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Sample records for radiographic image quality

  1. Assessment of Radiographic Image Quality by Visual Examination of Neutron Radiographs of the Calibration Fuel Pin

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    of a calibration fuel pin. The radiographs were made by the direct, transfer and tracketch methods using different film recording materials. These neutron radiographs of the calibration fuel pin were used for the assessement of radiographic image quality. This was done by visual examination of the radiographs...... and assessing their radiographic image quality on an arbitrary scale....

  2. Image quality in digital radiographic systems

    Directory of Open Access Journals (Sweden)

    Almeida Solange Maria de

    2003-01-01

    Full Text Available The aim of the present study was to evaluate the image quality of four direct digital radiographic systems. Radiographs were made of the maxillary central incisor and mandibular left molar regions of a dry skull, and an aluminum step-wedge. The X-ray generator operated at 10 mA, 60 and 70 kVp, and images were acquired with 3, 5, 8, 12, 24 and 48 exposure pulses. Six well-trained observers classified the images by means of scores from 1 to 3. Collected data were submitted to nonparametric statistical analysis using Fisher's exact test. Statistical analysis showed significant differences (p<0.01 in image quality with the four systems. Based on the results, it was possible to conclude that: 1 all of the digital systems presented good performance in producing acceptable images for diagnosis, if the exposures of the step-wedge and the maxillary central incisor region were made at 5 pulses, as well as at 8 pulses for the mandibular left molar region, selecting 60 or 70kVp; 2 higher percentages of acceptable images were obtained with the administration of lower radiation doses in CCD-sensors (charge-coupled device; 3 the Storage Phosphor systems produced acceptable images at a large range of exposure settings, that included low, intermediate and high radiation doses.

  3. Quantitative metrics to evaluate image quality for computed radiographic images

    Science.gov (United States)

    Pitcher, Christopher D.

    Traditional methods of evaluating a computed radiography (CR) imaging system's performance (e.g. the noise power spectrum (NPS), the modulation transfer function (MTF), the detective quantum efficiency (DQE) and contrast-detail analysis) were adapted in order to evaluate the feasibility of identifying a quantitative metric to evaluate image quality for digital radiographic images. The addition of simulated patient scattering media when acquiring the images to calculate these parameters altered their fundamental meaning. To avoid confusion with other research they were renamed the clinical noise power spectrum (NPSC), the clinical modulation transfer function (MTFC), the clinical detective quantum efficiency (DQEC) and the clinical contrast detail score (CDSC). These metrics were then compared to the subjective evaluation of radiographic images of an anthropomorphic phantom representing a one-year old pediatric patient. Computer algorithms were developed to implement the traditional mathematical procedures for calculating the system performance parameters. In order to easily compare these three metrics, the integral up to the system Nyquist frequency was used as the final image quality metric. These metrics are identified as the INPSC, the IMTFC and the IDQEC respectively. A computer algorithm was also developed, based on the results of the observer study, to determine the threshold contrast to noise ratio (CNRT) for objects of different sizes. This algorithm was then used to determine the CDSC by scoring images without the use of observers. The four image quality metrics identified in this study were evaluated to determine if they could distinguish between small changes in image acquisition parameters e.g., current-time product and peak-tube potential. All of the metrics were able to distinguish these small changes in at least one of the image acquisition parameters, but the ability to digitally manipulate the raw image data made the identification of a broad

  4. A Reduction in Radiographic Exposure and Image Quality in Film ...

    African Journals Online (AJOL)

    Purpose: To develop a protocol for the optimization of diagnostic chest radiography examination, the effect of radiographic exposure reduction on image quality is investigated. Procedure: Fourty-eight adult patients presenting for posterior-anterior (PA) chest radiography in a tertiary health care centre were categorized into 3 ...

  5. A patient image-based technique to assess the image quality of clinical chest radiographs

    Science.gov (United States)

    Lin, Yuan; Samei, Ehsan; Luo, Hui; Dobbins, James T., III; McAdams, H. Page; Wang, Xiaohui; Sehnert, William J.; Barski, Lori; Foos, David H.

    2011-03-01

    Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system DQE and MTF, the exposure technique, and the particular image processing method and processing parameters. However, when assessing a clinical image, radiologists seldom refer to these factors, but rather examine several specific regions of the image to see whether the image is suitable for diagnosis. In this work, we developed a new strategy to learn and simulate radiologists' evaluation process on actual clinical chest images. Based on this strategy, a preliminary study was conducted on 254 digital chest radiographs (38 AP without grids, 35 AP with 6:1 ratio grids and 151 PA with 10:1 ratio grids). First, ten regional based perceptual qualities were summarized through an observer study. Each quality was characterized in terms of a physical quantity measured from the image, and as a first step, the three physical quantities in lung region were then implemented algorithmically. A pilot observer study was performed to verify the correlation between image perceptual qualities and physical quantitative qualities. The results demonstrated that our regional based metrics have promising performance for grading perceptual properties of chest radiographs.

  6. Evolution of Entrance Surface Doses and Image Quality in Pediatric Chest Radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Campello, A.C.; Marques, D.T.; Medeiros, C.B.; Carvalho, P.P.; Khoury, H.J. [Departamento de Energia Nuclear, UFPe, 50740-540 Recife (Brazil); Azevedo, A.C.P. [Escola Nacional de Saude Publica, 21041-210 Rio de Janeiro (Brazil)

    2006-05-15

    This work presents the results of a survey about image quality, radiographic techniques and patient doses in a large public hospital located in the city of Recife, Brazil. It was detected that the quality criteria are not fully reached and represent 70% of the agreement with recommendations from the European Community. Concerning the radiographic techniques the kV is in accordance with international recommendations in 90% if the examinations while the exposure time is 72%. The results also show that the dose values change in the range from 0.020 to 0.250 mGy. The variability is mainly caused by the disparity on the radiographic techniques employed in the examinations as well as by the radiographer's expertise. It could be concluded that the ALARA principle is not being applied in the hospital, which becomes a concern in terms of public health. (author)

  7. Standard practice for determining relative image quality response of industrial radiographic imaging systems

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This standard provides a practice whereby industrial radiographic imaging systems may be comparatively assessed using the concept of relative image quality response (RIQR). The RIQR method presented within this practice is based upon the use of equivalent penetrameter sensitivity (EPS) described within Practice E 1025 and subsection 5.2 of this practice. Figure 1 illustrates a relative image quality indicator (RIQI) that has four different steel plaque thicknesses (.015, .010, .008, and .005 in.) sequentially positioned (from top to bottom) on a ¾-in. thick steel plate. The four plaques contain a total of 14 different arrays of penetrameter-type hole sizes designed to render varied conditions of threshold visibility ranging from 1.92 % EPS (at the top) to .94 % EPS (at the bottom) when exposed to nominal 200 keV X-ray radiation. Each “EPS” array consists of 30 identical holes; thus, providing the user with a quantity of threshold sensitivity levels suitable for relative image qualitative response com...

  8. Radiographic quality control devices.

    Science.gov (United States)

    2000-04-01

    In this study, we evaluate eight radiographic quality control (QC) devices, which noninvasively measure the output from a variety of diagnostic x-ray production systems. When used as part of a quality assurance (QA) program, radiographic QC devices help ensure that x-ray equipment is working within acceptable limits. This in turn helps ensure that high-quality images are achieved with appropriate radiation doses and that resources are used efficiently (for example, by minimizing the number of repeat exposures required). Our testing focused on the physical performance, ease of use, and service and maintenance characteristics that affect the use of these devices for periodic, routine measurements of x-ray system parameters. We found that all the evaluated models satisfactorily measure all the parameters normally needed for a QA program. However, we did identify a number of differences among the models--particularly in the range of exposure levels that can be effectively measured and the ease of use. Three models perform well for a variety of applications and are very easy to use; we rate them Preferred. Three additional models have minor limitations but otherwise perform well; we rate them Acceptable. We recommend against purchasing two models because, although each performs acceptably for most applications, neither model can measure low levels of radiation. This Evaluation covers devices designed to measure the output of x-ray tubes noninvasively. These devices, called radiographic quality control (QC) devices, or QC meters, are typically used by medical physicists, x-ray engineers, biomedical engineers, and suitably trained radiographic technologists to make QC measurements. We focus on the use of these devices as part of an overall quality assurance (QA) program. We have not evaluated their use for other applications, such as acceptance testing. To be included in this study, a device must be able to measure the exposure- and kVp-related characteristics of most x

  9. Novel Card Games for Learning Radiographic Image Quality and Urologic Imaging in Veterinary Medicine.

    Science.gov (United States)

    Ober, Christopher P

    Second-year veterinary students are often challenged by concepts in veterinary radiology, including the fundamentals of image quality and generation of differential lists. Four card games were developed to provide veterinary students with a supplemental means of learning about radiographic image quality and differential diagnoses in urogenital imaging. Students played these games and completed assessments of their subject knowledge before and after playing. The hypothesis was that playing each game would improve students' understanding of the topic area. For each game, students who played the game performed better on the post-test than students who did not play that game (all pgames, students who played each respective game demonstrated significant improvement in scores between the pre-test and the post-test (pgames were both helpful and enjoyable. Educationally focused games can help students learn classroom and laboratory material. However, game design is important, as the game using the most passive learning process also demonstrated the weakest results. In addition, based on participants' comments, the games were very useful in improving student engagement in the learning process. Thus, use of games in the classroom and laboratory setting seems to benefit the learning process.

  10. Relationship between image plates physical structure and quality of digital radiographic images in weld inspections

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Davi F.; Silva, Aline S.S.; Machado, Alessandra S.; Gomes, Celio S.; Nascimento, Joseilson; Lopes, Ricardo T., E-mail: davi@lin.ufrj.br.br, E-mail: aline@lin.ufrj.br, E-mail: celio@lin.ufrj.br, E-mail: alemachado@lin.ufrj.br, E-mail: joseilson@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear

    2015-07-01

    In the last decades a new type of detector which is based on photostimulable luminescence was developed. There are currently many kinds of image plates (IPs) available on the market, originating from different manufacturers. Each kind of plate distinguishes itself from the others by its peculiar physical structure and composition, two factors which have a direct influence upon the quality of the digital radiographic images obtained through them. For this study, several kinds of IPs were tested in order to determine in which way such influence takes place. For this purpose, each kind of IP has been characterized and correlated to its response in the final image. The aim of this work was to evaluate procedures for employing Computed Radiography (CR) to welding inspections in laboratory conditions using the Simple Wall Simple Image Technique (SWSI). Tests were performed in steel welded joins of thickness 5.33, 12.70 and 25.40 mm, using CR scanner and IPs available on the market. It was used an X-Ray equipment as radiation source. The image quality parameters Basic Spatial Resolution (BSR), Normalized Signal-to-Noise Ratio (SNR{sub N}), contrast and detectability were evaluated. In order to determine in which way the IPs' properties are correlated to its response in the final image, the thickness of the sensitive layer was determined and the grain size and the elemental composition of this layer were evaluated. Based on the results drawn from this study, it is possible to conclude that the physical characteristics of image plates are essential for determining the quality of the digital radiography images acquired with them. Regarding the chemical composition of the plates, it was possible to determine that, apart from the chemical elements that were expected to be found (Ba, I and Br), only two plates, with high resolution, do not have fluorine in their composition; the presence of Strontium was also detected in the chemical composition of the plates supplied by a

  11. [Evaluation method with radiographic image quality indicator for internal defects of dental casting metallic restoration].

    Science.gov (United States)

    Li, Y; Zheng, G; Lin, H

    2014-12-18

    To develop a new kind of dental radiographic image quality indicator (IQI) for internal quality of casting metallic restoration to influence on its usage life. Radiographic image quality indicator method was used to evaluate the depth of the defects region and internal quality of 127 casting metallic restoration and the accuracy was compared with that of conventional callipers method. In the 127 cases of casting metallic restoration, 9 were found the thickness less than 0.7 mm and the thinnest thickness only 0.2 mm in 26 casting metallic crowns or bridges' occlusal defects region. The data measured by image quality indicator were consistent with those measured by conventional gauging. Two metal inner crowns were found the thickness less than 0.3 mm in 56 porcelain crowns or bridges. The thickness of casting removable partial denture was more than 1.0 mm, but thinner regions were not found. It was found that in a titanium partial denture, the X-ray image of clasp was not uniform and there were internal porosity defects in the clasp. Special dental image quality indicator can solve the visual error problems caused by different observing backgrounds and estimate the depth of the defects region in the casting.

  12. Super-resolution convolutional neural network for the improvement of the image quality of magnified images in chest radiographs

    Science.gov (United States)

    Umehara, Kensuke; Ota, Junko; Ishimaru, Naoki; Ohno, Shunsuke; Okamoto, Kentaro; Suzuki, Takanori; Shirai, Naoki; Ishida, Takayuki

    2017-02-01

    Single image super-resolution (SR) method can generate a high-resolution (HR) image from a low-resolution (LR) image by enhancing image resolution. In medical imaging, HR images are expected to have a potential to provide a more accurate diagnosis with the practical application of HR displays. In recent years, the super-resolution convolutional neural network (SRCNN), which is one of the state-of-the-art deep learning based SR methods, has proposed in computer vision. In this study, we applied and evaluated the SRCNN scheme to improve the image quality of magnified images in chest radiographs. For evaluation, a total of 247 chest X-rays were sampled from the JSRT database. The 247 chest X-rays were divided into 93 training cases with non-nodules and 152 test cases with lung nodules. The SRCNN was trained using the training dataset. With the trained SRCNN, the HR image was reconstructed from the LR one. We compared the image quality of the SRCNN and conventional image interpolation methods, nearest neighbor, bilinear and bicubic interpolations. For quantitative evaluation, we measured two image quality metrics, peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). In the SRCNN scheme, PSNR and SSIM were significantly higher than those of three interpolation methods (pimage resolution and that the use of the SRCNN can yield substantial improvement of the image quality of magnified images in chest radiographs.

  13. Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Sensakovic, William F.; O' Dell, M.C.; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura [Florida Hospital, Imaging Administration, Orlando, FL (United States)

    2016-10-15

    Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA{sup 2} by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P < 0.0001). Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image

  14. Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs.

    Science.gov (United States)

    Sensakovic, William F; O'Dell, M Cody; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura

    2016-10-01

    Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA(2) by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image processing can

  15. Benchmarking the performance of fixed-image receptor digital radiographic systems part 1: a novel method for image quality analysis.

    Science.gov (United States)

    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.

  16. Development and validation of a visual grading scale for assessing image quality of AP pelvis radiographic images

    Science.gov (United States)

    England, Andrew; Cassidy, Simon; Eachus, Peter; Dominguez, Alejandro; Hogg, Peter

    2016-01-01

    Objective: The aim of this article was to apply psychometric theory to develop and validate a visual grading scale for assessing the visual perception of digital image quality anteroposterior (AP) pelvis. Methods: Psychometric theory was used to guide scale development. Seven phantom and seven cadaver images of visually and objectively predetermined quality were used to help assess scale reliability and validity. 151 volunteers scored phantom images, and 184 volunteers scored cadaver images. Factor analysis and Cronbach's alpha were used to assess scale validity and reliability. Results: A 24-item scale was produced. Aggregated mean volunteer scores for each image correlated with the rank order of the visually and objectively predetermined image qualities. Scale items had good interitem correlation (≥0.2) and high factor loadings (≥0.3). Cronbach's alpha (reliability) revealed that the scale has acceptable levels of internal reliability for both phantom and cadaver images (α = 0.8 and 0.9, respectively). Factor analysis suggested that the scale is multidimensional (assessing multiple quality themes). Conclusion: This study represents the first full development and validation of a visual image quality scale using psychometric theory. It is likely that this scale will have clinical, training and research applications. Advances in knowledge: This article presents data to create and validate visual grading scales for radiographic examinations. The visual grading scale, for AP pelvis examinations, can act as a validated tool for future research, teaching and clinical evaluations of image quality. PMID:26943836

  17. Digitized hand-wrist radiographs: comparison of subjective and software-derived image quality at various compression ratios.

    Science.gov (United States)

    McCord, Layne K; Scarfe, William C; Naylor, Rachel H; Scheetz, James P; Silveira, Anibal; Gillespie, Kevin R

    2007-05-01

    The objectives of this study were to compare the effect of JPEG 2000 compression of hand-wrist radiographs on observer image quality qualitative assessment and to compare with a software-derived quantitative image quality index. Fifteen hand-wrist radiographs were digitized and saved as TIFF and JPEG 2000 images at 4 levels of compression (20:1, 40:1, 60:1, and 80:1). The images, including rereads, were viewed by 13 orthodontic residents who determined the image quality rating on a scale of 1 to 5. A quantitative analysis was also performed by using a readily available software based on the human visual system (Image Quality Measure Computer Program, version 6.2, Mitre, Bedford, Mass). ANOVA was used to determine the optimal compression level (P quality. When we used quantitative indexes, the JPEG 2000 images had lower quality at all compression ratios compared with the original TIFF images. There was excellent correlation (R2 >0.92) between qualitative and quantitative indexes. Image Quality Measure indexes are more sensitive than subjective image quality assessments in quantifying image degradation with compression. There is potential for this software-based quantitative method in determining the optimal compression ratio for any image without the use of subjective raters.

  18. Optimum image compression rate maintaining diagnostic image quality of digital intraoral radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ju Seop; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology and Institute of Oral Bio Science, School of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    2000-12-15

    The aims of the present study are to determine the optimum compression rate in terms of file size reduction and diagnostic quality of the images after compression and evaluate the transmission speed of original or each compressed images. The material consisted of 24 extracted human premolars and molars. The occlusal surfaces and proximal surfaces of the teeth had a clinical disease spectrum that ranged from sound to varying degrees of fissure discoloration and cavitation. The images from Digora system were exported in TIFF and the images from conventional intraoral film were scanned and digitalized in TIFF by Nikon SF-200 scanner(Nikon, Japan). And six compression factors were chosen and applied on the basis of the results from a pilot study. The total number of images to be assessed were 336. Three radiologists assessed the occlusal and proximal surfaces of the teeth with 5-rank scale. Finally diagnosed as either sound or carious lesion by one expert oral pathologist. And sensitivity and specificity and kappa value for diagnostic agreement was calculated. Also the area (Az) values under the ROC curve were calculated and paired t-test and oneway ANOVA test was performed. Thereafter, transmission time of the image files of the each compression level were compared with that of the original image files. No significant difference was found between original and the corresponding images up to 7% (1:14) compression ratio for both the occlusal and proximal caries (p<0.05). JPEG3 (1:14) image files are transmitted fast more than 10 times, maintained diagnostic information in image, compared with original image files. 1:14 compressed image file may be used instead of the original image and reduce storage needs and transmission time.

  19. Large Format Radiographic Imaging

    Energy Technology Data Exchange (ETDEWEB)

    J. S. Rohrer; Lacey Stewart; M. D. Wilke; N. S. King; S. A Baker; Wilfred Lewis

    1999-08-01

    Radiographic imaging continues to be a key diagnostic in many areas at Los Alamos National Laboratory (LANL). Radiographic recording systems have taken on many form, from high repetition-rate, gated systems to film recording and storage phosphors. Some systems are designed for synchronization to an accelerator while others may be single shot or may record a frame sequence in a dynamic radiography experiment. While film recording remains a reliable standby in the radiographic community, there is growing interest in investigating electronic recording for many applications. The advantages of real time access to remote data acquisition are highly attractive. Cooled CCD camera systems are capable of providing greater sensitivity with improved signal-to-noise ratio. This paper begins with a review of performance characteristics of the Bechtel Nevada large format imaging system, a gated system capable of viewing scintillators up to 300 mm in diameter. We then examine configuration alternatives in lens coupled and fiber optically coupled electro-optical recording systems. Areas of investigation include tradeoffs between fiber optic and lens coupling, methods of image magnification, and spectral matching from scintillator to CCD camera. Key performance features discussed include field of view, resolution, sensitivity, dynamic range, and system noise characteristics.

  20. Computed radiography versus mobile direct radiography for bedside chest radiographs: impact of dose on image quality and reader agreement.

    NARCIS (Netherlands)

    Boo, D.W. De; Weber, M.; Deurloo, E.E.; Streekstra, G.J.; Freling, N.J.; Dongelmans, D.A.; Schaefer-Prokop, C.M.

    2011-01-01

    AIM: To asses the image quality and potential for dose reduction of mobile direct detector (DR) chest radiography as compared with computed radiography (CR) for intensive care unit (ICU) chest radiographs (CXR). METHODS AND MATERIALS: Three groups of age-, weight- and disease-matched ICU patients

  1. Improving the quality of radiographic images acquired with conical radiation beams through divergence correction and filtering

    Science.gov (United States)

    Silvani, M. I.; Almeida, G. L.; Latini, R. M.; Bellido, A. V. B.; Souza, E. S.; Lopes, R. T.

    2015-07-01

    Earlier works have shown the feasibility to correct the deformation of the attenuation map in radiographs acquired with conical radiation beams provided that the inspected object could be expressed into analytical geometry terms. This correction reduces the contribution of the main object in the radiograph, allowing thus the visualization of its otherwise concealed heterogeneities. However, the non-punctual character of the source demanded a cumbersome trial-and-error approach in order to determine the proper correction parameters for the algorithm. Within this frame, this work addresses the improvement of radiographs of specially tailored test-objects acquired with a conical beam through correction of its divergence by using the information contained in the image itself. The corrected images have afterwards undergone a filtration in the frequency domain aiming at the reduction of statistical fluctuation and noise by using a 2D Fourier transform. All radiographs have been acquired using 165Dy and 198Au gamma-ray sources produced at the Argonauta research reactor in Institutode Engenharia Nuclear - CNEN, and an X-ray sensitive imaging plate as detector. The processed images exhibit features otherwise invisible in the original ones. Their processing by conventional histogram equalization carried out for comparison purposes did not succeed to detect those features.

  2. Dynamic Radiographic Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, A.; Turley, D.; Veeser, L.; Lukyanov, N.; Yegorov, N.; Baker, S.A.; Mirenko, V.; Lewis, W.; Kuropatkin, Y.

    1999-06-01

    A radiographic system recently developed by American and Russian collaborators is designed to capture multiple images of a dynamic event lasting less than 10 microseconds. Various optical and electro-optical components were considered and their performance compared. The final system employed a solid crystal of lutetium oxyorthosilicate doped with cerium (LSO:Ce or LSO) for X-ray-to-light conversion with a coherent fiber optic bundle to relay the scintillator image to a streak camera with charge coupled device (CCD) readout. Resolution and sensitivity studies were carried out for this system on two different sources of X-rays: a 20 MeV microtron and a 70 MeV betatron.

  3. Optimization of Dose and Image Quality in Full-fiand Computed Radiography Systems for Common Digital Radiographic Examinations

    Directory of Open Access Journals (Sweden)

    Soo-Foon Moey

    2018-01-01

    Full Text Available IntroductionA fine balance of image quality and radiation dose can be achieved by optimization to minimize stochastic and deterministic effects. This study aimed in ensuring that images of acceptable quality for common radiographic examinations in digital imaging were produced without causing harmful effects. Materials and MethodsThe study was conducted in three phases. The pre-optimization involved ninety physically abled patients aged between 20 to 60 years and weighed between 60 and 80 kilograms for four common digital radiographic examinations. Kerma X_plus, DAP meter was utilized to measure the entrance surface dose (ESD while effective dose (ED was estimated using CALDose_X 5.0 Monte Carlo software. The second phase, an experimental study utilized an anthropomorphic phantom (PBU-50 and Leeds test object TOR CDR for relative comparison of image quality. For the optimization phase, the imaging parameters with acceptable image quality and lowest ESD from the experimental study was related to patient’s body thickness. Image quality were evaluated by two radiologists using the modified evaluation criteria score lists. ResultsSignificant differences were found for image quality for all examinations. However significant difference for ESD were found for PA chest and AP abdomen only. The ESD for three of the examinations were lower than all published data. Additionally, the ESD and ED obtained for all examinations were lower than that recommended by radiation regulatory bodies. ConclusionOptimization of image quality and dose was achieved by utilizing an appropriate tube potential, calibrated automatic exposure control and additional filtration of 0.2mm copper.

  4. Radiographic image quality and dose at thorax, abdomen and skull of patients at HC-FMB-UNESP

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    Alvarez, Matheus; Giacomini, Guilherme; Bacchim Neto, Fernando A.; Alves, Allan F.F.; Velo, Alexandre F.; Miranda, Jose R.A., E-mail: matheus@ibb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (IBB/UNESP), Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Fisica e Biofisica; Pina, Diana R. de, E-mail: drpina@fmb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (FMB/UNESP), Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Doencas Tropicais e Diagnostico por Imagem

    2013-11-01

    ICRP 103 specifies reference dose levels to be used during radiographic exams. Usually, the radiographer qualitative determines the best radiographic technique (kV and mAs) in order to obtain better image quality with the lowest dose. The objective of this study was to evaluate the doses used in examination of the chest, abdomen and skull in patients of different physical sizes, and infer about the amount of dose required to maintain acceptable radiological contrast in patients of different physical sizes. Techniques used by experienced radiographers of HC-FMB-UNESP for examinations of the chest (PA), abdomen (AP) and skull (AP) for patients of different thickness (small, medium and thick body) were obtained. Dose measurements were performed referring to all kV/mAs combinations. PMMA phantoms were placed below the ionization chamber. The Signal Difference Noise Ratio (SDNR) of the images of the phantoms were calculated from an area of contrast and a region of normal tissue. The Figure of Merit (FoM) was calculated for each of the exam modality. Measured FoM decreased according to the thickness of the chest and abdomen, indicating the need to increase the dose level to maintain the same level of image contrast. Patients thicker usually end up getting more than twice the dose of lean patients. Required image quality levels for correct diagnosis should be obtained using dose levels as low as reasonably practicable examination. These factors highlight the need for a program of quality assurance and effective dose studies in actual service. (author)

  5. Practical evaluation of image quality in computed radiographic (CR) imaging systems

    Science.gov (United States)

    Desai, Nikunj; Singh, Abhinav; Valentino, Daniel J.

    2010-04-01

    A number of complementary metrics are available to assess the performance of digital X-ray imaging systems. However, the sensitivity of these metrics to changes in the electro-optical imaging chain is poorly understood. Some of the commonly used metrics include Contrast to Noise ratio (CNR), limiting spatial resolution, Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and the Detective Quantum Efficiency (DQE). We evaluated the utility of these metrics in characterizing the imaging plate, imaging system optics and electronic components of computed radiography (CR) systems. We developed practical and easy to use test objects (phantoms) and implemented software to aid in calculating each metric. The results of this research will facilitate the characterization of differences in CR systems using the appropriate metrics.

  6. 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.

    Science.gov (United States)

    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%.

  7. Radiographic imaging of aids

    CERN Document Server

    Gasmalla, O A A K

    2002-01-01

    Over the past decade, many different imaging techniques have been proposed and shown to be capable of producing NMR images. Four Gd-based contrast agents for intravenous administration are now being used and tested nationally and internationally. Two of these are ionic (magnevist , dotarem) and two are non-ionic (omni scan, prohance). This article review information about MR imaging contrast agents, their types, chemical components, administration and reaction, to enable MR user to be aware of the basic pharmacokinetics, side effects and the potential for adverse events.

  8. Radiographic imaging of aids

    CERN Document Server

    Mahmoud, M B

    2002-01-01

    The acquired immunodeficiency syndrome (AIDS) has impacted the civilized world like no other disease. This research aimed to discuss some of the main aids-related complications and their detection by radiology tests, specifically central nervous system and musculoskeletal system disorders. The objectives are: to show specific characteristics of various diseases of HIV patient, to analyze the effect of pathology in patients by radiology, to enhance the knowledge of technologists in aids imaging and to improve communication skills between patient and radiology technologists.

  9. Digital processing of radiographic images

    Science.gov (United States)

    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.

  10. Use of a sensitometric method in quality control of radiographic images; Utilizacao de sensitometria no controle de qualidade de imagens radiograficas

    Energy Technology Data Exchange (ETDEWEB)

    Lima, A.A.; Furtado, A.P.A.; Nied, L.; Bacelar, A.; Pinto, A.L.A.; Acunha, B. [Hospital das Clinicas, Porto Alegre, RS (Brazil). Grupo de Pesquisa e Pos-graduacao em Fisica Medica

    1996-12-31

    A sensitometric method is used to evaluate the characteristic answer of several radiographic films and the quality of produced images. Data was collected daily in a period of three months. Results from this research show a disagreement of a 100% from the pattern of the sensitometric characteristics to the analysed films 2 refs.

  11. Clarity and diagnostic quality of digitized conventional intraoral radiographs.

    Science.gov (United States)

    Goga, R; Chandler, N P; Love, R M

    2004-03-01

    To compare digital images of conventional radiographs with the original radiographs for perceived clarity of endodontic files, periapical lesions and carious lesions, and to establish the diagnostic value of the digital images. Four groups of ten radiographs were used: standardized bitewings demonstrating carious lesions, periapical radiographs of apical lesions, periapical radiographs showing endodontic files of various sizes at working length, and standardized periapical radiographs with size 08 files at working length. Radiographs were photographed using an Olympus C 2500-L digital camera and a Nikon D1X digital camera and were scanned using a Nikon Supercoolscan 4000 ED film/slide scanner. The digital images were then transferred to a Toshiba Satellite 2210 laptop. Three general dental practitioners compared each conventional radiograph with the three matching digital images. Images were ranked for clarity and were assessed for diagnostic quality. Data were analysed using General Estimating Equations. The clarity and diagnostic quality of the conventional radiographs were superior to the digital images produced by the three techniques (P harness the potential of digital technology.

  12. Digital image analysis of NDT radiographs

    Science.gov (United States)

    Eizember, A. C.; Graeme, W. A., Jr.; Douglass, J.

    Prior to the introduction of Charge Coupled Device (CCD) detectors the majority of image analysis performed on NDT radiographic images was done visually in the analog domain. While some film digitization was being performed, the process was often unable to capture all the usable information in the radiograph or was too time consuming. CCD technology now provides a method to digitize radiographic film images without losing the useful information captured in the original radiograph in a timely process. Incorporating that technology into a complete digital radiographic workstation allows analog radiographic information to be processed, providing additional information to the radiographer. Once in the digital domain that data can be stored and fused with radioscopic and other forms of digital data. The result is a more productive analysis and management of radiographic inspection data.

  13. Image quality in the anteroposterior cervical spine radiograph: Comparison between moving, stationary and non-grid techniques in a lamb neck

    Energy Technology Data Exchange (ETDEWEB)

    Keating, Michelle [School of Health and Social Care, Faculty of Health and Life Sciences, University of the West of England, Stapleton, Bristol BS16 1DD (United Kingdom); Grange, Stuart, E-mail: Stuart2.Grange@uwe.ac.u [School of Health and Social Care, Faculty of Health and Life Sciences, University of the West of England, Stapleton, Bristol BS16 1DD (United Kingdom)

    2011-05-15

    Background: Cervical spine radiography is a commonly employed examination for degenerative disease and trauma in the cervical spine. Traditionally, the anteroposterior projection is undertaken with the use of an anti-scatter grid. Some practitioners appear to have rejected this practice in favour of a non-grid technique, possibly because of the dose saving it affords. It is necessary to determine if image quality in the cervical spine is significantly degraded and whether the omission of the grid is justified. Method: Using a slaughtered lamb neck as a model of the human neck triplicate radiographs were obtained using a non-grid, a stationary grid and a moving grid technique. Entrance surface dose and dose area product was measured for these techniques. Image quality in terms of contrast, sharpness and overall acceptability was evaluated by 9 independent and blinded observers. Results: A significant reduction in measured dose was observed when the non-grid technique was compared to stationary or moving grid techniques. A statistically significant reduction in image contrast, sharpness and acceptability was also seen in the non-grid compared to grid techniques. Conclusion: These results show evidence of significantly greater image quality in the presence of either a moving or stationary grid in the lamb model. As such they support the continued use of scatter rejection methods such as the anti-scatter grid in AP radiography of the human cervical spine, to optimise radiographic image quality in this critical structure.

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

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-03-15

    his 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.

  15. Antero-posterior (AP) pelvis x-ray imaging on a trolley: Impact of trolley design, mattress design and radiographer practice on image quality and radiation dose.

    Science.gov (United States)

    Tugwell, J R; England, A; Hogg, P

    2017-08-01

    Physical and technical differences exist between imaging on an x-ray tabletop and imaging on a trolley. This study evaluates how trolley imaging impacts image quality and radiation dose for an antero-posterior (AP) pelvis projection whilst subsequently exploring means of optimising this imaging examination. An anthropomorphic pelvis phantom was imaged on a commercially available trolley under various conditions. Variables explored included two mattresses, two image receptor holder positions, three source to image distances (SIDs) and four mAs values. Image quality was evaluated using relative visual grading analysis with the reference image acquired on the x-ray tabletop. Contrast to noise ratio (CNR) was calculated. Effective dose was established using Monte Carlo simulation. Optimisation scores were derived as a figure of merit by dividing effective dose with visual image quality scores. Visual image quality reduced significantly (p images acquired on the trolley using identical acquisition parameters to the reference image. The trolley image with the highest optimisation score was acquired using 130 cm SID, 20 mAs, the standard mattress and platform not elevated. A difference of 12.8 mm was found between the image with the lowest and highest magnification factor (18%). The acquisition parameters used for AP pelvis on the x-ray tabletop are not transferable to trolley imaging and should be modified accordingly to compensate for the differences that exist. Exposure charts should be developed for trolley imaging to ensure optimal image quality at lowest possible dose. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  16. Can Neutron Beam Components and Radiographic Image Quality be determined by the Use of Beam Purity and Sensitivity Indicators?

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    In the Euratom Neutron Radiography Working Group Test Program beam purity and s e n s i t i v i t y indicators, as prescribed by the ASTM E 545-81 were used together with the NRWG beam purity i n d i c a t o r - f u e l and c a l i b r a t i o n fuel pin. They were radiographed together at neutron...

  17. Multiscale shape analysis for computed radiographic images

    Science.gov (United States)

    Jang, Ben K.

    1996-04-01

    The construction of a multiscale (scale space) representation requires the smoothing of the given image to generate a set of corresponding images at other coarser scales, and the extraction of features at these scales. Various methods of smoothing, combined with various feature extractors, will result in drastically different scale space representations. The particular application and desired criteria determine the choice of smoothing and feature extractor. In this paper, we first put foreword a framework for the scale space representation. Then we focus on the Gaussian and morphological scale space for planar shape analysis of computed radiographic (CR) images. The discussion of the various scale space methods is organized into three categories -- boundary approach, region approach, and hybrid approach. Properties, limitations, performance, and applications of these scale space methods are discussed. Extensive experiments on CR images of various exam types were conducted and the results are evaluated.

  18. A quality initiative of postoperative radiographic imaging performed on mastectomy specimens to reduce histology cost and pathology report turnaround time.

    Science.gov (United States)

    Kallen, Michael E; Sim, Myung S; Radosavcev, Bryan L; Humphries, Romney M; Ward, Dawn C; Apple, Sophia K

    2015-10-01

    Breast pathology relies on gross dissection for accurate diagnostic work, but challenges can necessitate submission of high tissue volumes resulting in excess labor, laboratory costs, and delays. To address these issues, a quality initiative was created through implementation of the Faxitron PathVision specimen radiography system as part of the breast gross dissection protocol; this report documents its impact on workflow and clinical care. Retrospective data from 459 patients who underwent simple or modified radical mastectomy at our institution between May 2012 and December 2014 were collected. Comparison was made between the mastectomy specimen control group before radiography use (233 patients, 340 breasts) and Faxitron group that underwent postoperative radiography (226 patients, 338 breasts). We observed a statistically significant decrease in mean number of blocks between control and Faxitron groups (47.0 vs 39.7 blocks; Pmastectomy. A statistically significant decrease in pathology report turnaround time was also observed (4.2 vs 3.8days; P=.038). Postoperative mastectomy specimen radiography has increased workflow efficiency and decreased histology costs and pathology report turnaround time. These findings may underestimate actual benefits and highlight the importance of quality improvement projects in anatomical pathology. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Image quality in mammography

    Energy Technology Data Exchange (ETDEWEB)

    Haus, A.G.; Doi, K.; Metz, C.E. Bernstein, J.

    1976-01-01

    In mammography, image quality is a function of the shape, size, and x-ray absorption properties of the anatomic part to be radiographed and of the lesion to be detected; it also depends on geometric unsharpness, and the resolution, characteristic curve and noise properties of the recording system. X-ray energy spectra, modulation transfer functions, Wiener spectra, characteristic and gradient curves, and radiographs of a breast phantom and of a resected breast specimen containing microcalcifications are used in a review of some current considerations of the factors, and the complex relationship among factors, that affect image quality in mammography. Image quality and patient radiation exposure in mammography are interrelated. An approach to the problem of evaluating the trade-off between diagnostic certainty and the cost or risk of performing a breast imaging procedure is discussed.

  20. Extraoral radiographic imaging of primary caries.

    Science.gov (United States)

    Clifton, T L; Tyndall, D A; Ludlow, J B

    1998-07-01

    To evaluate three extra-oral radiographic imaging modalities as alternatives to conventional intra-oral film for the detection of primary caries. Sixty-four extracted primary molar teeth with eighty-five carious lesions were radiographed using D-speed film (N = 8), panoramic imaging (N = 8), multidirectional tomography (N = 8), and linear tomography (N = 8). Eight trained observers were asked to identify the presence or absence of caries on each surface using a five point scale. Ground sections were viewed microscopically to determine truth. ROC curve areas (Az) were generated from observer responses and assessed with ANOVA. Average of Az for the detection of combined results for proximal and occlusal lesions were 0.70 for D-speed, film, 0.58 for linear tomography, 0.64 for both multidirectional tomography, and panoramic film. Turkey's pairwise comparisons of Az revealed that D-speed film was significantly better than linear tomography (P = 0.0039). When data were divided into proximal and occlusal surfaces the variability due to modality remained significant (P = 0.0003 and P = 0.0024 respectively). Turkey's comparisons for proximal surfaces revealed that D-speed film was significantly better than linear tomography (P = 0.0007), multidirectional tomography (P = 0.0010) and panoramic radiography (P = 0.0100). For detection of occlusal lesions, multidirectional tomography was significantly better than linear tomography (P = 0.0075) and panoramic radiography (P = 0.0034), but not significantly different from D-speed film (P = 0.2337). Multidirectional tomography and panoramic radiography performed as well as intra-oral D-speed film for the combined assessment of proximal and occlusal caries in the model used. when proximal surfaces were evaluated alone, D-speed film was significantly better. For occlusal caries there was no statistically significant difference between multidirectional tomography and D-speed film.

  1. Bone texture analysis on dental radiographic images: results with several angulated radiographs on the same region of interest

    Science.gov (United States)

    Amouriq, Yves; Guedon, Jeanpierre; Normand, Nicolas; Arlicot, Aurore; Benhdech, Yassine; Weiss, Pierre

    2011-03-01

    Bone microarchitecture is the predictor of bone quality or bone disease. It can only be measured on a bone biopsy, which is invasive and not available for all clinical situations. Texture analysis on radiographs is a common way to investigate bone microarchitecture. But relationship between three-dimension histomorphometric parameters and two-dimension texture parameters is not always well known, with poor results. The aim of this study is to performed angulated radiographs of the same region of interest and see if a better relationship between texture analysis on several radiographs and histomorphometric parameters can be developed. Computed radiography images of dog (Beagle) mandible section in molar regions were compared with high-resolution micro-CT (Computed-Tomograph) volumes. Four radiographs with 27° angle (up, down, left, right, using Rinn ring and customized arm positioning system) were performed from initial radiograph position. Bone texture parameters were calculated on all images. Texture parameters were also computed from new images obtained by difference between angulated images. Results of fractal values in different trabecular areas give some caracterisation of bone microarchitecture.

  2. Stereoscopic radiographic images with thermal neutrons

    Science.gov (United States)

    Silvani, M. I.; Almeida, G. L.; Rogers, J. D.; Lopes, R. T.

    2011-10-01

    Spatial structure of an object can be perceived by the stereoscopic vision provided by eyes or by the parallax produced by movement of the object with regard to the observer. For an opaque object, a technique to render it transparent should be used, in order to make visible the spatial distribution of its inner structure, for any of the two approaches used. In this work, a beam of thermal neutrons at the main port of the Argonauta research reactor of the Instituto de Engenharia Nuclear in Rio de Janeiro/Brazil has been used as radiation to render the inspected objects partially transparent. A neutron sensitive Imaging Plate has been employed as a detector and after exposure it has been developed by a reader using a 0.5 μm laser beam, which defines the finest achievable spatial resolution of the acquired digital image. This image, a radiographic attenuation map of the object, does not represent any specific cross-section but a convoluted projection for each specific attitude of the object with regard to the detector. After taking two of these projections at different object attitudes, they are properly processed and the final image is viewed by a red and green eyeglass. For monochromatic images this processing involves transformation of black and white radiographies into red and white and green and white ones, which are afterwards merged to yield a single image. All the processes are carried out with the software ImageJ. Divergence of the neutron beam unfortunately spoils both spatial and contrast resolutions, which become poorer as object-detector distance increases. Therefore, in order to evaluate the range of spatial resolution corresponding to the 3D image being observed, a curve expressing spatial resolution against object-detector gap has been deduced from the Modulation Transfer Functions experimentally. Typical exposure times, under a reactor power of 170 W, were 6 min for both quantitative and qualitative measurements. In spite of its intrinsic constraints

  3. Proton Radiography Imager:Generates Synthetic Proton Radiographs

    Energy Technology Data Exchange (ETDEWEB)

    2017-09-12

    ProRad is a computer program that is used to generate synthetic images of proton (or other charged particles) radiographs. The proton radiographs arc images that arc obtained by sending energetic protons (or electrons or positrons, for example) through 11 plasma where electric and/or magnetic fields alter the particles trajectory, Dnd the variations me imaged on RC film, image plate, or equivalent

  4. Comparison of radiographic measurements obtained with conventional an indirect digital imaging during endontic treatment

    Directory of Open Access Journals (Sweden)

    Ligia Buloto Schmitd

    2008-04-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  6. Quality assessment and quality control of radiographic units using simple tests. Experiences and results from Egypt.

    Science.gov (United States)

    de Rhoter, W; Feenstra, B W

    1995-01-01

    To assess the image quality of radiographic units we developed a set of three relatively simple tests. With this set we investigated the performance of two small film x-ray units and seven dark rooms in chest disease clinics in Egypt. As a reference we performed the same tests at the Consultation Bureau for Tuberculosis and at the Radiology Department of the Medical Centre, Leeuwarden, The Netherlands. The tests revealed deficiencies during several phases of the production of radiographs at the chest disease clinics in Egypt, as well as at the Consultation Bureau for Tuberculosis, Leeuwarden, The Netherlands. The results of the tests were used to advise the radiology units tested on how to improve their quality. We believe, that this set of tests can be applied to any radiography unit to find ways for image quality improvement.

  7. Preliminary analysis of doses to evaluate the image quality in radiographic examinations in veterinary radiology;Analise preliminar das doses para avaliacao da qualidade da imagem em exames radiograficos na radiologia veterinaria

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Ana Carolina B.C.F.; Dias, Mayara T.P.; Santos, Andrea C. [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia; Melo, Camila S.; Furquim, Tania A.C. [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

    2009-07-01

    This work has as objective to promote the analysis of the radiological doses and quality of the image of the technical letter used for the accomplishment of thorax and coxal radiographic examination of animals of canine and feline species. The study was accomplished in the service of Diagnosis for Image in Veterinarian Hospital of Veterinary Medicine and Zootecnia College of University of Sao Paulo, in two conventional equipment. Initially, physical features of the animals and the technique used were collected for each one of the 188 radiographic examinations of thorax and 52 examinations of coxal. The animals were placed in different groups, according to their body weight. For each group, the averages for each feature were calculated: thickness of the radiographed region, tension, electric current, time of exhibition, current product electric-time, size of the used film, presence or absence of bucky and feature of focus (narrow or thick). On the basis of the averages of group M (of lesser weights that 5kg for cats and between 10,1kg and 20kg for dogs), was executed a physical analysis of the current technical letter, using the equipment: ionization chamber (to determinate the value of kerma in air), simulator objects (representative of the thickness of the animal) and three dispositive standards of test that evaluate space resolution, resolution in low contrast and contrast-detail. The obtained images were analyzed and compared for a physicist and a radiologist medical veterinary. The results had shown that the examinations supply dose considered high for techniques used mainly for coxal. The equipment A, although to supply higher doses, presents the better images for the majority of the projections. However, the study indicates that there are not exactly reference levels, but these examinations must pass for improvement of quality of image (author)

  8. Content-based image recognition for digital radiographs

    Science.gov (United States)

    Luo, Hui; Luo, Jiebo

    2008-03-01

    Before a radiographic image is sent to a picture archiving and communications system (PACS), its projection information needs to be correctly identified at capture modalities to facilitate image archive and retrieval. Currently, annotating radiographic images is manually performed by technologists. It is labor intensive and cost ineffective. Moreover, man-made annotation errors occur frequently during image acquisition. To address this issue, an automatic image recognition method is developed. It first extracts a set of visual features from the most indicative region in a radiograph for image recognition, and then uses a family of classifiers, each of which is trained for a specific projection to determine the most appropriate projection for the image. The method has been tested on a large number of clinical images and has shown excellent robustness and efficiency.

  9. Generation and Analysis of Wire Rope Digital Radiographic Images

    Science.gov (United States)

    Chakhlov, S.; Anpilogov, P.; Batranin, A.; Osipov, S.; Zhumabekova, Sh; Yadrenkin, I.

    2016-06-01

    The paper is dealt with different structures of the digital radiographic system intended for wire rope radiography. The scanning geometry of the wire rope is presented and the main stages of its digital radiographic image generation are identified herein. Correction algorithms are suggested for X-ray beam hardening. A complex internal structure of the wire rope is illustrated by its 25 mm diameter image obtained from X-ray computed tomography. The paper considers the approach to the analysis of digital radiographic image algorithms based on the closeness of certain parameters (invariants) of all unit cross-sections of the reference wire rope or its sections with the length equaling to the lay. The main invariants of wire rope radiographic images are identified and compared with its typical defects.

  10. Generation and Analysis of Wire Rope Digital Radiographic Images

    OpenAIRE

    Chakhlov, Sergey Vladimirovich; Anpilogov, P.; Batranin, Andrey Viktorovich; Osipov, Sergey Pavlovich; Zhumabekova, Sh.; Yadrenkin, I.

    2016-01-01

    The paper is dealt with different structures of the digital radiographic system intended for wire rope radiography. The scanning geometry of the wire rope is presented and the main stages of its digital radiographic image generation are identified herein. Correction algorithms are suggested for X-ray beam hardening. A complex internal structure of the wire rope is illustrated by its 25 mm diameter image obtained from X-ray computed tomography. The paper considers the approach to the analysis ...

  11. New Developed DR Detector Performs Radiographs of Hand, Pelvic and Premature Chest Anatomies at a Lower Radiation Dose and/or a Higher Image Quality

    DEFF Research Database (Denmark)

    Precht, Helle; Outzen, Claus Bjørn; Tingberg, Anders

    2013-01-01

    using Visual Grading Analysis (VGA). The results from the technical phantom studies showed that the image quality expressed as IQFINV values was on average approximately 45 % higher with the CXDI-70C detector compared to the CXDI-55C detector. Consistently, the VGA results from the anatomical phantom......A newly developed Digital Radiography (DR) detector has smaller pixel size and higher fill factor than earlier detector models. These technical advantages should theoretically lead to higher sensitivity and higher spatial resolution, thus making dose reduction possible without scarifying image...... quality compared to previous DR detector versions. To examine whether the newly developed Canon CXDI-70C DR detector provides an improved image quality and/or allows for dose reductions in hand and pelvic bone examinations as well as premature chest examinations, compared to the previous (CXDI-55C) DR...

  12. Digital image processing of mandibular trabeculae on radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Ogino, Toshi

    1987-06-01

    The present study was aimed to reveal the texture patterns of the radiographs of the mandibular trabeculae by digital image processing. The 32 cases of normal subjects and the 13 cases of patients with mandibular diseases of ameloblastoma, primordial cysts, squamous cell carcinoma and odontoma were analyzed by their intra-oral radiographs in the right premolar regions. The radiograms were digitized by the use of a drum scanner densitometry method. The input radiographic images were processed by a histogram equalization method. The result are as follows : First, the histogram equalization method enhances the image contrast of the textures. Second, the output images of the textures for normal mandible-trabeculae radiograms are of network pattern in nature. Third, the output images for the patients are characterized by the non-network pattern and replaced by the patterns of the fabric texture, intertwined plants (karakusa-pattern), scattered small masses and amorphous texture. Thus, these results indicates that the present digital image system is expected to be useful for revealing the texture patterns of the radiographs and in the future for the texture analysis of the clinical radiographs to obtain quantitative diagnostic findings.

  13. Automatic Radiographic Position Recognition from Image Frequency and Intensity

    Directory of Open Access Journals (Sweden)

    Ning-ning Ren

    2017-01-01

    Full Text Available Purpose. With the development of digital X-ray imaging and processing methods, the categorization and analysis of massive digital radiographic images need to be automatically finished. What is crucial in this processing is the automatic retrieval and recognition of radiographic position. To address these concerns, we developed an automatic method to identify a patient’s position and body region using only frequency curve classification and gray matching. Methods. Our new method is combined with frequency analysis and gray image matching. The radiographic position was determined from frequency similarity and amplitude classification. The body region recognition was performed by image matching in the whole-body phantom image with prior knowledge of templates. The whole-body phantom image was stitched by radiological images of different parts. Results. The proposed method can automatically retrieve and recognize the radiographic position and body region using frequency and intensity information. It replaces 2D image retrieval with 1D frequency curve classification, with higher speed and accuracy up to 93.78%. Conclusion. The proposed method is able to outperform the digital X-ray image’s position recognition with a limited time cost and a simple algorithm. The frequency information of radiography can make image classification quicker and more accurate.

  14. Non-contrast CT at comparable dose to an abdominal radiograph in patients with acute renal colic; impact of iterative reconstruction on image quality and diagnostic performance

    OpenAIRE

    McLaughlin, P. D.; Murphy, K. P.; Hayes, S.A; Carey, K; Sammon, J.; Crush, L.; O’Neill, F.; Normoyle, B.; McGarrigle, A. M.; Barry, J E; Maher, M. M.

    2014-01-01

    Objectives The aim was to assess the performance of low-dose non-contrast CT of the urinary tract (LD-CT) acquired at radiation exposures close to that of abdominal radiography using adaptive statistical iterative reconstruction (ASiR). Methods Thirty-three patients with clinically suspected renal colic were prospectively included. Conventional dose (CD-CT) and LD-CT data sets were contemporaneously acquired. LD-CT images were reconstructed with 40 %, 70 % and 90 % ASiR. Image quality was sub...

  15. Evaluation of trabecular bone patterns on dental radiographic images: influence of cortical bone

    Science.gov (United States)

    Amouriq, Yves; Evenou, Pierre; Arlicot, Aurore; Normand, Nicolas; Layrolle, Pierre; Weiss, Pierre; Guédon, Jean-Pierre

    2010-03-01

    For some authors trabecular bone is highly visible in intraoral radiographs. For other authors, the observed intrabony trabecular pattern is a representation of only the endosteal surface of cortical bone, not of intermedullary striae. The purpose of this preliminary study was to investigate the true anatomical structures that are visible in routine dental radiographs and classically denoted trabecular bone. This is a major point for bone texture analysis on radiographs. Computed radiography (CR) images of dog mandible section in molar region were compared with simulations calculated from high-resolution micro-CT volumes. Calculated simulations were obtained using the Mojette Transform. By digitally editing the CT volume, the simulations were separated into trabecular and cortical components into a region of interest. Different images were compared and correlated, some bone micro-architecture parameters calculated. A high correlation was found between computed radiographs and calculated simulations from micro-CT. The Mojette transform was successful to obtain high quality images. Cortical bone did not contribute to change in a major way simulated images. These first results imply that intrabony trabecular pattern observed on radiographs can not only be a representation of the cortical bone endosteal surface and that trabecular bone is highly visible in intraoral radiographs.

  16. Fluxen Project:. A portable apparatus for absolute quantitative analysis of imaging properties of radiographic systems

    Science.gov (United States)

    Tangaro, S.; Golosio, B.; Oliva, P.; Stumbo, S.

    2003-12-01

    The correct use of imaging equipment in radiological units is based on an appropriate knowledge of physical characteristics of the X-ray beam used. The aim of the FLUXEN project is the realization of a portable apparatus able of providing an exact spectral reconstruction of the radiation produced by a given X-ray tube. The apparatus is designed for quality controls in hospitals and for studying quality of new radiographic imaging systems, particularly for their comparison with older ones.

  17. Non-contrast CT at comparable dose to an abdominal radiograph in patients with acute renal colic; impact of iterative reconstruction on image quality and diagnostic performance.

    Science.gov (United States)

    McLaughlin, P D; Murphy, K P; Hayes, S A; Carey, K; Sammon, J; Crush, L; O'Neill, F; Normoyle, B; McGarrigle, A M; Barry, J E; Maher, M M

    2014-04-01

    The aim was to assess the performance of low-dose non-contrast CT of the urinary tract (LD-CT) acquired at radiation exposures close to that of abdominal radiography using adaptive statistical iterative reconstruction (ASiR). Thirty-three patients with clinically suspected renal colic were prospectively included. Conventional dose (CD-CT) and LD-CT data sets were contemporaneously acquired. LD-CT images were reconstructed with 40 %, 70 % and 90 % ASiR. Image quality was subjectively and objectively measured. Images were also clinically interpreted. Mean ED was 0.48 ± 0.07 mSv for LD-CT compared with 4.43 ± 3.14 mSv for CD-CT. Increasing the percentage ASiR resulted in a step-wise reduction in mean objective noise (p ASiR LD-CT images had higher diagnostic acceptability and spatial resolution than 90 % ASiR LD-CT images (p ASiR LD-CT with two false positives and 16 false negatives (diameter = 2.3 ± 0.7 mm) equating to a sensitivity and specificity of 72 % and 94 %. Seventy % ASiR LD-CT had a sensitivity and specificity of 87 % and 100 % for detection of calculi >3 mm. Reconstruction of LD-CT images with 70 % ASiR resulted in superior image quality than FBP, 40 % ASIR and 90 % ASIR. LD-CT with ASIR demonstrates high sensitivity and specificity for detection of calculi >3 mm. • Low-dose CT studies for urinary calculus detection were performed with a mean dose of 0.48 ± 0.07 mSv • Low-dose CT with 70 % ASiR detected calculi >3 mm with a sensitivity and specificity of 87 % and 100 % • Reconstruction with 70 % ASiR was superior to filtered back projection, 40 % ASiR and 90 % ASiR images.

  18. APPLICATION OF HYBRID WAVELET-FRACTAL COMPRESSION ALGORITHM FOR RADIOGRAPHIC IMAGES OF WELD DEFECTS

    OpenAIRE

    Faiza Mekhalfa; Daoud Berkani

    2011-01-01

    Based on the standard fractal transformation in spatial domain, simple relations may be found relating coefficients in detail subbands in the wavelet domain. In this work we evaluate a hybrid wavelet-fractal image coder, and we test its ability to compress radiographic images of weld defects. A comparative study between the hybrid coder and standard fractal compression technique have been made in order to investigate the compression ratio and corresponding quality of the image using peak sign...

  19. Improving the diagnostic quality and adequacy of shoulder radiographs in a District General Hospital.

    Science.gov (United States)

    Richards, Bethany; Riley, James; Saithna, Adnan

    2016-01-01

    A high rate of suboptimal shoulder radiographs was identified during a service evaluation exercise in our orthopaedic outpatient clinics. Inadequate radiographs require a return to the radiology department for further imaging, a resultant increased workload, delays in the clinic, increased radiation for patients, and inconvenience and decreased patient satisfaction. Furthermore, if a sub-optimal radiograph is accepted there is concern that diagnoses may be missed. The aim of this project was to decrease the rate of suboptimal radiographs by delivering a teaching package directed towards quality improvement. Evaluation criteria were set for standard orthopaedic shoulder radiographs (Anterior-posterior, axillary, and Velpeau views). Baseline data collection was performed over three, two-week periods and included all patients attending the shoulder clinic. The percentage of x-rays which were deemed adequate was only 19.4% for anterior-posterior views and 57.9% for axillary views. A comprehensive educational package was delivered to radiographers. This included a formal PowerPoint based teaching session, hands on training with practice using a skeleton, posters with step-by step instructions on how to obtain an adequate image, and PDF aide memoires suitable for viewing on a smartphone. Two subsequent two-week periods of data collection were performed to evaluate the benefit of this intervention. Delivery of focussed training and provision of easily accessible aide memoires to facilitate improved quality of radiographs resulted in a significant (p<0.05) reduction in the rate of inadequate images. There was also a significant decreases in the rate of return to the radiology department for repeat imaging.

  20. [Transparency regime: semiotics of radiographical images in urological diagnostics].

    Science.gov (United States)

    Martin, M; Fangerau, H

    2012-10-01

    Shortly after Röntgen discovered x-rays urology became one of the main test fields for the application of this new technology. Initial scepticism among physicians, who were inclined to cling to traditional manual methods of diagnosing, was replaced by enthusiasm for radiographic technologies and the new method soon became the standard in, for example the diagnosis of concrements. Patients favoring radiographic procedures over the use of probes and a convincing documentation of stones in radiograms were factors that impacted the relatively rapid integration of radiology into urology. The radiographic representation of soft tissues and body cavities was more difficult and the development of contrast agents in particular posed a serious problem. Several patients died during this research. A new diagnostic dimension was revealed when radiography and cystography were combined to form the method of retrograde pyelography. However, the problem of how urologists could learn how to read the new images remained. In order to allow trainee physicians to practice interpreting radiograms atlases were produced which offered explanatory texts and drawings for radiographic images of the kidneys, the bladder etc. Thus, urologists developed a self-contained semiotics which facilitated the appropriation of a unique urological radiographical gaze.

  1. Exposição de pacientes e qualidade da imagem em radiografias de tórax: uma avaliação crítica Patients exposure and imaging quality in chest radiographs: a critical evaluation

    Directory of Open Access Journals (Sweden)

    Adelaja Otolorin Osibote

    2007-04-01

    Full Text Available OBJETIVO: Foi realizada avaliação da dose de entrada na pele, da dose efetiva e da qualidade da imagem em radiografias de tórax de pacientes adultos. MATERIAIS E MÉTODOS: O estudo realizou-se em oito hospitais, sendo sete públicos (dois filantrópicos e um particular nos municípios de Angra dos Reis, Cabo Frio, Campos dos Goytacazes, Itaperuna, Niterói, Recife e Rio de Janeiro. Foram avaliadas a dose de entrada na pele e a dose efetiva de 735 radiografias de tórax nas incidências póstero-anterior/ântero-posterior e perfil. No que se refere aos critérios de imagem, foram avaliadas 44 radiografias. RESULTADOS: Constatou-se variação de até nove vezes nos valores da dose de entrada na pele e de até seis vezes na dose efetiva para um mesmo tipo de projeção. Os valores das técnicas radiográficas também apresentaram grandes discrepâncias. A qualidade das imagens também não é boa, pois foi obtido valor médio de presença dos critérios de apenas 55%. CONCLUSÃO: Há necessidade de melhoria/padronização de procedimentos em radiologia convencional, o que pode ser atingido se for implantado um programa de controle e garantia de qualidade no setor de radiologia, incluindo o treinamento dos técnicos, a aferição do desempenho dos equipamentos emissores de radiação e o controle sensitométrico do sistema de processamento radiográfico.OBJECTIVE: Entrance skin dose, effective dose, and imaging quality in chest radiographs of adult patients have been evaluated. MATERIALS AND METHODS: The study has been developed in eight institutions - seven public hospitals (two of them philanthropic institutions and one private - in the cities of Agra dos Reis, Cabo Frio, Campos dos Goytacazes, Itaperuna, Niterói, Recife and Rio de Janeiro. Entrance skin dose and effective dose have been evaluated in 735 chest radiographs obtained in posteroanterior/anteroposterior and lateral projections. As regards imaging criteria, 44 radiographs have been

  2. [Effects of image post-processing parameters on digital radiography chest radiograph for the diagnosis of pneumoconiosis].

    Science.gov (United States)

    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 image post-processing can make DR chest radiograph to meet the requirements of chest radiograph quality for the diagnosis of pneumoconiosis.

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

    Science.gov (United States)

    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.

  4. Radiographic images and relationship of the internal morphology and physiological potential of broccoli seeds

    OpenAIRE

    Haynna Fernandes Abud; Silvio Moure Cícero; Francisco Guilhien Gomes Junior

    2017-01-01

    Image analysis using X-rays is an efficient technique for assessing the seed quality of several species, presenting itself as a rapid response method that is simple to execute, reproducible and non-destructive. Thus, this research adjusted a methodology that aims to relate the internal morphology of broccoli seeds to their physiological potential through radiographic analysis of seeds and computerized images of seedlings. The broccoli cultivars used were Piracicaba Precoce and Ramoso Santana ...

  5. An ROC Study of Chest Radiographs: 2K Versus 4K High-Resolution Soft-Copy Images

    OpenAIRE

    Kim, Su Young; Hwang, Yoon Joon; Han, Yoon Hee; Seo, Jung Wook; Lee, Ji Young; Kim, Yong Hoon; Cha, Soon Joo; Hur, Gham; Lee, Sung Soon

    2006-01-01

    Computed radiography of chest with a 4K image array was recently introduced. We performed a multiobserver study to compare the diagnostic accuracy of 2K (standard) and 4K (high quality) chest radiographs displayed on a 5-mega-pixel monitor (2K monitor). One hundred cases of posteroanterior chest radiographs (a total of 200 images) were selected by two chest radiologists. Those radiographs included pneumothorax (n = 14), nodules (n = 15), interstitial disease (n = 10), or neither abnormality (...

  6. Skeletal Growth Estimation Using Radiographic Image Processing and Analysis

    OpenAIRE

    Mahmoodi, Sasan; Sharif, Bayan; Chester, Graeme; OWEN, John; Lee, Richard

    2000-01-01

    An automated knowledge-based vision system for skeletal growth estimation in children is reported in this paper. Images were obtained from hand radiographs of 32 male and 25 female children of age 1–16 yr. Phalanx bones were automatically localized and segmented using hierarchical inferences and active shape models, respectively. A number of shape descriptors were obtained from the segmented bone contour to quantify skeletal growth. From these descriptors, a feature vector was selected for a ...

  7. A study on secondary images in panoramic radiograph

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dai Hee; Kim, Han Pyong [Department of Dental Science, Yonsei University, Seoul (Korea, Republic of)

    1984-11-15

    This study was performed to observe the secondary images and to analyse the relationships between the primary and secondary images in panoramic radiograph. Using the Morita's Panex-EC panoramic x-ray machine and the human dry skull, the author analysed 17 radiographs which were selected from 65 radiographs of the dry skull that attached the radiopaque materials, and the attached regions of the radiopaque materials were the normal anatomical structures which were important and selected as a region for the evaluation of the secondary images effectively. The results were as follows; 1. The cervical vertebrae showed three images. The midline image was the most distorted and less clear, and bilateral images were slightly superimposed over the posterior border of the mandibular ramus. 2. In mandible, the secondary image of the posterior border of the ramus was superimposed on the opposite ramus region, and this image was elongated from the anterior border of the ramus to the lateral side of the posterior border of the ramus. The secondary image of the condyle was observed on the upper area of the coronoid process, the sigmoid notch and the condyle in opposite side. 3. In maxilla, the posterior region of the hard palate showed the secondary image on the lower part of the nasal cavity and the medial wall of the maxillary sinus. 4. The primary images of the occipital condyle and the mastoid process appeared on the same region, and only the secondary image of the occipital condyle was observed symmetrically on the opposite side with similar shape to the primary one. 5. In the cranial base, the anatomical structures of the midsagittal portions like a inferior border of the frontal sinus, sella turcica, inferior border of the sphenoid sinus and inferior border of the posterior part of the occipital bone showed the similar shape between the primary and secondary images symmetrically. 6. The petrous portion of the temporal bone showed the secondary image of the lateral side

  8. Radiographic image analysis of cylindrical implosion experiments (invited)

    Science.gov (United States)

    Scott, J. M.; Beck, J. B.; Batha, S. H.; Barnes, C. W.; Tubbs, D. L.

    2001-01-01

    Radiography is a heavily used tool for diagnosing laser-based hydrodynamic experiments. A successful experiment relies on the gathering of data over a time window where the relevant physics occurs and on an accurate analysis of those data. Comparison of this experimental data to theory is often best done by generating simulated images from hydrodynamic calculations, including all necessary and important experimental details. Care must be taken to treat both the experimental and theoretical images identically in the analysis. Frequently, image filtering and enhancement routines are used to obtain interface location and perturbation information from the radiographic image. Previous techniques were found to be too sensitive to global image details. New procedures have been developed which utilize local operators that provide better edge or interface identification without bias. These procedures are benchmarked and validated using static radiographic targets of known configuration that mock up experimental situations of interest. The experiment and the image analysis development are described, including discussion of key contributions to the uncertainty of the results.

  9. Image quality analysis of digital mammographic equipments

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, P.; Pascual, A.; Verdu, G. [Valencia Univ. Politecnica, Chemical and Nuclear Engineering Dept. (Spain); Rodenas, F. [Valencia Univ. Politecnica, Applied Mathematical Dept. (Spain); Campayo, J.M. [Valencia Univ. Hospital Clinico, Servicio de Radiofisica y Proteccion Radiologica (Spain); Villaescusa, J.I. [Hospital Clinico La Fe, Servicio de Proteccion Radiologica, Valencia (Spain)

    2006-07-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  10. Harmonisation of the appearance of digital radiographs from different vendors by means of common external image processing.

    Science.gov (United States)

    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 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.

  11. Development of practical digital radiographic image viewing and commitment dose/image quality; Desarrollo de practicas de visualizacion de imagenes radiograficas digitales y su compromiso dosis/calidad de imagen

    Energy Technology Data Exchange (ETDEWEB)

    Chinillach Ferrando, N.; Salvador, R.; Diez, S.; Reinado, D.; Cortina, T.; Lopez, F. J.; Jover, A.; Cebrian, R.; Gonzalez, R.; Dalmases, F.; Romero, C.; Rosello, J.

    2011-07-01

    Today it is essential to use X-ray diagnosis in health, so it is essential that professionals have a strong background in all aspects of radiological images dependent. It is also necessary to understand the dependence between dose and image quality and thus introduce the concept of optimization in the performance of radiologic studies, from a simple test to a complex, establishing a dependency between patient dose and the aim of the study to be performed.

  12. Dedicated Filter for Defects Clustering in Radiographic Image

    Science.gov (United States)

    Sikora, R.; Świadek, K.; Chady, T.

    2009-03-01

    Defect clusters such as linear or clustered porosity are in some cases even more important than single flaws. This paper presents two methods of defect clustering and algorithm for calculation of distances between flaws in digital radiographic image. Dedicated lookup table based filter is used for calculation of distances between objects in the specified range. For defect clustering two functions were developed. First one is based on MMD (Minimum Mean Distance) algorithm. Second one uses hierarchical procedures for clustering defects of various types, shapes and size.

  13. Method to Develop Pseudo Three-dimensional Dental Image from Dental Panoramic Radiograph

    OpenAIRE

    Kuroda, Tomohiro; Kaga, Tetsuro; Azuma, Hiroko; Yagi, Masakazu; Kuroda, Yoshihiro; Imura, Masataka; Oshiro, Osamu; Takada, Kenji

    2011-01-01

    Although three-dimensional imaging can be a powerful tool for dentists to explain treatments to patients, obtaining of three-dimensional image of teeth in general dental clinics is difficult. This paper proposed a method to develop pseudo three-dimensional dental image from conventional dental panoramic radiograph and dental impression. The method estimates imaging parameters of given panoramic radiograph through comparison with dental cast, and re-projects the radiograph into three-dimension...

  14. Construction of a homogeneous phantom for radiographic image standardization; Construcao de um fantoma homogeneo para padronizacao de imagens radiograficas

    Energy Technology Data Exchange (ETDEWEB)

    Pina, Diana Rodrigues de

    1996-12-31

    The principle of radiodiagnosis consists in the fact the X-ray beam is attenuated at different degrees by distinct tissues. For this reason, the anatomical structures have distinct radiological opacities, that produce the radiographic image. The progresses in radiology are related to the development if new radiographic image formation systems that enable an amplification in the quality, with low dose and/or risk to the patient. The objective of this work is the sensitometric valuation of a screen-film combination, that is still the most used, for the standardization, of radiographic images. Thinking about this, were constructed homogeneous phantoms of the chest, skull and pelvis, for the calibration of X-ray beams, with the purpose of obtaining radiographic images of good quality, basing in the routine of a radiodiagnosis service and in the scientific knowledge. Questions were approached about the choice of the suitable equipment, that allow the obtention of k Vp and m As combinations, to produce radiographic images of good quality, and the reproduction of these combinations to any conventional equipment of diagnostic X-rays. Also presented are the comparison of the doses imparted by these combinations and those used in routine of the Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto`s radiodiagnosis service. (author) 24 refs., 27 figs., 12 tabs.

  15. Radiographic alveolar bone loss in untreated Taiwan Chinese subjects with adult periodontitis measured by the digital scanning radiographic image analysis method

    National Research Council Canada - National Science Library

    Hou, G-L; Hung, C-C; Yang, Y-S; Shieh, T-Y; Tsai, C-C

    2003-01-01

    To determine differences in radiographic alveolar bone loss (RABL) by age group, gender and tooth type in subjects with adult periodontitis using the digital scanning radiographic image analysis (DSRIA) method...

  16. Short-term impact of pictorial posters and a crash course on radiographic errors for improving the quality of paediatric chest radiographs in an unsupervised unit - a pilot study for quality-assurance outreach.

    Science.gov (United States)

    Hlabangana, Linda Tebogo; Andronikou, Savvas

    2015-02-01

    Chest radiography is the most commonly performed diagnostic X-ray examination. The radiation dose to the patient for this examination is relatively low but because of its frequent use, the contribution to the collective dose is considerable. Optimized image quality not only allows for more accurate diagnosis but also supports radiation protection, which is particularly important in children. To determine whether the introduction of a poster of technical errors in paediatric radiography accompanied by a short lecture (crash course) for radiographers on common errors can sustainably decrease the number and rate of these errors in an unsupervised radiology department (without a paediatric-trained radiologist or paediatric-trained radiography personnel). We conducted a pilot study for quality-assurance outreach, with retrospective and prospective components, in the paediatric radiology department of a teaching hospital. The technical errors in frontal chest radiographs performed in the unit were assessed by quality-assurance analysis using a customized tick-sheet. The review was performed before and after an intervention that involved a half-hour crash course and poster displays in the department. We compared the rate of technical errors made before and after the intervention. There was statistically significant improvement in quality of radiographs (P radiographs performed >2 months after the intervention. A simple intervention of a crash course and poster placement resulted in improved quality of paediatric chest radiographs. A decline in quality after 2 months suggests the need to repeat this or another type of intervention regularly.

  17. CT imaging vs. traditional radiographic imaging for evaluating Harris Lines in tibiae

    DEFF Research Database (Denmark)

    Primeau, Charlotte; Jakobsen, Lykke Schrøder; Lynnerup, Niels

    2016-01-01

    This paper is the first to systematically investigate computer tomography (CT) images vs. ordinary flat plane radiography for evaluating Harris Lines (HL) on tibiae. Harris Lines are traditionally investigated using radiographic images and recorded as either present or absent, or by counting...... the number of HL. Seventy-four pairs of human sub-adult and adult archaeological tibiae were used in this study. Both image methods were tested for intra- and inter-observer agreement and the methods were then compared. Analysis was performed with the tibiae divided into younger (n = 19) and older sub......-adults (n = 26) and adults (n = 29), as well as all tibiae combined (n = 74). This study found that the intra- and inter-observer agreement was very similar for each method, but both image methods performed less well for counting the number of HL. Direct comparison between CT images and radiographic images...

  18. Continuing challenges in defining image quality.

    Science.gov (United States)

    Shet, Narendra; Chen, Joseph; Siegel, Eliot L

    2011-05-01

    To achieve significant dose reduction without compromising diagnostic efficacy, it is important to understand the effects of exposure reduction on image quality, a concept that is often mentioned but not well defined in the imaging literature. Studies to assess subjective image quality for digital radiography (DR) demonstrate wide variability among radiologists and technologists, resulting in substantial variability in the determination of acceptable image quality and optimal radiation exposure required to obtain a high-quality radiograph. In addition to improving detector technology and image processing techniques and tailoring exposure to the exam type and patient body habitus, it is possible to take advantage of informatics-based and psychoperceptual approaches. These can be used to establish the relative trade-offs among patient exposure, perceived image quality, and diagnostic efficacy. Innovations such as automated quality assessment of digital radiographs, use of a mathematical model of the human visual system to predict the perceived impact of lower radiation exposure, the creation of a quality-assessment database of images, and better definition and training of radiologists in the determination of image quality can help to reduce variability in assessment and facilitate reductions in dose while minimizing negative effects on image quality.

  19. The 'radiographer-referrer game': image interpretation dynamics in rural practice.

    Science.gov (United States)

    Squibb, Kathryn; Smith, Anthony; Dalton, Lisa; Bull, Rosalind M

    2016-03-01

    Effective interprofessional communication is intrinsic to safe health care. Despite the identified positive impact of collaborative radiographic interpretation between rural radiographers and referrers, communication difficulties still exist. This article describes the strategies that Australian rural radiographers use for communication of their radiographic opinion to the referring doctor. In a two-phase interpretive doctoral study completed in 2012, data were collected from radiographers working in rural New South Wales, Western Australia and Tasmania using a paper based questionnaire followed by in-depth semistructured interviews. Data were analysed thematically in order to identify, analyse and report the emergent themes. The overarching theme was Patient Advocacy, where in the interest of patient care radiographers took measures to ensure that a referring doctor did not miss radiographic abnormalities. Strong interprofessional relationships enabled direct communication pathways. Interprofessional boundaries shaped by historical hierarchical relationships, together with a lack of confidence and educational preparation for radiographic interpretation result in barriers to direct communication pathways. These barriers prompted radiographers to pursue indirect communication pathways, such as side-stepping and hint and hope. A lack of formal communication pathways and educational preparation for this role has resulted in radiographers playing the radiographer-referrer game to overtly or covertly assist referrers in reaching a radiographic diagnosis. The findings from this study may be used to plan interventions for strengthening interprofessional communication pathways and improve quality of healthcare for patients.

  20. Development of profession and quality in radiography with focus on evaluation criteria and image quality of chest x-rays

    DEFF Research Database (Denmark)

    Debess, Jeanne; Thomsen, Henrik; Conradsen, Jacob

    2011-01-01

    Learning Objectives: Learning Objectives: To improve quality of chest xrays by Education Conferences for radiographers and evaluation of image quality. Background: Introduction of digital imaging technology and picture archiving and communication system (PACS) has changed the workflow in the x...

  1. Assessment of Chest Radiographs for Quality Assurance and ...

    African Journals Online (AJOL)

    A retrospective study of 1000 chest radiographs randomly selected from various government and private owned hospitals in the southern part of Nigeria covering a period of twenty years was carried out. Accuracy in patient positioning, beam collimation and identification of radiographs were assessed as indicators for ...

  2. Retropharyngeal Tendinitis: Radiographic and Magnetic Resonance Imaging Findings

    Energy Technology Data Exchange (ETDEWEB)

    Gelineck, J.; Salomonsen, M.; Hviid, C. [Aarhus Univ. Hospital (Denmark). Dept. of Radiology

    2006-10-15

    Purpose: To describe the magnetic resonance imaging (MRI) findings in retropharyngeal tendinitis. Material and methods: Within 1 year, four patients presenting with symptoms of retropharyngeal tendinitis were examined by radiography and MRI. Results: On MRI and radiographs, all patients had characteristic soft-tissue swellings and calcifications related to the tendon of the longus colli muscle situated inferior to the anterior arc of C1. MRI showed well-defined edema, with high signal in the retropharyngeal tissue anterior to C1-C5 on short T1 inversion recovery (STIR) sequences, low signal on T1-weighted sequences, and low signal in the calcification on both sequences. In addition, three patients had high signal intensity changes on STIR sequences in the atlantoaxial joint situated posterior to the anterior arc of C1. Conclusion: MRI is a sensitive and accurate method in the diagnosis of retropharyngeal tendinitis. A new finding in this condition is an effusion or synovitis in the anterior atlantoaxial joint. MRI is a valuable tool in differentiating retropharyngeal tendinitis from other diagnoses such as retropharyngeal abscess, pyogenic spondylitis, and spondyloarthropathy.

  3. [Evaluation of the quality of screen-film radiographic systems: physical principles and methods of measurement].

    Science.gov (United States)

    Borasi, G; Berardi, P; Ferretti, P P; Piccagli, V

    1990-09-01

    Comparative evaluation of radiographic film-screen systems presents several problems from both the theoretical and the experimental point of view. From the theoretical point of view the main difficulties are related to the choice of the parameters best suited to express the "overall quality" of a system. From the practical point of view the main problem is that to measure some basic quantities (resolution and noise) sophisticated and expensive instruments are required. This paper deals with both these problems. To express image quality we have assumed the signal-to-noise power ratio: this index depends in a explicit way on contrast, resolution and noise of the system. The dependence on sensitivity is implicit and was derived using literature data. From a knowledge of the dependence of image quality on sensitivity it is possible to develop an "overall quality" index which is considered to express the "technological level" of the system. This index can be used in the comparative evaluation of the different systems. In this work some basic physical quantities (characteristic curve, sensitivity) were evaluated using standard instruments. To measure spatial resolution and noise an inexpensive, PC-based, TV-digitizer system was developed. As an example, both image and overall quality indices were evaluated on three mammographic systems which are typical of the three different "phases" of the development of this technique.

  4. An Algorithm for Data Hiding in Radiographic Images and ePHI/R Application

    Directory of Open Access Journals (Sweden)

    Aqsa Rashid

    2018-01-01

    Full Text Available Telemedicine is the use of Information and Communication Technology (ICT for clinical health care from a distance. The exchange of radiographic images and electronic patient health information/records (ePHI/R for diagnostic purposes has the risk of confidentiality, ownership identity, and authenticity. In this paper, a data hiding technique for ePHI/R is proposed. The color information in the cover image is used for key generation, and stego-images are produced with ideal case. As a result, the whole stego-system is perfectly secure. This method includes the features of watermarking and steganography techniques. The method is applied to radiographic images. For the radiographic images, this method resembles watermarking, which is an ePHI/R data system. Experiments show promising results for the application of this method to radiographic images in ePHI/R for both transmission and storage purpose.

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

    Directory of Open Access Journals (Sweden)

    Gulnara Scaf

    2007-12-01

    Full Text Available 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.

  6. A stopping criterion to halt iterations at the Richardson-Lucy deconvolution of radiographic images

    Science.gov (United States)

    Almeida, G. L.; Silvani, M. I.; Souza, E. S.; Lopes, R. T.

    2015-07-01

    Radiographic images, as any experimentally acquired ones, are affected by spoiling agents which degrade their final quality. The degradation caused by agents of systematic character, can be reduced by some kind of treatment such as an iterative deconvolution. This approach requires two parameters, namely the system resolution and the best number of iterations in order to achieve the best final image. This work proposes a novel procedure to estimate the best number of iterations, which replaces the cumbersome visual inspection by a comparison of numbers. These numbers are deduced from the image histograms, taking into account the global difference G between them for two subsequent iterations. The developed algorithm, including a Richardson-Lucy deconvolution procedure has been embodied into a Fortran program capable to plot the 1st derivative of G as the processing progresses and to stop it automatically when this derivative - within the data dispersion - reaches zero. The radiograph of a specially chosen object acquired with thermal neutrons from the Argonauta research reactor at Institutode Engenharia Nuclear - CNEN, Rio de Janeiro, Brazil, have undergone this treatment with fair results.

  7. Sonographic Imaging of Meniscal Subluxation in Patients with Radiographic Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Chun-Hung Ko

    2007-09-01

    Conclusion: Meniscal subluxation is a prominent feature on weight-bearing sonographic imaging in patients with radiographic osteoarthritis and could be considered as a risk factor for the development of knee osteoarthritis. By using musculoskeletal ultrasonography, one can detect this occult meniscal derangement early before the appearance of radiographic signs of osteoarthritis.

  8. Radiographic constant exposure technique

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1985-01-01

    The constant exposure technique has been applied to assess various industrial radiographic systems. Different X-ray films and radiographic papers of two producers were compared. Special attention was given to fast film and paper used with fluorometallic screens. Radiographic image quality was tes...... was tested by the use of ISO wire IQI's and ASTM penetrameters used on Al and Fe test plates. Relative speed and reduction of kilovoltage obtained with the constant exposure technique were calculated. The advantages of fast radiographic systems are pointed out...

  9. Patient doses and image quality in chest radiography: The influence of different beam qualities

    Directory of Open Access Journals (Sweden)

    Ciraj-Bjelac Olivera

    2007-01-01

    Full Text Available A simple method of assessing optimal X-ray beam quality in respect to patient exposure and image quality in chest screen-film radiography is presented here. Different beam qualities were generated by the use of various combinations of tube voltages (70 kV to 110 kV and Al and Cu filter thick nesses. Patient doses were assessed by kerma-area product measurements. Simultaneously, image quality was evaluated by a twofold method: a clinical study applying European quality criteria for the radiographic technique of image on image of 126 patients and a multifunctional home-made dosimetric phantom with embedded test objects. The quantification of image quality criteria yields a simpler method of optimizing image quality and patient dose relationships. Modifications of radiographic practice, based on image quality assessment and dose measurements, resulted in significant dose reductions and preservation of image quality. Through the use of harder beam quality, dose reduction of up to a value of factor 3 were observed, compared to the doses from previously used radiographic techniques, implying that sufficient image quality does not necessarily imply higher doses. As a result of the optimization process, an optimal radiographic technique was suggested.

  10. ‘Virtual anthropology’ and radiographic imaging in the Forensic Medical Sciences

    National Research Council Canada - National Science Library

    Franklin, Daniel; Swift, Lauren; Flavel, Ambika

    2016-01-01

    .... Some of the pioneering practical examples of radiographic imaging being applied in the forensic analysis of human skeletal remains date to the initial introduction of radiography in the late 19th...

  11. A study of trabecular bone strength and morphometric analysis of bone microstructure from digital radiographic image

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Yun; Lee, Sun Bok; Oh, Sung Ook; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Jong Dae [Hallym University, Choonchun (Korea, Republic of)

    2003-06-15

    To evaluate the relationship between morphometric analysis of microstructure from digital radiographic image and trabecular bone strength. One hundred eleven bone specimens with 5 mm thickness were obtained from the mandibles of 5 pigs. Digital images of specimens were taken using a direct digital intraoral radiographic system. After selection of ROI(100 x 100 pixel) within the trabecular bone, mean gray level and standard deviation were obtained. Fractal dimension and the variants of morphometric analysis (trabecular area, periphery, length of skeletonized trabeculae, number of terminal point, number of branch point) were obtained from ROI. Punch sheer strength analysis was performed using Instron (model 4465, Instron Corp., USA). The loading force (loading speed 1mm/min) was applied to ROI of bone specimen by a 2 mm diameter punch. Stress-deformation curve was obtained from the punch sheer strength analysis and maximum stress, yield stress, Young's modulus were measured. Maximum stress had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). Yield stress had a negative linear correlation with mean gray level, periphery, fractal dimension and the length of skeletonized trabeculae significantly (p<0.05). Young's modulus had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). The strength of cancellous bone exhibited a significantly linear relationship between mean gray level, fractal dimension and morphometric analysis. The methods described above can be easily used to evaluate bone quality clinically.

  12. Perceived quality, clarity, and accuracy of manually processed and self-developing radiographs in endodontics.

    Science.gov (United States)

    Alshwaimi, Emad; Majeed, Abdul

    2013-06-01

    To evaluate perceived quality, clarity, and accuracy of self-developing films compared to conventional D- and E-speed manually processed films, and to evaluate their ease of use and satisfaction amongst pre-clinical dental students. Mesiobuccal root canals of 30 extracted mandibular molar teeth were instrumented and size 10 K-files were glued into the canals at 3 different levels. Each tooth was exposed thrice with the same angulation using conventional E-speed, D-speed, and self-developing films. Conventional films were processed manually and self-developing films according to the manufacturer's instructions, which required 50 seconds of contact time with the solution. Radiographs were evaluated by 4 examiners for quality, clarity, and apical position of the file. A questionnaire-based survey was conducted to evaluate the ease of use, quality, and satisfaction of undergraduate students. Data were analyzed using one-way ANOVA and Tukey-Kramer multiple comparison test, significant at p clarity of conventional E-speed films was perceived as significantly better than that of D-speed and self-developing films (p 0.05). The results of the student survey corroborated the examiners' views that the self-developing radiographic films were of poor quality. Manually processed E-speed films provided significantly superior quality and clarity of images, but for apical file position, no significant differences were found amongst the 3 film types. Conventional E-speed, D-speed, and self-developing films are all adequate for measuring endodontic working lengths.

  13. Imaging Food Quality

    DEFF Research Database (Denmark)

    Møller, Flemming

    Imaging and spectroscopy have long been established methods for food quality control both in the laboratories and online. An ever increasing number of analytical techniques are being developed into imaging methods and existing imaging methods to contain spectral information. Images and especially...... spectral images contain large amounts of data which should be analysed appropriately by techniques combining structure and spectral information. This dissertation deals with how different types of food quality can be measured by imaging techniques, analysed with appropriate image analysis techniques...... and finally use the image data to predict or visualise food quality. A range of different food quality parameters was addressed, i.e. water distribution in bread throughout storage, time series analysis of chocolate milk stability, yoghurt glossiness, graininess and dullness and finally structure and meat...

  14. Performance of a Digital Real Time Radiographic Imaging System,

    Science.gov (United States)

    1987-06-01

    through a flat diecast metal plate was measured for various X-ray magnifications and tube voltages. These measurements were carried out for both the 160...minimum wire thickness detectable through a diecast plate remains nearly constant over an X-ray magnification range of 1.2 to 1.5. The radiographic

  15. DIGITIZING RADIOGRAPHIC FILMS: A SIMPLE WAY TO EVALUATE INDIRECT DIGITAL IMAGES

    Science.gov (United States)

    Rubira-Bullen, Izabel Regina Fischer; Escarpinati, Maurício Cunha; Schiabel, Homero; Vieira, Marcelo Andrade da Costa; Rubira, Cássia Maria Fischer; Lauris, José Roberto Pereira

    2007-01-01

    Objectives: This study applied a simple method to evaluate the performance of three digital devices (two scanners and one digital camera) using the reproducibility of pixel values attributed to the same radiographic image. Methods: Using the same capture parameters, a radiographic image was repeatedly digitized in order to determine the variability of pixel values given to the image throughout the digitization process. One coefficient value was obtained and was called pixel value reproducibility. Results: A significant difference in pixel values was observed among the three devices for the digitized images (ANOVA, pdigitization conditions for one scanner and the digital camera. Conclusions: Digital devices may assign pixel values differently in consecutive digitization depending on the optical density of the radiographic image and the equipment. The pixel value reproducibility was not satisfactory as tested for two devices. It is maybe advisable knowing the digitization variations regarding pixel values whenever using digital radiography images in longitudinal clinical examinations. PMID:19089093

  16. An evaluation of image quality for the assessment of the marginal bone level in panoramic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, L.; Rohlin, M. (Lund Univ., Malmoe (Sweden). Dept. of Oral Radiology); Haakansson, J. (Lund Univ., Malmoe (Sweden). Dept. of Periodontology); Zoeger, B. (Draco AB, Lund (Sweden))

    1993-01-01

    A diagnostic image quality of panoramic radiographs originating from different clinics was examined. Two samples of 98 and 100 radiographs, respectively, were from a department of oral radiology. The radiographs of one of these samples were checked using immediate subjective analysis of the image quality before inclusion in the study whereas the radiographs of the other sample were randomly selected. A third sample consisted of radiographs from 20 randomly selected dental clinics. The subjective overall image quality of the whole panoramic radiograph was classified as adequate, marginal or inadequate. The three observers also assessed the reason for inferior image quality. The overall image quality of the radiographs was better for the checked sample from the department of oral radiology compared to the sample from the 20 dental clinics. The main reason for unacceptable image quality of the radiographs was too low density and/or contrast irrespective of sample. Other faults were incorrect positioning of the patient but in the sample from the 20 clinics improper film handling was also frequent. We conclude that image quality in panoramic radiography can be improved. Improvement of the image quality is a prerequisite if panoramic radiography in the future is to replace the full-mouth examination. 22 refs, 2 figs, 7 tabs.

  17. Accuracy of cephalometric landmarks on monitor-displayed radiographs with and without image emboss enhancement.

    Science.gov (United States)

    Leonardi, Rosalia Maria; Giordano, Daniela; Maiorana, Francesco; Greco, Mariagrazia

    2010-06-01

    The aim of this study was to evaluate the accuracy of some commonly used cephalometric landmarks of monitor-displayed images with and without image emboss enhancement. The following null hypothesis was tested: there is no improvement in landmark detection accuracy between monitor-displayed images, with and without image embossing enhancement. Forty lateral cephalometric radiographs, taken from the data files of subjects were used in this study. A purpose-made software allowed recording of the cephalometric points and then, with the help of algorithms based on cellular neural networks, to transfer the previously processed radiographs into an embossed image. Five observers recorded 22 landmarks on the displayed images from the two image modalities, i.e. monitor-displayed radiograph (mode A) and monitor-displayed embossed radiograph (mode B). The positions of the landmarks were recorded and saved in the format of x and y co-ordinates and as Euclidean distance. The mean errors and standard deviation of landmarks location according to the two modalities were compared with the 'best estimate' for each landmark and the values were calculated for each of the 22 landmarks. One-way analysis of variance was then used to evaluate any statistically significant differences. Euclidean distance mean errors were higher for the embossed images (except for Po) than for the unfiltered radiographs. These differences were all statistically significant (P improved on the embossed radiograph but only for a few points (Or on x axis and Po, PM, Co, and APOcc on y axis), as these were not statistically significant. The use of radiographic enhancement techniques, such as embossing, does not improve the level of accuracy for cephalometric points detection. Unless more precise algorithms are designed, this feature should not be used for clinical or research purposes.

  18. Study of influence of buildup factor form on simulated radiographic image

    Directory of Open Access Journals (Sweden)

    Marinković Predrag

    2009-01-01

    Full Text Available The objective of the study presented in this paper is the analysis of influence of different buildup factor forms on a simulated radiographic image. Simulated radiographic images are obtained by means of the ray-tracing technique. Scattered photons are modelled using the generally accepted geometric progression form, linear form and tabulated data of buildup factors. Simulated images were compared to the reference results obtained by Monte Carlo calculation. The best agreement to Monte Carlo simulated images is achieved for the geometric progression form of buildup factor.

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

    Science.gov (United States)

    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.

  20. Implant treatment planning regarding augmentation procedures: panoramic radiographs vs. cone beam computed tomography images.

    Science.gov (United States)

    Dagassan-Berndt, Dorothea C; Zitzmann, Nicola U; Walter, Clemens; Schulze, Ralf K W

    2016-08-01

    To evaluate the impact of cone beam computed tomography (CBCT) imaging on treatment planning regarding augmentation procedures for implant placement. Panoramic radiographs and CBCT images of 40 patients requesting single-tooth implants in 59 sites were retrospectively analyzed by six specialists in implantology, and treatment planning was performed. Therapeutic recommendations were compared with the surgical protocol performed initially. Bone height estimation from panoramic radiographs yielded to higher measures and greater variability compared to CBCT. The suggested treatment plan for lateral and vertical augmentation procedures based on CBCT or panoramic radiographs coincided for 55-72% of the cases. A trend to a more invasive augmentation procedure was seen when planning was based on CBCT. Panoramic radiography revealed 57-63% (lateral) vs. 67% (vertical augmentation) congruent plans in agreement with surgery. Among the dissenting sites, there was a trend toward less invasive planning for lateral augmentation with panoramic radiographs, while vertical augmentation requirements were more frequently more invasive when based on CBCT. Vertical augmentation requirements can be adequately determined from panoramic radiographs. In difficult cases with a deficient lateral alveolar bone, the augmentation schedule may better be evaluated from CBCT to avoid underestimation, which occurs more frequently when based on panoramic radiographs only. However, overall, radiographic interpretation and diagnostic thinking accuracy seem to be mainly depending on the opinion of observers. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. A comparative analysis of magnetic resonance imaging and radiographic examinations of patients with atypical odontalgia.

    Science.gov (United States)

    Pigg, Maria; List, Thomas; Abul-Kasim, Kasim; Maly, Pavel; Petersson, Arne

    2014-01-01

    To examine (1) the occurrence of magnetic resonance imaging (MRI) signal changes in the painful regions of patients with atypical odontalgia (AO) and (2) the correlation of such findings to periapical bone defects detected with a comprehensive radiographic examination including cone beam computed tomography (CBCT). A total of 20 patients (mean age 52 years, range 34 to 65) diagnosed with AO participated. Mean pain intensity (± standard deviation) was 5.6 ± 1.8 on a 0-10 numerical rating scale, and mean pain duration was 4.3 ± 5.2 years. The inclusion criterion was chronic pain (> 6 months) located in a region with no clear pathologic cause identified clinically or in periapical radiographs. In addition to a clinical examination and a self-report questionnaire, the assessments included radiographic examinations (panoramic, periapical, and CBCT images), and an MRI examination. Changes in MRI signal in the painful region were recorded. Spearman's rank correlation between radiographic and MRI findings was calculated. Eight of the patients (40%) had MRI signal changes in the pain region. The correlation to radiographic periapical radiolucencies was 0.526 (P = .003). Of the eight teeth displaying changes in MRI signal, six showed periapical radiolucency in the radiographs. MRI examination revealed no changes in the painful region in a majority of patients with AO, suggesting that inflammation was not present. MRI findings were significantly correlated to radiographic findings.

  2. Radiographic assessment of proximal caries: A comparison between film-based and dexis digital imaging systems

    Directory of Open Access Journals (Sweden)

    Anupama N Kalappanavar

    2011-01-01

    Full Text Available This study compared Kodak Ektaspeed film and Dexis digital imaging systems for their diagnostic accuracy in detection of proximal canes in 210 proximal surfaces from 105 extracted human teeth (20 premolars and 85 molars, 129 of which were carious. Ground teeth were evaluated histologically. The images were assessed by an observer. ANOVA revealed that groups differ in scoring patterns with f-value of 26.72 and p < 0.01. The mean caries score by histologic assessment was significantly (p < 0.01 more when compared with the scores obtained by conventional and Dexis digital radiographic methods. The mean score for conventional radiographic method was slightly more than Dexis digital radiographic method, but the difference was statistically insignificant (p < 0.05. Both the radiographic methods were less accurate in detecting proximal canes confined to enamel, but as the lesion depth was increased to dentin, the rate of caries detection increased dramatically. It was concluded that both conventional and Dexis digital radiographic methods under estimated canes depth when compared with histologic method. Lastly, conventional film radiographs and Dexis digital radiographs did not perform significantly different from each other in the detection of canes.

  3. Development of profession and quality in radiography with focus on evaluation criteria and image quality of chest x-rays

    DEFF Research Database (Denmark)

    Debess, Jeanne; Thomsen, Henrik; Conradsen, Jacob

    Learning Objectives: Learning Objectives: To improve quality of chest xrays by Education Conferences for radiographers and evaluation of image quality. Background: Introduction of digital imaging technology and picture archiving and communication system (PACS) has changed the workflow in the x-ray...... of patients. Data was collected at two regional Danish x-ray departments including 200 AP and 200 LAT chest examinations. Evaluation was performed at 1) primary monitor by radiographer, 2) diagnostic monitor by expert radiographer 3) diagnostic monitor by radiologist. After evaluation of 100 examinations...... department including evaluation of image quality and feedback from radiologist to radiographer. Imaging Findings or Procedure Details: Procedure Details: Data for evaluation of image quality was collected by questionnaires aimed at: anatomy, image-focusing, image-collimation, exposure and body habitus...

  4. Radiographic Images Produced by Cosmic-Ray Muons

    Science.gov (United States)

    Alfaro, Rubén

    2006-09-01

    An application of high energy physics instrumentation is to look for structure or different densities (materials) hidden in a matrix (tons) of material. By tracing muons produced by primary Cosmic Rays, it has been possible to generate a kind of radiographs which shows the inner structure of dense containers, monuments or mountains. In this paper I review the basics principles of such techniques with emphasis in the Sun Pyramid project, carried out by IFUNAM in collaboration with Instituto Nacioanal de Antropologia e Historia.

  5. An ROC study of chest radiographs: 2K Versus 4K high-resolution soft-copy images.

    Science.gov (United States)

    Kim, Su Young; Hwang, Yoon Joon; Han, Yoon Hee; Seo, Jung Wook; Lee, Ji Young; Kim, Yong Hoon; Cha, Soon Joo; Hur, Gham; Lee, Sung Soon

    2007-12-01

    Computed radiography of chest with a 4K image array was recently introduced. We performed a multiobserver study to compare the diagnostic accuracy of 2K (standard) and 4K (high quality) chest radiographs displayed on a 5-mega-pixel monitor (2K monitor). One hundred cases of posteroanterior chest radiographs (a total of 200 images) were selected by two chest radiologists. Those radiographs included pneumothorax (n = 14), nodules (n = 15), interstitial disease (n = 10), or neither abnormality (n = 61). These were interpreted by four radiologists in two separate sessions. They recorded their confidence scale for the presence or absence of abnormality. Diagnostic accuracy was determined by receiver operating characteristic (ROC) analysis for each observer. ROC analysis showed no statistically significant difference between the 2K and 4K modes for the detection of any of the different abnormalities by individual readers. Our preliminary study suggests that 2K mode would be sufficient for the detection of abnormality on chest radiograph and there is no considerable validity to incline toward the 4K mode in current picture archiving and communication system environment using 2K monitor. However, we think that additional investigation using more subtle parenchymal or rib lesion should be followed.

  6. Social image quality

    Science.gov (United States)

    Qiu, Guoping; Kheiri, Ahmed

    2011-01-01

    Current subjective image quality assessments have been developed in the laboratory environments, under controlledconditions, and are dependent on the participation of limited numbers of observers. In this research, with the help of Web 2.0 and social media technology, a new method for building a subjective image quality metric has been developed where the observers are the Internet users. A website with a simple user interface that enables Internet users from anywhere at any time to vote for a better quality version of a pair of the same image has been constructed. Users' votes are recorded and used to rank the images according to their perceived visual qualities. We have developed three rank aggregation algorithms to process the recorded pair comparison data, the first uses a naive approach, the second employs a Condorcet method, and the third uses the Dykstra's extension of Bradley-Terry method. The website has been collecting data for about three months and has accumulated over 10,000 votes at the time of writing this paper. Results show that the Internet and its allied technologies such as crowdsourcing offer a promising new paradigm for image and video quality assessment where hundreds of thousands of Internet users can contribute to building more robust image quality metrics. We have made Internet user generated social image quality (SIQ) data of a public image database available online (http://www.hdri.cs.nott.ac.uk/siq/) to provide the image quality research community with a new source of ground truth data. The website continues to collect votes and will include more public image databases and will also be extended to include videos to collect social video quality (SVQ) data. All data will be public available on the website in due course.

  7. Imaging of juvenile idiopathic arthritis. Part I: Clinical classifications and radiographs

    Directory of Open Access Journals (Sweden)

    Iwona Sudoł-Szopińska

    2016-09-01

    Full Text Available Juvenile idiopathic arthritis is the most common autoimmune systemic disease of the connective tissue affecting individuals at the developmental age. Radiography is the primary modality employed in the diagnostic imaging in order to identify changes typical of this disease entity and rule out other bone-related pathologies, such as neoplasms, posttraumatic changes, developmental defects and other forms of arthritis. The standard procedure involves the performance of comparative joint radiographs in two planes. Radiographic changes in juvenile idiopathic arthritis are detected in later stages of the disease. Bone structures are assessed in the first place. Radiographs can also indirectly indicate the presence of soft tissue inflammation (i.e. in joint cavities, sheaths and bursae based on swelling and increased density of the soft tissue as well as dislocation of fat folds. Signs of articular cartilage defects are also seen in radiographs indirectly – based on joint space width changes. The first part of the publication presents the classification of juvenile idiopathic arthritis and discusses its radiographic images. The authors list the affected joints as well as explain the spectrum and specificity of radiographic signs resulting from inflammatory changes overlapping with those caused by the maturation of the skeletal system. Moreover, certain dilemmas associated with the monitoring of the disease are reviewed. The second part of the publication will explain issues associated with ultrasonography and magnetic resonance imaging, which are more and more commonly applied in juvenile idiopathic arthritis for early detection of pathological features as well as the disease complications.

  8. Objective Image Quality Metrics for Ultrasound Imaging

    OpenAIRE

    Simpson, Cecilie Øinæs

    2009-01-01

    Objective evaluation of the image quality on ultrasound images is a comprehensive task due to the relatively low image quality compared to other imaging techniques. It is desirable to objectively determine the quality of ultrasound images since quantification of the quality removes the subjective evaluation which can lead to varying results. The scanner will also be more user friendly if the user is given feedback on the quality of the current image. This thesis has investigated in the obje...

  9. 3-D Reconstruction From 2-D Radiographic Images and Its Application to Clinical Veterinary Medicine

    Science.gov (United States)

    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.

  10. Adaptive pseudo-color enhancement method of weld radiographic images based on HSI color space and self-transformation of pixels.

    Science.gov (United States)

    Jiang, Hongquan; Zhao, Yalin; Gao, Jianmin; Gao, Zhiyong

    2017-06-01

    The radiographic testing (RT) image of a steam turbine manufacturing enterprise has the characteristics of low gray level, low contrast, and blurriness, which lead to a substandard image quality. Moreover, it is not conducive for human eyes to detect and evaluate defects. This study proposes an adaptive pseudo-color enhancement method for weld radiographic images based on the hue, saturation, and intensity (HSI) color space and the self-transformation of pixels to solve these problems. First, the pixel's self-transformation is performed to the pixel value of the original RT image. The function value after the pixel's self-transformation is assigned to the HSI components in the HSI color space. Thereafter, the average intensity of the enhanced image is adaptively adjusted to 0.5 according to the intensity of the original image. Moreover, the hue range and interval can be adjusted according to personal habits. Finally, the HSI components after the adaptive adjustment can be transformed to display in the red, green, and blue color space. Numerous weld radiographic images from a steam turbine manufacturing enterprise are used to validate the proposed method. The experimental results show that the proposed pseudo-color enhancement method can improve image definition and make the target and background areas distinct in weld radiographic images. The enhanced images will be more conducive for defect recognition. Moreover, the image enhanced using the proposed method conforms to the human eye visual properties, and the effectiveness of defect recognition and evaluation can be ensured.

  11. Adaptive pseudo-color enhancement method of weld radiographic images based on HSI color space and self-transformation of pixels

    Science.gov (United States)

    Jiang, Hongquan; Zhao, Yalin; Gao, Jianmin; Gao, Zhiyong

    2017-06-01

    The radiographic testing (RT) image of a steam turbine manufacturing enterprise has the characteristics of low gray level, low contrast, and blurriness, which lead to a substandard image quality. Moreover, it is not conducive for human eyes to detect and evaluate defects. This study proposes an adaptive pseudo-color enhancement method for weld radiographic images based on the hue, saturation, and intensity (HSI) color space and the self-transformation of pixels to solve these problems. First, the pixel's self-transformation is performed to the pixel value of the original RT image. The function value after the pixel's self-transformation is assigned to the HSI components in the HSI color space. Thereafter, the average intensity of the enhanced image is adaptively adjusted to 0.5 according to the intensity of the original image. Moreover, the hue range and interval can be adjusted according to personal habits. Finally, the HSI components after the adaptive adjustment can be transformed to display in the red, green, and blue color space. Numerous weld radiographic images from a steam turbine manufacturing enterprise are used to validate the proposed method. The experimental results show that the proposed pseudo-color enhancement method can improve image definition and make the target and background areas distinct in weld radiographic images. The enhanced images will be more conducive for defect recognition. Moreover, the image enhanced using the proposed method conforms to the human eye visual properties, and the effectiveness of defect recognition and evaluation can be ensured.

  12. Oblique radiographs compared favorably with computed tomography images in assessing cervical foraminal area.

    Science.gov (United States)

    Miller, Christopher P; Sabino, Jennifer; Bible, Jesse E; Whang, Peter G; Grauer, Jonathan N

    2011-05-01

    Oblique radiographs are often ordered to evaluate the patency of cervical intervertebral foramina. Previous studies have shown that computed tomography (CT) provides accurate measurements of foraminal dimensions. Up until now, no study has directly compared the diagnostic utility of oblique radiographs and CT. We conducted a study to quantify the correlation between cervical foramina dimensions measured on oblique radiographs and on CT scans. Heights, widths, and cross-sectional areas were evaluated at every level from C2-C3 through C7-T1 using both oblique radiographs and oblique CT reconstructions. Both measurements were performed at a 50% oblique angle. Interreliability and intrareliability statistics for radiographs and CT were 0.91 and 0.99 for height, 0.90 and 0.97 for width, and 0.84 and 0.92 for area. Pearson correlation coefficients for height, width, and area were 0.439, 0.871, and 0.899, respectively. Oblique radiographs of the cervical spine provide accurate estimates of intervertebral foraminal dimensions--estimates similar to those generated from CT reconstructions. Thus, these radiographs may serve as an acceptable first-line imaging study for initial assessment of patients suspected of having nerve root compression that precludes the higher cost and radiation exposure associated with CT scans.

  13. Determining a Magnetic Resonance Imaging Inflammatory Activity Acceptable State Without Subsequent Radiographic Progression in Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Gandjbakhch, Frédérique; Haavardsholm, Espen A; Conaghan, Philip G

    2014-01-01

    OBJECTIVE: To assess the predictive value of magnetic resonance imaging (MRI)-detected subclinical inflammation for subsequent radiographic progression in a longitudinal study of patients with rheumatoid arthritis (RA) in clinical remission or low disease activity (LDA), and to determine cutoffs...... for an MRI inflammatory activity acceptable state in RA in which radiographic progression rarely occurs. METHODS: Patients with RA in clinical remission [28-joint Disease Activity Score-C-reactive protein (DAS28-CRP) ... and radiographic data were included from 5 cohorts (4 international centers). MRI were assessed according to the Outcome Measures in Rheumatology (OMERACT) RA MRI scoring system (RAMRIS). Statistical analyses included an underlying conditional logistic regression model stratified per cohort, with radiographic...

  14. Radiographic images and relationship of the internal morphology and physiological potential of broccoli seeds

    Directory of Open Access Journals (Sweden)

    Haynna Fernandes Abud

    2017-11-01

    Full Text Available Image analysis using X-rays is an efficient technique for assessing the seed quality of several species, presenting itself as a rapid response method that is simple to execute, reproducible and non-destructive. Thus, this research adjusted a methodology that aims to relate the internal morphology of broccoli seeds to their physiological potential through radiographic analysis of seeds and computerized images of seedlings. The broccoli cultivars used were Piracicaba Precoce and Ramoso Santana represented by ten lots of each one. The study was conducted using X-ray imaging for seed analysis, in which the area, density and circularity measures were obtained as internal morphology characteristics of seeds. After a germination test, the seedling length was obtained 5 days after sowing. Multivariate analysis was carried out using principal components analysis. It was concluded that the X-ray test is efficient for evaluating the internal morphology of broccoli seeds and associating it with seedling length, thereby classifying seed lots at different levels of vigor.

  15. A Comparative Study on Diagnostic Accuracy of Colour Coded Digital Images, Direct Digital Images and Conventional Radiographs for Periapical Lesions – An In Vitro Study

    Science.gov (United States)

    Mubeen; K.R., Vijayalakshmi; Bhuyan, Sanat Kumar; Panigrahi, Rajat G; Priyadarshini, Smita R; Misra, Satyaranjan; Singh, Chandravir

    2014-01-01

    Objectives: The identification and radiographic interpretation of periapical bone lesions is important for accurate diagnosis and treatment. The present study was undertaken to study the feasibility and diagnostic accuracy of colour coded digital radiographs in terms of presence and size of lesion and to compare the diagnostic accuracy of colour coded digital images with direct digital images and conventional radiographs for assessing periapical lesions. Materials and Methods: Sixty human dry cadaver hemimandibles were obtained and periapical lesions were created in first and second premolar teeth at the junction of cancellous and cortical bone using a micromotor handpiece and carbide burs of sizes 2, 4 and 6. After each successive use of round burs, a conventional, RVG and colour coded image was taken for each specimen. All the images were evaluated by three observers. The diagnostic accuracy for each bur and image mode was calculated statistically. Results: Our results showed good interobserver (kappa > 0.61) agreement for the different radiographic techniques and for the different bur sizes. Conventional Radiography outperformed Digital Radiography in diagnosing periapical lesions made with Size two bur. Both were equally diagnostic for lesions made with larger bur sizes. Colour coding method was least accurate among all the techniques. Conclusion: Conventional radiography traditionally forms the backbone in the diagnosis, treatment planning and follow-up of periapical lesions. Direct digital imaging is an efficient technique, in diagnostic sense. Colour coding of digital radiography was feasible but less accurate however, this imaging technique, like any other, needs to be studied continuously with the emphasis on safety of patients and diagnostic quality of images. PMID:25584318

  16. Optimization of standard patient radiographic images for chest, skull and pelvis exams in conventional x-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Pina, D R [Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Campus de Ribeirao Preto, SP 14040-901 (Brazil); Duarte, S B [Centro Brasileiro de Pesquisas FIsicas, Rio de Janeiro, RJ 22290-180 (Brazil); Netto, T Ghilardi [Centro de Ciencias da Imagem e FIsica Medica, Hospital das ClInicas da Faculdade de Medicina de Ribeirao Preto, SP 14048-900 (Brazil); Trad, C S [Centro de Ciencias da Imagem e FIsica Medica, Hospital das ClInicas da Faculdade de Medicina de Ribeirao Preto, SP 14048-900 (Brazil); Brochi, M A C [Centro de Ciencias da Imagem e FIsica Medica, Hospital das ClInicas da Faculdade de Medicina de Ribeirao Preto, SP 14048-900 (Brazil); Oliveira, S C de [Lehigh Valley Hospital, Allentown, PA 18103 (United States)

    2004-07-21

    Optimized radiographic techniques for clinical images of chest, skull and pelvis using conventional single-phase, three-phase and high-frequency x-ray units for a standard patient have been developed. Optimization of image contrast and optical density was obtained by using a homogeneous phantom (PEP) and an Anderson Rando anthropomorphic phantom. Image quality was evaluated by nine radiologists in independent analyses, leading to the choice of the optimized technique. A course of action to implement and validate these techniques in other radiographic systems has also been introduced. A realistic-analytic phantom (RAP) was constructed to certify the validation process. The optimized radiographic technique was implemented in the routine of our home hospital radiodiagnostic routine, enabling a reduction in patient doses around 25, 14 and 72%, respectively, for chest, skull and pelvis exams when compared with the previously used techniques. In addition, a corresponding reduction in the x-ray tube load of 68, 14 and 62% for the respective mentioned exams has been observed. In conclusion, implemented optimal techniques can lead to a reduction in the rate of film rejection, thus contributing to a better risk-benefit relationship for the patient and cost-benefit for the radiodiagnostic facility. (note)

  17. SSA Image Quality Modeling

    Science.gov (United States)

    Luna, C.; Gerwe, D.; Calef, B.

    2010-09-01

    This paper evaluates the ITIQUE image quality modeling framework for SSA applications. Based on Bovik and Sheik’s VIF metric, ITIQUE evaluates the Shannon mutual information (MI) at multiple spatial scales between a pristine object and the image output from a detailed image formation chain simulation. Integrating the MI at each spatial scale and applying a calibration offset produces a prediction of NIIRS image quality indicating the level of interpretation tasks that could be supported. The model enables prediction of NIIRS quality obtainable as dependent on image collection conditions and image system design including both hardware and processing algorithms. The ITIQUE framework could facilitate concept evaluation and engineering design by quantitatively relating image formation performance directly in terms of end end-user mission needs. Previous work focused on overhead imagery of terrestrial scenes and linear processing only. This paper considers ground-based imaging of SSA targets and extends the previous study to include non-linear processing. A range of turbulence strengths and SNRs are included. ITIQUE predictions are shown to match well to results from a human visual assessment study in which a panel of human observers rated NIIRS quality of the same imagery.

  18. Methodological approaches to evaluating the practice of radiographers' interpretation of images: A review

    Energy Technology Data Exchange (ETDEWEB)

    Brealey, S. [Department of Health Sciences, University of York, 2nd Floor, Area 4 Seebohm Rowntree Building, York YO1 5DD (United Kingdom)], E-mail: sb143@york.ac.uk; Scally, A.J. [Division of Radiography, University of Bradford, Bradford BD5 0BB (United Kingdom)

    2008-12-15

    Recent initiatives to modernise the National Health Service describe how improving pay structures and staff working lives can be achieved in the form of advanced practitioner and consultant posts. Role development in Radiography represents a fundamental change to professional practice of radiographers and is subject to the provisions of the statutory and professional codes of conduct which govern such practice. In Diagnostic Radiography the response to Government initiatives has led to a change in practice so that radiographers in these new posts provide reports for a variety of imaging modalities. At the same time as there have been changes in the practice of Radiography, the discipline of evidence-based medicine has emerged. Changes in clinical practice should be underpinned by evidence from research. The purpose of this paper is to discuss the methodological approaches used to conduct research that evaluates one of the most salient areas of development in Radiography practice, that is the role of radiographers as advanced or consultant practitioners when interpreting plain radiographs. We begin by discussing what an evaluation is and two broad approaches for conducting health services research, and then appraise the evidence about radiographer reporting in the context of these methods of evaluation. We then suggest future considerations about the methodological approaches to evaluating radiographer reporting practice and identify where there are evidence gaps and the need for further research to inform evidence-based Radiography.

  19. Assembling and use of homogeneous phantoms to standardization of radiographic images; Construcao e utilizacao de um fantomas homogeneos para padronizacao de imagens radiograficas

    Energy Technology Data Exchange (ETDEWEB)

    Pina, Diana Rodrigues de; Ghilardi Netto, Thomaz [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica; Rocha, Sergio; Brochi, Marco Aurelio Corte; Trad, Clovis Simao [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Diagnostico para Imagem e Fisica Medica

    1996-12-31

    Homogeneous phantoms of chest, skull and pelvis are built for the calibration of X-ray beams, aiming to obtain radiographic images based upon the routine of a radiodiagnostic service. The choice of the adequate equipment, obtention of kVp and m As arrangements that produce radiographic images of good quality, and the reproduction of these arrangements to any conventional diagnostic X-ray equipment are considered. A comparison of doses from the kVp and m As arrangements proposed in this work and those used in the routines of the Hospital das Clinicas de Ribeirao Preto, SP, Brazil is presented 4 refs., 2 figs., 1 tab.

  20. Mammographic positioning quality of newly trained versus experienced radiographers in the Dutch breast cancer screening programme

    NARCIS (Netherlands)

    van Landsveld-Verhoeven, Cary; den Heeten, Gerard J.; Timmers, Janine; Broeders, Mireille J. M.

    2015-01-01

    Our purpose was to compare mammographic positioning quality of new (NR) versus experienced screening radiographers (ER) in the Netherlands. Before starting to work in breast screening, NR must complete an education programme including a theoretical course (four days), practical training (six weeks),

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

    Science.gov (United States)

    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.

  2. Contrast reference values in panoramic radiographic images using an arch-form phantom stand

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae Myung [Dept. of Oral and Maxillofacial Surgery, Ilsan Paik Hospital, Inje University College of Medicine, Goyang (Korea, Republic of); Lee, Che Na; Kim, Jo Eun; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Choi, Soon Chul; Lee, Sam Sun [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2016-09-15

    The purpose of this study was to investigate appropriate contrast reference values (CRVs) by comparing the contrast in phantom and clinical images. Phantom contrast was measured using two methods: (1) counting the number of visible pits of different depths in an aluminum plate, and (2) obtaining the contrast-to-noise ratio (CNR) for 5 tissue-equivalent materials (porcelain, aluminum, polytetrafluoroethylene [PTFE], polyoxymethylene [POM], and polymethylmethacrylate [PMMA]). Four panoramic radiographs of the contrast phantom, embedded in the 4 different regions of the arch-form stand, and 1 real skull phantom image were obtained, post-processed, and compared. The clinical image quality evaluation chart was used to obtain the cut-off values of the phantom CRV corresponding to the criterion of being adequate for diagnosis. The CRVs were obtained using 4 aluminum pits in the incisor and premolar region, 5 aluminum pits in the molar region, and 2 aluminum pits in the temporomandibular joint (TMJ) region. The CRVs obtained based on the CNR measured in the anterior region were: porcelain, 13.95; aluminum, 9.68; PTFE, 6.71; and POM, 1.79. The corresponding values in the premolar region were: porcelain, 14.22; aluminum, 8.82; PTFE, 5.95; and POM, 2.30. In the molar region, the following values were obtained: porcelain, 7.40; aluminum, 3.68; PTFE, 1.27; and POM, - 0.18. The CRVs for the TMJ region were: porcelain, 3.60; aluminum, 2.04; PTFE, 0.48; and POM, - 0.43. CRVs were determined for each part of the jaw using the CNR value and the number of pits observed in phantom images.

  3. Mammographic positioning quality of newly trained versus experienced radiographers in the Dutch breast cancer screening programme.

    Science.gov (United States)

    van Landsveld-Verhoeven, Cary; den Heeten, Gerard J; Timmers, Janine; Broeders, Mireille J M

    2015-11-01

    Our purpose was to compare mammographic positioning quality of new (NR) versus experienced screening radiographers (ER) in the Netherlands. Before starting to work in breast screening, NR must complete an education programme including a theoretical course (four days), practical training (six weeks), and a portfolio-review of 50 mammographic screening examinations performed by the radiographer. Furthermore, Dutch screening has an extensive system of quality assurance, including an audit-review of positioning quality of mammograms by ER. We analysed 13,520 portfolio views (NR) and 14,896 audit views (ER) based on pre-specified criteria, e.g., depiction of inframammary angle. Overall positioning was more adequate for NR than ER (CC views: 97% versus 86%, p = 0.00; MLO views: 92% versus 84%, p = 0.00). NR scored better for most of the CC-criteria and showed, for instance, less folds (inadequate: 10% versus 16%, p = 0.00). In contrast, NR encountered more difficulties for MLO views in, for example, depiction of infra-mammary angle (inadequate: 38% versus 34%, p = 0.00). Overall, mammograms from NR were more often considered adequate, because of less severe errors. NR perform better than ER in overall positioning technique. These results stress the need for continuous monitoring and training in breast screening programmes to keep positioning skills up to date. • We evaluated positioning quality of new and experienced Dutch screening radiographers. • New radiographers outperform their experienced colleagues in mammographic positioning quality. • New radiographers make less severe errors compared to experienced colleagues. • There is a need for a continuous individual monitoring and feedback system.

  4. Supine magnetic resonance imaging Cobb measurements for idiopathic scoliosis are linearly related to measurements from standing plain radiographs.

    Science.gov (United States)

    Lee, Mark C; Solomito, Matthew; Patel, Archit

    2013-05-15

    Retrospective. To demonstrate a relationship between adolescent idiopathic scoliosis Cobb angle measurements obtained with standing plain radiographs and standard supine magnetic resonance (MR) images. Patients with adolescent idiopathic scoliosis are exposed to repeated doses of ionizing radiation during the course of their treatment with significant potential long-term health consequences. Supine MR images of the spine may allow measurements of coronal plane spinal deformity equivalent to plain radiographs while minimizing exposure to ionizing radiation. A retrospective chart and radiograph review was conducted for patients with adolescent idiopathic scoliosis. Cobb angle measures were derived from available plain radiographs and MR images obtained within 6 months of each other. Pearson correlation and linear regression analysis was used to test the relationship between plain radiographical and magnetic resonance imaging Cobb measures. Inter- and intraobserver reliability for the Cobb measures was tested with a random sample of 20 patients using intraclass correlation coefficients. Supine MR images tended to underestimate plain radiographs by 10° on average. However, radiographical and MR measures showed a strong positive correlation (r= 0.90-0.94) for all curves, structural or nonstructural, and this correlation was not influenced by patient age or body mass index. The relationship allowed the development of a simple linear equation for converting MR image measures to radiograph measures with an acceptable absolute error of ±5°. Cobb angle measures from supine magnetic resonance imaging of the spine can reliably be translated to the equivalent radiographical measures with an acceptable range of error. The data suggest that standard supine magnetic resonance imaging sequences may be a viable substitute for plain radiographs in the clinical diagnosis and serial evaluation of adolescent idiopathic scoliosis while obviating the associated dangers of ionizing

  5. Diagnostic ability of the periapical radiographs and digital image in the detection of the artificial proximal caries

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Min Suk; You, Dong Soo [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1994-08-15

    Recently, the digital image was introduced into radiological image. The digital image has the power of contrast enhancement, histogram control, and other digitally enhancement. At the point of the resolution, periapical radiograph is superior to the digital image, but enhanced digital procedure improves the diagnostic ability of the digital image. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries in conventional radiographs, digital radiographs and enhanced digital radiographs (histogram specification). ROC (Receiver Operating Characteristic) analysis and paired t-test were used for the evaluation of detectability, and following results were acquired: 1. The mean ROC area of conventional radiographs was 0.9274. 2. The mean ROC area of unenhanced digital image was 0.9168. 3. The mean ROC area of enhanced digital image was 0.9339. 4. The diagnostic ability of three imaging methods was not significant difference (p>0.05). So, the digital images had similar diagnostic ability of artificial proximal caries to conventional radiographs. If properly enhanced digital image, it may be superior to conventional radiographs.

  6. ‘Virtual anthropology’ and radiographic imaging in the Forensic Medical Sciences

    OpenAIRE

    Franklin, Daniel; Swift,Lauren; Flavel,Ambika

    2016-01-01

    Technological advancements in forensic imaging have had tremendous flow-on benefits to the professional practice of forensic anthropology, not only in respect of case-work analyses, but in facilitating empirical research that has validated and/or improved existing, and introduced novel, methods into the discipline. Some of the pioneering practical examples of radiographic imaging being applied in the forensic analysis of human skeletal remains date to the initial introduction of radiography i...

  7. Advanced and extended scope practice of diagnostic radiographers in Scotland: Exploring strategic imaging service imperatives.

    Science.gov (United States)

    Henderson, I; Mathers, S A; McConnell, J

    2017-08-01

    The development of diagnostic imaging services manifests features specific to the Scottish environment, in particular development of the radiographic workforce through implementing skills mix and role developments to enhance outcomes for patients. A component of a College of Radiographers Industry Partnership Scheme (CoRIPS) supported study, this research investigates perspectives of strategic service managers with Health Board responsibility for service delivery. A questionnaire survey was administered to strategic service managers across Scotland (N = 14), followed up with telephone interviews. There was a return rate of 57% (n = 8) for the questionnaires and n = 4 agreed to be interviewed. Data collected related to radiographer roles across their Board area; awareness and understanding of service development issues and features as well as perspective on opportunities and barriers in the context of Scottish Government policy, workforce logistics, attitudes and inter-professional relationships. The results indicate evidence of financial, logistical and political barriers to service evolution, offset by a sense of optimism that scope for beneficial change may be approaching. There are a range of significant initiatives in place and an appetite exists to pursue the development of radiographer roles and skill mix for the benefit of service users more generally. The difficulties in achieving change are well understood and there are basic issues related to finance and industrial relations. There are also however, cultural elements to contend with in the form of attitudes demonstrated by some radiographers and significantly, the radiological community whose influence on the practice of independently regulated radiographers seems incongruent. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  8. Evaluation of mammographic image quality: pilot study comparing five methods.

    Science.gov (United States)

    Caldwell, C B; Fishell, E K; Jong, R A; Weiser, W J; Yaffe, M J

    1992-08-01

    A radiograph is considered of high quality when it allows a radiologist to identify abnormalities with high sensitivity and specificity. Although many methods for assessing image quality have been devised, it is not clear which is most meaningful or how well these methods correlate with one another. A pilot study was undertaken to compare five methods of evaluating mammographic image quality. Each of the methods was used to form separate rankings of 11 mammographic system configurations. In two of the methods, observers (three radiologists and three physicists) subjectively ranked the "image quality" of radiographs of phantoms obtained with each configuration. The third method ranked the systems according to contrast as measured densitometrically with an aluminum step wedge, and the fourth, in terms of lowest to highest mean glandular radiation doses to the breast. In the final method, observers based their rankings on mammograms of patients. The intra- and interobserver variabilities of each ranking method were assessed, as well as the correlations between methods, by using standard nonparametric statistical tests. Intraobserver consistency was high with any of the image quality ranking methods; however, image quality rankings based on either of the two phantoms provided better agreement among observers than did rankings based on images of patients. Surprisingly, no significant degree of correlation was found between any two image quality evaluation methods. Our work may have two implications for the American College of Radiology Mammography Accreditation Program: (1) small variations in phantom scores do not necessarily correlate with subjective variation in image quality in radiographs of patients, and (2) when small numbers of radiographs are used, the assessment of the quality of mammograms of patients may vary considerably among radiologists.

  9. Digitizing radiographic films: a simple way to evaluate indirect digital images

    Directory of Open Access Journals (Sweden)

    Izabel Regina Fischer Rubia-Bullen

    2007-02-01

    Full Text Available OBJECTIVES: This study applied a simple method to evaluate the performance of three digital devices (two scanners and one digital camera using the reproducibility of pixel values attributed to the same radiographic image. METHODS: Using the same capture parameters, a radiographic image was repeatedly digitized in order to determine the variability of pixel values given to the image throughout the digitization process. One coefficient value was obtained and was called pixel value reproducibility. RESULTS: A significant difference in pixel values was observed among the three devices for the digitized images (ANOVA, p<0.00001. There was significant pixel value variability at the same digitization conditions for one scanner and the digital camera. CONCLUSIONS: Digital devices may assign pixel values differently in consecutive digitization depending on the optical density of the radiographic image and the equipment. The pixel value reproducibility was not satisfactory as tested for two devices. It is maybe advisable knowing the digitization variations regarding pixel values whenever using digital radiography images in longitudinal clinical examinations.

  10. Image Quality Experience

    NARCIS (Netherlands)

    Alers, H.

    2015-01-01

    While the world we live in becomes more saturated with ubiquitous digital displays, and as the threshold for creating digital media continues to drop, image quality is an issue that concerns an increasingly large segment of the population. Higher resolutions, increased dynamic range, and faster

  11. Is there a relation between local bone quality as assessed on panoramic radiographs and alveolar bone level?

    Science.gov (United States)

    Nackaerts, Olivia; Gijbels, Frieda; Sanna, Anna-Maria; Jacobs, Reinhilde

    2008-03-01

    The aim was to explore the relation between radiographic bone quality on panoramic radiographs and relative alveolar bone level. Digital panoramic radiographs of 94 female patients were analysed (mean age, 44.5; range, 35-74). Radiographic density of the alveolar bone in the premolar region was determined using Agfa Musica software. Alveolar bone level and bone quality index (BQI) were also assessed. Relationships between bone density and BQI on one hand and the relative loss of alveolar bone level on the other were assessed. Mandibular bone density and loss of alveolar bone level were weakly but significantly negatively correlated for the lower premolar area (r = -.27). The BQI did not show a statistically significant relation to alveolar bone level. Radiographic mandibular bone density on panoramic radiographs shows a weak but significant relation to alveolar bone level, with more periodontal breakdown for less dense alveolar bone.

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

    Science.gov (United States)

    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

  13. Methodology to evaluation of the density in radiographic image; Metodologia para avaliacao de densidade em imagem radiografica

    Energy Technology Data Exchange (ETDEWEB)

    Louzada, M.J.Q. [UNESP, Aracatuba, SP (Brazil). Curso de Medicina Veterinaria; Pela, C.A. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras; Belangero, W.D. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas; Santos-Pinto, R. [UNESP, Aracatuba, SP (Brazil). Faculdade de Odontologia

    1998-12-01

    This study was designed in order to optimize the optical densitometry technique in radiographic images by the setorization of the characteristic curves of the radiographic films. We used 24 radiographs of a stepped aluminium wedge that were taken without rigorous control development and manually revealed. The densitometric values of the steps images and its thickness, for each radiographic, was utilized to generate its particular mathematics expressions that represent its characteristic densitometric curves and then it were used for setorization. The densitometric values were obtained by a Macbeth TD528 densitometer. The study showed an optimization in the representation of the relationship between the optical density of the steps images of the wedge and its correspondent thickness, provided by the setorization, with mean square error around 10{sup -5}. This optimization will allow the use of this methodology in quantitative evaluations of bone mass, by radiographic images. (author)

  14. A computer-aided diagnosis system to detect pathologies in temporal subtraction images of chest radiographs

    Science.gov (United States)

    Looper, Jared; Harrison, Melanie; Armato, Samuel G.

    2016-03-01

    Radiologists often compare sequential radiographs to identify areas of pathologic change; however, this process is prone to error, as human anatomy can obscure the regions of change, causing the radiologists to overlook pathology. Temporal subtraction (TS) images can provide enhanced visualization of regions of change in sequential radiographs and allow radiologists to better detect areas of change in radiographs. Not all areas of change shown in TS images, however, are actual pathology. The purpose of this study was to create a computer-aided diagnostic (CAD) system that identifies which regions of change are caused by pathology and which are caused by misregistration of the radiographs used to create the TS image. The dataset used in this study contained 120 images with 74 pathologic regions on 54 images outlined by an experienced radiologist. High and low ("light" and "dark") gray-level candidate regions were extracted from the images using gray-level thresholding. Then, sampling techniques were used to address the class imbalance problem between "true" and "false" candidate regions. Next, the datasets of light candidate regions, dark candidate regions, and the combined set of light and dark candidate regions were used as training and testing data for classifiers by using five-fold cross validation. Of the classifiers tested (support vector machines, discriminant analyses, logistic regression, and k-nearest neighbors), the support vector machine on the combined candidates using synthetic minority oversampling technique (SMOTE) performed best with an area under the receiver operating characteristic curve value of 0.85, a sensitivity of 85%, and a specificity of 84%.

  15. Image Segmentation and Analysis of Flexion-Extension Radiographs of Cervical Spines

    Directory of Open Access Journals (Sweden)

    Eniko T. Enikov

    2014-01-01

    Full Text Available We present a new analysis tool for cervical flexion-extension radiographs based on machine vision and computerized image processing. The method is based on semiautomatic image segmentation leading to detection of common landmarks such as the spinolaminar (SL line or contour lines of the implanted anterior cervical plates. The technique allows for visualization of the local curvature of these landmarks during flexion-extension experiments. In addition to changes in the curvature of the SL line, it has been found that the cervical plates also deform during flexion-extension examination. While extension radiographs reveal larger curvature changes in the SL line, flexion radiographs on the other hand tend to generate larger curvature changes in the implanted cervical plates. Furthermore, while some lordosis is always present in the cervical plates by design, it actually decreases during extension and increases during flexion. Possible causes of this unexpected finding are also discussed. The described analysis may lead to a more precise interpretation of flexion-extension radiographs, allowing diagnosis of spinal instability and/or pseudoarthrosis in already seemingly fused spines.

  16. Sonographic and radiographic imaging features of the neonate with necrotizing enterocolitis: correlating findings with outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Muchantef, Karl [Perelman School of Medicine at the University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); McGill University, Department of Diagnostic Radiology, Montreal Children' s Hospital, Montreal (Canada); Epelman, Monica [Perelman School of Medicine at the University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Nemours Children' s Hospital, Department of Radiology, Orlando, FL (United States); Darge, Kassa; Anupindi, Sudha A. [Perelman School of Medicine at the University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Kirpalani, Haresh [Perelman School of Medicine at the University of Pennsylvania, Division of Neonatology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Laje, Pablo [Perelman School of Medicine at the University of Pennsylvania, Department of Surgery, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States)

    2013-11-15

    Abdominal radiography is the reference standard in imaging neonates with necrotizing enterocolitis (NEC); however, ultrasound of the abdomen including bowel may be of value in this setting. To correlate sonographic and radiographic findings with patient outcomes in NEC. We reviewed sonographic and radiographic exams, as well as clinical, pathological and laboratory records. Ultrasound images were reviewed for free intraperitoneal gas, peritoneal fluid, pneumatosis intestinalis, portal gas, bowel vascularity, bowel wall thickness and echogenicity, peristalsis and the presence of dilated bowel with anechoic contents. Contemporaneously acquired radiographs were reviewed for intraperitoneal gas, pneumatosis intestinalis, portal gas, the sentinel loop sign and gas pattern. Patients were categorized into two groups based on clinical outcome. Forty-four neonates receiving 55 sonograms were included. Focal fluid collections, echogenic free fluid, increased bowel wall echogenicity and increased bowel wall thickness were statistically significant in predicting an unfavorable outcome. Other features approached significance in predicting poor outcomes: free peritoneal gas, pneumatosis intestinalis, aperistalsis, bowel wall thinning and absent bowel perfusion. Anechoic free peritoneal fluid predicted a good outcome. The sentinel loop sign on radiographs predicted an unfavorable outcome. Abdominal sonography and radiography in patients with NEC can help prognosticate the outcome. (orig.)

  17. Detector or system? Extending the concept of detective quantum efficiency to characterize the performance of digital radiographic imaging systems.

    Science.gov (United States)

    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

  18. Basic imaging properties of a large image intensifier-TV digital chest radiographic system.

    Science.gov (United States)

    Fujita, H; Doi, K; MacMahon, H; Kume, Y; Giger, M L; Hoffmann, K R; Katafuchi, T; Ohara, K; Chan, H P

    1987-04-01

    The basic imaging properties of a large (57 cm) image intensifier (I.I.)-TV digital imaging system were examined to determine the effects of various physical parameters on the quality of the digital chest images obtained, and also to explore the clinical usefulness of the system. The characteristic curve of the digital system, which relates the output pixel value to the input relative x-ray intensity, was measured with an aluminum stepwedge. MTFs were determined using slit images, and the veiling-glare fraction was measured with a lead-disk technique. Noise Wiener spectra were obtained from uniformly exposed images. The current limitations of the large II-TV digital chest system are its low spatial resolution, and the presence of large amounts of veiling glare and structure mottle. Advantages of this system over other digital chest imaging systems include the high speed of image data acquisition and the capability of "real-time" dynamic imaging of the chest at a radiation dose comparable to that in conventional radiography of the chest.

  19. Image Analysis Concerns for ICF: Simulating a Static Target Radiograph with Comparison to Experiment

    Science.gov (United States)

    Beck, J. B.; Scott, J. M.; Tubbs, D. L.; Batha, S. H.; Barnes, C. W.

    1999-11-01

    In the ongoing validation process for physics simulation codes, experiments are conducted which must be compared to predicted simulation results on an equivalent basis. For some ICF experiments, this requires the generation of radiographic images from simulation data for comparison to experimentally obtained radiographs. Therefore, post-processing software must be developed to generate experimental-like images from the primary physics simulation. Essentially, the post-processing software attempts to simulate the diagnostic response used to obtain the experimental data. Furthermore, data-reduction enhancement routines (e.g. spatial and temporal smoothing) are frequently used to improve image sharpness, and this must also be incorporated into the simulation. Consequently, valid comparisons are based on similarly post processed experimental and simulation data. In order to validate the process of creating simulated radiographs, static target experiments have been performed. In these experiments, on the OMEGA laser facility, an x-ray backlighter illuminated a target of known configuration. No drive beams interacted with the target, hence the name "static target". Comparisons of simulated data with experimental images will be presented with discussions of the differences in the results. This work was performed under the auspices of the U. S. Department of Energy by the Los Alamos National Laboratory under contract No. W-7405-Eng-36.

  20. Fatigue stress fractures of the pubic ramus in the army: imaging features with radiographic, scintigraphic and MR imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Woo; Lee, Chang Hyun [The Armed Forces Capital Hospital, Seongnam (Korea, Republic of)

    2005-03-15

    Although fatigue fractures are not unusual in athletes and military personnel those of the pubic ramus are rare. We report three cases of fatigue fractures of the inferior pubic rami in two male recruits and one female military cadet. On the initial radiograph, most of the lesions were subtle and easy to overlook. However, bone scintigraphy provided more distinct images that allowed easy and early detection of lesion, and MR imaging presented more diagnostic information, which allowed a precise diagnosis.

  1. Study of digital mammographic equipments by phantom image quality.

    Science.gov (United States)

    Mayo, P; Rodenas, F; Verdú, G; Campayo, J M; Villaescusa, J I

    2006-01-01

    Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast-detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is CDMAM 3.4. One of the most extended indexes to measure the image quality in an objective way is the image quality figure (IQF). The aim of this work is to study the image quality of different images contrast-detail phantom CDMAM 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments that facilitates the evaluation of image contrast and detail resolution.

  2. New radiographic image processing tested on the simple and double-flux platform at OMEGA

    Science.gov (United States)

    Poujade, Olivier; Ferri, Michel; Geoffray, Isabelle

    2017-10-01

    Ablation fronts and shocks are two radiative/hydrodynamic features ubiquitous in inertial confinement fusion (ICF). A specially designed shock-tube experiment was tested on the OMEGA laser facility to observe that these two features evolve at once and to assess thermodynamical and radiative properties. It is a basic science experiment aimed at improving our understanding of shocked and ablated matter which is critical to ICF design. At all time, these two moving "interfaces" separate the tube into three distinct zones where matter is ablated, shocked, or unshocked. The simple-flux or double-flux experiments, respectively, one or two halfraum-plus-tube, have been thought up to observe and image these zones using x-ray and visible image diagnostic. The possibility of observing all three regions at once was instrumental in our new radiographic image processing used to remove the backlighter background otherwise detrimental to quantitative measurements. By so doing, after processing the radiographic images of the 15 shots accumulated during the 2013 and 2015 campaigns, a quantitative comparison between experiments and our radiative hydrocode simulations was made possible. One point of the principal Hugoniot of the aerogel used as a light material in the shock-tube was inferred from that comparison. Most surprisingly, rapid variations of relative-transmission in the ablated region were observed during radiographic irradiations while it remained constant in the shocked region. This effect might be attributed to the spectral distribution variability of the backlighter during the radiographic pulse. Numerically, that distribution is strongly dependent upon NLTE models and it could potentially be used as a means to discriminate among them.

  3. Analysis of several ways to minimize the scatter contribution in radiographic digital images of offshore pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Edmilson M.; Silva, Ademir X.; Lopes, Ricardo T., E-mail: emonteiro@nuclear.ufrj.b, E-mail: ademir@nuclear.ufrj.b, E-mail: Ricardo@lin.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Correa, Samanda C.A., E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (DIAPI/CGMI/CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao Geral de Instalacoes Medicas e Industriais. Div. de Aplicacoes Industriais

    2011-07-01

    The aim of this work is to evaluate, through MCNPX simulations, several ways to minimize the scatter contribution in radiographic digital images of offshore pipelines. The influence of liquid inside the pipes and water surrounded the pipelines in the scatter contribution will be analyzed. The use of lead screen behind the detector to reduce the backscattered radiation and filter between the radiation source and the pipes will be discussed. (author)

  4. Magnetic resonance imaging of osteonecrosis in divers: comparison with plain radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Shinoda, S. [Department of Orthopaedic Surgery, Atsumi Hospital, Atsumi-gun, Aichi-ken (Japan)]|[Department of Orthopaedic Surgery, Aichi-ken Saiseikai Hospital, Nagoya (Japan); Hasegawa, Y. [Department of Orthopaedic Surgery, Nagoya University School of Medicine, Showa-ku, Nagoya (Japan); Kawasaki, S. [Department of Orthopaedic Surgery, Atsumi Hospital, Atsumi-gun, Aichi-ken (Japan); Tagawa, N. [Department of Orthopaedic Surgery, Atsumi Hospital, Atsumi-gun, Aichi-ken (Japan); Iwata, H. [Department of Orthopaedic Surgery, Nagoya University School of Medicine, Showa-ku, Nagoya (Japan)

    1997-06-01

    Objective. To assess the diagnostic value of magnetic resonance imaging (MRI) as compared with radiographic findings in osteonecrosis in divers. Design and patients. MRI scans and conventional radiographs of the shoulder, hip and knee joints of 23 professional male scuba divers were reviewed together with their clinical findings and personal histories. Correlations between the MRI findings and the radiographic evaluation, clinical symptoms, and personal history were then investigated. Results and conclusions. Lesions found on MRI in 23 divers included 27 in 39 proximal humeri, 17 in 36 proximal femora, 13 in 32 distal femora, and 12 in 32 proximal tibiae. Diffuse, marginated, or irregular patterns were observed. No lesions were seen in epiphyses of the distal femur or proximal tibia. We tried to classify these MRI findings by location and appearance. MRI showed no patients with only one affected bone. A close correlation between the MRI findings and maximum diving depth was observed in the proximal humerus. MRI depicted bone lesions that could not be detected on the radiographs. A routine MRI investigation of the hip joints should be performed in every diver in whom osteonecrosis is diagnosed at another site, for early detection of femoral head osteonecrosis. MRI of the shoulder joint is also the best surveillance in divers who dive deeper than 15 m. (orig.). With 4 figs., 5 tabs.

  5. Specific developed phantoms and software to assess radiological equipment image quality

    Energy Technology Data Exchange (ETDEWEB)

    Verdu, G., E-mail: gverdu@iqn.upv.es [Universidad Politecnica de Valencia (Spain). Dept. de Ingenieria Quimica y Nuclear; Mayo, P., E-mail: p.mayo@titaniast.com [TITANIA Servicios Teconologicos, Valencia (Spain); Rodenas, F., E-mail: frodenas@mat.upv.es [Universidad Politecnica de Valencia (Spain). Dept. de Matematica Aplicada; Campayo, J.M., E-mail: j.campayo@lainsa.com [Logistica y Acondicionamientos Industriales S.A.U (LAINSA), Valencia (Spain)

    2011-07-01

    The use of radiographic phantoms specifically designed to evaluate the operation of the radiographic equipment lets the study of the image quality obtained by this equipment in an objective way. In digital radiographic equipment, the analysis of the image quality can be automatized because the acquisition of the image is possible in different technologies that are, computerized radiography or phosphor plate and direct radiography or detector. In this work we have shown an application to assess automatically the constancy quality image in the image chain of the radiographic equipment. This application is integrated by designed radiographic phantoms which are adapted to conventional, dental equipment and specific developed software for the automatic evaluation of the phantom image quality. The software is based on digital image processing techniques that let the automatic detection of the different phantom tests by edge detector, morphological operators, threshold histogram techniques, etc. The utility developed is enough sensitive to the radiographic equipment of operating conditions of voltage (kV) and charge (mAs). It is a friendly user programme connected with a data base of the hospital or clinic where it has been used. After the phantom image processing the user can obtain an inform with a resume of the imaging system state with accepting and constancy results. (author)

  6. Development of a joint space width measurement method based on radiographic hand images.

    Science.gov (United States)

    Choi, Samjin; Lee, Gi-Ja; Hong, Seung-Jae; Park, Ki-Ho; Urtnasan, Tur; Park, Hun-Kuk

    2011-10-01

    This study presents a novel algorithm to measure joint space widths (JSWs) in patients with rheumatoid arthritis (RA) using radiographic hand images. Radiographic images were first preprocessed, and then phalangeal regions corresponding to the bone structures of each finger were extracted using step-wedge functions. Phalangeal branch paths were also extracted. Each of the five extracted phalangeal branch paths matched the bone structures of each finger exactly and ran through the center of each finger. The algorithm automatically detected 14 joints, which were identified as sharp changes in gray scale intensity along phalangeal branch paths through the profile plot. The regions of interest corresponding to the 14 joints were subsequently extracted. A total of 35 radiographic images from three groups were tested. The performance of our algorithm was evaluated by measuring joint location percentage errors and mean JSWs for three joints in the phalanges. The algorithm correctly detected 94.69% of total joints and had a low detection rate in RA patients with severe deformities or ankylosis. The mean JSW in the control group was significantly greater than that in the RA group (p<0.05). In contrast, the standard deviation of JSW in the control group was lower than that in the RA groups (p<0.005). Control and seropositive RA groups showed significant symmetry in JSW values. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Measuring Three-Dimensional Thorax Motion Via Biplane Radiographic Imaging: Technique and Preliminary Results.

    Science.gov (United States)

    Baumer, Timothy G; Giles, Joshua W; Drake, Anne; Zauel, Roger; Bey, Michael J

    2016-01-01

    Measures of scapulothoracic motion are dependent on accurate imaging of the scapula and thorax. Advanced radiographic techniques can provide accurate measures of scapular motion, but the limited 3D imaging volume of these techniques often precludes measurement of thorax motion. To overcome this, a thorax coordinate system was defined based on the position of rib pairs and then compared to a conventional sternum/spine-based thorax coordinate system. Alignment of the rib-based coordinate system was dependent on the rib pairs used, with the rib3:rib4 pairing aligned to within 4.4 ± 2.1 deg of the conventional thorax coordinate system.

  8. Field-Based Radiographic Imaging of Marine Megafauna: Marine Iguanas (Amblyrhynchus cristatus as a Case Study

    Directory of Open Access Journals (Sweden)

    Gregory A. Lewbart

    2018-02-01

    Full Text Available Effective conservation of marine megafauna requires a thorough understanding of the ecology, physiology, population dynamics, and health of vulnerable species. Assessing the health of large, mobile marine animals poses particular challenges, in part because the subjects are difficult to capture and restrain, and in part because standard laboratory and diagnostic tools are difficult to apply in a field setting. Radiography is a critically important diagnostic tool used routinely by veterinarians, but it has seldom been possible to image live marine vertebrates in the field. As a first step toward assessing the feasibility of incorporating radiography into studies of vulnerable species in remote locations, we used portable radiographic equipment to acquire the first digital internal images of living marine iguanas, Amblyrhynchus cristatus, an iconic lizard endemic only to the Galápagos Islands of Ecuador. The radiographic machinery was powered by batteries and performed well on a rocky beach environment of an uninhabited island, despite high heat and humidity. The accuracy of radiographic measurements was validated by computing a snout-vent length (SVL using bone dimensions and comparing this to standard measurements of SVL made externally with a tape measure. These results demonstrate the feasibility of using radiography to study animals in remote sites, a technique that may prove useful for a variety of physiological, ecological, and biomechanical studies in which reliable measurements of skeletal and soft-tissue dimensions must be acquired under challenging field conditions. Refinements are discussed that will help the technology reach its full potential in field studies.

  9. Comparison of three digital radiographic imaging systems for the visibility of endodontic files

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Won; Kim, Eun Kyung; Han, Won Jeong [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2004-07-15

    To compare three digital radiographic imaging sensors by evaluating the visibility of endodontic file tips with interobserver reproducibility and assessing subjectively the clarity of images in comparison with the x-ray film images. Forty-five extracted sound premolars were used for this study. Fifteen plaster blocks were made with three premolars each and 8, 10, 15 K-flexofiles were inserted into the root canal of premolars. They were radiographically exposed using periapical x-ray films (Kodak Insight Dental film, Eastmann Kodak company, Rochester, USA), Digora imaging plates (Soredex-Orion Co., Helsinki, Finland), CDX 2000HQ sensors (Biomedisys Co., Seoul, Korea), and CDR sensors (Schick Inc., Long Island, USA). The visibility of endodontic files was evaluated with interobserver reproducibility, which was calculated as the standard deviations of X, Y coordinated of endodontic file tips measured on digital images by three oral and maxillofacial radiologists. The clarity of images was assessed subjectively using 3 grades, i.e, plus, equal, and minus in comparison with the conventional x-ray film images. Interobserver reproducibility of endodontic file tips was the highest in CDR sensor (p<0.05) only except at Y coordinates of 15 file. In the subjective assessment of the image clarity, the plus grade was the most frequent in CDR sensor at all size of endodontic file (p<0.05). CDR sensor was the most superior to the other sensors, CDX 2000HQ sensor and Digora imaging plate in the evaluation of interobserver reproducibility of endodontic file tip and subjective assessment of image clarity.

  10. Diagnostic agreement between panoramic radiographs and color doppler images of carotid atheroma

    Directory of Open Access Journals (Sweden)

    Claudia Maria Romano-Sousa

    2009-02-01

    Full Text Available The aim of this study was to investigate the agreement between diagnoses of calcified atheroma seen on panoramic radiographs and color Doppler images. Our interest stems from the fact that panoramic images can show the presence of atheroma regardless of the level of obstruction detected by color Doppler images. Panoramic and color Doppler images of 16 patients obtained from the archives of the Health Department of the city of Valença, RJ, Brazil, were analyzed in this study. Both sides of each patient were observed on the images, with a total of 32 analyzed cervical regions. The level of agreement between diagnoses was analyzed using the Kappa statistics. There was a high level of agreement, with a Kappa value of 0.78. In conclusion, panoramic radiographs can help detecting calcifications in the cervical region of patients susceptible to vascular diseases predisposing to myocardial infarction and cerebrovascular accidents. If properly trained and informed, dentists can refer their patients to a physician for a cardiovascular evaluation in order to receive proper and timely medical treatment.

  11. Improved texture analysis for automatic detection of tuberculosis (TB) on chest radiographs with bone suppression images

    Science.gov (United States)

    Maduskar, Pragnya; Hogeweg, Laurens; Philipsen, Rick; Schalekamp, Steven; van Ginneken, Bram

    2013-03-01

    Computer aided detection (CAD) of tuberculosis (TB) on chest radiographs (CXR) is challenging due to over-lapping structures. Suppression of normal structures can reduce overprojection effects and can enhance the appearance of diffuse parenchymal abnormalities. In this work, we compare two CAD systems to detect textural abnormalities in chest radiographs of TB suspects. One CAD system was trained and tested on the original CXR and the other CAD system was trained and tested on bone suppression images (BSI). BSI were created using a commercially available software (ClearRead 2.4, Riverain Medical). The CAD system is trained with 431 normal and 434 abnormal images with manually outlined abnormal regions. Subtlety rating (1-3) is assigned to each abnormal region, where 3 refers to obvious and 1 refers to subtle abnormalities. Performance is evaluated on normal and abnormal regions from an independent dataset of 900 images. These contain in total 454 normal and 1127 abnormal regions, which are divided into 3 subtlety categories containing 280, 527 and 320 abnormal regions, respectively. For normal regions, original/BSI CAD has an average abnormality score of 0.094+/-0.027/0.085+/-0.032 (p - 5.6×10-19). For abnormal regions, subtlety 1, 2, 3 categories have average abnormality scores for original/BSI of 0.155+/-0.073/0.156+/-0.089 (p = 0.73), 0.194+/-0.086/0.207+/-0.101 (p = 5.7×10-7), 0.225+/-0.119/0.247+/-0.117 (p = 4.4×10-7), respectively. Thus for normal regions, CAD scores slightly decrease when using BSI instead of the original images, and for abnormal regions, the scores increase slightly. We therefore conclude that the use of bone suppression results in slightly but significantly improved automated detection of textural abnormalities in chest radiographs.

  12. Development and evaluation of a digital radiographic system based on CMOS image sensor

    Science.gov (United States)

    Kim, Ho Kyung; Cho, Gyuseong; Lee, Seung Wook; Shin, Young Hoon; Cho, Hyo Sung

    2001-06-01

    A cost-effective digital radiographic system with a large field-of-view (FOV) of 17"/spl times/17" has been developed. The cascaded imaging system mainly consists of three parts: (1) a phosphor screen to convert incident X-rays into visible photons; (2) a matrix of 8/spl times/8 array of lens assembly to efficiently collect visible photons emitted by the phosphor screen; and (3) 8/spl times/8 complementary metal-oxide-semiconductor (CMOS) image sensors, aligned to the corresponding lens assembly. Although low in cost due to economical CMOS image sensors, the overall performance features are comparable with other commercial digital radiographic systems. From the analysis of signal and noise propagation, the system is not an "X-ray quantum-limited" system, rather the system has secondary quantum sink at the light collecting stage. The system resolution is about 2 line pairs per millimeter from both of measured from X-ray images of a line-pair test pattern and the calculation of the modulation-transfer function. Detailed experimental and theoretical analysis of performance are discussed.

  13. Seed viability detection using computerized false-color radiographic image enhancement

    Science.gov (United States)

    Vozzo, J. A.; Marko, Michael

    1994-01-01

    Seed radiographs are divided into density zones which are related to seed germination. The seeds which germinate have densities relating to false-color red. In turn, a seed sorter may be designed which rejects those seeds not having sufficient red to activate a gate along a moving belt containing the seed source. This results in separating only seeds with the preselected densities representing biological viability lending to germination. These selected seeds demand a higher market value. Actual false-coloring isn't required for a computer to distinguish the significant gray-zone range. This range can be predetermined and screened without the necessity of red imaging. Applying false-color enhancement is a means of emphasizing differences in densities of gray within any subject from photographic, radiographic, or video imaging. Within the 0-255 range of gray levels, colors can be assigned to any single level or group of gray levels. Densitometric values then become easily recognized colors which relate to the image density. Choosing a color to identify any given density allows separation by morphology or composition (form or function). Additionally, relative areas of each color are readily available for determining distribution of that density by comparison with other densities within the image.

  14. Comparison of lumbar lordosis in lateral radiographs in standing position with supine MR imaging in consideration of the sacral slope

    Energy Technology Data Exchange (ETDEWEB)

    Benditz, Achim; Boluki, Daniel; Weber, Markus; Grifka, Joachim; Voellner, Florian [Regensburg Univ. Medical Center (Germany). Orthopedic Surgery; Zeman, Florian [Regensburg Univ. Medical Center (Germany). Center for Clinical Studies

    2017-03-15

    To investigate the influence of sacral slope on the correlation between measurements of lumbar lordosis obtained by standing radiographs and magnetic resonance images in supine position (MRI). Little information is available on the correlation between measurements of lumbar lordosis obtained by radiographic and MR images. Most relevant studies have shown correlations for the thoracic spine, but detailed analyses on the lumbar spine are lacking. MR images and standing lateral radiographs of 63 patients without actual low back pain or radiographic pathologies of the lumbar spine were analyzed. Standing radiographic measurements included the sagittal parameters pelvic incidence (PI) pelvic tilt (PT), and sacral slope (SS); MR images were used to additionally measure lumbar L1-S1 lordosis and single level lordosis. Differences between radiographic and MRI measurements were analyzed and divided into 4 subgroups of different sacral slope according to Roussouly's classification. Global lumbar lordosis (L1-S1) was 44.99 (± 10754) on radiographs and 47.91 (±9.170) on MRI, yielding a clinically relevant correlation (r = 0.61, p < 0.01). Measurements of single level lordosis only showed minor differences. At all levels except for L5 / S1, lordosis measured by means of standing radiographs was higher than that measured by MRI. The difference in global lumbar L1-S1 lordosis was -2.9 . Analysis of the Roussouly groups showed the largest difference for L1-S1 (-8.3 ) in group 2. In group 4, when measured on MRI, L5 / S1 lordosis (25.71 ) was lower than L4 / L5 lordosis (27.63 ) compared to the other groups. Although measurements of global lumbar lordosis significantly differed between the two scanning technologies, the mean difference was just 2.9 . MRI in supine position may be used for estimating global lumbar lordosis, but single level lordosis should be determined by means of standing radiographs.

  15. Radiographic findings in late-presenting congenital diaphragmatic hernia: helpful imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Muzzafar, Sofia; Swischuk, Leonard E.; Jadhav, Siddharth P. [University of Texas Medical Branch, Department of Pediatric Radiology, Galveston, TX (United States)

    2012-03-15

    Imaging findings in delayed presentation of congenital diaphragmatic hernia can be confusing and misleading, resulting in a delay in diagnosis. To evaluate the often puzzling plain film findings of late-presenting CDH in an effort to determine whether any of the findings could be helpful in arriving at an early diagnosis. We reviewed and documented the plain film findings and clinical data in eight patients seen during the last 20 years with late-presenting CDH. IRB exempt status was obtained in this study. There were five boys and three girls. The age range was 4 months to 12 years with a mean of 2.4 years. Five children presented with acute respiratory problems while three presented with acute abdominal pain. Two children presented with both respiratory and abdominal findings and one also presented with hematemesis. Two children had radiographic findings that were not difficult to analyze while the remaining six had findings that posed initial diagnostic problems. Although not common, late-presenting CDH can result in confusing plain film radiographic findings and a delay in diagnosis. We found that the most important finding in analyzing these radiographs is in evaluating the location and position of the gastric bubble with the more common left-side hernias. (orig.)

  16. Comparative analysis of sagittal condylar guidance by protrusive interocclusal records with panoramic and lateral cephalogram radiographs in dentulous population: A clinico-radiographic study

    Directory of Open Access Journals (Sweden)

    Girish Galagali

    2016-01-01

    Conclusion: This study highlighted on the correlation between protrusive interocclusal records and the lateral cephalogram radiograph tracings which were more positively related than the panoramic radiograph. The values of lateral cephalogram radiograph tracings are closer as separate radiographs for left and right side were taken, causing the amount and quality of image distortion less. Lateral cephalogram radiograph may be taken as an important tool to rely on for recording the Sagittal condylar guidance angle.

  17. Evaluation of pneumonia in children: comparison of MRI with fast imaging sequences at 1.5T with chest radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Yikilmaz, Ali; Koc, Ali; Coskun, Abdulhakim (Dept. of Radiology, Erciyes Medical School, Kayseri (Turkey)); Ozturk, Mustafa K (Dept. of Pediatric Infectious Diseases, Erciyes Medical School, Kayseri (Turkey)); Mulkern, Robert V; Lee, Edward Y (Dept. of Radiology and Dept. of Medicine, Pulmonary Div., Children' s Hospital Boston and Harvard Medical School, Boston (United States)), email: Edward.lee@childrens.harvard.edu

    2011-10-15

    Background Although there has been a study aimed at magnetic resonance imaging (MRI) evaluation of pneumonia in children at a low magnetic field (0.2T), there is no study which assessed the efficacy of MRI, particularly with fast imaging sequences at 1.5T, for evaluating pneumonia in children. Purpose To investigate the efficacy of chest MRI with fast imaging sequences at 1.5T for evaluating pneumonia in children by comparing MRI findings with those of chest radiographs. Material and Methods This was an Institutional Review Board-approved, HIPPA-compliant prospective study of 40 consecutive pediatric patients (24 boys, 16 girls; mean age 7.3 years +- 6.6 years) with pneumonia, who underwent PA and lateral chest radiographs followed by MRI within 24 h. All MRI studies were obtained in axial and coronal planes with two different fast imaging sequences: T1-weighted FFE (Fast Field Echo) (TR/TE: 83/4.6) and T2-weighted B-FFE M2D (Balanced Fast Field Echo Multiple 2D Dimensional) (TR/TE: 3.2/1.6). Two experienced pediatric radiologists reviewed each chest radiograph and MRI for the presence of consolidation, necrosis/abscess, bronchiectasis, and pleural effusion. Chest radiograph and MRI findings were compared with Kappa statistics. Results All consolidation, lung necrosis/abscess, bronchiectasis, and pleural effusion detected with chest radiographs were also detected with MRI. There was statistically substantial agreement between chest radiographs and MRI in detecting consolidation (k = 0.78) and bronchiectasis (k = 0.72) in children with pneumonia. The agreement between chest radiographs and MRI was moderate for detecting necrosis/abscess (k = 0.49) and fair for detecting pleural effusion (k = 0.30). Conclusion MRI with fast imaging sequences is comparable to chest radiographs for evaluating underlying pulmonary consolidation, bronchiectasis, necrosis/abscess, and pleural effusion often associated with pneumonia in children

  18. Images in industrial radiography: factors affecting the quality of the image; Imagens em radiografia industrial: fatores que alteram a qualidade da imagem

    Energy Technology Data Exchange (ETDEWEB)

    Trombini, Henrique; Dytz, Aline Guerra, E-mail: henriquetrom@yahoo.com.br, E-mail: alinedytz@furg.br [Universidade Federal do Rio Grande (FURG), RS (Brazil)

    2013-07-01

    This work was performed several radiographic images of a instruction model two stroke petrol engine to verify the use of X-rays as non-invasive testing. The images were made by varying technical and operational factors to assess the image quality and visualization of the model structures in radiographic films. These images are held as non-destructive tests to verify the integrity of the sample. (author)

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

    Science.gov (United States)

    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.

  20. Automatic image analysis of X-ray radiographs: a new method for ichnofabric evaluation

    Science.gov (United States)

    Löwemark, Ludvig

    2003-06-01

    Automated ichnofabric analysis was performed on X-ray radiographs from five gravity cores retrieved from Late Quaternary sediments from the SW Portuguese continental slope. The image analysis program DIAna was used to detect and quantify the part of the ichnofabric consisting of pyritized microburrows, presumably Trichichnus and " Mycellia". Abundance and orientation of the burrows were determined at 5-cm intervals. The results agree with manual counts of burrows in the coarse fraction of the sediment, and they indicate that the abundance of the pyritized burrows depends on enhanced organic carbon content, fine grain size, and low bottom water oxygenation. In contrast, no clear correlation between burrow orientation and environmental conditions was observed.

  1. Two-Dimensional Image Fusion of Planar Bone Scintigraphy and Radiographs in Patients with Clinical Scaphoid Fracture: An Imaging Study

    DEFF Research Database (Denmark)

    Henriksen, O.M.; Lonsdale, M.N.; Jensen, T.D.

    2008-01-01

    experienced nuclear medicine physicians. In addition to the diagnosis, the degree of diagnostic confidence was scored in each case. Results: The addition of fusion images changed the interpretation of each of the three observers in seven, four, and two cases, respectively, reducing the number of positive....... Bone scintigraphy is highly sensitive for the detection of fractures, but exact localization of scintigraphic lesions may be difficult and can negatively affect diagnostic accuracy. Purpose: To investigate the influence of image fusion of planar bone scintigraphy and radiographs on image interpretation...... in patients with suspected scaphoid fracture. Material and Methods: In 24 consecutive patients with suspected scaphoid fracture, a standard planar bone scintigraphy of both hands was supplemented with fusion imaging of the injured wrist. Standard and fusion images were evaluated independently by three...

  2. Two-dimensional fusion imaging of planar bone scintigraphy and radiographs in patients with clinical scaphoid fracture: an imaging study

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Lonsdale, Markus Georg; Jensen, T D

    2009-01-01

    experienced nuclear medicine physicians. In addition to the diagnosis, the degree of diagnostic confidence was scored in each case. RESULTS: The addition of fusion images changed the interpretation of each of the three observers in seven, four, and two cases, respectively, reducing the number of positive....... Bone scintigraphy is highly sensitive for the detection of fractures, but exact localization of scintigraphic lesions may be difficult and can negatively affect diagnostic accuracy. PURPOSE: To investigate the influence of image fusion of planar bone scintigraphy and radiographs on image interpretation...... in patients with suspected scaphoid fracture. MATERIAL AND METHODS: In 24 consecutive patients with suspected scaphoid fracture, a standard planar bone scintigraphy of both hands was supplemented with fusion imaging of the injured wrist. Standard and fusion images were evaluated independently by three...

  3. Preliminayr Study on Diffraction Enhanced Radiographic Imaging for a Canine Model of Cartilage Damage

    Energy Technology Data Exchange (ETDEWEB)

    Muehleman,C.; Li, J.; Zhong, Z.

    2006-01-01

    Objective: To demonstrate the ability of a novel radiographic technique, Diffraction Enhanced Radiographic Imaging (DEI), to render high contrast images of canine knee joints for identification of cartilage lesions in situ. Methods: DEI was carried out at the X-15A beamline at Brookhaven National Laboratory on intact canine knee joints with varying levels of cartilage damage. Two independent observers graded the DE images for lesions and these grades were correlated to the gross morphological grade. Results: The correlation of gross visual grades with DEI grades for the 18 canine knee joints as determined by observer 1 (r2=0.8856, P=0.001) and observer 2 (r2=0.8818, P=0.001) was high. The overall weighted ? value for inter-observer agreement was 0.93, thus considered high agreement. Conclusion: The present study is the first study for the efficacy of DEI for cartilage lesions in an animal joint, from very early signs through erosion down to subchondral bone, representing the spectrum of cartilage changes occurring in human osteoarthritis (OA). Here we show that DEI allows the visualization of cartilage lesions in intact canine knee joints with good accuracy. Hence, DEI may be applicable for following joint degeneration in animal models of OA.

  4. ‘Virtual anthropology’ and radiographic imaging in the Forensic Medical Sciences

    Directory of Open Access Journals (Sweden)

    Daniel Franklin

    2016-06-01

    Full Text Available Technological advancements in forensic imaging have had tremendous flow-on benefits to the professional practice of forensic anthropology, not only in respect of case-work analyses, but in facilitating empirical research that has validated and/or improved existing, and introduced novel, methods into the discipline. Some of the pioneering practical examples of radiographic imaging being applied in the forensic analysis of human skeletal remains date to the initial introduction of radiography in the late 19th and early 20th centuries. Subsequent modern applications have developed concurrent to the use of computed tomography in the forensic morgue for autopsy procedures by pathologists; virtopsy (as it is now termed represents a powerful non-invasive supplement/alternative to traditional autopsy practices where dissection may not be allowable due to religious objection (amongst other reasons. The present review considers a brief history of skeletal radiographic imaging and the specific modalities typically employed. Forensic applications of ‘virtual anthropology’ are then discussed, as are applications of the latter in DVI and other case-work scenarios. Throughout the review we emphasise the research importance of virtual modelling and conclude with some thoughts for future directions.

  5. Radiographic evaluation of the maxillary sinus prior to dental implant therapy: A comparison between two dimensional and three dimensional radiographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tadinada, Aditya; Fung, Karen; Thacker, Sejal; Mahdian, Mina; Jadhaw, Aniket; Schincaglia, Gian Pietro [University of Connecticut School of Dental Medicine, Farmington (United States)

    2015-09-15

    This study was performed to evaluate the diagnostic efficacy of panoramic radiography and cone-beam computed tomography (CBCT) in detecting sinus pathology. This study was based on a retrospective evaluation of patients who had undergone both a panoramic radiograph and a CBCT exam. A total of 100 maxillary sinuses were evaluated. Four examiners with various levels of expertise evaluated the images using a five-point scoring system. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic efficacy of the two modalities. The image analysis was repeated twice, with at least two weeks between the evaluation sessions. Interobserver reliability was assessed using Cronbach's alpha, and intraobserver reliability was assessed using Cohen's kappa. Maxillary sinus pathology was detected in 72% of the patients. High interobserver and intraobserver reliability were observed for both imaging modalities and among the four examiners. Statistical analyses using ROC curves demonstrated that the CBCT images had a larger area under the curve (0.940) than the panoramic radiographs (0.579). Three-dimensional evaluation of the sinus with CBCT was significantly more reliable in detecting pathology than panoramic imaging.

  6. IMAGE QUALITY ENHANCEMENT.

    Science.gov (United States)

    PHOTOGRAPHIC RECONNAISSANCE, *AERIAL PHOTOGRAPHY, *PHOTOGRAPHIC IMAGES , PHOTOINTERPRETABILITY, PHOTOGRAPHIC ACUTANCE, VISUAL PERCEPTION, DISPLAY...SYSTEMS, INTELLIGIBILITY, VISIBILITY, VIDEO SIGNALS, IMAGE INTENSIFIERS(ELECTRONICS), ELECTRON OPTICS.

  7. Deltoid Tuberosity Index: A Simple Radiographic Tool to Assess Local Bone Quality in Proximal Humerus Fractures.

    Science.gov (United States)

    Spross, Christian; Kaestle, Nicola; Benninger, Emanuel; Fornaro, Jürgen; Erhardt, Johannes; Zdravkovic, Vilijam; Jost, Bernhard

    2015-09-01

    Osteoporosis may complicate surgical fixation and healing of proximal humerus fractures and should be assessed preoperatively. Peripheral quantitative CT (pQCT) and the Tingart measurement are helpful methods, but both have limitations in clinical use because of limited availability (pQCT) or fracture lines crossing the area of interest (Tingart measurement). The aim of our study was to introduce and validate a simple cortical index to assess the quality of bone in proximal humerus fractures using AP radiographs. We asked: (1) How do the deltoid tuberosity index and Tingart measurement correlate with each other, with patient age, and local bone mineral density (BMD) of the humeral head, measured by pQCT? (2) Which threshold values for the deltoid tuberosity index and Tingart measurement optimally discriminate poor local bone quality of the proximal humerus? (3) Are the deltoid tuberosity index and Tingart measurement clinically applicable and reproducible in patients with proximal humerus fractures? The deltoid tuberosity index was measured immediately above the upper end of the deltoid tuberosity. At this position, where the outer cortical borders become parallel, the deltoid tuberosity index equals the ratio between the outer cortical and inner endosteal diameter. In the first part of our study, we retrospectively measured the deltoid tuberosity index on 31 patients (16 women, 15 men; mean age, 65 years; range, 22-83 years) who were scheduled for elective surgery other than fracture repair. Inclusion criteria were available native pQCT scans, AP shoulder radiographs taken in internal rotation, and no previous shoulder surgery. The deltoid tuberosity index and the Tingart measurement were measured on the preoperative internal rotation AP radiograph. The second part of our study was performed by reviewing 40 radiographs of patients with proximal humerus fractures (31 women, nine men; median age, 65 years; range, 22-88 years). Interrater (two surgeons) and

  8. Radiographers' Ability to Detect Low-Contrast Detail in Digital Radiography Systems.

    Science.gov (United States)

    Alsleem, Haney; Davidson, Robert

    2015-01-01

    To evaluate radiographers' ability to detect low-contrast detail using various digital planar radiographic systems. A low-contrast detail phantom was placed between two 5-cm thick Perspex sheets (Lucite International). Images were obtained using different kilovoltage peak and milliamperage second (mAs) settings with computed radiography (CR), indirect conversion digital radiography (IDR), and direct conversion digital radiography (DR) systems. Six groups of 6 radiographers were asked to score 39 images; each group scored 2 images from each system for a total of 6 images. The seventh group scored only one image from each system for a total of 3 images. The radiographers' results were compared with the results of analyzer software. The inverse image quality factor was used to measure low-contrast detail detectability performance. Radiographers performed significantly worse than the computerized software in determining low-contrast detail in planar radiographic images (P detail detectability performance. On average, radiographers were able to detect increased image quality resulting from increased mAs. Radiographers reached results similar to the software regarding whether IDR and DR have better detectability performances than CR. Differences found among individual radiographers were not as significant with DR. When radiographers' performance in detecting low-contrast detail was evaluated and compared with that of the software, radiographers exhibited poorer performances. Because radiographers are responsible for image quality optimization, additional training might improve their ability to detect low-contrast detail in DR systems.

  9. Technical Quality of Root Fillings Performed by Undergraduate Students: A Radiographic Study

    Science.gov (United States)

    Blažić, Larisa; Kantardžić, Ivana

    2014-01-01

    Aim. The aim of this study was to evaluate the radiographic technical quality of endodontic treatment performed by undergraduate students at the School of Dentistry, Faculty of Medicine, University of Novi Sad, Serbia. Materials and Methods. Electronic records of 220 patients treated by final-year undergraduate students during the school year 2011/2012 were examined, and the final sample consisted of 212 patients, 322 teeth, and 565 root canals. The criteria for overall radiographic adequacy of root canal fillings were defined as the presence of adequate length and density and absence of iatrogenic errors (ledge, fractured instrument, untreated canal, and apical transportation). Chi-square test was used to determine statistical significance between different parameters. Results. Adequate root canal fillings were found in 74.22% of the teeth. The percentage of root fillings with adequate length and density was 89.73% and 92.6%, respectively. Fractured instruments and ledges were present in 16 root canals (2.8%), while the presence of missed canal and apical transportation was observed in 2 cases, each (0.3%). Conclusions. Overall, the technical quality of root canal fillings performed by undergraduate students was satisfactory. PMID:24672365

  10. Comparison of Lumbar Lordosis in Lateral Radiographs in Standing Position with supine MR Imaging in consideration of the Sacral Slope.

    Science.gov (United States)

    Benditz, Achim; Boluki, Daniel; Weber, Markus; Zeman, Florian; Grifka, Joachim; Völlner, Florian

    2017-03-01

    Purpose To investigate the influence of sacral slope on the correlation between measurements of lumbar lordosis obtained by standing radiographs and magnetic resonance images in supine position (MRI). Little information is available on the correlation between measurements of lumbar lordosis obtained by radiographic and MR images. Most relevant studies have shown correlations for the thoracic spine, but detailed analyses on the lumbar spine are lacking. Methods MR images and standing lateral radiographs of 63 patients without actual low back pain or radiographic pathologies of the lumbar spine were analyzed. Standing radiographic measurements included the sagittal parameters pelvic incidence (PI) pelvic tilt (PT), and sacral slope (SS); MR images were used to additionally measure lumbar L1-S1 lordosis and single level lordosis. Differences between radiographic and MRI measurements were analyzed and divided into 4 subgroups of different sacral slope according to Roussouly's classification. Results Global lumbar lordosis (L1-S1) was 44.99° (± 10 754) on radiographs and 47.91° (± 9.170) on MRI, yielding a clinically relevant correlation (r = 0.61, p Roussouly groups showed the largest difference for L1-S1 (-8.3°) in group 2. In group 4, when measured on MRI, L5 / S1 lordosis (25.71°) was lower than L4 / L5 lordosis (27.63°) compared to the other groups. Conclusions Although measurements of global lumbar lordosis significantly differed between the two scanning technologies, the mean difference was just 2.9°. MRI in supine position may be used for estimating global lumbar lordosis, but single level lordosis should be determined by means of standing radiographs. Key Points  · Large difference between radiographic and MRI measurements of level L5 / S1.. · MRI can be used for estimating global lumbar lordosis.. · Analysis of single level lordosis necessitates measurement in standing radiographs.. Citation Format · Benditz A

  11. Evaluating radiographers' diagnostic accuracy in screen-reading mammograms: what constitutes a quality study?

    Energy Technology Data Exchange (ETDEWEB)

    Debono, Josephine C, E-mail: josephine.debono@bci.org.au [Westmead Breast Cancer Institute, Westmead, New South Wales (Australia); Poulos, Ann E [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales (Australia); Westmead Breast Cancer Institute, Westmead, New South Wales (Australia)

    2015-03-15

    The aim of this study was to first evaluate the quality of studies investigating the diagnostic accuracy of radiographers as mammogram screen-readers and then to develop an adapted tool for determining the quality of screen-reading studies. A literature search was used to identify relevant studies and a quality evaluation tool constructed by combining the criteria for quality of Whiting, Rutjes, Dinnes et al. and Brealey and Westwood. This constructed tool was then applied to the studies and subsequently adapted specifically for use in evaluating quality in studies investigating diagnostic accuracy of screen-readers. Eleven studies were identified and the constructed tool applied to evaluate quality. This evaluation resulted in the identification of quality issues with the studies such as potential for bias, applicability of results, study conduct, reporting of the study and observer characteristics. An assessment of the applicability and relevance of the tool for this area of research resulted in adaptations to the criteria and the development of a tool specifically for evaluating diagnostic accuracy in screen-reading. This tool, with further refinement and rigorous validation can make a significant contribution to promoting well-designed studies in this important area of research and practice.

  12. A study of the mandibular canal in digital panoramic radiographic images of a selected Korean population

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Duk; Kim, Jin Soo [Chosun Univ., Gwangju (Korea, Republic of)

    2007-03-15

    To determine the more valuable information to detect the mandibular canal and the mental foramen in panoramic radiographs of a selected Korean population for the implant. This study analysed 288 panoramic radiographic images of patients taken at the Dental hospital of Chosun University retrospectively. Indirect digital panoramic X-ray machine (ProlineXC, PLANMECA, Finland) with processing by using Directview CR950 (Kodak, U.S.A.) and Direct digital panoramic X-ray machine (Promax, PLANMECA, Finland) were used for all exposures. All images were converted into Dicom format. The common position of the mental foramen was in line with the longitudinal axis of the second premolar (68.1%). The mental foramen was lower symmetrical in 81.8% of cases. The mandibular canal was not identified at anterior portion and discontinued with the mental foramen in 27.8% of all cases, in 42.4% identified with lower border line continued with the mental foramen, in 14.6% with both upper and lower border lines, and in 15.3% unilaterally identified with lower border line. Clinicians can estimate the upper border line of the mandibular canal from the confirmation of the mental foramen and the lower border line of the mandibular canal symmetrically on the panoramic radiography taken in adjusted midsaggital plane of patient's head.

  13. The detectability of bone loss in the bifurcation of mandibular molars on periapical radiographs and digital images : an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Geon Ill [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Wonkwang University, Icksan (Korea, Republic of); You, Hyung Keun; Shin, Hyung Shik [Dept. of Periodontology, College of Dentistry, Wonkwang National University, Icksan (Korea, Republic of)

    1995-02-15

    The aim of this study was to evaluated clinician's detectability in the diagnosis of bone loss in the bifurcation of mandibular molars on periapical radiographs and Digital images. Periapical radiographs were obtained of the first molars in 2 dry mandibles after preparation of bony defects corresponding to degree I, degree II and degree III buccal furcation involvements. The radiographs were randomly presented to 39 clinicians (1 oral radiologist, 4 periodontist, 34 general dentists) who were asked to determine the presence or absence of bone loss. Periapical films were digitized with a TV camera. Digital images were assessed by 15 clinicians (1 oral radiologist, 4 periodontist, 10 general dentists). 1. the overall diagnostic accuracy of Digital images for detection of bone loss in the bifurcation of mandibular molars was higher than that of the periapical radiographs. 2. the largest increase in diagnostic accuracy was found between lesion grade II and III on both radiographs and Digital images (p<0.05). 3. there was no significant difference between the standard state and the controlled contrast state on Digital images. 4. the overall diagnostic accuracy of 1 radiologist and 4 periodontists was better than that of the general dentists for detecting bifurcation involvements

  14. Image Enhancement, Image Quality, and Noise

    Science.gov (United States)

    Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.; Hines, Glenn D.

    2005-01-01

    The Multiscale Retinex With Color Restoration (MSRCR) is a non-linear image enhancement algorithm that provides simultaneous dynamic range compression, color constancy and rendition. The overall impact is to brighten up areas of poor contrast/lightness but not at the expense of saturating areas of good contrast/brightness. The downside is that with the poor signal-to-noise ratio that most image acquisition devices have in dark regions, noise can also be greatly enhanced thus affecting overall image quality. In this paper, we will discuss the impact of the MSRCR on the overall quality of an enhanced image as a function of the strength of shadows in an image, and as a function of the root-mean-square (RMS) signal-to-noise (SNR) ratio of the image.

  15. Radiographic quality of root canal fillings performed in a postgraduate program in endodontics.

    Science.gov (United States)

    Santos, Suelleng Maria Cunha; Soares, Janir Alves; César, Carlos Augusto Santos; Brito-Júnior, Manoel; Moreira, Allyson Nogueira; Magalhães, Cláudia Silami de

    2010-01-01

    The aim of this study was to evaluate the standard quality of 1,347 root fillings performed by postgraduate students in Endodontics according to 3 radiographic quality parameters. The analyzed quality parameters included apical extension (AE), taper (TA) and homogeneity (HO), which received scores S2 (ideal standard), S1 (slight deviation) or S0 (accentuated deviation). A perfect filling (PF) received S2 for all parameters. In the absence of one or two S2 score, the fillings were deemed as satisfactory (SF) or deficient (DF), respectively. The results showed 51.7%, 41.5% and 6.8% of PF, SF, and DF, respectively. AE, TA, and HO presented equivalent quality parameters in root-filled canals of mandibular incisors and mandibular premolars (p>0.05). Conversely, in maxillary incisors, canines and distal root of mandibular molars, significant differences (p<0.05) were found between 2 parameters. Besides, there were significant differences (p<0.05) among the measured parameters in root-filled canals of maxillary premolars, all root canals of the maxillary molars and mesial root of the mandibular molars. AE showed the lowest frequency of S2 score for all groups. In conclusion the prevalence of perfect, satisfactory and deficient fillings varied significantly according to the root canal group. The quality parameters categorized fillings in 3 complexity degrees. AE was the most critical parameter of quality in root canal fillings.

  16. Mammography image restoration based on a radiographic scattering model from a single projection: Experimental study

    Science.gov (United States)

    Kim, Kyuseok; Park, Soyoung; Kim, Guna; Cho, Hyosung; Je, Uikyu; Park, Chulkyu; Lim, Hyunwoo; Lee, Dongyeon; Lee, Hunwoo; Kang, Seokyoon

    2017-03-01

    In conventional mammography, contrast sensitivity remains limited due to the superimposition of breast tissue and scattered X-rays, which induces low visibility of lesions in the breast and, thus, an excessive number of false-positive findings. Several methods, including digital breast tomosynthesis as a multiplanar imaging modality, air-gap and slot techniques for the reduction of scatters, phase-contrast imaging as another image-contrast modality, etc., have been investigated in attempt to overcome these difficulties. However, those techniques typically require a higher imaging dose or special equipment. In this work, as an alternative, we propose a new image restoration method based on a radiographic scattering model in which the intensity of scattered X-rays and the direct transmission function of a given medium are estimated from a single projection by using the dark-channel prior. We implemented the proposed algorithm and performed an experiment to demonstrate its viability. Our results indicate that most of the structures in the examined breast were very discernable even with no adjustment in the display-window level, thus preserving superior image features and edge sharpening.

  17. Segmentation of radiographic images under topological constraints: application to the femur

    Energy Technology Data Exchange (ETDEWEB)

    Gamage, Pavan; Xie, Sheng Quan [University of Auckland, Department of Mechanical Engineering (Mechatronics), Auckland (New Zealand); Delmas, Patrice [University of Auckland, Department of Computer Science, Auckland (New Zealand); Xu, Wei Liang [Massey University, School of Engineering and Advanced Technology, Auckland (New Zealand)

    2010-09-15

    A framework for radiographic image segmentation under topological control based on two-dimensional (2D) image analysis was developed. The system is intended for use in common radiological tasks including fracture treatment analysis, osteoarthritis diagnostics and osteotomy management planning. The segmentation framework utilizes a generic three-dimensional (3D) model of the bone of interest to define the anatomical topology. Non-rigid registration is performed between the projected contours of the generic 3D model and extracted edges of the X-ray image to achieve the segmentation. For fractured bones, the segmentation requires an additional step where a region-based active contours curve evolution is performed with a level set Mumford-Shah method to obtain the fracture surface edge. The application of the segmentation framework to analysis of human femur radiographs was evaluated. The proposed system has two major innovations. First, definition of the topological constraints does not require a statistical learning process, so the method is generally applicable to a variety of bony anatomy segmentation problems. Second, the methodology is able to handle both intact and fractured bone segmentation. Testing on clinical X-ray images yielded an average root mean squared distance (between the automatically segmented femur contour and the manual segmented ground truth) of 1.10 mm with a standard deviation of 0.13 mm. The proposed point correspondence estimation algorithm was benchmarked against three state-of-the-art point matching algorithms, demonstrating successful non-rigid registration for the cases of interest. A topologically constrained automatic bone contour segmentation framework was developed and tested, providing robustness to noise, outliers, deformations and occlusions. (orig.)

  18. Quality assurance in digital dental imaging: a systematic review.

    Science.gov (United States)

    Metsälä, Eija; Henner, Anja; Ekholm, Marja

    2014-07-01

    Doses induced by individual dental examinations are low. However, dental radiography accounts for nearly one third of the total number of radiological examinations in the European Union. Therefore, special attention is needed with regard to radiation protection. In order to lower patient doses, the staff performing dental examinations must have competence in imaging as well as in radiation protection issues. This paper presents a systematic review about the core competencies needed by the healthcare staff in performing digital dental radiological imaging quality assurance. The following databases were searched: Pubmed, Cinahl, Pro Quest and IEEXplore digital library. Also volumes of some dental imaging journals and doctoral theses of the Finnish universities educating dentists were searched. The search was performed using both MeSH terms and keywords using the option 'search all text'. The original keywords were: dental imaging, digital, x-ray, panoramic, quality, assurance, competence, competency, skills, knowledge, radiographer, radiologist technician, dentist, oral hygienist, radiation protection and their Finnish synonyms. Core competencies needed by the healthcare staff performing digital dental radiological imaging quality assurance described in the selected studies were: management of dental imaging equipment, competence in image quality and factors associated with it, dose optimization and quality assurance. In the future there will be higher doses in dental imaging due to increasing use of CBCT and digital imaging. The staff performing dental imaging must have competence in dental imaging quality assurance issues found in this review. They also have to practice ethical radiation safety culture in clinical practice.

  19. 2D-3D radiograph to cone-beam computed tomography (CBCT) registration for C-arm image-guided robotic surgery.

    Science.gov (United States)

    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.

  20. Improvement of density resolution in short-pulse hard x-ray radiographic imaging using detector stacks

    Energy Technology Data Exchange (ETDEWEB)

    Borm, B.; Gärtner, F.; Khaghani, D. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Johann Wolfgang Goethe-Universität, Frankfurt am Main (Germany); Neumayer, P. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany)

    2016-09-15

    We demonstrate that stacking several imaging plates (IPs) constitutes an easy method to increase hard x-ray detection efficiency. Used to record x-ray radiographic images produced by an intense-laser driven hard x-ray backlighter source, the IP stacks resulted in a significant improvement of the radiograph density resolution. We attribute this to the higher quantum efficiency of the combined detectors, leading to a reduced photon noise. Electron-photon transport simulations of the interaction processes in the detector reproduce the observed contrast improvement. Increasing the detection efficiency to enhance radiographic imaging capabilities is equally effective as increasing the x-ray source yield, e.g., by a larger drive laser energy.

  1. The importance of radiographic imaging in the microscopic assessment of bone tumors

    Energy Technology Data Exchange (ETDEWEB)

    Larousserie, F., E-mail: frederique.larousserie@cch.aphp.fr [Université Paris Descartes, Sorbonne Paris Cité, Paris (France); Department of pathology, Rizzoli Institute, Bologna (Italy); Kreshak, J.; Gambarotti, M.; Alberghini, M.; Vanel, D. [Department of pathology, Rizzoli Institute, Bologna (Italy)

    2013-12-01

    Introduction: Primary bone tumors are rare and require a multidisciplinary approach. Diagnosis involves primarily the radiologist and the pathologist. Bone lesions are often heterogeneous and the microscopic diagnostic component(s) may be in the minority, especially on core needle biopsies. Reactive processes, benign, and malignant tumors may have similar microscopic aspects. For these challenging cases, the correlation of microscopic and radiologic information is critical, or diagnostic mistakes may be made with severe clinical consequences for the patient. The purpose of this article is to explain how pathologists can best use imaging studies to improve the diagnostic accuracy of bone lesions. Diagnosis: Many bone lesions are microscopically and/or radiographically heterogeneous, especially those with both lytic and matrix components. Final diagnosis may require specific microscopic diagnostic features that may be present in the lesion, but not the biopsy specimen. A review of the imaging helps assess if sampling was adequate. The existence of a pre-existing bone lesion, syndrome (such as Ollier disease or multiple hereditary exostosis), or oncologic history may be of crucial importance. Finally, imaging information is very useful for the pathologist to perform accurate local and regional staging during gross examination. Conclusion: Close teamwork between pathologists, radiologists, and clinicians is of utmost importance in the evaluation and management of bone tumors. These lesions can be very difficult to interpret microscopically; imaging studies therefore play a crucial role in their accurate diagnosis.

  2. Diagnosis of alveolar and root fractures: an in vitro study comparing CBCT imaging with periapical radiographs

    Directory of Open Access Journals (Sweden)

    Solange KOBAYASHI-VELASCO

    Full Text Available Abstract Objective To compare periapical radiograph (PR and cone-beam computed tomography (CBCT in the diagnosis of alveolar and root fractures. Material and Methods Sixty incisor teeth (20 higid and 40 with root fracture from dogs were inserted in 60 anterior alveolar sockets (40 higid and 20 with alveolar fracture of 15 macerated canine maxillae. Each fractured socket had a root fractured tooth inserted in it. Afterwards, each maxilla was submitted to PR in two different vertical angulation incidences, and to CBCT imaging with a small field of view (FOV and high-definition protocol. Images were randomized and posteriorly analyzed by two oral and maxillofacial radiologists two times, with a two-week interval between observations. Results Sensitivity and specificity values were good for root fractures for PR and CBCT. For alveolar fractures, sensitivity ranged from 0.10 to 0.90 for PR and from 0.50 to 0.65 for CBCT. Specificity for alveolar fractures showed lower results than for root fractures for PR and CBCT. Areas under the ROC curve showed good results for both PR and CBCT for root fractures. However, results were fair for both PR and CBCT for alveolar fractures. When submitted to repeated measures ANOVA tests, there was a statistically significant difference between PR and CBCT for root fractures. Root fracture intraobserver agreement ranged from 0.90 to 0.93, and alveolar fracture intraobserver agreement ranged from 0.30 to 0.57. Interobserver agreement results were substantial for root fractures and poor/fair for alveolar fractures (0.11 for PR and 0.30 for CBCT. Conclusion Periapical radiograph with two different vertical angulations may be considered an accurate method to detect root fractures. However, PR showed poorer results than CBCT for the diagnosis of alveolar fractures. When no fractures are diagnosed in PR and the patient describes pain symptoms, the subsequent exam of choice is CBCT.

  3. Restorative Treatment Thresholds for Interproximal Primary Caries Based on Radiographic Images: Findings from The Dental PBRN

    Science.gov (United States)

    Gordan, Valeria V; Garvan, Cynthia W; Heft, Marc W.; Fellows, Jeffrey L; Qvist, Vibeke; Rindal, D. Brad; Gilbert, Gregg H

    2010-01-01

    Objectives To: (1) quantify at which proximal caries lesion depths dentists in regular clinical practice intervene restoratively, based on hypothetical scenarios that present radiographic images and patient background information, and (2) identify characteristics that are associated with restorative intervention in lesions that have penetrated only the enamel surface. Methods Dentists in a practice-based research network (www.DentalPBRN.org) who reported doing at least some restorative dentistry were surveyed (n=901). Dentists were asked to indicate at which lesion depth they would intervene restoratively based on a series of radiographic images depicting interproximal caries at increasing lesion depths in a mandibular premolar tooth. Dentists were also questioned regarding two caries risk scenarios: one patient with low caries risk and another at higher risk. We used logistic regression to analyze associations between the decision to intervene restoratively and specific dentist, practice, and patient characteristics. Results Five hundred (56%) DPBRN practitioner-investigators completed the survey. In a high caries risk patient, 66% of dentists indicated that they would restore a proximal enamel lesion, and 24% would once the lesion had reached into the outer one-third of the dentin. In a low caries risk patient, 39% of dentists reported that they would restore an enamel lesion, and 54% would once the lesion had reached into the outer one-third of the dentin. In multivariate analyses, when accounting for dentist and practice characteristics, dentists in large group practices were less likely to intervene surgically for enamel caries regardless of patient's caries risk. Conclusions Restorative treatment thresholds based on radiographic lesion depth varied substantially among dentists. Most dentists would restore lesions that were still within the enamel surface for high caries risk individuals. Dentists’ decisions to intervene surgically in the caries process

  4. Image quality in context

    NARCIS (Netherlands)

    Besuijen, J.

    2008-01-01

    An analysis of the ergonomic quality of the current standards for the visual display quality leads to a number of recommendations for the development of new international standards: - Separation for different types of users, esp. display designers, purchasers, and end users, -Independence of display

  5. Cotton trash assessment in radiographic x-ray images with scale-space filtering and stereo analysis

    Science.gov (United States)

    Dogan, Mehmet S.; Sari-Sarraf, Hamed; Hequet, Eric F.

    2005-02-01

    Trash content of raw cotton is a critical quality attribute. Therefore, accurate trash assessment is crucial for evaluating cotton"s processing and market value. Current technologies, including gravimetric and surface scanning methods, suffer from various limitations. Furthermore, worldwide, the most commonly used method is still human grading. One of the best alternatives to the aforementioned approaches is 2D x-ray imaging since it allows a thorough analysis of contaminants in a very precise and quick manner. The segmentation of trash particles in 2D transmission images is difficult since the background cotton is not uniform. Furthermore, there is considerable overlap between the gray levels of trash and cotton. We dealt with this problem by characterizing and identifying the background cotton via scale-space filtering, followed by a "background normalization" process that removes the background cotton, while leaving the trash particles intact. Furthermore, we have successfully employed stereo x-ray vision for recovering the depth information of the piled trash in controlled samples. Finally, the proposed technique was tested on 280 cotton radiographs-with various trash levels-and the results compared favorably to the existing systems of cotton trash evaluation. Given that the approach described here provides the trash mass in real-time, when realized, it will have a wide-spread impact on the cotton industry.

  6. Selective Energy Neutron Radiographic Imaging Origins and Lessons for Low Cost Systems

    Science.gov (United States)

    Barton, J. P.; Rogers, J. D.

    Major advances in selective energy techniques for neutron radiographic imaging have been demonstrated recently at very advanced, high flux, shared user facilities. The origins of selective energy methods for neutron radiography have been reviewed and options for low cost systems at lower flux, lower budget, single-user neutron source facilities are discussed. An original cold NR Imaging demonstration used a simple filter of polycrystalline beryllium and single crystal bismuth cooled by liquid nitrogen. An expensive refrigerated moderator source block is not essential. A less expensive option omits use of the single crystal bismuth. A low cost boost to cold neutron flux at a low power reactor uses a refrigerated source block of solid methane. For NR Imaging at selective epithermal energies, a single crystal neutron monochromator provides a low cost option. Alternatively a pulsed neutron source and time of flight technique is included in the original reports on selective energy methods. The original demonstrations using low cost systems indicate new advanced selective energy techniques pioneered at high flux sources may be developed at lower flux, single-user sources.

  7. The relationship between cartilage loss on magnetic resonance imaging and radiographic progression in men and women with knee osteoarthritis.

    Science.gov (United States)

    Amin, Shreyasee; LaValley, Michael P; Guermazi, Ali; Grigoryan, Mikayel; Hunter, David J; Clancy, Margaret; Niu, Jingbo; Gale, Daniel R; Felson, David T

    2005-10-01

    To determine the relationship between radiographic progression of joint space narrowing and cartilage loss on magnetic resonance imaging (MRI) in patients with symptomatic knee osteoarthritis (OA), and to investigate the location of MRI-based cartilage loss in the knee and its relation to radiographic progression. Two hundred twenty-four men and women (mean age 66 years) were studied. Radiographs and MRI of the more symptomatic knee were obtained at baseline and at 15- and 30-month followup. Radiographs of the knee (with weight-bearing) were read for joint space narrowing (scale 0-3), with progression defined as any worsening in score. We used a semiquantitative method to score cartilage morphology in all 5 regions of the tibiofemoral joint, and defined cartilage loss as an increase in score (scale 0-4) at any region. We examined the relationship between progression of joint space narrowing on radiographic images and cartilage loss on MRI, using a generalized estimating equation proportional odds logistic regression, adjusted for baseline cartilage score, age, body mass index, and sex. The medial and lateral compartments were analyzed separately. In the medial compartment, 104 knees (46%) had cartilage loss detected by MRI. The adjusted odds ratio was 3.7 (95% confidence interval 2.2-6.3) for radiographic progression being predictive of cartilage loss on MRI. However, there was still a substantial proportion of knees (80 of 189 [42%]) with cartilage loss visible on MRI when no radiographic progression was apparent. Cartilage loss occurred frequently in the central regions of the femur and tibia as well as the posterior femur region, but radiographic progression was less likely to be observed when posterior femur regions showed cartilage loss. Radiographic progression appeared specific (91%) but not sensitive (23%) for cartilage loss. Overall findings were similar for the lateral compartment. While our results provide longitudinal evidence that radiographic

  8. Global quality imaging: emerging issues.

    Science.gov (United States)

    Lau, Lawrence S; Pérez, Maria R; Applegate, Kimberly E; Rehani, Madan M; Ringertz, Hans G; George, Robert

    2011-07-01

    Quality imaging may be described as "a timely access to and delivery of integrated and appropriate procedures, in a safe and responsive practice, and a prompt delivery of an accurately interpreted report by capable personnel in an efficient, effective, and sustainable manner." For this article, radiation safety is considered as one of the key quality elements. The stakeholders are the drivers of quality imaging. These include those that directly provide or use imaging procedures and others indirectly supporting the system. Imaging is indispensable in health care, and its use has greatly expanded worldwide. Globalization, consumer sophistication, communication and technological advances, corporatization, rationalization, service outsourcing, teleradiology, workflow modularization, and commoditization are reshaping practice. This article defines the emerging issues; an earlier article in the May 2011 issue described possible improvement actions. The issues that could threaten the quality use of imaging for all countries include workforce shortage; increased utilization, population radiation exposure, and cost; practice changes; and efficiency drive and budget constraints. In response to these issues, a range of quality improvement measures, strategies, and actions are used to maximize the benefits and minimize the risks. The 3 measures are procedure justification, optimization of image quality and radiation protection, and error prevention. The development and successful implementation of such improvement actions require leadership, collaboration, and the active participation of all stakeholders to achieve the best outcomes that we all advocate. Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  9. Development and Assessment of an E-Learning Course on Breast Imaging for Radiographers: A Stratified Randomized Controlled Trial

    Science.gov (United States)

    Ventura, Sandra Rua; Ramos, Isabel; Rodrigues, Pedro Pereira

    2015-01-01

    Background Mammography is considered the best imaging technique for breast cancer screening, and the radiographer plays an important role in its performance. Therefore, continuing education is critical to improving the performance of these professionals and thus providing better health care services. Objective Our goal was to develop an e-learning course on breast imaging for radiographers, assessing its efficacy, effectiveness, and user satisfaction. Methods A stratified randomized controlled trial was performed with radiographers and radiology students who already had mammography training, using pre- and post-knowledge tests, and satisfaction questionnaires. The primary outcome was the improvement in test results (percentage of correct answers), using intention-to-treat and per-protocol analysis. Results A total of 54 participants were assigned to the intervention (20 students plus 34 radiographers) with 53 controls (19+34). The intervention was completed by 40 participants (11+29), with 4 (2+2) discontinued interventions, and 10 (7+3) lost to follow-up. Differences in the primary outcome were found between intervention and control: 21 versus 4 percentage points (pp), Pe-learning course is effective, especially for radiographers, which highlights the need for continuing education. PMID:25560547

  10. The comparison of subjective image quality in conventional and digital panoramic radiography

    OpenAIRE

    Peker Ilkay; Toraman Alkurt; Usalan G; Altunkaynak B

    2009-01-01

    Objective: The purpose of this study was to compare the subjective image quality of (1) regular intensifying screens with medium intensifying screens, (2) regular intensifying screens with digital radiography, and (3) medium intensifying screens with digital radiography for panoramic radiographs. Materials and Methods: Forty-five patients participated and a total of 90 radiographs were obtained in the study. The patients were divided into three groups (regular-medium intensifying screen, r...

  11. Computed tomography versus magnetic resonance imaging versus bone scintigraphy for clinically suspected scaphoid fractures in patients with negative plain radiographs

    NARCIS (Netherlands)

    Mallee, Wouter H.; Wang, Junfeng; Poolman, Rudolf W.; Kloen, Peter; Maas, Mario; de Vet, Henrica C. W.; Doornberg, Job N.

    2015-01-01

    In clinically suspected scaphoid fractures, early diagnosis reduces the risk of non-union and minimises loss in productivity resulting from unnecessary cast immobilisation. Since initial radiographs do not exclude the possibility of a fracture, additional imaging is needed. Computed tomography (CT),

  12. The Influence of Different Technique Factors on Image Quality for Chest Radiographys: Application of the Recent CEC Image Quality Criteria

    Energy Technology Data Exchange (ETDEWEB)

    Lanhede, B.; Tingberg, A.; Maansson, L.G.; Kheddache, S.; Widell, M.; Bjoerneld, L.; Sund, P.; Almen, A.; Besjakov, J.; Mattsson, S.; Zankl, M.; Panzer, W.; Herrmann, C

    2000-07-01

    The aim of this work was to evaluate and possibly improve the CEC image criteria for radiographic chest images. Chest images of healthy volunteers were acquired using different technique factors. The image criteria were used as a tool to discriminate between the different images. The technique factors were chosen so that the image quality would differ slightly. Four different technique parameters, each with two possible settings used in clinical practice today, were used: tube voltage, 102 and 141 kV; screen-film speed, 160 and 320; maximum optical density in the parenchyma, 1.3 and 1.8; method for scatter reduction, air gap and moving grid. The results showed that the image criteria were able to distinguish different technique groups. Optical density 1.8 was better than 1.3 independent of the other parameters. No difference was seen for screen-film speed. No correlation was seen between the ranking of the systems and patient dose. (author)

  13. Rapidly destructive arthrosis of the shoulder joints: radiographic, magnetic resonance imaging, and histopathologic findings.

    Science.gov (United States)

    Kekatpure, Aashay L; Sun, Ji-Ho; Sim, Gyeong-Bo; Chun, Jae-Myeung; Jeon, In-Ho

    2015-06-01

    Rapidly destructive arthrosis of the humeral head is a rare condition with an elusive pathophysiologic mechanism. In this study, radiographic and histopathologic findings were analyzed to determine the clinical characteristics of this rare condition. We retrospectively analyzed 189 patients who underwent total shoulder arthroplasty from January 2001 to August 2012. Among them, 9 patients showed a particular pattern of rapid collapse of the humeral head on plain radiography and magnetic resonance imaging (MRI) within 12 months from symptom onset. Patients with trauma, rheumatoid arthritis, steroid intake, neurologic osteoarthropathy, osteonecrosis, renal osteoarthropathy, or gout were excluded. All patients were women, with a mean age of 72.0 years (range, 63-85 years). The right side was involved in 7 cases and the left in 2 cases. The mean duration of humeral head collapse was 5.6 months (range, 2-11 months) from the onset of shoulder pain. Plain radiographs of all patients showed a unique pattern of humeral head flattening, which appeared like a clean surgical cut with bone debris around the humeral head. MRI findings revealed significant joint effusion and bone marrow edema in the humeral head, without involvement of the glenoid. Pathologic findings showed both fragmentation and regeneration of bone matrix, representing fracture healing. The important features of rapidly destructive shoulder arthrosis are unique flattened humeral head collapse with MRI showing massive joint effusion and bone marrow edema in the remnant humeral head. This condition should be considered in the differential diagnosis of elderly women with insidious shoulder pain. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  14. Computer simulation of radiographic images sharpness in several system of image record; Processamento para simulacao da nitidez de imagens radiograficas para diversos sistemas de registro da imagem

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcia Aparecida; Schiable, Homero; Frere, Annie France; Marques, Paulo M.A. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Engenharia Eletrica; Oliveira, Henrique J.Q. de; Alves, Fatima F.R. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica; Medeiros, Regina B. [Universidade Federal de Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem

    1996-12-31

    A method to predict the influence of the record system on radiographic images sharpness by computer simulation is studied. The method intend to previously show the image to be obtained for each type of film or screen-film combination used during the exposure 8 refs., 2 figs.

  15. SNOM images of X-ray radiographs at nano-scale stored in a thin layer of lithium fluoride.

    Science.gov (United States)

    Oliva, C; Ustione, A; Almaviva, S; Baldacchini, G; Bonfigli, F; Flora, F; Lai, A; Montereali, R M; Faenov, A Ya; Pikuz, T A; Francucci, M; Gaudio, P; Martellucci, S; Richetta, M; Reale, L; Cricenti, A

    2008-03-01

    In this work, we report a method to observe soft X-ray radiographs at nanoscale of various kind of samples, biological and metallic, stored in a thin layer of lithium fluoride, employing scanning near-field optical microscopy with an optical resolution that reaches 50 nm. Lithium fluoride material works as a novel image detector for X-ray nano-radiographs, due to the fact that extreme ultraviolet radiation and soft X-rays efficiently produce stable point defects emitting optically stimulated visible luminescence in a thin surface layer. The bi-dimensional distribution of the so-created defects depends on the local nanostructure of the investigated sample.

  16. Characteristic radiographic or magnetic resonance images of fresh osteoporotic vertebral fractures predicting potential risk for nonunion: a prospective multicenter study.

    Science.gov (United States)

    Tsujio, Tadao; Nakamura, Hiroaki; Terai, Hidetomi; Hoshino, Masatoshi; Namikawa, Takashi; Matsumura, Akira; Kato, Minori; Suzuki, Akinobu; Takayama, Kazushi; Fukushima, Wakaba; Kondo, Kyoko; Hirota, Yoshio; Takaoka, Kunio

    2011-07-01

    Prospective multicenter study. To identify radiographic or magnetic resonance (MR) images of fresh vertebral fractures that can predict a high risk for delayed union or nonunion of osteoporotic vertebral fractures (OVFs). Vertebral body fractures are the most common fractures in osteoporosis patients. Conservative treatments are typically chosen for OVFs, and associated back pain generally subsides within several weeks with residual persistent deformity of the vertebral body. In some patients, OVF healing is impaired and correlated with prolonged back pain. However, assessments such as plain radiograph or MR images taken during the early phase to predict high risks for nonunions of OVFs and/or poor prognoses have not been identified. A total of 350 OVF patients from 25 institutes were enrolled in this clinical study. Plain radiograph and MR images of the OVFs were routinely taken at enrollment at the respective institutes. The findings on the plain radiograph and MR images were classified after enrollment in the study. All the patients were treated conservatively without any surgical intervention. After a 6-month follow-up, the patients were classified into two groups, a union group and a nonunion group, depending on the presence of an intravertebral cleft on plain radiograph or MR images. The associations of the images from the first visit with those of the corresponding nonunions at the 6-month follow-up were analyzed by multivariate logistic regression to elucidate specific image characteristics that may predict a high risk for nonunion of OVFs. Forty-eight patients (49 vertebrae) among the 350 patients (363 vertebrae) were classified as nonunions, indicating a nonunion incidence of 13.5% for conventional conservative treatments for OVFs. The statistical analyses revealed that a vertebral fracture in the thoracolumbar spine, presence of a middle-column injury, and a confined high intensity or a diffuse low intensity area in the fractured vertebrae on T2-weighted

  17. AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

    Science.gov (United States)

    Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

    2014-11-01

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  18. Use of effective detective quantum efficiency to optimise radiographic exposures for chest imaging with computed radiography

    Science.gov (United States)

    Ertan, Ferihan; Mackenzie, Alistair; Urbanczyk, Hannah J.; Ranger, Nicole T.; Samei, Ehsan

    2009-02-01

    The purpose of the work was to test if effective detective quantum efficiency (eDQE) could be useful for optimisation of radiographic factors for computed radiography (CR) for adult chest examinations. The eDQE was therefore measured across a range of kilovoltage, with and without an anti-scatter grid. The modulation transfer function, noise power spectra, transmission factor and scatter fraction were measured with a phantom made of sheets of Aluminum and Acrylic. The entrance air kerma was selected to give an effective dose of 4.9 μSv. The effective noise equivalent quanta (eNEQ) is introduced in this work. eNEQ can be considered equal to the number of X-ray quanta equivalent in the image corrected for the amount of scatter and the blurring processes. The eNEQ was then normalised to account for slight differences in the effective dose (eNEQED). The peak eNEQED was largest at 80 kV and 100 kV with no grid and with grid respectively. At each kilovoltage, the eNEQED and eDQE were between 10% and 70% larger when the grid was not used. The results show that 80 kV without grid is the most suitable exposure conditions for CR in chest. This is consistent with clinical practice in the UK and previous publications recommending a low kV technique for CR for average sized adult chest imaging.

  19. [Evaluation of direct digital radiography image quality in dentistry].

    Science.gov (United States)

    Wang, Feng-Qiong; Huang, Wen; Qin, Yan-Ling; Qin, Xiao-Dan; Jiang, Yi-Fang; Tu, Xiao-Ning; Chang, Xiao-Jie

    2008-10-01

    To evaluate the quality of direct digital radiograph according to its application in dentistry. 1195 patients with dental caries, periodontal diseases, periapical diseases, trauma of teeth or hypodontia were tested with Trophy elitys Radio Visio Graphy(RVG) and the quality of the tests was evaluated at four levels. It was convenient to operate RVG and easy to save the images, which reduced the amount of X-rays. 1587 pictures were taken, among which 92.3% was at level I, 6.3% was at level II,1.14% was at level III and level IV. The quality of the images at different positions is good, which can meet the requirement for clinical diagnosis. However, the radiography receptor should be improved for better images.

  20. An image processing technique for the radiographic assessment of vertebral derangements

    Energy Technology Data Exchange (ETDEWEB)

    Breen, A.C. (Anglo-European Coll. of Chiropractic, Bournemouth (UK)); Allen, R. (Southampton Univ. (UK). Dept. of Mechanical Engineering); Morris, A. (Odstock Hospital, Salisbury (UK). Dept. of Radiology)

    1989-01-01

    A technique for measuring inter-vertebral motion by the digitization and processing of intensifier images is described. The technique reduces the time and X-ray dosage currently required to make such assessments. The errors associated with computing kinematic indices at increments of coronal plane rotations in the lumbar spine have been calculated using a calibration model designed to produce a facsimile of in vivo conditions in terms of image quality and geometric distortion. (author).

  1. Quality assurance: using the exposure index and the deviation index to monitor radiation exposure for portable chest radiographs in neonates

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Mervyn D. [Indiana University School of Medicine, Department of Radiology, Riley Children' s Hospital, Indianapolis, IN (United States); Riley Hospital for Children, Department of Radiology, Indianapolis, IN (United States); Cooper, Matt L.; Piersall, Kelly [Indiana University School of Medicine, Department of Radiology, Riley Children' s Hospital, Indianapolis, IN (United States); Apgar, Bruce K. [Agfa HealthCare Corporation, Greenville, SC (United States)

    2011-05-15

    Many methods are used to track patient exposure during acquisition of plain film radiographs. A uniform international standard would aid this process. To evaluate and describe a new, simple quality-assurance method for monitoring patient exposure. This method uses the ''exposure index'' and the ''deviation index,'' recently developed by the International Electrotechnical Commission (IEC) and American Association of Physicists in Medicine (AAPM). The deviation index measures variation from an ideal target exposure index value. Our objective was to determine whether the exposure index and the deviation index can be used to monitor and control exposure drift over time. Our Agfa workstation automatically keeps a record of the exposure index for every patient. The exposure index and deviation index were calculated on 1,884 consecutive neonatal chest images. Exposure of a neonatal chest phantom was performed as a control. Acquisition of the exposure index and calculation of the deviation index was easily achieved. The weekly mean exposure index of the phantom and the patients was stable and showed <10% change during the study, indicating no exposure drift during the study period. The exposure index is an excellent tool to monitor the consistency of patient exposures. It does not indicate the exposure value used, but is an index to track compliance with a pre-determined target exposure. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Molon, Rafael Scaf; Morais Camillo, Juliana Aparecida Najarro Dearo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara [Araraquara Dental School, Universidade Estadual Paulista, Sao Paulo (Brazil); Sakakura, Celso Eduardo [Barretos Dental School, Barretos Educational Fundation, Sao Paulo (Brazil)

    2012-09-15

    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{sub 95%}:6.04-6.54) and 6.79 mm (IC{sub 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 6.64 mm(IC{sub 95%}:6.40-6.89) and 6.79 mm(IC{sub 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.

  3. Conventional versus virtual radiographs of the injured pelvis and acetabulum

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Julius A.; Rao, Allison J.; Pouliot, Michael A.; Bellino, Michael [Stanford University School of Medicine, Department of Orthopaedic Surgery, Stanford, CA (United States); Beaulieu, Christopher [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

    2015-09-15

    Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans. Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA). Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p = 0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p = 0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well. Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs. (orig.)

  4. Image quality metrics for the evaluation of print quality

    Science.gov (United States)

    Pedersen, Marius; Bonnier, Nicolas; Hardeberg, Jon Y.; Albregtsen, Fritz

    2011-01-01

    Image quality metrics have become more and more popular in the image processing community. However, so far, no one has been able to define an image quality metric well correlated with the percept for overall image quality. One of the causes is that image quality is multi-dimensional and complex. One approach to bridge the gap between perceived and calculated image quality is to reduce the complexity of image quality, by breaking the overall quality into a set of quality attributes. In our research we have presented a set of quality attributes built on existing attributes from the literature. The six proposed quality attributes are: sharpness, color, lightness, artifacts, contrast, and physical. This set keeps the dimensionality to a minimum. An experiment validated the quality attributes as suitable for image quality evaluation. The process of applying image quality metrics to printed images is not straightforward, because image quality metrics require a digital input. A framework has been developed for this process, which includes scanning the print to get a digital copy, image registration, and the application of image quality metrics. With quality attributes for the evaluation of image quality and a framework for applying image quality metrics, a selection of suitable image quality metrics for the different quality attributes has been carried out. Each of the quality attributes has been investigated, and an experimental analysis carried out to find the most suitable image quality metrics for the given quality attributes. For the sharpness attributes the Structural SIMilarity index (SSIM) by Wang et al. (2004) is the the most suitable, and for the other attributes further evaluation is required.

  5. Image quality control of mammography equipment -Mammography System MX-300- of the Teachers Hospital of UNSA and dose measurement in breasts with radiographic films; Control de calidad de imagen del equipo de mamografia -Mammography System MX-300- del Hospital de Docentes de la UNSA y medicion de dosis en mamas con peliculas radiograficas

    Energy Technology Data Exchange (ETDEWEB)

    Quispe F, L. K.; Vega R, J., E-mail: karinaqflores839@gmail.com [Universidad Nacional de San Agustin, Escuela Profesional de Fisica, Arequipa (Peru)

    2015-10-15

    This work is part of medical imaging for the evaluation of quality. Will have an accredited breast phantom Rmi-156 that allows evaluating the image quality of mammography equipment and through a series of techniques and processes that will submit to mammography films we obtain characteristic curves, which allows to evaluate different parameters that will serve for our study. Images were acquired with different k Vp and m As of the equipment, also with different thicknesses of the breast phantom. Also we want to use the lowest possible dose for obtaining our images. In this paper we develop a simple protocol that aims to unify the conditions under which are acquired the images for later evaluation. By obtaining these characteristic curves demonstrate that the Kodak film is the most suitable for our study because it requires lower dose for obtaining our images. (Author)

  6. The comparison of subjective image quality in conventional and digital panoramic radiography

    Directory of Open Access Journals (Sweden)

    Peker Ilkay

    2009-01-01

    Full Text Available Objective: The purpose of this study was to compare the subjective image quality of (1 regular intensifying screens with medium intensifying screens, (2 regular intensifying screens with digital radiography, and (3 medium intensifying screens with digital radiography for panoramic radiographs. Materials and Methods: Forty-five patients participated and a total of 90 radiographs were obtained in the study. The patients were divided into three groups (regular-medium intensifying screen, regular intensifying screen-digital radiography, and medium intensifying screen-digital radiography that consisted of 15 people each. All radiographs were assessed by three oral radiologists independently. The observers evaluated the images using a 3-point scale (1=well visible, 0=partly visible, -1=not or hardly visible for anatomical structures and pathological findings that are commonly found on panoramic radiographs. Subjective image quality of the groups and comparison of the observers were assessed by using non parametric Kruskal Wallis and Mann-Whitney U tests. Results: For all groups and observers, no statistically significant difference (p>0.05 was found for both anatomical structures and pathologies and between anatomical structures and pathologies according to the Mann Whitney U test. In comparison with observers, no statistically significant difference (p>0.05 was found for both anatomical structures and pathologies and between anatomical structures and pathologies for all groups according to the Kruskal Wallis test. Conclusion: The subjective image quality of medium and regular intensifying screens and conventional and digital panoramic radiographs were found statistically equal in this study.

  7. The comparison of subjective image quality in conventional and digital panoramic radiography.

    Science.gov (United States)

    Peker, Ilkay; Toraman, Alkurt M; Usalan, G; Altunkaynak, B

    2009-01-01

    The purpose of this study was to compare the subjective image quality of (1) regular intensifying screens with medium intensifying screens, (2) regular intensifying screens with digital radiography, and (3) medium intensifying screens with digital radiography for panoramic radiographs. Forty-five patients participated and a total of 90 radiographs were obtained in the study. The patients were divided into three groups (regular-medium intensifying screen, regular intensifying screen-digital radiography, and medium intensifying screen-digital radiography) that consisted of 15 people each. All radiographs were assessed by three oral radiologists independently. The observers evaluated the images using a 3-point scale (1=well visible, 0=partly visible, -1=not or hardly visible) for anatomical structures and pathological findings that are commonly found on panoramic radiographs. Subjective image quality of the groups and comparison of the observers were assessed by using non parametric Kruskal Wallis and Mann-Whitney U tests. For all groups and observers, no statistically significant difference (p>0.05) was found for both anatomical structures and pathologies and between anatomical structures and pathologies according to the Mann Whitney U test. In comparison with observers, no statistically significant difference (p>0.05) was found for both anatomical structures and pathologies and between anatomical structures and pathologies for all groups according to the Kruskal Wallis test. The subjective image quality of medium and regular intensifying screens and conventional and digital panoramic radiographs were found statistically equal in this study.

  8. Pediatric spinal cord injury without radiographic abnormality in the era of advanced imaging.

    Science.gov (United States)

    Farrell, Caitlin A; Hannon, Megan; Lee, Lois K

    2017-06-01

    The current review describes the current evidence on pediatric spinal cord injury without radiographic abnormality (SCIWORA) with attention to the definition, epidemiology, and clinical presentation of the condition, as well as common MRI findings, management strategies, and outcomes. Recent literature demonstrates that with more widespread MRI use, our understanding of SCIWORA has improved. The new literature, although still limited, provides a more granular conceptualization of patterns of injury as well as potential prognostic stratification of patients based on MRI findings. Through case studies and national database analyses, researchers have further defined the epidemiology and outcomes of SCIWORA. Although SCIWORA occurs infrequently, thus making robust research a challenge, maintaining a high suspicion in the appropriate clinical setting ought to prompt acquisition of advanced imaging. For patients with persisting neurologic symptoms after trauma, despite negative plain films and cervical spine computed tomography, MRI can be helpful diagnostically as well as prognostically. Once SCIWORA is diagnosed, patients are treated nonoperatively with hard collar immobilization and physical therapy.

  9. Global quality imaging: improvement actions.

    Science.gov (United States)

    Lau, Lawrence S; Pérez, Maria R; Applegate, Kimberly E; Rehani, Madan M; Ringertz, Hans G; George, Robert

    2011-05-01

    Workforce shortage, workload increase, workplace changes, and budget challenges are emerging issues around the world, which could place quality imaging at risk. It is important for imaging stakeholders to collaborate, ensure patient safety, improve the quality of care, and address these issues. There is no single panacea. A range of improvement measures, strategies, and actions are required. Examples of improvement actions supporting the 3 quality measures are described under 5 strategies: conducting research, promoting awareness, providing education and training, strengthening infrastructure, and implementing policies. The challenge is to develop long-term, cost-effective, system-based improvement actions that will bring better outcomes and underpin a sustainable future for quality imaging. In an imaging practice, these actions will result in selecting the right procedure (justification), using the right dose (optimization), and preventing errors along the patient journey. To realize this vision and implement these improvement actions, a range of expertise and adequate resources are required. Stakeholders should collaborate and work together. In today's globalized environment, collaboration is strength and provides synergy to achieve better outcomes and greater success. Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  10. Digital Chest Images For Bronchopulmonary Dysplasia In Children

    Science.gov (United States)

    Wang, Yen; Gross, George W.; D'Adamo, Arthur J.

    1989-05-01

    The clinical application of digital radiographic imaging has been the subject of several recent investigations (1-7). The digital radiographic image possesses certain advantages over the conventional analog radiographic image, such as wider dynamic range, potential for image manipulation, transfer, and storage, and radiation exposure reduction. However, the quality of image remains a valid concern to radiologists because they are accustomed to viewing conventional radiographs with a higher imaging quality.

  11. Restorative treatment thresholds for interproximal primary caries based on radiographic images: findings from the Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Gordan, Valeria V; Garvan, Cynthia W; Heft, Marc W

    2009-01-01

    This study sought to quantify the depths of proximal caries lesions that lead dentists in regular clinical practice to intervene restoratively, based on hypothetical scenarios that present radiographic images and patient background information, and to identify characteristics associated...... that they would restore a proximal enamel lesion, while 24% would do so once the lesion had reached into the outer third of the dentin. For a low caries risk patient, 39% of respondents reported that they would restore an enamel lesion, and 54% would do so once the lesion had reached into the outer third...... a lesion, based on a series of radiographic images depicting interproximal caries at increasing lesion depths in a mandibular premolar; in addition, the dentists were questioned regarding two caries risk scenarios: one involving a patient with low caries risk and another involving a patient at higher risk...

  12. Evaluation of the linear measurements by conventional radiographs and indirect digital images in the endodontic treatment

    National Research Council Canada - National Science Library

    Nicole Kawauchi; Izabel Regina Fischer Rubira Bullen; Luiz Eduardo Montenegro Chinellato

    2004-01-01

    INTRODUCTION: A successful endodontic therapy depends on the linear measurements obtained by means of radiographs taken during odontometry and also on the application of the established working length up to the final obturation. OBJECTIVE...

  13. A universal color image quality metric

    NARCIS (Netherlands)

    Toet, A.; Lucassen, M.P.

    2003-01-01

    We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated color space. The resulting color image quality index quantifies the distortion of a processed color image relative to its original version. We evaluated the new color image quality

  14. Quality metrics for sensor images

    Science.gov (United States)

    Ahumada, AL

    1993-01-01

    Methods are needed for evaluating the quality of augmented visual displays (AVID). Computational quality metrics will help summarize, interpolate, and extrapolate the results of human performance tests with displays. The FLM Vision group at NASA Ames has been developing computational models of visual processing and using them to develop computational metrics for similar problems. For example, display modeling systems use metrics for comparing proposed displays, halftoning optimizing methods use metrics to evaluate the difference between the halftone and the original, and image compression methods minimize the predicted visibility of compression artifacts. The visual discrimination models take as input two arbitrary images A and B and compute an estimate of the probability that a human observer will report that A is different from B. If A is an image that one desires to display and B is the actual displayed image, such an estimate can be regarded as an image quality metric reflecting how well B approximates A. There are additional complexities associated with the problem of evaluating the quality of radar and IR enhanced displays for AVID tasks. One important problem is the question of whether intruding obstacles are detectable in such displays. Although the discrimination model can handle detection situations by making B the original image A plus the intrusion, this detection model makes the inappropriate assumption that the observer knows where the intrusion will be. Effects of signal uncertainty need to be added to our models. A pilot needs to make decisions rapidly. The models need to predict not just the probability of a correct decision, but the probability of a correct decision by the time the decision needs to be made. That is, the models need to predict latency as well as accuracy. Luce and Green have generated models for auditory detection latencies. Similar models are needed for visual detection. Most image quality models are designed for static imagery

  15. Diagnostic yield of conventional radiographic and cone-beam computed tomographic images in patients with atypical odontalgia.

    Science.gov (United States)

    Pigg, M; List, T; Petersson, K; Lindh, C; Petersson, A

    2011-12-01

    To investigate whether the additional diagnostic yield of a cone-beam computed tomography (CBCT) examination over conventional radiographs in patients primarily suspected of having atypical odontalgia (AO) improves differentiation between AO and symptomatic apical periodontitis (SAP) in patients with severe chronic intraoral pain. In this clinical study, 25 patients (mean age 54 ± 11 years, range 34-72) participated; 20 were diagnosed with AO and 5 with SAP. All patients were recruited from the clinics of the Faculty of Odontology, Malmö University. AO inclusion criteria were chronic pain (>6 months) in a region where a tooth had been endodontically or surgically treated, with no pathological cause detectable in clinical or radiologic examinations. SAP inclusion criteria were recurrent pain from a tooth diagnosed with apical periodontitis in clinical and radiographic examinations. Assessments comprised a self-report questionnaire on pain characteristics, a comprehensive clinical examination and a radiographic examination including panoramic and intraoral radiographs and CBCT images. The main outcome measure was periapical bone destruction. Sixty per cent of patients with AO had no periapical bone destructions detectable with any radiographic method. Overall, CBCT rendered 17% more periapical bone destructions than conventional radiography. Average pain intensity in patients with AO was 5.6 (± 1.8) on a 0-10 numerical rating scale, and average pain duration was 4.3 (± 5.2) years. Cone-beam computed tomography improves identification of patients without periapical bone destruction, which may facilitate differentiation between AO and SAP. © 2011 International Endodontic Journal.

  16. Comparison of magnetic resonance imaging with standing cervical radiographs for evaluation of vertebral canal stenosis in equine cervical stenotic myelopathy.

    Science.gov (United States)

    Janes, J G; Garrett, K S; McQuerry, K J; Pease, A P; Williams, N M; Reed, S M; MacLeod, J N

    2014-11-01

    The sensitivity and specificity of lateral cervical radiographs to evaluate horses suspected of cervical stenotic myelopathy (CSM) are limited by the assessment being restricted to the sagittal plane. To determine whether magnetic resonance imaging (MRI) allows for a more accurate identification of stenosis than lateral cervical radiographs in horses with CSM. Case control study. Nineteen Thoroughbred horses with CSM (17 males, 2 females, age 6-50 months) were compared to 9 control Thoroughbreds (6 males, 3 females, age 9-67 months). Ante mortem, the subjects had neurological examinations and standing cervical radiographs with sagittal ratios calculated from C3 to C7. Intact cervical column MRI scans and histological examinations of the spinal cord were performed post mortem. Morphometric parameters were measured on the vertebral canal, spinal cord and intervertebral foramen. Radiographic cervical canal height measurements categorised by standard minimal sagittal diameter intravertebral and intervertebral ratios produced several false positive and false negative determinations of canal stenosis as defined by spinal cord histopathology. Post mortem MRI measurements of canal area and cord canal area ratio more accurately predicted sites of cord compression in CSM cases. No differences in spinal cord measurements were observed when comparing CSM to control horses, but each of the vertebral canal parameters achieved significance at multiple sites. Vertebral canal area and cord canal area ratio are better parameters to predict the location of cervical canal stenosis compared to only the sagittal plane of canal height. Additional visual planes and measurements obtained by MRI, specifically vertebral canal area and the cord canal area ratio, will provide a more accurate method to identify regions of canal stenosis than lateral cervical radiographs. The development of MRI or computed tomography equipment capable of evaluating the cervical column of mature horses may

  17. The effect of a technical quality assessment of hip-extended radiographs on interobserver agreement in the diagnosis of canine hip dysplasia.

    Science.gov (United States)

    Verhoeven, Geert E C; Fortrie, Ruth R; Duchateau, Luc; Saunders, Jimmy H; Van Ryssen, Bernadette; Van Bree, Henri; Coopman, Frank

    2010-01-01

    Experienced and inexperienced observers evaluated the assessability of 50 radiographs (25 dogs) and determined the hip status (dysplasia/nondysplasia and final scoring according Fédération Cynologique Internationale [FCI]-criteria) individually. A radiographic technical quality assessment was performed in a separate reading session. Interobserver agreement in determining dysplasia/nondysplasia and FCI-scoring did not significantly increase with the increasing quality of a radiograph, irrespective whether these observers are experienced or not. There was a significant agreement between the technical quality assessment and assessability (P dysplasia/nondysplasia and final scoring, remains low, even in the experienced group. Although increased radiographic quality narrows the range of scoring, the range remains unacceptably high.

  18. Comparison of clinical, radiographic, computed tomographic, and magnetic resonance imaging methods for early prediction of canine hip laxity and dysplasia.

    Science.gov (United States)

    Ginja, Mário M D; Ferreira, António J; Jesus, Sandra S; Melo-Pinto, Pedro; Bulas-Cruz, José; Orden, Maria A; San-Roman, Fidel; Llorens-Pena, Maria P; Gonzalo-Orden, José M

    2009-01-01

    The purpose of the study was to use two palpation methods (Bardens and Ortolani), a radiographic distraction view, three computed tomography (CT) measurements (dorsolateral subluxation score, the lateral center-edge angle, and acetabular ventroversion angle) and two magnetic resonance (MR) imaging hip studies (synovial fluid and acetabular depth indices) in the early monitoring of hip morphology and laxity in 7-9 week old puppies; and in a follow-up study to compare their accuracy in predicting later hip laxity and dysplasia. The MR imaging study was performed with the dog in dorsal recumbency and the CT study with the animal in a weight-bearing position. There was no association between clinical laxity with later hip laxity or dysplasia. The dorsolateral subluxation score and the lateral center-edge angle were characterized by a weak negative correlation with later radiographic passive hip laxity (-0.26 hip dysplasia was not significant. There was an association between early radiographic passive hip laxity and synovial fluid index with later passive hip laxity (0.41 hips (P hip laxity or dysplasia. The overlapping ranges of early passive hip laxity and synovial fluid index for hip dysplasia grades and the moderate correlations with the later passive hip laxity make the results of these variables unreliable for use in predicting hip laxity and dysplasia susceptibility.

  19. A reflection on the role of an emergency care Consultant Radiographer in achieving appropriate imaging conditions for nasogastric tube positioning

    Energy Technology Data Exchange (ETDEWEB)

    Jones, H.C. [Royal Liverpool University Hospital Trust, Prescot Street, Liverpool L7 8XP (United Kingdom)], E-mail: helen.jones@rlbuht.nhs.uk; Robinson, L. [University of Salford, Frederick Road, Salford M6 6UP (United Kingdom)

    2008-12-15

    The College of Radiographers state that the role of a Consultant Radiographer comprises four core functions [College of Radiographers. Developing a business case for consultant radiographers. London: College of Radiographers; 2003; Hardy M, Snaith B. How to achieve consultant practitioner status: a discussion paper. Radiography, in press. doi:10.1016/j.radi.2006.04.003 [accessed 16.08.07

  20. Radiographic evaluation of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Goud, Ajay [Division of Musculoskeletal Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: mskrads@gmail.com; Segal, Dmitri [Division of Musculoskeletal Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: dsegal1@partners.org; Hedayati, Pejman [Division of Musculoskeletal Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: phedayati@partners.org; Pan, John J. [Division of Musculoskeletal Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: jjpan@partners.org; Weissman, Barbara N. [Harvard Medical School, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: bweissman@partners.org

    2008-10-15

    Imaging evaluation of shoulder disorders should begin with radiographs. Several radiographic projections have been developed to best show areas affected by particular clinical disorders. This paper reviews the radiographic examinations that are used at our hospital for evaluating arthritis, impingement, trauma and instability. The techniques used to obtain each of these radiographs are briefly described to better understand the resulting images. An organized approach to assessment of these radiographs is delineated including evaluation of the ABCs (alignment, bone density, cartilage spaces and soft tissues). The expected radiographic findings in normal individuals and in patients with common abnormal conditions are reviewed.

  1. Are radiographs needed when MR imaging is performed for non-acute knee symptoms in patients younger than 45 years of age?

    Energy Technology Data Exchange (ETDEWEB)

    Braak, Bert P.M. ter; Vincken, Patrice W.J.; Erkel, Arian R. van; Bloem, Johan L. [Leiden University Medical Center, Department of Radiology, P.O. Box 9600, Leiden (Netherlands); Bloem, Rolf M. [Leiden University Medical Center, Department of Orthopaedic Surgery, Leiden (Netherlands); Napoleon, L.J.; Coene, M.N. [HAGA Hospital, Department of Orthopaedic Surgery, The Hague (Netherlands); Luijt, Peter A. van [Leiden University Medical Center, Department of Traumatology, Leiden (Netherlands); Lange, Sam de [Medical Center Haaglanden, Department of Orthopaedic Surgery, The Hague (Netherlands); Department of Orthopaedic Surgery, Delft (Netherlands)

    2007-12-15

    The objective was to determine the value of radiographs in young adults with non-acute knee symptoms who are scheduled for magnetic resonance imaging (MRI). Nine hundred and sixty-one consecutive patients aged between 16 and 45 years with knee symptoms of at least 4 weeks' duration were prospectively included in three participating hospitals. After applying exclusion criteria, 798 patients remained. Exclusion criteria were previous knee surgery (including arthroscopy) or MRI, history of rheumatoid arthritis, clinical diagnosis of retropatellar chondromalacia, contra-indication for MRI and recent trauma. We identified two groups: group A with no history of trauma (n = 332), and group B with an old (>4 weeks) history of trauma (n = 466). Patients had a standardized history taken, and underwent a physical exam, antero-posterior (AP) and lateral radiographs and MRI. We evaluated the radiographs and MRI for osseous lesions, articular surface lesions, fractures, osteoarthritis, loose bodies, bone marrow edema and incidental findings. Subsequently, patients with osseous abnormalities (Kellgren grade 1 and 2 excluded) on radiographs and a matched control group was evaluated again using MRI without radiographs. Median duration of symptoms was 20 weeks. In group A, radiographs showed 36 osseous abnormalities in 332 patients (10.8%). Only 13 of these, all Kellgren grade 1 osteoarthritis, were not confirmed on MRI. MRI showed 72 (21.7%) additional abnormalities not confirmed on radiographs. In group B, radiographs showed 40 osseous abnormalities (8.6%) in 466 patients. Only 15 of these, all Kellgren grade 1 osteoarthritis, were not confirmed on MRI. MRI showed 194 (41.6%) additional abnormalities not confirmed on radiographs. The second evaluation of MRI without radiographs in 34 patients was identical to the first MRI evaluation. Common lesions were significantly more often diagnosed with MRI than with radiographs. Radiographs should not be obtained routinely when MRI is

  2. 3D volume reconstruction from serial breast specimen radiographs for mapping between histology and 3D whole specimen imaging.

    Science.gov (United States)

    Mertzanidou, Thomy; Hipwell, John H; Reis, Sara; Hawkes, David J; Ehteshami Bejnordi, Babak; Dalmis, Mehmet; Vreemann, Suzan; Platel, Bram; van der Laak, Jeroen; Karssemeijer, Nico; Hermsen, Meyke; Bult, Peter; Mann, Ritse

    2017-03-01

    In breast imaging, radiological in vivo images, such as x-ray mammography and magnetic resonance imaging (MRI), are used for tumor detection, diagnosis, and size determination. After excision, the specimen is typically sliced into slabs and a small subset is sampled. Histopathological imaging of the stained samples is used as the gold standard for characterization of the tumor microenvironment. A 3D volume reconstruction of the whole specimen from the 2D slabs could facilitate bridging the gap between histology and in vivo radiological imaging. This task is challenging, however, due to the large deformation that the breast tissue undergoes after surgery and the significant undersampling of the specimen obtained in histology. In this work, we present a method to reconstruct a coherent 3D volume from 2D digital radiographs of the specimen slabs. To reconstruct a 3D breast specimen volume, we propose the use of multiple target neighboring slices, when deforming each 2D slab radiograph in the volume, rather than performing pairwise registrations. The algorithm combines neighborhood slice information with free-form deformations, which enables a flexible, nonlinear deformation to be computed subject to the constraint that a coherent 3D volume is obtained. The neighborhood information provides adequate constraints, without the need for any additional regularization terms. The volume reconstruction algorithm is validated on clinical mastectomy samples using a quantitative assessment of the volume reconstruction smoothness and a comparison with a whole specimen 3D image acquired for validation before slicing. Additionally, a target registration error of 5 mm (comparable to the specimen slab thickness of 4 mm) was obtained for five cases. The error was computed using manual annotations from four observers as gold standard, with interobserver variability of 3.4 mm. Finally, we illustrate how the reconstructed volumes can be used to map histology images to a 3D specimen

  3. Optimization of Synthetic Aperture Image Quality

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Jensen, Jonas; Villagómez Hoyos, Carlos Armando

    2016-01-01

    resolution (CTR). The results of the study showed that SA imaging with only 32 emissions and maximum sweep angle of 22 degrees yields a very good image quality compared with using 256 emissions and the full aperture size. Therefore the number of emissions and the maximum sweep angle in the SA can......Synthetic Aperture (SA) imaging produces high-quality images and velocity estimates of both slow and fast flow at high frame rates. However, grating lobe artifacts can appear both in transmission and reception. These affect the image quality and the frame rate. Therefore optimization of parameters...... effecting the image quality of SA is of great importance, and this paper proposes an advanced procedure for optimizing the parameters essential for acquiring an optimal image quality, while generating high resolution SA images. Optimization of the image quality is mainly performed based on measures...

  4. Simple radiographic assessment of bone quality is associated with loss of surgical fixation in patients with proximal humeral fractures.

    Science.gov (United States)

    Newton, Ashley W; Selvaratnam, Veenesh; Pydah, Satya K; Nixon, Matthew F

    2016-04-01

    This study aimed to determine if the ratio of cortical thickness to shaft diameter of the humerus, as measured on a simple anterior-posterior shoulder radiograph, is associated with surgical fixation failure. 64 consecutive fractures in 63 patients (mean age 66.1 years, range 35-90) operated with surgical fixation between March 2011 and July 2014 using PERI-LOC locking plate and screws (Smith and Nephew, UK) were identified. Predictors of bone quality were measured from preoperative radiographs, including ratio of the medial cortex to shaft diameter (medial cortical ratio, MCR). Loss of fixation (displacement, screw cut out, or change in neck-shaft angle >4 degrees) was determined on follow-up radiographs. Loss of fixation occurred in 14 patients (21.9%) during the follow up. Patients were older in the failure group 72.8 vs. 64.2 years (p=0.007). The MCR was significantly lower in patients with failed fixation 0.170 vs 0.202, p=0.019. Loss of fixation is three times more likely in patients with a MCR fracture parts led to increased failure rate (p=0.0005). Medial cortex ratio is significantly associated with loss of surgical fixation and may prove to be a useful adjunct for clinical decision making in patients with proximal humeral fractures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Radiographic image analysis of Anacardium othonianum Rizz (anacardiaceae achenes subjected to desiccation

    Directory of Open Access Journals (Sweden)

    Lílian Abadia da Silva

    2017-04-01

    Full Text Available Studies evaluating the internal morphology and seed quality of native species are essential for successful conservation programs. Our aim was to verify the efficiency of X-ray imagery in evaluating cashew-tree-of-the-cerrado (Anacardium othonianum Rizz. achene viability after desiccation. The achenes were collected at 12% water content (w.b. and dried in silica gel until they reached 10, 8, 6, and 4% (w.b.. The fruit morphology and the quality of the seeds were evaluated by X-ray test together with vigor, electrical conductivity and emergence tests. Achenes with different water contents were exposed to an X-ray machine at 18 kV for 11 s and were thereafter submitted to emergence tests. The images were analyzed, and the achenes were classified based on internal morphology as completely full, malformed, or empty. These results were compared to those from the emergence tests. The statistical design was a complete randomized factorial (5 x 3. Desiccation to 4% (w.b. did not damage or modify the internal structures. X-ray was efficient in evaluating the internal morphology and detecting achene quality, making it possible to remove empty and abnormal fruit and form vigorous seed lots, reducing the cost of storage and bedding plant production for this native species.

  6. Effect of scatter on image quality in synchrotron radiation mammography

    Science.gov (United States)

    Moeckli, Raphael; Verdun, Francis R.; Fiedler, Stefan; Pachoud, Marc; Schnyder, Pierre; Valley, Jean-Francois

    2001-06-01

    The display of low-contrast structures and fine microcalcifications is essential for the early diagnosis of breast cancer. In order to achieve a high image quality level with a minimum amount of radiation delivered to the patient, the use of different spectra (Mo or Rh anode and filters) was introduced. The European Synchrotron Radiation Facility is able to produce a monochromatic beam with a high photon flux. It is thus a powerful tool to study the effect of beam energy on image quality and dose in mammography. Our image quality assessment is based on the calculation of the size of the smallest microcalcification detectable on a radiograph, derived from the statistical decision theory. The mean glandular dose is simultaneously measured. Compared with conventional mammography units, the monochromaticity of synchrotron beams improves contrast and the use of a slit instead of an anti-scatter grid leads to a higher primary beam transmission. The relative contribution of these two effects on image quality and dose is discussed.

  7. Arcuate sign of posterolateral knee injuries: anatomic, radiographic, and MR imaging data related to patterns of injury

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Josephine; Trudell, Debra; Resnick, Donald L. [Department of Radiology, Veterans Affairs Medical Center, University of California, San Diego, CA (United States); Papakonstantinou, Olympia [Department of Radiology, Veterans Affairs Medical Center, University of California, San Diego, CA (United States); Department of Radiology/MRI Unit, University Hospital of Heraklion (Greece); Brookenthal, Keith R. [Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA (United States)

    2003-11-01

    The ''arcuate sign'' is considered a pathognomonic sign for injuries of the posterolateral (PL) corner of the knee. The purpose of our study was to identify different patterns of injury to the fibular head that may associate with injuries to specific ligaments and tendons of the PL corner of the knee. The anatomic relations between the insertions of fibular collateral ligament (FCL), biceps femoris tendon (BFT), popliteofibular ligament (PFL), and arcuate ligament in normal cadaveric knees were also investigated. Magnetic resonance imaging was performed in two cadaveric knees which subsequently were dissected. Radiopaque markers were placed upon the fibular insertions of the FCL, BFT, PFL, and arcuate ligament in the dissected knees, and knee radiographs were then obtained. Twelve patients with radiographic or MR imaging evidence of isolated injury to the PL corner of the knee were retrospectively reviewed, with regard to avulsion fractures and marrow edema in the fibular head and the integrity of the ligaments of the PL corner of the knee. The PFL and arcuate ligament were seen to attach directly to the posterior and medial aspect of the styloid process of the fibular head. The FCL and BFT attached as a conjoined structure on the lateral aspect of the fibular head lateral, anterior and inferior to the attachment site of the PFL and arcuate ligament. Injury to the arcuate ligament or PFL was diagnosed in 8 patients who presented with a small avulsion fracture of the styloid process of the fibula (n=2), bone marrow edema in the medial aspect of the fibular head (n=3), or both (n=3). In 4 patients with injury to the conjoined tendon or FCL, a larger avulsion fragment and more diffuse proximal fibular edema were seen. Radiographic and MR imaging findings in injuries of the posterolateral corner of the knee may suggest injury to specific structures inserting in the fibular head. (orig.)

  8. Assessment of image quality in orthopaedic radiography with digital detectors: a visual grading analysis

    Science.gov (United States)

    Decoster, Robin; Mol, Harrie; van den Broeck, Renaat; Smits, Dirk

    2013-03-01

    Background: The introduction of digital detectors in the radiology predicted a dose reduction. Due to the dynamic range, radiographs of sufficient quality can be produced with a lower detector air kerma (DAK). However, this reduction was not observed. Some authors indicate a creep towards higher DAK, explained by a better appreciation of the radiographs due to a higher contrast-to-noise ratio. Methodology: To investigate the relation between the DAK and the appreciation of image quality by radiologists, 172 anterior-posterior (AP) radiographs of the knee and 152 radiographs of the pelvis were collected in 19 radiology centres. A Visual Grading Analysis (VGA) with a five-point scale was used to judge the image quality of seven different anatomic structures. The mid-point of the scale (3) was equalized to diagnostic image quality. Six experienced radiologists scored both datasets, in a controlled environment, with ViewDex®. Every observer received instructions and a training dataset. Moreover, twenty radiographs were repeated to determine intra-observer variability. Results: The intra-observer variability was not significant (p>0.05) for both datasets. The knee AP obtained a VGAS score of 3.91, the pelvis AP obtained a VGAS score of 3.71. In both cases, the inter-observer correlation was high and significant. The correlation between the VGAS and the DAK (0.41μGy - 6.18μGy) was not significant in either of the cases; neither did other analysises based on technical parameters. Conclusion: The VGA revealed an image quality higher than diagnostic necessary. Based on the DAK, an overexposure is suspected. The relation between DAK and the appreciation has to be further investigated in detail.

  9. Internet-accessible radiographic database of Vietnam War casualties for medical student education.

    Science.gov (United States)

    Critchley, Eric P; Smirniotopoulos, James G

    2003-04-01

    The purpose of this study was to determine the feasibility of archiving radiographic images from Vietnam era conflict casualties into a personal computer-based electronic database of text and images and displaying the data using an Internet-accessible database for preservation and educational purposes. Thirty-two patient cases were selected at random from a pool of 1,000 autopsy reports in which radiographs were available. A total of 74 radiographs from these cases were digitized using a commercial image scanner and then uploaded into an Internet accessible database. The quality of the digitized images was assessed by administering an image-based test to a group of 12 medical students. No statistically significant (p > 0.05) differences were found between test scores when using the original radiographs versus using the digitized radiographs on the Internet-accessible database. An Internet-accessible database is capable of effectively archiving Vietnam era casualty radiographs for educational purposes.

  10. Development of the long bones in the hands and feet of children: radiographic and MR imaging correlation

    Energy Technology Data Exchange (ETDEWEB)

    Laor, Tal [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Clarke, Jeffrey P. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Children' s Healthcare of Atlanta, Department of Radiology, Atlanta, GA (United States); Yin, Hong [Children' s Healthcare of Atlanta, Department of Pathology, Atlanta, GA (United States)

    2016-04-15

    The long bones of the hands and feet in children have an epiphyseal end with a secondary center of ossification and an adjacent transverse physis. In contrast to other long bones in the body, the opposite end in the hands and feet, termed the non-epiphyseal end, is characterized by direct metaphyseal extension of bone to complete terminal ossification. The purpose of this pictorial essay is to illustrate the developmental stages of each end of the long bones of the hands and feet with radiographic and MR imaging to provide a foundation from which to differentiate normal from abnormal growth. (orig.)

  11. Application of radiographic images in diagnosis and treatment of deep neck infections with necrotizing fasciitis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Joo; Kim, Ju Dong; Ryu, Hye In; Cho, Yeon Hee; Kong, Jun Ha; Ohe, Joo Young; Kwon, Yong Dae; Choi, Byung Joon; Kim, Gyu Tae [School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    2011-12-15

    The advent and wide use of antibiotics have decreased the incidence of deep neck infection. When a deep neck infection does occur, however, it can be the cause of significant morbidity and death, resulting in airway obstruction, mediastinitis, pericarditis, epidural abscesses, and major vessel erosion. In our clinic, a patient with diffuse chronic osteomyelitis of mandible and fascial space abscess and necrotic fasciitis due to odontogenic infection at the time of first visit came. We successfully treated the patient by early diagnosis using contrast-enhanced CT and follow up dressing through the appropriate use of radiographic images.

  12. Referenceless image quality evaluation for whole slide imaging

    Directory of Open Access Journals (Sweden)

    Noriaki Hashimoto

    2012-01-01

    Full Text Available Objective: The image quality in whole slide imaging (WSI is one of the most important issues for the practical use of WSI scanners. In this paper, we proposed an image quality evaluation method for scanned slide images in which no reference image is required. Methods: While most of the conventional methods for no-reference evaluation only deal with one image degradation at a time, the proposed method is capable of assessing both blur and noise by using an evaluation index which is calculated using the sharpness and noise information of the images in a given training data set by linear regression analysis. The linear regression coefficients can be determined in two ways depending on the purpose of the evaluation. For objective quality evaluation, the coefficients are determined using a reference image with mean square error as the objective value in the analysis. On the other hand, for subjective quality evaluation, the subjective scores given by human observers are used as the objective values in the analysis. The predictive linear regression models for the objective and subjective image quality evaluations, which were constructed using training images, were then used on test data wherein the calculated objective values are construed as the evaluation indices. Results: The results of our experiments confirmed the effectiveness of the proposed image quality evaluation method in both objective and subjective image quality measurements. Finally, we demonstrated the application of the proposed evaluation method to the WSI image quality assessment and automatic rescanning in the WSI scanner.

  13. T1-weighted MR images in radiographic stage of fragmentation of Legg-Calve-Perthes disease

    Energy Technology Data Exchange (ETDEWEB)

    Kumasaka, Yukiko; Watanabe, Hitoshi; Kishimoto, Harumasa; Higashihara, Tokuro (Kansai Rosai Hospital, Amagasaki, Hyogo (Japan)); Harada, Koshi; Kozuka, Takahiro

    1991-04-01

    Seven femoral heads of Legg-Calve-Perthes disease (LCPD) in radiographic stage of fragmentation were examined in 6 boys by MRI. Characteristic appearances of capital epiphysis and the surrounding cartilaginous structures can be seen. These were proved by four indices for measurement of cartilaginous contour. Cartilaginous contour of epiphysis is enlarged with crescent like deformity resulting from deformity of growth plate. Characteristic layers or honeycomb pattern of extremely low and intermediate signal intensity can be seen. (author).

  14. Heterogeneous Disease Trajectories Explain Variable Radiographic, Function and Quality of Life Outcomes in the Canadian Early Arthritis Cohort (CATCH.

    Directory of Open Access Journals (Sweden)

    Cheryl Barnabe

    Full Text Available Our objective was to identify distinct trajectories of disease activity state (DAS and assess variation in radiographic progression, function and quality of life over the first two years of early rheumatoid arthritis (ERA. The CATCH (Canadian early ArThritis CoHort is a prospective study recruiting ERA patients from academic and community rheumatology clinics in Canada. Sequential DAS28 scores were used to identify five mutually exclusive groups in the cohort (n = 1,586 using growth-based trajectory modeling. Distinguishing baseline sociodemographic and disease variables, treatment required, and differences in radiographic progression and quality of life measures over two years were assessed. The trajectory groups are characterized as: Group 1 (20% initial high DAS improving rapidly to remission (REM; Group 2 (21% initial moderate DAS improving rapidly to REM; Group 3 (30% initial moderate DAS improving gradually to low DAS; Group 4 (19% initial high DAS improving continuously to low DAS; and Group 5 (10% initial high DAS improving gradually only to moderate DAS. Groups differed significantly in age, sex, race, education, employment, income and presence of comorbidities. Group 5 had persistent steroid requirements and the highest biologic therapy use. Group 2 had lower odds (OR 0.22, 95%CI 0.09 to 0.58 and Group 4 higher odds (OR 1.94, 95%CI 0.90 to 4.20 of radiographic progression compared to Group 1. Group 1 had the best improvement in physical function (Health Assessment Questionnaire 1.08 (SD 0.68 units, Physical Component Score (16.4 (SD 10.2 units, Mental Component Score (9.7 (SD 12.5 units and fatigue (4.1 (SD 3.3 units. In conclusion, distinct disease activity state trajectories explain variable outcomes in ERA. Early prediction of disease course to tailor therapy and addressing social determinants of health could optimize outcomes.

  15. Image quality in partially erased DenOptix® storage phosphor plates

    Directory of Open Access Journals (Sweden)

    Sérgio Lúcio Pereira de Castro Lopes

    2008-03-01

    Full Text Available This study aimed at investigating the effect of the partial erasing of DenOptix® system storage phosphor plates on the image quality of digital radiographs. Standardized digital radiographs were acquired of a phantom mandible, using size 2 intraoral DenOptix® storage phosphor plates (n = 10. Subsequently, the active areas of the plates were placed in a viewing box with a constant light intensity of 1,700 lux for 130 seconds to achieve complete erasing (control plate, as well as for 0, 5, 10, 15, 20, 25, 34, 66, and 98 seconds, to compose the experimental group of partially erased plates. The same exposure settings were repeated using the control and experimental plates, which were scanned at a resolution of 300 dpi. Five radiologists independently examined the pairs of digital radiographs obtained with the control and partially erased plates, in random order, and indicated the best image for oral diagnosis. Cochran-Mantel-Haenszel’s chi-square test, at a significance level of 5%, was used to compare the percentages of superior quality images in each combination of control and partially erased plates, subjectively assessed. No significant differences were found between radiographic images acquired with control and partially erased plates, except for the combination of 0 second (30% versus 130 seconds (70%, p = 0.0047. It can be concluded that, under adequate light intensity conditions, erasing intraoral DenOptix® storage phosphor plates may require time intervals of as little as 5 seconds.

  16. Technical errors in intraoral radiographs performed by undergraduate students

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Laureano da Rosa

    Full Text Available Objectives: To evaluate the technical errors in periapical examinations performed by dental students. Methods: Patient record charts at the dental clinic of the dentistry course were analyzed. Of these, the charts that presented at least ten periapical intraoral radiographs were used in the study, therefore a total of 219 patient record charts were selected, totaling 2 821 radiographs. The radiographs were analyzed one by one, using an uniform light negatoscope, in a darkened room, by a professional radiologist, taking into consideration the following evaluation criteria: technically good and unsatisfactory radiographs. The technical errorswere classified as errors in radiographic technique and radiographic processing errors. The data on quality critera stipulated and obtainedin the evaluation were tabulated, intervals of confidence were used to infer the percentage that were suitable and unsuitable in the studied period, and were statistically analyzed using the chi-square test, at the level of significance of 5%. Results: The results were: of the 2 821 radiographs analyzed, only 1 425 (50.51% were technically good. of the 1 396 (49.49% considered inadequat, 1 155 (82.74% presented errors in radiographic technique, while 241 (17.26% presented radiographic processing errors. The most frequently repeated error was image overlapping (32.88%, followed by the underexposure (25.43%, cut of the tooth (9.31%, chemicalcontamination problems (4.51%, cone cut (3.15%, other errors in radiographic technique (1.86% and other radiographic processing errors (1.43%. Conclusion: The conclusion was that steps must be taken to improve the quality of radiographs obtained because, although they did not make it impossible to interpret the radiographs, this was made extremely difficult, and the depreciated the value of the achives of past clinical situations and cases.

  17. A review of computer aided interpretation technology for the evaluation of radiographs of aluminum welds

    Science.gov (United States)

    Lloyd, J. F., Sr.

    1987-01-01

    Industrial radiography is a well established, reliable means of providing nondestructive structural integrity information. The majority of industrial radiographs are interpreted by trained human eyes using transmitted light and various visual aids. Hundreds of miles of radiographic information are evaluated, documented and archived annually. In many instances, there are serious considerations in terms of interpreter fatigue, subjectivity and limited archival space. Quite often it is difficult to quickly retrieve radiographic information for further analysis or investigation. Methods of improving the quality and efficiency of the radiographic process are being explored, developed and incorporated whenever feasible. High resolution cameras, digital image processing, and mass digital data storage offer interesting possibilities for improving the industrial radiographic process. A review is presented of computer aided radiographic interpretation technology in terms of how it could be used to enhance the radiographic interpretation process in evaluating radiographs of aluminum welds.

  18. Digital radiography: optimization of image quality and dose using multi-frequency software.

    Science.gov (United States)

    Precht, H; Gerke, O; Rosendahl, K; Tingberg, A; Waaler, D

    2012-09-01

    New developments in processing of digital radiographs (DR), including multi-frequency processing (MFP), allow optimization of image quality and radiation dose. This is particularly promising in children as they are believed to be more sensitive to ionizing radiation than adults. To examine whether the use of MFP software reduces the radiation dose without compromising quality at DR of the femur in 5-year-old-equivalent anthropomorphic and technical phantoms. A total of 110 images of an anthropomorphic phantom were imaged on a DR system (Canon DR with CXDI-50 C detector and MLT[S] software) and analyzed by three pediatric radiologists using Visual Grading Analysis. In addition, 3,500 images taken of a technical contrast-detail phantom (CDRAD 2.0) provide an objective image-quality assessment. Optimal image-quality was maintained at a dose reduction of 61% with MLT(S) optimized images. Even for images of diagnostic quality, MLT(S) provided a dose reduction of 88% as compared to the reference image. Software impact on image quality was found significant for dose (mAs), dynamic range dark region and frequency band. By optimizing image processing parameters, a significant dose reduction is possible without significant loss of image quality.

  19. Reproducibility of sagittal radiographic parameters in adolescent idiopathic scoliosis-a guide to reference values using serial imaging.

    Science.gov (United States)

    Hey, Hwee Weng Dennis; Wong, Gordon Chengyuan; Chan, Chloe Xiaoyun; Lau, Leok-Lim; Kumar, Naresh; Thambiah, Joseph Shantakumar; Ruiz, John Nathaniel; Liu, Ka-Po Gabriel; Wong, Hee-Kit

    2017-06-01

    Knowledge of sagittal radiographic parameters in adolescent idiopathic scoliosis (AIS) patients has not yet caught up with our understanding of their roles in patients with adult spinal deformity. It is likely that more emphasis will be placed in restoring sagittal parameters for AIS patients in the future. Therefore, we need to understand how these parameters may vary in AIS to facilitate management plans. This study aimed to determine the reproducibility of sagittal spinal parameters on lateral film radiographs in patients with AIS. This was a retrospective, comparative study conducted in a tertiary health-care institution from January 2013 to February 2016 (3-year period). All AIS patients who underwent deformity correction surgery from January 2013 to February 2016 and had two preoperative serial lateral radiographs taken within the time period of a month were included in the study. Radiographic sagittal spinal parameters including sagittal vertical axis (SVA), cervical lordosis (CL), thoracic kyphosis (TK), thoracolumbar alignment (TL), lumbar lordosis (LL); standard spinopelvic measurements such as pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS); as well as end and apical vertebrae of cervical, thoracic, and lumbar curves were the outcome measures. All patient data were pooled from electronic medical records, and X-ray images were retrieved from Centricity Enterprise Web. Averaged X-ray measurements by two independent assessors were analyzed by comparing two radiographs of the same patients performed within a 1-month time period. Chi-squared and Wilcoxon signed-rank tests were used for categorical and continuous variables. The study cohort comprised 138 patients, 28 men and 110 women, with a mean age of 15 years (range 11-20). Between the two lateral X-rays, there was a mean difference of 0.79 cm in SVA (p<.001), 0.70° in LL (p=.033), and 0.73° in PT (p=.010). In the combined Lenke 1 and 2 subgroup, there was a similar 0.77 cm (p=.002), 0.79

  20. Limited magnetic resonance imaging in low back pain instead of plain radiographs: Experience with first 1000 cases

    Energy Technology Data Exchange (ETDEWEB)

    McNally, Eugene G.; Wilson, David J.; Ostlere, Simon J

    2001-11-01

    AIM: We report our experience with the first 1000 patients with non-traumatic low back pain (LBP) without radiculopathy undergoing limited sequence magnetic resonance imaging (MRI) instead of plain radiography. METHODS: Between January 1996 and December 1998, 1042 patients with low back pain unresponsive to conservative treatment were examined using a limited MR protocol comprising sagittal T1-weighted and STIR imaging. Plain radiographs were not performed. RESULTS: Malignancy, infection, vertebral fracture, spondylitis, pars defects and cord tumours were detected in 20%. Of the 82 osteoporotic vertebral fractures detected, 51 (62%) were recent and 31 had normal marrow signal indicating that they were old. Eighty pars defects were identified, 45(56%) had spondylolisthesis, 29(37%) were undisplaced and 6 (7%) had pars oedema only. Neoplastic disease was found in 17(8%) of which none was suspected before imaging. Benign neoplastic diseases such as vertebral AVM/haemangiomata were excluded. Twenty-one patients had a variety of disorders including ankylosing spondylitis (7), large vessel aneurysm (3), discitis (2), ovarian cyst (2), sequestered disc (2), sacral insufficiency fracture (2) and one patient each with burst fracture, retroperitoneal haematoma and a previously unsuspected horseshoe kidney. CONCLUSION: The majority of patients with LBP are best assessed clinically and imaging is usually not required. In patients with worrying symptoms, MRI with a limited protocol detects a greater number of abnormalities than previously reported studies using plain radiographs and has replaced plain radiography in our hospital. We report our experience with the first 1000 patients and highlight issues such as protocols, detection rates and communication issues. McNally E.G. et al. (2001)

  1. A parameterized logarithmic image processing method with Laplacian of Gaussian filtering for lung nodule enhancement in chest radiographs.

    Science.gov (United States)

    Chen, Sheng; Yao, Liping; Chen, Bao

    2016-11-01

    The enhancement of lung nodules in chest radiographs (CXRs) plays an important role in the manual as well as computer-aided detection (CADe) lung cancer. In this paper, we proposed a parameterized logarithmic image processing (PLIP) method combined with the Laplacian of a Gaussian (LoG) filter to enhance lung nodules in CXRs. We first applied several LoG filters with varying parameters to an original CXR to enhance the nodule-like structures as well as the edges in the image. We then applied the PLIP model, which can enhance lung nodule images with high contrast and was beneficial in extracting effective features for nodule detection in the CADe scheme. Our method combined the advantages of both the PLIP algorithm and the LoG algorithm, which can enhance lung nodules in chest radiographs with high contrast. To test our nodule enhancement method, we tested a CADe scheme, with a relatively high performance in nodule detection, using a publically available database containing 140 nodules in 140 CXRs enhanced through our nodule enhancement method. The CADe scheme attained a sensitivity of 81 and 70 % with an average of 5.0 frame rate (FP) and 2.0 FP, respectively, in a leave-one-out cross-validation test. By contrast, the CADe scheme based on the original image recorded a sensitivity of 77 and 63 % at 5.0 FP and 2.0 FP, respectively. We introduced the measurement of enhancement by entropy evaluation to objectively assess our method. Experimental results show that the proposed method obtains an effective enhancement of lung nodules in CXRs for both radiologists and CADe schemes.

  2. ORIGINAL ARTICLE Image quality dependence on image ...

    African Journals Online (AJOL)

    The software package developed by Agfa and used in Agfa CR readers is called MUSICA; an upgrade was recently released: MUSICA2.3,4. The acronym stands for Multi Scale Image Contrast Amplification, and the algorithm is essentially a multi-scale transform of the image data into a stack of detail layers. This is done in ...

  3. Image quality assessment using deep convolutional networks

    Science.gov (United States)

    Li, Yezhou; Ye, Xiang; Li, Yong

    2017-12-01

    This paper proposes a method of accurately assessing image quality without a reference image by using a deep convolutional neural network. Existing training based methods usually utilize a compact set of linear filters for learning features of images captured by different sensors to assess their quality. These methods may not be able to learn the semantic features that are intimately related with the features used in human subject assessment. Observing this drawback, this work proposes training a deep convolutional neural network (CNN) with labelled images for image quality assessment. The ReLU in the CNN allows non-linear transformations for extracting high-level image features, providing a more reliable assessment of image quality than linear filters. To enable the neural network to take images of any arbitrary size as input, the spatial pyramid pooling (SPP) is introduced connecting the top convolutional layer and the fully-connected layer. In addition, the SPP makes the CNN robust to object deformations to a certain extent. The proposed method taking an image as input carries out an end-to-end learning process, and outputs the quality of the image. It is tested on public datasets. Experimental results show that it outperforms existing methods by a large margin and can accurately assess the image quality on images taken by different sensors of varying sizes.

  4. Impact of bone suppression imaging on the detection of lung nodules in chest radiographs: analysis of multiple reading sessions

    Science.gov (United States)

    Schalekamp, S.; van Ginneken, B.; Schaefer-Prokop, C. M.; Karssemeijer, N.

    2013-03-01

    Observer studies are frequently performed to test new modalities. Correct study design is important to generate reliable results. Two most frequently used observer study designs are the sequential and the independent reading design. We investigated the effect of different observer study designs on reader performance results and statistical power. The study included multiple assessments of chest radiographs (CXR) with bone suppression images (BSI) for the detection of lung nodules. In a fully crossed study design 8 observers assessed first radiographs without and with BSI sequentially. Secondly they scored radiographs independently having BSI available from the beginning. Five months later, the same readers scored the same cases again in an independent reading session, completing the three scorings for CXRs with BSI. Observer performance was compared using multi reader multi case (MRMC) receiver operating characteristics (ROC). To estimate reader variance, Dorfman, Berbaum, Metz (DBM) variance component estimates were calculated. No significant difference between the sequential and the independent reading sessions could be found (p=0.51; p=0.61). Both reading designs showed increased performance with BSI, with a significant increase for the sequential and the independent reading session after five months (p=0.002; p=0.007). Total observer variance between sequential and independent reading design remained the same. A strong increase of uncorrelated components was found in the independent reading sessions, masking the ability to demonstrate differences in observer performance across modalities. In conclusion, results of the sequential and the independent study design did not show a significant difference. The independent study design had less power compared to the sequential study design due to a strong increase of uncorrelated variance components.

  5. A radiographic study of the relationship between technical quality of coronoradicular posts and periapical status in a Jordanian population.

    Science.gov (United States)

    Jamani, Kifah Dafi; Aqrabawi, Jamal; Fayyad, Mohammed Ali

    2005-09-01

    A radiographic study was conducted to investigate the relationship between the technical quality of coronoradicular posts and periapical status. A total of 400 periapical radiographs, including 560 posts, of patients attending the Dental Department at Jordan University Hospital were scanned and studied. It was found that maxillary teeth were more frequently restored with posts (65.36%) than mandibular teeth (34.64%). Tapered posts accounted for 73.93% of the posts used. The ratio of the mean post length to crown length was 0.8, and that to root length was 0.45. The mean length of the remaining gutta percha apical to the end of the post was 6.22 mm. In addition, 25% of the posts deviated from the line of the root canal. Periapical radiolucency was evident in 53.93% of the assessed teeth. It is concluded that inadequate root canal treatment and coronoradicular posts are associated with increased prevalence of periapical radiolucency, and that general dental practitioners should be better trained in performing endodontic treatment and restoring endodontically treated teeth.

  6. Analysis of trabecular structure in radiographic bone images using bi-dimensional empirical mode decomposition - biomed 2011.

    Science.gov (United States)

    Udayakumar, G; Sujatha, C M; Ramakrishnan, S

    2011-01-01

    Non-invasive assessment of bone strength is an important component of biomechanics research. Soft tissue structures like trabeculae in femur bones are to be assessed precisely for tissue modeling and fracture mechanics. The strength and architecture of these structures in femur bones are routinely analyzed by varied image based methods for diagnosis and monitoring of osteoporosis like metabolic disorders. In this work, an attempt has been made towards development of an automated system for analysis of trabecular femur bone architecture using spatial frequency decomposition method. Conventional Radiographic femur images recorded using standard protocols are used for the study. The compressive and tensile regions in the images are delineated using pre-processing procedures. The delineated images are decomposed into their corresponding Intrinsic Mode Functions using bi-dimensional empirical mode decomposition method. The characteristic feature vectors corresponding to regional variations are used for further analysis. The result shows that the extracted features are distinct for compressive and tensile regions and are found to be consistent for the first three modes. The values are high for compressive regions. The higher modes are not observed in tensile regions of abnormal images which are attributed to the loss of structural patterns. As the strength of the bone depend on architectural variation in addition to bone mass, this study seems to be clinically useful. The objectives, methodology and analysis are presented in this paper.

  7. Digitizing an Analog Radiography Teaching File Under Time Constraint: Trade-Offs in Efficiency and Image Quality.

    Science.gov (United States)

    Loehfelm, Thomas W; Prater, Adam B; Debebe, Tequam; Sekhar, Aarti K

    2017-02-01

    We digitized the radiography teaching file at Black Lion Hospital (Addis Ababa, Ethiopia) during a recent trip, using a standard digital camera and a fluorescent light box. Our goal was to photograph every radiograph in the existing library while optimizing the final image size to the maximum resolution of a high quality tablet computer, preserving the contrast resolution of the radiographs, and minimizing total library file size. A secondary important goal was to minimize the cost and time required to take and process the images. Three workers were able to efficiently remove the radiographs from their storage folders, hang them on the light box, operate the camera, catalog the image, and repack the radiographs back to the storage folder. Zoom, focal length, and film speed were fixed, while aperture and shutter speed were manually adjusted for each image, allowing for efficiency and flexibility in image acquisition. Keeping zoom and focal length fixed, which kept the view box at the same relative position in all of the images acquired during a single photography session, allowed unused space to be batch-cropped, saving considerable time in post-processing, at the expense of final image resolution. We present an analysis of the trade-offs in workflow efficiency and final image quality, and demonstrate that a few people with minimal equipment can efficiently digitize a teaching file library.

  8. Self-calibration of biplanar radiographic images through geometric spine shape descriptors.

    Science.gov (United States)

    Kadoury, Samuel; Cheriet, Farida; Labelle, Hubert

    2010-07-01

    This paper presents a novel self-calibration method of an X-ray scene applied for the 3-D reconstruction of the scoliotic spine. Current calibration techniques either use a cumbersome calibration apparatus or depend on manually identified landmarks to determine the geometric configuration, thus limiting routine clinical evaluation. The proposed approach uses high-level information automatically extracted from biplanar X-rays to solve the radiographic scene parameters. We first present a segmentation method that takes into account the variable appearance and geometry of a scoliotic spine in order to isolate and extract the silhouettes of the anterior vertebral body. By incorporating prior anatomical information through a Bayesian formulation of the morphological distribution, a multiscale spine segmentation framework is proposed for scoliotic patients. An iterative nonlinear optimization procedure, integrating a 3-D visual hull reconstruction and geometrical torsion properties of the spine, is then applied to globally refine the geometrical parameters of the 3-D viewing scene and obtain the optimal 3-D reconstruction. An experimental comparison with data provided from reference synthetic models yields similar accuracy on the retroprojection of low-level primitives such as anatomical landmarks identified on each vertebra (2.2 mm). Results obtained from a clinical validation on 60 pairs of uncalibrated digitized X-rays of adolescents with scoliosis show that the 3-D reconstructions from the new system offer geometrically accurate models with insignificant differences for 3-D clinical indexes commonly used in the evaluation of spinal deformities. The reported experiments demonstrate a viable and accurate alternative to previous reconstruction techniques, offering the first automatic approach for routine 3-D clinical assessment in radiographic suites.

  9. The smallest detectable difference and sensitivity to change of magnetic resonance imaging and radiographic scoring of structural joint damage in rheumatoid arthritis finger, wrist, and toe joints: a comparison of the OMERACT rheumatoid arthritis magnetic resonance imaging score applied

    DEFF Research Database (Denmark)

    Ejbjerg, Bo Jannik; Vestergaard, Aage; Jacobsen, Søren

    2005-01-01

    To compare 2 magnetic resonance imaging (MRI) approaches and radiographic evaluation according to the Sharp/van der Heijde method with respect to sensitivity to change in joint destruction in patients with rheumatoid arthritis (RA).......To compare 2 magnetic resonance imaging (MRI) approaches and radiographic evaluation according to the Sharp/van der Heijde method with respect to sensitivity to change in joint destruction in patients with rheumatoid arthritis (RA)....

  10. Conventional versus virtual radiographs of the injured pelvis and acetabulum.

    Science.gov (United States)

    Bishop, Julius A; Rao, Allison J; Pouliot, Michael A; Beaulieu, Christopher; Bellino, Michael

    2015-09-01

    Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans. Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA). Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p = 0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p = 0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well. Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs.

  11. IMAGE QUALITY FORECASTING FOR SPACE OBJECTS

    Directory of Open Access Journals (Sweden)

    A. I. Altukhov

    2013-05-01

    Full Text Available The article deals with an approach to quality predicting of the space objects images, which can be used to plan optoelectronic systems of remote sensing satellites work programs. The proposed approach is based on evaluation of the optoelectronic equipment transfer properties and calculation of indexes images quality considering the influence of the orbital shooting conditions.

  12. Decision theory on the quality evaluation of medical images; A teoria da decisao na avaliacao da qualidade da imagem medica

    Energy Technology Data Exchange (ETDEWEB)

    Lessa, Patricia Silva

    2001-10-01

    The problem of quality has been a constant issue in every organization.One is always seeking to produce more, to do it at a lower cost, and to do it with better quality. However, in this country, there is no radiographic film quality control system for radiographic services. The tittle that actually gets done is essentially ad hoc and superficial. The implications of this gap, along with some other shortcomings that exist in process as a whole (the state of the x-ray equipment, the adequate to use in order to obtain a radiography, the quality of the film, the processing of the film, the brightness and homogeneity of the viewing boxes, the ability of the radiologist), have a very negative impact on the quality of the medical image, and, as result, to the quality of the medical diagnosis and therapy. It frequently happens that many radiographs have to be repeated, which leads to an increase of the patient's exposure to radiation, as well as of the cost of the procedure for the patient. Low quality radiographs that are not repeated greatly increase the probability of a wrong diagnosis, and consequently, of inadequate therapeutical procedures, thus producing increased incidence of bad outcomes and higher costs. The paradigm proposed in order to establish a system for the measurement of the image's quality is Decision Theory. The problem of the assessment of the image is studied by proposing a Decision Theory approach. The review of the literature reveals a great concern with the quality of the image, along with an absence of an adequate paradigm and several essentially empirical procedures. Image parameters are developed in order to formalize the problem in terms of Decision Theory, and various aspects of image digitalisation are exposed. Finally, a solution is presented, including a protocol for quality control. (author)

  13. The reliability of tablet computers in depicting maxillofacial radiographic landmarks

    Energy Technology Data Exchange (ETDEWEB)

    Tadinada, Aditya; Mahdian, Mina; Sheth, Sonam; Chandhoke, Taranpreet K.; Gopalakrishna, Aadarsh; Potluri, Anitha; Yadav, Sumit [University of Connecticut School of Dental Medicine, Farmington (United States)

    2015-09-15

    This study was performed to evaluate the reliability of the identification of anatomical landmarks in panoramic and lateral cephalometric radiographs on a standard medical grade picture archiving communication system (PACS) monitor and a tablet computer (iPad 5). A total of 1000 radiographs, including 500 panoramic and 500 lateral cephalometric radiographs, were retrieved from the de-identified dataset of the archive of the Section of Oral and Maxillofacial Radiology of the University Of Connecticut School Of Dental Medicine. Major radiographic anatomical landmarks were independently reviewed by two examiners on both displays. The examiners initially reviewed ten panoramic and ten lateral cephalometric radiographs using each imaging system, in order to verify interoperator agreement in landmark identification. The images were scored on a four-point scale reflecting the diagnostic image quality and exposure level of the images. Statistical analysis showed no significant difference between the two displays regarding the visibility and clarity of the landmarks in either the panoramic or cephalometric radiographs. Tablet computers can reliably show anatomical landmarks in panoramic and lateral cephalometric radiographs.

  14. Restorative treatment thresholds for interproximal primary caries based on radiographic images: findings from the Dental Practice-Based Research Network.

    Science.gov (United States)

    Gordan, Valeria V; Garvan, Cynthia W; Heft, Marc W; Fellows, Jeffrey L; Qvist, Vibeke; Rindal, D Brad; Gilbert, Gregg H

    2009-01-01

    This study sought to quantify the depths of proximal caries lesions that lead dentists in regular clinical practice to intervene restoratively, based on hypothetical scenarios that present radiographic images and patient background information, and to identify characteristics associated with restorative intervention in lesions that have penetrated only the enamel surface. This study surveyed dentists from the Dental Practice-Based Research Network (DPBRN) who had reported doing at least some restorative dentistry (n = 901). Dentists were asked to indicate the depth at which they would restore a lesion, based on a series of radiographic images depicting interproximal caries at increasing lesion depths in a mandibular premolar; in addition, the dentists were questioned regarding two caries risk scenarios: one involving a patient with low caries risk and another involving a patient at higher risk. Logistic regression was used to analyze associations between the decision to intervene restoratively and specific dentist, practice, and patient characteristics. Of the 901 DPBRN practitioner-investigators, 500 (56%) completed the survey. For a high caries risk patient, 66% of respondents indicated that they would restore a proximal enamel lesion, while 24% would do so once the lesion had reached into the outer third of the dentin. For a low caries risk patient, 39% of respondents reported that they would restore an enamel lesion, and 54% would do so once the lesion had reached into the outer third of the dentin. In multivariate analyses that accounted for dentist and practice characteristics, dentists in large group practices were less likely to intervene surgically for enamel caries, regardless of patient's caries risk.

  15. Modeling Perceived Quality for Imaging Applications

    NARCIS (Netherlands)

    Liu, H.

    2011-01-01

    People of all generations are making more and more use of digital imaging systems in their daily lives. The image content rendered by these digital imaging systems largely differs in perceived quality depending on the system and its applications. To be able to optimize the experience of viewers of

  16. An Automatic Image Processing Workflow for Daily Magnetic Resonance Imaging Quality Assurance.

    Science.gov (United States)

    Peltonen, Juha I; Mäkelä, Teemu; Sofiev, Alexey; Salli, Eero

    2017-04-01

    The performance of magnetic resonance imaging (MRI) equipment is typically monitored with a quality assurance (QA) program. The QA program includes various tests performed at regular intervals. Users may execute specific tests, e.g., daily, weekly, or monthly. The exact interval of these measurements varies according to the department policies, machine setup and usage, manufacturer's recommendations, and available resources. In our experience, a single image acquired before the first patient of the day offers a low effort and effective system check. When this daily QA check is repeated with identical imaging parameters and phantom setup, the data can be used to derive various time series of the scanner performance. However, daily QA with manual processing can quickly become laborious in a multi-scanner environment. Fully automated image analysis and results output can positively impact the QA process by decreasing reaction time, improving repeatability, and by offering novel performance evaluation methods. In this study, we have developed a daily MRI QA workflow that can measure multiple scanner performance parameters with minimal manual labor required. The daily QA system is built around a phantom image taken by the radiographers at the beginning of day. The image is acquired with a consistent phantom setup and standardized imaging parameters. Recorded parameters are processed into graphs available to everyone involved in the MRI QA process via a web-based interface. The presented automatic MRI QA system provides an efficient tool for following the short- and long-term stability of MRI scanners.

  17. [Evaluation of image quality using the normalized-rank approach for primary class liquid-crystal display (LCD) monitors with different colors and resolution].

    Science.gov (United States)

    Kuroki, Hidefumi; Katayama, Reiji; Sakaguchi, Taro; Maeda, Takashi; Morishita, Junji; Hayabuchi, Naofumi

    2010-11-20

    The purposes of this study were to evaluate the image quality of five types of liquid-crystal display (LCD) monitors by utilizing the normalized-rank approach and to investigate the effect of LCD monitor specifications, such as display colors, luminance, and resolution, on the evaluators' ranking. The LCD monitors used in this study were 2, 3 and 5 mega-pixel monochrome LCD monitors, and 2 and 3 mega-pixel color LCD monitors (Eizo Nanao Corporation). All LCD monitors were calibrated to the grayscale standard display function (GSDF) with different maximum luminance (recommended luminance) settings. Also, four kinds of radiographs were used for observer study based on the normalized-rank approach: three adult chest radiographs, three pediatric chest radiographs, three ankle joint radiographs, and four double-contrasted upper gastrointestinal radiographs. Ten radiological technologists participated in the observer study. Monochrome LCD monitors exhibited superior ranking with statistically significant differences (pLCD monitors in all kinds of radiographs. The major difference between monochrome and color monitors was luminance. Therefore, it is considered that the luminance of LCD monitors affects observers' evaluations based on image quality. Moreover, in the case of radiographs that include high frequency image components, the monitor resolution also affects the evaluation. In clinical practice, it is necessary to optimize the luminance and choose appropriate LCD monitors for diagnostic images.

  18. Image quality assessment metric for frame accumulated image

    Science.gov (United States)

    Yu, Jianping; Li, Gang; Wang, Shaohui; Lin, Ling

    2018-01-01

    The medical image quality determines the accuracy of diagnosis, and the gray-scale resolution is an important parameter to measure image quality. But current objective metrics are not very suitable for assessing medical images obtained by frame accumulation technology. Little attention was paid to the gray-scale resolution, basically based on spatial resolution and limited to the 256 level gray scale of the existing display device. Thus, this paper proposes a metric, "mean signal-to-noise ratio" (MSNR) based on signal-to-noise in order to be more reasonable to evaluate frame accumulated medical image quality. We demonstrate its potential application through a series of images under a constant illumination signal. Here, the mean image of enough images was regarded as the reference image. Several groups of images by different frame accumulation and their MSNR were calculated. The results of the experiment show that, compared with other quality assessment methods, the metric is simpler, more effective, and more suitable for assessing frame accumulated images that surpass the gray scale and precision of the original image.

  19. Using machine learning to classify image features from canine pelvic radiographs

    DEFF Research Database (Denmark)

    McEvoy, Fintan; Amigo Rubio, Jose Manuel

    2013-01-01

    As the number of images per study increases in the field of veterinary radiology, there is a growing need for computer-assisted diagnosis techniques. The purpose of this study was to evaluate two machine learning statistical models for automatically identifying image regions that contain the canine...

  20. A comparative study of anatomic structures on the panoramic radiograph and some extraoral radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Kyu; Kim, Han Pyoung [Department of dental science, Yonsei University, Seoul (Korea, Republic of)

    1984-11-15

    The author has studied each landmark for successful interpretation in the radiograph of the head that have the complex anatomic structures, using panoramic radiograph, postero-anterior cephalometric radiograph, lateral cephalometric radiograph, Waters' radiograph of the skull. The anatomic structures of the human dry skull attached by radiopaque materials were taken radiographs and analysed comparatively. The results were as follows: 1. The overall anatomic structures of the mandible showed sharp images in the panoramic radiograph than other radiographs with relatively less distortion, superimposition, blurring of the image. 2. The anatomic structures were situated on sagittal plane of the skull showed blurred images in panoramic radiograph than other radiographs. 3. The anatomic structures which were situated on the basal portion of the skull showed blurred and secondary images in the panoramic radiograph than other radiographs. 4. In the panoramic radiograph, the lower 3rd portion of the orbit appeared to be superimposed with the superior portion of the maxillary sinus and the medial and lateral surface of the nasal cavity showed extensively superimposition of the orbit and the maxillary sinus, which images showed blurring. 5. The inferior surface and posterior surface of maxillary sinus showed to be good image in the panoramic radiograph than other radiographs. 6. In the panoramic radiograph, line of maxillary bone between lateral pterygoid plate, line of maxillary bone between zygomatic bone showed distinct image with another structures.

  1. Testing a Novel 3D Printed Radiographic Imaging Device for Use in Forensic Odontology.

    Science.gov (United States)

    Newcomb, Tara L; Bruhn, Ann M; Giles, Bridget; Garcia, Hector M; Diawara, Norou

    2017-01-01

    There are specific challenges related to forensic dental radiology and difficulties in aligning X-ray equipment to teeth of interest. Researchers used 3D printing to create a new device, the combined holding and aiming device (CHAD), to address the positioning limitations of current dental X-ray devices. Participants (N = 24) used the CHAD, soft dental wax, and a modified external aiming device (MEAD) to determine device preference, radiographer's efficiency, and technique errors. Each participant exposed six X-rays per device for a total of 432 X-rays scored. A significant difference was found at the 0.05 level between the three devices (p = 0.0015), with the MEAD having the least amount of total errors and soft dental wax taking the least amount of time. Total errors were highest when participants used soft dental wax-both the MEAD and the CHAD performed best overall. Further research in forensic dental radiology and use of holding devices is needed. © 2016 American Academy of Forensic Sciences.

  2. Image analysis algorithms for the advanced radiographic capability (ARC) grating tilt sensor at the National Ignition Facility

    Science.gov (United States)

    Roberts, Randy S.; Bliss, Erlan S.; Rushford, Michael C.; Halpin, John M.; Awwal, Abdul A. S.; Leach, Richard R.

    2014-09-01

    The Advance Radiographic Capability (ARC) at the National Ignition Facility (NIF) is a laser system designed to produce a sequence of short pulses used to backlight imploding fuel capsules. Laser pulses from a short-pulse oscillator are dispersed in wavelength into long, low-power pulses, injected in the NIF main laser for amplification, and then compressed into high-power pulses before being directed into the NIF target chamber. In the target chamber, the laser pulses hit targets which produce x-rays used to backlight imploding fuel capsules. Compression of the ARC laser pulses is accomplished with a set of precision-surveyed optical gratings mounted inside of vacuum vessels. The tilt of each grating is monitored by a measurement system consisting of a laser diode, camera and crosshair, all mounted in a pedestal outside of the vacuum vessel, and a mirror mounted on the back of a grating inside the vacuum vessel. The crosshair is mounted in front of the camera, and a diffraction pattern is formed when illuminated with the laser diode beam reflected from the mirror. This diffraction pattern contains information related to relative movements between the grating and the pedestal. Image analysis algorithms have been developed to determine the relative movements between the gratings and pedestal. In the paper we elaborate on features in the diffraction pattern, and describe the image analysis algorithms used to monitor grating tilt changes. Experimental results are provided which indicate the high degree of sensitivity provided by the tilt sensor and image analysis algorithms.

  3. [Influence of tandem optics and television tube of modern digital fluoroscopy equipment on image quality].

    Science.gov (United States)

    Kunz, G; Britzen, S; Busch, H P

    2001-01-01

    The influence of the tandem optics and the TV-tube to the image quality of 1k- and 2k-radiographs of a modern fluoroscopy equipment should be assessed on the basis of objective parameters and clinical requirements. Radiographs of different phantoms with 1k- and 2k-image matrix, different illumination point corrections (IPC) and signal gray levels were taken, examined and evaluated, in order to determine the objective image parameters and the clinical relevancy of these parameters. On the one hand, the digital images data could be used directly for evaluation; on the other hand, the radiographs could be visually evaluated by experienced radiologists within the framework of a blind study. The IPC is controlled by the aperture of the iris diaphragm and the insertion of a neutral gray filter in the tandem optics. The larger the aperture of the iris diaphragm (at constant image receiver dose) the higher were gradation, signal to noise ratio (SNR) and image homogeneity. Furthermore, the larger the aperture, the lower was the square wave response function (SWRF). The insertion of a gray filter in the tandem optics decreases gradation, SNR and homogeneity, and improves the SWRF.

  4. Digital radiography image quality: image processing and display.

    Science.gov (United States)

    Krupinski, Elizabeth A; Williams, Mark B; Andriole, Katherine; Strauss, Keith J; Applegate, Kimberly; Wyatt, Margaret; Bjork, Sandra; Seibert, J Anthony

    2007-06-01

    This article on digital radiography image processing and display is the second of two articles written as part of an intersociety effort to establish image quality standards for digital and computed radiography. The topic of the other paper is digital radiography image acquisition. The articles were developed collaboratively by the ACR, the American Association of Physicists in Medicine, and the Society for Imaging Informatics in Medicine. Increasingly, medical imaging and patient information are being managed using digital data during acquisition, transmission, storage, display, interpretation, and consultation. The management of data during each of these operations may have an impact on the quality of patient care. These articles describe what is known to improve image quality for digital and computed radiography and to make recommendations on optimal acquisition, processing, and display. The practice of digital radiography is a rapidly evolving technology that will require timely revision of any guidelines and standards.

  5. Sensitivity of radiographic features and specificity of scintigraphic imaging in hand osteoarthritis; Sensibilite des signes radiographiques et specificite de la scintigraphie dans l`arthrose de la main

    Energy Technology Data Exchange (ETDEWEB)

    Buckland-Wright, J.C.; MacFarlane, D.G.; Lynch, J.A. [Guy`s and St. Thomas`s Hospitals, London (United Kingdom)

    1995-06-01

    We undertook to determine which of the radiographic features most reliably detected the presence and disease progression in osteoarthritis in the hand; and which of the radiographic features corresponded with the radionuclide bone scan images. 32 patients with osteoarthritis had X5 macroradiographs taken of their wrists and hands at 6 monthly intervals over an 18 month period. The high magnification and resolution of microfocal radiography permitted quantitative detection of the extent and change in joint space width, subchondral sclerosis, osteophytosis and juxtaarticular radiolucencies. 4-hour technetium 99{sup m} methylene bisphophonate bone scans were taken at 0 and 12 months and the activity of the tracer uptake at each joint scored. The latter was compared with the radiographic features at each visit and the changes between visits analysed. In hand OA the most sensitive radiographic parameters for detecting disease were osteophytes, subchondral sclerosis and justaarticular radiolucencies, with radionuclide imaging demonstrating the increased activity in bone formation associated with the growth and remodelling of osteophytes. Changes in the number and size of osteophytes and joint space narrowing were the only reliable and sensitive parameters for assessing disease progression. We conclude that in osteoarthritis, the bony changes progress significantly before the occurrence of radiographically evident joint space narrowing indicative of cartilage thinning. (authors). 48 refs., 2 tabs., 11 figs.

  6. Postoperative evaluation after anterior cruciate ligament reconstruction: Measurements and abnormalities on radiographic and CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Cheol; Choi, Yun Sun; KIm, Hyoung Seop; Choi, Nam Hong [Nowon Eulji Medical Center, Eulji University, Seoul (Korea, Republic of)

    2016-11-15

    Reconstruction of a ruptured anterior cruciate ligament (ACL) is a well-established procedure for repair of ACL injury. Despite improvement of surgical and rehabilitation techniques over the past decades, up to 25% of patients still fail to regain satisfactory function after an ACL reconstruction. With development of CT imaging techniques for reducing metal artifacts, multi-planar reconstruction, and three-dimensional reconstruction, early post-operative imaging is increasingly being used to provide immediate feedback to surgeons regarding tunnel positioning, fixation, and device placement. Early post-operative radiography and CT imaging are easy to perform and serve as the baseline examinations for future reference.

  7. Postoperative Evaluation after Anterior Cruciate Ligament Reconstruction: Measurements and Abnormalities on Radiographic and CT Imaging.

    Science.gov (United States)

    Kim, Minchul; Choi, Yun Sun; Kim, Hyoungseop; Choi, Nam-Hong

    2016-01-01

    Reconstruction of a ruptured anterior cruciate ligament (ACL) is a well-established procedure for repair of ACL injury. Despite improvement of surgical and rehabilitation techniques over the past decades, up to 25% of patients still fail to regain satisfactory function after an ACL reconstruction. With development of CT imaging techniques for reducing metal artifacts, multi-planar reconstruction, and three-dimensional reconstruction, early post-operative imaging is increasingly being used to provide immediate feedback to surgeons regarding tunnel positioning, fixation, and device placement. Early post-operative radiography and CT imaging are easy to perform and serve as the baseline examinations for future reference.

  8. Image quality of a cone beam O-arm 3D imaging system

    Science.gov (United States)

    Zhang, Jie; Weir, Victor; Lin, Jingying; Hsiung, Hsiang; Ritenour, E. Russell

    2009-02-01

    The O-arm is a cone beam imaging system designed primarily to support orthopedic surgery and is also used for image-guided and vascular surgery. Using a gantry that can be opened or closed, the O-arm can function as a 2-dimensional (2D) fluoroscopy device or collect 3-dimensional (3D) volumetric imaging data like a CT system. Clinical applications of the O-arm in spine surgical procedures, assessment of pedicle screw position, and kyphoplasty procedures show that the O-arm 3D mode provides enhanced imaging information compared to radiographs or fluoroscopy alone. In this study, the image quality of an O-arm system was quantitatively evaluated. A 20 cm diameter CATPHAN 424 phantom was scanned using the pre-programmed head protocols: small/medium (120 kVp, 100 mAs), large (120 kVp, 128 mAs), and extra-large (120 kVp, 160 mAs) in 3D mode. High resolution reconstruction mode (512×512×0.83 mm) was used to reconstruct images for the analysis of low and high contrast resolution, and noise power spectrum. MTF was measured using the point spread function. The results show that the O-arm image is uniform but with a noise pattern which cannot be removed by simply increasing the mAs. The high contrast resolution of the O-arm system was approximately 9 lp/cm. The system has a 10% MTF at 0.45 mm. The low-contrast resolution cannot be decided due to the noise pattern. For surgery where locations of a structure are emphasized over a survey of all image details, the image quality of the O-arm is well accepted clinically.

  9. Image processing and analysis program for measurement of bone density changes in reference and follow-up standardized extraoral oblique lateral cephalometric radiographs of the mandible

    NARCIS (Netherlands)

    Ruijter, J. M.; Verhoeven, J. W.; van der Linden, J. A. M.; Cune, M. S.; Terlou, M.

    2003-01-01

    The aim of this study was to develop an image processing and analysis program for peri-implant bone density measurements of the mandible using extraoral radiographs, which includes a correction for the variable projection of the soft tissues of the face. The measurement procedure is based on pairs

  10. A comparison of periapical radiographs and their digital images for the detection of dental caries

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byung Cheol [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Chonnam National University, Kwangju (Korea, Republic of)

    1994-02-15

    In summary, it has been demonstrated by this study that the detection rate of definite large proximal surface caries (C2) on the digital images was good and the detection rate of the first stage caries (C1) was somewhat inferior to film based images. It has been demonstrated by this study and others that the detection of proximal surface caries by present clinical methodologies is still poor. Every effort should be made to develop new means to improve digitizing process.

  11. Validation of a novel technique for creating simulated radiographs using computed tomography datasets.

    Science.gov (United States)

    Mendoza, Patricia; d'Anjou, Marc-André; Carmel, Eric N; Fournier, Eric; Mai, Wilfried; Alexander, Kate; Winter, Matthew D; Zwingenberger, Allison L; Thrall, Donald E; Theoret, Christine

    2014-01-01

    Understanding radiographic anatomy and the effects of varying patient and radiographic tube positioning on image quality can be a challenge for students. The purposes of this study were to develop and validate a novel technique for creating simulated radiographs using computed tomography (CT) datasets. A DICOM viewer (ORS Visual) plug-in was developed with the ability to move and deform cuboidal volumetric CT datasets, and to produce images simulating the effects of tube-patient-detector distance and angulation. Computed tomographic datasets were acquired from two dogs, one cat, and one horse. Simulated radiographs of different body parts (n = 9) were produced using different angles to mimic conventional projections, before actual digital radiographs were obtained using the same projections. These studies (n = 18) were then submitted to 10 board-certified radiologists who were asked to score visualization of anatomical landmarks, depiction of patient positioning, realism of distortion/magnification, and image quality. No significant differences between simulated and actual radiographs were found for anatomic structure visualization and patient positioning in the majority of body parts. For the assessment of radiographic realism, no significant differences were found between simulated and digital radiographs for canine pelvis, equine tarsus, and feline abdomen body parts. Overall, image quality and contrast resolution of simulated radiographs were considered satisfactory. Findings from the current study indicated that radiographs simulated using this new technique are comparable to actual digital radiographs. Further studies are needed to apply this technique in developing interactive tools for teaching radiographic anatomy and the effects of varying patient and tube positioning. © 2013 American College of Veterinary Radiology.

  12. MO-DE-209-03: Assessing Image Quality

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, W. [Stony Brook Medicine (United States)

    2016-06-15

    Digital Breast Tomosynthesis (DBT) is rapidly replacing mammography as the standard of care in breast cancer screening and diagnosis. DBT is a form of computed tomography, in which a limited set of projection images are acquired over a small angular range and reconstructed into tomographic data. The angular range varies from 15° to 50° and the number of projections varies between 9 and 25 projections, as determined by the equipment manufacturer. It is equally valid to treat DBT as the digital analog of classical tomography – that is, linear tomography. In fact, the name “tomosynthesis” stands for “synthetic tomography.” DBT shares many common features with classical tomography, including the radiographic appearance, dose, and image quality considerations. As such, both the science and practical physics of DBT systems is a hybrid between computed tomography and classical tomographic methods. In this lecture, we will explore the continuum from radiography to computed tomography to illustrate the characteristics of DBT. This lecture will consist of four presentations that will provide a complete overview of DBT, including a review of the fundamentals of DBT acquisition, a discussion of DBT reconstruction methods, an overview of dosimetry for DBT systems, and summary of the underlying image theory of DBT thereby relating image quality and dose. Learning Objectives: To understand the fundamental principles behind tomosynthesis image acquisition. To understand the fundamentals of tomosynthesis image reconstruction. To learn the determinants of image quality and dose in DBT, including measurement techniques. To learn the image theory underlying tomosynthesis, and the relationship between dose and image quality. ADM is a consultant to, and holds stock in, Real Time Tomography, LLC. ADM receives research support from Hologic Inc., Analogic Inc., and Barco NV.; ADM is a member of the Scientific Advisory Board for Gamma Medica Inc.; A. Maidment, Research Support

  13. Film reject analysis and image quality in diagnostic Radiology Department of a Teaching hospital in Ghana

    Directory of Open Access Journals (Sweden)

    J. Owusu-Banahene

    2014-10-01

    Full Text Available Patients usually undergo repeated X-ray examinations after their initial X-ray radiographs are rejected due to poor image quality. This subjects the patients to an excess radiation exposure and extra cost and necessitates the need to investigate the causes of reject. The use of reject analysis as part of the overall quality assurance programs in clinical radiography and radiology services is vital in the evaluation of image quality of a well-established practice. It is shown that, in spite of good quality control maintained by the Radiology Department of a Teaching hospital in Ghana, reject analysis performed on a number of radiographic films developed indicated 14.1% reject rate against 85.9% accepted films. The highest reject rate was 57.1 ± 0.7% which occurs in cervical spine and the lowest was7.7 ± 0.5% for lumbar spine. The major factors contributing to film rejection were found to be over exposure and patient positioning in cervical spine examinations. The most frequent examination was chest X-ray which accounts for about 42.2% of the total examinations. The results show low reject rates by considering the factors for radiographic rejection analysis in relation to both equipment functionality and film development in the facility.

  14. End-to-end image quality assessment

    Science.gov (United States)

    Raventos, Joaquin

    2012-05-01

    An innovative computerized benchmarking approach (US Patent pending Sep 2011) based on extensive application of photometry, geometrical optics, and digital media using a randomized target, for a standard observer to assess the image quality of video imaging systems, at different day time, and low-light luminance levels. It takes into account, the target's contrast and color characteristics, as well as the observer's visual acuity and dynamic response. This includes human vision as part of the "extended video imaging system" (EVIS), and allows image quality assessment by several standard observers simultaneously.

  15. TNF blockers inhibit spinal radiographic progression in ankylosing spondylitis by reducing disease activity: results from the Swiss Clinical Quality Management cohort.

    Science.gov (United States)

    Molnar, Christoph; Scherer, Almut; Baraliakos, Xenofon; de Hooge, Manouk; Micheroli, Raphael; Exer, Pascale; Kissling, Rudolf O; Tamborrini, Giorgio; Wildi, Lukas M; Nissen, Michael J; Zufferey, Pascal; Bernhard, Jürg; Weber, Ulrich; Landewé, Robert B M; van der Heijde, Désirée; Ciurea, Adrian

    2018-01-01

    To analyse the impact of tumour necrosis factor inhibitors (TNFis) on spinal radiographic progression in ankylosing spondylitis (AS). Patients with AS in the Swiss Clinical Quality Management cohort with up to 10 years of follow-up and radiographic assessments every 2 years were included. Radiographs were scored by two readers according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) with known chronology. The relationship between TNFi use before a 2-year radiographic interval and progression within the interval was investigated using binomial generalised estimating equation models with adjustment for potential confounding and multiple imputation of missing values. Ankylosing Spondylitis Disease Activity Score (ASDAS) was regarded as mediating the effect of TNFi on progression and added to the model in a sensitivity analysis. A total of 432 patients with AS contributed to data for 616 radiographic intervals. Radiographic progression was defined as an increase in ≥2 mSASSS units in 2 years. Mean (SD) mSASSS increase was 0.9 (2.6) units in 2 years. Prior use of TNFi reduced the odds of progression by 50% (OR 0.50, 95% CI 0.28 to 0.88) in the multivariable analysis. While no direct effect of TNFi on progression was present in an analysis including time-varying ASDAS (OR 0.61, 95% CI 0.34 to 1.08), the indirect effect, via a reduction in ASDAS, was statistically significant (OR 0.75, 95% CI 0.59 to 0.97). TNFis are associated with a reduction of spinal radiographic progression in patients with AS. This effect seems mediated through the inhibiting effect of TNFi on disease activity. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  16. A single-pixel X-ray imager concept and its application to secure radiographic inspections

    Science.gov (United States)

    Gilbert, Andrew J.; Miller, Brian W.; Robinson, Sean M.; White, Timothy A.; Pitts, William Karl; Jarman, Kenneth D.; Seifert, Allen

    2017-07-01

    Imaging technology is generally considered too invasive for arms control inspections due to the concern that it cannot properly secure sensitive features of the inspected item. However, this same sensitive information, which could include direct information on the form and function of the items under inspection, could be used for robust arms control inspections. The single-pixel X-ray imager (SPXI) is introduced as a method to make such inspections, capturing the salient spatial information of an object in a secure manner while never forming an actual image. The method is built on the theory of compressive sensing and the single pixel optical camera. The performance of the system is quantified using simulated inspections of simple objects. Measures of the robustness and security of the method are introduced and used to determine how robust and secure such an inspection would be. In particular, it is found that an inspection with low noise ( 256 ×) exhibits high robustness and security.

  17. Computerized evaluation of mammographic image quality using phantom images.

    Science.gov (United States)

    Dougherty, G

    1998-01-01

    A simple, quick and computerized method for quantitatively evaluating the image quality of mammography phantom images has been developed. Images of the American College of Radiology (ACR) mammographic accreditation phantoms were acquired under different X-ray techniques, scored and ranked subjectively by five expert readers, and digitized for quantitative analysis. The contrast and signal-to-noise (contrast-to-noise) ratios of the main nodule and microcalcification group were obtained accurately and reproducibly using an image processing protocol. The contrast values were successful at discriminating differences in image quality due to variations in scatter conditions (as a result of different kVp's, and the presence or absence of an acrylic scatterer and/or a moving Bucky grid). They were more precise, reproducible and sensitive than the ACR score. In particular, the contrast of the main nodule was highly correlated (r(s) = 0.988: pimage quality by our panel of expert readers.

  18. Quality assessment for online iris images

    CSIR Research Space (South Africa)

    Makinana, S

    2015-01-01

    Full Text Available -1 Computer Science & Information Technology (CS & IT), Dubai, UAE, 23-24 January 2015 Quality assessment for online iris images Sisanda Makinana, Tendani Malumedzha, and Fulufhelo V Nelwamondo Modelling and Digital Science, CSIR, Pretoria, South...

  19. Radiographic image analysis of Anacardium othonianum Rizz (anacardiaceae) achenes subjected to desiccation

    OpenAIRE

    Lílian Abadia da Silva; Juliana de Fátima Sales; José Maria Gomes Neves; Heloísa Oliveira dos Santos; Glicélia Pereira Silva

    2017-01-01

    Studies evaluating the internal morphology and seed quality of native species are essential for successful conservation programs. Our aim was to verify the efficiency of X-ray imagery in evaluating cashew-tree-of-the-cerrado (Anacardium othonianum Rizz.) achene viability after desiccation. The achenes were collected at 12% water content (w.b.) and dried in silica gel until they reached 10, 8, 6, and 4% (w.b.). The fruit morphology and the quality of the seeds were evaluated by X-ray test toge...

  20. Radiographic image analysis of Anacardium othonianum Rizz (anacardiaceae) achenes subjected to desiccation

    OpenAIRE

    Silva,Lílian Abadia da; Sales, Juliana de Fátima; Neves, Jose Maria Gomes; Santos, Heloísa Oliveira dos; Silva, Glicélia Pereira

    2017-01-01

    ABSTRACT. Studies evaluating the internal morphology and seed quality of native species are essential for successful conservation programs. Our aim was to verify the efficiency of X-ray imagery in evaluating cashew-tree-of-the-cerrado (Anacardium othonianum Rizz.) achene viability after desiccation. The achenes were collected at 12% water content (w.b.) and dried in silica gel until they reached 10, 8, 6, and 4% (w.b.). The fruit morphology and the quality of the seeds were evaluated by X-ray...

  1. New radiographic bone erosions in the wrists of patients with rheumatoid arthritis are detectable with magnetic resonance imaging a median of two years earlier

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Hansen, Michael; Stoltenberg, Michael

    2003-01-01

    OBJECTIVE: In a 5-year followup study, we investigated the temporal relationship between development of wrist joint erosions as visualized by magnetic resonance imaging (MRI) versus conventional radiography (CR), in patients with rheumatoid arthritis. We also evaluated the risk of erosive...... at 5-year followup was 4.5 (95% confidence interval [95% CI] 2.6-7.6), compared with bones without baseline MRI erosions. If bones with baseline radiographic erosions were excluded from the analysis, the relative risk was 4.1 (95% CI 2.2-7.5). CONCLUSION: Most new radiographic bone erosions (78%) were...... visualized at least 1 year earlier by MRI than by CR. This illustrates that the information on joint destruction provided by CR is considerably delayed compared with that provided by MRI. A significantly increased risk of progression of radiographic erosion in bones with baseline MRI erosions was observed...

  2. Optimizing radiation exposure for CT localizer radiographs.

    Science.gov (United States)

    Bohrer, Evelyn; Schäfer, Stefan; Mäder, Ulf; Noël, Peter B; Krombach, Gabriele A; Fiebich, Martin

    2017-06-01

    The trend towards submillisievert CT scans leads to a higher dose fraction of localizer radiographs in CT examinations. The already existing technical capabilities make dose optimization of localizer radiographs worthwhile. Modern CT scanners apply automatic exposure control (AEC) based on attenuation data in such a localizer. Therefore not only this aspect but also the detectability of anatomical landmarks in the localizer for the desired CT scan range adjustment needs to be considered. The effective dose of a head, chest, and abdomen-pelvis localizer radiograph with standard factory settings and user-optimized settings was determined using Monte Carlo simulations. CT examinations of an anthropomorphic phantom were performed using multiple sets of acquisition parameters for the localizer radiograph and the AEC for the subsequent helical CT scan. Anatomical landmarks were defined to assess the image quality of the localizer. CTDIvol and effective mAs per slice of the helical CT scan were recorded to examine the impact of localizer settings on a helical CT scan. The dose of the localizer radiograph could be decreased by more than 90% while the image quality remained sufficient when selecting the lowest available settings (80kVp, 20mA, pa tube position). The tube position during localizer acquisition had a greater impact on the AEC than the reduction of tube voltage and tube current. Except for the use of a pa tube position, all changes of acquisition parameters for the localizer resulted in a decreased total radiation exposure. A dose reduction of CT localizer radiograph is necessary and possible. In the examined CT system there was no negative impact on the modulated helical CT scan when the lowest tube voltage and tube current were used for the localizer. Copyright © 2016. Published by Elsevier GmbH.

  3. Optimizing radiation exposure for CT localizer radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Bohrer, Evelyn; Maeder, Ulf; Fiebich, Martin [Univ. of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection-IMPS; Schaefer, Stefan; Krombach, Gabriele A. [Univ. Hospital Giessen (Germany). Dept. of Radiology; Noel, Peter B. [Technische Univ. Muenchen (Germany). Dept. of Diagnostic and Interventional Radiology

    2017-08-01

    The trend towards submillisievert CT scans leads to a higher dose fraction of localizer radiographs in CT examinations. The already existing technical capabilities make dose optimization of localizer radiographs worthwhile. Modern CT scanners apply automatic exposure control (AEC) based on attenuation data in such a localizer. Therefore not only this aspect but also the detectability of anatomical landmarks in the localizer for the desired CT scan range adjustment needs to be considered. The effective dose of a head, chest, and abdomen-pelvis localizer radiograph with standard factory settings and user-optimized settings was determined using Monte Carlo simulations. CT examinations of an anthropomorphic phantom were performed using multiple sets of acquisition parameters for the localizer radiograph and the AEC for the subsequent helical CT scan. Anatomical landmarks were defined to assess the image quality of the localizer. CTDI{sub vol} and effective mAs per slice of the helical CT scan were recorded to examine the impact of localizer settings on a helical CT scan. The dose of the localizer radiograph could be decreased by more than 90% while the image quality remained sufficient when selecting the lowest available settings (80 kVp, 20 mA, pa tube position). The tube position during localizer acquisition had a greater impact on the AEC than the reduction of tube voltage and tube current. Except for the use of a pa tube position, all changes of acquisition parameters for the localizer resulted in a decreased total radiation exposure. A dose reduction of CT localizer radiograph is necessary and possible. In the examined CT system there was no negative impact on the modulated helical CT scan when the lowest tube voltage and tube current were used for the localizer.

  4. No training blind image quality assessment

    Science.gov (United States)

    Chu, Ying; Mou, Xuanqin; Ji, Zhen

    2014-03-01

    State of the art blind image quality assessment (IQA) methods generally extract perceptual features from the training images, and send them into support vector machine (SVM) to learn the regression model, which could be used to further predict the quality scores of the testing images. However, these methods need complicated training and learning, and the evaluation results are sensitive to image contents and learning strategies. In this paper, two novel blind IQA metrics without training and learning are firstly proposed. The new methods extract perceptual features, i.e., the shape consistency of conditional histograms, from the joint histograms of neighboring divisive normalization transform coefficients of distorted images, and then compare the length attribute of the extracted features with that of the reference images and degraded images in the LIVE database. For the first method, a cluster center is found in the feature attribute space of the natural reference images, and the distance between the feature attribute of the distorted image and the cluster center is adopted as the quality label. The second method utilizes the feature attributes and subjective scores of all the images in the LIVE database to construct a dictionary, and the final quality score is calculated by interpolating the subjective scores of nearby words in the dictionary. Unlike the traditional SVM based blind IQA methods, the proposed metrics have explicit expressions, which reflect the relationships of the perceptual features and the image quality well. Experiment results in the publicly available databases such as LIVE, CSIQ and TID2008 had shown the effectiveness of the proposed methods, and the performances are fairly acceptable.

  5. Radiographic progression is associated with resolution of systemic inflammation in patients with axial spondylarthritis treated with tumor necrosis factor α inhibitors: A study of radiographic progression, inflammation on magnetic resonance imaging, and circulating biomarkers of inflammation

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Sørensen, Inge Juul; Lambert, Robert G W

    2011-01-01

    To investigate the relationship of circulating biomarkers of inflammation (C-reactive protein [CRP], interleukin-6 [IL-6], and YKL-40), angiogenesis (vascular endothelial growth factor), cartilage turnover (C-terminal crosslinking telopeptide of type II collagen [CTX-II], total aggrecan, matrix...... metalloproteinase 3 [MMP-3], and cartilage oligomeric matrix protein [COMP]), and bone turnover (CTX-I and osteocalcin) to inflammation on magnetic resonance imaging (MRI) and radiographic progression in patients with axial spondylarthritis (SpA) beginning tumor necrosis factor a (TNFa) inhibitor therapy....

  6. Radiographic progression is associated with resolution of systemic inflammation in patients with axial spondylarthritis treated with tumor necrosis factor a inhibitors: a study of radiographic progression, inflammation on magnetic resonance imaging, and circulating biomarkers of inflammation

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Sørensen, Inge Juul; Lambert, Robert G. W.

    2011-01-01

    To investigate the relationship of circulating biomarkers of inflammation (C-reactive protein [CRP], interleukin-6 [IL-6], and YKL-40), angiogenesis (vascular endothelial growth factor), cartilage turnover (C-terminal crosslinking telopeptide of type II collagen [CTX-II], total aggrecan, matrix...... metalloproteinase 3 [MMP-3], and cartilage oligomeric matrix protein [COMP]), and bone turnover (CTX-I and osteocalcin) to inflammation on magnetic resonance imaging (MRI) and radiographic progression in patients with axial spondylarthritis (SpA) beginning tumor necrosis factor α (TNFα) inhibitor therapy....

  7. Image Quality Assessment via Quality-aware Group Sparse Coding

    Directory of Open Access Journals (Sweden)

    Minglei Tong

    2014-12-01

    Full Text Available Image quality assessment has been attracting growing attention at an accelerated pace over the past decade, in the fields of image processing, vision and machine learning. In particular, general purpose blind image quality assessment is technically challenging and lots of state-of-the-art approaches have been developed to solve this problem, most under the supervised learning framework where the human scored samples are needed for training a regression model. In this paper, we propose an unsupervised learning approach that work without the human label. In the off-line stage, our method trains a dictionary covering different levels of image quality patch atoms across the training samples without knowing the human score, where each atom is associated with a quality score induced from the reference image; at the on-line stage, given each image patch, our method performs group sparse coding to encode the sample, such that the sample quality can be estimated from the few labeled atoms whose encoding coefficients are nonzero. Experimental results on the public dataset show the promising performance of our approach and future research direction is also discussed.

  8. Topological image texture analysis for quality assessment

    Science.gov (United States)

    Asaad, Aras T.; Rashid, Rasber Dh.; Jassim, Sabah A.

    2017-05-01

    Image quality is a major factor influencing pattern recognition accuracy and help detect image tampering for forensics. We are concerned with investigating topological image texture analysis techniques to assess different type of degradation. We use Local Binary Pattern (LBP) as a texture feature descriptor. For any image construct simplicial complexes for selected groups of uniform LBP bins and calculate persistent homology invariants (e.g. number of connected components). We investigated image quality discriminating characteristics of these simplicial complexes by computing these models for a large dataset of face images that are affected by the presence of shadows as a result of variation in illumination conditions. Our tests demonstrate that for specific uniform LBP patterns, the number of connected component not only distinguish between different levels of shadow effects but also help detect the infected regions as well.

  9. Color Image Quality in Presentation Software

    Directory of Open Access Journals (Sweden)

    Edison Valencia

    2008-01-01

    Full Text Available The color image quality of presentation programs is evaluated and measured using S-CIELAB and CIEDE2000 color difference formulae. A color digital image in its original format is compared with the same image already imported by the program and introduced as a part of a slide. Two widely used presentation programs—Microsoft PowerPoint 2004 for Mac and Apple's Keynote 3.0.2—are evaluated in this work.

  10. Image quality assessment of digital intraoral radiography – perception to caries diagnosis

    Directory of Open Access Journals (Sweden)

    Kazunori Yoshiura

    2012-02-01

    Full Text Available The radiological diagnostic process is composed of the three major phases, psychophysical, psychological and nosological. An apparent improvement in image quality in the psychophysical phase does not necessarily imply an increased diagnostic performance. This may be true for the general diagnostic processes, but may not for the caries diagnosis, because psychophysical phase is of most significance in such special and relatively simplified task. In this article the processes to correlate perception to approximal caries diagnosis are reviewed using the Perceptibility Curve (PC tests and Receiver Operating Characteristic (ROC curve tests. The PC test was developed to represent the psychophysical property of the radiographic imaging system. Since physical properties are shown to be closely correlated with psychophysical properties, it is possible to theoretically calculate psychophysical properties of the radiographic systems from their physical properties. In a similar manner, observers' low contrast detectability in the psychophysical phase can be predicted from some physical parameters of the radiographic system. observers' low contrast detectability is also correlated with the diagnostic performance obtained from ROC curve in the task of approximal caries diagnosis. Thus, considerably high correlation between psychophysical properties and diagnostic accuracy indicates close relationship between perception and approximal caries diagnosis. It implies that an improvement in the physical image quality leads to increased diagnostic performance to some extent in the approximal caries diagnosis.

  11. Quantitative assessment of structural image quality.

    Science.gov (United States)

    Rosen, Adon F G; Roalf, David R; Ruparel, Kosha; Blake, Jason; Seelaus, Kevin; Villa, Lakshmi P; Ciric, Rastko; Cook, Philip A; Davatzikos, Christos; Elliott, Mark A; Garcia de La Garza, Angel; Gennatas, Efstathios D; Quarmley, Megan; Schmitt, J Eric; Shinohara, Russell T; Tisdall, M Dylan; Craddock, R Cameron; Gur, Raquel E; Gur, Ruben C; Satterthwaite, Theodore D

    2017-12-24

    Data quality is increasingly recognized as one of the most important confounding factors in brain imaging research. It is particularly important for studies of brain development, where age is systematically related to in-scanner motion and data quality. Prior work has demonstrated that in-scanner head motion biases estimates of structural neuroimaging measures. However, objective measures of data quality are not available for most structural brain images. Here we sought to identify quantitative measures of data quality for T1-weighted volumes, describe how these measures relate to cortical thickness, and delineate how this in turn may bias inference regarding associations with age in youth. Three highly-trained raters provided manual ratings of 1840 raw T1-weighted volumes. These images included a training set of 1065 images from Philadelphia Neurodevelopmental Cohort (PNC), a test set of 533 images from the PNC, as well as an external test set of 242 adults acquired on a different scanner. Manual ratings were compared to automated quality measures provided by the Preprocessed Connectomes Project's Quality Assurance Protocol (QAP), as well as FreeSurfer's Euler number, which summarizes the topological complexity of the reconstructed cortical surface. Results revealed that the Euler number was consistently correlated with manual ratings across samples. Furthermore, the Euler number could be used to identify images scored "unusable" by human raters with a high degree of accuracy (AUC: 0.98-0.99), and out-performed proxy measures from functional timeseries acquired in the same scanning session. The Euler number also was significantly related to cortical thickness in a regionally heterogeneous pattern that was consistent across datasets and replicated prior results. Finally, data quality both inflated and obscured associations with age during adolescence. Taken together, these results indicate that reliable measures of data quality can be automatically derived from T1

  12. [Niobium filtration in dental radiology. Effects on image quality and on dosage].

    Science.gov (United States)

    Bianchi, S D; Giovannetti, P; Albrito, F

    1997-06-01

    The necessity of reducing the radiation dose to the patient in diagnostic radiology according to the ALARA guideline established by the ICRP has stimulated the research on additional filtration systems capable of removing the low-energy photons increasing the dose and worsening image quality. Very few literature studies deal with the effects of niobium filtration on image quality in dental radiography with the use of modulation transfer function (MTF) and square wave response function (SWRF). Only one study has considered those effects measuring dose absorption in an anthropomorphic phantom. 1) to study the effects of a 30 microns additional niobium filter on image quality using the SWRF; 2) to compare the doses absorbed in vivo during a complete radiographic survey of the mouth, both with and without niobium filtration. Qualitative studies led us to conclude that niobium filtration does not significantly worsen radiographic image quality. The following doses were measured in the exposures with niobium filtration: 1678 microGy to 6000 microGy (intraoral doses) and 75 microGy to 3643 microGy (skin doses). The comparison with the doses measured during the exposures made with conventional filtration indicates that dose reduction is not significantly advantageous relative to risk reduction. In conclusion, additional niobium filtration is not advisable in dental radiology, also because of the filter cost and of the increased wear of the unit.

  13. Perceptual image quality and telescope performance ranking

    Science.gov (United States)

    Lentz, Joshua K.; Harvey, James E.; Marshall, Kenneth H.; Salg, Joseph; Houston, Joseph B.

    2010-08-01

    Launch Vehicle Imaging Telescopes (LVIT) are expensive, high quality devices intended for improving the safety of vehicle personnel, ground support, civilians, and physical assets during launch activities. If allowed to degrade from the combination of wear, environmental factors, and ineffective or inadequate maintenance, these devices lose their ability to provide adequate quality imagery to analysts to prevent catastrophic events such as the NASA Space Shuttle, Challenger, accident in 1986 and the Columbia disaster of 2003. A software tool incorporating aberrations and diffraction that was developed for maintenance evaluation and modeling of telescope imagery is presented. This tool provides MTF-based image quality metric outputs which are correlated to ascent imagery analysts' perception of image quality, allowing a prediction of usefulness of imagery which would be produced by a telescope under different simulated conditions.

  14. Are digital images good enough? A comparative study of conventional film-screen vs digital radiographs on printed images of total hip replacement

    Energy Technology Data Exchange (ETDEWEB)

    Eklund, K.; Jonsson, K.; Lindblom, G.; Lundin, B.; Sanfridsson, J.; Sloth, M. [Department of Radiology, Center for Medical Imaging and Physiology, Lund University Hospital, 22185, Lund (Sweden); Sivberg, B. [Department of Nursing, Faculty of Medicine, Lund University, P.O. Box 157, 22100, Lund (Sweden)

    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}{sub 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}{sub w} 0.29-0.71. For cement-bone region 7 an agreement of 87.21-90.45% was found, which is a varied {kappa}{sub 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. (orig.)

  15. MATLAB-Based Applications for Image Processing and Image Quality Assessment – Part I: Software Description

    Directory of Open Access Journals (Sweden)

    L. Krasula

    2011-12-01

    Full Text Available This paper describes several MATLAB-based applications useful for image processing and image quality assessment. The Image Processing Application helps user to easily modify images, the Image Quality Adjustment Application enables to create series of pictures with different quality. The Image Quality Assessment Application contains objective full reference quality metrics that can be used for image quality assessment. The Image Quality Evaluation Applications represent an easy way to compare subjectively the quality of distorted images with reference image. Results of these subjective tests can be processed by using the Results Processing Application. All applications provide Graphical User Interface (GUI for the intuitive usage.

  16. Lung imaging during acute chest syndrome in sickle cell disease: computed tomography patterns and diagnostic accuracy of bedside chest radiograph.

    Science.gov (United States)

    Mekontso Dessap, Armand; Deux, Jean-François; Habibi, Anoosha; Abidi, Nour; Godeau, Bertrand; Adnot, Serge; Brun-Buisson, Christian; Rahmouni, Alain; Galacteros, Frederic; Maitre, Bernard

    2014-02-01

    The lung computed tomography (CT) features of acute chest syndrome (ACS) in sickle cell disease patients is not well described, and the diagnostic performance of bedside chest radiograph (CR) has not been tested. Our objectives were to describe CT features of ACS and evaluate the reproducibility and diagnostic performance of bedside CR. We screened 127 consecutive patients during 166 ACS episodes and 145 CT scans (in 118 consecutive patients) were included in the study. Among the 145 CT scans, 139 (96%) exhibited a new pulmonary opacity and 84 (58%) exhibited at least one complete lung segment consolidation. Consolidations were predominant as compared with ground-glass opacities and atelectasis. Lung parenchyma was increasingly consolidated from apex to base; the right and left inferior lobes were almost always involved in patients with a new complete lung segment consolidation on CT scan (98% and 95% of cases, respectively). Patients with a new complete lung segment consolidation on CT scan had a more severe presentation and course as compared with others. The sensitivity of bedside CR for the diagnosis of ACS using CT as a reference was good (>85%), whereas the specificity was weak (lung bases. The reproducibility and diagnostic capacity of bedside CR were far from perfect. These findings may help improve the bedside imaging diagnosis of ACS.

  17. Effects of Clinical Training and Case Difficulty on the Radiographic Quality of Root Canal Fillings Performed by Dental Students in Saudi Arabia.

    Science.gov (United States)

    Alsulaimani, Reem Siraj; Al-Manei, Kholod Khalil; A Alsubait, Sara; AlAqeely, Razan Shafik; A M Al-Shehri, Sharifa; M Al-Madi, Ebtissam

    2015-01-01

    The aim of this study was to evaluate the effects of training duration and case difficulty on the radiographic quality of root canal fillings performed by dental students in Saudi Arabia. A longitudinal cohort study was conducted at King Saud University. Root canal treatments performed by 55 dental students from 2012-2014 were included in the study. Each student treated at least five teeth during the first year of clinical endodontic training and another five teeth during the second year. Case difficulty was assessed based on tooth position in the dental arch and preoperative conditions. The radiographic quality of the root canal filling was evaluated by two endodontists blinded to treatment completion date. The evaluation criteria were adequate obturation, presence of mishaps and preparation taper. The data were statistically analysed using univariate and multivariate logistic regression analyses; and the level of significance was set at 0.05. Inadequate obturation and mishaps were significantly less prevalent in teeth treated after 2 years of clinical training. The odds ratios for inadequate obturation and mishaps increased significantly as tooth position moved posteriorly. Inadequate obturation and more mishaps were significantly more prevalent in teeth with preoperative conditions. Preparation taper was not significantly affected by training duration or case difficulty. The quality of root canal fillings performed by Saudi students was adversely affected by case difficulty. The radiographic quality of root canal fillings improved significantly after 2 years of clinical training. Preparation taper outcome is likely dependent on the preparation technique and instrument taper.

  18. CLINICAL AUDIT OF IMAGE QUALITY IN RADIOLOGY USING VISUAL GRADING CHARACTERISTICS ANALYSIS.

    Science.gov (United States)

    Tesselaar, Erik; Dahlström, Nils; Sandborg, Michael

    2016-06-01

    The aim of this work was to assess whether an audit of clinical image quality could be efficiently implemented within a limited time frame using visual grading characteristics (VGC) analysis. Lumbar spine radiography, bedside chest radiography and abdominal CT were selected. For each examination, images were acquired or reconstructed in two ways. Twenty images per examination were assessed by 40 radiology residents using visual grading of image criteria. The results were analysed using VGC. Inter-observer reliability was assessed. The results of the visual grading analysis were consistent with expected outcomes. The inter-observer reliability was moderate to good and correlated with perceived image quality (r(2) = 0.47). The median observation time per image or image series was within 2 min. These results suggest that the use of visual grading of image criteria to assess the quality of radiographs provides a rapid method for performing an image quality audit in a clinical environment. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. A radiographic imaging system based upon a 2-D silicon microstrip sensor

    CERN Document Server

    Papanestis, A; Corrin, E; Raymond, M; Hall, G; Triantis, F A; Manthos, N; Evagelou, I; Van den Stelt, P; Tarrant, T; Speller, R D; Royle, G F

    2000-01-01

    A high resolution, direct-digital detector system based upon a 2-D silicon microstrip sensor has been designed, built and is undergoing evaluation for applications in dentistry and mammography. The sensor parameters and image requirements were selected using Monte Carlo simulations. Sensors selected for evaluation have a strip pitch of 50mum on the p-side and 80mum on the n-side. Front-end electronics and data acquisition are based on the APV6 chip and were adapted from systems used at CERN for high-energy physics experiments. The APV6 chip is not self-triggering so data acquisition is done at a fixed trigger rate. This paper describes the mammographic evaluation of the double sided microstrip sensor. Raw data correction procedures were implemented to remove the effects of dead strips and non-uniform response. Standard test objects (TORMAX) were used to determine limiting spatial resolution and detectability. MTFs were determined using the edge response. The results indicate that the spatial resolution of the...

  20. Digital systems to acquire radiological imaging. Characteristics and quality control; Sistemas digitales de adquisicion de imagenes radiograficas. Caracteristicas y Control de Calidad

    Energy Technology Data Exchange (ETDEWEB)

    Torres Cabrera, R.; Hernando Gonzalez, I.

    2006-07-01

    Due to its special characteristics, quality control in digital radiographic systems is very important, even more than in conventional film-screen systems. Differences between digital and analogical images,a in terms of dynamics range, spatial and contrast resolution, and the flexibility of data post-processing require some actions to maintain clinical images in an optimum quality level. Revision 1 of the Spanish Protocol of Quality Control in Diagnostic Radiology includes a chapter dedicated to the quality control of these digital systems for the acquisition of radiographic images. In this paper the different parameters for quality control procedures are described. Also some difficulties to be concerned about (absence of levels of tolerance, access to the raw-data images and related information, availability of use anthropomorphic phantoms, etc, etc) are noted, as well as the most significant aspects of the differences in relation to the ana logical systems. (Author) 15 refs.

  1. Evaluation of X ray attenuation by means of radiographic images; Avaliacao da atenuacao da radiacao X por meio de imagens radiograficas

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Frieda Saicla, E-mail: saicla@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Paredes, Ramon S.C., E-mail: ramon@ufpr.b [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Godoi, Walmor C., E-mail: walmor.godoi@gmail.co [Faculdade de Tecnologia Camoes (FATEC), Curitiba, PR (Brazil); Souza, Gabriel Pinto de [Universidade Estadual Paulista (UNESP), SP (Brazil)

    2011-07-01

    This paper's main goal is to adopt a qualitative methodology to evaluate the attenuation of x-radiation through X-ray images in polymeric materials plus residual lead. To determinate the images it was initially used an experimental setup at the Laboratory for Materials Diagnostics LACTEC. These results correspond to a more qualitative analysis, even with quantitative answers. Through analysis of radiographic images we can measure the intensity of radiation that goes through the plate, making possible to establish a relationship between the attenuation coefficient and the thickness of the material. (author)

  2. Subjective matters: from image quality to image psychology

    Science.gov (United States)

    Fedorovskaya, Elena A.; De Ridder, Huib

    2013-03-01

    From the advent of digital imaging through several decades of studies, the human vision research community systematically focused on perceived image quality and digital artifacts due to resolution, compression, gamma, dynamic range, capture and reproduction noise, blur, etc., to help overcome existing technological challenges and shortcomings. Technological advances made digital images and digital multimedia nearly flawless in quality, and ubiquitous and pervasive in usage, provide us with the exciting but at the same time demanding possibility to turn to the domain of human experience including higher psychological functions, such as cognition, emotion, awareness, social interaction, consciousness and Self. In this paper we will outline the evolution of human centered multidisciplinary studies related to imaging and propose steps and potential foci of future research.

  3. Quality image analysis and radiation protection in dental radiodiagnosis in Sobral city, BA, Brazil; Analise da qualidade de imagem e da radioprotecao em radiodiagnostico odontologico na cidade de Sobral

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Francisca L. [Universidade Estadual Vale do Acarau (UVA), Sobral, CE (Brazil); Ferreira, Fernanda C.L. [Universidade Federal do Sul e Sudeste do Para, Maraba, PA (Brazil); Paschoal, Cinthia M.M. [Universidade da Integracao Internacional da Lusofonia Afro-Brasileira, Redencao, CE (Brazil); Belinato, Walmir [Instituto Federal da Bahia, Vitoria da Conquista, BA (Brazil)

    2015-08-15

    The radiographic processing is one of the steps to acquire radiographic images and requires appropriate quality control. The image should allow an accurate diagnosis and avoid repetition of examinations, which is consistent with the principles of radiation protection. This study aimed to verify the quality of periapical radiographic imaging and to investigate the suitability of dental X-ray equipment on the principles of radiation protection established by the Health Ministry Decree 453/98, by applying radiation field test and application questionnaires to dentists professionals. The result showed that it takes greater care professionals about the treatment radiographic and radiation protection, requiring that inspection agencies require compliance with the rules so that there is maintaining the quality of dental diagnostic radiology services. (author)

  4. New radiographic bone erosions in the wrists of patients with rheumatoid arthritis are detectable with magnetic resonance imaging a median of two years earlier

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Hansen, Michael; Stoltenberg, Michael

    2003-01-01

    at 5-year followup was 4.5 (95% confidence interval [95% CI] 2.6-7.6), compared with bones without baseline MRI erosions. If bones with baseline radiographic erosions were excluded from the analysis, the relative risk was 4.1 (95% CI 2.2-7.5). CONCLUSION: Most new radiographic bone erosions (78%) were......OBJECTIVE: In a 5-year followup study, we investigated the temporal relationship between development of wrist joint erosions as visualized by magnetic resonance imaging (MRI) versus conventional radiography (CR), in patients with rheumatoid arthritis. We also evaluated the risk of erosive...... progression on CR associated with the presence of MRI erosions. METHODS: In 10 patients with rheumatoid arthritis, MRI and CR of the dominant wrist were performed annually for 5 years. In each image set, each wrist bone (metacarpal bases, carpal bones, radius, and ulna) was assessed for the absence...

  5. Multiple Image Arrangement for Subjective Quality Assessment

    Science.gov (United States)

    Wang, Yan; Zhai, Guangtao

    2017-12-01

    Subjective quality assessment serves as the foundation for almost all visual quality related researches. Size of the image quality databases has expanded from dozens to thousands in the last decades. Since each subjective rating therein has to be averaged over quite a few participants, the ever-increasing overall size of those databases calls for an evolution of existing subjective test methods. Traditional single/double stimulus based approaches are being replaced by multiple image tests, where several distorted versions of the original one are displayed and rated at once. And this naturally brings upon the question of how to arrange those multiple images on screen during the test. In this paper, we answer this question by performing subjective viewing test with eye tracker for different types arrangements. Our research indicates that isometric arrangement imposes less duress on participants and has more uniform distribution of eye fixations and movements and therefore is expected to generate more reliable subjective ratings.

  6. The effect of compensating filter on image quality in lateral projection of thoraco lumbar radiography

    Science.gov (United States)

    Daud, N. A. A.; Ali, M. H.; Nazri, N. A. Ahmad; Hamzah, N. J.; Awang, N. A.

    2014-11-01

    The aim of this project was to study the effect of compensating filter on image quality in lateral projection of thoraco lumbar radiography. The specific objectives of this study were to verify the relationship between density, contrast and noise of lateral thoraco lumbar radiography using various thickness of compensating filter and to determine the appropriate filter thickness with the thoraco lumbar density. The study was performed by an X- ray unit exposed to the body phantom where different thicknesses of aluminium were used as compensating filter. The radiographs were processed by CR reader and being imported to KPACS software to analyze the pixel depth value, contrast and noise. Result shows different thickness of aluminium compensating filter improved the image quality of lateral projection thoraco lumbar radiography. The compensating filter of 8.2 mm was considered as the optimal filter to compensate the thoraco lumbar junction (T12-L1), 1 mm to compensate lumbar region and 5.9 mm to compensate thorax region. The addition of aluminium compensating filter is advantageous in terms of efficiency which saving radiograph film, workload of the radiographer and radiation dose to patient.

  7. Characteristic functionals in imaging and image-quality assessment: tutorial.

    Science.gov (United States)

    Clarkson, Eric; Barrett, Harrison H

    2016-08-01

    Characteristic functionals are one of the main analytical tools used to quantify the statistical properties of random fields and generalized random fields. The viewpoint taken here is that a random field is the correct model for the ensemble of objects being imaged by a given imaging system. In modern digital imaging systems, random fields are not used to model the reconstructed images themselves since these are necessarily finite dimensional. After a brief introduction to the general theory of characteristic functionals, many examples relevant to imaging applications are presented. The propagation of characteristic functionals through both a binned and list-mode imaging system is also discussed. Methods for using characteristic functionals and image data to estimate population parameters and classify populations of objects are given. These methods are based on maximum likelihood and maximum a posteriori techniques in spaces generated by sampling the relevant characteristic functionals through the imaging operator. It is also shown how to calculate a Fisher information matrix in this space. These estimators and classifiers, and the Fisher information matrix, can then be used for image quality assessment of imaging systems.

  8. A software program to measure the three-dimensional length of the spine from radiographic images: Validation and reliability assessment for adolescent idiopathic scoliosis.

    Science.gov (United States)

    Berger, Steve; Hasler, Carol-Claudius; Grant, Caroline A; Zheng, Guoyan; Schumann, Steffen; Büchler, Philippe

    2017-01-01

    The aim of this study was to validate a new program which aims at measuring the three-dimensional length of the spine's midline based on two calibrated orthogonal radiographic images. The traditional uniplanar T1-S1 measurement method is not reflecting the actual three dimensional curvature of a scoliotic spine and is therefore not accurate. The Spinal Measurement Software (SMS) is an alternative to conveniently measure the true spine's length. The validity, inter- and intra-observer variability and usability of the program were evaluated. The usability was quantified based on a subjective questionnaire filled by eight participants using the program for the first time. The validity and variability were assessed by comparing the length of five phantom spines measured based on CT-scan data and on radiographic images with the SMS. The lengths were measured independently by each participant using both techniques. The SMS is easy and intuitive to use, even for non-clinicians. The SMS measured spinal length with an error below 2 millimeters compared to length obtained using CT scan datasets. The inter- and intra-observer variability of the SMS measurements was below 5 millimeters. The SMS provides accurate measurement of the spinal length based on orthogonal radiographic images. The software is easy to use and could easily integrate the clinical workflow and replace current approximations of the spinal length based on a single radiographic image such as the traditional T1-S1 measurement. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

  9. Retinal-image quality and maximum disparity

    Science.gov (United States)

    Castro, José J.; Jiménez, J. R.; Ortiz, Carolina; Alarcón, Aixa

    2010-01-01

    The aim of this paper is to evaluate the role of interocular differences in retinal-image quality in stereoscopic depth perception. To characterize retinal-image quality, we took the Strehl ratio from a double-pass device. Stereopsis was quantified through maximum disparity using random-dot stereograms (RDS). Data were taken for 25 observers with ages ranging from 21 to 61 years. The results show a significant correlation between maximum disparity and interocular differences in the Strehl ratio: the lower interocular differences, the higher maximum disparity. No significant dependence with age was found.

  10. Functional and radiographic evaluation and quality of life analysis after cementless total hip arthroplasty with ceramic bearings: minimum of 5 years follow-up

    Directory of Open Access Journals (Sweden)

    Rafael Borghi Mortat

    2013-12-01

    Full Text Available Objective: The aim of the study is to analyze and correlate functional and radiographic results and quality of life in patients undergoing cementless total hip arthroplasty with ceramic surface, performed at Hospital Servidor Publico de Sao Paulo from 2001 to 2006. Methods: We retrospectively analyzed 35 hips treated with cementless total hip arthroplasty with ceramic surfaces with a minimum follow-up of 5 years. Functional evaluation was based on the Harris Hip Score (HHS. Radiographic evaluation was based on the method proposed by Charles Engh for evaluation of femoral osseointegration and on DeLee and Charnley zones for acetabulum. Quality of life was assessed by SF-36 questionnaire. Results: The HHS presented excellent and good results in 91% of patients postoperatively (mean of 93.14 points HHS. As for radiographic evaluation, we found excellent results in 100% of evaluated hips (proven osseointegration. SF-36 scores were not compared to the control group for the following components: pain, vitality, mental health and social aspects. The difference between HHS pre and postoperatively had a statistically significant correlation with physical functioning of the SF-36. Conclusion: Total hip arthroplasty with ceramic surface is a treatment that enables functional improvement of the hip and increases quality of life of patients to levels close to those of people without joint diseases.

  11. Pleomorphic adenoma: Choice of radiographic imaging modality - Computed tomography or magnetic resonance imaging? Illustration through a case report

    Directory of Open Access Journals (Sweden)

    Shalu Rai

    2013-01-01

    Full Text Available Introduction: Pleomorphic adenoma (PA is the most common benign neoplasm of the major salivary glands arising primarily from the parotid gland. Computed tomography (CT is one of the primary imaging modalities used to assess the tumors of salivary glands. However, magnetic resonance imaging (MRI may provide additional information over CT. Case Report: We report the case of a 60-year-old male with a slowly enlarging, well-defined, round, painless, non-fixated, rubber-like swelling over the left ramus region below the ear, measuring about 4 × 4.5 cm, covering the lower border of the mandible near the angle. A provisional diagnosis of PA was given and CT and MRI were used to study the lesion. Discussion: Through this case, which was suspected to have undergone malignant transformation because of indistinct margins and focal hypodense areas on CT but was later confirmed to be a benign salivary gland tumor on MRI, we illustrate the role of CT and MRI as diagnostic aids in PA and emphasize on what should be the choice of imaging modality for parotid tumors.

  12. Association between findings on palmarodorsal radiographic images and detection of a fracture in the proximal sesamoid bones of forelimbs obtained from cadavers of racing Thoroughbreds.

    Science.gov (United States)

    Anthenill, Lucy A; Stover, Susan M; Gardner, Ian A; Hill, Ashley E; Lee, Christina M; Anderson, Mark L; Barr, Bradd C; Read, Deryck H; Johnson, Bill J; Woods, Leslie W; Daft, Barbara M; Kinde, Hailu; Moore, Janet D; Farman, Cynthia A; Odani, Jenee S; Pesavento, Patricia A; Uzal, Francisco A; Case, James T; Ardans, Alex A

    2006-05-01

    To determine the distribution for limbs and bones in horses with fractures of the proximal sesamoid bones and relationships with findings on palmarodorsal radiographic images. Proximal sesamoid bones obtained from both forelimbs of cadavers of 328 racing Thoroughbreds. Osteophytes; large vascular channels; and fracture location, orientation, configuration, and margin distinctness were categorized by use of high-detail contact palmarodorsal radiographs. Distributions of findings were determined. Relationships between radiographic findings and fracture characteristics were examined by use of chi2 and logistic regression techniques. Fractures were detected in 136 (41.5%) horses. Biaxial fractures were evident in 109 (80%) horses with a fracture. Osteophytes and large vascular channels were evident in 266 (81%) and 325 (99%) horses, respectively. Medial bones typically had complete transverse or split transverse simple fractures, indistinct fracture margins, > 1 vascular channel that was > 1 mm in width, and osteophytes in abaxial wing and basilar middle or basilar abaxial locations. Lateral bones typically had an oblique fracture and distinct fracture margins. Odds of proximal sesamoid bone fracture were approximately 2 to 5 times higher in bones without radiographic evidence of osteophytes or large vascular channels, respectively. Biaxial fractures of proximal sesamoid bones were common in cadavers of racing Thoroughbreds. Differences between medial and lateral bones for characteristics associated with fracture may relate to differences in fracture pathogeneses for these bones. Osteophytes and vascular channels were common findings; however, fractures were less likely to occur in bones with these features.

  13. Ultrasonic and radiographic evaluation of advanced aerospace materials: Ceramic composites

    Science.gov (United States)

    Generazio, Edward R.

    1990-01-01

    Two conventional nondestructive evaluation techniques were used to evaluate advanced ceramic composite materials. It was shown that neither ultrasonic C-scan nor radiographic imaging can individually provide sufficient data for an accurate nondestructive evaluation. Both ultrasonic C-scan and conventional radiographic imaging are required for preliminary evaluation of these complex systems. The material variations that were identified by these two techniques are porosity, delaminations, bond quality between laminae, fiber alignment, fiber registration, fiber parallelism, and processing density flaws. The degree of bonding between fiber and matrix cannot be determined by either of these methods. An alternative ultrasonic technique, angular power spectrum scanning (APSS) is recommended for quantification of this interfacial bond.

  14. Perceptual Quality Assessment of Screen Content Images.

    Science.gov (United States)

    Yang, Huan; Fang, Yuming; Lin, Weisi

    2015-11-01

    Research on screen content images (SCIs) becomes important as they are increasingly used in multi-device communication applications. In this paper, we present a study on perceptual quality assessment of distorted SCIs subjectively and objectively. We construct a large-scale screen image quality assessment database (SIQAD) consisting of 20 source and 980 distorted SCIs. In order to get the subjective quality scores and investigate, which part (text or picture) contributes more to the overall visual quality, the single stimulus methodology with 11 point numerical scale is employed to obtain three kinds of subjective scores corresponding to the entire, textual, and pictorial regions, respectively. According to the analysis of subjective data, we propose a weighting strategy to account for the correlation among these three kinds of subjective scores. Furthermore, we design an objective metric to measure the visual quality of distorted SCIs by considering the visual difference of textual and pictorial regions. The experimental results demonstrate that the proposed SCI perceptual quality assessment scheme, consisting of the objective metric and the weighting strategy, can achieve better performance than 11 state-of-the-art IQA methods. To the best of our knowledge, the SIQAD is the first large-scale database published for quality evaluation of SCIs, and this research is the first attempt to explore the perceptual quality assessment of distorted SCIs.

  15. REQUIREMENTS FOR IMAGE QUALITY OF EMERGENCY SPACECRAFTS

    Directory of Open Access Journals (Sweden)

    A. I. Altukhov

    2015-05-01

    Full Text Available The paper deals with the method for formation of quality requirements to the images of emergency spacecrafts. The images are obtained by means of remote sensing of near-earth space orbital deployment in the visible range. of electromagnetic radiation. The method is based on a joint taking into account conditions of space survey, characteristics of surveillance equipment, main design features of the observed spacecrafts and orbital inspection tasks. Method. Quality score is the predicted linear resolution image that gives the possibility to create a complete view of pictorial properties of the space image obtained by electro-optical system from the observing satellite. Formulation of requirements to the numerical value of this indicator is proposed to perform based on the properties of remote sensing system, forming images in the conditions of outer space, and the properties of the observed emergency spacecraft: dimensions, platform construction of the satellite, on-board equipment placement. For method implementation the authors have developed a predictive model of requirements to a linear resolution for images of emergency spacecrafts, making it possible to select the intervals of space shooting and get the satellite images required for quality interpretation. Main results. To verify the proposed model functionality we have carried out calculations of the numerical values for the linear resolution of the image, ensuring the successful task of determining the gross structural damage of the spacecrafts and identifying changes in their spatial orientation. As input data were used with dimensions and geometric primitives corresponding to the shape of deemed inspected spacecrafts: Resurs-P", "Canopus-B", "Electro-L". Numerical values of the linear resolution images have been obtained, ensuring the successful task solution for determining the gross structural damage of spacecrafts.

  16. Evaluating the role of the diagnostic research radiographer

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Karen, E-mail: karen.reid@nnuh.nhs.uk [Radiology Directorate, Level 2 East Block, Norfolk and Norwich University Hospital, Colney Lane, Norwich, NR4 7UY (United Kingdom); Edwards, Hazel, E-mail: hazel.edwards@nnuh.nhs.uk [Norwich Radiology Academy, Norfolk and Norwich University Hospital, Colney Lane, Norwich, NR4 7UB (United Kingdom)

    2011-08-15

    The NHS has an increasingly strong focus on evidence-based medicine to underpin policy making and the development of a culture of evaluation and learning. Good quality research is the foundation for this ethos. Numbers of research projects and clinical trials involving imaging are increasing and therefore more radiographers are contributing to these studies but perhaps on some occasions they may be unaware. This paper describes the benefits of having a dedicated research radiographer within a radiology department to organise and monitor studies. We explain the procedures of the research process, the knowledge and skills that such a radiographer requires and the value of coordination and governance in developing a culture of research in a radiology department. We make suggestions to overcome perceived barriers to engaging with research and discuss the advantages and limitations of the role. Others who are considering appointing a dedicated research radiographer may find our experience helpful.

  17. Effect of picture archiving and communication system image manipulation on the agreement of chest radiograph interpretation in the neonatal intensive care unit

    Directory of Open Access Journals (Sweden)

    Denise A Castro

    2016-01-01

    Full Text Available Objective: Variability in image interpretation has been attributed to differences in the interpreters′ knowledge base, experience level, and access to the clinical scenario. Picture archiving and communication system (PACS has allowed the user to manipulate the images while developing their impression of the radiograph. The aim of this study was to determine the agreement of chest radiograph (CXR impressions among radiologists and neonatologists and help determine the effect of image manipulation with PACS on report impression. Materials and Methods: Prospective cohort study included 60 patients from the Neonatal Intensive Care Unit undergoing CXRs. Three radiologists and three neonatologists reviewed two consecutive frontal CXRs of each patient. Each physician was allowed manipulation of images as needed to provide a decision of "improved," "unchanged," or "disease progression" lung disease for each patient. Each physician repeated the process once more; this time, they were not allowed to individually manipulate the images, but an independent radiologist presets the image brightness and contrast to best optimize the CXR appearance. Percent agreement and opposing reporting views were calculated between all six physicians for each of the two methods (allowing and not allowing image manipulation. Results: One hundred percent agreement in image impression between all six observers was only seen in 5% of cases when allowing image manipulation; 100% agreement was seen in 13% of the cases when there was no manipulation of the images. Conclusion: Agreement in CXR interpretation is poor; the ability to manipulate the images on PACS results in a decrease in agreement in the interpretation of these studies. New methods to standardize image appearance and allow improved comparison with previous studies should be sought to improve clinician agreement in interpretation consistency and advance patient care.

  18. Image Quality Indicator for Infrared Inspections

    Science.gov (United States)

    Burke, Eric

    2011-01-01

    The quality of images generated during an infrared thermal inspection depends on many system variables, settings, and parameters to include the focal length setting of the IR camera lens. If any relevant parameter is incorrect or sub-optimal, the resulting IR images will usually exhibit inherent unsharpness and lack of resolution. Traditional reference standards and image quality indicators (IQIs) are made of representative hardware samples and contain representative flaws of concern. These standards are used to verify that representative flaws can be detected with the current IR system settings. However, these traditional standards do not enable the operator to quantify the quality limitations of the resulting images, i.e. determine the inherent maximum image sensitivity and image resolution. As a result, the operator does not have the ability to optimize the IR inspection system prior to data acquisition. The innovative IQI described here eliminates this limitation and enables the operator to objectively quantify and optimize the relevant variables of the IR inspection system, resulting in enhanced image quality with consistency and repeatability in the inspection application. The IR IQI consists of various copper foil features of known sizes that are printed on a dielectric non-conductive board. The significant difference in thermal conductivity between the two materials ensures that each appears with a distinct grayscale or brightness in the resulting IR image. Therefore, the IR image of the IQI exhibits high contrast between the copper features and the underlying dielectric board, which is required to detect the edges of the various copper features. The copper features consist of individual elements of various shapes and sizes, or of element-pairs of known shapes and sizes and with known spacing between the elements creating the pair. For example, filled copper circles with various diameters can be used as individual elements to quantify the image sensitivity

  19. Image quality in coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Precht, Helle; Gerke, Oke; Thygesen, Jesper

    2018-01-01

    Background Computed tomography (CT) technology is rapidly evolving and software solution developed to optimize image quality and/or lower radiation dose. Purpose To investigate the influence of adaptive statistical iterative reconstruction (ASIR) at different radiation doses in coronary CT...... angiography (CCTA) in detailed image quality. Material and Methods A total of 160 CCTA were reconstructed as follows: 55 scans with filtered back projection (FBP) (650 mA), 51 scans (455 mA) with 30% ASIR (ASIR30), and 54 scans (295 mA) with 60% ASIR (ASIR60). For each reconstruction, subjective image quality...... was assessed by five independent certified cardiologists using a visual grading analysis (VGA) with five predefined image quality criteria consisting of a 5-point scale. Objective measures were contrast, noise, and contrast-to-noise ratio (CNR). Results The CTDIvol resulted in 10.3 mGy, 7.4 mGy, and 4.6 m...

  20. Review of Image Quality Measures for Solar Imaging

    Science.gov (United States)

    Popowicz, Adam; Radlak, Krystian; Bernacki, Krzysztof; Orlov, Valeri

    2017-12-01

    Observations of the solar photosphere from the ground encounter significant problems caused by Earth's turbulent atmosphere. Before image reconstruction techniques can be applied, the frames obtained in the most favorable atmospheric conditions (the so-called lucky frames) have to be carefully selected. However, estimating the quality of images containing complex photospheric structures is not a trivial task, and the standard routines applied in nighttime lucky imaging observations are not applicable. In this paper we evaluate 36 methods dedicated to the assessment of image quality, which were presented in the literature over the past 40 years. We compare their effectiveness on simulated solar observations of both active regions and granulation patches, using reference data obtained by the Solar Optical Telescope on the Hinode satellite. To create images that are affected by a known degree of atmospheric degradation, we employed the random wave vector method, which faithfully models all the seeing characteristics. The results provide useful information about the method performances, depending on the average seeing conditions expressed by the ratio of the telescope's aperture to the Fried parameter, D/r0. The comparison identifies three methods for consideration by observers: Helmli and Scherer's mean, the median filter gradient similarity, and the discrete cosine transform energy ratio. While the first method requires less computational effort and can be used effectively in virtually any atmospheric conditions, the second method shows its superiority at good seeing (D/r0<4). The third method should mainly be considered for the post-processing of strongly blurred images.

  1. Observer agreement in the reporting of knee and lumbar spine magnetic resonance (MR) imaging examinations: Selectively trained MR radiographers and consultant radiologists compared with an index radiologist

    Energy Technology Data Exchange (ETDEWEB)

    Brealey, S., E-mail: stephen.brealey@york.ac.uk [Department of Health Sciences, University of York, York YO10 5DD (United Kingdom); Piper, K., E-mail: keith.piper@canterbury.ac.uk [Department of Allied Health Professions, Canterbury Christ Church University, Canterbury, Kent CT1 1QU (United Kingdom); King, D., E-mail: david.g.king@york.nhs.uk [York Hospital, Wigginton Road, York YO31 8HE (United Kingdom); Bland, M., E-mail: martin.bland@york.ac.uk [Department of Health Sciences, University of York, York YO10 5DD (United Kingdom); Caddick, J., E-mail: Julie.Caddick@york.nhs.uk [York Hospital, Wigginton Road, York YO31 8HE (United Kingdom); Campbell, P., E-mail: peter.campbell@york.nhs.uk [York Hospital, Wigginton Road, York YO31 8HE (United Kingdom); Gibbon, A., E-mail: anthony.j.gibbon@york.nhs.uk [York Hospital, Wigginton Road, York YO31 8HE (United Kingdom); Highland, A., E-mail: Adrian.Highland@sth.nhs.uk [Sheffield Teaching Hospitals, Herries Road, Sheffield S5 7AU (United Kingdom); Jenkins, N., E-mail: neil.jenkins@york.nhs.uk [York Hospital, Wigginton Road, York YO31 8HE (United Kingdom); Petty, D., E-mail: daniel.petty@york.nhs.uk [York Hospital, Wigginton Road, York YO31 8HE (United Kingdom); Warren, D., E-mail: david.warren@york.nhs.uk [York Hospital, Wigginton Road, York YO31 8HE (United Kingdom)

    2013-10-01

    Purpose: To assess agreement between trained radiographers and consultant radiologists compared with an index radiologist when reporting on magnetic resonance imaging (MRI) examinations of the knee and lumbar spine and to examine the subsequent effect of discordant reports on patient management and outcome. Methods: At York Hospital two MR radiographers, two consultant radiologists and an index radiologist reported on a prospective, random sample of 326 MRI examinations. The radiographers reported in clinical practice conditions and the radiologists during clinical practice. An independent consultant radiologist compared these reports with the index radiologist report for agreement. Orthopaedic surgeons then assessed whether the discordance between reports was clinically important. Results: Overall observer agreement with the index radiologist was comparable between observers and ranged from 54% to 58%; for the knee it was 46–57% and for the lumbar spine was 56–66%. There was a very small observed difference of 0.6% (95% CI −11.9 to 13.0) in mean agreement between the radiographers and radiologists (P = 0.860). For the knee, lumbar spine and overall, radiographers’ discordant reports, when compared with the index radiologist, were less likely to have a clinically important effect on patient outcome than the radiologists’ discordant reports. Less than 10% of observer's reports were sufficiently discordant with the index radiologist's reports to be clinically important. Conclusion: Carefully selected MR radiographers with postgraduate education and training reported in clinical practice conditions on specific MRI examinations of the knee and lumbar spine to a level of agreement comparable with non-musculoskeletal consultant radiologists.

  2. Development of Stand Alone Application Tool for Processing and Quality Measurement of Weld Imperfection Image Captured by μ-Focused Digital Radiography Using MATLAB- Based Graphical User Interface

    Directory of Open Access Journals (Sweden)

    PZ Nadila

    2012-12-01

    Full Text Available Digital radiography incresingly is being applied in the fabrication industry. Compared to film- based radiography, digitally radiographed images can be acquired with less time and fewer exposures. However, noises can simply occur on the digital image resulting in a low-quality result. Due to this and the system’s complexity, parameters’ sensitivity, and environmental effects, the results can be difficult to interpret, even for a radiographer. Therefore, the need of an application tool to improve and evaluate the image is becoming urgent. In this research, a user-friendly tool for image processing and image quality measurement was developed. The resulting tool contains important components needed by radiograph inspectors in analyzing defects and recording the results. This tool was written by using image processing and the graphical user interface development environment and compiler (GUIDE toolbox available in Matrix Laboratory (MATLAB R2008a. In image processing methods, contrast adjustment, and noise removal, edge detection was applied. In image quality measurement methods, mean square error (MSE, peak signal-to-noise ratio (PSNR, modulation transfer function (MTF, normalized signal-to-noise ratio (SNRnorm, sensitivity and unsharpness were used to measure the image quality. The graphical user interface (GUI wass then compiled to build a Windows, stand-alone application that enables this tool to be executed independently without the installation of MATLAB.

  3. Influence of physical parameters on radiation protection and image quality in intra-oral radiology

    Energy Technology Data Exchange (ETDEWEB)

    Belinato, W. [Instituto Federal de Ensino Basico, Tecnico e Tecnologico da Bahia, Av. Amazonas, 1350-45030-220, Zabele, Vitoria da Conquista, BA (Brazil); Departamento de Fisica, Universidade Federal de Sergipe, Av. Marechal Rondon s/n, 49100-000 Rosa Elze, Sao Cristovao, SE (Brazil); Souza, D.N., E-mail: divanizi@ufs.br [Departamento de Fisica, Universidade Federal de Sergipe, Av. Marechal Rondon s/n, 49100-000 Rosa Elze, Sao Cristovao, SE (Brazil)

    2011-10-01

    In the world of diagnostic imaging, radiography is an important supplementary method for dental diagnosis. In radiology, special attention must be paid to the radiological protection of patients and health professionals, and also to image quality for correct diagnosis. In Brazil, the national rules governing the operation of medical and dental radiology were specified in 1998 by the National Sanitary Surveillance Agency, complemented in 2005 by the guide 'Medical radiology: security and performance of equipment.' In this study, quality control tests were performed in public clinics with dental X-ray equipment in the State of Sergipe, Brazil, with consideration of the physical parameters that influence radiological protection and also the quality of images taken in intra-oral radiography. The accuracy of the exposure time was considered acceptable for equipment with digital timers. Exposure times and focal-spot size variations can lead to increased entrance dose. Increased dose has also been associated with visual processing of radiographic film, which often requires repeating the radiographic examination.

  4. Influence of physical parameters on radiation protection and image quality in intra-oral radiology

    Science.gov (United States)

    Belinato, W.; Souza, D. N.

    2011-10-01

    In the world of diagnostic imaging, radiography is an important supplementary method for dental diagnosis. In radiology, special attention must be paid to the radiological protection of patients and health professionals, and also to image quality for correct diagnosis. In Brazil, the national rules governing the operation of medical and dental radiology were specified in 1998 by the National Sanitary Surveillance Agency, complemented in 2005 by the guide "Medical radiology: security and performance of equipment." In this study, quality control tests were performed in public clinics with dental X-ray equipment in the State of Sergipe, Brazil, with consideration of the physical parameters that influence radiological protection and also the quality of images taken in intra-oral radiography. The accuracy of the exposure time was considered acceptable for equipment with digital timers. Exposure times and focal-spot size variations can lead to increased entrance dose. Increased dose has also been associated with visual processing of radiographic film, which often requires repeating the radiographic examination.

  5. Variability amongst radiographers in the categorization of clinical acceptability for digital trauma radiography

    Science.gov (United States)

    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, pConclusion: 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-off values.

  6. Correlation of contrast-detail analysis and clinical image quality assessment in chest radiography with a human cadaver study.

    Science.gov (United States)

    De Crop, An; Bacher, Klaus; Van Hoof, Tom; Smeets, Peter V; Smet, Barbara S; Vergauwen, Merel; Kiendys, Urszula; Duyck, Philippe; Verstraete, Koenraad; D'Herde, Katharina; Thierens, Hubert

    2012-01-01

    To determine the correlation between the clinical and physical image quality of chest images by using cadavers embalmed with the Thiel technique and a contrast-detail phantom. The use of human cadavers fulfilled the requirements of the institutional ethics committee. Clinical image quality was assessed by using three human cadavers embalmed with the Thiel technique, which results in excellent preservation of the flexibility and plasticity of organs and tissues. As a result, lungs can be inflated during image acquisition to simulate the pulmonary anatomy seen on a chest radiograph. Both contrast-detail phantom images and chest images of the Thiel-embalmed bodies were acquired with an amorphous silicon flat-panel detector. Tube voltage (70, 81, 90, 100, 113, 125 kVp), copper filtration (0.1, 0.2, 0.3 mm Cu), and exposure settings (200, 280, 400, 560, 800 speed class) were altered to simulate different quality levels. Four experienced radiologists assessed the image quality by using a visual grading analysis (VGA) technique based on European Quality Criteria for Chest Radiology. The phantom images were scored manually and automatically with use of dedicated software, both resulting in an inverse image quality figure (IQF). Spearman rank correlations between inverse IQFs and VGA scores were calculated. A statistically significant correlation (r = 0.80, P detail phantom analysis for evaluating clinical image quality in chest radiography. © RSNA, 2011.

  7. Image quality assessment and medical physics evaluation of different portable dental X-ray units.

    Science.gov (United States)

    Pittayapat, Pisha; Oliveira-Santos, Christiano; Thevissen, Patrick; Michielsen, Koen; Bergans, Niki; Willems, Guy; Debruyckere, Deborah; Jacobs, Reinhilde

    2010-09-10

    Recently developed portable dental X-ray units increase the mobility of the forensic odontologists and allow more efficient X-ray work in a disaster field, especially when used in combination with digital sensors. This type of machines might also have potential for application in remote areas, military and humanitarian missions, dental care of patients with mobility limitation, as well as imaging in operating rooms. To evaluate radiographic image quality acquired by three portable X-ray devices in combination with four image receptors and to evaluate their medical physics parameters. Images of five samples consisting of four teeth and one formalin-fixed mandible were acquired by one conventional wall-mounted X-ray unit, MinRay 60/70 kVp, used as a clinical standard, and three portable dental X-ray devices: AnyRay 60 kVp, Nomad 60 kVp and Rextar 70 kVp, in combination with a phosphor image plate (PSP), a CCD, or a CMOS sensor. Three observers evaluated images for standard image quality besides forensic diagnostic quality on a 4-point rating scale. Furthermore, all machines underwent tests for occupational as well as patient dosimetry. Statistical analysis showed good quality imaging for all system, with the combination of Nomad and PSP yielding the best score. A significant difference in image quality between the combination of the four X-ray devices and four sensors was established (p1m: Rextar <0.2 microGy, MinRay <0.1 microGy). The present study demonstrated the feasibility of three portable X-ray systems to be used for specific indications, based on acceptable image quality and sufficient accuracy of the machines and following the standard guidelines for radiation hygiene. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  8. A randomized controlled trial on 2 simulation-based training methods in radiology: effects on radiologic technology student skill in assessing image quality.

    Science.gov (United States)

    Ahlqvist, Jan B; Nilsson, Tore A; Hedman, Leif R; Desser, Terry S; Dev, Parvati; Johansson, Magnus; Youngblood, Patricia L; Cheng, Robert P; Gold, Garry E

    2013-12-01

    A simulator for virtual radiographic examinations was developed. In the virtual environment, the user can perform and analyze radiographic examinations of patient models without the use of ionizing radiation. We investigated if this simulation technique could improve education of radiology technology students. We compared student performance in the assessment of radiographic image quality after training with a conventional manikin or with the virtual radiography simulator. A randomized controlled experimental study involving 31 first-year radiology technology students was performed. It was organized in 4 phases as follows: (I) randomization to control or experimental group based on the results of an anatomy examination; (II) proficiency testing before training; (III) intervention (control group, exposure and analysis of radiographic images of the cervical spine of a manikin; experimental group, exposure and analysis of the cervical spine images in the virtual radiography simulator); and (IV) proficiency testing after training. The experimental group showed significantly higher scores after training compared with those before training (P Virtual radiographic simulation is an effective tool for learning image quality assessment. Simulation can therefore be a valuable adjunct to traditional educational methods and reduce exposure to x-rays and tutoring time.

  9. BRAGA: an easy to use and accurate grid alignment system to control scatter and improve image quality in bedside radiography

    Science.gov (United States)

    Gauntt, David M.; Barnes, Gary T.

    2008-03-01

    BRAGA (Bedside Radiography Automatic Grid Alignment) is a means of easily and automatically aligning the x-ray tube and grid in bedside radiography. BRAGA permits the use of high ratio (12:1 or 15:1) grids and produces portable radiographs with markedly improved image quality compared to conventional techniques, with no increase in patient dose. BRAGA's design and operational principles are described. Virtually perfect focal spot grid alignment is achieved in less than ten seconds with little additional effort on the part of the technologist. Presented are comparison conventional (non grid) and BRAGA (15:1 grid) chest portable radiographs obtained employing the same kVp, mAs and patient dose. The BRAGA X-ray has markedly better image quality than the conventional portable X-ray.

  10. Detectability of normal anatomy in digital panoramic radiographs.

    Science.gov (United States)

    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.

  11. Shaped, lead-loaded acrylic filters for patient exposure reduction and image-quality improvement

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.E.; Stears, J.G.; Frank, E.D.

    1983-03-01

    Shaped filters that are constructed of lead-loaded acrylic material for use in patient radiography are discussed. Use of the filters will result in improved overall image quality with significant exposure reduction to the patient (approximately a 2X reduction in breast exposure and a 3X reduction in thyroid gland exposure). Detailed drawings of the shaped filters for scoliosis radiography, cervical spine radiography, and for long film changers in special procedures are provided. The use of the scoliosis filters is detailed and includes phantom and patient radiographs and dose reduction information.

  12. Image quality assessment and human visual system

    Science.gov (United States)

    Gao, Xinbo; Lu, Wen; Tao, Dacheng; Li, Xuelong

    2010-07-01

    This paper summaries the state-of-the-art of image quality assessment (IQA) and human visual system (HVS). IQA provides an objective index or real value to measure the quality of the specified image. Since human beings are the ultimate receivers of visual information in practical applications, the most reliable IQA is to build a computational model to mimic the HVS. According to the properties and cognitive mechanism of the HVS, the available HVS-based IQA methods can be divided into two categories, i.e., bionics methods and engineering methods. This paper briefly introduces the basic theories and development histories of the above two kinds of HVS-based IQA methods. Finally, some promising research issues are pointed out in the end of the paper.

  13. Radiographic tales

    DEFF Research Database (Denmark)

    Mussmann, Bo Redder

    . Methods The study is designed as an observational study with a narrative approach. The participant observations took place in a Danish radiological department and involved 20 examinations followed up by three semi-structured interviews. Conclusions Through emergent narratives radiographers construct...... a practice in which the relationship between man and technology is marked by a struggle of domination of one over the other. The struggle expresses itself through two competing plots: A diagnostic plot with a prevailing, but not merely chronological structure mostly composed of events tied to pathology...

  14. Image quality evaluation: the data mining approach

    Science.gov (United States)

    Cui, Chengwu

    2005-01-01

    It is difficult if not impossible to derive a model to adequately describe the entire visual, cognitive and preference decision process of image quality evaluation and to replace it with objective alternatives. Even if some parts of the process can be modeled based on the current knowledge of the visual system, there is often a lack of sufficient data to support the modeling process. On the other hand, image quality evaluation is constantly required for those working on imaging devices and software. Measurements and surveys are regularly conducted to test a newer processing algorithm or a methodology. Large scale subjective measurement or surveys are often conducted before a product is released. Here we propose to combine the two processes and apply data mining techniques to achieve both goals of routine subjective testing and modeling. Specifically, we propose to use relational databases to log and store regular evaluation processes. When combined with web applications, the relational databases approach allow one to maximally improve the efficiency of designing, conducting, analyzing, and reporting test data. The collection of large amounts of data makes it possible to apply data mining techniques to discover knowledge and patterns in the data. Here we report one such system for printing quality evaluation and some theories on data mining including data visualization, observer mining, text comment mining, test case mining, model mining. We also present some preliminary results based on some of these techniques.

  15. Ultrasound image quality assessment: a framework for evaluation of clinical image quality

    Science.gov (United States)

    Hemmsen, Martin Christian; Petersen, Mads Møller; Nikolov, Svetoslav Ivanov; Nielsen, Michael Backmann; Jensen, Jørgen Arendt

    2010-03-01

    Improvement of ultrasound images should be guided by their diagnostic value. Evaluation of clinical image quality is generally performed subjectively, because objective criteria have not yet been fully developed and accepted for the evaluation of clinical image quality. Based on recommendation 500 from the International Telecommunication Union - Radiocommunication (ITU-R) for such subjective quality assessment, this work presents equipment and a methodology for clinical image quality evaluation for guiding the development of new and improved imaging. The system is based on a BK-Medical 2202 ProFocus scanner equipped with a UA2227 research interface, connected to a PC through X64-CL Express camera link. Data acquisition features subject data recording, loading/saving of exact scanner settings (for later experiment reproducibility), free access to all system parameters for beamformation and is applicable for clinical use. The free access to all system parameters enables the ability to capture standardized images as found in the clinic and experimental data from new processing or beamformation methods. The length of the data sequences is only restricted by the memory of the external PC. Data may be captured interleaved, switching between multiple setups, to maintain identical transducer, scanner, region of interest and recording time on both the experimental- and standardized images. Data storage is approximately 15.1 seconds pr. 3 sec sequence including complete scanner settings and patient information, which is fast enough to get sufficient number of scans under realistic operating conditions, so that statistical evaluation is valid and reliable.

  16. Radiographic evaluation of the quality of root canal obturation of single-matched cone Gutta-percha root canal filling versus hot lateral technique

    OpenAIRE

    Randa Suleiman Obeidat; Hassan Abdallah

    2014-01-01

    Aim: The aim of this study is to evaluate radiographically the quality of root canal filling in mesiodistal and buccolingual view when comparing matched cone condensation and warm lateral Gutta-percha condensation using system B heating instrument in a low-heat warm lateral condensation technique in0 vitro. Materials and Methods: A total of 40 mandibular premolars with straight single canals were divided into two groups with 20 each. The root canals were shaped by hand file and Revo-S rotary ...

  17. Cone beam computed tomography radiation dose and image quality assessments.

    Science.gov (United States)

    Lofthag-Hansen, Sara

    2010-01-01

    Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: patient positioning, volume size (FOV), radiation quality, image capturing and reconstruction, image resolution and radiation dose. When new technology is introduced one must make sure that diagnostic accuracy is better or at least as good as the one it can be expected to replace. The CBCT brand tested was two versions of Accuitomo (Morita, Japan): 3D Accuitomo with an image intensifier as detector, FOV 3 cm x 4 cm and 3D Accuitomo FPD with a flat panel detector, FOVs 4 cm x 4 cm and 6 cm x 6 cm. The 3D Accuitomo was compared with intra-oral radiography for endodontic diagnosis in 35 patients with 46 teeth analyzed, of which 41 were endodontically treated. Three observers assessed the images by consensus. The result showed that CBCT imaging was superior with a higher number of teeth diagnosed with periapical lesions (42 vs 32 teeth). When evaluating 3D Accuitomo examinations in the posterior mandible in 30 patients, visibility of marginal bone crest and mandibular canal, important anatomic structures for implant planning, was high with good observer agreement among seven observers. Radiographic techniques have to be evaluated concerning radiation dose, which requires well-defined and easy-to-use methods. Two methods: CT dose index (CTDI), prevailing method for CT units, and dose-area product (DAP) were evaluated for calculating effective dose (E) for both units. An asymmetric dose distribution was revealed when a clinical situation was simulated. Hence, the CTDI method was not applicable for these units with small FOVs. Based on DAP values from 90 patient examinations effective dose was estimated for three diagnostic tasks: implant planning in posterior mandible and

  18. Radiographic Assessment of the Technical Quality and Periapical Health of Root-Filled Teeth Performed by General Practitioners in a Turkish Subpopulation

    Directory of Open Access Journals (Sweden)

    E. Tarim Ertas

    2013-01-01

    Full Text Available Aim. The aim of this study was to evaluate by means of radiographs the technical quality of root fillings performed by dental practitioners. Methods and Material. Standardized periapical radiographs were made on 484 patients who received endodontic treatment in private practice. A total of 831 endodontically treated teeth with 1448 roots were evaluated for technical quality of the root canal filling and the periapical status of the teeth. Also, the apical status of each root-filled tooth was assessed according to the length, density, and taper of root fillings, and the presence of apical transportation, broken root instruments, and overfilled sealer or gutta-percha material was recorded for each root canal. Results. Of the endodontically treated teeth 26.6% had healthy periapical tissues, while technically good endodontic treatment constituted 12.8%. Based on the treatment success, there was no significant difference between the tooth groups. Statistical analysis of the data did not demonstrate statistically significant differences between the various parameters that were evaluated (. Conclusions. Technical quality of root fillings in a population who received treatment in private practice was poor and was consistent with a low prevalence of apical health. The probable reasons for this failure are multifactorial and may be improved if the operators improve their skills with continuing postgraduate education programs.

  19. Low Quality Image Retrieval System For Generic Databases

    Directory of Open Access Journals (Sweden)

    W.A.D.N. Wijesekera

    2015-08-01

    Full Text Available Abstract Content Based Image Retrieval CBIR systems have become the trend in image retrieval technologies as the index or notation based image retrieval algorithms give less efficient results in high usage of images. These CBIR systems are mostly developed considering the availability of high or normal quality images. High availability of low quality images in databases due to usage of different quality equipment to capture images and different environmental conditions the photos are being captured has opened up a new path in image retrieval research area. The algorithms which are developed for low quality image based image retrieval are only a few and have been performed only for specific domains. Low quality image based image retrieval algorithm on a generic database with a considerable accuracy level for different industries is an area which remains unsolved. Through this study an algorithm has been developed to achieve above mentioned gaps. By using images with inappropriate brightness and compressed images as low quality images the proposed algorithm is tested on a generic database which includes many categories of data instead of using a specific domain. The new algorithm developed gives better precision and recall values when they are clustered into the most appropriate number of clusters which changes according to the level of quality of the image. As the quality of the image decreases the accuracy of the algorithm also tends to be reduced a space for further improvement.

  20. The skeleton in congenital, generalized lipodystrophy: evaluation using whole-body radiographic surveys, magnetic resonance imaging and technetium-99m bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Fleckenstein, J.L.; Bonte, F.J. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Radiology); Garg, A. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Internal Medicine); Vuitch, M.F. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Pathology); Peshock, R.M. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Radiology Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Internal Medicine)

    1992-08-01

    Congenital generalized lipodystrophy (CGL) is a rare genetic disease characterized by the absence of body fat from birth. Focal bone lesions have also been reported, but their pathophysiology is poorly understood. To characterize skeletal abnormalities further in 3 patients with CGL, we employed whole-body radiographic skeletal surveys, magnetic resonance imaging (MRI, including gadolinium enhancement), and triple phase technetium-99m methylene diphosphonate bone scintigraphy. We conclude that the appendicular skeleton of patients with CGL is diffusely abnormal and is predisposed to focal osteolysis and cyst formation. (orig./DG).

  1. Paediatric x-ray radiation dose reduction and image quality analysis.

    Science.gov (United States)

    Martin, L; Ruddlesden, R; Makepeace, C; Robinson, L; Mistry, T; Starritt, H

    2013-09-01

    Collaboration of multiple staff groups has resulted in significant reduction in the risk of radiation-induced cancer from radiographic x-ray exposure during childhood. In this study at an acute NHS hospital trust, a preliminary audit identified initial exposure factors. These were compared with European and UK guidance, leading to the introduction of new factors that were in compliance with European guidance on x-ray tube potentials. Image quality was assessed using standard anatomical criteria scoring, and visual grading characteristics analysis assessed the impact on image quality of changes in exposure factors. This analysis determined the acceptability of gradual radiation dose reduction below the European and UK guidance levels. Chest and pelvis exposures were optimised, achieving dose reduction for each age group, with 7%-55% decrease in critical organ dose. Clinicians confirmed diagnostic image quality throughout the iterative process. Analysis of images acquired with preliminary and final exposure factors indicated an average visual grading analysis result of 0.5, demonstrating equivalent image quality. The optimisation process and final radiation doses are reported for Carestream computed radiography to aid other hospitals in minimising radiation risks to children.

  2. A Dental Radiograph Recognition System Using Phase-Only Correlation for Human Identification

    Science.gov (United States)

    Ito, Koichi; Nikaido, Akira; Aoki, Takafumi; Kosuge, Eiko; Kawamata, Ryota; Kashima, Isamu

    In mass disasters such as earthquakes, fire disasters, tsunami, and terrorism, dental records have been used for identifying victims due to their processing time and accuracy. The greater the number of victims, the more time the identification tasks require, since a manual comparison between the dental radiograph records is done by forensic experts. Addressing this problem, this paper presents an efficient dental radiograph recognition system using Phase-Only Correlation (POC) for human identification. The use of phase components in 2D (two-dimensional) discrete Fourier transforms of dental radiograph images makes possible to achieve highly robust image registration and recognition. Experimental evaluation using a set of dental radiographs indicates that the proposed system exhibits efficient recognition performance for low-quality images.

  3. Peritoneal tuberculosis: radiographic diagnosis

    Directory of Open Access Journals (Sweden)

    Carolina Ospina-Moreno

    2014-12-01

    Full Text Available Peritoneal tuberculosis (TB is an extrapulmonary form of presentation of tuberculosis. HIV infection is a primary risk factor for this condition. Diagnosis requires microbiological or histopathological confirmation in addition to supporting radiological imaging studies. Abdominal ultrasonography and CT are useful to obtain a radiographic diagnosis, with typical findings including diffuse peritoneal thickening, presence of ascites in varying volumes, adenopathies, and caseating nodes. We report 2 cases of patients with ascites and nodular peritoneal thickening on diagnostic images, as well as high CA-125 levels in laboratory tests. In both patients, a diagnosis of peritoneal tuberculosis was reached following a US-guided peritoneal biopsy.

  4. Automatic delamination defect detection in radiographic sequence of rocket boosters; Determination automatique de defauts de delaminage dans des sequences d'images radiographiques de propulseurs de fusee

    Energy Technology Data Exchange (ETDEWEB)

    Rebuffel, V.; Pires, S. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI/DSIS/SSBS), 38 (France); Caplier, A. [Institut National Polytechnique, 38 - Grenoble (France); Lamarque, P. [SNPE, 75 - Paris (France)

    2003-07-01

    Solid rocket motors are routinely examined in real-time X-ray radioscopic mode. The large and cylindrical boosters are rotating between a high energy source and a two dimensional detector. The purpose of this control is to detect possible defects all through the sample. In the tangential configuration, the part of the object that intersects the X-rays beam is the peripheral one, allowing to detect the delamination defect between the propellant and the external metal envelope. But the defect detectability is very poor due to the strong attenuation of the X-rays through the motors. During the rotation of the booster, the system acquires a sequence of radiographs where the defects are visible over several successive instants. We have previously developed a real-time tomo-synthesis system, processing the radiographs on line, and based on a tomo-synthesis reconstruction algorithm in order to improve the signal-to-noise ratio. This system is installed at the industrial site of Kourou, and is currently used by the operators in charge of the visual inspection of the boosters. In this paper, we present a method that processes the digital images obtained by the system in the purpose of automatically extracting the delamination defects. Due to the size and the poor contrast of the defects, a single image is not sufficient to perform this detection. A spatio-temporal aspect is required for the algorithm to be robust and efficient. In a first step, the proposed method computes the apparent local displacement between the current radiograph and a reference one. This reference image is acquired at the beginning of the rotation, with few noise, and is supposed to be defect free. The apparent displacement is due to the non-perfect rotation positioning. It may be uniform or not, depending on the deformation of the insulation liner of the metallic wall. The images are then registered and compared. On the resulting difference image we apply a smoothed threshold to obtain an

  5. The x-ray light valve: a low-cost, digital radiographic imaging system--spatial resolution.

    Science.gov (United States)

    MacDougall, Robert D; Koprinarov, Ivaylo; Rowlands, J A

    2008-09-01

    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.

  6. Image analysis for dental bone quality assessment using CBCT imaging

    Science.gov (United States)

    Suprijanto; Epsilawati, L.; Hajarini, M. S.; Juliastuti, E.; Susanti, H.

    2016-03-01

    Cone beam computerized tomography (CBCT) is one of X-ray imaging modalities that are applied in dentistry. Its modality can visualize the oral region in 3D and in a high resolution. CBCT jaw image has potential information for the assessment of bone quality that often used for pre-operative implant planning. We propose comparison method based on normalized histogram (NH) on the region of inter-dental septum and premolar teeth. Furthermore, the NH characteristic from normal and abnormal bone condition are compared and analyzed. Four test parameters are proposed, i.e. the difference between teeth and bone average intensity (s), the ratio between bone and teeth average intensity (n) of NH, the difference between teeth and bone peak value (Δp) of NH, and the ratio between teeth and bone of NH range (r). The results showed that n, s, and Δp have potential to be the classification parameters of dental calcium density.

  7. Simulation of High Quality Ultrasound Imaging

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Kortbek, Jacob; Nikolov, Svetoslav Ivanov

    2010-01-01

    This paper investigates if the influence on image quality using physical transducers can be simulated with an sufficient accuracy to reveal system performance. The influence is investigated in a comparative study between Synthetic Aperture Sequential Beamformation (SASB) and Dynamic Receive Focus...... is modeled by incorporating measured element pulse echo responses into the simulation software. Validation is performed through measurements on a water phantom with three metal wires, each with a diameter of 0.07 mm. Results show that when comparing measurement and simulation, the lateral beam profile using...

  8. MRI visualisation by digitally reconstructed radiographs

    Science.gov (United States)

    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.

  9. Image quality of cone beam computed tomography for evaluation of extremity fractures in the presence of metal hardware: visual grading characteristics analysis.

    Science.gov (United States)

    Osgood, Greg M; Thawait, Gaurav K; Hafezi-Nejad, Nima; Shakoor, Delaram; Shaner, Adam; Yorkston, John; Zbijewski, Wojciech B; Siewerdsen, Jeffrey H; Demehri, Shadpour

    2017-05-01

    To evaluate image quality and interobserver reliability of a novel cone-beam CT (CBCT) scanner in comparison with plain radiography for assessment of fracture healing in the presence of metal hardware. In this prospective institutional review board-approved Health Insurance Portability and Accountability Act of 1996-complaint study, written informed consent was obtained from 27 patients (10 females and 17 males; mean age 44 years, age range 21-83 years) with either upper or lower extremity fractures, and with metal hardware, who underwent CBCT scans and had a clinical radiograph of the affected part. Images were assessed by two independent observers for quality and interobserver reliability for seven visualization tasks. Visual grading characteristic (VGC) curve analysis determined the differences in image quality between CBCT and plain radiography. Interobserver agreement was calculated using Pearson's correlation coefficient. VGC results displayed preference of CBCT images to plain radiographs in terms of visualizing (1) cortical and (2) trabecular bones; (3) fracture line; (4) callus formation; (5) bridging ossification; and (6) screw thread-bone interface and its inferiority to plain radiograph in the visualization of (7) large metallic side plate contour with strong interobserver correlation (p-value < 0.05), except for visualizing large metallic side plate contour. For evaluation of fracture healing in the presence of metal hardware, CBCT image quality is preferable to plain radiograph for all visualization tasks, except for large metallic side plate contours. Advances in knowledge: CBCT has the potential to be a good diagnostic alternative to plain radiographs in evaluation of fracture healing in the presence of metal hardware.

  10. Radiation dose and image quality in diagnostic radiology. Optimization of the dose-image quality relationship with clinical experience from scoliosis radiography, coronary intervention and a flat-panel digital detector.

    Science.gov (United States)

    Geijer, Håkan

    2002-03-01

    X-rays are known to cause malignancies, skin damage and other side effects and they are thus potentially dangerous. Therefore, it is essential and in fact mandatory to reduce the radiation dose in diagnostic radiology as far as possible. This is also known as the ALARA (as low as reasonably achievable) principle. However, the dose is linked to image quality and the image quality may not be lowered so far that it jeopardizes the diagnostic outcome of a radiographic procedure. The process of reaching this balance between dose and image quality is called optimization. The aim of this thesis was to propose and evaluate methods for optimizing the radiation dose-image quality relationship in diagnostic radiography with a focus on clinical usefulness. The work was performed in three main parts. OPTIMIZATION OF SCOLIOSIS RADIOGRAPHY: In the first part, two recently developed methods for digital scoliosis radiography (digital exposure and pulse fluoroscopy) were evaluated and compared to the standard screen-film method. Radiation dose was measured as kerma area-product (KAP), entrance surface dose (ESD) and effective dose; image quality was assessed with a contrast-detail phantom and through visual grading analysis. Accuracy in angle measurements was also evaluated. The radiation dose for digital exposure was nearly twice as high as the screen-film method at a comparable image quality while the dose for pulsed fluoroscopy was very low but with a considerably lower image quality. The variability in angle measurements was sufficiently low for all methods. Then, the digital exposure protocol was optimized to a considerably lower dose with a slightly lower image quality compared to the baseline. FLAT-PANEL DETECTOR: In the second part, an amorphous-silicon direct digital flat-panel detector was evaluated using a contrast-detail phantom, measuring dose as entrance dose. The flat-panel detector yielded a superior image quality at a lower dose than both storage phosphor plates and

  11. Stereoscopic image quality assessment using disparity-compensated view filtering

    Science.gov (United States)

    Song, Yang; Yu, Mei; Jiang, Gangyi; Shao, Feng; Peng, Zongju

    2016-03-01

    Stereoscopic image quality assessment (IQA) plays a vital role in stereoscopic image/video processing systems. We propose a new quality assessment for stereoscopic image that uses disparity-compensated view filtering (DCVF). First, because a stereoscopic image is composed of different frequency components, DCVF is designed to decompose it into high-pass and low-pass components. Then, the qualities of different frequency components are acquired according to their phase congruency and coefficient distribution characteristics. Finally, support vector regression is utilized to establish a mapping model between the component qualities and subjective qualities, and stereoscopic image quality is calculated using this mapping model. Experiments on the LIVE 3-D IQA database and NBU 3-D IQA databases demonstrate that the proposed method can evaluate stereoscopic image quality accurately. Compared with several state-of-the-art quality assessment methods, the proposed method is more consistent with human perception.

  12. Fingerprint matching algorithm for poor quality images

    Directory of Open Access Journals (Sweden)

    Vedpal Singh

    2015-04-01

    Full Text Available The main aim of this study is to establish an efficient platform for fingerprint matching for low-quality images. Generally, fingerprint matching approaches use the minutiae points for authentication. However, it is not such a reliable authentication method for low-quality images. To overcome this problem, the current study proposes a fingerprint matching methodology based on normalised cross-correlation, which would improve the performance and reduce the miscalculations during authentication. It would decrease the computational complexities. The error rate of the proposed method is 5.4%, which is less than the two-dimensional (2D dynamic programming (DP error rate of 5.6%, while Lee's method produces 5.9% and the combined method has 6.1% error rate. Genuine accept rate at 1% false accept rate is 89.3% but at 0.1% value it is 96.7%, which is higher. The outcome of this study suggests that the proposed methodology has a low error rate with minimum computational effort as compared with existing methods such as Lee's method and 2D DP and the combined method.

  13. Cardiothoracic ratio on chest radiograph in pediatric heart disease: How does it correlate with heart volumes at magnetic resonance imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Grotenhuis, Heynric B. [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); Zhou, Cheng; Isaac, Kathryn V. [The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Tomlinson, George [University of Toronto, Department of Medicine, Toronto General Hospital and Mt. Sinai Hospital, Toronto (Canada); Seed, Mike; Grosse-Wortmann, Lars; Yoo, Shi-Joon [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada)

    2015-10-15

    The cardiothoracic ratio by chest radiograph is widely used as a marker of cardiac size. The purpose of this study is to correlate cardiothoracic ratio and cardiac volumes as measured by cardiovascular magnetic resonance (MR) in common structural and myopathic heart disease with increased cardiac size due to volume overload or hypertrophy. A retrospective single center study was performed in all patients between 2007 and 2013 with repaired tetralogy of Fallot (TOF), aortic regurgitation, isolated left-to-right shunt and hypertrophic cardiomyopathy (HCM) who underwent cardiovascular MR and chest radiograph within 6 months of each other. Cardiothoracic ratios by chest radiograph (frontal and lateral) were compared to cardiac volumes (indexed for body surface area) by cardiovascular MR. One hundred twenty-seven patients (mean age: 11.2 ± 5.5 years) were included in this study (76 with TOF, 23 with isolated left-to-right shunt, 16 with aortic regurgitation and 12 with HCM). Frontal cardiothoracic ratio of all groups correlated with indexed right ventricular (RV) end-diastolic volume (EDVI) (r = 0.40, P < 0.01) and indexed total heart volume (THVI) (r = 0.27, P < 0.01). In TOF patients, frontal cardiothoracic ratio correlated with RVEDVI (r = 0.34, P < 0.01; coefficient of variation = 27.6%), indexed RV end-systolic volume (ESVI) (r = 0.44, P < 0.01; coefficient of variation = 33.3%) and THVI (r = 0.35, P < 0.01; coefficient of variation = 19.6%), although RV volumes and THVI showed widespread variation given the high coefficients of variation. In patients with aortic regurgitation, frontal cardiothoracic ratio correlated with left ventricular (LV) EDVI (r = 0.50, P = 0.047), but not with THVI and aortic regurgitant fraction, and widespread variation for LV EDVI (coefficient of variation = 19.2%), LV ESVI (coefficient of variation = 32.5%) and THVI (coefficient of variation = 13.6%) was also observed. Frontal cardiothoracic ratio was not correlated with cardiac volumes

  14. Analysis of the confluence of three patterns using the Centering and Pointing System (CAPS) images for the Advanced Radiographic Capability (ARC) at the National Ignition Facility

    Science.gov (United States)

    Leach, Richard R.; Awwal, Abdul; Bliss, Erlan; Roberts, Randy; Rushford, Michael; Wilhelmsen, Karl; Zobrist, Thomas

    2014-09-01

    The Advance Radiographic Capability (ARC) at the National Ignition Facility (NIF) is a laser system that employs up to four petawatt (PW) lasers to produce a sequence of short pulses that generate X-rays which backlight highdensity internal confinement fusion (ICF) targets. Employing up to eight backlighters, ARC can produce an X-ray "motion picture" to diagnose the compression and ignition of a cryogenic deuterium-tritium target with tens-ofpicosecond temporal resolution during the critical phases of an ICF shot. Multi-frame, hard-X-ray radiography of imploding NIF capsules is a capability which is critical to the success of NIF's missions. The function of the Centering and Pointing System (CAPS) in ARC is to provide superimposed near-field and far-field images on a common optical path. The Images are then analyzed to extract beam centering and pointing data for the control system. The images contain the confluence of pointing, centering, and reference patterns. The patterns may have uneven illumination, particularly when the laser is misaligned. In addition, the simultaneous appearance of three reference patterns may be co-incidental, possibly masking one or more of the patterns. Image analysis algorithms have been developed to determine the centering and pointing position of ARC from these images. In the paper we describe the image analysis algorithms used to detect and identify the centers of these patterns. Results are provided, illustrating how well the process meets system requirements.

  15. Image quality and dose in mammography in 17 countries in Africa, Asia and Eastern Europe: Results from IAEA projects

    Energy Technology Data Exchange (ETDEWEB)

    Ciraj-Bjelac, Olivera, E-mail: ociraj@vinca.rs [Vinca Institute of Nuclear Sciences, Belgrade (Serbia); Avramova-Cholakova, Simona, E-mail: s_avramova@mail.bg [National Centre of Radiobiology and Radiation Protection (NCRRP), Ministry of Health, Sofia (Bulgaria); Beganovic, Adnan, E-mail: adnanbeg@gmail.com [University of Sarajevo, Institute of Radiology, Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegovina); Economides, Sotirios, E-mail: adnanbeg@gmail.com [Ministry of Development, Greek Atomic Energy Commission, Athens (Greece); Faj, Dario, E-mail: dariofaj@mefos.hr [University Hospital Osijek, Osijek (Croatia); Gershan, Vesna, E-mail: vgersan@gmail.com [National Commission on Radiation Protection, Institute of Radiology, Skopje, The Former Yugoslav Republic of Macedonia (Macedonia, The Former Yugoslav Republic of); Grupetta, Edward, E-mail: edward.gruppetta@gov.mt [St. Luke' s Hospital, Diagnostic Radiology Unit, Guardamangia (Malta); Kharita, M.H., E-mail: mhkharita@aec.org.sy [Atomic Energy Commission of Syria (AECS), Department of Protection and Safety, Radiation and Nuclear Regulatory Office, Damascus (Syrian Arab Republic); Milakovic, Milomir, E-mail: mmilomir@teol.net [Ministry of Health of the Republic of Srpska, Public Health Institute of Republic of Srpska, Banja Luka, Bosnia and Herzegovina (Bosnia and Herzegovina); Milu, Constantin, E-mail: milu.constantin@yahoo.com [Institute of Public Health, SSDL, Bucharest (Romania); Muhogora, Wilbroad E., E-mail: wmuhogora@yahoo.com [Tanzania Atomic Energy Commission, Arusha, Tanzania (Tanzania, United Republic of); Muthuvelu, Pirunthavany, E-mail: mpvany@gmail.com [Ministry of Health, Radiation Health Safety Branch, Putra Jaya (Malaysia); Oola, Samuel, E-mail: ooladavidson@yahoo.com [Mulago Hospital, Department of Radiology, Kampala (Uganda); Setayeshi, Saeid, E-mail: setayesh@aut.ac.ir [Ministry of Health, Treatment, and Medical Training, Tehran (Iran, Islamic Republic of); and others

    2012-09-15

    Purpose: The objective is to study mammography practice from an optimisation point of view by assessing the impact of simple and immediately implementable corrective actions on image quality. Materials and methods: This prospective multinational study included 54 mammography units in 17 countries. More than 21,000 mammography images were evaluated using a three-level image quality scoring system. Following initial assessment, appropriate corrective actions were implemented and image quality was re-assessed in 24 units. Results: The fraction of images that were considered acceptable without any remark in the first phase (before the implementation of corrective actions) was 70% and 75% for cranio-caudal and medio-lateral oblique projections, respectively. The main causes for poor image quality before corrective actions were related to film processing, damaged or scratched image receptors, or film-screen combinations that are not spectrally matched, inappropriate radiographic techniques and lack of training. Average glandular dose to a standard breast was 1.5 mGy (mean and range 0.59–3.2 mGy). After optimisation the frequency of poor quality images decreased, but the relative contributions of the various causes remained similar. Image quality improvements following appropriate corrective actions were up to 50 percentage points in some facilities. Conclusions: Poor image quality is a major source of unnecessary radiation dose to the breast. An increased awareness of good quality mammograms is of particular importance for countries that are moving towards introduction of population-based screening programmes. The study demonstrated how simple and low-cost measures can be a valuable tool in improving of image quality in mammography.

  16. Image quality and dose in mammography in 17 countries in Africa, Asia and Eastern Europe: results from IAEA projects.

    Science.gov (United States)

    Ciraj-Bjelac, Olivera; Avramova-Cholakova, Simona; Beganovic, Adnan; Economides, Sotirios; Faj, Dario; Gershan, Vesna; Grupetta, Edward; Kharita, M H; Milakovic, Milomir; Milu, Constantin; Muhogora, Wilbroad E; Muthuvelu, Pirunthavany; Oola, Samuel; Setayeshi, Saeid; Schandorf, Cyril; Ursulean, Ion; Videnovic, Ivan R; Zaman, Areesha; Ziliukas, Julius; Rehani, Madan M

    2012-09-01

    The objective is to study mammography practice from an optimisation point of view by assessing the impact of simple and immediately implementable corrective actions on image quality. This prospective multinational study included 54 mammography units in 17 countries. More than 21,000 mammography images were evaluated using a three-level image quality scoring system. Following initial assessment, appropriate corrective actions were implemented and image quality was re-assessed in 24 units. The fraction of images that were considered acceptable without any remark in the first phase (before the implementation of corrective actions) was 70% and 75% for cranio-caudal and medio-lateral oblique projections, respectively. The main causes for poor image quality before corrective actions were related to film processing, damaged or scratched image receptors, or film-screen combinations that are not spectrally matched, inappropriate radiographic techniques and lack of training. Average glandular dose to a standard breast was 1.5 mGy (mean and range 0.59-3.2 mGy). After optimisation the frequency of poor quality images decreased, but the relative contributions of the various causes remained similar. Image quality improvements following appropriate corrective actions were up to 50 percentage points in some facilities. Poor image quality is a major source of unnecessary radiation dose to the breast. An increased awareness of good quality mammograms is of particular importance for countries that are moving towards introduction of population-based screening programmes. The study demonstrated how simple and low-cost measures can be a valuable tool in improving of image quality in mammography. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. A prospective study of the impact of musculoskeletal pain and radiographic osteoarthritis on health related quality of life in community dwelling older people

    Directory of Open Access Journals (Sweden)

    Laslett Laura L

    2012-09-01

    Full Text Available Abstract Background Pain and radiographic changes are common in persons with osteoarthritis, but their relative contributions to quality of life are unknown. Methods Prospective cohort study of 1098 men and women aged 50–80 years, randomly selected from the electoral roll. Participants were interviewed at baseline and approximately 2.6 and five years later. Participants self-reported prior diagnosis of arthritis and presence of joint pain. Joint space narrowing (JSN and osteophytes at the hip and knee were assessed by X-ray. Quality of life (QoL was assessed using the Assessment of QoL (AQoL instrument. Data was analysed using linear regression and mixed modelling. Results The median AQoL score at baseline was 7.0, indicating very good QoL. Prevalence of pain ranged from 38-62%. Over five years of observation, pain in the neck, shoulders, back, hips, hands, knees and feet were all independently and negatively associated with QoL, in a dose–response relationship. Diagnosed osteoarthritis at all sites was associated with poorer QoL but after adjustment for pain, this only remained significant at the back. Radiographic OA was not associated with QoL. While AQoL scores declined over five years, there was no evidence of an interaction between pain and time. Conclusions Pain is common in older adults, is stable over time, and the strongest musculoskeletal correlate of QoL. It also mediates the association between diagnosed OA and QoL. Since the same factors were associated with quality of life over time as at baseline, this suggests that quality of life tracks over a five year period.

  18. Evaluation of cassette-based digital radiography detectors using standardized image quality metrics: AAPM TG-150 Draft Image Detector Tests.

    Science.gov (United States)

    Li, Guang; Greene, Travis C; Nishino, Thomas K; Willis, Charles E

    2016-09-08

    The purpose of this study was to evaluate several of the standardized image quality metrics proposed by the American Association of Physics in Medicine (AAPM) Task Group 150. The task group suggested region-of-interest (ROI)-based techniques to measure nonuniformity, minimum signal-to-noise ratio (SNR), number of anomalous pixels, and modulation transfer function (MTF). This study evaluated the effects of ROI size and layout on the image metrics by using four different ROI sets, assessed result uncertainty by repeating measurements, and compared results with two commercially available quality control tools, namely the Carestream DIRECTVIEW Total Quality Tool (TQT) and the GE Healthcare Quality Assurance Process (QAP). Seven Carestream DRX-1C (CsI) detectors on mobile DR systems and four GE FlashPad detectors in radiographic rooms were tested. Images were analyzed using MATLAB software that had been previously validated and reported. Our values for signal and SNR nonuniformity and MTF agree with values published by other investigators. Our results show that ROI size affects nonuniformity and minimum SNR measurements, but not detection of anomalous pixels. Exposure geometry affects all tested image metrics except for the MTF. TG-150 metrics in general agree with the TQT, but agree with the QAP only for local and global signal nonuniformity. The difference in SNR nonuniformity and MTF values between the TG-150 and QAP may be explained by differences in the calculation of noise and acquisition beam quality, respectively. TG-150's SNR nonuniformity metrics are also more sensitive to detector nonuniformity compared to the QAP. Our results suggest that fixed ROI size should be used for consistency because nonuniformity metrics depend on ROI size. Ideally, detector tests should be performed at the exact calibration position. If not feasible, a baseline should be established from the mean of several repeated measurements. Our study indicates that the TG-150 tests can be

  19. Magnetic resonance imaging-based cartilage loss in painful contralateral knees with and without radiographic joint space narrowing: Data from the Osteoarthritis Initiative.

    Science.gov (United States)

    Eckstein, Felix; Benichou, Olivier; Wirth, Wolfgang; Nelson, David R; Maschek, Susanne; Hudelmaier, Martin; Kwoh, C Kent; Guermazi, Ali; Hunter, David

    2009-09-15

    To determine by magnetic resonance imaging (MRI), whether knees with advanced radiographic disease (medial joint space narrowing [mJSN]) encounter greater longitudinal cartilage loss than contralateral knees with earlier disease (no or less mJSN). Participants were selected from 2,678 cases in the Osteoarthritis Initiative, based on exhibition of bilateral pain, body mass index >25 (kg/m(2)), mJSN in 1 knee, no or less mJSN in the contralateral knee, and no lateral JSN in both knees. Eighty participants (mean +/- SD age 60.6 +/- 9.1 years) fulfilled these criteria. Medial tibial and femoral cartilage morphology was analyzed from the baseline and the 1-year followup MRI (sagittal double echo at steady state by 3.0T) of both knees by experienced readers blinded to the time point and mJSN status. Knees with more radiographic mJSN displayed greater medial cartilage loss (-80 mum) assessed by MRI than contralateral knees with less mJSN (-57 mum). The difference reached statistical significance in participants with an mJSN grade of 2 or 3 (P = 0.005-0.08), but not in participants with an mJSN grade of 1 (P = 0.28-0.98). In knees with more mJSN, cartilage loss increased with higher grades of mJSN (P = 0.003 in the medial femur). Knees with an mJSN grade of 2 or 3 displayed greater cartilage loss in the weight-bearing medial femur than in the posterior femur or in the medial tibia (P = 0.048). Knees with advanced mJSN displayed greater cartilage loss than contralateral knees with less mJSN. These data suggest that radiography can be used to stratify fast structural progressors, and that MRI cartilage thickness loss is more pronounced at advanced radiographic disease stage.

  20. Modified newman and friedman extraoral radiographic technique.

    Science.gov (United States)

    Saberi, Eshagali; Hafezi, Ladan; Farhadmolashahi, Narges; Mokhtari, Manoochehr

    2012-01-01

    Good radiographs are required for endodontic therapy and because some patient's are intolerant to intraoral films and/or sensors, this can cause complications in endodontic treatment. Extraoral film placement can be used to obtain clinically diagnostic and working radiographs. The no. 2 receptor was placed against the model's cheek and centered in the molar-premolar area. The central beam was directed toward this area from the opposite side. The vertical and horizontal angles that achieved the most accurate radiograph were calculated by trial and error. The best method equated with the patient sitting upright and the Frankfort plane being horizontal to the floor and when the head was tilted 10 degrees toward the side being examined. For the upper posterior teeth the center of the image receptor was placed on the intersection of the ala-tragus and a parasagittal line while the upper border of receptor was parallel to the canthomeatal line; the cone was positioned a negative 25 degrees from the horizontal plane. The central beam was directed from midway between maxillary and mandibular premolars and molars of the opposite side. For the lower posterior teeth, the receptor was placed against the cheek on the side of interest and its lower border was parallel and 2 cm above the inferior border of the mandible. The cone was angled -20 degrees from the horizontal plane while the central beam was directed towards the mandibular molar-premolar region 1 cm below the lower border of the mandibular of the contralateral premolar/molar region. Using this novel technique, high quality images can be acquired for patients who cannot tolerate intraoral radiographs.

  1. Image quality transfer and applications in diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C.; Zikic, Darko; Ghosh, Aurobrata

    2017-01-01

    This paper introduces a new computational imaging technique called image quality transfer (IQT). IQT uses machine learning to transfer the rich information available from one-off experimental medical imaging devices to the abundant but lower-quality data from routine acquisitions. The procedure u...

  2. The effects of frame-rate and image quality on perceived video quality in videoconferencing

    OpenAIRE

    Thakur, Aruna; Gao, Chaunsi; Larsson, Andreas; Parnes, Peter

    2001-01-01

    This report discusses the effect of frame-rate and image quality on the perceived video quality in a specific videoconferencing application (MarratechPro). Subjects with various videoconferencing experiences took part in four experiments wherein they gave their opinions on the quality of video upon the variations in frame-rate and image quality. The results of the experiments showed that the subjects preferred high frame rate over high image quality, under the condition of limited bandwidth. ...

  3. A benchmark concept for simulation in radiographic testing

    Science.gov (United States)

    Ewert, U.; Deresch, A.; Bellon, C.; Jaenisch, G.-R.

    2014-02-01

    The new standard ISO 17636-2:2013 "NDT of welds: Radiographic testing - Part 2: X- and gamma ray techniques with digital detectors" describes a complex procedure for film replacement by phosphor imaging plates and digital detector arrays. RT modeling software should consider these detector types, X-ray film, and the standard requirements for image quality. Practitioners expect the same visibility of image quality indicators (IQI) in the simulated radiographs as in the experimental exposures. The proposed benchmark test is based on the comparison of experimental radiographs taken at BAM with modeled ones of participants. The experimental setup and the determination of the equivalent penetrameter sensitivity (EPS) as described in the procedure of ASTM E 746 are used for quantitative evaluation of the achievable contrast sensitivity for step hole IQIs as considered in Annex B of ISO 17636-2. System classification data for Computed Radiography (CR) and film systems will be provided by BAM according to ISO 11699-1 for selected film systems and according to ASTM E 2446 for selected CR systems. The classification of films and digital detectors is based on the measurement of the dose response function, the basic spatial resolution (SRb) of the image, and the measured image noise, which depends on the detector efficiency, the quantum statistics, and the detector fixed pattern noise.

  4. A benchmark concept for simulation in radiographic testing

    Energy Technology Data Exchange (ETDEWEB)

    Ewert, U.; Deresch, A.; Bellon, C.; Jaenisch, G.-R. [Federal Institute for Materials Research and Testing Unter den Eichen 87, 12205 Berlin (Germany)

    2014-02-18

    The new standard ISO 17636–2:2013 “NDT of welds: Radiographic testing - Part 2: X- and gamma ray techniques with digital detectors” describes a complex procedure for film replacement by phosphor imaging plates and digital detector arrays. RT modeling software should consider these detector types, X-ray film, and the standard requirements for image quality. Practitioners expect the same visibility of image quality indicators (IQI) in the simulated radiographs as in the experimental exposures. The proposed benchmark test is based on the comparison of experimental radiographs taken at BAM with modeled ones of participants. The experimental setup and the determination of the equivalent penetrameter sensitivity (EPS) as described in the procedure of ASTM E 746 are used for quantitative evaluation of the achievable contrast sensitivity for step hole IQIs as considered in Annex B of ISO 17636–2. System classification data for Computed Radiography (CR) and film systems will be provided by BAM according to ISO 11699–1 for selected film systems and according to ASTM E 2446 for selected CR systems. The classification of films and digital detectors is based on the measurement of the dose response function, the basic spatial resolution (SR{sub b}) of the image, and the measured image noise, which depends on the detector efficiency, the quantum statistics, and the detector fixed pattern noise.

  5. Image quality, threshold contrast and mean glandular dose in CR mammography.

    Science.gov (United States)

    Jakubiak, R R; Gamba, H R; Neves, E B; Peixoto, J E

    2013-09-21

    In many countries, computed radiography (CR) systems represent the majority of equipment used in digital mammography. This study presents a method for optimizing image quality and dose in CR mammography of patients with breast thicknesses between 45 and 75 mm. Initially, clinical images of 67 patients (group 1) were analyzed by three experienced radiologists, reporting about anatomical structures, noise and contrast in low and high pixel value areas, and image sharpness and contrast. Exposure parameters (kV, mAs and target/filter combination) used in the examinations of these patients were reproduced to determine the contrast-to-noise ratio (CNR) and mean glandular dose (MGD). The parameters were also used to radiograph a CDMAM (version 3.4) phantom (Artinis Medical Systems, The Netherlands) for image threshold contrast evaluation. After that, different breast thicknesses were simulated with polymethylmethacrylate layers and various sets of exposure parameters were used in order to determine optimal radiographic parameters. For each simulated breast thickness, optimal beam quality was defined as giving a target CNR to reach the threshold contrast of CDMAM images for acceptable MGD. These results were used for adjustments in the automatic exposure control (AEC) by the maintenance team. Using optimized exposure parameters, clinical images of 63 patients (group 2) were evaluated as described above. Threshold contrast, CNR and MGD for such exposure parameters were also determined. Results showed that the proposed optimization method was effective for all breast thicknesses studied in phantoms. The best result was found for breasts of 75 mm. While in group 1 there was no detection of the 0.1 mm critical diameter detail with threshold contrast below 23%, after the optimization, detection occurred in 47.6% of the images. There was also an average MGD reduction of 7.5%. The clinical image quality criteria were attended in 91.7% for all breast thicknesses evaluated in

  6. Determination of characteristic defect features for computer-aided image evaluation of welded joint radiographs; Bestimmung charakteristischer Fehlermerkmale zur rechnergestuetzten Bildauswertung von Schweissnahtradiographien

    Energy Technology Data Exchange (ETDEWEB)

    Rose, P.

    1995-08-01

    Automatic inspection of weld radiographs require a reliable detection and evaluation of the existing defects. Pretentious image processing is necessary to identify the right defect type after the defect detection is already finished. For that, features must be extracted from the image plane to describe the special characteristics of the different defect types. Which kind of features are most important for the recogniction of the defect types will be discussed in this papaer. All features, used in this investigation, are based upon geometric shape and gray level distribution of the defect representation in the radiographic image. The features are tested as single features and feature combinations on more than 500 samples of real weld defects. In the one-dimensional case, all features are evaluated by the Fisher discriminant and the Bhattacharyya coefficient. For evaluation in the multi-dimensional feature space the principal component transformation is additionally used. The tests consider different defect types and different configurations of defect classes. The results are presented in a final statistical interpretation. (orig.) [Deutsch] Die automatische Auswertung von Schweissnahtradiographien erfordert eine zuverlaessige Erkennung und Beurteilung der im Roentgenbild wiedergegebenen Schweissnahtfehler. Hierzu sind aufwendige Bildverarbeitungsoperationen notwendig, die nach der Detektion der Fehler auch eine Fehlertypenbestimmung ermoeglichen. Um aus den Fehlerabbildungen die zur Typenbestimmung relevanten Informationen zu gewinnen, werden Merkmale zur Unterscheidung verschiedener Fehlertypen geeignet sind und wie sich diese Merkmale an Abbildungen realer Schweissnahtfehler verhalten, wird im Rahmen dieser Arbeit untersucht. Es werden insgesamt 15 Merkmale vorgestellt, die ihre fehlerspezifischen Kennwerte aus der Geometrie und der Grauwertverteilung der Fehlerabbildungen ermitteln. Die Merkmale werden als Einzelmerkmale und als Merkmalskombination an einem

  7. Image simulation and a model of noise power spectra across a range of mammographic beam qualities.

    Science.gov (United States)

    Mackenzie, Alistair; Dance, David R; Diaz, Oliver; Young, Kenneth C

    2014-12-01

    The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise in CR. The use of the

  8. Image simulation and a model of noise power spectra across a range of mammographic beam qualities

    Energy Technology Data Exchange (ETDEWEB)

    Mackenzie, Alistair, E-mail: alistairmackenzie@nhs.net; Dance, David R.; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford GU2 7XX, United Kingdom and Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Diaz, Oliver [Centre for Vision, Speech and Signal Processing, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom and Computer Vision and Robotics Research Institute, University of Girona, Girona 17071 (Spain)

    2014-12-15

    Purpose: The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Methods: Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. Results: The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise

  9. Food quality assessment by NIR hyperspectral imaging

    Science.gov (United States)

    Whitworth, Martin B.; Millar, Samuel J.; Chau, Astor

    2010-04-01

    Near infrared reflectance (NIR) spectroscopy is well established in the food industry for rapid compositional analysis of bulk samples. NIR hyperspectral imaging provides new opportunities to measure the spatial distribution of components such as moisture and fat, and to identify and measure specific regions of composite samples. An NIR hyperspectral imaging system has been constructed for food research applications, incorporating a SWIR camera with a cooled 14 bit HgCdTe detector and N25E spectrograph (Specim Ltd, Finland). Samples are scanned in a pushbroom mode using a motorised stage. The system has a spectral resolution of 256 pixels covering a range of 970-2500 nm and a spatial resolution of 320 pixels covering a swathe adjustable from 8 to 300 mm. Images are acquired at a rate of up to 100 lines s-1, enabling samples to be scanned within a few seconds. Data are captured using SpectralCube software (Specim) and analysed using ENVI and IDL (ITT Visual Information Solutions). Several food applications are presented. The strength of individual absorbance bands enables the distribution of particular components to be assessed. Examples are shown for detection of added gluten in wheat flour and to study the effect of processing conditions on fat distribution in chips/French fries. More detailed quantitative calibrations have been developed to study evolution of the moisture distribution in baguettes during storage at different humidities, to assess freshness of fish using measurements of whole cod and fillets, and for prediction of beef quality by identification and separate measurement of lean and fat regions.

  10. Improvement of the clinical use of computed radiography for mobile chest imaging: Image quality and patient dose

    Science.gov (United States)

    Rill, Lynn Neitzey

    Chest radiography is technically difficult because of the wide variation of tissue attenuations in the chest and limitations of screen-film systems. Mobile chest radiography, performed bedside on hospital inpatients, presents additional difficulties due to geometrical and equipment limitations inherent to mobile x-ray procedures and the severity of illness in patients. Computed radiography (CR) offers a new approach for mobile chest radiography by utilizing a photostimulable phosphor. Photostimulable phosphors are more efficient in absorbing lower-energy x-rays than standard intensifying screens and overcome some image quality limitations of mobile chest imaging, particularly because of the inherent latitude. This study evaluated changes in imaging parameters for CR to take advantage of differences between CR and screen-film radiography. Two chest phantoms, made of acrylic and aluminum, simulated x-ray attenuation for average-sized and large- sized adult chests. The phantoms contained regions representing the lungs, heart and subdiaphragm. Acrylic and aluminum disks (1.9 cm diameter) were positioned in the chest regions to make signal-to-noise ratio (SNR) measurements for different combinations of imaging parameters. Disk thicknesses (contrast) were determined from disk visibility. Effective dose to the phantom was also measured for technique combinations. The results indicated that using an anti-scatter grid and lowering x- ray tube potential improved the SNR significantly; however, the dose to the phantom also increased. An evaluation was performed to examine the clinical applicability of the observed improvements in SNR. Parameter adjustments that improved phantom SNRs by more than 50% resulted in perceived image quality improvements in the lung region of clinical mobile chest radiographs. Parameters that produced smaller improvements in SNR had no apparent effect on clinical image quality. Based on this study, it is recommended that a 3:1 grid be used for

  11. Radiographical and Implant-Related Complications in Adult Spinal Deformity Surgery: Incidence, Patient Risk Factors, and Impact on Health-Related Quality of Life.

    Science.gov (United States)

    Soroceanu, Alexandra; Diebo, Bassel G; Burton, Douglas; Smith, Justin S; Deviren, Vedat; Shaffrey, Christopher; Kim, Han Jo; Mundis, Gregory; Ames, Christopher; Errico, Thomas; Bess, Shay; Hostin, Richard; Hart, Robert; Schwab, Frank; Lafage, Virginie

    2015-09-15

    A multicenter, prospective review of surgical patients with adult spine deformity. Assessment of the incidence, risk factor, and impact of radiographical and implant-related complications (RIC) on health-related quality of life measures. This study provides assessment of the incidence of RIC in adult spinal deformity surgery and impact of these complications on need for reoperation. Risk factors for development of RIC are also assessed, as well as the impact of these complications on health-related quality of life (HRQOL) outcomes measures. A multicenter, prospective database of surgical patients with adult spinal deformity was reviewed. All patients with complete 2-year follow-up were included. HRQOL was measured using the Oswestry Disability Index, General Health Survey (36-Item Short Form Health Survey [SF-36]), and Scoliosis Research Society-22 (SRS-22r) at baseline, 6 weeks, 1 year, and 2 years postoperatively. Univariate testing was performed as appropriate. Multivariate logistic regression modeling was used to determine independent predictors of RIC. Multivariate repeated-measures mixed models were used to examine HRQOL, accounting for confounders. A total of 245 patients met inclusion criteria. The incidence of RIC was 31.7% and 52.6% of those patients required reoperation. Rod breakage accounted for 47% of the implant-related complications, and proximal junctional kyphosis accounted for 54.5% of radiographical complications. Univariate analysis identified the following potential risk factors for RIC: weight, American Society of Anesthesiologists score, revision, stopping the fusion in the lower thoracic spine, worse SRS-Schwab classification modifiers (pelvic tilt++, pelvic incidence minus lumbar lordosis++, sagittal vertical axis++), higher T1 spinopelvic inclination, and higher T1 slope. Independent predictors of RIC as identified on multivariate logistic regression included American Society of Anesthesiologists (odds ratio: 1.75, P = 0.029) and sagittal

  12. Perceived quality and image: When all is not "rosy"

    National Research Council Canada - National Science Library

    Homer, Pamela Miles

    2008-01-01

    .... This study explores the relationship between quality and image with special attention on brands plagued with negative impressions, including instances where consumers' perceptions of a product's...

  13. Quality Assessment of Sharpened Images: Challenges, Methodology, and Objective Metrics.

    Science.gov (United States)

    Krasula, Lukas; Le Callet, Patrick; Fliegel, Karel; Klima, Milos

    2017-01-10

    Most of the effort in image quality assessment (QA) has been so far dedicated to the degradation of the image. However, there are also many algorithms in the image processing chain that can enhance the quality of an input image. These include procedures for contrast enhancement, deblurring, sharpening, up-sampling, denoising, transfer function compensation, etc. In this work, possible strategies for the quality assessment of sharpened images are investigated. This task is not trivial because the sharpening techniques can increase the perceived quality, as well as introduce artifacts leading to the quality drop (over-sharpening). Here, the framework specifically adapted for the quality assessment of sharpened images and objective metrics comparison in this context is introduced. However, the framework can be adopted in other quality assessment areas as well. The problem of selecting the correct procedure for subjective evaluation was addressed and a subjective test on blurred, sharpened, and over-sharpened images was performed in order to demonstrate the use of the framework. The obtained ground-truth data were used for testing the suitability of state-ofthe- art objective quality metrics for the assessment of sharpened images. The comparison was performed by novel procedure using ROC analyses which is found more appropriate for the task than standard methods. Furthermore, seven possible augmentations of the no-reference S3 metric adapted for sharpened images are proposed. The performance of the metric is significantly improved and also superior over the rest of the tested quality criteria with respect to the subjective data.

  14. Correction for Patient Sway in Radiographic Biplanar Imaging for Three-Dimensional Reconstruction of the Spine: In Vitro Study of a New Method

    Energy Technology Data Exchange (ETDEWEB)

    Legaye, J. (Dept. of Orthopedic Surgery, Univ. of Louvain - Mont-Godinne, Yvoir (Belgium)); Saunier, P.; Dumas, R. (Univ. of Lyon 1 - INRETS, Villeurbanne (France)); Vallee, C. (Radiology Dept., Hpital Raymond Poincare, Garches (France))

    2009-08-15

    Background: Three-dimensional (3D) reconstructions of the spine in the upright position are classically obtained using two-dimensional, non-simultaneous radiographic imaging. However, a subject's sway between exposures induces inaccuracy in the 3D reconstructions. Purpose: To evaluate the impact of patient sway between successive radiographic exposures, and to test if 3D reconstruction accuracy can be improved by a corrective method with simultaneous Moire-X-ray imaging. Material and Methods: Using a calibrated deformable phantom perceptible by both techniques (Moire and X-ray), the 3D positional and rotational vertebral data from 3D reconstructions with and without the corrective procedure were compared to the corresponding data of computed tomography (CT) scans, considered as a reference. All were expressed in the global axis system, as defined by the Scoliosis Research Society. Results: When a sagittal sway of 10 deg occurred between successive biplanar X-rays, the accuracy of the 3D reconstruction without correction was 8.8 mm for the anteroposterior vertebral locations and 6.4 deg for the sagittal orientations. When the corrective method was applied, the accuracy was improved to 1.3 mm and 1.5 deg, respectively. Conclusion: 3D accuracy improved significantly by using the corrective method, whatever the subject's sway. This technique is reliable for clinical appraisal of the spine, if the subject's sway does not exceed 10 deg. For greater sway, improvement persists, but a risk of lack of accuracy exists

  15. Effect of pre-cardiac and adult stages of Dirofilaria immitis in pulmonary disease of cats: CBC, bronchial lavage cytology, serology, radiographs, CT images, bronchial reactivity, and histopathology.

    Science.gov (United States)

    Ray Dillon, A; Tillson, D M; Wooldridge, A; Cattley, R; Hathcock, J; Brawner, W R; Cole, R; Welles, B; Christopherson, P W; Lee-Fowler, T; Bordelon, S; Barney, S; Sermersheim, M; Garbarino, R; Wells, S Z; Diffie, E B; Schachner, E R

    2014-11-15

    A controlled, blind study was conducted to define the initial inflammatory response and lung damage associated with the death of precardiac stages of Dirofilaria immitis in cats as compared to adult heartworm infections and normal cats. Three groups of six cats each were used: UU: uninfected untreated controls; PreS I: infected with 100 D. immitis L3 by subcutaneous injection and treated topically with selamectin 32 and 2 days pre-infection and once monthly for 8 months); IU: infected with 100 D. immitis L3 and left untreated. Peripheral blood, serum, bronchial lavage, and thoracic radiographic images were collected from all cats on Days 0, 70, 110, 168, and 240. CT images were acquired on Days 0, 110, and 240. Cats were euthanized, and necropsies were conducted on Day 240 to determine the presence of heartworms. Bronchial rings were collected for in vitro reactivity. Lung, heart, brain, kidney, and liver tissues were collected for histopathology. Results were compared for changes within each group. Pearson and Spearman correlations were performed for association between histologic, radiographic, serologic, hematologic and bronchoalveolar lavage (BAL) results. Infected cats treated with selamectin did not develop radiographically evident changes throughout the study, were heartworm antibody negative, and were free of adult heartworms and worm fragments at necropsy. Histologic lung scores and CT analysis were not significantly different between PreS I cats and UU controls. Subtle alveolar myofibrosis was noted in isolated areas of several PreS I cats and an eosinophilic BAL cytology was noted on Days 75 and 120. Bronchial ring reactivity was blunted in IU cats but was normal in PreS I and UU cats. The IU cats became antibody positive, and five cats developed adult heartworms. All cats with heartworms were antigen positive at one time point; but one cat was antibody positive, antigen negative, with viable adult females at necropsy. The CT revealed early involvement

  16. Recognizable or Not: Towards Image Semantic Quality Assessment for Compression

    Science.gov (United States)

    Liu, Dong; Wang, Dandan; Li, Houqiang

    2017-12-01

    Traditionally, image compression was optimized for the pixel-wise fidelity or the perceptual quality of the compressed images given a bit-rate budget. But recently, compressed images are more and more utilized for automatic semantic analysis tasks such as recognition and retrieval. For these tasks, we argue that the optimization target of compression is no longer perceptual quality, but the utility of the compressed images in the given automatic semantic analysis task. Accordingly, we propose to evaluate the quality of the compressed images neither at pixel level nor at perceptual level, but at semantic level. In this paper, we make preliminary efforts towards image semantic quality assessment (ISQA), focusing on the task of optical character recognition (OCR) from compressed images. We propose a full-reference ISQA measure by comparing the features extracted from text regions of original and compressed images. We then propose to integrate the ISQA measure into an image compression scheme. Experimental results show that our proposed ISQA measure is much better than PSNR and SSIM in evaluating the semantic quality of compressed images; accordingly, adopting our ISQA measure to optimize compression for OCR leads to significant bit-rate saving compared to using PSNR or SSIM. Moreover, we perform subjective test about text recognition from compressed images, and observe that our ISQA measure has high consistency with subjective recognizability. Our work explores new dimensions in image quality assessment, and demonstrates promising direction to achieve higher compression ratio for specific semantic analysis tasks.

  17. Objective and Subjective Assessment of Digital Pathology Image Quality

    Directory of Open Access Journals (Sweden)

    Prarthana Shrestha

    2015-03-01

    Full Text Available The quality of an image produced by the Whole Slide Imaging (WSI scanners is of critical importance for using the image in clinical diagnosis. Therefore, it is very important to monitor and ensure the quality of images. Since subjective image quality assessments by pathologists are very time-consuming, expensive and difficult to reproduce, we propose a method for objective assessment based on clinically relevant and perceptual image parameters: sharpness, contrast, brightness, uniform illumination and color separation; derived from a survey of pathologists. We developed techniques to quantify the parameters based on content-dependent absolute pixel performance and to manipulate the parameters in a predefined range resulting in images with content-independent relative quality measures. The method does not require a prior reference model. A subjective assessment of the image quality is performed involving 69 pathologists and 372 images (including 12 optimal quality images and their distorted versions per parameter at 6 different levels. To address the inter-reader variability, a representative rating is determined as a one-tailed 95% confidence interval of the mean rating. The results of the subjective assessment support the validity of the proposed objective image quality assessment method to model the readers’ perception of image quality. The subjective assessment also provides thresholds for determining the acceptable level of objective quality per parameter. The images for both the subjective and objective quality assessment are based on the HercepTestTM slides scanned by the Philips Ultra Fast Scanners, developed at Philips Digital Pathology Solutions. However, the method is applicable also to other types of slides and scanners.

  18. Diagnostic accuracy of DXA compared to conventional spine radiographs for the detection of vertebral fractures in children

    Energy Technology Data Exchange (ETDEWEB)

    Adiotomre, E. [Sheffield Teaching Hospitals NHS Foundation Trust, Radiology Department, Sheffield, South Yorkshire (United Kingdom); Sheffield Children' s Hospital NHS Foundation Trust, Radiology Department, Sheffield, South Yorkshire (United Kingdom); Summers, L.; Digby, M. [University of Sheffield, Sheffield Medical School, Sheffield, South Yorkshire (United Kingdom); Allison, A.; Walters, S.J. [University of Sheffield, School of Health and Related Research, Sheffield, South Yorkshire (United Kingdom); Broadley, P.; Lang, I. [Sheffield Children' s Hospital NHS Foundation Trust, Radiology Department, Sheffield, South Yorkshire (United Kingdom); Morrison, G. [Sheffield Teaching Hospitals NHS Foundation Trust, Medical Physics, Sheffield, South Yorkshire (United Kingdom); Bishop, N.; Arundel, P. [University of Sheffield, Academic Unit of Child Health, Sheffield, South Yorkshire (United Kingdom); Offiah, A.C. [Sheffield Children' s Hospital NHS Foundation Trust, Radiology Department, Sheffield, South Yorkshire (United Kingdom); University of Sheffield, Academic Unit of Child Health, Sheffield, South Yorkshire (United Kingdom)

    2017-05-15

    In children, radiography is performed to diagnose vertebral fractures and dual energy x-ray absorptiometry (DXA) to assess bone density. In adults, DXA assesses both. We aimed to establish whether DXA can replace spine radiographs in assessment of paediatric vertebral fractures. Prospectively, lateral spine radiographs and lateral spine DXA of 250 children performed on the same day were independently scored by three radiologists using the simplified algorithm-based qualitative technique and blinded to results of the other modality. Consensus radiograph read and second read of 100 random images were performed. Diagnostic accuracy, inter/intraobserver and intermodality agreements, patient/carer experience and radiation dose were assessed. Average sensitivity and specificity (95 % confidence interval) in diagnosing one or more vertebral fractures requiring treatment was 70 % (58-82 %) and 97 % (94-100 %) respectively for DXA and 74 % (55-93 %) and 96 % (95-98 %) for radiographs. Fleiss' kappa for interobserver and average kappa for intraobserver reliability were 0.371 and 0.631 respectively for DXA and 0.418 and 0.621 for radiographs. Average effective dose was 41.9 μSv for DXA and 232.7 μSv for radiographs. Image quality was similar. Given comparable image quality and non-inferior diagnostic accuracy, lateral spine DXA should replace conventional radiographs for assessment of vertebral fractures in children. (orig.)

  19. Digital Watermarking Method Warranting the Lower Limit of Image Quality of Watermarked Images

    Directory of Open Access Journals (Sweden)

    Iwata Motoi

    2010-01-01

    Full Text Available We propose a digital watermarking method warranting the lower limit of the image quality of watermarked images. The proposed method controls the degradation of a watermarked image by using a lower limit image. The lower limit image means the image of the worst quality that users can permit. The proposed method accepts any lower limit image and does not require it at extraction. Therefore lower limit images can be decided flexibly. In this paper, we introduce 2-dimensional human visual MTF model as an example of obtaining lower limit images. Also we use JPEG-compressed images of quality 75% and 50% as lower limit images. We investigate the performance of the proposed method by experiments. Moreover we compare the proposed method using three types of lower limit images with the existing method in view of the tradeoff between PSNR and the robustness against JPEG compression.

  20. The effect of different radiographic parameters on the height, width and visibility of cross-sectional image of mandible in spiral tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Wan; Han, Won Jeong; Kim, Eun Kyung [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2003-03-15

    To evaluate the differences in bone height, bone width, and visibility of posterior spiral tomographic images according to various exposure directions, image layer thickness, and inclination of the mandibular inferior border. Six partially and completely edentulous dry mandibles were radiographed using Scanora spiral tomography. Spiral tomography was performed at different exposure directions (dentotangential and maxillotangential projection), image layer thicknesses (2 mm, 4 mm and 8 mm), and at various inclinations to the mandibular border (+10 .deg., 0 .deg. and -10 .deg. ). The bone height and width was measured using selected tomographic images. The visibility of mandibular canal, crestal bone, and buccal and lingual surfaces were graded as 0, 1, or 2. The bone width at the maxillo-tangential projection was wider than at the dento-tangential projection (p<0.05). The visibility of buccal and lingual surface at the maxillo-tangential projection was higher than at the dento-tangential projection (p<0.05). Thinner image layer thicknesses resulted in greater visibility of buccal and lingual surfaces (p<0.05). Bone height was greatest in the -10 .deg. group, and at the same time the bone width of the same group was the narrowest (p<0.05). The visibility of alveolar crest and buccal surface of the +10 .deg. group was the highest, while the visibility of the mandibular canal was greatest in the 0 .deg. group. When spiral tomography is performed at the mandibular posterior portion for visualization prior to implant surgery, it is important that the inferior border of mandible be positioned as parallel as possible to the floor. A greater improvement of visibility can be achieved by maintaining a thin image layer thickness when performing spiral tomography.

  1. Standard practice for digital imaging and communication in nondestructive evaluation (DICONDE) for digital radiographic (DR) test methods

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice facilitates the interoperability of digital X-ray imaging equipment by specifying image data transfer and archival methods in commonly accepted terms. This document is intended to be used in conjunction with Practice E2339 on Digital Imaging and Communication in Nondestructive Evaluation (DICONDE). Practice E2339 defines an industrial adaptation of the NEMA Standards Publication titled Digital Imaging and Communications in Medicine (DICOM, see http://medical.nema.org), an international standard for image data acquisition, review, storage and archival storage. The goal of Practice E2339, commonly referred to as DICONDE, is to provide a standard that facilitates the display and analysis of NDE results on any system conforming to the DICONDE standard. Toward that end, Practice E2339 provides a data dictionary and a set of information modules that are applicable to all NDE modalities. This practice supplements Practice E2339 by providing information object definitions, information modules and a ...

  2. Image aesthetic quality evaluation using convolution neural network embedded learning

    Science.gov (United States)

    Li, Yu-xin; Pu, Yuan-yuan; Xu, Dan; Qian, Wen-hua; Wang, Li-peng

    2017-11-01

    A way of embedded learning convolution neural network (ELCNN) based on the image content is proposed to evaluate the image aesthetic quality in this paper. Our approach can not only solve the problem of small-scale data but also score the image aesthetic quality. First, we chose Alexnet and VGG_S to compare for confirming which is more suitable for this image aesthetic quality evaluation task. Second, to further boost the image aesthetic quality classification performance, we employ the image content to train aesthetic quality classification models. But the training samples become smaller and only using once fine-tuning cannot make full use of the small-scale data set. Third, to solve the problem in second step, a way of using twice fine-tuning continually based on the aesthetic quality label and content label respective is proposed, the classification probability of the trained CNN models is used to evaluate the image aesthetic quality. The experiments are carried on the small-scale data set of Photo Quality. The experiment results show that the classification accuracy rates of our approach are higher than the existing image aesthetic quality evaluation approaches.

  3. Radiographic, CT and MRI features of cherubism

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Vaibhav; Sharma, Raju [All India Institute of Medical Sciences, Department of Radiodiagnosis, New Delhi (India)

    2006-10-15

    Cherubism is a paediatric disease affecting the jaws. It is a close radiological mimic of giant cell lesions of the mandible. The radiographic features of this condition are well known; however, the MR imaging features have not been well described. We describe the radiographic, CT and MR imaging features of cherubism in a 5-year-old girl. We highlight the MR appearances of cherubic lesions and the ability of MRI to not only accurately depict the anatomical extent of the lesions, but also to reveal signal intensity changes in those areas that are apparently normal on radiographs and CT images. (orig.)

  4. [Effects of high-strip density anti-scatter grid on image quality and radiation dose].

    Science.gov (United States)

    Wamser, G; Maier, W; Aichinger, H; Bohndorf, K

    1997-06-01

    Using a new type of a stationary high strip density grid (13/75) for plain films of the abdomen, the effect was evaluated with regard to quality and patient dose in comparison with an established moving radiographic grid (12/40). The high strip density grid (13/75) was compared with a 12/40 grid using test objects and 100 patients per each grid type for plain films of the abdomen. The examinations were carried out via the screen-film system, speed class (SC) 400. Patients' weight, age and dose measurements were recorded. The image quality was evaluated via a multi-reader study using delineation of anatomical structures and a rating scale (score 1-5 or 1-3). Both measurements with test objects and patients abdominal plain films showed a decrease in radiation dose of 17% using the 13/75 grid, and 24%, respectively. The delineation of 4 out of 7 anatomical structures was slightly reduced with the new high strip density grid (maximum score reduction: 0.4), the image contrast, as well as the radiologists' subjective rating. Apart from an acceptable loss in image quality compared with the 12/40 grid, the new high strip density grid (13/ 75) enables a clear reduction in radiation dose.

  5. Automated FMV image quality assessment based on power spectrum statistics

    Science.gov (United States)

    Kalukin, Andrew

    2015-05-01

    Factors that degrade image quality in video and other sensor collections, such as noise, blurring, and poor resolution, also affect the spatial power spectrum of imagery. Prior research in human vision and image science from the last few decades has shown that the image power spectrum can be useful for assessing the quality of static images. The research in this article explores the possibility of using the image power spectrum to automatically evaluate full-motion video (FMV) imagery frame by frame. This procedure makes it possible to identify anomalous images and scene changes, and to keep track of gradual changes in quality as collection progresses. This article will describe a method to apply power spectral image quality metrics for images subjected to simulated blurring, blocking, and noise. As a preliminary test on videos from multiple sources, image quality measurements for image frames from 185 videos are compared to analyst ratings based on ground sampling distance. The goal of the research is to develop an automated system for tracking image quality during real-time collection, and to assign ratings to video clips for long-term storage, calibrated to standards such as the National Imagery Interpretability Rating System (NIIRS).

  6. Analysis of image quality according to BMI of digital chest radiography: Focusing on bureau of radiological health evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Seong Jin [Gammaknife center, Inje University Haeundae Paik Hospital, Busan (Korea, Republic of); Im, In Chul [Dept. of Radiological Science, Dongeui University, Busan (Korea, Republic of); Cho, Ji Hwan [Dept. of Health Care Clinic, Inje University Busan Paik Hospital, Busan (Korea, Republic of)

    2017-03-15

    Visual evaluation of chest radiograph images is the most practical and effective method. This study compared the Body Mass Index, waist circumference, and mAs with chest radiographs of 351 women. The Bureau of Radiological Health method was used to evaluate the image quality of chest X-ray images by anatomical and physical methods. The average age of the subjects was 30.17±4.73 and the average waist circumference was 66.91±4.67 cm. The mean Body Mass Index value was 20.21±2.23, the mean value of mAs was 3.04±0.78, and the mean value of Bureau of Radiological Health was 79.83±8.45. When the Body Mass Index value increased, waist circumference and mAs mean value increased. The mean value of Body Mass Index was statistically significant(p<0.05) in Group 4 compared to Groups 1 and 2, with increasing Body Mass Index. Exposure control of the automatic exposure control system is considered to be well performed according to body thickness or Body Mass Index at the time of chest radiography. As the Body Mass Index increases, the thickness of the body increases and the breast thickness of the woman also increases. Therefore, it is considered that the exposure amount is changed by the automatic exposure control device to affect the image quality.

  7. Numerical analysis of radiographic image applied in measurements and examinations of corrosion development in petrochemical installations; Numeryczna analiza obrazu radiograficznego w zastosowaniu do pomiarow i sledzenia rozwoju korozji w instalacjach petrochemicznych

    Energy Technology Data Exchange (ETDEWEB)

    Helleringer, H.

    1995-12-31

    Corrosion control of petrochemical pipelines is the great importance for the safety and economy of their exploitation. The gamma radiography is one of the best tools for material testing. The numerical analysis of radiographic images in the paper enables significant elevation of their interpretation.

  8. Monitoring Radiographic Brain Tumor Progression

    Directory of Open Access Journals (Sweden)

    John H. Sampson

    2011-03-01

    Full Text Available Determining radiographic progression in primary malignant brain tumors has posed a significant challenge to the neuroncology community. Glioblastoma multiforme (GBM, WHO Grade IV through its inherent heterogeneous enhancement, growth patterns, and irregular nature has been difficult to assess for progression. Our ability to detect tumor progression radiographically remains inadequate. Despite the advanced imaging techniques, detecting tumor progression continues to be a clinical challenge. Here we review the different criteria used to detect tumor progression, and highlight the inherent challenges with detection of progression.

  9. Construction of anthropomorphic hybrid, dual-lattice voxel models for optimizing image quality and dose in radiography

    Science.gov (United States)

    Petoussi-Henss, Nina; Becker, Janine; Greiter, Matthias; Schlattl, Helmut; Zankl, Maria; Hoeschen, Christoph

    2014-03-01

    In radiography there is generally a conflict between the best image quality and the lowest possible patient dose. A proven method of dosimetry is the simulation of radiation transport in virtual human models (i.e. phantoms). However, while the resolution of these voxel models is adequate for most dosimetric purposes, they cannot provide the required organ fine structures necessary for the assessment of the imaging quality. The aim of this work is to develop hybrid/dual-lattice voxel models (called also phantoms) as well as simulation methods by which patient dose and image quality for typical radiographic procedures can be determined. The results will provide a basis to investigate by means of simulations the relationships between patient dose and image quality for various imaging parameters and develop methods for their optimization. A hybrid model, based on NURBS (Non Linear Uniform Rational B-Spline) and PM (Polygon Mesh) surfaces, was constructed from an existing voxel model of a female patient. The organs of the hybrid model can be then scaled and deformed in a non-uniform way i.e. organ by organ; they can be, thus, adapted to patient characteristics without losing their anatomical realism. Furthermore, the left lobe of the lung was substituted by a high resolution lung voxel model, resulting in a dual-lattice geometry model. "Dual lattice" means in this context the combination of voxel models with different resolution. Monte Carlo simulations of radiographic imaging were performed with the code EGS4nrc, modified such as to perform dual lattice transport. Results are presented for a thorax examination.

  10. The relationship between compression force, image quality and ...

    African Journals Online (AJOL)

    Background. Mammography aims to obtain mammograms of the best possible image quality with the least possible radiation dose. Theoretically, an increase in breast compression gives a reduction in thickness without changing the density, resulting in improved image quality and reduced radiation dose. Aim. This study ...

  11. QUALITY AWARDS: AN IMAGE OF BUSINESS EXCELLENCE

    Directory of Open Access Journals (Sweden)

    Ilies Liviu

    2015-07-01

    Full Text Available Across the world, increasingly more governmental organizations and industrial are doing everything possible to promote quality and to survive, the basic principle remains customer satisfaction and even more than that, it speaks of the principle of customer delight. In this sense, quality has become the source of sustained competitive advantage that provides organizations the supremacy of the global markets characterized by competition which becoming more and more intensified. Juran, one of the highest quality gurus say that “just as the twentieth century was the century of productivity, the twenty-first century will be the quality century” which is a very relevant and comprehensive statement of the economic reality of the past and a profound forecast for future business of the twenty-first century. In this regard, in order to achieve this competitive advantage, quality must be managed and this is accomplished through Total Quality Management (TQM. Quality awards models are instruments of total quality management through which quality can be assessed and improved, thus, knowing the quality awards models is critical for findings the new ways to improve the quality and performance of the organizations. The present paper aims to illustrate the best practices on quality improvement in this respect we intend to present the general framework of the quality awards for business excellence. In this sense we present the most important international quality awards, namely: "Malcolm Baldrige National Quality Award", "European Quality Award" and “Romanian Quality Award J. M. Juran". For this purpose we used as main sources of analyzing the structure and the operation mode of these three important quality awards, Juran's work (which is probably the most important work in the field of quality and other relevant sources in total quality management which treats issues related to quality awards and also we used as sources of updated information the official

  12. Influence of chroma variations on naturalness and image quality of stereoscopic images

    NARCIS (Netherlands)

    Kuijsters, A.; IJsselsteijn, W.A.; Lambooij, M.T.M.; Heyndrickx, I.E.J.

    2009-01-01

    The computational view on image quality of Janssen and Blommaert states that the quality of an image is determined by the degree to which the image is both useful (discriminability) and natural (identifiability). This theory is tested by creating two manipulations. Firstly, multiplication of the

  13. Using image quality measures and features to choose good images for classification of ISAR imagery

    CSIR Research Space (South Africa)

    Steyn, JM

    2014-10-01

    Full Text Available the quality measures and to determine the minimum dwell-time for ISAR image formation. Keywords—ISAR (inverse synthetic aperture radar), Dwell-time, Quality Measure, Image Contrast, Image Entropy, SNR (signal-to-noise ratio), Maritime Vessels ...

  14. The effect of image sharpness on quantitative eye movement data and on image quality evaluation while viewing natural images

    Science.gov (United States)

    Vuori, Tero; Olkkonen, Maria

    2006-01-01

    The aim of the study is to test both customer image quality rating (subjective image quality) and physical measurement of user behavior (eye movements tracking) to find customer satisfaction differences in imaging technologies. Methodological aim is to find out whether eye movements could be quantitatively used in image quality preference studies. In general, we want to map objective or physically measurable image quality to subjective evaluations and eye movement data. We conducted a series of image quality tests, in which the test subjects evaluated image quality while we recorded their eye movements. Results show that eye movement parameters consistently change according to the instructions given to the user, and according to physical image quality, e.g. saccade duration increased with increasing blur. Results indicate that eye movement tracking could be used to differentiate image quality evaluation strategies that the users have. Results also show that eye movements would help mapping between technological and subjective image quality. Furthermore, these results give some empirical emphasis to top-down perception processes in image quality perception and evaluation by showing differences between perceptual processes in situations when cognitive task varies.

  15. Image quality assessment for CT used on small animals

    Energy Technology Data Exchange (ETDEWEB)

    Cisneros, Isabela Paredes, E-mail: iparedesc@unal.edu.co; Agulles-Pedrós, Luis, E-mail: lagullesp@unal.edu.co [Universidad Nacional de Colombia, Departamento de Física, Grupo de Física Médica (Colombia)

    2016-07-07

    Image acquisition on a CT scanner is nowadays necessary in almost any kind of medical study. Its purpose, to produce anatomical images with the best achievable quality, implies the highest diagnostic radiation exposure to patients. Image quality can be measured quantitatively based on parameters such as noise, uniformity and resolution. This measure allows the determination of optimal parameters of operation for the scanner in order to get the best diagnostic image. A human Phillips CT scanner is the first one minded for veterinary-use exclusively in Colombia. The aim of this study was to measure the CT image quality parameters using an acrylic phantom and then, using the computational tool MATLAB, determine these parameters as a function of current value and window of visualization, in order to reduce dose delivery by keeping the appropriate image quality.

  16. Effect of image quality on calcification detection in digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Lucy M.; Mackenzie, Alistair; Cooke, Julie; Given-Wilson, Rosalind M.; Wallis, Matthew G.; Chakraborty, Dev P.; Dance, David R.; Bosmans, Hilde; Young, Kenneth C. [National Co-ordinating Centre for the Physics of Mammography, Royal Surrey County Hospital NHS Foundation Trust, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom); Jarvis Breast Screening and Diagnostic Centre, Guildford GU1 1LJ (United Kingdom); Department of Radiology, St. George' s Healthcare NHS Trust, Tooting, London SW17 0QT (United Kingdom); Cambridge Breast Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, United Kingdom and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0QQ (United Kingdom); Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15210 (United States); National Co-ordinating Centre for the Physics of Mammography, Royal Surrey County Hospital NHS Foundation Trust, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom); University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); National Co-ordinating Centre for the Physics of Mammography, Royal Surrey County Hospital NHS Foundation Trust, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2012-06-15

    Purpose: This study aims to investigate if microcalcification detection varies significantly when mammographic images are acquired using different image qualities, including: different detectors, dose levels, and different image processing algorithms. An additional aim was to determine how the standard European method of measuring image quality using threshold gold thickness measured with a CDMAM phantom and the associated limits in current EU guidelines relate to calcification detection. Methods: One hundred and sixty two normal breast images were acquired on an amorphous selenium direct digital (DR) system. Microcalcification clusters extracted from magnified images of slices of mastectomies were electronically inserted into half of the images. The calcification clusters had a subtle appearance. All images were adjusted using a validated mathematical method to simulate the appearance of images from a computed radiography (CR) imaging system at the same dose, from both systems at half this dose, and from the DR system at quarter this dose. The original 162 images were processed with both Hologic and Agfa (Musica-2) image processing. All other image qualities were processed with Agfa (Musica-2) image processing only. Seven experienced observers marked and rated any identified suspicious regions. Free response operating characteristic (FROC) and ROC analyses were performed on the data. The lesion sensitivity at a nonlesion localization fraction (NLF) of 0.1 was also calculated. Images of the CDMAM mammographic test phantom were acquired using the automatic setting on the DR system. These images were modified to the additional image qualities used in the observer study. The images were analyzed using automated software. In order to assess the relationship between threshold gold thickness and calcification detection a power law was fitted to the data. Results: There was a significant reduction in calcification detection using CR compared with DR: the alternative FROC

  17. Design and evaluation of learning strategies for a group of radiographers in radiostereometric analysis (RSA)

    DEFF Research Database (Denmark)

    Muharemovic, O; Troelsen, A; Thomsen, M G

    2017-01-01

    INTRODUCTION: The purpose of this study was to design and evaluate a radiostereometric analysis (RSA) program aimed at radiographers in order to increase their cognitive and practical skills, thereby increasing image quality and minimizing exposure repetition. METHODS AND MATERIALS: Twenty radiog...

  18. Quaternion structural similarity: a new quality index for color images.

    Science.gov (United States)

    Kolaman, Amir; Yadid-Pecht, Orly

    2012-04-01

    One of the most important issues for researchers developing image processing algorithms is image quality. Methodical quality evaluation, by showing images to several human observers, is slow, expensive, and highly subjective. On the other hand, a visual quality matrix (VQM) is a fast, cheap, and objective tool for evaluating image quality. Although most VQMs are good in predicting the quality of an image degraded by a single degradation, they poorly perform for a combination of two degradations. An example for such degradation is the color crosstalk (CTK) effect, which introduces blur with desaturation. CTK is expected to become a bigger issue in image quality as the industry moves toward smaller sensors. In this paper, we will develop a VQM that will be able to better evaluate the quality of an image degraded by a combined blur/desaturation degradation and perform as well as other VQMs on single degradations such as blur, compression, and noise. We show why standard scalar techniques are insufficient to measure a combined blur/desaturation degradation and explain why a vectorial approach is better suited. We introduce quaternion image processing (QIP), which is a true vectorial approach and has many uses in the fields of physics and engineering. Our new VQM is a vectorial expansion of structure similarity using QIP, which gave it its name-Quaternion Structural SIMilarity (QSSIM). We built a new database of a combined blur/desaturation degradation and conducted a quality survey with human subjects. An extensive comparison between QSSIM and other VQMs on several image quality databases-including our new database-shows the superiority of this new approach in predicting visual quality of color images.

  19. Impact of image quality on OCT angiography based quantitative measurements.

    Science.gov (United States)

    Al-Sheikh, Mayss; Ghasemi Falavarjani, Khalil; Akil, Handan; Sadda, SriniVas R

    2017-01-01

    To study the impact of image quality on quantitative measurements and the frequency of segmentation error with optical coherence tomography angiography (OCTA). Seventeen eyes of 10 healthy individuals were included in this study. OCTA was performed using a swept-source device (Triton, Topcon). Each subject underwent three scanning sessions 1-2 min apart; the first two scans were obtained under standard conditions and for the third session, the image quality index was reduced using application of a topical ointment. En face OCTA images of the retinal vasculature were generated using the default segmentation for the superficial and deep retinal layer (SRL, DRL). Intraclass correlation coefficient (ICC) was used as a measure for repeatability. The frequency of segmentation error, motion artifact, banding artifact and projection artifact was also compared among the three sessions. The frequency of segmentation error, and motion artifact was statistically similar between high and low image quality sessions (P = 0.707, and P = 1 respectively). However, the frequency of projection and banding artifact was higher with a lower image quality. The vessel density in the SRL was highly repeatable in the high image quality sessions (ICC = 0.8), however, the repeatability was low, comparing the high and low image quality measurements (ICC = 0.3). In the DRL, the repeatability of the vessel density measurements was fair in the high quality sessions (ICC = 0.6 and ICC = 0.5, with and without automatic artifact removal, respectively) and poor comparing high and low image quality sessions (ICC = 0.3 and ICC = 0.06, with and without automatic artifact removal, respectively). The frequency of artifacts is higher and the repeatability of the measurements is lower with lower image quality. The impact of image quality index should be always considered in OCTA based quantitative measurements.

  20. Hyperspectral Image Analysis of Food Quality

    DEFF Research Database (Denmark)

    Arngren, Morten

    , the visualisation and interpretation of hyperspectral images are discussed.A Bayesian based unmixing method is presented as a novel approachto decompose a hyperspectral image into interpretable components. Secondly,hyperspectral imaging is applied to a dedicated application of predicting the degreeof pre-germination...

  1. No-reference quality index for color retinal images.

    Science.gov (United States)

    Abdel-Hamid, Lamiaa; El-Rafei, Ahmed; Michelson, Georg

    2017-11-01

    Retinal image quality assessment (RIQA) is essential to assure that the images investigated by ophthalmologists or automatic systems are suitable for reliable medical diagnosis. Measure-based RIQA techniques have several advantages over the more commonly used binary classification-based RIQA methods. Numeric quality measures can aid ophthalmologists in associating a degree of confidence to the diagnosis performed through the investigation of a certain retinal image. Moreover, a numeric quality index can provide a mean for identifying the degree of enhancement required as well as to evaluate and compare the improvement achieved by enhancement techniques. In this work, a no-reference retinal image sharpness numeric quality index is introduced that is computed from the wavelet decomposition of the images. In order to account for the obscured retinal structures in unevenly illuminated image regions, the quality index is modified by a homogeneity parameter calculated from the previously introduced retinal image saturation channel. The proposed quality index was validated and tested on two datasets having different resolutions and quality grades. A strong (Spearman's coefficient > 0.8) and statistically highly significant (p-value quality index and the subjective human scores for the two different datasets. Moreover, multiclass classification using solely the devised retinal image quality index as a feature resulted in a micro average F-measure of 0.84 and 0.95 using the high and low resolution datasets, respectively. Several comparisons with other retinal image quality measures demonstrated superiority of the proposed quality index in both performance and speed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Clinical and radiographic outcomes of minimally invasive percutaneous pedicle screw placement with intraoperative CT (O-arm) image guidance navigation.

    Science.gov (United States)

    Kim, Terrence T; Drazin, Doniel; Shweikeh, Faris; Pashman, Robert; Johnson, J Patrick

    2014-03-01

    Intraoperative CT image-guided navigation (IGN) has been increasingly incorporated into minimally invasive spine surgery (MIS). The vast improvement in image resolution and virtual real-time images with CT-IGN has proven superiority over traditional fluoroscopic techniques. The authors describe their perioperative MIS technique using the O-arm with navigation, and they report their postoperative experience, accuracy results, and technical aspects. A retrospective review of 48 consecutive adult patients undergoing minimally invasive percutaneous posterior spinal fusion with intraoperative CT-IGN between July 2010 and August 2013 at Cedars-Sinai Medical Center was performed. Two surgeons assessed 290 screws in a blinded fashion on intraoperative O-arm images and postoperative CT scans for bony pedicle wall breach. Grade 1 breach was defined to be 4 mm. Additionally, anterior vertebral body breach was recorded. Of 290 pedicle screws placed, 280 (96.6%) were in an acceptable position without cortical wall or anterior breach. Of the 10 breaches (3.4%) 5 were lateral (50%), 4 were medial, and 1 was anterior; 90% of breaches were Grade 1-2 and all medial breaches were Grade 1. The one Grade 3 breach was lateral. No vascular or neurological complications were observed intraoperatively, and no significant postoperative complications were noted. The mean clinical follow-up period was 18 months (range 3-39 months). The overall clinical outcomes, measured using the visual analog scale (back pain scores), were improved significantly postoperatively at 3 months compared with preoperatively (visual analog score 6.35 vs 3.57; p imaging methods are lower occupational radiation exposure for the surgical team, reduced need for postoperative imaging, and decreased rates of revision surgery. For now, the authors simply conclude that use of intraoperative CT-IGN is safe and accurate.

  3. Standardizing Quality Assessment of Fused Remotely Sensed Images

    Science.gov (United States)

    Pohl, C.; Moellmann, J.; Fries, K.

    2017-09-01

    The multitude of available operational remote sensing satellites led to the development of many image fusion techniques to provide high spatial, spectral and temporal resolution images. The comparison of different techniques is necessary to obtain an optimized image for the different applications of remote sensing. There are two approaches in assessing image quality: 1. Quantitatively by visual interpretation and 2. Quantitatively using image quality indices. However an objective comparison is difficult due to the fact that a visual assessment is always subject and a quantitative assessment is done by different criteria. Depending on the criteria and indices the result varies. Therefore it is necessary to standardize both processes (qualitative and quantitative assessment) in order to allow an objective image fusion quality evaluation. Various studies have been conducted at the University of Osnabrueck (UOS) to establish a standardized process to objectively compare fused image quality. First established image fusion quality assessment protocols, i.e. Quality with No Reference (QNR) and Khan's protocol, were compared on varies fusion experiments. Second the process of visual quality assessment was structured and standardized with the aim to provide an evaluation protocol. This manuscript reports on the results of the comparison and provides recommendations for future research.

  4. Effect of image quality on calcification detection in digital mammography.

    Science.gov (United States)

    Warren, Lucy M; Mackenzie, Alistair; Cooke, Julie; Given-Wilson, Rosalind M; Wallis, Matthew G; Chakraborty, Dev P; Dance, David R; Bosmans, Hilde; Young, Kenneth C

    2012-06-01

    This study aims to investigate if microcalcification detection varies significantly when mammographic images are acquired using different image qualities, including: different detectors, dose levels, and different image processing algorithms. An additional aim was to determine how the standard European method of measuring image quality using threshold gold thickness measured with a CDMAM phantom and the associated limits in current EU guidelines relate to calcification detection. One hundred and sixty two normal breast images were acquired on an amorphous selenium direct digital (DR) system. Microcalcification clusters extracted from magnified images of slices of mastectomies were electronically inserted into half of the images. The calcification clusters had a subtle appearance. All images were adjusted using a validated mathematical method to simulate the appearance of images from a computed radiography (CR) imaging system at the same dose, from both systems at half this dose, and from the DR system at quarter this dose. The original 162 images were processed with both Hologic and Agfa (Musica-2) image processing. All other image qualities were processed with Agfa (Musica-2) image processing only. Seven experienced observers marked and rated any identified suspicious regions. Free response operating characteristic (FROC) and ROC analyses were performed on the data. The lesion sensitivity at a nonlesion localization fraction (NLF) of 0.1 was also calculated. Images of the CDMAM mammographic test phantom were acquired using the automatic setting on the DR system. These images were modified to the additional image qualities used in the observer study. The images were analyzed using automated software. In order to assess the relationship between threshold gold thickness and calcification detection a power law was fitted to the data. There was a significant reduction in calcification detection using CR compared with DR: the alternative FROC (AFROC) area decreased from

  5. Effect of image quality on calcification detection in digital mammography

    Science.gov (United States)

    Warren, Lucy M.; Mackenzie, Alistair; Cooke, Julie; Given-Wilson, Rosalind M.; Wallis, Matthew G.; Chakraborty, Dev P.; Dance, David R.; Bosmans, Hilde; Young, Kenneth C.

    2012-01-01

    Purpose: This study aims to investigate if microcalcification detection varies significantly when mammographic images are acquired using different image qualities, including: different detectors, dose levels, and different image processing algorithms. An additional aim was to determine how the standard European method of measuring image quality using threshold gold thickness measured with a CDMAM phantom and the associated limits in current EU guidelines relate to calcification detection. Methods: One hundred and sixty two normal breast images were acquired on an amorphous selenium direct digital (DR) system. Microcalcification clusters extracted from magnified images of slices of mastectomies were electronically inserted into half of the images. The calcification clusters had a subtle appearance. All images were adjusted using a validated mathematical method to simulate the appearance of images from a computed radiography (CR) imaging system at the same dose, from both systems at half this dose, and from the DR system at quarter this dose. The original 162 images were processed with both Hologic and Agfa (Musica-2) image processing. All other image qualities were processed with Agfa (Musica-2) image processing only. Seven experienced observers marked and rated any identified suspicious regions. Free response operating characteristic (FROC) and ROC analyses were performed on the data. The lesion sensitivity at a nonlesion localization fraction (NLF) of 0.1 was also calculated. Images of the CDMAM mammographic test phantom were acquired using the automatic setting on the DR system. These images were modified to the additional image qualities used in the observer study. The images were analyzed using automated software. In order to assess the relationship between threshold gold thickness and calcification detection a power law was fitted to the data. Results: There was a significant reduction in calcification detection using CR compared with DR: the alternative FROC

  6. Thoracic and heart biometrics of non-anesthetized agouti (Dasyprocta primnolopha Wagler, 1831 measured on radiographic images

    Directory of Open Access Journals (Sweden)

    Anaemilia das N. Diniz

    2013-03-01

    Full Text Available The agouti is a species intensively hunted throughout the Amazon and the semi-arid regions of northeastern Brazil. Considering the current trend in conservation management of wild species, the aim of this study was to determine the morphometric reference to the heart of agouti raised in captivity, based on thoracic and cardiac measurements in these animals. Thirty adult agoutis, 1 to 3 years of age, without clinical signs of cardiac disease were selected. The animals were physically restrained and radiographies in laterolateral (LL and ventrodorsal (VD recumbence were produced. The following measures were taken: the apicobasilar length of the heart (at the most cranial height of the Carina region to the heart apex (AB, maximum width of the heart perpendicular to AB (CD, heart inclination angle (AIC, trachea inclination angle (AIT, distance from the right heart wall (DPTd, distance from the left heart wall (DPTe and vertical depth of the thorax, and the ventral face of the vertebral column to the dorsal border of the sternum at the level of the trachea bifurcation (H. The ratios between AB/CD, AB/H and CD/H were also analyzed. To calculate the vertebral heart scale (VHS, the AB and CD measurements were laid over the thoracic vertebra starting at T4. Radiographic evaluation showed values consistent with those reported in small animals and some wild and exotic species. The main biometric values in the chest cavity and heart of agouti are arranged as follows: (1 The ratios between AB/H ratio and CD/H were not sensitive for identifying heart increases (p>0.05, while the ratio AB/CD was more sensitive in this identification (p<0.05; (2 AIC: 21.2±6.4º (mean between male and famale; (3 AIT for males and females: 9.93±3.23° and 8.4±3.94°; (4 DPTd and DPTe for males: 0.97±0.40cm and 0.7±0.30cm; (5 DPTd and DPTe for females: 1.12±0.42cm and 01.02±0.43cm; (6 VHS for males and females: 7.75±0.48v e 7.61±0.34v; (7 The caudal vena cava (CVC was

  7. Peritendinous calcinosis of calcaneus tendon associated with dermatomyositis: correlation between conventional radiograph, ultrasound, magnetic resonance imaging and gross surgical pathology; Calcinose peritendinea do tendao calcaneo associada a dermatomiosite: correlacao entre radiografia convencional, ultra-sonografia, ressonancia magnetica e macroscopia cirurgica

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Ana Claudia Ferreira; Gomide, Lidyane Marques de Paula; Lemes, Marcella Stival [Universidade Federal de Goias (UFG), Goiana, GO (Brazil). Faculdade de Medicina. Hospital das Clinicas; Costa, Edegmar Nunes; Rocha, Valney Luiz da [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Faculdade de Medicina. Dept. de Ortopedia; Machado, Marcio Martins; Santos Junior, Rubens Carneiro dos; Barros, Nestor de; Cerri, Giovanni Guido [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Faculdade de Medicina. Dept. de Radiologia; Sernik, Renato Antonio [Sao Paulo Univ., SP (Brazil). Hospital das Clinicas. Inst. de Radiologia; Nunes, Rodrigo Alvarenga [Universidade do Vale do Sapucai (UNIVAS), Pouso Alegre, MG (Brazil). Faculdade de Ciencias Medicas; Albieri, Alexandre Daher [Hospital de Acidentados de Goiania, GO (Brazil)

    2006-01-15

    Interstitial calcinosis is an uncommon condition in which there is either localized or widely disseminated deposition of calcium in the skin, subcutaneous tissues, muscles, and tendons. Calcinosis is often associated with collagen diseases, scleroderma and dermatomyositis. The authors report a case of interstitial calcinosis associated with dermatomyositis studied with conventional radiograph, ultrasound and magnetic resonance imaging, and correlate the imaging findings with the results of surgical pathology gross examination. (author)

  8. Low-cost oblique illumination: an image quality assessment.

    Science.gov (United States)

    Ruiz-Santaquiteria, Jesus; Espinosa-Aranda, Jose Luis; Deniz, Oscar; Sanchez, Carlos; Borrego-Ramos, Maria; Blanco, Saul; Cristobal, Gabriel; Bueno, Gloria

    2018-01-01

    We study the effectiveness of several low-cost oblique illumination filters to improve overall image quality, in comparison with standard bright field imaging. For this purpose, a dataset composed of 3360 diatom images belonging to 21 taxa was acquired. Subjective and objective image quality assessments were done. The subjective evaluation was performed by a group of diatom experts by psychophysical test where resolution, focus, and contrast were assessed. Moreover, some objective nonreference image quality metrics were applied to the same image dataset to complete the study, together with the calculation of several texture features to analyze the effect of these filters in terms of textural properties. Both image quality evaluation methods, subjective and objective, showed better results for images acquired using these illumination filters in comparison with the no filtered image. These promising results confirm that this kind of illumination filters can be a practical way to improve the image quality, thanks to the simple and low cost of the design and manufacturing process. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  9. Image processing system performance prediction and product quality evaluation

    Science.gov (United States)

    Stein, E. K.; Hammill, H. B. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. A new technique for image processing system performance prediction and product quality evaluation was developed. It was entirely objective, quantitative, and general, and should prove useful in system design and quality control. The technique and its application to determination of quality control procedures for the Earth Resources Technology Satellite NASA Data Processing Facility are described.

  10. Performance comparison of different graylevel image fusion schemes through a universal image quality index

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2003-01-01

    We applied a recently introduced universal image quality index Q that quantifies the distortion of a processed image relative to its original version, to assess the performance of different graylevel image fusion schemes. The method is as follows. First, we adopt an original test image as the

  11. Homogeneous Canine Chest Phantom Construction: A Tool for Image Quality Optimization.

    Directory of Open Access Journals (Sweden)

    Ana Luiza Menegatti Pavan

    Full Text Available Digital radiographic imaging is increasing in veterinary practice. The use of radiation demands responsibility to maintain high image quality. Low doses are necessary because workers are requested to restrain the animal. Optimizing digital systems is necessary to avoid unnecessary exposure, causing the phenomenon known as dose creep. Homogeneous phantoms are widely used to optimize image quality and dose. We developed an automatic computational methodology to classify and quantify tissues (i.e., lung tissue, adipose tissue, muscle tissue, and bone in canine chest computed tomography exams. The thickness of each tissue was converted to simulator materials (i.e., Lucite, aluminum, and air. Dogs were separated into groups of 20 animals each according to weight. Mean weights were 6.5 ± 2.0 kg, 15.0 ± 5.0 kg, 32.0 ± 5.5 kg, and 50.0 ± 12.0 kg, for the small, medium, large, and giant groups, respectively. The one-way analysis of variance revealed significant differences in all simulator material thicknesses (p < 0.05 quantified between groups. As a result, four phantoms were constructed for dorsoventral and lateral views. In conclusion, the present methodology allows the development of phantoms of the canine chest and possibly other body regions and/or animals. The proposed phantom is a practical tool that may be employed in future work to optimize veterinary X-ray procedures.

  12. Radiation levels and image quality in patients undergoing chest X-ray examinations

    Science.gov (United States)

    de Oliveira, Paulo Márcio Campos; do Carmo Santana, Priscila; de Sousa Lacerda, Marco Aurélio; da Silva, Teógenes Augusto

    2017-11-01

    Patient dose monitoring for different radiographic procedures has been used as a parameter to evaluate the performance of radiology services; skin entrance absorbed dose values for each type of examination were internationally established and recommended aiming patient protection. In this work, a methodology for dose evaluation was applied to three diagnostic services: one with a conventional film and two with digital computerized radiography processing techniques. The x-ray beam parameters were selected and "doses" (specifically the entrance surface and incident air kerma) were evaluated based on images approved in European criteria during postero-anterior (PA) and lateral (LAT) incidences. Data were collected from 200 patients related to 200 PA and 100 LAT incidences. Results showed that doses distributions in the three diagnostic services were very different; the best relation between dose and image quality was found in the institution with the chemical film processing. This work contributed for disseminating the radiation protection culture by emphasizing the need of a continuous dose reduction without losing the quality of the diagnostic image.

  13. Retinal image quality assessment through a visual similarity index

    Science.gov (United States)

    Pérez, Jorge; Espinosa, Julián; Vázquez, Carmen; Mas, David

    2013-04-01

    Retinal image quality is commonly analyzed through parameters inherited from instrumental optics. These parameters are defined for 'good optics' so they are hard to translate into visual quality metrics. Instead of using point or artificial functions, we propose a quality index that takes into account properties of natural images. These images usually show strong local correlations that help to interpret the image. Our aim is to derive an objective index that quantifies the quality of vision by taking into account the local structure of the scene, instead of focusing on a particular aberration. As we show, this index highly correlates with visual acuity and allows inter-comparison of natural images around the retina. The usefulness of the index is proven through the analysis of real eyes before and after undergoing corneal surgery, which usually are hard to analyze with standard metrics.

  14. Ranking images based on aesthetic qualities.

    OpenAIRE

    Gaur, Aarushi

    2015-01-01

    The qualitative assessment of image content and aesthetic impression is affected by various image attributes and relations between the attributes. Modelling of such assessments in the form of objective rankings and learning image representations based on them is not a straightforward problem. The criteria can be varied with different levels of complexity for various applications. A highly-complex problem could involve a large number of interrelated attributes and features alongside varied rul...

  15. No-reference visual quality assessment for image inpainting

    Science.gov (United States)

    Voronin, V. V.; Frantc, V. A.; Marchuk, V. I.; Sherstobitov, A. I.; Egiazarian, K.

    2015-03-01

    Inpainting has received a lot of attention in recent years and quality assessment is an important task to evaluate different image reconstruction approaches. In many cases inpainting methods introduce a blur in sharp transitions in image and image contours in the recovery of large areas with missing pixels and often fail to recover curvy boundary edges. Quantitative metrics of inpainting results currently do not exist and researchers use human comparisons to evaluate their methodologies and techniques. Most objective quality assessment methods rely on a reference image, which is often not available in inpainting applications. Usually researchers use subjective quality assessment by human observers. It is difficult and time consuming procedure. This paper focuses on a machine learning approach for no-reference visual quality assessment for image inpainting based on the human visual property. Our method is based on observation that Local Binary Patterns well describe local structural information of the image. We use a support vector regression learned on assessed by human images to predict perceived quality of inpainted images. We demonstrate how our predicted quality value correlates with qualitative opinion in a human observer study. Results are shown on a human-scored dataset for different inpainting methods.

  16. Digital evaluation of the influence of interruption of the fixation process on radiographic contrast and base-plus-fog density in three commercial brands of radiographic films

    Directory of Open Access Journals (Sweden)

    Paula Verona Ragusa da Silva

    Full Text Available INTRODUCTION : With the interest in anticipating access to the result of intraoral radiography, the radiographic processing is frequently neglected, compromising image quality. OBJECTIVE : The aim of this study was to evaluate the influence of interrupting the fixation process on the radiographic contrast and base-plus-fog density (BPFD in three brands of periapical films. MATERIAL AND METHOD : Ninety radiographs were taken of an aluminum stepwedge and a lead plate for each brand, and they were divided according to the time of initial immersion in the fixative in: control group (without interrupting the fixing, 5, 10, 20, 30 and 40 seconds. During processing, films had the fixing stage stopped and were exposed to a negatoscope for 1 minute, then the fixation time of 10 minutes was completed. The radiographs were digitized and exported to Image Tool 3.0.software. RESULT : Kodak(r film showed no statistically significant differences between groups, while Agfa(r film presented difference in BPFD compared with Group 5 seconds, and Dentix(r film showed statistical difference in all groups in comparison with the control group. CONCLUSION : Under the conditions studied, Kodak(r film is not influenced by disruption of fixation as regards BPFD and image contrast, enabling early access to the results of radiographs, whereas Agfa(r film requires at least 10 seconds of initial fixation, and Dentix(r film obtains better results when the process of fixation is not interrupted.

  17. Impact of image acquisition timing on image quality for dual energy contrast-enhanced breast tomosynthesis

    Science.gov (United States)

    Hill, Melissa L.; Mainprize, James G.; Puong, Sylvie; Carton, Ann-Katherine; Iordache, Razvan; Muller, Serge; Yaffe, Martin J.

    2012-03-01

    Dual-energy contrast-enhanced digital breast tomosynthesis (DE CE-DBT) image quality is affected by a large parameter space including the tomosynthesis acquisition geometry, imaging technique factors, the choice of reconstruction algorithm, and the subject breast characteristics. The influence of most of these factors on reconstructed image quality is well understood for DBT. However, due to the contrast agent uptake kinetics in CE imaging, the subject breast characteristics change over time, presenting a challenge for optimization . In this work we experimentally evaluate the sensitivity of the reconstructed image quality to timing of the low-energy and high-energy images and changes in iodine concentration during image acquisition. For four contrast uptake patterns, a variety of acquisition protocols were tested with different timing and geometry. The influence of the choice of reconstruction algorithm (SART or FBP) was also assessed. Image quality was evaluated in terms of the lesion signal-difference-to-noise ratio (LSDNR) in the central slice of DE CE-DBT reconstructions. Results suggest that for maximum image quality, the low- and high-energy image acquisitions should be made within one x-ray tube sweep, as separate low- and high-energy tube sweeps can degrade LSDNR. In terms of LSDNR per square-root dose, the image quality is nearly equal between SART reconstructions with 9 and 15 angular views, but using fewer angular views can result in a significant improvement in the quantitative accuracy of the reconstructions due to the shorter imaging time interval.

  18. Image quality transfer and applications in diffusion MRI.

    Science.gov (United States)

    Alexander, Daniel C; Zikic, Darko; Ghosh, Aurobrata; Tanno, Ryutaro; Wottschel, Viktor; Zhang, Jiaying; Kaden, Enrico; Dyrby, Tim B; Sotiropoulos, Stamatios N; Zhang, Hui; Criminisi, Antonio

    2017-05-15

    This paper introduces a new computational imaging technique called image quality transfer (IQT). IQT uses machine learning to transfer the rich information available from one-off experimental medical imaging devices to the abundant but lower-quality data from routine acquisitions. The procedure uses matched pairs to learn mappings from low-quality to corresponding high-quality images. Once learned, these mappings then augment unseen low quality images, for example by enhancing image resolution or information content. Here, we demonstrate IQT using a simple patch-regression implementation and the uniquely rich diffusion MRI data set from the human connectome project (HCP). Results highlight potential benefits of IQT in both brain connectivity mapping and microstructure imaging. In brain connectivity mapping, IQT reveals, from standard data sets, thin connection pathways that tractography normally requires specialised data to reconstruct. In microstructure imaging, IQT shows potential in estimating, from standard "single-shell" data (one non-zero b-value), maps of microstructural parameters that normally require specialised multi-shell data. Further experiments show strong generalisability, highlighting IQT's benefits even when the training set does not directly represent the application domain. The concept extends naturally to many other imaging modalities and reconstruction problems. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. High quality image oriented telemedicine with multimedia technology.

    Science.gov (United States)

    Takeda, H; Minato, K; Takahasi, T

    1999-07-01

    Researchers at Osaka and Kyoto University hospital performed three experiments, beginning in 1995, which looked at high quality-oriented telemedicine. This paper describes the system design for the three projects. Experiment 1 applied high-definition TV images and B-ISDN for distance learning and medical information exchange. Experiment 2 developed a super high-definition medical image filing system and the images were transmitted via B-ISDN for teleconferences and experiment 3 utilized digital, high-definition, TV images and communication satellites for teleconferences. Multimedia and communication technologies were considered to be fundamental components of telemedicine. The three projects were evaluated initially for quality of images, operability and utility. The experimental design and its implementation showed that it was possible to provide high quality image-oriented telemedicine in the health care environment. Obstacles to establishing practical telemedicine are also discussed.

  20. New Adaptive Image Quality Assessment Based on Distortion Classification

    Directory of Open Access Journals (Sweden)

    Xin JIN

    2014-01-01

    Full Text Available This paper proposes a new adaptive image quality assessment (AIQA method, which is based on distortion classifying. AIQA contains two parts, distortion classification and image quality assessment. Firstly, we analysis characteristics of the original and distorted images, including the distribution of wavelet coefficient, the ratio of edge energy and inner energy of the differential image block, we divide distorted images into White Noise distortion, JPEG compression distortion and fuzzy distortion. To evaluate the quality of first two type distortion images, we use pixel based structure similarity metric and DCT based structural similarity metric respectively. For those blurriness pictures, we present a new wavelet-based structure similarity algorithm. According to the experimental results, AIQA takes the advantages of different structural similarity metrics, and it’s able to simulate the human visual perception effectively.

  1. Meat quality evaluation by hyperspectral imaging technique: an overview.

    Science.gov (United States)

    Elmasry, Gamal; Barbin, Douglas F; Sun, Da-Wen; Allen, Paul

    2012-01-01

    During the last two decades, a number of methods have been developed to objectively measure meat quality attributes. Hyperspectral imaging technique as one of these methods has been regarded as a smart and promising analytical tool for analyses conducted in research and industries. Recently there has been a renewed interest in using hyperspectral imaging in quality evaluation of different food products. The main inducement for developing the hyperspectral imaging system is to integrate both spectroscopy and imaging techniques in one system to make direct identification of different components and their spatial distribution in the tested product. By combining spatial and spectral details together, hyperspectral imaging has proved to be a promising technology for objective meat quality evaluation. The literature presented in this paper clearly reveals that hyperspectral imaging approaches have a huge potential for gaining rapid information about the chemical structure and related physical properties of all types of meat. In addition to its ability for effectively quantifying and characterizing quality attributes of some important visual features of meat such as color, quality grade, marbling, maturity, and texture, it is able to measure multiple chemical constituents simultaneously without monotonous sample preparation. Although this technology has not yet been sufficiently exploited in meat process and quality assessment, its potential is promising. Developing a quality evaluation system based on hyperspectral imaging technology to assess the meat quality parameters and to ensure its authentication would bring economical benefits to the meat industry by increasing consumer confidence in the quality of the meat products. This paper provides a detailed overview of the recently developed approaches and latest research efforts exerted in hyperspectral imaging technology developed for evaluating the quality of different meat products and the possibility of its widespread

  2. Technical and radiological image quality comparison of different liquid crystal displays for radiology

    Directory of Open Access Journals (Sweden)

    Dams FE

    2014-10-01

    Full Text Available Francina EM Dams,2 KY Esther Leung,1 Pieter HM van der Valk,2 Marc CJM Kock,2 Jeroen Bosman,1 Sjoerd P Niehof1 1Medical Physics and Technology, 2Department of Radiology, Albert Schweitzer Hospital, Dordrecht, The Netherlands Background: To inform cost-effective decisions in purchasing new medical liquid crystal displays, we compared the image quality in displays made by three manufacturers. Methods: We recruited 19 radiologists and residents to compare the image quality of four liquid crystal displays, including 3-megapixel Barco®, Eizo®, and NEC® displays and a 6-megapixel Barco display. The evaluators were blinded to the manufacturers' names. Technical assessments were based on acceptance criteria and test patterns proposed by the American Association of Physicists in Medicine. Radiological assessments were performed on images from the American Association of Physicists in Medicine Task Group 18. They included X-ray images of the thorax, knee, and breast, a computed tomographic image of the thorax, and a magnetic resonance image of the brain. Image quality was scored on an analog scale (range 0–10. Statistical analysis was performed with repeated-measures analysis of variance. Results: The Barco 3-megapixel display passed all acceptance criteria. The Eizo and NEC displays passed the acceptance criteria, except for the darkest pixel value in the grayscale display function. The Barco 6-megapixel display failed criteria for the maximum luminance response and the veiling glare. Mean radiological assessment scores were 7.8±1.1 (Barco 3-megapixel, 7.8±1.2 (Eizo, 8.1±1.0 (NEC, and 8.1±1.0 (Barco 6-megapixel. No significant differences were found between displays. Conclusion: According to the tested criteria, all the displays had comparable image quality; however, there was a three-fold difference in price between the most and least expensive displays. Keywords: data display, humans, radiographic image enhancement, user-computer interface

  3. A new bite block for panoramic radiographs of anterior edentulous patients: A technical report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Woong; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of); Symkhampha, Khanthaly [Dept. of Oral and Maxillofacial Radiology, Department of Basic Science, Faculty of Dentistry, University of Health Sciences, Vientiane (Lao People' s Democratic Republic)

    2015-06-15

    Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues. A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device. Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block. Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.

  4. SEGMENTATION AND QUALITY ANALYSIS OF LONG RANGE CAPTURED IRIS IMAGE

    Directory of Open Access Journals (Sweden)

    Anand Deshpande

    2016-05-01

    Full Text Available The iris segmentation plays a major role in an iris recognition system to increase the performance of the system. This paper proposes a novel method for segmentation of iris images to extract the iris part of long range captured eye image and an approach to select best iris frame from the iris polar image sequences by analyzing the quality of iris polar images. The quality of iris image is determined by the frequency components present in the iris polar images. The experiments are carried out on CASIA-long range captured iris image sequences. The proposed segmentation method is compared with Hough transform based segmentation and it has been determined that the proposed method gives higher accuracy for segmentation than Hough transform.

  5. Evaluating Picture Quality of Image Plates in Digital CR Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Byung Joon [Dept. of Radiological Tecnology, Choonhae College of Health Science, Ulsan (Korea, Republic of); Ji Tae Jeong [Dept. of Radiological Science, Kaya University, Kimhae (Korea, Republic of)

    2011-12-15

    Lab effectively supplemented the effects of outside radiation on image plates in the process of image acquisition of CR (computed radiography) systems and conducted for effective utilization in the case of clinical application. For this, Lab classified the storage places and time periods of image plates and compared and analyzed the differences between small dark spots. Lab also assessed the concentration distribution within the boundaries of images. Lab compared and measured the number of dark spots in a light room and a dark room depending on the storage places of image plates and found that dark spots slightly increased in an image plate when stored in a light room on the first and second days. Dark spots increased in proportion to the length of time stored. In the case of the image plate stored in a dark room, the number of dark spots remarkably decreased. With regard to picture quality as related to the location of image plates, the damage to picture quality could be reduced by locating regions of interest in the center. With regard to differences in sharpness following changes in the thickness of subjects, fewer scatter rays occurred and sharpness improved by reducing the thickness of subjects as much as possible. To get medical images of excellent quality, image plates should be managed effectively and it is desirable to keep images plates in dark iron plate boxes and not to expose them to outside radiation for a long time.

  6. Scanning radiographic apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Albert, R.D.

    1980-04-01

    Visual display of dental, medical or other radiographic images is realized with an x-ray tube in which an electron beam is scanned through an x-y raster pattern on a broad anode plate, the scanning being synchronized with the x-y sweep signals of a cathode ray tube display and the intensity signal for the display being derived from a small x-ray detector which receives x-rays that have passed through the subject to be imaged. Positioning and support of the detector are provided for by disposing the detector in a probe which may be attached to the x-ray tube at any of a plurality of different locations and by providing a plurality of such probes of different configuration in order to change focal length, to accommodate to different detector placements relative to the subject, to enhance patient comfort and to enable production of both periapical images and wider angle pantomographic images. High image definition with reduced radiation dosage is provided for by a lead glass collimator situated between the x-ray tube and subject and having a large number of spaced-apart minute radiation transmissive passages convergent on the position of the detector. Releasable mounting means enable changes of collimator in conjunction with changes of the probe to change focal length. A control circuit modifies the x-y sweep signals applied to the x-ray tube and modulates electron beam energy and current in order to correct for image distortions and other undesirable effects which can otherwise be present in a scanning x-ray system.

  7. Assessment of CT image quality using a Bayesian approach

    Science.gov (United States)

    Reginatto, M.; Anton, M.; Elster, C.

    2017-08-01

    One of the most promising approaches for evaluating CT image quality is task-specific quality assessment. This involves a simplified version of a clinical task, e.g. deciding whether an image belongs to the class of images that contain the signature of a lesion or not. Task-specific quality assessment can be done by model observers, which are mathematical procedures that carry out the classification task. The most widely used figure of merit for CT image quality is the area under the ROC curve (AUC), a quantity which characterizes the performance of a given model observer. In order to estimate AUC from a finite sample of images, different approaches from classical statistics have been suggested. The goal of this paper is to introduce task-specific quality assessment of CT images to metrology and to propose a novel Bayesian estimation of AUC for the channelized Hotelling observer (CHO) applied to the task of detecting a lesion at a known image location. It is assumed that signal-present and signal-absent images follow multivariate normal distributions with the same covariance matrix. The Bayesian approach results in a posterior distribution for the AUC of the CHO which provides in addition a complete characterization of the uncertainty of this figure of merit. The approach is illustrated by its application to both simulated and experimental data.

  8. INCREASED IMAGE QUALITY BY SYNTHESIZING SPACE PHOTOS WITH DIFFERENT EXPOSURES

    Directory of Open Access Journals (Sweden)

    A. I. Altukhov

    2017-01-01

    Full Text Available Subject of Research. The paper deals withan approach to the image quality improvement of the underlying surface, obtained by space-based facilities in the visible spectrum. The approach is based on the idea of the region image synthesis with different exposures. This enables to increase the dynamic range of image brightness and display bright and poorly lighted places on the result picture. The relevance of the proposed approach is confirmed by simulation results of objects image quality under a variety of lighting conditions. Linear ground resolution is selected as the quality indicator. Main Results. We have carried out behavior analysis of possible changes in the lighting conditions of the underlying surface in the range of onboard equipment swath of spacecraft observation.We have performed calculation of the terrain linear resolution in narrow spectral ranges of visible light for the space image fragments of the underlying surface with different illumination. It was concluded that the quality of satellite images is limited, since the parameters of onboard equipment monitoring are not selected individually for each object detected within the swath. We have proposed an approach to improve the image quality. Practical Relevance. The proposed approach to the processing of the Earth remote sensing data gives the possibility to obtain images suitable for interpretation with account for specific features of illumination area, as well as to improve the dataware accuracy during the survey support and mapping of areas.

  9. Quantifying radiation safety and quality in medical imaging, part 3: the quality assurance scorecard.

    Science.gov (United States)

    Reiner, Bruce I

    2009-10-01

    The practice of medical imaging is fraught with inconsistency as it relates to quality assurance, which is due in part to the lack of standardization and objective quality-centric data. By applying the scientific methods of Shewhart and Deming to medical imaging quality assessment, one can devise an objective, data-driven quality model, encompassing the various steps and processes that take place within the medical imaging chain. Through automated recording, tracking, and analysis of these quality data elements, a quantitative scorecard can be derived that provides an objective measure of quality performance, relating to each individual process, participating stakeholder, and technology being used. Through meta-analysis of these quality-centric data, best practice guidelines can be created, which in turn promote quality as the major differentiating feature of service providers.

  10. Perceived no reference image quality measurement for chromatic aberration

    Science.gov (United States)

    Lamb, Anupama B.; Khambete, Madhuri

    2016-03-01

    Today there is need for no reference (NR) objective perceived image quality measurement techniques as conducting subjective experiments and making reference image available is a very difficult task. Very few NR perceived image quality measurement algorithms are available for color distortions like chromatic aberration (CA), color quantization with dither, and color saturation. We proposed NR image quality assessment (NR-IQA) algorithms for images distorted with CA. CA is mostly observed in images taken with digital cameras, having higher sensor resolution with inexpensive lenses. We compared our metric performance with two state-of-the-art NR blur techniques, one full reference IQA technique and three general-purpose NR-IQA techniques, although they are not tailored for CA. We used a CA dataset in the TID-2013 color image database to evaluate performance. Proposed algorithms give comparable performance with state-of-the-art techniques in terms of performance parameters and outperform them in terms of monotonicity and computational complexity. We have also discovered that the proposed CA algorithm best predicts perceived image quality of images distorted with realistic CA.

  11. The application of neutron activation analysis, scanning electron microscope, and radiographic imaging for the characterization of electrochemically deposited layers of lanthanide and actinide elements

    Science.gov (United States)

    Liebe, D.; Eberhardt, K.; Hartmann, W.; Häger, T.; Hübner, A.; Kratz, J. V.; Kindler, B.; Lommel, B.; Thörle, P.; Schädel, M.; Steiner, J.

    2008-06-01

    Lanthanide and actinide targets are prepared at the University of Mainz by molecular plating, an electrochemical deposition from an organic solvent, for heavy-ion reaction studies at GSI. To acquire information about deposition yield, target thickness, and target homogeneity, the following analysis methods are applied. With neutron activation analysis (NAA) the deposition yield and the average thickness of the deposited material is determined. We report on the analytical procedure of NAA performed subsequent to the molecular plating process. Scanning electron microscope (SEM) is used to determine the morphology of the target surfaces. In combination with energy dispersive X-ray spectrometer (EDS), we also could obtain qualitative information about the chemical form of the deposited material. So far, gadolinium, samarium, holmium, and uranium targets have been investigated with SEM/EDS. With radiographic imaging (RI), targets of uranium prepared by molecular plating and by vacuum vaporization are investigated. This method is suitable to obtain information about the spatial distribution, the homogeneity, and the thickness of the target layer deposition.

  12. Spatial resolution measurements of the advanced radiographic capability x-ray imaging system at energies relevant to Compton radiography

    Science.gov (United States)

    Hall, G. N.; Izumi, N.; Landen, O. L.; Tommasini, R.; Holder, J. P.; Hargrove, D.; Bradley, D. K.; Lumbard, A.; Cruz, J. G.; Piston, K.; Lee, J. J.; Romano, E.; Bell, P. M.; Carpenter, A. C.; Palmer, N. E.; Felker, B.; Rekow, V.; Allen, F. V.

    2016-11-01

    Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro-channel plate) to provide gating and high DQE at the 40-200 keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution. Experiments were performed at energies relevant to Compton radiography to begin characterization of the spatial resolution of the AXIS diagnostic.

  13. Spatial resolution measurements of the advanced radiographic capability x-ray imaging system at energies relevant to Compton radiography

    Energy Technology Data Exchange (ETDEWEB)

    Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Landen, O. L.; Tommasini, R.; Holder, J. P.; Hargrove, D.; Bradley, D. K.; Lumbard, A.; Cruz, J. G.; Piston, K.; Bell, P. M.; Carpenter, A. C.; Palmer, N. E.; Felker, B.; Rekow, V.; Allen, F. V. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Lee, J. J.; Romano, E. [National Security Technologies LLC, 161 S Vasco Rd., Livermore, California 94551 (United States)

    2016-11-15

    Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro-channel plate) to provide gating and high DQE at the 40–200 keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution. Experiments were performed at energies relevant to Compton radiography to begin characterization of the spatial resolution of the AXIS diagnostic.

  14. Beef quality parameters estimation using ultrasound and color images

    National Research Council Canada - National Science Library

    Nunes, Jose; Piquerez, Martín; Pujadas, Leonardo; Armstrong, Eileen; Fernández, Alicia; Lecumberry, Federico

    2015-01-01

    .... In this paper we set out to obtain beef quality estimates from the analysis of ultrasound (in vivo) and color images (post mortem), with the measurement of various parameters related to tenderness and amount of meat...

  15. Mammographic image quality in relation to positioning of the breast

    DEFF Research Database (Denmark)

    Taylor, K; Parashar, D; Bouverat, G

    2017-01-01

    INTRODUCTION: Optimum mammography positioning technique is necessary to maximise cancer detection. Current criteria for mammography appraisal lack reliability and validity with a need to develop a more objective system. We aimed to establish current international practice in assessing image quality...

  16. Dosimetry and image quality assessment in a direct radiography system

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Bruno Beraldo; Paixao, Lucas; Nogueira, Maria do Socorro, E-mail: boliveira.mg@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Marcio Alves de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina. Dept. de Anatomia e Imagem; Teixeira, Maria Helena Araujo [Clinica Dra. Maria Helena Araujo Teixeira, Belo Horizonte, MG (Brazil)

    2014-11-15

    Objective: to evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms. Materials and methods: Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms. Results: considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values. Conclusion: the present study contributes to verify the equipment conformity as regards dose values and image quality. (author)

  17. MATLAB-based Applications for Image Processing and Image Quality Assessment – Part II: Experimental Results

    Directory of Open Access Journals (Sweden)

    L. Krasula

    2012-04-01

    Full Text Available The paper provides an overview of some possible usage of the software described in the Part I. It contains the real examples of image quality improvement, distortion simulations, objective and subjective quality assessment and other ways of image processing that can be obtained by the individual applications.

  18. ANALYSIS OF THE EFFECTS OF IMAGE QUALITY ON DIGITAL MAP GENERATION FROM SATELLITE IMAGES

    Directory of Open Access Journals (Sweden)

    H. Kim

    2012-07-01

    Full Text Available High resolution satellite images are widely used to produce and update a digital map since they became widely available. It is well known that the accuracy of digital map produced from satellite images is decided largely by the accuracy of geometric modelling. However digital maps are made by a series of photogrammetric workflow. Therefore the accuracy of digital maps are also affected by the quality of satellite images, such as image interpretability. For satellite images, parameters such as Modulation Transfer Function(MTF, Signal to Noise Ratio(SNR and Ground Sampling Distance(GSD are used to present images quality. Our previous research stressed that such quality parameters may not represent the quality of image products such as digital maps and that parameters for image interpretability such as Ground Resolved Distance(GRD and National Imagery Interpretability Rating Scale(NIIRS need to be considered. In this study, we analyzed the effects of the image quality on accuracy of digital maps produced by satellite images. QuickBird, IKONOS and KOMPSAT-2 imagery were used to analyze as they have similar GSDs. We measured various image quality parameters mentioned above from these images. Then we produced digital maps from the images using a digital photogrammetric workstation. We analyzed the accuracy of the digital maps in terms of their location accuracy and their level of details. Then we compared the correlation between various image quality parameters and the accuracy of digital maps. The results of this study showed that GRD and NIIRS were more critical for map production then GSD, MTF or SNR.

  19. Perceived quality of wood images influenced by the skewness of image histogram

    Science.gov (United States)

    Katsura, Shigehito; Mizokami, Yoko; Yaguchi, Hirohisa

    2015-08-01

    The shape of image luminance histograms is related to material perception. We investigated how the luminance histogram contributed to improvements in the perceived quality of wood images by examining various natural wood and adhesive vinyl sheets with printed wood grain. In the first experiment, we visually evaluated the perceived quality of wood samples. In addition, we measured the colorimetric parameters of the wood samples and calculated statistics of image luminance. The relationship between visual evaluation scores and image statistics suggested that skewness and kurtosis affected the perceived quality of wood. In the second experiment, we evaluated the perceived quality of wood images with altered luminance skewness and kurtosis using a paired comparison method. Our result suggests that wood images are more realistic if the skewness of the luminance histogram is slightly negative.

  20. Improving MRT image quality in patients with movement disorders.

    Science.gov (United States)

    Schültke, Elisabeth; Nanko, Norbert; Pinsker, Marcus; Katzev, Michael; Sebastian, Alexandra; Feige, Bernd; Nikkhah, Guido

    2013-01-01

    In order to improve image quality in a simultaneous fMRI-EEG study with patients suffering from the involuntary movements typical for Huntington's disease, the aim was to develop a technique for immobilizing the heads of our patients inside an MRI head coil. We modified a mask technique previously used for reliable repositioning in temporally fractionated radiotherapy. The mask was tested in three patients with Huntington's disease, acquiring structural and functional MR images with simultaneous EEG with and without the mask. Image as well as EEG signal quality were significantly improved in patients wearing the mask. However, the image quality with mask was comparable to acquisitions from patients without movement disorders only in patients with light to moderate dyskinesia. Although image quality was also significantly improved in a patient suffering from severe dyskinesia with quasi-continuous involuntary movements, the quality of both the MR images as well as the EEG signal was lower than what would be expected in a healthy control person. We have succeeded in developing a mask that fits into the MRI head coil, does not disturb the MRI signal, and significantly improves both fMRI and EEG signal quality.

  1. Applying image quality in cell phone cameras: lens distortion

    Science.gov (United States)

    Baxter, Donald; Goma, Sergio R.; Aleksic, Milivoje

    2009-01-01

    This paper describes the framework used in one of the pilot studies run under the I3A CPIQ initiative to quantify overall image quality in cell-phone cameras. The framework is based on a multivariate formalism which tries to predict overall image quality from individual image quality attributes and was validated in a CPIQ pilot program. The pilot study focuses on image quality distortions introduced in the optical path of a cell-phone camera, which may or may not be corrected in the image processing path. The assumption is that the captured image used is JPEG compressed and the cellphone camera is set to 'auto' mode. As the used framework requires that the individual attributes to be relatively perceptually orthogonal, in the pilot study, the attributes used are lens geometric distortion (LGD) and lateral chromatic aberrations (LCA). The goal of this paper is to present the framework of this pilot project starting with the definition of the individual attributes, up to their quantification in JNDs of quality, a requirement of the multivariate formalism, therefore both objective and subjective evaluations were used. A major distinction in the objective part from the 'DSC imaging world' is that the LCA/LGD distortions found in cell-phone cameras, rarely exhibit radial behavior, therefore a radial mapping/modeling cannot be used in this case.

  2. Analyzing and Improving Image Quality in Reflective Ghost Imaging

    Science.gov (United States)

    2011-02-01

    Aii (t) and Ai2 (t) are statistically independent, zero-mean, random processes whose correlation functions are (-Aim(tI)Aim(t 2 )) = q 2 Pm(ti)(ti - t 2...the same as the image-bearing term for phase-insensitive imaging (except for the coordinate inversion ). To evaluate at the contrast we will use Eq (2.16...sian random process, with the coherence length be- a new realization at each time epoch. ing inversely proportional to the extent of the SLM, and the

  3. Noninvasive Femur Bone Volume Estimation Based on X-Ray Attenuation of a Single Radiographic Image and Medical Knowledge

    Science.gov (United States)

    Kiattisin, Supaporn; Chamnongthai, Kosin

    Bone Mineral Density (BMD) is an indicator of osteoporosis that is an increasingly serious disease, particularly for the elderly. To calculate BMD, we need to measure the volume of the femur in a noninvasive way. In this paper, we propose a noninvasive bone volume measurement method using x-ray attenuation on radiography and medical knowledge. The absolute thickness at one reference pixel and the relative thickness at all pixels of the bone in the x-ray image are used to calculate the volume and the BMD. First, the absolute bone thickness of one particular pixel is estimated