supported by lower 2D:4D in girls with congenital adrenal hyperplasia (CAH), higher 2D:4D in individuals with complete androgen insensitivity syndrome (CAIS) and a relationship between 2D:4D and polymorphisms in the androgen receptor. In contrast, individuals with Klinefelter syndrome (KS), who have reduced testosterone secretion throughout life, have a mean 2D:4D value similar to those found in female population norms. Nevertheless, its validity has not yet been conclusively demonstrated and is currently debated. In this context, our aim was to review and debate the relationship between 2D:4D ratio and sex-steroids activity in children, adolescents and young adults. Copyright© of YS Medical Media ltd.

  10. Meta-analysis of digit ratio 2D:4D shows greater sex difference in the right hand.

    PubMed

    Hönekopp, Johannes; Watson, Steven

    2010-01-01

    Our aims are, first, to describe the sex difference in the length ratio of the second and fourth digits (2D:4D), which likely reflects prenatal testosterone levels in humans. Second, to infer the loss of reliability observed in 2D:4D based on self-measured finger lengths. We used random-effects meta-analysis of 2D:4D based on expert-measured finger lengths (116 samples with 13,260 females and 11,789 males). We find a moderate sex difference (with lower 2D:4D for males), which shows substantial heterogeneity (which is unrelated to age). The sex difference is moderated by the type of finger length measurement and by hand. Measurement involving the distortion of soft tissue leads to a significantly larger sex difference than finger length measurement avoiding this. The sex difference in 2D:4D is larger in the right hand than in the left. The reliability of self-measured 2D:4D in the BBC internet study, by far the largest study on 2D:4D, is estimated to be 46% of that of expert-measured 2D:4D. Right-hand 2D:4D might be a better indicator of prenatal androgenisation than left-hand 2D:4D. The view that 2D:4D has allometric properties (Kratochvil L, Flegr J. 2009. Differences in 2nd to 4th digit length ratio in humans reflect shifts along the common allometric line. Biol Lett 5:643-646.) is not supported. Bone lengths contribute to the sex difference in 2D:4D. In addition, there might be a sex difference in fingers' soft tissue, which should be investigated. Because of measurement unreliability, correlations between 2D:4D and variables of interest are about one-third smaller in the BBC internet study than in studies in which 2D:4D is based on expert-measured finger lengths. (c) 2010 Wiley-Liss, Inc.

  11. Male infants with hypospadias and/or cryptorchidism show a lower 2D/4D digit ratio than normal boys.

    PubMed

    Abbo, O; Ferdynus, C; Kalfa, N; Huiart, L; Sauvat, F; Harper, L H

    2015-07-01

    In humans the ratio of the index finger to the ring finger is sexually dimorphic, with the mean ratio being larger in women than in men. It has been suggested that this difference is related to prenatal androgen exposure. This has been further demonstrated in children with congenital adrenal hyperplasia. Normal development of the male external genitalia is linked to androgen-mediated events during gestation. We therefore wanted to determine if the 2D:4D digit ratio was normal in boys with cryptorchidism or hypospadias. We prospectively enrolled all prepubertal patients seen in the outpatient clinic for cryptorchidism or hypospadias between September and December 2012. We then compared their 2D:4D digit ratio with two control groups made up of normal boys and normal girls. Interobserver and intraobserver variability was evaluated. We included 57 boys with hypospadias and/or cryptorchidism, 79 boys without genital abnormalities and 25 girls without genital abnormalities. The mean 2D:4D ratio for both hands was significantly different between the three groups, with the digit ratio for boys with genital anomalies being lower than for normal boys and normal girls (p<0.0001). It appears that boys with genital abnormalities (cryptorchidism and/or hypospadias) have a lower 2D:4D digit ratio than boys without genital anomalies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. Value of digit ratio 2D:4D, a biomarker of prenatal hormone exposure, is stable across the menstrual cycle.

    PubMed

    Klimek, Magdalena; Marcinkowska, Urszula M; Jasienska, Grazyna

    2017-07-01

    Digit ratio (2D:4D) is used as a marker of prenatal hormone exposure and, consequently, as a predictor of many characteristics throughout a woman's lifespan. A previous study has suggested that values of 2D:4D vary across menstrual cycles and further questioned the reliability of a single measurement of 2D:4D among cycling women, while another study failed to confirm these results. However, these studies estimated the timing of cycle phases based on a date of menstruation reported by participants and also had small sample sizes. For our study, we evaluated potential changes in 2D:4D values across a menstrual cycle in a group of women among whom the phases of the menstrual cycle were determined by hormonal (luteinizing hormone based) ovulation tests. We studied 32 naturally cycling women aged 22-37 from rural Poland. Lengths of second and fourth digits were measured based on scans of both hands taken three times (i.e. in the follicular phase, peri-ovulatory phase and luteal phase of the cycle) for each participant. No differences in 2D:4D value across the menstrual cycle were detected either when right-hand, left-hand, and mean 2D:4D for both hands were analysed, nor when difference in the 2D:4D value between hands (Dleft-right) was evaluated. We documented that 2D:4D is independent of the phase of the menstrual cycle and these findings suggest that among naturally cycling women, a value of 2D:4D can be reliably obtained from measurements taken during any day of the menstrual cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. [Technical parameters to decrease the radiation dose from conventional and digital radiographs].

    PubMed

    Foulquier, J N

    2010-11-01

    Reducing radiation dose while maintaining adequate image quality on conventional and digital radiographs requires optimal use of the unit. Additional filtration avoids unnecessary tissue exposure and improves photon transmission. Automatic exposure control may reduce exposure and dose. The volume of tissue imaged must be limited by the use of diaphragms and shutters or compression. Sensitive detectors with increased photon detection also contribute to reduce dose. Radiographic films combined to rare-earth screens also afford a good photon-conversion efficiency. Large area flat panel amorphous silicon x-ray sensors may also reduce dose up to 50% compared to films. Finally, calculation of the Kerma-area product independent of the source distance constitutes an important indicator of radiation dose.

  14. Evaluation of proximal caries in images resulting from different modes of radiographic digitalization.

    PubMed

    Xavier, C R G; Araujo-Pires, Ana Claudia; Poleti, M L; Rubira-Bullen, I R F; Ferreira, O; Capelozza, A L A

    2011-09-01

    The aim of this study was to evaluate the performances of observers in diagnosing proximal caries in digital images obtained from digital bitewing radiographs using two scanners and four digital cameras in Joint Photographic Experts Group (JPEG) and tagged image file format (TIFF) files, and comparing them with the original conventional radiographs. In total, 56 extracted teeth were radiographed with Kodak Insight film (Eastman Kodak, Rochester, NY) in a Kaycor Yoshida X-ray device (Kaycor X-707; Yoshida Dental Manufacturing Co., Tokyo, Japan) operating at 70 kV and 7 mA with an exposure time of 0.40 s. The radiographs were obtained and scanned by CanonScan D646U (Canon USA Inc., Newport News, VA) and Genius ColorPage HR7X (KYE Systems Corp. America, Doral, FL) scanners, and by Canon Powershot G2 (Canon USA Inc.), Canon RebelXT (Canon USA Inc.), Nikon Coolpix 8700 (Nikon Inc., Melville, NY), and Nikon D70s (Nikon Inc.) digital cameras in JPEG and TIFF formats. Three observers evaluated the images. The teeth were then observed under the microscope in polarized light for the verification of the presence and depth of the carious lesions. The probability of no diagnosis ranged from 1.34% (Insight film) to 52.83% (CanonScan/JPEG). The sensitivity ranged from 0.24 (Canon RebelXT/JPEG) to 0.53 (Insight film), the specificity ranged from 0.93 (Nikon Coolpix/JPEG, Canon Powershot/TIFF, Canon RebelXT/JPEG and TIFF) to 0.97 (CanonScan/TIFF and JPEG) and the accuracy ranged from 0.82 (Canon RebelXT/JPEG) to 0.91 (CanonScan/JPEG). The carious lesion diagnosis did not change in either of the file formats (JPEG and TIFF) in which the images were saved for any of the equipment used. Only the CanonScan scanner did not have adequate performance in radiography digitalization for caries diagnosis and it is not recommended for this purpose.

  15. Evaluation of proximal caries in images resulting from different modes of radiographic digitalization

    PubMed Central

    Xavier, CRG; Araujo-Pires, AC; Poleti, ML; Rubira-Bullen, IRF; Ferreira, O; Capelozza, ALA

    2011-01-01

    Objective The aim of this study was to evaluate the performances of observers in diagnosing proximal caries in digital images obtained from digital bitewing radiographs using two scanners and four digital cameras in Joint Photographic Experts Group (JPEG) and tagged image file format (TIFF) files, and comparing them with the original conventional radiographs. Method In total, 56 extracted teeth were radiographed with Kodak Insight film (Eastman Kodak, Rochester, NY) in a Kaycor Yoshida X-ray device (Kaycor X-707; Yoshida Dental Manufacturing Co., Tokyo, Japan) operating at 70 kV and 7 mA with an exposure time of 0.40 s. The radiographs were obtained and scanned by CanonScan D646U (Canon USA Inc., Newport News, VA) and Genius ColorPage HR7X (KYE Systems Corp. America, Doral, FL) scanners, and by Canon Powershot G2 (Canon USA Inc.), Canon RebelXT (Canon USA Inc.), Nikon Coolpix 8700 (Nikon Inc., Melville, NY), and Nikon D70s (Nikon Inc.) digital cameras in JPEG and TIFF formats. Three observers evaluated the images. The teeth were then observed under the microscope in polarized light for the verification of the presence and depth of the carious lesions. Results The probability of no diagnosis ranged from 1.34% (Insight film) to 52.83% (CanonScan/JPEG). The sensitivity ranged from 0.24 (Canon RebelXT/JPEG) to 0.53 (Insight film), the specificity ranged from 0.93 (Nikon Coolpix/JPEG, Canon Powershot/TIFF, Canon RebelXT/JPEG and TIFF) to 0.97 (CanonScan/TIFF and JPEG) and the accuracy ranged from 0.82 (Canon RebelXT/JPEG) to 0.91 (CanonScan/JPEG). Conclusion The carious lesion diagnosis did not change in either of the file formats (JPEG and TIFF) in which the images were saved for any of the equipment used. Only the CanonScan scanner did not have adequate performance in radiography digitalization for caries diagnosis and it is not recommended for this purpose. PMID:21831972

  16. Investigating digit ratio (2D:4D) in a highly male-dominated occupation: the case of firefighters.

    PubMed

    Voracek, Martin; Pum, Ulrike; Dressler, Stefan G

    2010-04-01

    Second-to-fourth digit ratio (2D:4D), a widely studied putative marker for masculinization through prenatal androgen exposure, is lower (more masculinized) in athletes than in general population controls, and athletes with lower 2D:4D have higher sporting success. Occupations differ markedly in perceived masculinity and actual maleness (sex ratios), but these givens have not yet been picked up and utilized in 2D:4D research. Accordingly, this study extended existing accounts on 2D:4D in athletes to a novel approach: 2D:4D and possible relationships to a variety of candidate variables (demographic, fertility-related, psychological, and other) were investigated in firefighters, a highly male-dominated occupation. Contrary to expectation, 2D:4D in firefighters (N = 134) was not lower than in local male population controls. Lower 2D:4D corresponded to lower service ranks. Replicating previous findings either unequivocally or partly, lower 2D:4D was associated with larger family size, later sibling position, left-handedness, and higher scores in the disinhibition component of sensation seeking. Not replicating prior evidence, 2D:4D was unrelated to body-mass index, offspring sex ratio, and sporting performance level. Novel findings included low 2D:4D in those with low relationship satisfaction and in cigarette smokers, especially among heavy smokers. Absolute finger length, a positive correlate of pubertal-adolescent androgen levels, was also considered. This marker showed negative associations with relationship consensus and satisfaction and positive ones with perceived quality of relationship alternatives and the experience seeking component of sensation seeking. The merits of this additional marker, relative to 2D:4D, for supplementing studies of possible sex-hormonal effects on personality and directions for future inquiry along these lines are discussed.

  17. SPORTS PREFERENCE AND DIGIT RATIO (2D:4D) AMONG FEMALE STUDENTS IN WROCŁAW, POLAND.

    PubMed

    Kociuba, Marek; Kozieł, Slawomir; Chakraborty, Raja; Ignasiak, Zofia

    2017-09-01

    Humans exhibit sex differences in competitiveness, sensation seeking and risk-taking attitude, which are required in sports. These attributes are often linked to prenatal testosterone (PT) exposure. The second-to-fourth digit length ratio (2D:4D) is an indicator of PT exposure. A lower 2D:4D indicates higher PT exposure and vice versa. Males generally have a lower 2D:4D than females. Sensation- and/or thrill-seeking behaviours have also been found to be negatively associated with 2D:4D. Boxing and judo are considered to be high-risk sports. Voluntary participation in judo/boxing in contrast to aerobics can be guided by such behaviours and thus have an association with lower 2D:4D. This cross-sectional study included 167 female students from a military academy in Wrocław, Poland. Of them, 119 had voluntarily chosen aerobic exercise, and 48 opted for judo/boxing. Height, weight and second and fourth digit lengths were measured. Physical fitness was assessed using Eurofit tests. The two groups showed similar physical fitness and body size. However, the judo/boxing group had significantly lower mean 2D:4D values than the aerobics group. It is proposed that voluntary choice of participation in a sport discipline by women could be linked to the 'organizational' effect of intrauterine testosterone exposure during prenatal growth.

  18. Damage Assessment and Digital 2D-3D Documentation of PetraTreasury

    NASA Astrophysics Data System (ADS)

    Bala'awi, Fadi; Alshawabkeh, Yahya; Alawneh, Firas; Masri, Eyed al

    The treasury is the icon monument of the world heritage site of ancient Petra city. Unfortunately, this important part of the world's cultural heritage is gradually being diminished due to weathering and erosion problems. This give rise to the need to have a comprehensive study and full documentation of the monument in order to evaluate its status. In this research a comprehensive approach utilizing 2D-3D documentation of the structure using laser scanner and photogrammetry is carried parallel with a laboratory analysis and a correlation study of the salt content and the surface weathering forms. In addition, the research extends to evaluate a set of chemical and physical properties of the case study monument. Studies of stone texture and spatial distribution of soluble salts were carried out at the monument in order to explain the mechanism of the weathering problem. Then a series of field work investigations and laboratory work were undertaken to study the effect of relative humidity, temperature, and wind are the main factors in the salt damage process. The 3D modelling provides accurate geometric and radiometric properties of the damage shape. In order to support the visual quality of 3D surface details and cracks, a hybrid approach combining data from the laser scanner and the digital imagery was developed. Based on the findings, salt damage appears to be one of the main problems at this monument. Although, the total soluble salt content are quite low, but the salts contamination is all over the tested samples in all seasons, with higher concentrations at deep intervals. The thermodynamic calculations carried out by this research have also shown that salt damage could be minimised by controlling the surrounding relative humidity conditions. This measure is undoubtedly the most challenging of all, and its application, if deemed feasible, should be carried out in parallel with other conservation measures.

  19. Sexual dimorphism in foramen magnum dimensions in the South Indian population: A digital submentovertex radiographic study

    PubMed Central

    Raikar, Neha Ajit; Meundi, Manasa A; David, Chaya M; Rao, Mahesh Dathu; Jogigowda, Sanjay Chikkarasinakere

    2016-01-01

    Purpose of the Study: Personal identification is a vital arena of forensic investigation, facilitating the search for missing persons. This process of identification is eased by the determination of age, sex, and ethnicity. In situations where there are fragmented and mutilated skeletal remains, sex determination is relatively difficult, and it becomes important to establish the accuracy of individual bones. Aim: This study aims to evaluate sexual dimorphism in foramen magnum (FM) dimensions in the South Indian population using digital submentovertex (SMV) radiograph. Materials and Methods: 150 individuals (75 males and 75 females) were subjected to digital SMV radiography. FM in the resultant image was assessed for longitudinal and transverse diameters, circumference, and area. Also, one particular shape was assigned to each image based on the classification of Chethan et al. of FM shapes. Three qualified oral radiologists performed all the measurements twice within an interval of 10 days. Results and Conclusion: The values obtained for all four parameters were statistically significant and higher in males than in females. The most common morphology of FM was an egg shape while hexagonal was the least common morphology. Circumference was the best indicator of sex followed by area, transverse diameter, and longitudinal diameter. Having achieved a high accuracy of 67.3% with digital SMV radiograph makes it a reliable and reproducible alternative to dry skulls for sex determination. PMID:28123285

  20. DIGITAL RADIOGRAPHIC EVALUATION OF OPTICAL DENSITY OF PORCELAINS USED FOR FABRICATION OF INLAY/ONLAY PROSTHESIS

    PubMed Central

    CASTILHO, Julio Cezar de Melo; TAKESHITA, Wilton Mitsunari; dos SANTOS, Luis Roque de Araújo; de MORAES, Luiz Cesar; MEDICI, Edmundo; de MORAES, Mari Eli Leonelli

    2006-01-01

    The purpose of this article was to compare the mean value of optical density of four porcelains commonly used for fabrication of inlay/onlay prostheses using direct digital radiograph. The sample consisted of 20 2-mm thick porcelain specimens (measured by digital pachymeter): Empress (Ivoclair), Simbios (Degussa), Vita Omega 900 and Vitadur Alpha (Vita Zahnfabrik). The values of optical density of the specimens were expressed in millimeters aluminum equivalent (mm eq Al). The samples were X-rayed using two charge coupled devices (CCD) - RVG (Trophy) - Visualix (Gendex) and a phosphor plate system – Digora (Soredex). The optical density reading was performed with Image Tool 1.28 in a total of 110 measurements. Statistical analysis showed that there were statistically significant differences in all materials studied (p < 0.05) regardless of the radiographic system used. The highest optical density value was found for Omega 900 (1.8988 mmeqAl – Visualix – Gendex) and the lowest for Vitadur Alpha (0.8647 – Visualix – Gendex). Thus, the material presenting the highest degree of optical density was Omega 900, Empress and Simbios presented intermediate optical density values, Vitadur Alpha presented the lowest value, and the optical density of porcelains was not influenced by the digital radiography systems. PMID:19089024

  1. Accuracy and Reliability of Preoperative On-screen Templating Using Digital Radiographs for Total Hip Arthroplasty

    PubMed Central

    Shin, Jong Ki; Son, Seung Min; Kim, Tae Woo; Shin, Won Chul; Lee, Jung Sub

    2016-01-01

    Purpose Preoperative on-screen templating is a method of using acetate templates on digital images. The aim of the present study was to evaluate the accuracy, intra- and interobserver reliabilities of preoperative on-screen templating using digital radiographs for total hip arthroplasty (THA). Materials and Methods Two hundred patients with hip disease who were treated with primary cementless THA were retrospectively evaluated. The accuracy of on-screen templating was assessed by comparing the predicted prosthesis sizes with the actual sizes used operatively. The inter- and intraobserver reliabilities of the templating results were also evaluated. Results The prosthesis prediction accuracy within ±one size was 96.6% for the cup size and 97.8% for the stem size. The inter- and intraobserver reliabilities for the implant size were substantial (kappa>0.70). The intra- and interobserver reliabilities for the leg length discrepancy and femoral offset difference using the intraclass correlation coefficient ranged from 0.89 to 0.97. Conclusion Preoperative on-screen templating using digital radiographs showed substantial accuracy and reliability for implant prediction. It is an effective method for predicting the size of implant, correcting the leg length discrepancy and restoring the femoral offset. PMID:28097109

  2. Determination of sexual dimorphism in humans by measurements of mandible on digital panoramic radiograph.

    PubMed

    Sairam, V; Geethamalika, M V; Kumar, Praveen B; Naresh, G; Raju, Gareema P

    2016-01-01

    Identification of sex is the first step in forensic science obtained from skeletal remains. Mandible, being a strong bone that is difficult to damage and disintegrate, is an important tool in sex determination. The present study is aimed to assess, compare, and evaluate the mandibular measurements as seen on digital panoramic radiographs to analyze their use in sexual dimorphism assessment. This retrospective study was conducted using digital panoramic images of 100 each in both genders. Mandibular measurements were carried out utilizing RadiAnt DICOM Viewer 2.2.9 (32 bit) software (Medixant Company, Poland) and subjected to statistical analysis. Descriptive statistics for all the parameters on the right and left sides of mandible in both males and females were analyzed. Inferential statistics were performed using t-test to compare males and females with different variables. A statistical significance of P < 0.001 has been demonstrated for all the variables (except linear measurement of mandibular foramen). All variables showed increased measurements in males than in females. The accuracy of sex determination in mandibular ramus measurements is 79.5% on right side and 77% on left side, where as, in linear mandibular measurements it is 76% on right side and 79.5% on left side. Mandibular measurements on digital radiograph are useful in sex determination, and this study can be compared with other similar studies.

  3. Determination of sexual dimorphism in humans by measurements of mandible on digital panoramic radiograph

    PubMed Central

    Sairam, V.; Geethamalika, M. V.; Kumar, Praveen B.; Naresh, G.; Raju, Gareema P.

    2016-01-01

    Background: Identification of sex is the first step in forensic science obtained from skeletal remains. Mandible, being a strong bone that is difficult to damage and disintegrate, is an important tool in sex determination. The present study is aimed to assess, compare, and evaluate the mandibular measurements as seen on digital panoramic radiographs to analyze their use in sexual dimorphism assessment. Materials and Methods: This retrospective study was conducted using digital panoramic images of 100 each in both genders. Mandibular measurements were carried out utilizing RadiAnt DICOM Viewer 2.2.9 (32 bit) software (Medixant Company, Poland) and subjected to statistical analysis. Results: Descriptive statistics for all the parameters on the right and left sides of mandible in both males and females were analyzed. Inferential statistics were performed using t-test to compare males and females with different variables. A statistical significance of P < 0.001 has been demonstrated for all the variables (except linear measurement of mandibular foramen). All variables showed increased measurements in males than in females. The accuracy of sex determination in mandibular ramus measurements is 79.5% on right side and 77% on left side, where as, in linear mandibular measurements it is 76% on right side and 79.5% on left side. Conclusion: Mandibular measurements on digital radiograph are useful in sex determination, and this study can be compared with other similar studies. PMID:27994407

  4. The development and evaluation of a computerized diagnosis scheme for pneumoconiosis on digital chest radiographs.

    PubMed

    Zhu, Biyun; Luo, Wei; Li, Baoping; Chen, Budong; Yang, Qiuying; Xu, Yan; Wu, Xiaohua; Chen, Hui; Zhang, Kuan

    2014-10-02

    To diagnose pneumoconiosis using a computer-aided diagnosis system based on digital chest radiographs. Lung fields were first extracted by combining the traditional Otsu-threshold method with a morphological reconstruction on digital radiographs (DRs), and then subdivided into six non-overlapping regions (region (a-f)). Twenty-two wavelet-based energy texture features were calculated exclusively from each region and selected using a decision tree algorithm. A support vector machine (SVM) with a linear kernel was trained using samples with texture features to classify an individual region of a healthy subject or a pneumoconiosis patient. The final classification results were obtained by integrating these individual classifiers with the weighted voting method. All models were developed on a dataset of 85 healthy controls and 40 stage I or II pneumoconiosis patients and validated by using the bootstrap resampling with replacement method. The areas under receiver operating characteristic curves (AUCs) of regions (c) and (f) were 0.688 and 0.563, which were worse than those of the other four regions. Region (c) and (f) were both excluded from the individual classifiers that were going to be assembled further. When built on the selected texture features, each individual SVM showed a higher diagnostic performance for the training set and the test set. The classification performance after an ensemble was 0.997 and 0.961 of the AUC value for the training and test sets, respectively. The final results were 0.974 ± 0.018 for AUC value and 0.929 ± 0.018 for accuracy. The integrated SVM model built on the selected feature set showed the highest diagnostic performance among all individual SVM models. The model has good potential in diagnosing pneumoconiosis based on digital chest radiographs.

  5. Digit ratio (2D:4D), dominance, reproductive success, asymmetry, and sociosexuality in the BBC Internet Study.

    PubMed

    Manning, John T; Fink, Bernhard

    2008-01-01

    Digit ratio (2D:4D) may be a correlate of prenatal sex steroids, and has been linked to traits, which are influenced by fetal testosterone and estrogen. Here we consider such links in a large Internet study of sex differences (the BBC Internet Study) in which finger lengths were self-measured. Consistent with lab-based findings the 2D:4D in this study shows sexual dimorphism, ethnic differences and higher dimorphism of right 2D:4D than left, thereby indicating that 2D:4D does measure real between-participant variation. High error in self-measurement of fingers reduces effect sizes. However, the large sample size gives assurance that significant effects are likely to be real. We controlled for ethnicity and sexual orientation by considering White heterosexuals only (153,429 participants). Sexual dimorphism was confirmed in 2D:4D and for the difference of right-left 2D:4D. After Bonferroni correction we found highly significant relationships with low effect sizes as follows. In males and females there were negative associations between 2D:4D and dominance. In males there were negative associations between 2D:4D and family size and factors associated with reproductive success. For females these associations were positive. For asymmetry we found U-shaped relationships with 2D:4D in both males and females. We found no relationship between 2D:4D and promiscuity (sociosexuality). In total, we considered 48 relationships and found 29 to be significant. We compare our findings with a similar study reported by Putz et al. (2004), which found only 2 out of 57 correlations to be significant and discuss possible reasons for the discrepancies between the studies.

  6. Second to fourth digit ratio (2D:4D) and testosterone in men.

    PubMed

    Manning, J T; Wood, S; Vang, E; Walton, J; Bundred, P E; van Heyningen, C; Lewis-Jones, D I

    2004-09-01

    To investigate the relationship between 2D:4D and testosterone in men attending an infertility clinic and men drawn from the general population. Data on 2D:4D and testosterone from two samples were collected: (1) 43 men attending an infertility clinic, and (2) 51 men drawn from the general population without regard to fertility. In sample (1) there were negative associations between 2D:4D and testicular function, and men with lower 2D:4D in their right compared to left hand had higher testosterone levels than men with higher 2D:4D in their right compared to left hand. Sample (2) showed no significant associations between 2D:4D or side differences in 2D:4D and testosterone. Adult levels of testosterone may be related to aspects of 2D:4D in samples which contain men with compromised testicular function, but not in men from normative samples. Associations between 2D:4D and fertility-associated traits probably arise from early organisational effects of testosterone rather than from activational effects of current testosterone.

  7. Evidence for assortative mating on digit ratio (2D:4D), a biomarker for prenatal androgen exposure.

    PubMed

    Voracek, Martin; Dressler, Stefan G; Manning, John T

    2007-07-01

    The second-to-fourth digit ratio (2D:4D) presents an anatomical sex difference in humans. On average, men tend to have lower 2D:4D compared with women. There is fairly strong evidence for a role of the 2D:4D ratio as a biomarker for the organizational (permanent) effects of prenatal testosterone on the brain and behaviour. Recently, an accumulating research programme has shown 2D:4D to be related to a multitude of sex-dependent, hormonally influenced biosocial traits and phenotypes which reach into the domains of ability, behaviour, fertility, health, personality and sexuality. This study investigated the degree of assortative mating (spousal similarity) in a sample of 239 native Austrian couples of parental or grandparental age, all of them having reproduced. Results included: (i) significant spousal correlations of +0.19 and +0.18 for right-hand and left-hand 2D:4D, respectively, and +0.24 for average 2D:4D; (ii) no assortative mating effect on the right-minus-left difference in 2D:4D; (iii) indications consistent with a possible generational decrease of spousal similarity in 2D:4D; (iv) a prevalence of couples with a lower right-hand 2D:4D observed in the husband compared with his wife; and (v) relations of spousal 2D:4D patterns to spousal age differences, such that matings of men with more male-typical trait expressions (namely, a generally low right-hand 2D:4D or showing a lower right-minus-left 2D:4D difference than their wives) implicated larger male-minus-female age differences, i.e. younger wives. It is argued that assortative mating on 2D:4D operates indirectly and may be mediated through the assortment on other, more perceptible, physical traits and psychological phenotypes that entertain associations with 2D:4D and are relevant for courtship and mate choice.

  8. The benefit of accounting for DQE variations in simulated dose reduction of digital radiographic systems.

    PubMed

    Svalkvist, Angelica; Båth, Magnus

    2010-01-01

    Adding noise to clinical radiographs to simulate dose reduction can be used to investigate the relationship between dose level and clinical image quality without exposing patients to additional radiation. The purpose of the present paper was to examine the benefits of using a method that accounts for detective quantum efficiency (DQE) variations that may occur in different dose ranges in the simulated dose reduction process. A method initially intended for simulated dose reduction in tomosynthesis was applied to extremely low-dose posterioanterior radiographs of an anthropomorphic chest phantom, selected from a group of projection images included in a tomosynthesis examination and compared with a previous method that do not account for DQE variations. A comparison of images simulated to be collected at a lower dose level (73 % of the original dose level) and images actually collected at this lower dose level revealed that the error in the integrated normalised noise power spectrum was smaller than 4 % for the method that accounts for DQE variations in the simulated dose reduction, whereas the error was larger than 20 % for the previous method. This indicates that an increased validity in dose reduction simulation of digital radiographic systems is obtained with a method accounting for DQE variations.

  9. Optical and digital processing of radiographs for the early detection of osteoporosis

    NASA Astrophysics Data System (ADS)

    Leichter, Isaac; Neeman, Victor; Bamberger, Phillipe; Leibergall, Meir

    1995-03-01

    The diagnosis of osteoporosis has traditionally been made by observing bone radiographs and analyzing the optical density. More advanced methods measure the mineral content or the quantity of bone tissue, but do not determine bone quality, which depends on the bone tissue architecture. The structure and organization of bone tissue is a vital factor for assessing bone strength, as minute changes in the structure strongly affect bone strength. This study describes a novel method, based on optical and digital image processing of conventional radiographs for a quantitative evaluation of bone tissue architecture. The trabecular pattern appearing on the femoral neck radiograph was analyzed based on the power spectrum of this pattern, which was obtained by optical Fourier transform. The two-dimensional optical power spectrum was captured to the computer by a CCD device and after filtering and noise reduction, it was characterized using spatial frequencies in different directions. Software was developed for the analysis of the power spectrum of the trabecular pattern to yield a bone index. The effect of the image optical density on the calculated bone index was not significant. On the other hand, the bone index, based on the trabecular structure, was found to differ significantly between normal and osteoporotic bones. Thus, the power spectrum analysis could differentiate normal from osteoporotic bones much better than the amount of radiation absorbed by the bone.

  10. Digital orthodontic radiographic set versus cone-beam computed tomography: an evaluation of the effective dose

    PubMed Central

    Chinem, Lillian Atsumi Simabuguro; Vilella, Beatriz de Souza; Maurício, Cláudia Lúcia de Pinho; Canevaro, Lucia Viviana; Deluiz, Luiz Fernando; Vilella, Oswaldo de Vasconcellos

    2016-01-01

    ABSTRACT Objective: The aim of this study was to compare the equivalent and effective doses of different digital radiographic methods (panoramic, lateral cephalometric and periapical) with cone-beam computed tomography (CBCT). Methods: Precalibrated thermoluminescent dosimeters were placed at 24 locations in an anthropomorphic phantom (Alderson Rando Phantom, Alderson Research Laboratories, New York, NY, USA), representing a medium sized adult. The following devices were tested: Heliodent Plus (Sirona Dental Systems, Bernsheim, Germany), Orthophos XG 5 (Sirona Dental Systems, Bernsheim, Germany) and i-CAT (Imaging Sciences International, Hatfield, PA, USA). The equivalent doses and effective doses were calculated considering the recommendations of the International Commission of Radiological Protection (ICRP) issued in 1990 and 2007. Results: Although the effective dose of the radiographic set corresponded to 17.5% (ICRP 1990) and 47.2% (ICRP 2007) of the CBCT dose, the equivalent doses of skin, bone surface and muscle obtained by the radiographic set were higher when compared to CBCT. However, in some areas, the radiation produced by the orthodontic set was higher due to the complete periapical examination. Conclusion: Considering the optimization principle of radiation protection, i-CAT tomography should be used only in specific and justified circumstances. Additionally, following the ALARA principle, single periapical radiographies covering restricted areas are more suitable than the complete periapical examination. PMID:27653266

  11. Second to fourth digit ratio (2D:4D) and concentrations of circulating sex hormones in adulthood

    PubMed Central

    2011-01-01

    Background The second to fourth digit ratio (2D:4D) is used as a marker of prenatal sex hormone exposure. The objective of this study was to examine whether circulating concentrations of sex hormones and SHBG measured in adulthood was associated with 2D:4D. Methods This analysis was based on a random sample from the Melbourne Collaborative Cohort Study. The sample consisted of of 1036 men and 620 post-menopausal women aged between 39 and 70 at the time of blood draw. Concentrations of circulating sex hormones were measured from plasma collected at baseline (1990-1994), while digit length was measured from hand photocopies taken during a recent follow-up (2003-2009). The outcome measures were circulating concentrations of testosterone, oestradiol, dehydroepiandrosterone sulphate, androstenedione, Sex Hormone Binding Globulin, androstenediol glucoronide for men only and oestrone sulphate for women only. Free testosterone and oestradiol were estimated using standard formulae derived empirically. Predicted geometric mean hormone concentrations (for tertiles of 2D:4D) and conditional correlation coefficients (for continuous 2D:4D) were obtained using mixed effects linear regression models. Results No strong associations were observed between 2D:4D measures and circulating concentrations of hormones for men or women. For males, right 2D:4D was weakly inversely associated with circulating testosterone (predicted geometric mean testosterone was 15.9 and 15.0 nmol/L for the lowest and highest tertiles of male right 2D:4D respectively (P-trend = 0.04). There was a similar weak association between male right 2D:4D and the ratio of testosterone to oestradiol. These associations were not evident in analyses of continuous 2D:4D. Conclusions There were no strong associations between any adult circulating concentration of sex hormone or SHGB and 2D:4D. These results contribute to the growing body of evidence indicating that 2D:4D is unrelated to adult sex hormone concentrations

  12. Perona Malik anisotropic diffusion model using Peaceman Rachford scheme on digital radiographic image

    SciTech Connect

    Halim, Suhaila Abd; Razak, Rohayu Abd; Ibrahim, Arsmah; Manurung, Yupiter HP

    2014-06-19

    In image processing, it is important to remove noise without affecting the image structure as well as preserving all the edges. Perona Malik Anisotropic Diffusion (PMAD) is a PDE-based model which is suitable for image denoising and edge detection problems. In this paper, the Peaceman Rachford scheme is applied on PMAD to remove unwanted noise as the scheme is efficient and unconditionally stable. The capability of the scheme to remove noise is evaluated on several digital radiography weld defect images computed using MATLAB R2009a. Experimental results obtained show that the Peaceman Rachford scheme improves the image quality substantially well based on the Peak Signal to Noise Ratio (PSNR). The Peaceman Rachford scheme used in solving the PMAD model successfully removes unwanted noise in digital radiographic image.

  13. Perona Malik anisotropic diffusion model using Peaceman Rachford scheme on digital radiographic image

    NASA Astrophysics Data System (ADS)

    Halim, Suhaila Abd; Razak, Rohayu Abd; Ibrahim, Arsmah; Manurung, Yupiter HP

    2014-06-01

    In image processing, it is important to remove noise without affecting the image structure as well as preserving all the edges. Perona Malik Anisotropic Diffusion (PMAD) is a PDE-based model which is suitable for image denoising and edge detection problems. In this paper, the Peaceman Rachford scheme is applied on PMAD to remove unwanted noise as the scheme is efficient and unconditionally stable. The capability of the scheme to remove noise is evaluated on several digital radiography weld defect images computed using MATLAB R2009a. Experimental results obtained show that the Peaceman Rachford scheme improves the image quality substantially well based on the Peak Signal to Noise Ratio (PSNR). The Peaceman Rachford scheme used in solving the PMAD model successfully removes unwanted noise in digital radiographic image.

  14. Optimisation of the digital radiographic imaging of suspected non-accidental injury

    NASA Astrophysics Data System (ADS)

    Offiah, Amaka

    Aim: To optimise the digital (radiographic) imaging of children presenting with suspected non-accidental injury (NAI). Objectives: (i) To evaluate existing radiographic quality criteria, and to develop a more suitable system if these are found to be inapplicable to skeletal surveys obtained in suspected NAI. (ii) To document differences in image quality between conventional film-screen and the recently installed Fuji5000R computed radiography (CR) system at Great Ormond Street Hospital for Children, (iii) To document the extent of variability in the standard of skeletal surveys obtained in the UK for suspected NAI. (iv) To determine those radiographic parameters which yield the highest diagnostic accuracy, while still maintaining acceptable radiation dose to the child, (v) To determine how varying degrees of edge-enhancement affect diagnostic accuracy. (vi) To establish the accuracy of soft compared to hard copy interpretation of images in suspected NAI. Materials and Methods: (i) and (ii) Retrospective analysis of 286 paediatric lateral spine radiographs by two observers based on the Commission of European Communities (CEC) quality criteria, (iii) Review of the skeletal surveys of 50 consecutive infants referred from hospitals throughout the United Kingdom (UK) with suspected NAI. (iv) Phantom studies. Leeds TO. 10 and TO. 16 test objects were used to compare the relationship between film density, exposure parameters and visualisation of object details, (iv) Clinical study. Anteroposterior and lateral post mortem skull radiographs of six consecutive infants were obtained at various exposures. Six observers independently scored the images based on visualisation of five criteria, (v) and (vi) A study of diagnostic accuracy in which six observers independently interpreted 50 radiographs from printed copies (with varying degrees of edge-enhancement) and from a monitor. Results: The CEC criteria are useful for optimisation of imaging parameters and allow the detection

  15. Validation of the International Labour Office Digitized Standard Images for Recognition and Classification of Radiographs of Pneumoconiosis

    PubMed Central

    Halldin, Cara N.; Petsonk, Edward L.; Laney, A. Scott

    2015-01-01

    Rationale and Objectives Chest radiographs are recommended for prevention and detection of pneumoconiosis. In 2011, the International Labour Office (ILO) released a revision of the International Classification of Radiographs of Pneumoconioses that included a digitized standard images set. The present study compared results of classifications of digital chest images performed using the new ILO 2011 digitized standard images to classification approaches used in the past. Materials and Methods Underground coal miners (N = 172) were examined using both digital and film-screen radiography (FSR) on the same day. Seven National Institute for Occupational Safety and Health-certified B Readers independently classified all 172 digital radiographs, once using the ILO 2011 digitized standard images (DRILO2011-D) and once using digitized standard images used in the previous research (DRRES). The same seven B Readers classified all the miners’ chest films using the ILO film-based standards. Results Agreement between classifications of FSR and digital radiography was identical, using a standard image set (either DRILO2011-D or DRRES). The overall weighted κ value was 0.58.Somespecific differences in the results were seen and noted. However, intrareader variability in this study was similar to the published values and did not appear to be affected by the use of the new ILO 2011 digitized standard images. Conclusions These findings validate the use of the ILO digitized standard images for classification of small pneumoconiotic opacities. When digital chest radiographs are obtained and displayed appropriately, results of pneumoconiosis classifications using the 2011 ILO digitized standards are comparable to film-based ILO classifications and to classifications using earlier research standards. PMID:24507420

  16. Building a 2.5D Digital Elevation Model from 2D Imagery

    NASA Technical Reports Server (NTRS)

    Padgett, Curtis W.; Ansar, Adnan I.; Brennan, Shane; Cheng, Yang; Clouse, Daniel S.; Almeida, Eduardo

    2013-01-01

    When projecting imagery into a georeferenced coordinate frame, one needs to have some model of the geographical region that is being projected to. This model can sometimes be a simple geometrical curve, such as an ellipse or even a plane. However, to obtain accurate projections, one needs to have a more sophisticated model that encodes the undulations in the terrain including things like mountains, valleys, and even manmade structures. The product that is often used for this purpose is a Digital Elevation Model (DEM). The technology presented here generates a high-quality DEM from a collection of 2D images taken from multiple viewpoints, plus pose data for each of the images and a camera model for the sensor. The technology assumes that the images are all of the same region of the environment. The pose data for each image is used as an initial estimate of the geometric relationship between the images, but the pose data is often noisy and not of sufficient quality to build a high-quality DEM. Therefore, the source imagery is passed through a feature-tracking algorithm and multi-plane-homography algorithm, which refine the geometric transforms between images. The images and their refined poses are then passed to a stereo algorithm, which generates dense 3D data for each image in the sequence. The 3D data from each image is then placed into a consistent coordinate frame and passed to a routine that divides the coordinate frame into a number of cells. The 3D points that fall into each cell are collected, and basic statistics are applied to determine the elevation of that cell. The result of this step is a DEM that is in an arbitrary coordinate frame. This DEM is then filtered and smoothed in order to remove small artifacts. The final step in the algorithm is to take the initial DEM and rotate and translate it to be in the world coordinate frame [such as UTM (Universal Transverse Mercator), MGRS (Military Grid Reference System), or geodetic] such that it can be saved in

  17. Impact of resolution and noise characteristics of digital radiographic detectors on the detectability of lung nodules.

    PubMed

    Saunders, Robert S; Samei, Ehsan; Hoeschen, Christoph

    2004-06-01

    One of the unanswered questions in digital radiography is the connection between physical image quality metrics and clinical detection performance. In this paper, we examine the impact of two physical metrics, resolution and noise, on the detectability of nodules in a pulmonary background for specific digital radiographic detectors. A detection experiment was performed on a simulated image set using anatomical backgrounds from a high-quality lung radiograph and three different simulated nodule sizes (2-3.5 mm). The resolution and noise of the resulting images were modified using existing routines to simulate a selenium-based and a cesium iodide-based flat-panel detector at comparable exposures. A location-known-exactly (LKE) observer performance experiment was performed in which four experienced chest radiologists and three physicists specializing in chest radiology scored the images. The data from the observer experiment were analyzed by receiver operating characteristic (ROC) methodology. The detectability, as measured by the parameter Az, was higher for the selenium detector than the cesium iodide detector for all nodule sizes by an average of 8.5%. For one nodule size (2.75 mm), the difference between detectors was statistically significant (p < 0.01). The findings indicate that for the particular task studied, the superior resolution performance of the selenium-based detector provided better detectability of subtle lung nodules even though the images had greater noise than images obtained with the cesium iodide detector.

  18. Subjective image quality of digital panoramic radiographs displayed on monitor and printed on various hardcopy media.

    PubMed

    Gijbels, Frieda; Sanderink, Gerard; Pauwels, Herman; Jacobs, Reinhilde

    2004-03-01

    The subjective image quality of panoramic radiographs shown on a diagnostic computer monitor were compared with professional direct thermal prints and with common inkjet prints on different paper qualities. Indirect digital panoramic radiographs were obtained from 15 patients. The images were printed with a direct thermal printer in their original format. Afterwards, these were loaded in an imaging software programme (Microsoft Photo Editor) and assessed both on computer monitor and inkjet prints on transparency, glossy, satin and regular paper. Five observers assessed subjective image quality for different regions and anatomical landmarks on a 5-point rating scale. Data were statistically analysed and inter- and intra-observer performances were calculated. Best image quality was obtained with direct thermal prints, followed in descending order by panoramic images viewed on the monitor, inkjet prints on transparencies, glossy paper, satin paper and finally regular paper. The differences were significant except for monitor images versus direct thermal prints, inkjet-transparencies and inkjet-glossy images and inkjet-satin versus inkjet-glossy images. The subjective image quality of indirect digital panoramic images is different for images shown on the computer monitor and for printed images depending on both the printer and paper type used.

  19. Digit ratio (2D:4D) and handgrip strength in a Chinese population of Han ethnicity.

    PubMed

    Shen, Dan; Ma, Zhanbing; Wang, Lu; Huo, Zhenghao; Lu, Hong; Zhao, Junli; Qian, Wenli

    2016-12-01

    In humans, the relative lengths of the index finger to the ring finger (2D:4D) is a sexually dimorphic trait which correlated with prenatal sex steroids and has been increasingly used as a promising tool to evaluate the impact of prenatal hormone exposure in some traits, such as physical performance. Handgrip strength (HGS) is one potent index of physical ability and its relationship with 2D:4D ratio has been discussed in several ethnic groups. To investigate whether there is a correlation between 2D:4D ratio and HGS in Chinese college students of Ningxia Han ethnicity. 608 students (211 males and 397 females) of Han ethnicity were recruited from Ningxia medical university. Photocopies and HGS of both hands were collected at Yinchuan city, in the Ningxia province of China. Sexual dimorphism of 2D:4D and HGS were found, males had significantly lower 2D:4D and greater HGS than females. 2D:4D in both hands were significantly negative correlated with HGS in females and not in males. 2D:4D ratio is negative correlated with HGS in a Chinese population of Ningxia Han ethnicity and this association should be considered on the anthropological research within an evolutionary concept in the future. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Digit ratio (2D:4D) and male facial attractiveness: new data and a meta-analysis.

    PubMed

    Hönekopp, Johannes

    2013-10-01

    Digit ratio (2D:4D) appears to correlate negatively with prenatal testosterone (T) effects in humans. As T probably increases facial masculinity, which in turn might be positively related to male facial attractiveness, a number of studies have looked into the relationship between 2D:4D and male facial attractiveness, showing equivocal results. Here, I present the largest and third largest samples so far, which investigate the relationship between 2D:4D and male facial attractiveness in adolescents (n = 115) and young men (n = 80). I then present random-effects meta-analyses of the available data (seven to eight samples, overall n = 362 to 469). These showed small (r ≈ -.09), statistically non-significant relationships between 2D:4D measures and male facial attractiveness. Thus, 2D:4D studies offer no convincing evidence at present that prenatal T has a positive effect on male facial attractiveness. However, a consideration of confidence intervals shows that, at present, a theoretically meaningful relationship between 2D:4D and male facial attractiveness cannot be ruled out either.

  1. Right-left digit ratio (2D:4D) predicts free testosterone levels associated with a physical challenge.

    PubMed

    Kilduff, Liam; Cook, Christian J; Bennett, Mark; Crewther, Blair; Bracken, Richard Michael; Manning, John

    2013-01-01

    There is evidence that the digit ratio (2D:4D) is a negative correlate of prenatal levels of testosterone, but there is no association between 2D:4D and the circulating levels of both total and free testosterone. Sports provide a physical challenge and participants often show increased levels of free testosterone immediately preceding and during competition. We tested this hypothesis of a link between 2D:4D and testosterone under challenge in 79 professional rugby players using the following procedures; (i) 25 players were physically challenged using a repeated sprint agility test, and saliva samples were assayed for testosterone immediately preceding the repeated sprint agility test (time 1) and 5 minutes (time 2) and 20 minutes after completion of the repeated sprint ability (time 3); (ii) 54 players were also tested for salivary testosterone in an unchallenged condition. We found that right-left 2D:4D was significantly and negatively related to testosterone concentrations at times 1, 2 and 3 following the repeated sprint agility test (P < 0.05) and there was no association between the 2D:4D and basal testosterone levels in the unchallenged group. We suggest that low right-left 2D:4D is a predictive marker of free testosterone responsiveness when trained men are physically challenged, and that this association is programmed by the action of prenatal testosterone.

  2. Digit ratio 2D:4D in relation to autism spectrum disorders, empathizing, and systemizing: a quantitative review.

    PubMed

    Hönekopp, Johannes

    2012-08-01

    Prenatal testosterone (PT) effects have been proposed to increase systemizing (the drive to understand lawful input-output relationships), to decrease empathizing (the drive to understand others), and to cause autism via hypermasculinization of the brain. Digit ratio 2D:4D is a putative marker of PT effects in humans. An online study (n = 1896) into the relationship between the Reading the Mind in the Eyes Test (a widely used measure of empathizing) and self-measured 2D:4D in a nonclinical sample is reported. No evidence for a link between empathizing and 2D:4D in either females or males emerged. Further, three meta-analyses are presented that look into the relationships of 2D:4D with autism spectrum disorder (ASD), systemizing, and empathizing. 2D:4D was substantially lower (more masculine) in ASD-affected individuals than in normal controls (d = -0.58, P < 0.001). However, 2D:4D was found to be virtually unrelated to systemizing and empathizing in normal adults. The results support the idea that high PT is a risk factor for autism, but they challenge the view that PT substantially contributes to sex differences in systemizing and empathizing. Possibly, this pattern reflects an interaction effect, whereby PT drives ASD characteristic changes only in brains with a specific damage. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.

  3. Digit ratio (2D:4D) predicts sporting success among female fencers independent from physical, experience, and personality factors.

    PubMed

    Voracek, M; Reimer, B; Dressler, S G

    2010-12-01

    Research particularly focusing on male athletes and popular sports (running and soccer) suggests associations of lower (masculinized) second-to-fourth digit ratio (2D:4D), a putative marker of prenatal androgen action, with better sports performance. Studies focusing on women, non-mainstream sports, or controlling for covariates relevant for sporting success are still sparse. This study examined associations between 2D:4D and performance of both male and female athletes active in fencing (a non-mainstream sport dominated by male participants), while controlling for covariates. National fencing rankings and 2D:4D of 58 male and 41 female Austrian tournament fencers (mean age 24 years) were correlated. Among female, but not male, fencers, lower 2D:4D was related to better national fencing rankings. 2D:4D still accounted for incremental variance (12%) in fencing success, when the effects of salient performance factors (age, body mass index, years of fencing, training intensity, and the personality variables achievement, control, harm avoidance, and social potency) were controlled for (totaling 35% attributable variance). Athletes active in the most aggressive form (the sabre) had lower 2D:4D than those active in the other forms (épée and foil fencing). Sporting success in adult life might be partly prenatally programmed via long-lasting extragenital effects of testosterone. © 2009 John Wiley & Sons A/S.

  4. Digit ratio (2D:4D) and month of birth: A link to the solstitial-melatonin-testosterone effect.

    PubMed

    Szwed, Anita; Kosinska, Magdalena; Manning, John T

    2017-01-01

    Digit ratio (2D:4D) is a sexually dimorphic trait and its determination in utero is influenced by testosterone. The solstitial-melatonin-testosterone hypothesis posits that melatonin inhibits the production of foetal testosterone and melatonin levels are at their lowest in months when light levels are high. We test the relationship between 2D:4D, month-of-birth and light levels. We recruited participants whose year of birth was spread across the 20th Century. 323 Polish men and women. Finger lengths, month-of-birth, mean daylight hours per month in and around Poznan, Poland. Our sample was born between 1907 and 1997. In comparison to late-Spring births, late-Autumn births had low right-left 2D:4D (high prenatal testosterone). Regarding light levels, there were significant relationships between low right 2D:4D and right-left 2D:4D (high prenatal testosterone) and long days at the end of the 1st trimester. These relationships were strongest for participants born in the first half of the 20th Century. Participants born in the late-Autumn and who experienced long days in the 2nd and 3rd prenatal months had low 2D:4D. The effects were strongest for early 20th Century births where photoperiods would be less disrupted by artificial light. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Digital radiograph of the middle phalanx of the third finger (MP3) region as a tool for skeletal maturity assessment.

    PubMed

    Hegde, Deepa Y; Baliga, Sudhindra; Yeluri, Ramakrishna; Munshi, A K

    2012-01-01

    To evaluate the reliability of the digital radiograph of the middle phalanx of the third finger (MP3) in skeletal maturity assessment. Fifty children (24 girls and 26 boys) belonging to the circumpubertal age-group were selected for the study. Two radiographs - lateral cephalogram and digital radiograph of the MP3 region - were taken in each child. Age assessment was based on the changes in shape of the cervical vertebrae and the epiphysis of the middle phalanx of the third finger of the left hand. The radiographs were assessed by three examiners. The inter- and intraexaminer variability were determined by the Wilcoxon rank sign test and the Kruskal-Wallis test and were found to be nonsignificant. Examiner 3 showed the best intraexaminer agreement and was selected to evaluate the radiographs for the entire study. The correlation determined between the MP3 stages and cervical vertebrae maturity index (CVMI) stages, the peak-wise distribution of the MP3 stages, and the correlation between the MP3 stages and the chronological age were found to be highly significant. Digital radiograph of the MP3 region is definitely a simple, reliable, cost-effective, and time-saving technique for the assessment of skeletal maturity.

  6. Digit ratio (2D:4D) and physical fitness (Eurofit test battery) in school children.

    PubMed

    Ranson, R; Stratton, G; Taylor, S R

    2015-05-01

    The relative lengths of the index finger to the ring finger (2D:4D) is sexually dimorphic and is thought to be a correlate of prenatal sex steroids (low 2D:4D=high prenatal testosterone and low prenatal oestrogen). In adults there have been reports that low 2D:4D is consistently associated with high sports performance. To investigate correlations between 2D:4D and fitness levels in children. Right 2D:4D and body size were measured, in addition to flexibility, speed, endurance and strength (Eurofit tests). 922 boys and 835 girls (mean ages (years): 10.8 ± 1.01 and 10.07 ± 1.00 respectively). height, mass, BMI, triceps and subscapular skinfolds, 20 m shuttle run, sit and reach, standing broad jump, hand grip strength, 10 × 5m sprint, and the sit and reach test. Boys significantly outperformed the girls in the 10 × 5m sprints, the 20 m shuttle run, standing broad jump, and hand grip strength. In boys but not girls, 2D:4D was significantly negatively correlated with scores in all these tests except the standing broad jump. In girls but not boys, 2D:4D was significantly positively correlated to stature, mass, BMI and waist circumference. It is suggested that high prenatal testosterone and low prenatal oestrogen (low 2D:4D) is implicated in high sprinting speed, endurance and hand grip strength in boys. In girls low prenatal testosterone and high prenatal oestrogen is associated with large body size. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. The second to fourth digit ratio (2D:4D) in Saudi boys with autism: A potential screening tool.

    PubMed

    Al-Zaid, Felwah S; Alhader, AbdelFattah A; Al-Ayadhi, Laila Y

    2015-07-01

    Autism is a neurodevelopment disorder with a strikingly higher prevalence in boys than girls. There are many theories regarding this gender bias, and prenatal exposure to high levels of fetal testosterone (FT) may be a predisposing factor. The second to fourth digit ratio (2D:4D) is the only indirect measure that reflects this association postnatally. Thus, this study measured the lengths of the index finger (2D) and the ring finger (4D) and calculated the 2D:4D ratio. Subsequently, this ratio was used to indirectly determine the potential prenatal exposure to high levels of FT in autistic children. This case-control study was conducted with 60 male children with 31 individuals having classic-onset autism and 29 individuals serving as age-matched, healthy controls. The lengths of both the index (2D) and the ring (4D) fingers of the right hand of both autism and control groups were obtained using a scanner and the 2D:4D ratio was calculated. The 2D:4D ratio in the current study was significantly lower in boys with autism compared to the controls (p ≤ 0.001). This study demonstrates a significantly lower 2D:4D ratio in Saudi boys with autism, which indirectly suggests that these boys were exposed to high levels of prenatal FT. Accordingly, prenatal exposure to high levels of FT is a risk factor for the development of autism, and the postnatal measurement of the 2D:4D ratio could be a potential screening tool. Copyright © 2015. Published by Elsevier Ireland Ltd.

  8. The relation of digit ratio (2D:4D) and absolute finger length to Pavlovian temperament dimensions.

    PubMed

    Voracek, Martin

    2008-12-01

    The associations of digit ratio (2D:4D), a likely marker for prenatal androgen exposure, and absolute finger length, a likely marker for postnatal androgen exposure, with self-reports on three Pavlovian temperament dimensions (strength of excitation, strength of inhibition, and mobility of nervous processes) were investigated in a sample of 84 men and 114 women. In men, left-hand 2D:4D was weakly, but significantly, negatively associated with strength of inhibition, and also weakly negatively, but not significantly, associated with the two other temperament dimensions. These effects were absent for men's right-hand 2D:4D. Finger lengths of both hands in men were weakly, but significantly, positively associated with mobility of nervous processes scores. All associations for women were negligible. Both prenatal and postnatal androgen action may contribute to small amounts of individual differences in Pavlovian temperament dimensions in men but apparently not in women.

  9. A critical review of the research on the extreme male brain theory and digit ratio (2D:4D).

    PubMed

    Teatero, Missy L; Netley, Charles

    2013-11-01

    Boys are more likely than girls to be diagnosed with an autism spectrum disorder (ASD). The extreme male brain (EMB) theory of ASD suggests that fetal testosterone (FT) exposure may underlie sex differences in autistic traits. A link between the organizational effects of FT on the brain and ASD is often drawn based on research using digit ratio (2D:4D), a putative biomarker, without a full survey of the findings. This paper critically and quantitatively reviews the research on the relationship between 2D:4D and ASD as well as autism spectrum, empathizing, and systemizing measures in neurotypical populations. Overall, there is some support for the EMB theory in all four areas, particularly the 2D:4D-ASD relationship. Recommendations for future research are provided.

  10. Automatic 3D-to-2D registration for CT and dual-energy digital radiography for calcification detection

    SciTech Connect

    Chen Xiang; Gilkeson, Robert C.; Fei, Baowei

    2007-12-15

    We are investigating three-dimensional (3D) to two-dimensional (2D) registration methods for computed tomography (CT) and dual-energy digital radiography (DEDR). CT is an established tool for the detection of cardiac calcification. DEDR could be a cost-effective alternative screening tool. In order to utilize CT as the 'gold standard' to evaluate the capability of DEDR images for the detection and localization of calcium, we developed an automatic, intensity-based 3D-to-2D registration method for 3D CT volumes and 2D DEDR images. To generate digitally reconstructed radiography (DRR) from the CT volumes, we developed several projection algorithms using the fast shear-warp method. In particular, we created a Gaussian-weighted projection for this application. We used normalized mutual information (NMI) as the similarity measurement. Simulated projection images from CT values were fused with the corresponding DEDR images to evaluate the localization of cardiac calcification. The registration method was evaluated by digital phantoms, physical phantoms, and clinical data sets. The results from the digital phantoms show that the success rate is 100% with a translation difference of less than 0.8 mm and a rotation difference of less than 0.2 deg. . For physical phantom images, the registration accuracy is 0.43{+-}0.24 mm. Color overlay and 3D visualization of clinical images show that the two images registered well. The NMI values between the DRR and DEDR images improved from 0.21{+-}0.03 before registration to 0.25{+-}0.03 after registration. Registration errors measured from anatomic markers decreased from 27.6{+-}13.6 mm before registration to 2.5{+-}0.5 mm after registration. Our results show that the automatic 3D-to-2D registration is accurate and robust. This technique can provide a useful tool for correlating DEDR with CT images for screening coronary artery calcification.

  11. Digit ratio (2D:4D), aggression, and dominance in the Hadza and the Datoga of Tanzania.

    PubMed

    Butovskaya, Marina; Burkova, Valentina; Karelin, Dmitry; Fink, Bernhard

    2015-01-01

    Digit ratio (2D:4D)-a putative marker of prenatal androgen activity-has been shown to correlate with self-reported physical aggression and dominance behavior, especially in male children and adolescents. This evidence is derived primarily from the study of Western samples. Digit ratios, self-reported aggression, and dominance behavior were collected from men and women in two traditional, small-scale societies, i.e., the Hadza and the Datoga of Tanzania. We found significant differences in physical and verbal aggression, anger, and hostility between the two societies with the Datoga reporting higher scores on all four measures. Moreover, self-reported dominance in the Datoga was higher than in the Hadza. The Datoga showed lower left and right hand 2D:4D ratios than the Hadza. Men reported higher physical and verbal aggression and dominance, and had lower 2D:4D ratios than women. A significant negative association between 2D:4D and dominance was found in Hadza women. We discuss our findings with reference to differences in mating systems between the two small-scale societies and previous findings of Western and other small-scale societies. © 2015 Wiley Periodicals, Inc.

  12. In vivo accuracy of conventional and digital radiographic methods in confirming root canal working length determination by Root ZX

    PubMed Central

    OROSCO, Fernando Accorsi; BERNARDINELI, Norberti; GARCIA, Roberto Brandão; BRAMANTE, Clovis Monteiro; DUARTE, Marco Antonio Húngaro; de MORAES, Ivaldo Gomes

    2012-01-01

    Objectives To compare, in vivo, the accuracy of conventional and digital radiographic methods in determining root canal working length. Material and Methods Twenty-five maxillary incisor or canine teeth from 22 patients were used in this study. Considering the preoperative radiographs as the baseline, a 25 K file was inserted into the root canal to the point where the Root ZX electronic apex locator indicated the APEX measurement in the screen. From this measurement, 1 mm was subtracted for positioning the file. The radiographic measurements were made using a digital sensor (Digora 1.51) or conventional type-E films, size 2, following the paralleling technique, to determine the distance of the file tip and the radiographic apex. Results The Student "t" test indicated mean distances of 1.11 mm to conventional and 1.20 mm for the digital method and indicated a significant statistical difference (p<0.05). Conclusions The conventional radiographic method was found to be superior to the digital one in determining the working length of the root canal. PMID:23138737

  13. Irreversible JPEG compression of digital chest radiographs for primary interpretation: assessment of visually lossless threshold.

    PubMed

    Slone, Richard M; Muka, Edward; Pilgram, Thomas K

    2003-08-01

    To determine if digital chest images could be compressed in a primary interpretation context without perceived loss of fidelity (below the visually lossless threshold) at transilluminated film or cathode ray tube (CRT) display. One hundred forty-four posteroanterior radiographs were obtained with a digital chest radiography system. At both film and CRT display, an identified original image was presented side by side with a replicate, which was either an unaltered image or an image that had been Joint Photographic Experts Group (JPEG) compressed to 10:1, 20:1, or 50:1 and reconstructed. Each of the 10 readers indicated whether the replicate was "indistinguishable from the original" or "degraded" at clinical reading distance and at close inspection. The readers' ability to detect compressed images was examined for patterns; 95% CIs were used for statistical testing. With transilluminated film at clinical reading distance, readers were as likely to rate originals (48 [20%] of 240 readings) as degraded as they were to rate 20:1 replicates (106 [22%] of 480 readings) as degraded, but they frequently identified 50:1 replicates (283 [59%] of 480 readings) as degraded. At close inspection, 20:1 replicates (163 [34%] of 480 readings) were often identified as degraded, but 10:1 replicates (19 [8%] of 240 readings) were not identified as degraded more often than originals (17 [7%] of 240 readings). With CRT display, the results were nearly identical. At reading distance for primary interpretation, full-size digital chest radiographs that have been JPEG compressed to 10:1 or 20:1 and reconstructed are visually lossless at film or CRT display. Images compressed to 10:1 remain visually lossless at close inspection. Copyright RSNA, 2003.

  14. Hard Copy to Digital Transfer: 3D Models that Match 2D Maps

    ERIC Educational Resources Information Center

    Kellie, Andrew C.

    2011-01-01

    This research describes technical drawing techniques applied in a project involving digitizing of existing hard copy subsurface mapping for the preparation of three dimensional graphic and mathematical models. The intent of this research was to identify work flows that would support the project, ensure the accuracy of the digital data obtained,…

  15. Hard Copy to Digital Transfer: 3D Models that Match 2D Maps

    ERIC Educational Resources Information Center

    Kellie, Andrew C.

    2011-01-01

    This research describes technical drawing techniques applied in a project involving digitizing of existing hard copy subsurface mapping for the preparation of three dimensional graphic and mathematical models. The intent of this research was to identify work flows that would support the project, ensure the accuracy of the digital data obtained,…

  16. Linear densitometry and digital image processing of proximal femur radiographs: implications for archaeological and forensic anthropology.

    PubMed

    Macchiarelli, R; Bondioli, L

    1994-01-01

    Age- and sex-related patterns of proximal femur trabecular bone loss have previously been used to establish radiographic reference standards for estimating age at death for human skeletal remains. Such standards are of interest to both anthropologists and forensic scientists. However, osteopenia as a physiological phenomenon is dependent on numerous genetic, environmental, and cultural factors. Thus, while general age- and sex-related trends can be clearly observed for trabecular bone loss, such patterns also demonstrate marked variation among individuals of both sexes at all ages. Moreover, clinical evidence shows that rates of bone loss are not steady but episodic, and that radiographically "normal" (i.e., young adult) patterns of trabecular bone architecture can also exist in femora of older individuals, particularly within samples of African origin. In this study, adult proximal femur radiographs were used to explore patterns of age- and sex-related proximal femur cancellous bone involution among a sample of 66 African-American individuals from the Terry collection (33 males and 33 females), ranging in age from 19 to 71 years. The proximal femur radiographs of these subjects were analyzed by digital image processing (DIP), and the results were compared to those obtained by laser linear densitometric analyses (LDA) previously performed on the same series (Macchiarelli et al., 1987). Results of LDA and DIP analyses indicate (a) more pronounced bone density decrease in females; (b) sex- and site-specific structural patterns of proximal femur trabecular bone loss; (c) a high level of individual variability, in which predicted age deviated from real age by as much as 22.26 (males) and 30.78 years (females); (d) a moderate linear correlation with age for all the variables analyzed; and (e) an average discrepancy between known age and predicted age (measured by root mean squared residual values) of 10.34 (males) and 12.71 years (females) for the most satisfactory DIP

  17. [Clinical and comparative study of the image quality of 3 digital radiographic systems, E-speed film and digitalized film

    PubMed

    Bóscolo, F N; de Oliveira, A E; de Almeida, S M; Haiter, C F; Haiter Neto, F

    2001-01-01

    The aim of this study was to evaluate, subjectively, the image quality of two CCD digital systems, a digital storage phosphor system, a digitized film and an E-speed film. Five objects were radiographed with 50, 60 and 70 kVp, with exposure times of 0.08, 0.13, 0.2, 0.4 and 0.8 s. In order to maximize the fidelity of the results, the dental X-ray unit employed was submitted to an evaluation so that the relation between exposure time and dose could be established. A good reproducibility was obtained. Six evaluators analyzed 375 images, using a scoring scale which ranged from 0 to 4. The results revealed different responses, indicating that the storage phosphor system had the best performance, in the various exposures employed. However, it was possible to conclude that all systems studied, except for the Sens-A-Ray, can offer images in ideal conditions for the diagnosis, as long as their latitudes are respected.

  18. Lack of association between digit ratio (2D:4D) and assertiveness: replication in a large sample.

    PubMed

    Voracek, Martin

    2009-12-01

    Findings regarding within-sex associations of digit ratio (2D:4D), a putative pointer to long-lasting effects of prenatal androgen action, and sexually differentiated personality traits have generally been inconsistent or unreplicable, suggesting that effects in this domain, if any, are likely small. In contrast to evidence from Wilson's important 1983 study, a forerunner of modern 2D:4D research, two recent studies in 2005 and 2008 by Freeman, et al. and Hampson, et al. showed assertiveness, a presumably male-typed personality trait, was not associated with 2D:4D; however, these studies were clearly statistically underpowered. Hence this study examined this question anew, based on a large sample of 491 men and 627 women. Assertiveness was only modestly sexually differentiated, favoring men, and a positive correlate of age and education and a negative correlate of weight and Body Mass Index among women, but not men. Replicating the two prior studies, 2D:4D was throughout unrelated to assertiveness scores. This null finding was preserved with controls for correlates of assertiveness, also in nonparametric analysis and with tests for curvilinear relations. Discussed are implications of this specific null finding, now replicated in a large sample, for studies of 2D:4D and personality in general and novel research approaches to proceed in this field.

  19. Digit ratio (2D:4D) predicts facial, but not voice or body odour, attractiveness in men.

    PubMed

    Ferdenzi, Camille; Lemaître, Jean-François; Leongómez, Juan David; Roberts, S Craig

    2011-12-07

    There is growing evidence that human second-to-fourth digit ratio (or 2D:4D) is related to facial features involved in attractiveness, mediated by in utero hormonal effects. The present study extends the investigation to other phenotypic, hormone-related determinants of human attractiveness: voice and body odour. Pictures of faces with a neutral expression, recordings of voices pronouncing vowels and axillary odour samples captured on cotton pads worn for 24 h were provided by 49 adult male donors. These stimuli were rated on attractiveness and masculinity scales by two groups of 49 and 35 females, approximately half of these in each sample using hormonal contraception. Multivariate regression analyses showed that males' lower (more masculine) right 2D:4D and lower right-minus-left 2D:4D (Dr-l) were associated with a more attractive (and in some cases more symmetrical), but not more masculine, face. However, 2D:4D and Dr-l did not predict voice and body odour masculinity or attractiveness. The results were interpreted in terms of differential effects of prenatal and circulating testosterone, male facial shape being supposedly more dependent on foetal levels (reflected by 2D:4D ratio), whereas body odour and vocal characteristics could be more dependent on variation in adult circulating testosterone levels.

  20. Digit ratio (2D:4D) predicts facial, but not voice or body odour, attractiveness in men

    PubMed Central

    Ferdenzi, Camille; Lemaître, Jean-François; Leongómez, Juan David; Roberts, S. Craig

    2011-01-01

    There is growing evidence that human second-to-fourth digit ratio (or 2D:4D) is related to facial features involved in attractiveness, mediated by in utero hormonal effects. The present study extends the investigation to other phenotypic, hormone-related determinants of human attractiveness: voice and body odour. Pictures of faces with a neutral expression, recordings of voices pronouncing vowels and axillary odour samples captured on cotton pads worn for 24 h were provided by 49 adult male donors. These stimuli were rated on attractiveness and masculinity scales by two groups of 49 and 35 females, approximately half of these in each sample using hormonal contraception. Multivariate regression analyses showed that males' lower (more masculine) right 2D:4D and lower right-minus-left 2D:4D (Dr−l) were associated with a more attractive (and in some cases more symmetrical), but not more masculine, face. However, 2D:4D and Dr−l did not predict voice and body odour masculinity or attractiveness. The results were interpreted in terms of differential effects of prenatal and circulating testosterone, male facial shape being supposedly more dependent on foetal levels (reflected by 2D:4D ratio), whereas body odour and vocal characteristics could be more dependent on variation in adult circulating testosterone levels. PMID:21508034

  1. Low digit ratio (2D:4D) in male suicide victims.

    PubMed

    Lenz, Bernd; Thiem, Daniela; Bouna-Pyrrou, Polyxeni; Mühle, Christiane; Stoessel, Christina; Betz, Peter; Kornhuber, Johannes

    2016-12-01

    Although women attempt suicides equally or more often than men do, men are more likely to die of suicide than women (sex paradox of suicidal behavior). Furthermore, the male traits of aggression and impulsivity predict suicide completion. Here, we studied the second-to-fourth-finger length ratio (2D:4D), a proxy for prenatal androgen exposure, in 46 suicide corpses and 25 non-suicide corpses. We report significantly lower 2D:4D in male suicide corpses than non-suicide corpses (p = .030, partial η (2) = .147). There was no significant association between 2D:4D and the suicide method. Our findings indicate increased risk of suicide following higher prenatal androgen exposure in males. The results may improve future efforts to predict and prevent suicides.

  2. Validation of digit-length ratio (2D:4D) assessments on the basis of DXA-derived hand scans.

    PubMed

    Romann, Michael; Fuchslocher, Jörg

    2015-02-03

    The second-to-fourth digit-length ratio (2D:4D) may be a correlate of prenatal sex steroids, and it has been linked to sporting prowess. The aim of the study was to validate dual-energy X-ray-absorptiometry (DXA) as a technique to assess 2D:4D in soccer players under 15 years of age (U-15). Paired X-ray and DXA scans of the left hands of 63 male U-15 elite soccer players (age: 14.0 ± 0.3 years) were performed, and 2D:4D was then compared between the two techniques. The 2D:4D measurements were performed twice by two blinded raters. Intrarater and interrater reliability, as well as agreement between the X-ray and the DXA assessments, were tested. Intrarater reliabilities of both raters using X-ray with intraclass correlation coefficients (ICCs) of 0.97 and 0.90 were excellent. Using DXA, the ICCs were 0.90 and 0.91 thus also showing excellent reliability. Interrater reliabilities were excellent using both the X-ray (ICC of 0.94) and the DXA (ICC of 0.90), assessments respectively. Bland-Altman plots demonstrated that the 2D:4D ratios of the two raters did not differ significantly between the X-ray and the DXA assessments. The standard errors of estimate were 0.01 for both techniques. The 95% limits of agreement of ±0.018 (±2.0%) and ±0.023 (±2.6%), respectively, were within the acceptable tolerance of 5%, and showed very good agreement. DXA offered a replicable technique for assessing 2D:4D in youth soccer players. Therefore, the DXA technique seems to be an alternative method for evaluating 2D:4D in youth sports.

  3. Digit ratio (2D:4D) and gender inequalities across nations.

    PubMed

    Manning, John T; Fink, Bernhard; Trivers, Robert

    2014-08-22

    Gender inequality varies across nations, where such inequality is defined as the disproportionate representation of one sex over the other in desirable social, economic, and biological roles (typically male over female). Thus in Norway, 40% of parliamentarians are women, in the USA 17%, and in Saudi Arabia 0%. Some of this variation is associated with economic prosperity but there is evidence that this cause and effect can go in either direction. Here we show that within a population the average ratio of index (2D) to ring (4D) finger lengths (2D:4D)-a proxy measure of the relative degree to which offspring is exposed in utero to testosterone versus estrogen-is correlated with measures of gender inequality between nations. We compared male and female 2D:4D ratios to female parliamentary representation, labor force participation, female education level, maternal mortality rates, and juvenile pregnancy rates per nation in a sample of 29 countries. We found those nations who showed higher than expected female fetal exposure to testosterone (low 2D:4D) and lower than expected male exposure to fetal testosterone (high 2D:4D) had higher rates of female parliamentary representation, and higher female labor force participation. In short, the more similar the two sexes were in 2D:4D, the more equal were the two sexes in parliamentary and labor force participation. The other variables were not as strongly correlated. We suggest that higher than expected fetal testosterone in females and lower fetal testosterone in males may lead to high female representation in the national labor force and in parliament.

  4. Removing Distortion of Periapical Radiographs in Dental Digital Radiography Using Embedded Markers in an External frame

    PubMed Central

    Kafieh, Rahele; Shahamoradi, Mahdi; Hekmatian, Ehsan; Foroohandeh, Mehrdad; Emamidoost, Mostafa

    2012-01-01

    To carry out in vivo and in vitro comparative pilot study to evaluate the preciseness of a newly proposed digital dental radiography setup. This setup was based on markers placed on an external frame to eliminate the measurement errors due to incorrect geometry in relative positioning of cone, teeth and the sensor. Five patients with previous panoramic images were selected to undergo the proposed periapical digital imaging for in vivo phase. For in vitro phase, 40 extracted teeth were replanted in dry mandibular sockets and periapical digital images were prepared. The standard reference for real scales of the teeth were obtained through extracted teeth measurements for in vitro application and were calculated through panoramic imaging for in vivo phases. The proposed image processing thechnique was applied on periapical digital images to distinguish the incorrect geometry. The recognized error was inversely applied on the image and the modified images were compared to the correct values. The measurement findings after the distortion removal were compared to our gold standards (results of panoramic imaging or measurements from extracted teeth) and showed the accuracy of 96.45% through in vivo examinations and 96.0% through in vitro tests. The proposed distortion removal method is perfectly able to identify the possible inaccurate geometry during image acquisition and is capable of applying the inverse transform to the distorted radiograph to obtain the correctly modified image. This can be really helpful in applications like root canal therapy, implant surgical procedures and digital subtraction radiography, which are essentially dependent on precise measurements. PMID:23724372

  5. Demonstration of digital radiographs by means of ink jet-printed paper copies: pilot study.

    PubMed

    Kirkhorn, T; Kehler, M; Nilsson, J; Lyttkens, K; Andersson, B; Holmer, N G

    1992-11-01

    Different digital medical images have been printed on paper with a continuous ink jet printer, and the quality has been evaluated. The emphasis has been on digital chest radiographs from a computed radiography system. The ink jet printing technique is described as well as the handling of the image data from image source to printer. Different versions of paper prints and viewing conditions were compared to find the optimum alternative. The evaluation has been performed to maximize the quality of the paper images to make them conform with the corresponding film prints and monitor images as much as possible. The continuous ink jet technique offers high-quality prints on paper at a considerably lower cost per copy compared with the cost of a film print. With a future switch-over from diagnosing of digital images on film to diagnosing them on monitors, hard copies for demonstration purposes will occasionally be needed. This need can be filled by ink jet-printed paper copies.

  6. Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System

    PubMed Central

    Firoozmand, Leily Macedo; Cordeiro, Mariana Gonçalves; Da Silva, Marcos André dos Santos

    2016-01-01

    The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow) cylindrical disks (5 × 1 mm) were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel. PMID:27722199

  7. A Comparison of Radiographic Film Densitometry Using a New Computerized Tool with a Digital Densitometer

    PubMed Central

    Fakhar, Hoorieh Bashizadeh; Razavi, Elham Sadat Emadian; Soheilifar, Sepideh; Kharazifard, Mohammad Javad

    2016-01-01

    Objectives: The purpose of this study was to develop and test a new tool for radiographic densitometry by combining periapical films and aluminum step wedge. Materials and Methods: We reviewed 50 Kodak E-speed intraoral films. An aluminum step wedge consisting of 16 steps was constructed. Each step was 1mm×3m×10mm. The step wedge was exposed to varying exposure times, ranging from 0.05 second to 0.5 second, increasing in 0.05 second increments. Films were digitalized after processing and the MATLAB software algorithm was ran subsequently. Density of the films was measured again using a digital densitometer. In order to compare the two imaging techniques, three steps were selected. Output data from the MATLAB algorithm were compared with data obtained from the digital densitometer. Results: The new method could detect significant differences between subsequent exposure times in step 7, while the densitometer did that in steps 7 and 12. The new method’s sensitivity in determining density changes was 5.26%, 84.1% and 93.02% in steps 2, 7, and 12 respectively. Conclusions: Our new method has an acceptable sensitivity for determining density changes of at least 7 mmEq/Al. PMID:28127317

  8. Current status on the application of image processing of digital intraoral radiographs amongst general dental practitioners.

    PubMed

    Tohidast, Parisa; Shi, Xie-Qi

    2016-01-01

    The objectives of this study were to present the subjective knowledge level and the use of image processing on digital intraoral radiographs amongst general dental practitioners at Distriktståndvrden AB, Stockholm. A questionnaire, consisting of12 questions, was sent to 12 dental prac- tices in Stockholm. Additionally, 2000 radiographs were randomly selected from these clinics for evaluation of applied image processing and its effect on image quality. Descriptive and analytical statistical methods were applied to present the current status of the use of image proces- sing alternatives for the dentists' daily clinical work. 50 out of 53 dentists participated in the survey.The survey showed that most of dentists in.this study had received education on image processing at some stage of their career. No correlations were found between application of image processing on one side and educa- tion received with regards to image processing, previous working experience, age and gender on the other. Image processing in terms of adjusting brightness and contrast was frequently used. Overall, in this study 24.5% of the 200 images were actually image processed in practice, in which 90% of the images were improved or maintained in image quality. According to our survey, image processing is experienced to be frequently used by the dentists at Distriktstandvåden AB for diagnosing anatomical and pathological changes using intraoral radiographs. 24.5% of the 200 images were actually image processed in terms of adjusting brightness and/or contrast. In the present study we did not found that the dentists' age, gender, previous working experience and education in image processing influence their viewpoint towards the application of image processing.

  9. Radiation dosage reduction in general dental practice using digital intraoral radiographic systems.

    PubMed

    Hayakawa, Y; Shibuya, H; Ota, Y; Kuroyanagi, K

    1997-02-01

    This report describes the radiation dosage reduction possible in the general dental practice with two CCD (charge-coupled device)-based intraoral radiographic systems: the RVG-S (Trophy Radiologie, Vincennes, France) and the Sens-A-Ray (Regam Medical Systems, Sundsvall, Sweden). Radiation dosages (air-kerma; Gy) necessary for obtaining clinically acceptable images were measured at the cone tip using an ionization chamber type 660-1 (Nuclear Associates, Victoreen, Inc., Carle Place, New York, USA). When the RVG-S was used with an Oramatic 70 (Trophy Radiologie) X-ray generator, dosages at the cone tip ranged from 322 to 612 microGy. These corresponded to 40-60% of the dosages necessary when using Ektaspeed dental X-ray film (Eastman Kodak, Rochester, New York, USA) with a Heliodent 70 (Siemens, Erlangen, Germany) X-ray generator. At 60 kVp, the Sens-A-Ray reduced the dosage in the order of 30% compared with Ektaspeed dental X-ray film. Reduction in radiation dosage is one of the benefits of digital intraoral radiographic systems in general dental clinics. The RVG-S provides greater dose savings than does the Sens-A-Ray.

  10. Semi-automated location identification of catheters in digital chest radiographs

    NASA Astrophysics Data System (ADS)

    Keller, Brad M.; Reeves, Anthony P.; Cham, Matthew D.; Henschke, Claudia I.; Yankelevitz, David F.

    2007-03-01

    Localization of catheter tips is the most common task in intensive care unit imaging. In this work, catheters appearing in digital chest radiographs acquired by portable chest x-rays were tracked using a semi-automatic method. Due to the fact that catheters are synthetic objects, its profile does not vary drastically over its length. Therefore, we use forward looking registration with normalized cross-correlation in order to take advantage of a priori information of the catheter profile. The registration is accomplished with a two-dimensional template representative of the catheter to be tracked generated using two seed points given by the user. To validate catheter tracking with this method, we look at two metrics: accuracy and precision. The algorithms results are compared to a ground truth established by catheter midlines marked by expert radiologists. Using 12 objects of interest comprised of naso-gastric, endo-tracheal tubes, and chest tubes, and PICC and central venous catheters, we find that our algorithm can fully track 75% of the objects of interest, with a average tracking accuracy and precision of 85.0%, 93.6% respectively using the above metrics. Such a technique would be useful for physicians wishing to verify the positioning of catheter tips using chest radiographs.

  11. Evaluation of a digital learning object (DLO) to support the learning process in radiographic dental diagnosis.

    PubMed

    Busanello, F H; da Silveira, P F; Liedke, G S; Arús, N A; Vizzotto, M B; Silveira, H E D; Silveira, H L D

    2015-11-01

    Studies have shown that inappropriate therapeutic strategies may be adopted if crown and root changes are misdiagnosed, potentially leading to undesirable consequences. Therefore, the aim of this study was to evaluate a digital learning object, developed to improve skills in diagnosing radiographic dental changes. The object was developed using the Visual Basic Application (VBA) software and evaluated by 62 undergraduate students (male: 24 and female: 38) taking an imaging diagnosis course. Participants were divided in two groups: test group, which used the object and control group, which attended conventional classes. After 3 weeks, students answered a 10-question test and took a practice test to diagnose 20 changes in periapical radiographs. The results show that test group performed better that control group in both tests, with statistically significant difference (P = 0.004 and 0.003, respectively). In overall, female students were better than male students. Specific aspects of object usability were assessed using a structured questionnaire based on the System Usability Scale (SUS), with a score of 90.5 and 81.6 by male and female students, respectively. The results obtained in this study suggest that students who used the DLO performed better than those who used conventional methods. This suggests that the DLO may be a useful teaching tool for dentistry undergraduates, on distance learning courses and as a complementary tool in face-to-face teaching. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. GPU acceleration for digitally reconstructed radiographs using bindless texture objects and CUDA/OpenGL interoperability.

    PubMed

    Abdellah, Marwan; Eldeib, Ayman; Owis, Mohamed I

    2015-01-01

    This paper features an advanced implementation of the X-ray rendering algorithm that harnesses the giant computing power of the current commodity graphics processors to accelerate the generation of high resolution digitally reconstructed radiographs (DRRs). The presented pipeline exploits the latest features of NVIDIA Graphics Processing Unit (GPU) architectures, mainly bindless texture objects and dynamic parallelism. The rendering throughput is substantially improved by exploiting the interoperability mechanisms between CUDA and OpenGL. The benchmarks of our optimized rendering pipeline reflect its capability of generating DRRs with resolutions of 2048(2) and 4096(2) at interactive and semi interactive frame-rates using an NVIDIA GeForce 970 GTX device.

  13. Flash Dent: an alternative charge-coupled device/scintillator-based direct digital intraoral radiographic system.

    PubMed

    Scarfe, W C; Farman, A G; Kelly, M S

    1994-02-01

    The Flash Dent digital intraoral radiographic system is yet to be described in the scientific literature. A Windows operating environment, a lens based optical scintillator charge-coupled device (CCD) and 'IMG' image format are the major features which distinguish this from other available systems. In this paper we describe the component of the Flash Dent system, investigate the validity of the X-ray generator specifications, determine comparative image doses and assess the performance of the intraoral sensor. Although we found Flash Dent software facilitates image processing, X-ray generator operation, sensor performance and dimensional measurements, inconsistencies between sensors and the use of a non-standard image format require further consideration for improvements on the part of the manufacturer.

  14. Image quality of film transparency printer output of digital dental radiographs.

    PubMed

    Sakurai, Takashi; Matsumoto, Yukiko; Onoyama, Kazuo; Kawamata, Ryota; Kashima, Isamu

    2005-04-01

    The purpose of this study was to evaluate the physical properties of the film transparency output of a printer and its potential use in dental radiography. A color printer (Sony UP-D70XR) was used to produce film transparencies of digital radiographs. A physical evaluation for the image quality was conducted including measurements of the image density reproducibility, the dose response function, the root mean square (RMS) granularity and the modulation transfer function (MTF). The characteristic curve of the hard copy image produced a nonlinear, sigmoid response for pixel value or x-ray absorbed dose. The RMS of the scan parallel direction was greater than that of the scan perpendicular direction in low density areas, but it reversed beyond density 1.3. The MTF of the scan perpendicular direction was superior to that of the scan parallel direction. It was suggested that further examination of the image qualities of this printer is worthwhile.

  15. Contrast, noise, and blur affect performance and appreciation of digital radiographs.

    PubMed

    van Overveld, I M

    1995-11-01

    We have studied the effect of the simultaneous variation of contrast, noise, and blur on the perceived quality of digital radiograph images. Three images were processed with different levels of roentgen photon noise, different luminance (gray-level) ranges, and different amounts of Gaussian blur. Observers had to rate the quality of the images on a numerical scale. To study how the quality judgment is related to the visibility of small details (diagnostic quality), an artificial detail was added to each image. The detail could be in two possible locations. The visibility of this detail was measured in a two-alternative forced-choice experiment. One of the conclusions is that the quality judgment was based mainly on blur, whereas the visibility of details was affected mostly by noise.

  16. Digital radiographic evaluation of alveolar bone loss, density and lamina dura integrity on post splinting mandibular anterior with chronic periodontitis

    NASA Astrophysics Data System (ADS)

    Rafini, F.; Priaminiarti, M.; Sukardi, I.; Lessang, R.

    2017-08-01

    The healing of periodontal splinting can be detected both with clinical and radiographic examination. In this study, the alveolar bone was evaluated by radiographic digital periapical analysis. Periodontal tooth splinting is periodontal support therapy used to prevent periodontal injury during repair and regeneration of periodontal therapy. Radiographic digital periapical analysis of alveolar bone in the mandibular anterior region with chronic periodontitis and 2/3 cervical bone loss after three months of periodontal splinting. Eighty four proximal site (43 mesial and 41 distal) from 16 patients with chronic periodontitis and treated with spinting were examined by taking periapical digital radiographic at day 1 and 91. The bone loss, bone density and utility of lamina dura were evaluated. The statistical analysis after three months evaluation using T-test for bone loss, Wilcoxon sign rank test for bone density and utility lamina dura showed no significantly differences (p<0.05) (p=0.44, 0.256 and 0.059). No radiographic change in bone loss, bone density and utility of lamina dura from chronic periodontitis with 2/3 alveolar bone loss after three months splinting.

  17. Alternative X-ray filters for an intra-oral digital radiographic system

    PubMed Central

    Stecke, J; Cruz, AD; Almeida, SM; Bóscolo, FN

    2012-01-01

    Objective The aim of this study was to evaluate the effect of the modulation of the radiation spectrum with the use of alternative X-ray filters in the quality of intra-oral digital images from storage phosphor plates. Methods The radiographic exposures were performed in a GE 1000 X-ray machine (General Electric Co., Milwaukee, WI), operating at 65 kVp, 10 mA, 40 cm focus receptor distance using three different exposure times: 0.05 s, 0.16 s and 0.35 s. The control filter (GC) was 100% aluminium (Al) with a thickness of 1.5 mm. The tested filters were: G1, 97% Al and 3% copper (Cu) with 1.47 mm thickness; G2, 96% Al and 4% Cu with 1.53 mm thickness; G3, 95% Al and 5% zinc (Zn) with 1.56 mm thickness; G4, 98% Al and 2% Zn with 1.5 mm thickness; and G5, 95% Cu and 5% Zn with 1.6 mm thickness. For formation of the image, a 12-step Al wedge (each step with increments of 1 mm in thickness) was radiographed 10 times. Pixel values measured in digital images were converted into optical density (OD). Results All replicates showed OD with high reproducibility (r > 0.95) for all exposure times and tested filters. In comparison between filters, statistically significant differences in density (p < 0.05) were observed. The OD curve of the G5 filter in all exposure times and G3 filter in an exposure time of 0.05 s showed changes in shape (p < 0.05). Conclusions Excluding the G5 filter, all others tested filters can be used as a substitute for GC without losses in image quality. PMID:22282509

  18. The contributions of Hans-Dieter Rösler: pioneer of digit ratio (2D:4D) research.

    PubMed

    Voracek, Martin; Dressler, Stefan G; Loibl, Lisa Mariella

    2008-12-01

    Over the past decade, the second-to-fourth digit ratio (2D:4D), a putative biomarker for the organizational (permanent) effects of prenatal androgens on the human brain, body, and behavior, has received extensive research attention in psychology. This account makes more widely accessible the contributions of the German psychologist, Hans-Dieter Rösler, an early, for a long time unnoticed, predecessor of modern 2D:4D research. In the mid-1950s, Rösler collected a massive sample of hand outline drawings, totalling nearly 7,000 individuals, ranging in age from 1 mo. to 70 yr. With regard to the distal finger-extent pattern, Rösler differentiated radial (longer index than ring finger), ulnar (reversed pattern), and intermediate hand types, which reflect higher (more female-typical), lower (more male-typical), and intermediate 2D:4D, respectively. Here is summarized Rösler's research. In a series of investigations into the hand types, he reported on their anatomical bases, unsuitability for paternity testing, developmental changes, heritability, sex, side, and occupational group differences, and associations with left-handedness, manual dexterity, mental retardation, and clinodactyly. Based on new data from 313 male and 316 female adults, hand type is further shown to be only a weak proxy of actual 2D:4D, leaving 75% of the interindividual variation in 2D:4D unexplained. Notwithstanding these shortcomings of the hand-type method, Rösler's work from the 1950s still has the potential to inform modern 2D:4D research, as it contains a multitude of testable hypotheses not yet picked up by current research.

  19. Endurance running and digit ratio (2D:4D): implications for fetal testosterone effects on running speed and vascular health.

    PubMed

    Manning, John T; Morris, Laura; Caswell, Noreen

    2007-01-01

    There is anatomical and physiological evidence that endurance running (ER), i.e., running one or more kilometers using aerobic metabolism, originated early in the evolution of Homo, and the consequences of early selection for ER may be important in modern Homo. Here we examine ER performance in competitive ER. ER is sex dependent such that men tend to run faster than women, and the influence of sex on ER suggests that it may be modified by testosterone (T). It is shown that a putative proxy for prenatal T, the ratio of the length of the 2nd and 4th digits (2D:4D), is correlated with ER. Thus performance in training for ER was associated with high prenatal T, as measured by low 2D:4D, in both men and women. In cross-country races from 1 to 4 miles, 2D:4D explained about 25% of the variance in both male and female ER. Therefore, speed in ER was dependent on a proxy for prenatal T. 2D:4D correlates with performance in sport and exercises, which test a mix of strength and fitness, but the associations are in general quite weak with 2D:4D accounting for less than 10% of the variance in performance. Our finding that 2D:4D explains about 25% of the variance in ER suggests that prenatal T is important in determining efficiency in aerobic exercise. Early populations of Homo may have been strongly selected for ER and high prenatal T. The implications of this for patterns of predisposition to cardiovascular disease in modern Homo are discussed. Copyright 2007 Wiley-Liss, Inc.

  20. Evaluation of developmental dental anomalies in digital panoramic radiographs in Southeast Iranian Population

    PubMed Central

    Saberi, Eshagh Ali; Ebrahimipour, Sediqe

    2016-01-01

    Objectives: The objective of this study was to evaluate the prevalence of dental developmental anomalies in digital panoramic radiographs of the patients referred to the Zahedan medical imaging center and to evaluate the frequency of anomalies regarding the disorders in shape, position and number in the Southeast of Iran. Materials and Methods: A total of 1172 panoramic radiographs from 581 males and 586 females aged over 16 years were obtained from the files of the Zahedan medical imaging center between the years of 2014 and 2015. The selected radiographs were evaluated in terms of the anomalies such as dilacerations, taurodontism, supernumerary teeth, congenitally missing teeth, fusion, gemination, tooth impaction, tooth transposition, dens invagination, and peg lateral. Then, the anomalies were compared to each other regarding the frequency of the anomaly type (morphological, positional and numerical). Data were evaluated using descriptive statistics such as frequency and percent, and statistical tests such as X2 at 0.05 significant level using the Statistical Package for the Social Sciences version 16.5. Results: The prevalence of dental anomaly was 213 (18.17%), which was higher in females (9.90) than male, (8.28), however, this difference was not statistically significant (P > 0.05). The prevalence of dilacerated teeth was 62 (5.29%), taurodontism 63 (5.38%), supernumerary teeth 6 (0.51%), congenitally missing teeth 13 (1.11%), fusion 1 (0.09%), gemination 1 (0.09%), impaction 40 (3.41%), transposition 2 (0.18%), dens invagination 16 (1.37) and peg lateral was 9 (0.77%). The prevalence of morphological anomaly was 152 (71.36%), malposition 42 (19.72%) and numerous anomaly was 19 (8.92%). Conclusions: Dental anomalies are relatively common; although their occurrence is not symptomatic, they can lead to several clinical problems in patients. Detailed clinical and radiographic assessment and counseling during patient visits is a critical factor in assessing the

  1. A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging.

    PubMed

    Gallio, Elena; Rampado, Osvaldo; Gianaria, Elena; Bianchi, Silvio Diego; Ropolo, Roberto

    2015-01-01

    Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems) were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies.

  2. A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging

    PubMed Central

    Gallio, Elena; Rampado, Osvaldo; Gianaria, Elena; Bianchi, Silvio Diego; Ropolo, Roberto

    2015-01-01

    Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems) were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies. PMID:26545097

  3. Revealing Invisible Beauty, Ultra Detailed: The Influence of Low Cost UV Exposure on Natural History Specimens in 2D+ Digitization

    PubMed Central

    Brecko, Jonathan; Mathys, Aurore; Dekoninck, Wouter; De Ceukelaire, Marleen; VandenSpiegel, Didier; Semal, Patrick

    2016-01-01

    Digitization of the natural history specimens usually occurs by taking detailed pictures from different sides or producing 3D models. Additionally this is normally limited to imaging the specimen while exposed by light of the visual spectrum. However many specimens can see in or react to other spectra as well. Fluorescence is a well known reaction to the ultraviolet (UV) spectrum by animals, plants, minerals etc. but rarely taken into account while examining natural history specimens. Our tests show that museum specimens still fluoresce when exposed to UV light of 395 nm and 365 nm, even after many years of preservation. When the UV exposure is used in the digitization of specimens using our low cost focus stacking (2D+) setup, the resulting pictures reveal more detail than the conventional 2D+ images. Differences in fluorescence using 395 nm or 365 nm UV lights were noticed, however there isn’t a preferred wavelength as some specimens react more to the first, while others have better results with the latter exposure. Given the increased detail and the low cost of the system, UV exposure should be considered while digitizing natural history museum collections. PMID:27536993

  4. Revealing Invisible Beauty, Ultra Detailed: The Influence of Low Cost UV Exposure on Natural History Specimens in 2D+ Digitization.

    PubMed

    Brecko, Jonathan; Mathys, Aurore; Dekoninck, Wouter; De Ceukelaire, Marleen; VandenSpiegel, Didier; Semal, Patrick

    2016-01-01

    Digitization of the natural history specimens usually occurs by taking detailed pictures from different sides or producing 3D models. Additionally this is normally limited to imaging the specimen while exposed by light of the visual spectrum. However many specimens can see in or react to other spectra as well. Fluorescence is a well known reaction to the ultraviolet (UV) spectrum by animals, plants, minerals etc. but rarely taken into account while examining natural history specimens. Our tests show that museum specimens still fluoresce when exposed to UV light of 395 nm and 365 nm, even after many years of preservation. When the UV exposure is used in the digitization of specimens using our low cost focus stacking (2D+) setup, the resulting pictures reveal more detail than the conventional 2D+ images. Differences in fluorescence using 395 nm or 365 nm UV lights were noticed, however there isn't a preferred wavelength as some specimens react more to the first, while others have better results with the latter exposure. Given the increased detail and the low cost of the system, UV exposure should be considered while digitizing natural history museum collections.

  5. Can we see enough? A comparative study of film-screen vs digital radiographs in small lesions in rheumatoid arthritis.

    PubMed

    van der Jagt, E J; Hofman, S; Kraft, B M; van Leeuwen, M A

    2000-01-01

    The aim of this study was to evaluate the performance of digital radiography in the detection of early very small erosions and joint space narrowing in the hands and feet in rheumatoid arthritis. Fifty-three sets of film-screen and digital radiographs of the same hands and feet with very small and sometimes questionable lesions (possible erosions and cysts) were scored independently two times by four investigators. The percentage of lesions found in exactly the same position for each investigator was calculated. Intra-observer agreement between first and second reading in film-screen radiography was 64-76 % (mean 67 %), and in digital radiographs 60-71 % (mean 64 %). Agreement between film-screen and digital radiographs ranged from 54 to 64 % (mean 58 %) in the first reading and from 56 to 66 % (mean 62 %) in the second reading. Overall agreement between both techniques between first and second reading ranged between 62 and 73 % (mean 65 %). Digital radiography of the hands and feet can be used in patients suspected of rheumatoid arthritis and in follow-up of those patients, because small and early erosions can be seen equally well with the digital technique as compared with the conventional film-screen technique.

  6. Multi-imaging capabilities of a 2D diffraction grating in combination with digital holography.

    PubMed

    Paturzo, Melania; Merola, Francesco; Ferraro, Pietro

    2010-04-01

    In this Letter we report on an alternative approach to get multiple images in microscopy, exploiting the capabilities of both a lithium niobate diffraction grating and digital holographic technique. We demonstrate that multi-imaging can be achieved in a lensless configuration by using a hexagonal diffraction grating but overcoming, thanks to digital holography (DH), the many constrains imposed by the grating parameters in multi-imaging with Talbot effect or Talbot array illuminators. In fact, DH permits the numerical reconstruction of the optical field diffracted by the grating, thus obtaining in-focus multiple images in a plane different from the fractional or entire Talbot ones.

  7. Digital Transfer Growth of Patterned 2D Metal Chalcogenides by Confined Nanoparticle Evaporation

    SciTech Connect

    Mahjouri-Samani, Masoud; Tian, Mengkun; Wang, Kai; Boulesbaa, Abdelaziz; Rouleau, Christopher M.; Puretzky, Alexander A.; McGuire, Michael A.; Srijanto, Bernadeta R.; Xiao, Kai; Eres, Gyula; Duscher, Gerd; Geohegan, David B.

    2014-10-19

    Developing methods for the facile synthesis of two-dimensional (2D) metal chalcogenides and other layered materials is crucial for emerging applications in functional devices. Controlling the stoichiometry, number of the layers, crystallite size, growth location, and areal uniformity is challenging in conventional vapor phase synthesis. Here, we demonstrate a new route to control these parameters in the growth of metal chalcogenide (GaSe) and dichalcogenide (MoSe2) 2D crystals by precisely defining the mass and location of the source materials in a confined transfer growth system. A uniform and precise amount of stoichiometric nanoparticles are first synthesized and deposited onto a substrate by pulsed laser deposition (PLD) at room temperature. This source substrate is then covered with a receiver substrate to form a confined vapor transport growth (VTG) system. By simply heating the source substrate in an inert background gas, a natural temperature gradient is formed that evaporates the confined nanoparticles to grow large, crystalline 2D nanosheets on the cooler receiver substrate, the temperature of which is controlled by the background gas pressure. Large monolayer crystalline domains (~ 100 m lateral sizes) of GaSe and MoSe2 are demonstrated, as well as continuous monolayer films through the deposition of additional precursor materials. This novel PLD-VTG synthesis and processing method offers a unique approach for the controlled growth of large-area, metal chalcogenides with a controlled number of layers in patterned growth locations for optoelectronics and energy related applications.

  8. Digital 2D-photogrammetry and direct anthropometry--a comparing study on test accomplishment and measurement data.

    PubMed

    Franke-Gromberg, Christine; Schüler, Grit; Hermanussen, Michael; Scheffler, Christiane

    2010-01-01

    The aim of this methodological anthropometric study was to compare direct anthropometry and digital two-dimensional photogrammetry in 18 male and 27 female subjects, aged 24 to 65 years, from Potsdam, Germany. In view of the rising interest in reliable biometric kephalofacial data, we focussed on head and face measurements. Out of 34 classic facial anatomical landmarks, 27 landmarks were investigated both by direct anthropometry and 2D-photogrammetry; 7 landmarks could not be localized by 2D-photogrammetry. Twenty-six kephalofacial distances were analysed both by direct anthropometry and digital 2D-photogrammetry. Kephalofacial distances are on average 7.6% shorter when obtained by direct anthropometry. The difference between the two techniques is particularly evident in total head height (vertex-gnathion) due to the fact that vertex is usually covered by hair and escapes from photogrammetry. Also the distances photographic sellion-gnathion (1.3 cm, i. e. 11.6%) and nasal-gnathion (1.2 cm, i. e. 9.4%) differ by more than one centimetre. Differences below 0.5 cm between the two techniques were found when measuring mucosa-lip-height (2.2%), gonia (3.0%), glabella-stomion (3.9%), and nose height (glabella-subnasal) (4.0%). Only the estimates of forehead width were significantly narrower when obtained by 2D-photogrammetry (-1.4 cm, -13.1%). The methodological differences increased with increasing magnitude of the kephalometric distance. Apart from these limitations, both techniques are similarly valid and may replace each other.

  9. The function-transferring model construction for X-ray digital radiographic system

    NASA Astrophysics Data System (ADS)

    Xiao, Wang; Yan, Han; Guo, Wenming

    2008-02-01

    This paper is aimed at presenting a renovated model-building method of transfer function for industrial X-ray digital radiography based on the amorphous silicon X-ray flat-panel detector. The system, known as point-spreading function (PSF), is composed of three parts: the system geometrical dispersion with a non-spot power source, the scintillating screen dispersion and the aperture sampling of the pixel detector. For the innovation purpose, we have first of all established a mathematical simulation of the PSF and the modulation transfer function (MTF) on the basis of analyzing the intensity distribution of X-ray penetration area in each part and by taking Gaussian functions as a mathematical equation for depicting the transfer behavior of each part of the system. And, then, we have worked out the approximately effective bandwidth of the system from its half-wave width. And, finally, by taking the digital radiography based on the flat-panel detector for sampling, the paper has provided a theoretical foundation for the industrial X-ray radiographic testing and measurement operation. In addition, the author has also estimated the validation of the model through experiments and proved that the method helps to make high resolutions of the diacritical tiniest details in the work-pieces, which has shown and will show its technical rationality, technical appropriateness and practical working value.

  10. Digital Transfer Growth of Patterned 2D Metal Chalcogenides by Confined Nanoparticle Evaporation

    DOE PAGES

    Mahjouri-Samani, Masoud; Tian, Mengkun; Wang, Kai; ...

    2014-10-19

    Developing methods for the facile synthesis of two-dimensional (2D) metal chalcogenides and other layered materials is crucial for emerging applications in functional devices. Controlling the stoichiometry, number of the layers, crystallite size, growth location, and areal uniformity is challenging in conventional vapor phase synthesis. Here, we demonstrate a new route to control these parameters in the growth of metal chalcogenide (GaSe) and dichalcogenide (MoSe2) 2D crystals by precisely defining the mass and location of the source materials in a confined transfer growth system. A uniform and precise amount of stoichiometric nanoparticles are first synthesized and deposited onto a substrate bymore » pulsed laser deposition (PLD) at room temperature. This source substrate is then covered with a receiver substrate to form a confined vapor transport growth (VTG) system. By simply heating the source substrate in an inert background gas, a natural temperature gradient is formed that evaporates the confined nanoparticles to grow large, crystalline 2D nanosheets on the cooler receiver substrate, the temperature of which is controlled by the background gas pressure. Large monolayer crystalline domains (~ 100 m lateral sizes) of GaSe and MoSe2 are demonstrated, as well as continuous monolayer films through the deposition of additional precursor materials. This novel PLD-VTG synthesis and processing method offers a unique approach for the controlled growth of large-area, metal chalcogenides with a controlled number of layers in patterned growth locations for optoelectronics and energy related applications.« less

  11. Comparison of maximum intensity projection and digitally reconstructed radiographic projection for carotid artery stenosis measurement

    SciTech Connect

    Hyde, Derek E.; Habets, Damiaan F.; Fox, Allan J.; Gulka, Irene; Kalapos, Paul; Lee, Don H.; Pelz, David M.; Holdsworth, David W.

    2007-07-15

    Digital subtraction angiography is being supplanted by three-dimensional imaging techniques in many clinical applications, leading to extensive use of maximum intensity projection (MIP) images to depict volumetric vascular data. The MIP algorithm produces intensity profiles that are different than conventional angiograms, and can also increase the vessel-to-tissue contrast-to-noise ratio. We evaluated the effect of the MIP algorithm in a clinical application where quantitative vessel measurement is important: internal carotid artery stenosis grading. Three-dimensional computed rotational angiography (CRA) was performed on 26 consecutive symptomatic patients to verify an internal carotid artery stenosis originally found using duplex ultrasound. These volumes of data were visualized using two different postprocessing projection techniques: MIP and digitally reconstructed radiographic (DRR) projection. A DRR is a radiographic image simulating a conventional digitally subtracted angiogram, but it is derived computationally from the same CRA dataset as the MIP. By visualizing a single volume with two different projection techniques, the postprocessing effect of the MIP algorithm is isolated. Vessel measurements were made, according to the NASCET guidelines, and percentage stenosis grades were calculated. The paired t-test was used to determine if the measurement difference between the two techniques was statistically significant. The CRA technique provided an isotropic voxel spacing of 0.38 mm. The MIPs and DRRs had a mean signal-difference-to-noise-ratio of 30:1 and 26:1, respectively. Vessel measurements from MIPs were, on average, 0.17 mm larger than those from DRRs (P<0.0001). The NASCET-type stenosis grades tended to be underestimated on average by 2.4% with the MIP algorithm, although this was not statistically significant (P=0.09). The mean interobserver variability (standard deviation) of both the MIP and DRR images was 0.35 mm. It was concluded that the MIP

  12. Use of a digitally reconstructed radiograph-based computer simulation for the optimisation of chest radiographic techniques for computed radiography imaging systems

    PubMed Central

    Moore, C S; Avery, G; Balcam, S; Needler, L; Swift, A; Beavis, A W; Saunderson, J R

    2012-01-01

    Objectives The purpose of this study was to derive an optimum radiographic technique for computed radiography (CR) chest imaging using a digitally reconstructed radiograph computer simulator. The simulator is capable of producing CR chest radiographs of adults with various tube potentials, receptor doses and scatter rejection. Methods Four experienced image evaluators graded images of average and obese adult patients at different potentials (average-sized, n=50; obese, n=20), receptor doses (n=10) and scatter rejection techniques (average-sized, n=20; obese, n=20). The quality of the images was evaluated using visually graded analysis. The influence of rib contrast was also assessed. Results For average-sized patients, image quality improved when tube potential was reduced compared with the reference (102 kVp). No scatter rejection was indicated. For obese patients, it has been shown that an antiscatter grid is indicated, and should be used in conjunction with as low a tube potential as possible (while allowing exposure times <20 ms). It is also possible to reduce receptor air kerma by 50% without adversely influencing image quality. Rib contrast did not interfere at any tube potential. Conclusions A virtual clinical trial has been performed with simulated chest CR images. Results indicate that low tube potentials (<102 kVp) are optimal for average and obese adults, the former acquired without scatter rejection, the latter with an anti-scatter grid. Lower receptor (and therefore patient doses) than those used clinically are possible while maintaining adequate image quality. PMID:22253349

  13. Use of a digitally reconstructed radiograph-based computer simulation for the optimisation of chest radiographic techniques for computed radiography imaging systems.

    PubMed

    Moore, C S; Avery, G; Balcam, S; Needler, L; Swift, A; Beavis, A W; Saunderson, J R

    2012-09-01

    The purpose of this study was to derive an optimum radiographic technique for computed radiography (CR) chest imaging using a digitally reconstructed radiograph computer simulator. The simulator is capable of producing CR chest radiographs of adults with various tube potentials, receptor doses and scatter rejection. Four experienced image evaluators graded images of average and obese adult patients at different potentials (average-sized, n=50; obese, n=20), receptor doses (n=10) and scatter rejection techniques (average-sized, n=20; obese, n=20). The quality of the images was evaluated using visually graded analysis. The influence of rib contrast was also assessed. For average-sized patients, image quality improved when tube potential was reduced compared with the reference (102 kVp). No scatter rejection was indicated. For obese patients, it has been shown that an antiscatter grid is indicated, and should be used in conjunction with as low a tube potential as possible (while allowing exposure times <20 ms). It is also possible to reduce receptor air kerma by 50% without adversely influencing image quality. Rib contrast did not interfere at any tube potential. A virtual clinical trial has been performed with simulated chest CR images. Results indicate that low tube potentials (<102 kVp) are optimal for average and obese adults, the former acquired without scatter rejection, the latter with an anti-scatter grid. Lower receptor (and therefore patient doses) than those used clinically are possible while maintaining adequate image quality.

  14. The effects of image compression on quantitative measurements of digital panoramic radiographs

    PubMed Central

    Apaydın, Burcu; Yılmaz, Hasan-Hüseyin

    2012-01-01

    Objectives: The aims of this study were to explore how image compression affects density, fractal dimension, linear and angular measurements on digital panoramic images and assess inter and intra-observer repeatability of these measurements. Study Design: Sixty-one digital panoramic images in TIFF format (Tagged Image File Format) were compressed to JPEG (Joint Photographic Experts Group) images. Two observers measured gonial angle, antegonial angle, mandibular cortical width, coronal pulp width of maxillary and mandibular first molar, tooth length of maxillary and mandibular first molar on the left side of these images twice. Fractal dimension of the selected regions of interests were calculated and the density of each panoramic radiograph as a whole were also measured on TIFF and JPEG compressed images. Intra-observer and inter-observer consistency was evaluated with Cronbach’s alpha. Paired samples t-test and Kolmogorov-Smirnov test was used to evaluate the difference between the measurements of TIFF and JPEG compressed images. Results: The repeatability of angular measurements had the highest Cronbach’s alpha value (0.997). There was statistically significant difference for both of the observers in mandibular cortical width (MCW) measurements (1st ob. p: 0.002; 2nd ob. p: 0.003), density (p<0.001) and fractal dimension (p<0.001) between TIFF and JPEG images. There was statistically significant difference for the first observer in antegonial angle (1st ob p< 0.001) and maxillary molar coronal pulp width (1st ob. p<0.001) between JPEG and TIFF files. Conclusions: The repeatability of angular measurements is better than linear measurements. Mandibular cortical width, fractal dimension and density are affected from compression. Observer dependent factors might also cause statistically significant differences between the measurements in TIFF and JPEG images. Key words:Digital panoramic radiography, image compression, linear measurements, angular measurements

  15. New requirements for digital radiographic testing of welds according to ISO standards

    SciTech Connect

    Zscherpel, U.; Ewert, U.; Jechow, M.

    2013-01-25

    Users of EN 14784-2 (general principles for computed radiography with phosphor imaging plates) reported about difficulties to achieve testing class B in weld testing with imaging plates. One of the reasons is the insufficient consideration of the inherent detector unsharpness (u{sub i}) in the minimum requirements. Digital detectors have a higher inherent unsharpness compared to film, which can even exceed the geometrical unsharpness (u{sub g}) of the typical contact technique. In EN 444 and ISO 5579 (general principles for film radiography) u{sub i} is neglected for the calculation of the minimum source-to-object distance (SOD), because it is small compared to the geometric unsharpness (u{sub g}). Considering u{sub i} for digital detectors results in a new equation for SOD (see ISO/FDIS 17636-2). Therefore, the increase in total image unsharpness requires the compensation by a larger SOD to reduce u{sub g}. This contribution discusses the need for change of the SOD for different setups (detectors, focal spots, etc.) and explains the difference in image quality, achieved on basis of the extended equation of ISO/FDIS 17636-2. Furthermore, the detection of image quality indicators depends on the achieved Contrast-to-Noise ratio (CNR) and total image unsharpness. Both of them are essential parameters, which influence the contrast sensitivity. Additionally, new compensation principles (e.g. compensation of missing spatial resolution by enhanced contrast sensitivity) allow to widen the application range of digital detectors for radiographic weld testing.

  16. Digital radiographs displayed on different devices: effect on the detection of vertical root fractures.

    PubMed

    Vasconcelos, T V; Santaella, G M; Nascimento, H A R; Rovaris, K; Ambrosano, G M B; Freitas, D Q

    2016-04-01

    To evaluate whether the type of display device affects the detection of vertical root fractures (VRFs) on digital radiographs in unfilled canals and canals with fibreglass posts. Forty single-rooted human teeth were decoronated, and the root canals were prepared. The teeth were divided into 2 groups: controls (20 teeth) and with VRF (20 teeth). The VRFs were induced using an universal testing machine. Periapical radiographs of all teeth, with canal unfilled or with a fibreglass post, were obtained using the parallel technique in 3 directions (ortho-, mesio- and distoradial) on storage phosphor plates (VistaScan®). All images were evaluated and re-evaluated after 30 days by 3 examiners on a 5-point scale using 4 different devices (notebook display with full high definition resolution, desktop display with a standard resolution, 8-inch Android(™) tablet with high definition resolution and a 9.7-inch iPad® tablet with Retina resolution). Areas under ROC curves, sensitivity, specificity and accuracy values were compared by anova. The weighted kappa values for intra- and interobserver reproducibility were 0.55-0.88 and 0.31-0.65, respectively. There was a significant difference (P < 0.05) in relation to the area under the ROC curve, specificity and sensitivity when unfilled canals were compared with canals with a fibreglass post; however, no difference was observed for the different devices studied. The type of display device did not affect the detection of VRFs. Thus, the detection of VRFs can be performed using different screen sizes and resolutions. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  17. Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study.

    PubMed

    de Molon, Rafael Scaf; Morais-Camillo, Juliana Aparecida Najarro Dearo; Sakakura, Celso Eduardo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara

    2012-12-01

    This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC(95%):6.04-6.54) and 6.79 mm (IC(95%):6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm(IC(95%):6.40-6.89) and 6.79mm(IC(95%):6.45-7.11), respectively. The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

  18. The second to fourth digit ratio (2D:4D): a risk factor of migraine and tension-type headache.

    PubMed

    Xie, Wei; He, Mianwang; Liu, Ruozhuo; Dong, Zhao; Xie, Jingdan; Wang, Dan; Yu, Shengyuan

    2015-02-11

    Migraine and Tension-type headache (TTH) are common and disabling primary headache disorders. They are more prevalent in females. The second to fourth digit ratio (2D:4D) is sexually dimorphic in humans and is considered to be a marker for the balance of prenatal testosterone and estrogen exposure. Therefore, we investigated the hypothesis that prenatal sex steroids constitute an independent risk factor for adult headaches later in life. A total of 891 individuals (303 males, 588 females) of 18-68 years in age (a mean of 37.0 ± 10.1 years), including 279 migraine, 300 TTH, and 312 healthy subjects were enrolled. The 2D:4D ratio was measured by a single investigator using a digital Vernier caliper. The females in the migraine group had lower 2D:4D ratios than those in the control group (left hand: 0.947 ± 0.034 vs. 0.955 ± 0.038, p = 0.048; right hand: 0.952 ± 0.035 vs. 0.965 ± 0.037, p = 0.001). There was a similar relationship between the TTH group and the control group (left hand: 0.946 ± 0.034 vs. 0.955 ± 0.038, p = 0.034; right hand: 0.954 ± 0.035 vs. 0.965 ± 0.037, p = 0.005), although this was not observed in males. Males showed lower 2D:4D ratios than females for the right hand in the control group (0.954 ± 0.039 vs. 0.965 ± 0.037, p = 0.015). No significant difference was found in the left hand. These results suggested that the 2D:4D ratio is a risk factor of migraine and TTH and that the balance of prenatal estrogen and testosterone in utero may impact adult primary headache disorders.

  19. Can digit ratio (2D:4D) studies be helpful in explaining the aetiology of idiopathic gynecomastia?

    PubMed

    Kasielska-Trojan, Anna; Antoszewski, Bogusław

    2015-01-01

    Aetiology of idiopathic form of gynecomastia is unknown and it has not been established if it is related to factors present at the prenatal period or if it is caused by yet unidentified environmental conditions. The aim of this study is to compare digit ratio (2D:4D) in men with idiopathic gynecomastia and unaffected male and female controls from the general population. The study involved 250 subjects (50 men with idiopathic gynecomastia, 100 control men and 100 control women). Eight measurements were taken: body height, waist and hip circumferences, II and IV digits' lengths (right and left), and body weight, and 4 indices were calculated: BMI, WHR, and 2D:4D for the right and left hand. 2D:4D in men with gynecomastia ([median (I-III quartiles)]: 1.03 (1.01-1.04) for right hand and 1.03 (1.01-1.03) for left hand) was significantly different than the ratio in control men [0.97 (0.95-0.99)] for right and left hand) (p<0.0001) and similar to the ratio found in control women [1.02 (1-1.03)] for right and left hand) (p=1). Men with gynecomastia were characterized with higher values of the following variables: weight, waist and hip circumferences, BMI and WHR. Their body height was significantly greater than in women (p<0.0001) but similar to the values observed in control men (p=0.2687). The findings presented in this study may influence the aetiology-related classification of gynecomastia and justify introducing the new group: "gynecomastia related to the prenatal sex hormones disturbances". Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Patterns of second-to-fourth digit length ratios (2D:4D) in two species of frogs and two species of lizards at La Selva, Costa Rica.

    PubMed

    Direnzo, Graziella Vittoria; Stynoski, Jennifer Lynn

    2012-04-01

    It is now well documented that androgen and estrogen signaling during early development cause a sexual dimorphism in second-to-fourth digit length ratio (2D:4D). It is also well documented that males of mammalian species have a smaller 2D:4D than females. Although there are discrepancies among 2D:4D studies in birds, the consensus is that birds exhibit the opposite pattern with males having a larger 2D:4D than females. The literature currently lacks substantial information regarding the phylogenetic pattern of this trait in amphibians and reptiles. In this study, we examined 2D:4D in two species of frogs (Oophaga pumilio and Craugastor bransfordii) and two species of lizards (Anolis humilis and Anolis limifrons) to determine the existence and the pattern of the sexual dimorphism. Male O. pumilio and C. bransfordii displayed larger 2D:4D than females in at least one of their two forelimbs. Male A. humilis had larger 2D:4D than females in both hindlimbs, but smaller 2D:4D than females in both forelimbs. Male A. limifrons may also have smaller 2D:4D than females in the right forelimb. Finally, digit ratios were sometimes positively related to body length, suggesting allometric growth. Overall, our results support the existence of the 2D:4D sexual dimorphism in amphibians and lizards and add to the knowledge of 2D:4D trait patterning among tetrapods. Copyright © 2012 Wiley Periodicals, Inc.

  1. Experimental validation of 2D uncertainty quantification for digital image correlation.

    SciTech Connect

    Reu, Phillip L.

    2010-03-01

    Because digital image correlation (DIC) has become such an important and standard tool in the toolbox of experimental mechanicists, a complete uncertainty quantification of the method is needed. It should be remembered that each DIC setup and series of images will have a unique uncertainty based on the calibration quality and the image and speckle quality of the analyzed images. Any pretest work done with a calibrated DIC stereo-rig to quantify the errors using known shapes and translations, while useful, do not necessarily reveal the uncertainty of a later test. This is particularly true with high-speed applications where actual test images are often less than ideal. Work has previously been completed on the mathematical underpinnings of DIC uncertainty quantification and is already published, this paper will present corresponding experimental work used to check the validity of the uncertainty equations.

  2. Impact of lens distortions on strain measurements obtained with 2D digital image correlation

    NASA Astrophysics Data System (ADS)

    Lava, P.; Van Paepegem, W.; Coppieters, S.; De Baere, I.; Wang, Y.; Debruyne, D.

    2013-05-01

    The determination of strain fields based on displacements obtained via digital image correlation (DIC) at the micro-strain level (≤1000 μm/m) is still a cumbersome task. In particular when high-strain gradients are involved, e.g. in composite materials with multidirectional fibre reinforcement, uncertainties in the experimental setup and errors in the derivation of the displacement fields can substantially hamper the strain identification process. In this contribution, the aim is to investigate the impact of lens distortions on strain measurements. To this purpose, we first perform pure rigid body motion experiments, revealing the importance of precise correction of lens distortions. Next, a uni-axial tensile test on a textile composite with spatially varying high strain gradients is performed, resulting in very accurately determined strains along the fibers of the material.

  3. HipMatch: an object-oriented cross-platform program for accurate determination of cup orientation using 2D-3D registration of single standard X-ray radiograph and a CT volume.

    PubMed

    Zheng, Guoyan; Zhang, Xuan; Steppacher, Simon D; Murphy, Stephen B; Siebenrock, Klaus A; Tannast, Moritz

    2009-09-01

    The widely used procedure of evaluation of cup orientation following total hip arthroplasty using single standard anteroposterior (AP) radiograph is known inaccurate, largely due to the wide variability in individual pelvic orientation relative to X-ray plate. 2D-3D image registration methods have been introduced for an accurate determination of the post-operative cup alignment with respect to an anatomical reference extracted from the CT data. Although encouraging results have been reported, their extensive usage in clinical routine is still limited. This may be explained by their requirement of a CAD model of the prosthesis, which is often difficult to be organized from the manufacturer due to the proprietary issue, and by their requirement of either multiple radiographs or a radiograph-specific calibration, both of which are not available for most retrospective studies. To address these issues, we developed and validated an object-oriented cross-platform program called "HipMatch" where a hybrid 2D-3D registration scheme combining an iterative landmark-to-ray registration with a 2D-3D intensity-based registration was implemented to estimate a rigid transformation between a pre-operative CT volume and the post-operative X-ray radiograph for a precise estimation of cup alignment. No CAD model of the prosthesis is required. Quantitative and qualitative results evaluated on cadaveric and clinical datasets are given, which indicate the robustness and the accuracy of the program. HipMatch is written in object-oriented programming language C++ using cross-platform software Qt (TrollTech, Oslo, Norway), VTK, and Coin3D and is transportable to any platform.

  4. Radiographic Evaluation of the Status of Third Molars in Sriganganagar Population - A Digital Panoramic Study.

    PubMed

    Goyal, Sharry; Verma, Pradhuman; Raj, Seetharamaiha Sunder

    2016-11-01

    Third molar (M3) agenesis and impaction are associated with evolution, changed dietary habits, and human jaw growth. The aim of the study was to radiographically evaluate the prevalence of M3s agenesis, impacted M3s with different impaction patterns, and the approximation of Inferior Dental Canal (IDC) with impacted mandibular M3s roots among the Sriganganagar population. The study included 700 randomly selected subjects from OPD with an age range of 25-45 years. Digital OPGs were taken for all subjects using Kodak 8000C digital OPG machine. The M3 impaction patterns were evaluated using Winter's classification. The prevalence of subjects with at least one M3 agenesis was found to be 34.1% and with 95% confidence interval was 30.6% to 37.6%. The overall M3s agenesis was 16.8% with more prevalence in the males. The patients with agenesis of one M3, two M3s, three M3s, and four M3s were 14.4%, 11.3%, 3.7% and 4.7%, respectively. M3 agenesis was more in the upper jaw and on the left side. The total impacted M3s were 21.11% with more prevalence in mixed diet subjects. Mesioangular was most common impaction pattern, and notching was most prevalent IDC relationship with impacted mandibular M3s roots. This study highlighted the evolutionary increasing M3 agenesis and the importance of diagnostic OPG for seeing the status of M3s in jaws.

  5. Radiographic Evaluation of the Status of Third Molars in Sriganganagar Population – A Digital Panoramic Study

    PubMed Central

    Goyal, Sharry; Verma, Pradhuman; Raj, Seetharamaiha Sunder

    2016-01-01

    Background Third molar (M3) agenesis and impaction are associated with evolution, changed dietary habits, and human jaw growth. The aim of the study was to radiographically evaluate the prevalence of M3s agenesis, impacted M3s with different impaction patterns, and the approximation of Inferior Dental Canal (IDC) with impacted mandibular M3s roots among the Sriganganagar population. Methods The study included 700 randomly selected subjects from OPD with an age range of 25–45 years. Digital OPGs were taken for all subjects using Kodak 8000C digital OPG machine. The M3 impaction patterns were evaluated using Winter’s classification. Results The prevalence of subjects with at least one M3 agenesis was found to be 34.1% and with 95% confidence interval was 30.6% to 37.6%. The overall M3s agenesis was 16.8% with more prevalence in the males. The patients with agenesis of one M3, two M3s, three M3s, and four M3s were 14.4%, 11.3%, 3.7% and 4.7%, respectively. M3 agenesis was more in the upper jaw and on the left side. The total impacted M3s were 21.11% with more prevalence in mixed diet subjects. Mesioangular was most common impaction pattern, and notching was most prevalent IDC relationship with impacted mandibular M3s roots. Conclusion This study highlighted the evolutionary increasing M3 agenesis and the importance of diagnostic OPG for seeing the status of M3s in jaws. PMID:28090184

  6. Digital breast tomosynthesis: application of 2D digital mammography CAD to detection of microcalcification clusters on planar projection image

    NASA Astrophysics Data System (ADS)

    Samala, Ravi K.; Chan, Heang-Ping; Lu, Yao; Hadjiiski, Lubomir; Wei, Jun; Helvie, Mark

    2015-03-01

    Computer-aided detection (CAD) has the potential to aid radiologists in detection of microcalcification clusters (MCs). CAD for digital breast tomosynthesis (DBT) can be developed by using the reconstructed volume, the projection views or other derivatives as input. We have developed a novel method of generating a single planar projection (PPJ) image from a regularized DBT volume to emphasize the high contrast objects such as microcalcifications while removing the anatomical background and noise. In this work, we adapted a CAD system developed for digital mammography (CADDM) to the PPJ image and compared its performance with our CAD system developed for DBT volumes (CADDBT) in the same set of cases. For microcalcification detection in the PPJ image using the CADDM system, the background removal preprocessing step designed for DM was not needed. The other methods and processing steps in the CADDM system were kept without modification while the parameters were optimized with a training set. The linear discriminant analysis classifier using cluster based features was retrained to generate a discriminant score to be used as decision variable. For view-based FROC analysis, at 80% sensitivity, an FP rate of 1.95/volume and 1.54/image were achieved, respectively, for CADDBT and CADDM in an independent test set. At a threshold of 1.2 FPs per image or per DBT volume, the nonparametric analysis of the area under the FROC curve shows that the optimized CADDM for PPJ is significantly better than CADDBT. However, the performance of CADDM drops at higher sensitivity or FP rate, resulting in similar overall performance between the two CAD systems. The higher sensitivity of the CADDM in the low FP rate region and vice versa for the CADDBT indicate that a joint CAD system combining detection in the DBT volume and the PPJ image has the potential to increase the sensitivity and reduce the FP rate.

  7. Magnification rate of digital panoramic radiographs and its effectiveness for pre-operative assessment of dental implants

    PubMed Central

    Kim, Y-K; Park, J-Y; Kim, S-G; Kim, J-S; Kim, J-D

    2011-01-01

    Objectives The purpose of this study was to determine the accuracy and effectiveness of digital panoramic radiographs for pre-operative assessment of dental implants. Methods We selected 86 patients (221 implants) and calculated the length of the planned implant based on the distance between a selection of critical anatomical structures and the alveolar crest using the scaling tools provided in the digital panoramic system. We analysed the magnification rate and the difference between the actual inserted implant length and planned implant length according to the location of the implant placement and the clarity of anatomical structures seen in the panoramic radiographs. Results There was no significant difference between the planned implant length and actual inserted implant length (P > 0.05). The magnification rate of the width and length of the inserted implants, seen in the digital panoramic radiographs, was 127.28 ± 13.47% and 128.22 ± 4.17%, respectively. The magnification rate of the implant width was largest in the mandibular anterior part and there was a significant difference in the magnification rate of the length of implants between the maxilla and the mandible (P < 0.05). When the clarity of anatomical structures seen in the panoramic radiographs is low, the magnification rate of the width of the inserted implants is significantly higher (P < 0.05), but there is no significant difference between the planned implant length and actual inserted implant length according to the clarity of anatomical structures (P < 0.05). Conclusions Digital panoramic radiography can be considered a simple, readily available and considerably accurate pre-operative assessment tool in the vertical dimension for dental implant therapy. PMID:21239569

  8. A method to produce and validate a digitally reconstructed radiograph-based computer simulation for optimisation of chest radiographs acquired with a computed radiography imaging system

    PubMed Central

    Moore, C S; Liney, G P; Beavis, A W; Saunderson, J R

    2011-01-01

    Objectives The purpose of this study was to develop and validate a computer model to produce realistic simulated computed radiography (CR) chest images using CT data sets of real patients. Methods Anatomical noise, which is the limiting factor in determining pathology in chest radiography, is realistically simulated by the CT data, and frequency-dependent noise has been added post-digitally reconstructed radiograph (DRR) generation to simulate exposure reduction. Realistic scatter and scatter fractions were measured in images of a chest phantom acquired on the CR system simulated by the computer model and added post-DRR calculation. Results The model has been validated with a phantom and patients and shown to provide predictions of signal-to-noise ratios (SNRs), tissue-to-rib ratios (TRRs: a measure of soft tissue pixel value to that of rib) and pixel value histograms that lie within the range of values measured with patients and the phantom. The maximum difference in measured SNR to that calculated was 10%. TRR values differed by a maximum of 1.3%. Conclusion Experienced image evaluators have responded positively to the DRR images, are satisfied they contain adequate anatomical features and have deemed them clinically acceptable. Therefore, the computer model can be used by image evaluators to grade chest images presented at different tube potentials and doses in order to optimise image quality and patient dose for clinical CR chest radiographs without the need for repeat patient exposures. PMID:21933979

  9. Detection of microcalcification clusters by 2D-mammography and narrow and wide angle digital breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Hadjipanteli, Andria; Elangovan, Premkumar; Looney, Padraig T.; Mackenzie, Alistair; Wells, Kevin; Dance, David R.; Young, Kenneth C.

    2016-03-01

    The aim of this study was to compare the detection of microcalcification clusters by human observers in breast images using 2D-mammography and narrow (15°/15 projections) and wide (50°/25 projections) angle digital breast tomosynthesis (DBT). Simulated microcalcification clusters with a range of microcalcification diameters (125 μm-275 μm) were inserted into 6 cm thick simulated compressed breasts. Breast images were produced with and without inserted microcalcification clusters using a set of image modelling tools, which were developed to represent clinical imaging by mammography and tomosynthesis. Commercially available software was used for image processing and image reconstruction. The images were then used in a series of 4-alternative forced choice (4AFC) human observer experiments conducted for signal detection with the microcalcification clusters as targets. The minimum detectable calcification diameter was found for each imaging modality: (i) 2D-mammography: 164+/-5 μm (ii) narrow angle DBT: 210+/-5 μm, (iii) wide angle DBT: 255+/-4 μm. A statistically significant difference was found between the minimum detectable calcification diameters that can be detected by the three imaging modalities. Furthermore, it was found that there was not a statistically significant difference between the results of the five observers that participated in this study. In conclusion, this study presents a method that quantifies the threshold diameter required for microcalcification detection, using high resolution, realistic images with observers, for the comparison of DBT geometries with 2D-mammography. 2Dmammography can visualise smaller detail diameter than both DBT imaging modalities and narrow-angle DBT can visualise a smaller detail diameter than wide-angle DBT.

  10. The Effect Of Pixel Size On The Detection Rate Of Early Pulmonary Sarcoidosis In Digital Chest Radiographic Systems

    NASA Astrophysics Data System (ADS)

    MacMahon, Heber; Vyborny, Carl; Powell, Gregory; Doi, Kunio; Metz, Charles E.

    1984-08-01

    In digital radiography the pixel size used determines the potential spatial resolution of the system. The need for spatial resolution varies depending on the subject matter imaged. In many areas, including the chest, the minimum spatial resolution requirements have not been determined. Sarcoidosis is a disease which frequently causes subtle interstitial infiltrates in the lungs. As the initial step in an investigation designed to determine the minimum pixel size required in digital chest radiographic systems, we have studied 1 mm pixel digitized images on patients with early pulmonary sarcoidosis. The results of this preliminary study suggest that neither mild interstitial pulmonary infiltrates nor other abnormalities such as pneumothoraces may be detected reliably with 1 mm pixel digital images.

  11. Multichannel response analysis on 2D projection views for detection of clustered microcalcifications in digital breast tomosynthesis

    SciTech Connect

    Wei, Jun Chan, Heang-Ping; Hadjiiski, Lubomir M.; Helvie, Mark A.; Lu, Yao; Zhou, Chuan; Samala, Ravi

    2014-04-15

    Purpose: To investigate the feasibility of a new two-dimensional (2D) multichannel response (MCR) analysis approach for the detection of clustered microcalcifications (MCs) in digital breast tomosynthesis (DBT). Methods: With IRB approval and informed consent, a data set of two-view DBTs from 42 breasts containing biopsy-proven MC clusters was collected in this study. The authors developed a 2D approach for MC detection using projection view (PV) images rather than the reconstructed three-dimensional (3D) DBT volume. Signal-to-noise ratio (SNR) enhancement processing was first applied to each PV to enhance the potential MCs. The locations of MC candidates were then identified with iterative thresholding. The individual MCs were decomposed with Hermite–Gaussian (HG) and Laguerre–Gaussian (LG) basis functions and the channelized Hotelling model was trained to produce the MCRs for each MC on the 2D images. The MCRs from the PVs were fused in 3D by a coincidence counting method that backprojects the MC candidates on the PVs and traces the coincidence of their ray paths in 3D. The 3D MCR was used to differentiate the true MCs from false positives (FPs). Finally a dynamic clustering method was used to identify the potential MC clusters in the DBT volume based on the fact that true MCs of clinical significance appear in clusters. Using two-fold cross validation, the performance of the 3D MCR for classification of true and false MCs was estimated by the area under the receiver operating characteristic (ROC) curve and the overall performance of the MCR approach for detection of clustered MCs was assessed by free response receiver operating characteristic (FROC) analysis. Results: When the HG basis function was used for MCR analysis, the detection of MC cluster achieved case-based test sensitivities of 80% and 90% at the average FP rates of 0.65 and 1.55 FPs per DBT volume, respectively. With LG basis function, the average FP rates were 0.62 and 1.57 per DBT volume at

  12. Multi-view learning based robust collimation detection in digital radiographs

    NASA Astrophysics Data System (ADS)

    Mao, Hongda; Peng, Zhigang; Dennerlein, Frank; Shinagawa, Yoshihisa; Zhan, Yiqiang; Zhou, Xiang Sean

    2014-03-01

    In X-ray examinations, it is essential that radiographers carefully use collimation to the appropriate anatomy of interest to minimize the overall integral dose to the patient. The shadow regions are not diagnostically meaningful and could impair the overall image quality. Thus, it is desirable to detect the collimation and exclude the shadow regions to optimize image display. However, due to the large variability of collimated images, collimation detection remains a challenging task. In this paper, we consider a region of interest (ROI) in an image, such as the collimation, can be described by two distinct views, a cluster of pixels within the ROI and the corners of the ROI. Based on this observation, we propose a robust multi-view learning based strategy for collimation detection in digital radiography. Specifically, one view is from random forests learning based region detector, which provides pixel-wise image classification and each pixel is labeled as either in-collimation or out-of-collimation. The other view is from a discriminative, learning-based landmark detector, which detects the corners and localizes the collimation within the image. Nevertheless, given the huge variability of the collimated images, the detection from either view alone may not be perfect. Therefore, we adopt an adaptive view fusing step to obtain the final detection by combining region and corner detection. We evaluate our algorithm in a database with 665 X-ray images in a wide variety of types and dosages and obtain a high detection accuracy (95%), compared with using region detector alone (87%) and landmark detector alone (83%).

  13. Improved human observer performance in digital reconstructed radiograph verification in head and neck cancer radiotherapy.

    PubMed

    Sturgeon, Jared D; Cox, John A; Mayo, Lauren L; Gunn, G Brandon; Zhang, Lifei; Balter, Peter A; Dong, Lei; Awan, Musaddiq; Kocak-Uzel, Esengul; Mohamed, Abdallah Sherif Radwan; Rosenthal, David I; Fuller, Clifton David

    2015-10-01

    Digitally reconstructed radiographs (DRRs) are routinely used as an a priori reference for setup correction in radiotherapy. The spatial resolution of DRRs may be improved to reduce setup error in fractionated radiotherapy treatment protocols. The influence of finer CT slice thickness reconstruction (STR) and resultant increased resolution DRRs on physician setup accuracy was prospectively evaluated. Four head and neck patient CT-simulation images were acquired and used to create DRR cohorts by varying STRs at 0.5, 1, 2, 2.5, and 3 mm. DRRs were displaced relative to a fixed isocenter using 0-5 mm random shifts in the three cardinal axes. Physician observers reviewed DRRs of varying STRs and displacements and then aligned reference and test DRRs replicating daily KV imaging workflow. A total of 1,064 images were reviewed by four blinded physicians. Observer errors were analyzed using nonparametric statistics (Friedman's test) to determine whether STR cohorts had detectably different displacement profiles. Post hoc bootstrap resampling was applied to evaluate potential generalizability. The observer-based trial revealed a statistically significant difference between cohort means for observer displacement vector error ([Formula: see text]) and for [Formula: see text]-axis [Formula: see text]. Bootstrap analysis suggests a 15% gain in isocenter translational setup error with reduction of STR from 3 mm to [Formula: see text]2 mm, though interobserver variance was a larger feature than STR-associated measurement variance. Higher resolution DRRs generated using finer CT scan STR resulted in improved observer performance at shift detection and could decrease operator-dependent geometric error. Ideally, CT STRs [Formula: see text]2 mm should be utilized for DRR generation in the head and neck.

  14. Improved human observer performance in digital reconstructed radiograph verification in head and neck cancer radiotherapy

    PubMed Central

    Sturgeon, Jared D.; Cox, John A.; Mayo, Lauren L.; Gunn, G. Brandon; Zhang, Lifei; Balter, Peter A.; Dong, Lei; Awan, Musaddiq; Kocak-Uzel, Esengul; Mohamed, Abdallah Sherif Radwan; Rosenthal, David I.

    2016-01-01

    Purpose Digitally reconstructed radiographs (DRRs) are routinely used as an a priori reference for setup correction in radiotherapy. The spatial resolution of DRRs may be improved to reduce setup error in fractionated radiotherapy treatment protocols. The influence of finer CT slice thickness reconstruction (STR) and resultant increased resolution DRRs on physician setup accuracy was prospectively evaluated. Methods Four head and neck patient CT-simulation images were acquired and used to create DRR cohorts by varying STRs at 0.5, 1, 2, 2.5, and 3 mm. DRRs were displaced relative to a fixed isocenter using 0–5 mm random shifts in the three cardinal axes. Physician observers reviewed DRRs of varying STRs and displacements and then aligned reference and test DRRs replicating daily KV imaging workflow. A total of 1,064 images were reviewed by four blinded physicians. Observer errors were analyzed using nonparametric statistics (Friedman’s test) to determine whether STR cohorts had detectably different displacement profiles. Post hoc bootstrap resampling was applied to evaluate potential generalizability. Results The observer-based trial revealed a statistically significant difference between cohort means for observer displacement vector error (p = 0.02) and for Z-axis (p < 0.01). Bootstrap analysis suggests a 15% gain in isocenter translational setup error with reduction of STR from 3 mm to ≤2 mm, though interobserver variance was a larger feature than STR-associated measurement variance. Conclusions Higher resolution DRRs generated using finer CT scan STR resulted in improved observer performance at shift detection and could decrease operator-dependent geometric error. Ideally, CT STRs ≤2 mm should be utilized for DRR generation in the head and break neck. PMID:25477277

  15. A method to incorporate the effect of beam quality on image noise in a digitally reconstructed radiograph (DRR) based computer simulation for optimisation of digital radiography

    NASA Astrophysics Data System (ADS)

    Moore, Craig S.; Wood, Tim J.; Saunderson, John R.; Beavis, Andrew W.

    2017-09-01

    The use of computer simulated digital x-radiographs for optimisation purposes has become widespread in recent years. To make these optimisation investigations effective, it is vital simulated radiographs contain accurate anatomical and system noise. Computer algorithms that simulate radiographs based solely on the incident detector x-ray intensity (‘dose’) have been reported extensively in the literature. However, while it has been established for digital mammography that x-ray beam quality is an important factor when modelling noise in simulated images there are no such studies for diagnostic imaging of the chest, abdomen and pelvis. This study investigates the influence of beam quality on image noise in a digital radiography (DR) imaging system, and incorporates these effects into a digitally reconstructed radiograph (DRR) computer simulator. Image noise was measured on a real DR imaging system as a function of dose (absorbed energy) over a range of clinically relevant beam qualities. Simulated ‘absorbed energy’ and ‘beam quality’ DRRs were then created for each patient and tube voltage under investigation. Simulated noise images, corrected for dose and beam quality, were subsequently produced from the absorbed energy and beam quality DRRs, using the measured noise, absorbed energy and beam quality relationships. The noise images were superimposed onto the noiseless absorbed energy DRRs to create the final images. Signal-to-noise measurements in simulated chest, abdomen and spine images were within 10% of the corresponding measurements in real images. This compares favourably to our previous algorithm where images corrected for dose only were all within 20%.

  16. Evolution of sexual dimorphism in the digit ratio 2D:4D--relationships with body size and microhabitat use in iguanian lizards.

    PubMed

    Gomes, Camilla M; Kohlsdorf, Tiana

    2011-01-01

    The ratio between lengths of digit II and IV (digit ratio 2D:4D) is a morphological feature that likely affects tetrapod locomotor performances in different microhabitats. Modifications of this trait may be triggered by changes in steroids concentrations during embryo development, which might reflect direct selection acting on digit ratio or be solely a consequence of hormonal differences related for example to body size. Here we apply both conventional and phylogenetic analyses on morphological data from 25 lizard species of 3 families of Iguania (Iguanidae, Polychrotidae, and Tropiduridae), in order to verify whether selective pressures related to locomotion in different microhabitats could override the prenatal developmental cues imposed on the digit ratio 2D:4D by differences in body size between males and females. Data suggest that this trait evolved in association with ecological divergence in the species studied, despite the clear effect of body size on the digit ratio 2D:4D. The ecological associations of size-corrected digit ratios were restricted to one sex, and females of species that often use perches exhibited small digit ratios in the front limbs, which translated into larger sexual dimorphism indexes of arboreal species. The results, together with the subsequent discussion, provide outlines for further investigation about possible developmental mechanisms related to the evolution of adaptive changes in digit lengths that may have occurred during the evolution of ecological divergence in squamates.

  17. Evolution of Sexual Dimorphism in the Digit Ratio 2D:4D - Relationships with Body Size and Microhabitat Use in Iguanian Lizards

    PubMed Central

    Gomes, Camilla M.; Kohlsdorf, Tiana

    2011-01-01

    The ratio between lengths of digit II and IV (digit ratio 2D:4D) is a morphological feature that likely affects tetrapod locomotor performances in different microhabitats. Modifications of this trait may be triggered by changes in steroids concentrations during embryo development, which might reflect direct selection acting on digit ratio or be solely a consequence of hormonal differences related for example to body size. Here we apply both conventional and phylogenetic analyses on morphological data from 25 lizard species of 3 families of Iguania (Iguanidae, Polychrotidae, and Tropiduridae), in order to verify whether selective pressures related to locomotion in different microhabitats could override the prenatal developmental cues imposed on the digit ratio 2D:4D by differences in body size between males and females. Data suggest that this trait evolved in association with ecological divergence in the species studied, despite the clear effect of body size on the digit ratio 2D:4D. The ecological associations of size-corrected digit ratios were restricted to one sex, and females of species that often use perches exhibited small digit ratios in the front limbs, which translated into larger sexual dimorphism indexes of arboreal species. The results, together with the subsequent discussion, provide outlines for further investigation about possible developmental mechanisms related to the evolution of adaptive changes in digit lengths that may have occurred during the evolution of ecological divergence in squamates. PMID:22162772

  18. Influence of education level and experience on detection of approximal caries in digital dental radiographs. An in vitro study.

    PubMed

    Hellén-Halme, Kristina; Petersson, Gunnel Hänsel

    2010-01-01

    This study evaluated whether variations in education level and experience among dental staff influence the diagnostic accuracy of carious lesions on digital radiographs. Three student groups and a fourth group of general practitioners (Dentists) with more than five years of clinical experience participated in this study.The student groups were (i) dental students in their final (tenth) semester (DS-10), (ii) dental students in the sixth semester (DS-6) who just finished dental radiology training, and (iii) dental hygiene students (DHS) in their final (fourth) semester. Seven observers from each group participated. Standard radiographs of 100 extracted teeth (premolars and molars) were taken. The 28 observers evaluated the images for approximal carious lesions on a standard monitor. All evaluations were made in ambient light below 50 lux. Receiver operating characteristic curves were plotted to assess results. The standard criterion for healthy or carious lesions was a histological examination of sliced teeth. Kappa statistics evaluated intra-observer agreement. For carious lesions that had extended into the dentine, significant differences were found between (i) Dentists and all other groups, (ii) Dentists and DS-10 (p < 0.01), and (iii) Dentists and DS-6 and DHS (p < 0.001). Differences between DS-10 and DHS (p < or = 0.05) were also significant. In this study, education level and experience clearly influenced the diagnostic accuracy of approximal carious lesions that had extended into the dentine on digital radiographs.

  19. The Left Hand Second to Fourth Digit Ratio (2D:4D) Is Not Related to Any Physical Fitness Component in Adolescent Girls

    PubMed Central

    Peeters, Maarten W.; Van Aken, Katrijn; Claessens, Albrecht L.

    2013-01-01

    Introduction The second to fourth-digit-ratio (2D:4D), a putative marker of prenatal androgen action and a sexually dimorphic trait, has been suggested to be related with fitness and sports performance, although results are not univocal. Most studies however focus on a single aspect of physical fitness or one sports discipline. Methods In this study the 2D:4D ratio of 178 adolescent girls (age 13,5–18 y) was measured on X-rays of the left hand. The relation between 2D:4D digit ratio and multiple aspects of physical fitness (balance, speed of limb movement, flexibility, explosive strength, static strength, trunk strength, functional strength, running speed/agility, and endurance) was studied by correlation analyses and stepwise multiple regression. For comparison the relation between these physical fitness components and a selected number of objectively measured anthropometric traits (stature, mass, BMI, somatotype components and the Bayer & Bailey androgyny index) are presented alongside the results of 2D:4D digit ratio. Results Left hand 2D:4D digit ratio (0.925±0.019) was not significantly correlated with any of the physical fitness components nor any of the anthropometric variables included in the present study. 2D:4D did not enter the multiple stepwise regression for any of the physical fitness components in which other anthropometric traits explained between 9,2% (flexibility) and 33,9% (static strength) of variance. Conclusion Unlike other anthropometric traits the 2D:4D digit ratio does not seem to be related to any physical fitness component in adolescent girls and therefore most likely should not be considered in talent detection programs for sporting ability in girls. PMID:23565167

  20. Digit ratio (2D:4D), sex differences, allometry, and finger length of 12-30-year olds: evidence from the British Broadcasting Corporation (BBC) Internet study.

    PubMed

    Manning, John T

    2010-01-01

    Many studies have reported digit ratio (2D:4D) to be sexually dimorphic, (males lower 2D:4D than females). However, Kratochvíl and Flegr ([2009]: Biol Lett 5:643-646) have suggested that 2D regressed on 4D has an allometric regression line with nonzero Y-intercept that is shared by males and females. Thus, 2D is shorter than expected when 4D is long, and males have lower 2D:4D than females because they have longer fingers. In this study, it is shown that this suggestion may be incorrect because sex differences in slope were not considered. Participants were recruited in an Internet study and had an age range of 12-30 years. The expected sex difference in 2D:4D was found, and the regression of 2D on 4D showed a significant sex difference in slope (males lower than females). A comparison of 10 age groups (12 years, 13 years..., 21-30 years) showed that sexual dimorphism for fingers was age dependent, varying from monomorphic to very dimorphic. Changes in sexual dimorphism of 2D:4D were much less marked, but there was a significant reduction in mean 2D:4D with age. The tendency for slopes of 2D regressed on 4D to be lower in males compared with females was significant in eight age groups. Sex difference in 2D:4D varied across the age groups and was positively related to the magnitude of the difference in female and male slopes. In contrast to the report of Kratochvíl and Flegr, it was found that the regression of 2D on 4D showed sex differences in slope, and such differences gave rise to the sexual dimorphism in 2D:4D.

  1. Sex differences in digit ratio (2D:4D) are disrupted in adolescents with schizotypal personality disorder: altered prenatal gonadal hormone levels as a risk factor.

    PubMed

    Walder, Deborah J; Andersson, Terese L C; McMillan, Amanda L; Breedlove, S Marc; Walker, Elaine F

    2006-09-01

    The 2nd to 4th finger digit ratio (2D:4D) is a sexually dimorphic feature determined during gestation indexing prenatal androgen/estrogen levels. More 'feminized' 2D:4D phenotype has been demonstrated in schizophrenia versus same-sex controls. This study examined 2D:4D in adolescents with schizotypal personality disorder (SPD). Among normal controls, right 2D:4D was significantly greater (more feminized) in females than males. We replicated laterality effects; significant sex differences only on right. There were no significant sex differences among SPDs. Diagnostic group differences were restricted to White/Caucasian males with greater right 2D:4D in SPDs. Findings suggest disruptions in prenatal gonadal hormones in vulnerability for schizophrenia.

  2. Digital radiographic evaluation of hand-wrist bone maturation and prediction of age in South Indian adolescents.

    PubMed

    Mohammed, Rezwana Begum; Reddy, M Asha Lata; Jain, Megha; Singh, Johar Rajvinder; Sanghvi, Praveen; Thetay, Anshuj Ajay Rao

    2014-09-01

    In the growing years, indicators of the level of maturational development of the individual provide the best means for evaluating biologic age and the associated timing of skeletal growth. The relative stage of maturity of a child may be determined by comparing the child's hand-wrist radiograph to the known standards of skeletal development. In this study, we assessed various levels of skeletal maturation and also identified the relationship between chronological age (CA) and maturation stage using the hand-wrist radiographs in adolescents of Indian origin. Three hundred and thirty hand-wrist digital radiographs of individuals aged 8 to 18 years were evaluated for skeletal maturity levels using Fishman's method. The data was analysed using the SPSS software package (version 12, SPSS Inc., Chicago, IL, USA). Regression analysis was performed for calculating bone age of both males and females. Spearman's rank-order correlation coefficients were estimated separately for males and females to assess the relation between CA and maturation level. An association between skeletal maturation indicator stages and CA (r = 0.82) was significant. Interestingly, female subjects were observed to be advanced in skeletal maturity compared to males. Regression equations were derived to calculate bone age in males, females and the whole sample. The results of this study showed significant association between hand-wrist skeletal maturation levels and CA. Digital radiographic assessment of hand-wrist skeletal maturation can be used as a better choice for predicting average bone age of an individual because of its simplicity, reliability and lesser radiation exposure.

  3. Assessment of the 3-d reconstruction and high-resolution geometrical modeling of the human skeletal trunk from 2-D radiographic images.

    PubMed

    Delorme, S; Petit, Y; de Guise, J A; Labelle, H; Aubin, C E; Dansereau, J

    2003-08-01

    This paper presents an in vivo validation of a method for the three-dimensional (3-D) high-resolution modeling of the human spine, rib cage, and pelvis for the study of spinal deformities. The method uses an adaptation of a standard close-range photogrammetry method called direct linear transformation to reconstruct the 3-D coordinates of anatomical landmarks from three radiographic images of the subject's trunk. It then deforms in 3-D 1-mm-resolution anatomical primitives (reference bones) obtained by serial computed tomography-scan reconstruction of a dry specimen. The free-form deformation is calculated using dual kriging equations. In vivo validation of this method on 40 scoliotic vertebrae gives an overall accuracy of 3.3 +/- 3.8 mm, making it an adequate tool for clinical studies and mechanical analysis purposes.

  4. Variability amongst radiographers in the categorization of clinical acceptability for digital trauma radiography

    NASA Astrophysics Data System (ADS)

    Decoster, Robin; Toomey, Rachel; Smits, Dirk; Mol, Harrie; Verhelle, Filip; Butler, Marie-Louise

    2016-03-01

    Introduction: Radiographers evaluate anatomical structures to judge clinical acceptability of a radiograph. Whether a radiograph is deemed acceptable for diagnosis or not depends on the individual decision of the radiographer. Individual decisions cause variation in the accepted image quality. To minimise these variations definitions of acceptability, such as in RadLex, were developed. On which criteria radiographers attribute a RadLex categories to radiographs is unknown. Insight into these criteria helps to further optimise definitions and reduce variability in acceptance between radiographers. Therefore, this work aims the evaluation of the correlation between the RadLex classification and the evaluation of anatomical structures, using a Visual Grading Analysis (VGA) Methods: Four radiographers evaluated the visibility of five anatomical structures of 25 lateral cervical spine radiographs on a secondary class display with a VGA. They judged clinical acceptability of each radiograph using RadLex. Relations between VGAS and RadLex category were analysed with Kendall's Tau correlation and Nagelkerke pseudo-R². Results: The overall VGA score (VGAS) and the RadLex score correlate (rτ= 0.62, p<0.01, R2=0.72) strongly. The observers' evaluation of contrast between bone, air (trachea) and soft tissue has low value in predicting (rτ=0.55, p<0.01, R2=0.03) the RadLex score. The reproduction of spinous processes (rτ=0.67, p<0.01, R2=0.31) and the evaluation of the exposure (rτ=0.65, p<0.01, R2=0.56) have a strong correlation with high predictive value for the RadLex score. Conclusion: RadLex scores and VGAS correlate positively, strongly and significantly. The predictive value of bony structures may support the use of these in the judgement of clinical acceptability. Considerable inter-observer variations in the VGAS within a certain RadLex category, suggest that observers use of observer specific cut

  5. Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects

    PubMed Central

    GUIMARÃES, Maria do Carmo Machado; PASSANEZI, Euloir; SANT’ANA, Adriana Campos Passanezi; GREGHI, Sebastião Luiz Aguiar; TABA JUNIOR, Mario

    2010-01-01

    Objectives This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. Material and Methods Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites) or collagen membrane only (control sites). The periodontal healing was clinically and radiographically monitored for six months. Standardized presurgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05). Results As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm2 in the test group and 2 mm2 in the control group (p>0.05). Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05). Conclusions The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions. PMID:20835573

  6. Second-to-fourth digit ratio (2D:4D) is unrelated to measures of somatic reproductive effort among young men from Cebu, the Philippines.

    PubMed

    Georgiev, Alexander V; Ryan, Calen P; Gettler, Lee T; McDade, Thomas W; Kuzawa, Christopher W

    2017-07-01

    A low second-to-fourth (2D:4D) digit ratio, a retrospective marker of high prenatal androgens, predicts increased investment in costly sexually dimorphic traits in men in some studies, although results are mixed. Here we test the hypothesis that the association of low 2D:4D ratios with increased muscularity and decreased adiposity depends on current testosterone (T) levels, such that digit ratio will be a particularly strong predictor of outcomes among men exhibiting a mating-effort-oriented endocrinological profile (high T). We also test the association between 2D:4D and somatic traits independently of T. We related 2D:4D digit ratios, and their interaction with T, to handgrip strength, lean mass, arm muscle area, and skinfold thickness in a sample of young, childess men (20-22 y) from Cebu, Philippines (N = 623). Digit ratio did not significantly predict men's T-dependent somatic traits. Interactions between 2D:4D and morning T, similarly, did not predict male muscularity or adiposity. Although two of the interactions were significant or marginally significant (p < .1), after adjusting for multiple testing the evidence in support of our hypothesis was weak. We found no evidence that 2D:4D predicted measures of somatic reproductive effort in this sample of young men from Cebu, who as a group could be considered mostly mating-oriented. These relationships were also not contingent upon, or stronger, when considering the moderating effect of concurrent T levels. In this sample, 2D:4D was therefore either a poor proxy of prenatal androgen exposure or prenatal androgens had limited influence on adult somatic outcomes. © 2017 Wiley Periodicals, Inc.

  7. Digital radiographic measurement of approximal caries progression in fluoridated and non-fluoridated areas of Rio de Janeiro, Brazil.

    PubMed

    Lawrence, H P; Benn, D K; Sheiham, A

    1997-12-01

    The effect of fluoridation on approximal caries progression was investigated using serial digitized bitewing images and conventional film images of 290 12-16-year-old schoolchildren who were lifetime residents of either Rio de Janeiro (a fluoridated area) or Mangaratiba and Angra dos Reis (non-fluoridated areas) in the state of Rio de Janeiro, Brazil. One examiner scored a maximum of 28 approximal surfaces of posterior teeth per subject using both methods. The intraexaminer reliability for rating lesion depth with digital images was comparable with that of the conventional bitewing films (namely, intraclass correlation of 0.99 and weighted Kappa scores of 0.82, respectively). Approximal surface D1S was 3.17 +/- 0.25 (sx) in fluoridated areas and 6.64 +/- 0.44 in non-fluoridated areas. After 1 year, the rate of caries progression in approximal surfaces was significantly lower in the fluoridated areas (0.54 +/- 0.14) as compared with the non-fluoridated areas (1.41 +/- 0.20) using Pitts' scoring system for conventional bitewing radiographs (P < 0.001). Similarly, the digital radiographic method was able to detect subtle differences in approximal caries progression in the enamel and the dentin (overall mean: 0.34 mm/year in fluoridated areas vs 0.49 mm/year in non-fluoridated areas, P < 0.05). The two radiographic methods were strongly correlated (rs = 0.7). Assuming a constant rate over time, these results indicate that lesion progression from the outer half of the enamel into the outer half of the dentin takes approximately 3-4 years in schoolchildren from the fluoridated areas compared to 2 1/2 years in the non-fluoridated areas.

  8. 2nd to 4th digit ratio (2D:4D) and number of sex partners: evidence for effects of prenatal testosterone in men.

    PubMed

    Hönekopp, Johannes; Voracek, Martin; Manning, John T

    2006-01-01

    The number of sexual partners per individual (NSP) is an important component of sexual behaviour. Here, we report two studies concerning the relationship between a probable negative correlate of prenatal testosterone, the ratio of the length of 2nd and 4th digits (2D:4D), and NSP in men. The right hand 2D:4D ratio appears to be more strongly related to prenatal testosterone than does the left hand. Accordingly we found: (a) in a sample of 99 German heterosexual male undergraduates right hand 2D:4D (but not left hand 2D:4D) was significantly negatively associated with reported lifetime NSP. The relationship between NSP and 2D:4D was independent of free testosterone, but free testosterone also showed a weak positive association with NSP (b) in a sample of 79 heterosexual and 95 homosexual Austrian men we found a significant negative association between right hand 2D:4D (but not left hand 2D:4D) and reported NSP in past year for heterosexual but not for homosexual men. The association in heterosexuals was independent of age, years of education, occupation and relationship status. We conclude that male NSP is likely to be influenced by the long-term organisational effects of prenatal testosterone. The relationship between NSP and 2D:4D appears to be confined to heterosexual men.

  9. Applying a 2D based CAD scheme for detecting micro-calcification clusters using digital breast tomosynthesis images: an assessment

    NASA Astrophysics Data System (ADS)

    Park, Sang Cheol; Zheng, Bin; Wang, Xiao-Hui; Gur, David

    2008-03-01

    Digital breast tomosynthesis (DBT) has emerged as a promising imaging modality for screening mammography. However, visually detecting micro-calcification clusters depicted on DBT images is a difficult task. Computer-aided detection (CAD) schemes for detecting micro-calcification clusters depicted on mammograms can achieve high performance and the use of CAD results can assist radiologists in detecting subtle micro-calcification clusters. In this study, we compared the performance of an available 2D based CAD scheme with one that includes a new grouping and scoring method when applied to both projection and reconstructed DBT images. We selected a dataset involving 96 DBT examinations acquired on 45 women. Each DBT image set included 11 low dose projection images and a varying number of reconstructed image slices ranging from 18 to 87. In this dataset 20 true-positive micro-calcification clusters were visually detected on the projection images and 40 were visually detected on the reconstructed images, respectively. We first applied the CAD scheme that was previously developed in our laboratory to the DBT dataset. We then tested a new grouping method that defines an independent cluster by grouping the same cluster detected on different projection or reconstructed images. We then compared four scoring methods to assess the CAD performance. The maximum sensitivity level observed for the different grouping and scoring methods were 70% and 88% for the projection and reconstructed images with a maximum false-positive rate of 4.0 and 15.9 per examination, respectively. This preliminary study demonstrates that (1) among the maximum, the minimum or the average CAD generated scores, using the maximum score of the grouped cluster regions achieved the highest performance level, (2) the histogram based scoring method is reasonably effective in reducing false-positive detections on the projection images but the overall CAD sensitivity is lower due to lower signal-to-noise ratio

  10. Digit ratio (2D:4D) in Lithuania once and now: testing for sex differences, relations with eye and hair color, and a possible secular change.

    PubMed

    Voracek, Martin; Bagdonas, Albinas; Dressler, Stefan G

    2007-09-01

    The second-to-fourth digit ratio (2D:4D) is a sexually dimorphic somatic trait and has been proposed as a biomarker for the organizational, i.e., permanent, effects of prenatal testosterone on the human brain. Accordingly, recent research has related 2D:4D to a variety of sex-dependent, hormonally influenced traits and phenotypes. The geographical variation in typical 2D:4D is marked and presently poorly understood. This study presents the first investigation into the 2D:4D ratio in a Baltic country. A contemporary sample of 109 Lithuanian men and women was compared with data from a historical sample of 100 Lithuanian men and women, collected and published in the 1880s and rediscovered only now. The findings included the following lines of evidence: (i) seen in an international perspective, the average 2D:4D in Lithuania is low; (ii) there was a sex difference in 2D:4D in the expected direction in both samples; (iii) a previously adduced hypothesis of an association of lighter eye and hair color with higher, i.e., more feminized, 2D:4D received no support in both samples; and (iv) the average 2D:4D in the contemporary sample was higher than in the historical sample. In view of a hypothesized increase in 2D:4D in modern populations, owing to increased environmental levels of endocrine disruptors such as xenoestrogens, this latter finding appears to be of particular notice. However, because finger-length measurement methods differed across the samples, it cannot be safely ruled out that the apparent time trend in Lithuanian 2D:4D in truth is an artifact. The puzzling geographical pattern seen in the 2D:4D ratio and the question of possible time trends therein deserve further investigations.

  11. The second to fourth digit ratio (2D:4D) in a Japanese twin sample: heritability, prenatal hormone transfer, and association with sexual orientation.

    PubMed

    Hiraishi, Kai; Sasaki, Shoko; Shikishima, Chizuru; Ando, Juko

    2012-06-01

    The second to fourth digit ratio has been argued to reflect prenatal hormonal influences and is reportedly associated with various psychological and behavioral traits, such as sexual orientation, cognitive abilities, and personality. We examined genetic and environmental influences on the second to fourth digit ratio (2D:4D) using a Japanese twin sample (N=300). The genetic analysis showed substantial additive genetic influences for both right and left hand 2D:4D. The rest of the variance was explained mainly by environmental influences not shared within twin pairs. These findings were, in general, in accordance with preceding studies with primarily Caucasian twin samples. The bivariate genetic analysis revealed that the additive genetic influences were largely shared between the right and left hand, while the non-shared environmental influences were largely unique to each hand. Results from a comparison of opposite-sex and same-sex twins were not significant, although they were in the predicted direction according to the prenatal hormone transfer hypothesis. Female monozygotic twin pairs discordant in sexual orientation showed significant within-pair differences in left hand 2D:4D, where non-heterosexual twins had lower (more masculinized) 2D:4D. In addition, we found that non-heterosexual male MZ twins had larger (more feminized) 2D:4D than their heterosexual co-twins. These results suggest the existence of non-shared environmental influences that affect both 2D:4D and sexual orientation.

  12. Digit ratio (2D:4D): Is it possible to use it for sex determination in the study of human skeletal remains?

    PubMed

    Bakholdina, Varvara Yu; Movsesian, Alla A; Sineva, Irina M

    2016-07-01

    Sexual dimorphism in the relative length of the second-to-fourth digits (the digit ratio, or 2D:4D) in humans has been reported in many studies. The aim of our study was to ascertain possibility of using the 2D:4D ratio as an additional marker for sex determination in the study of human skeletal remains. We have studied 2D:4D ratios obtained from measurements of finger phalanges and metacarpal bones in Russian (45 adult males and 26 adult females) and German (58 adult males and 29 adult females) skeletal series. The difference in 2D:4D ratio between the male and female subsamples in both skeletal series was not statistically significant. Analysis of variance revealed that the 2D:4D ratios in our sample varied more by ethnicity than by the sexual identity of the skeletal material. Our results suggest that the 2D:4D ratio cannot be used as an appropriate trait for the sex determination of human skeletal remains. Am. J. Hum. Biol. 28:591-593, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  13. Scaling digital radiographs for templating in total hip arthroplasty using conventional acetate templates independent of calibration markers.

    PubMed

    Brew, Christopher J; Simpson, Philip M; Whitehouse, Sarah L; Donnelly, William; Crawford, Ross W; Hubble, Matthew J W

    2012-04-01

    We describe a scaling method for templating digital radiographs using conventional acetate templates independent of template magnification without the need for a calibration marker. The mean magnification factor for the radiology department was determined (119.8%; range, 117%-123.4%). This fixed magnification factor was used to scale the radiographs by the method described. Thirty-two femoral heads on postoperative total hip arthroplasty radiographs were then measured and compared with the actual size. The mean absolute accuracy was within 0.5% of actual head size (range, 0%-3%) with a mean absolute difference of 0.16 mm (range, 0-1 mm; SD, 0.26 mm). Intraclass correlation coefficient showed excellent reliability for both interobserver and intraobserver measurements with intraclass correlation coefficient scores of 0.993 (95% CI, 0.988-0.996) for interobserver measurements and intraobserver measurements ranging between 0.990 and 0.993 (95% CI, 0.980-0.997). Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  14. Benchmarking the performance of fixed-image receptor digital radiographic systems part 1: a novel method for image quality analysis.

    PubMed

    Lee, Kam L; Ireland, Timothy A; Bernardo, Michael

    2016-06-01

    This is the first part of a two-part study in benchmarking the performance of fixed digital radiographic general X-ray systems. This paper concentrates on reporting findings related to quantitative analysis techniques used to establish comparative image quality metrics. A systematic technical comparison of the evaluated systems is presented in part two of this study. A novel quantitative image quality analysis method is presented with technical considerations addressed for peer review. The novel method was applied to seven general radiographic systems with four different makes of radiographic image receptor (12 image receptors in total). For the System Modulation Transfer Function (sMTF), the use of grid was found to reduce veiling glare and decrease roll-off. The major contributor in sMTF degradation was found to be focal spot blurring. For the System Normalised Noise Power Spectrum (sNNPS), it was found that all systems examined had similar sNNPS responses. A mathematical model is presented to explain how the use of stationary grid may cause a difference between horizontal and vertical sNNPS responses.

  15. Digitized crime scene forensics: automated trace separation of toolmarks on high-resolution 2D/3D CLSM surface data

    NASA Astrophysics Data System (ADS)

    Clausing, Eric; Vielhauer, Claus

    2015-03-01

    Locksmith forensics is an important and very challenging part of classic crime scene forensics. In prior work, we propose a partial transfer to the digital domain, to effectively support forensic experts and present approaches for a full process chain consisting of five steps: Trace positioning, 2D/3D acquisition with a confocal 3D laser scanning microscope, detection by segmentation, trace type determination, and determination of the opening method. In particular the step of trace segmentation on high-resolution 3D surfaces thereby turned out to be the part most difficult to implement. The reason for that is the highly structured and complex surfaces to be analyzed. These surfaces are cluttered with a high number of toolmarks, which overlap and distort each other. In Clausing et al., we present an improved approach for a reliable segmentation of relevant trace regions but without the possibility of separating single traces out of segmented trace regions. However, in our past research, especially features based on shape and dimension turned out to be highly relevant for a fully automated analysis and interpretation. In this paper, we consequently propose an approach for this separation. To achieve this goal, we use our segmentation approach and expand it with a combination of the watershed algorithm with a graph-based analysis. Found sub-regions are compared based on their surface character and are connected or divided depending on their similarity. We evaluate our approach with a test set of about 1,300 single traces on the exemplary locking cylinder component 'key pin' and thereby are able of showing the high suitability of our approach.

  16. Maternal corticosterone but not testosterone level is associated with the ratio of second-to-fourth digit length (2D:4D) in field vole offspring (Microtus agrestis).

    PubMed

    Lilley, Thomas; Laaksonen, Toni; Huitu, Otso; Helle, Samuli

    2010-03-30

    The steroid environment encountered by a foetus can strongly affect its post-natal physiology and behaviour. It has been proposed that steroid concentrations experienced in utero could be estimated from adults by measuring their second-to-fourth digit length ratio (2D:4D). However, there is still little direct evidence that intra-uterine steroid levels affect individual 2D:4D. We examined whether maternal pre-pregnancy testosterone and corticosterone levels (as estimates of intra-uterine testosterone and corticosterone exposure) affected the 2D:4D of pups in non-domesticated field voles (Microtus agrestis), measured by X-rays at the age of weaning (21 days). Furthermore, for the first time in a non-human species, we studied whether testosterone and corticosterone levels correlated with 2D:4D in adult females. We found that the maternal pre-pregnancy level of testosterone was not associated with offspring 2D:4D in either the left or the right paw. Instead, maternal pre-pregnancy corticosterone level was positively correlated with offspring 2D:4D in the right paw, but unrelated to 2D:4D in the left paw. In addition, the 2D:4D of adult females was not associated with either their circulating testosterone or corticosterone levels. Our results suggest that in field voles maternally administered testosterone is not a major determinant of offspring 2D:4D, whereas maternal stress appears to account for some of the variation in the 2D:4D of their offspring. (c) 2009 Elsevier Inc. All rights reserved.

  17. The presence of aggression cues inverts the relation between digit ratio (2D:4D) and prosocial behaviour in a dictator game.

    PubMed

    Millet, Kobe; Dewitte, Siegfried

    2009-02-01

    Digit ratio (2D:4D) is a sexually dimorphic trait. Men have relatively shorter index (2D) compared to ring (4D) fingers than women. More masculine ratios are thought to be influenced by higher prenatal testosterone levels. In the present paper, we aim to show the context-dependency of the relation between 2D:4D and social behaviour. In two studies, we expose participants either to control or to aggression cues. Afterwards, they make a decision in a dictator game. Participants with low 2D:4D showed higher allocation levels (i.e. they were more prosocial) than participants with high 2D:4D in a neutral situation. However, this relationship inverts after exposure to an aggression cue. It turns out that in high 2D:4D people, aggression cues even increase prosocial behaviour. We call for future research which focuses on other plausible interactions between 2D:4D and context cues rather than on linear relations.

  18. Your fate is in your hands? Handedness, digit ratio (2D:4D), and selection to a national talent development system.

    PubMed

    Baker, Joseph; Kungl, Ann-Marie; Pabst, Jan; Strauß, Bernd; Büsch, Dirk; Schorer, Jörg

    2013-01-01

    Over the past decade a small evidence base has highlighted the potential importance of seemingly innocuous variables related to one's hands, such as hand dominance and the relative length of the second and fourth digits (2D:4D ratio), to success in sport. This study compared 2D:4D digit ratio and handedness among handball players selected to advance in a national talent development system with those not selected. Participants included 480 youth handball players (240 females and 240 males) being considered as part of the talent selection programme for the German Youth National team. Hand dominance and digit ratio were compared to age-matched control data using standard t-tests. There was a greater proportion of left-handers compared to the normal population in males but not in females. There was also a lower digit ratio in both females and males. However, there were no differences between those selected for the next stage of talent development and those not selected on either handedness or digit ratio. These results add support for general effects for both digit ratio and handedness in elite handball; however, these factors seem inadequate to explain talent selection decisions at this level.

  19. Errors in calculating A-P tibial contact locations in total knee arthroplasty using 3D model-to-2D image registration in radiographs: An in vitro study of two methods.

    PubMed

    Ross, Derrick; Howell, Stephen; Hull, Maury

    2017-08-17

    Knowledge of A-P tibial contact locations provides an objective assessment of the relative motion of the tibia on the femur following total knee arthroplasty, which can be used to compare the effects of different components, surgical techniques, and alignment goals on knee function in vivo. Both the closest point method and the penetration method have been used to calculate A-P tibial contact locations using 3D model-to-2D image registration. Because the errors in calculating the A-P tibial contact locations using these two methods are unknown, the primary purpose of this study was to determine these errors. The A-P tibial contact locations were calculated with the two methods and simultaneously measured with a tibial force sensor in ten fresh frozen cadaveric knee specimens with a total knee arthroplasty. Single-plane radiographs of the knee specimens were taken at 0°, 30°, 60°, and 90° of flexion in neutrally, internally, and externally rotated orientations. While the radiographs were exposed, reference A-P tibial contact locations were simultaneously collected using the tibial force sensor to be compared to the calculated A-P tibial contact locations. The overall root mean squared errors (RMSEs) in the A-P tibial contact location calculated with the closest point method, the penetration method with penetration, and penetration method without penetration were 5.5 mm, 3.6 mm, and 8.9 mm, respectively. The overall RMSE was lowest for the penetration method with.

  20. From palmistry to anthropometry: can 2nd to 4th digit length (2D:4D) predict the risk of prostate cancer?

    PubMed

    Salomão, Layla; Figueiredo, Rui Teófilo; Oliveira Santos, Rafael; Damião, Ronaldo; da Silva, Eloisio Alexsandro

    2014-01-01

    The 2nd to 4th digit length (2D:4D) is inversely related to androgen exposure during the fetal period, which may represent a risk factor for several steroid-related diseases. We aimed to evaluate the relationship between 2D:4D ratio and the risk of developing prostate cancer (PCa). We assessed the 2D:4D ratio of 474 men >40 years old, stratified into three groups: group 1 (n = 222) patients with PCa, group 2 (n = 82) subjects with high risk of PCa, and group 3 (n = 170) men with low risk of PCa. Subjects were submitted to a digital picture of the ventral surface of the right hand and 2nd and 4th fingers measurements were determined by the distance from the proximal crease to the tip using computer-assisted analysis. The mean serum prostate-specific antigen level was 7.5 ng/ml in the high-risk group and 0.92 ng/ml in the low-risk group (p < 0.05). The mean 2D:4D ratios were 0.96 ± 0.04, 0.97 ± 0.04 and 0.96 ± 0.04 for the PCa, high-risk and low-risk groups, respectively, and no difference was found among the three groups (p = 0.12). Anthropometry of the hand using the 2D:4D ratio is not a predictor of PCa. 2013 S. Karger AG, Basel.

  1. Comparison of 2D Radiographic Images and 3D Cone Beam Computed Tomography for Positioning Head-and-Neck Radiotherapy Patients

    SciTech Connect

    Li Heng; Zhu, X. Ronald Zhang Lifei; Dong Lei; Tung, Sam; Ahamad, Anesa M.D.; Chao, K. S. Clifford; Morrison, William H.; Rosenthal, David I.; Schwartz, David L.; Mohan, Radhe; Garden, Adam S.

    2008-07-01

    Purpose: To assess the positioning accuracy using two-dimensional kilovoltage (2DkV) imaging and three-dimensional cone beam CT (CBCT) in patients with head and neck (H and N) cancer receiving radiation therapy. To assess the benefit of patient-specific headrest. Materials and Methods: All 21 patients studied were immobilized using thermoplastic masks with either a patient-specific vacuum bag (11 of 21, IMA) or standard clear plastic (10 of 21, IMB) headrests. Each patient was imaged with a pair of orthogonal 2DkV images in treatment position using onboard imaging before the CBCT procedure. The 2DkV and CBCT images were acquired weekly during the same session. The 2DkV images were reviewed by oncologists and also analyzed by a software tool based on mutual information (MI). Results: Ninety-eight pairs of assessable 2DkV-CBCT alignment sets were obtained. Systematic and random errors were <1.6 mm for both 2DkV and CBCT alignments. When we compared shifts determined by CBCT and 2DkV for the same patient setup, statistically significant correlations were observed in all three major directions. Among all CBCT couch shifts, 4.1% {>=} 0.5 cm and 18.7% {>=} 0.3 cm, whereas among all 2DkV (MI) shifts, 1.7% {>=} 0.5 cm and 11.2% {>=} 0.3 cm. Statistically significant difference was found on anteroposterior direction between IMA and IMB with the CBCT alignment only. Conclusions: The differences between 2D and 3D alignments were mainly caused by the relative flexibility of certain H and N structures and possibly by rotation. Better immobilization of the flexible neck is required to further reduce the setup errors for H and N patients receiving radiotherapy.

  2. Hand asymmetry in heterosexual and homosexual men and women: relationship to 2D:4D digit ratios and other sexually dimorphic anatomical traits.

    PubMed

    Martin, James T; Puts, David A; Breedlove, S Marc

    2008-02-01

    Sexual differentiation leads to the development of distinctive anatomical structures (e.g., gonads and genitalia); it also produces less obvious anatomical shifts in brain, bones, muscles, etc. This study is a retrospective analysis of growth patterns in the hands in relation to sex and sexual orientation. Using data from three published studies, we analyzed four hand traits in adults: hand width, hand length, second digit length, and fourth digit length. Using these measurements, we derived estimates of trait laterality (directional asymmetry or DA) and developmental instability (fluctuating asymmetry or FA). High FA is a putative indicator of interference with the cellular and molecular mechanisms regulating development. We focused on how these derived variables were related to sex, sexual orientation, and putative markers of early sex steroid exposure (e.g., the second to fourth digit ratio or 2D:4D). Our data point to three principal conclusions. First, individual differences in DA appeared to be a major source of variation in the 2D:4D ratio. The 2D:4D ratios of heterosexual men differed depending on whether they had leftward or rightward DA in their digits. Homosexual women showed the same pattern. Individuals with leftward DA in both digits had lower 2D:4D ratios than those with rightward DA. This effect was absent in heterosexual women and homosexual men. This led to sex differences in 2D:4D and sexual orientation differences in 2D:4D in the leftward DA group, but not in the rightward DA group. The second conclusion was that DA in digit length and hand width varied with sex; women were more likely to have rightward asymmetry than men. Homosexual men and women were generally sex typical in DA. The third conclusion was that homosexuality is unlikely to be a result of increased developmental instability. Although limited in scope, the present evidence actually suggests that homosexuals have lower FA than heterosexuals, raising the question of whether the

  3. Digit ratio (2D:4D) in twins: heritability estimates and evidence for a masculinized trait expression in women from opposite-sex pairs.

    PubMed

    Voracek, Martin; Dressler, Stefan G

    2007-02-01

    The second-to-fourth digit ratio (2D:4D) is sexually dimorphic in humans, such that men on average have a lower 2D:4D than women. This somatic trait has been proposed as a biomarker for the organizational (permanent) effects of prenatal testosterone on the brain and behavior. Over the past few years, an accumulating research program has shown 2D:4D to be related to a multitude of sex-dependent, hormonally influenced psychological and behavioral traits. The present study investigated the 2D:4D ratio of 44 men and 70 women from 36 identical and 21 fraternal twin pairs. Both basic and advanced approaches for estimating heritability concordantly suggested that the trait is substantially heritable. The best-fitting structural equation model indicated that the contributions to individual differences in 2D:4D are 81% additively genetic, 19% nonshared environmental, and 0% shared environmental. Supplemental analyses showed that, consistent with a prediction from sex-hormone transfer theory, women from opposite-sex fraternal twin pairs had significantly lower (more male-typical) 2D:4D than women from same-sex fraternal twin pairs. Directions for research are discussed, such as investigating possible influences of the sex chromosomes on the expression of 2D:4D. Further family studies will be needed to test whether the transmission mode of 2D:4D is consistent with X-linked or Y-linked inheritance. The study of sex chromosome aberrations should indicate whether the presence of additional X or Y chromosomes is associated with 2D:4D levels.

  4. Digit ratio (2D:4D) does not correlate with daily 17β-estradiol and progesterone concentrations in healthy women of reproductive age.

    PubMed

    Klimek, Magdalena; Galbarczyk, Andrzej; Colleran, Heidi; Thune, Inger; Ellison, Peter T; Ziomkiewicz, Anna; Jasienska, Grazyna

    2015-01-01

    Second-to-fourth digit ratio (2D:4D) is proposed as a proxy for the prenatal balance of sex hormones, is related to hormone-dependent characteristics in adult life, and is a possible predictor of disease later in life. Here, we studied the relationship between 2D:4D and ovarian steroid hormones (17β-estradiol and progesterone) among women of reproductive age. From 186 healthy premenopausal women, aged 24-37 years, we collected saliva samples daily during the entire menstrual cycle. Data on reproductive and lifestyle characteristics were collected via questionnaires, and anthropometric measurements were performed. No statistically significant relationships were detected between adult women's sex hormone concentrations (17β-estradiol and progesterone) during the menstrual cycle and 2D:4D, in either left or right hand, when controlling for size at birth, body mass index, and physical activity. This study shows, for the first time in a large sample of women of reproductive age, that 2D:4D is not a predictor of adult women's sex hormone concentration. The lack of relationship may be because 2D:4D might be genetically determined and is not related to maternal nutritional environment during fetal development. These results support the hypothesis that, in contrast to the nutritional quality of the fetal environment, the fetal hormonal environment (reflected by 2D:4D) does not determine reproductive physiology in later life. © 2015 Wiley Periodicals, Inc.

  5. The effect of system geometry and dose on the threshold detectable calcification diameter in 2D-mammography and digital breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Hadjipanteli, Andria; Elangovan, Premkumar; Mackenzie, Alistair; Looney, Padraig T.; Wells, Kevin; Dance, David R.; Young, Kenneth C.

    2017-02-01

    Digital breast tomosynthesis (DBT) is under consideration to replace or to be used in combination with 2D-mammography in breast screening. The aim of this study was the comparison of the detection of microcalcification clusters by human observers in simulated breast images using 2D-mammography, narrow angle (15°/15 projections) and wide angle (50°/25 projections) DBT. The effects of the cluster height in the breast and the dose to the breast on calcification detection were also tested. Simulated images of 6 cm thick compressed breasts were produced with and without microcalcification clusters inserted, using a set of image modelling tools for 2D-mammography and DBT. Image processing and reconstruction were performed using commercial software. A series of 4-alternative forced choice (4AFC) experiments was conducted for signal detection with the microcalcification clusters as targets. Threshold detectable calcification diameter was found for each imaging modality with standard dose: 2D-mammography: 2D-mammography (165  ±  9 µm), narrow angle DBT (211  ±  11 µm) and wide angle DBT (257  ±  14 µm). Statistically significant differences were found when using different doses, but different geometries had a greater effect. No differences were found between the threshold detectable calcification diameters at different heights in the breast. Calcification clusters may have a lower detectability using DBT than 2D imaging.

  6. Digit ratio (2D:4D) in individuals with intellectual disability: investigating the role of testosterone in the establishment of cerebral lateralisation.

    PubMed

    Ypsilanti, Antonia; Ganou, Maria; Koidou, Irene; Grouios, George

    2008-11-01

    It has been proposed that the ratio of the second to fourth digits (2D:4D) may be a proxy of prenatal androgen exposure, such that low 2D:4D ratio is associated with high prenatal androgen exposure. The aim of the present study was to measure the 2D:4D ratio in 100 right- and non-right-handed individuals with intellectual disability of unknown idiopathic origin and compare them to a control group of 85 typically developing individuals. We also sought to determine whether sexually dimorphic traits, such as 2D:4D ratio, tend to be more pronounced on the right hand of these groups than on the left. Our results indicated that males had lower 2D:4D ratios than females in both groups, and individuals with intellectual disability had higher ratios only in their right hand compared to typically developing individuals. Further, right-handed individuals had lower ratios in both hands compared to non-right-handed individuals. Our results are discussed in relation to the "Geschwind-Behan-Galaburda theory of cerebral lateralisation" and Witelson's callosal hypothesis that differential levels of prenatal testosterone exposure will cause atypical cerebral laterality in individuals with intellectual disability, and the suggestion that this atypicality will become evident in the 2D:4D ratio (Manning, Scutt, Wilson, & Lewis-Jones, 1998).

  7. Are digital images good enough? A comparative study of conventional film-screen vs digital radiographs on printed images of total hip replacement.

    PubMed

    Eklund, K; Jonsson, K; Lindblom, G; Lundin, B; Sanfridsson, J; Sloth, M; Sivberg, B

    2004-05-01

    The aim of this study was to evaluate the inter- and intra-observer variability and to find differences in diagnostic safety between digital and analog technique in diagnostic zones around hip prostheses. In 80 patients who had had a total hip replacement (THR) for more than 2 years, a conventional image and a digital image were taken. Gruen's model of seven distinct regions of interest was used for evaluations. Five experienced radiologists observed the seven regions and noted in a protocol the following distances: stem-cement; cement-bone; and stem-bone. All images were printed on hard copies and were read twice. Weighted kappa, kappa(w), analyses were used. The two most frequently loosening regions, stem-cement region 1 and cement-bone region 7, were closely analyzed. In region 1 the five observers had an agreement of 86.75-97.92% between analog and digital images in stem-cement, which is a varied kappa(w) 0.29-0.71. For cement-bone region 7 an agreement of 87.21-90.45% was found, which is a varied kappa(w) of 0.48-0.58. All the kappa values differ significantly from nil. The result shows that digital technique is as good as analog radiographs for diagnosing possible loosening of hip prostheses.

  8. Reliability of Assessing Hand Osteoarthritis on Digital Photographs and Associations With Radiographic and Clinical Findings

    PubMed Central

    Marshall, Michelle; Jonsson, Helgi; Helgadottir, Gudrun P; Nicholls, Elaine; van der Windt, Danielle; Myers, Helen; Dziedzic, Krysia

    2014-01-01

    Objective To investigate the reliability and construct validity of an atlas for grading hand osteoarthritis (OA) on photographs in a separate younger community-dwelling population than the development cohort. Methods Participants were community-dwelling adults (ages ≥50 years) in North Staffordshire, UK with hand pain or hand problems in the last year who attended a research clinic. High-quality photographs were taken in a standardized position. A photographic atlas was used to score hand joints (second and third distal interphalangeal [DIP], second and third proximal interphalangeal [PIP], and first carpometacarpal [CMC] joints) and joint groups (DIP, PIP, and CMC joints) for OA on a 0–3 scale. Hand radiographs were graded for OA using the Kellgren/Lawrence (K/L) grading system. Clinical features (nodes, bony enlargement, and deformity) were determined by physical examination. Associations of photographic hand OA grades with radiographic OA and clinical features were determined to assess construct validity. Results In total, 558 participants (mean age 64 years, 62% women) were included in the analyses. Reliability for scoring OA on the photographs was good (mean intrarater intraclass correlation coefficient [ICC] 0.77 and mean interrater ICC 0.71). At the joint level, photographic hand OA grade was positively associated with radiographic OA grade (Spearman's ρ = 0.19–0.57, P < 0.001) and the number of clinical features (Spearman's ρ = 0.36–0.59, P < 0.001). At the person level, individuals with higher global photographic OA scores had higher summed K/L scores and higher percentages meeting the American College of Rheumatology clinical hand OA criteria. Conclusion This photographic scoring system was reliable and a good indicator of hand OA in a separate younger community-dwelling population than the development cohort. This method of data collection offers researchers a feasible alternative to physical examination and radiography. PMID:26259552

  9. Digit ratio (2D:4D), testosterone, cortisol, aggression, personality and hand-grip strength: Evidence for prenatal effects on strength.

    PubMed

    Ribeiro, Evaldo; Neave, Nick; Morais, Rosana Nogueiro; Kilduff, Liam; Taylor, Suzan R; Butovskaya, Marina; Fink, Bernhard; Manning, John T

    2016-09-01

    Digit ratio (2D:4D) is a putative marker for prenatal testosterone and is correlated with performance in many sports. Low 2D:4D has been linked to strength but the evidence is mixed and strength is also influenced by mass, testosterone, and behavioural factors. It has been hypothesised that the 2D:4D-strength correlation may be strongest in challenge conditions when short-term changes occur in steroid hormones. We tested this suggestion in men. We used a cross-over study design with a challenge (an aggressive video of rugby tackles) and control (a blank screen) condition. 89 healthy men. Finger lengths (2nd and 4th for both hands), hand-grip strength (HGS), testosterone (T), cortisol (C), aggression (Buss-Perry Aggression Questionnaire) and personality type (Ten Item Personality Measure). In both conditions participants provided saliva samples (for hormone assays). In the challenge condition there was a highly significant increase in HGS, and modest changes in T, physical aggression and emotional stability. HGS correlated negatively with left hand 2D:4D. In a multiple regression, left hand 2D:4D was negatively related to HGS and emotional stability was positively related to HGS. In the control condition HGS was not correlated with 2D:4D. In a multiple regression, BMI, physical aggression, and emotional stability were significantly related to HGS. 2D:4D is a negative correlate of strength in challenge situations. This finding may in part explain associations between 2D:4D and sports performance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. 42 CFR 37.42 - Chest radiograph specifications-digital radiography systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specifications—digital radiography systems. (a) Miners must be disrobed from the waist up at the time the... 200µm, with a minimum bit depth of 10. Spatial resolution must be at least 2.5 line pairs per millimeter...

  11. Digit ratio (2D:4D) as an indicator of body size, testosterone concentration and number of children in human males.

    PubMed

    Klimek, Magdalena; Galbarczyk, Andrzej; Nenko, Ilona; Alvarado, Louis Calistro; Jasienska, Grazyna

    2014-01-01

    The 2nd to 4th digit ratio (2D:4D) is thought to reflect exposure to androgens during foetal development. This study examined the relationship between low (more masculine) and high (more feminine) 2D:4D and body size at different stages of the life course, adult testosterone levels and number of children among males. Five hundred and fifty-eight men from rural Poland at the Mogielica Human Ecology Study Site participated in this study. Life history data and anthropometric measurements were collected. Salivary morning and evening testosterone levels among 110 men from the same population were measured. Low 2D:4D was related to higher birth weight (p = 0.04), higher birth length (p = 0.01), higher body mass during childhood and adolescence (p = 0.01), higher BMI (borderline significance, p = 0.06), higher number of children among fathers (p = 0.04) and higher testosterone levels during adulthood (p = 0.04). This study shows, for the first time in a single population, that digit ratio is related to sub-adult body size at different stages of the life course, adult testosterone levels and number of children. The observed results suggest that digit ratio might be a valuable predictor of male body size and reproductive characteristics.

  12. Length of endodontic files measured in digital radiographs with and without noise-suppression filters: an ex-vivo study.

    PubMed

    Brüllmann, D D; Röhrig, B; Sulayman, S L; Schulze, R

    2011-03-01

    The aim of this study is to evaluate if theoretically possible edge shifts induced by noise-suppression filters potentially occur on objects found in digital radiographs. Most manufacturers carry out noise-suppression filtering of their images before they are displayed to the user. It is not usually possible for the user to disrupt the function of the filters. The use of these filters can lead to deletion of small image structures. K-files (ISO size 06, 08, 10 and 15) were placed in the root canals of 6 human teeth located in cadaver jaw segments. File tip positions were measured on original and filtered digital images by three observers. The file position was marked on each filtered image and compared with the unfiltered ones. The 5 × 5 pixel-sized median and mean filters caused the largest underestimation of measured lengths between -7.87 pixels and -10.8 pixels (-306.93 μm and -421.2 μm). Maximum standard deviation for length differences was found for the calculated position ( = gold standard) and the original unfiltered images with 13.31 pixels. The standard deviation found for the 5 × 5 mean and median filter was 7.62 pixels and 8.68 pixels. Different studies showed that noise-suppression filters can induce edge shifts in diagnostic radiographs. The high standard deviations found for length differences between the defined gold-standard and the original images indicate that theoretical edge shifts may not be clinically relevant for length measurements of endodontic files.

  13. Comparison of visibility of circumscribed masses on Digital Breast Tomosynthesis (DBT) and 2D mammography: are circumscribed masses better visualized and assured of being benign on DBT?

    PubMed

    Nakashima, Kazuaki; Uematsu, Takayoshi; Itoh, Takahiro; Takahashi, Kaoru; Nishimura, Seiichirou; Hayashi, Tomomi; Sugino, Takashi

    2017-02-01

    To compare the visibility of circumscribed masses on digital breast tomosynthesis (DBT) images and 2D mammograms and determine the usefulness of DBT for differentiation between benign and malignant circumscribed masses. Seventy-one (19 malignant and 52 benign) mammographic well-circumscribed masses were included. Visibility of the masses and halo signs on DBT images were retrospectively compared with 2D mammograms. The effects of mammographic breast density on mass visibility were also evaluated. For DBT, 83% were superior and 17% were equivalent in visibility of the masses to that of 2D, and superiority of DBT was significantly enhanced in the high breast density group compared with the low breast density group (91% vs 68%, respectively, p = 0.016). Three lesions were only detected on DBT. There was no significant difference in the superiority of DBT for lesion visibility between malignant and benign masses. The halo sign was detected in 58% lesions on DBT and in 4% on 2D (p < 0.001). Circumscribed masses were better visualized on DBT than on 2D mammograms, particularly in high-density breasts. The halo sign often appeared on DBT and gave a clearer mass margin. However, circumscribed masses on DBT are not assured of being benign. • Circumscribed masses were better visualized on breast tomosynthesis than on 2D mammography. • Tomosynthesis visualized circumscribed masses better than 2D for all breast density categories. • Halo signs often appeared on tomosynthesis and contributed to detect circumscribed margins. • Circumscribed masses on tomosynthesis images are not assured of being benign lesions.

  14. Adult digit ratio (2D:4D) is not related to umbilical cord androgen or estrogen concentrations, their ratios or net bioactivity.

    PubMed

    Hollier, Lauren P; Keelan, Jeffrey A; Jamnadass, Esha S L; Maybery, Murray T; Hickey, Martha; Whitehouse, Andrew J O

    2015-02-01

    Ratio of second digit length to fourth digit length (2D:4D) has been extensively used in human and experimental research as a marker of fetal sex steroid exposure. However, very few human studies have measured the direct relationship between fetal androgen or estrogen concentrations and digit ratio. We investigated the relationships between both androgen and estrogen concentrations in umbilical cord blood and digit ratio in young adulthood. In addition we calculated measures of total serum androgen and total estrogen bioactivity and investigated their relationship to digit ratio. Prospective cohort study. An unselected subset of the Western Australian Pregnancy Cohort (Raine) Study (159 female; 182 male). Cord serum samples were collected immediately after delivery. Samples were assayed for androgen (testosterone, Δ4-androstenedione, dehydroepiandrosterone) and estrogen (estrone, estradiol, estriol, estetrol) concentrations using liquid-chromatography mass-spectrometry. Digit ratio measurements were taken from hand photocopies at age 19-22years. For both males and females, there were no significant correlations between digit ratio and any androgen or estrogen concentrations considered individually, the testosterone to estradiol ratio, total androgen bioactivity measure or ratio of androgen to estrogen bioactivity (all p>.05). In males, but not females, total estrogen bioactivity was negatively correlated with left hand digit ratio (r=-.172, p=.02), but this relationship was no longer significant when adjusted for variables known to affect sex steroid concentrations in cord blood. Our findings indicate that digit ratio is not related to fetal androgens or estrogens at late gestation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Computer-aided diagnosis for detection of cardiomegaly in digital chest radiographs

    NASA Astrophysics Data System (ADS)

    Ishida, Takayuki; Katsuragawa, Shigehiko; Chida, Koichi; MacMahon, Heber; Doi, Kunio

    2005-04-01

    The cardio-thoracic ratio (CTR) is commonly measured manually for the evaluation of cardiomegaly. To determine the CTR automatically, we have developed a computerized scheme based on gray-level histogram analysis and an edge detection technique with feature analysis. The database used in this study consisted of 392 chest radiographs, which included 304 normals and 88 abnormals with cardiomegaly. The pixel size and the quantization level of the image were 0.175 mm and 1024, respectively. We performed a nonlinear density correction to maintain consistency in the density and contrast of the image. Initial heart edge detection was performed by selection of a certain range of pixel values in the histogram of a rectangular area at the center of a low-resolution image. Feature analysis with use of an edge gradient and with the orientation obtained by a Sobel operator was applied for accurate identification of the heart edges, which tend to have large edge gradients in a certain range of orientations. In addition, to determine the CTR, we detected the ribcage edges automatically by using image profile analysis. In 94.9% of all of the cases, the heart edges were detected accurately by use of this scheme. The area under the ROC curve (Az value) in distinguishing between normals and abnormals with cardiomegaly based on the CTR was 0.912. Because the CTR is measured automatically and quickly (in less than 1 sec.), radiologists could save reading time. The computerized scheme will be useful for the assessment of cardiomegaly on chest radiographs.

  16. The Left Hand Second to Fourth Digit Ratio (2D:4D) Does Not Discriminate World-Class Female Gymnasts from Age Matched Sedentary Girls

    PubMed Central

    Peeters, Maarten W.; Claessens, Albrecht L.

    2012-01-01

    Introduction The second to fourth-digit-ratio (2D:4D), a putative marker of prenatal androgen action and a sexually dimorphic trait, has been suggested to be related with sports performance, although results are not univocal. If this relation exists, it is most likely to be detected by comparing extreme groups on the continuum of sports performance. Methods In this study the 2D:4D ratio of world-class elite female artistic gymnasts (n = 129), competing at the 1987 Rotterdam World-Championships was compared to the 2D:4D ratio of sedentary age-matched sedentary girls (n = 129), alongside with other anthropometric characteristics including other sexually dimorphic traits such as an androgyny index (Bayer & Bayley) and Heath-Carter somatotype components (endomorphy, mesomorphy, ectomorphy) using AN(C)OVA. 2D:4D was measured on X-rays of the left hand. Results Left hand 2D:4D digit ratio in world class elite female gymnasts (0.921±0.020) did not differ significantly from 2D:4D in age-matched sedentary girls (0.924±0.018), either with or without inclusion of potentially confounding covariates such as skeletal age, height, weight, somatotype components or androgyny index. Height (161.9±6.4 cm vs 155.4±6.6 cm p<0.01), weight (53.9±7.6 kg vs 46.2 6.3 kg p<0.01), BMI (20.51±2.41 kg/m2 vs 19.05±1.56 kg/m2), skeletal age (15.2±1.1 y vs 14.5±1.2 y p>0.01), somatotype components (4.0/3.0/2.9 vs 1.7/3.7/3.2 for endomorphy (p<0.01), mesomorphy (p<0.01) and ectomorphy (p<0.05) respectively) all differed significantly between sedentary girls and elite gymnasts. As expressed by the androgyny index, gymnasts have, on average, broader shoulders relative to their hips, compared to the reference sample. Correlations between the 2D:4D ratio and chronological age, skeletal age, and the anthropometric characteristics are low and not significant. Conclusion Although other anthropometric characteristics of sexual dimorphism were significantly different between the two samples

  17. SEX DIFFERENCES IN DIGIT RATIO (2D:4D) AMONG MILITARY AND CIVIL COHORTS AT A MILITARY ACADEMY IN WROCŁAW, POLAND.

    PubMed

    Kociuba, Marek; Kozieł, Slawomir; Chakraborty, Raja

    2016-09-01

    The ratio of second-to-fourth digit length (2D:4D), which is generally higher in women compared with men, is a putative marker of prenatal testosterone (PT) exposure. Lower 2D:4D is linked with greater physical ability and strength, better sporting performance and a propensity towards jobs demanding greater physical ability. The objectives of this paper were to examine the sexual dimorphism in 2D:4D in both hands 1and compare this dimorphism in the students of military and civil courses at the General Kuściuszko Military Academy of Land Forces in Wrocław. The cross-sectional study compared 59 female and 118 male students from the military courses and 53 females and 64 male students from the civil courses. Besides calculating 2D:4D (2D/4D) for each hand, height and weight were also recorded. Physical fitness and endurance were assessed using Eurofit tests. Handgrip strength was measured using a standardized isometric dynamometer. In almost all physical tests, students in the military cohort showed highly significant greater physical ability and strength (e.g. handgrip strength) when compared with the civil cohort. Male participants had a significantly lower 2D:4D than females for each hand, as well as for the average value for both hands. The sexual dimorphism was, however, a little more pronounced in the right hand than in the left. Both sex and course type were significant predictors of 2D:4D. There were significant interactions between sex and the student type. Among females, but not in males, the military cohort had a significantly lower, i.e. more 'masculine', 2D:4D for the left hand and right hand and average for both hands (t=3.290, p<0.001) than the civil cohort. This was not the case in males. However, the sex difference in 2D:4D was only significant among the civil students, and not among the military cadets. In conclusion, higher PT exposure, as represented by a lower 2D:4D, among the Polish females might be an indicator of relatively increased physical

  18. 2D:4D digit ratio is associated with cognitive decline but not frailty in community-dwelling older adults.

    PubMed

    Gonçalves, Celina; Coelho, Tiago; Machado, Sérgio; Rocha, Nuno Barbosa

    2017-09-10

    To understand the relation between 2D:4D ratio, frailty, and cognitive decline in community-dwelling elderly people. A total of 175 community-dwelling elderly people were included. To determine frailty, participants completed the Tilburg Frailty Indicator (TFI) and the Survey of Health, Ageing and Retirement in Europe (SHARE-FI). Cognitive functioning was determined using the Mini-Mental State Examination (MMSE). 2D and 4D finger lengths of each hand were measured using a scanner. Barthel Index, Lawton, and Brody scale were also completed for each participant to determine the level of daily living functioning. We did not find any correlations between 2D:4D ratio and frailty measures. We found a significant correlation between 2D:4D ratio and MMSE scores in the women sampled. We cannot ascertain any contribution of prenatal exposure to androgens to the frailty status of community-dwelling elderly people. We found that reduced prenatal exposure to testosterone in women may contribute to the prevention of cognitive decline in elderly women. © 2017 Wiley Periodicals, Inc.

  19. Texture analysis of mandibular cortical bone on digital dental panoramic radiographs for the diagnosis of osteoporosis in Korean women.

    PubMed

    Kavitha, Muthu Subash; An, Seo-Young; An, Chang-Hyeon; Huh, Kyung-Hoe; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul

    2015-03-01

    To determine whether individual measurements or a combination of textural features and mandibular cortical width (MCW) derived from digital dental panoramic radiographs (DPRs) are more useful in assessment of osteoporosis. Textural features were obtained by using fractal dimension (FD) and gray-level co-occurrence matrix (GLCM). Digital DPRs and bone mineral densities (BMDs) of the lumbar spine and the femoral neck were obtained from 141 female patients. A naïve Bayes classifier, a k-nearest neighbor (k-NN) algorithm, and a support vector machine were assessed for classifying osteoporosis. The combinations of FD plus MCW (95.3%, 92.1%, 96.8%) and GLCM plus MCW (93.7%, 89.5%, 94.2%) for femoral neck BMD showed the highest diagnostic accuracy with the use of the naïve Bayes, k-NN, and support vector machine classifiers, respectively. The combination of textural features and MCW contributed a better assessment of osteoporosis compared with the use of only individual measurements. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. An evaluation of the impact of digital imaging on radiographic practice and patient doses

    NASA Astrophysics Data System (ADS)

    Horrocks, J.; Violaki, K.

    2015-09-01

    Direct digital imaging technology was implemented in all areas in general and mobile radiology at Barts and the Royal London Hospitals in 2012. Evidence from recent radiation incident investigations indicates optimum exposure factors are not consistently selected, with the greater dynamic range of the digital detectors allowing sub-optimal practice. To investigate further patient dose data were extracted from the Radiology Information System for adult chest X-ray examinations in 2014, covering over 50,000 studies in the Trust. Chest X-ray examinations were selected as they are low dose but frequent examinations. The patient dose data were evaluated taking into account X-ray system type and detector performance measurements, and individual cases studies were used to highlight where practice can be improved.

  1. 3D and 2D marginal fit of pressed and CAD/CAM lithium disilicate crowns made from digital and conventional impressions.

    PubMed

    Anadioti, Evanthia; Aquilino, Steven A; Gratton, David G; Holloway, Julie A; Denry, Isabelle; Thomas, Geb W; Qian, Fang

    2014-12-01

    This in vitro study evaluated the 3D and 2D marginal fit of pressed and computer-aided-designed/computer-aided-manufactured (CAD/CAM) all-ceramic crowns made from digital and conventional impressions. A dentoform tooth (#30) was prepared for an all-ceramic crown (master die). Thirty type IV definitive casts were made from 30 polyvinyl siloxane (PVS) impressions. Thirty resin models were produced from thirty Lava Chairside Oral Scanner impressions. Thirty crowns were pressed in lithium disilicate (IPS e.max Press; 15/impression technique). Thirty crowns were milled from lithium disilicate blocks (IPS e.max CAD; 15/impression technique) using the E4D scanner and milling engine. The master die and the intaglio of the crowns were digitized using a 3D laser coordinate measurement machine with accuracy of ±0.00898 mm. For each specimen a separate data set was created for the Qualify 2012 software. The digital master die and the digital intaglio of each crown were merged using best-fitting alignment. An area above the margin with 0.75 mm occlusal-gingival width circumferentially was defined. The 3D marginal fit of each specimen was an average of all 3D gap values on that area. For the 2D measurements, the marginal gap was measured at two standardized points (on the margin and at 0.75 mm above the margin), from standardized facial-lingual and mesial-distal digitized sections. One-way ANOVA with post hoc Tukey's honestly significant difference and two-way ANOVA tests were used, separately, for statistical analysis of the 3D and 2D marginal data (alpha = 0.05). One-way ANOVA revealed that both 3D and 2D mean marginal gap for group A: PVS impression/IPS e.max Press (0.048 mm ± 0.009 and 0.040 mm ± 0.009) were significantly smaller than those obtained from the other three groups (p < 0.0001), while no significant differences were found among groups B: PVS impression/IPS e.max CAD (0.088 mm ± 0.024 and 0.076 mm ± 0.023), C: digital impression/IPS e.max Press (0.089 mm ± 0

  2. Digit ratio (2D:4D) and salivary testosterone, oestradiol and cortisol levels under challenge: Evidence for prenatal effects on adult endocrine responses.

    PubMed

    Crewther, Blair; Cook, Christian; Kilduff, Liam; Manning, John

    2015-08-01

    Digit ratio (2D:4D) is a marker for prenatal sex steroids and a correlate of sporting performance. This association may exist because low 2D:4D is linked to high prenatal levels of testosterone (T) and low oestrogens (E). It was recently suggested that low 2D:4D, and particularly low right-left 2D:4D (or Dr-l), is a marker for T changes in response to physical and aggressive challenges. If correct, this link may in part explain the association between 2D:4D and sports performance. We tested this hypothesis in adults. Three experimental treatments were completed using a randomised, cross-over design; (i) cycle sprints plus an aggressive video (S+V), (ii) aggressive video plus cycle sprints (V+S), and (iii) a control session. 24 healthy adults (12 men and 12 women). Salivary T, oestradiol (E2) and cortisol (C) levels were measured on six occasions across each session and pooled for analysis. The S+V treatment was associated with a rise in T and C levels, and Dr-l was significantly and negatively correlated with T and E2 with these effects confined to men. The right 2D:4D and Dr-l were also negatively correlated with the T/C ratio and Dr-l negatively related to the E2/C ratio in men during the S+V treatment. We suggest that the hormonal responses to a challenge are programmed by prenatal levels of T and E with possible links to sporting performance in adulthood. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Optimal angular dose distribution to acquire 3D and extra 2D images for digital breast tomosynthesis (DBT)

    NASA Astrophysics Data System (ADS)

    Park, Hye-Suk; Kim, Ye-Seul; Lee, Haeng-Hwa; Gang, Won-Suk; Kim, Hee-Joung; Choi, Young-Wook; Choi, JaeGu

    2015-08-01

    The purpose of this study is to determine the optimal non-uniform angular dose distribution to improve the quality of the 3D reconstructed images and to acquire extra 2D projection images. In this analysis, 7 acquisition sets were generated by using four different values for the number of projections (11, 15, 21, and 29) and total angular range (±14°, ±17.5°, ±21°, and ±24.5° ). For all acquisition sets, the zero-degree projection was used as the 2D image that was close to that of standard conventional mammography (CM). Exposures used were 50, 100, 150, and 200 mR for the zero-degree projection, and the remaining dose was distributed over the remaining projection angles. To quantitatively evaluate image quality, we computed the CNR (contrast-to-noise ratio) and the ASF (artifact spread function) for the same radiation dose. The results indicate that, for microcalcifications, acquisition sets with approximately 4 times higher exposure on the zero-degree projection than the average exposure for the remaining projection angles yielded higher CNR values and were 3% higher than the uniform distribution. However, very high dose concentrations toward the zero-degree projection may reduce the quality of the reconstructed images due to increasing noise in the peripheral views. The zero-degree projection of the non-uniform dose distribution offers a 2D image similar to that of standard CM, but with a significantly lower radiation dose. Therefore, we need to evaluate the diagnostic potential of extra 2D projection image when diagnose breast cancer by using 3D images with non-uniform angular dose distributions.

  4. An analog-digital hybrid RX beamformer chip with non-uniform sampling for ultrasound medical imaging with 2D CMUT array.

    PubMed

    Um, Ji-Yong; Kim, Yoon-Jee; Cho, Seong-Eun; Chae, Min-Kyun; Song, Jongkeun; Kim, Baehyung; Lee, Seunghun; Bang, Jihoon; Kim, Youngil; Cho, Kyungil; Kim, Byungsub; Sim, Jae-Yoon; Park, Hong-June

    2014-12-01

    To reduce the memory area, a two-stage RX beamformer (BF) chip with 64 channels is proposed for the ultrasound medical imaging with a 2D CMUT array. The chip retrieved successfully two B-mode phantom images with a steering angle from -45 (°) to +45 (°), the maximum delay range of 8 μs, and the delay resolution of 6.25 ns. An analog-digital hybrid BF (HBF) is chosen for the proposed chip to utilize the easy beamforming operation in the digital domain and also to reduce chip area by minimizing the number of ADCs. The chip consists of eight analog beamformers (ABF) for the 1st-stage and a digital beamformer (DBF) for the 2nd-stage. The two-stage architecture reduces the memory area of both ABF and DBF by around four times. The DBF circuit is divided into three steps to further reduce the digital FIFO memory area by around twice. Coupled with the non-uniform sampling scheme, the proposed two-stage HBF chip reduces the total memory area by around 40 times compared to the uniform-sampling single-stage BF chip. The chip fabricated in a 0.13- μm CMOS process occupies the area of 19.4 mm(2), and dissipates 1.14 W with the analog supply of 3.3 V and the digital supply of 1.2 V.

  5. Spatial Ability and Prenatal Androgens: Meta-analyses of CAH and Digit Ratio (2D:4D) Studies

    PubMed Central

    Puts, David Andrew; McDaniel, Michael A.; Jordan, Cynthia L.; Breedlove, S. Marc

    2010-01-01

    Hormonal manipulations indicate that early androgens organize sex differences in spatial ability in animal models. In humans, spatial ability is also sexually dimorphic, and information about the effects of prenatal androgens on spatial ability can be obtained from studies of congenital adrenal hyperplasia (CAH) and the ratio of the second and fourth finger lengths (2D:4D). CAH is a condition characterized by prenatal overproduction of adrenal androgens, and several lines of evidence suggest that 2D:4D reflects prenatal androgen exposure. Some studies have found that these proxy measures of prenatal androgenization predict spatial ability, others have found no significant relationship, and yet others have obtained results in opposite directions. In light of these mixed findings, we conducted meta-analyses of published literature and unpublished results to determine if, across studies, either of these indications of prenatal androgens predicts spatial ability. In addition, we applied a trim and fill analysis to the data in search of asymmetry that might be an indication of publication bias. Results indicate that females with CAH have significantly better spatial abilities, and CAH males have worse spatial abilities, than do controls. Little or no relationship exists between 2D:4D and spatial ability. Implications for possible hormonal contributions and the developmental timing of sex differences in spatial cognition are discussed. PMID:18074217

  6. An endocrine basis for tomboy identity: The second-to-fourth digit ratio (2D:4D) in "tomboys".

    PubMed

    Atkinson, Beth M; Smulders, Tom V; Wallenberg, Joel C

    2017-05-01

    This paper investigates the relationship between organizational effects of pre-natal testosterone and the use of "tomboy" as a descriptor for young women. We show in a sample of 44 women that a woman's right hand 2D:4D ratio is a significant predictor of whether they will be labeled as a "tomboy", with a decrease in 2D:4D ratio corresponding to an increase in the probability of being called "tomboy". Taking the right hand 2D:4D ratio as a proxy for the abundance of testosterone in the early life hormonal milieu, we propose that organizing effects of higher pre-natal T lead to increased masculine-typical behavior in childhood, which increases the likelihood some women will be referred to as tomboys. We suggest that the increase in masculine-typical behaviors is a result of how the organizing effects of T on the brain interact with children's social modeling of male-coded and female-coded behaviors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Detector or system? Extending the concept of detective quantum efficiency to characterize the performance of digital radiographic imaging systems.

    PubMed

    Samei, Ehsan; Ranger, Nicole T; MacKenzie, Alistair; Honey, Ian D; Dobbins, James T; Ravin, Carl E

    2008-12-01

    To develop an experimental method for measuring the effective detective quantum efficiency (eDQE) of digital radiographic imaging systems and evaluate its use in select imaging systems. A geometric phantom emulating the attenuation and scatter properties of the adult human thorax was employed to assess eight imaging systems in a total of nine configurations. The noise power spectrum (NPS) was derived from images of the phantom acquired at three exposure levels spanning the operating range of the system. The modulation transfer function (MTF) was measured by using an edge device positioned at the anterior surface of the phantom. Scatter measurements were made by using a beam-stop technique. All measurements, including those of phantom attenuation and estimates of x-ray flux, were used to compute the eDQE. The MTF results showed notable degradation owing to focal spot blur. Scatter fractions ranged between 11% and 56%, depending on the system. The eDQE(0) results ranged from 1%-17%, indicating a reduction of up to one order of magnitude and different rank ordering and performance among systems, compared with that implied in reported conventional detective quantum efficiency results from the same systems. The eDQE method was easy to implement, yielded reproducible results, and provided a meaningful reflection of system performance by quantifying image quality in a clinically relevant context. The difference in the magnitude of the measured eDQE and the ideal eDQE of 100% provides a great opportunity for improving the image quality of radiographic and mammographic systems while reducing patient dose. RSNA, 2008

  8. Detector or System? Extending the Concept of Detective Quantum Efficiency to Characterize the Performance of Digital Radiographic Imaging Systems

    PubMed Central

    Samei, Ehsan; Ranger, Nicole T.; MacKenzie, Alistair; Honey, Ian D.; Dobbins, James T.; Ravin, Carl E.

    2008-01-01

    Purpose: To develop an experimental method for measuring the effective detective quantum efficiency (eDQE) of digital radiographic imaging systems and evaluate its use in select imaging systems. Materials and Methods: A geometric phantom emulating the attenuation and scatter properties of the adult human thorax was employed to assess eight imaging systems in a total of nine configurations. The noise power spectrum (NPS) was derived from images of the phantom acquired at three exposure levels spanning the operating range of the system. The modulation transfer function (MTF) was measured by using an edge device positioned at the anterior surface of the phantom. Scatter measurements were made by using a beam-stop technique. All measurements, including those of phantom attenuation and estimates of x-ray flux, were used to compute the eDQE. Results: The MTF results showed notable degradation owing to focal spot blur. Scatter fractions ranged between 11% and 56%, depending on the system. The eDQE(0) results ranged from 1%–17%, indicating a reduction of up to one order of magnitude and different rank ordering and performance among systems, compared with that implied in reported conventional detective quantum efficiency results from the same systems. Conclusion: The eDQE method was easy to implement, yielded reproducible results, and provided a meaningful reflection of system performance by quantifying image quality in a clinically relevant context. The difference in the magnitude of the measured eDQE and the ideal eDQE of 100% provides a great opportunity for improving the image quality of radiographic and mammographic systems while reducing patient dose. © RSNA, 2008 PMID:19011189

  9. [Correlation between basic imaging properties and subjective evaluations of two digital radiographic X-ray systems based on direct-conversion flat panel detector].

    PubMed

    Sakaguchi, Taro; Katayama, Reiji; Morishita, Junji; Sakai, Shinji; Kuroki, Hidefumi; Ohkubo, Seiji; Maeda, Takashi; Hayabuchi, Naofumi

    2010-11-20

    The purpose of this study was to examine the correlation between the basic imaging properties of two digital radiographic X-ray systems with a direct conversion flat-panel detector and their image qualities, which were evaluated by the observer in hard copy and soft copy studies. The subjective image quality was evaluated and compared in terms of the low-contrast detectability and image sharpness in the two digital radiographic X-ray systems. We applied the radiographs of a contrast detail phantom to the evaluation of low-contrast detectability and analyzed the contrast detail diagrams. Finally, low-contrast detectability was evaluated by the image quality figure (IQF) calculated from the contrast detail diagrams. Also, the subjective image sharpness of human dry bones of two systems was examined and evaluated by the normalized-rank method. The results indicated that System A tended to provide superior subjective image quality compared to System B in both observer studies. We also found high correlations between IQFs and basic imaging properties, such as the noise power spectrum (NPS) and the noise equivalent quantum (NEQ). In conclusion, the low-contrast detectability of the two digital radiographic X-ray systems with a direct conversion flat-panel detector corresponded to the NPS and the NEQ in both outputs (soft copy and hard copy). On the other hand, the subjective image sharpness of human dry bones was affected by their noise properties.

  10. Digit ratio (2D:4D) moderates the relationship between cortisol reactivity and self-reported externalizing behavior in young adolescent males.

    PubMed

    Portnoy, Jill; Raine, Adrian; Glenn, Andrea L; Chen, Frances R; Choy, Olivia; Granger, Douglas A

    2015-12-01

    Although reduced cortisol reactivity to stress and increased circulating testosterone level are hypothesized to be associated with higher levels of externalizing behavior, empirical findings are inconsistent. One factor that may account for the heterogeneity in these relationships is prenatal testosterone exposure. This study examined whether the second-to-fourth digit ratio (2D:4D), a putative marker of prenatal testosterone exposure, moderates the relationships of testosterone and cortisol reactivity with externalizing behavior. Left and right hand 2D:4D and self-reported externalizing behavior were measured in a sample of 353 young adolescents (M age=11.92 years; 178 females; 79.7% African American). Saliva samples were collected before and after a stress task and later assayed for cortisol. Testosterone levels were determined from an AM saliva sample. 2D:4D interacted with cortisol reactivity to predict externalizing behavior in males, but not females. In males, low cortisol reactivity was associated with higher levels of aggression and rule-breaking behavior, but only among subjects with low 2D:4D (i.e., high prenatal testosterone). Findings suggest the importance of a multi-systems approach in which interactions between multiple hormones are taken into account. Furthermore, results demonstrate the importance of considering the organizational influence of prenatal testosterone in order to understand the activational influence of circulating hormones during adolescence. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Sub-nanosecond multi-channel time-to-digital converter for the 2-D position-sensitive neutron detectors at TriCS and AMOR

    NASA Astrophysics Data System (ADS)

    Buehler, Ch.; Greuter, U.; Frey, G.; Zaharko, O.; Koennecke, M.; Schefer, J.; Rasmussen, P.; Schaniel, D.; Clemens, D.; Gabriel, A.; Felsche, J.; Schlumpf, N.

    We have developed an ultra-fast multi-channel time-to-digital converter (mC-TDC). The mC-TDC electronics is used to read out the delay-line-based 2-D detectors of the neutron diffractometer and reflectometer TriCS and AMOR, respectively. The high time resolution of the mC-TDC ( 145 ps) allows the conversion of the position-sensitive detector signals into accurate 2-D scattering coordinates ( 2×2 mm2). The mC-TDC also generates low-jitter time-of-flight signals and incorporates an efficient two-stage pileup-rejection mechanism. Neutron rates exceeding 100000cps can be processed.

  12. Effect of monitor display on detection of approximal caries lesions in digital radiographs.

    PubMed

    Isidor, S; Faaborg-Andersen, M; Hintze, H; Kirkevang, L-L; Frydenberg, M; Haiter-Neto, F; Wenzel, A

    2009-12-01

    The aim was to compare the accuracy of five flat panel monitors for detection of approximal caries lesions. Five flat panel monitors, Mermaid Ventura (15 inch, colour flat panel, 1024 x 768, 32 bit, analogue), Olórin VistaLine (19 inch, colour, 1280 x 1024, 32 bit, digital), Samsung SyncMaster 203B (20 inch, colour, 1024 x 768, 32 bit, analogue), Totoku ME251i (21 inch, greyscale, 1400 x 1024, 32 bit, digital) and Eizo FlexScan MX190 (19 inch, colour, 1280 x 1024, 32 bit, digital), were assessed. 160 approximal surfaces of human teeth were examined with a storage phosphor plate system (Digora FMX, Soredex) and assessed by seven observers for the presence of caries lesions. Microscopy of the teeth served as validation for the presence/absence of a lesion. The sensitivities varied between observers (range 7-25%) but the variation between the monitors was not large. The Samsung monitor obtained a significantly higher sensitivity than the Mermaid and Olórin monitors (P<0.02) and a lower specificity than the Eizo and Totoku monitors (P<0.05). There were no significant differences between any other monitors. The percentage of correct scores was highest for the Eizo monitor and significantly higher than for the Mermaid and Olórin monitors (P<0.03). There was no clear relationship between the diagnostic accuracy and the resolution or price of the monitor. The Eizo monitor was associated with the overall highest percentage of correct scores. The standard analogue flat panel monitor, Samsung, had higher sensitivity and lower specificity than some of the other monitors, but did not differ in overall accuracy for detection of carious lesions.

  13. The digital radiographic and computed tomography imaging of two types of explosive devices.

    PubMed

    Galiano Riveros, Eduardo

    2002-12-01

    Two well-established medical imaging methods, digital radiography (DR) and computed tomography (CT), were employed to obtain images of two types of explosive devices, model rocket engines and shotgun shells. The images were evaluated from an airport security perspective. In terms of geometrical shape, the detection probability of the explosive devices appears to be higher with DR imaging, but in terms of the actual explosive compounds in the devices, CT appears to offer a higher detection probability. DR imaging offers a low detection probability for the explosive powder in the shotgun shells, but a rather significant detection probability for the explosive propellant in the model rocket engines.

  14. Physician experience with viewing digital radiographs in an intensive care unit environment.

    PubMed

    Humphrey, L M; Fitzpatrick, K; Paine, S S; Ravin, C E

    1993-02-01

    After several years of continuous operation, the utility of digital viewing stations as assessed by bedside clinicians has been investigated through the distribution of questionnaires to past and present users. The results of the questionnaire have indicated that the bedside physicians prefer using the workstations over handling film. For evaluation of line placements, chest tubes, and pleural effusions, the physicians prefer softcopy display over hardcopy. However, for analysis of air space disease and diagnosis of pneumothorax, images displayed on the workstation were not believed to be as useful as standard hardcopy.

  15. A Critical Review of the Research on the Extreme Male Brain Theory and Digit Ratio (2D:4D)

    ERIC Educational Resources Information Center

    Teatero, Missy L.; Netley, Charles

    2013-01-01

    Boys are more likely than girls to be diagnosed with an autism spectrum disorder (ASD). The extreme male brain (EMB) theory of ASD suggests that fetal testosterone (FT) exposure may underlie sex differences in autistic traits. A link between the organizational effects of FT on the brain and ASD is often drawn based on research using digit ratio…

  16. A Critical Review of the Research on the Extreme Male Brain Theory and Digit Ratio (2D:4D)

    ERIC Educational Resources Information Center

    Teatero, Missy L.; Netley, Charles

    2013-01-01

    Boys are more likely than girls to be diagnosed with an autism spectrum disorder (ASD). The extreme male brain (EMB) theory of ASD suggests that fetal testosterone (FT) exposure may underlie sex differences in autistic traits. A link between the organizational effects of FT on the brain and ASD is often drawn based on research using digit ratio…

  17. Reconstruction-based 3D/2D image registration.

    PubMed

    Tomazevic, Dejan; Likar, Bostjan; Pernus, Franjo

    2005-01-01

    In this paper we present a novel 3D/2D registration method, where first, a 3D image is reconstructed from a few 2D X-ray images and next, the preoperative 3D image is brought into the best possible spatial correspondence with the reconstructed image by optimizing a similarity measure. Because the quality of the reconstructed image is generally low, we introduce a novel asymmetric mutual information similarity measure, which is able to cope with low image quality as well as with different imaging modalities. The novel 3D/2D registration method has been evaluated using standardized evaluation methodology and publicly available 3D CT, 3DRX, and MR and 2D X-ray images of two spine phantoms, for which gold standard registrations were known. In terms of robustness, reliability and capture range the proposed method outperformed the gradient-based method and the method based on digitally reconstructed radiographs (DRRs).

  18. High-accuracy 2D digital image correlation measurements using low-cost imaging lenses: implementation of a generalized compensation method

    NASA Astrophysics Data System (ADS)

    Pan, Bing; Yu, Liping; Wu, Dafang

    2014-02-01

    The ideal pinhole imaging model commonly assumed for an ordinary two-dimensional digital image correlation (2D-DIC) system is neither perfect nor stable because of the existence of small out-of-plane motion of the test sample surface that occurred after loading, small out-of-plane motion of the sensor target due to temperature variation of a camera and unavoidable geometric distortion of an imaging lens. In certain cases, these disadvantages can lead to significant errors in the measured displacements and strains. Although a high-quality bilateral telecentric lens has been strongly recommended to be used in the 2D-DIC system as an essential optical component to achieve high-accuracy measurement, it is not generally applicable due to its fixed field of view, limited depth of focus and high cost. To minimize the errors associated with the imperfectness and instability of a common 2D-DIC system using a low-cost imaging lens, a generalized compensation method using a non-deformable reference sample is proposed in this work. With the proposed method, the displacement of the reference sample rigidly attached behind the test sample is first measured using 2D-DIC, and then it is fitted using a parametric model. The fitted parametric model is then used to correct the displacements of the deformed sample to remove the influences of these unfavorable factors. The validity of the proposed compensation method is first verified using out-of-plane translation, out-of-plane rotation, in-plane translation tests and their combinations. Uniaxial tensile tests of an aluminum specimen were also performed to quantitatively examine the strain accuracy of the proposed compensation method. Experiments show that the proposed compensation method is an easy-to-implement yet effective technique for achieving high-accuracy deformation measurement using an ordinary 2D-DIC system.

  19. Harmonisation of the appearance of digital radiographs from different vendors by means of common external image processing.

    PubMed

    Larsson, Lars; Båth, Magnus; Engman, Eva-Lena; Månsson, Lars Gunnar

    2010-01-01

    The aim of the present study was to evaluate the use of common external image processing to compensate for differences in appearance between digital X-ray images from different vendors. Twenty posteroanterior chest radiographs were collected from each of three different modalities from different vendors (GE, Siemens and Canon) with vendor-specific image processing applied. The images were also extracted with neutral process parameters and processed with external image-processing software. Six experienced radiologists rated the quality and the similarity of the images with the original Siemens images. The externally processed GE images were rated of higher quality than the original GE images and more similar to the original Siemens images (p < 0.001). The opposite was obtained for the Canon images. The externally processed Siemens images were rated of similar quality as the original images. The present study indicates the possibility of using common external image processing to harmonise the appearance of images from different vendors, although the exposure parameters may need to be adjusted for individual vendors.

  20. A retrospective study of digital subtraction technique to detect sclerotic changes in alveolar bone on intraoral radiographs of bisphosphonate-treated patients

    PubMed Central

    Zaman, M U; Nakamoto, T; Tanimoto, K

    2013-01-01

    Objectives: Several reports have suggested that sclerotic changes in cancellous bone of the jaw and thickening of the lamina dura are characteristic radiographic changes of an early silent stage of bisphosphonate (BP)-related osteonecrosis of the jaw. No quantitative evaluation has been reported to support this hypothesis. Emago® software (Oral Diagnostic Systems, Amsterdam, Netherlands) can perform digital subtraction on intraoral radiographs even if they were obtained by non-standardized radiography, provided the dimensional error is within a certain limit. The purpose of this study was to evaluate whether sclerotic changes of alveolar bone or thickening of lamina dura in patients using BP can be detected using the subtraction function of Emago. Methods: The authors selected 46 pairs of intraoral radiographs of the mandibular molar area in dental patients. All radiographs were obtained at intervals of 6 months or more. Among the 46 pairs, 7 pairs were from patients who were being treated with BP (study subjects), and 39 pairs were from patients who had not been using BP (controls). All pairs of radiographs underwent digital subtraction by Emago. The number of pixels of the sclerotic areas was counted and compared between subjects and controls. Results: The sclerotic changes were significantly distinguishable in two of the seven subjects (28.6%) using BP. Conclusions: Digital subtraction function of Emago was able to detect sclerotic changes in alveolar bone. Therefore, it is suggested that the subtraction function of Emago is a useful tool for quantitatively detecting sclerotic changes that are observed at an early, silent stage of BP-related osteonecrosis of the jaw. PMID:24170801

  1. Doses under automatic exposure control (AEC) for direct digital radiographic (DDR) X-ray systems.

    PubMed

    Bowden, Louise; Faulkner, Ronan; Clancy, Conor; Gallagher, Aoife; Devine, Mark; Gorman, Dermot; O'Reilly, Geraldine; Dowling, Anita

    2011-09-01

    Current guidelines quote tolerances for automatic exposure control (AEC) device performance for X-ray systems as 'Baseline ± X %'. However, in the situation where a baseline figure has not yet been achieved, as in the case of commissioning assessments, this tolerance is not relevant. The purpose of this work is to provide mean doses for direct digital radiography (DDR) X-ray system, operating in AEC, against which comparisons can be made. Dose measurements have been recorded under AEC operation on 29 DDR detectors from three different manufacturers. Two different testing protocols were examined: (1) water equivalent phantoms in front of the DDR detector and (2) aluminium block at the tube head. The average patient exit dose, using the aluminium block was 4.6 μGy with the antiscatter grid in place and 4.0 μGy with the grid removed. Using the water phantoms, the average dose was measured at 17.1 μGy with the antiscatter grid in place and 5.4 μGy with grid removed. Based on these results, it is clear that different testing configurations significantly impact on the measured dose.

  2. Knowledge-based automated feature extraction to categorize secondary digitized radiographs

    NASA Astrophysics Data System (ADS)

    Kohnen, Michael; Vogelsang, Frank; Wein, Berthold B.; Kilbinger, Markus W.; Guenther, Rolf W.; Weiler, Frank; Bredno, Joerg; Dahmen, Joerg

    2000-06-01

    An essential part of the IRMA-project (Image Retrieval in Medical Applications) is the categorization of digitized images into predefined classes using a combination of different independent features. To obtain an automated and content-based categorization, the following features are extracted from the image data: Fourier coefficients of normalized projections are computed to supply a scale- and translation-invariant description. Furthermore, histogram information and Co-occurrence matrices are calculated to supply information about the gray value distribution and textural information. But the key part of the feature extraction is the shape information of the objects represented by an Active Shape Model. The Active Shape Model supports various form variations given by a representative training set; we use one particular Active Shape Model for each image class. These different Active Shape Models are matched on preprocessed image data with a simulated annealing optimization. The different extracted features were chosen with regard to the different characteristics of the image content. They give a comprehensive description of image content using only few different features. Using this combination of different features for categorization results in a robust classification of image data, which is a basic step towards medical archives that allow retrieval results for queries of diagnostic relevance.

  3. Assessment of two-dimensional (2D) and three-dimensional (3D) lower limb measurements in adults: Comparison of micro-dose and low-dose biplanar radiographs.

    PubMed

    Rosskopf, Andrea B; Pfirrmann, Christian W A; Buck, Florian M

    2016-09-01

    To evaluate reliability of 2D and 3D lower limb measurements in adults using micro-dose compared to low-dose biplanar radiographs(BPR). One hundred patients (mean 54.9 years) were examined twice using micro-dose and low-dose BPR. Length and mechanical axis of lower limbs were measured on the antero-posterior(ap) micro-dose and low-dose images by two independent readers. Femoral and tibial torsions of 50 patients were measured by two independent readers using reconstructed 3D-models based on the micro-dose and low-dose BPR. Intermethod and interreader agreements were calculated using descriptive statistics, intraclass-correlation-coefficient(ICC), and Bland-Altman analysis. Mean interreader-differences on micro-dose were 0.3 cm(range 0-1.0)/ 0.7°(0-2.9) for limb length/axis and 0.4 cm (0-1.0)/0.8°(0-3.3) on low-dose BPR. Mean intermethod-difference was 0.04 cm ± 0.2/0.04° ± 0.6 for limb length/axis. Interreader-ICC for limb length/axis was 0.999/0.991 on micro-dose and 0.999/0.987 on low-dose BPR. Interreader-ICC for micro-dose was 0.879/0.826 for femoral/ tibial torsion, for low-dose BPR was 0.924/0.909. Mean interreader-differences on micro-dose/low-dose BPR were 3°(0-13°)/2°(0°-12°) for femoral and 4°(0-18°)/3°(0°-10°) for tibial torsion. Mean intermethod-difference was -0.1° ± 5.0/-0.4° ± 2.9 for femoral/tibial torsion. Mean dose-area-product was significantly lower (9.9 times;p < 0.001) for micro-dose BPR. 2D-and 3D-measurements of lower limbs based on micro-dose BPR are reliable and provide a 10-times lower radiation dose. • Lower limb length and mechanical axis can be reliably measured with micro-dose. • Femoral and tibial torsion can be reliably assessed with micro-dose. • Micro-dose allows a huge reduction of radiation exposure.

  4. Prenatal sex hormone exposure and risk of Alzheimer disease: a pilot study using the 2D:4D digit length ratio.

    PubMed

    Vladeanu, Matei; Giuffrida, Orazio; Bourne, Victoria J

    2014-06-01

    Our aim was to investigate an association between prenatal sex hormone exposure and dementia diagnosis. Some evidence indicates that relatively low testosterone levels are a risk factor for men to develop Alzheimer disease (AD). Most research has examined current rather than premorbid testosterone levels, and little research has addressed testosterone and AD in women. In 20 men and women diagnosed with AD and 20 controls, we estimated prenatal exposure to testosterone and estrogen using the ratio of the length of the second to the fourth digit (2D:4D). We analyzed the data using a 2 (men versus women)×2 (controls versus AD participants) analysis of variance. The men with AD had significantly higher 2D:4D ratios than the male controls, indicating lower levels of prenatal testosterone and higher levels of prenatal estrogen exposure. The women with AD had significantly lower 2D:4D ratios than the female controls, indicating higher levels of prenatal testosterone and lower levels of prenatal estrogen exposure. These findings suggest that lower levels of prenatal testosterone and higher levels of estrogen exposure are a risk factor for AD in men, and that higher levels of prenatal testosterone and lower levels of prenatal estrogen exposure are a risk factor for women. Risk for AD may be related to prenatal exposure to a sex hormone different from an individual's chromosomal sex.

  5. Effect of image processing version on detection of non-calcification cancers in 2D digital mammography imaging

    NASA Astrophysics Data System (ADS)

    Warren, L. M.; Cooke, J.; Given-Wilson, R. M.; Wallis, M. G.; Halling-Brown, M.; Mackenzie, A.; Chakraborty, D. P.; Bosmans, H.; Dance, D. R.; Young, K. C.

    2013-03-01

    Image processing (IP) is the last step in the digital mammography imaging chain before interpretation by a radiologist. Each manufacturer has their own IP algorithm(s) and the appearance of an image after IP can vary greatly depending upon the algorithm and version used. It is unclear whether these differences can affect cancer detection. This work investigates the effect of IP on the detection of non-calcification cancers by expert observers. Digital mammography images for 190 patients were collected from two screening sites using Hologic amorphous selenium detectors. Eighty of these cases contained non-calcification cancers. The images were processed using three versions of IP from Hologic - default (full enhancement), low contrast (intermediate enhancement) and pseudo screen-film (no enhancement). Seven experienced observers inspected the images and marked the location of regions suspected to be non-calcification cancers assigning a score for likelihood of malignancy. This data was analysed using JAFROC analysis. The observers also scored the clinical interpretation of the entire case using the BSBR classification scale. This was analysed using ROC analysis. The breast density in the region surrounding each cancer and the number of times each cancer was detected were calculated. IP did not have a significant effect on the radiologists' judgment of the likelihood of malignancy of individual lesions or their clinical interpretation of the entire case. No correlation was found between number of times each cancer was detected and the density of breast tissue surrounding that cancer.

  6. Poster - Thur Eve - 75: Towards MR only simulation: MR based digitally reconstructed radiograph of head and neck.

    PubMed

    Yu, H; Mah, K; Balogh, J

    2012-07-01

    To develop a practical method to obtain bony structures from Magnetic Resonance (MR) images and to create MR- based digitally reconstructed radiographs (DRR) for MR only simulation. Using T1-weighted MR images, air regions including the sinuses and the airway in the head and neck were manually contoured. The bone and soft tissue masks were automatically generated based on the statistical data calculated from the air contour and MR intensities. "CT like" MR images were generated by mapping the MR intensities of the voxels within these masks into the CT number ranges of these tissues. The MR-based DRRs created from "CT like" MR images were quantitatively evaluated using the co-registered MR and CT images of 10 stereotactic radiosurgery CNS patients. Ten anatomical control points, set on the contours of the skull segmented using a threshold of 300 HU were used to determine the differences in distance between MR-based DRRs and CT-based DRRs, and to evaluate the geometrical accuracy of MR-based DRRs. The bony structures were visible in the MR-based DRRs. The mean geometric difference and standard deviation between the ten anatomical control points on MR- based and CT-based DRRs were -0.03±1.11 mm (including uncertainty of image fusion). The maximum distance difference was 1.67mm. The study provides a practical method to generate MR- based DRRs from MR-only simulations of the head and neck regions. The image quality and anatomical accuracy of MR-based DRRs is comparable to that of CT-based DRRs. © 2012 American Association of Physicists in Medicine.

  7. Computer-aided detection of masses in digital tomosynthesis mammography: combination of 3D and 2D detection information

    NASA Astrophysics Data System (ADS)

    Chan, Heang-Ping; Wei, Jun; Zhang, Yiheng; Moore, Richard H.; Kopans, Daniel B.; Hadjiiski, Lubomir; Sahiner, Berkman; Roubidoux, Marilyn A.; Helvie, Mark A.

    2007-03-01

    We are developing a computer-aided detection (CAD) system for masses on digital breast tomosynthesis mammograms (DBTs). The CAD system includes two parallel processes. In the first process, mass detection and feature analysis are performed in the reconstructed 3D DBT volume. A mass likelihood score is estimated for each mass candidate using a linear discriminant (LDA) classifier. In the second process, mass detection and feature analysis are applied to the individual projection view (PV) images. A mass likelihood score is estimated for each mass candidate using another LDA classifier. The mass likelihood images derived from the PVs are back-projected to the breast volume to estimate the 3D spatial distribution of the mass likelihood scores. The mass likelihood scores estimated by the two processes at the corresponding 3D location are then merged and evaluated using FROC analysis. In this preliminary study, a data set of 52 DBT cases acquired with a GE prototype system at the Massachusetts General Hospital was used. The LDA classifiers with stepwise feature selection were designed with leave-one-case-out resampling. In an FROC analysis, the CAD system for detection in the DBT volume alone achieved test sensitivities of 80% and 90% at an average FP rate of 1.6 and 3.0 per breast, respectively. In comparison, the average FP rates of the combined system were 1.2 and 2.3 per breast, respectively, at the same sensitivities. The combined system is a promising approach to improving mass detection on DBTs.

  8. Influence of Image Filters and Variation in Horizontal Angle of Incidence of X-ray Beam in Digital Interproximal Radiographs for Diagnosis of Secondary Caries in Esthetic Restorations.

    PubMed

    Deprá, Lucas de Carvalho; Vessoni Iwaki, Lilian Cristina; Chicarelli, Mariliani; Takeshita, Wilton Mitsunari

    2015-10-01

    Secondary or recurrent caries are located around restoration margins or under these lesions, and can lead to tooth loss. The interproximal or bite wing radiograph is the technique of choice to assist diagnosis of secondary caries. To evaluate diagnostic accuracy of secondary caries in pulpal walls artificially created in extracted human premolars, observed in digital bitewing radiographs using variations in horizontal X-ray beam angle of incidence and application of enhancement filters. The sample consisted of 20 healthy premolars, in which secondary caries lesions were simulated by means of subjecting the pulpal wall of the cavity to wear with spherical carbide drill half, fitted to a high speed handpiece, under constant cooling, focused perpendicular to the tooth surface. The orifices were filled with wax and all teeth were restored with composite resin Filtek Z350 XT(®). Later teeth were radiographed with a digital sensor complementary metal-oxide-semiconductor (CMOS) varying the horizontal angle at intervals of 2°, covering a range of -10 to +10°. The results showed that in the diagnosis of secondary caries, there was no statistically significant difference between the 2 pseudocolor filters, and negative and direct digital radiography. The pseudocolor filter no. 1 showed statistically significant differences, except at a horizontal angle of 0°, thus indicating lower efficiency in the diagnosis of secondary caries. Secondary caries with esthetic pulp wall restoration can be diagnosed irrespective of variation in the horizontal angle of incidence of the X-ray beam. The use of different radiographic enhancement filters did not result in improved diagnosis of secondary caries.

  9. Androgens concentrations and second-to fourth-digit ratio (2D:4D) in girls with congenital adrenal hyperplasia (21-hydroxylase deficiency).

    PubMed

    Oswiecimska, Joanna M; Ksiazek, Agnieszka; Sygulla, Katarzyna; Pys-Spychala, Magdalena; Roczniak, Grzegorz R; Roczniak, Wojciech; Stojewska, Malgorzata; Ziora, Katarzyna

    2012-01-01

    Excessive hyperandrogenism, though proper hydrocortisone supplementation is a frequent clinical problem in girls with congenital adrenal hyperplasia (CAH). This may result from autonomic regulation of androgen production established in prenatal life. It has been suggested that the length of the second finger relative to the length of the fourth finger (2D;4D ratio) is negatively related to prenatal testosterone concentration. The retrospective study aimed to establish the relationship between the level of androgenization in utero determined using 2D:4D ratio and serum androgen concentrations in treated girls with CAH (21-OH deficiency) has been performed on 19 girls with CAH (21-OH deficiency) at the age of 3.7-19 years (mean 13.8 ± 4.07 years). All subjects were adequately treated with hydrocortisone (10-19 mg/m2; mean 13.81 ± 4.07 mg/m2). Anthropometric measurements of digits length were performed in all girls on X-rays obtained for bone age estimation. Apart from it, serum androgens concentrations (testosterone, androstenedione, s-DHEA) and 17-OH-progesterone (17-OHP) were assayed. Mean androgens serum concentrations in examined group were: testosterone 150.21 ± 155.44 ng/ml; androstenedione 4.15 ± 5.32 ng/ml, s-DHEA 70.39 ± 85.52 µg/dl. Mean 2D:4D ratio was 0.96 ± 0.04. Analysis of correlation showed positive linear correlations between testosterone, s-DHEA and 2D:4D ratio (r=0.53, p=0.023 and r=0.53; p=0.019, respectively). 2D:4D ratio parameter may be a simple test in indentification of female CAH patients prone to excessive androgen secretion despite proper treatment. The autonomization of adrenal androgens production in foetal life may cause its elevated levels in female patients with CAH although treated adequately.

  10. Cerebral laterality for language is related to adult salivary testosterone levels but not digit ratio (2D:4D) in men: A functional transcranial Doppler ultrasound study.

    PubMed

    Papadatou-Pastou, Marietta; Martin, Maryanne

    2017-03-01

    The adequacy of three competing theories of hormonal effects on cerebral laterality are compared using functional transcranial Doppler sonography (fTCD). Thirty-three adult males participated in the study (21 left-handers). Cerebral lateralization was measured by fTCD using an extensively validated word generation task. Adult salivary testosterone (T) and cortisol (C) concentrations were measured by luminescence immunoassay and prenatal T exposure was indirectly estimated by the somatic marker of 2nd to 4th digit length ratio (2D:4D). A significant quadratic relationship between degree of cerebral laterality for language and adult T concentrations was observed, with enhanced T levels for strong left hemisphere dominance and strong right hemisphere dominance. No systematic effects on laterality were found for cortisol or 2D:4D. Findings suggest that higher levels of T are associated with a relatively attenuated degree of interhemispheric sharing of linguistic information, providing support for the callosal and the sexual differentiation hypotheses rather than the Geschwind, Behan and Galaburda (GBG) hypothesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. [Effects of image post-processing parameters on digital radiography chest radiograph for the diagnosis of pneumoconiosis].

    PubMed

    Chen, Jun-Qiang; Jiang, Zhao-Qiang; Zhou, Bin; Zhu, Qiang; Liu, Bin; Zhang, Xing

    2012-01-01

    To explore the effects of image post-processing parameters on DR chest radiograph for the diagnosis of pneumoconiosis. Eighty three coal miners were examined with high-kV and DR chest radiographs at the same time. Image post-processing parameters (density, contrast and so on) were designed in a Philips Essenta DR machine were designed, then differences of image quality between high-kV and DR chest radiographs were compared. After regulating image and proceeding the parameters, the OD (optical density) values of high density areas in the upper-middle lung fields, subphrenic and direct exposure areas were 1.58 +/- 0.10, 0.23 +/- 0.02 and 2.80 +/- 0.21, respectively. The quality of chest films met the requirements of diagnostic criteria of pneumoconiosis. The rate of excellent chest films for DR chest radiograph was 95.18%, which was significantly higher than that (80.72%) for high-kV chest radiograph (P < 0.01). Appropriate parameters of image post-processing can make DR chest radiograph to meet the requirements of chest radiograph quality for the diagnosis of pneumoconiosis.

  12. UmUTracker: A versatile MATLAB program for automated particle tracking of 2D light microscopy or 3D digital holography data

    NASA Astrophysics Data System (ADS)

    Zhang, Hanqing; Stangner, Tim; Wiklund, Krister; Rodriguez, Alvaro; Andersson, Magnus

    2017-10-01

    We present a versatile and fast MATLAB program (UmUTracker) that automatically detects and tracks particles by analyzing video sequences acquired by either light microscopy or digital in-line holographic microscopy. Our program detects the 2D lateral positions of particles with an algorithm based on the isosceles triangle transform, and reconstructs their 3D axial positions by a fast implementation of the Rayleigh-Sommerfeld model using a radial intensity profile. To validate the accuracy and performance of our program, we first track the 2D position of polystyrene particles using bright field and digital holographic microscopy. Second, we determine the 3D particle position by analyzing synthetic and experimentally acquired holograms. Finally, to highlight the full program features, we profile the microfluidic flow in a 100 μm high flow chamber. This result agrees with computational fluid dynamic simulations. On a regular desktop computer UmUTracker can detect, analyze, and track multiple particles at 5 frames per second for a template size of 201 ×201 in a 1024 × 1024 image. To enhance usability and to make it easy to implement new functions we used object-oriented programming. UmUTracker is suitable for studies related to: particle dynamics, cell localization, colloids and microfluidic flow measurement. Program Files doi : http://dx.doi.org/10.17632/fkprs4s6xp.1 Licensing provisions : Creative Commons by 4.0 (CC by 4.0) Programming language : MATLAB Nature of problem: 3D multi-particle tracking is a common technique in physics, chemistry and biology. However, in terms of accuracy, reliable particle tracking is a challenging task since results depend on sample illumination, particle overlap, motion blur and noise from recording sensors. Additionally, the computational performance is also an issue if, for example, a computationally expensive process is executed, such as axial particle position reconstruction from digital holographic microscopy data. Versatile

  13. WE-AB-BRA-07: Quantitative Evaluation of 2D-2D and 2D-3D Image Guided Radiation Therapy for Clinical Trial Credentialing, NRG Oncology/RTOG

    SciTech Connect

    Giaddui, T; Yu, J; Xiao, Y; Jacobs, P; Manfredi, D; Linnemann, N

    2015-06-15

    Purpose: 2D-2D kV image guided radiation therapy (IGRT) credentialing evaluation for clinical trial qualification was historically qualitative through submitting screen captures of the fusion process. However, as quantitative DICOM 2D-2D and 2D-3D image registration tools are implemented in clinical practice for better precision, especially in centers that treat patients with protons, better IGRT credentialing techniques are needed. The aim of this work is to establish methodologies for quantitatively reviewing IGRT submissions based on DICOM 2D-2D and 2D-3D image registration and to test the methodologies in reviewing 2D-2D and 2D-3D IGRT submissions for RTOG/NRG Oncology clinical trials qualifications. Methods: DICOM 2D-2D and 2D-3D automated and manual image registration have been tested using the Harmony tool in MIM software. 2D kV orthogonal portal images are fused with the reference digital reconstructed radiographs (DRR) in the 2D-2D registration while the 2D portal images are fused with DICOM planning CT image in the 2D-3D registration. The Harmony tool allows alignment of the two images used in the registration process and also calculates the required shifts. Shifts calculated using MIM are compared with those submitted by institutions for IGRT credentialing. Reported shifts are considered to be acceptable if differences are less than 3mm. Results: Several tests have been performed on the 2D-2D and 2D-3D registration. The results indicated good agreement between submitted and calculated shifts. A workflow for reviewing these IGRT submissions has been developed and will eventually be used to review IGRT submissions. Conclusion: The IROC Philadelphia RTQA center has developed and tested a new workflow for reviewing DICOM 2D-2D and 2D-3D IGRT credentialing submissions made by different cancer clinical centers, especially proton centers. NRG Center for Innovation in Radiation Oncology (CIRO) and IROC RTQA center continue their collaborative efforts to enhance

  14. Evaluation of the image quality of ink-jet printed paper copies of digital chest radiographs as compared with film: a receiver operating characteristic study.

    PubMed

    Lyttkens, K; Kirkhorn, T; Kehler, M; Andersson, B; Ebbesen, A; Hochbergs, P; Jarlman, O; Lindberg, C G; Holmer, N G

    1994-05-01

    Paper copies of digital radiographs printed with the continuous ink-jet technique have proved to be of a high enough quality for demonstration purposes. We present a study on the image quality of ink-jet printed paper copies of digital chest radiographs, based on receiver operating characteristic (ROC) analysis. Eighty-three digital radiographs of a chest phantom with simulated tumors in the mediastinum and right lung, derived from a computed radiography (CR) system were presented in two series of hard copies as ink-jet printed paper copies and as laser recorded film. The images, with a matrix of 1,760 x 2,140 pixels, were printed with a spatial resolution of 10 pixels/mm in the CR film recorder as well as in the ink-jet printer. On film, every image was recorded in two versions, one optimized for the mediastinum and one for the lungs. On paper, only one image was printed; this constituted an effort to optimize both the mediastinum and the lungs. The ink-jet printed images, printed on a matt coated paper, were viewed as on-sight images with reflected light. The examinations were reviewed by six radiologists, and ROC curves were constructed. No significant difference was found between the performance of film and that of ink-jet paper prints. Because the cost for a paper copy is only a tenth of that of film, remarkable cost reductions can be achieved by using the ink jet technique instead. Our results show that further quality studies of ink-jet printed images are worthwhile.

  15. Diagnostic accuracy of carious lesions in digital radiographs at a public dental clinic - can it be improved by optimizing viewing conditions and further education?.

    PubMed

    Milosavljevic, Aleksandar; Westerberg, Jane; Hellén-Halme, Kristina

    2016-01-01

    This study investigated the diagnostic accuracy of digital dental radiograpny for detecting carious lesions on approximal surfaces before and after optimization of the environ- ment, and after joint training on evaluation and review of x-rays. A further aim was to evaluate differences in diagnostic accuracy between general dental practitioners (GDPs) and dental hygienists (DHs). One hundred extracted teeth (premolars and molars) underwent standardized radiography. Eleven participants (seven GDPs and four DHs) evaluated digital images for approximal carious lesions in three sessions: (1) at current conditions with no optimization or further training, (2) under optimized viewing conditions, and (3) under optimized viewing conditions after a short educational session. Receiver operating characteristic curves were,used to evaluate the results. Histological evaluation was made and served as a cri- terion standard for differentiating sound teeth and teeth with carious lesions. Kappa statistics evaluated intra-observer agreement. Diagnostic accuracy in the GDP group differed sig- nificantlyfor all types of carious lesions between the first and third evaluations (p=0.002), and also between the second and third (p=0.015). Diagnostic accuracy also differed significantly for carious lesions into the dentin between the first and third evaluations (p=0.010) and between the second and third (p=0.015). Most of the staff had optimized the environment when evaluating digital radiographs. A short educational session highlighting the difficulty of caries diagnostics in digital dental radiography can increase diagnostic accuracy. Diagnostic accuracy in the detection of approximal carious lesions on digital radiographs did not differ between GDPs and DHs.

  16. Is early postnatal growth velocity, a proxy of minipubertal androgen action, related to adult second-to-fourth digit (2D:4D) ratios in men? A test in Cebu, Philippines.

    PubMed

    Georgiev, Alexander V; Ryan, Calen P; Borja, Judith B; Kuzawa, Christopher W

    2017-07-31

    The ratio of the length of the second to the fourth digit (2D:4D) of the hand is often used as an index of prenatal androgen exposure but it might also be affected by androgens during "minipuberty," a period of temporarily high testosterone (T) production in the first few months of life. To examine this, we tested the prediction that men with lower 2D:4D ratios had greater weight growth velocities during the first months of life-a metric recently shown to correlate with concurrent T levels. We related early growth data to 2D:4D ratios of both hands measured in 756 men (25-26 years) from Cebu, The Philippines. Birth-to-fourth-month (B4M) weight gain velocity (a proxy of early postnatal androgen action) was not associated with adult 2D:4D ratios of either hand, when the latter was measured continuously. When comparing men with more male-typical digit ratios (<1.0) to those with more female-typical ratios (≥ 1.0), the group of men with more male-typical ratios had greater B4M weight velocity, but this was only the case for the left hand. We found modest evidence that adult digit ratios relate to an anthropometric correlate of androgen exposure during minipuberty. Definitive assessment of the role of postnatal T in shaping digit ratios will require direct measures of perinatal T related to longitudinally assessed digit ratios. © 2017 Wiley Periodicals, Inc.

  17. Anatomical evaluation of the cervical vertebrae of Wistar rats by means of digital radiographs and its correlation with the maturation stages of human cervical vertebrae.

    PubMed

    Matsui, Roberto Hiroshi; Castilho, Julio Cezar de Melo; de Moraes, Luiz César; Gomes, Mônica Fernandes; Faltin Júnior, Kurt; Matsui, Miriam Yumi

    2013-01-01

    Biological age is an important parameter for growth and development assessment. It can be evaluated through the observation of radiographic changes in skeletal maturation of cervical vertebrae. This study aims to: a) verify if there is correlation between growth curve and the stages of bone age of animals used in laboratories, by evaluating radiographs of the cervical vertebrae; b) correlate these stages with their correspondents in humans. 35 Wistar rats were evaluated for a period of 160 days, starting at day 22nd (weaning), with cross sections for periodic weighing, length measurement and digital radiography. Radiographs of the cervical vertebrae (C2 and C3) were measured by means of a computer program (Radio IMP). Data were submitted to statistical analysis (ANOVA) and Pearson correlation. Growth spurt was characterized by fast increasing in weight and length. Through ANOVA, differences were observed in the cervical measurements between days 22, 97, 127, 157, 187 and 217 (p <0.001). A high correlation was found between increasing in body length and weight, as well as in cervical vertebrae height (r = 0.86). Increments in concavities of vertebrae were also observed, similar to humans. There is correlation between body growth and maturation of cervical vertebrae in rats. Despite the continuous development of concavities, it was not possible to clearly identify the 5/6 stages as in studies of cervical vertebrae maturation in humans.

  18. Analysis and Visualization of 2D and 3D Grain and Pore Size ofFontainebleau Sandstone Using Digital Rock Physics

    NASA Astrophysics Data System (ADS)

    Latief, FDE

    2016-08-01

    Fontainebleau sandstone is sandstone found in one of the cities in France. This sandstone has unique characteristics, which is a clean-fme sandstone, composed of 99% quartz, virtually devoid of clay, with the grain size of about 200 μm. Fontainebleau sandstone is widely used as a reference in the study of rock microstructure analysis and modelling. In this work analysis regarding the grain and pore size of Fontainebleau is presented. Calculation of 2D pore size and grain size distribution were done on the 299 slice of digital image of the Fontainebleau sandstone using Feret's diameters, equivalent diameters (d = 4A/P), and by means of local thickness/separation using plate model. For the 3D grain and pore size distribution, calculation of local thickness and local separation of the structure were used. Two dimensional analysis by means of Feret's diameter and equivalent diameter reveal that both grain and pore size distributions are in the form of reverse-J shaped (right skewed) while the local thickness/separation approach produces almost similar to symmetric Gaussian distribution. Three dimensional analysis produces fairly symmetric Gaussian distribution for both the grain and pore size. Further image processing were conducted and were succeed in producing three dimensional visual of the colour coded structure thickness (grain related) and structure separation (pore related).

  19. FURTHER EVIDENCE OF AN ASSOCIATION BETWEEN LOW SECOND-TO-FOURTH DIGIT RATIO (2D:4D) AND SELECTION FOR THE UNIFORMED SERVICES: A STUDY AMONG POLICE PERSONNEL IN WROCŁAW, POLAND.

    PubMed

    Kozieł, Sławomir; Kociuba, Marek; Chakraborty, Raja; Sitek, Aneta; Ignasiak, Zofia

    2017-08-22

    Males and females differ in their preference for occupations and sporting activities, and differ also in risk-taking attitudes. In addition to other explanations, prenatal hormone exposure has been implicated in these gender-associated differences. The ratio of the relative lengths of the second-to-fourth digits (2D:4D) is a proxy indicator of prenatal exposure to testosterone relative to oestrogen. The 2D:4D ratio has been found to be associated with choice of occupation, particularly among females. This study investigated whether 2D:4D differed between police officers and a control group of civilians in Wrocław, Poland. Participants were 147 male and 55 female police officers and 91 male and 75 female civilian controls. The police officers had to undergo rigorous physical ability tests during recruitment and their job bore relatively higher risk, whereas the controls had a normal civilian lifestyle. Height, weight, hand grip strength and lengths of the second and fourth digits were measured. Analyses of variance and covariance were employed to assess the significance of difference in digit ratio between groups (police officers and civilians) allowing for interaction with sex. The policewomen, compared with the female controls, were taller and had stronger hand grip strength, but had lower 2D:4D in the right hand and average 2D:4D of both hands. However, male and female police officers slightly differed only in the right hand digit ratio but not in the left hand ratio or the average for the two hands. However, the control group showed significant sex differences in all digit ratios with higher (feminine) mean values in females. The study provides further evidence that prenatal testosterone exposure, as reflected in the 2D:4D ratio, might have an association with choice of occupation, particularly among females.

  20. Early prediction of mandibular third molar eruption/impaction using linear and angular measurements on digital panoramic radiography: A radiographic study

    PubMed Central

    Kaur, Rachninder; Kumar, Anand C.; Garg, Ranjana; Sharma, Sugandha; Rastogi, Trisha; Gupta, Vivek Vijay

    2016-01-01

    Background: The impaction rate is higher for the third molars than for any other tooth in modern human population. This study was conducted with the aim to evaluate the validity of linear and angular measurements on the digital panoramic radiograph as a reference for early prediction of mandibular third molar eruption/impaction. Materials and Methods: Digital panoramic radiographs of 200 subjects were selected based on their status of eruption of mandibular third molars; fully erupted (Group A), partially erupted (Group B), fully developed but not erupted (Group C) and partially developed groups (Group D). Each group comprised 50 subjects with 25 males and 25 females. Nine variables (linear measurements, angles, and ratios) were determined and measured bilaterally by two observers and values were compared between the study groups and genders. Results: The data thus obtained were analyzed for comparison among all the study groups. It was found that the difference in the mean values of lower eruption space (LES) measurements, α-angle (angle between long axis of the third molar and gonial-symphyseal plane) and β-angle (angle between long axis of mandibular second and third molars) were significant (P < 0.05). The mean values of mesiodistal width, LES-ramus, LES-Xi point and β-angle were found more in males than in females. No significant difference was observed between the sides. Conclusion: α- and β-angle together with LES measurements give the accurate information on early prediction of lower third molar eruption or impaction. PMID:27433048

  1. Diagnostic yield of ink-jet prints from digital radiographs for the assessment of approximal carious lesions: ROC-analysis.

    PubMed

    Schulze, Ralf K W; Grimm, Stefanie; Schulze, Dirk; Voss, Kai; Keller, Hans-Peter; Wedel, Matthias

    2011-08-01

    To investigate the diagnostic quality of different quality, individually calibrated ink-jet printers for the very challenging dental radiographic task of approximal carious lesion detection. A test-pattern evaluating resolution, contrast and homogeneity of the ink-jet prints was developed. 50 standardized dental radiographs each showing two neighbouring teeth in natural contact were printed on glossy paper with calibrated, randomly selected ink-jet printers (Canon S520 and iP4500, Epson Stylus Photo R2400). Printing size equalled the viewing size on a 17″ cathode-ray-tube monitor daily quality-tested according to German regulations. The true caries status was determined from serial sectioning and microscopic evaluation. 16 experienced observers evaluated the radiographs on a five-point confidence scale on all prints plus the viewing monitor with respect to the visibility of a carious lesion. A non-parametric Receiver-Operating Characteristics (ROC-) analysis was performed explicitly designed for the evaluation of readings stemming from identical samples but different modality. Significant differences are expressed by a critical ratio z exceeding ±2. Diagnostic accuracy was determined by the area (Az) underneath the ROC-curves. Average Az-values ranged between 0.62 (S520 and R2400) and 0.64 (monitor, iP4500), with no significant difference between modalities (P=0.172). Neither significant (range mean z: -0.40 (S520) and -0.11 (iP4500)) nor clinically relevant differences were found between printers and viewing monitor. Our results for a challenging task in dental radiography indicate that calibrated, off-the-shelf ink-jet printers are able to reproduce (dental) radiographs at quality levels sufficient for radiographic diagnosis in a typical dental working environment. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  2. Digital Paper Prints as Replacement for LASER Films: A Study of Intra-Observer Agreement for Wrist Radiographic Findings in Rickets.

    PubMed

    Jain, Abhinav; Gupta, Priyanka; Anand, Surinder Pal Singh; Dang, Archana

    2016-08-01

    Replacement of conventional LASER films with digital paper prints as supplement to radiology reports may serve as an economical and environment friendly method. However, it is essential that such a change does not compromise patient's intended diagnostic outcome. The aim of this study was to assess the reliability and acceptability of digital paper prints for the radiographic images by the treating physicians and radiologists. This observational analytical study was done at a tertiary care hospital of New Delhi, India. A total of 58 consecutively ordered wrist radiographs of paediatric patients (6 months to 12 years of age) for ruling out rickets were retrieved from the PACS (Picture Archiving and Communication System). These 58 radiographs, out of which 21 (36.2%) had radiological evidence of rickets over PACS were printed on two different media i.e., LASER films and glossy photographic paper. An objective scoring for the severity of rickets was done on both LASER films and paper prints by six observers independently. Overall comfort level with paper prints was rated on a 1-5 point Likert scale. Data was analysed using STATA 14.0 (Stata Corp, College Station, TX). Intra-observer percentage agreement and value of Cohen's kappa for PACS vs. LASER films and PACS vs. paper prints was equal i.e., 98.3% and 0.97, respectively. Intra-observer agreement between LASER films and paper prints for all six observers was excellent, ranging from 0.92 to 1.00; percentage agreement ranging from 94.8% to 100%. Fracture of ulna/radius present in 4 sets of the X-rays was well demonstrated in both LASER films and paper prints. Comfort level with paper prints was rated as 5 out of 5 by all due to no requirement of any special illuminated view box and dark room. This study concludes that the use of paper prints may serve as a reliable alternative to LASER films to communicate the report of wrist radiographs for the treating physicians without any compromise over diagnostic information

  3. Digital Paper Prints as Replacement for LASER Films: A Study of Intra-Observer Agreement for Wrist Radiographic Findings in Rickets

    PubMed Central

    Jain, Abhinav; Anand, Surinder Pal Singh; Dang, Archana

    2016-01-01

    Introduction Replacement of conventional LASER films with digital paper prints as supplement to radiology reports may serve as an economical and environment friendly method. However, it is essential that such a change does not compromise patient’s intended diagnostic outcome. Aim The aim of this study was to assess the reliability and acceptability of digital paper prints for the radiographic images by the treating physicians and radiologists. Materials and Methods This observational analytical study was done at a tertiary care hospital of New Delhi, India. A total of 58 consecutively ordered wrist radiographs of paediatric patients (6 months to 12 years of age) for ruling out rickets were retrieved from the PACS (Picture Archiving and Communication System). These 58 radiographs, out of which 21 (36.2%) had radiological evidence of rickets over PACS were printed on two different media i.e., LASER films and glossy photographic paper. An objective scoring for the severity of rickets was done on both LASER films and paper prints by six observers independently. Overall comfort level with paper prints was rated on a 1-5 point Likert scale. Data was analysed using STATA 14.0 (Stata Corp, College Station, TX). Results Intra-observer percentage agreement and value of Cohen’s kappa for PACS vs. LASER films and PACS vs. paper prints was equal i.e., 98.3% and 0.97, respectively. Intra-observer agreement between LASER films and paper prints for all six observers was excellent, ranging from 0.92 to 1.00; percentage agreement ranging from 94.8% to 100%. Fracture of ulna/radius present in 4 sets of the X-rays was well demonstrated in both LASER films and paper prints. Comfort level with paper prints was rated as 5 out of 5 by all due to no requirement of any special illuminated view box and dark room. Conclusion This study concludes that the use of paper prints may serve as a reliable alternative to LASER films to communicate the report of wrist radiographs for the treating

  4. Evaluation of hand bone loss by digital X-ray radiogrammetry as a complement to clinical and radiographic assessment in early rheumatoid arthritis: results from the SWEFOT trial

    PubMed Central

    2013-01-01

    Background To investigate hand bone loss (HBL) measured by digital X-ray radiogrammetry (DXR) in patients with early rheumatoid arthritis (RA) receiving different treatment regimens, and to evaluate if DXR change rates during the first 12 months correlate with radiological damage after 24 months. Methods From the total SWEFOT trial population, 159 patients had hand radiographs correctly timed and taken with same modality to be analyzed with DXR. All patients started treatment with methotrexate. After 3–4 months, patients with DAS28 > 3.2 were randomized to add sulfasalazine and hydroxychloroquine (triple therapy) or infliximab (MTX + INF). Those with DAS28 ≤3.2 were followed in regular care. Radiographic progression over 24 months was scored according to the Sharp van der Heijde score (SHS) and defined as >5 increase in T-SHS over 24 months. Hand bone mineral density (BMD) was measured by DXR at inclusion and 12 months and a change ≥2.5 mg/cm2/month was used as a cut-off for HBL. Results In the MTX responders, triple therapy, and MTX + INF groups, the proportions with HBL were 4.1%, 22.2% and 16.4%, respectively (p = 0.01), and the mean (SD) radiological progression in these groups was 3.91 (6.72), 7.40 (14.63) and 2.72 (4.55) respectively (p = 0.06). Patients with HBL had significantly greater risk for radiographic progression, compared with patients without HBL (odds ratio 3.09, 95% CI =1.20–7.79, p = 0.02). Conclusions Non-responders to MTX had a significantly greater risk of HBL than MTX-responders, despite the add-on therapies. Patients with HBL during the 12 months had greater risk of radiographic progression after 24 months. Evaluation of HBL may help to identify patients who are at risk of radiographic progression. PMID:23497111

  5. 2D/3D Image Registration using Regression Learning

    PubMed Central

    Chou, Chen-Rui; Frederick, Brandon; Mageras, Gig; Chang, Sha; Pizer, Stephen

    2013-01-01

    In computer vision and image analysis, image registration between 2D projections and a 3D image that achieves high accuracy and near real-time computation is challenging. In this paper, we propose a novel method that can rapidly detect an object’s 3D rigid motion or deformation from a 2D projection image or a small set thereof. The method is called CLARET (Correction via Limited-Angle Residues in External Beam Therapy) and consists of two stages: registration preceded by shape space and regression learning. In the registration stage, linear operators are used to iteratively estimate the motion/deformation parameters based on the current intensity residue between the target projec-tion(s) and the digitally reconstructed radiograph(s) (DRRs) of the estimated 3D image. The method determines the linear operators via a two-step learning process. First, it builds a low-order parametric model of the image region’s motion/deformation shape space from its prior 3D images. Second, using learning-time samples produced from the 3D images, it formulates the relationships between the model parameters and the co-varying 2D projection intensity residues by multi-scale linear regressions. The calculated multi-scale regression matrices yield the coarse-to-fine linear operators used in estimating the model parameters from the 2D projection intensity residues in the registration. The method’s application to Image-guided Radiation Therapy (IGRT) requires only a few seconds and yields good results in localizing a tumor under rigid motion in the head and neck and under respiratory deformation in the lung, using one treatment-time imaging 2D projection or a small set thereof. PMID:24058278

  6. 2D/3D Image Registration using Regression Learning.

    PubMed

    Chou, Chen-Rui; Frederick, Brandon; Mageras, Gig; Chang, Sha; Pizer, Stephen

    2013-09-01

    In computer vision and image analysis, image registration between 2D projections and a 3D image that achieves high accuracy and near real-time computation is challenging. In this paper, we propose a novel method that can rapidly detect an object's 3D rigid motion or deformation from a 2D projection image or a small set thereof. The method is called CLARET (Correction via Limited-Angle Residues in External Beam Therapy) and consists of two stages: registration preceded by shape space and regression learning. In the registration stage, linear operators are used to iteratively estimate the motion/deformation parameters based on the current intensity residue between the target projec-tion(s) and the digitally reconstructed radiograph(s) (DRRs) of the estimated 3D image. The method determines the linear operators via a two-step learning process. First, it builds a low-order parametric model of the image region's motion/deformation shape space from its prior 3D images. Second, using learning-time samples produced from the 3D images, it formulates the relationships between the model parameters and the co-varying 2D projection intensity residues by multi-scale linear regressions. The calculated multi-scale regression matrices yield the coarse-to-fine linear operators used in estimating the model parameters from the 2D projection intensity residues in the registration. The method's application to Image-guided Radiation Therapy (IGRT) requires only a few seconds and yields good results in localizing a tumor under rigid motion in the head and neck and under respiratory deformation in the lung, using one treatment-time imaging 2D projection or a small set thereof.

  7. Second to fourth digit length ratio (2D:4D) and adult sex hormone levels: new data and a meta-analytic review.

    PubMed

    Hönekopp, Johannes; Bartholdt, Luise; Beier, Lothar; Liebert, Andreas

    2007-05-01

    The relative length of the second (index) to the fourth (ring) finger (2D:4D) is a putative negative correlate of prenatal testosterone (T) exposure. Therefore, 2D:4D (and to a lesser extent D(r-l), the difference between 2D:4D in the right hand and in the left hand) has often been used to study effects of prenatal androgenization on human behavior and cognition. However, evidence suggests that 2D:4D may also be related to levels of circulating sex hormones in adults. This would question the validity of 2D:4D as a means of studying the effects of prenatal sex hormones. Here we present new data from two non-clinical samples (64 women and 102 men) regarding the relationships of 2D:4D and D(r-l) with circulating sex hormone levels. We then present a meta-analytic review of all the present evidence regarding this issue. The results suggest that, in the normal population, 2D:4D and D(r-l) are not associated with adult sex hormone levels. The findings from this current study add to the growing body of evidence demonstrating that 2D:4D is a suitable tool to study the effects of prenatal androgenization on human behavior and cognition.

  8. Automatic and exam-type independent algorithm for the segmentation and extraction of foreground, background, and anatomy regions in digital radiographic images

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohui; Luo, Hui

    2004-05-01

    Processing optimization of digital radiographs requires the knowledge of the location and characteristics of both diagnostically relevant and irrelevant image regions. An algorithm has been developed that can automatically detect and extract foreground, background, and anatomy regions from a digital radiograph. This algorithm is independent of exam-type information and can deal with multiple-exposed computed radiography (CR) images. First, the image is subsampled, and the processing is done on the sub-sampled image to improve subsequent processing efficiency and reduce algorithm dependency on image noise and detector characteristics. Second, an initial background is detected using adaptive thresholding on the cumulative histogram of significant transition pixels and an iterative process, based on background variance. Third, foreground detection is conducted by: (1) classifying all significant transitions using a smart-edge detection, (2) delineating all lines that are possible collimation blades using Hough transform, (3) finding candidate partition blade pairs if the image has several radiation fields, (4) partitioning the image into sub-images containing only one radiation field using a divide-and-conquer process, and (5) identifying the best collimation for each sub-image from a tree-structured hypothesis list. Fourth, the background is regenerated using a region-growing process from identified background "seeds." Fifth, the background and foreground regions are merged and removed; the rest of the image is labeled and those large, connected regions are identified as anatomy regions. The algorithm has been trained and tested separately with two image sets from a wide variety of exam types. Each set consists of more than 2700 CR images acquired with KODAK DIRECTVIEW CR 800 Systems. The overall success rate in detecting both foreground and background is 97%.

  9. Comparison of changes in dental and bone radiographic densities in the presence of different soft-tissue simulators using pixel intensity and digital subtraction analyses

    PubMed Central

    de Molon, R S; Batitucci, R G; Spin-Neto, R; Paquier, G M; Sakakura, C E; Tosoni, G M

    2013-01-01

    Objectives: To evaluate the influence of soft-tissue simulation materials on dental and bone tissue radiographic densities using pixel intensity (PI) and digital subtraction radiography (DSR) analyses. Methods: 15 dry human mandibles were divided into halves. Each half was radiographed using a charge-coupled device sensor without a soft-tissue simulation material (Wm) and with 5 types of materials: acrylic (Ac), wax (Wx), water (Wt), wood (Wd) and frozen bovine tissue (Bt). Three thicknesses were tested for each material: 10 mm, 15 mm and 20 mm. The material was positioned in front of the mandible and the sensor parallel to the molar region. The radiation beam was perpendicular to the sensor at 30 cm focal spot-to-object distance. The digital images of the bone and dental tissue were captured for PI analyses. The subtracted images were marked with 14 landmark magnifications, and 2 areas of analyses were defined, forming the regions of interest. Shapiro–Wilk and Kruskal–Wallis tests followed by Dunn's post-test were used (p < 0.05). Results: DSR showed that both the material type and the thickness tested influenced the gain of density in bone tissue (p < 0.05). PI analyses of the bone region did not show these differences, except for the lower density observed in the image without soft-tissue simulation material. In the dental region, both DSR and PI showed that soft-tissue simulators did not influence the density in these regions. Conclusions: This study showed that the materials evaluated and their thicknesses significantly influenced the density-level gain in alveolar bone. In dental tissues, there was no density-level gain with any soft-tissue material tested. PMID:24005061

  10. An Analysis of Visibility and Anatomic Variations of Mandibular Canal in Digital Panoramic Radiographs of Dentulous and Edentulous Patients in Northern Iran Populations

    PubMed Central

    Nemati, Somayeh; Ashouri Moghadam, Anahita; Dalili Kajan, Zahra; Mohtavipour, Seyedeh Tahereh; Amouzad, Hasan

    2016-01-01

    Statement of the Problem Insufficient information about the anatomical positions and structure of mandibular canal provokes unwanted damage to this important structure of mandible. Purpose The aim of this study was to determine the visibility and anatomical variations of mandibular canal in digital panoramic radiographs of dentulous and edentulous patients in a sample of Iranian population. Materials and Method In this retrospective-analytical research, 249 digital panoramic radiographs in dentulous group and 126 in edentulous group were studied by an expert oral and maxillofacial radiologist. In both groups, the visibility of canal borders in anterior, middle, and posterior areas were examined. In dentulous group, the distance between the canal and apex of the first and second molars were measured. Canal-to-alveolar crest distance and lower mandibular border was measured in three different points for both groups. Finally, the upper-lower positions of canals were determined. Results In both groups, most visibility occurred in 1/3 of posterior and the least visibility was detected in 1/3 of anterior, with the intermediate being the most visible part (Type 2). There was no significant difference between the left and right sides in all cases. In dentulous group, no correlation was found between the visibility, age, and gender (p> 0.05); however, canal position was related to gender (p= 0.03 and p= 0.04 in right and left sides, respectively). High position was more frequent in females and intermediate position was more common in males. In edentulous group, no correlation was found between age, gender, and canal position (p> 0.05). Conclusion The most visibility of mandibular canal was in its third posterior and the least was in its third anterior part. Although the middle position of canal was more frequently visible than the high position in this study, it does not refute the possibility of damaging the mandibular canal in critical surgeries. PMID:27284556

  11. Comparison of changes in dental and bone radiographic densities in the presence of different soft-tissue simulators using pixel intensity and digital subtraction analyses.

    PubMed

    de Molon, R S; Batitucci, R G; Spin-Neto, R; Paquier, G M; Sakakura, C E; Tosoni, G M; Scaf, G

    2013-01-01

    To evaluate the influence of soft-tissue simulation materials on dental and bone tissue radiographic densities using pixel intensity (PI) and digital subtraction radiography (DSR) analyses. 15 dry human mandibles were divided into halves. Each half was radiographed using a charge-coupled device sensor without a soft-tissue simulation material (Wm) and with 5 types of materials: acrylic (Ac), wax (Wx), water (Wt), wood (Wd) and frozen bovine tissue (Bt). Three thicknesses were tested for each material: 10 mm, 15 mm and 20 mm. The material was positioned in front of the mandible and the sensor parallel to the molar region. The radiation beam was perpendicular to the sensor at 30 cm focal spot-to-object distance. The digital images of the bone and dental tissue were captured for PI analyses. The subtracted images were marked with 14 landmark magnifications, and 2 areas of analyses were defined, forming the regions of interest. Shapiro-Wilk and Kruskal-Wallis tests followed by Dunn's post-test were used (p < 0.05). DSR showed that both the material type and the thickness tested influenced the gain of density in bone tissue (p < 0.05). PI analyses of the bone region did not show these differences, except for the lower density observed in the image without soft-tissue simulation material. In the dental region, both DSR and PI showed that soft-tissue simulators did not influence the density in these regions. This study showed that the materials evaluated and their thicknesses significantly influenced the density-level gain in alveolar bone. In dental tissues, there was no density-level gain with any soft-tissue material tested.

  12. The relationship between second-to-fourth digit (2D:4D) ratios and problematic and pathological Internet use among Turkish university students

    PubMed Central

    Canan, Fatih; Karaca, Servet; Düzgün, Melike; Erdem, Ayşe Merve; Karaçaylı, Esranur; Topan, Nur Begüm; Lee, Sang-Kyu; Zhai, Zu Wei; Kuloğlu, Murat; Potenza, Marc N.

    2017-01-01

    Background and aims The ratio of the second and fourth fingers (2D:4D ratio) is a sexually dimorphic trait, with men tending to have lower values than women. This ratio has been related to prenatal testosterone concentrations and addictive behaviors including problematic video-gaming. We aimed to investigate the possible association between 2D:4D ratios and Internet addiction and whether such a relationship would be independent of impulsivity. Methods A total of 652 university students (369 women, 283 men), aged 17–27 years, were enrolled in the study. Problematic and pathological Internet use (PPIU) was assessed using the Internet Addiction Test (IAT). The participants also completed the Barratt Impulsiveness Scale (version 11; BIS-11) and had their 2D:4D ratios measured. Results 2D:4D ratios were not significantly different in women with PPIU and in those with adaptive Internet use (AIU). Men with PPIU exhibited lower 2D:4D ratios on both hands when compared with those with AIU. Correlation analysis revealed that 2D:4D ratios on both hands were negatively correlated with IAT scores among men, but not among women. The multiple linear regression analysis revealed that age, duration of weekly Internet use, impulsiveness, and 2D:4D ratios on the right hand were independently associated with IAT scores among men, and impulsivity did not mediate the relationship between 2D:4D ratios and PPIU. Conclusions For men, 2D:4D ratios on the right hand were inversely correlated with Internet addiction severity even after controlling for individual differences in impulsivity. These findings suggest that high prenatal testosterone levels may contribute to the occurrence of PPIU among men. PMID:28358645

  13. The relationship between second-to-fourth digit (2D:4D) ratios and problematic and pathological Internet use among Turkish university students.

    PubMed

    Canan, Fatih; Karaca, Servet; Düzgün, Melike; Erdem, Ayşe Merve; Karaçaylı, Esranur; Topan, Nur Begüm; Lee, Sang-Kyu; Zhai, Zu Wei; Kuloğlu, Murat; Potenza, Marc N

    2017-03-01

    Background and aims The ratio of the second and fourth fingers (2D:4D ratio) is a sexually dimorphic trait, with men tending to have lower values than women. This ratio has been related to prenatal testosterone concentrations and addictive behaviors including problematic video-gaming. We aimed to investigate the possible association between 2D:4D ratios and Internet addiction and whether such a relationship would be independent of impulsivity. Methods A total of 652 university students (369 women, 283 men), aged 17-27 years, were enrolled in the study. Problematic and pathological Internet use (PPIU) was assessed using the Internet Addiction Test (IAT). The participants also completed the Barratt Impulsiveness Scale (version 11; BIS-11) and had their 2D:4D ratios measured. Results 2D:4D ratios were not significantly different in women with PPIU and in those with adaptive Internet use (AIU). Men with PPIU exhibited lower 2D:4D ratios on both hands when compared with those with AIU. Correlation analysis revealed that 2D:4D ratios on both hands were negatively correlated with IAT scores among men, but not among women. The multiple linear regression analysis revealed that age, duration of weekly Internet use, impulsiveness, and 2D:4D ratios on the right hand were independently associated with IAT scores among men, and impulsivity did not mediate the relationship between 2D:4D ratios and PPIU. Conclusions For men, 2D:4D ratios on the right hand were inversely correlated with Internet addiction severity even after controlling for individual differences in impulsivity. These findings suggest that high prenatal testosterone levels may contribute to the occurrence of PPIU among men.

  14. Can Sex Differences in Science Be Tied to the Long Reach of Prenatal Hormones? Brain Organization Theory, Digit Ratio (2D/4D), and Sex Differences in Preferences and Cognition.

    PubMed

    Valla, Jeffrey; Ceci, Stephen J

    2011-03-01

    Brain organization theory posits a cascade of physiological and behavioral changes initiated and shaped by prenatal hormones. Recently, this theory has been associated with outcomes including gendered toy preference, 2D/4D digit ratio, personality characteristics, sexual orientation, and cognitive profile (spatial, verbal, and mathematical abilities). We examine the evidence for this claim, focusing on 2D/4D and its putative role as a biomarker for organizational features that influence cognitive abilities/interests predisposing males toward mathematically and spatially intensive careers. Although massive support exists for early brain organization theory overall, there are myriad inconsistencies, alternative explanations, and outright contradictions that must be addressed while still taking the entire theory into account. Like a fractal within the larger theory, the 2D/4D hypothesis mirrors this overall support on a smaller scale while likewise suffering from inconsistencies (positive, negative, and sex-dependent correlations), alternative explanations (2D/4D related to spatial preferences rather than abilities per se), and contradictions (feminine 2D/4D in men associated with higher spatial ability). Using the debate over brain organization theory as the theoretical stage, we focus on 2D/4D evidence as an increasingly important player on this stage, a demonstrative case in point of the evidential complexities of the broader debate, and an increasingly important topic in its own right.

  15. Can Sex Differences in Science Be Tied to the Long Reach of Prenatal Hormones? Brain Organization Theory, Digit Ratio (2D/4D), and Sex Differences in Preferences and Cognition

    PubMed Central

    Valla, Jeffrey; Ceci, Stephen J.

    2011-01-01

    Brain organization theory posits a cascade of physiological and behavioral changes initiated and shaped by prenatal hormones. Recently, this theory has been associated with outcomes including gendered toy preference, 2D/4D digit ratio, personality characteristics, sexual orientation, and cognitive profile (spatial, verbal, and mathematical abilities). We examine the evidence for this claim, focusing on 2D/4D and its putative role as a biomarker for organizational features that influence cognitive abilities/interests predisposing males toward mathematically and spatially intensive careers. Although massive support exists for early brain organization theory overall, there are myriad inconsistencies, alternative explanations, and outright contradictions that must be addressed while still taking the entire theory into account. Like a fractal within the larger theory, the 2D/4D hypothesis mirrors this overall support on a smaller scale while likewise suffering from inconsistencies (positive, negative, and sex-dependent correlations), alternative explanations (2D/4D related to spatial preferences rather than abilities per se), and contradictions (feminine 2D/4D in men associated with higher spatial ability). Using the debate over brain organization theory as the theoretical stage, we focus on 2D/4D evidence as an increasingly important player on this stage, a demonstrative case in point of the evidential complexities of the broader debate, and an increasingly important topic in its own right. PMID:22164187

  16. The x-ray light valve: a potentially low-cost, digital radiographic imaging system--a liquid crystal cell design for chest radiography.

    PubMed

    Szeto, Timothy C; Webster, Christie Ann; Koprinarov, Ivaylo; Rowlands, J A

    2008-03-01

    Digital x-ray radiographic systems are desirable as they offer high quality images which can be processed, transferred, and stored without secondary steps. However, current clinical systems are extraordinarily expensive in comparison to film-based systems. Thus, there is a need for an economical digital imaging system for general radiology. The x-ray light valve (XLV) is a novel digital x-ray detector concept with the potential for high image quality and low cost. The XLV is comprised of a photoconductive detector layer and liquid crystal (LC) cell physically coupled in a sandwich structure. Upon exposure to x rays, charge is collected at the surface of the photoconductor, causing a change in the reflective properties of the LC cell. The visible image so formed can subsequently be digitized with an optical scanner. By choosing the properties of the LC cell in combination with the appropriate photoconductor thickness and bias potentials, the XLV can be optimized for various diagnostic imaging tasks. Specifically for chest radiography, we identified three potentially practical reflective cell designs by selecting from those commonly used in LC display technology. The relationship between reflectance and x-ray exposure (i.e., the characteristic curve) was determined for all three cells using a theoretical model. The results indicate that the reflective electrically controlled birefringence (r-ECB) cell is the preferred choice for chest radiography, provided that the characteristic curve can be shifted towards lower exposures. The feasibility of the shift of the characteristic curve is shown experimentally. The experimental results thus demonstrate that an XLV based on the r-ECB cell design exhibits a characteristic curve suitable for chest radiography.

  17. The ratio of second to fourth digit length (2D:4D) and coronary artery disease in a Han Chinese population.

    PubMed

    Wu, Xing-Li; Yang, Ding-You; Chai, Wen-Hui; Jin, Ming-Lei; Zhou, Xing-Chun; Peng, Li; Zhao, Yu-Sheng

    2013-01-01

    The association between index finger to ring finger length ratio (2D:4D) and cardiac disorders has been reported, however it has not been discussed in terms of coronary artery disease (CAD). We investigated whether 2D:4D could be used as a marker for predisposition to CAD as assessed by coronary angiography in Chinese men and women. This study included 1764 persons divided into 4 groups, 441 cases with CAD and 441 persons without CAD as control in each sex of the same age. Finger lengths were measured twice for both hands using electronic calipers. Student t test was used to detect the difference of 2D:4D among groups. The receiver operator characteristic curves (ROCs) were used to detect the diagnostic effect of 2D:4D for CAD. There were no significant differences in age among the four groups. A significant difference of 2D:4D ratios between right and left hand were observed only in men in both control and CAD groups. On the right hand in the control group and on both hands in the CAD group, the 2D:4D ratios were higher in women than in men (all, P < 0.001). In men with CAD, mean 2D:4D was higher than mean 2D:4D in control men (right hand 0.962±0.042:0.927±0.038; left hand 0.950±0.044:0.934±0.048; both hands, P < 0.001), but this was not observed in women. No relationship was found between 2D:4D and age (all, P >0.05). The area under the curve of right hand 2D:4D in male was 0.72 (95% CI 0.683-0.753, p<0.001), while it was 0.602 (95% CI 0.565-0.639, p<0.001) in left hand. The present study showed an association between high 2D:4D ratio and CAD in both hands in men. There were no significant differences in mean 2D:4D between women with CAD and controls.

  18. The Ratio of Second to Fourth Digit Length (2D:4D) and Coronary Artery Disease in a Han Chinese Population

    PubMed Central

    Wu, Xing-li; Yang, Ding-you; Chai, Wen-hui; Jin, Ming-lei; Zhou, Xing-chun; Peng, Li; Zhao, Yu-sheng

    2013-01-01

    Background: The association between index finger to ring finger length ratio (2D:4D) and cardiac disorders has been reported, however it has not been discussed in terms of coronary artery disease (CAD). We investigated whether 2D:4D could be used as a marker for predisposition to CAD as assessed by coronary angiography in Chinese men and women. Methods: This study included 1764 persons divided into 4 groups, 441 cases with CAD and 441 persons without CAD as control in each sex of the same age. Finger lengths were measured twice for both hands using electronic calipers. Student t test was used to detect the difference of 2D:4D among groups. The receiver operator characteristic curves (ROCs) were used to detect the diagnostic effect of 2D:4D for CAD. Results: There were no significant differences in age among the four groups. A significant difference of 2D:4D ratios between right and left hand were observed only in men in both control and CAD groups. On the right hand in the control group and on both hands in the CAD group, the 2D:4D ratios were higher in women than in men (all, P < 0.001). In men with CAD, mean 2D:4D was higher than mean 2D:4D in control men (right hand 0.962±0.042:0.927±0.038; left hand 0.950±0.044:0.934±0.048; both hands, P < 0.001), but this was not observed in women. No relationship was found between 2D:4D and age (all, P >0.05). The area under the curve of right hand 2D:4D in male was 0.72 (95% CI 0.683-0.753, p<0.001), while it was 0.602 (95% CI 0.565-0.639, p<0.001) in left hand. Conclusions: The present study showed an association between high 2D:4D ratio and CAD in both hands in men. There were no significant differences in mean 2D:4D between women with CAD and controls. PMID:24046536

  19. Potential sources of quantification error when retrospectively assessing metacarpal bone loss from historical radiographs by using digital X-ray radiogrammetry: an experimental study.

    PubMed

    Kälvesten, Johan; Brismar, Torkel B; Persson, Anders

    2014-01-01

    During the past 15 yr, digital X-ray radiogrammetry (DXR) has been used to measure metacarpal bone mineral density (BMD). BMD is often measured in existing cohorts where X-ray images were not acquired in accordance with the DXR imaging protocol (DIP). The purpose of the present study was to analyze how deviations from DIP in historical radiographs may affect the reproducibility of DXR-BMD measurements. Cadaver hand phantoms were used to conduct repeat measurements of deviations from DIP with respect to voltage, exposure, lateral displacement, supination, combination of lateral displacement and supination or rotation, extension of the wrist, and edge enhancement. Direct digital radiography (Aristos; Siemens Healthcare, Erlangen, Germany) was used for image acquisition and dxr-online (Sectra, Linköping, Sweden) for DXR-BMD measurements. The influence of the tested deviations from DIP ranged from 0 to 32.5 mg/cm(2) (0-6.8%). On repetition with the same specimen, none of the deviations resulted in a within-specimen reproducibility error greater than 2 mg/cm(2) (0.4%, equivalent to a T-score of 0.042). Among the tested deviations, all except tube voltage had a magnitude greater than the normal measurement noise for the technique and must therefore be considered when planning a study based on historical images. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  20. Doses measured using AEC on direct digital radiographic (DDR) X-rays systems: updated results with an RP 162 perspective.

    PubMed

    Bowden, L; Faulkner, R; Gallagher, A; O'Connor, U; Walsh, C; Dowling, A; O'Reilly, G

    2013-02-01

    As digital technology in diagnostic radiology systems becomes more prevalent, there is a need to provide comparative dose information for these new systems. This is needed in particular for testing the automatic exposure control (AEC) devices on direct digital radiography (DDR) systems as there is no consensus on the receptor dose level in the current guidelines. The new European Commission RP 162 document sets the suspension level for the 'verification of kerma at receptor entrance in computed radiography and DDR systems under AEC' as ≥10 µGy. This document also notes that alternate methodologies are acceptable, and may require adjustment in the suspension level if used. This study provides a range of typical doses under AEC for DDR systems, for a variety measurement methodologies, including that described in RP 162.

  1. Replicated nil associations of digit ratio (2D:4D) and absolute finger lengths with implicit and explicit measures of aggression.

    PubMed

    Voracek, Martin; Stieger, Stefan

    2009-08-01

    Preliminary evidence suggests that within-sex individual variation in the length ratio of the index finger to the ring finger (2D:4D), a putative marker of prenatal androgen levels, may be more strongly or consistently related to implicit measures (Implicit Association Test, IAT) than to corresponding explicit (self-report) measures of candidate personality traits. The underlying logic is that the non-introspective IAT may reflect earlier and inaccessible experiences, whereas introspective self-reports reflect more recent and necessarily accessible experiences. Associations of 2D:4D and absolute finger length (a marker of pubertal-adolescent androgen levels) with implicit versus explicit aggression measures (IAT vs. Buss-Perry Aggression Questionnaire and a feeling thermometer) were examined in two samples with identical procedures (Ns=244 and 233). Attesting to procedural validity and data typicality, several experiments of related research were replicated in both samples, including sex differences in 2D:4D and theory compliant interrelations among psychometric measures. However, no theory compliant, reliable, or replicable associations of 2D:4D or finger length with implicit or explicit aggression measures resulted. These nil findings cast doubt on hypothesized advantages of implicitly (over explicitly) measured target traits for 2D:4D research. More generally, they add to a growing number of replication failures in this area.

  2. An in vitro radiographic analysis of the density of dental luting cements as measured by CCD-based digital radiography.

    PubMed

    Antonijevic, Djordje; Jevremovic, Danimir; Jovanovic, Svetlana; Obradovic-Djuricic, Kosovka

    2012-05-01

    According to the ISO, the radiopacity of luting cements should be equal to or greater than that of aluminum. The aim of this in vitro study was to determine the radiopacity of 13 commercially available dental luting cements and compare them with human enamel and dentin. Five classes of luting cements were evaluated: zinc phosphate (Cegal N and Harvard Zinc Phosphate), zinc polycarboxylate (Harvard Polycarboxylate and Hoffmann's Carboxylate), glass ionomers (Ketac Cem Easymix, Ketac Cem Radiopaque, and Fuji I), resin-modified glass ionomer (Rely X Luting), and resin cements (Multilink Automix, Variolink II, Speed CEM, Rely X Unicem Automix, and three shades of Variolink Veneer). Tooth slices served as controls. Five specimens of each material measuring 8 mm in diameter and 1 mm thick were prepared and radiographed alongside tooth slices and an aluminum stepwedge using a Trophy RVG sensor. The radiopacity values were expressed in mm Al and analyzed by the ANOVA and Tukey tests (P < .05). All the cements examined except Variolink Veneer had significantly higher radiopacities than that of dentin. Rely X Unicem Automix, glass ionomer, and resin-modified glass-ionomer cements demonstrated radiopacities that were not significantly different with respect to enamel. Zinc phosphate, zinc polycarboxylate, and three of the resin cements presented radiopacity values that were significantly greater than that of enamel. Almost all the investigated materials presented an acceptable radiopacity. Radiopacity of dental cements seems to depend more on the presence of elements with high atomic numbers than on the type of the material.

  3. Generalized two-dimensional (2D) linear system analysis metrics (GMTF, GDQE) for digital radiography systems including the effect of focal spot, magnification, scatter, and detector characteristics

    PubMed Central

    Kuhls-Gilcrist, Andrew T.; Gupta, Sandesh K.; Bednarek, Daniel R.; Rudin, Stephen

    2010-01-01

    The MTF, NNPS, and DQE are standard linear system metrics used to characterize intrinsic detector performance. To evaluate total system performance for actual clinical conditions, generalized linear system metrics (GMTF, GNNPS and GDQE) that include the effect of the focal spot distribution, scattered radiation, and geometric unsharpness are more meaningful and appropriate. In this study, a two-dimensional (2D) generalized linear system analysis was carried out for a standard flat panel detector (FPD) (194-micron pixel pitch and 600-micron thick CsI) and a newly-developed, high-resolution, micro-angiographic fluoroscope (MAF) (35-micron pixel pitch and 300-micron thick CsI). Realistic clinical parameters and x-ray spectra were used. The 2D detector MTFs were calculated using the new Noise Response method and slanted edge method and 2D focal spot distribution measurements were done using a pin-hole assembly. The scatter fraction, generated for a uniform head equivalent phantom, was measured and the scatter MTF was simulated with a theoretical model. Different magnifications and scatter fractions were used to estimate the 2D GMTF, GNNPS and GDQE for both detectors. Results show spatial non-isotropy for the 2D generalized metrics which provide a quantitative description of the performance of the complete imaging system for both detectors. This generalized analysis demonstrated that the MAF and FPD have similar capabilities at lower spatial frequencies, but that the MAF has superior performance over the FPD at higher frequencies even when considering focal spot blurring and scatter. This 2D generalized performance analysis is a valuable tool to evaluate total system capabilities and to enable optimized design for specific imaging tasks. PMID:21243038

  4. A radiolucent chair for sitting-posture radiographs in non-ambulatory children: use in biplanar digital slot-scanning.

    PubMed

    Bouloussa, Houssam; Dubory, Arnaud; Seiler, Catherine; Morel, Baptiste; Bachy, Manon; Vialle, Raphaël

    2015-11-01

    EOS imaging (EOS System; EOS imaging, Paris, France) enables fast 2-D/3-D imaging of children in standing load-bearing position. Non-ambulatory children with neuromuscular scoliosis need evaluation of their spinal balance while in a normal daily position. We designed a customized chair fitting the EOS patient-area dimensions to obtain images in natural sitting postures. The chair is a 360° rotating orthopaedic chair made of fully radiolucent polyethylene and equipped with an adjustable headrest and three-point belts. Out of 41 consecutive patients, 36 (88%, 95% confidence interval 74-96%) had successful imaging. In most patients with severe neuromuscular trunk deformities, the EOS system combined with our chair was useful for assessing preoperative trunk collapse, pelvic obliquity and postoperative corrections in all planes. This specific device changed our daily practice for the assessment of spinal deformities in non-ambulatory patients.

  5. Impact of chronic cyanosis and reoxygenation on the microheterogeneity of the myocardial blood flow: digital radiographic study in neonatal rats.

    PubMed

    Tomii, Tomoko; Honjo, Osami; Matsumoto, Takeshi; Tachibana, Hiroyuki; Fujii, Yasuhiro; Ishino, Kozo; Ogasawara, Yasuo; Sano, Shunji

    2011-10-01

    This study sought to show the heterogeneity of myocardial blood flow in the chronically hypoxic infantile myocardium and its response to reoxygenation using a novel type of digital radiography. Newborn rats were housed in a hypoxic chamber or in a normal chamber (controls). After 4 or 8 weeks, the control rats were ventilated with normoxic conditions, and the rats housed under hypoxia were ventilated with either hypoxic (cyanotic group) or normoxic conditions (reoxygenation group). Desmethylimipramine labeled with tritium (HDMI) was injected into the left ventricle, and both ventricular free walls were sectioned and sliced from the subepicardium to the subendocardium at 10 mm thickness. The within-layer distribution of HDMI density was measured by digital radiography, and its spatial heterogeneity (i.e., flow heterogeneity) was quantified by the coefficient of variation (CV) of flows. There were no differences in the CV between the groups in either ventricle at 4 weeks of age and no differences in the right ventricle at 8 weeks of age. There was a trend toward a higher left ventricular CV in the cyanotic group than in the control group at 8 weeks of age (0.637 ± 0.099 vs. 0.510 ± 0.060, P = 0.06). At 8 weeks of age, the CV was lower in both ventricles in the reoxygenation group than in those of the control and cyanotic groups. The chronically hypoxic infantile myocardium exhibits regional flow heterogeneity similar to that observed in the normal myocardium in both ventricles and exhibits reduced flow heterogeneity in response to reoxygenation.

  6. Digital radiographic evaluation of mandibular third molar for age estimation in young adults and adolescents of South Indian population using modified Demirjian's method

    PubMed Central

    Mohammed, Rezwana Begum; Koganti, Ravichandra; Kalyan, Siva V.; Tircouveluri, Saritha; Singh, Johar Rajvinder; Srinivasulu, Enganti

    2014-01-01

    In recent years, it has become increasingly important to determine the age of living people for a variety of reasons, including identifying criminal and legal responsibility and for many other social events such as birth certificate, marriage, beginning a job, joining the army and retirement Objectives: The aim of this study was to assess the developmental stages of mandibular third molar for estimation of dental age (DA) in different age groups and to evaluate the possible correlation between DA and chronological age (CA) in South Indian population. Materials and Methods: Digital orthopantomography of 330 subjects (165 males, 165 females) who fit the study and the criteria were obtained. Assessment of mandibular third molar development was performed using Demirjian et al., modified method and DA was assessed using tooth specific stages. Results and Discussion: The present study showed a significant correlation between DA and CA in both males and females. Third molar development commenced around 9 years and root completion takes place around 18.9 years in males and in females 9 years and 18.6 years respectively. Demirjian modified method underestimated the mean age of males by 0.8 years and females by 0.5 years and also showed that females mature earlier than males in selected population. Conclusion: Digital radiographic assessment of mandibular third molar development can be used to generate mean DA using Demirjian modified method and also the estimated age range for an individual of unknown CA. Since the Demirjian method is based on French-Canadian population, to enhance the accuracy of forensic age estimates based on third molar development, the use of population-specific standards is recommended. PMID:25177143

  7. Age at menarche and digit ratio (2D:4D): relationships with body dissatisfaction, drive for thinness, and bulimia symptoms in women.

    PubMed

    Oinonen, Kirsten A; Bird, Jessica L

    2012-03-01

    This study examined the hypothesis that lower prenatal androgen exposure and earlier puberty are associated with more dysfunctional eating attitudes and behaviors. Relationships between both age at menarche (AAM) and 2D:4D (a marker of prenatal androgen exposure), and EDI-2-Body Dissatisfaction, EDI-2-Drive for Thinness, and EDI-2-Bulimia scores, were examined in women using correlations and regressions. Earlier menarche was associated with higher drive for thinness after controlling for BMI and negative affect, but only in women who were not exclusively heterosexual. Higher 2D:4D was associated with higher Bulimia and Body Dissatisfaction scores, but only in exclusively heterosexual women, and relationships disappeared when covariates were controlled. Later AAM and higher 2D:4D were unique predictors of higher Bulimia scores for exclusive heterosexuals when BMI was controlled. These findings suggest future research should examine sexual orientation as a mediator or moderator of prenatal and postnatal organizational hormonal effects on women's disordered eating attitudes and behaviors.

  8. Digit ratio (2D:4D) and psychopathic traits moderate the effect of exogenous testosterone on socio-cognitive processes in men.

    PubMed

    Carré, Justin M; Ortiz, Triana L; Labine, Brandy; Moreau, Benjamin J P; Viding, Essi; Neumann, Craig S; Goldfarb, Bernard

    2015-12-01

    Recent evidence suggests that testosterone is negatively correlated with empathic processes in both men and women. Also, administration of testosterone to young women impairs socio-cognitive performance as assessed using the "Reading the Mind in the Eyes Task", especially among those exposed to elevated testosterone concentrations prenatally. However, the extent to which testosterone plays a similar causal role in socio-cognitive abilities in men is currently unknown. Here, using a crossover, double-blind, placebo-controlled, within-subject design, we investigated the extent to which a single administration of testosterone to healthy young men (N=30) would impair socio-cognitive abilities assessed using the "Reading the Mind in the Eyes Task" (RMET). Also, we investigated whether individual differences in 2D:4D ratio and psychopathic traits would moderate the effect of testosterone on task performance. Results indicated that testosterone administration on its own did not impair RMET performance. However, variability in both 2D:4D ratio and psychopathic traits moderated the effect of testosterone on task performance. Specifically, testosterone impaired RMET performance among individuals with relatively low (i.e., masculinized) 2D:4D ratio and among individuals scoring relatively low on the interpersonal/affective facet (i.e., Factor 1) of psychopathy. Our findings highlight the importance of considering theoretically- and empirically-based individual difference factors when attempting to characterize the neuroendocrine mechanisms underlying socio-cognitive processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. WE-G-204-08: Optimized Digital Radiographic Technique for Lost Surgical Devices/Needle Identification

    SciTech Connect

    Gorman, A; Seabrook, G; Brakken, A; Dubois, M; Marn, C; Wilson, C; Jacobson, D; Liu, Y

    2015-06-15

    Purpose: Small surgical devices and needles are used in many surgical procedures. Conventionally, an x-ray film is taken to identify missing devices/needles if post procedure count is incorrect. There is no data to indicate smallest surgical devices/needles that can be identified with digital radiography (DR), and its optimized acquisition technique. Methods: In this study, the DR equipment used is a Canon RadPro mobile with CXDI-70c wireless DR plate, and the same DR plate on a fixed Siemens Multix unit. Small surgical devices and needles tested include Rubber Shod, Bulldog, Fogarty Hydrogrip, and needles with sizes 3-0 C-T1 through 8-0 BV175-6. They are imaged with PMMA block phantoms with thickness of 2–8 inch, and an abdomen phantom. Various DR techniques are used. Images are reviewed on the portable x-ray acquisition display, a clinical workstation, and a diagnostic workstation. Results: all small surgical devices and needles are visible in portable DR images with 2–8 inch of PMMA. However, when they are imaged with the abdomen phantom plus 2 inch of PMMA, needles smaller than 9.3 mm length can not be visualized at the optimized technique of 81 kV and 16 mAs. There is no significant difference in visualization with various techniques, or between mobile and fixed radiography unit. However, there is noticeable difference in visualizing the smallest needle on a diagnostic reading workstation compared to the acquisition display on a portable x-ray unit. Conclusion: DR images should be reviewed on a diagnostic reading workstation. Using optimized DR techniques, the smallest needle that can be identified on all phantom studies is 9.3 mm. Sample DR images of various small surgical devices/needles available on diagnostic workstation for comparison may improve their identification. Further in vivo study is needed to confirm the optimized digital radiography technique for identification of lost small surgical devices and needles.

  10. The x-ray light valve: A low-cost, digital radiographic imaging system—Spatial resolution

    PubMed Central

    MacDougall, Robert D.; Koprinarov, Ivaylo; Rowlands, J. A.

    2008-01-01

    An x-ray light valve (XLV) coupled with an optical scanner has the potential to meet the need for a low-cost, high quality digital imaging system for general radiography. The XLV∕scanner concept combines three well-established, and hence, low-cost technologies: An amorphous selenium (a-Se) layer as an x-ray-to-charge transducer, a liquid crystal (LC) cell as an analog display, and an optical scanner for image digitization. The XLV consists of an a-Se layer and LC cell in a sandwich structure which produces an optical image in the LC layer upon x-ray exposure. The XLV∕scanner system consists of an XLV in combination with an optical scanner for image readout. Here, the effect of each component on the spatial resolution of an XLV∕scanner system is investigated. A theoretical model of spatial resolution of an XLV is presented based on calculations of the modulation transfer function (MTF) for a-Se and a LC cell. From these component MTFs, the theoretical MTF of the XLV is derived. The model was validated by experiments on a prototype XLV∕scanner system. The MTF of the scanner alone was obtained by scanning an optical test target and the MTF of the XLV∕scanner system was measured using x rays. From the measured MTF of the scanner, the theoretical MTF of the XLV∕scanner system was established and compared with the experimental results. Good general agreement exists between experimental and theoretical results in the frequency range of interest for general radiography, although the theoretical curves slightly overstate the measured MTFs. The experimental MTF of the XLV was compared with the MTF of two clinical systems and was shown to have the capability to exceed the resolution of flat-panel detectors. From this, the authors can conclude that the XLV has an adequate resolution for general radiography. The XLV∕scanner also has the potential to eliminate aliasing while maintaining a MTF that exceeds that of a flat-panel imager. PMID:18841872

  11. Digit-Length Ratios (2D:4D) as a Phenotypic Indicator of in Utero Androgen Exposure is Not Prognostic for Androgenic Alopecia: a Descriptive-Analytic Study of 1200 Iranian Men.

    PubMed

    Feily, Amir; Hosseinpoor, Masoomeh; Bakhti, Ali; Nekuyi, Mohamad; Sobhanian, Saeed; Fathinezhad, Zahra; Sahraei, Reza; Ramirez-Fort, Marigdalia K

    2016-06-15

    The etiology of androgenic alopecia (AGA) involves several factors, including genetics, androgens, age and nutrition. Digit-length ratio of the index and ring finger (2D:4D) is an indicator of prenatal exposure to sex hormones. There is a paucity of studies that systemically review the possible positive predictive value of 2D:4D in the development of AGA. We performed a single-site, descriptive-analytical study among a racially homogeneous population. Our results revealed that no significant association was determined between right 2D:4D and AGA severity within our entire population (P=0.384, r=0.025), however a positive correlation coefficient was identified in subjects above the age of 40. Based on the receiver operating characteristic curve analysis, 2D:4D does not predict the development of AGA. AGA is truly a multifactorial disease. Further, our findings suggest that increased in utero exposure to androgens as a fetus does not predispose men to develop AGA.

  12. Digit (2D:4D) ratio is associated with muscle mass (MM) and strength (MS) in older adults: possible effect of in utero androgen exposure.

    PubMed

    Halil, Meltem; Gurel, Esin Ileri; Kuyumcu, Mehmet Emin; Karaismailoglu, Serkan; Yesil, Yusuf; Ozturk, Zeynel Abidin; Yavuz, Burcu Balam; Cankurtaran, Mustafa; Ariogul, Servet

    2013-01-01

    Decline in MM and MS with aging, defined as sarcopenia, is related with physical disability, poor quality of life and death. Its mechanisms are not fully understood. Testosterone increases muscle protein synthesis. However, the effects of in utero androgen exposure to MM and MS in older adults have not been studied. In utero androgen exposure is inversely related with 2D:4D ratio. The aim of this study was to investigate the relationship between 2D:4D ratio as an indicator of in utero androgen exposure and MM and MS in elderly patients. A total of 151 older adults were included. Calf-circumference (CC) and skeletal muscle mass index (SMI) were used for the assessment of MM and hand grip strength for the assessment of MS. Mean age ± SD of the patients was 73.72 ± 6.23. Fifty-two (34.4%) of patients were male, 99 (65.6%) were female. Right and left 2D:4D were significantly and negatively correlated with hand grip strength (r=-0.365, p=0.018 and r=-0.434, p=0.005, respectively), CC (r=-0.422, p=0.002 and r=-0.459, p=0.001, respectively) and SMI (r=-0.354, p=0.018 and r=-0.348, p=0.022, respectively) in men. In women, right and left 2D:4D were significantly and negatively correlated with hand grip strength (r=-0.252, p=0.022 and r=-0.234, p=0.033, respectively), CC (r=-0.229, p=0.024 and r=-0.302, p=0.003, respectively) and SMI (r=-0.382, p<0.001 and r=-0.431, p<0.001, respectively). In this study, we found that 2D:4D ratio was significantly and negatively correlated with parameters depicting MM and MS which may suggest the possible role of in utero androgen exposure in the development of MM and MS loss in the elderly. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  13. Influence of materials radiopacity in the radiographic diagnosis of secondary caries: evaluation in film and two digital systems

    PubMed Central

    Pedrosa, RF; Brasileiro, IV; dos Anjos Pontual, ML; dos Anjos Pontual, A; da Silveira, MMF

    2011-01-01

    Objectives The aim of this study was to evaluate the influence of restorative materials on false-positive diagnoses of secondary caries using three imaging systems. Methods Class II preparations were made on the occlusal and mesial or distal faces of extracted healthy third molar teeth. The teeth were divided into five groups and, with the exception of Group 5, they received a flow resin base. Groups 1, 2, 3 and 4 received a layer of Natural Flow (DFL, Rio de Janeiro, Brazil), Filtek Flow (3M-ESPE, St. Paul, MN), Tetric Flow (Ivoclar/Vivadent, Liechtenstein, Germany) and Protect Liner F (Kuraray, Okayama, Japan) resins, respectively, and were restored with Filtek Supreme resin (3M-ESPE). Group 5 was restored with Filtek Supreme resin. The images on film and on the Digora Optime® (Helsinki, Finland) and charge coupled device (CCD) IOX (IOX, Monninkylä, Finland) digital systems were evaluated by five examiners and the data were analysed using the Fisher's exact and Friedman tests at a 5% level of significance. Results Group 3 showed the highest rate of correct answers (restored tooth) and the lowest proportion of secondary caries diagnosis (P ≤ 0.05). Group 4 showed the highest rate of secondary caries diagnosis and the lowest proportion of correct answers (P ≤ 0.05). The systems for obtaining images presented were similar for each material. Conclusons The restorative material was found to have an influence on the diagnosis of secondary caries lesions by imaging. The imaging system had no influence. Materials with greater radiopacity, higher than that of enamel, were favourable for a true-negative diagnosis. PMID:21831973

  14. A New Radiographic Corrosion Inspection Capability.

    DTIC Science & Technology

    1986-01-01

    significantly enhance the corrosion detection and damage assessment capabilities of a digital radiographic system. 2.0 PROGRAM DESCRIPTION Corrosion of...detection and assessment technology by applying dual-energy techniques to digital radiographic systems. 2.2 Program Objectives The overall objective of the...CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP dual energy photoelectric digital

  15. Differential correlations of digit ratio (2D:4D) with aggressive dominance and sociable dominance are not demonstrated: commentary on van der Meij, Almela, Buunk, Dubbs, and Salvador (2012, Aggressive Behavior, 38(3), 208-212).

    PubMed

    Voracek, Martin

    2013-01-01

    Van der Meij, Almela, Buunk, Dubbs, and Salvador reported that, among young men (N = 84), a putative biomarker for prenatal androgen exposure (second-to-fourth digit ratio; 2D:4D) correlated negatively to self-reported aggressive dominance, but not to sociable dominance. A critical examination of this allegedly differential effect shows it to be unsupported and unlikely to be replicable. Statistical power of the sample was so low that the nominally significant correlation coefficient with aggressive dominance and the nominally not significant one with sociable dominance actually did not differ significantly from each other. Apart from these data-analytic and statistical power issues, a number of further substantive comments are raised, including conceptual and study design issues, 2D:4D measurement and reliability issues, and biased presentation (i.e. selective citation) of prior related research evidence. More generally, it is suggested that 2D:4D research would benefit from adopting publishing standards requiring discovery and replication samples (i.e. successful replication of novel findings by the initial researchers themselves), as is now increasingly required for publishing in various fields of inconsistent, hard-to-replicate evidence. © 2013 Wiley Periodicals, Inc.

  16. Pilot Study on the Detection of Simulated Lesions Using a 2D and 3D Digital Full-Field Mammography System with a Newly Developed High Resolution Detector Based on Two Shifts of a-Se

    PubMed Central

    Schulz-Wendtland, R.; Bani, M.; Lux, M. P.; Schwab, S.; Loehberg, C. R.; Jud, S. M.; Rauh, C.; Bayer, C. M.; Beckmann, M. W.; Uder, M.; Fasching, P. A.; Adamietz, B.; Meier-Meitinger, M.

    2012-01-01

    Purpose: Experimental study of a new system for digital 2D and 3D full-field mammography (FFDM) using a high resolution detector based on two shifts of a-Se. Material and Methods: Images were acquired using the new FFDM system Amulet® (FujiFilm, Tokio, Japan), an a-Se detector (receptor 24 × 30 cm2, pixel size 50 µm, memory depth 12 bit, spatial resolution 10 lp/mm, DQE > 0.50). Integrated in the detector is a new method for data transfer, based on optical switch technology. The object of investigation was the Wisconsin Mammographic Random Phantom, Model 152A (Radiation Measurement Inc., Middleton, WI, USA) and the same parameters and exposure data (Tungsten, 100 mAs, 30 kV) were consistently used. We acquired 3 different pairs of images in the c-c and ml planes (2D) and in the c-c and c-c planes with an angle of 4 degrees (3D). Five radiologists experienced in mammography (experience ranging from 3 months to more than 5 years) analyzed the images (monitoring) which had been randomly encoded (random generator) with regard to the recognition of details such as specks of aluminum oxide (200–740 µm), nylon fibers (0.4–1.6 mm) and round lesions/masses (diameters 5–14 mm), using special linear glasses for 3D visualization, and compared the results. Results: A total of 225 correct positive decisions could be detected: we found 222 (98.7 %) correct positive results for 2D and 3D visualization in each case. Conclusion: The results of this phantom study showed the same detection rates for both 2D and 3D imaging using full field digital mammography. Our results must be confirmed in further clinical trials. PMID:25298545

  17. Pilot Study on the Detection of Simulated Lesions Using a 2D and 3D Digital Full-Field Mammography System with a Newly Developed High Resolution Detector Based on Two Shifts of a-Se.

    PubMed

    Schulz-Wendtland, R; Bani, M; Lux, M P; Schwab, S; Loehberg, C R; Jud, S M; Rauh, C; Bayer, C M; Beckmann, M W; Uder, M; Fasching, P A; Adamietz, B; Meier-Meitinger, M

    2012-05-01

    Purpose: Experimental study of a new system for digital 2D and 3D full-field mammography (FFDM) using a high resolution detector based on two shifts of a-Se. Material and Methods: Images were acquired using the new FFDM system Amulet® (FujiFilm, Tokio, Japan), an a-Se detector (receptor 24 × 30 cm(2), pixel size 50 µm, memory depth 12 bit, spatial resolution 10 lp/mm, DQE > 0.50). Integrated in the detector is a new method for data transfer, based on optical switch technology. The object of investigation was the Wisconsin Mammographic Random Phantom, Model 152A (Radiation Measurement Inc., Middleton, WI, USA) and the same parameters and exposure data (Tungsten, 100 mAs, 30 kV) were consistently used. We acquired 3 different pairs of images in the c-c and ml planes (2D) and in the c-c and c-c planes with an angle of 4 degrees (3D). Five radiologists experienced in mammography (experience ranging from 3 months to more than 5 years) analyzed the images (monitoring) which had been randomly encoded (random generator) with regard to the recognition of details such as specks of aluminum oxide (200-740 µm), nylon fibers (0.4-1.6 mm) and round lesions/masses (diameters 5-14 mm), using special linear glasses for 3D visualization, and compared the results. Results: A total of 225 correct positive decisions could be detected: we found 222 (98.7 %) correct positive results for 2D and 3D visualization in each case. Conclusion: The results of this phantom study showed the same detection rates for both 2D and 3D imaging using full field digital mammography. Our results must be confirmed in further clinical trials.

  18. Radiographic determinants of implant performance.

    PubMed

    Reddy, M S; Wang, I C

    1999-06-01

    This paper reviews and compares the strengths and weaknesses of radiographic techniques including periapical, occlusal, panoramic, direct digital, motion tomography, and computed tomography. Practical considerations for each method, including availability and accessibility, are discussed. To date, digital subtraction radiography is the most versatile and sensitive method for measuring boss loss. It can detect both bone height and bone mass changes on root-form or blade-form dental implants. Criteria for implant success have changed substantially over the past two decades. In clinical trials of dental implants, the outcomes require certain radiographic analyses to address the hypothesis or clinical question adequately. Radiographic methods best suited to the objective assessment of implant performance and hypothesis were reviewed.

  19. ProgRes 3000: a digital color camera with a 2-D array CCD sensor and programmable resolution up to 2994 x 2320 picture elements

    NASA Astrophysics Data System (ADS)

    Lenz, Reimar K.; Lenz, Udo

    1990-11-01

    A newly developed imaging principle two dimensional microscanning with Piezo-controlled Aperture Displacement (PAD) allows for high image resolutions. The advantages of line scanners (high resolution) are combined with those of CCD area sensors (high light sensitivity geometrical accuracy and stability easy focussing illumination control and selection of field of view by means of TV real-time imaging). A custom designed sensor optimized for small sensor element apertures and color fidelity eliminates the need for color filter revolvers or mechanical shutters and guarantees good color convergence. By altering the computer controlled microscan patterns spatial and temporal resolution become interchangeable their product being a constant. The highest temporal resolution is TV real-time (50 fields/sec) the highest spatial resolution is 2994 x 2320 picture elements (Pels) for each of the three color channels (28 MBytes of raw image data in 8 see). Thus for the first time it becomes possible to take 35mm slide quality still color images of natural 3D scenes by purely electronic means. Nearly " square" Pels as well as hexagonal sampling schemes are possible. Excellent geometrical accuracy and low noise is guaranteed by sensor element (Sel) synchronous analog to digital conversion within the camera head. The cameras principle of operation and the procedure to calibrate the two-dimensional piezo-mechanical motion with an accuracy of better than O. 2. tm RMSE in image space is explained. The remaining positioning inaccuracy may be further

  20. 3D-2D Deformable Image Registration Using Feature-Based Nonuniform Meshes

    PubMed Central

    Guo, Xiaohu; Cai, Yiqi; Yang, Yin; Wang, Jing; Jia, Xun

    2016-01-01

    By using prior information of planning CT images and feature-based nonuniform meshes, this paper demonstrates that volumetric images can be efficiently registered with a very small portion of 2D projection images of a Cone-Beam Computed Tomography (CBCT) scan. After a density field is computed based on the extracted feature edges from planning CT images, nonuniform tetrahedral meshes will be automatically generated to better characterize the image features according to the density field; that is, finer meshes are generated for features. The displacement vector fields (DVFs) are specified at the mesh vertices to drive the deformation of original CT images. Digitally reconstructed radiographs (DRRs) of the deformed anatomy are generated and compared with corresponding 2D projections. DVFs are optimized to minimize the objective function including differences between DRRs and projections and the regularity. To further accelerate the above 3D-2D registration, a procedure to obtain good initial deformations by deforming the volume surface to match 2D body boundary on projections has been developed. This complete method is evaluated quantitatively by using several digital phantoms and data from head and neck cancer patients. The feature-based nonuniform meshing method leads to better results than either uniform orthogonal grid or uniform tetrahedral meshes. PMID:27019849

  1. 3D-2D Deformable Image Registration Using Feature-Based Nonuniform Meshes.

    PubMed

    Zhong, Zichun; Guo, Xiaohu; Cai, Yiqi; Yang, Yin; Wang, Jing; Jia, Xun; Mao, Weihua

    2016-01-01

    By using prior information of planning CT images and feature-based nonuniform meshes, this paper demonstrates that volumetric images can be efficiently registered with a very small portion of 2D projection images of a Cone-Beam Computed Tomography (CBCT) scan. After a density field is computed based on the extracted feature edges from planning CT images, nonuniform tetrahedral meshes will be automatically generated to better characterize the image features according to the density field; that is, finer meshes are generated for features. The displacement vector fields (DVFs) are specified at the mesh vertices to drive the deformation of original CT images. Digitally reconstructed radiographs (DRRs) of the deformed anatomy are generated and compared with corresponding 2D projections. DVFs are optimized to minimize the objective function including differences between DRRs and projections and the regularity. To further accelerate the above 3D-2D registration, a procedure to obtain good initial deformations by deforming the volume surface to match 2D body boundary on projections has been developed. This complete method is evaluated quantitatively by using several digital phantoms and data from head and neck cancer patients. The feature-based nonuniform meshing method leads to better results than either uniform orthogonal grid or uniform tetrahedral meshes.

  2. Validation of a computer analysis to determine 3-D rotations and translations of the rib cage in upright posture from three 2-D digital images

    PubMed Central

    Harrison, Deed E.; Janik, Tadeusz J.; Cailliet, Rene; Normand, Martin C.; Perron, Denise L.; Ferrantelli, Joseph R

    2006-01-01

    Since thoracic cage posture affects lumbar spine coupling and loads on the spinal tissues and extremities, a scientific analysis of upright posture is needed. Common posture analyzers measure human posture as displacements from a plumb line, while the PosturePrint™ claims to measure head, rib cage, and pelvic postures as rotations and translations. In this study, it was decided to evaluate the validity of the PosturePrint™ Internet computer system’s analysis of thoracic cage postures. In a university biomechanics laboratory, photographs of a mannequin thoracic cage were obtained in different postures on a stand in front of a digital camera. For each mannequin posture, three photographs were obtained (left lateral, right lateral, and AP). The mannequin thoracic cage was placed in 68 different single and combined postures (requiring 204 photographs) in five degrees of freedom: lateral translation (Tx), lateral flexion (Rz), axial rotation (Ry), flexion–extension (Rx), and anterior–posterior translation (Tz). The PosturePrint™ system requires 13 reflective markers to be placed on the subject (mannequin) during photography and 16 additional “click-on” markers via computer mouse before a set of three photographs is analyzed by the PosturePrint™ computer system over the Internet. Errors were the differences between the positioned mannequin and the calculated positions from the computer system. Average absolute value errors were obtained by comparing the exact inputted posture to the PosturePrint™’s computed values. Mean and standard deviation of computational