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Sample records for comparative imaging study

  1. Comparative study of image restoration techniques in forensic image processing

    Science.gov (United States)

    Bijhold, Jurrien; Kuijper, Arjan; Westhuis, Jaap-Harm

    1997-02-01

    In this work we investigated the forensic applicability of some state-of-the-art image restoration techniques for digitized video-images and photographs: classical Wiener filtering, constrained maximum entropy, and some variants of constrained minimum total variation. Basic concepts and experimental results are discussed. Because all methods appeared to produce different results, a discussion is given of which method is the most suitable, depending on the image objects that are questioned, prior knowledge and type of blur and noise. Constrained minimum total variation methods produced the best results for test images with simulated noise and blur. In cases where images are the most substantial part of the evidence, constrained maximum entropy might be more suitable, because its theoretical basis predicts a restoration result that shows the most likely pixel values, given all the prior knowledge used during restoration.

  2. Comparative imaging study on monkeys with hemi-parkinsonism

    International Nuclear Information System (INIS)

    Wang Wei; Yu Xiaoping; Mao Jun; Liu Sheng; Wang Xiaoyi; Peng Guangchun; Wang Ruiwen

    2003-01-01

    Objective: To study the imaging appearance of experimental Parkinson's disease (PD) and to evaluate the different medical imaging exams on PD. Methods: CT, MRI, SPECT (dopamine transporter imaging and regional cerebral blood flow imaging, DAT imaging and rCBF imaging), and PET (glucose metabolism imaging) were performed on 8 monkeys before and after the infusion of MPTP into unilateral internal carotid artery to develop hemi-Parkinsonism models. Results: Hemi-Parkinsonism models were successfully induced on all 8 monkeys. On DAT imaging, the uptake values of the lesioned striatums decreased obviously after the MPTP treatment and were lower than that of the contralateral ones. The glucose metabolic rates of the lesioned striatums and thalamus in PD models were lower, compared to that of the healthy monkeys and that of the contralateral sides of themselves. Neither DAT nor glucose metabolism abnormalities was found on both the contralateral sides of the healthy and PD monkeys. On MRI images before MPTP treatment, only 4 of 8 PD models showed hypointense in bilateral globus pallidus. No abnormal MRI findings occurred in the first 2 months after injection of MPTP. At tile third month, hypointense appeared in globus pallidus of three monkeys. Enlarged hyposignal region in globus pallidus were found in three models. Of the above 6 monkeys, two appeared hypointense in putamina. Substantia nigra demonstrated no abnormalities before and after MPTP treatment. All rCBF and CT images were normal. Conclusion: The decreased density of DAT and decreased glucose metabolism on experimental PD can be showed early by DAT imaging and glucose metabolism imaging, MRI can show abnormal signal in the basal ganglia of PD but it is later than DAT and glucose metabolism imaging. CT and rCBF find no abnormality on PD

  3. Image based 3D city modeling : Comparative study

    Directory of Open Access Journals (Sweden)

    S. P. Singh

    2014-06-01

    Full Text Available 3D city model is a digital representation of the Earth’s surface and it’s related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India. This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can’t do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good

  4. A comparative study of image low level feature extraction algorithms

    Directory of Open Access Journals (Sweden)

    M.M. El-gayar

    2013-07-01

    Full Text Available Feature extraction and matching is at the base of many computer vision problems, such as object recognition or structure from motion. Current methods for assessing the performance of popular image matching algorithms are presented and rely on costly descriptors for detection and matching. Specifically, the method assesses the type of images under which each of the algorithms reviewed herein perform to its maximum or highest efficiency. The efficiency is measured in terms of the number of matches founds by the algorithm and the number of type I and type II errors encountered when the algorithm is tested against a specific pair of images. Current comparative studies asses the performance of the algorithms based on the results obtained in different criteria such as speed, sensitivity, occlusion, and others. This study addresses the limitations of the existing comparative tools and delivers a generalized criterion to determine beforehand the level of efficiency expected from a matching algorithm given the type of images evaluated. The algorithms and the respective images used within this work are divided into two groups: feature-based and texture-based. And from this broad classification only three of the most widely used algorithms are assessed: color histogram, FAST (Features from Accelerated Segment Test, SIFT (Scale Invariant Feature Transform, PCA-SIFT (Principal Component Analysis-SIFT, F-SIFT (fast-SIFT and SURF (speeded up robust features. The performance of the Fast-SIFT (F-SIFT feature detection methods are compared for scale changes, rotation, blur, illumination changes and affine transformations. All the experiments use repeatability measurement and the number of correct matches for the evaluation measurements. SIFT presents its stability in most situations although its slow. F-SIFT is the fastest one with good performance as the same as SURF, SIFT, PCA-SIFT show its advantages in rotation and illumination changes.

  5. a Comparative Case Study of Reflection Seismic Imaging Method

    Science.gov (United States)

    Alamooti, M.; Aydin, A.

    2017-12-01

    Seismic imaging is the most common means of gathering information about subsurface structural features. The accuracy of seismic images may be highly variable depending on the complexity of the subsurface and on how seismic data is processed. One of the crucial steps in this process, especially in layered sequences with complicated structure, is the time and/or depth migration of seismic data.The primary purpose of the migration is to increase the spatial resolution of seismic images by repositioning the recorded seismic signal back to its original point of reflection in time/space, which enhances information about complex structure. In this study, our objective is to process a seismic data set (courtesy of the University of South Carolina) to generate an image on which the Magruder fault near Allendale SC can be clearly distinguished and its attitude can be accurately depicted. The data was gathered by common mid-point method with 60 geophones equally spaced along an about 550 m long traverse over a nearly flat ground. The results obtained from the application of different migration algorithms (including finite-difference and Kirchhoff) are compared in time and depth domains to investigate the efficiency of each algorithm in reducing the processing time and improving the accuracy of seismic images in reflecting the correct position of the Magruder fault.

  6. Comparative study of low-energy neutral atom imaging techniques

    International Nuclear Information System (INIS)

    Funsten, H.O.; McComas, D.J.; Scime, E.E.

    1994-01-01

    Low-energy neutral atom (LENA) imaging promise to be a revolutionary tool for global imaging of space plasmas. The technical challenges of LENA detection include separating them from the intense ambient UV without losing information about their incident trajectories, quantifying their trajectories, and obtaining high-sensitivity measurements. Two techniques that have been proposed for this purpose are based on fundamentally different atomic interaction mechanisms between LENAs and a solid; LENA transmission through an ultra thin foil and LENA reflection from a solid surface. Both of these methods provide LENA ionization (for subsequent removal from the UV by electrostatic deflection) and secondary electron emission (for time-of-flight start pulse generation and/or coincidence). They present a comparative study of the transmission and reflection techniques based on differences in atomic interactions with solids and surfaces. Transmission methods are shown to be superior for secondary electron emission rather than reflection methods. Furthermore, transmission methods are shown to be a sufficient for LENA imaging at LENA energies of approximately 1 keV to greater than 30 keV. A hybrid instrument using reflection from a low work function surface for LENA ionization and transmission for secondary electron emission is optimal for imaging of LENAs with energies less than approximately 1 keV

  7. Comparative Study on Ultrasonic Imaging Methods with Array Transducers

    Science.gov (United States)

    Matsuoka, C.; Nakahata, K.; Baba, A.; Kono, N.; Hirose, S.

    2008-02-01

    The performance of ultrasonic imaging methods developed in time domain and frequency domain algorithms is investigated in this study. The sectorial synthetic aperture focusing technique (S-SAFT) outputs the flaw image by superposing the sector-scan images obtained at various measurement points in the time domain. The inverse scattering imaging method (ISIM) is based on the elastodynamic inversion in the frequency domain and reconstructs the mathematical function which represents the flaw shape. The advantages and usabilities of these methods are discussed, taking into account the practical application to the NDE field.

  8. A comparative study on medical image segmentation methods

    Directory of Open Access Journals (Sweden)

    Praylin Selva Blessy SELVARAJ ASSLEY

    2014-03-01

    Full Text Available Image segmentation plays an important role in medical images. It has been a relevant research area in computer vision and image analysis. Many segmentation algorithms have been proposed for medical images. This paper makes a review on segmentation methods for medical images. In this survey, segmentation methods are divided into five categories: region based, boundary based, model based, hybrid based and atlas based. The five different categories with their principle ideas, advantages and disadvantages in segmenting different medical images are discussed.

  9. A comparative study in ultrasound breast imaging classification

    Science.gov (United States)

    Yap, Moi Hoon; Edirisinghe, Eran A.; Bez, Helmut E.

    2009-02-01

    American College of Radiology introduces a standard in classification, the breast imaging reporting and data system (BIRADS), standardize the reporting of ultrasound findings, clarify its interpretation, and facilitate communication between clinicians. The effective use of new technologies to support healthcare initiatives is important and current research is moving towards implementing computer tools in the diagnostics process. Initially a detailed study was carried out to evaluate the performance of two commonly used appearance based classification algorithms, based on the use of Principal Component Analysis (PCA), and two dimensional linear discriminant analysis (2D-LDA). The study showed that these two appearance based classification approaches are not capable of handling the classification of ultrasound breast image lesions. Therefore further investigations in the use of a popular feature based classifier - Support Vector Machine (SVM) was conducted. A pre-processing step before feature based classification is feature extraction, which involve shape, texture and edge descriptors for the Region of Interest (ROI). The input dataset to SVM classification is from a fully automated ROI detection. We achieve the success rate of 0.550 in PCA, 0.500 in LDA, and 0.931 in SVM. The best combination of features in SVM classification is to combine the shape, texture and edge descriptors, with sensitivity 0.840 and specificity 0.968. This paper briefly reviews the background to the project and then details the ongoing research. In conclusion, we discuss the contributions, limitations, and future plans of our work.

  10. Maxillary sinusitis - a comparative study of different imaging diagnosis methods

    International Nuclear Information System (INIS)

    Hueb, Marcelo Miguel; Borges, Fabiano de Almeida; Pulcinelli, Emilte; Souza, Wandir Ferreira; Borges, Luiz Marcondes

    1999-01-01

    We conducted prospective study comparing different methods (plain X-rays, computed tomography and ultrasonography mode-A) for the initial diagnosis of maxillary sinusitis. Twenty patients (40 maxillary sinuses) with a clinical history suggestive of sinusitis included in this study. The results were classified as abnormal or normal, using computed tomography as gold standard. The sensitivity for ultrasonography and plain X-rays was 84.6% and 69.2%, respectively. The specificity of both methods was 92.6%. This study suggests that ultrasonography can be used as a good follow-up method for patients with maxillary. sinusitis. (author)

  11. Image quality and stability of image-guided radiotherapy (IGRT) devices: A comparative study

    Science.gov (United States)

    Stock, Markus; Pasler, Marlies; Birkfellner, Wolfgang; Homolka, Peter; Poetter, Richard; Georg, Dietmar

    2010-01-01

    Introduction Our aim was to implement standards for quality assurance of IGRT devices used in our department and to compare their performances with that of a CT simulator. Materials and methods We investigated image quality parameters for three devices over a period of 16 months. A multislice CT was used as a benchmark and results related to noise, spatial resolution, low contrast visibility (LCV) and uniformity were compared with a cone beam CT (CBCT) at a linac and simulator. Results All devices performed well in terms of LCV and, in fact, exceeded vendor specifications. MTF was comparable between CT and linac CBCT. Integral nonuniformity was, on average, 0.002 for the CT and 0.006 for the linac CBCT. Uniformity, LCV and MTF varied depending on the protocols used for the linac CBCT. Contrast-to-noise ratio was an average of 51% higher for the CT than for the linac and simulator CBCT. No significant time trend was observed and tolerance limits were implemented. Discussion Reasonable differences in image quality between CT and CBCT were observed. Further research and development are necessary to increase image quality of commercially available CBCT devices in order for them to serve the needs for adaptive and/or online planning. PMID:19695725

  12. What Images Reveal: a Comparative Study of Science Images between Australian and Taiwanese Junior High School Textbooks

    Science.gov (United States)

    Ge, Yun-Ping; Unsworth, Len; Wang, Kuo-Hua; Chang, Huey-Por

    2017-07-01

    From a social semiotic perspective, image designs in science textbooks are inevitably influenced by the sociocultural context in which the books are produced. The learning environments of Australia and Taiwan vary greatly. Drawing on social semiotics and cognitive science, this study compares classificational images in Australian and Taiwanese junior high school science textbooks. Classificational images are important kinds of images, which can represent taxonomic relations among objects as reported by Kress and van Leeuwen (Reading images: the grammar of visual design, 2006). An analysis of the images from sample chapters in Australian and Taiwanese high school science textbooks showed that the majority of the Taiwanese images are covert taxonomies, which represent hierarchical relations implicitly. In contrast, Australian classificational images included diversified designs, but particularly types with a tree structure which depicted overt taxonomies, explicitly representing hierarchical super-ordinate and subordinate relations. Many of the Taiwanese images are reminiscent of the specimen images in eighteenth century science texts representing "what truly is", while more Australian images emphasize structural objectivity. Moreover, Australian images support cognitive functions which facilitate reading comprehension. The relationships between image designs and learning environments are discussed and implications for textbook research and design are addressed.

  13. COMPARATIVE STUDY OF EDGE BASED LSB MATCHING STEGANOGRAPHY FOR COLOR IMAGES

    Directory of Open Access Journals (Sweden)

    A.J. Umbarkar

    2016-02-01

    Full Text Available Steganography is a very pivotal technique mainly used for covert transfer of information over a covert communication channel. This paper proposes a significant comparative study of the spatial LSB domain technique that focuses on sharper edges of the color as well as gray scale images for the purpose of data hiding and hides secret message first in sharper edge regions and then in smooth regions of the image. Message embedding depends on content of the image and message size. The experimental results illustrate that, for low embedding rate the method hides the message in sharp edges of cover image to get better stego image visualization quality. For high embedding rate, smooth regions and edges of the cover image are used for the purpose of data hiding. In this steganography method, color image and textured kind of image preserves better visual quality of stego image. The novelty of the comparative study is that, it helps to analyze the efficiency and performance of the method as it gives better results because it directly works on color images instead of converting to gray scale image.

  14. Comparative study of texture features in OCT images at different scales for human breast tissue classification.

    Science.gov (United States)

    Yu Gan; Xinwen Yao; Chang, Ernest; Bin Amir, Syed; Hibshoosh, Hanina; Feldman, Sheldon; Hendon, Christine P

    2016-08-01

    Breast cancer is the second leading cause of death in women in the United States due to cancer. Early detection of breast cancerous regions will aid the diagnosis, staging, and treatment of breast cancer. Optical coherence tomography (OCT), a non-invasive imaging modality with high resolution, has been widely used to visualize various tissue types within the human breast and has demonstrated great potential for assessing tumor margins. Imaging large resected samples with a fast imaging speed can be accomplished by under-sampling in the spatial domain, resulting in a large image scale. However, it is unclear whether there is an impact on the ability to classify tissue types based on the selected imaging scale. Our objective is to evaluate how the scale at which the images are acquired impacts texture features and the accuracy of an automated classification algorithm. To this end, we present a comparative study of texture features in OCT images at two image scales for human breast tissue classification. Texture features and attenuation coefficients were inputs to a statistical classification model, relevance vector machine. The automated classification results from the two image scales were compared. We found that more informative tissue features are preserved in small image scale and accordingly, small image scale leads to more accurate tissue type classification.

  15. A Comparative Study of Contemporary Color Tongue Image Extraction Methods Based on HSI

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    Mingfeng Zhu

    2014-01-01

    Full Text Available Tongue image with coating is of important clinical diagnostic meaning, but traditional tongue image extraction method is not competent for extraction of tongue image with thick coating. In this paper, a novel method is suggested, which applies multiobjective greedy rules and makes fusion of color and space information in order to extract tongue image accurately. A comparative study of several contemporary tongue image extraction methods is also made from the aspects of accuracy and efficiency. As the experimental results show, geodesic active contour is quite slow and not accurate, the other 3 methods achieve fairly good segmentation results except in the case of the tongue with thick coating, our method achieves ideal segmentation results whatever types of tongue images are, and efficiency of our method is acceptable for the application of quantitative check of tongue image.

  16. A Comparative Study of Contemporary Color Tongue Image Extraction Methods Based on HSI.

    Science.gov (United States)

    Zhu, Mingfeng; Du, Jianqiang; Ding, Chenghua

    2014-01-01

    Tongue image with coating is of important clinical diagnostic meaning, but traditional tongue image extraction method is not competent for extraction of tongue image with thick coating. In this paper, a novel method is suggested, which applies multiobjective greedy rules and makes fusion of color and space information in order to extract tongue image accurately. A comparative study of several contemporary tongue image extraction methods is also made from the aspects of accuracy and efficiency. As the experimental results show, geodesic active contour is quite slow and not accurate, the other 3 methods achieve fairly good segmentation results except in the case of the tongue with thick coating, our method achieves ideal segmentation results whatever types of tongue images are, and efficiency of our method is acceptable for the application of quantitative check of tongue image.

  17. Comparing the performance of different ultrasonic images enhancement for speckle noise reduction in ultrasound images using techniques: a preference study

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    Rana, Md. Shohel; Sarker, Kaushik; Bhuiyan, Touhid; Hassan, Md. Maruf

    2017-06-01

    Diagnostic ultrasound (US) is an important tool in today's sophisticated medical diagnostics. Nearly every medical discipline benefits itself from this relatively inexpensive method that provides a view of the inner organs of the human body without exposing the patient to any harmful radiations. Medical diagnostic images are usually corrupted by noise during their acquisition and most of the noise is speckle noise. To solve this problem, instead of using adaptive filters which are widely used, No-Local Means based filters have been used to de-noise the images. Ultrasound images of four organs such as Abdomen, Ortho, Liver, Kidney, Brest and Prostrate of a Human body have been used and applied comparative analysis study to find out the output. These images were taken from Siemens SONOLINE G60 S System and the output was compared by matrices like SNR, RMSE, PSNR IMGQ and SSIM. The significance and compared results were shown in a tabular format.

  18. Distinguishing Features of Teacher Image and Faculty Member’s Image: Comparative Study

    OpenAIRE

    Mynbayeva, Aigerim; Yessenova, Kamchat

    2016-01-01

    Educator’s image has become a necessary attribute of professional activity in the modern postindustrial society. There has been a lot of scientific research on political image. Personal image contributes to professional’s competitiveness in the labour market, especially in the modern globalising world. On the one hand, image encourages personal promotion and success in the labour market. On the other hand, it encourages personal self-fulfillment through recognition by the society and personal...

  19. [Change in self-image in the population of adolescents in 15 years--comparative study].

    Science.gov (United States)

    Modrzejewska, Renata; Badura-Madej, Wanda

    2008-01-01

    The image of the self changes over time. The changes are conditioned by the culture and the social structure that the adolescents live in. The study aimed to compare self-image in the non- treated 17 y.o. population of adolescents during 15 years. In 1987 and 2001, a representative sample of school-attending adolescents was screened with OSIQ (The Offer Self-Image Questionnaire for Adolescents). In the period surveyed, the self-image of 17-year-olds improved. In the boys' group, there is still an incoherence of the self-image, while in girls the coherence grows. As a result ofmacrocultural factors, favourable changes take place in the area of mental health and coping that are reflected in the improvement of the self-image.

  20. Comparative study of thin sectional anatomical images from Chinese visible human data set and computed tomography images of superior mediastinum.

    Science.gov (United States)

    Wu, Yi; Luo, Na; Tan, Li-Wen; Fang, Bing-Ji; Li, Ying; Xie, Bing; Xu, Hao-Tong; Hu, Nan; Yang, Wei-Ping; Wu, Wei; Lamers, Wouter H; Zhang, Shao-Xiang

    2012-11-01

    The structures of superior mediastinum and their spatial relationships are complex and difficult to master. This study aimed to compare visualization of the superior mediastinum based on computed tomography (CT) images and on the thin sections of the Chinese visible human (CVH) data set to provide a sectional anatomical basis for diagnostic imaging of superior mediastinal pathology. CVH sections of the mediastinum of a 35-year old male were compared with plain and enhanced CT images of a 45-year old male without apparent abnormalities in the upper chest. In addition, a three-dimensional model based on the CVH sections was compared with a model based on CT images. Although CT imaging is noninvasive and can be carried out in many individuals, its weakness is clearly the visualization of small soft tissue structures. In this respect, the sectional anatomical approach of the CVH images is complementary, as it visualizes these small soft tissue structures due to the higher resolution in the plain of sectioning and the color of the different structures in the section. Three-dimensional surface and volume rendering of reconstructions of the CVH data set can help medical students and less experienced thoracic surgeons to familiarize themselves with the topographic anatomy of the superior mediastinal structures and their spatial relationships, and thus with interpreting CT images of patients. Copyright © 2012 Wiley Periodicals, Inc.

  1. Optimal metabolic conditions during fluorine-18 fluorodeoxyglucose imaging; a comparative study using different protocols

    International Nuclear Information System (INIS)

    Bax, J.J.; Veening, M.A.; Visser, F.C.; Lingen, A. van; Heine, R.J.; Cornel, J.H.; Visser, C.A.

    1997-01-01

    Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) can identify viable myocardium in patients with coronary artery disease. Recently, FDG imaging with single-photon emission tomography (SPET) and 511-keV collimators has been described. To obtain optimal image quality in all patients, cardiac FDG studies should be performed during hyperinsulinaemic glucose clamping. It has been suggested that FDG imaging after the administration of a nicotinic acid derivative may yield comparable image quality to clamping. We studied eight patients and compared the image quality of cardiac FDG SPET studies after oral glucose loading, after administration of a nicotinic acid derivative (acipimox, 250 mg orally) and during hyperinsulinaemic glucose clamping. The image quality was expressed as the myocardial to blood pool (M/B) activity ratio, which is used as a measure of the target-to-background ratio The M/B ratios were comparable after clamping and acipimox (2.8±0.8 vs 2.9±0.7), whereas the M/B ratio was lower after oral glucose loading (2.2±0.3, P 1/2 oral load=16.2 ±5.7 min) as compared with clamping (T 1/2 clamp=8.1 ±3.1 min) and acipimox (T 1/2 acipimox=10.7 ±4.0 min, NS vs clamp, P <0.05 vs oral load). It may be concluded that FDG SPET imaging after acipimox administration yields image quality and clearance rates comparable to those obtained during clamping. FDG SPET in combination with acipimox may useful in clinical routine for the assessment of myocardial viability. (orig.). With 6 figs., 3 tabs

  2. Application of multispectral imaging in quantitative immunohistochemistry study of breast cancer: a comparative study.

    Science.gov (United States)

    Liu, Wen-Lou; Wang, Lin-Wei; Chen, Jia-Mei; Yuan, Jing-Ping; Xiang, Qing-Ming; Yang, Gui-Fang; Qu, Ai-Ping; Liu, Juan; Li, Yan

    2016-04-01

    Multispectral imaging (MSI) based on imaging and spectroscopy, as relatively novel to the field of histopathology, has been used in biomedical multidisciplinary researches. We analyzed and compared the utility of multispectral (MS) versus conventional red-green-blue (RGB) images for immunohistochemistry (IHC) staining to explore the advantages of MSI in clinical-pathological diagnosis. The MS images acquired of IHC-stained membranous marker human epidermal growth factor receptor 2 (HER2), cytoplasmic marker cytokeratin5/6 (CK5/6), and nuclear marker estrogen receptor (ER) have higher resolution, stronger contrast, and more accurate segmentation than the RGB images. The total signal optical density (OD) values for each biomarker were higher in MS images than in RGB images (all P images (AUC = 0.91, 89.1 %, 83.2 %) than RGB images (AUC = 0.87, 84.5, and 81.8 %). There was no significant difference between quantitative results of RGB images and clinico-pathological characteristics (P > 0.05). However, by quantifying MS images, the total signal OD values of HER2 positive expression were correlated with lymph node status and histological grades (P = 0.02 and 0.04). Additionally, the consistency test results indicated the inter-observer agreement was more robust in MS images for HER2 (inter-class correlation coefficient (ICC) = 0.95, r s = 0.94), CK5/6 (ICC = 0.90, r s = 0.88), and ER (ICC = 0.94, r s = 0.94) (all P images for HER2 (ICC = 0.91, r s = 0.89), CK5/6 (ICC = 0.85, r s = 0.84), and ER (ICC = 0.90, r s = 0.89) (all P images in quantitative IHC analysis could obtain higher accuracy, reliability, and more information of protein expression in relation to clinico-pathological characteristics versus conventional RGB images. It may become an optimal IHC digital imaging system used in quantitative pathology.

  3. Comparative Study of Thin Sectional Anatomical Images from Chinese Visible Human Data Set and Computed Tomography Images of Superior Mediastinum

    NARCIS (Netherlands)

    Wu, Yi; Luo, Na; Tan, Li-Wen; Fang, Bing-Ji; Li, Ying; Xie, Bing; Xu, Hao-Tong; Hu, Nan; Yang, Wei-Ping; Wu, Wei; Lamers, Wouter H.; Zhang, Shao-Xiang

    2012-01-01

    The structures of superior mediastinum and their spatial relationships are complex and difficult to master. This study aimed to compare visualization of the superior mediastinum based on computed tomography (CT) images and on the thin sections of the Chinese visible human (CVH) data set to provide a

  4. Image quality assessment in panoramic dental radiography: a comparative study between conventional and digital systems

    Science.gov (United States)

    Tiau, Yu Jin

    2013-01-01

    This study is designed to compare and evaluate the diagnostic image quality of dental panoramic radiography between conventional and digital systems. Fifty-four panoramic images were collected and divided into three groups consisting of conventional, digital with and without post processing image. Each image was printed out and scored subjectively by two experienced dentists who were blinded to the exposure parameters and system protocols. The evaluation covers of anatomical coverage and structures, density and image contrast. The overall image quality score revealed that digital panoramic with post-processing scored the highest of 3.45±0.19, followed by digital panoramic system without post-processing and conventional panoramic system with corresponding scores of 3.33±0.33 and 2.06±0.40. In conclusion, images produced by digital panoramic system are better in diagnostic image quality than that from conventional panoramic system. Digital post-processing visualization can improve diagnostic quality significantly in terms of radiographic density and contrast. PMID:23483085

  5. Comparative study of digital laser film and analog paper image recordings

    International Nuclear Information System (INIS)

    Lee, K.R.; Cox, G.G.; Templeton, A.W.; Preston, D.F.; Anderson, W.H.; Hensley, K.S.; Dwyer, S.J.

    1987-01-01

    The increase in the use of various imaging modalities demands higher quality and more efficacious analog image recordings. Laser electronic recordings with digital array prints of 4,000 x 5,000 x 12 bits obtained using laser-sensitive film or paper are being evaluated. Dry silver paper recordings are being improved and evaluated. High-resolution paper dot printers are being studied to determine their gray-scale capabilities. The authors evaluated the image quality, costs, clinical utilization, and acceptability of CT scans, MR images, digital subtraction angiograms, digital radiographs, and radionuclide scans recorded by seven different printers (three laser, three silver paper, and one dot) and compared the same features in conventional film recording. This exhibit outlines the technical developments and instrumentation of digital laser film and analog paper recorders and presents the results of the study

  6. A comparative study of lossless compression algorithms on multispectral imager data

    Science.gov (United States)

    Grossberg, Michael; Gottipati, Srikanth; Gladkova, Irina; Rabinowitz, Malka; Alabi, Paul; George, Tence; Pacheco, Amnia

    2009-05-01

    This paper reports a comparative study of current lossless compression algorithms for data from a representative selection of satellite based earth science multispectral imagers. The study includes the performance of compression algorithms on Advanced Very High Resolution Radiometer(AVHRR), SEVIRI, the Moderate Resolution Imaging Spectroradiometer(MODIS) imager, as well as a subset of MODIS bands as a proxy for the upcoming GOES-R series. SEVIRI aboard the ESA/EUMETSAT operated Meteosat Second Generation (MSG) satellites is a geostationary imager. The AVHRR aboard the NOAA Polar Orbiting Environmental Satellites and MODIS aboard the NASA Terra and Aqua satellites have polar orbits. Thus this study will present representatives from both polar and geostationary orbiting imagers. The imagers we include have sensors for both reflected and emissive radiance. We also note that the older satellites have coarser quantizations and present our conclusions on the impact on compression ratios. Faced with a enormous growing large volume of data on a new emerging current generation images from faster scanning, finer spatial resolution, and greater spectral resolution, this study provides a comparison of current compression algorithms as a baseline for future work. With growing satellite Earth science multispectral imager volume data, it becomes increasingly important to evaluate which compression algorithms are most appropriate for data management in transmission and archiving. This comparative compression study uses a wide range standard implementations of the leading lossless compression algorithms. Examples include image compression algorithms such as PNG and JPEG2000, and widely-used file compression formats such as BZIP2 and 7z. This study includes a comparison with the Consultative Committee for Space Data Systems (CCSDS) recommended Szip software which uses the extended-Rice lossless compression algorithm as well as the most recent recommended compression standard which

  7. A comparative study on preprocessing techniques in diabetic retinopathy retinal images: illumination correction and contrast enhancement.

    Science.gov (United States)

    Rasta, Seyed Hossein; Partovi, Mahsa Eisazadeh; Seyedarabi, Hadi; Javadzadeh, Alireza

    2015-01-01

    To investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal image quality, a comparative study was carried out. We studied and implemented a few illumination correction and contrast enhancement techniques on color retinal images to find out the best technique for optimum image enhancement. To compare and choose the best illumination correction technique we analyzed the corrected red and green components of color retinal images statistically and visually. The two contrast enhancement techniques were analyzed using a vessel segmentation algorithm by calculating the sensitivity and specificity. The statistical evaluation of the illumination correction techniques were carried out by calculating the coefficients of variation. The dividing method using the median filter to estimate background illumination showed the lowest Coefficients of variations in the red component. The quotient and homomorphic filtering methods after the dividing method presented good results based on their low Coefficients of variations. The contrast limited adaptive histogram equalization increased the sensitivity of the vessel segmentation algorithm up to 5% in the same amount of accuracy. The contrast limited adaptive histogram equalization technique has a higher sensitivity than the polynomial transformation operator as a contrast enhancement technique for vessel segmentation. Three techniques including the dividing method using the median filter to estimate background, quotient based and homomorphic filtering were found as the effective illumination correction techniques based on a statistical evaluation. Applying the local contrast enhancement technique, such as CLAHE, for fundus images presented good potentials in enhancing the vasculature segmentation.

  8. Comparative study of the magnetic resonance imaging in myocardial infarction model

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Cheong Hwan; Jung, Hong Ryang; Kim, Jeong Koo [College of Medicine, Hanseo Univ., Seosan (Korea, Republic of)

    2001-04-01

    The purpose of this study is to evaluate time course of signal enhancement on Gadomer-17 enhance MRI, and to correlate the size of enhanced area with that of the infarct area on 2'3'5'-triphenyl tetrazolium chloride(TTC) histochemical examination for the assessment of myocardial viability in reperfused Myocardial Infarction in a cat model. Tan cats(average weight : 3.8 kg) which had undergone 90 minutes of occlusion of the LAD followed by 90 minutes of reperfusion underwent MR T2-weighted imaging, and T1-weighted imaging, enhanced T1-weighted imaging. We used 1.5T Magnetom Vision MRI system(Siemens, Erlangen, Germany). Signal intensities were measured in the enhanced and non-enhanced areas of enhanced T1-weighted imaging. and TTC histochemical staining the size of the abnormal signal area on each image was compared with that of the infarct area. Maximum enhancement was detected during a 40{approx}60 minute period with an average enhancement of 168{+-}9.9% of normal myocardium. TTC staining revealed that the size of the high signal area on T2-weighted images and of the enhanced area on enhanced T1-weighted images was greater than that of the infarct area(T2=48.1%{+-}3.7, enhanced T1=47.2%{+-}2.6, TTC staining=38.7%{+-}3.1 ; p <0.05). In reperfused Myocardial Infarction in a cat model, enhanced MR imaging delineates reversibly and irreversibly damaged myocardium, with a strong enhancement and a broad temporal window. We may therefore expect that enhanced MR image is useful for demonstrating myocardial injury.

  9. A comparative study of metal artifacts from common metal orthodontic brackets in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Kajan, Zahra Dalili; Alizadeh, Ahmad; Hemmaty, Yasmin Babael; Roushan, Zahra Atrkar; Khademi, Jalil

    2015-01-01

    This study was performed to compare the metal artifacts from common metal orthodontic brackets in magnetic resonance imaging. A dry mandible with 12 intact premolars was prepared, and was scanned ten times with various types of brackets: American, 3M, Dentaurum, and Masel orthodontic brackets were used, together with either stainless steel (SS) or nickel titanium (NiTi) wires. Subsequently, three different sequences of coronal and axial images were obtained: spin-echo T1-weighted images, fast spin-echo T2-weighted images, and fluid-attenuated inversion recovery images. In each sequence, the two sequential axial and coronal images with the largest signal-void area were selected. The largest diameters of the signal voids in the direction of the X-, Y-, and Z-axes were then measured twice. Finally, the mean linear values associated with different orthodontic brackets were analyzed using one-way analysis of variation, and the results were compared using the independent t-test to assess whether the use of SS or NiTi wires had a significant effect on the images. Statistically significant differences were only observed along the Z-axis among the four different brands of orthodontic brackets with SS wires. A statistically significant difference was observed along all axes among the brackets with NiTi wires. A statistically significant difference was found only along the Z-axis between nickel-free and nickel-containing brackets. With respect to all axes, the 3M bracket was associated with smaller signal-void areas. Overall, the 3M and Dentaurum brackets with NiTi wires induced smaller artifacts along all axes than those with SS wires

  10. A comparative study of metal artifacts from common metal orthodontic brackets in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kajan, Zahra Dalili; Alizadeh, Ahmad; Hemmaty, Yasmin Babael; Roushan, Zahra Atrkar; Khademi, Jalil [Guilan University of Medical Sciences, Rasht (Iran, Islamic Republic of)

    2015-09-15

    This study was performed to compare the metal artifacts from common metal orthodontic brackets in magnetic resonance imaging. A dry mandible with 12 intact premolars was prepared, and was scanned ten times with various types of brackets: American, 3M, Dentaurum, and Masel orthodontic brackets were used, together with either stainless steel (SS) or nickel titanium (NiTi) wires. Subsequently, three different sequences of coronal and axial images were obtained: spin-echo T1-weighted images, fast spin-echo T2-weighted images, and fluid-attenuated inversion recovery images. In each sequence, the two sequential axial and coronal images with the largest signal-void area were selected. The largest diameters of the signal voids in the direction of the X-, Y-, and Z-axes were then measured twice. Finally, the mean linear values associated with different orthodontic brackets were analyzed using one-way analysis of variation, and the results were compared using the independent t-test to assess whether the use of SS or NiTi wires had a significant effect on the images. Statistically significant differences were only observed along the Z-axis among the four different brands of orthodontic brackets with SS wires. A statistically significant difference was observed along all axes among the brackets with NiTi wires. A statistically significant difference was found only along the Z-axis between nickel-free and nickel-containing brackets. With respect to all axes, the 3M bracket was associated with smaller signal-void areas. Overall, the 3M and Dentaurum brackets with NiTi wires induced smaller artifacts along all axes than those with SS wires.

  11. A comparative study of metal artifacts from common metal orthodontic brackets in magnetic resonance imaging

    Science.gov (United States)

    Khademi, Jalil; Alizadeh, Ahmad; Babaei Hemmaty, Yasamin; Atrkar Roushan, Zahra

    2015-01-01

    Purpose This study was performed to compare the metal artifacts from common metal orthodontic brackets in magnetic resonance imaging. Materials and Methods A dry mandible with 12 intact premolars was prepared, and was scanned ten times with various types of brackets: American, 3M, Dentaurum, and Masel orthodontic brackets were used, together with either stainless steel (SS) or nickel titanium (NiTi) wires. Subsequently, three different sequences of coronal and axial images were obtained: spin-echo T1-weighted images, fast spin-echo T2-weighted images, and fluid-attenuated inversion recovery images. In each sequence, the two sequential axial and coronal images with the largest signal-void area were selected. The largest diameters of the signal voids in the direction of the X-, Y-, and Z-axes were then measured twice. Finally, the mean linear values associated with different orthodontic brackets were analyzed using one-way analysis of variation, and the results were compared using the independent t-test to assess whether the use of SS or NiTi wires had a significant effect on the images. Results Statistically significant differences were only observed along the Z-axis among the four different brands of orthodontic brackets with SS wires. A statistically significant difference was observed along all axes among the brackets with NiTi wires. A statistically significant difference was found only along the Z-axis between nickel-free and nickel-containing brackets. Conclusion With respect to all axes, the 3M bracket was associated with smaller signal-void areas. Overall, the 3M and Dentaurum brackets with NiTi wires induced smaller artifacts along all axes than those with SS wires. PMID:26389058

  12. A COMPARATIVE STUDY OF THE IMAGING AND TREATMENT MODALITIES IN THE MANAGEMENT OF CHOLEDOCHOLITHIASIS

    Directory of Open Access Journals (Sweden)

    Harish

    2016-02-01

    Full Text Available AIM The objectives of this study are to compare the investigative modalities used in the diagnosis and to compare the treatment undertaken in the management of patients with choledocholithiasis. MATERIAL AND METHODS Data was collected in prefixed proforma in our hospital between April 2012 to Oct 2014 after considering inclusion and exclusion criteria.  Data regarding imaging studies for diagnosis of choledocholithiasis was collected.  After diagnosis, patients were subjected to different treatment modalities.  The outcomes, complications and morbidity of the procedures were compared analysed. RESULTS  Mean age was more than 50 years. Pain abdomen was the most common preventing complaint.  Ultrasound was the commonest imaging modality done with sensitivity of more than 60% in finding the CBD stone  CT and MRCP in diagnosis of choledocholithiasis were concerned and dilatation of the common bile duct was detected equally by both methods.  ERCP and surgical methods in form of laparoscopic or open surgery were different treatment modalities used; ERCP was the common treatment modality done. Open surgery and laparoscopic cholecystectomy were next commonest treatment modalities done respectively. CONCLUSIONS  Occurrence of choledocholithiasis increases with age.  USG is both cheap and effective with sensitivity more than 60% but MRCP is more preferable as a biliary imaging modality.  Choledochoduodenostomy is an optional method of management following CBD exploration while T-tube drainage and primary closure of the CBD following exploration have comparable results.

  13. Methods for obtaining 3D training images for multiple-point statistics simulations: a comparative study

    Science.gov (United States)

    Jha, S. K.; Comunian, A.; Mariethoz, G.; Kelly, B. F.

    2013-12-01

    In recent years, multiple-point statistics (MPS) has been used in several studies for characterizing facies heterogeneity in geological formations. MPS uses a conceptual representation of the expected facies distribution, called a Training image (TI), to generate patterns of facies heterogeneity. In two-dimensional (2D) simulations the TI can be a hand-drawn image, an analogue outcrop image, or derived from geological reconstructions using a combination of geological analogues and geophysical data. However, obtaining suitable TI in three-dimensions (3D) from geological analogues or geophysical data is harder and has limited the use of MPS for simulating facies heterogeneity in 3D. There have been attempts to generate 3D training images using object-based simulation (OBS). However, determining suitable values for the large number of parameters required by OBS is often challenging. In this study, we compare two approaches for generating three-dimensional training images to model a valley filling sequence deposited by meandering rivers. The first approach is based on deriving statistical information from two-dimensional TIs. The 3D domain is simulated with a sequence of 2D MPS simulation steps, performed along different directions on slices of the 3D domain. At each 2D simulation step, the facies simulated at the previous steps that lie on the current 2D slice are used as conditioning data. The second approach uses hand-drawn two-dimensional TIs and produces complex patterns resembling the geological structures by applying rotation and affinity transformations in the facies simulation. The two techniques are compared using transition probabilities, facies proportions, and connectivity metrics. In the presentation we discuss the benefits of each approach for generating three-dimensional facies models.

  14. The quest for 'diagnostically lossless' medical image compression: a comparative study of objective quality metrics for compressed medical images

    Science.gov (United States)

    Kowalik-Urbaniak, Ilona; Brunet, Dominique; Wang, Jiheng; Koff, David; Smolarski-Koff, Nadine; Vrscay, Edward R.; Wallace, Bill; Wang, Zhou

    2014-03-01

    Our study, involving a collaboration with radiologists (DK,NSK) as well as a leading international developer of medical imaging software (AGFA), is primarily concerned with improved methods of assessing the diagnostic quality of compressed medical images and the investigation of compression artifacts resulting from JPEG and JPEG2000. In this work, we compare the performances of the Structural Similarity quality measure (SSIM), MSE/PSNR, compression ratio CR and JPEG quality factor Q, based on experimental data collected in two experiments involving radiologists. An ROC and Kolmogorov-Smirnov analysis indicates that compression ratio is not always a good indicator of visual quality. Moreover, SSIM demonstrates the best performance, i.e., it provides the closest match to the radiologists' assessments. We also show that a weighted Youden index1 and curve tting method can provide SSIM and MSE thresholds for acceptable compression ratios.

  15. Comparative study on developmental stages of the clavicle by postmortem MRI and CT imaging

    DEFF Research Database (Denmark)

    Larsen, Sara Tangmose; Lynnerup, Niels; Jensen, K.E.

    2013-01-01

    Objectives: The developmental stages of the clavicles are important for forensic age estimation purposes in adolescents. This study compares the 4-stage system to evaluate the ossification of the medial end of the clavicle as visualized by magnetic resonance imaging (MRI) and computed tomography...... (CT). As several forensic institutes routinely perform CT scans, the large amount of available data may serve as reference sample for MRI in specific cases. Material and methods: This prospective study included an MRI and CT scan of 47 autopsy cases performed prior to medico-legal autopsy (age range...... 12.9-27.5 years). All images were scored in blind trials using a 4-stage system by a trained observer. Results: Intra-observer agreements were substantial within (MRI: K=0.685, CT: K=0.611) and between modalities (K=0.644, p...

  16. [The alcoholic's self-image: a comparative study between men and women].

    Science.gov (United States)

    Aubry, C; Gay, M-C; Romo, L; Joffre, S

    2004-01-01

    Self-image is a central problem in alcoholism. Most theories about the relationships between the self-image of alcoholics and their behaviour have been derived from -clinical observations rather than empirical research. Most observations have pointed out that alcoholics are prone to underevaluation of themselves and that low self-image is the basis of much of the problem drinker's behaviour. All the research on self-image has concluded that alcoholics have a lower self-image than non-alcoholics. Some empirical research has been conducted on the self-image of alcoholics; it has, however, been carried out only a few times, restricted to small samples, and concerned with a limited number of aspects of self-image. Moreover, most of these studies are not recent, and it seems that this area of research is not well covered. Even though the hypothesis of a bad self-image in alcoholics was validated by various older studies, the representation of alcoholism has since changed. Because of this evolution, the ways in which the disease has been viewed have changed. One can question to what extent changes in society can influence the self-image of alcoholics. This question seems all the more pertinent for alcoholic women, given the evolution of the female condition since the Seventies. The objectives of this study are to evaluate the self-image of alcoholics and non-alcoholics, and to compare the self-image of male and female alcoholics. Our hypotheses are that: 1) the self-image of an alcoholic is more negative than that of a non-alcoholic, and that: 2) female alcoholics have a more negative self-image than male alcoholics. Two groups of 30 subjects each were made up: a group of alcoholics recruited in an alcohol-dependency unit and a group of non-alcoholics recruited in a public place. The comparison of socio-demographic data between the alcoholic group and the control group does not show a significant difference except for age and level of schooling. The average age of the

  17. Comparative study on developmental stages of the clavicle by postmortem MRI and CT imaging

    DEFF Research Database (Denmark)

    Larsen, Sara Tangmose; Lynnerup, Niels; Jensen, K.E.

    2013-01-01

    Objectives: The developmental stages of the clavicles are important for forensic age estimation purposes in adolescents. This study compares the 4-stage system to evaluate the ossification of the medial end of the clavicle as visualized by magnetic resonance imaging (MRI) and computed tomography...... (CT). As several forensic institutes routinely perform CT scans, the large amount of available data may serve as reference sample for MRI in specific cases. Material and methods: This prospective study included an MRI and CT scan of 47 autopsy cases performed prior to medico-legal autopsy (age range...

  18. A comparative study on methods of improving SCR for ship detection in SAR image

    Science.gov (United States)

    Lang, Haitao; Shi, Hongji; Tao, Yunhong; Ma, Li

    2017-10-01

    Knowledge about ship positions plays a critical role in a wide range of maritime applications. To improve the performance of ship detector in SAR image, an effective strategy is improving the signal-to-clutter ratio (SCR) before conducting detection. In this paper, we present a comparative study on methods of improving SCR, including power-law scaling (PLS), max-mean and max-median filter (MMF1 and MMF2), method of wavelet transform (TWT), traditional SPAN detector, reflection symmetric metric (RSM), scattering mechanism metric (SMM). The ability of SCR improvement to SAR image and ship detection performance associated with cell- averaging CFAR (CA-CFAR) of different methods are evaluated on two real SAR data.

  19. A comparative study of deep learning models for medical image classification

    Science.gov (United States)

    Dutta, Suvajit; Manideep, B. C. S.; Rai, Shalva; Vijayarajan, V.

    2017-11-01

    Deep Learning(DL) techniques are conquering over the prevailing traditional approaches of neural network, when it comes to the huge amount of dataset, applications requiring complex functions demanding increase accuracy with lower time complexities. Neurosciences has already exploited DL techniques, thus portrayed itself as an inspirational source for researchers exploring the domain of Machine learning. DL enthusiasts cover the areas of vision, speech recognition, motion planning and NLP as well, moving back and forth among fields. This concerns with building models that can successfully solve variety of tasks requiring intelligence and distributed representation. The accessibility to faster CPUs, introduction of GPUs-performing complex vector and matrix computations, supported agile connectivity to network. Enhanced software infrastructures for distributed computing worked in strengthening the thought that made researchers suffice DL methodologies. The paper emphases on the following DL procedures to traditional approaches which are performed manually for classifying medical images. The medical images are used for the study Diabetic Retinopathy(DR) and computed tomography (CT) emphysema data. Both DR and CT data diagnosis is difficult task for normal image classification methods. The initial work was carried out with basic image processing along with K-means clustering for identification of image severity levels. After determining image severity levels ANN has been applied on the data to get the basic classification result, then it is compared with the result of DNNs (Deep Neural Networks), which performed efficiently because of its multiple hidden layer features basically which increases accuracy factors, but the problem of vanishing gradient in DNNs made to consider Convolution Neural Networks (CNNs) as well for better results. The CNNs are found to be providing better outcomes when compared to other learning models aimed at classification of images. CNNs are

  20. Assessing Leg length Discrepancy Using a Biplane Low Dose Imaging System. A Comparative Diagnostic Study

    DEFF Research Database (Denmark)

    Jensen, Janni; Mussmann, Bo Redder; Torfing, Trine

    study was to evaluate the diagnostic accuracy of leg length (LL) measurements performed on low dose pre-view images acquired using a new bi-planar imaging system. The administered radiation dose from the pre-view image is approximately 20,17μGycm2 vs. 2670μGycm2 when acquiring the diagnostic image....... Materials and Methods. Pre-view and diagnostic images from 22 patients were retrospectively collected (44 images) and included in the study. All images were anonymized and interpreted independently by two senior musculoskeletal radiologists. Three sets of measurements were performed on both the pre......-view- and the diagnostic images, the mechanical axis lines of the femur and the tibia as well as the anatomical line of the entire extremity. Variance within and between the two raters was assessed by the intra-class correlation coefficient (ICC) and comparisons between LL measurements in the pre-view and the diagnostic...

  1. A comparative study of 2 computer-assisted methods of quantifying brightfield microscopy images.

    Science.gov (United States)

    Tse, George H; Marson, Lorna P

    2013-10-01

    Immunohistochemistry continues to be a powerful tool for the detection of antigens. There are several commercially available software packages that allow image analysis; however, these can be complex, require relatively high level of computer skills, and can be expensive. We compared 2 commonly available software packages, Adobe Photoshop CS6 and ImageJ, in their ability to quantify percentage positive area after picrosirius red (PSR) staining and 3,3'-diaminobenzidine (DAB) staining. On analysis of DAB-stained B cells in the mouse spleen, with a biotinylated primary rat anti-mouse-B220 antibody, there was no significant difference on converting images from brightfield microscopy to binary images to measure black and white pixels using ImageJ compared with measuring a range of brown pixels with Photoshop (Student t test, P=0.243, correlation r=0.985). When analyzing mouse kidney allografts stained with PSR, Photoshop achieved a greater interquartile range while maintaining a lower 10th percentile value compared with analysis with ImageJ. A lower 10% percentile reflects that Photoshop analysis is better at analyzing tissues with low levels of positive pixels; particularly relevant for control tissues or negative controls, whereas after ImageJ analysis the same images would result in spuriously high levels of positivity. Furthermore comparing the 2 methods by Bland-Altman plot revealed that these 2 methodologies did not agree when measuring images with a higher percentage of positive staining and correlation was poor (r=0.804). We conclude that for computer-assisted analysis of images of DAB-stained tissue there is no difference between using Photoshop or ImageJ. However, for analysis of color images where differentiation into a binary pattern is not easy, such as with PSR, Photoshop is superior at identifying higher levels of positivity while maintaining differentiation of low levels of positive staining.

  2. Three-dimensional imaging of the spine using the EOS system: is it reliable? A comparative study using computed tomography imaging

    DEFF Research Database (Denmark)

    Al-Aubaidi, Z.; Lebel, D.; Oudjhane, K.

    2013-01-01

    The aim of this study was to evaluate the precision of three-dimensional geometry compared with computed tomography (CT) images. This retrospective study included patients who had undergone both imaging of the spine using the EOS imaging system and CT scanning of the spine. The apical vertebral o...

  3. Simultaneous storage of medical images in the spatial and frequency domain: A comparative study

    Directory of Open Access Journals (Sweden)

    Acharya U Rajendra

    2004-06-01

    Full Text Available Abstract Background Digital watermarking is a technique of hiding specific identification data for copyright authentication. This technique is adapted here for interleaving patient information with medical images, to reduce storage and transmission overheads. Methods The patient information is encrypted before interleaving with images to ensure greater security. The bio-signals are compressed and subsequently interleaved with the image. This interleaving is carried out in the spatial domain and Frequency domain. The performance of interleaving in the spatial, Discrete Fourier Transform (DFT, Discrete Cosine Transform (DCT and Discrete Wavelet Transform (DWT coefficients is studied. Differential pulse code modulation (DPCM is employed for data compression as well as encryption and results are tabulated for a specific example. Results It can be seen from results, the process does not affect the picture quality. This is attributed to the fact that the change in LSB of a pixel changes its brightness by 1 part in 256. Spatial and DFT domain interleaving gave very less %NRMSE as compared to DCT and DWT domain. Conclusion The Results show that spatial domain the interleaving, the %NRMSE was less than 0.25% for 8-bit encoded pixel intensity. Among the frequency domain interleaving methods, DFT was found to be very efficient.

  4. Preoperative imaging for DIEA perforator flaps: a comparative study of computed tomographic angiography and Doppler ultrasound.

    Science.gov (United States)

    Rozen, Warren M; Phillips, Timothy J; Ashton, Mark W; Stella, Damien L; Gibson, Robert N; Taylor, G Ian

    2008-01-01

    Abdominal donor-site flaps, including the transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric artery (DIEA) perforator flaps, are standard in autologous breast reconstruction. With significant variation in the vascular anatomy of the abdominal wall, preoperative imaging is essential for preoperative planning and reducing intraoperative error. Doppler and color duplex sonography have been used with varying results, and the quest continues for optimal preoperative assessment. Computed tomographic angiography has recently been proposed as a noninvasive modality for this purpose. This is the first study to formally compare preoperative Doppler ultrasound with computed tomographic angiography for imaging the DIEA. Eight consecutive patients undergoing DIEA perforator flap surgery for breast reconstruction underwent both computed tomographic angiography and Doppler ultrasound preoperatively. All investigations and procedures were performed at the same institution with the same primary and assisting surgeons and the same radiology team. Computed tomographic angiography was superior to Doppler ultrasound at identifying the course of the DIEA and its branching pattern, and in visualizing its perforators. Preoperative computed tomographic angiography was highly specific (100 percent) and more sensitive in mapping and visualizing perforators (p = 0.0078). It was also proficient at identifying the superficial epigastric arterial system and for effectively displaying the results intraoperatively. It was substantially quicker and removed the interobserver error associated with Doppler ultrasonography. The study was ceased after eight patients because of the overwhelming benefit of computed tomographic angiography over Doppler ultrasonography. Computed tomographic angiography is a valuable imaging modality for the preoperative assessment of the donor-site vascular supply for TRAM and DIEA perforator flaps.

  5. Comparative studies of physical characteristics and clinical efficacy of digitized chest images

    International Nuclear Information System (INIS)

    Yamasaki, K.; Sato, K.; Kusumoto, M.; Adachi, S.; Kono, M.

    1989-01-01

    The authors have investigated the diagnostic accuracy of a cathode-ray-tube (CRT) image by using image physics, receiver operating characteristic (ROC) analysis, and clinical evaluation. On the ROC study, they used images of a volunteer's chest with a simulated hairline positioned in different places. The hairline was positioned vertically and horizontally for the raster line. Statistically significant differences in accuracy were found between the different positions. Image physics showed a good correlation with clinical evaluation. The authors conclude that a 100-μm sampling pitch of digitization and >2,000 raster lines would be required for a primary diagnosis on a CRT

  6. Comparative study of image registration techniques for bladder video-endoscopy

    Science.gov (United States)

    Ben Hamadou, Achraf; Soussen, Charles; Blondel, Walter; Daul, Christian; Wolf, Didier

    2009-07-01

    Bladder cancer is widely spread in the world. Many adequate diagnosis techniques exist. Video-endoscopy remains the standard clinical procedure for visual exploration of the bladder internal surface. However, video-endoscopy presents the limit that the imaged area for each image is about nearly 1 cm2. And, lesions are, typically, spread over several images. The aim of this contribution is to assess the performance of two mosaicing algorithms leading to the construction of panoramic maps (one unique image) of bladder walls. The quantitative comparison study is performed on a set of real endoscopic exam data and on simulated data relative to bladder phantom.

  7. Advanced noise reduction in placental ultrasound imaging using CPU and GPU: a comparative study

    Science.gov (United States)

    Zombori, G.; Ryan, J.; McAuliffe, F.; Rainford, L.; Moran, M.; Brennan, P.

    2010-03-01

    This paper presents a comparison of different implementations of 3D anisotropic diffusion speckle noise reduction technique on ultrasound images. In this project we are developing a novel volumetric calcification assessment metric for the placenta, and providing a software tool for this purpose. The tool can also automatically segment and visualize (in 3D) ultrasound data. One of the first steps when developing such a tool is to find a fast and efficient way to eliminate speckle noise. Previous works on this topic by Duan, Q. [1] and Sun, Q. [2] have proven that the 3D noise reducing anisotropic diffusion (3D SRAD) method shows exceptional performance in enhancing ultrasound images for object segmentation. Therefore we have implemented this method in our software application and performed a comparative study on the different variants in terms of performance and computation time. To increase processing speed it was necessary to utilize the full potential of current state of the art Graphics Processing Units (GPUs). Our 3D datasets are represented in a spherical volume format. With the aim of 2D slice visualization and segmentation, a "scan conversion" or "slice-reconstruction" step is needed, which includes coordinate transformation from spherical to Cartesian, re-sampling of the volume and interpolation. Combining the noise filtering and slice reconstruction in one process on the GPU, we can achieve close to real-time operation on high quality data sets without the need for down-sampling or reducing image quality. For the GPU programming OpenCL language was used. Therefore the presented solution is fully portable.

  8. Multiparametric magnetic resonance imaging for prostate cancer-a comparative study including radical prostatectomy specimens.

    Science.gov (United States)

    Toner, Liam; Papa, Nathan; Perera, Marlon; Katelaris, Nikolas; Weerakoon, Mahesha; Chin, Kwang; Harewood, Laurence; Bolton, Damien M; Lawrentschuk, Nathan

    2017-06-01

    To evaluate the diagnostic and staging ability of multiparametric MRI (mpMRI) compared to radical prostatectomy (RP) specimens after dissemination of this technology to several centres. mpMRI is an evolving technique aiming to improve upon the diagnostic sensitivity of prostate biopsy for the diagnosis of prostate cancer. Differences in interpretation, expertise and application of mpMRI are responsible for the range of reported results. This retrospective clinical study was conducted with consecutive patients through an electronic database of tertiary hospitals and adjacent private urology practices in Australia. Patients having undergone RP were assessed for the presence of a pre-operative mpMRI performed between 2013 and 2015 which was evaluated against the reference standard of the RP whole-mount specimen. MRI reports were evaluated using the Prostate Imaging Reporting and Data System (PI-RADS). In our cohort of 152 patients, the sensitivity and specificity of mpMRI (PI-RADS ≥ 4) for prostate cancer (Gleason ≥ 4 + 3) detection were 83 and 47%, respectively. For the identification of extraprostatic disease, the sensitivity and specificity were 29 and 94%, respectively. These results represent a 'real-world' approach to mpMRI and appear comparable to other single-centre studies. MRI staging information should be interpreted in context with other risk factors for extraprostatic disease. mpMRI has a useful role as an adjunct for prostate cancer diagnosis and directing management towards improving patient outcomes.

  9. Measurements of Corneal Thickness in Eyes with Pseudoexfoliation Syndrome: Comparative Study of Different Image Processing Protocols

    Directory of Open Access Journals (Sweden)

    Katarzyna Krysik

    2017-01-01

    Full Text Available Purpose. Comparative analysis of central and peripheral corneal thickness in PEX patients using three different imaging systems: Pentacam-Scheimpflug device, time-domain optical coherence tomography (OCT Visante, and swept-source OCT Casia. Materials and Methods. 128 eyes of 80 patients with diagnosed PEX were examined and compared with 112 normal, non-PEX eyes of 72 cataract patients. The study parameters included 5 measured zones: central and 4 peripheral (superior, inferior, nasal, and temporal. Results. The mean CCT in eyes with PEX syndrome measured with all three instruments was thicker than that in normal eyes. Corneal thickness measurements in the PEX group were statistically significantly different between Pentacam and OCT Casia: central corneal thickness (p=0.04, inferior corneal zone (p=0.01, and nasal and temporal corneal zones (p<0.01. Between Pentacam and OCT Visante inferior, nasal and temporal corneal zones were statistically significantly different (p<0.01. Between OCT Casia and OCT Visante, there were no statistically significant differences in measured parameters values. Conclusion. The central corneal thickness in eyes with PEX syndrome measured with three different independent methods is higher than that in the non-PEX group, and despite variable peripheral corneal thickness, this one parameter is still crucial in intraocular pressure measurements.

  10. Comparative study of various imaging methods to retinoblastoma and malignant melanoma of the uvea

    International Nuclear Information System (INIS)

    Sakiyama, Yutaka

    1999-01-01

    Clinical usefulness of ultrasonography, CT-scan and MRI was compared in diagnosis of retinoblastoma and malignant melanoma of the uvea. In retinoblastoma, ultrasonography was effective to detect a small tumor, detached retinas and dissemination of vitreous body. The calcified part presented a high internal reflection. CT-scan was difficult to detect a small tumor, but useful for the detection of the calcified part and invasion to optic nerve. A tumor showed as high intensity in T1 weighted image and low intensity in T2 weighted image of MRI. The calcified part showed low intensity and necrosis part showed high intensity in T2 weighted image. The degree of differentiation of tumors could not be determined from these images. In malignant melanoma of the uvea, peculiar findings were obtained in A-scan of ultrasonography, and inside reflection was high with irregularity in cases with much necrosis. Tumors uniformly showed high density in CT-scan, and CT-scan was useful to detect invasion of the sclera. Tumors showed high intensity in T1 weighted image of MRI, and low intensity in T2 weighted image, and the part containing much melanin showed clear low intensity. Ultrasonography and MRI were superior to detect the detached retinas and dissemination of vitreous body. A diagnosis of malignant tumor in eyes becomes easy by combined use of ultrasonography, CT-scan and MRI. (K.H.)

  11. Comparative study of the macroscopic finding, conventional tomographic imaging, and computed tomographic imaging in locating the mandibular canal

    International Nuclear Information System (INIS)

    Choi, Hang Moon; You, Dong Soo

    1995-01-01

    The purpose of this study was comparison of conventional tomography with reformatted computed tomography for dental implant in locating the mandibular canal. Five dogs were used and after conventional tomographs and fitted computed tomographs were taken, four dentist traced all films. Mandibles were sectioned with 2 mm slice thickness and the sections were then radiographed (contact radiography). Each radiograpic image was traced and linear measurements were made from mandibular canal to alveolar crest, buccal cortex, lingual cortex, and inferior border. The following results were obtained; 1. Reformatted computed tomographs were exacter than conventional tomography by alveolar crest to canal length of -0.6 mm difference between real values and radiographs 2. The average measurements of buccal cortex to mandibular canal width and lingual cortex to mandibular canal width of conventional tomographs were exacter than reformatted computed tomographs, but standard deviations were higher than reformatted computed tomographs. 3. Standard deviations of reformatted computed tomographs were lower than conventional tomographs at all comparing sites 4. At reformatted computed tomography 62.5% of the measurements performed were within ±1 mm of the true value, and at conventional tomography 24.1% were. 5. Mandibular canal invisibility was 0.8% at reformatted computed tomography and 9.2% at conventional tomography. Reformatted computed tomography has been shown to be more useful radiographic technique for assessment of the mandibular canal than conventional tomography.

  12. SU-E-J-248: Comparative Study of Two Image Registration for Image-Guided Radiation Therapy in Esophageal Cancer

    International Nuclear Information System (INIS)

    Shang, K; Wang, J; Liu, D; Li, R; Cao, Y; Chi, Z

    2014-01-01

    Purpose: Image-guided radiation therapy (IGRT) is one of the major treatment of esophageal cancer. Gray value registration and bone registration are two kinds of image registration, the purpose of this work is to compare which one is more suitable for esophageal cancer patients. Methods: Twenty three esophageal patients were treated by Elekta Synergy, CBCT images were acquired and automatically registered to planning kilovoltage CT scans according to gray value or bone registration. The setup errors were measured in the X, Y and Z axis, respectively. Two kinds of setup errors were analysed by matching T test statistical method. Results: Four hundred and five groups of CBCT images were available and the systematic and random setup errors (cm) in X, Y, Z directions were 0.35, 0.63, 0.29 and 0.31, 0.53, 0.21 with gray value registration, while 0.37, 0.64, 0.26 and 0.32, 0.55, 0.20 with bone registration, respectively. Compared with bone registration and gray value registration, the setup errors in X and Z axis have significant differences. In Y axis, both measurement comparison results of T value is 0.256 (P value > 0.05); In X axis, the T value is 5.287(P value < 0.05); In Z axis, the T value is −5.138 (P value < 0.05). Conclusion: Gray value registration is recommended in image-guided radiotherapy for esophageal cancer and the other thoracic tumors. Manual registration could be applied when it is necessary. Bone registration is more suitable for the head tumor and pelvic tumor department where composed of redundant interconnected and immobile bone tissue

  13. 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

  14. 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)

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

    2014-11-01

    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. 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. 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. 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.

  15. A comparative study of automatic image segmentation algorithms for target tracking in MR-IGRT.

    Science.gov (United States)

    Feng, Yuan; Kawrakow, Iwan; Olsen, Jeff; Parikh, Parag J; Noel, Camille; Wooten, Omar; Du, Dongsu; Mutic, Sasa; Hu, Yanle

    2016-03-01

    On-board magnetic resonance (MR) image guidance during radiation therapy offers the potential for more accurate treatment delivery. To utilize the real-time image information, a crucial prerequisite is the ability to successfully segment and track regions of interest (ROI). The purpose of this work is to evaluate the performance of different segmentation algorithms using motion images (4 frames per second) acquired using a MR image-guided radiotherapy (MR-IGRT) system. Manual contours of the kidney, bladder, duodenum, and a liver tumor by an experienced radiation oncologist were used as the ground truth for performance evaluation. Besides the manual segmentation, images were automatically segmented using thresholding, fuzzy k-means (FKM), k-harmonic means (KHM), and reaction-diffusion level set evolution (RD-LSE) algorithms, as well as the tissue tracking algorithm provided by the ViewRay treatment planning and delivery system (VR-TPDS). The performance of the five algorithms was evaluated quantitatively by comparing with the manual segmentation using the Dice coefficient and target registration error (TRE) measured as the distance between the centroid of the manual ROI and the centroid of the automatically segmented ROI. All methods were able to successfully segment the bladder and the kidney, but only FKM, KHM, and VR-TPDS were able to segment the liver tumor and the duodenum. The performance of the thresholding, FKM, KHM, and RD-LSE algorithms degraded as the local image contrast decreased, whereas the performance of the VP-TPDS method was nearly independent of local image contrast due to the reference registration algorithm. For segmenting high-contrast images (i.e., kidney), the thresholding method provided the best speed (image contrast was low, the VR-TPDS method had the best automatic contour. Results suggest an image quality determination procedure before segmentation and a combination of different methods for optimal segmentation with the on-board MR

  16. A comparative study of scintillator combining methods for flat-panel X-ray image sensors

    Science.gov (United States)

    Kim, M. S.; Lim, K. T.; Kim, G.; Cho, G.

    2018-02-01

    An X-ray transmission imaging based on scintillation detection method is the most widely used radiation technique particularly in the medical and industrial areas. As the name suggests, scintillation detection uses a scintillator as an intermediate material to convert incoming radiation into visible-light particles. Among different types of scintillators, CsI(Tl) in a columnar configuration is the most popular type used for applications that require an energy less than 150 keV due to its capability in obtaining a high spatial resolution with a reduced light spreading effect. In this study, different methods in combining a scintillator with a light-receiving unit are investigated and their relationships are given in terms of the image quality. Three different methods of combining a scintillator with a light-receiving unit are selected to investigate their performance in X-ray imaging: upward or downward oriented needles structure of CsI(Tl), coating layer deposition around CsI(Tl), and insertion of FOP. A charge-coupled device was chosen to serve as the light-receiving unit for the proposed system. From the result, the difference of needle directions in CsI(Tl) had no significant effects in the X-ray image. In contrast, deposition of the coating material around CsI(Tl) showed 17.3% reduction in the DQE. Insertion of the FOP increased the spatial resolution by 38%, however, it decreased the light yield in the acquired image by 56%. In order to have the maximum scintillation performance in X-ray imaging, not only the reflection material but also the bonding method must be considered when combining the scintillator with the light-receiving unit. In addition, the use of FOP should be carefully decided based on the purpose of X-ray imaging, e.g., image sharpness or SNR.

  17. In vivo study of approximal caries depth on storage phosphor plate images compared with dental x-ray film.

    Science.gov (United States)

    Versteeg, K H; Sanderink, G C; Velders, X L; van Ginkel, F C; van der Stelt, P F

    1997-08-01

    The aim of this in vivo study was to compare approximal caries depth on storage phosphor plate images to conventional film. A Soredex Digora imaging plate was placed in a film bite-wing positioner behind a Kodak Ektaspeed Plus film package without lead foil. The effect of scattered radiation on film without lead foil with a storage phosphor plate at the back was studied in a separate in vitro experiment. Compared with film protected by lead foil, the film showed higher density, but comparable contrast. For the in vivo study, clinical bite-wing exposures were made with the setup described above, with exposure settings for Ektaspeed Plus film. A four-point scale was chosen for approximal caries depth: 0 = no caries; 1 = caries in enamel; 2 = caries reaching dentino-enamel junction; 3 = caries into dentin. The bite-wing film images were shown to a panel of four experts. Sixty surfaces were selected for observer performance, based on identical scorings of the experts consensus classification. Next, six dentists evaluated both film and storage phosphor plate images with the same four point scale. Analysis of variance revealed a significant observer and image modality effect without an interaction effect. In conclusion, caries depth on storage phosphor plate images was underestimated compared with film-based images.

  18. A comparative study of some methods for color medical images segmentation

    Science.gov (United States)

    Stanescu, Liana; Dan Burdescu, Dumitru; Brezovan, Marius

    2011-12-01

    The aim of this article is to study the problem of color medical images segmentation. The images represent pathologies of the digestive tract such as ulcer, polyps, esophagites, colitis, or ulcerous tumors, gathered with the help of an endoscope. This article presents the results of an objective and quantitative study of three segmentation algorithms. Two of them are well known: the color set back-projection algorithm and the local variation algorithm. The third method chosen is our original visual feature-based algorithm. It uses a graph constructed on a hexagonal structure containing half of the image pixels in order to determine a forest of maximum spanning trees for connected component representing visual objects. This third method is a superior one taking into consideration the obtained results and temporal complexity. These three methods were successfully used in generic color images segmentation. In order to evaluate these segmentation algorithms, we used error measuring methods that quantify the consistency between them. These measures allow a principled comparison between segmentation results on different images, with differing numbers of regions generated by different algorithms with different parameters.

  19. Magnetic resonance imaging and ultrasonography in diagnosing arthritis of the hand joints: a comparative study

    International Nuclear Information System (INIS)

    Ciechomska, A.; Bachta, A.; Tlustochowicz, W.; Serafin-Krol, M.; Jakubowski, W.; Andrysiak, R.; Krolicki, L.

    2005-01-01

    Assessment of joint inflammation in clinical practice is based on physical examination. Imaging modalities which allow soft tissues to be visualized may be helpful in making the assessment impartial and to evaluate the severity of inflammation. The aim of the study was to compare magnetic resonance imaging (MRI) and ultrasonography (USG) findings in visualizing joint inflammation of the hand. The study comprised 113 patients with chronic arthritis, of whom 88 patients had rheumatoid arthritis (RA) and 25 arthritis of etiology unconnected with RA. MRI of the hand was performed in 98 patients and USG of the hand in 86 patients. Sixty-four patients underwent both USG and MRI. In the USG examinations a linear, high-frequency transducer of 5-9 MHz and a Color Doppler option (CD-USG) were used. MRI was performed with a 1.5 T unit in the SE sequences T1, T1 with fat saturation, and before and after Gd-DTPA injection. Assessed joints included the wrist joints, etacarpophalangeal joints, and proximal and distal interphalangeal joints (1921 joints in total). Tenosynovitis of the flexors and extensors was also evaluated. MRI showed inflammation in 277 joints (16.6%) of 66 patients. The mean number of inflamed joints found using MRI was 2.8 ± 2.9. US visualized synovitis in a larger number of joints (350, 23.9%) in 63 patients. The mean number of inflamed joints found by USG was 4.1 ± 4.0. Increased blood flow on CD-USG was seen in 202 joints (13.8%) of 72 patients. The difference between RA and non-RA patients as visible on MRI and USG were statistically significant. There were correlations in showing joint inflammation between MRI and USG (τ = 0.64; p < 0.00001) and between CD-USG and MRI (τ = 0.44; p < 0.00001) and concordance in showing flexor tendon sheath inflammation. MRI and USG both show inflammation of the joints. The concordance between the methods in showing joint inflammation depends upon analyzing the features of inflammation. Availability and the

  20. A comparative study of three speckle reducing methods for intima-media thickness ultrasound images.

    Science.gov (United States)

    Rafati, Mehravar; Arabfard, Masoud; Rafati Rahimzadeh, Mehrdad; Voshtani, Hasan; Moladoust, Hassan

    2015-02-01

    Ultrasonic evaluation of intima-media thickness (IMT) is an early marker of assessing the development of atherosclerosis and determining cardiovascular risk. To attain the best possible diagnosis, it is essential that medical images be clear, sharp and without noise and artifacts. Comparison of speckle reducing anisotropic diffusion (SRAD), discrete (DTD) and continuum topological derivative (CTD) on B-mode ultrasound images of common carotid and brachial arteries throughout the cardiac cycle. In a cross-sectional design, an examination was performed on forty-two human subjects with a mean age of 44 ± 6 years from April 2013 to June 2013. This study was approved by the ethics committees of Kashan University of Medical Sciences and Beheshti Hospital. An ultrasonic examination of common carotid and brachial arteries of forty-two human subjects was performed. The program was designed in MATLAB software to extract consecutive B-mode images and apply region of interest (ROI) on the IMT of the common carotid and brachial arteries. Then, three different noise reduction filters with the Canny edge detection were used in ROI separately. Finally, the program measured the image quality metrics. According to values of eleven different image quality metrics (mentioned in the main text), there was a significant difference between CTD, DTD and SRAD filters with the Canny edge detection status in the common carotid and brachial arteries throughout the cardiac cycle (all P values quality metrics, this study showed that DTD and CTD filters with the Canny edge detection respectively, are better than SRAD filter with the Canny detection for speckle suppression and details preservation in both arteries in the ultrasound images.

  1. Comparative study on 3D-2D convertible integral imaging systems

    Science.gov (United States)

    Choi, Heejin; Kim, Joohwan; Kim, Yunhee; Lee, Byoungho

    2006-02-01

    In spite of significant improvements in three-dimensional (3D) display fields, the commercialization of a 3D-only display system is not achieved yet. The mainstream of display market is a high performance two-dimensional (2D) flat panel display (FPD) and the beginning of the high-definition (HD) broadcasting accelerates the opening of the golden age of HD FPDs. Therefore, a 3D display system needs to be able to display a 2D image with high quality. In this paper, two different 3D-2D convertible methods based on integral imaging are compared and categorized for its applications. One method uses a point light source array and a polymer-dispersed liquid crystal and one display panel. The other system adopts two display panels and a lens array. The former system is suitable for mobile applications while the latter is for home applications such as monitors and TVs.

  2. In vivo comparative study of hydroxyapatite labeled with different radioisotopes: evaluation of the scintigraphic images

    International Nuclear Information System (INIS)

    Couto, Renata Martinussi; Barboza, Marycel Figols de; Souza, Adriano Aparecido de; Muramoto, Emiko; Mengatti, Jair; Araujo, Elaine Bortoleti de

    2008-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disorder of joints that is characterized by the inflammation and proliferation of synovial tissues. Approximately 3% of the adult population in the world is affected by this disease which causes pain, joint immobility and disability. Adyo synovectomy (RSV) is a radiotherapeutic modality where a b--emitting radionuclide is administered locally by intra-articular injection on the form of a colloid or radiolabeled particulate. RSV is a well-accepted therapeutic procedure in inflammatory joint diseases and has been successfully employed for more than 50 years as a viable alternative to surgical and chemical synovectomy in the treatment of RA and other inflammatory arthropathies. There are several radionuclides available for this purpose such as 177 Lu, 90 Y, 153 Sm, 165 Dy, and 166 Ho. Hydroxyapatite (HA) is one of the preferred particulates for this application because it is the major chemical constituent of skeletal bone and it is converted into Ca and PO4 ions in the body. In addition HA is completely eliminated over a period of six weeks. The aim of this work is to compare the in vivo stability of hydroxyapatite labeled with 177 Lu, 90 Y and 153 Sm in order to determine the influence of the radionuclide on biological pattern. In biological studies, 100mL of labeled HAs suspended in normal saline were injected into normal knee joints of Wistar rats and the retention of the activity into the synovium was determined. Labeled particles were also injected by intravenous and intramuscular administration, to verify the biodistribution in the case of an eventual leakage of the products from the joint. Sequential scintigraphic images were acquired from 1 hour to 7 days p.i. after anesthetizing the animals with ketamine. Hydroxyapatite was radiolabeled by all radionuclides with high yield. 177 Lu-HA, 90 Y-HA and 153 Sm-HA were retained in the joint for 7 days, showing stability and usefulness as tools in the RSV treatment

  3. In vivo comparative study of hydroxyapatite labeled with different radioisotopes: evaluation of the scintigraphic images

    Energy Technology Data Exchange (ETDEWEB)

    Couto, Renata Martinussi; Barboza, Marycel Figols de; Souza, Adriano Aparecido de; Muramoto, Emiko; Mengatti, Jair; Araujo, Elaine Bortoleti de, E-mail: rmcouto@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia

    2008-07-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disorder of joints that is characterized by the inflammation and proliferation of synovial tissues. Approximately 3% of the adult population in the world is affected by this disease which causes pain, joint immobility and disability. Adyo synovectomy (RSV) is a radiotherapeutic modality where a b--emitting radionuclide is administered locally by intra-articular injection on the form of a colloid or radiolabeled particulate. RSV is a well-accepted therapeutic procedure in inflammatory joint diseases and has been successfully employed for more than 50 years as a viable alternative to surgical and chemical synovectomy in the treatment of RA and other inflammatory arthropathies. There are several radionuclides available for this purpose such as {sup 177}Lu, {sup 90}Y, {sup 153}Sm, {sup 165}Dy, and {sup 166}Ho. Hydroxyapatite (HA) is one of the preferred particulates for this application because it is the major chemical constituent of skeletal bone and it is converted into Ca and PO4 ions in the body. In addition HA is completely eliminated over a period of six weeks. The aim of this work is to compare the in vivo stability of hydroxyapatite labeled with {sup 177}Lu, {sup 90}Y and {sup 153}Sm in order to determine the influence of the radionuclide on biological pattern. In biological studies, 100mL of labeled HAs suspended in normal saline were injected into normal knee joints of Wistar rats and the retention of the activity into the synovium was determined. Labeled particles were also injected by intravenous and intramuscular administration, to verify the biodistribution in the case of an eventual leakage of the products from the joint. Sequential scintigraphic images were acquired from 1 hour to 7 days p.i. after anesthetizing the animals with ketamine. Hydroxyapatite was radiolabeled by all radionuclides with high yield. {sup 177}Lu-HA, {sup 90}Y-HA and {sup 153}Sm-HA were retained in the joint for 7 days, showing

  4. Comparative study of clinicopathological states and imaging diagnosis in patients with fatty liver

    International Nuclear Information System (INIS)

    Ariga, Hisayuki; Arakawa, Yasuyuki; Miyamoto, Masatoshi

    1985-01-01

    The authors clarified the characteristics of the clinicopathological states of 74 patients with the fatty liver classified by the etiology, simultaneously evaluating clinically the usefulness of imaging diagnosis with ultrasound and CT by the comparison of pathohistological findings(the rate of fat occupation in the liver). It was confirmed that, although the outcome of ultrasonic diagnosis was inferior to that of CT in the diagnostic capacity, the so-called bright liver finding was obtained, provided that the accumulation of fat in the liver was over Grade III (40 - 60 %), and that clinical diagnosis for fatty liver was possible. With CT, on the other hand, there was negative correlation between the degree of fat accumulation in the liver vs. the liver CT level and the CT ratio of the liver/spleen. Particularly, the CT ratio of the liver/spleen in this disease was 0.80 ± 0.18, indicating a significantly lower level as compared with 1.13 ± 0.13 in the control (p < 0.001). It is therefore suggested that, in patients in whom accumulation of fat in the liver is comparatively a lower level of Grade II (20 - 40 %), diagnosis for fatty liver by CT may be possible at a considerably high probability. Since these imaging diagnostic methods have been highly evaluated as non-invasive and convenient screening means of the fatty liver, it is important to establish the diagnostic criteria for graphic quantification of the fatty liver. (author)

  5. Comparative study of computed tomography and magnetic resonance imaging: report on fourteen regions

    International Nuclear Information System (INIS)

    Schouman-Claeys, Elisabeth; Richou, Francois; Falise Mirat, Beatrice

    2011-01-01

    In early 2010, the French national agency for supporting the performance of health care and medico-social establishments (ANAP) ran a benchmarking campaign on imaging facilities operating CT and MRI devices in 14 French regions. This innovative approach, which was the result of close collaboration with the ARS and the radiologists' representatives (SFR, FNMR, SRH, CERF) for the first time gave a large-scale comparison of the performance of these techniques, the use of which is constantly rising for treatment of the population. This qualitative and quantitative inventory covers three levels: - nationwide, observe the major trends concerning the efficiency of the organisations set up around MRI and CT devices, make an objective assessment of their accessibility, understand the clinical examinations performed for both scheduled procedures and emergencies. - for the participating regions, draw up a map of the diagnostic supply and the ability to meet the population's demand for major imaging facilities. The time taken to obtain an appointment can be compared with the map of the machines and their uses, as well as the radiologist population, in order to construct an adequate regional response. - the participating establishments receive a comparative analysis of the organisation concerning their CT or MRI devices and can thus identify the areas for improvement and implement action plans. (authors)

  6. Dual-energy compared to single-energy CT in pediatric imaging: a phantom study for DECT clinical guidance

    International Nuclear Information System (INIS)

    Zhu, Xiaowei; Servaes, Sabah; Darge, Kassa; McCullough, William P.; Mecca, Patricia

    2016-01-01

    Dual-energy CT technology is available on scanners from several vendors and offers significant advantages over classic single-energy CT technology in multiple clinical applications. Many studies have detailed dual-energy CT applications in adults and several have evaluated the relative radiation dose performance of dual-energy CT in adult imaging. However, little has been published on dual-energy CT imaging in the pediatric population, and the relative dose performance of dual-energy CT imaging in the pediatric population is not well described. When evaluating dual-energy CT technology for implementation into a routine clinical pediatric imaging practice, the radiation dose implications must be considered, and when comparing relative CT dose performance, image quality must also be evaluated. Therefore the purpose of this study is to develop dual-energy CT scan protocols based on our optimized single-energy scan protocols and compare the dose. We scanned the head, chest and abdomen regions of pediatric-size anthropomorphic phantoms with contrast inserts, using our optimized single-energy clinical imaging protocols on a Siemens Flash registered CT scanner. We then scanned the phantoms in dual-energy mode using matching image-quality reference settings. The effective CT dose index volume (CTDI vol ) of the scans was used as a surrogate for relative dose in comparing the single- and dual-energy scans. Additionally, we evaluated image quality using visual assessment and contrast-to-noise ratio. Dual-energy CT scans of the head and abdomen were dose-neutral for all three phantoms. Dual-energy CT scans of the chest showed a relative dose increase over the single-energy scan for 1- and 5-year-old child-based age-equivalent phantoms, ranging 11-20%. Quantitative analysis of image quality showed no statistically significant difference in image quality between the single-energy and dual-energy scans. There was no clinically significant difference in image quality by visual

  7. Dual-energy compared to single-energy CT in pediatric imaging: a phantom study for DECT clinical guidance

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaowei; Servaes, Sabah; Darge, Kassa [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, The Perelman School of Medicine, Philadelphia, PA (United States); McCullough, William P. [University of Virginia Health System, Department of Radiology and Medical Imaging, Charlottesville, VA (United States); Mecca, Patricia [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2016-11-15

    Dual-energy CT technology is available on scanners from several vendors and offers significant advantages over classic single-energy CT technology in multiple clinical applications. Many studies have detailed dual-energy CT applications in adults and several have evaluated the relative radiation dose performance of dual-energy CT in adult imaging. However, little has been published on dual-energy CT imaging in the pediatric population, and the relative dose performance of dual-energy CT imaging in the pediatric population is not well described. When evaluating dual-energy CT technology for implementation into a routine clinical pediatric imaging practice, the radiation dose implications must be considered, and when comparing relative CT dose performance, image quality must also be evaluated. Therefore the purpose of this study is to develop dual-energy CT scan protocols based on our optimized single-energy scan protocols and compare the dose. We scanned the head, chest and abdomen regions of pediatric-size anthropomorphic phantoms with contrast inserts, using our optimized single-energy clinical imaging protocols on a Siemens Flash {sup registered} CT scanner. We then scanned the phantoms in dual-energy mode using matching image-quality reference settings. The effective CT dose index volume (CTDI{sub vol}) of the scans was used as a surrogate for relative dose in comparing the single- and dual-energy scans. Additionally, we evaluated image quality using visual assessment and contrast-to-noise ratio. Dual-energy CT scans of the head and abdomen were dose-neutral for all three phantoms. Dual-energy CT scans of the chest showed a relative dose increase over the single-energy scan for 1- and 5-year-old child-based age-equivalent phantoms, ranging 11-20%. Quantitative analysis of image quality showed no statistically significant difference in image quality between the single-energy and dual-energy scans. There was no clinically significant difference in image quality by

  8. A Comparative Study of Histogram Equalization Based Image Enhancement Techniques for Brightness Preservation and Contrast Enhancement

    OpenAIRE

    Patel, Omprakash; Maravi, Yogendra P. S.; Sharma, Sanjeev

    2013-01-01

    Histogram Equalization is a contrast enhancement te chnique in the image processing which uses the histogram of image. However histogram equalization is not the best method for contrast enhancement because the mean brightness of the output image is significantly different from the input image. There are several extensions of histogram equalization has be en proposed to overcome the brightness preservation cha...

  9. A comparative study of minimum norm inverse methods for MEG imaging

    Energy Technology Data Exchange (ETDEWEB)

    Leahy, R.M.; Mosher, J.C.; Phillips, J.W.

    1996-07-01

    The majority of MEG imaging techniques currently in use fall into the general class of (weighted) minimum norm methods. The minimization of a norm is used as the basis for choosing one from a generally infinite set of solutions that provide an equally good fit to the data. This ambiguity in the solution arises from the inherent non- uniqueness of the continuous inverse problem and is compounded by the imbalance between the relatively small number of measurements and the large number of source voxels. Here we present a unified view of the minimum norm methods and describe how we can use Tikhonov regularization to avoid instabilities in the solutions due to noise. We then compare the performance of regularized versions of three well known linear minimum norm methods with the non-linear iteratively reweighted minimum norm method and a Bayesian approach.

  10. A Comparative Study of Landsat TM and SPOT HRG Images for Vegetation Classification in the Brazilian Amazon

    Science.gov (United States)

    Lu, Dengsheng; Batistella, Mateus; de Miranda, Evaristo E.; Moran, Emilio

    2009-01-01

    Complex forest structure and abundant tree species in the moist tropical regions often cause difficulties in classifying vegetation classes with remotely sensed data. This paper explores improvement in vegetation classification accuracies through a comparative study of different image combinations based on the integration of Landsat Thematic Mapper (TM) and SPOT High Resolution Geometric (HRG) instrument data, as well as the combination of spectral signatures and textures. A maximum likelihood classifier was used to classify the different image combinations into thematic maps. This research indicated that data fusion based on HRG multispectral and panchromatic data slightly improved vegetation classification accuracies: a 3.1 to 4.6 percent increase in the kappa coefficient compared with the classification results based on original HRG or TM multispectral images. A combination of HRG spectral signatures and two textural images improved the kappa coefficient by 6.3 percent compared with pure HRG multispectral images. The textural images based on entropy or second-moment texture measures with a window size of 9 pixels × 9 pixels played an important role in improving vegetation classification accuracy. Overall, optical remote-sensing data are still insufficient for accurate vegetation classifications in the Amazon basin. PMID:19789716

  11. Comparative Analysis and Modification of Imaging Techniques in the Parametric Studies of Control Systems

    Directory of Open Access Journals (Sweden)

    I. K. Romanova

    2017-01-01

    Full Text Available Bauman Moscow State Technical University, MoscowКалининградский государственный технический университет, КалининградThe article considers practical application aspects of various imaging techniques for parametric analysis of control systems. It is interpreted as a multivariate analysis aimed at studying the influence of external and internal parameters of the system on the quality of its functioning determined by direct and indirect quality criteria. The ultimate goal is to identify regions in the parameter space to provide an appropriate quality of the system. It is noted that visualization is a very important task-supporting aid for a designer to make decision. Stressed that the problem of parametric studies, in most cases, intersects with the major problem of inconsistency of separate partial criteria, i.e., the problem of multi-criteria optimization (MCO. Therefore, the aim of the article was to solve a joint task of visualization and multi-criteria optimization.The article considers traditional types of visualization in deterministic tasks (a 3-D graphics, plotting contour lines, gradient fields, Andrews curves, parallel coordinates, as well as methods used in statistics (graph matrices, etc.. Testing these methods as applied to the practical task of studying a double-circuit stabilization system allowed formulation of requirements for imaging techniques with multiple criteria.Provides a new perspective on using the traditional means to significantly enhance information capacity of imaging. A generic method of visualization is represented as a three-phase study agreed with the task of finding the compromise solutions. The first phase of the research involved identifying the monotony and contra-monotony domains. The second phase was aimed at identifying a region of compromise, or a weak Pareto optimum. The third phase involved the search for a consistent optimum (strong Pareto

  12. 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.

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

    Science.gov (United States)

    KOBAYASHI-VELASCO, Solange; SALINEIRO, Fernanda Cristina Sales; GIALAIN, Ivan Onone; CAVALCANTI, Marcelo Gusmão Paraiso

    2017-01-01

    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. PMID:28403364

  14. MR-Imaging of teeth and periodontal apparatus: an experimental study comparing high-resolution MRI with MDCT and CBCT

    International Nuclear Information System (INIS)

    Gaudino, Chiara; Csernus, Reka; Pham, Mirko; Bendszus, Martin; Rohde, Stefan; Cosgarea, Raluca; Kim, Ti-Sun; Heiland, Sabine; Beomonte Zobel, Bruno

    2011-01-01

    The aim of this study was (1) to assess the ability of magnetic resonance imaging (MRI) to visualize dental and periodontal structures and (2) to compare findings with multidetector computed tomography (MDCT) and cone beam CT (CBCT). Four porcine mandibles were examined with (1) 3T-MRI, (2) MDCT and (3) CBCT. Two observers independently reviewed MR, MDCT and CBCT images and assessed image quality of different dental and periodontal structures. To assess quantitatively the accuracy of the different imaging technique, both observers measured burr holes, previously drilled in the mandibles. Dental structures, e.g. teeth roots, pulpa chamber and dentin, were imaged accurately with all imaging sources. Periodontal space and cortical/trabecular bone were better visualized by MRI (p < 0.001). MRI could excellently display the lamina dura, not detectable with MDCT and only inconstant visible with CBCT (p < 0.001). Burr hole measurements were highly precise with all imaging techniques. This experimental study shows the diagnostic feasibility of MRI in visualization of teeth and periodontal anatomy. Detection of periodontal structures was significantly better with MRI than with MDCT or CBCT. Prospective trials have to evaluate further the potential benefit of MRI in a clinical setting. (orig.)

  15. The comparative study of MR diffusion-weighted imaging and MR perfusion-weighted imaging in diagnosing soft tissue tumors

    International Nuclear Information System (INIS)

    Wang Shaowu; Zhang Li'na; Sun Meiyu; Song Qingwei; Jia Feige

    2009-01-01

    Objective: To evaluate MR diffusion-weighted imaging (DWI)and MR perfusion- weighted imaging(PWI) in differentiating benign from malignant soft tissue tumors by comparing the related parameters. Methods: Fifty patients with soft tissue tumors verified by pathology (benign 24, malignant 26) underwent DWI and dynamic contrast-enhanced T 2 * -weighted PWI. DWI and PWI data of benign and malignant soft tissue tumors were acquired at the workstation and their difference was analyzed with t-test. The diagnostic accordance rate was verified with x 2 -test. Subjective overall performance of two techniques were evaluated with receiver operating characteristic (ROC) analysis. Results: ADC values of benign and malignant tumors were (2.03±0.36) x 10 -3 mm 2 /s, (1.52±0.39) x 10 -3 mm 2 /s, respectively. The signal intensity decrease of them during the first-pass perfusion (SI decrease ) were (13.54 ± 3.37)%, (47.57 ± 5.21)%, respectively. The maximum linearity slope rate of TIC (SS max ) of them were (5.51 ± 2.54)%, (7.94 ± 3.33)%, respectively. There were significant differences between benign and malignant tumors of ADC value and SI decrease (t=2.515, 2.938; P max (t= 1.272,P>0.05). When the threshold of ADC value was 1.866 x mm 2 /s, sensitivity and specificity for determining malignant tumors were 84.6% (22/26)and 83.3% (20/24). When the threshold of SI decrease was 40.33%, sensitivity and specificity for determining malignant tumors were 88.5% (23/26)and 75.0% (18/24). In type la of TIC, the proportion of benign soft tissue tumor was 3/24 and malignant tumor was 20/26. In type Ib, benign tumor was 14/24 and malignant tumor was 3/26. In type Ic, malignant tumor was 3/26. In type II, benign tumor was 7/24. The diagnostic accordance rate of DWI and PWI were 84.0% (42/50)and 82.0% (41/50), respectively. There was no significant difference between them (χ 2 =0.8, P>0.05). The accuracies of them were 81.7%, 83.6% respectively by the area under the ROC curve (AUC). The

  16. International Image Concordance Study to Compare a Point-of-Care Tampon Colposcope With a Standard-of-Care Colposcope.

    Science.gov (United States)

    Mueller, Jenna L; Asma, Elizabeth; Lam, Christopher T; Krieger, Marlee S; Gallagher, Jennifer E; Erkanli, Alaattin; Hariprasad, Roopa; Malliga, J S; Muasher, Lisa C; Mchome, Bariki; Oneko, Olola; Taylor, Peyton; Venegas, Gino; Wanyoro, Anthony; Mehrotra, Ravi; Schmitt, John W; Ramanujam, Nimmi

    2017-04-01

    Barriers to cervical cancer screening in low-resource settings include lack of accessible, high-quality services, high cost, and the need for multiple visits. To address these challenges, we developed a low-cost, intravaginal, optical cervical imaging device, the point-of-care tampon (POCkeT) colposcope and evaluated whether its performance is comparable with a standard-of-care colposcope. There were 2 protocols, which included 44 and 18 patients. For the first protocol, white-light cervical images were collected in vivo, blinded by device, and sent electronically to 8 physicians from high-, middle-, and low-income countries. For the second protocol, green-light images were also collected and sent electronically to the highest performing physician from the first protocol who has experience in both a high- and low-income country. For each image, physicians completed a survey assessing cervix characteristics and severity of precancerous lesions. Corresponding pathology was obtained for all image pairs. For the first protocol, average percent agreement between devices was 70% across all physicians. The POCkeT and standard-of-care colposcope images had 37% and 51% agreement with pathology for high-grade squamous intraepithelial lesions (HSILs), respectively. Investigation of HSIL POCkeT images revealed decreased visibility of vascularization and lack of contrast in lesion margins. After changes were made for the second protocol, the 2 devices achieved similar agreement to pathology for HSIL lesions (55%). Based on the exploratory study, physician interpretation of cervix images acquired using a portable, low-cost POCkeT colposcope was comparable to a standard-of-care colposcope.

  17. Comparative study of different approaches for multivariate image analysis in HPTLC fingerprinting of natural products such as plant resin.

    Science.gov (United States)

    Ristivojević, Petar; Trifković, Jelena; Vovk, Irena; Milojković-Opsenica, Dušanka

    2017-01-01

    Considering the introduction of phytochemical fingerprint analysis, as a method of screening the complex natural products for the presence of most bioactive compounds, use of chemometric classification methods, application of powerful scanning and image capturing and processing devices and algorithms, advancement in development of novel stationary phases as well as various separation modalities, high-performance thin-layer chromatography (HPTLC) fingerprinting is becoming attractive and fruitful field of separation science. Multivariate image analysis is crucial in the light of proper data acquisition. In a current study, different image processing procedures were studied and compared in detail on the example of HPTLC chromatograms of plant resins. In that sense, obtained variables such as gray intensities of pixels along the solvent front, peak area and mean values of peak were used as input data and compared to obtained best classification models. Important steps in image analysis, baseline removal, denoising, target peak alignment and normalization were pointed out. Numerical data set based on mean value of selected bands and intensities of pixels along the solvent front proved to be the most convenient for planar-chromatographic profiling, although required at least the basic knowledge on image processing methodology, and could be proposed for further investigation in HPLTC fingerprinting. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Comparative study of image contrast in scanning electron microscope and helium ion microscope.

    Science.gov (United States)

    O'Connell, R; Chen, Y; Zhang, H; Zhou, Y; Fox, D; Maguire, P; Wang, J J; Rodenburg, C

    2017-12-01

    Images of Ga + -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga + density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  19. Comparative Study of C-arms for Intraoperative 3-dimensional Imaging and Navigation in Minimally Invasive Spine Surgery Part I: Applicability and Image Quality.

    Science.gov (United States)

    Klingler, Jan-Helge; Sircar, Ronen; Scheiwe, Christian; Kogias, Evangelos; Volz, Florian; Krüger, Marie T; Hubbe, Ulrich

    2017-07-01

    This was a retrospective analysis. This study compares 2 different 3-dimensional (3D) C-arm devices for intraoperative imaging and navigation with regard to clinical applicability and image quality. Minimally invasive spine surgery requires intraoperative imaging techniques to adequately visualize the unexposed spine. For this purpose, mobile 3D C-arms became available along with the evolution of intraoperative navigation techniques. The C-arm devices Siremobil Iso-C 3D (Siemens) and Vision FD Vario 3D (Ziehm) perform an automated orbital rotation around the patient acquiring a 3D image set out of multiple successive fluoroscopic images. We report on technical specifications of the C-arms and our daily experience regarding clinical applicability. Furthermore, 5 spine surgeons evaluated blinded triplanar planes of 40 cervical, thoracic, and lumbar 3D scans that were obtained during routine surgery regarding usability for navigation. We assessed the delineation of cortical bone, artifacts, and overall image quality using a 0-10 numeric rating scale. The Siremobil Iso-C 3D requires 128 seconds for its 190-degree scanning arc with equidistant isocenter. The Vision FD Vario 3D performs an elliptical scanning arc and completes its 135-degree scan in 64 seconds; furthermore, it features a flat panel detector and fully digital imaging. The smaller dimensions of the Vision FD Vario 3D made it easier to maneuver in the operating room compared with the more bulky Siremobil Iso-C 3D. With respect to image quality in cervical 3D scans, the Siremobil Iso-C 3D reached significantly higher scores in all categories. The Vision FD Vario 3D revealed less artifacts in lumbar 3D scans. The Siremobil Iso-C 3D provides high-quality 3D scans in slender spine regions (eg, cervical spine), whereas the Vision FD Vario 3D appears to have advantages in the lumbar spine. Further evolution and novel devices are needed to optimize image quality and handling.

  20. Emotional responses to images of food in adults with an eating disorder: a comparative study with healthy and clinical controls.

    Science.gov (United States)

    Hay, Phillipa; Katsikitis, Mary

    2014-08-01

    Emotive responses to foods in people with eating disorders are incompletely understood in relation to whether the extent of emotional response is due to the eating disorder or non-specific emotional states. The aims of the present study were to investigate negative and positive emotive responses to food images in adults with an eating disorder, and to compare responses to a (i) healthy and a (ii) clinic (psychiatry) control group. Participants viewed 20 images (16 of foods previously found to evoke fear, disgust and happiness and 4 neutral images) at half-minute intervals and rated emotive responses on 3 visual analogue scales for each image. Participants with an eating disorder (n=26) were found to have significantly increased negative emotive (disgust and fear) responses and reduced positive (happiness) responses to the images compared to the 20 clinic and 61 healthy participants. Differences between groups remained significant when controlling for baseline levels of fear, disgust and happiness. Thus, the emotive responses to foods did not appear due to non-specific increases in anxiety or depression but rather was due to the presence of an eating disorder. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Comparative study of paranasal sinus between 16-slice spiral CT coronary reforming imagines and scanning images

    International Nuclear Information System (INIS)

    Lei Ziqiao; Han Ping; Yu Jianming; Chen Yan; Shi Heshui; Liu Yonghua; Yu Qun; Wu Hongying

    2007-01-01

    Objective: To explore the effect of different scanning methods and different constructive arithmetic on displaying the anatomy of ostiomeatal complex (OMC). Methods: Fifty-six patients undergoing paranasal sinus CT were divided into normal group (34 cases) and inflammation group (22 cases). According to scanning methods, all the cases reconstructed with soft tissue arithmetic were divided into coronary reforming group and coronary scanning group. Among 56 cases, 18 normal cases and 16 inflammation cases were reconstructed using high resolution arithmetic simultaneously. The imaging quality of OMC was assessed with different scanning methods and different constructive arithmetic. Results: There are no significant difference between coronary reforming images and coronary scanning images in two groups. There are significant difference between high resolution arithmetic and soft tissue arithmetic in normal group, but not in inflammation group. Conclusions: The information of axial images and coronary reforming images with 16-slice CT is superior to coronary scanning images on displaying the anatomy of OMC. High resolution arithmetic is better in displaying the tiny structure of OMC than soft tissue arithmetic in normal group. (authors)

  2. Wavelet-Based Visible and Infrared Image Fusion: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Angel D. Sappa

    2016-06-01

    Full Text Available This paper evaluates different wavelet-based cross-spectral image fusion strategies adopted to merge visible and infrared images. The objective is to find the best setup independently of the evaluation metric used to measure the performance. Quantitative performance results are obtained with state of the art approaches together with adaptations proposed in the current work. The options evaluated in the current work result from the combination of different setups in the wavelet image decomposition stage together with different fusion strategies for the final merging stage that generates the resulting representation. Most of the approaches evaluate results according to the application for which they are intended for. Sometimes a human observer is selected to judge the quality of the obtained results. In the current work, quantitative values are considered in order to find correlations between setups and performance of obtained results; these correlations can be used to define a criteria for selecting the best fusion strategy for a given pair of cross-spectral images. The whole procedure is evaluated with a large set of correctly registered visible and infrared image pairs, including both Near InfraRed (NIR and Long Wave InfraRed (LWIR.

  3. GPR Imaging for Deeply Buried Objects: A Comparative Study Based on FDTD Models and Field Experiments

    Science.gov (United States)

    Tilley, roger; Dowla, Farid; Nekoogar, Faranak; Sadjadpour, Hamid

    2012-01-01

    Conventional use of Ground Penetrating Radar (GPR) is hampered by variations in background environmental conditions, such as water content in soil, resulting in poor repeatability of results over long periods of time when the radar pulse characteristics are kept the same. Target objects types might include voids, tunnels, unexploded ordinance, etc. The long-term objective of this work is to develop methods that would extend the use of GPR under various environmental and soil conditions provided an optimal set of radar parameters (such as frequency, bandwidth, and sensor configuration) are adaptively employed based on the ground conditions. Towards that objective, developing Finite Difference Time Domain (FDTD) GPR models, verified by experimental results, would allow us to develop analytical and experimental techniques to control radar parameters to obtain consistent GPR images with changing ground conditions. Reported here is an attempt at developing 20 and 3D FDTD models of buried targets verified by two different radar systems capable of operating over different soil conditions. Experimental radar data employed were from a custom designed high-frequency (200 MHz) multi-static sensor platform capable of producing 3-D images, and longer wavelength (25 MHz) COTS radar (Pulse EKKO 100) capable of producing 2-D images. Our results indicate different types of radar can produce consistent images.

  4. A comparative study of correspondence-search algorithms in MIS images.

    Science.gov (United States)

    Puerto, Gustavo A; Mariottini, Gian-Luca

    2012-01-01

    The ability to find image similarities (feature matching) between laparoscopic views is essential in many robotic-assisted Minimally-Invasive Surgery (MIS) applications. Differently from feature tracking methods, feature matching does not make any restrictive assumption about the sequential nature of the two images or about the organ motion, and could then be used, e.g., to recover tracked features that were lost due to a prolonged occlusion, a sudden endoscopic-camera retraction, or a strong illumination change. This paper provides researchers in the medical-imaging computing community with an extensive comparison of the most up-to-date feature-matching algorithms over a large (and annotated) data set of 100 MIS-image pairs obtained from real interventions. The accuracy of these methods, as well as their ability to consistently retrieve as many good matches as possible, are evaluated for popular feature detectors. In addition, the dataset and the software implementations of these methods are made freely available on the Internet.

  5. Spatial Pyramids and Two-layer Stacking SVM classifiers for Image Categorization: A Comparative Study

    NARCIS (Netherlands)

    Abdullah, Azizi; Veltkamp, Remco C.; Wiering, Marco

    2009-01-01

    Recent research in image recognition has shown that combining multiple descriptors is a very useful way to improve classification performance. Furthermore, the use of spatial pyramids that compute descriptors at multiple spatial resolution levels generally increases the discriminative power of the

  6. Comparative study of fat-suppression techniques for hip arthroplasty MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Moliere, Sebastien [University Hospital of Strasbourg, Imaging Department, Strasbourg (France); Dillenseger, Jean-Philippe; Kremer, Stephane; Bierry, Guillaume [University Hospital of Strasbourg, Imaging Department, Strasbourg (France); ICube UMR 7357, University of Strasbourg, Strasbourg (France); Ehlinger, Matthieu [ICube UMR 7357, University of Strasbourg, Strasbourg (France); University Hospital of Strasbourg, Orthopaedic Department, Strasbourg (France)

    2017-09-15

    The goal of this study was to evaluate different fat-suppressed fluid-sensitive sequences in association with different metal artifacts reduction techniques (MARS) to determine which combination allows better fat suppression around metallic hip implants. An experimental study using an MRI fat-water phantom quantitatively evaluated contrast shift induced by metallic hip implant for different fat-suppression techniques and MARS. Then a clinical study with patients addressed to MRI unit for painful hip prosthesis compared these techniques in terms of fat suppression quality and diagnosis confidence. Among sequences without MARS, both T2 Dixon and short tau inversion recuperation (STIR) had significantly lower contrast shift (p < 0.05), Dixon offering the best fat suppression. Adding MARS (view-angle tilting or slice-encoding for metal artifact correction (SEMAC)) to STIR gave better results than Dixon alone, and also better than SPAIR and fat saturation with MARS (p < 0.05). There were no statistically significant differences between STIR with view-angle tilting and STIR with SEMAC in terms of fat suppression quality. STIR sequence is the preferred fluid-sensitive MR sequence in patients with metal implant. In combination with MARS (view-angle tilting or SEMAC), STIR appears to be the best option for high-quality fat suppression. (orig.)

  7. In vivo comparative study of hydroxyapatite labeled with different radioisotopes: evaluation of the scintigraphic images.

    Science.gov (United States)

    Couto, R M; De Barboza, M F; De Souza, A A; Muramoto, E; Mengatti, J; De Araújo, E B

    2010-05-10

    Radyosinovectomy (RSV) is a radiotherapeutic modality where a beta-emitting radionuclide is administered locally by intra-articular injection on the form of a colloid or radiolabeled particulate. RSV is a well-accepted therapeutic procedure in inflammatory joint diseases and has been successfully employed for more than 50 years as a viable alternative to surgical and chemical synovectomy. The aim of this work is to compare the in vivo stability of hydroxyapatite labelled with (177)Lu, (90)Y and (153)Sm. All radionuclides were labelled with high yield and were retained in the joint for 7 days, showing stability and usefulness as tools in the RSV treatment. A similar retention of the products in the muscle was observed when the particles were administrated in the muscle. However, the pure form of the radionuclides were rapidly cleared from the blood and accumulated in the liver when injected i.v.. Although (153)Sm-HA is already available for nuclear medicine procedures and clinical studies with (90)Y-HA have been developed, (177)Lu-labeled RSV agents will be economically more viable and has not been studied yet. Its favorable characteristics contribute to follow, to predict and asses the success of RSV by bone scintigraphy studies.

  8. Accuracy of reading liquid based cytology slides using the ThinPrep Imager compared with conventional cytology: prospective study

    Science.gov (United States)

    d'Assuncao, Jefferson; Irwig, Les; Macaskill, Petra; Chan, Siew F; Richards, Adele; Farnsworth, Annabelle

    2007-01-01

    Objective To compare the accuracy of liquid based cytology using the computerised ThinPrep Imager with that of manually read conventional cytology. Design Prospective study. Setting Pathology laboratory in Sydney, Australia. Participants 55 164 split sample pairs (liquid based sample collected after conventional sample from one collection) from consecutive samples of women choosing both types of cytology and whose specimens were examined between August 2004 and June 2005. Main outcome measures Primary outcome was accuracy of slides for detecting squamous lesions. Secondary outcomes were rate of unsatisfactory slides, distribution of squamous cytological classifications, and accuracy of detecting glandular lesions. Results Fewer unsatisfactory slides were found for imager read cytology than for conventional cytology (1.8% v 3.1%; Pcytology (7.4% v 6.0% overall and 2.8% v 2.2% for cervical intraepithelial neoplasia of grade 1 or higher). Among 550 patients in whom imager read cytology was cervical intraepithelial neoplasia grade 1 or higher and conventional cytology was less severe than grade 1, 133 of 380 biopsy samples taken were high grade histology. Among 294 patients in whom imager read cytology was less severe than cervical intraepithelial neoplasia grade 1 and conventional cytology was grade 1 or higher, 62 of 210 biopsy samples taken were high grade histology. Imager read cytology therefore detected 71 more cases of high grade histology than did conventional cytology, resulting from 170 more biopsies. Similar results were found when one pathologist reread the slides, masked to cytology results. Conclusion The ThinPrep Imager detects 1.29 more cases of histological high grade squamous disease per 1000 women screened than conventional cytology, with cervical intraepithelial neoplasia grade 1 as the threshold for referral to colposcopy. More imager read slides than conventional slides were satisfactory for examination and more contained low grade cytological

  9. Comparative study of imaging at 3.0 T versus 1.5 T of the knee

    International Nuclear Information System (INIS)

    Wong, Scott; Steinbach, Lynne; Zhao, Jian; Link, Thomas M.; Stehling, Christoph; Ma, C.B.

    2009-01-01

    The objectives of the study were to compare MR imaging at 1.5 and 3.0 T in the same patients concerning image quality and visualization of cartilage pathology and to assess diagnostic performance using arthroscopy as a standard of reference. Twenty-six patients were identified retrospectively as having comparative 1.5 and 3.0 T MR studies of the knee within an average of 102 days. Standard protocols included T1-weighted and fat-saturated intermediate-weighted fast spin-echo sequences in three planes; sequence parameters had been adjusted to account for differences in relaxation at 3.0 T. Arthroscopy was performed in 19 patients. Four radiologists reviewed each study independently, scored image quality, and analyzed pathological findings. Sensitivities, specificities, and accuracies in diagnosing cartilage lesions were calculated in the 19 patients with arthroscopy, and differences between 1.5 and 3.0 T exams were compared using paired Student's t tests with a significance threshold of p<0.05. Each radiologist scored the 3.0 T studies higher than those obtained at 1.5 T in visualizing anatomical structures and abnormalities (p<0.05). Using arthroscopy as a standard of reference, diagnosis of cartilage abnormalities was improved at 3.0 T with higher sensitivity (75.7% versus 70.6%), accuracy (88.2% versus 86.4%), and correct grading of cartilage lesions (51.3% versus 42.9%). Diagnostic confidence scores were higher at 3.0 than 1.5 T (p<0.05) and signal-to-noise ratio at 3.0 T was approximately twofold higher than at 1.5 T. MRI at 3.0 T improved visualization of anatomical structures and improved diagnostic confidence compared to 1.5 T. This resulted in significantly better sensitivity and grading of cartilage lesions at the knee. (orig.)

  10. A comparative study between the imaging system and the optical tracking system in proton therapy at CNAO

    CERN Document Server

    Desplanques, Maxime; Fontana, Giulia; Pella, Andrea; Riboldi, Marco; Fattori, Giovanni; Donno, Andrea; Baroni, Guido; Orecchia, Roberto

    2013-01-01

    The synergy between in-room imaging and optical tracking, in co-operation with highly accurate robotic patient handling represents a concept for patient-set-up which has been implemented at CNAO (Centro Nazionale di Adroterapia Oncologica). In-room imaging is based on a double oblique X-ray projection system; optical tracking consists of the detection of the position of spherical markers placed directly on the patient’s skin or on the immobilization devices. These markers are used as external fiducials during patient positioning and dose delivery. This study reports the results of a comparative analysis between in-room imaging and optical tracking data for patient positioning within the framework of high-precision particle therapy. Differences between the optical tracking system (OTS) and the imaging system (IS) were on average within the expected localization accuracy. On the first 633 fractions for head and neck (H&N) set-up procedures, the corrections applied by the IS, after patient positioning usin...

  11. Magnetic resonance imaging for prostate cancer: Comparative studies including radical prostatectomy specimens and template transperineal biopsy

    Directory of Open Access Journals (Sweden)

    Liam Toner

    2015-12-01

    Conclusions: mpMRI has an increasing role for PCa diagnosis, staging, and directing management toward improving patient outcomes. Its sensitivity and specificity when compared with RP and TTPB specimens are less than what some expect, possibly reflecting a learning curve for the technique of mpMRI.

  12. A multivendor phantom study comparing the image quality produced from three state-of-the-art SPECT-CT systems.

    Science.gov (United States)

    Hughes, Tyler; Celler, Anna

    2012-06-01

    Ongoing advancements in single photon emission computed tomography with on-board X-ray computed tomography (SPECT-CT) hardware and software raise important questions regarding the relative performances of various cameras and their respective image-processing software. This phantom-based study compares images produced from three state-of-the-art cameras using four image quality measurements. A thorax phantom modeling the spine, lungs, a healthy heart, and three tumors (cylindrical bottles) was scanned using the following SPECT-CT systems: Philips' Precedence (PP), GE's Infinia-Hawkeye (GH), and Siemens' Symbia-T6 (SS). For each scan, Tc-99m solutions were injected into the heart, three bottles, and thorax to yield activity concentration ratios of roughly 6:1 for both heart:thorax and tumor:thorax. The data were reconstructed using the most advanced software available on the cameras, namely, Evolution for Bone and Evolution for Cardiac (EVB and EVC, respectively), Astonish (AST), and Flash3D (FLA) for GH, PP, and SS, respectively. In addition, all sets of data were reconstructed using our in-house software. The mean values of activity error, uniformity, signal-to-noise ratio, and contrast error were used as figures of merit (FOM). No significant differences were observed for all FOM between all in-house reconstructions using PP, GH, and SS acquisition data. The mean activity error for the AST reconstruction (-24.0±1.6%) was significantly closer to the truth relative to EVB (-38.0±1.6%), EVC (-34.5±2.3%), and FLA (-33.8±1.6%). No significant differences were found between EVC and FLA for all FOM. In this phantom-based study, Philips' AST provided the most quantitatively accurate and highest contrast images, whereas Siemens' FLA and GE's EVC provided relatively higher signal-to-noise ratios and more uniform images.

  13. Comparative study of radiation dose and image noise between single-source fast kilo voltage peak switching technique and conventional mode on abdominal CT

    International Nuclear Information System (INIS)

    Lin Xiaozhu; Xu Xueqin; Chen Kemin; Yan Fuhua; Isao Tanaka; Rika Fukui; Haruhiko Machida; Eiko Ueno

    2013-01-01

    Objective: To investigate the radiation dose and image noise of abdominal CT with spectral imaging and conventional scan mode. Methods: This was a retrospective study. The first part of this study was a phantom study. A standard quality assessment phantom was scanned with gemstone spectral imaging mode and conventional helical mode using 120 kVp with different mAs. A regression function for the mAs between conventional scan mode and spectral imaging mode was obtained. According to the regression function, the mAs on 120 kVp corresponding to different gemstone spectral imaging protocol were calculated. The second part of this study was a clinical study. Twenty-two patients who underwent contrast enhanced abdominal CT scanning were included. The pre-contrast CT was scanned by a conventional mode with automatic exposure control technique. According to the mAs of pre-contrast scan, corresponding spectral imaging parameters were selected for the portal venous phase of post-contrast scan. Five sets of images with 5 mm slice thickness were reconstructed, with 65 keV monochromatic image for spectral imaging and FBP, 20%,40% and 60% ASIR image for conventional imaging respectively. Image noise was measured on hepatic parenchyma and urinary bladder for each set of image. Radiation dose and image noise were compared between CT spectral imaging and conventional imaging with paired t-test. Results: No significant differences were found for the CTDIvol [(13.8 ± 4.8) mGy versus (14.0 ± 7.0) mGy] and DLP [(691.1 ± 274.2) mGy · cm versus (678.8 ± 385.0) mGy · cm] between CT spectral imaging and conventional imaging. Monochromatic image (65 keV) by spectral imaging [(7.6 ± 1.4) HU for hepatic parenchyma and (9.1 ± 1.3) HU for urinary bladder] had equal image noise with 40% ASIR [hepatic parenchyma: (7.8 ±0.7) HU] and 20% ASIR [urinary bladder: (9.2 ± 1.2) HU] and lower image noise than FBP image [(10.4 ± 1.0) HU for hepatic parenchyma and (10.5 ± 1.3) HU for urinary

  14. Studies on diagnostic value of CT images for hypopharyngeal cancer by comparing with sliced specimens

    International Nuclear Information System (INIS)

    Fujimura, Akiko

    1988-01-01

    The findings of preoperative CT were compared with extirpated specimens in 11 patients to evaluate the value of CT in diagnosing the extent of hypopharyngeal cancer. CT was capable of detecting tumor extent to the submucosal fibrofatty tissue, except for the case of tumor extent to the laryngeal ventricle that contains many mucous glands and is usually depicted as a dense shadow. When the margin of ossified cortex of the thyroid cartilage was irregular and surrounded by tumor shadow, or when the margin of the cricoid cartilage was irregular and accompanied by increased medullary concentration, the invasion of the tumor into these cartilages was histopathologically demonstrated. Tumor extension next to these ossified cartilages did not indicate histopathological invasion of the tumor whenever their margins were smooth and regular. The intrinsic laryngeal muscle and the inferior pharyngeal constrictor muscle were identified on CT. Tumor extent to these muscles was well correlated to histologically demonstrated tumor invasion. When vocal cord fixation was present, CT showed tumor extent either to the paralaryngeal space only or to the paralaryngeal space and thyroarytenoid muscle or posterior cricoarytenoid muscle. Extraluminal spread through the thyrohyoid membrane was depicted on CT as a distinctive shadow in the visceral space that surrounds the hypopharyngeal cavity. Computed tomography overestimated tumor invation into the submucosal layer, muscles, or laryngeal cartilages. (Namekawa, K.)

  15. Muscle lesion comparing of imaging procedures (sonography and MRT) -experimental and clinical study

    International Nuclear Information System (INIS)

    Mellerowicz, H.; Lubasch, A.; Dulce, M.; Wagner, S.; Paul, B.

    1993-01-01

    Muscle injuries in sports are more common now. Diagnosis and follow up of muscle injuries is nowadays achieved by sonography and MRT. In order to assess the two imagine procedures, a direct test for comparison of sonography and MRT was performed in an experimental study: A standardised disconnection of m. triceps surae in rats was either sutured and glued or not treated. Clinical studies were performed in 26 patients suffering from muscle trauma. Sonography was proved to be a reliable procedure especially in follow up control until full weight bearing and should be used first. Negative or doubtfull findings require further investigation by MRT. Especially contrast medium (Gd-DTPA) assisted examinations enables a long term follow up and may even show small (muscle strain) and deep lying injuries. (orig.) [de

  16. Comparative study of MR imaging and X-ray in Med-anemia

    International Nuclear Information System (INIS)

    Huang Zhongkui; Long Liling; Song Yingru

    2002-01-01

    Objective: To evaluate the diagnostic value of MRI and X-ray and to analyze MRI and X-ray characteristics in Med-anemia. Methods: MRI was performed in thoracic spine, lumbar spine, sacral spine, pelvis, and superior femurs in 15 patients with pathologically proved Med-anemia with T 1 WI and T 2 WI. Seven of them were examined on X-ray. Twenty volunteers were examined on MR as control group. The authors analyzed the manifestations of MRI in the Med-anemia, including abnormality of signal intensity of bone marrow, T 1 value, vertebral alteration of size and shaped, spinal cord compression due to epidural extramedullary haematopoiesis, and compared with the findings of bone on X-ray. Results: In the control group, bone marrow showed an inhomogeneous iso-signal intensity with band-shaped, triangular or motley high signal intensity in the middle or back part of the vertebra, neck of the femur on T 1 WI and a homogeneous iso-signal intensity on T 2 WI in the vertebra, pelvis, and superior femur. All cases with Med-anemia had low homogenous signal intensity in the bone marrow of the vertebra, pelvis and superior femur on T 1 WI but had no alterations on T 2 WI. The spinal cord was constricted resulting from protruding crushed vertebra with bullet-like shape in 4 cases. The soft tissue masses, confirmed as extramedullary haematopoiesis by operation, were demonstrated in 4 cases. Among 7 cases with X-ray examinations, 2 cases showed normal on X-ray but abnormal bone marrow on MRI, another 5 cases demonstrated bone alteration including osteoporosis, widening of striations, enlargement of ribs and vertebras. T 1 value showed (897.4 +- 75.43) ms in the Med- anemia group and (401.5 +- 28.1) ms in the control group with significant statistical difference (P 1 WI; (2) MRI is useful in demonstrating the space occupying lesion due to vertebral deformity, enlargement of ribs and extramedullary haematopoiesis

  17. MR imaging in recurrent pain after back surgery. A comparative study using standard and high doses of gadolinium contrast agents

    International Nuclear Information System (INIS)

    Aakeson, P.; Jonsson, E.; Holtaas, S.

    1996-01-01

    Purpose: To compare the diagnostic results following injection of (a) a high dose (0.3 mmol/kg b.w.) of gadodiamide injection and (b) the standard dose (0.1 mmol/kg b.w.) of Gd-DTPA, in patients with recurrent symptoms after surgery for lumbar disc herniation. Material and Methods: Twenty patients with recurrent or sustained symptoms after surgery for lumbar disc herniations were examined. MR imaging (0.3 T) was first performed before and after Gd-DTPA at 0.1 mmol/kg b.w., and then within one month (17 patients) or within 3 months (3 patients) before and after gadodiamide injection at 0.3 mmol/kg b.w. The examinations were first evaluated by 2 neuroradiologists blinded to dose but not to patient as the images were presented in pairs. Six months later the same investigators evaluated the examinations again, this time blinded to both dose and patient. Results: At the evaluation in pairs (with the investigators blinded to dose only) the high-dose examinations were considered the most informative (p=0.05). However, at the later evaluation (with the investigators blinded both to dose and patient) no significant difference between high and standard dose was found regarding diagnosis or diagnostic certainty. Conclusion: In this study the high-dose contrast enhancement of MR imaging at 0.3 T did not increase the diagnostic information for differentiating between scar and recurrent hernia. The high-dose images were considered more informative when evaluated in pairs, but gave no additional or different information when evaluated separately. The study also indicated that comparisons in pairs should be interpreted with caution. (orig.)

  18. MR imaging in recurrent pain after back surgery. A comparative study using standard and high doses of gadolinium contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Aakeson, P. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Annertz, M. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Kristoffersen, D.T. [Nycomed Imaging AS, Oslo (Norway); Jonsson, E. [Nycomed AB, Stockholm (Sweden); Holtaas, S. [Univ. Hospital, Lund (Sweden). Dept. of Radiology

    1996-11-01

    Purpose: To compare the diagnostic results following injection of (a) a high dose (0.3 mmol/kg b.w.) of gadodiamide injection and (b) the standard dose (0.1 mmol/kg b.w.) of Gd-DTPA, in patients with recurrent symptoms after surgery for lumbar disc herniation. Material and Methods: Twenty patients with recurrent or sustained symptoms after surgery for lumbar disc herniations were examined. MR imaging (0.3 T) was first performed before and after Gd-DTPA at 0.1 mmol/kg b.w., and then within one month (17 patients) or within 3 months (3 patients) before and after gadodiamide injection at 0.3 mmol/kg b.w. The examinations were first evaluated by 2 neuroradiologists blinded to dose but not to patient as the images were presented in pairs. Six months later the same investigators evaluated the examinations again, this time blinded to both dose and patient. Results: At the evaluation in pairs (with the investigators blinded to dose only) the high-dose examinations were considered the most informative (p=0.05). However, at the later evaluation (with the investigators blinded both to dose and patient) no significant difference between high and standard dose was found regarding diagnosis or diagnostic certainty. Conclusion: In this study the high-dose contrast enhancement of MR imaging at 0.3 T did not increase the diagnostic information for differentiating between scar and recurrent hernia. The high-dose images were considered more informative when evaluated in pairs, but gave no additional or different information when evaluated separately. The study also indicated that comparisons in pairs should be interpreted with caution. (orig.).

  19. A systematic review of studies comparing body image concerns among female college athletes and non-athletes, 1997-2012.

    Science.gov (United States)

    Varnes, Julia R; Stellefson, Michael L; Janelle, Christopher M; Dorman, Steven M; Dodd, Virginia; Miller, M David

    2013-09-01

    Research prior to 2001 indicated that athletes experienced better body image than non-athletes, with no differences among sport types. Since then, female athletes have become increasingly sexually objectified in the media, and the sociocultural beauty ideal has shifted to emphasize appearing both athletic and thin. Part I of this paper explores the literature describing these changes. Part II presents a systematic and comprehensive literature review of 10 recent studies comparing body image concerns (BIC) among collegiate female athletes and non-athletes to identify the current status of BIC in female athletes. Findings indicate that involvement in collegiate athletics provides some protection from BIC; however, this protection appears attenuated for athletes in more feminine sports (e.g., gymnastics), and higher level athletes (Division I). Researchers should examine how sociocultural pressures unrelated to competition predict female athletes' BIC using measures that focus on objectification, positive body image, body functionality, and thin- and athletic-ideal internalization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. The cervical spinal cord in neuromyelitis optica patients: A comparative study with multiple sclerosis using diffusion tensor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pessôa, Fernanda Miraldi Clemente, E-mail: fernandamiraldi@hotmail.com [Federal University of Rio de Janeiro, Medical Student, Rua Rodolpho Paulo Rocco, 255, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Lopes, Fernanda Cristina Rueda, E-mail: frueda81@hotmail.com [Department of Radiology, Federal University of Rio de Janeiro, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); Costa, João Victor Altamiro, E-mail: victoraltamiro@gmail.com [Department of Radiology, Federal University of Rio de Janeiro, Rua Rodolpho Paulo Rocco, 255, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Leon, Soniza Vieira Alves, E-mail: sonizavleon@globo.com [Department of Neurology, Federal University of Rio de Janeiro, Rua Rodolpho Paulo Rocco, 255, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Domingues, Romeu Côrtes, E-mail: romeu@CDPi.com.br [CDPI – Clínica de Diagnóstico Por Imagem, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); Gasparetto, Emerson Leandro, E-mail: egasparetto@gmail.com [Department of Radiology, Federal University of Rio de Janeiro, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); CDPI – Clínica de Diagnóstico Por Imagem, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil)

    2012-10-15

    Introduction: This study aims to evaluate “in vivo” the integrity of the normal-appearing spinal cord in patients with neuromyelitis optica (NMO), using diffusion tensor MR imaging, comparing to controls and patients with multiple sclerosis (MS). Materials and methods: We studied 8 patients with NMO and 17 without any neurologic disorder. Also, 32 MS patients were selected. Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD) were calculated within regions of interest at C2 and C7 levels in the four columns of the spinal cord. Results: At C2, the FA value was decreased in NMO patients compared to MS and controls in the anterior column. Also in this column, RD value showed increase in NMO compared to MS and to controls. The FA value of the posterior column was decreased in NMO in comparison to controls. At C7, AD value was higher in NMO than in MS in the right column. At the same column, MD values were increased in NMO compared to MS and to controls. Conclusions: There is extensive NASC damage in NMO patients, including peripheral areas of the cervical spinal cord, affecting the white matter, mainly caused by demyelination. This suggests a new spinal cord lesion pattern in NMO in comparison to MS.

  1. Coronary artery size and origin imaging in children: a comparative study of MRI and trans-thoracic echocardiography

    International Nuclear Information System (INIS)

    Hussain, Tarique; Mathur, Sujeev; Peel, Sarah A.; Valverde, Israel; Bilska, Karolina; Henningsson, Markus; Botnar, Rene M.; Simpson, John; Greil, Gerald F.

    2015-01-01

    The purpose of this study was to see how coronary magnetic resonance angiography (CMRA) compared to echocardiography for the detection of coronary artery origins and to compare CMRA measurements for coronary dimensions in children with published echocardiographic reference values. Enrolled patients underwent dual cardiac phase CMRA and echocardiography under the same anesthetic. Echocardiographic measurements of the right coronary artery (RCA), left anterior descending (LAD) and left main (LM) were made. CMRA dimensions were assessed manually at the same points as the echocardiographic measurements. The number of proximal LAD branches imaged was also recorded in order to give an estimate of distal coronary tree visualization. Fifty patients (24 boys, mean age 4.0 years (range 18 days to 18 years)) underwent dual-phase CMRA. Coronary origins were identified in 47/50 cases for CMRA (remaining 3 were infants aged 3, 9 and 11 months). In comparison, origins were identified in 41/50 cases for echo (remaining were all older children). CMRA performed better than echocardiography in terms of distal visualization of the coronary tree (median 1 LAD branch vs. median 0; p = 0.001). Bland-Altman plots show poor agreement between echocardiography and CMRA for coronary measurements. CMRA measurements did vary according to cardiac phase (systolic mean 1.90, s.d. 0.05 mm vs. diastolic mean 1.84, s.d. 0.05 mm; p = 0.002). Dual-phase CMRA has an excellent (94 %) success rate for the detection of coronary origins in children. Newborn infants remain challenging and echocardiography remains the accepted imaging modality for this age group. Echocardiographic reference ranges are not applicable to CMRA measurements as agreement was poor between modalities. Future coronary reference values, using any imaging modality, should quote the phase in which it was measured

  2. Computed tomography compared to magnetic resonance imaging in occult or suspect hip fractures. A retrospective study in 44 patients

    Energy Technology Data Exchange (ETDEWEB)

    Collin, David; Goethlin, Jan H. [Sahlgrenska University Hospital, Department of Radiology, Moelndal (Sweden); Geijer, Mats [Lund University, Department of Medical Imaging and Physiology, Skaane University Hospital, Lund (Sweden)

    2016-11-15

    Computed tomography (CT) for evaluation of occult and suspect hip fractures has been proposed as a good second-line investigation. The diagnostic precision compared to magnetic resonance imaging (MRI) is unclear. To compare the diagnostic performance of CT and MRI in a retrospective study on patients with suspect and occult hip fractures. Forty-four elderly consecutive patients with low-energy trauma to the hip were identified where negative or suspect CT was followed by MRI. Primary reporting and review by two observers as well as the diagnostic performance of the two modalities were compared. Surgical treatment and clinical course were used as outcomes. Compared to the primary reports, the CT reviewers found fewer normal and no suspect cases. MRI changed the primary diagnoses in 27 cases, and in 14 and 15 cases, respectively, at review. There was no disagreement on MRI diagnoses. In our patient population, MRI was deemed a more reliable modality for hip fracture diagnosis in comparison to CT. For clinical decision making, MRI seems to have a higher accuracy than CT. A negative CT finding cannot completely rule out a hip fracture in patients where clinical findings of hip fracture persevere. (orig.)

  3. Multimodal imaging in the elastase-induced aneurysm model in rabbits: a comparative study using serial DSA, MRA and CTA

    International Nuclear Information System (INIS)

    Doerfler, A.; Becker, W.; Wanke, I.; Goericke, S.; Oezkan, N.; Forsting, M.

    2004-01-01

    Background and Purpose: The elastase-induced aneurysm model in rabbits has proved to be suitable for testing new endovascular occlusion devices. The purpose of this study was to evaluate different imaging modalities for the depiction of anatomy and size of elastase-induced aneurysms and for serial follow-up imaging. Materials and Methods: Elastase-induced aneurysms were created in eight Chinchilla bastard rabbits by endoluminal incubation of porcine elastase. Serial imaging was performed using intravenous DSA (IVDSA), contrast-enhanced MRA (CEMRA), and time-of-flight MRA (TOF) 14 days, 4 weeks and 3 months after aneurysm creation. Intraarterial DSA (IADSA) and CT angiography (CTA) were performed after 3 months. Aneurysm size and geometry (height H, width W, neck width N) were compared. Results: On IVDSA after two weeks mean aneurysm height was 6.2 mm (range 2.8-11.0 mm), mean aneurysm neck width was 2.7 mm (range 2.0-4.2 mm) and mean aneurysm neck width was 2.7 mm (range 2.0-4.2 mm). We did not observed any statistically significant change in aneurysm dimensions during follow-up at 4 weeks (CEMRA: H: 5.4, W: 2.4, N: 2.4; TOF: H: 5.7, W: 2.4, N: 2.7) and 3 months (CEMRA: H: 5.8, W: 2.6, N: 2.6; TOF: H: 6.9, W: 2.8, N: 3.0). Aneurysm dimensions could be best seen on IADSA (H: 6.2, W: 3.0, N: 2.7) with good correlation to CTA (r=0.94; H: 6.1, W: 2.8, N: 2.6), CE-MRA (r=0.92), and TOF (r=0.97). TOF was superior to CEMRA in delineating the aneurysm wall. Conclusions: Serial imaging using MRA, CTA or intravenous and intraarterial angiography is feasible in the elastase-induced aneurysm model. Contrast-enhanced MRA, TOF-MRA and CTA showed good correlation to IADSA and are all suitable for non-invasive pretherapeutic measurement of aneurysm size. (orig.) [de

  4. Comparative study of fast T 2-weighted images using respiratory triggered, breath-hold, fat suppression and phased array multi coil for liver evaluation by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Abbehusen, Cristiane L.; D'Ippolito, Giuseppe; Palacio, Glaucia A.S.; Szejnfeld, Jacob

    2003-01-01

    The objective of this study was to compare both qualitatively and quantitatively six T 2-weighted turbo spin-echo sequences varying the respiratory compensation technique, associating or not fat tissue suppression and using different types of coils. We performed a prospective study of 71 consecutive patients that were submitted to MRI of the liver using a 1.5 T magnet. The six following pulse sequences were used: fat-suppressed respiratory triggered with conventional body coil; breath-hold fat-suppressed with conventional body coil; non-suppressed respiratory triggered with conventional body coil; breath-hold non fat-suppressed with conventional body coil; fat-suppressed respiratory triggered with phased-array multi coil; breath-hold fat-suppressed with phased-array multi coil. Images were analyzed quantitatively by measuring the signal-to-noise ratios and qualitatively by evaluating the sharpness of hepatic contours, visibility of intrahepatic vessels and other segmental landmarks, and the presence of artifacts. Results: the qualitative analysis showed that the mean values obtained with the six sequences were 7.8, 4.6, 7.9, 5.2, 6.7 and 4.6 respectively. The respiratory-triggered sequences were better than the breath-hold sequences in both qualitative and quantitative analysis (p < 0.001). No significant differences in the values of signal-to-noise ratios and in overall image quality were found between the sequences with and without fat suppression (p . 0.05). The sequences using the body coil were similar in terms of image quality (p . 0.05) and better regarding signal-to-noise ratios than those obtained with the phased=array multi coil (p ,0.001). Our qualitative and quantitative results suggest that the best MRI sequences for the valuation of the liver are the sequences with respiratory triggering using a conventional body coil, with or without fat suppression. (author)

  5. A comparative study of brachial plexus sonography and magnetic resonance imaging in chronic inflammatory demyelinating neuropathy and multifocal motor neuropathy

    NARCIS (Netherlands)

    Goedee, H S; Jongbloed, B A; van Asseldonk, J.T.H.; Hendrikse, J; Vrancken, A F J E; Franssen, H; Nikolakopoulos, S; Visser, L H; van der Pol, W L; van den Berg, L H

    2017-01-01

    BACKGROUND AND PURPOSE: To compare the performance of neuroimaging techniques, i.e. high-resolution ultrasound (HRUS) and magnetic resonance imaging (MRI), when applied to the brachial plexus, as part of the diagnostic work-up of chronic inflammatory demyelinating neuropathy (CIDP) and multifocal

  6. Diagnostic accuracy of an artificial neural network compared with statistical quantitation of myocardial perfusion images. A Japanese multicenter study

    International Nuclear Information System (INIS)

    Nakajima, Kenichi; Matsuo, Shinro; Kudo, Takashi; Nakata, Tomoaki; Kiso, Keisuke; Kasai, Tokuo; Taniguchi, Yasuyo; Momose, Mitsuru; Nakagawa, Masayasu; Sarai, Masayoshi; Hida, Satoshi; Tanaka, Hirokazu; Yokoyama, Kunihiko; Okuda, Koichi; Edenbrandt, Lars

    2017-01-01

    Artificial neural networks (ANN) might help to diagnose coronary artery disease. This study aimed to determine whether the diagnostic accuracy of an ANN-based diagnostic system and conventional quantitation are comparable. The ANN was trained to classify potentially abnormal areas as true or false based on the nuclear cardiology expert interpretation of 1001 gated stress/rest 99m Tc-MIBI images at 12 hospitals. The diagnostic accuracy of the ANN was compared with 364 expert interpretations that served as the gold standard of abnormality for the validation study. Conventional summed stress/rest/difference scores (SSS/SRS/SDS) were calculated and compared with receiver operating characteristics (ROC) analysis. The ANN generated a better area under the ROC curves (AUC) than SSS (0.92 vs. 0.82, p < 0.0001), indicating better identification of stress defects. The ANN also generated a better AUC than SDS (0.90 vs. 0.75, p < 0.0001) for stress-induced ischemia. The AUC for patients with old myocardial infarction based on rest defects was 0.97 (0.91 for SRS, p = 0.0061), and that for patients with and without a history of revascularization based on stress defects was 0.94 and 0.90 (p = 0.0055 and p < 0.0001 vs. SSS, respectively). The SSS/SRS/SDS steeply increased when ANN values (probability of abnormality) were >0.80. The ANN was diagnostically accurate in various clinical settings, including that of patients with previous myocardial infarction and coronary revascularization. The ANN could help to diagnose coronary artery disease. (orig.)

  7. Diagnostic accuracy of an artificial neural network compared with statistical quantitation of myocardial perfusion images. A Japanese multicenter study

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Kenichi; Matsuo, Shinro [Kanazawa University Hospital, Kanazawa (Japan); Kudo, Takashi [Nagasaki University Hospital, Nagasaki (Japan); Nakata, Tomoaki [Hakodate Goryoukaku Hospital, Hakodate (Japan); Kiso, Keisuke [National Cerebral and Cardiovascular Center, Suita (Japan); Kasai, Tokuo [Tokyo Medical University Hachioji Medical Center, Hachioji (Japan); Taniguchi, Yasuyo [Hyogo Brain and Heart Center, Himeji (Japan); Momose, Mitsuru [Tokyo Women' s Medical University, Tokyo (Japan); Nakagawa, Masayasu [Akita City Hospital, Akita (Japan); Sarai, Masayoshi [Fujita Health University Hospital, Toyoake (Japan); Hida, Satoshi [Tokyo Medical University Hospital, Tokyo (Japan); Tanaka, Hirokazu [Tokyo Medical University Ibaraki Medical Center, Ibaraki (Japan); Yokoyama, Kunihiko [Public Central Hospital of Matto Ishikawa, Hakusan (Japan); Okuda, Koichi [Kanazawa Medical University, Kahoku (Japan); Edenbrandt, Lars [University of Gothenburg, Gothenburg (Sweden)

    2017-12-15

    Artificial neural networks (ANN) might help to diagnose coronary artery disease. This study aimed to determine whether the diagnostic accuracy of an ANN-based diagnostic system and conventional quantitation are comparable. The ANN was trained to classify potentially abnormal areas as true or false based on the nuclear cardiology expert interpretation of 1001 gated stress/rest {sup 99m}Tc-MIBI images at 12 hospitals. The diagnostic accuracy of the ANN was compared with 364 expert interpretations that served as the gold standard of abnormality for the validation study. Conventional summed stress/rest/difference scores (SSS/SRS/SDS) were calculated and compared with receiver operating characteristics (ROC) analysis. The ANN generated a better area under the ROC curves (AUC) than SSS (0.92 vs. 0.82, p < 0.0001), indicating better identification of stress defects. The ANN also generated a better AUC than SDS (0.90 vs. 0.75, p < 0.0001) for stress-induced ischemia. The AUC for patients with old myocardial infarction based on rest defects was 0.97 (0.91 for SRS, p = 0.0061), and that for patients with and without a history of revascularization based on stress defects was 0.94 and 0.90 (p = 0.0055 and p < 0.0001 vs. SSS, respectively). The SSS/SRS/SDS steeply increased when ANN values (probability of abnormality) were >0.80. The ANN was diagnostically accurate in various clinical settings, including that of patients with previous myocardial infarction and coronary revascularization. The ANN could help to diagnose coronary artery disease. (orig.)

  8. A comparative study on the accuracy of digital subtraction radiography according to the acquisition methods of reconstructed images

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Young June; Jeon, In Seong; Heo, Min Suk; Park, Tae Won [College of Dentistry, Seoul National University, Seoul (Korea, Republic of); Lee, Sam Sun; Choi, Soon Chul [Department of Dentistry, Inje University Sanggyepaik Hospital, Seoul (Korea, Republic of); Kim, Jong Dae [Division of Information and Communication Engineering, Hallym University, Chuncheon (Korea, Republic of)

    2002-06-15

    To compare the accuracy of digital subtraction images acquired by two different methods different in positioning four reference points for geometrical standardization. A total of 36 digital radiographic images of 6 volunteers were taken at the areas of the incisor, premolar, and molar of both the maxilla and mandible using the Digora system. Each image was moved 4 mm vertically and horizontally. Four oral and maxillofacial radiologists performed digital subtraction radiography between the paired images before and after movement using Emago (Oral Diagnostic Systems, Amsterdam, The Netherlands) and Sunny (Biomedisys Co., Seoul, Korea). The standard deviation of the internal gray value in Region of Interest (ROI) was statistically analyzed between the two programs using the paired t-test. The standard deviation of pixel gray values from the digital subtraction images using the Sunny program were lower than that of the Emago program (p<0.05). All observers showed significant differences between each other when the Sunny program was used (p<0.05), but one observer showed a significantly higher score than other observers when they used Emago (p<0.05). The standard deviations of premolar area from both Sunny and Emago programs were significantly higher than those of anterior and molar regions (p<0.05). The subtracted images using the Sunny program were more accurate and sensitive than those taken using the Emago program.

  9. Atomic imaging by x-ray-fluorescence holography and electron-emission holography: A comparative theoretical study

    International Nuclear Information System (INIS)

    Len, P.M.; Thevuthasan, S.; Fadley, C.S.; Kaduwela, A.P.; Van Hove, M.A.

    1994-01-01

    We consider from a theoretical viewpoint the direct imaging of atoms at and near the surfaces of solids by both x-ray-fluorescence holography (XFH) and electron-emission holography (EEH). The more ideal nature of x-ray scattering makes XFH images superior to those in single-energy EEH. The overlap of real and twin features for pairs of atoms at ±a can cause their XFH or EEH atomic images to cancel for certain combinations of wave vector and |a|. The relative merits of XFH and EEH for structure studies are considered

  10. Product-country images as stereotypes: A comparative study of Danish food products in Germany and Turkey

    DEFF Research Database (Denmark)

    Askegaard, Søren; Ger, Güliz

    such as schemas and cognitive structures. 2. In this study, we examine product-country images in terms of stereotypes. In order to explore stereotypes of country and product meaning, we conducted research on the meanings pertaining to Denmark and Danish food products in two selected cultures: Germany and Turkey...... with Turkish food culture. 5. Other studies show that Danish exporters tend to have a more positive idea of Danish products' and Denmark's image on export markets than our results can confirm. Thus, there seems to be a clash between the way Danish exporters think others see us and the actual image on export...... of products from other countries, that product and country images do influence each other, and that consumer imagery is an important factor for international economic life....

  11. A randomized study comparing digital imaging to traditional glass slide microscopy for breast biopsy and cancer diagnosis

    Directory of Open Access Journals (Sweden)

    Joann G Elmore

    2017-01-01

    Full Text Available Background: Digital whole slide imaging may be useful for obtaining second opinions and is used in many countries. However, the U.S. Food and Drug Administration requires verification studies. Methods: Pathologists were randomized to interpret one of four sets of breast biopsy cases during two phases, separated by ≥9 months, using glass slides or digital format (sixty cases per set, one slide per case, n = 240 cases. Accuracy was assessed by comparing interpretations to a consensus reference standard. Intraobserver reproducibility was assessed by comparing the agreement of interpretations on the same cases between two phases. Estimated probabilities of confirmation by a reference panel (i.e., predictive values were obtained by incorporating data on the population prevalence of diagnoses. Results: Sixty-five percent of responding pathologists were eligible, and 252 consented to randomization; 208 completed Phase I (115 glass, 93 digital; and 172 completed Phase II (86 glass, 86 digital. Accuracy was slightly higher using glass compared to digital format and varied by category: invasive carcinoma, 96% versus 93% (P = 0.04; ductal carcinoma in situ (DCIS, 84% versus 79% (P < 0.01; atypia, 48% versus 43% (P = 0.08; and benign without atypia, 87% versus 82% (P < 0.01. There was a small decrease in intraobserver agreement when the format changed compared to when glass slides were used in both phases (P = 0.08. Predictive values for confirmation by a reference panel using glass versus digital were: invasive carcinoma, 98% and 97% (not significant [NS]; DCIS, 70% and 57% (P = 0.007; atypia, 38% and 28% (P = 0.002; and benign without atypia, 97% and 96% (NS. Conclusions: In this large randomized study, digital format interpretations were similar to glass slide interpretations of benign and invasive cancer cases. However, cases in the middle of the spectrum, where more inherent variability exists, may be more problematic in digital format. Future

  12. Assessment of periapical status : a comparative study using film-based periapical radiographs and digital panoramic images

    OpenAIRE

    Ríos Santos, José Vicente; Ridao Sacie, Cristina; Bullón, Pedro; Fernández Palacín, Ana; Segura-Egea, Juan J.

    2010-01-01

    Aim: To compare the use of film-based periapical radiographs and digital panoramic images displayed on monitor and glossy paper in the assessment of the periapical status of the teeth. Methodology: A total of 86 subjects were examined. All participants underwent a full-mouth radiographic survey (14 periapical radiographs) and a digital panoramic radiography. The periapical status of all appraised teeth was assessed. Results: Periapical radiographs allowed the assessment of the periapical ...

  13. Geometry-based vs. intensity-based medical image registration: A comparative study on 3D CT data.

    Science.gov (United States)

    Savva, Antonis D; Economopoulos, Theodore L; Matsopoulos, George K

    2016-02-01

    Spatial alignment of Computed Tomography (CT) data sets is often required in numerous medical applications and it is usually achieved by applying conventional exhaustive registration techniques, which are mainly based on the intensity of the subject data sets. Those techniques consider the full range of data points composing the data, thus negatively affecting the required processing time. Alternatively, alignment can be performed using the correspondence of extracted data points from both sets. Moreover, various geometrical characteristics of those data points can be used, instead of their chromatic properties, for uniquely characterizing each point, by forming a specific geometrical descriptor. This paper presents a comparative study reviewing variations of geometry-based, descriptor-oriented registration techniques, as well as conventional, exhaustive, intensity-based methods for aligning three-dimensional (3D) CT data pairs. In this context, three general image registration frameworks were examined: a geometry-based methodology featuring three distinct geometrical descriptors, an intensity-based methodology using three different similarity metrics, as well as the commonly used Iterative Closest Point algorithm. All techniques were applied on a total of thirty 3D CT data pairs with both known and unknown initial spatial differences. After an extensive qualitative and quantitative assessment, it was concluded that the proposed geometry-based registration framework performed similarly to the examined exhaustive registration techniques. In addition, geometry-based methods dramatically improved processing time over conventional exhaustive registration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. A retrospective comparative study of cone-beam computed tomography versus rendered panoramic images in identifying the presence, types, and characteristics of dens invaginatus in a Turkish population.

    Science.gov (United States)

    Capar, Ismail Davut; Ertas, Huseyin; Arslan, Hakan; Tarim Ertas, Elif

    2015-04-01

    This study assessed the presence, characteristics, and type of dens invaginatus (DI) by using cone-beam computed tomography (CBCT) and panoramic images rendered from CBCT images. In addition, the findings of the imaging techniques were compared. We evaluated 300 CBCT images to determine the type of DI, the presence of an impacted tooth near the DI, and the presence of apical pathosis. The McNemar test was used to compare the prevalence of DI according to CBCT and panoramic images rendered from CBCT images. The presence of DI was lower on panoramic images rendered from CBCT images (3% of the patients) compared with on CBCT images (10.7% of the patients) (P invaginatus (65.9%), followed by type II (29.5%) and type III (4.6%). All patients with type III DI and 25% of the patients with type II DI had apical pathosis at the time of referral, but periapical lesions were not observed in teeth with type I DI. In total, 13.6% of DI cases had impacted teeth. CBCT can be recommended as an effective diagnostic device for identifying DI because it provides an accurate representation of the external and internal dental anatomy. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Comparative study between the radiopacity levels of high viscosity and of flowable composite resins, using digital imaging.

    Science.gov (United States)

    Arita, Emiko S; Silveira, Gilson P; Cortes, Arthur R; Brucoli, Henrique C

    2012-01-01

    The development of countless types and trends of high viscosite and flowable composite resins, with different physical and chemical properties applicable to their broad use in dental clinics calls for further studies regarding their radiopacity level. The aim of this study was to evaluate the radiopacity levels of high viscosity and the flowable composite resins, using digital imaging. 96 composite resin discs 5 mm in diameter and 3 mm thick were radiographed and analyzed. The image acquisition system used was the Digora® Phosphor Storage System and the images were analyzed with the Digora software for Windows. The exposure conditions were: 70 kVp, 8 mA, and 0.2 s. The focal distance was 40 cm. The image densities were obtained with the pixel values of the materials in the digital image. Most of the high viscosity composite resins presented higher radiopacity levels than the flowable composite resins, with statistically significant differences between the trends and groups analyzed (P composite resins, Tetric®Ceram presented the highest radiopacity levels and Glacier® presented the lowest. Among the flowable composite resins, Tetric®Flow presented the highest radiopacity levels and Wave® presented the lowest.

  16. Indium-111 antimyosin antibody imaging and thallium-201 imaging. A comparative myocardial scintigraphic study using single-photon emission computed tomography in patients with myocarditis and dilated cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Takehiko; Matsumori, Akira; Nohara, Ryuji; Konishi, Junji; Sasayama, Shigetake [Kyoto Univ. (Japan). Faculty of Medicine; Tamaki, Nagara

    1997-10-01

    Indium-111 antimyosin antibody imaging (a tracer of myocardial necrosis) and thallium-201 imaging (a tracer of myocardial perfusion) were compared in patients with myocarditis and dilated cardiomyopathy. The distribution of each tracer and antimyosin/thallium-201 overlapping were evaluated with single-photon emission computed tomography (SPECT). Scintigraphic data were classified into 5 patterns according to the distribution of both images and were compared with histologic findings of endomyocardial biopsy: AM-D, intense and diffuse antimyosin uptake and no perfusion abnormality (active myocarditis); AM-L, localized antimyosin uptake and no perfusion abnormality (active myocarditis); HM, no antimyosin uptake with or without perfusion abnormality (healed myocarditis); DCM-NH, diffuse antimyosin uptake and inhomogeneous thallium-201 uptake (dilated cardiomyopathy); DCM-PD, diffuse or localized antimyosin uptake and myocardial perfusion defect(s) (dilated cardiomyopathy). Patients with dilated-phase hypertrophic cardiomyopathy were frequently found in the DCM-PD group. Taken together, comparative antimyosin/thallium-201 SPECT images are useful for evaluating the activity of myocarditis and ongoing myocardial damage even in areas with no perfusion in patients with dilated cardiomyopathy. (author)

  17. Computed tomography versus intravenous urography in diagnosis of acute flank pain from urolithiasis: a randomized study comparing imaging costs and radiation dose

    International Nuclear Information System (INIS)

    Thomson, J.M.Z.; Maling, T.M.J.; Glocer, J.; Mark, S.; Abbott, C.

    2001-01-01

    The equivalent sensitivity of non-contrast computed tomography (NCCT) and intravenous urography (IVU) in the diagnosis of suspected ureteric colic has been established. Approximately 50% of patients with suspected ureteric colic do not have a nephro-urological cause for pain. Because many such patients require further imaging studies, NCCT may obviate the need for these studies and, in so doing, be more cost effective and involve less overall radiation exposure. The present study compares the total imaging cost and radiation dose of NCCT versus IVU in the diagnosis of acute flank pain. Two hundred and twenty-four patients (157 men; mean age 45 years; age range 19-79 years) with suspected renal colic were randomized either to NCCT or IVU. The number of additional diagnostic imaging studies, cost (IVU A$ 136; CTU A$ 173), radiation exposure and imaging times were compared. Of 119(53%) patients with renal obstruction, 105 had no nephro-urological causes of pain. For 21 (20%) of these patients an alternative diagnosis was made at the initial imaging, 10 of which were significant. Of 118 IVU patients, 28 (24%) required 32 additional imaging tests to reach a diagnosis, whereas seven of 106 (6%) NCCT patients required seven additional imaging studies. The average total diagnostic imaging cost for the NCCT group was A$181.94 and A$175.46 for the IVU group (P< 0.43). Mean radiation dose to diagnosis was 5.00 mSv (NCCT) versus 3.50 mSv (IVU) (P < 0.001). Mean imaging time was 30 min (NCCT) versus 75 min (IVU) (P < 0.001). Diagnostic imaging costs were remarkably similar. Although NCCT involves a higher radiation dose than IVU, its advantages of faster diagnosis, the avoidance of additional diagnostic imaging tests and its ability to diagnose other causes makes it the study of choice for acute flank pain at Christchurch Hospital. Copyright (2001) Blackwell Science Pty Ltd

  18. Image of Nursing Profession as Perceived by Egyptian and Jordanian Undergraduate Male Nursing Students: A Comparative Study

    Science.gov (United States)

    Ibrahim, Azza Fathi; Akel, Dalal Talat; Alzghoul, Husam Wasil Mohammed

    2015-01-01

    The hiring and maintaining of male nurses in the nursing field is a very apparent issue nowadays. Hence, there is an urgent need to promote a professional nursing image and enhance its standing in the community, especially for men. Although they have an important position in nursing, men are still proportionately in the minority. This study aimed…

  19. Prostate cancer: a comparative study of {sup 11}C-choline PET and MR imaging combined with proton MR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Takako; Lee, Jin; Takahashi, Nobukazu; Oka, Takashi; Shizukuishi, Kazuya; Inoue, Tomio [Yokohama City University School of Medicine, Department of Radiology, Yokohama (Japan); Uemura, Hiroji; Kubota, Yoshinobu [Yokohama City University School of Medicine, Department of Urology, Kanagawa (Japan); Sasaki, Takeshi [Yokohama City University School of Medicine, Department of Pathology, Kanagawa (Japan); Endou, Hisashi [Yokohama City University School of Medicine, Department of Pharmacy, Kanagawa (Japan)

    2005-07-01

    Prostate cancer is difficult to visualise in its early stages using current imaging technology. The present study aimed to clarify the utility of {sup 11}C-choline PET for localising and evaluating cancer lesions in patients with prostate cancer by conducting a prospective comparison with magnetic resonance (MR) imaging combined with proton MR spectroscopy. PET and MR imaging combined with proton MR spectroscopy were performed in 20 patients with prostate cancer. Correlations among the metabolite ratio of choline + creatine to citrate (Cho+Cr/Ci) on MR spectroscopy, serum PSA and maximum standardised uptake value (SUV{sub max}) of {sup 11}C-choline were assessed. The location of the primary lesion was assessed by the site of SUV{sub max} and the laterality of the highest Cho+Cr/Ci ratio and confirmed by examination of surgical pathology specimens (n=16). PET exhibited a diagnostic sensitivity of 100% (20/20) for primary lesions, while the sensitivities of MR imaging and MR spectroscopy were 60% (12/20) and 65% (13/20), respectively. Weak linear correlations were observed between SUV{sub max} and serum PSA (r=0.52, p<0.05), and between SUV{sub max} and Cho+Cr/Ci ratio (r=0.49, p<0.05). Regarding the localisation of main primary lesions, PET results agreed with pathological findings in 13 patients (81%) ({kappa}=0.59), while MR spectroscopy results were in accordance with pathological findings in eight patients (50%) ({kappa}=0.11). This preliminary study suggests that {sup 11}C-choline PET may provide more accurate information regarding the localisation of main primary prostate cancer lesions than MR imaging/MR spectroscopy. A further clinical study of {sup 11}C-choline PET in a large number of patients suspected of prostate cancer will be necessary to determine the clinical utility of {sup 11}C-choline PET in patients who clinically require biopsy. (orig.)

  20. Experiences that Count: A Comparative Study of the ICTY and SCSL in Shaping the Image of Justice

    Directory of Open Access Journals (Sweden)

    Kristin Xueqin Wu

    2013-01-01

    Full Text Available The legitimacy of international criminal trials is not automatic: it is conditional upon endorsement by local communities. If the very communities involved do not 'feel' a sense of justice, these trials would not only contribute little to the post-conflict peace process, but also create a backlash against these international courts and tribunals, tarnishing the image of international criminal justice. Despite its critical importance, this image management process is still at the stage of trial and error. The first outreach programme, established by the International Criminal Tribunal for the former Yugoslavia (ICTY, has been fighting a losing battle against the Tribunal's poor image in the former Yugoslavia region. In contrast, the Special Court for Sierra Leone (SCSL has been highly praised for promoting a holistic experience of 'just'. What causes these differences, and what could be learnt from them? After comparing the various undertakings by these two ad-hoc tribunals - in terms of outreach strategies, press strategies and resource management - this paper draws three lessons for the permanent International Criminal Court (ICC: gaining acceptance, smoothing communication and boosting judicial efficiency.

  1. Parenchymal lymphoma of the brain on initial MR imaging: A comparative study between primary and secondary brain lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Senocak, Efsun, E-mail: eurger@yahoo.com [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Sihhiye-Ankara (Turkey); Oguz, Kader Karli; Ozgen, Burce [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Sihhiye-Ankara (Turkey); Mut, Melike; Ayhan, Selim; Berker, Mustafa [Hacettepe University, Faculty of Medicine, Department of Neurosurgery (Turkey); Ozdemir, Pinar [Hacettepe University, Faculty of Medicine, Department of Biostatistics and Medical Informatics (Turkey); Cila, Aysenur [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Sihhiye-Ankara (Turkey)

    2011-08-15

    Background and purpose: Parenchymal lymphomatous brain masses have not been investigated considering if they are primary or as a part of systemic lymphoma (secondary) on imaging studies previously. We aimed to determine characteristics of the secondary parenchymal lymphomatous involvement of the brain and to find if there is any radiologic feature to help discrimination of untreated primary and secondary central nervous system lymphoma on patients' initial magnetic resonance imaging. Materials and methods: We evaluated MR images of 18 patients with the diagnosis of primary (n = 12) and secondary central nervous system lymphoma (n = 6). We considered the number, localization, enhancement pattern, signal characteristics, diffusion properties, presence of hemorrhage and presence of butterfly pattern on MR imaging at initial presentation. Results: Secondary central nervous system lymphomas predominantly presented as multiple (n = 4, 66.7%) lesions. Homogenous nodular enhancement and supratentorial white matter involvement were present in all patients with butterfly pattern and infiltrative/perivenular enhancement in half (n = 3) of the patients. Deep gray matter (n = 1, 16.7%) and infratentorial involvement (n = 1, 16.7%) were scarce and no ring enhancement was observed. There was no statistically significant difference in any of the investigated MR features between the two groups. Conclusion: Statistical analyses revealed no significant distinctive radiologic characteristics between primary and secondary lymphoma of the brain parenchyma.

  2. Computed tomography versus intravenous urography in diagnosis of acute flank pain from urolithiasis: a randomized study comparing imaging costs and radiation dose.

    Science.gov (United States)

    Thomson, J M; Glocer, J; Abbott, C; Maling, T M; Mark, S

    2001-08-01

    The equivalent sensitivity of non-contrast computed tomography (NCCT) and intravenous urography (IVU) in the diagnosis of suspected ureteric colic has been established. Approximately 50% of patients with suspected ureteric colic do not have a nephro-urological cause for pain. Because many such patients require further imaging studies, NCCT may obviate the need for these studies and, in so doing, be more cost effective and involve less overall radiation exposure. The present study compares the total imaging cost and radiation dose of NCCT versus IVU in the diagnosis of acute flank pain. Two hundred and twenty-four patients (157 men; mean age 45 years; age range 19-79 years) with suspected renal colic were randomized either to NCCT or IVU. The number of additional diagnostic imaging studies, cost (IVU A$136; CTU A$173), radiation exposure and imaging times were compared. Of 119 (53%) patients with renal obstruction, 105 had no nephro-urological causes of pain. For 21 (20%) of these patients an alternative diagnosis was made at the initial imaging, 10 of which were significant. Of 118 IVU patients, 28 (24%) required 32 additional imaging tests to reach a diagnosis, whereas seven of 106 (6%) NCCT patients required seven additional imaging studies. The average total diagnostic imaging cost for the NCCT group was A$181.94 and A$175.46 for the IVU group (P IVU) (P IVU) (P IVU, its advantages of faster diagnosis, the avoidance of additional diagnostic imaging tests and its ability to diagnose other causes makes it the study of choice for acute flank pain at Christchurch Hospital.

  3. The comparative study of MR perfusion-weighted imaging and 1H-MR spectroscopy in diagnosing soft tissue tumors

    International Nuclear Information System (INIS)

    Zhang Li'na; Wang Shaowu; Song Qingwei; Sun Meiyu

    2008-01-01

    Objective: To evaluate multiple magnetic resonance (MR) imaging techniques in the differentiation of benign and malignant soft tissue tumors by comparing different information from MR perfusion-weighted Imaging (MR-PWI) and 1 HMR spectroscopy ( 1 H-MRS). Methods: Forty patients with soft tissue tumors underwent conventional MR imaging, dynamic contrast-enhanced T 2 * -weighted MR-PWI and 1 H proton MR spectroscopy. The differences of perfusion and 1 H-MRS parameters of benign and malignant tumors were analyzed with t test. Results: There was significant difference between benign and malignant tumoral tissues of BF value and Cho/Cr ratio (t=2.531, 2.927, P -1 ·min -1 , sensitivity and specificity for determining malignant tumors were 81.8% (18/22), 72.2% (13/18), respectively. When the threshold value of Cho/Cr ratio was 3.22, Sensitivity and specificity for determining malignant tumors were 86.4% (19/22), 88.9% (16/18), respectively. The abnormal wave crest is detected at 2.0-2.1 ppm in 5 malignant tumors (2 malignant schwannoma and 3 malignant fibrous histiocytoma), while the other 55 cases were not. Conclusion: The BF value and Cho/Cr ratio were both valuable diagnostic parameters in differentiating benign and malignant soft tissue tumors. TIC was helpful to distinguish malignant tumors from benign tumors, while the sensitivity and specificity of 1 H-MRS in diagnosing malignant soft tissue tumors were both higher. (authors)

  4. Evaluation of meniscal repair with serial magnetic resonance imaging: a comparative study between conventional MRI and indirect MR arthrography

    International Nuclear Information System (INIS)

    Hantes, Michael E.; Zachos, Vasilios C.; Zibis, Aristidis H.; Papanagiotou, Panagiotis; Karahalios, Theophilos; Malizos, Konstantinos N.; Karantanas, Apostolos H.

    2004-01-01

    Objective: To prospectively investigate the healing process of meniscal repair with plain magnetic resonance imaging (MRI) and indirect MR arthrography and to compare the two methods. Materials and methods: Twenty patients with an arthroscopic meniscal repair without clinical symptoms underwent conventional and indirect MR arthrography of the affected knee, 3, 6 and 12 months after the index operation applying a T1-w Spin Echo sequence in three planes. The size of the tear gap was measured on transverse images. The signal-to-noise ratio and the configuration of the abnormal signal were evaluated in the coronal images. Results: All patients demonstrated abnormal signal intensity at the side of the meniscal repair. The size of the gap at the previous tear side, reduced significantly by 45 and 40% on conventional MRI and indirect MR arthrography respectively, from 3 months to 1 year (P<0.05). The signal-to-noise ratio of the intrameniscal abnormal signal reduced significantly and approximately 50% from 3 to 6 months, and from 6 to 12 months postoperatively, as demonstrated with indirect MR arthrography. However, as opposed to normal meniscus, the signal-to-noise ratio of the abnormal area remains 5.5 times higher 12 months postoperatively. In contrast, the reduction of signal-to-noise ratio of the abnormal area at conventional MRI was not significant even from 3 to 12 months. In 90% of the cases, the indirect MR arthrography showed the intrameniscal abnormal signal on plain MRI, to extend to the articular surface as opposed to 25% on plain MRI. Conclusion: With indirect MR arthrography, the natural process of meniscal healing can be evaluated. Significant reduction of the size of the tear gap and significant reduction of the signal-to-noise ratio of the abnormal signal as well as its configuration are the main parameters interpretating the normal healing process

  5. Evaluation of meniscal repair with serial magnetic resonance imaging: a comparative study between conventional MRI and indirect MR arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Hantes, Michael E. E-mail: hantesmi@otenet.gr; Zachos, Vasilios C.; Zibis, Aristidis H.; Papanagiotou, Panagiotis; Karahalios, Theophilos; Malizos, Konstantinos N.; Karantanas, Apostolos H

    2004-06-01

    Objective: To prospectively investigate the healing process of meniscal repair with plain magnetic resonance imaging (MRI) and indirect MR arthrography and to compare the two methods. Materials and methods: Twenty patients with an arthroscopic meniscal repair without clinical symptoms underwent conventional and indirect MR arthrography of the affected knee, 3, 6 and 12 months after the index operation applying a T1-w Spin Echo sequence in three planes. The size of the tear gap was measured on transverse images. The signal-to-noise ratio and the configuration of the abnormal signal were evaluated in the coronal images. Results: All patients demonstrated abnormal signal intensity at the side of the meniscal repair. The size of the gap at the previous tear side, reduced significantly by 45 and 40% on conventional MRI and indirect MR arthrography respectively, from 3 months to 1 year (P<0.05). The signal-to-noise ratio of the intrameniscal abnormal signal reduced significantly and approximately 50% from 3 to 6 months, and from 6 to 12 months postoperatively, as demonstrated with indirect MR arthrography. However, as opposed to normal meniscus, the signal-to-noise ratio of the abnormal area remains 5.5 times higher 12 months postoperatively. In contrast, the reduction of signal-to-noise ratio of the abnormal area at conventional MRI was not significant even from 3 to 12 months. In 90% of the cases, the indirect MR arthrography showed the intrameniscal abnormal signal on plain MRI, to extend to the articular surface as opposed to 25% on plain MRI. Conclusion: With indirect MR arthrography, the natural process of meniscal healing can be evaluated. Significant reduction of the size of the tear gap and significant reduction of the signal-to-noise ratio of the abnormal signal as well as its configuration are the main parameters interpretating the normal healing process.

  6. Comparative analysis of MR imaging, Ictal SPECT and EEG in temporal lobe epilepsy: a prospective IAEA multi-center study

    International Nuclear Information System (INIS)

    Zaknun, John J.; Bal, Chandrasekhar; Maes, Alex; Tepmongkol, Supatporn; Vazquez, Silvia; Dupont, Patrick; Dondi, Maurizio

    2008-01-01

    MR imaging, ictal single-photon emission CT (SPECT) and ictal EEG play important roles in the presurgical localization of epileptic foci. This multi-center study was established to investigate whether the complementary role of perfusion SPECT, MRI and EEG for presurgical localization of temporal lobe epilepsy could be confirmed in a prospective setting involving centers from India, Thailand, Italy and Argentina. We studied 74 patients who underwent interictal and ictal EEG, interictal and ictal SPECT and MRI before surgery of the temporal lobe. In all but three patients, histology was reported. The clinical outcome was assessed using Engel's classification. Sensitivity values of all imaging modalities were calculated, and the add-on value of SPECT was assessed. Outcome (Engel's classification) in 74 patients was class I, 89%; class II, 7%; class III, 3%; and IV, 1%. Regarding the localization of seizure origin, sensitivity was 84% for ictal SPECT, 70% for ictal EEG, 86% for MRI, 55% for interictal SPECT and 40% for interictal EEG. Add-on value of ictal SPECT was shown by its ability to correctly localize 17/22 (77%) of the seizure foci missed by ictal EEG and 8/10 (80%) of the seizure foci not detected by MRI. This prospective multi-center trial, involving centers from different parts of the world, confirms that ictal perfusion SPECT is an effective diagnostic modality for correctly identifying seizure origin in temporal lobe epilepsy, providing complementary information to ictal EEG and MRI. (orig.)

  7. A comparative study of seed localization and dose calculation on pre- and post-implantation ultrasound and CT images for low-dose-rate prostate brachytherapy

    International Nuclear Information System (INIS)

    Ali, Imad; Algan, Ozer; Thompson, Spencer; Sindhwani, Puneet; Herman, Terence; Cheng, C.-Y.; Ahmad, Salahuddin

    2009-01-01

    This work investigates variation in the volume of the prostate measured at different stages through the prostate brachytherapy procedure for 30 patients treated with I-125 radioactive seeds. The implanted seeds were localized on post-implantation ultrasound (US) images and the effect of prostate enlargement due to edema on dose coverage for 15 patients was studied. The volume of the prostate was measured at four stages as follows: (a) 2-3 weeks prior to implantation using US imaging, (b) then at the start of the intra-operative prostate brachytherapy procedure on the day of the implant, (c) immediately post-implantation using US imaging in the operating room and (d) finally by CT imaging at nearly 4 weeks post-implantation. Comparative prostate volume studies were performed using US imaging stepper and twister modes. For the purpose of this study, the implanted seeds were localized successfully on post-implant ultrasound twister images, retrospectively. The plans using post-implant US imaging were compared with intra-operative plans on US and plans created on CT images. The prostate volume increases about 10 cm 3 on average due to edema induced by needle insertion and seed loading during implantation. The visibility of the implanted seeds on US twister images acquired post-implantation is as good as those on CT images and can be localized and used for dose calculation. The dose coverage represented by parameters such as D90 (dose covering 90% of the volume) and V100 (volume covered by 100% dose) is poorer on plans performed on post-implantation twister US studies than on the intra-operative live plan or the CT scan performed 4 weeks post-operatively. For example, the mean D90 difference on post-implantation US is lower by more than 15% than that on pre-implantation US. The volume enlargement of the prostate due to edema induced by needle insertion and seed placement has a significant effect on the quality of dosimetric coverage in brachytherapy prostate seed

  8. A comparative study of seed localization and dose calculation on pre- and post-implantation ultrasound and CT images for low-dose-rate prostate brachytherapy

    Science.gov (United States)

    Ali, Imad; Algan, Ozer; Thompson, Spencer; Sindhwani, Puneet; Herman, Terence; Cheng, Chih-Yao; Ahmad, Salahuddin

    2009-09-01

    This work investigates variation in the volume of the prostate measured at different stages through the prostate brachytherapy procedure for 30 patients treated with I-125 radioactive seeds. The implanted seeds were localized on post-implantation ultrasound (US) images and the effect of prostate enlargement due to edema on dose coverage for 15 patients was studied. The volume of the prostate was measured at four stages as follows: (a) 2-3 weeks prior to implantation using US imaging, (b) then at the start of the intra-operative prostate brachytherapy procedure on the day of the implant, (c) immediately post-implantation using US imaging in the operating room and (d) finally by CT imaging at nearly 4 weeks post-implantation. Comparative prostate volume studies were performed using US imaging stepper and twister modes. For the purpose of this study, the implanted seeds were localized successfully on post-implant ultrasound twister images, retrospectively. The plans using post-implant US imaging were compared with intra-operative plans on US and plans created on CT images. The prostate volume increases about 10 cm3 on average due to edema induced by needle insertion and seed loading during implantation. The visibility of the implanted seeds on US twister images acquired post-implantation is as good as those on CT images and can be localized and used for dose calculation. The dose coverage represented by parameters such as D90 (dose covering 90% of the volume) and V100 (volume covered by 100% dose) is poorer on plans performed on post-implantation twister US studies than on the intra-operative live plan or the CT scan performed 4 weeks post-operatively. For example, the mean D90 difference on post-implantation US is lower by more than 15% than that on pre-implantation US. The volume enlargement of the prostate due to edema induced by needle insertion and seed placement has a significant effect on the quality of dosimetric coverage in brachytherapy prostate seed

  9. Comparative study on identification of healthy and osteoarthritic articular cartilages by fourier transform infrared imaging and chemometrics methods

    Directory of Open Access Journals (Sweden)

    Zhi-Hua Mao

    2017-05-01

    Full Text Available Two discriminant methods, partial least squares-discriminant analysis (PLS-DA and Fisher’s discriminant analysis (FDA, were combined with Fourier transform infrared imaging (FTIRI to differentiate healthy and osteoarthritic articular cartilage in a canine model. Osteoarthritic cartilage had been developed for up to two years after the anterior cruciate ligament (ACL transection in one knee. Cartilage specimens were sectioned into 10 μm thickness for FTIRI. A PLS-DA model was developed after spectral pre-processing. All IR spectra extracted from FTIR images were calculated by PLS-DA with the discriminant accuracy of 90%. Prior to FDA, principal component analysis (PCA was performed to decompose the IR spectral matrix into informative principal component matrices. Based on the different discriminant mechanism, the discriminant accuracy (96% of PCA-FDA with high convenience was higher than that of PLS-DA. No healthy cartilage sample was mis-assigned by these two methods. The above mentioned suggested that both integrated technologies of FTIRI-PLS-DA and, especially, FTIRI-PCA-FDA could become a promising tool for the discrimination of healthy and osteoarthritic cartilage specimen as well as the diagnosis of cartilage lesion at microscopic level. The results of the study would be helpful for better understanding the pathology of osteoarthritics.

  10. Histological, magnetic resonance imaging, and discographic findings on cervical disc degeneration in cadaver spines. A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Yuichiro [Juntendo Univ., Tokyo (Japan). School of Medicine

    1995-11-01

    A total of 210 cervical intervertebral discs were taken at autopsy from 36 cadavers, and underwent both magnetic resonance imaging (MRI) and discography to compare their diagnostic efficacies for investigating degenerative changes in the cervical spine. The age of the subjects had ranged from 43 to 92 years with an average of 68.1 years. Following the autopsy, MRI and discography were performed on the excised cervical spinal column, and the specimen was then prepared for histological examination. The findings were compared with those of the lumbar spine that had previously been reported by Yasuma et al. on 1238 lumbar discs from 197 cadavers ranging in age from 11 to 92 years. The results were as follows: Low intensity in the T2-weighted MRI was well correlated with histological degeneration in the cervical disc. The rate of appearance of the posterior protrusion of the cervical disc on the MRI was in accordance with the degree of histological disc degeneration, but it did not always correspond with histological posterior protrusion. There was a remarkably high incidence for false-positive posterior protrusion on the MRI, which should be kept in mind on reading the MRI. In the comparison of the MRI with the discography, a certain positive correlation was found as for disc degeneration, but not in complete accordance. There was a considerable difference in the patterns of degeneration and in posterior protrusion of the discs between the cervical spine and the lumbar spine. The posterior protrusion in the cervical disc was more likely related to horizontal fissure and hyalinization of the posterior annulus, while posterior protrusion in the lumbar disc was often related to reversed orientation of the bundles and myxomatous degeneration of the posterior annulus. This difference was attributed to the difference in the mechanical properties of the cervical and lumbar spines. (author).

  11. Histological, magnetic resonance imaging, and discographic findings on cervical disc degeneration in cadaver spines. A comparative study

    International Nuclear Information System (INIS)

    Maruyama, Yuichiro

    1995-01-01

    A total of 210 cervical intervertebral discs were taken at autopsy from 36 cadavers, and underwent both magnetic resonance imaging (MRI) and discography to compare their diagnostic efficacies for investigating degenerative changes in the cervical spine. The age of the subjects had ranged from 43 to 92 years with an average of 68.1 years. Following the autopsy, MRI and discography were performed on the excised cervical spinal column, and the specimen was then prepared for histological examination. The findings were compared with those of the lumbar spine that had previously been reported by Yasuma et al. on 1238 lumbar discs from 197 cadavers ranging in age from 11 to 92 years. The results were as follows: Low intensity in the T2-weighted MRI was well correlated with histological degeneration in the cervical disc. The rate of appearance of the posterior protrusion of the cervical disc on the MRI was in accordance with the degree of histological disc degeneration, but it did not always correspond with histological posterior protrusion. There was a remarkably high incidence for false-positive posterior protrusion on the MRI, which should be kept in mind on reading the MRI. In the comparison of the MRI with the discography, a certain positive correlation was found as for disc degeneration, but not in complete accordance. There was a considerable difference in the patterns of degeneration and in posterior protrusion of the discs between the cervical spine and the lumbar spine. The posterior protrusion in the cervical disc was more likely related to horizontal fissure and hyalinization of the posterior annulus, while posterior protrusion in the lumbar disc was often related to reversed orientation of the bundles and myxomatous degeneration of the posterior annulus. This difference was attributed to the difference in the mechanical properties of the cervical and lumbar spines. (author)

  12. Body-image and obesity in adolescence: a comparative study of social-demographic, psychological, and behavioral aspects.

    Science.gov (United States)

    de Sousa, Pedro Miguel Lopes

    2008-11-01

    In current society, body and beauty's cult emerge as one of the main factors of adolescence. That leads adolescents to be dissatisfied with their own appearance, to psychological maladjustment, and nutritional disorders. This quantitative, exploratory, and cross-sectional research evaluates how adolescents perceive their weight and the prevalence of obesity in a sample of adolescents from the district of Viseu (Portugal). It also attempted to compare the relation of body-image and obesity with sociodemographic (school, sex, age, socioeconomic status, family functioning), psychological (self-concept, depression, school success) and behavioral aspects (physical inactivity). After data analyses, it was verified that the prevalence of obesity was 8.8% but 12.7% considered themselves obese. These adolescents had higher physical inactivity, poorer family functioning, a lower self-concept, and a higher depression index. The really obese adolescents were older and had poorer academic results. Obesity was higher in boys, but girls perceived themselves more as being obese. In conclusion, it is essential to evaluate weight perception in addition to body mass index (BMI), because the main problem could be related not only to being obese, but also to the perception of having a higher than ideal weight.

  13. Comparative study of image quality between axial T2-weighted BLADE and turbo spin-echo MRI of the upper abdomen on 3.0 T.

    Science.gov (United States)

    Zhang, Lin; Tian, ChunMei; Wang, PeiYuan; Chen, Liang; Mao, XiJin; Wang, ShanShan; Wang, Xu; Dong, JingMin; Wang, Bin

    2015-09-01

    To compare image quality of turbo spin-echo (TSE) with BLADE [which is also named periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER)] on magnetic resonance imaging (MRI) for upper abdomen. This study involved the retrospective evaluation of 103 patients (63 males, 40 females; age range 19-76 years; median age 53.8 years) who underwent 3.0 T MRI with both conventional TSE T2-weighted imaging (T2WI) and BLADE TSE T2WI. Two radiologists assessed respiratory motion, gastrointestinal peristalsis, and vascular pulsation artifacts, as well as the sharpness of the liver and pancreas edges. Scores for all magnetic resonance (MR) images were recorded. Wilcoxon's rank test was used to compare hierarchical data. Cohen's kappa coefficient was adopted to analyze interobserver consistency. Compared to TSE T2WI, BLADE TSE T2WI reduced all of the examined motion artifacts and increased the sharpness of the liver and pancreas edges (all P image quality.

  14. Post mortem magnetic resonance imaging in the fetus, infant and child: A comparative study with conventional autopsy (MaRIAS Protocol

    Directory of Open Access Journals (Sweden)

    Thayyil Sudhin

    2011-12-01

    Full Text Available Abstract Background Minimally invasive autopsy by post mortem magnetic resonance (MR imaging has been suggested as an alternative for conventional autopsy in view of the declining consented autopsy rates. However, large prospective studies rigorously evaluating the accuracy of such an approach are lacking. We intend to compare the accuracy of a minimally invasive autopsy approach using post mortem MR imaging with that of conventional autopsy in fetuses, newborns and children for detection of the major pathological abnormalities and/or determination of the cause of death. Methods/Design We recruited 400 consecutive fetuses, newborns and children referred for conventional autopsy to one of the two participating hospitals over a three-year period. We acquired whole body post mortem MR imaging using a 1.5 T MR scanner (Avanto, Siemens Medical Solutions, Enlargen, Germany prior to autopsy. The total scan time varied between 90 to 120 minutes. Each MR image was reported by a team of four specialist radiologists (paediatric neuroradiology, paediatric cardiology, paediatric chest & abdominal imaging and musculoskeletal imaging, blinded to the autopsy data. Conventional autopsy was performed according to the guidelines set down by the Royal College of Pathologists (UK by experienced paediatric or perinatal pathologists, blinded to the MR data. The MR and autopsy data were recorded using predefined categorical variables by an independent person. Discussion Using conventional post mortem as the gold standard comparator, the MR images will be assessed for accuracy of the anatomical morphology, associated lesions, clinical usefulness of information and determination of the cause of death. The sensitivities, specificities and predictive values of post mortem MR alone and MR imaging along with other minimally invasive post mortem investigations will be presented for the final diagnosis, broad diagnostic categories and for specific diagnosis of each system

  15. A comparative study of mandibular movements with their MR images in patients with internal derangement of the TMJ

    International Nuclear Information System (INIS)

    Miyamoto, Satoshi; Ogawa, Takumi; Hosoda, Yutaka

    1993-01-01

    Thirty one patients with internal derangement of the TMJ and 12 subjects with normal TMJ were selected and their MR imaging and border movements of the mandible were recorded. In addition, the relationship between them were examined. In this study, the disk position and configuration in MR findings were classified as follows. Disk position: superior, anterior and anterolateral (medial and lateral were omitted), grade of anterior disk displacement (with and without reduction): slight, moderate and severe, disk configuration: biconcave, enlargement of posterior band, even thickness and biconvex. Border movements of the mandible were influenced not only by unilateral or bilateral interior derangement but also by with or without reduction of the disk. Border movements in patients with anterolateral disk displacement were more severely restricted than those with anterior disk displacement. Border movements were remarkably limited in patients with slight disk displacement, especially in unilateral cases with reduction of the disk. Border movements in patients with even thickness and biconvex types of disk configuration were a little restricted and rather similar to those of normal subjects. There was significant correlation between border movements and disk position and configuration. It means that measurement of the mandibular movements is very significant to diagnose the condition of internal derangements of the TMJ. (author)

  16. Comparative Studies for What?

    Directory of Open Access Journals (Sweden)

    Pedro Guedes de Carvalho

    2017-12-01

    Education Society (BCES & the International Society for Comparative Physical Education and Sport (ISCPES - will jointly organize an International Conference on Sport Governance around the World. Sports and Physical Education are facing complex problems worldwide, which need to be solved. For health reasons, a vast number of organizations are popularizing the belief that physical education and sports are ‘a must’ in order to promote human activity and movement. However, several studies show that modern lifestyles are the main cause for people's inactivity and sedentary lifestyles. Extensive funded programs used to promote healthy lifestyles; sports media advertising several athletes, turning them into global heroes, influencers in a new emerging industry around sports organizations. Therefore, there is a rise in the number of unethical cases and corruption that influence the image of physical education and sports roles. We, the people emotional and physically involved with sports and physical activity must be aware of this, studying, discussing and comparing global facts and events around the world. This Conference aims to offer an incentive to colleagues from all continents to participate and present their latest results on four specific topics: 1. Sport Governance Systems; 2. Ethics and Corruption in Physical Education and Sports Policies; 3. Physical Education and Sport Development; 4. Training Physical Educators and Coaches. Please consider your selves invited to attend. Details in http://bcesconvention.com/

  17. A comparative study of volumetric breast density estimation in digital mammography and magnetic resonance imaging: results from a high-risk population

    Science.gov (United States)

    Kontos, Despina; Xing, Ye; Bakic, Predrag R.; Conant, Emily F.; Maidment, Andrew D. A.

    2010-03-01

    We performed a study to compare methods for volumetric breast density estimation in digital mammography (DM) and magnetic resonance imaging (MRI) for a high-risk population of women. DM and MRI images of the unaffected breast from 32 women with recently detected abnormalities and/or previously diagnosed breast cancer (age range 31-78 yrs, mean 50.3 yrs) were retrospectively analyzed. DM images were analyzed using QuantraTM (Hologic Inc). The MRI images were analyzed using a fuzzy-C-means segmentation algorithm on the T1 map. Both methods were compared to Cumulus (Univ. Toronto). Volumetric breast density estimates from DM and MRI are highly correlated (r=0.90, pwomen with very low-density breasts (peffects in MRI and differences in the computational aspects of the image analysis methods in MRI and DM. The good correlation between the volumetric and the area-based measures, shown to correlate with breast cancer risk, suggests that both DM and MRI volumetric breast density measures can aid in breast cancer risk assessment. Further work is underway to fully-investigate the association between volumetric breast density measures and breast cancer risk.

  18. Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging

    International Nuclear Information System (INIS)

    Xiao, Hua-Feng; Chen, Zhi-Ye; Wang, Yu-Lin; Wang, Yan; Ma, Lin; Lou, Xin; Gui, Qiu-Ping; Shi, Kai-Ning; Zhou, Zhen-Yu; Zheng, Dan-Dan

    2015-01-01

    We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 x 10 -3 mm 2 /s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. (orig.)

  19. Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Hua-Feng [302 Hospital of Chinese People' s Liberation Army, Department of Radiology, Beijing (China); Chen, Zhi-Ye; Wang, Yu-Lin; Wang, Yan; Ma, Lin [People' s Liberation Army General Hospital, Department of Radiology, Beijing (China); Lou, Xin [People' s Liberation Army General Hospital, Department of Radiology, Beijing (China); University of California, Department of Neurology, Los Angeles, CA (United States); Gui, Qiu-Ping [People' s Liberation Army General Hospital, Department of Pathology, Beijing (China); Shi, Kai-Ning; Zhou, Zhen-Yu; Zheng, Dan-Dan [General Electric Healthcare (China) Co., Ltd., Beijing; Wang, Danny J.J. [University of California, Department of Neurology, Los Angeles, CA (United States)

    2015-12-15

    We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 x 10{sup -3} mm{sup 2}/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. (orig.)

  20. Mammographic parenchymal texture as an imaging marker of hormonal activity: a comparative study between pre- and post-menopausal women

    Science.gov (United States)

    Daye, Dania; Bobo, Ezra; Baumann, Bethany; Ioannou, Antonios; Conant, Emily F.; Maidment, Andrew D. A.; Kontos, Despina

    2011-03-01

    Mammographic parenchymal texture patterns have been shown to be related to breast cancer risk. Yet, little is known about the biological basis underlying this association. Here, we investigate the potential of mammographic parenchymal texture patterns as an inherent phenotypic imaging marker of endogenous hormonal exposure of the breast tissue. Digital mammographic (DM) images in the cranio-caudal (CC) view of the unaffected breast from 138 women diagnosed with unilateral breast cancer were retrospectively analyzed. Menopause status was used as a surrogate marker of endogenous hormonal activity. Retroareolar 2.5cm2 ROIs were segmented from the post-processed DM images using an automated algorithm. Parenchymal texture features of skewness, coarseness, contrast, energy, homogeneity, grey-level spatial correlation, and fractal dimension were computed. Receiver operating characteristic (ROC) curve analysis was performed to evaluate feature classification performance in distinguishing between 72 pre- and 66 post-menopausal women. Logistic regression was performed to assess the independent effect of each texture feature in predicting menopause status. ROC analysis showed that texture features have inherent capacity to distinguish between pre- and post-menopausal statuses (AUC>0.5, pcontraception use and hormonal replacement therapy (HRT) use lead to a modest model improvement (AUC=0.78) while texture features maintained significant contribution (p<0.05). The observed differences in parenchymal texture features between pre- and post- menopausal women suggest that mammographic texture can potentially serve as a surrogate imaging marker of endogenous hormonal activity.

  1. Cerebral Anatomy of the Spider Monkey Ateles Geoffroyi Studied Using Magnetic Resonance Imaging. First Report: a Comparative Study with the Human Brain Homo Sapiens

    Directory of Open Access Journals (Sweden)

    Fernando Chico-Ponce de León

    2009-04-01

    Full Text Available The objective of the present qualitative studywas to analyze the morphological aspects of theinner cerebral anatomy of two species of primates,using magnetic resonance images (MRI:spider monkey (A. geoffroyi and human (H.sapiens, on the basis of a comparative study ofthe cerebral structures of the two species, focusingupon the brain of the spider monkey and,primarily, its limbic system. In spite of beingan endemic Western hemisphere species, a factwhich is by its own right interesting for researchdue to this animal’s social organization and motorfunctions, the spider monkey (A. geoffroyihas hardly been studied in regard to its neuroanatomy.MRI was carried out, in one spidermonkey, employing a General Electric Signa1.5 T scanner. This investigation was carried inaccordance to international regulations for theprotection of animals in captivity, taking intoaccount all protective means utilized in experimentalhandling, and not leaving behind any residualeffects, either physiological or behavioral.From a qualitative point of view, the brains ofthe spider monkey and the human were found to have similar structures. In reference to shape,the most similar structures were found in thelimbic system; proportionally, however, cervical curvature, amygdala, hippocampus, anteriorcommissure and the colliculi, were larger in thespider monkey than in the human.

  2. Reconstruction algorithms based on l1-norm and l2-norm for two imaging models of fluorescence molecular tomography: a comparative study.

    Science.gov (United States)

    Yi, Huangjian; Chen, Duofang; Li, Wei; Zhu, Shouping; Wang, Xiaorui; Liang, Jimin; Tian, Jie

    2013-05-01

    Fluorescence molecular tomography (FMT) is an important imaging technique of optical imaging. The major challenge of the reconstruction method for FMT is the ill-posed and underdetermined nature of the inverse problem. In past years, various regularization methods have been employed for fluorescence target reconstruction. A comparative study between the reconstruction algorithms based on l1-norm and l2-norm for two imaging models of FMT is presented. The first imaging model is adopted by most researchers, where the fluorescent target is of small size to mimic small tissue with fluorescent substance, as demonstrated by the early detection of a tumor. The second model is the reconstruction of distribution of the fluorescent substance in organs, which is essential to drug pharmacokinetics. Apart from numerical experiments, in vivo experiments were conducted on a dual-modality FMT/micro-computed tomography imaging system. The experimental results indicated that l1-norm regularization is more suitable for reconstructing the small fluorescent target, while l2-norm regularization performs better for the reconstruction of the distribution of fluorescent substance.

  3. A comparative study of 99mTc-HL91 and 99mTc-MIBI imaging in experimental tumor and inflammatory models

    International Nuclear Information System (INIS)

    Cao, W.; Zhang, X.Y.; An, R.

    2002-01-01

    Aim: 99m Tc-HL91 is a newly developed hypoxic imaging agent for ischemic myocardium and tumor imaging. 99m Tc-MIBI is one of imaging agent for mammary tumor imaging. The aim of this experiment is to evaluate the diagnostic value of 99m Tc-HL91 in detection of solid tumor in experimental tumor and inflammatory models, via comparative study with 99m Tc-MIBI. Material and Methods: HL91 kits was provided by China Nine Star Co. Three kinds of bearing solid neoplasm mice groups (bearing Ehrlich carcinoma mice, bearing H 22 carcinoma mice and bearing human ovarian COC 1 neoplasm nude mice) and two inflammatory model groups (chemical and bacterial inflammation) underwent static whole body planar images at 1 and 4 hours post injection of 99m Tc-HL91. Two kinds of bearing neoplasm mice groups (bearing Ehrlich carcinoma mice, bearing H 22 carcinoma mice) and two inflammatory model groups (chemical and bacterial inflammation) underwent static planar images post injection of 99m Tc-MIBI, at early phase (10∼20 minutes) and delayed phase (2 hrs). All of mice were sacrificed at 4 hrs. The tumors, or inflammatory lesions, blood and contralateral muscles were removed, weighed and the radioactivity was measured. Regions of interesting (ROIs) were drawn around tumor, inflammatory lesions and contralateral muscles in planar images, and the radioactivity ratios of target (tumor or inflammatory lesions)-to-blood (T/B), target-to-non target (contralateral muscles) i. e. T/NT was calculated. Results: Neoplasm can be clearly visible in planar images at 1hr and 4 hrs post injection of 99m Tc-HL91 in all tumor models. At same time inflammatory lesions cannot be seen clearly. Neoplasm can be seen in delayed phase in 99m Tc-MIBI groups, but not easy to distinguish them from inflammation. Conclusion: Compared with 99m Tc-MIBI imaging, 99m Tc-HL91 has much more diagnostic value in detection of solid neoplasm, and can distinguish neoplasm from inflammation

  4. Comparative Study of C-Arms for Intraoperative 3-dimensional Imaging and Navigation in Minimally Invasive Spine Surgery Part II: Radiation Exposure.

    Science.gov (United States)

    Klingler, Jan-Helge; Sircar, Ronen; Scheiwe, Christian; Kogias, Evangelos; Krüger, Marie T; Scholz, Christoph; Hubbe, Ulrich

    2017-07-01

    A radiation exposure study in vitro. This study aimed to compare the radiation exposure of 2 different 3-dimensional (3D) C-arm devices on an anthropomorphic phantom. Minimally invasive pedicle screw placement requires intraoperative imaging techniques for visualization of the unexposed spine. Mobile 3D C-arms compose a 3D image data set out of multiple successive fluoroscopic images. We compared the 3D C-arm devices Siremobil Iso-C 3D (Siemens Sector Healthcare, Erlangen, Germany) and Vision FD Vario 3D (Ziehm Imaging, Nuremberg, Germany) regarding their radiation exposure. For this purpose, dosimeters were attached on an anthropomorphic phantom at various sites (eye lenses, thyroid gland, female, and male gonads). With each C-arm, 10 automated 3D scans as well as 400 fluoroscopic images were performed on the cervical and lumbar spine, respectively. The Vision FD Vario 3D generally causes higher radiation exposures than the Siremobil Iso-C 3D. Significantly higher radiation exposures were assessed at the eye lenses performing cervical (294.1 vs. 84.6 μSv) and lumbar 3D scans (22.5 vs. 11.2 μSv) as well as at the thyroid gland performing cervical 3D scans (4405.2 vs. 2761.9 μSv). Moreover, the Vision FD Vario 3D caused significantly higher radiation exposure at the eye lenses for standard cervical fluoroscopic images (3.2 vs. 0.4 μSv). 3D C-arms facilitate minimally invasive and accurate pedicle screw placement by providing 3D image datasets for intraoperative 3D imaging and navigation. However, the hereby potentially increased radiation exposure has to be considered. In particular, the Vision FD Vario 3D appears to generally evoke higher radiation exposures than the Siremobil Iso-C 3D. Well-indicated application of ionizing radiation and compliance with radiation protection principles remain mandatory to keep radiation exposure to patient and staff as low as reasonably achievable.

  5. Transportal femoral drilling creates more horizontal ACL graft orientation compared to transtibial drilling: A 3D CT imaging study.

    Science.gov (United States)

    Clockaerts, S; Van Haver, A; Verhaegen, J; Vuylsteke, K; Leenders, T; Lagae, K C; Verdonk, P

    2016-06-01

    The principle of anatomic anterior cruciate ligament (ACL) reconstruction is to create a femoral and tibial tunnel that resembles the insertion of the native ACL. Anatomic reconstruction leads to a more horizontal graft orientation that provides more rotational stability. The aim of this study is to investigate the best method to achieve anatomical reconstruction of femoral insertion of the ACL and thus, a more horizontal orientation of the ACL. We compared tunnel position and orientation between transportal femoral drilling technique and transtibial technique. Thirty-two patients were included. Post-operative CT scans were obtained and femur, tibia and ACL tunnels were reconstructed. The position and orientation of tibial and femoral tunnels were quantified using the quadrant method, and femoral tunnel length, ellipticity and posterior wall breakage were assessed. We also investigated clinical outcome. Analyses show that transportal drilled femoral tunnels were situated significantly lower than transtibial drilled tunnels (p<0.0001), resulting in a significantly more horizontal oriented ACL in the transportal group in coronal (p<0.0001) and sagittal plane (p=0.01). No differences were observed in depth of femoral tunnel position (p=0.44). Femoral tunnel length was shorter in the transportal group (p=0.01) with a more ellipsoidal femoral aperture (p=0.01). There were no differences between both groups in tibial position. There were no differences in clinical outcome measure between the transportal and transtibial groups. This study indicates that transportal drilling of the femoral tunnel leads to a more horizontal graft orientation of the ACL, without differences in clinical outcome. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Comparing imaging procedures: techniques and examples. Gastroenterology

    International Nuclear Information System (INIS)

    Malmud, L.S.

    1982-01-01

    The distinct advantages of nuclear medicine procedures, in comparison to radiography, contrast studies, computerized tomography and ultrasound, are emphasized. Scintigraphic methods offer quantitative data regarding function which competing imaging modalities are unable to provide, and make them the studies of choice in the evaluation of gastrointestinal physiology and functional abnormalities

  7. Animal-specific positioning molds for registration of repeat imaging studies: comparative microPET imaging of F18-labeled fluoro-deoxyglucose and fluoro-misonidazole in rodent tumors

    International Nuclear Information System (INIS)

    Zanzonico, Pat; Campa, Jose; Polycarpe-Holman, Dolores; Forster, Gregor; Finn, Ronald; Larson, Steven; Humm, John; Ling, Clifton

    2006-01-01

    Introduction: Comparative imaging of multiple radiotracers in the same animal can be invaluable in elucidating and validating their respective mechanisms of localization. Comparative imaging of PET tracers, particularly in small animals, is problematic, however: such tracers must be administered and imaged separately because simultaneously imaged positron emitters cannot be separated based on energy discrimination. Objective: As part of our ongoing development of hypoxia imaging radiotracers, the intratumoral distributions of sequentially administered F18-fluoro-deoxyglucose (FDG) and the hypoxia tracer F18-fluoromisonidazole (FMiso) were compared in rats by registered microPET imaging with positioning of each animal in a custom-fabricated whole-body mold. Methods: Nude rats with a hindlimb R3327-AT anaplastic rat prostate tumor xenograft and a hindlimb FaDu human squamous cell carcinoma (each up to 20x20x30 mm in size) were studied. Rapid-Foam (Soule Medical, Lutz, FL) was used to fabricate animal-specific molds for immobilization and reproducible positioning. Each rat was injected via the tail vein with ∼33 MBq (900 μCi) of FDG and imaged in its mold at 1 h postinjection (pi) on the microPET. The next day, each rat was injected with ∼22 MBq (600 μCi) of FMiso and positioned and imaged in its mold at ∼2 h pi. Custom-manufactured germanium-68 rods (10 μCi each, 1x10 mm) were reproducibly positioned in the mold as fiduciary markers. Results: The registered microPET images unambiguously demonstrated grossly similar though not identical distributions of FDG and FMiso in the tumors - a high-activity rim surrounding a lower-activity core. There were subtle but possibly significant differences in the intratumoral distributions of FDG and FMiso, however. These may not have been discerned without careful image registration. Conclusion: Animal-specific molds are inexpensive and straightforward to fabricate and use for registration (±1 to 2 mm) of sequential PET

  8. Assessment of left atrial volume and function: a comparative study between echocardiography, magnetic resonance imaging and multi slice computed tomography

    DEFF Research Database (Denmark)

    Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas

    2012-01-01

    dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty......Measurement of left atrial (LA) maximal volume (LA(max)) using two-dimensional transthoracic echocardiography (TTE) provides prognostic information in several cardiac diseases. However, the relationship between LA(max) and LA function is poorly understood and TTE is less well suited for measuring......-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir...

  9. Comparative study of rabbit VX2 hepatic implantation tumor and normal liver tissue on magnetic resonance perfusion weighted imaging

    International Nuclear Information System (INIS)

    Jiao Zimei; Wang Xizhen; Wang Bin; Liu Feng; Li Haiqing; Sun Yequan; Dong Peng

    2012-01-01

    Objective: To investigate the value of magnetic resonance (MR) perfusion weighted imaging (PWI) in evaluating the blood perfusion of tumor by analyzing the features and indexes of PWI on rabbit VX2 hepatic implantation tumor and normal liver tissue. Methods: Twenty-four New Zealand White rabbits with VX2 carcinoma were established under direct surgical vision embedding tumor tissue. MR examination was performed at 21 days after the tumor implantation. The signal intensity -time curve of hepatic tumor and normal liver tissue were obtained. Mean time to enhance (MTE), negative enhancement integral (NEI), time to minimum (TM), maximum slope of decrease (MSD) and maximum slope of increase (MSI) were measured. Results: MTE, NEI, TM, MSD, and MSI of the normal liver tissue were 208.341±2.226 ms, 78.334±8.152, 24.059±1.927 ms, 38.221±2.443, and 15.389±2.526, respectively. MTE, NEI, TM, MSD, and MSI of the tumor tissue were 175.437±4.182 ms, 123.203±19.455, 17.061±1.834 ms, 125.740±4.842, and 67.832±2.882, respectively. The MTE and TM of tumor were shorter than those of normal hepatic tissue (P<0.05). NEI, MSD, and MSI of tumor were higher than those of normal hepatic tissue (P<0.05). Conclusion: PWI can distinguish the normal liver tissue from the tumor tissue, which is helpful in evaluating blood perfusion of different hepatic tissues. (authors)

  10. The Institutional Logic of Images of the Poor and Welfare Recipients. A Comparative Study of British, Swedish and Danish Newspapers

    DEFF Research Database (Denmark)

    Larsen, Christian Albrekt; Dejgaard, Thomas Engel

    2013-01-01

    The article investigates how the poor and welfare recipients are depicted in British, Danish and Swedish newspapers. The study was inspired by American media studies that have documented a negative stereotypic way of portraying the poor and welfare recipients; especially in the case...... they are African-Americans. The article argues that there is an institutional welfare-regime logic behind the way the poor and welfare recipients are depicted in the mass media. It is not only a matter of race. This argument is substantiated by showing that the poor and welfare recipients are a) also depicted...

  11. Predictors of Images towards the "Other": A Comparative Study between Jordanian and Greek Pre-Service Teachers

    Science.gov (United States)

    Kostoulas-Makrakis, Nelly; Al-Said, Khaleel; Makrakis, Vassilios; Kalogiannakis, Pella; de Baz, Theodora

    2010-01-01

    The present study examined the perceptions of Jordanian and Greek pre-service teachers (N = 489) towards the "Other" as well as towards tolerance and intolerance. Frequencies, "t"-tests and one-way analysis of variance, as well as multiple regression analyses, were performed for the data analysis. The results show that although…

  12. Dual-energy CT in the assessment of mediastinal lymph nodes: Comparative study of virtual non-contrast and true non-contrast images

    International Nuclear Information System (INIS)

    Yoo, Seon Young; Kim, Yoo Kyung; Cho, Hyun Hae; Choi, Mi Joo; Shim, Sung Shine; Lee, Jeong Kyong; Baek, Seung Yon

    2013-01-01

    To evaluate the reliability of virtual non-contrast (VNC) images reconstructed from contrast-enhanced, dual-energy scans compared with true non-contrast (TNC) images in the assessment of high CT attenuation or calcification of mediastinal lymph nodes. A total of 112 mediastinal nodes from 45 patients who underwent non-contrast and dual-energy contrast-enhanced scans were analyzed. Node attenuation in TNC and VNC images was compared both objectively, using computed tomography (CT) attenuation, and subjectively, via visual scoring (0, attenuation ≤ the aorta; 1, > the aorta; 2, calcification). The relationship among attenuation difference between TNC and VNC images, CT attenuation in TNC images, and net contrast enhancement (NCE) was analyzed. CT attenuation in TNC and VNC images showed moderate agreement (intraclass correlation coefficient, 0.612). The mean absolute difference was 7.8 ± 7.6 Hounsfield unit (HU) (range, 0-36 HU), and the absolute difference was equal to or less than 10 HU in 65.2% of cases (73/112). Visual scores in TNC and VNC images showed fair agreement (κ value, 0.335). Five of 16 nodes (31.3%) which showed score 1 (n = 15) or 2 (n = 1) in TNC images demonstrated score 1 in VNC images. The TNC-VNC attenuation difference showed a moderate positive correlation with CT attenuation in TNC images (partial correlation coefficient [PCC] adjusted by NCE: 0.455) and a weak negative correlation with NCE (PCC adjusted by CT attenuation in TNC: -0.245). VNC images may be useful in the evaluation of mediastinal lymph nodes by providing additional information of high CT attenuation of nodes, although it is underestimated compared with TNC images.

  13. A comparative study between data obtained from conventional lateral cephalometry and reconstructed three-dimensional computed tomography images.

    Science.gov (United States)

    Oh, Suseok; Kim, Ci-Young; Hong, Jongrak

    2014-06-01

    The aim of this study was to verify the concordance of the measurement values when the same cephalometric analysis method was used for two-dimensional (2D) cephalometric radiography and three-dimensional computed tomography (3D CT), and to identify which 3D Frankfort horizontal (FH) plane was the most concordant with FH plane used for cephalometric radiography. Reference horizontal plane was FH plane. Palatal angle and occlusal plane angle was evaluated with FH plane. Gonial angle (GA), palatal angle, upper occlusal plane angle (UOPA), mandibular plane angle (MPA), U1 to occlusal plane angle, U1 to FH plane angle, SNA and SNB were obtained on 2D cephalmetries and reconstructed 3D CT. The values measured eight angles in 2D lateral cephalometry and reconstructed 3D CT were evaluated by intraclass correlation coefficiency (ICC). It also was evaluated to identify 3D FH plane with high degree of concordance to 2D one by studying which one in four FH planes shows the highest degree of concordance with 2D FH plane. ICCs of MPA (0.752), UOPA (0.745), SNA (0.798) and SNB (0.869) were high. On the other hand, ICCs of gonial angle (0.583), palatal angle (0.287), U1 to occlusal plane (0.404), U1 to FH plane (0.617) were low respectively. Additionally GA and MPA acquired from 2D were bigger than those on 3D in all 20 patients included in this study. Concordance between one UOPA from 2D and four UOPAs from 3D CT were evaluated by ICC values. Results showed no significant difference among four FH planes defined on 3D CT. FH plane that can be set on 3D CT does not have difference in concordance from FH plane on lateral cephalometry. However, it is desirable to define FH plane on 3D CT with two orbitales and one porion considering the reproduction of orbitale itself.

  14. A comparative study on generating simulated Landsat NDVI images using data fusion and regression method-the case of the Korean Peninsula.

    Science.gov (United States)

    Lee, Mi Hee; Lee, Soo Bong; Eo, Yang Dam; Kim, Sun Woong; Woo, Jung-Hun; Han, Soo Hee

    2017-07-01

    Landsat optical images have enough spatial and spectral resolution to analyze vegetation growth characteristics. But, the clouds and water vapor degrade the image quality quite often, which limits the availability of usable images for the time series vegetation vitality measurement. To overcome this shortcoming, simulated images are used as an alternative. In this study, weighted average method, spatial and temporal adaptive reflectance fusion model (STARFM) method, and multilinear regression analysis method have been tested to produce simulated Landsat normalized difference vegetation index (NDVI) images of the Korean Peninsula. The test results showed that the weighted average method produced the images most similar to the actual images, provided that the images were available within 1 month before and after the target date. The STARFM method gives good results when the input image date is close to the target date. Careful regional and seasonal consideration is required in selecting input images. During summer season, due to clouds, it is very difficult to get the images close enough to the target date. Multilinear regression analysis gives meaningful results even when the input image date is not so close to the target date. Average R 2 values for weighted average method, STARFM, and multilinear regression analysis were 0.741, 0.70, and 0.61, respectively.

  15. Operations dashboard: comparative study

    Science.gov (United States)

    Ramly, Noor Nashriq; Ismail, Ahmad Zuhairi; Aziz, Mohd Haris; Ahmad, Nurul Haszeli

    2011-10-01

    In this present days and age, there are increasing needs for companies to monitor application and infrastructure health. Apart from having proactive measures to secure their application and infrastructure, many see monitoring dashboards as crucial investment in disaster preparedness. As companies struggle to find the best solution to cater for their needs and interest for monitoring their application and infrastructure's health, this paper summarizes the studies made on several known off-the-shelf operations dashboard and in-house developed dashboard. A few criteria of good dashboard are collected from previous studies carried out by several researchers and rank them according to importance and business needs. The finalized criteria that will be discussed in later sections are data visualization, performance indicator, dashboard personalization, audit capability and alert/ notification. Comparative studies between several popular dashboards were then carried out to determine whether they met these criteria that we derived from the first exercise. The findings hopefully can be used to educate and provide an overview of selecting the best IT application and infrastructure operations dashboard that suit business needs, thus become the main contribution of this paper.

  16. Comparative study between quantitative digital image analysis and fluorescence in situ hybridization of breast cancer equivocal human epidermal growth factor receptors 2 score 2(+) cases.

    Science.gov (United States)

    Ayad, Essam; Mansy, Mina; Elwi, Dalal; Salem, Mostafa; Salama, Mohamed; Kayser, Klaus

    2015-01-01

    Optimization of workflow for breast cancer samples with equivocal human epidermal growth factor receptors 2 (HER2)/neu score 2(+) results in routine practice, remains to be a central focus of the on-going efforts to assess HER2 status. According to the College of American Pathologists/American Society of Clinical Oncology guidelines equivocal HER2/neu score 2(+) cases are subject for further testing, usually by fluorescence in situ hybridization (FISH) investigations. It still remains on open question, whether quantitative digital image analysis of HER2 immunohistochemistry (IHC) stained slides can assist in further refining the HER2 score 2(+). To assess utility of quantitative digital analysis of IHC stained slides and compare its performance to FISH in cases of breast cancer with equivocal HER2 score 2(+). Fifteen specimens (previously diagnosed as breast cancer and was evaluated as HER 2(-) score 2(+)) represented the study population. Contemporary new cuts were prepared for re-evaluation of HER2 immunohistochemical studies and FISH examination. All the cases were digitally scanned by iScan (Produced by BioImagene [Now Roche-Ventana]). The IHC signals of HER2 were measured using an automated image analyzing system (MECES, www.Diagnomx.eu/meces). Finally, a comparative study was done between the results of the FISH and the quantitative analysis of the virtual slides. Three out of the 15 cases with equivocal HER2 score 2(+), turned out to be positive (3(+)) by quantitative digital analysis, and 12 were found to be negative in FISH too. Two of these three positive cases proved to be positive with FISH, and only one was negative. Quantitative digital analysis is highly sensitive and relatively specific when compared to FISH in detecting HER2/neu overexpression. Therefore, it represents a potential reliable substitute for FISH in breast cancer cases, which desire further refinement of equivocal IHC results.

  17. Evaluation of focus laterality in temporal lobe epilepsy: a quantitative study comparing double inversion-recovery MR imaging at 3T with FDG-PET.

    Science.gov (United States)

    Morimoto, Emiko; Okada, Tomohisa; Kanagaki, Mitsunori; Yamamoto, Akira; Fushimi, Yasutaka; Matsumoto, Riki; Takaya, Shigetoshi; Ikeda, Akio; Kunieda, Takeharu; Kikuchi, Takayuki; Paul, Dominik; Miyamoto, Susumu; Takahashi, Ryosuke; Togashi, Kaori

    2013-12-01

    To quantitatively compare the diagnostic capability of double inversion-recovery (DIR) with F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) for detection of seizure focus laterality in temporal lobe epilepsy (TLE). This study was approved by the institutional review board, and written informed consent was obtained. Fifteen patients with TLE and 38 healthy volunteers were enrolled. All magnetic resonance (MR) images were acquired using a 3T-MRI system. Voxel-based analysis (VBA) was conducted for FDG-PET images and white matter segments of DIR images (DIR-WM) focused on the whole temporal lobe (TL) and the anterior part of the temporal lobe (ATL). Distribution of hypometabolic areas on FDG-PET and increased signal intensity areas on DIR-WM were evaluated, and their laterality was compared with clinically determined seizure focus laterality. Correct diagnostic rates of laterality were evaluated, and agreement between DIR-WM and FDG-PET was assessed using κ statistics. Increased signal intensity areas on DIR-WM were located at the vicinity of the hypometabolic areas on FDG-PET, especially in the ATL. Correct diagnostic rates of seizure focus laterality for DIR-WM (0.80 and 0.67 for the TL and the ATL, respectively) were slightly higher than those for FDG-PET (0.67 and 0.60 for the TL and the ATL, respectively). Agreement of laterality between DIR-WM and FDG-PET was substantial for the TL and almost perfect for the ATL (κ = 0.67 and 0.86, respectively). High agreement in localization between DIR-WM and FDG-PET and nearly equivalent detectability of them show us an additional role of MRI in TLE. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

  18. Comparative study and implementation of images re processing methods for the tomography by positrons emission: interest of taking into account a priori information; Etude comparative et implementation de methodes de reconstruction d`images pour la tomographie par emission de positons: interet de la prise en compte d`informations a priori

    Energy Technology Data Exchange (ETDEWEB)

    Bouchet, F.

    1996-09-25

    The tomography by positron emission has for aim to explore an organ by injection of a radiotracer and bidimensional representation with processing techniques. The most used in routine is the filtered retro projection that gives smoothed images. this work realizes a comparative study of new techniques. The methods of preservations of contours are studied here, the idea is to use NMR imaging as a priori information. Two techniques of images construction are viewed more particularly: the resolution by pseudo inverse and the Bayesian method. (N.C.).

  19. Flexible image evaluation: iPad versus secondary-class monitors for review of MR spinal emergency cases, a comparative study.

    Science.gov (United States)

    McNulty, Jonathan P; Ryan, John T; Evanoff, Michael G; Rainford, Louise A

    2012-08-01

    Studies have highlighted the potential of handheld viewing devices for rapid diagnosis and increased smartphone usage among physicians and radiologists is known as is the clinical applicability of hand-held devices for computed tomography (CT) spinal injury cases. Magnetic resonance (MR), however, is the accepted gold standard for spinal imaging, providing visualization of both ligament and spinal cord pathology. This study investigated the diagnostic accuracy of the iPad, the most probable alternative display device outside the radiology environment and financially viable alternative, when reviewing emergency spinal MR images, in comparison with secondary-class LCD devices in the case of the interpretation of CT and MR imaging examinations. In total 31 MR cases including both positives (n = 13) containing one of four possible presentations: spinal cord compression, cauda equine syndrome, spinal cord hemorrhage, or spinal cord edema and controls (n = 18) were reviewed. Ziltron iPad software facilitated the display of cases and the receiver operating characteristic (ROC) analysis. Thirteen American Board of Radiology board-certified radiologists reviewed all cases on both displays. Standardized viewing conditions were maintained. Dorfman-Berbaum-Metz multireader-multicase (DBM MRMC) analysis was performed including random readers/random cases, fixed readers/random cases and random readers/fixed cases. No differences of statistical significance (P ≤ .05) could be found in terms of area under the curve, sensitivity and specificity between the iPad and secondary-class display. The iPad performed with equal diagnostic accuracy when compared with the secondary-class LCD device after DBM MRMC analysis, demonstrating the iPad as an option to aid initial review of MR spinal emergency cases. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

  20. Comparative waste forms study

    International Nuclear Information System (INIS)

    Wald, J.W.; Lokken, R.O.; Shade, J.W.; Rusin, J.M.

    1980-12-01

    A number of alternative process and waste form options exist for the immobilization of nuclear wastes. Although data exists on the characterization of these alternative waste forms, a straightforward comparison of product properties is difficult, due to the lack of standardized testing procedures. The characterization study described in this report involved the application of the same volatility, mechanical strength and leach tests to ten alternative waste forms, to assess product durability. Bulk property, phase analysis and microstructural examination of the simulated products, whose waste loading varied from 5% to 100% was also conducted. The specific waste forms investigated were as follows: Cold Pressed and Sintered PW-9 Calcine; Hot Pressed PW-9 Calcine; Hot Isostatic Pressed PW-9 Calcine; Cold Pressed and Sintered SPC-5B Supercalcine; Hot Isostatic pressed SPC-5B Supercalcine; Sintered PW-9 and 50% Glass Frit; Glass 76-68; Celsian Glass Ceramic; Type II Portland Cement and 10% PW-9 Calcine; and Type II Portland Cement and 10% SPC-5B Supercalcine. Bulk property data were used to calculate and compare the relative quantities of waste form volume produced at a spent fuel processing rate of 5 metric ton uranium/day. This quantity ranged from 3173 L/day (5280 Kg/day) for 10% SPC-5B supercalcine in cement to 83 L/day (294 Kg/day) for 100% calcine. Mechanical strength, volatility, and leach resistance tests provide data related to waste form durability. Glass, glass-ceramic and supercalcine ranked high in waste form durability where as the 100% PW-9 calcine ranked low. All other materials ranked between these two groupings

  1. Minimally invasive, imaging guided virtual autopsy compared to conventional autopsy in foetal, newborn and infant cases: study protocol for the paediatric virtual autopsy trial

    Science.gov (United States)

    2014-01-01

    Background In light of declining autopsy rates around the world, post-mortem MR imaging is a promising alternative to conventional autopsy in the investigation of infant death. A major drawback of this non-invasive autopsy approach is the fact that histopathological and microbiological examination of the tissue is not possible. The objective of this prospective study is to compare the performance of minimally invasive, virtual autopsy, including CT-guided biopsy, with conventional autopsy procedures in a paediatric population. Methods/Design Foetuses, newborns and infants that are referred for autopsy at three different institutions associated with the University of Zurich will be eligible for recruitment. All bodies will be examined with a commercial CT and a 3 Tesla MRI scanner, masked to the results of conventional autopsy. After cross-sectional imaging, CT-guided tissue sampling will be performed by a multifunctional robotic system (Virtobot) allowing for automated post-mortem biopsies. Virtual autopsy results will be classified with regards to the likely final diagnosis and major pathological findings and compared to the results of conventional autopsy, which remains the diagnostic gold standard. Discussion There is an urgent need for the development of alternative post-mortem examination methods, not only as a counselling tool for families and as a quality control measure for clinical diagnosis and treatment but also as an instrument to advance medical knowledge and clinical practice. This interdisciplinary study will determine whether virtual autopsy will narrow the gap in information between non-invasive and traditional autopsy procedures. Trial Registration ClinicalTrials.gov: NCT01888380 PMID:24438163

  2. The effects of breathing motion on DCE-MRI images: Phantom studies simulating respiratory motion to compare CAIPARINHA-VIBE, radial VIBE, and conventional VIBE

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Kyung; Seo, Nieun; Kim, Bohyun; Huh, Jimi; Kim, Jeong Kon; Lee, Seung Soo; KIm, Kyung Won [Dept. of Radiology, and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Kim, In Seong [Siemens Healthcare Korea, Seoul (Korea, Republic of); Nickel, Dominik [MR Application Predevelopment, Siemens Healthcare, Erlangen (Germany)

    2017-04-15

    To compare the breathing effects on dynamic contrast-enhanced (DCE)-MRI between controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-volumetric interpolated breath-hold examination (VIBE), radial VIBE with k-space-weighted image contrast view-sharing (radial-VIBE), and conventional VIBE (c-VIBE) sequences using a dedicated phantom experiment. We developed a moving platform to simulate breathing motion. We conducted dynamic scanning on a 3T machine (MAGNETOM Skyra, Siemens Healthcare) using CAIPIRINHA-VIBE, radial-VIBE, and c-VIBE for six minutes per sequence. We acquired MRI images of the phantom in both static and moving modes, and we also obtained motion-corrected images for the motion mode. We compared the signal stability and signal-to-noise ratio (SNR) of each sequence according to motion state and used the coefficients of variation (CoV) to determine the degree of signal stability. With motion, CAIPIRINHA-VIBE showed the best image quality, and the motion correction aligned the images very well. The CoV (%) of CAIPIRINHA-VIBE in the moving mode (18.65) decreased significantly after the motion correction (2.56) (p < 0.001). In contrast, c-VIBE showed severe breathing motion artifacts that did not improve after motion correction. For radial-VIBE, the position of the phantom in the images did not change during motion, but streak artifacts significantly degraded image quality, also after motion correction. In addition, SNR increased in both CAIPIRINHA-VIBE (from 3.37 to 9.41, p < 0.001) and radial-VIBE (from 4.3 to 4.96, p < 0.001) after motion correction. CAIPIRINHA-VIBE performed best for free-breathing DCE-MRI after motion correction, with excellent image quality.

  3. Performance of cone-beam computed tomography and multidetector computed tomography in diagnostic imaging of the midface: A comparative study on Phantom and cadaver head scans

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Simon [University Medical Center Hamburg, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); University Hospital Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); Schoellchen, Maximilian; Hanken, H.; Precht, C.; Heiland, M. [University Medical Center Hamburg, Department of Oral- and Maxillofacial Surgery, Hamburg (Germany); Henes, F.O.; Adam, G.; Regier, M. [University Medical Center Hamburg, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Schoen, G. [University Medical Center Hamburg, Department of Medical Biometry and Epidemiology, Hamburg (Germany); Nagel, H.D. [Science and Technology for Radiology, Buchholz (Germany); Schumacher, U. [University Medical Center Hamburg, Institute of Anatomy, Hamburg (Germany)

    2017-02-15

    To compare multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) regarding radiation, resolution, image noise, and image quality. CBCT and 256-MDCT were compared based on three scan protocols: Standard-dose (∼24 mGy), reduced-dose (∼9 mGy), and low-dose (∼4 mGy). MDCT images were acquired in standard- and high-resolution mode (HR-MDCT) and reconstructed using filtered back projection (FBP) and iterative reconstruction (IR). Spatial resolution in linepairs (lp) and objective image noise (OIN) were assessed using dedicated phantoms. Image quality was assessed in scans of 25 cadaver heads using a Likert scale. OIN was markedly higher in FBP-MDCT when compared to CBCT. IR lowered the OIN to comparable values in standard-mode MDCT only. CBCT provided a resolution of 13 lp/cm at standard-dose and 11 lp/cm at reduced-dose vs. 11 lp/cm and 10 lp/cm in HR-MDCT. Resolution of 10 lp/cm was observed for both devices using low-dose settings. Quality scores of MDCT and CBCT did not differ at standard-dose (CBCT, 3.4; MDCT, 3.3-3.5; p > 0.05). Using reduced- and low-dose protocols, CBCT was superior (reduced-dose, 3.2 vs. 2.8; low dose, 3.0 vs. 2.3; p < 0.001). Using the low-dose protocol, the assessed CBCT provided better objective and subjective image quality and equality in resolution. Similar image quality, but better resolution using CBCT was observed at higher exposure settings. (orig.)

  4. Helical-Tip Needle for Transthoracic Percutaneous Image-Guided Biopsy of Lung Tumors: Results of a Pilot Prospective Comparative Study with a Standard Tru-Cut Needle

    Energy Technology Data Exchange (ETDEWEB)

    Veltri, Andrea, E-mail: andrea.veltri@unito.it; Busso, Marco; Sardo, Diego; Angelino, Valeria; Priola, Adriano M. [University of Torino, Department of Radiology, San Luigi Gonzaga Hospital (Italy); Novello, Silvia [University of Torino, Department of Oncology, San Luigi Gonzaga Hospital (Italy); Barba, Matteo [University of Torino, Department of Radiology, San Luigi Gonzaga Hospital (Italy); Gatti, Gaia; Righi, Luisella [University of Torino, Department of Pathology, San Luigi Gonzaga Hospital (Italy)

    2017-06-15

    PurposeTo prospectively evaluate feasibility and diagnostic performance of the 14-gauge helical-tip (Spirotome™, Cook{sup ®} Medical, Bloomington, USA) needle in transthoracic needle biopsy (TTNB) of lung lesions, compared to a conventional 18-gauge Tru-Cut needle.Materials and MethodsStudy was institutional review board approved, with informed consent obtained. Data from synchronous Spirotome and Tru-Cut image-guided TTNB of 20 consecutive patients with malignant peripheral lung tumors larger than 3 cm were enrolled for pathologic characterization and mutational analysis. Samples obtained with Spirotome and Tru-Cut needle were compared for fragmentation, length, weight, morphologic and immunohistochemistry typifying, tumor cellularity (TC) and DNA concentration.ResultsThe technical success rate for TTNB with Spirotome was 100%, and no major complications occurred. Less fragmentation (mean 2 vs. 3 fragments, P = .418), greater weight (mean 13 vs. 8.5 mg, P = .027) and lower length (mean 10.2 vs. 12.6 mm, P = .174) were observed with Spirotome compared to Tru-Cut needle. Accuracy of Spirotome and Tru-Cut needle in defining cancer histotype was similar (90%). Absolute and relative TC (mean 42 vs. 38, 124 vs. 108/10HPF), and DNA concentration (mean 49.6 vs. 39.0 ng/μl) were higher with Spirotome compared to Tru-Cut needle, with no statistical significance (P = .787 and P = .140, respectively).Conclusions Percutaneous 14-gauge Spirotome TTNB of selected lesions is feasible and accurate. It provides adequate samples for diagnosis, comparable to 18-gauge Tru-Cut needle, with a higher amount of tumor tissue (weight, TC, DNA concentration) even in shorter samples.

  5. Comparative Packaging Study

    Science.gov (United States)

    Perchonok, Michele H.; Oziomek, Thomas V.

    2009-01-01

    Future long duration manned space flights beyond low earth orbit will require the food system to remain safe, acceptable and nutritious. Development of high barrier food packaging will enable this requirement by preventing the ingress and egress of gases and moisture. New high barrier food packaging materials have been identified through a trade study. Practical application of this packaging material within a shelf life test will allow for better determination of whether this material will allow the food system to meet given requirements after the package has undergone processing. The reason to conduct shelf life testing, using a variety of packaging materials, stems from the need to preserve food used for mission durations of several years. Chemical reactions that take place during longer durations may decrease food quality to a point where crew physical or psychological well-being is compromised. This can result in a reduction or loss of mission success. The rate of chemical reactions, including oxidative rancidity and staling, can be controlled by limiting the reactants, reducing the amount of energy available to drive the reaction, and minimizing the amount of water available. Water not only acts as a media for microbial growth, but also as a reactant and means by which two reactants may come into contact with each other. The objective of this study is to evaluate three packaging materials for potential use in long duration space exploration missions.

  6. [Evaluation of the clinical suitability of automated left ventricle's fraction and volume measurements in 3-dimensional echocardiography compared to values obtained in magnetic resonance imaging (pilot study)].

    Science.gov (United States)

    Żygadło, Agnieszka; Kaźnica-Wiatr, Magdalena; Błaut-Jurkowska, Justyna; Knap, Klaudia; Lenart-Migdalska, Aleksandra; Smaś-Suska, Monika; Skubera, Maciej; Urbańczyk-Zawadzka, Małgorzata; Podolec, Piotr; Olszowska, Maria

    2017-10-23

    Recently a lot of authors have been trying to determine the usefulness of 3-dimensional echocardiography (TTE 3D) in evaluation of ejection fraction and left ventricular volume, but few attempt to compare it to the current gold standard of cardiac magnetic resonance (CMR). 3D imaging technics allows to avoid errors caused by geometry of the heart chambers and foreshortened views. American Echocardiographic Guidelines recommend the use of 3-dimensional echocardiography in daily clinical practice. The aim of the study was to establish clinical usefulness of automated 3D TTE software to calculate left ventricle ejection fraction (LVEF), left ventricle end diastolic volume (LVEDV) and left ventricle end systolic volume (LVESV), and to compare those measurements calculated in CMR and in 3D TTE. The aim of the study was to establish clinical usefulness of automated 3D TTE software to calculate left ventricle ejection fraction (LVEF), left ventricle end diastolic volume (LVEDV) and left ventricle end systolic volume (LVESV), and to compare those measurements calculated in CMR and in 3D TTE. The mean LVEF in 3D TTE was 65% +/- 12%; LVEDV 123 ml +/- 67 ml, LVESV 42 ml +/- 29 ml. The CMR LVEF in the study group was 61% +/- 9%, LVEDV 134 ml +/- 51ml, LVESV 54 ml +/- 33 ml. Wilcoxon rank test showed no difference between medians of the measurements, the correlation coefficient between LVEF in 3D TTE and CMR was R = 0.84 (p = 0.036). LVEF calculated in 3D TTE shows good correlation with LVEF computed in CMR. However good visualization of the endocardium, especially in the apex, is essential. The volume of left ventricle is underestimated in 3D TTE. In previous studies underestimation of LVEDV and LVESV was explained by exclusion of endocardial trabeculae from the left ventricle cavity in automated measurement. The automated 3D TTE software allows simple, fast and precise evaluation of parameters of the left ventricle - especially LVEF. Automated 3D TTE software gives hope for

  7. Long-term outcome study in patients with abdominal wound dehiscence: a comparative study on quality of life, body image, and incisional hernia.

    Science.gov (United States)

    van Ramshorst, Gabrielle H; Eker, Hasan H; van der Voet, Jan A; Jeekel, Johannes; Lange, Johan F

    2013-08-01

    Long-term quality of life and body image of patients with abdominal wound dehiscence were assessed. Thirty-seven patients with abdominal wound dehiscence from a prospectively followed cohort of 967 patients (2007-2009) were reviewed. Patients completed the Short Form 36 quality of life questionnaire and Body Image Questionnaire and participated in semi-structured telephone interviews. For each patient, four controls were matched by age and gender. Analyses were adjusted for age, gender, comorbidity, and follow-up length. Of the 37 patients with abdominal wound dehiscence, 23 were alive after a mean follow-up of 40 months (range 33-49 months). Nineteen patients developed incisional hernias (83 %). Patients with abdominal wound dehiscence reported significantly lower scores for physical and mental component summaries (p = 0.038, p = 0.013), general health (p = 0.003), mental health (p = 0.011), social functioning (p = 0.002), and change (p = 0.034). No differences were found for physical functioning (p = 0.072), role physical (p = 0.361), bodily pain (p = 0.133), vitality (p = 0.150), and role emotional (p = 0.138). Patients with abdominal wound dehiscence reported lower body image scores (median 16.5 vs. 18, p = 0.087), cosmetic scores (median 13 vs. 16, p = 0.047), and total body image scores (median 30 vs. 34, p = 0.042). At long-term follow-up, patients with abdominal wound dehiscence demonstrated a high incidence of incisional hernia, low body image, and low quality of life.

  8. Thoracic magnetic resonance venography using Gadofosveset in patients with venous pathology-A comparative study of image quality and inter-rater variability.

    Science.gov (United States)

    Åkesson, Michael; Lehti, Leena; Höglund, Peter; Åkeson, Per; Wassélius, Johan

    2017-08-01

    Background High-quality non-invasive imaging of the deep venous system in the thorax is challenging, but nevertheless required for diagnosis of vascular pathology as well as for patient selection and preoperative planning for endovascular procedures. Purpose To compare the diagnostic quality of Gadofosveset-enhanced thoracic magnetic resonance venography, seven consecutive patients with suspected or known disease affecting the central thoracic veins were compared to seven consecutive magnetic resonance venography using conventional gadolinium-based contrast agents. Materials and methods Diagnostic capability, defined as the ability to assess vessel patency and pathologic conditions, for the major thoracic deep venous segments was assessed by two-independent readers. Both reviewers rated the overall subjective image quality on a four-graded scale, and inter-rater variability was analyzed using unweighted and weighted Cohen's kappa values. Results Diagnostic capability was generally considerably higher in the Gadofosveset group for all examined vessel segments. The overall images quality rating was significantly higher for the Gadofosveset group with a mean rating of 2.9 and 2.7 for the two-independent readers, compared to 1.2 and 1.0 for the control croup. Inter-rater variability showed less variability for the Gadofosveset group with a quadratic-weighted Cohen's Kappa value of 0.58 compared to 0.36 for the control group. Conclusion Our results show that Gadofosveset-enhanced magnetic resonance venography of the central thoracic veins is a reliable technique in clinical routine practice that results in diagnostic images, superior to conventional gadolinium-based contrast medium.

  9. Visual rating method and tensor-based morphometry in the diagnosis of mild cognitive impairment and Alzheimer's disease: a comparative magnetic resonance imaging study.

    Science.gov (United States)

    Tuokkola, Terhi; Koikkalainen, Juha; Parkkola, Riitta; Karrasch, Mira; Lötjönen, Jyrki; Rinne, Juha O

    2016-03-01

    Atrophy of the medial temporal lobe (MTL) is the main structural magnetic resonance imaging (MRI) finding in the brain of patients with Alzheimer's disease (AD). However, evaluating the degree of atrophy is still demanding. The visual rating method (VRM) was compared with multi-template tensor-based morphometry (TBM), in terms of its efficacy in diagnosing of mild cognitive impairment (MCI) and AD. Forty-seven patients with MCI, 80 patients with AD and 84 controls were studied. TBM seems to be more sensitive than VRM at the early stage of dementia in the areas of MTL and ventricles. The methods were equally good in distinguishing controls and the MCI group from the AD group. At the frontal areas TBM was better than VRM in all comparisons. A user-friendly VRM is still useful for the clinical evaluation of MCI patients, but multi-template TBM is more sensitive for diagnosing the early stages of dementia. However, TBM is currently too demanding to use for daily clinical work. © The Foundation Acta Radiologica 2015.

  10. A comparative study of the anatomy of adipose tissue in areas with and without raised lesions of cellulite using magnetic resonance imaging.

    Science.gov (United States)

    Hexsel, Doris; Siega, Carolina; Schilling-Souza, Juliana; Porto, Manoela Donida; Rodrigues, Ticiana Costa

    2013-12-01

    Cellulite is considered a noninflammatory phenomenon characterized by alterations to the skin surface, with depressed and raised lesions. Few studies have evaluated subcutaneous fat in patients with cellulite, and there is no information about the anatomy of raised lesions. Sixty women with raised cellulite lesions were evaluated using magnetic resonance imaging (MRI). Cellulite grade was evaluated using the Cellulite Severity Scale (CSS). Raised cellulite lesions were marked and compared with control areas on the opposite side of the body (buttocks, abdomen, and upper thighs). Mean age was 39.3 ± 11.0 years and average body mass index (BMI) was 25.4 ± 4.1 kg/m(2) . There were no differences between the raised lesions and the control areas in the anatomy of the fat lobes and their size. CSS scores were higher in older patients and in those with higher BMI. Patients with higher BMI had more fat lobes. The anatomy of subcutaneous fat was similar in raised and control areas for shape, size, and thickness. Higher CSS scores were found in older patients and those with higher BMI. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  11. Comparative study of the detection of joint injury in early-stage rheumatoid arthritis by magnetic resonance imaging of the wrist and finger joints and physical examination.

    Science.gov (United States)

    Tamai, Mami; Kawakami, Atsushi; Iwamoto, Naoki; Kawashiri, Shin-Ya; Fujikawa, Keita; Aramaki, Toshiyuki; Kita, Junko; Okada, Akitomo; Koga, Tomohiro; Arima, Kazuhiko; Kamachi, Makoto; Yamasaki, Satoshi; Nakamura, Hideki; Ida, Hiroaki; Origuchi, Tomoki; Takao, Shoichiro; Aoyagi, Kiyoshi; Uetani, Masataka; Eguchi, Katsumi

    2011-03-01

    To verify whether magnetic resonance imaging (MRI)-proven joint injury is sensitive as compared with joint injury determined by physical examination. MRI of the wrist and finger joints of both hands was examined in 51 early-stage rheumatoid arthritis (RA) patients by both plain and gadolinium diethylenetriaminepentaacetic acid-enhanced MRI. Synovitis, bone edema, and bone erosion (the latter two included as bone lesions at the wrist joints); metacarpophalangeal joints; and proximal interphalangeal joints were considered as MRI-proven joint injury. Japan College of Rheumatology-certified rheumatologists had given a physical examination just before the MRI study. The presence of tender and/or swollen joints in the same fields as MRI was considered as joint injury on physical examination. The association of MRI-proven joint injury with physical examination-proven joint injury was examined. A total of 1,110 sites were available to be examined. MRI-proven joint injury was found in 521 sites, whereas the other 589 sites were normal. Physical examination-proven joint injury was found in 305 sites, which was significantly low as compared with MRI-proven joint injury (P = 1.1 × 10(-12) versus MRI). Joint injury on physical examination was not found in 81.5% of the sites where MRI findings were normal. Furthermore, an association of the severity of MRI-proven joint injury with that of joint injury on physical examination was clearly demonstrated (P = 1.6 × 10(-15), r(s) = 0.469). Our present data suggest that MRI is not only sensitive but accurately reflects the joint injury in patients with early-stage RA. Copyright © 2011 by the American College of Rheumatology.

  12. X-ray angiography perfusion imaging with an intra-arterial injection: comparative study with 15O-gas/water positron emission tomography.

    Science.gov (United States)

    Asai, Katsunori; Nakamura, Hajime; Watabe, Tadashi; Nishida, Takeo; Sakaguchi, Manabu; Hatazawa, Jun; Yoshimine, Toshiki; Kishima, Haruhiko

    2017-12-04

    X-ray angiography perfusion (XAP) is a perfusion imaging technique based on conventional DSA. In this study, we aimed to validate parameters derived from XAP by comparing them with 15 O-gas/water positron emission tomography (PET), using data from patients with chronic ischemic cerebrovascular disease. 18 consecutive patients were included. XAP was performed with intra-arterial infusion of contrast media, and a time-density curve was constructed for each cerebral hemisphere. From the curves, the relative values of mean transit time (rMTT) and wash-in rate (rWiR) were obtained by dividing the values of the right hemisphere by those of the left hemisphere. These were then compared with the relative values of cerebral blood flow (rCBF) and rMTT calculated from the PET data. XAP rWiR correlated strongly with PET rCBF (r=0.86, P<0.0001). rMTT measurements from the two modalities were also strongly correlated (r=0.85, P<0.0001). Bland-Altman analysis revealed a bias of 0.14±0.18 (95% limits of agreement -0.22 to 0.51) for PET rCBF versus XAP rWiR, and 0.016±0.093 (95% limits of agreement -0.17 to 0.20) for rMTT between the two modalities. The relative values obtained from XAP were validated across a population of patients with chronic ischemic cerebrovascular disease. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Meningiomas: A Comparative Study of 68Ga-DOTATOC, 68Ga-DOTANOC and 68Ga-DOTATATE for Molecular Imaging in Mice

    Science.gov (United States)

    Soto-Montenegro, María Luisa; Peña-Zalbidea, Santiago; Mateos-Pérez, Jose María; Oteo, Marta; Romero, Eduardo; Morcillo, Miguel Ángel; Desco, Manuel

    2014-01-01

    Purpose The goal of this study was to compare the tumor uptake kinetics and diagnostic value of three 68Ga-DOTA-labeled somatostatin analogues (68Ga-DOTATOC, 68Ga-DOTANOC, and 68Ga-DOTATATE) using PET/CT in a murine model with subcutaneous meningioma xenografts. Methods The experiment was performed with 16 male NUDE NU/NU mice bearing xenografts of a human meningioma cell line (CH-157MN). 68Ga-DOTATOC, 68Ga-DOTANOC, and 68Ga-DOTATATE were produced in a FASTLab automated platform. Imaging was performed on an Argus small-animal PET/CT scanner. The SUVmax of the liver and muscle, and the tumor-to-liver (T/L) and tumor-to-muscle (T/M) SUV ratios were computed. Kinetic analysis was performed using Logan graphical analysis for a two-tissue reversible compartmental model, and the volume of distribution (Vt) was determined. Results Hepatic SUVmax and Vt were significantly higher with 68Ga-DOTANOC than with 68Ga-DOTATOC and 68Ga-DOTATATE. No significant differences between tracers were found for SUVmax in tumor or muscle. No differences were found in the T/L SUV ratio between 68Ga-DOTATATE and 68Ga-DOTATOC, both of which had a higher fraction than 68Ga-DOTANOC. The T/M SUV ratio was significantly higher with 68Ga-DOTATATE than with 68Ga-DOTATOC and 68Ga-DOTANOC. The Vt for tumor was higher with 68Ga-DOTATATE than with 68Ga-DOTANOC and relatively similar to that of 68Ga-DOTATOC. Conclusions This study demonstrates, for the first time, the ability of the three radiolabeled somatostatin analogues tested to image a human meningioma cell line. Although Vt was relatively similar with 68Ga-DOTATATE and 68Ga-DOTATOC, uptake was higher with 68Ga-DOTATATE in the tumor than with 68Ga-DOTANOC and 68Ga-DOTATOC, suggesting a higher diagnostic value of 68Ga-DOTATATE for detecting meningiomas. PMID:25369268

  14. Comparative Canadian-American Studies.

    Science.gov (United States)

    Ezell, Macel D.

    1988-01-01

    Outlines topics for comparative study of Canada and the United States. Includes geography, politics, settlement patterns, economics, education, religion, and sports. Suggests materials to aid teachers in formulating comparative approaches to Canadian and U.S. studies. (DB)

  15. Evaluation of myocardial viability-a comparative study using dobutamine Doppler tissue imaging and nitroglycerin intervened 99Tcm -sestamibi myocardial SPECT

    International Nuclear Information System (INIS)

    Wu, H.; Yang, J.

    2002-01-01

    Aim: Doppler tissue imaging (DTI) is a newly developed ultrasonic technique and has rarely be used to study the myocardial viability. In the present study low dose dobutamine stressed DTI and nitroglycerin intervened 99 Tc m -sestamibi (MIBI) myocardial perfusion single photon emission computer tomography (SPECT) were compared in detecting viable hibernating myocardium. Material and Methods: Twenty patients with coronary artery disease and chronic left ventricular dysfunction underwent low dose dobutamine stressed DTI. Nine of them underwent 99 Tc m -MIBI SPECT under baseline condition and during nitroglycerin infusion. Low dose dobutamine stressed echocardiography was used as standard evaluation of myocardial viability in the present study. In echocardiography demonstrated 100/240 asynergic segments, 35 segments improved after dobutamine infusion, which were defined to be viable myocardium and classified as group A, the other 65 segments did not show improvement, which were defined to be non-viable and classified as group B. Results: In DTI evaluation, peak systolic velocity of S wave (Vs) was used as quantitative index. The change rate of Vs was calculated as: VR= (Vs post-dobutamine - Vs pre-dobutamine)/Vs pre-dobutamine. VR in group A was significantly higher than in group B (0.6∫0.4 vs 0.25±0.32, p 0.8 were in group A. When using 0.4 for VR as cut-off of viable myocardium, the sensitivity and specificity of detecting myocardial viability with DTI were 73.3% and 75.8%, respectively. In the nine patients who underwent SPECT there were 48/108 dysfunctional segments demonstrated by echocardiography. There were 15/48 segments in group A and 33/48 in group B. Nitroglycerin induced significant decrease of the defect area of black-out polar map in group A while no significant changes in group B. When using a cut-off of 20% for decrement of black-out size in a special segment after nitroglycerin intervention, the sensitivity and specificity were 75.8% and 81

  16. Encoding and recall of finger sequences in experienced pianists compared with musically naïve controls: a combined behavioral and functional imaging study.

    Science.gov (United States)

    Pau, S; Jahn, G; Sakreida, K; Domin, M; Lotze, M

    2013-01-01

    Long-term intensive sensorimotor training alters functional representation of the motor and sensory system and might even result in structural changes. However, there is not much knowledge about how previous training impacts learning transfer and functional representation. We tested 14 amateur pianists and 15 musically naïve participants in a short-term finger sequence training procedure, differing considerably from piano playing and measured associated functional representation with functional magnetic resonance imaging. The conditions consisted of encoding a finger sequence indicated by hand symbols ("sequence encoding") and subsequently replaying the sequence from memory, both with and without auditory feedback ("sequence retrieval"). Piano players activated motor areas and the mirror neuron system more strongly than musically naïve participants during encoding. When retrieving the sequence, musically naïve participants showed higher activation in similar brain areas. Thus, retrieval activations of naïve participants were comparable to encoding activations of piano players, who during retrieval performed the sequences more accurately despite lower motor activations. Interestingly, both groups showed primary auditory activation even during sequence retrieval without auditory feedback, supporting previous reports about coactivation of the auditory cortex after learned association with motor performance. When playing with auditory feedback, only pianists lateralized to the left auditory cortex. During encoding activation in left primary somatosensory cortex in the height of the finger representations had a predictive value for increased motor performance later on (error rates). Contrarily, decreased performance was associated with increased visual cortex activation during encoding. Our study extends previous reports about training transfer of motor knowledge resulting in superior training effects in musicians. Performance increase went along with activity in

  17. Comparative Study of Fluorodeoxyglucose Positron Emission Tomography and Magnetic Resonance Imaging for the Detection of Spinal Bone Marrow Infiltration in Untreated Patients with Multiple Myeloma

    International Nuclear Information System (INIS)

    Hur, J.; Yoon, C.S.; Hoon Ryu, Y.; Yun, M.J.; Suh, J.S.

    2008-01-01

    Background: The presence and extent of osteolytic bone lesions in untreated patients with multiple myeloma are important factors in the staging of the disease, and the extent of bone lesions in multiple myeloma cases significantly influences decisions regarding therapy. Recently, fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI) have been used to detect bone marrow involvement in patients with multiple myeloma. Purpose: To compare the efficacy of FDG-PET and MRI for the detection of bone marrow infiltration into the spine in untreated patients with multiple myeloma. Material and Methods: Twenty-two patients with multiple myeloma underwent both FDG-PET and spine MRI. The examined spinal regions by MRI included 21 thoracic and lumbar spines, one lumbar spine, and 12 cervical spines. The following imaging sequences were performed: T1-weighted spin-echo MRI with and without fat suppression, and T2-weighted spin-echo MRI in the sagittal plane. In the patients with bone marrow abnormalities, an additional contrast-enhanced T1-weighted spin-echo MR image and a fat-suppressed T1-weighted spin-echo MR image were obtained. Patients were divided into three groups on the basis of the criteria defined by Durie and Salmon: stage I (n=9), stage II (n=3), and stage III (n=10). The number and location of lesions detected in both FGD-PET and MRI were recorded, and the lesions were compared using the McNemar test. Bone marrow biopsy results, the patient's clinical examinations, and other imaging findings (MRI, FDG-PET, etc.) were used as references. Results: In stages I and II (37 lesions in 12 patients), FDG-PET and MRI detected lesions in 78% (29 of 37 lesions) and 86% (32 of 37 lesions), respectively. However, the difference between the abilities of FDG-PET and MRI to detect lesions was not statistically significant (P=0.317). In stage III (101 lesions in 10 patients), FDG-PET and MRI detected lesions in 80% (81 of 101 lesions) and 92

  18. Comparative Study of Fluorodeoxyglucose Positron Emission Tomography and Magnetic Resonance Imaging for the Detection of Spinal Bone Marrow Infiltration in Untreated Patients with Multiple Myeloma

    Energy Technology Data Exchange (ETDEWEB)

    Hur, J.; Yoon, C.S.; Hoon Ryu, Y.; Yun, M.J.; Suh, J.S. (Dept. of Diagnostic Radiology and Research Inst. of Radiological Science, and Dept. of Nuclear Medicine, Yonsei Univ. College of Medicine, Seoul (KR))

    2008-05-15

    Background: The presence and extent of osteolytic bone lesions in untreated patients with multiple myeloma are important factors in the staging of the disease, and the extent of bone lesions in multiple myeloma cases significantly influences decisions regarding therapy. Recently, fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI) have been used to detect bone marrow involvement in patients with multiple myeloma. Purpose: To compare the efficacy of FDG-PET and MRI for the detection of bone marrow infiltration into the spine in untreated patients with multiple myeloma. Material and Methods: Twenty-two patients with multiple myeloma underwent both FDG-PET and spine MRI. The examined spinal regions by MRI included 21 thoracic and lumbar spines, one lumbar spine, and 12 cervical spines. The following imaging sequences were performed: T1-weighted spin-echo MRI with and without fat suppression, and T2-weighted spin-echo MRI in the sagittal plane. In the patients with bone marrow abnormalities, an additional contrast-enhanced T1-weighted spin-echo MR image and a fat-suppressed T1-weighted spin-echo MR image were obtained. Patients were divided into three groups on the basis of the criteria defined by Durie and Salmon: stage I (n=9), stage II (n=3), and stage III (n=10). The number and location of lesions detected in both FGD-PET and MRI were recorded, and the lesions were compared using the McNemar test. Bone marrow biopsy results, the patient's clinical examinations, and other imaging findings (MRI, FDG-PET, etc.) were used as references. Results: In stages I and II (37 lesions in 12 patients), FDG-PET and MRI detected lesions in 78% (29 of 37 lesions) and 86% (32 of 37 lesions), respectively. However, the difference between the abilities of FDG-PET and MRI to detect lesions was not statistically significant (P=0.317). In stage III (101 lesions in 10 patients), FDG-PET and MRI detected lesions in 80% (81 of 101 lesions) and

  19. Comparative study of reconstruction filters for cranio examinations of the Philips system and its influence on the quality of the tomographic image

    International Nuclear Information System (INIS)

    Silveira, V.C.; Kodlulovich, S.; Delduck, R.S.; Oliveira, L.C.G.

    2011-01-01

    The aim of this study was to evaluate different reconstruction algorithm (kernels) applied for head examinations. The research was carried out using 40-slice MDCT (Philips, Brilliance 40 CT scanner) and an ACR Phantoms to evaluate the image quality. The doses were estimated applying the coefficients obtained by IMPACT .The study showed that independently of the filter used the values of CT number have no change. The low contrast showed that the choice of correct filter might result a decrease of 9% of doses values. For special resolution, the sharp filter showed a better response for low m As. The noise value of image to certain filters smooth has no changed, even by reducing the m As values. (author)

  20. Recent lung imaging studies

    International Nuclear Information System (INIS)

    Taplin, G.V.; Chopra, S.K.

    1976-01-01

    Radionuclide lung imaging procedures have been available for 11 years but only the perfusion examination has been used extensively and mainly for the diagnosis of pulmonary embolism (P.E.). Its ability to reveal localized ischemia makes it a valuable test of regional lung function as well as a useful diagnostic aid in P.E. Although it had been recognized for several years that chronic obstructive pulmonary disease (COPD) can cause lung perfusion defects which may simulate pulmonary embolism, relatively little use has been made of either the radioxenon or the radioaerosol inhalation lung imaging procedures until the last few years as a means of distinguishing P.E. from COPD. In this review emphasis is placed on our recent experience with both of these inhalation procedures in comparison with pulmonary function tests and roentgenography for the early detection of COPD in population studies. Equal emphasis is given to simultaneous aerosol ventilation-perfusion (V/P) imaging for a functional diagnosis of P.E. Two new developments in regional lung diffusion imaging, performed after the inhalation of radioactive gases and/or rapidly absorbed radioaerosols are described. The experimental basis for their potential clinical application in pulmonary embolism detection is presented

  1. Risk factors associated with inferior alveolar nerve injury after extraction of the mandibular third molar--a comparative study of preoperative images by panoramic radiography and computed tomography.

    Science.gov (United States)

    Hasegawa, T; Ri, S; Shigeta, T; Akashi, M; Imai, Y; Kakei, Y; Shibuya, Y; Komori, T

    2013-07-01

    In this study we investigated the relationships among the risk factors for inferior alveolar nerve injury (IANI), and the difference between preoperative imaging findings on panoramic radiographs and computed tomography (CT), by univariate and multivariate analyses. We determined the following to be significant variables by multivariate analysis: panoramic radiographic signs, such as the loss of the white line of the inferior alveolar canal or the diversion of the canal; excessive haemorrhage during extraction; and a close relationship of the roots to the IAN (type 1 cases) on CT examination. CT findings of type 1 were associated with a significantly higher risk (odds ratio 43.77) of IANI. In addition, many panoramic findings were not consistent with CT findings (275 of 440 teeth; 62.5%). These results suggest that CT findings may be able to predict the development of IANI more accurately than panoramic findings. Panoramic radiography alone did not provide sufficiently reliable images required for predicting IANI. Therefore, when the panoramic image is suggestive of a close relationship between the impacted tooth and the IAN, CT should be recommended as a means of conducting further investigations. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Low-field MR imaging of the spine. A comparative study of a traditional and a new, completely balanced gradient-echo sequence

    Energy Technology Data Exchange (ETDEWEB)

    Drejer, J. [Dept. of Diagnostic Radiology, Herlev Hospital, Univ. Copenhagen (Denmark); Thomsen, H.S. [Dept. of Diagnostic Radiology, Herlev Hospital, Univ. Copenhagen (Denmark); Tanttu, J. [Picker Nordstar, Helsinki (Finland)

    1995-09-01

    49 patients underwent 53 examinations with both a traditional T1-weighted gradient-echo (PS) sequence and a new completely balanced steady-state 3-D (CBASS3D) sequence; 20 examinations included the cervical spine, 8 the thoracic spine and 25 the lumbar spine. All 106 examinations were reviewed twice regarding visibility of selected structures in the spinal region and diagnostic usefulness. The CBASS3D sequence delineated the medulla, nerve roots, CSF, the intervertebral discs and the posterior longitudinal ligament significantly better than the PS sequence. Disc hernia was also better visualised (p<0.01). There were significantly more artefacts on images obtained with the CBASS3D sequence, but they were usually outside the region of interest and occurred less frequently over time due to increased experience of the staff. Both reviewers found the diagnostic usefulness of CBASS3D to be superior compared to that of PS and excellent for diagnostic purposes. (orig./MG).

  3. Low-field MR imaging of the spine. A comparative study of a traditional and a new, completely balanced gradient-echo sequence

    International Nuclear Information System (INIS)

    Drejer, J.; Thomsen, H.S.; Tanttu, J.

    1995-01-01

    49 patients underwent 53 examinations with both a traditional T1-weighted gradient-echo (PS) sequence and a new completely balanced steady-state 3-D (CBASS3D) sequence; 20 examinations included the cervical spine, 8 the thoracic spine and 25 the lumbar spine. All 106 examinations were reviewed twice regarding visibility of selected structures in the spinal region and diagnostic usefulness. The CBASS3D sequence delineated the medulla, nerve roots, CSF, the intervertebral discs and the posterior longitudinal ligament significantly better than the PS sequence. Disc hernia was also better visualised (p<0.01). There were significantly more artefacts on images obtained with the CBASS3D sequence, but they were usually outside the region of interest and occurred less frequently over time due to increased experience of the staff. Both reviewers found the diagnostic usefulness of CBASS3D to be superior compared to that of PS and excellent for diagnostic purposes. (orig./MG)

  4. Comparing hardcopy and softcopy results in the study of the impact of workflow on perceived reproduction quality of fine art images

    Science.gov (United States)

    Farnand, Susan; Jiang, Jun; Frey, Franziska

    2011-01-01

    A project, supported by the Andrew W. Mellon Foundation, is currently underway to evaluate current practices in fine art image reproduction, determine the image quality generally achievable, and establish a suggested framework for art image interchange. To determine the image quality currently being achieved, experimentation has been conducted in which a set of objective targets and pieces of artwork in various media were imaged by participating museums and other cultural heritage institutions. Prints and images for display made from the delivered image files at the Rochester Institute of Technology were used as stimuli in psychometric testing in which observers were asked to evaluate the prints as reproductions of the original artwork and as stand alone images. The results indicated that there were limited differences between assessments made using displayed images relative to printed reproductions. Further, the differences between rankings made with and without the original artwork present were much smaller than expected.

  5. Postoperative satisfaction and the patient's body image, life satisfaction, and self-esteem: a retrospective study comparing adolescent girls and boys after cosmetic surgery.

    Science.gov (United States)

    Kamburoğlu, Haldun O; Ozgür, Figen

    2007-01-01

    Cosmetic surgery procedures are more complex for adolescents than for adults because there are more factors affecting patient satisfaction, especially psychological factors. This study was designed to find answers to four main questions: (1) whether postoperative satisfaction rates differ statistically between males and females, (2) whether postoperative satisfaction correlates significantly with the self-esteem, body image, life satisfaction trilogy, (3) what the postoperative patient satisfaction and cosmetic procedure rates are among adolescents by years, and (4) whether a statistically significant relationship exists between postoperative satisfaction and a willingness of adolescents to undergo another cosmetic surgery. The study enrolled 86 of 165 patients who underwent surgery between January 2001 and June 2005. A simple poll consisting of 12 simple questions was used to collect data. No statistically significant difference was found in postoperative satisfaction rates between males and females. The findings show that postoperative satisfaction is significantly related to self-esteem, body image, and life satisfaction. The patient satisfaction rate was 93.83%, and there was no increase in adolescent cosmetic surgery rates over the years. Adolescents are good candidates for cosmetic surgery, but patients must be evaluated carefully. Any suspicion about a patient's psychological status must result in a psychiatric consultation.

  6. Signal intensity change on unenhanced T1-weighted images in dentate nucleus and globus pallidus after multiple administrations of gadoxetate disodium: an intraindividual comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Giorgio; Minotti, Marta; De Piano, Francesca [Universita degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan (Italy); Preda, Lorenzo [Universita degli Studi di Pavia, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, Pavia (Italy); National Center of Oncological Hadrontherapy (CNAO Foundation), Division of Radiology, Pavia (Italy); Cocorocchio, Emilia; Ferrucci, Pier Francesco [European Institute of Oncology, Melanoma and Sarcoma Medical Oncology Division, Milan (Italy); Raimondi, Sara [European Institute of Oncology, Division of Epidemiology and Biostatistics, Milan (Italy); Giannitto, Caterina; Petralia, Giuseppe [European Institute of Oncology, Division of Radiology, Milan (Italy); Bellomi, Massimo [European Institute of Oncology, Division of Radiology, Milan (Italy); Universita degli Studi di Milano, Oncology and Haematology/Oncology Department, Milan (Italy)

    2017-10-15

    To investigate whether there is an increased signal intensity (SI) of dentate nucleus (DN) and globus pallidus (GP) on unenhanced T1-weighted magnetic resonance imaging (MRI), in patients who had undergone multiple administrations of gadoxetate disodium. We retrospectively included stage III melanoma patients, who had been previously enrolled in a trial of adjuvant therapy and who had undergone whole-body contrast-enhanced MRIs with gadoxetate disodium every three months for their follow-up. The SI ratios of DN-to-pons and GP-to-thalamus on unenhanced T1-weighted images were calculated. The difference in SI ratios between the first and the last MRI examinations was assessed and a linear mixed model was performed to detect how SI ratios varied with the number of administrations. Eighteen patients were included in our study. The number of gadoxetate disodium administrations ranged from 2 to 18. Paired t-test did not show any significant difference in DN-to-pons (p=0.21) and GP-to-thalamus (p=0.09) SI ratios by the end of the study. DN-to-pons SI ratio and GP-to-thalamus SI ratio did not significantly increase with increasing the number of administrations (p=0.14 and p=0.06, respectively). Multiple administrations of gadoxetate disodium are not associated with increased SI in DN and GP in the brain. (orig.)

  7. Body hair counts during hair length reduction procedures: a comparative study between Computer Assisted Image Analysis after Manual Processing (CAIAMP) and Trichoscan(™).

    Science.gov (United States)

    Van Neste, D J J

    2015-08-01

    To compare two measurement methods for body hair. Calibration of computer assisted image analysis after manual processing (CAIAMP) showed variation body sites with 'good natural contrast between hair and skin' were taken before hair dye, after hair dye or after hair length reduction without hair extraction or destruction. Data in the same targets were compared with Trichoscan(™) quoted for 'unambiguous evaluation of the hair growth after shaving'. CAIAMP detected a total of 337 hair and showed no statistically significant differences with the three procedures confirming 'good natural contrast between hair and skin' and that reduction methods did not affect hair counts. While CAIAMP found a mean number of 19 thick hair (≥30 μm) before dye, 18 after dye and 20 after hair reduction, Trichoscan(™) found in the same sites respectively 44, 73 and 61. Trichoscan(™) generated counts differed statistically significantly from CAIAMP-data. Automated analyses were considered un-specifically influenced by hair medulla and natural or artificial skin background. Quality control including all steps of human intervention and measurement technology are mandatory for body hair measurements during experimental or clinical trials on body hair grooming, shaving or removal. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Comparative study of ultrasonography, computed tomography, magnetic resonance imaging, and magnetic resonance spectroscopy for the diagnosis for fatty liver in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Hoon; Song, Xiao Li; Heo, Suk Hee; Kim, Jin Woong; Jeong, Yong Yeon; Kang, Heoung Keun [Dept. of Radiology, Chonnam National University Hwasun Hospital, Hwasun (Korea, Republic of); Shin, Sang Soo [Dept. of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of); Ahn, Kyu Youn [Dept. of Anatomy, Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2017-01-15

    To compare the accuracy of ultrasonography (US), single-energy CT (SECT), dual-energy CT (DECT), MR imaging (MRI), and MR spectroscopy (MRS) for detecting fatty liver in a rat model. Fatty liver was induced by 60% high-fat diet for 1, 2, 3, 4, or 5 weeks (3 rats per group, a total of 15 rats). The control group comprised of five rats fed 10% high-fat diet. US, SECT, DECT, MRI, and MRS of the liver were performed weekly. Histologic steatosis grade and intrahepatocelluar triglyceride level were determined histologically for the livers of sacrificed rats. Pearson correlation test was used to assess the correlation between examinations and standard reference levels. Receiver operating characteristic curves were constructed. Area under the curve (AUC), sensitivity, and specificity were calculated. US, SECT, DECT, MRI, and MRS were significantly correlated with histologic steatosis grade. The diagnostic performance of AUC, sensitivity, and specificity were 0.893, 80%, and 80% for US, 0.960, 80%, and 80% for SECT, 0.947, 100%, and 60% for DECT, 0.933, 93.3%, and 100% for MRI, and 0.960, 93.3%, and 100% for MRS. MRS showed the strongest correlation with histologic steatosis grade with the highest sensitivity and specificity for diagnosis of fatty liver compared to other modalities.

  9. Comparative study of ultrasonography, computed tomography, magnetic resonance imaging, and magnetic resonance spectroscopy for the diagnosis for fatty liver in a rat model

    International Nuclear Information System (INIS)

    Noh, Hoon; Song, Xiao Li; Heo, Suk Hee; Kim, Jin Woong; Jeong, Yong Yeon; Kang, Heoung Keun; Shin, Sang Soo; Ahn, Kyu Youn

    2017-01-01

    To compare the accuracy of ultrasonography (US), single-energy CT (SECT), dual-energy CT (DECT), MR imaging (MRI), and MR spectroscopy (MRS) for detecting fatty liver in a rat model. Fatty liver was induced by 60% high-fat diet for 1, 2, 3, 4, or 5 weeks (3 rats per group, a total of 15 rats). The control group comprised of five rats fed 10% high-fat diet. US, SECT, DECT, MRI, and MRS of the liver were performed weekly. Histologic steatosis grade and intrahepatocelluar triglyceride level were determined histologically for the livers of sacrificed rats. Pearson correlation test was used to assess the correlation between examinations and standard reference levels. Receiver operating characteristic curves were constructed. Area under the curve (AUC), sensitivity, and specificity were calculated. US, SECT, DECT, MRI, and MRS were significantly correlated with histologic steatosis grade. The diagnostic performance of AUC, sensitivity, and specificity were 0.893, 80%, and 80% for US, 0.960, 80%, and 80% for SECT, 0.947, 100%, and 60% for DECT, 0.933, 93.3%, and 100% for MRI, and 0.960, 93.3%, and 100% for MRS. MRS showed the strongest correlation with histologic steatosis grade with the highest sensitivity and specificity for diagnosis of fatty liver compared to other modalities

  10. Endodontic Working Length Measurement Using Cone-beam Computed Tomographic Images Obtained at Different Voxel Sizes and Field of Views, Periapical Radiography, and Apex Locator: A Comparative Ex Vivo Study.

    Science.gov (United States)

    Yılmaz, Funda; Kamburoğlu, Kıvanç; Şenel, Buğra

    2017-01-01

    The aim of this study was to evaluate the accuracy of working length determination by using an electronic apex locator, periapical radiography, and cone-beam computed tomographic (CBCT) imaging obtained at different voxel sizes and field of views (FOVs) in extracted human teeth. Thirty extracted human mandibular premolar teeth were used. The electronic working length measurements were performed by using an electronic apex locator (Root ZX; J Morita Corp, Kyoto, Japan). Five different image sets were obtained as follows: (1) CBCT imaging: 40 × 40 mm FOV, 0.080 mm 3 (FOV 40 ); (2) CBCT imaging: 60 × 60 mm FOV, 0.125 mm 3 (FOV 60 ); (3) CBCT imaging: 80 × 80 mm FOV, 0.160 mm 3 (FOV 80 ); (4) CBCT imaging: 100 × 100 mm FOV, 0.250 mm 3 (FOV 100 ); and (5) periapical digital radiography. Direct measurements performed with an electronic digital caliper were considered as the gold standard and compared with the electronic apex locator, CBCT, and periapical image measurements. Data were analyzed using a 2-way analysis of variance test. Significance level was set at P  .05 and the Gage R&R value was 30%). There were significant differences in the methods in terms of mean differences from the gold standard (P < .05). This study showed that available CBCT scans with different FOVs can be used for working length measurement. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Maxillary sinusitis - a comparative study of different imaging diagnosis methods; Sinusopatias maxilares - um estudo comparativo de diferentes metodos de diagnostico por imagem

    Energy Technology Data Exchange (ETDEWEB)

    Hueb, Marcelo Miguel; Borges, Fabiano de Almeida; Pulcinelli, Emilte; Souza, Wandir Ferreira; Borges, Luiz Marcondes [Faculdade de Medicina do Triangulo Mineiro (FMTM), Uberaba, MG (Brazil)

    1999-12-01

    We conducted prospective study comparing different methods (plain X-rays, computed tomography and ultrasonography mode-A) for the initial diagnosis of maxillary sinusitis. Twenty patients (40 maxillary sinuses) with a clinical history suggestive of sinusitis included in this study. The results were classified as abnormal or normal, using computed tomography as gold standard. The sensitivity for ultrasonography and plain X-rays was 84.6% and 69.2%, respectively. The specificity of both methods was 92.6%. This study suggests that ultrasonography can be used as a good follow-up method for patients with maxillary. sinusitis. (author)

  12. Evaluation of vocal fold vibration with an assessment form for high-speed digital imaging: comparative study between healthy young and elderly subjects.

    Science.gov (United States)

    Yamauchi, Akihito; Imagawa, Hiroshi; Yokonishi, Hisayuki; Nito, Takaharu; Yamasoba, Tatsuya; Goto, Takao; Takano, Shingo; Sakakibara, Ken-Ichi; Tayama, Niro

    2012-11-01

    We conducted a prospective study with a subjective assessment form for high-speed digital imaging (HSDI) to elucidate the features of vocal fold vibrations in vocally healthy subjects and to clarify gender- and age-related differences. Healthy adult volunteers participated in this study. They were divided into young (aged 35 and younger) and elderly (aged 65 and older) groups, and the scores of an assessment form for HSDI characteristics elaborated at our institution were statistically analyzed. Twenty-six young subjects (males: 9, females: 17; mean age: 27 years) and 20 elderly subjects (males: 8, females: 12; mean age: 72 years) were assigned to our study. Posterior gap and posterior-to-anterior longitudinal phase difference were characteristic to young females, whereas in young males, mucosal wave, anterior-to-posterior longitudinal phase difference, and supraglottic hyperactivity were frequent. In elderly males, axis shift, asymmetry, supraglottic hyperactivity, increased mucosal wave, lateral phase difference, and anterior-to-posterior longitudinal phase difference were frequent; and in elderly females, high incidence of lateral phase difference, atrophic change, anterior gap, and asymmetry were observed. The results show that the behaviors of vocal fold vibrations were diverse even in healthy subjects with no vocal complaints or history of laryngeal diseases, and hence, the diversity of vocal fold vibrations in normal subjects must be taken into account in evaluating vocal fold vibrations. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  13. Correlation between the tissue Doppler, strain rate, strain imaging during the dobutamine infusion and coronary fractional flow reserve during catheterization: a comparative study.

    Science.gov (United States)

    Dagdelen, Sinan; Yuce, Murat; Emiroglu, Yunus; Ergelen, Mehmet; Pala, Selcuk; Tanalp, Ali Cevat; Izgi, Akin; Kirma, Cevat

    2005-06-22

    Coronary fractional flow reserve (FFR) as an invasive, and dobutamine stress echocardiography (DSE) as a noninvasive technique were used to detect critical coronary stenosis. This study was undertaken to assess correlation between these two techniques by using tissue Doppler, strain rate (SR), and strain imaging (S). In 17 patients (aged 54.9+/-12.6, 4 F), a total of 22 vessels were studied. On dobutamine stress echocardiography, baseline and peak systolic (Sm), early (Em) and late (Am) diastolic myocardial velocities, SR and S were recorded from parasternal view (mid-posterior segment) for radial and apical view (mid-septum) for longitudinal deformation. Then coronary FFR was performed by using intracoronary adenosine infusion, and the value of system were analyzed for longitudinal SR and S values, it had a mild correlation with SR (r = 0.47, p = 0.044) and a good correlation with S (r = 0.66, p = 0.002). The quantification of regional myocardial deformation by using DSE rather than the motion would be more appropriate in detecting the ischemic dysfunctional segment supplied by the critical coronary stenosis. Strain measurement during the dobutamine infusion may provide an information on the FFR results of the culprit vessel.

  14. Head CT: Image quality improvement of posterior fossa and radiation dose reduction with ASiR - comparative studies of CT head examinations

    Energy Technology Data Exchange (ETDEWEB)

    Guzinski, Maciej; Waszczuk, Lukasz; Sasiadek, Marek J. [Wroclaw Medical University, Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw (Poland)

    2016-10-15

    To evaluate head CT protocol developed to improve visibility of the brainstem and cerebellum, lower bone-related artefacts in the posterior fossa and maintain patient radioprotection. A paired comparison of head CT performed without Adaptive Statistical Iterative Reconstruction (ASiR) and a clinically indicated follow-up with 40 % ASiR was acquired in one group of 55 patients. Patients were scanned in the axial mode with different scanner settings for the brain and the posterior fossa. Objective image quality analysis was performed with signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality analysis was based on brain structure visibility and evaluation of the artefacts. We achieved 19 % reduction of total DLP and significantly better image quality of posterior fossa structures. SNR for white and grey matter in the cerebellum were 34 % to 36 % higher, respectively, CNR was improved by 142 % and subjective analyses were better for images with ASiR. When imaging parameters are set independently for the brain and the posterior fossa imaging, ASiR has a great potential to improve CT performance: image quality of the brainstem and cerebellum is improved, and radiation dose for the brain as well as total radiation dose are reduced. (orig.)

  15. Time in internationally comparative studies

    NARCIS (Netherlands)

    Scheerens, Jaap; Luyten, Johannes W.; Glas, Cornelis A.W.; Scheerens, J

    2014-01-01

    In this chapter, illustrative internationally comparative data about time at school, time spent in out-of-school programs, and homework/ individual study time are presented. In the first section this is done in a more descriptive way, while in the second and third sections, the association between

  16. Imaging the Moho beneath Sedimentary Basins: A Comparative Study of Virtual Deep Seismic Sounding (VDSS) and P Wave Receiver Functions (PRF)

    Science.gov (United States)

    Liu, T.; Klemperer, S. L.; Yu, C.; Ning, J.

    2017-12-01

    In the past decades, P wave receiver functions (PRF) have been routinely used to image the Moho, although it is well known that PRFs are susceptible to contamination from sedimentary multiples. Recently, Virtual Deep Seismic Sounding (VDSS) emerged as a novel method to image the Moho. However, despite successful applications of VDSS on multiple datasets from different areas, how sedimentary basins affect the waveforms of post-critical SsPmp, the Moho reflection phase used in VDSS, is not widely understood. Here, motivated by a dataset collected in the Ordos plateau, which shows distinct effects of sedimentary basins on SsPmp and Pms waveforms, we use synthetic seismograms to study the effects of sedimentary basins on SsPmp and Pms, the phases used in VDSS and PRF respectively. The results show that when the sedimentary thickness is on the same order of magnitude as the dominant wavelength of the incident S wave, SsPmp amplitude decreases significantly with S velocity of the sedimentary layer, whereas increasing sedimentary thickness has little effect in SsPmp amplitude. Our explanation is that the low S velocity layer at the virtual source reduces the incident angle of S wave at the free surface, thus decreases the S-to-P reflection coefficient at the virtual source. In addition, transmission loss associated with the bottom of sedimentary basins also contributes to reducing SsPmp amplitude. This explains not only our observations from the Ordos plateau, but also observations from other areas where post-critical SsPmp is expected to be observable, but instead is too weak to be identified. As for Pms, we observe that increasing sedimentary thickness and decreasing sedimentary velocities both can cause interference between sedimentary multiples and Pms, rendering the Moho depths inferred from Pms arrival times unreliable. The reason is that although Pms amplitude does not vary with sedimentary thickness or velocities, as sedimentary velocities decrease and thickness

  17. Comparative study of mountain sickness

    OpenAIRE

    Cuba Caparó, Alberto

    2014-01-01

    In order to make a comparative study of Mountain Sickness affecting humans and cattle and sheep has been reviewed briefly the clinical, hematologic and pathologic aspects found in the literature. The anatomic correlation of clinical symptoms and major injuries in the bovine and ovine, emphasizing, among other things, the similarity of symptoms and lesions observed in the myocardium and the adrenal cortex does. Mountain Sickness In the three species considered in this study polycythemia is one...

  18. Comparing Generative Adversarial Network Techniques for Image Creation and Modification

    NARCIS (Netherlands)

    Pieters, Mathijs; Wiering, Marco

    2018-01-01

    Generative adversarial networks (GANs) have demonstrated to be successful at generating realistic real-world images. In this paper we compare various GAN techniques, both supervised and unsupervised. The effects on training stability of different objective functions are compared. We add an encoder

  19. Left ventricular function and functional recovery early and late after myocardial infarction: a prospective pilot study comparing two-dimensional strain, conventional echocardiography, and radionuclide myocardial perfusion imaging.

    Science.gov (United States)

    Carasso, Shemy; Agmon, Yoram; Roguin, Ariel; Keidar, Zohar; Israel, Ora; Hammerman, Haim; Lessick, Jonathan

    2013-11-01

    Visual left ventricular (LV) wall motion scoring is well established for the assessment of LV function, yet it is subjective, circumstantial, and relative and requires long training. Quantification of myocardial shortening (strain) using two-dimensional speckle-tracking is potentially less subjective. In this study, quantifiable LV contraction (two-dimensional strain) was prospectively cross-related with wall motion score (WMS) and radionuclide myocardial perfusion imaging (MPI) score in 20 patients (mean age, 54 ± 9 years) with acute myocardial infarctions, early and late after percutaneous revascularization. Echocardiography and rest MPI were performed 3 to 5 days after acute myocardial infarction. Echocardiography was repeated at 4 months. Peak segmental and global endocardial longitudinal strain (LS) and circumferential strain (CS) were measured, and principal strain was calculated. Volumes, WMS, MPI scores, and strain were assessed independently. Two-dimensional strain, visual WMS, and radionuclide MPI score correlated closely. Strain thresholds for abnormal WMS were 11.7% for early LS, 18.2% for early CS, 13.9% for late LS, and 19.1% for late CS. Late principal strain correlated better with WMS and MPI score than either LS or CS. CS varied minimally over time, while LS improved in most segments. Higher early CS (>15%) was predictive of segmental functional recovery. MPI score correlated better with late rather than early strain, probably because early resting perfusion defects represent permanent damage. In this pilot study, strain correlated with echocardiographic WMS and the extent of ischemia (MPI score) early and late after revascularization in patients with acute myocardial infarction. Longitudinal and circumferential strain uncoupling was observed. LS appeared to be more sensitive to acute ischemia, whereas CS correlated better with improvement after revascularization. Copyright © 2013 American Society of Echocardiography. Published by Mosby, Inc. All

  20. Comparative study using Monte Carlo methods of the radiation detection efficiency of LSO, LuAP, GSO and YAP scintillators for use in positron emission imaging (PET)

    International Nuclear Information System (INIS)

    Nikolopoulos, Dimitrios; Kandarakis, Ioannis; Tsantilas, Xenophon; Valais, Ioannis; Cavouras, Dionisios; Louizi, Anna

    2006-01-01

    The radiation detection efficiency of four scintillators employed, or designed to be employed, in positron emission imaging (PET) was evaluated as a function of the crystal thickness by applying Monte Carlo Methods. The scintillators studied were the LuSiO 5 (LSO), LuAlO 3 (LuAP), Gd 2 SiO 5 (GSO) and the YAlO 3 (YAP). Crystal thicknesses ranged from 0 to 50 mm. The study was performed via a previously generated photon transport Monte Carlo code. All photon track and energy histories were recorded and the energy transferred or absorbed in the scintillator medium was calculated together with the energy redistributed and retransported as secondary characteristic fluorescence radiation. Various parameters were calculated e.g. the fraction of the incident photon energy absorbed, transmitted or redistributed as fluorescence radiation, the scatter to primary ratio, the photon and energy distribution within each scintillator block etc. As being most significant, the fraction of the incident photon energy absorbed was found to increase with increasing crystal thickness tending to form a plateau above the 30 mm thickness. For LSO, LuAP, GSO and YAP scintillators, respectively, this fraction had the value of 44.8, 36.9 and 45.7% at the 10 mm thickness and 96.4, 93.2 and 96.9% at the 50 mm thickness. Within the plateau area approximately (57-59)% (59-63)% (52-63)% and (58-61)% of this fraction was due to scattered and reabsorbed radiation for the LSO, GSO, YAP and LuAP scintillators, respectively. In all cases, a negligible fraction (<0.1%) of the absorbed energy was found to escape the crystal as fluorescence radiation

  1. Sonography compared with MR imaging in the evaluation of card tethering following myelomeningocele repair

    International Nuclear Information System (INIS)

    Newman, B.; Bowen, A.; Albright, L.

    1989-01-01

    This paper reports on MR imaging and videotaped US spine examinations to evaluate cord tethering were retrospectively compared in 12 children with prior myelomeningocele repair and correlated with clinical and surgical findings. Although US did not delineate normal or abnormal anatomy as well as MR imaging, both types of studies confirmed the presence of tethering in 10 patients. One child with a normal US examination and abnormal MR images had tethering confirmed surgically. A second child had a US study suggestive of tethering with equivocal MR images. Postoperative studies in eight patients correlated less well; US suggested persistent tethering in five patients and MR imaging indicated tethering in two

  2. Gadolinium- and manganite-based contrast agents with fluorescent probes for both magnetic resonance and fluorescence imaging of pancreatic islets: a comparative study

    Czech Academy of Sciences Publication Activity Database

    Berková, Z.; Jirák, D.; Zacharovová, K.; Lukeš, I.; Kotková, Z.; Kotek, J.; Kačenka, M.; Kaman, Ondřej; Řehoř, I.; Hájek, M.; Saudek, F.

    2013-01-01

    Roč. 8, č. 4 (2013), s. 614-621 ISSN 1860-7179 Institutional support: RVO:68378271 Keywords : contrast agents * gadolinium * magnetic resonance imaging * manganite * pancreatic islets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.046, year: 2013

  3. Characterization of liver lesions with mangafodipir trisodium-enhanced MR imaging: multicenter study comparing MR and dual-phase spiral CT

    NARCIS (Netherlands)

    M. Oudkerk (Matthijs); C.G. Torres; B. Song; M. Konig; J. Grimm; J. Fernandez-Cuadrado; B. op de Beeck; M. Marquardt; P. van Dijk (Pieter); J.C. de Groot (Jan Cees)

    2002-01-01

    textabstractPURPOSE: To evaluate whether mangafodipir trisodium (Mn-DPDP)-enhanced magnetic resonance (MR) imaging surpasses dual-phase spiral computed tomography (CT) in differentiating focal liver lesions. MATERIALS AND METHODS: One hundred forty-five patients who had or were

  4. Image Transmission Studies

    Science.gov (United States)

    Blaine, G. James; Hill, Rexford L.; Rueter, Allen P.; Senol, Evren; Studt, James W.

    1988-06-01

    Radiological PACS image sizes and desired retrieval response times demand high-bandwidth communication networks. Local area network technology at speeds higher that 10 Megabits/second (IEEE 802.3) have not achieved standardization nor production volume. Our current PACS experiments are based on a three-level subnet approach using 10 Mb/s Ethernet channels. An Ethernet channel is shown to support image transfers at an average throughput of 3 Mb/s. Preliminary measurements and simulation results suggest that traffic from as many as two-to-three archives can be supported on the same channel.

  5. Image transmission studies

    International Nuclear Information System (INIS)

    Blaine, G.J.; Hill, R.L.; Rueter, A.P.; Senol, E.; Studt, J.W.

    1988-01-01

    This paper discusses radiological PACS image sizes and desired retrieval response time that demand high-bandwidth communication networks. Local area network technology at speeds higher that 10 Megabits/second (IEEE 802.3) have not achieved standardization nor production volume. The authors describe current PACS experiments based on a three-level subnet approach using 10 Mb/s Ethernet channels. An Ethernet channel is shown to support image transfers at an average throughput of 3 Mb/s. Preliminary measurements and simulation results suggest that traffic from as many as two-to-three archives can be supported on the same channel

  6. Automated image registration for FDOPA PET studies

    International Nuclear Information System (INIS)

    Kang-Ping Lin; Sung-Cheng Huang, Dan-Chu Yu; Melega, W.; Barrio, J.R.; Phelps, M.E.

    1996-01-01

    In this study, various image registration methods are investigated for their suitability for registration of L-6-[18F]-fluoro-DOPA (FDOPA) PET images. Five different optimization criteria including sum of absolute difference (SAD), mean square difference (MSD), cross-correlation coefficient (CC), standard deviation of pixel ratio (SDPR), and stochastic sign change (SSC) were implemented and Powell's algorithm was used to optimize the criteria. The optimization criteria were calculated either unidirectionally (i.e. only evaluating the criteria for comparing the resliced image 1 with the original image 2) or bidirectionally (i.e. averaging the criteria for comparing the resliced image 1 with the original image 2 and those for the sliced image 2 with the original image 1). Monkey FDOPA images taken at various known orientations were used to evaluate the accuracy of different methods. A set of human FDOPA dynamic images was used to investigate the ability of the methods for correcting subject movement. It was found that a large improvement in performance resulted when bidirectional rather than unidirectional criteria were used. Overall, the SAD, MSD and SDPR methods were found to be comparable in performance and were suitable for registering FDOPA images. The MSD method gave more adequate results for frame-to-frame image registration for correcting subject movement during a dynamic FDOPA study. The utility of the registration method is further demonstrated by registering FDOPA images in monkeys before and after amphetamine injection to reveal more clearly the changes in spatial distribution of FDOPA due to the drug intervention. (author)

  7. MRI with intraoral orthodontic appliance-a comparative in vitro and in vivo study of image artefacts at 1.5 T.

    Science.gov (United States)

    Zachriat, C; Asbach, P; Blankenstein, K I; Peroz, I; Blankenstein, F H

    2015-01-01

    We investigated artefacts caused from orthodontic appliances at 1.5-T MRI of the head and neck region and whether the image quality can be improved utilizing the artefact-minimizing sequence WARP. In vitro tests were performed by phantom measurements of different orthodontic devices applying different types of MR sequences [echoplanar imaging (EPI), turbo spin echo (TSE) and TSE-WARP, gradient echo (GRE)]. Two independent readers determined after calibration the level of artefacts. Subsequently, the interobserver agreement was calculated. The measurement of artefacts was based on the American Society for Testing Materials Standard F 2119-07. For in vivo imaging, one test person was scanned with an inserted multibracket appliance. The level of artefacts for 27 target regions was evaluated. In vitro: ceramic brackets and ferromagnetic steel brackets produced artefact radii up to 1.12 and 7.40 cm, respectively. WARP reduced these artefacts by an average of 32.7%. The Bland-Altman-Plot indicated that maximum measurement differences of 3 mm have to be expected with two calibrated observers. In vivo: the EPI sequence for brain imaging was not analysable. The TSE sequence of the brain did not demonstrate artefacts except for the nasal cavity. Conversely, the TSE sequence of the cervical spine revealed severe artefacts in the midface region. The GRE sequence appeared to be more susceptible to artefacts than did the TSE sequence. In vitro measurements allow an estimation of the in vivo artefact size. Orthodontic appliances may often remain intraorally when performing MRI. WARP showed a more significant effect in vitro than in vivo.

  8. MRI with intraoral orthodontic appliance—a comparative in vitro and in vivo study of image artefacts at 1.5 T

    Science.gov (United States)

    Zachriat, C; Asbach, P; Blankenstein, K I; Peroz, I

    2015-01-01

    Objectives: We investigated artefacts caused from orthodontic appliances at 1.5-T MRI of the head and neck region and whether the image quality can be improved utilizing the artefact-minimizing sequence WARP. Methods: In vitro tests were performed by phantom measurements of different orthodontic devices applying different types of MR sequences [echoplanar imaging (EPI), turbo spin echo (TSE) and TSE-WARP, gradient echo (GRE)]. Two independent readers determined after calibration the level of artefacts. Subsequently, the interobserver agreement was calculated. The measurement of artefacts was based on the American Society for Testing Materials Standard F 2119-07. For in vivo imaging, one test person was scanned with an inserted multibracket appliance. The level of artefacts for 27 target regions was evaluated. Results: In vitro: ceramic brackets and ferromagnetic steel brackets produced artefact radii up to 1.12 and 7.40 cm, respectively. WARP reduced these artefacts by an average of 32.7%. The Bland–Altman-Plot indicated that maximum measurement differences of 3 mm have to be expected with two calibrated observers. In vivo: the EPI sequence for brain imaging was not analysable. The TSE sequence of the brain did not demonstrate artefacts except for the nasal cavity. Conversely, the TSE sequence of the cervical spine revealed severe artefacts in the midface region. The GRE sequence appeared to be more susceptible to artefacts than did the TSE sequence. Conclusions: In vitro measurements allow an estimation of the in vivo artefact size. Orthodontic appliances may often remain intraorally when performing MRI. WARP showed a more significant effect in vitro than in vivo. PMID:25734243

  9. Comparative effects of Facebook and conventional media on body image dissatisfaction

    OpenAIRE

    Cohen, Rachel; Blaszczynski, Alex

    2015-01-01

    Background Appearance comparison has consistently been shown to engender body image dissatisfaction. To date, most studies have demonstrated this relationship between appearance comparison and body image dissatisfaction in the context of conventional media images depicting the thin-ideal. Social comparison theory posits that people are more likely to compare themselves to similar others. Since social media forums such as Facebook involve one?s peers, the current study aimed to determine wheth...

  10. [Comparative study of X-ray digital tomosynthesis imaging based on intravenous urography and unenhanced multidetector-row computerized tomography in urinary calculi].

    Science.gov (United States)

    Tuerdi, Batuer; Wang, Hui; Huo, Zhong; Abula, Gulipiyan; Mahemuti, Biekemulati; Abulizi, Maihemuti

    2014-04-22

    To evaluate the clinical application value of X-ray digital DTSynthesis (DTS) based on IVU (Intravenous Urography)in urinary calculi contrasted with unenhanced multidetector-row computerized tomography. 75 patients suspected of urinary calculi underwent IVU, DTS based on IVU and UMDCT. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive of the three imaging ways were acquired according to operations, respectively. Chi-square test was used to evaluate the difference among the three ways. In 75 cases, 60 cases were proved to be urinary calculi. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive of IVU, DTS based on IVU,UMDCT is 70.0%, 73.3%, 70.7%, 91.3%, 37.9%; 91.7%, 86.7%, 90.7%, 96.5%, 72.2%; 96.7%, 86.7%, 94.7%, 96.7%, 86.7%, respectively.No significant differences between DTS based on IVU and UMDCT were found in sensitivity, specificity, accuracy, positive predictive value and negative predictive. Both cases are better than IVU in diagnostic ability. There is no significant difference in diagnostic ability of urinary calculi between DTS and UMDCT. DTS can be used as a routine imaging technique in diagnosis and follow up of urinary calculi.

  11. Imaging hydrated microbial extracellular polymers: Comparative analysis by electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dohnalkova, A.C.; Marshall, M. J.; Arey, B. W.; Williams, K. H.; Buck, E. C.; Fredrickson, J. K.

    2011-01-01

    Microbe-mineral and -metal interactions represent a major intersection between the biosphere and geosphere but require high-resolution imaging and analytical tools for investigating microscale associations. Electron microscopy has been used extensively for geomicrobial investigations and although used bona fide, the traditional methods of sample preparation do not preserve the native morphology of microbiological components, especially extracellular polymers. Herein, we present a direct comparative analysis of microbial interactions using conventional electron microscopy approaches of imaging at room temperature and a suite of cryogenic electron microscopy methods providing imaging in the close-to-natural hydrated state. In situ, we observed an irreversible transformation of the hydrated bacterial extracellular polymers during the traditional dehydration-based sample preparation that resulted in their collapse into filamentous structures. Dehydration-induced polymer collapse can lead to inaccurate spatial relationships and hence could subsequently affect conclusions regarding nature of interactions between microbial extracellular polymers and their environment.

  12. Importance of comparative study of CT dose between different centers

    International Nuclear Information System (INIS)

    Ramos Amores, D.; Serna Berna, A.; Mata Colodro, F.; Puchades Puchades, V.

    2013-01-01

    This work aims to show the importance of comparative analysis to get CT study can be made with fewer doses without impeding optimal image quality for diagnosis. With this work we can see that statistical studies on the dose given at two different sites can have beneficial consequences for patients because scanners can work with fewer doses and optimal image quality for diagnosis. (Author)

  13. Comparing Images of Seyfert Galaxies in Multiple Bands

    Science.gov (United States)

    Terrien, Ryan; Perlman, Eric; Packham, Christopher; Telesco, Charles; Radomski, James; Mason, Rachel

    2008-05-01

    Galaxies with Active Galactic Nuclei (AGN) are expected to host aconsiderable amount of gas and dust that emit strongly in themid-infrared (MIR) and can be related to structures seen in otherbands. This dust can either be associated with the AGN phenomenonitself or concentrated in star formation regions on a variety ofscales. We quantify and examine the spatial cross-correlation ofthe extended structure (>100pc from nucleus) in various emissionline images, X-ray images, and MIR images of a sample of five Seyfertgalaxies. Previous studies have determined that each object inthe sample shows thermal emission from warm dust that is primarilyheated by either the AGN central engine or by star formation. Wecannot define any trends with such a small sample, but we find thatboth varieties have significant correlation between their Paαand MIR images, and the AGN-dominated galaxies usually have significntcorrelation between their OIII images and MIR images. We findonly one case of significant correlation between the X-ray and MIRimages, in an object dominated by star formation.

  14. A Comparative Study of the Crystallite Size and the Dislocation Density of Bent Steel Plates using Bragg-edge Transmission Imaging, TOF Neutron Diffraction and EBSD

    Science.gov (United States)

    Oikawa, K.; Su, Y. H.; Tomota, Y.; Kawasaki, T.; Shinohara, T.; Kai, T.; Hiroi, K.; Zhang, S. Y.; Parker, J. D.; Sato, H.; Kiyanagi, Y.

    Line broadening analysis was performed on the time-of-flight neutron diffraction data for the plastically bent plates of a ferritic steel and a duplex stainless steel. A Rietveld analysis program, Z-Rietveld ver. 1.0 was used to fit the anisotropically broadened patterns where the increase in Lorentzian full width at half maximum (FWHM) and the Gaussian FWHM involves information of the crystallite size and the dislocation density, respectively. The derived results were compared with those obtained by using Bragg-edge transmission spectrum analysis and electron backscatter diffraction (EBSD) observations.

  15. Are Compassionate and Self-Image Goals Comparable across Cultures?

    Directory of Open Access Journals (Sweden)

    Kuncewicz Dariusz

    2015-12-01

    Full Text Available This study tested whether compassionate goals to support others and self-image goals to maintain and defend desired self-images: 1 are equivalent constructs across three cultures (U.S., Japan, Poland; 2 overlap with interdependent self-construal; and 3 predict relationships and growth measures similarly in each country. We re-analyzed data from American (n = 130 and Japanese (n = 203 students, reported in Niiya et al. (2013, along with new data from Poland (n = 246. Single and multiple group confirmatory analyses showed that the two-factor structure holds across the three cultures. Interdependence correlated with compassionate and self-image goals only in Japan. In all three samples, compassionate goals correlated with non-zero-sum belief, feeling close, growth-seeking, self-compassion, and learning from failures, whereas self-image goals correlated with defensive responses to conflicts and validation-seeking. Our results suggest that compassionate and self-image goals may serve similar functions in relationships and growth across cultures.

  16. A comparative study of the diagnostic value of contrast-enhanced breast MR imaging and mammography on patients with BI-RADS 3-5 microcalcifications.

    Directory of Open Access Journals (Sweden)

    Erni Li

    Full Text Available OBJECTIVE: To retrospectively investigate the diagnostic value of breast MRI in patients with BI-RADS 3-5 microcalcifications in mammography. METHODS: Eighty-four patients with BI-RADS 3-5 microcalcifications on mammography underwent breast MR exams before surgical biopsy with a hookwire position under mammographic guidance. Two radiologists reviewed each lesion with BI-RADS by consensus. The diagnostic value of mammography and MRI was compared. RESULTS: Histopathological examination revealed 49 benign lesions and 42 malignant lesions. In the assessments of mammography, 21 lesions (23.1% were assigned to category 3, 51 lesions (56.0% to category 4, and 19 lesions (20.9% to category 5. The area under the receiver operating characteristic(ROC curve for mammography and MR assessment was 0.844, and 0.945, respectively (p<0.05. In cases of category 3 microcalcifications, the specificity of mammography and MR was 100%, and 95.2% (p = 1.000, respectively. In cases of category 4 microcalcifications, the specificity, PPV and accuracy of mammography was 0%, 45.1% and 45.1%; whereas those for MR was 82.1% (p<0.05, 80.8% (P = 0.003 and 86.3% (p<0.05. All microcalcifications of category 5 were correctly diagnosed by mammography and MR. CONCLUSIONS: Breast MRI has the potential to significantly improve the diagnosis of category 4 microcalcifications on mammography. Among mammographic category 4 microcalcifications, about 82% of benign lesions can be degraded to BI-RADS 1∼3 by MRI. However for microcalcifications of category 3 and 5, MR exams do not show significant improvement over mammography.

  17. Paracetamol suppositories: a comparative study.

    Science.gov (United States)

    Cullen, S; Kenny, D; Ward, O C; Sabra, K

    1989-01-01

    Paracetamol suppositories in two different bases were given to children who had fever after operations. Plasma concentrations and the effect on temperature were compared. There was a significant correlation between peak plasma concentrations and maximum drop in temperature. A lipophilic base produced better results than a hydrophilic base. PMID:2817936

  18. Paracetamol suppositories: a comparative study.

    OpenAIRE

    Cullen, S; Kenny, D; Ward, O C; Sabra, K

    1989-01-01

    Paracetamol suppositories in two different bases were given to children who had fever after operations. Plasma concentrations and the effect on temperature were compared. There was a significant correlation between peak plasma concentrations and maximum drop in temperature. A lipophilic base produced better results than a hydrophilic base.

  19. Digital radiography of the thorax - the selenium detector compared with other imaging systems

    International Nuclear Information System (INIS)

    Schaefer-Prokop, C.; Prokop, M.

    1996-01-01

    Phantom studies were compared with clinical studies for a comparative analysis of the diagnostic performance of conventional and digital imaging systems. The selenium detector is found to be superior in a number of tasks, and on the whole is judged to adequately perform the multiple tasks of thorax radiography.(Orig.) [de

  20. Students' Difficulties in Reading Images. Comparing Results from Four National Research Groups.

    Science.gov (United States)

    Pinto, Roser; Ametller, Jaume

    2002-01-01

    Compares the results of four studies made under the auspices of the Science Teacher Training in an Information Society (STTIS) project researching the difficulties students have in reading images. The studies are compared under such categories as pre-eminence of narrative readings, real-world versus symbolic elements, verbal elements, and…

  1. Imaging study on acupuncture points

    Energy Technology Data Exchange (ETDEWEB)

    Yan, X H; Zhang, X Y [Synchrotron Radiation Research Center, Physics Department, and Surface Physics Laboratory (State Key Laboratory) of Fudan University, Shanghai 200433 (China); Liu, C L [Physics Department of Yancheng Teachers College, Yancheng 224002 (China); Dang, R S [Second Military Medical University, Shanghai 200433 (China); Ando, M [DDS center, Research Institute for Science and Technology, Tokyo University of Science, Yamasaki 2541, Noda, Chiba 278-8510 (Japan); Sugiyama, H [Photon Factory, Institute of Material Structure Science, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Chen, H S [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Ding, G H, E-mail: xy-zhang@fudan.edu.c [Shanghai Research Center of Acupuncture and Meridian, Shanghai 201203 (China)

    2009-09-01

    The topographic structures of acupuncture points were investigated by using the synchrotron radiation based Dark Field Image (DFI) method. Four following acupuncture points were studied: Sanyinjiao, Neiguan, Zusanli and Tianshu. We have found that at acupuncture point regions there exists the accumulation of micro-vessels. The images taken in the surrounding tissue out of the acupuncture points do not show such kind of structure. It is the first time to reveal directly the specific structure of acupuncture points by X-ray imaging.

  2. Imaging study on acupuncture points

    International Nuclear Information System (INIS)

    Yan, X H; Zhang, X Y; Liu, C L; Dang, R S; Ando, M; Sugiyama, H; Chen, H S; Ding, G H

    2009-01-01

    The topographic structures of acupuncture points were investigated by using the synchrotron radiation based Dark Field Image (DFI) method. Four following acupuncture points were studied: Sanyinjiao, Neiguan, Zusanli and Tianshu. We have found that at acupuncture point regions there exists the accumulation of micro-vessels. The images taken in the surrounding tissue out of the acupuncture points do not show such kind of structure. It is the first time to reveal directly the specific structure of acupuncture points by X-ray imaging.

  3. Comparative analysis of the particle size and shape of commercially available mineral trioxide aggregates and Portland cement: a study with a flow particle image analyzer.

    Science.gov (United States)

    Komabayashi, Takashi; Spångberg, Larz S W

    2008-01-01

    The aim of this study is to characterize the particle size distribution and circularity of various Mineral Trioxide Aggregates (MTA) (ProRoot MTA/ MTA Angelus/Gray and White) and Portland cements with effective size ranges of 1.5-160 microm using a flow particle analyzer (Sysmex FPIA-3000, Kobe, Japan). Cumulative percentage of particles between 6 and 10 microm were, 65, 73, 48, 53, and 70 %, for Gray ProRoot MTA, White ProRoot MTA, Gray MTA Angelus, White MTA Angelus, and Portland cement, respectively. ProRoot MTA contains fewer large particles than MTA Angelus. MTA Angelus contains a higher number of small particles than ProRoot MTA. White MTA contains smaller particles with a narrower range of size distribution than Gray MTA. MTA Angelus particles have relatively low circularity and wide size distribution and are less homogeneous than ProRoot MTA.

  4. Right Ventricular Systolic Dysfunction in Chagas Disease Defined by Speckle-Tracking Echocardiography: A Comparative Study with Cardiac Magnetic Resonance Imaging.

    Science.gov (United States)

    Moreira, Henrique T; Volpe, Gustavo J; Marin-Neto, José A; Nwabuo, Chike C; Ambale-Venkatesh, Bharath; Gali, Luis G; Almeida-Filho, Oswaldo C; Romano, Minna M D; Pazin-Filho, Antonio; Maciel, Benedito C; Lima, João A C; Schmidt, André

    2017-05-01

    Chagas disease leads to biventricular heart failure, usually with prominent systemic congestion. Although echocardiography is widely used in clinical routine, the utility of echocardiographic parameters to detect right ventricular (RV) systolic dysfunction in patients with Chagas disease is unknown. We sought to study the diagnostic value of echocardiography, including speckle-tracking parameters, to distinguish individuals with RV systolic dysfunction from those with normal RV systolic function in Chagas disease using cardiac magnetic resonance (CMR) as the reference method. In this cross-sectional study, 63 individuals with Chagas disease underwent echocardiography and CMR evaluations. Conventional echocardiographic parameters for RV functional evaluation were tricuspid annular plane systolic excursion, RV systolic excursion velocity, fractional area change, and RV index of myocardial performance. Strain and strain rate were obtained by two-dimensional speckle-tracking echocardiography and defined as "RV free wall," when based only in segments from RV free wall, or "RV free wall and septum," when segments from both free RV wall and interventricular septum were included. RV systolic dysfunction was defined as RV ejection fraction (RVEF) -22.5% for men and >-23.3% for women) exhibited the highest area under the receiver operating characteristic curve (area under the curve = 0.829) to differentiate the presence from the absence of RV systolic dysfunction in Chagas disease, with a sensitivity and specificity of 67% and 83%, respectively. RV free wall strain is an appropriate and superior echocardiographic variable for evaluating RV systolic function in Chagas disease, and it should be the method of choice for this purpose. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  5. Positron imaging studies

    International Nuclear Information System (INIS)

    Budinger, T.F.; Ganz, E.; Moyer, B.R.; Yano, Y.; Mathis, C.A.; Friedland, R.P.

    1982-01-01

    Several methods for the noninvasive evaluation of the metabolism and blood perfusion of brain and heart are reviewed. Heart muscle perfusion can be followed by measuring the accumulation of rubidium-82 simultaneously with the measurement of the arterial input. Deoxyglucose labelled with fluorine-18 was used to study the role of insulin in deoxyglucose accumulation

  6. A case study of comparing radiometrically calibrated reflectance of an image mosaic from unmanned aerial system with that of a single image from manned aircraft over a same area

    Science.gov (United States)

    Although conventional high-altitude airborne remote sensing and low-altitude unmanned aerial system (UAS) based remote sensing share many commonalities, one of the major differences between the two remote sensing platforms is that the latter has much smaller image footprint. To cover the same area o...

  7. Comparative Studies of Acculturative Stress.

    Science.gov (United States)

    Berry, J. W.; And Others

    1987-01-01

    Studies of acculturative stress are reported from Canada. The reduction in health status among people undergoing acculturation has psychological, somatic, and social aspects. The stress varies across types of groups and individual differences. Further study is needed to determine variations across host societies. (VM)

  8. Comparative effects of Facebook and conventional media on body image dissatisfaction.

    Science.gov (United States)

    Cohen, Rachel; Blaszczynski, Alex

    2015-01-01

    Appearance comparison has consistently been shown to engender body image dissatisfaction. To date, most studies have demonstrated this relationship between appearance comparison and body image dissatisfaction in the context of conventional media images depicting the thin-ideal. Social comparison theory posits that people are more likely to compare themselves to similar others. Since social media forums such as Facebook involve one's peers, the current study aimed to determine whether the relationship between appearance comparison and body image dissatisfaction would be stronger for those exposed to social media images, compared to conventional media images. A sample of 193 female first year university students were randomly allocated to view a series of either Facebook or conventional media thin-ideal images. Participants completed questionnaires assessing pre- and post- image exposure measures of thin-ideal internalisation, appearance comparison, self-esteem, Facebook use and eating disorder risk. Type of exposure was not found to moderate the relationship between appearance comparison and changes in body image dissatisfaction. When analysed according to exposure type, appearance comparison only significantly predicted body image dissatisfaction change for those exposed to Facebook, but not conventional media. Facebook use was found to predict higher baseline body image dissatisfaction and was associated with higher eating disorder risk. The findings suggest the importance of extending the body image dissatisfaction literature by taking into account emerging social media formats. It is recommended that interventions for body image dissatisfaction and eating disorders consider appearance comparison processes elicited by thin-ideal content on social media forums, such as Facebook, in addition to conventional media.

  9. Quantitative measurement of hepatic fibrosis with gadoxetic acid-enhanced magnetic resonance imaging in patients with chronic hepatitis B infection: A comparative study on aspartate aminotransferase to platelet ratio index and fibrosis-4 index

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Guy Mok; Kim, Youe Ree; Cho, Eun Young; Lee, Young Hwan; Yoon, Kwon Ha [Wonkwang University School of Medicine, Iksan (Korea, Republic of); Ryu, Jong Hyun; Kim, Tae Hoon [Imaging Science Research Center, Wonkwang University, Iksan (Korea, Republic of)

    2017-06-15

    To quantitatively measure hepatic fibrosis on gadoxetic acid-enhanced magnetic resonance (MR) in chronic hepatitis B (CHB) patients and identify the correlations with aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) values. This study on gadoxetic acid-enhanced 3T MR imaging included 81 patients with CHB infection. To quantitatively measure hepatic fibrosis, MR images were analyzed with an aim to identify inhomogeneous signal intensities calculated from a coefficient of variation (CV) map in the liver parenchyma. We also carried out a comparative analysis between APRI and FIB-4 based on metaregression results. The diagnostic performance of the CV map was evaluated using a receiver-operating characteristic (ROC) curve. In the MR images, the mean CV values in control, groups I, II, and III based on APRI were 4.08 ± 0.92, 4.24 ± 0.80, 5.64 ± 1.11, and 5.73 ± 1.28, respectively (p < 0.001). In CHB patients grouped by FIB-4, the mean CV values of groups A, B, and C were 4.22 ± 0.95, 5.40 ± 1.19, and 5.71 ± 1.17, respectively (p < 0.001). The mean CV values correlated well with APRI (r = 0.392, p < 0.001) and FIB-4 (r = 0.294, p < 0.001). In significant fibrosis group, ROC curve analysis yielded an area under the curve of 0.875 using APRI and 0.831 using FIB-4 in HB, respectively. Gadoxetic acid-enhanced MR imaging for calculating a CV map showed moderate correlation with APRI and FIB-4 values and could be employed to quantitatively measure hepatic fibrosis in patients with CHB.

  10. Benchmarked Library Websites Comparative Study

    KAUST Repository

    Ramli, Rindra M.

    2015-01-01

    This presentation provides an analysis of services provided by the benchmarked library websites. The exploratory study includes comparison of these websites against a list of criterion and presents a list of services that are most commonly deployed by the selected websites. In addition to that, the investigators proposed a list of services that could be provided via the KAUST library website.

  11. MRI quality control: six imagers studied using eleven unified image quality parameters

    International Nuclear Information System (INIS)

    Ihalainen, T.; Sipilae, O.; Savolainen, S.

    2004-01-01

    Quality control of the magnetic resonance imagers of different vendors in the clinical environment is non-harmonised, and comparing the performance is difficult. The purpose of this study was to develop and apply a harmonised long-term quality control protocol for the six imagers in our organisation in order to assure that they fulfil the same basic image quality requirements. The same Eurospin phantom set and identical imaging parameters were used with each imager. Values of 11 comparable parameters describing the image quality were measured. Automatic image analysis software was developed to objectively analyse the images. The results proved that the imagers were operating at a performance level adequate for clinical imaging. Some deficiencies were detected in image uniformity and geometry. The automated analysis of the Eurospin phantom images was successful. The measurements were successfully repeated after 2 weeks on one imager and after half a year on all imagers. As an objective way of examining the image quality, this kind of comparable and objective quality control of different imagers is considered as an essential step towards harmonisation of the clinical MRI studies through a large hospital organisation. (orig.)

  12. COMPARATIVE STUDY ON CORPORATE GOVERNANCE

    Directory of Open Access Journals (Sweden)

    Gavrea Corina

    2011-12-01

    Full Text Available Corporate governance is a key element of today’s economic reality being more and more present in many countries around the world. This paper has two main objectives. The first one is to offer more insight into the concept of corporate governance by a thorough literature review and by presenting and analyzing a framework of corporate governance. The second objective of this paper is to investigate the corporate governance situation in three developing economies (Romania, Bulgaria and Hungary. The World Bank and the European Bank for Reconstruction and Development published a series of reports on corporate governance. The present study uses data from these reports in order to illustrate how these developing economies are dealing with corporate governance. Based on ROSC Reports a corporate governance score was calculated. As this score shows, there is room for improvement for all three developing economies. This study is important because it shows the differences in corporate governance among developing economies and the need to study these nations at the individual country level. Corporate governance has many benefits for developing economies. It helps developing economies to register sustainable growth rates, to increases investors’ confidence in the national economy, and to increase the ability of capital markets to mobilize savings.

  13. Tumor hypoxia imaging in orthotopic liver tumors and peritoneal metastasis: a comparative study featuring dynamic 18F-MISO and 124I-IAZG PET in the same study cohort

    International Nuclear Information System (INIS)

    Riedl, Christopher C.; Brader, Peter; Hricak, Hedvig; Zanzonico, Pat; Humm, John L.; Reid, Vincent; Woo, Yanghee; Fong, Yuman; Wen, Bixiu; Ling, C.C.

    2008-01-01

    The purpose of this paper is to compare the uptake of two clinically promising positron emission tomography (PET) hypoxia targeting agents, 124 I-iodoazomycin galactopyranoside ( 124 I-IAZG) and 18 F-fluoromisonidazole ( 18 F-FMISO), by dynamic microPET imaging, in the same rats bearing liver tumors and peritoneal metastasis. Morris hepatoma (RH7777) fragments were surgically implanted into the livers of four nude rats. Tumors formed in the liver and disseminated into the peritoneal cavity. Each rat had a total of two to three liver tumors and peritoneal metastasis measuring 10-15 mm in size. Animals were injected with 18 F-FMISO, followed on the next day (upon complete 18 F decay) by 124 I-IAZG. The animals were imaged in list mode on the microPET system from the time of injection of each tracer for 3 h and then again at 6 h and 24 h for the long-lived 124 I-IAZG tracer (4.2-day half-life). Micro computed tomography (CT) scans of each rat were performed for co-registration with the microPET scans acquired with a liver contrast agent, allowing tumor identification. Regions of interest (ROIs) were drawn over the heart, liver, muscle, and the hottest areas of the tumors. Time-activity curves (TACs) were drawn for each tissue ROI. The 18 F-FMISO signal increased in tumors over the 3-h time course of observation. In contrast, after the initial injection, the 124 I-IAZG signal slowly and continuously declined in the tumors. Nevertheless, the tumor-to-normal-tissue ratios of 124 I-IAZG increased, but more slowly than those of 18 F-FMISO and as a result of the differentially faster clearance from the surrounding normal tissues. These pharmacokinetic patterns were seen in all 11 tumors of the four animals. 18 F-FMISO localizes in the same intra-tumor regions as 124 I-IAZG. The contrast ratios (tumor/background) reach similar values for the two hypoxia tracers, but at later times for 124 I-IAZG than for 18 F-FMISO and, therefore, with poorer count statistics. As a

  14. Magnetic resonance imaging of the cranial nerves in the posterior fossa: a comparative study of t2-weighted spin-echo sequences at 1.5 and 3.0 tesla.

    Science.gov (United States)

    Fischbach, F; Müller, M; Bruhn, H

    2008-04-01

    High-field magnetic resonance imaging (MRI) at 3.0 Tesla (T) is rapidly gaining clinical acceptance. Whether doubling of the field strength of 1.5T and the subsequent increase in signal-to-noise ratio (SNR) leads to a significant improvement of image quality is not automatically given. To evaluate the depiction of fine anatomic detail in the posterior fossa, focusing on brain nerves, on T2-weighted imaging, and to define the potential advantage of imaging at 3.0T versus 1.5T. In total, 10 brainstem nerve pairs of 12 volunteers were identified on T2-weighted MR images of 2- and 5-mm section thickness acquired at 1.5T and 3.0T. The MR images were compared for each subject at both field strengths by three independent readers who rated image quality according to depiction of anatomic detail and contrast by using a rating scale. In general, MR images at 3.0T were considered more conspicuous and less noisy than images at 1.5T. The SNR value measured was almost doubled. With respect to structural identification and contrast according to the rating scale, observer scores were significantly improved both for standard imaging with 5-mm sections and high-resolution imaging with 2-mm sections at 3.0T. Direct comparison revealed a significant increase for evaluated image quality criteria and the number of nerves detected. The comparison revealed a clear advantage in favor of T2-weighted MRI at 3.0T vs. 1.5T in depicting the roots and course of brain nerves in the posterior fossa.

  15. Study on the improvement of overall optical image quality via digital image processing

    Science.gov (United States)

    Tsai, Cheng-Mu; Fang, Yi Chin; Lin, Yu Chin

    2008-12-01

    This paper studies the effects of improving overall optical image quality via Digital Image Processing (DIP) and compares the promoted optical image with the non-processed optical image. Seen from the optical system, the improvement of image quality has a great influence on chromatic aberration and monochromatic aberration. However, overall image capture systems-such as cellphones and digital cameras-include not only the basic optical system but also many other factors, such as the electronic circuit system, transducer system, and so forth, whose quality can directly affect the image quality of the whole picture. Therefore, in this thesis Digital Image Processing technology is utilized to improve the overall image. It is shown via experiments that system modulation transfer function (MTF) based on the proposed DIP technology and applied to a comparatively bad optical system can be comparable to, even possibly superior to, the system MTF derived from a good optical system.

  16. Comparative evaluation of RetCam vs. gonioscopy images in congenital glaucoma

    Directory of Open Access Journals (Sweden)

    Raj V Azad

    2014-01-01

    Full Text Available Purpose: To compare clarity, exposure and quality of anterior chamber angle visualization in congenital glaucoma patients, using RetCam and indirect gonioscopy images. Design: Cross-sectional study Participants. Congenital glaucoma patients over age of 5 years. Materials and Methods: A prospective consecutive pilot study was done in congenital glaucoma patients who were older than 5 years. Methods used are indirect gonioscopy and RetCam imaging. Clarity of the image, extent of angle visible and details of angle structures seen were graded for both methods, on digitally recorded images, in each eye, by two masked observers. Outcome Measures: Image clarity, interobserver agreement. Results: 40 eyes of 25 congenital glaucoma patients were studied. RetCam image had excellent clarity in 77.5% of patients versus 47.5% by gonioscopy. The extent of angle seen was similar by both methods. Agreement between RetCam and gonioscopy images regarding details of angle structures was 72.50% by observer 1 and 65.00% by observer 2. Conclusions: There was good agreement between RetCam and indirect gonioscopy images in detecting angle structures of congenital glaucoma patients. However, RetCam provided greater clarity, with better quality, and higher magnification images. RetCam can be a useful alternative to gonioscopy in infants and small children without the need for general anesthesia.

  17. Comparative analysis of imaging configurations and objectives for Fourier microscopy.

    Science.gov (United States)

    Kurvits, Jonathan A; Jiang, Mingming; Zia, Rashid

    2015-11-01

    Fourier microscopy is becoming an increasingly important tool for the analysis of optical nanostructures and quantum emitters. However, achieving quantitative Fourier space measurements requires a thorough understanding of the impact of aberrations introduced by optical microscopes that have been optimized for conventional real-space imaging. Here we present a detailed framework for analyzing the performance of microscope objectives for several common Fourier imaging configurations. To this end, we model objectives from Nikon, Olympus, and Zeiss using parameters that were inferred from patent literature and confirmed, where possible, by physical disassembly. We then examine the aberrations most relevant to Fourier microscopy, including the alignment tolerances of apodization factors for different objective classes, the effect of magnification on the modulation transfer function, and vignetting-induced reductions of the effective numerical aperture for wide-field measurements. Based on this analysis, we identify an optimal objective class and imaging configuration for Fourier microscopy. In addition, the Zemax files for the objectives and setups used in this analysis have been made publicly available as a resource for future studies.

  18. Functional MR imaging study of the shoulder

    International Nuclear Information System (INIS)

    Minami, M.; Yoshikawa, K.; Shibuta, H.; Kokubo, T.; Itai, Y.; Iio, M.

    1989-01-01

    This paper presents a functional MR study of the shoulder performed with the positioning in which patients were about to complain of shoulder pain. A 0.064-T permanent MR system was used. The effectiveness of this study was evaluated in the diagnosis of rotator cuff impingement syndrome. Thirteen patients (11 males and two female) were examined prospectively. Three-dimensional Fourier transformation coronal images were obtained with patients' arms at the maximal abduction. They were compared with images obtained while patients' arms were at their sides, chiefly from the viewpoint of severity of impingement and intensity change of the supraspinatus muscle

  19. Traffic Sign Recognition System based on Cambridge Correlator Image Comparator

    Directory of Open Access Journals (Sweden)

    J. Turan

    2012-06-01

    Full Text Available Paper presents basic information about application of Optical Correlator (OC, specifically Cambridge Correlator, in system to recognize of traffic sign. Traffic Sign Recognition System consists of three main blocks, Preprocessing, Optical Correlator and Traffic Sign Identification. The Region of Interest (ROI is defined and chosen in preprocessing block and then goes to Optical Correlator, where is compared with database of Traffic Sign. Output of Optical Correlation is correlation plane, which consist of highly localized intensities, know as correlation peaks. The intensity of spots provides a measure of similarity and position of spots, how images (traffic signs are relatively aligned in the input scene. Several experiments have been done with proposed system and results and conclusion are discussed.

  20. Post-contrast T1-weighted sequences in pediatric abdominal imaging: comparative analysis of three different sequences and imaging approach

    International Nuclear Information System (INIS)

    Roque, Andreia; Ramalho, Miguel; AlObaidy, Mamdoh; Heredia, Vasco; Burke, Lauren M.; De Campos, Rafael O.P.; Semelka, Richard C.

    2014-01-01

    Post-contrast T1-weighted imaging is an essential component of a comprehensive pediatric abdominopelvic MR examination. However, consistent good image quality is challenging, as respiratory motion in sedated children can substantially degrade the image quality. To compare the image quality of three different post-contrast T1-weighted imaging techniques - standard three-dimensional gradient-echo (3-D-GRE), magnetization-prepared gradient-recall echo (MP-GRE) and 3-D-GRE with radial data sampling (radial 3-D-GRE) - acquired in pediatric patients younger than 5 years of age. Sixty consecutive exams performed in 51 patients (23 females, 28 males; mean age 2.5 ± 1.4 years) constituted the final study population. Thirty-nine scans were performed at 3 T and 21 scans were performed at 1.5 T. Two different reviewers independently and blindly qualitatively evaluated all sequences to determine image quality and extent of artifacts. MP-GRE and radial 3-D-GRE sequences had the least respiratory motion (P < 0.0001). Standard 3-D-GRE sequences displayed the lowest average score ratings in hepatic and pancreatic edge definition, hepatic vessel clarity and overall image quality. Radial 3-D-GRE sequences showed the highest scores ratings in overall image quality. Our preliminary results support the preference of fat-suppressed radial 3-D-GRE as the best post-contrast T1-weighted imaging approach for patients under the age of 5 years, when dynamic imaging is not essential. (orig.)

  1. Imaging characteristics of hepatocellular adenoma compared with pathologic findings

    International Nuclear Information System (INIS)

    Zhao Jing; Zhao Xinming; Ouyang Han; Huang Wenting; Zhou Chunwu

    2012-01-01

    Objective: To retrospectively compare CT and MR features of hepatocellular adenoma with pathologic findings. Methods: Twelve patients with histopathologically proved hepatocellular adenoma were classified on the basis of pathologic and genotype phenotype findings into four groups: steatotic type, cytological abnormality type, telangiectatic adenoma with inflammatory infiltrates type and atypical adenoma type. The CT and MR features of each type were reviewed retrospectively compared with the pathological results. Results: In this retrospective study, 12 patients were examined with CT (8 patients) and MR (8 patients). Among 12 patients, 4 patients showed a steatotic type. One patient showed hypo-density on the non-enhanced CT and 3 patients demonstrated hypo-density on all phases of the post-contrast scans. Two lesions showed iso-intense signal on the in-phase T 1 WI with signal dropout on the out-of-phase T 1 WI, and hypo-intense signal on the T 2 WI with fat suppression sequences. One lesion demonstrated moderate hypointense signal on all phases of the post-contrast MRI scans. Two patients with the telangiectatic adenoma inflammatory infiltrates type were found. One patient showed hypo-density on the non-enhanced CT scans and hyper-density on all phases of the post-contrast CT scans. One patient demonstrated iso-intense signal and the other hypo-intense signal on the T 1 WI, and both displayed moderate hyper-intense signal on the T 2 WI with fat suppression sequences and hyper-intense signal with gradual enhancement on all phases of post-contrast MR scans. There were 3 patients with a cytological abnormality type. One patient appeared hypo-density and 1 patient showed uniform iso-density on non-enhanced CT scans. All patients who had undergone contrast-enhanced CT scans were found to have hyper-density on the hepatic arterial-dominant phase and became slightly lower on the portal venous phase. On the delay phase the density reduced further. One mass showed iso

  2. Detection rates in pediatric diagnostic imaging: a picture archive and communication system compared with a web-based imaging system

    International Nuclear Information System (INIS)

    McDonald, L.; Cramer, B.; Barrett, B.

    2006-01-01

    This prospective study assesses whether there are differences in accuracy of interpretation of diagnostic images among users of a picture archive and communication system (PACS) diagnostic workstation, compared with a less costly Web-based imaging system on a personal computer (PC) with a high resolution monitor. One hundred consecutive pediatric chest or abdomen and skeletal X-rays were selected from hospital inpatient and outpatient studies over a 5-month interval. They were classified as normal (n = 32), obviously abnormal (n = 33), or having subtle abnormal findings (n = 35) by 2 senior radiologists who reached a consensus for each individual case. Subsequently, 5 raters with varying degrees of experience independently viewed and interpreted the cases as normal or abnormal. Raters viewed each image 1 month apart on a PACS and on the Web-based PC imaging system. There was no relation between accuracy of detection and the system used to evaluate X-ray images (P = 0.92). The total percentage of incorrect interpretations on the Web-based PC imaging system was 23.2%, compared with 23.6% on the PACS (P = 0.92). For all raters combined, the overall difference in proportion assessed incorrectly on the PACS, compared with the PC system, was not significant at 0.4% (95%CI, -3.5% to 4.3%). The high-resolution Web-based imaging system via PC is an adequate alternative to a PACS clinical workstation. Accordingly, the provision of a more extensive network of workstations throughout the hospital setting could have potentially significant cost savings. (author)

  3. Compare to evaluate the image dose of MVCT and CBCT

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Bo Reum; Hong, Mi Lan; Ahn, Jong Ho; Song, Ki Won [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2014-06-15

    In case of the intensity modulated radiation therapy (IMRT) using Tomotherapy and linear accelerator (Linac), it was to compare and to evaluate the imaging dose of MVCT and CBCT that were performed daily for the correct set up of the patient. The human body model Phantom (Anderson rando Phantom, USA) was divided into the three parts as Head, Thorax, pelvis, and after GafChromic EBT3 film cut to the size of 0.5x0.5 cm2.in the center of the recording area were situated on the ant, post, left, and right surface of the phantom and 2cm in depth from the ant, post, left, right, and center surface of the phantom, the surface dose and inner dose were measured repeatedly three times, respectively, using the tomotherapy (Hi Art) and the OBI of NovalisTx. The measured film calculated the output value by RIP version 6.0 and then the average value of the dose was calculated by the one-way analysis of variance. Using the human body model phantom, the results of MVCT and CBCT performance were that measurements of MVCT inner dose were showed 15.43cGy ± 6.05 in the head, 16.62cGy ± 3.08 in the thorax, 16.81cGy ± 5.24 in the pelvis, and measurements of CBCT inner dose were showed 13.28 ± 3.68 in the head, from 13.66 ± 4.04 in the thorax, 15.52 ± 3.52 in the pelvis. The measurements of surface dose were showed in case of MVCT performance, 11.64 ± 4.05 in the head, 12.16 ± 4.38 in the thorax, 12.05 ± 2.71 in the pelvis, and in case of CBCT performance, 14.59 ± 3.51 in the head, 15.82 ± 2.89 in the thorax, 17.48 ± 2.80 in the pelvis, respectively. In case of Inner dose, the MVCT using MV energy showed higher than the CBCT using kV energy at 1.16 times in the head, at 1.22 times in the thorax, at 1.08 times in the pelvis, and in case of surface dose, the CBCT was higher than MVCT, at 1.25 times in the head, at 1.30 times in the thorax, at 1.45 times in the pelvis. Imaging dose was a small amount compared to the therapeutic dose but it was thought to affect partially to

  4. A Study of Image Colourfulness

    OpenAIRE

    Amati, C.; Mitra, N.; Weyrich, T.

    2014-01-01

    Colourfulness is often thought of as a mere measure of quantity of colour, but user studies suggest that there are more factors influencing the perception of colourfulness. Boosting and enhancing colours are operations often performed for improving image aesthetics, but the relationship between colourfulness and aesthetics has not been thoroughly explored. By gathering perceptual data from a large-scale user study we have shown how existing colourfulness metrics relate to it and that there is...

  5. Image editing : case study HDR

    OpenAIRE

    Kääriä, Jussi

    2008-01-01

    When a photograph is taken, a single capture can represent only a specific amount of information from the captured scene when comparing what a human eye can detect from the same scene. A single capture cannot record the whole dynamic range of shadows, details and colors with only one exposure. The same problem continues when the image is reproduced on a display or on a print. That one print simply can’t show everything that a human eye sees when looking at the same scene. People have become u...

  6. Comparing features sets for content-based image retrieval in a medical-case database

    Science.gov (United States)

    Muller, Henning; Rosset, Antoine; Vallee, Jean-Paul; Geissbuhler, Antoine

    2004-04-01

    Content-based image retrieval systems (CBIRSs) have frequently been proposed for the use in medical image databases and PACS. Still, only few systems were developed and used in a real clinical environment. It rather seems that medical professionals define their needs and computer scientists develop systems based on data sets they receive with little or no interaction between the two groups. A first study on the diagnostic use of medical image retrieval also shows an improvement in diagnostics when using CBIRSs which underlines the potential importance of this technique. This article explains the use of an open source image retrieval system (GIFT - GNU Image Finding Tool) for the retrieval of medical images in the medical case database system CasImage that is used in daily, clinical routine in the university hospitals of Geneva. Although the base system of GIFT shows an unsatisfactory performance, already little changes in the feature space show to significantly improve the retrieval results. The performance of variations in feature space with respect to color (gray level) quantizations and changes in texture analysis (Gabor filters) is compared. Whereas stock photography relies mainly on colors for retrieval, medical images need a large number of gray levels for successful retrieval, especially when executing feedback queries. The results also show that a too fine granularity in the gray levels lowers the retrieval quality, especially with single-image queries. For the evaluation of the retrieval peformance, a subset of the entire case database of more than 40,000 images is taken with a total of 3752 images. Ground truth was generated by a user who defined the expected query result of a perfect system by selecting images relevant to a given query image. The results show that a smaller number of gray levels (32 - 64) leads to a better retrieval performance, especially when using relevance feedback. The use of more scales and directions for the Gabor filters in the

  7. [{sup 18}F]Fluoroazomycinarabinofuranoside ({sup 18}FAZA) and [{sup 18}F]Fluoromisonidazole ({sup 18}FMISO): a comparative study of their selective uptake in hypoxic cells and PET imaging in experimental rat tumors

    Energy Technology Data Exchange (ETDEWEB)

    Sorger, Dietlind E-mail: sord@medizin.uni-leipzig.de; Patt, Marianne; Kumar, Piyush; Wiebe, Leonard I.; Barthel, Henryk; Seese, Anita; Dannenberg, Claudia; Tannapfel, Andrea; Osama Sabri, Regine Kluge

    2003-04-01

    The present study compares the uptake of [{sup 18}F]Fluoroazomycinarabinofuranoside ({sup 18}FAZA), a recently developed hypoxia tracer for PET imaging of tissue hypoxia, with an established tracer [{sup 18}F]Fluoromisonidazole ({sup 18}FMISO) both in vitro, using Walker 256 rat carcinosarcoma cells, and in vivo in experimental rat tumors eleven to twelve days after tumor cell implantation. In vitro studies indicated that hypoxia-selective uptake of both {sup 18}FAZA and {sup 18}FMISO in tumor cells, 20 and 100 minutes post-incubation was of the same magnitude (20 min: 1.24 {+-} 0.4% ({sup 18}FAZA); 1.19 {+-} 0.7% ({sup 18}FMISO); 100 min: 3.6 {+-} 1.6% ({sup 18}FAZA); 3.3 {+-} 1.7% ({sup 18}FMISO)). PET imaging reflected a similar radiotracer distribution in rat tumors for {sup 18}FAZA and {sup 18}FMISO one h after radiotracer injection. The concentration of {sup 18}FAZA in the tumors as measured by PET, however, was lower in comparison to {sup 18}FMISO (SUV{sub FAZA} 0.61 {+-} 0.2 vs. SUV{sub FMISO} = 0.92 {+-} 0.3, p < 0.05) although the tumor to muscle ratios for {sup 18}FAZA and {sup 18}FMISO did not differ in the PET images that were obtained after one h (SUV{sub FAZA} = 2.5 {+-} 0.5 vs. SUV{sub FMISO} = 2.9 {+-} 0.7). A comparison of PET data three h post-injection (SUV{sub FAZA} = 3.0 {+-} 0.5 vs. SUV{sub FMISO} = 4.6 {+-} 1.8, p < 0.05) demonstrated a lower {sup 18}FAZA uptake that indicates a lower sensitivity of {sup 18}FAZA in comparison to {sup 18}FMISO in detecting hypoxic regions at a longer time in this animal model. However, these data also show a faster elimination of {sup 18}FAZA from blood, viscera and muscle tissue, via the renal system. This advantage of a faster reduction of unspecific binding, in light of similar or marginally lower tumor uptake, warrants further investigation of {sup 18}FAZA as a marker of regional hypoxia in tumors.

  8. Impact of model-based iterative reconstruction on low-contrast lesion detection and image quality in abdominal CT: a 12-reader-based comparative phantom study with filtered back projection at different tube voltages

    Energy Technology Data Exchange (ETDEWEB)

    Euler, Andre; Stieltjes, Bram; Eichenberger, Reto; Reisinger, Clemens; Hirschmann, Anna; Zaehringer, Caroline; Kircher, Achim; Streif, Matthias; Bucher, Sabine; Buergler, David; D' Errico, Luigia; Kopp, Sebastien; Wilhelm, Markus [University Hospital Basel, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Szucs-Farkas, Zsolt [Hospital Centre of Biel, Institute of Radiology, Biel (Switzerland); Schindera, Sebastian T. [University Hospital Basel, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Cantonal Hospital Aarau, Institute of Radiology, Aarau (Switzerland)

    2017-12-15

    To evaluate the impact of model-based iterative reconstruction (MBIR) on image quality and low-contrast lesion detection compared with filtered back projection (FBP) in abdominal computed tomography (CT) of simulated medium and large patients at different tube voltages. A phantom with 45 hypoattenuating lesions was placed in two water containers and scanned at 70, 80, 100, and 120 kVp. The 120-kVp protocol served as reference, and the volume CT dose index (CTDI{sub vol}) was kept constant for all protocols. The datasets were reconstructed with MBIR and FBP. Image noise and contrast-to-noise-ratio (CNR) were assessed. Low-contrast lesion detectability was evaluated by 12 radiologists. MBIR decreased the image noise by 24% and 27%, and increased the CNR by 30% and 29% for the medium and large phantoms, respectively. Lower tube voltages increased the CNR by 58%, 46%, and 16% at 70, 80, and 100 kVp, respectively, compared with 120 kVp in the medium phantom and by 9%, 18% and 12% in the large phantom. No significant difference in lesion detection rate was observed (medium: 79-82%; large: 57-65%; P > 0.37). Although MBIR improved quantitative image quality compared with FBP, it did not result in increased low-contrast lesion detection in abdominal CT at different tube voltages in simulated medium and large patients. (orig.)

  9. Advances in comparative physiology from high-speed imaging of animal and fluid motion.

    Science.gov (United States)

    Lauder, George V; Madden, Peter G A

    2008-01-01

    Since the time of Muybridge and Marey in the last half of the nineteenth century, studies of animal movement have relied on some form of high-speed or stop-action imaging to permit analysis of appendage and body motion. In the past ten years, the advent of megapixel-resolution high-speed digital imaging with maximal framing rates of 250 to 100,000 images per second has allowed new views of musculoskeletal function in comparative physiology that now extend to imaging flow around moving animals and the calculation of fluid forces produced by animals moving in fluids. In particular, the technique of digital particle image velocimetry (DPIV) has revolutionized our ability to understand how moving animals generate fluid forces and propel themselves through air and water. DPIV algorithms generate a matrix of velocity vectors through the use of image cross-correlation, which can then be used to calculate the force exerted on the fluid as well as locomotor work and power. DPIV algorithms can also be applied to images of moving animals to calculate the velocity of different regions of the moving animal, providing a much more detailed picture of animal motion than can traditional digitizing methods. Although three-dimensional measurement of animal motion is now routine, in the near future model-based kinematic reconstructions and volumetric analyses of animal-generated fluid flow patterns will provide the next step in imaging animal biomechanics and physiology.

  10. Local zone wise elastic and plastic properties of electron beam welded Ti-6Al-4V alloy using digital image correlation technique: A comparative study between uniform stress and virtual fields method

    Science.gov (United States)

    Saranath, K. M.; Ramji, M.

    2015-05-01

    Joining of materials using welding results in the formation of material zones with varying microstructure across the weld. Extraction of the mechanical properties of those individual heterogeneous zones are important in designing components and structures comprised of welds. In this study, the zone wise local extraction of the elastic and plastic properties of an electron beam welded Ti-6Al-4V titanium alloy has been carried out using both the uniform stress method (USM) and the virtual fields method (VFM) involving digital image correlation (DIC) technique. The surface strain field obtained using DIC technique from a transverse weld specimen tensile testing is used for extracting the zone wise strain evolution. Initially, using uniform stress assumption, zone wise full range stress-strain curves are extracted. In USM methodology, the elastic and plastic material models are fitted to the zone wise stress-strain curves and required parameters are extracted from it. But inherent disadvantage is lot of images need to be processed for the parameter extraction. Recently, VFM is gaining lot of popularity in characterization domain as it is robust, accurate and faster. VFM is based on the principle of virtual work where, the weak form of local equilibrium equations and kinematically admissible virtual displacement fields are utilized for parameter extraction. Hollomon's power law is used here as the hardening rule. Young's modulus, Poisson's ratio, yield stress, strength coefficient and strain hardening exponent are the parameters extracted zone wise using both USM and VFM. A Vicker's microhardness measurement is also conducted across the weld zone towards mapping the strength behavior. Fusion zone has reported higher yield strength, strength coefficient and Poisson's ratio. Young's modulus value is found decreasing from base metal towards the fusion zone. The trend observed in parameter variation across the weld zone obtained by both USM and VFM compares very well. Due

  11. Physics studies in Europe; a comparative study

    NARCIS (Netherlands)

    Steenstrup, S; dalle Rose, LFD; Jones, WG; Tugulea, L; van Steenwijk, FJ

    What are the differences and similarities between physics studies at different universities across Europe (here the definition of Europe is broad)? How much does a student have to work to obtain a degree in physics? Questions like those prompted EUPEN (European Physics Education Network) to make a

  12. Perinatal mortality: clinical value of postmortem magnetic resonance imaging compared with autopsy in routine obstetric practice

    NARCIS (Netherlands)

    Alderliesten, Marianne E.; Peringa, Jan; van der Hulst, Victor P. M.; Blaauwgeers, Hans L. G.; van Lith, Jan M. M.

    2003-01-01

    Objective To compare postmortem magnetic resonance imaging (MRI) with autopsy in perinatal deaths. To determine the acceptance and feasibility of postmortem perinatal MRI. Design Cohort study. Setting Large teaching hospital. Population Fetuses and neonates from 16 weeks gestational age until 28

  13. Effect of contrast material on image noise and radiation dose in adult chest computed tomography using automatic exposure control: A comparative study between 16-, 64- and 128-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Jijo, E-mail: jijopaul1980@gmail.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Goethe University, Department of Biophysics, Max von Laue-Strasse 1, 60438 Frankfurt am Main (Germany); Schell, Boris, E-mail: boris.schell@googlemail.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Kerl, J. Matthias, E-mail: matthias.kerl@gmai.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Maentele, Werner, E-mail: maentele@biophysik.uni-frankfurt.de [Goethe University, Department of Biophysics, Max von Laue-Strasse 1, 60438 Frankfurt am Main (Germany); Vogl, Thomas J., E-mail: t.vogl@em.uni-frankfurt.de [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Bauer, Ralf W., E-mail: ralfwbauer@aol.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany)

    2011-08-15

    Purpose: To determine the difference in radiation dose between non-enhanced (NECT) and contrast-enhanced (CECT) chest CT examinations contributed by contrast material with different scanner generations with automatic exposure control (AEC). Methods and materials: Each 42 adult patients received a NECT and CECT of the chest in one session on a 16-, 64- or 128-slice CT scanner with the same scan protocol settings. However, AEC technology (Care Dose 4D, Siemens) underwent upgrades in each of the three scanner generations. DLP, CTDIvol and image noise were compared. Results: Although absolute differences in image noise were very small and ranged between 10 and 13 HU for NECT and CECT in median, the differences in image noise and dose (DLP: 16-slice:+2.8%; 64-slice:+3.9%; 128-slice:+5.6%) between NECT and CECT were statistically significant in all groups. Image noise and dose parameters were significantly lower in the most recent 128-slice CT generation for both NECT and CECT (DLP: 16-slice:+35.5-39.2%; 64-slice:+6.8-8.5%). Conclusion: The presence of contrast material lead to an increase in dose for chest examinations in three CT generations with AEC. Although image noise values were significantly higher for CECT, the absolute differences were in a range of 3 HU. This can be regarded as negligible, thus indicating that AEC is able to fulfill its purpose of maintaining image quality. However, technological developments lead to a significant reduction of dose and image noise with the latest CT generation.

  14. Comparing neutron and X-ray images from NIF implosions

    Directory of Open Access Journals (Sweden)

    Wilson D.C.

    2013-11-01

    Full Text Available Directly laser driven and X-radiation driven DT filled capsules differ in the relationship between neutron and X-ray images. Shot N110217, a directly driven DT-filled glass micro-balloon provided the first neutron images at the National Ignition Facility. As seen in implosions on the Omega laser, the neutron image can be enclosed inside time integrated X-ray images. HYDRA simulations show the X-ray image is dominated by emission from the hot glass shell while the neutron image arises from the DT fuel it encloses. In the absence of mix or jetting, X-ray images of a cryogenically layered THD fuel capsule should be dominated by emission from the hydrogen rather than the cooler plastic shell that is separated from the hot core by cold DT fuel. This cool, dense DT, invisible in X-ray emission, shows itself by scattering hot core neutrons. Germanium X-ray emission spectra and Ross pair filtered X-ray energy resolved images suggest that germanium doped plastic emits in the torus shaped hot spot, probably reducing the neutron yield.

  15. Discrimination of benign and malignant lymph nodes at 7.0T compared to 1.5T magnetic resonance imaging using ultrasmall particles of iron oxide: a feasibility preclinical study.

    Science.gov (United States)

    Kinner, Sonja; Maderwald, Stefan; Albert, Juliane; Parohl, Nina; Corot, Claire; Robert, Philippe; Baba, Hideo A; Barkhausen, Jörg

    2013-12-01

    To investigate the feasibility and performance of 7T magnetic resonance imaging compared to 1.5T imaging to discriminate benign (normal and inflammatory changed) from tumor-bearing lymph nodes in rabbits using ultrasmall particles of iron oxide (USPIO)-based contrast agents. Six New Zealand White rabbits were inoculated with either complete Freund's adjuvant cell suspension (n = 3) to induce reactively enlarged lymph nodes or with VX2 tumor cells to produce metastatic lymph nodes (n = 3). Image acquisition was performed before and 24 hours after bolus injection of an USPIO contrast agent at 1.5T and afterward at 7T using T1-weighted and T2*-weighted sequences. Sensitivities, specificities, and negative and positive predictive values for the detection of lymph node metastases were calculated for both field strengths with histopathology serving as reference standard. Sizes of lymph nodes with no, inflammatory, and malignant changes were compared using a Mann-Whitney U-test. All 24 lymph nodes were detected at 1.5T as well as at 7T. At 1.5T, sensitivity amounted to 0.67, while specificity reached a value of 1. At the higher field strength (7T), imaging was able to reach sensitivity and specificity values of 1. No statistical differences were detected concerning lymph node sizes. Magnetic resonance lymphography with USPIO contrast agents allows for differentiation of normal and reactively enlarged lymph nodes compared to metastatic nodes. First experiments at 7T show promising results compared to 1.5T, which have to be evaluated in further trials. Copyright © 2013. Published by Elsevier Inc.

  16. Body Image Disturbance in Acromegaly Patients Compared to Nonfunctioning Pituitary Adenoma Patients and Controls

    Directory of Open Access Journals (Sweden)

    Helen M. Conaglen

    2015-01-01

    Full Text Available Purpose. Excess growth hormone secretion in adults results in acromegaly, a condition in which multiple physical changes occur including bony and soft tissue overgrowth. Over time these changes can markedly alter a person’s appearance. The aim of this study was to compare body image disturbance in patients with acromegaly to those with nonfunctioning pituitary adenomas (NFAs and controls and assess the impact of obesity in these groups. Methods. A cross-sectional survey including quality of life, body image disturbance, anxiety and depression measures, growth hormone, and BMI measurement was carried out. Results. The groups did not differ with respect to body image disturbance. However separate analysis of obese participants demonstrated relationships between mood scales, body image disturbance, and pain issues, particularly for acromegaly patients. Conclusions. While the primary hypothesis that acromegaly might be associated with body image disturbance was not borne out, we have shown that obesity together with acromegaly and NFA can be associated with body image issues, suggesting that BMI rather than primary diagnosis might better indicate whether patients might experience body image disturbance problems.

  17. Comparing the difference of measured GFR of ectopic pelvic kidney between anterior and posterior imaging processing in renal dynamic imaging

    International Nuclear Information System (INIS)

    Li Baojun; Zhao Deshan

    2014-01-01

    Objective: To compare and analyze the difference of measured glomerular filtration rate (GFR) of ectopic pelvic kidney between anterior and posterior imaging processing in renal dynamic imaging. Methods: There were 10 patients collected retrospectively, with ectopic kidneys in pelvic cavity confirmed by ultrasound, CT, renal dynamic imaging and other imaging modalities. All images of ectopic kidneys in renal dynamic imaging were processed by anterior and posterior methods respectively. The ectopic kidney was only processed in anterior imaging, ectopic kidney and contralateral normal kidney were processed in posterior imaging. Total GFR equalled the sum of GFR of normal kidney in posterior imaging and GFR of ectopic kidney in anterior imaging, was compared with total GFR of two kidneys in posterior imaging and GFR in two-sample method. All correlation analysis were completed between GFRs from three methods and all patients were followed up. Statistically paired t-test and bivariate correlation analysis test were used. Results: The mean GFR of ectopic kidney in anterior imaging equal to (27.48±12.24) ml/(min · 1.73 m 2 ). It was more than GFR [(10.71 ±4.74) ml/ (min · 1.73 m 2 )] in posterior imaging above 46% (t=5.481, P<0.01). There was no significant difference (t=-2.238, P>0.05), but better correlation (r=0.704, P<0.05) between total GFR in anterior imaging and GFR in two-sample method. There was significant difference (t=4.629, P<0.01)and worse correlation (r=0.576, P>0.05) between total GFR in posterior imaging and GFR in two-sample method. Conclusion: Comparing with GFR in posterior imaging, GFR in anterior imaging can more truly reflect function condition of ectopic pelvic kidney in renal dynamic imaging. (authors)

  18. Randomized, interventional, prospective, comparative study to ...

    African Journals Online (AJOL)

    Randomized, interventional, prospective, comparative study to evaluate the antihypertensive efficacy and tolerability of ramipril versus telmisartan in stage 1 hypertensive patients with diabetes mellitus.

  19. Comparative studies on pectinases obtained from Aspergillus ...

    African Journals Online (AJOL)

    Comparative studies on pectinases obtained from Aspergillus fumigatus and Aspergillus niger in submerged fermentation system using pectin extracted from mango, orange and pineapple peels as carbon sources.

  20. Comparative Evaluation of the Ostium After External and Nonendoscopic Endonasal Dacryocystorhinostomy Using Image Processing (Matlabs and Image J) Softwares.

    Science.gov (United States)

    Ganguly, Anasua; Kaza, Hrishikesh; Kapoor, Aditya; Sheth, Jenil; Ali, Mohammad Hasnat; Tripathy, Devjyoti; Rath, Suryasnata

    The purpose of this study was to compare the characteristics of the ostium after external dacryocystorhinostomy and nonendoscopic endonasal dacryocystorhinostomy (NEN-DCR). This cross-sectional study included patients who underwent a successful external dacryocystorhinostomy or NEN-DCR and had ≥1 month follow up. Pictures of the ostium were captured with a nasal endoscope (4 mm, 30°) after inserting a lacrimal probe premarked at 2 mm. Image analyses were performed using Image J and Contour softwares. Of the 113 patients included, external dacryocystorhinostomy group had 53 patients and NEN-DCR group had 60 patients. The mean age of patients in the NEN-DCR group (38 years) was significantly (p 0.05) in mean follow up (6 vs. 4 months), maximum diameter of ostium (8 vs. 7 mm), perpendicular drawn to it (4 vs. 4 mm), area of ostium (43 vs. 36 mm), and the minimum distance between common internal punctum and edge of the ostium (1 vs. 1 mm) between the external and NEN-DCR groups. Image processing softwares offer simple and objective method to measure the ostium. While ostia are comparable in size, their relative position differs with posteriorly placed ostia in external compared with inferior in NEN-DCR.

  1. Dentomaxillofacial imaging with computed-radiography techniques: a preliminary study

    Science.gov (United States)

    Shaw, Chris C.; Kapa, Stanley F.; Furkart, Audrey J.; Gur, David

    1993-09-01

    A preliminary study was conducted to investigate the feasibility of using high resolution computed radiography techniques for dentomaxillofacial imaging. Storage phosphors were cut into various sizes and used with an experimental laser scanning reader for three different imaging procedures: intraoral, cephalometric and panoramic. Both phantom and patient images were obtained for comparing the computed radiography technique with the conventional screen/film or dental film techniques. It has been found that current computed radiography techniques are largely adequate for cephalometric and panoramic imaging but need further improvement on their spatial resolution capability for intraoral imaging. In this paper, the methods of applying the computer radiography techniques to dentomaxillofacial imaging are described and discussed. Images of phantoms, resolution bar patterns and patients are presented and compared. Issues on image quality and cost are discussed.

  2. Post-mortem imaging compared with autopsy in trauma victims--A systematic review.

    Science.gov (United States)

    Jalalzadeh, Hamid; Giannakopoulos, Georgios F; Berger, Ferco H; Fronczek, Judith; van de Goot, Frank R W; Reijnders, Udo J; Zuidema, Wietse P

    2015-12-01

    Post-mortem imaging or virtual autopsy is a rapidly advancing field of post-mortem investigations of trauma victims. In this review we evaluate the feasibility of complementation or replacement of conventional autopsy by post-mortem imaging in trauma victims. A systematic review was performed in compliance with the PRISMA guidelines. MEDLINE, Embase and Cochrane databases were systematically searched for studies published between January 2008 and January 2014, in which post-mortem imaging was compared to conventional autopsy in trauma victims. Studies were included when two or more trauma victims were investigated. Twenty-six studies were included, with a total number of 563 trauma victims. Post-mortem computer tomography (PMCT) was performed in 22 studies, post-mortem magnetic resonance imaging (PMMRI) in five studies and conventional radiography in two studies. PMCT and PMMRI both demonstrate moderate to high-grade injuries and cause of death accurately. PMCT is more sensitive than conventional autopsy or PMMRI in detecting skeletal injuries. For detecting minor organ and soft tissue injuries, autopsy remains superior to imaging. Aortic injuries are missed frequently by PMCT and PMMRI and form their main limitation. PMCT should be considered as an essential supplement to conventional autopsy in trauma victims since it detects many additional injuries. Despite some major limitations, PMCT could be used as an alternative for conventional autopsy in situations where conventional autopsy is rejected or unavailable. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. NMR imaging studies of coal

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Z.R.; Zhang, P.Z.; Ding, G.L.; Li, L.Y.; Ye, C.H. [University of Science and Technology, Beijing (China). Dept. of Chemistry

    1996-06-01

    The permeation transportation and swelling behavior of solvents into coal are investigated by NMR imaging using pyridine-d{sub 5} and acetone-d{sub 6}. Images of coal swollen with deuterated solvents illuminate proton distributions of mobile phases within the coal macromolecular networks. More information about the chemical and physical structure of coal can be obtained using NMR imaging techniques.

  4. Comparative assessment of panoramic radiography and CBCT imaging for radiodiagnostics in the posterior maxilla.

    Science.gov (United States)

    Shahbazian, Maryam; Vandewoude, Charlotte; Wyatt, Jan; Jacobs, Reinhilde

    2014-01-01

    The purpose of this study was to assess whether and how the information obtained by means of cone beam computed tomography (CBCT) on maxillary posterior teeth differs from that obtained by panoramic radiography. From 157 subjects (mean age 48 years, range 19-84 years; 89 females) referred to the oral imaging center, a pair of panoramic and CBCT images was selected for further analysis. Both imaging modalities were analyzed to determine the topographic relationship of maxillary teeth to the sinus floor. Pathologic conditions, apical periodontitis, and presence of soft tissue thickening were also examined with both techniques. CBCT showed an intimate relationship of the first and second molar with the maxillary sinus in 54 and 38%, respectively. Thirty-nine apical periodontitis lesions causing reactive changes in the maxillary sinus were detected by CBCT, while just six of them were diagnosed with panoramic imaging. A total of 26 teeth with apical extension to the maxillary sinus were detected with CBCT, from which two could be identified with panoramic radiography. This study emphasizes that anatomical and pathological involvement of the maxillary sinus in relation to posterior teeth is considerably high. It is of clinical importance that the 3D nature of CBCT imaging allowed a better assessment of the relationship between the maxillary sinus and posterior root apices compared to the low detection on panoramic radiographs. CBCT imaging can be a valuable adjunct in radioanatomical and radiodiagnostic observations in the posterior maxilla. It may better visualize maxillary sinus involvement for posterior upper teeth than panoramic radiography.

  5. MRI Compatibility of Robot Actuation Techniques – A Comparative Study

    Science.gov (United States)

    Fischer, Gregory S.; Krieger, Axel; Iordachita, Iulian; Csoma, Csaba; Whitcomb, Louis L.; Fichtinger, Gabor

    2010-01-01

    This paper reports an experimental evaluation of the following three different MRI-compatible actuators: a Shinsei ultrasonic motor, a Nanomotion ultrasonic motor and a pneumatic cylinder actuator. We report the results of a study comparing the effect of these actuators on the signal to noise ratio (SNR) of MRI images under a variety of experimental conditions. Evaluation was performed with the controller inside and outside the scanner room and with both 1.5T and 3T MRI scanners. Pneumatic cylinders function with no loss of SNR with controller both inside and outside of the scanner room. The Nanomotion motor performs with moderate loss of SNR when moving during imaging. The Shinsei is unsuitable for motion during imaging. All may be used when motion is appropriately interleaved with imaging cycles. PMID:18982643

  6. Endometrial cancer: preoperative staging using three-dimensional T2-weighted turbo spin-echo and diffusion-weighted MR imaging at 3.0 T: a prospective comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Hori, Masatoshi; Kim, Tonsok; Onishi, Hiromitsu; Nakamoto, Atsushi; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Radiology, Suita, Osaka (Japan); Imaoka, Izumi; Kagawa, Yuki; Murakami, Takamichi [Kinki University School of Medicine, Department of Radiology, Osaka (Japan); Ueguchi, Takashi; Tatsumi, Mitsuaki [Osaka University Hospital, Department of Radiology, Osaka (Japan); Enomoto, Takayuki [Osaka University Graduate School of Medicine, Department of Obstetrics and Gynecology, Osaka (Japan); Niigata University School of Medicine, Department of Obstetrics and Gynecology, Niigata (Japan); Kimura, Tadashi [Osaka University Graduate School of Medicine, Department of Obstetrics and Gynecology, Osaka (Japan)

    2013-08-15

    To prospectively assess the efficacy of 3-T magnetic resonance (MR) imaging using the three-dimensional turbo spin-echo T2-weighted and diffusion-weighted technique (3D-TSE/DW) compared with that of conventional imaging using the two-dimensional turbo spin-echo T2-weighted and dynamic contrast-enhanced technique (2D-TSE/DCE) for the preoperative staging of endometrial cancer, with pathological analysis as the reference standard. Seventy-one women with endometrial cancer underwent MR imaging using 3D-TSE/DW (b = 1,000 s/mm{sup 2}) and 2D-TSE/DCE. Two radiologists independently assessed the two imaging sets. Accuracy, sensitivity, and specificity for staging were analysed with the McNemar test; the areas under the receiver operating characteristic curve (Az) were compared with a univariate z-score test. The results for assessing deep myometrial invasion, accuracy, sensitivity, specificity and Az, respectively, were as follows: 3D-TSE/DW - observer 1, 87 %, 95 %, 85 % and 0.96; observer 2, 92 %, 84 %, 94 % and 0.95; 2D-TSE/DCE - observer 1, 80 %, 79 %, 81 % and 0.89; observer 2, 86 %, 84 %, 87 % and 0.86. Most of the values were higher with 3D-TSE/DW without significant differences (P > 0.12). For assessing cervical stromal invasion, there were no significant differences in those values for both observers (P > 0.6). Accuracy of 3D-TSE/DW was at least equivalent to that of the conventional technique for the preoperative assessment of endometrial cancer. (orig.)

  7. How does C-VIEW image quality compare with conventional 2D FFDM?

    International Nuclear Information System (INIS)

    Nelson, Jeffrey S.; Wells, Jered R.; Baker, Jay A.; Samei, Ehsan

    2016-01-01

    Purpose: The FDA approved the use of digital breast tomosynthesis (DBT) in 2011 as an adjunct to 2D full field digital mammography (FFDM) with the constraint that all DBT acquisitions must be paired with a 2D image to assure adequate interpretative information is provided. Recently manufacturers have developed methods to provide a synthesized 2D image generated from the DBT data with the hope of sparing patients the radiation exposure from the FFDM acquisition. While this much needed alternative effectively reduces the total radiation burden, differences in image quality must also be considered. The goal of this study was to compare the intrinsic image quality of synthesized 2D C-VIEW and 2D FFDM images in terms of resolution, contrast, and noise. Methods: Two phantoms were utilized in this study: the American College of Radiology mammography accreditation phantom (ACR phantom) and a novel 3D printed anthropomorphic breast phantom. Both phantoms were imaged using a Hologic Selenia Dimensions 3D system. Analysis of the ACR phantom includes both visual inspection and objective automated analysis using in-house software. Analysis of the 3D anthropomorphic phantom includes visual assessment of resolution and Fourier analysis of the noise. Results: Using ACR-defined scoring criteria for the ACR phantom, the FFDM images scored statistically higher than C-VIEW according to both the average observer and automated scores. In addition, between 50% and 70% of C-VIEW images failed to meet the nominal minimum ACR accreditation requirements—primarily due to fiber breaks. Software analysis demonstrated that C-VIEW provided enhanced visualization of medium and large microcalcification objects; however, the benefits diminished for smaller high contrast objects and all low contrast objects. Visual analysis of the anthropomorphic phantom showed a measureable loss of resolution in the C-VIEW image (11 lp/mm FFDM, 5 lp/mm C-VIEW) and loss in detection of small microcalcification

  8. How does c-view image quality compare with conventional 2D FFDM?

    Science.gov (United States)

    Nelson, Jeffrey S; Wells, Jered R; Baker, Jay A; Samei, Ehsan

    2016-05-01

    The FDA approved the use of digital breast tomosynthesis (DBT) in 2011 as an adjunct to 2D full field digital mammography (FFDM) with the constraint that all DBT acquisitions must be paired with a 2D image to assure adequate interpretative information is provided. Recently manufacturers have developed methods to provide a synthesized 2D image generated from the DBT data with the hope of sparing patients the radiation exposure from the FFDM acquisition. While this much needed alternative effectively reduces the total radiation burden, differences in image quality must also be considered. The goal of this study was to compare the intrinsic image quality of synthesized 2D c-view and 2D FFDM images in terms of resolution, contrast, and noise. Two phantoms were utilized in this study: the American College of Radiology mammography accreditation phantom (ACR phantom) and a novel 3D printed anthropomorphic breast phantom. Both phantoms were imaged using a Hologic Selenia Dimensions 3D system. Analysis of the ACR phantom includes both visual inspection and objective automated analysis using in-house software. Analysis of the 3D anthropomorphic phantom includes visual assessment of resolution and Fourier analysis of the noise. Using ACR-defined scoring criteria for the ACR phantom, the FFDM images scored statistically higher than c-view according to both the average observer and automated scores. In addition, between 50% and 70% of c-view images failed to meet the nominal minimum ACR accreditation requirements-primarily due to fiber breaks. Software analysis demonstrated that c-view provided enhanced visualization of medium and large microcalcification objects; however, the benefits diminished for smaller high contrast objects and all low contrast objects. Visual analysis of the anthropomorphic phantom showed a measureable loss of resolution in the c-view image (11 lp/mm FFDM, 5 lp/mm c-view) and loss in detection of small microcalcification objects. Spectral analysis of the

  9. How does C-VIEW image quality compare with conventional 2D FFDM?

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Jeffrey S., E-mail: nelson.jeffrey@duke.edu; Wells, Jered R. [Department of Radiology, Clinical Imaging Physics Group, Duke University Medical Center, Durham, North Carolina 27705 (United States); Baker, Jay A. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Samei, Ehsan [Department of Radiology, Clinical Imaging Physics Group, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Departments of Biomedical Engineering and Electrical and Computer Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina 27705 (United States)

    2016-05-15

    Purpose: The FDA approved the use of digital breast tomosynthesis (DBT) in 2011 as an adjunct to 2D full field digital mammography (FFDM) with the constraint that all DBT acquisitions must be paired with a 2D image to assure adequate interpretative information is provided. Recently manufacturers have developed methods to provide a synthesized 2D image generated from the DBT data with the hope of sparing patients the radiation exposure from the FFDM acquisition. While this much needed alternative effectively reduces the total radiation burden, differences in image quality must also be considered. The goal of this study was to compare the intrinsic image quality of synthesized 2D C-VIEW and 2D FFDM images in terms of resolution, contrast, and noise. Methods: Two phantoms were utilized in this study: the American College of Radiology mammography accreditation phantom (ACR phantom) and a novel 3D printed anthropomorphic breast phantom. Both phantoms were imaged using a Hologic Selenia Dimensions 3D system. Analysis of the ACR phantom includes both visual inspection and objective automated analysis using in-house software. Analysis of the 3D anthropomorphic phantom includes visual assessment of resolution and Fourier analysis of the noise. Results: Using ACR-defined scoring criteria for the ACR phantom, the FFDM images scored statistically higher than C-VIEW according to both the average observer and automated scores. In addition, between 50% and 70% of C-VIEW images failed to meet the nominal minimum ACR accreditation requirements—primarily due to fiber breaks. Software analysis demonstrated that C-VIEW provided enhanced visualization of medium and large microcalcification objects; however, the benefits diminished for smaller high contrast objects and all low contrast objects. Visual analysis of the anthropomorphic phantom showed a measureable loss of resolution in the C-VIEW image (11 lp/mm FFDM, 5 lp/mm C-VIEW) and loss in detection of small microcalcification

  10. How Does Imaging of Congenital Zika Compare with Imaging of Other TORCH Infections?

    Science.gov (United States)

    Levine, Deborah; Jani, Jacques C; Castro-Aragon, Ilse; Cannie, Mieke

    2017-12-01

    The acronym TORCH is used to refer to congenital infections, such as toxoplasmosis, other infections (such as syphillis, varicella-zoster, and parvovirus B19), cytomegalovirus, and herpes simplex virus. The classic findings in patients with TORCH infections include rash in the mother during pregnancy and ocular findings in the newborn. Zika virus has emerged as an important worldwide congenital infection. It fits well with other congenital TORCH infections since there is a rash in the mother and there are commonly ocular abnormalities in the newborn. TORCH infections are recognized to have neurologic effects, such as ventriculomegaly, intraventricular adhesions, subependymal cysts, intracerebral calcifications, and microcephaly; however, the Zika virus is intensely neurotropic. Thus, it targets neural progenitor cells, leading to a more severe spectrum of central nervous system abnormalities than is typically seen in other TORCH infections, while relatively sparing the other organ systems. In this review, nonspecific findings of congenital infections initially will be described, then individual TORCH infections will be described and compared with the imaging findings associated with congenital Zika virus infection. For the radiologist, awareness of imaging features of common congenital infections may facilitate early diagnosis and may, at times, lead to prompt initiation of therapy. Online supplemental material is available for this article.

  11. I.v. contrast administration with dual source 128-MDCT: a randomized controlled study comparing 18-gauge nonfenestrated and 20-gauge fenestrated catheters for catheter placement success, infusion rate, image quality, and complications.

    Science.gov (United States)

    Johnson, Pamela T; Christensen, Gale M; Fishman, Elliot K

    2014-06-01

    The purpose of this study was to compare the performance of a 20-gauge fenestrated catheter with an 18-gauge nonfenestrated catheter for i.v. contrast infusion during MDCT. Two hundred five adult outpatients imaged on a dual-source 128-MDCT scanner with arterial phase body CT (flow rates, 5.0-7.5 mL/s) were randomized to either an 18-gauge nonfenestrated or 20-gauge fenestrated catheter. After randomization, any 18-gauge nonfenestrated subjects whose veins were deemed insufficient for that catheter gauge were assigned to a third cohort for placement of a 20-gauge fenestrated catheter. Catheter placement success, infusion rate, contrast volume, maximum pressure, complications, and aortic enhancement levels were recorded. Catheters were placed on the first attempt in 97% (100/103) for 18-gauge nonfenestrated and 94% (96/102) for 20-gauge fenestrated placements and in two or fewer attempts in 99% of both groups. Mean infusion rates (5.74 mL/s for 18-gauge nonfenestrated and 5.58 mL/s for 20-gauge fenestrated placements) and aortic enhancement levels were not significantly different. Maximum pressure was higher with 20-gauge fenestrated catheters (mean ± SD, 230.5 ± 27.6 pounds per square inch [psi]) than 18-gauge nonfenestrated catheters (mean ± SD 215.6 ± 32.8 psi) (p = 0.002). One subject with an 18-gauge nonfenestrated catheter had a high-pressure alarm. In the third cohort, a 20-gauge fenestrated catheter was successfully placed in two or fewer attempts in 85% (28/33), with one minor extravasation attributed to vein insufficiency. A 20-gauge fenestrated catheter performs similarly to an 18-gauge nonfenestrated catheter with respect to i.v. contrast infusion rates and aortic enhancement levels and can be placed in most subjects whose veins are deemed insufficient for an 18-gauge catheter.

  12. A comparative study of 18F-fluorodeoxyglucose positron emission tomography/computed tomography and (99m)Tc-MDP whole-body bone scanning for imaging osteolytic bone metastases.

    Science.gov (United States)

    Zhang, Lin; Chen, Lihua; Xie, Qiao; Zhang, Yongke; Cheng, Lin; Li, Haitao; Wang, Jian

    2015-03-01

    The objective of this study was to evaluate the feasibility and diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and (99m)Tc-methylenediphosphonate (MDP) whole-body bone scanning (BS) for the detection of osteolytic bone metastases. Thirty-four patients with pathologically confirmed malignancies and suspected osteolytic bone metastases underwent 18F-FDG PET/CT and (99m)Tc-MDP whole-body BS within 30 days. The sensitivity, specificity, and accuracy with respect to the diagnosis of osteolytic bone metastases and bone lesions were compared between the two imaging methods. The sensitivity, specificity, and accuracy of 18F-FDG PET/CT for the diagnosis of osteolytic bone metastases were 94.3% (95% confidence interval [CI], 91.6-96.2%), 83.3% (95% CI, 43.6-96.9%), and 94.2% (95% CI, 91.5-96.1%), respectively. It was found that (99m)Tc-MDP whole-body BS could discriminate between patients with 50.2% (95% CI, 45.4-55.1%) sensitivity, 50.0% (95% CI, 18.8-81.2%) specificity, and 50.2% (95% CI, 45.5-55.1%) accuracy. 18F-FDG PET/CT achieved higher sensitivity, specificity, and accuracy in detecting osteolytic bone metastases than 99mTc-MDP whole-body BS (pMDP whole-body BS in the detection of osteolytic bone metastases, especially in the vertebra.

  13. A Comparative Study on Error Analysis

    DEFF Research Database (Denmark)

    Wu, Xiaoli; Zhang, Chun

    2015-01-01

    of the grammatical errors with using comparative sentences is developed, which include comparative item-related errors, comparative result-related errors and blend errors. The results further indicate that these errors could attribute to negative L1 transfer and overgeneralization of grammatical rule and structures......Title: A Comparative Study on Error Analysis Subtitle: - Belgian (L1) and Danish (L1) learners’ use of Chinese (L2) comparative sentences in written production Xiaoli Wu, Chun Zhang Abstract: Making errors is an inevitable and necessary part of learning. The collection, classification and analysis...... the occurrence of errors either in linguistic or pedagogical terms. The purpose of the current study is to demonstrate the theoretical and practical relevance of error analysis approach in CFL by investigating two cases - (1) Belgian (L1) learners’ use of Chinese (L2) comparative sentences in written production...

  14. Clinical findings versus imaging studies in the diagnosis of infantile ...

    African Journals Online (AJOL)

    Background: Infantile hypertrophic pyloric stenosis is the most common surgical cause of vomiting in early infancy and can be diagnosed clinically or by imaging studies. Objectives: The aim of this study was to assess the accuracy of clinical examination compared with ultrasound and upper gastrointestinal contrast imaging ...

  15. Symptomatic magnetic resonance imaging-confirmed lumbar disk herniation patients: a comparative effectiveness prospective observational study of 2 age- and sex-matched cohorts treated with either high-velocity, low-amplitude spinal manipulative therapy or imaging-guided lumbar nerve root injections.

    Science.gov (United States)

    Peterson, Cynthia K; Leemann, Serafin; Lechmann, Marco; Pfirrmann, Christian W A; Hodler, Juerg; Humphreys, B Kim

    2013-05-01

    The purpose of this study was to compare self-reported pain and "improvement" of patients with symptomatic, magnetic resonance imaging-confirmed, lumbar disk herniations treated with either high-velocity, low-amplitude spinal manipulative therapy (SMT) or nerve root injections (NRI). This prospective cohort comparative effectiveness study included 102 age- and sex-matched patients treated with either NRI or SMT. Numerical rating scale (NRS) pain data were collected before treatment. One month after treatment, current NRS pain levels and overall improvement assessed using the Patient Global Impression of Change scale were recorded. The proportion of patients, "improved" or "worse," was calculated for each treatment. Comparison of pretreatment and 1-month NRS scores used the paired t test. Numerical rating scale and NRS change scores for the 2 groups were compared using the unpaired t test. The groups were also compared for "improvement" using the χ(2) test. Odds ratios with 95% confidence intervals were calculated. Average direct procedure costs for each treatment were calculated. No significant differences for self-reported pain or improvement were found between the 2 groups. "Improvement" was reported in 76.5% of SMT patients and in 62.7% of the NRI group. Both groups reported significantly reduced NRS scores at 1 month (P = .0001). Average cost for treatment with SMT was Swiss Francs 533.77 (US $558.75) and Swiss Francs 697 (US $729.61) for NRI. Most SMT and NRI patients with radicular low back pain and magnetic resonance imaging-confirmed disk herniation matching symptomatic presentation reported significant and clinically relevant reduction in self-reported pain level and increased global perception of improvement. There were no significant differences in outcomes between NRI and SMT. When considering direct procedure costs, the average cost of SMT was slightly less expensive. Copyright © 2013 National University of Health Sciences. Published by Mosby, Inc

  16. Feedforward Object-Vision Models Only Tolerate Small Image Variations Compared to Human

    Directory of Open Access Journals (Sweden)

    Masoud eGhodrati

    2014-07-01

    Full Text Available Invariant object recognition is a remarkable ability of primates' visual system that its underlying mechanism has constantly been under intense investigations. Computational modelling is a valuable tool toward understanding the processes involved in invariant object recognition. Although recent computational models have shown outstanding performances on challenging image databases, they fail to perform well when images with more complex variations of the same object are applied to them. Studies have shown that making sparse representation of objects by extracting more informative visual features through a feedforward sweep can lead to higher recognition performances. Here, however, we show that when the complexity of image variations is high, even this approach results in poor performance compared to humans. To assess the performance of models and humans in invariant object recognition tasks, we built a parametrically controlled image database consisting of several object categories varied in different dimensions and levels, rendered from 3D planes. Comparing the performance of several object recognition models with human observers shows that only in low-level image variations the models perform similar to humans in categorization tasks. Furthermore, the results of our behavioral experiments demonstrate that, even under difficult experimental conditions (i.e. briefly presented masked stimuli with complex image variations, human observers performed outstandingly well, suggesting that the models are still far from resembling humans in invariant object recognition. Taken together, we suggest that learning sparse informative visual features, although desirable, is not a complete solution for future progresses in object-vision modelling. We show that this approach is not of significant help in solving the computational crux of object recognition (that is invariant object recognition when the identity-preserving image variations become more complex.

  17. COMPARATIVE STUDY ON SPECIFIC AND EARLY DETECTION ...

    African Journals Online (AJOL)

    The objective of this study was to compare the sensitivity and specificity of smear and culture methods with rapid serological EIA myco kits manufactured by Omega diagnostics, for the early detection of Mycobacterium tuberculosis (MTB) complex. Sera from various categories of smear and culture results were compared ...

  18. Diagnostic assessment of painless microhematuria: prospective study comparing image quality, assessibility and diagnostic certainty of multidetector-row CT and intravenous pyelography within a single examination; Diagnostische Abklaerung der schmerzlosen Mikrohaematurie: Prospektive Studie zum Vergleich von Bildqualitaet, Beurteilbarkeit und diagnostischer Sicherheit von MDCT und IVU in einem Untersuchungsgang

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, T. [Inst. fuer Diagnostische Radiologie, UniversitaetsSpital Zuerich (Switzerland); Dept. fuer Radiologie, Spitaeler Chur AG, Graubuenden (Switzerland); John, H.; Ruedi, C.; Marincek, B. [Klinik fuer Urologie, UniversitaetsSpital Zuerich (Switzerland); Wildermuth, S.; Michael, M. [Inst. fuer Diagnostische Radiologie, UniversitaetsSpital Zuerich (Switzerland)

    2005-10-01

    Purpose: The purpose of this study is to prospectively compare intravenous pyelography (IVP) and combined unenhanced and excretory phase multidetector-row CT (MDCT) with respect to image quality, diagnostic certainty and diagnostic concordance with the final clinical diagnosis in patients with painless microhematuria. Materials and Methods: Unenhanced MDCT, IVP and excretory phase MDCT were performed in 59 consecutive patients (21 women, 38 men, mean age 56{+-}19 years, range 23-83 years) with painless microhematuria of unknown origin during a single examination with a single contrast media application (100 ml, non-ionic iodinate contrast media). Images were assessed by two experienced urogenital radiologists in consensus for image quality, diagnostic certainty of stone detection, obstruction, parenchymal lesions and morphological distinctive features. Imaging diagnoses of MDCT and IVP were compared with the final clinical diagnoses. In case of failure to detect an relevant pathology, the final clinical diagnosis was established after a mean follow-up period of 18{+-}6 months (10 months to 2 years). Costs and radiation exposure of IVP and MDCT were compared. Results: MDCT scan performed better than IVP in terms of image quality for all regarded variables. Image quality of MDCT was rated in all parameters as very good or good; the image quality of IVP differed in a wide range. MDCT and IVP reached a sensitivity of 100% and 50% for stone detection (n=14, p=0.008), respectively. Two bladder stones were not detected by IVU but correctly seen with MDCT. MDCT and IVP were unsatisfactory for detecting transitional cell carcinomas (n=4, 2 of 4 detected with MDCT, 0 of 4 detected with IVU). One false positive transitional cell carcinoma was detected with IVP, none with MDCT. Additional relevant pathological changes (one teratoma, one abdominal aortic aneurysma and one abscess) were detected using MDCT but missed with IVP. In 38 of 59 patients (64%) imaging and clinical

  19. Comparing an FPGA to a Cell for an Image Processing Application

    Directory of Open Access Journals (Sweden)

    Robert W. Ives

    2010-01-01

    Full Text Available Modern advancements in configurable hardware, most notably Field-Programmable Gate Arrays (FPGAs, have provided an exciting opportunity to discover the parallel nature of modern image processing algorithms. On the other hand, PlayStation3 (PS3 game consoles contain a multicore heterogeneous processor known as the Cell, which is designed to perform complex image processing algorithms at a high performance. In this research project, our aim is to study the differences in performance of a modern image processing algorithm on these two hardware platforms. In particular, Iris Recognition Systems have recently become an attractive identification method because of their extremely high accuracy. Iris matching, a repeatedly executed portion of a modern iris recognition algorithm, is parallelized on an FPGA system and a Cell processor. We demonstrate a 2.5 times speedup of the parallelized algorithm on the FPGA system when compared to a Cell processor-based version.

  20. MR elastography of liver fibrosis: preliminary results comparing spin-echo and echo-planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huwart, Laurent; Salameh, Najat; Peeters, Frank; Beers, Bernard E. van [Universite Catholique de Louvain, St-Luc University Hospital, Diagnostic Radiology Unit, Brussels (Belgium); Beek, Leon ter [Philips Medical Systems, Best (Netherlands); Vicaut, Eric [Universite Paris Diderot, Hopital Lariboisiere, Paris (France); Sinkus, Ralph [Universite Paris Diderot, Laboratoire Ondes et Acoustique, Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris, Paris (France)

    2008-11-15

    The purpose of this study was to prospectively compare the performance of magnetic resonance (MR) elastography using echo-planar and spin-echo imaging for staging of hepatic fibrosis. Twenty-four patients who had liver biopsy for suspicion of chronic liver disease had MR elastography performed with both spin-echo and echo-planar sequences. At histology, the fibrosis stage was assessed according to METAVIR. The data acquisition time was about 20 min using spin-echo, and only 2 min using echo-planar imaging. The hepatic signal-to-noise ratios were similar on both images (22.51 {+-} 5.37 for spin-echo versus 21.02 {+-} 4.76 for echo-planar, p = 0.33). The elasticity measurements and the fibrosis stages were strongly correlated. The Spearman correlation coefficients were r = 0.91 (p < 0.01) with spin-echo and r = 0.84 (p < 0.01) with echo-planar sequences. These correlation coefficients did not differ significantly (p = 0.17). A strong correlation was also observed between spin-echo and echo-planar elasticity (r = 0.83, p < 0.001), without systematic bias. The results of our study showed that echo-planar imaging substantially decreased the data acquisition time of MR elastography, while maintaining the image quality and diagnostic performance for staging of liver fibrosis. This suggests that echo-planar MR elastography could replace spin-echo MR elastography in clinical practice. (orig.)

  1. Comparative value of thallium and glucose SPECT imaging in childhood brain tumors.

    Science.gov (United States)

    Maria, B L; Drane, W E; Mastin, S T; Jimenez, L A

    1998-11-01

    Thallium-201 chloride (201Tl) single-photon emission computed tomography (SPECT) detects a high percentage of histologically and anatomically diverse pediatric brain tumors. Thallium-201 chloride SPECT and F-18 fluoro-deoxy-glucose (18F-FDG) positron emission tomography (PET) are the most commonly used radionuclide techniques in neuro-oncology. Having developed a methodology to image 18F-FDG with SPECT, the authors performed SPECT scans coupled with magnetic resonance imaging to assess the comparative sensitivity of 201Tl and 18F-FDG in 19 children with brain tumors. Tumors were detected using 201Tl SPECT in 14 of 19 patients. Five of five postoperative residual tumors were detected by 201Tl SPECT, and six of seven after irradiation recurrences were detected. F-18 fluoro-deoxy-glucose SPECT detected tumors in only three of 19 patients, all of whom had abnormal 201Tl studies (all three after therapy recurrences). Thallium-201 chloride SPECT could be interpreted in 18 of 19 patients without magnetic resonance imaging confirmation, but none of the 19 18F-FDG SPECT studies could be interpreted without magnetic resonance imaging. Thallium-201 chloride SPECT is more sensitive than 18F-FDG SPECT in the detection of primary or recurrent childhood brain tumors. The failure of 18F-FDG SPECT in follow-up after therapy is primarily a problem of limited fluoro-deoxy-glucose uptake, not spatial resolution. Thallium-201 chloride SPECT is a promising imaging modality in neuro-oncology.

  2. Mathematics education and comparative historical studies

    Directory of Open Access Journals (Sweden)

    Wagner RODRIGUES VALENTE

    2013-11-01

    Full Text Available This paper has as its aims: to characterize the area of research «history of mathematics education» and to defend the idea that mathematics education has constituted a privileged research theme within the field of comparative historical studies. To achieve these aims, the text includes references to a review of the literature concerning comparative studies, the analysis of two fundamental moments focused on attempts to internationalize the mathematics curriculum, both of which occurred during the 20th century, and, to end, a case study emanating from an international cooperation between researchers in Brazil and Portugal.

  3. Comparative studies in Chelicerata III. Opilionida

    NARCIS (Netherlands)

    Hammen, van der L.

    1985-01-01

    A comparative study is made of the three groups (Cyphophthalmi, Laniatores and Palpatores) into which Opilionida are currently subdivided. Methods, principles and terminology, adopted in this paper, correspond with those of parts I and II of the present series of studies in Chelicerata. Special

  4. Comparative study of bioethanol production from sugarcane ...

    African Journals Online (AJOL)

    The study was designed to compare the bioethanol production from Zymomonas mobilis and Saccharomyces cerevisiae using molasses as production medium. The focus was on the retention time at lab scale. Bioethanol and petroleum blend can be used in existing gasoline engines. Present study showed a more ...

  5. Supplementary data: Comparative studies on sequence ...

    Indian Academy of Sciences (India)

    Unknown

    Supplementary data: Comparative studies on sequence characteristics around translation initiation codon in four eukaryotes. Qingpo Liu and Qingzhong Xue. J. Genet. 84, 317–322. Table 1. Spearman's rank correlation coefficients of 39 base positions around the AUG codon in the four eukaryotic species studied. – 30.

  6. Comparative study of fast T 2-weighted images using respiratory triggered, breath-hold, fat suppression and phased array multi coil for liver evaluation by magnetic resonance imaging; Estudo comparativo das sequencias rapidas ponderadas em T2, utilizando-se sincronizacao respiratoria, apneia, supressao de gordura, bobina de corpo e bobina de sinergia para a avaliacao do figado pela ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Abbehusen, Cristiane L.; D' Ippolito, Giuseppe; Palacio, Glaucia A.S.; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina (EPM). Dept. de Diagnostico por Imagem]. E-mail: cabbehusen@hotmail.com

    2003-10-01

    The objective of this study was to compare both qualitatively and quantitatively six T 2-weighted turbo spin-echo sequences varying the respiratory compensation technique, associating or not fat tissue suppression and using different types of coils. We performed a prospective study of 71 consecutive patients that were submitted to MRI of the liver using a 1.5 T magnet. The six following pulse sequences were used: fat-suppressed respiratory triggered with conventional body coil; breath-hold fat-suppressed with conventional body coil; non-suppressed respiratory triggered with conventional body coil; breath-hold non fat-suppressed with conventional body coil; fat-suppressed respiratory triggered with phased-array multi coil; breath-hold fat-suppressed with phased-array multi coil. Images were analyzed quantitatively by measuring the signal-to-noise ratios and qualitatively by evaluating the sharpness of hepatic contours, visibility of intrahepatic vessels and other segmental landmarks, and the presence of artifacts. Results: the qualitative analysis showed that the mean values obtained with the six sequences were 7.8, 4.6, 7.9, 5.2, 6.7 and 4.6 respectively. The respiratory-triggered sequences were better than the breath-hold sequences in both qualitative and quantitative analysis (p < 0.001). No significant differences in the values of signal-to-noise ratios and in overall image quality were found between the sequences with and without fat suppression (p . 0.05). The sequences using the body coil were similar in terms of image quality (p . 0.05) and better regarding signal-to-noise ratios than those obtained with the phased=array multi coil (p ,0.001). Our qualitative and quantitative results suggest that the best MRI sequences for the valuation of the liver are the sequences with respiratory triggering using a conventional body coil, with or without fat suppression. (author)

  7. A simple data compression scheme for binary images of bacteria compared with commonly used image data compression schemes

    NARCIS (Netherlands)

    Wilkinson, M.H.F.

    A run length code compression scheme of extreme simplicity, used for image storage in an automated bacterial morphometry system, is compared with more common compression schemes, such as are used in the tag image file format. These schemes are Lempel-Ziv and Welch (LZW), Macintosh Packbits, and

  8. A comparative study of dietary curcumin, nanocurcumin, and other classical amyloid-binding dyes for labeling and imaging of amyloid plaques in brain tissue of 5×-familial Alzheimer's disease mice.

    Science.gov (United States)

    Maiti, Panchanan; Hall, Tia C; Paladugu, Leela; Kolli, Nivya; Learman, Cameron; Rossignol, Julien; Dunbar, Gary L

    2016-11-01

    Deposition of amyloid beta protein (Aβ) is a key component in the pathogenesis of Alzheimer's disease (AD). As an anti-amyloid natural polyphenol, curcumin (Cur) has been used as a therapy for AD. Its fluorescent activity, preferential binding to Aβ, as well as structural similarities with other traditional amyloid-binding dyes, make it a promising candidate for labeling and imaging of Aβ plaques in vivo. The present study was designed to test whether dietary Cur and nanocurcumin (NC) provide more sensitivity for labeling and imaging of Aβ plaques in brain tissues from the 5×-familial AD (5×FAD) mice than the classical Aβ-binding dyes, such as Congo red and Thioflavin-S. These comparisons were made in postmortem brain tissues from the 5×FAD mice. We observed that Cur and NC labeled Aβ plaques to the same degree as Aβ-specific antibody and to a greater extent than those of the classical amyloid-binding dyes. Cur and NC also labeled Aβ plaques in 5×FAD brain tissues when injected intraperitoneally. Nanomolar concentrations of Cur or NC are sufficient for labeling and imaging of Aβ plaques in 5×FAD brain tissue. Cur and NC also labeled different types of Aβ plaques, including core, neuritic, diffuse, and burned-out, to a greater degree than other amyloid-binding dyes. Therefore, Cur and or NC can be used as an alternative to Aβ-specific antibody for labeling and imaging of Aβ plaques ex vivo and in vivo. It can provide an easy and inexpensive means of detecting Aβ-plaque load in postmortem brain tissue of animal models of AD after anti-amyloid therapy.

  9. Microwave Imaging of Human Forearms: Pilot Study and Image Enhancement

    Directory of Open Access Journals (Sweden)

    Colin Gilmore

    2013-01-01

    Full Text Available We present a pilot study using a microwave tomography system in which we image the forearms of 5 adult male and female volunteers between the ages of 30 and 48. Microwave scattering data were collected at 0.8 to 1.2 GHz with 24 transmitting and receiving antennas located in a matching fluid of deionized water and table salt. Inversion of the microwave data was performed with a balanced version of the multiplicative-regularized contrast source inversion algorithm formulated using the finite-element method (FEM-CSI. T1-weighted MRI images of each volunteer’s forearm were also collected in the same plane as the microwave scattering experiment. Initial “blind” imaging results from the utilized inversion algorithm show that the image quality is dependent on the thickness of the arm’s peripheral adipose tissue layer; thicker layers of adipose tissue lead to poorer overall image quality. Due to the exible nature of the FEM-CSI algorithm used, prior information can be readily incorporated into the microwave imaging inversion process. We show that by introducing prior information into the FEM-CSI algorithm the internal anatomical features of all the arms are resolved, significantly improving the images. The prior information was estimated manually from the blind inversions using an ad hoc procedure.

  10. A Comparative Study on Error Analysis

    DEFF Research Database (Denmark)

    Wu, Xiaoli; Zhang, Chun

    2015-01-01

    Title: A Comparative Study on Error Analysis Subtitle: - Belgian (L1) and Danish (L1) learners’ use of Chinese (L2) comparative sentences in written production Xiaoli Wu, Chun Zhang Abstract: Making errors is an inevitable and necessary part of learning. The collection, classification and analysis...... of errors in the written and spoken production of L2 learners has a long tradition in L2 pedagogy. Yet, in teaching and learning Chinese as a foreign language (CFL), only handful studies have been made either to define the ‘error’ in a pedagogically insightful way or to empirically investigate...... the occurrence of errors either in linguistic or pedagogical terms. The purpose of the current study is to demonstrate the theoretical and practical relevance of error analysis approach in CFL by investigating two cases - (1) Belgian (L1) learners’ use of Chinese (L2) comparative sentences in written production...

  11. Recognition of Faces in Unconstrained Environments: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Javier Ruiz-del-Solar

    2009-01-01

    Full Text Available The aim of this work is to carry out a comparative study of face recognition methods that are suitable to work in unconstrained environments. The analyzed methods are selected by considering their performance in former comparative studies, in addition to be real-time, to require just one image per person, and to be fully online. In the study two local-matching methods, histograms of LBP features and Gabor Jet descriptors, one holistic method, generalized PCA, and two image-matching methods, SIFT-based and ERCF-based, are analyzed. The methods are compared using the FERET, LFW, UCHFaceHRI, and FRGC databases, which allows evaluating them in real-world conditions that include variations in scale, pose, lighting, focus, resolution, facial expression, accessories, makeup, occlusions, background and photographic quality. Main conclusions of this study are: there is a large dependence of the methods on the amount of face and background information that is included in the face's images, and the performance of all methods decreases largely with outdoor-illumination. The analyzed methods are robust to inaccurate alignment, face occlusions, and variations in expressions, to a large degree. LBP-based methods are an excellent election if we need real-time operation as well as high recognition rates.

  12. [Comparative research on the NIR and MIR micro-imaging of two similar plastic materials].

    Science.gov (United States)

    Wang, Dong; Ma, Zhi-Hong; Zhao, Liu; Pan, Li-Gang; Li, Xiao-Ting; Wang, Ji-Hua

    2011-09-01

    The NIR/MIR micro-imaging can supply not only the information of spectra, but also the information of spacial distribution of the sample, which is superior to the traditional NIR/MIR spectroscopy analysis. In the present paper, polyethylene and parafilm, with similar appearances, were regarded as the research objects, of which the NIR/MIR micro-imaging was collected. Chemical imaging (CI) and compare correlation imaging were carried out for the two materials respectively to discuss the imaging methods of the two materials. The result indicated that the differentiation of the CI values of the two materials in the NIR/MIR CI for material II was 0.004 8 and 0.254 8 respectively, while those in the NIR/MIR CI for material I were 0.002 6 and 0.326 5, respectively. Clear CI was acquired, and the two materials could be differentiated. The result of the compare correlation imagings indicated that the compare correlation imagings, in which the NIR/MIR spectra of the two materials were regarded as reference spectra respectively, can differentiate the two materials remarkably with clear imagings. In the compare correlation imagings of MIR micro-imaging, the difference of the correlation coefficients between the two materials' MIR spectra and the reference spectrum was more than 0.12, which showed a better imaging result; while a tiny difference of the correlation coefficients between the two materials' NIR spectra and the reference spectrum could be employed to show a clear imaging result for NIR compare correlation imaging so as to differentiate the two materials. This thesis, to some extent, can supply the reference to not only the rapid discrimination of the safety of the packaging material for agri-food, but also the imaging methods for NIR/MIR micro-imaging to differentiate the different materials.

  13. MRI Compatibility of Robot Actuation Techniques – A Comparative Study

    OpenAIRE

    Fischer, Gregory S.; Krieger, Axel; Iordachita, Iulian; Csoma, Csaba; Whitcomb, Louis L.; Fichtinger, Gabor

    2008-01-01

    This paper reports an experimental evaluation of the following three different MRI-compatible actuators: a Shinsei ultrasonic motor, a Nanomotion ultrasonic motor and a pneumatic cylinder actuator. We report the results of a study comparing the effect of these actuators on the signal to noise ratio (SNR) of MRI images under a variety of experimental conditions. Evaluation was performed with the controller inside and outside the scanner room and with both 1.5T and 3T MRI scanners. Pneumatic cy...

  14. A comparative study of microbiological and physicochemical ...

    African Journals Online (AJOL)

    A comparative study of microbiological and physicochemical characteristics of water distributed from two water treatment plants in Rwanda. ... Thus, as recommendation to WASAC authority, there is a need for improvement in the water management strategy for better water quality especially along the distribution network.

  15. A Comparative Study of Probabilistic Roadmap Planners

    NARCIS (Netherlands)

    Geraerts, R.J.; Overmars, M.H.

    2004-01-01

    The probabilistic roadmap approach is one of the leading motion planning techniques. Over the past eight years the technique has been studied by many different researchers. This has led to a large number of variants of the approach, each with its own merits. It is difficult to compare the different

  16. A comparative study of map use

    DEFF Research Database (Denmark)

    Bouvin, Niels Olof; Brodersen, Ann Christina; Bødker, Susanne

    2006-01-01

    We present a study comparing the handling of three kinds of maps, each on a physical device: a paper map, a tablet-PC based map, and a cellular phone based one. Six groups of users were asked to locate eight landmarks, looking out a window, and using a particular map. We have begun analyzing video...

  17. Adding attenuation corrected images in myocardial perfusion imaging reduces the need for a rest study

    International Nuclear Information System (INIS)

    Trägårdh, Elin; Valind, Sven; Edenbrandt, Lars

    2013-01-01

    The American Society of Nuclear Cardiology and the Society of Nuclear Medicine conclude that incorporation of attenuation corrected (AC) images in myocardial perfusion scintigraphy (MPS) will improve diagnostic accuracy. The aim was to investigate the value of adding AC stress-only images for the decision whether a rest study is necessary or not. 1,261 patients admitted to 99m Tc MPS were studied. The stress studies were interpreted by two physicians who judged each study as “no rest study necessary” or “rest study necessary”, by evaluating NC stress-only and NC + AC stress-only images. When there was disagreement between the two physicians, a third physician evaluated the studies. Thus, agreement between 2 out of 3 physicians was evaluated. The physicians assessed 214 more NC + AC images than NC images as “no rest study necessary” (17% of the study population). The number of no-rest-study-required was significantly higher for NC + AC studies compared to NC studies (859 vs 645 cases (p < 0.0001). In the final report according to clinical routine, ischemia or infarction was reported in 23 patients, assessed as “no rest study necessary” (22 NC + AC cases; 8 NC cases), (no statistically significant difference). In 11 of these, the final report stated “suspected/possible ischemia or infarction in a small area”. Adding AC stress-only images to NC stress-only images reduce the number of unnecessary rest studies substantially

  18. Comparing the Zeiss Callisto Eye and the Alcon Verion Image Guided System Toric Lens Alignment Technologies.

    Science.gov (United States)

    Hura, Arjan S; Osher, Robert H

    2017-07-01

    To compare the alignment meridian generated by the Zeiss Callisto Eye (Carl Zeiss AG, Dublin, CA) and the Alcon Verion Image Guided System (Alcon Laboratories, Inc., Fort Worth, TX). In this retrospective comparative evaluation of technology, intraoperative images were captured at different steps in the same surgery, allowing the comparison of the guidance lines generated by the Verion system to the parallel guidance lines generated by the Callisto Eye system. Measurements of each hemi-meridian were quantified using Adobe Photoshop 2015 CC software (Adobe Systems, San Jose, CA). The numbers of degrees separating these alignment meridians were calculated, entered into a database, and analyzed. The authors found that of 98 captured images of 16 eyes, the two technologies were identical in 0 eyes (θ 1 = θ 2 = 0), similar by 3° in 52 (53%) captured images (θ 1 ≠ θ 2 ≠ 0), and different by at least 3° in 46 (47%) captured images (θ 1 ≠ θ 2 ≠ 0). The target meridians were superimposed, the target lines were minimally separated, and the target lines were dissimilar. It was noted that some intraoperative variation occurred from measurement to measurement. Within the small group of 16 cases of routine toric lens implantation in this study, the absolute average number of degrees of misalignment between the Verion and Callisto Eye systems was 3.355 for θ 1 and 3.838 for θ 2 . On average, the intraoperative variation termed "drift" was noted to be 3.963° for θ 1 , and 4.557° for θ 2 . The authors found that small deviations were frequent when comparing two sophisticated technologies. Although deviations greater than 3° occurred in less than 47% of captured images from 16 eyes, smaller but significant variations of less than 3° occurred in 53% of captured images from 16 eyes. It was rare to identify a large deviation. However, the authors identified "drift" in the same eye when measurements were taken at different times. The results indicate that the two

  19. A comparative study of Averrhoabilimbi extraction method

    Science.gov (United States)

    Zulhaimi, H. I.; Rosli, I. R.; Kasim, K. F.; Akmal, H. Muhammad; Nuradibah, M. A.; Sam, S. T.

    2017-09-01

    In recent year, bioactive compound in plant has become a limelight in the food and pharmaceutical market, leading to research interest to implement effective technologies for extracting bioactive substance. Therefore, this study is focusing on extraction of Averrhoabilimbi by different extraction technique namely, maceration and ultrasound-assisted extraction. Fewplant partsof Averrhoabilimbiweretaken as extraction samples which are fruits, leaves and twig. Different solvents such as methanol, ethanol and distilled water were utilized in the process. Fruit extractsresult in highest extraction yield compared to other plant parts. Ethanol and distilled water have significant role compared to methanol in all parts and both extraction technique. The result also shows that ultrasound-assisted extraction gave comparable result with maceration. Besides, the shorter period on extraction process gives useful in term of implementation to industries.

  20. PET imaging of α{sub 7} nicotinic acetylcholine receptors: a comparative study of [{sup 18}F]ASEM and [{sup 18}F]DBT-10 in nonhuman primates, and further evaluation of [{sup 18}F]ASEM in humans

    Energy Technology Data Exchange (ETDEWEB)

    Hillmer, Ansel T.; Li, Songye; Zheng, Ming-Qiang; Lin, Shu-fei; Nabulsi, Nabeel; Holden, Daniel; Pracitto, Richard; Labaree, David; Ropchan, Jim; Esterlis, Irina; Cosgrove, Kelly P.; Carson, Richard E.; Huang, Yiyun [Yale University, PET Center, New Haven, CT (United States); Scheunemann, Matthias; Teodoro, Rodrigo; Deuther-Conrad, Winnie; Brust, Peter [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Leipzig (Germany)

    2017-06-15

    The α{sub 7} nicotinic acetylcholine receptor (nAChR) is implicated in many neuropsychiatric disorders, making it an important target for positron emission tomography (PET) imaging. The first aim of this work was to compare two α{sub 7} nAChRs PET radioligands, [{sup 18}F]ASEM 3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-6-([{sup 18}F]fluorodibenzo[b,d]thiophene 5,5-dioxide) and [{sup 18}F]DBT-10 7-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-2-([{sup 18}F]fluorodibenzo[b,d]thiophene 5,5-dioxide), in nonhuman primates. The second aim was to assess further the quantification and test-retest variability of [{sup 18}F]ASEM in humans. PET scans with high specific activity [{sup 18}F]ASEM or [{sup 18}F]DBT-10 were acquired in three rhesus monkeys (one male, two female), and the kinetic properties of these radiotracers were compared. Additional [{sup 18}F]ASEM PET scans with blocking doses of nicotine, varenicline, and cold ASEM were acquired separately in two animals. Next, six human subjects (five male, one female) were imaged with [{sup 18}F]ASEM PET for 180 min, and arterial sampling was used to measure the parent input function. Different modeling approaches were compared to identify the optimal analysis method and scan duration for quantification of [{sup 18}F]ASEM distribution volume (V{sub T}). In addition, retest scans were acquired in four subjects (three male, one female), and the test-retest variability of V{sub T} was assessed. In the rhesus monkey brain [{sup 18}F]ASEM and [{sup 18}F]DBT-10 exhibited highly similar kinetic profiles. Dose-dependent blockade of [{sup 18}F]ASEM binding was observed, while administration of either nicotine or varenicline did not change [{sup 18}F]ASEM V{sub T}. [{sup 18}F]ASEM was selected for further validation because it has been used in humans. Accurate quantification of [{sup 18}F]ASEM V{sub T} in humans was achieved using multilinear analysis with at least 90 min of data acquisition, resulting in V{sub T} values ranging from 19.6 ± 2

  1. Comparative Study of Bancruptcy Prediction Models

    Directory of Open Access Journals (Sweden)

    Isye Arieshanti

    2013-09-01

    Full Text Available Early indication of bancruptcy is important for a company. If companies aware of  potency of their bancruptcy, they can take a preventive action to anticipate the bancruptcy. In order to detect the potency of a bancruptcy, a company can utilize a a model of bancruptcy prediction. The prediction model can be built using a machine learning methods. However, the choice of machine learning methods should be performed carefully. Because the suitability of a model depends on the problem specifically. Therefore, in this paper we perform a comparative study of several machine leaning methods for bancruptcy prediction. According to the comparative study, the performance of several models that based on machine learning methods (k-NN, fuzzy k-NN, SVM, Bagging Nearest Neighbour SVM, Multilayer Perceptron(MLP, Hybrid of MLP + Multiple Linear Regression, it can be showed that fuzzy k-NN method achieve the best performance with accuracy 77.5%

  2. Detection ability of FDG-PET/CT comparing with other imaging modalities in multiple myeloma patients

    International Nuclear Information System (INIS)

    Chae, Min Jeong; Lee, Tae Hyun; Pai, Moon Sun; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo

    2007-01-01

    Multiple myeloma (MM) is characterized by bone marrow infiltration with malignant plasma cells. It is important to detect involving bone for diagnosis and management of MM. The aim of this study was to evaluate the diagnostic ability and limitation of 18F-FDG-PET/CT (PET/CT) comparing other imaging modalities (separated PET and CT, whole body plain X-ray (XR), bone scintigraphy (BS), and MRI) in MM. Twenty PET/CT scans were performed in 16 patients (M: F=6: 10, median age=59 y). PET/CT findings were compared with available other images (n of CT=21, XR=21, BS=8, and MRI=5). Concordance with more than 2 image modalities, laboratory data, symptom, and biopsies were used for diagnosis of detected lesions. PET/CT revealed 256 of total 287 sites (sensitivity, 89.2%; accuracy, 84.8%). The sensitivity and accuracy of separating PET, CT, and XR were 86.3%, 70.4%; 47.4%, 50.3%; and 72.8%, 72.4%, respectively. Available BS identified 67 of 202 sites (sensitivity, 33.2%; accuracy, 44.0%). MRI detected 20 of 24 sites (sensitivity, 83.3%; accuracy, 36.3%). False positive rate (FP) of PET, XR, and MRI was as high as 87.8%, 95.1%, and 100%. PET for rib lesion identified 9 of 10 patients (90.0%) but for skull lesion only 4 of 7 patients (57.2%) with underestimation. 5 patients in MRI showed diffuse marrow signal change but only 3 had marrow involvement. But PET/CT showed higher accuracy than MRI. PET/CT was the most useful tool for detecting involving bone of MM comparing with other imaging modalities. Moreover, PET/CT is expected to overcome the limitations for the small osteolytic bone lesions with diffuse FDG uptake on PET

  3. Idealized media images and adolescent body image: "comparing" boys and girls.

    Science.gov (United States)

    Hargreaves, Duane A; Tiggemann, Marika

    2004-12-01

    Sociocultural theories of body image suggest that body dissatisfaction results from unrealistic societal beauty ideals, and one way of transmitting these ideals is through the mass media. The present research aimed to examine the effect of exposure to images of idealized beauty in the media on adolescent girls' and boys' body image. The participants (595 adolescents) viewed television commercials containing either images of the thin ideal for women, images of the muscular ideal for men, or non-appearance television commercials. Body dissatisfaction was measured before and after commercial viewing. It was found that exposure to idealized commercials led to increased body dissatisfaction for girls but not for boys. Idealized commercials led to increased negative mood and appearance comparison for girls and boys, although the effect on appearance comparison was stronger for girls. Further, participants high on appearance investment reported greater appearance comparison after viewing idealized commercials than those less strongly invested in their appearance. The results suggest the immediate impact of the media on body image is both stronger and more normative for girls than for boys, but that some boys may also be affected.

  4. Pocahontas: Comparing the Disney Image with Historical Evidence

    Science.gov (United States)

    Golden, Margaret

    2006-01-01

    Fourth grade students "know about" Pocahontas, but is this knowledge based on historical fact, or on information from the media, specifically the Disney movies "Pocahontas" and "Pocahontas II"? To address this question within the context of the New York State Social Studies curriculum and the New York State English…

  5. Comparative studies of brain activation with MEG and functional MRI

    International Nuclear Information System (INIS)

    George, J.S.; Aine, C.J.; Sanders, J.A.; Lewine, J.D.; Caprihan, A.

    1993-01-01

    The past two years have witnessed the emergence of MRI as a functional imaging methodology. Initial demonstrations involved the injection of a paramagnetic contrast agent and required ultrafast echo planar imaging capability to adequately resolve the passage of the injected bolus. By measuring the local reduction in image intensity due to magnetic susceptibility, it was possible to calculate blood volume, which changes as a function of neural activation. Later developments have exploited endogenous contrast mechanisms to monitor changes in blood volume or in venous blood oxygen content. Recently, we and others have demonstrated that it is possible to make such measurements in a clinical imager, suggesting that the large installed base of such machines might be utilized for functional imaging. Although it is likely that functional MRI (fMRI) will subsume some of the clinical and basic neuroscience applications now touted for MEG, it is also clear that these techniques offer different largely complementary, capabilities. At the very least, it is useful to compare and cross-validate the activation maps produced by these techniques. Such studies will be valuable as a check on results of neuromagnetic distributed current reconstructions and will allow better characterization of the relationship between neurophysiological activation and associated hemodynamic changes. A more exciting prospect is the development of analyses that combine information from the two modalities to produce a better description of underlying neural activity than is possible with either technique in isolation. In this paper we describe some results from initial comparative studies and outline several techniques that can be used to treat MEG and fMRI data within a unified computational framework

  6. Linear pneumatic motors – a comparative study

    Directory of Open Access Journals (Sweden)

    Deaconescu Tudor

    2017-01-01

    Full Text Available The paper presents a comparative study of the performance of single-acting cylinders, diaphragm cylinders and pneumatic muscles, and offers users information that allows the selection of an optimum technical solution. Such a study was necessary, in view of the numerous papers on pneumatic muscle applications found in literature, that assert the superiority of pneumatic muscles over other pneumatic linear motors in relation to quantities like dimensions, mass, developed force or energy-to-mass ratios, however without offering concrete data.

  7. Prospective nonrandomized study of diagnostic accuracy comparing prostate cancer detection by transrectal ultrasound-guided biopsy to magnetic resonance imaging with subsequent MRI-guided biopsy in biopsy-naïve patients.

    Science.gov (United States)

    Castellucci, Roberto; Linares Quevedo, Ana I; Sánchez Gómez, Francisco J; Díez Rodríguez, Jesús; Cogorno, Leopoldo; Cogollos Acuña, Isidro; Salmerón Béliz, Isabel; Muñoz Fernández de Legaría, Marta; Martínez Piñeiro, Luis

    2017-12-01

    To evaluate the diagnostic efficacy in cancer prostate (PCa) of Multiparametric prostate magnetic resonance imaging (mp-MRI) targeted biopsy compared to standard systematic transrectal ultrasound-guided biopsy (TRUSGB) in biopsy-naïve patients. A total of 168 biopsy-naïve men with clinical suspicion of PCa due to elevated PSA levels and/or an abnormal digital rectal examination were consecutively enrolled from July 2011 to July 2014. All patients underwent TRUSGB. Patients with equivocal (Pi-rads 3) or suspicious lesion (Pi-rads 4-5), were additionally biopsied using two cores, by the same operator (cognitive technique). Among the 168 cases, mp-MRI was equivocal for PCa (Pi-rads 3) in 46 subjects (27.4%) and suspicious (Pi-rads 4, 5) in 40 cases (23.8%). Of the 69 patients with PCa, standard TRUSGB showed Gleason ≥7 in 75% of patients with Pirads 3 and 77.8% in cases with Pirads 4-5 on mp-MRI. Among the 40 patients with Pi-rads 4-5 lesion on the MRI, cognitive mp-MRI-guided biopsy (MRCGB) detected a higher number of cases of PCa with a Gleason score equal or superior to 7 (90%) with a higher negative predictive value (97.5%) than cases with Pi-rads 3 lesion or subjects with TRUSGB alone. mp-MRI followed by selective biopsy seems to be a valuable tool to improve the diagnosis of intermediate and high risk PCa compared to standard TRUSGB.

  8. A comparative study of image-guided percutaneous procedures for the treatment of liver abscesses; Estudos comparativos dos procedimentos percutaneos orientados por metodos de imagem no tratamento das colecoes hepaticas

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Giselle Guedes Netto de; Meirelles, Gustavo de Souza Portes; Oliveira, Jose Marcelo Amatuzzi de; Ajzen, Sergio; D' Ippolito, Giuseppe; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagem

    2001-04-01

    The objective was to determine and compare the efficacy of percutaneous needle aspiration and percutaneous catheter drainage, both guided by imaging methods, for the treatment of liver abscesses. From 52 patients referred to our service for percutaneous treatment of abdominal abscesses, 17 presented liver abscesses, 13 of which were considered non complex and four were considered complex (multiloculated, multiple or associated to fistulas). Percutaneous needle aspiration was performed in 7/17 patients and 10/17 patients were submitted to percutaneous catheter drainage. The method used was considered successful when there was complete abscess resolution with both clinical and laboratorial improvement. The procedures were successful in 82.4% of all cases. In the group submitted to percutaneous needle aspiration the rate of success was 57.1% and in the group submitted to percutaneous catheter drainage the rate of success was 100%. Successful treatment was achieved in 75% of the patients submitted to percutaneous needle aspiration for abscesses smaller than 100 ml, but in only 33.3% of the patients with abscesses between 100 and 250 ml. There was complete resolution of the abscesses with percutaneous needle aspiration in 75% of the simple abscesses and in 25% of the complex abscesses. Percutaneous catheter drainage is more effective than percutaneous needle aspiration for the treatment of liver abscesses. Needle aspiration may probably be used as a valid alternative for smaller and non complex abscesses. (author)

  9. A Comparative Study in Communication Texts & Theories

    Directory of Open Access Journals (Sweden)

    Mahdi Mohsenian Rad

    2011-04-01

    Full Text Available The present article is to study the characteristics and general nature of audience and is described it as "Audience phantasm" in developing countries. It firstly notes that there will be consequences such as audience distancing themselves from local and official media if policy makers and media officials' imaginations of audiences become far from related bare facts have happened in the era of global media and the nature of audiences. Knowing and analyzing the image of audiences presented in new communication theories. Accordingly, as the abovementioned authorities’ viewpoint of audiences exposed to media messages keeps distance from the true nature of media activities, media‐message receivers and their current position in the booming market of media, as termed by Mohsenyan Rad as “Message Bazaar”, there will possibly be disastrous social, cultural, political, and even economic consequences with regard to media uses.Then the history and definitions of “audience”, "uses & gratifications theory" and the concept of "Audience Phantasm" is described. After that, based on those and the increased options as well as the right of selecting of today-audience in the situation of message bazaar, as a result the characteristics of them are explained.

  10. Display of nuclear medicine imaging studies

    CERN Document Server

    Singh, B; Samuel, A M

    2002-01-01

    Nuclear medicine imaging studies involve evaluation of a large amount of image data. Digital signal processing techniques have introduced processing algorithms that increase the information content of the display. Nuclear medicine imaging studies require interactive selection of suitable form of display and pre-display processing. Static imaging study requires pre-display processing to detect focal defects. Point operations (histogram modification) along with zoom and capability to display more than one image in one screen is essential. This album mode of display is also applicable to dynamic, MUGA and SPECT data. Isometric display or 3-D graph of the image data is helpful in some cases e.g. point spread function, flood field data. Cine display is used on a sequence of images e.g. dynamic, MUGA and SPECT imaging studies -to assess the spatial movement of tracer with time. Following methods are used at the investigator's discretion for inspection of the 3-D object. 1) Display of orthogonal projections, 2) Disp...

  11. EFQPSK Versus CERN: A Comparative Study

    Science.gov (United States)

    Borah, Deva K.; Horan, Stephen

    2001-01-01

    This report presents a comparative study on Enhanced Feher's Quadrature Phase Shift Keying (EFQPSK) and Constrained Envelope Root Nyquist (CERN) techniques. These two techniques have been developed in recent times to provide high spectral and power efficiencies under nonlinear amplifier environment. The purpose of this study is to gain insights into these techniques and to help system planners and designers with an appropriate set of guidelines for using these techniques. The comparative study presented in this report relies on effective simulation models and procedures. Therefore, a significant part of this report is devoted to understanding the mathematical and simulation models of the techniques and their set-up procedures. In particular, mathematical models of EFQPSK and CERN, effects of the sampling rate in discrete time signal representation, and modeling of nonlinear amplifiers and predistorters have been considered in detail. The results of this study show that both EFQPSK and CERN signals provide spectrally efficient communications compared to filtered conventional linear modulation techniques when a nonlinear power amplifier is used. However, there are important differences. The spectral efficiency of CERN signals, with a small amount of input backoff, is significantly better than that of EFQPSK signals if the nonlinear amplifier is an ideal clipper. However, to achieve such spectral efficiencies with a practical nonlinear amplifier, CERN processing requires a predistorter which effectively translates the amplifier's characteristics close to those of an ideal clipper. Thus, the spectral performance of CERN signals strongly depends on the predistorter. EFQPSK signals, on the other hand, do not need such predistorters since their spectra are almost unaffected by the nonlinear amplifier, Ibis report discusses several receiver structures for EFQPSK signals. It is observed that optimal receiver structures can be realized for both coded and uncoded EFQPSK

  12. Significant improvement in synovitis, osteitis, and bone erosion following golimumab and methotrexate combination therapy as compared with methotrexate alone: A magnetic resonance imaging study of 318 methotrexate-naive rheumatoid arthritis patients

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Emery, Paul; Conaghan, Philip G

    2011-01-01

    To evaluate the effects of golimumab on inflammation/structural damage detected by magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA).......To evaluate the effects of golimumab on inflammation/structural damage detected by magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA)....

  13. Study of Body Image in Fertile and Infertile Men

    Science.gov (United States)

    Akhondi, Mohammad Mehdi; Dadkhah, Asghar; Bagherpour, Ahmad; Ardakani, Zohreh Behjati; Kamali, Kourosh; Binaafar, Sima; Kosari, Haleh; Ghorbani, Behzad

    2011-01-01

    Background Body Image as a multidimensional entity is related to both physical and psychological aspects of the image one has of his or her own body. Lack/absence of an acceptable body image is one of the reasons of mental distress in infertile individuals. Methods In this study, an equal number (No=120) of fertile and infertile men attending Avicenna Infertility Clinic (AIC) were enrolled. The participants were compared in regard to body image variables based on the "Multidimensional Body-Self Relations Questionnaire (MBSRQ)" consisting of 10 subscales. Data was analyzed by SPSS, version 11.5, using Chi square and independent t-tests. Results Fertile men had a more positive body image as compared to infertile individuals. Significant statistical differences were observed when body image subscales were compared in both groups; in other words appearance evaluation, appearance orientation, Novy, health evaluation, health orientation, illness orientation, body satisfaction, overweight preoccupation and self-classified weight showed differences, while no significant difference was observed in regard to fitness orientation. Conclusion It seems that the ability and efficiency of body image is affected by infertility leading to dissatisfaction of one's body image. PMID:23926517

  14. CURRICULAR OFFER INFLUENCING STUDENTS’ SATISFACTION: COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Oana DUMITRASCU

    2014-11-01

    Full Text Available The main objective of the study is the determination of students’ satisfaction regarding curricular activities. The study has been accomplished using the qualitative and quantitative research, using the bibliographic study, various secondary sources and different primary sources. The study is developed with a marketing research and accomplished using the survey method. 699 students from four universities have been questioned. Due to a comparative study the University of Applied Sciences Worms, University of Applied Sciences Wiesbaden Rüsselsheim, University of Applied Sciences Frankfurt am Main and Nürtingen-Geislingen University have been analysed and their similarities and differences have been identified. The collected data, based on the established sample, is evaluated through univariate and bivariate analysis. In accordance with the evaluated sample, specific gaps from each region are identified regarding the curricular offer of the analysed universities. As a result to the conducted study, recommendations for the University of Applied Sciences Worms regarding the student’s satisfaction concerning the curricular offer are presented.

  15. A comparative study of teenage pregnancy.

    Science.gov (United States)

    Mahavarkar, S H; Madhu, C K; Mule, V D

    2008-08-01

    Teenage pregnancy is a global problem and is considered a high-risk group, in spite of conflicting evidence. Our objective was to compare obstetric outcomes of pregnancy in teenagers and older women. This was a retrospective study of case records of pregnancies from August 2000 to July 2001. Girls aged pregnancy outcomes in older women (19-35 years) in the same hospital. The study took place in the Government General Hospital, Sangli, India, a teaching hospital in rural India, with an annual delivery rate of over 3,500. A total of 386 teenage pregnancies were compared with pregnancies in 3,326 older women. Socioeconomic data, age, number of pregnancies, antenatal care and complications, mode of delivery, and neonatal outcomes were considered. The incidence of teenage pregnancy in the study was 10%. A significant proportion of teenage pregnant mothers were in their first pregnancies. The teenage mothers were nearly three times more at risk of developing anaemia (OR = 2.83, 95% CI = 2.2-3.7, p Teenage mothers were twice as likely to develop hypertensive problems in pregnancy (OR = 2.2, 95% CI = 1.5-3.2, p teenage pregnancies are still a common occurrence in rural India in spite of various legislations and government programmes and teenage pregnancy is a risk factor for poor obstetric outcome in rural India. Cultural practices, poor socioeconomic conditions, low literacy rate and lack of awareness of the risks are some of the main contributory factors. Early booking, good care during pregnancy and delivery and proper utilisation of contraceptive services can prevent the incidence and complications in this high-risk group.

  16. A comparative study of bike lane injuries.

    Science.gov (United States)

    Wee, Jung Hee; Park, Jeong Ho; Park, Kyu Nam; Choi, Seung Pill

    2012-02-01

    Because of the increased number of bicycle riders and governmental promotions, a recent increase in the construction of bicycle lanes has occurred. We aimed to characterize injuries specific to bicycle lane accidents by comparing them with injuries that occurred on regular roadways. On the basis of our findings, we provide suggestions on proper preventive strategies. We performed a retrospective study on 408 cases obtained between January 1, 2009, and December 31, 2010. Of these cases, 387 met the criterion that the location of the injury could be confirmed by telephone or via review of the patient's chart. Data regarding age, gender, Injury Severity Score, time of the accident, location of the accident, and other characteristics were collected. Data were analyzed using SPSS 12.0K. Of the 387 cases, 204 (52.7%) patients were injured in bicycle lanes and 183 (47.3%) were injured on regular roadways. Comparing cases of bicycle lane injuries and non-bicycle lane injuries, there were no differences in age, day of the week, season, or the time at which the accident occurred. Bicycle helmets were used more frequently in bicycle lane injuries (33.2% vs. 13.7%; p gear or preventing the use of bicycle lanes by pedestrians. More safety education programs are also needed. III.

  17. Comparative study of different fuel cell technologies

    International Nuclear Information System (INIS)

    Alvarado-Flores, J.

    2013-01-01

    Fuel cells generate electricity and heat during electrochemical reaction which happens between the oxygen and hydrogen to form the water. Fuel cell technology is a promising way to provide energy for rural areas where there is no access to the public grid or where there is a huge cost of wiring and transferring electricity. In addition, applications with essential secure electrical energy requirement such as uninterruptible power supplies (UPS), power generation stations and distributed systems can employ fuel cells as their source of energy. The current paper includes a comparative study of basic design, working principle, applications, advantages and disadvantages of various technologies available for fuel cells. In addition, techno-economic features of hydrogen fuel cell vehicles (FCV) and internal combustion engine vehicles (ICEV) are compared. The results indicate that fuel cell systems have simple design, high reliability, noiseless operation, high efficiency and less environmental impact. The aim of this paper is to serve as a convenient reference for fuel cell power generation reviews. (Author)

  18. Sedation with nitrous oxide compared with no sedation during catheterization for urologic imaging in children

    International Nuclear Information System (INIS)

    Zier, Judith L.; Kvam, Kathryn A.; Kurachek, Stephen C.; Finkelstein, Marsha

    2007-01-01

    Various strategies to mitigate children's distress during voiding cystourethrography (VCUG) have been described. Sedation with nitrous oxide is comparable to that with oral midazolam for VCUG, but a side-by-side comparison of nitrous oxide sedation and routine care is lacking. The effects of sedation/analgesia using 70% nitrous oxide and routine care for VCUG and radionuclide cystography (RNC) were compared. A sample of 204 children 4-18 years of age scheduled for VCUG or RNC with sedation or routine care were enrolled in this prospective study. Nitrous oxide/oxygen (70%/30%) was administered during urethral catheterization to children in the sedated group. The outcomes recorded included observed distress using the Brief Behavioral Distress Score, self-reported pain, and time in department. The study included 204 patients (99 nonsedated, 105 sedated) with a median age of 6.3 years (range 4.0-15.2 years). Distress and pain scores were greater in nonsedated than in sedated patients (P < 0.001). Time in department was longer in the sedated group (90 min vs. 30 min); however, time from entry to catheterization in a non-imaging area accounted for most of the difference. There was no difference in radiologic imaging time. Sedation with nitrous oxide is effective in reducing distress and pain during catheterization for VCUG or RNC in children. (orig.)

  19. Comparative X-ray investigation of lateral and anterior-posterior ankle-joint images - comparison with pathological and anatomical findings concerning lateral ankle-joint lesions and their clinical importance, studied in a special type of holding device

    International Nuclear Information System (INIS)

    John, F.

    1982-01-01

    The study reports on a possibility to interpret the relation of the different bone structures of the upper ankle-joint to one another in the X-ray picture without using contrast media. Modern funtional diagnostic methods increasingly make use of X-ray pictures taken in fixed position. It seems useful to standardize such X-ray images of the ankle-joint in order to make them reproducible. The author developed a device that would suit these purposes. A diagnosis required the reproduction of the accidental mechanism. The clinical symptoms do not permit to clearly state the extent of the lesion of the ligaments. The results of the post-operative follow-up examinations confirm the urgent necessity of the standardized diagnostic method presented and the success of the therapy applied. The presented X-ray method permits safe diagnosis of ruptures of the ligaments. Location of a certain rupture is not possible with the fixed-position X-ray screening. For a clear assessment of lesions of the ligaments at the lateral ankle-joint, X-ray pictures must be taken both in the anterior-posterior path of rays and in the lateral one. A normal result in the lateral path of rays does not exclude a pathologic result in the anterior-posterior path of rays, and vice versa. (orig./MG) [de

  20. Comparative microscopy study of Vibrio cholerae flagella

    Science.gov (United States)

    Konnov, Nikolai P.; Baiburin, Vil B.; Zadnova, Svetlana P.; Volkov, Uryi P.

    1999-06-01

    A fine structure of bacteria flagella is an important problem of molecular cell biology. Bacteria flagella are the self-assembled structures that allow to use the flagellum protein in a number of biotechnological applications. However, at present, there is a little information about high resolution scanning probe microscopy study of flagellum structure, in particular, about investigation of Vibrio cholerae flagella. In our lab have been carried out the high resolution comparative investigation of V. cholerae flagella by means of various microscopes: tunneling (STM), scanning force (SFM) and electron transmission. As a scanning probe microscope is used designed in our lab versatile SPM with replaceable measuring heads. Bacteria were grown, fixed and treated according to the conventional techniques. For STM investigations samples were covered with Pt/Ir thin films by rotated vacuum evaporation, in SFM investigations were used uncovered samples. Electron microscopy of the negatively stained bacteria was used as a test procedure.

  1. [Anxiety in eating disorders: a comparative study].

    Science.gov (United States)

    Solano Pinto, Natalia; Cano Vindel, Antonio

    2012-01-01

    Scientific literature shows that anxiety is an important factor in eating disorders. The aim of this case-control study was to compare the anxiety manifestations obtained by means of the Anxiety Situations and Responses Inventory of in a clinical sample of 74 females (46, anorexia nervosa; 28, bulimia) to those obtained by a control group (130 girls without disorders). The between-group ANOVA results showed higher anxiety scores in the clinical group with a medium effect size for the anxiety trait, finding a flat profile (within-group ANOVA) for the three response systems (cognitive, physiological and motor) and the four specific anxiety traits (test, interpersonal, phobic, and daily life situations). Moreover, high scores in anxiety involved a greater risk of being diagnosed with an eating disorder in the 8 bivariate comparisons. The estimations were more precise for cognitive anxiety and for the specific interpersonal anxiety trait.

  2. Study on Processing Method of Image Shadow

    Directory of Open Access Journals (Sweden)

    Wang Bo

    2014-07-01

    Full Text Available In order to effectively remove disturbance of shadow and enhance robustness of information processing of computer visual image, this paper makes study on inspection and removal of image shadow. It makes study the continual removal algorithm of shadow based on integration, the illumination surface and texture, it respectively introduces their work principles and realization method, it can effectively carrying processing for shadow by test.

  3. Magnetic resonance imaging findings compared with histological findings of the labrum in hip osteoarthritis

    Energy Technology Data Exchange (ETDEWEB)

    Kanezaki, Shiho; Nakamura, Shigeru; Matsushita, Takashi [Teikyo University School of Medicine, Department of Orthopaedic Surgery, Itabashi-ku, Tokyo (Japan); Yamamoto, Asako; Osawa, Marie [Teikyo University School of Medicine, Department of Radiology, Itabashi-ku, Tokyo (Japan)

    2015-06-01

    Patients with disorders such as acetabular dysplasia or femoroacetabular impingement are at risk of developing hip osteoartbritis. Assessment of the cartilage and labrum in the hip joint based on magnetic resonance imaging (MRI) has been challenging because of the low signal-to-noise ratio (SNR) due to its deep location, ball and socket structure, and small volume of those structures compared with the whole joint size. To achieve better imaging assessment, direct MR. arthrography (d-MRA) and other techniques such as T2* mapping, T2 mapping, Tlrho, and delayed gadolinium-enhanced MRI (dGEMRIC) have been developed along with the increasing use of high-field MRI. In patients with no apparent osteoarthritic changes such as joint space narrowing or osteophyte and subchondral cyst formation on radiographs, these techniques can detect early cartilage or labral damage. A recently developed semiquantitative MRI-based scoring system for hip osteoarthritis includes evaluation of the labrum, and its application as a potential therapeutic monitoring tool is anticipated. The labrum shows pathological changes such as macroscopic hypertrophy and histological degeneration in hip osteoartbritis, but the pathological background is not well understood when evaluated by MRI. Kubo et al. compared radial MRI findings with histological changes of the labrum in ll hips with osteoarthritis using 1.5-T MRJ and found that fibrous separation and mucoid deposition occurred in the labrum with a ''diffuse high signal'' or ''obscure'' pattern. However, to the best of our knowledge, no studies have demonstrated a correlation between MRI fmdings and histological evidence of the severity of degeneration of the labrum. We hypothesized that radially reconstructed images of the acetabular labrum acquired by 3-T MRI can depict degenerative changes of the labrum. In this study, we sought to determine the correlation between MRI and histological findings of the

  4. Comparing Fourier optics and contrast transfer function modeling of image formation in low energy electron microscopy.

    Science.gov (United States)

    Yu, K M; Locatelli, A; Altman, M S

    2017-12-01

    A theoretical understanding of image formation in cathode lens microscopy can facilitate image interpretation. We compare Fourier Optics (FO) and Contrast Transfer Function (CTF) approaches that were recently adapted from other realms of microscopy to model image formation in low energy electron microscopy (LEEM). Although these two approaches incorporate imaging errors from several sources similarly, they differ in the way that the image intensity is calculated. The simplification that is used in the CTF calculation advantageously leads to its computational efficiency. However, we find that lens aberrations, and spatial and temporal coherence may affect the validity of the CTF approach to model LEEM image formation under certain conditions. In particular, these effects depend strongly on the nature of the object being imaged and also become more pronounced with increasing defocus. While the use of the CTF approach appears to be justified for objects that are routinely imaged with LEEM, comparison of theory to experimental observations of a focal image series for rippled, suspended graphene reveals one example where FO works, but CTF does not. This work alerts us to potential pitfalls and guides the effective use of FO and CTF approaches. It also lays the foundation for quantitative image evaluation using these methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. SU-E-J-89: Comparative Analysis of MIM and Velocity’s Image Deformation Algorithm Using Simulated KV-CBCT Images for Quality Assurance

    Energy Technology Data Exchange (ETDEWEB)

    Cline, K; Narayanasamy, G; Obediat, M; Stanley, D; Stathakis, S; Kirby, N [University of Texas Health Science Center at San Antonio, Cancer Therapy and Research Center, San Antonio, TX (United States); Kim, H [University of California San Francisco, San Francisco, CA (United States)

    2015-06-15

    Purpose: Deformable image registration (DIR) is used routinely in the clinic without a formalized quality assurance (QA) process. Using simulated deformations to digitally deform images in a known way and comparing to DIR algorithm predictions is a powerful technique for DIR QA. This technique must also simulate realistic image noise and artifacts, especially between modalities. This study developed an algorithm to create simulated daily kV cone-beam computed-tomography (CBCT) images from CT images for DIR QA between these modalities. Methods: A Catphan and physical head-and-neck phantom, with known deformations, were used. CT and kV-CBCT images of the Catphan were utilized to characterize the changes in Hounsfield units, noise, and image cupping that occur between these imaging modalities. The algorithm then imprinted these changes onto a CT image of the deformed head-and-neck phantom, thereby creating a simulated-CBCT image. CT and kV-CBCT images of the undeformed and deformed head-and-neck phantom were also acquired. The Velocity and MIM DIR algorithms were applied between the undeformed CT image and each of the deformed CT, CBCT, and simulated-CBCT images to obtain predicted deformations. The error between the known and predicted deformations was used as a metric to evaluate the quality of the simulated-CBCT image. Ideally, the simulated-CBCT image registration would produce the same accuracy as the deformed CBCT image registration. Results: For Velocity, the mean error was 1.4 mm for the CT-CT registration, 1.7 mm for the CT-CBCT registration, and 1.4 mm for the CT-simulated-CBCT registration. These same numbers were 1.5, 4.5, and 5.9 mm, respectively, for MIM. Conclusion: All cases produced similar accuracy for Velocity. MIM produced similar values of accuracy for CT-CT registration, but was not as accurate for CT-CBCT registrations. The MIM simulated-CBCT registration followed this same trend, but overestimated MIM DIR errors relative to the CT

  6. Hip imaging of avascular necrosis at 7 Tesla compared with 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Theysohn, J.M.; Kraff, O.; Theysohn, N.; Orzada, S.; Lauenstein, T.C. [University Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); University Hospital Essen, Institute for Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Landgraeber, S. [University Hospital Essen, Department of Orthopedic Surgery, Essen (Germany); Ladd, M.E. [University Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); German Cancer Research Center, Department of Medical Physics in Radiology, Heidelberg (Germany)

    2014-05-15

    To compare ultra-high field, high-resolution bilateral magnetic resonance imaging (MRI) of the hips at 7 Tesla (T) with 3 T MRI in patients with avascular necrosis (AVN) of the femoral head by subjective image evaluations, contrast measurements, and evaluation of the appearance of imaging abnormalities. Thirteen subjects with avascular necrosis treated using advanced core decompression underwent MRI at both 7 T and 3 T. Sequence parameters as well as resolution were kept identical for both field strengths. All MR images (MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR) were evaluated by two radiologists with regard to subjective image quality, soft tissue contrasts, B1 homogeneity (four-point scale, higher values indicating better image quality) and depiction of imaging abnormalities of the femoral heads (three-point scale, higher values indicating the superiority of 7 T). Contrast ratios of soft tissues were calculated and compared with subjective data. 7-T imaging of the femoral joints, as well as 3-T imaging, achieved ''good'' to ''very good'' quality in all sequences. 7 T showed significantly higher soft tissue contrasts for T2w and MEDIC compared with 3 T (cartilage/fluid: 2.9 vs 2.2 and 3.6 vs 2.6), better detailed resolution for cartilage defects (PDw, T2w, T1w, MEDIC, DESS > 2.5) and better visibility of joint effusions (MEDIC 2.6; PDw/T2w 2.4; DESS 2.2). Image homogeneity compared with 3 T (3.9-4.0 for all sequences) was degraded, especially in TSE sequences at 7 T through signal variations (7 T: 2.1-2.9); to a lesser extent also GRE sequences (7 T: 2.9-3.5). Imaging findings related to untreated or treated AVN were better delineated at 3 T (≤1.8), while joint effusions (2.2-2.6) and cartilage defects (2.5-3.0) were better visualized at 7 T. STIR performed much more poorly at 7 T, generating large contrast variations (1.5). 7-T hip MRI showed comparable results in hip joint imaging compared with 3 T with slight

  7. Hip imaging of avascular necrosis at 7 Tesla compared with 3 Tesla

    International Nuclear Information System (INIS)

    Theysohn, J.M.; Kraff, O.; Theysohn, N.; Orzada, S.; Lauenstein, T.C.; Landgraeber, S.; Ladd, M.E.

    2014-01-01

    To compare ultra-high field, high-resolution bilateral magnetic resonance imaging (MRI) of the hips at 7 Tesla (T) with 3 T MRI in patients with avascular necrosis (AVN) of the femoral head by subjective image evaluations, contrast measurements, and evaluation of the appearance of imaging abnormalities. Thirteen subjects with avascular necrosis treated using advanced core decompression underwent MRI at both 7 T and 3 T. Sequence parameters as well as resolution were kept identical for both field strengths. All MR images (MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR) were evaluated by two radiologists with regard to subjective image quality, soft tissue contrasts, B1 homogeneity (four-point scale, higher values indicating better image quality) and depiction of imaging abnormalities of the femoral heads (three-point scale, higher values indicating the superiority of 7 T). Contrast ratios of soft tissues were calculated and compared with subjective data. 7-T imaging of the femoral joints, as well as 3-T imaging, achieved ''good'' to ''very good'' quality in all sequences. 7 T showed significantly higher soft tissue contrasts for T2w and MEDIC compared with 3 T (cartilage/fluid: 2.9 vs 2.2 and 3.6 vs 2.6), better detailed resolution for cartilage defects (PDw, T2w, T1w, MEDIC, DESS > 2.5) and better visibility of joint effusions (MEDIC 2.6; PDw/T2w 2.4; DESS 2.2). Image homogeneity compared with 3 T (3.9-4.0 for all sequences) was degraded, especially in TSE sequences at 7 T through signal variations (7 T: 2.1-2.9); to a lesser extent also GRE sequences (7 T: 2.9-3.5). Imaging findings related to untreated or treated AVN were better delineated at 3 T (≤1.8), while joint effusions (2.2-2.6) and cartilage defects (2.5-3.0) were better visualized at 7 T. STIR performed much more poorly at 7 T, generating large contrast variations (1.5). 7-T hip MRI showed comparable results in hip joint imaging compared with 3 T with slight advantages in contrast detail (cartilage defects

  8. Comparative studies of groundwater vulnerability assessment

    Science.gov (United States)

    Maria, Rizka

    2018-02-01

    Pollution of groundwater is a primary issue because aquifers are susceptible to contamination from land use and anthropogenic impacts. Groundwater susceptibility is intrinsic and specific. Intrinsic vulnerability refers to an aquifer that is susceptible to pollution and to the geological and hydrogeological features. Vulnerability assessment is an essential step in assessing groundwater contamination. This approach provides a visual analysis for helping planners and decision makers to achieve the sustainable management of water resources. Comparative studies are applying different methodologies to result in the basic evaluation of the groundwater vulnerability. Based on the comparison of methods, there are several advantages and disadvantages. SI can be overlaid on DRASTIC and Pesticide DRASTIC to extract the divergence in sensitivity. DRASTIC identifies low susceptibility and underestimates the pollution risk while Pesticide DRASTIC and SI represents better risk and is recommended for the future. SINTACS method generates very high vulnerability zones with surface waters and aquifer interactions. GOD method could be adequate for vulnerability mapping in karstified carbonate aquifers at small-moderate scales, and EPIK method can be used for large scale. GOD method is suitable for designing large area such as land management while DRASTIC has good accuracy and more real use in geoenvironmental detailed studies.

  9. Comparing Destination Image and Loyalty between First-time and Repeat-visit Tourists

    OpenAIRE

    Mohamad M.; Ab Ghani N. I.

    2014-01-01

    The objective of this study was to investigate the difference between destination image and loyalty among first-time and repeat-visit tourists. The study was undertaken to examine aspects of underlying factors of destination image that influenced tourists’ willingness to recommend Malaysia to their friends and relatives as well as spread positive word-of-mouth to others. In addition, it was to ascertain the relationship between destination image and loyalty among first-time and repeat-visit t...

  10. Head and neck paragangliomas: improved tumor detection using contrast-enhanced 3D time-of-flight MR angiography as compared with fat-suppressed MR imaging techniques

    NARCIS (Netherlands)

    van den Berg, René; Verbist, Berit M.; Mertens, Bart J. A.; van der Mey, Andel G. L.; van Buchem, Mark A.

    2004-01-01

    BACKGROUND AND PURPOSE: MR imaging techniques have proved their efficacy in imaging the head and neck region. In this study, we compared T1-weighted, dual T2-weighted, and fat-suppressed MR imaging and unenhanced and contrast-enhanced 3D time-of-flight MR angiography sequences for detection of head

  11. Shape Recognition and Description: A Comparative Study.

    Science.gov (United States)

    1983-07-01

    form," Pattern Recognition, Uhr(ed.), pp. 123-141, Wiley, 1966. [BAUD73] Patrick Baudelaire , "Linear Stretch-Invariant Systems," Proceedings IEEE, Vol...Acedemic Press, N.Y., 1966. [GIAR77] Charles R. Giardina and Frank P. Kuhl, "Accuracy of Curve Approximation by Harmonically Related Vectors with...Elliptical Loci," Computer Graphics and Image Processing 6, pp. 277-285, 1977. [GIAR78] Charles R. Giardina, "Bounds on the Truncation Error for Walsh

  12. Better visualization of vermiform appendix with tissue harmonic imaging compared to conventional sonography.

    Science.gov (United States)

    Inal, Mikail; Unal, Birsen; Bilgili, Yasemin Karadeniz

    2014-12-01

    Surgery of appendicitis carries 7-11% negative appendectomy rates. Sonographically visualized normal appendix precludes unnecessary computed tomography (CT) examination and may reduce negative appendectomy rates. Tissue harmonic imaging (THI) has been reported to improve the overall image quality. We aimed to assess whether THI is more successful than conventional ultrasonography (US) in detecting normal and pathologic appendices. The study was performed on 185 patients who applied for routine US examinations in whom clinical findings of appendicitis were detected in 25. We searched for the appendix; applying both THI and conventional US to each patient, one before and the other after the routine US examinations. Patients were divided into two groups; one was evaluated first with conventional US and the other first with THI. When the appendix was found, localization, diameter and time spent for visualization were recorded. Twelve patients were operated; all of whom had appendicitis pathologically. Two methods were compared for: 1. Success rates in all patients; female, male and child groups separately; 2. Visualization of pathologic and normal appendices; 3. Time for visualization of appendix; 4. Comparison of success rates in the adult and child population. The relationship between the rate of visualization and body mass index was evaluated. The appendix was visualized better by THI in all patients, and in the female and male groups (P appendix faster. Both methods were more successful in lean patients (P = 0.004 for THI, P = 0.001 for conventional US imaging). THI visualizes appendix better than conventional US. It is a simple and time saving method that may eliminate further diagnostic imaging, and it may decrease negative appendectomy rates and related complications.

  13. Automated Diabetic Retinopathy Image Assessment Software: Diagnostic Accuracy and Cost-Effectiveness Compared with Human Graders.

    Science.gov (United States)

    Tufail, Adnan; Rudisill, Caroline; Egan, Catherine; Kapetanakis, Venediktos V; Salas-Vega, Sebastian; Owen, Christopher G; Lee, Aaron; Louw, Vern; Anderson, John; Liew, Gerald; Bolter, Louis; Srinivas, Sowmya; Nittala, Muneeswar; Sadda, SriniVas; Taylor, Paul; Rudnicka, Alicja R

    2017-03-01

    With the increasing prevalence of diabetes, annual screening for diabetic retinopathy (DR) by expert human grading of retinal images is challenging. Automated DR image assessment systems (ARIAS) may provide clinically effective and cost-effective detection of retinopathy. We aimed to determine whether ARIAS can be safely introduced into DR screening pathways to replace human graders. Observational measurement comparison study of human graders following a national screening program for DR versus ARIAS. Retinal images from 20 258 consecutive patients attending routine annual diabetic eye screening between June 1, 2012, and November 4, 2013. Retinal images were manually graded following a standard national protocol for DR screening and were processed by 3 ARIAS: iGradingM, Retmarker, and EyeArt. Discrepancies between manual grades and ARIAS results were sent to a reading center for arbitration. Screening performance (sensitivity, false-positive rate) and diagnostic accuracy (95% confidence intervals of screening-performance measures) were determined. Economic analysis estimated the cost per appropriate screening outcome. Sensitivity point estimates (95% confidence intervals) of the ARIAS were as follows: EyeArt 94.7% (94.2%-95.2%) for any retinopathy, 93.8% (92.9%-94.6%) for referable retinopathy (human graded as either ungradable, maculopathy, preproliferative, or proliferative), 99.6% (97.0%-99.9%) for proliferative retinopathy; Retmarker 73.0% (72.0 %-74.0%) for any retinopathy, 85.0% (83.6%-86.2%) for referable retinopathy, 97.9% (94.9%-99.1%) for proliferative retinopathy. iGradingM classified all images as either having disease or being ungradable. EyeArt and Retmarker saved costs compared with manual grading both as a replacement for initial human grading and as a filter prior to primary human grading, although the latter approach was less cost-effective. Retmarker and EyeArt systems achieved acceptable sensitivity for referable retinopathy when compared

  14. Comparing orbiter and rover image-based mapping of an ancient sedimentary environment, Aeolis Palus, Gale crater, Mars

    Science.gov (United States)

    Stack, Kathryn M.; Edwards, Christopher; Grotzinger, J. P.; Gupta, S.; Sumner, D.; Edgar, Lauren; Fraeman, A.; Jacob, S.; LeDeit, L.; Lewis, K.W.; Rice, M.S.; Rubin, D.; Calef, F.; Edgett, K.; Williams, R.M.E.; Williford, K.H.

    2016-01-01

    This study provides the first systematic comparison of orbital facies maps with detailed ground-based geology observations from the Mars Science Laboratory (MSL) Curiosity rover to examine the validity of geologic interpretations derived from orbital image data. Orbital facies maps were constructed for the Darwin, Cooperstown, and Kimberley waypoints visited by the Curiosity rover using High Resolution Imaging Science Experiment (HiRISE) images. These maps, which represent the most detailed orbital analysis of these areas to date, were compared with rover image-based geologic maps and stratigraphic columns derived from Curiosity’s Mast Camera (Mastcam) and Mars Hand Lens Imager (MAHLI). Results show that bedrock outcrops can generally be distinguished from unconsolidated surficial deposits in high-resolution orbital images and that orbital facies mapping can be used to recognize geologic contacts between well-exposed bedrock units. However, process-based interpretations derived from orbital image mapping are difficult to infer without known regional context or observable paleogeomorphic indicators, and layer-cake models of stratigraphy derived from orbital maps oversimplify depositional relationships as revealed from a rover perspective. This study also shows that fine-scale orbital image-based mapping of current and future Mars landing sites is essential for optimizing the efficiency and science return of rover surface operations.

  15. FAIR imaging of the liver. A preliminary study

    International Nuclear Information System (INIS)

    Kiryu, Shigeru; Machida, Toru; Noda, Masanobu

    1998-01-01

    Flow-sensitive alternating inversion recovery (FAIR) technique has recently been introduced for perfusion or functional MR studies of the brain. In the imaging of liver neoplasms, the evaluation of tumor vascularity is important for diagnosis, and therefore the FAIR technique may potentially complement liver MR imaging. The purpose of this study was to evaluate the usefulness of a FAIR sequence in MR imaging of the liver and to compare it with arterial-phase images of dynamic MR imaging. One volunteer and six patients with focal hepatic lesions (one with hepatocellular carcinoma (HCC), three with metastasis, and two with cavernous hemangioma) underwent FAIR. Short TI (600 ms) and long TI (1200 ms) images were obtained during breath-hold. In normal volunteers, the vessels generated remarkably bright signal in both short and long TI. Signal intensity of liver parenchyma was low in short TI, and became stronger in long TI. Two HCC (in one patient) (100%), one hemangioma (50%), and three metastases (100%) were well delineated as bright lesions. One HCC produced peripheral high intensity in short-TI FAIR image, and this finding was consistent with the result of dynamic MR study. Another HCC, which showed no clear enhancement in the arterial-phase dynamic MRI, was visualized only in long-TI FAIR. One hemangioma, which was clearly seen in FAIR image, showed rapid and strong enhancement on dynamic MRI. It is concluded that FAIR is a promising technique for evaluation of vascularity of hepatic tumors without using contrast materials. (author)

  16. Assessment of local reaction to vaccines in live piglets with magnetic resonance imaging compared to histopathology.

    Science.gov (United States)

    Bernau, Maren; Kremer, Prisca V; Kreuzer, Lena S; Emrich, Daniela; Pappenberger, Elke; Cussler, Klaus; Hoffmann, Andreas; Leipig, Miriam; Hermanns, Walter; Scholz, Armin Manfred

    2016-01-01

    The safety of veterinary vaccines is assessed in clinical trials in Europe. The assessment of the local tissue reaction to vaccination by magnetic resonance imaging (MRI) could reduce the number of animals needed because repeated examinations can be performed in the same animal over time. The present study compared the evaluation of local tissue reactions to vaccination using MRI in live pigs with histopathology of porcine tissue, the current gold standard in regulatory safety testing. Eight piglets each were administered one of two commercial vaccines into marked injection sites. All animals were sedated and scanned repeatedly by MRI using a contrast agent up to day 29 after vaccination. On day 29, the animals were euthanized and underwent a pathological examination. The MRI results were compared with the pathomorphological findings at the injection site by regression analysis. The MR images and the pathological examinations yielded matching results concerning the sizes of the affected tissue volumes or areas. The use of MRI for regulatory safety testing can reduce the number of animals needed to 8 per examination group. The volume of a local reaction and its progression over time can be evaluated and documented. If persistent lesions develop a final pathomorphological examination is needed to identify the kind and local distribution of the reaction.

  17. Familial Essential Tremor Studied With Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Hernandez, A.; Salgado, P.; Gil, A.; Barrios, F. A.

    2003-09-01

    Functional Magnetic Resonance Imaging has become an important analytical tool to study neurodegenerative diseases. We applied the EPI-BOLD functional Magnetic Resonance Imaging technique to acquire functional images of patients with familial essential tremor (FET) disorder and healthy control volunteers, during a motor task activity. Functional and anatomic images were used to produce the brain activation maps of the patients and volunteers. These functional maps of the primary somatosensorial and motor cortexes of patients and control subjects were compared for functional differences per subject. The averaged functional brain images of eight of each case were acquired were, it can be clearly observed the differences in active zones. The results presented in this work show that there are differences in the functional maps during motor task activation between control subjects and FET patients suggesting a cerebral functional reorganization that can be mapped with BOLD-fMRI.

  18. Clinical findings versus imaging studies in the diagnosis of infantile ...

    African Journals Online (AJOL)

    Objectives The aim of this study was to assess the accuracy of clinical examination compared with ultrasound and upper .... patients, and increased muscle diameter of more than. 14mm in 54 (90%) patients with both longitudinal and transverse images. A barium study was performed in all patients and different signs were ...

  19. A Study of Identification Performance of Facial Regions from CCTV Images

    NARCIS (Netherlands)

    Ali, Tauseef; Tome, Pedro; Fierrez, Julian; Vera-Rodriguez, Ruben; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.; Garain, Utpal; Shafait, Faisal

    This paper focuses on automatic face identification for forensic applications. Forensic examiners compare different parts of the face image obtained from a closed-circuit television (CCTV) image with a database of mug shots or good quality image(s) taken from the suspect. In this work we study and

  20. A study of identification performance of facial regions from CCTV images

    NARCIS (Netherlands)

    Ali, Tauseef; Tom, P.; Fierrez, J.; Vera-Rodriguez, R.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.

    2012-01-01

    This paper focuses on automatic face identification for forensic applications. Forensic examiners compare different parts of the face image obtained from a closed-circuit television (CCTV) image with a database of mug shots or good quality image(s) taken from the suspect. In this work we study and

  1. Chronic pelvic pain: how does noninvasive imaging compare with diagnostic laparoscopy?

    Science.gov (United States)

    Tirlapur, Seema A; Daniels, Jane P; Khan, Khalid S

    2015-12-01

    Chronic pelvic pain (CPP) has an annual prevalence of 38/1000 in the UK, with coexisting pathologies often present. Diagnostic laparoscopy has long been the gold standard diagnostic test, but with up to 40% showing no abnormality, we explore the value of noninvasive imaging, such as pelvic ultrasound and MRI. A literature review from inception until January 2015 of the following databases: PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Excerpta Medica database, and System for Information on Grey Literature in Europe were performed to identify published studies assessing the usefulness of ultrasound, MRI, and laparoscopy in the diagnosis of CPP. Three studies (194 women) addressed their comparative performance in patients with endometriosis, showing the sensitivity of ultrasound ranged between 58 and 88.5%; MRI was 56-91.5% and in the one study using histology as its reference standard, the sensitivity of laparoscopy was 85.7%. Noninvasive imaging has the additional benefit of being well tolerated, safer, and cheaper than surgery. CPP, by nature of its multifactorial causation, can be difficult to manage and often requires a multidisciplinary team. Ultrasound and MRI may provide information about the presence or lack of abnormality, which would allow general practitioners or office gynaecologists to initiate treatment and think about surgery as a second-line investigative tool.

  2. COMPARATIVE STUDY ON ACCOUNTING AND FISCAL AMORTIZATION

    Directory of Open Access Journals (Sweden)

    MARIANA GURAU

    2012-05-01

    Full Text Available Placed in the international trend, Romanian accounting had experienced various changes, especially as regards of progress on disconnection between accounting and fiscality. In the present, fiscal rules should not have any role in accounting decisions, because accounting rules are applied to produce accounting information that is useful in making decisions and to provide a "true and fair view" upon financial reality of the entity. However, the barrier in the habit of accounting to thinking for fiscal point of view all economic transactions remains insurmountable, yet. Starting from this perspective on disconnection between accounting and fiscality would mean that amortization recorded in the accounting, as a result of management policy, to be different from fiscality amortization, to calculate income tax. Although formally accepted, disconnect between accounting and fiscality continues to meet many difficulties. In this sense, it is usual in practice to use the same method of amortization for accounting purposes and for fiscal purposes to prevent complications of double track amortization and prevent wandering in the rules in this field. Accounting rule is deliberately eluded in favor of the fiscal rules. This is the reason we proposed to make in this paper a comparative study between norms and rules on accounting and fiscal amortization, paper in which we intend to show the benefits of applying accounting and fiscal rules separately.

  3. Comparative study on Charpy specimen reconstitution techniques

    International Nuclear Information System (INIS)

    Bourdiliau, B.; Decroix, G.-M.; Averty, X.; Wident, P.; Bienvenu, Y.

    2011-01-01

    Highlights: → Welding processes are used to reconstitute previously tested Charpy specimens. → Stud welding is preferred for a quick installation, almost immediately operational. → Friction welding produces better quality welds, but requires a development effort. - Abstract: Reconstitution techniques are often used to allow material from previously fractured Charpy-V specimens to be reused for additional experiments. This paper presents a comparative experimental study of various reconstitution techniques and evaluates the feasibility of these methods for future use in shielded cells. The following techniques were investigated: arc stud welding, 6.0 kW CO 2 continuous wave laser welding, 4.5 kW YAG continuous wave laser welding and friction welding. Subsize Charpy specimens were reconstituted using a 400 W YAG pulsed wave laser. The best result was obtained with arc stud welding; the resilience of the reconstituted specimens and the load-displacement curves agreed well with the reference specimens, and the temperature elevation caused by the welding process was limited to the vicinity of the weld. Good results were also obtained with friction welding; this process led to the best quality welds. Laser welding seems to have affected the central part of the specimens, thus leading to different resilience values and load-displacement curves.

  4. Display of nuclear medicine imaging studies

    International Nuclear Information System (INIS)

    Singh, B.; Kataria, S.K.; Samuel, A.M.

    2002-08-01

    Nuclear medicine imaging studies involve evaluation of a large amount of image data. Digital signal processing techniques have introduced processing algorithms that increase the information content of the display. Nuclear medicine imaging studies require interactive selection of suitable form of display and pre-display processing. Static imaging study requires pre-display processing to detect focal defects. Point operations (histogram modification) along with zoom and capability to display more than one image in one screen is essential. This album mode of display is also applicable to dynamic, MUGA and SPECT data. Isometric display or 3-D graph of the image data is helpful in some cases e.g. point spread function, flood field data. Cine display is used on a sequence of images e.g. dynamic, MUGA and SPECT imaging studies -to assess the spatial movement of tracer with time. Following methods are used at the investigator's discretion for inspection of the 3-D object. 1) Display of orthogonal projections, 2) Display of album of user selected coronal/ sagital/ transverse orthogonal slices, 3) Display of three orthogonal slices through user selected point, 4) Display of a set of orthogonal slices generated in the user-selected volume, 5) Generation and display of 3-D shaded surface. 6) Generation of volume data and display along with the 3-D shaded surface, 7) Side by side display orthogonal slices of two 3-D objects. Displaying a set of two-dimensional slices of a 3-D reconstructed object through shows all the defects but lacks the 3-D perspective. Display of shaded surface lacks the ability to show the embedded defects. Volume display -combining the 3-D surface and gray level volume data is perhaps the best form of display. This report describes these forms of display along with the theory. (author)

  5. Fundus autofluorescence and colour fundus imaging compared during telemedicine screening in patients with diabetes.

    Science.gov (United States)

    Kolomeyer, Anton M; Baumrind, Benjamin R; Szirth, Bernard C; Shahid, Khadija; Khouri, Albert S

    2013-06-01

    We investigated the use of fundus autofluorescence (FAF) imaging in screening the eyes of patients with diabetes. Images were obtained from 50 patients with type 2 diabetes undergoing telemedicine screening with colour fundus imaging. The colour and FAF images were obtained with a 15.1 megapixel non-mydriatic retinal camera. Colour and FAF images were compared for pathology seen in nonproliferative and proliferative diabetic retinopathy (NPDR and PDR, respectively). A qualitative assessment was made of the ease of detecting early retinopathy changes and the extent of existing retinopathy. The mean age of the patients was 47 years, most were male (82%) and most were African American (68%). Their mean visual acuity was 20/45 and their mean intraocular pressure was 14.3 mm Hg. Thirty-eight eyes (76%) did not show any diabetic retinopathy changes on colour or FAF imaging. Seven patients (14%) met the criteria for NPDR and five (10%) for severe NPDR or PDR. The most common findings were microaneurysms, hard exudates and intra-retinal haemorrhages (IRH) (n = 6 for each). IRH, microaneurysms and chorioretinal scars were more easily visible on FAF images. Hard exudates, pre-retinal haemorrhage and fibrosis, macular oedema and Hollenhorst plaque were easier to identify on colour photographs. The value of FAF imaging as a complementary technique to colour fundus imaging in detecting diabetic retinopathy during ocular screening warrants further investigation.

  6. A voxel based comparative analysis using magnetization transfer imaging and T1-weighted magnetic resonance imaging in progressive supranuclear palsy

    Directory of Open Access Journals (Sweden)

    Mangalore Sandhya

    2014-01-01

    Full Text Available Aims: In progressive supranuclear palsy (PSP tissue damage occurs in specific cortical and subcortical regions. Voxel based analysis using T1-weighted images depict quantitative gray matter (GM atrophy changes. Magnetization transfer (MT imaging depicts qualitative changes in the brain parenchyma. The purpose of our study was to investigate whether MT imaging could indicate abnormalities in PSP. Settings and Design: A total of 10 patients with PSP (9 men and 1 woman and 8 controls (5 men and 3 women were studied with T1-weighted magnetic resonance imaging (MRI and 3DMT imaging. Voxel based analysis of T1-weighted MRI was performed to investigate brain atrophy while MT was used to study qualitative abnormalities in the brain tissue. We used SPM8 to investigate group differences (with two sample t-test using the GM and white matter (WM segmented data. Results: T1-weighted imaging and MT are equally sensitive to detect changes in GM and WM in PSP. Magnetization transfer ratio images and magnetization-prepared rapid acquisition of gradient echo revealed extensive bilateral volume and qualitative changes in the orbitofrontal, prefrontal cortex and limbic lobe and sub cortical GM. The prefrontal structures involved were the rectal gyrus, medial, inferior frontal gyrus (IFG and middle frontal gyrus (MFG. The anterior cingulate, cingulate gyrus and lingual gyrus of limbic lobe and subcortical structures such as caudate, thalamus, insula and claustrum were also involved. Cerebellar involvement mainly of anterior lobe was also noted. Conclusions: The findings suggest that voxel based MT imaging permits a whole brain unbiased investigation of central nervous system structural integrity in PSP.

  7. Comparative performance evaluation of transform coding in image pre-processing

    Science.gov (United States)

    Menon, Vignesh V.; NB, Harikrishnan; Narayanan, Gayathri; CK, Niveditha

    2017-07-01

    We are in the midst of a communication transmute which drives the development as largely as dissemination of pioneering communication systems with ever-increasing fidelity and resolution. Distinguishable researches have been appreciative in image processing techniques crazed by a growing thirst for faster and easier encoding, storage and transmission of visual information. In this paper, the researchers intend to throw light on many techniques which could be worn at the transmitter-end in order to ease the transmission and reconstruction of the images. The researchers investigate the performance of different image transform coding schemes used in pre-processing, their comparison, and effectiveness, the necessary and sufficient conditions, properties and complexity in implementation. Whimsical by prior advancements in image processing techniques, the researchers compare various contemporary image pre-processing frameworks- Compressed Sensing, Singular Value Decomposition, Integer Wavelet Transform on performance. The paper exposes the potential of Integer Wavelet transform to be an efficient pre-processing scheme.

  8. Comparing the performance of storage phosphor plate and Insight film images for the detection of proximal caries depth.

    Science.gov (United States)

    Crombie, K; Parker, M E; Nortje, C J; Sanderink, G C H

    2009-11-01

    To compare proximal caries depth between conventional film images, unenhanced and enhanced storage phosphor plate images. Bitewing radiographs were taken on 100 patients presenting for Conservative and Periodontal treatment. Only one bitewing was taken on a patient either the right or left hand side of the patient A DenOptics storage phosphor plate and size 3 Kodak Insight film were simultaneously placed into a Rinn bitewing holder. The Insight film was placed behind the phosphor plate. Both were simultaneously exposed to radiation. The unenhanced phosphor plate images were copied four times. Contrast and brightness were either increased or decreased on the copied images. A five point scale was chosen for proximal caries depth: 0--sound, 1--caries in enamel, 2--caries reaching dentino-enamel junction, 3--caries into dentine, 4--caries in a restored area. The bitewing images were evaluated by 4 clinicians. Images with technical errors were excluded from the study. Altogether 1848 tooth surfaces were evaluated of which 136 surfaces were excluded due to technical errors. The results show that for the detection of proximal caries there is no significant difference in accuracy between unenhanced storage phosphor plate and Kodak Insight film images (p > 0.001). When decreasing both contrast and brightness there was no significant difference in diagnostic accuracy (p > 0.001) between unenhanced and enhanced storage phosphor plate images. More surfaces were analyzed for caries into the dentine on the enhanced images when both contrast and brightness were increased. Although contrast-enhanced and brightness-enhanced images retween conventional film, unenhanced and enhanced images.

  9. Comparative Analysis between LDR and HDR Images for Automatic Fruit Recognition and Counting

    Directory of Open Access Journals (Sweden)

    Tatiana M. Pinho

    2017-01-01

    Full Text Available Precision agriculture is gaining an increasing interest in the current farming paradigm. This new production concept relies on the use of information technology (IT to provide a control and supervising structure that can lead to better management policies. In this framework, imaging techniques that provide visual information over the farming area play an important role in production status monitoring. As such, accurate representation of the gathered production images is a major concern, especially if those images are used in detection and classification tasks. Real scenes, observed in natural environment, present high dynamic ranges that cannot be represented by the common LDR (Low Dynamic Range devices. However, this issue can be handled by High Dynamic Range (HDR images since they have the ability to store luminance information similarly to the human visual system. In order to prove their advantage in image processing, a comparative analysis between LDR and HDR images, for fruits detection and counting, was carried out. The obtained results show that the use of HDR images improves the detection performance to more than 30% when compared to LDR.

  10. HVS scheme for DICOM image compression: Design and comparative performance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakar, B. [Biomedical and Engineering Division, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu (India)]. E-mail: prabhakarb@iitm.ac.in; Reddy, M. Ramasubba [Biomedical and Engineering Division, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu (India)

    2007-07-15

    Advanced digital imaging technology in medical domain demands efficient and effective DICOM image compression for progressive image transmission and picture archival. Here a compression system, which incorporates sensitivities of HVS coded with SPIHT quantization, is discussed. The weighting factors derived from luminance CSF are used to transform the wavelet subband coefficients to reflect characteristics of HVS in best possible manner. Mannos et al. and Daly HVS models have been used and results are compared. To evaluate the performance, Eskicioglu chart metric is considered. Experiment is done on both Monochrome and Color Dicom images of MRI, CT, OT, and CR, natural and benchmark images. Reconstructed image through our technique showed improvement in visual quality and Eskicioglu chart metric at same compression ratios. Also the Daly HVS model based compression shows better performance perceptually and quantitatively when compared to Mannos et el. model. Further 'bior4.4' wavelet filter provides better results than 'db9' filter for this compression system. Results give strong evidence that under common boundary conditions; our technique achieves competitive visual quality, compression ratio and coding/decoding time, when compared with jpeg2000 (kakadu)

  11. A study of image processing in CR mammography

    International Nuclear Information System (INIS)

    Muramatsu, Yukio; Nawano, Shigeru; Anan, Mitsuhiro; Hanmura, Katsuhiro; Tanaka, Takashi; Matsue, Hirohito; Yamada, Tatsuya

    1990-01-01

    CR image is made by several kinds of image processings. Gradation processing is most important to make images among them and its type can be decided by the kinds of x-ray examinations. 1.2G gradation processing is generally recommended for CR-mammography by the CR maker, but it has not been fully studied that whether 1.2G was the ideal one or not to image masses and/or calcifications. So, we compared the image obtained by 1.2G gradation processing with one by 1.0d gradation processing that we made about imaging sensitivity of them in 18 cases with breast cancer. 15 out of 18 cases had good mass images and all of 6 cases showed good calcified images in the latter condition due to its high declination (=γ). So, we have concluded that 1.0d gradation processing was better than 1.2G in CR-mammography. (author)

  12. Automated diabetic retinopathy imaging in Indian eyes: A pilot study

    Directory of Open Access Journals (Sweden)

    Rupak Roy

    2014-01-01

    Full Text Available Aim: To evaluate the efficacy of an automated retinal image grading system in diabetic retinopathy (DR screening. Materials and Methods: Color fundus images of patients of a DR screening project were analyzed for the purpose of the study. For each eye two set of images were acquired, one centerd on the disk and the other centerd on the macula. All images were processed by automated DR screening software (Retmarker. The results were compared to ophthalmologist grading of the same set of photographs. Results: 5780 images of 1445 patients were analyzed. Patients were screened into two categories DR or no DR. Image quality was high, medium and low in 71 (4.91%, 1117 (77.30% and 257 (17.78% patients respectively. Specificity and sensitivity for detecting DR in the high, medium and low group were (0.59, 0.91; (0.11, 0.95 and (0.93, 0.14. Conclusion: Automated retinal image screening system for DR had a high sensitivity in high and medium quality images. Automated DR grading software′s hold promise in future screening programs.

  13. Old people in pain : a comparative study

    OpenAIRE

    Jakobsson, Ulf; Klevsgård, Rosemarie; Westergren, Albert; Rahm Hallberg, Ingalill

    2003-01-01

    To investigate the prevalence of pain in older people (75+), compare those in pain to those without regarding demographics, social network, functional limitations, fatigue, sleeping problems, depressed mood and quality of life (QOL), and identify variables associated with pain, a cross-sectional, prospective survey was conducted in an age-stratified sample of 4,093 people aged 75-105 years old. Those reporting pain (n=1,654) were compared with those who did not (n=2,439). Pain was more common...

  14. Digital image analysis of fingernail colour in cadavers comparing carbon monoxide poisoning to controls.

    Science.gov (United States)

    Langlois, Neil E I

    2010-03-01

    Carbon monoxide is a component of motor vehicle exhaust fumes, provided a functional catalytic converter is not present. This gas binds avidly to the hemoglobin molecule in red blood cells preventing its oxygen transport function, effectively poisoning the body by starving it of oxygen. In binding to hemoglobin, carbon monoxide forms carboxyhemoglobin, which has a characteristic bright pink color. It has been remarked that the fingernails of victims of carbon monoxide tend to exhibit pink color, otherwise fingernails of deceased bodies tend towards a dark red to blue color. This study sought to objectively determine by using digital image analysis if a color difference occurred between the fingernails of a group of cadavers with carbon monoxide poisoning compared to a group of controls. The fingernails of the carbon monoxide group did tend to be more red than the controls, but due to overlap between the two groups assessment of the fingernails cannot be recommended as a rapid screening test.

  15. Magnetic resonance imaging compared with trimodal evoked potentials in possible multiple sclerosis

    International Nuclear Information System (INIS)

    Roullet, E.; Leger-Ravet, M.B.; Amarenco, P.; Marteau, R.; Lavallard-Rousseau, M.-C.; Dupuch, K.; Iba-Zizen, M.T.; Tamraz, J.; Cabanis, E.A.

    1988-01-01

    Magnetic Resonance Imaging (MRI) of the brain and Evoked Potentials (EP) can both demonstrate the presence of clinically unsuspected demyelinating lesions and have proven to be sensitive (but not specific) in the diagnosis of multiple sclerosis (MS). MRI and EP are positive in 90 to 100% of patients with a definite diagnosis of MS. However, few studies have been conducted in patients with a lesser diagnostic certainty. In possible or suspected MS they gave conflicting results, possibly because of technical discrepancies and different clinical inclusion criteria. Since a number of putative new treatments can be evaluated in patients who have a definite diagnosis of MS, but nevertheless a short duration of disease and a low disability, it was decided to compare the sensitivity of MRI and EP as diagnostic tools in possible MS patients. MRI is shown to be more sensitive, shows more multiple lesions and gives a clearer appreciation of their size and exact location than EP. 10 refs.; 3 tabs

  16. Comparative diagnostic imaging of the canine shoulder joint ultrasonography and radiography

    CERN Document Server

    Mayer, B

    2000-01-01

    radiographically. 6 of 17 supraspinatus insertion tendinopathies (35.3 %) and 4 of 5 bicipital tendon calcifications (80 %) were detected only with ultrasonography. Radiographic findings of bony proliferations in the intertuberal groove without signs of degenerative joint disease of the shoulder joint are indicative of severe or chronic biciptal tendon disease. In many cases, the stage and severity of cartilaginous and subchondral bone lesions with osteochondritis dissecans can be determined ultrasonographically. Osteochondritis dissecans defects not seen on radiographs are occasionally visible with ultrasound, although a negative finding is not always accurate. Ultrasonography of shoulder joint disease has been applied in humans for some time. In this study, the use of radiography and ultrasonography as diagnostic imaging modalities to determine shoulder joint lesions is presented. The ultrasonographic anatomy and pathology of the shoulder joint are described. Comparative radiographic and ultrasonographic fi...

  17. Image and surgery-related costs comparing cone beam CT and panoramic imaging before removal of impacted mandibular third molars

    DEFF Research Database (Denmark)

    Petersen, L. B.; Rose Olsen, Kim; Christensen, J.

    2014-01-01

    Objectives: The aim of this prospective clinical study was to derive the absolute and relative costs of cone beam CT (CBCT) and panoramic imaging before removal of an impacted mandibular third molar. Furthermore, the study aimed to analyse the influence of different cost-setting scenarios...

  18. Studies on the computer processing of the radioisotope images, 1

    International Nuclear Information System (INIS)

    Mukai, Takao

    1975-01-01

    In order to improve the quality of radioisotope (RI) images, several trials of the mathematical data processing of RI images obtained from a scintiscanner and a scinticamera and their clinical application were attempted. Images from the scinticamera were divided into a 40 x 40 matrix and the counts in each element were transferred onto the 7 track digital magnetic tape recorder (TM-7). Pulses from a scanning area of 1 mm length obtained during scanning of the scintiscanner were stored in each channel of the 1600 word memory successively. After the scanning of each line, the data were transferred onto the TM-7. Present data processing involves the followings: data smoothing in order to reduce the statistical fluctuation of the data, image enhancement to improve spatial resolution, correction for spatial distortion of the images and graded image display. Both the iterative approximation (IA) method and the Fourier transform (FT) method were tried and compared in order to improve the spatial resolution of the image. The IA method was superior to the latter in the stability of the reconstructed images. Correction of the field non-uniformity of the scinticamera was performed by multiplying the counts in each element by the correction coefficients obtained from the flat field phantom studies. When the short half-life nuclides were used, images obtained with a scintiscanner might be affected by the decay of the nuclide. However, the true distribution of the radioactivity could be reproduced by correcting the image by a decay factor matched with the scan speed. It was concluded that the computer processing of RI images was clinically useful by significantly improving the details of scan display. (Saito, K.)

  19. Comparative Effectiveness Trials of Imaging-Guided Strategies in Stable Ischemic Heart Disease.

    Science.gov (United States)

    Shaw, Leslee J; Phillips, Lawrence M; Nagel, Eike; Newby, David E; Narula, Jagat; Douglas, Pamela S

    2017-03-01

    The evaluation of patients with suspected stable ischemic heart disease is among the most common diagnostic evaluations with nearly 20 million imaging and exercise stress tests performed annually in the United States. Over the past decade, there has been an evolution in imaging research with an ever-increasing focus on larger registries and randomized trials comparing the effectiveness of varying diagnostic algorithms. The current review highlights recent randomized trial evidence with a particular focus comparing the effectiveness of cardiac imaging procedures within the stable ischemic heart disease evaluation for coronary artery disease detection, angina, and other quality of life measures, and major clinical outcomes. Also highlighted are secondary analyses from these trials on the economic findings related to comparative cost differences across diagnostic testing strategies. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. Comparative studies on organoleptic and nutritional characteristics ...

    African Journals Online (AJOL)

    Low consumption of meat is associated with high poverty level, and protein deficiency in Nigeria. Meat analogue (Texturized Vegetable Protein – TVP) was processed from protein concentrate and defatted soybean flour, and was flavoured as beef and compared to beef from animal source. The nutritional composition of ...

  1. Comparative Studies on Some Physicochemical Properties of ...

    African Journals Online (AJOL)

    Industrial and nutritional processes have increased the demands for oil and this in turn has led to the search for oils from different types of seeds. It is in this vein that baobab seed oil was extracted, analyzed and some of it physicochemical properties compared with those of vegetable, peanut and palm oils. The percentage ...

  2. A COMPARATIVE STUDY OF THE STARCH PASTING ...

    African Journals Online (AJOL)

    Past~ng properties (gelatinization temperature, gelatinization time, viscosity, ease of cooking and starch stat;ility) of cassava, plantain and banana flours have been found to be affected by processing. Roasting and boiling, reduced peak .... and compare the effect of the afore mentioned processing methods on the pasting ...

  3. Energy band offset extraction - a comparative study

    NARCIS (Netherlands)

    van der Steen, J.P.J.; Hueting, Raymond Josephus Engelbart; Schmitz, Jurriaan

    2008-01-01

    Structural quantum confinement in thin silicon double-gate MOSFETs has been quantified using the temperature dependence of the subthreshold current. The results were compared with the shifts in threshold voltage. Data was obtained from simulations after initial verification with experimental data.

  4. Comparative study of environmental impact assessment methods ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... components (in the construction or operation of the pro- ject). iv) Lack of unity. v) Lack of consideration of the comparative impacts of the components result from the changes happened in the environment. vi) Lack of possibility of benefiting from aggregative opi- nions of experts. In fact, there is no unity ...

  5. Comparative Studies on Some Physicochemical Properties of ...

    African Journals Online (AJOL)

    ABSTRACT: Industrial and nutritional processes have increased the demands for oil and this in turn has led to the search for oils from different types of seeds. It is in this vein that baobab seed oil was extracted, analyzed and some of it physicochemical properties compared with those of vegetable, peanut and palm oils.

  6. Counseling in Costa Rica: A Comparative Study

    Science.gov (United States)

    Collier, Crystal

    2013-01-01

    With one of the world's most comprehensive universal healthcare systems, medical tourism in Costa Rica has increased significantly over the past few decades. American tourists save up to 80% of comparative costs for procedures, from heart surgery to root canal treatment. Although many Costa Rican healthcare professionals receive training in North…

  7. A Comparative Study of Navigation Meshes

    NARCIS (Netherlands)

    van Toll, W.G.; Triesscheijn, Roy; Kallmann, Marcelo; Oliva, Ramon; Pelechano, Nuria; Pettré, Julien; Geraerts, R.J.

    2016-01-01

    A navigation mesh is a representation of a 2D or 3D virtual environment that enables path planning and crowd simulation for walking characters. Various state-of-the-art navigation meshes exist, but there is no standardized way of evaluating or comparing them. Each implementation is in a different

  8. Comparative diagnostic imaging of the canine shoulder joint: ultrasonography and radiography

    International Nuclear Information System (INIS)

    Mayer, B.

    2000-11-01

    Ultrasonography of shoulder joint disease has been applied in humans for some time. In this study, the use of radiography and ultrasonography as diagnostic imaging modalities to determine shoulder joint lesions is presented. The ultrasonographic anatomy and pathology of the shoulder joint are described. Comparative radiographic and ultrasonographic findings in 67 dogs with front limb lameness and/or radiographically visible shoulder joint lesions are presented. Shoulder joint lesions include insertion tendinopathies of the supra- and infraspinatus muscles, distension of the subtendinous bursa of the infraspinatus muscle, bicipital tendinopathies, such as tendovaginitis, calcifications, partial and complete rupture, and avulsion fractures at the supraglenoid tubercle, osteochondritis dissecans, degenerative joint disease, bony proliferations in the intertuberal groove, and neoplasia of bones and soft-tissues. Ultrasonographic diagnosis of tendon abnormalities and other soft tissue lesions is a necessary supplemental examination to radiographs, which should always be the basis for orthopedic diagnostic imaging. When using both imaging techniques, the exact location of radio-opaque mineralizations can be determined and a more accurate diagnosis made. The ultrasonographic appearance of an infraspinatus muscle insertion tendinopathy in conjunction with distension of the subtendinous bursa is reported for the first time. Low-density calcifications are not visible radiographically. 6 of 17 supraspinatus insertion tendinopathies (35.3 %) and 4 of 5 bicipital tendon calcifications (80 %) were detected only with ultrasonography. Radiographic findings of bony proliferations in the intertuberal groove without signs of degenerative joint disease of the shoulder joint are indicative of severe or chronic biciptal tendon disease. In many cases, the stage and severity of cartilaginous and subchondral bone lesions with osteochondritis dissecans can be determined ultrasonographically

  9. Magnetic Resonance Imaging of Japanese monkey brains compared with X-ray photography and histology

    International Nuclear Information System (INIS)

    Kaji, Shinji; Matsuda, Keiji; Kawano, Kenji; Komatsu, Hidehiko; Yamane, Shigeru; Yoshizawa, Takashi; Nose, Tadao.

    1991-01-01

    The localization of a small target area in the brain is usually estimated by using stereotaxic atlases, assisted by X-ray photography or electrophysiological mapping, and determined finally by histological reconstruction. Magnetic Resonance Imaging (MRI) can visualize, noninvasively cross sections in any plane of three dimensional structures of the brain. We compared images of MRI, X-ray, and histology from a monkey brain. A Japanese monkey (Macaca fuscata, male, 11 kg) was anesthetised, fixed in a newly developed magnetic-free stereotaxic apparatus, and mounted in the MRI scanner unit (BRUKER, BIOSPEC 24/40, 2.4 Tesla). Some para-saggital (5 mm thick) and para-frontal (2.5 mm thick, every 5 mm distance) images were obtained. The outline of the bone on the MRI image was compared with that on the X-ray photograph taken by an X-ray instrument (Toshiba, TR-80A). The two images fitted very well. The animal was sacrificed, the brain was sliced in 100 μm and stained with Cresyl violet. The histological preparations were shrunk some 10 % during the process, which was revealed by comparison of MRI, X-ray, and histological images. In conclusion, MRI images are reliable enough to determine a small target in deep structures of the brain, and their superimposed images on X-rays will assist in identifying the location of electrode or needle tips. We constructed a data base of these MRI and histological images on a Macintosh computer, and they can be easily accessed by a mouse operation. (author)

  10. An exploratory study of the relationship between store image, trust ...

    African Journals Online (AJOL)

    This is achieved by investigating the roles of store image, trust and satisfaction in predicting loyalty to a particular store type. By analysing empirical results, this study shows that compared to corporate-owned stores, consumers have an overall better perception of franchise stores, especially in terms of trust and customer ...

  11. Four in vivo g-ratio-weighted imaging methods: Comparability and repeatability at the group level.

    Science.gov (United States)

    Ellerbrock, Isabel; Mohammadi, Siawoosh

    2018-01-01

    A recent method, denoted in vivo g-ratio-weighted imaging, has related the microscopic g-ratio, only accessible by ex vivo histology, to noninvasive MRI markers for the fiber volume fraction (FVF) and myelin volume fraction (MVF). Different MRI markers have been proposed for g-ratio weighted imaging, leaving open the question which combination of imaging markers is optimal. To address this question, the repeatability and comparability of four g-ratio methods based on different combinations of, respectively, two imaging markers for FVF (tract-fiber density, TFD, and neurite orientation dispersion and density imaging, NODDI) and two imaging markers for MVF (magnetization transfer saturation rate, MT, and, from proton density maps, macromolecular tissue volume, MTV) were tested in a scan-rescan experiment in two groups. Moreover, it was tested how the repeatability and comparability were affected by two key processing steps, namely the masking of unreliable voxels (e.g., due to partial volume effects) at the group level and the calibration value used to link MRI markers to MVF (and FVF). Our data showed that repeatability and comparability depend largely on the marker for the FVF (NODDI outperformed TFD), and that they were improved by masking. Overall, the g-ratio method based on NODDI and MT showed the highest repeatability (90%) and lowest variability between groups (3.5%). Finally, our results indicate that the calibration procedure is crucial, for example, calibration to a lower g-ratio value (g = 0.6) than the commonly used one (g = 0.7) can change not only repeatability and comparability but also the reported dependency on the FVF imaging marker. Hum Brain Mapp 39:24-41, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Comparative study of some new EPR dosimeters

    International Nuclear Information System (INIS)

    Alzimami, K.S.; Maghraby, Ahmed M.; Bradley, D.A.

    2014-01-01

    Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (W PP ) and peak-to-peak signal height (H PP ). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic. - Highlights: ► Several EPR dosimeters were suggested based on SO 3 − radical. ► Taurine, homotaurine, sulfanilic, and sulfamic acid all possess simple EPR spectra. ► Dosimeters were compared to each other in terms of the dosimetric point of view. ► Energy dependence curves of the selected dosimeters were compared to eachother

  13. CT-based attenuation and scatter correction compared with uniform attenuation correction in brain perfusion SPECT imaging for dementia

    Science.gov (United States)

    Gillen, Rebecca; Firbank, Michael J.; Lloyd, Jim; O'Brien, John T.

    2015-09-01

    This study investigated if the appearance and diagnostic accuracy of HMPAO brain perfusion SPECT images could be improved by using CT-based attenuation and scatter correction compared with the uniform attenuation correction method. A cohort of subjects who were clinically categorized as Alzheimer’s Disease (n=38 ), Dementia with Lewy Bodies (n=29 ) or healthy normal controls (n=30 ), underwent SPECT imaging with Tc-99m HMPAO and a separate CT scan. The SPECT images were processed using: (a) correction map derived from the subject’s CT scan or (b) the Chang uniform approximation for correction or (c) no attenuation correction. Images were visually inspected. The ratios between key regions of interest known to be affected or spared in each condition were calculated for each correction method, and the differences between these ratios were evaluated. The images produced using the different corrections were noted to be visually different. However, ROI analysis found similar statistically significant differences between control and dementia groups and between AD and DLB groups regardless of the correction map used. We did not identify an improvement in diagnostic accuracy in images which were corrected using CT-based attenuation and scatter correction, compared with those corrected using a uniform correction map.

  14. Comparative diagnostic efficacy of scintigraphy, scanography and NMR imaging in osteonecrosis of femoral head and decalcifying osteodystrophy of hip

    Energy Technology Data Exchange (ETDEWEB)

    Sarrat, P.; Felix, T.; Acquaviva, P.C.; Guerra, L.; Kaphan, G.; Chevrot, L.; Bouscarle, B.

    1985-12-01

    Effectiveness of modern imaging techniques were compared when used for diagnosis of the painful hip in adults, particularly the distinction between aseptic osteonecrosis and decalcifying osteodystrophy. Although a small number of patients were studied (5 cases of osteonecrosis and 5 of decalcification) the series was homogeneous (same investigator for each technique and identical equipment for each patient), and the different methods of investigation (conventional radiology, scintigraphy computed scanography CE 10,000 and 0.15 resistive NMR imaging) could be validly compared. NMR images were recorded in only 5 patients but evaluation involved findings during use of this method of hip investigation over a period of 8 months. Results of comparison of the different imaging methods in osteonecrosis and osteodystrophy of hip showed conventional radiology to be much less effective for diagnosis. Conventional bone scintigraphy appeared to provide a good diagnostic approach, while CT images appeared to be as effective or even more specific than scintigraphy for differential diagnosis of the two affections. The only incertitude is based on the radiologic latency in early stage disease, probably able to be filled by a densitometry. The use of NMR imaging appears to be promising, since it provides data as early as scintigraphy and as specific as scanography, particularly in view of apparent discrimination between osteonecrosis and osteodystrophy of the hip with respect to measurement of relaxation parameters.

  15. Comparative study of some new EPR dosimeters

    Science.gov (United States)

    Alzimami, K. S.; Maghraby, Ahmed M.; Bradley, D. A.

    2014-02-01

    Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (WPP) and peak-to-peak signal height (HPP). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic.

  16. Comparative transport studies of ''1212'' superconductors

    International Nuclear Information System (INIS)

    Gapud, Albert; Wu, Judy; Yan, Shaolin; Xie, Yi-Yuan; Kang, Byeongwon; Siegal, Michael P.; Overmyer, Donald L.

    2000-01-01

    HgBa 2 CaCu 2 O 6+δ (Hg-1212) thin films were fabricated by exchanging the TI cations in TlBa 2 CaCu 2 O 7-δ (Tl-1212) thin films with Hg cations, causing a 30-K increase in Tc. To determine how this exchange effects such a Tc increase, the irreversibility lines, temperature dependence of critical current density, and temperature dependence of Hall angle of Hg-1212 and T1-1212 thin films were measured and then compared. The results strongly suggest that the Tc shift is caused by a doubling of charge carrier density

  17. Comparative study of emphathy in adolescents

    Directory of Open Access Journals (Sweden)

    Racu Iulia

    2016-11-01

    Full Text Available The problem of empathy is an important one in modern psychology. Empathy is reliving states, thoughts and actions of others like yours. The present research is focused on empathy at adolescents. So we can mention that 23,3 % of adolescents presents low level of empathy, 66,7% - moderate level of empathy and 10% - high level of empathy. Comparative analyzes permit to establish that high school adolescents and adolescent in conflict with laws are characterized by different levels of empathy. Adolescents in conflict with laws present a lower level of empathetic tendencies than high school adolescents.

  18. Interatrial septum pacing decreases atrial dyssynchrony on strain rate imaging compared with right atrial appendage pacing.

    Science.gov (United States)

    Yasuoka, Yoshinori; Abe, Haruhiko; Umekawa, Seiko; Katsuki, Keiko; Tanaka, Norio; Araki, Ryo; Imanaka, Takahiro; Matsutera, Ryo; Morisawa, Daisuke; Kitada, Hirokazu; Hattori, Susumu; Noda, Yoshiki; Adachi, Hidenori; Sasaki, Tatsuya; Miyatake, Kunio

    2011-03-01

    Interatrial septum pacing (IAS-P) decreases atrial conduction delay compared with right atrial appendage pacing (RAA-P). We evaluate the atrial contraction with strain rate of tissue Doppler imaging (TDI) during sinus activation or with IAS-P or RAA-P. Fifty-two patients with permanent pacemaker for sinus node disease were enrolled in the study. Twenty-three subjects were with IAS-P and 29 with RAA-P. The time from end-diastole to peak end-diastolic strain rate was measured and corrected with RR interval on electrocardiogram. It was defined as the time from end-diastole to peak end-diastolic strain rate (TSRc), and the balance between maximum and minimum TSRc at three sites (ΔTSRc) was compared during sinus activation and with pacing rhythm in each group. There were no significant differences observed in general characteristics and standard echocardiographic parameters except the duration of pacing P wave between the two groups. The duration was significantly shorter in the IAS-P group compared with the RAA-P group (95 ± 34 vs 138 ± 41; P = 0.001). TSRc was significantly different between sinus activation and pacing rhythm (36.3 ± 35.7 vs 61.6 ± 36.3; P = 0.003) in the RAA-P group, whereas no significant differences were observed in the IAS-P group (25.4 ± 12.1 vs 27.7 ± 14.7; NS). During the follow-up (mean 2.4 ± 0.7 years), the incidence of paroxysmal atrial fibrillation (AF) conversion to permanent AF was not significantly different between the two groups. IAS-P decreased the contraction delay on atrial TDI compared to RAA-P; however, it did not contribute to the reduction of AF incidence in the present study. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

  19. Functional brain response to food images in successful adolescent weight losers compared with normal-weight and overweight controls.

    Science.gov (United States)

    Jensen, Chad D; Kirwan, C Brock

    2015-03-01

    Research conducted with adults suggests that successful weight losers demonstrate greater activation in brain regions associated with executive control in response to viewing high-energy foods. No previous studies have examined these associations in adolescents. Functional neuroimaging was used to assess brain response to food images among groups of overweight (OW), normal-weight (NW), and successful weight-losing (SWL) adolescents. Eleven SWL, 12 NW, and 11 OW participants underwent functional magnetic resonance imaging while viewing images of high- and low-energy foods. When viewing high-energy food images, SWLs demonstrated greater activation in the dorsolateral prefrontal cortex (DLPFC) compared with OW and NW controls. Compared with NW and SWL groups, OW individuals demonstrated greater activation in the ventral striatum and anterior cingulate in response to food images. Adolescent SWLs demonstrated greater neural activation in the DLPFC compared with OW/NW controls when viewing high-energy food stimuli, which may indicate enhanced executive control. OW individuals' brain responses to food stimuli may indicate greater reward incentive processes than either SWL or NW groups. © 2015 The Obesity Society.

  20. Image quality assessment of single-shot turbo spin echo diffusion-weighted imaging with parallel imaging technique: a phantom study.

    Science.gov (United States)

    Yoshida, Tsukasa; Urikura, Atsushi; Shirata, Kensei; Nakaya, Yoshihiro; Terashima, Shingo; Hosokawa, Yoichiro

    2016-09-01

    This study aimed to evaluate the image quality and apparent diffusion coefficient (ADC) values of single-shot turbo spin echo (TSE) diffusion-weighted (DW) images obtained using a parallel imaging (PI) technique. All measurements were performed on a 3.0-T whole-body MRI system and 32-channel phased-array coil. Signal-to-noise ratio (SNR) and ADC values were measured with a DW imaging (DWI) phantom comprising granulated sugar and agar. The SNRs were calculated using a subtraction method and compared among TSE-DW images at acceleration factors (AFs) of 1-4. Image blur was visually assessed on TSE-DW images of a pin phantom at AFs of 1-4. The ADC values were calculated using DW images with b = 0 and 1000 s mm(-2). The ADC values of TSE-DW images and echo-planar imaging EPI-DW images were compared. The SNRs decreased as AFs increased, despite selecting the shortest echo time. A lower AF caused increased image blur in the phase-encoding direction. The ADC values of TSE-DWI tended to be lower than those of EPI-DWI, and AFs of 3 and 4 yielded variable ADC values on TSE-DW images. TSE-DWI with an AF of 3 or 4 yielded reduced SNRs; in addition, the image noise and artefacts associated with PI technique may have affected ADC measurements, despite improving image blur in the phase-encoding direction. Optimizing the imaging parameters of TSE-DWI is useful for providing good image quality and accurate ADC measurements.

  1. Comparative studies on different molecular methods for ...

    African Journals Online (AJOL)

    The present study aims to evaluate two molecular methods for epidemiological typing of multi drug resistant Klebsiella pneumoniae isolated from Mansoura Hospitals. In this study, a total of 300 clinical isolates were collected from different patients distributed among Mansoura Hospitals, Dakahlia governorate, Egypt.

  2. Advertisement Analysis: A Comparative Critical Study

    Science.gov (United States)

    Abdelaal, Noureldin Mohamed; Sase, Amal Saleh

    2014-01-01

    This study aimed at analyzing two advertisements, and investigating how advertisers use discourse and semiotics to make people and customers buy into their ideas, beliefs, or simply their products. The two advertisements analyzed are beauty products which have been selected from internet magazines. The methodology adopted in this study is…

  3. Child Labor in Africa: A Comparative Study

    DEFF Research Database (Denmark)

    Canagarajah, Sudharshan; Nielsen, Helena Skyt

    2001-01-01

    This paper analyzes the determinants of child labor in Africa as inferred from recent empirical studies. The empirical analysis is based upon five country studies undertaken in three different African countries, namely Côte d'Ivoire, Ghana, and Zambia. Some support is found for the popular belief...

  4. A comparative contrast-detail study of five medical displays

    International Nuclear Information System (INIS)

    Samei, Ehsan; Ranger, Nicole T.; Delong, David M.

    2008-01-01

    The objective of this study was to compare the contrast-detail performance of five different commercial liquid crystal displays (LCDs) to other LCD and cathode-ray tube (CRT) displays for medical applications. A contrast-detail phantom, supplemented with 5 in. of acrylic, was imaged on a commercial digital radiographic system using techniques comparable to chest radiography. The phantom design enabled observer evaluation by a four-alternative forced choice paradigm. The acquired images were independently scored by five observers on five medical display devices: a 5 megapixel monochrome LCD, a 3 megapixel monochrome LCD, a 9 megapixel color LCD, a 5 megapixel monochrome CRT, and a mammographic-grade monochrome CRT. The data were analyzed using the method suggested by the manufacturer based on a nearest neighbor correction technique. They were further analyzed using a logistic regression response model with a natural threshold using an overall chi-square test for display type followed by pairwise comparisons for individual display performance. The differences between the display devices were small. The standard analysis of the results based on the manufacturer-recommended method did not yield any statistically discernible trend among displays. The logistic regression analysis, however, indicated that the 5 megapixel monochrome LCD was statistically significantly (p<0.0001) superior to the others, followed by the 3 megapixel monochrome LCD (p<0.0001). The three other displays exhibited lower but generally similar performance characteristics. The findings suggest that 5 and 3 megapixel monochrome LCDs provide comparable but subtly superior contrast detectability than other tested displays, with the former performing slightly better in the detection of subtle and fine details

  5. Comparative study of void fraction models

    International Nuclear Information System (INIS)

    Borges, R.C.; Freitas, R.L.

    1985-01-01

    Some models for the calculation of void fraction in water in sub-cooled boiling and saturated vertical upward flow with forced convection have been selected and compared with experimental results in the pressure range of 1 to 150 bar. In order to know the void fraction axial distribution it is necessary to determine the net generation of vapour and the fluid temperature distribution in the slightly sub-cooled boiling region. It was verified that the net generation of vapour was well represented by the Saha-Zuber model. The selected models for the void fraction calculation present adequate results but with a tendency to super-estimate the experimental results, in particular the homogeneous models. The drift flux model is recommended, followed by the Armand and Smith models. (F.E.) [pt

  6. Clinical methods of goniometry: a comparative study.

    Science.gov (United States)

    Goodwin, J; Clark, C; Deakes, J; Burdon, D; Lawrence, C

    1992-01-01

    This investigation compared the reliability and interchangeable use of three currently available goniometers--a universal goniometer, a fluid goniometer, and an electrogoniometer. Three consecutive readings of the active range of movement of the right elbow joint were taken from each of 23 healthy female volunteers; three experienced observers each used each type of goniometer on two occasions. A balanced experimental design was used to eliminate order effects with respect to subject, tester, or goniometer, and a rigid protocol was employed to reduce error due to diurnal or methodological variations. The results show that there are significant differences between the goniometers used, the testers, and the replications. Significant interaction effects also exist between the goniometers and the occasion, the goniometers and the testers, and the testers and replications. The data suggest that the interchangeable use of different types of goniometer in a clinical setting is inadvisable.

  7. COMPARATIVE STUDY OF LIGHT SOURCES FOR HOUSEHOLD

    Directory of Open Access Journals (Sweden)

    Andrzej PAWLAK

    2017-01-01

    Full Text Available The article describes test results that provided the ground to define and evaluate basic photometric, colorimetric and electric parameters of selected, widely available light sources, which are equivalent to a traditional incandescent 60-Watt light bulb. Overall, one halogen light bulb, three compact fluorescent lamps and eleven LED light sources were tested. In general, it was concluded that in most cases (branded products, in particular the measured and calculated parameters differ from the values declared by manufacturers only to a small degree. LED sources prove to be the most beneficial substitute for traditional light bulbs, considering both their operational parameters and their price, which is comparable with the price of compact fluorescent lamps or, in some instances, even lower.

  8. Thalamus segmentation from MP2RAGE: a comparative study

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Næss-Schmidt, Erhard; Blicher, Jakob

    MPRAGE images with different inversion times to construct an MP2RAGE image, free of B1 bias problems [1]. Since this so-called MP2RAGE sequence is independent of B1 as well as M0 and T2*, the T1 image contrast is improved but also different from conventional MPRAGE images. Thus, existing segmentation...... methods may not work well with this new sequence. In this study we tested three different automatic methods for the important task of segmenting the thalamus from human brain MP2RAGE images. Methods: Twelve healthy control subjects (age range 19 – 38 years, two females) were scanned with a whole brain MP2...... the thalami of all subjects using in-house software. Images were separately processed with Freesurfer (version 5.3) [2] and a recent processing pipeline [3], where anatomical structures are segmented with ANIMAL [4]. Finally, a non-local means patch based segmentation method (SNIPE) was applied using...

  9. Andersson lesions of whole spine magnetic resonance imaging compared with plain radiography in ankylosing spondylitis.

    Science.gov (United States)

    Kim, Seong-Kyu; Shin, Kichul; Song, Yoonah; Lee, Seunghun; Kim, Tae-Hwan

    2016-12-01

    The objective of this study was to identify the characteristics of Andersson lesions using whole spine magnetic resonance imaging (MRI) compared with plain radiography in ankylosing spondylitis (AS). A total of 62 patients with AS who had undergone whole spine MRI and plain radiography were retrospectively enrolled in this study. We compared the number of discovertebral units (DVUs) with Andersson lesions with clinical and radiographic indices such as erythrocyte sediment rate (ESR), C-reactive protein (CRP), the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), and modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Fifty-three patients (85.5 %) by whole spine MRI and 23 patients (37.1 %) by plain radiography had at least one Andersson lesion. We found 129 DVUs with Andersson lesions (11.1 %) by MRI and 35 DVUs by plain radiography over all the spine levels. Andersson lesions by MRI were most commonly detected at the lower thoracic spine (from T7-8 to T12-L1). Among the 151 total Andersson lesions by whole spine MRI, 41 were identified as central disc type, 26 as anterior peripheral disc type, 44 as posterior peripheral disc type, and 40 as diffuse disc type. However, the number of Andersson lesions did not correlate with ESR, CRP, BASDAI, BASFI, or mSASSS (p > 0.05 for all). Our study indicates that the presence of Andersson lesions in patients with AS is clearly underestimated. MRI is a superior technique for detecting early Andersson lesions compared with plain radiography.

  10. Brain imaging studies of sleep disorder

    International Nuclear Information System (INIS)

    Nakamura, Masaki; Inoue, Yuichi

    2014-01-01

    Brain imaging studies of narcolepsy (NA)/cataplexy (CA), a typical sleep disorder, are summarized together with techniques of functional and structural imaging means. single photon emission CT (SPECT) is based on the distribution of tracers labeled by single photon emitters like 99m Tc and 123 I for seeing the blood flow and receptors. PET using positron emitters like 15 O and 18 F for blood flow and for glucose metabolism, respectively, is of higher resolution and more quantitative than SPECT. Functional MRI (fMRI) depicts the cerebral activity through signal difference by blood oxygenation level dependence (BOLD) effect, and MR spectroscopy (MRS) depicts and quantifies biomaterials through the difference of their nuclear chemical shifts in the magnetic field. Morphologic imaging studies involve the measurement of the volume of the region of interest by comparison with the reference region such as the whole brain volume. Voxel-based morphometry (VBM) has changed to its more advanced surface-based analysis (SBA) of T1-enhanced image. Diffusion tensor imaging (DTI) is based on the tissue water diffusion. Functional SPECT/PET studies have suggested the decrease of blood flow and metabolic activity in the hypothalamus (HT) and other related regions at the conscious resting state, and locally increased blood flow in cingulate gyrus (CG) and amygdaloid complex (AC) at affective CA/PA seizure. fMRI has suggested the hypoactivity of HT and hyperactivity of AC at the seizure. VBM-based studies have not given the consistent results, but DTI studies have suggested an important participation of AC at the seizure. (T.T.)

  11. A Comparative Study : Microprogrammed Vs Risc Architectures For Symbolic Processing

    Science.gov (United States)

    Heudin, J. C.; Metivier, C.; Demigny, D.; Maurin, T.; Zavidovique, B.; Devos, F.

    1987-05-01

    It is oftenclaimed that conventional computers are not well suited for human-like tasks : Vision (Image Processing), Intelligence (Symbolic Processing) ... In the particular case of Artificial Intelligence, dynamic type-checking is one example of basic task that must be improved. The solution implemented in most Lisp work-stations consists in a microprogrammed architecture with a tagged memory. Another way to gain efficiency is to design a well suited instruction set for symbolic processing, which reduces the semantic gap between the high level language and the machine code. In this framework, the RISC concept provides a convenient approach to study new architectures for symbolic processing. This paper compares both approaches and describes our projectof designing a compact symbolic processor for Artificial Intelligence applications.

  12. Comparative anatomy of rabbit and human achilles tendons with magnetic resonance and ultrasound imaging.

    Science.gov (United States)

    Doherty, Geoffrey P; Koike, Yoichi; Uhthoff, Hans K; Lecompte, Martin; Trudel, Guy

    2006-02-01

    We sought to describe the comparative anatomy of the Achilles tendon in rabbits and humans by using macroscopic observation, magnetic resonance imaging, and ultrasonography. The calcaneus-Achilles tendon-gastrocnemius-soleus complexes from 18 New Zealand white rabbits underwent ultrasound (US) and magnetic resonance (MR) imaging and gross anatomic sectioning; these results were compared with those from a cadaveric gastrocnemius-soleus-Achilles tendon-calcaneus specimen from a 68-y-old human male. The medial and lateral gastrocnemius muscle tendons merged 5.2 +/- 0.6 mm proximal to the calcaneal insertion macroscopically, at 93% of their course, different from the gastrocnemius human tendons, which merged at 23% of their overall course. The rabbit flexor digitorum superficialis tendon, corresponding to the flexor digitorum longus tendon in human and comparable in size with the gastrocnemius tendons, was located medial and anterior to the medial gastrocnemius tendon proximally and rotated dorsally and laterally to run posterior to the Achilles tendon-calcaneus insertion. In humans, the flexor digitorum longus tendon tracks posteriorly to the medial malleolus. The soleus muscle and tendon are negligible in the rabbit; these particular comparative anatomic features in the rabbit were confirmed on the MR images. Therefore the rabbit Achilles tendon shows distinctive gross anatomical and MR imaging features that must be considered when using the rabbit as a research model, especially for mechanical testing, or when generalizing results from rabbits to humans.

  13. The Kinematics of Core and Cusp Galaxies: Comparing HST Imaging and Integral-Field Observations

    NARCIS (Netherlands)

    Falcón-Barroso, J.; Bacon, R.; Cappellari, M.; Davies, R. L.; de Zeeuw, P. T.; Emsellem, E.; Krajnović, D.; Kuntschner, H.; McDermid, R. M.; Peletier, R. F.; Sarzi, M.; van de Ven, G.

    2010-01-01

    In this proceeding we look at the relationship between the photometric nuclear properties of early-type galaxies from Hubble Space Telescope imaging and their overall kinematics as observed with the SAURON integral-field spectrograph. We compare the inner slope of their photometric profiles and the

  14. Study of TCP densification via image analysis

    International Nuclear Information System (INIS)

    Silva, R.C.; Alencastro, F.S.; Oliveira, R.N.; Soares, G.A.

    2011-01-01

    Among ceramic materials that mimic human bone, β-type tri-calcium phosphate (β-TCP) has shown appropriate chemical stability and superior resorption rate when compared to hydroxyapatite. In order to increase its mechanical strength, the material is sintered, under controlled time and temperature conditions, to obtain densification without phase change. In the present work, tablets were produced via uniaxial compression and then sintered at 1150°C for 2h. The analysis via XRD and FTIR showed that the sintered tablets were composed only by β-TCP. The SEM images were used for quantification of grain size and volume fraction of pores, via digital image analysis. The tablets showed small pore fraction (between 0,67% and 6,38%) and homogeneous grain size distribution (∼2μm). Therefore, the analysis method seems viable to quantify porosity and grain size. (author)

  15. Comparative study of connectivity in telemedicine.

    Science.gov (United States)

    Singh, Indra Pratap; Kapoor, Lily; Daman, Repu; Mishra, Saroj Kanta

    2008-10-01

    Communication links are the lifelines for telemedicine practice. Various terrestrial and satellite media can be used; however, each has its own plus and minus side. The current study was designed to evaluate three types of telecommunication media used for telemedical videoconference at the Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow Telemedicine program over a period of 20 months. The evaluation was based on analysis of technical parameters recorded in a prescribed proforma designed for the study purpose and maintained prospectively after completion of each event. Only technical issues were addressed. At the end of the study period, analysis of data revealed that leased line-based terrestrial Internet Protocol (IP) was better than Sky IP. Integrated Services Digital Network media were found technically less acceptable for telemedical videoconference.

  16. Child Labor in Africa: A Comparative Study

    DEFF Research Database (Denmark)

    Nielsen, Helena Skyt; Canagarajah, Sudharshan

    1999-01-01

    This paper analyzes the determinants of child labor in Africa as inferred from recent empirical studies. The empirical analysis is based upon five country studies undertaken in three different African countries, namely Côte d'Ivoire, Ghana, and Zambia. Some support is found for the popular belief...... of poverty as a determinant of child labor, however other determinants are of similar importance. Among school costs, transportation costs have the greatest effect on child labor and school attendance, whereas the hypothesis of imperfect capital markets and that of household composition generally find some...

  17. A Comparative Study of Orthodontic Coil Springs

    OpenAIRE

    Deepak Kumar Agarwal; Anup Razdan; Abhishek Agarwal; Preeti Bhattacharya; Ankur Gupta; D N Kapoor

    2011-01-01

    Several types of force delivering system are used to carry out tooth movement in orthodontics. Coil springs being one of them are used for the same thus requiring minimal operator manipulation. Aims and objectives : The purpose of this study was to determine the effect of wire diameter, lumen size and length of coil spring on the load produced as a function of displacement of SS and NiTi coil spring. Materials and methods : The study consisted of 60 samples of open and closed coil sprin...

  18. Child Labor in Africa: A Comparative Study

    DEFF Research Database (Denmark)

    Canagarajah, Sudharshan; Nielsen, Helena Skyt

    2001-01-01

    This paper analyzes the determinants of child labor in Africa as inferred from recent empirical studies. The empirical analysis is based upon five country studies undertaken in three different African countries, namely Côte d'Ivoire, Ghana, and Zambia. Some support is found for the popular belief...... of poverty as a determinant of child labor, however other determinants are of similar importance. Among school costs, transportation costs have the greatest effect on child labor and school attendance, whereas the hypothesis of imperfect capital markets and that of household composition generally find some...

  19. Advertisement Analysis: A Comparative Critical Study

    Directory of Open Access Journals (Sweden)

    Noureldin Mohamed Abdelaal

    2014-12-01

    Full Text Available This study aimed at analyzing two advertisements, and investigating how advertisers use discourse and semiotics to make people and customers buy into their ideas, beliefs, or simply their products. The two advertisements analyzed are beauty products which have been selected from internet magazines. The methodology adopted in this study is qualitative method. The first advertisement is analyzed qualitatively in terms of content; there was no focus on a specific theoretical frame work, while the second advertisement analysis is based on Fairclough’s framework, the critical discourse analysis framework.

  20. Comparative study on software development methodologies

    Directory of Open Access Journals (Sweden)

    Mihai Liviu DESPA

    2014-12-01

    Full Text Available This paper focuses on the current state of knowledge in the field of software development methodologies. It aims to set the stage for the formalization of a software development methodology dedicated to innovation orientated IT projects. The paper starts by depicting specific characteristics in software development project management. Managing software development projects involves techniques and skills that are proprietary to the IT industry. Also the software development project manager handles challenges and risks that are predominantly encountered in business and research areas that involve state of the art technology. Conventional software development stages are defined and briefly described. Development stages are the building blocks of any software development methodology so it is important to properly research this aspect. Current software development methodologies are presented. Development stages are defined for every showcased methodology. For each methodology a graphic representation is illustrated in order to better individualize its structure. Software development methodologies are compared by highlighting strengths and weaknesses from the stakeholder's point of view. Conclusions are formulated and a research direction aimed at formalizing a software development methodology dedicated to innovation orientated IT projects is enunciated.

  1. Comparative Anticonvulsant Study of Epoxycarvone Stereoisomers

    Directory of Open Access Journals (Sweden)

    Paula Regina Rodrigues Salgado

    2015-10-01

    Full Text Available Stereoisomers of the monoterpene epoxycarvone (EC, namely (+-cis-EC, (−-cis-EC, (+-trans-EC, and (−-trans-EC, were comparatively evaluated for anticonvulsant activity in specific methodologies. In the pentylenetetrazole (PTZ-induced anticonvulsant test, all of the stereoisomers (at 300 mg/kg increased the latency to seizure onset, and afforded 100% protection against the death of the animals. In the maximal electroshock-induced seizures (MES test, prevention of tonic seizures was also verified for all of the isomers tested. However, the isomeric forms (+ and (−-trans-EC showed 25% and 12.5% inhibition of convulsions, respectively. In the pilocarpine-induced seizures test, all stereoisomers demonstrated an anticonvulsant profile, yet the stereoisomers (+ and (−-trans-EC (at 300 mg/kg showed a more pronounced effect. A strychnine-induced anticonvulsant test was performed, and none of the stereoisomers significantly increased the latency to onset of convulsions; the stereoisomers probably do not act in this pathway. However, the stereoisomers (+-cis-EC and (+-trans-EC greatly increased the latency to death of the animals, thus presenting some protection. The four EC stereoisomers show promise for anticonvulsant activity, an effect emphasized in the isomers (+-cis-EC, (+-trans-EC, and (−-trans-EC for certain parameters of the tested methodologies. These results serve as support for further research and development of antiepileptic drugs from monoterpenes.

  2. Bilingual Language Proficiency : A comparative study

    NARCIS (Netherlands)

    Duarte, Joana

    2011-01-01

    his book investigates the role native language plays in the process of acquiring a second language within a bilingual educational model. The research presented is based on a 2 year longitudinal study of students in a bilingual school. Particular attention is paid to the development of academic

  3. Comparative study of two treatment planning systems

    International Nuclear Information System (INIS)

    Ramos Caballero, L. J.; Quinones Rodriguez, L. A.; Lupiani Castellanos, J.

    2013-01-01

    In this study of the comparison of the clinical dosimetry between planners can deduce that the differences are in the majority of the cases below 3%, and only in cases where the field size is small, we found significant discrepancies, although justifiable. On the one hand it is different calculation algorithm and implementation on the other, the modeling of the accelerator. (Author)

  4. Comparative study of different Schlieren diffracting elements

    Indian Academy of Sciences (India)

    Raj Kumar et al test studies on transparent objects such as depicting deviations in light beams in- duced by density, temperature or refractive index gradients in combustion research, laminar and turbulent fluid .... The results presented in this paper have been captured using a Canon S-50 Power Shot digital camera (1024.

  5. A Comparative Study of Pycnodysostosis, Cleidocranial Dysostosis ...

    African Journals Online (AJOL)

    A radiological study of cases of pycnodysostosis, osteopetrosis, cleidocranial dysostosis and acro-osteolysis revealed an interwoven relationship as regards the X-ray findings with numerous identical signs that these conditions had in common. Open fontanelles and sutures as well as metopic sutures were found in all 4 ...

  6. Comparative study of environmental impact assessment methods ...

    African Journals Online (AJOL)

    Environmental Impacts Assessment has been developed as a critically substantial approach to determine, predict and interpret the ecological impact on the environment, public hygiene and healthy ecosystems. This study aims to introduce and systematically investigate the environmental issues during important ...

  7. Children's Friendship Development: A Comparative Study

    Science.gov (United States)

    Yu, SeonYeong; Ostrosky, Michaelene M.; Fowler, Susan A.

    2011-01-01

    Establishing friendships is an important developmental goal of early childhood, but little research has addressed ways in which parents support the friendship development of their young children with disabilities. The purpose of this survey study was to explore the support strategies that parents use to facilitate their children's friendships.…

  8. Earthquake correlations and networks: A comparative study

    International Nuclear Information System (INIS)

    Krishna Mohan, T. R.; Revathi, P. G.

    2011-01-01

    We quantify the correlation between earthquakes and use the same to extract causally connected earthquake pairs. Our correlation metric is a variation on the one introduced by Baiesi and Paczuski [M. Baiesi and M. Paczuski, Phys. Rev. E 69, 066106 (2004)]. A network of earthquakes is then constructed from the time-ordered catalog and with links between the more correlated ones. A list of recurrences to each of the earthquakes is identified employing correlation thresholds to demarcate the most meaningful ones in each cluster. Data pertaining to three different seismic regions (viz., California, Japan, and the Himalayas) are comparatively analyzed using such a network model. The distribution of recurrence lengths and recurrence times are two of the key features analyzed to draw conclusions about the universal aspects of such a network model. We find that the unimodal feature of recurrence length distribution, which helps to associate typical rupture lengths with different magnitude earthquakes, is robust across the different seismic regions. The out-degree of the networks shows a hub structure rooted on the large magnitude earthquakes. In-degree distribution is seen to be dependent on the density of events in the neighborhood. Power laws, with two regimes having different exponents, are obtained with recurrence time distribution. The first regime confirms the Omori law for aftershocks while the second regime, with a faster falloff for the larger recurrence times, establishes that pure spatial recurrences also follow a power-law distribution. The crossover to the second power-law regime can be taken to be signaling the end of the aftershock regime in an objective fashion.

  9. Comparative biochemical studies of type 3 poliovirus.

    OpenAIRE

    Minor, P D

    1980-01-01

    A study of the biochemistry of type 3 poliovirus strains which involves the examination of the virus-coded polypeptides in infected cells and the preparation of oligonucleotide maps is reported. The polypeptide patterns were shown to be a relatively stable property of virus strains and distinguished Sabin vaccine strains from wild strains of poliovirus type 3. This approach may be of value in deciding the origin (vaccine or nonvaccine) of field isolates of poliovirus. Oligonucleotide maps wer...

  10. Conjunctivitis in the newborn- A comparative study

    Directory of Open Access Journals (Sweden)

    Meenakshi Wadhwani

    2011-01-01

    Full Text Available Background: Conjunctivitis of the newborn is defined as hyperemia and eye discharge in the neonates and is a common infection occurring in the neonates in the first month of life. In the United States, the incidence of neonatal conjunctivitis ranges from 1-2%, in India, the prevalence is 0.5-33% and varies in the world from 0.9-21% depending on the socioeconomic status. Aim: To study the organisms causing conjunctivitis of the newborn and to correlate the etiology with the mode of delivery. Design: Single center, prospective, observational study. Materials and Methods: A total of 300 mothers and their newborns, born over a period of one year, were included in the study. Of these 200 newborns were delivered through vaginal route (Group A and 100 (Group B delivered by lower segment caesarean section (LSCS. At the time of labour, high vaginal swabs were taken from the mothers. Two conjunctival swabs each from both eyes of the newborn were collected at birth and transported to Microbiology department in a candle jar immediately. Results: Eight babies in Group A, developed conjunctivitis at birth. None of the babies in Group B developed conjunctivitis, this difference was statistically highly significant (P<0.000. The organisms found in the conjunctiva of the newborns in Group A were Coagulase negative Staphylococcus, α hemolytic Streptococcus, Escherichia coli and Pseudomonas spps. However, the commonest organism leading to conjunctivitis in the newborn in this study was Coagulase negative Staphylococcus. It was observed that the mothers of 5 out of 8 babies (60% developing conjunctivitis gave history of midwife interference and premature rupture of membranes so the presence of risk factors contribute to the occurrence of conjunctivitis in the newborn. Conclusions: It is inferred that the mode of delivery and the presence of risk factors is responsible for conjunctivitis in the newborn.

  11. Comparative study of radon in Sudan

    International Nuclear Information System (INIS)

    Gharbi, Shaza Ismail Mohammed

    2014-07-01

    This study was conducted primarily to contribute radon data for radon map in Sudan and identify regions with elevated radon levels and improve data collection and analysis for the future radon levels evaluation. This study partially covered three states of Sudan ( Red Sea - Khartoum - South Khordofan). Previous work done has been considered in this study which focused and investigated the levels of radon concentration in ( indoor radon gas and water) by using gamma spectrometry equipped with ( HPGe detector) or (Na1 (T1) detector). The results obtained are within the acceptable levels and dose not poses any risk from radiation protection point of view. Red Sea state ( port-sudan): (124.39±6.21) Bq/m 3 . Khartoum state ( Suba): (151.52) Bq/m 3 . (Omdurman): ( 127±23) Bq/m 3 . Radon in water: (59) Bq/L. South Kordofan State: (102.8) Bq/m 3 . In water (Kadugli): (3 1 39)) Bq/L.(Author)

  12. Agoraphobia and Panic Disorder: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Ayse Kart

    2016-01-01

    Full Text Available Aim: In this study we aim to get more information about agoraphobia (AG which is an independent diagnosis in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5 and to evaluate overlaps or differences between agoraphobia and panic disorder (PD upon sociodemographic features and comorbidity with considering relation of these two disorders. Material and Method: Sociodemographic Data Form was given and Structural Clinical Interview for DSM Axis I Disorders (SCID-I was applied to 33 patients diagnosed as AG and 34 patients diagnosed as PD with AG (PDA.Results: AG group consisted of 21 females (63.1%, 12 males (36%, totally 33 patients and PDA group consisted of 23 females (67.6%, 11 males (32.4%, totally 34 patients. Mean age of onset was 32.4±10.2 in PDA group and 31.1±12.1 in AG group. According to sociodemographic features, violence in family and smoking rates were significantly higher in PDA group than AG group. Major Depressive Disorder (MDD as a comorbidity was higher in PDA group. Discussion: In this study, we tried to identify the overlaps and differences of PDA and AG. For a better recognition of AG, further studies are needed.

  13. A comparative study of various decalcification techniques

    Directory of Open Access Journals (Sweden)

    Prathibha Prasad

    2013-01-01

    Full Text Available Background : Study of fibrilar, cellular and sub cellular structures of mineralized tissues is only possible after the removal of the calcium apatite of these tissues by the process of demineralization. Aims: The present study aims to evaluate six commonly used demineralizing agents to identify the best decalcifying agent. Materials and Methods: The present study included six different decalcifying solutions: 10% formal nitric acid, 8% formal nitric acid, 10% formic acid, 8% formic acid, Perenyi′s fluid and Ethylene Di-Amine Tetra Acetic Acid. eight samples of posterior mandible of rat were decalcified in each of the decalcifying solutions and subjected to chemical end-point test. Ehrlich′s Hematoxylin stain was used. Statistical Analysis Used: One way ANOVA was used for multiple group comparisons and Chi-square test was used for analyzing categorical data. P value of 0.05/less was set for statistical significance. Results: Samples treated with EDTA showed the best overall histological impression and the tissue integrity were well preserved. Formal nitric of both the percentages 10 and 8% gave fairly good cellular detail and were rapid in their action. Conclusion: The final impression led to the proposition that EDTA was indeed the best decalcifying agent available. However, with time constraint, the use of formal nitric acid is advocated.

  14. Plasmonic nanogap structures studied via cathodoluminescence imaging

    Science.gov (United States)

    Bauman, Stephen J.; Yan, Qigeng; Benamara, Mourad; Herzog, Joseph B.

    2017-08-01

    Cathodoluminescence makes use of the beam raster capabilities of a scanning electron microscope to excite electrons in a sample and collects the luminescent light to produce images or obtain spectra that can reveal useful information about the sample. This technique has been shown to be particularly interesting for studying the plasmonic oscillations of metallic nanostructures. A recently developed fabrication technique has allowed for the creation of sub-10 nm gaps between metallic nanostructures for use as plasmonically active samples that can be tailored for various potential applications. The high degree of control over the geometries capable of being fabricated via this nanomasking technique allow for unique types of structures that are otherwise difficult to fabricate. In this work, the plasmonic response of metallic structures separated by sub-10 nm gaps is studied via CL imaging. Hyperspectral images can demonstrate the effectiveness with which various geometries produce specific wavelength resonances. The results can be helpful in determining which structures are optimal for specific applications based on these resonances. Also, the images can help to guide future fabrication, as the plasmon modes become better understood.

  15. Comparative value of diagnostic imaging techniques in a cat with exophthalmos

    International Nuclear Information System (INIS)

    Ramsey, D.T.; Gerding, P.A. Jr.; Losonsky, J.M.; Kuriashkin, I.V.; Clarkson, R.D.

    1994-01-01

    A mass that appeared to originate from the frontal bone and extended into retrobulbar tissues of the light orbit was imaged in a cat using ultrasound, skull radiographs, computed tomography, and magnetic resonance imaging. The cat was presented with ventrolateral strabismus, exophthalmos, and elevated nictitans membrane of the tight eye. The mass was not delineated entirely after orbital echography and survey radiography of the skull was performed. Cytologic examination of fine-needle aspirate of the mass was suggestive of a neoplastic disease. Results of computed tomography indicated lysis of the calvarium but did not delineate borders of the mass in the calvarium. Magnetic resonance imaging was then used to confirm borders of the neoplasm. Magnetic resonance imaging was the only imaging technique that delineated the entire border of the neoplasm, including in the calvarium, when compared to postmortem evaluation. Results of orbital echography, skull radiographs, or computed tomography, when used as the only diagnostic imaging modality, must be interpreted with caution when evaluating borders of retrobulbar neoplasia prior to surgical planning

  16. Experimental study of bubbly flow using image processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yucheng, E-mail: ycfu@vt.edu; Liu, Yang, E-mail: liu130@vt.edu

    2016-12-15

    This paper presents an experimental study of bubbly flows at relatively high void fractions using an advanced image processing method. Bubble overlapping is a common problem in such flows and the past studies often treat the overlapping bubbles as a whole, which introduces considerable measurement uncertainties. In this study, a hybrid method combining intersection point detection and watershed segmentation is used to separate the overlapping bubbles. In order to reconstruct bubbles from separated segments, a systematic procedure is developed which can preserve more features captured in the raw image compared to the simple ellipse fitting method. The distributions of void fraction, interfacial area concentration, number density and velocity are obtained from the extracted bubble information. High-speed images of air-water bubbly flows are acquired and processed for eight test runs conducted in a 30 mm × 10 mm rectangular channel. The developed image processing scheme can effectively separate overlapping bubbles and the results compare well with the measurements by the gas flow meter and double-sensor conductivity probe. The development of flows in transverse and mainstream directions are analyzed and compared with the prediction made by the one-dimensional interfacial area transport equation (IATE) and the bubble number density transport equation.

  17. Comparative study on dermatoglyphics in alcoholic patients.

    Science.gov (United States)

    Devcić, Sanja; Mihanović, Mate; Milicić, Jasna; Glamuzina, Ljubomir; Silić, Ante

    2009-12-01

    According to the world's prevalence rate, alcoholism is in the third place after heart and blood vessel diseases and malignant tumors. With the development of neuroscience, the causes of alcoholism's biological etiologic sources are still being studied. Considering that dermatoglyphics are highly determined by heritage, we contemplated the possibilities of their discrimination in alcoholic patients in relation to phenotypically healthy subjects. We analyzed the quantitative and qualitative dermatoglyphics properties of 100 alcoholic patients without psychiatric comorbidity, who have been cured in the Psychiatric Hospital Sveti Ivan two or more times, and those of 100 phenotypically healthy men. Through the t-test we evaluated the heterogeneity of the examined groups. Results showed a statistically significant difference on five examined variables. In the calculation of fluctuating asymmetry measure, we found no statistically significant differences in the correlation of values of the right and the left hand on the tested variables, beside one. Chi-square tests showed that there is no relation between the dermatoglyphic qualitative properties of alcoholic patients and those of the examinees from the comparison group. Despite the indisputable genetic role in the genesis of alcoholism, the analysis of the dermatoglyphics carried out in our study did not show any etiological connection between the results of the test on dermatoglyphics and the appearance of alcoholism.

  18. Breast Cancer: Comparative Effectiveness of Positron Emission Mammography and MR Imaging in Presurgical Planning for the Ipsilateral Breast1

    Science.gov (United States)

    Madsen, Kathleen S.; Schilling, Kathy; Tartar, Marie; Pisano, Etta D.; Larsen, Linda Hovanessian; Narayanan, Deepa; Ozonoff, Al; Miller, Joel P.; Kalinyak, Judith E.

    2011-01-01

    Purpose: To determine the performance of positron emission mammography (PEM), as compared with magnetic resonance (MR) imaging, including the effect on surgical management, in ipsilateral breasts with cancer. Materials and Methods: Four hundred seventy-two women with newly diagnosed breast cancer who were offered breast-conserving surgery consented from September 2006 to November 2008 to participate in a multicenter institutional review board–approved, HIPAA-compliant protocol. Participants underwent contrast material–enhanced MR imaging and fluorine 18 fluorodeoxyglucose PEM in randomized order; resultant images were interpreted independently. Added biopsies and changes in surgical procedure for the ipsilateral breast were correlated with histopathologic findings. Performance characteristics were compared by using the McNemar test and generalized estimating equations. Results: Three hundred eighty-eight women (median age, 58 years; age range, 26–93 years; median estimated tumor size, 1.5 cm) completed the study. Additional cancers were found in 82 (21%) women (82 ipsilateral breasts; median tumor size, 0.7 cm). Twenty-eight (34%) of the 82 breasts were identified with both PEM and MR imaging; 21 (26%) breasts, with MR imaging only; 14 (17%) breasts, with PEM only; and seven (8.5%) breasts, with mammography and ultrasonography. Twelve (15%) cases of additional cancer were missed at all imaging examinations. Integration of PEM and MR imaging increased cancer detection—to 61 (74%) of 82 breasts versus 49 (60%) of 82 breasts identified with MR imaging alone (P breasts without additional cancer, 279 (91.2%) were correctly assessed with PEM compared with 264 (86.3%) that were correctly assessed with MR imaging (P = .03). The positive predictive value of biopsy prompted by PEM findings (47 [66%] of 71 cases) was higher than that of biopsy prompted by MR findings (61 [53%] of 116 cases) (P = .016). Of 116 additional cancers, 61 (53%) were depicted by MR imaging

  19. Breast cancer: comparative effectiveness of positron emission mammography and MR imaging in presurgical planning for the ipsilateral breast.

    Science.gov (United States)

    Berg, Wendie A; Madsen, Kathleen S; Schilling, Kathy; Tartar, Marie; Pisano, Etta D; Larsen, Linda Hovanessian; Narayanan, Deepa; Ozonoff, Al; Miller, Joel P; Kalinyak, Judith E

    2011-01-01

    To determine the performance of positron emission mammography (PEM), as compared with magnetic resonance (MR) imaging, including the effect on surgical management, in ipsilateral breasts with cancer. Four hundred seventy-two women with newly diagnosed breast cancer who were offered breast-conserving surgery consented from September 2006 to November 2008 to participate in a multicenter institutional review board-approved, HIPAA-compliant protocol. Participants underwent contrast material-enhanced MR imaging and fluorine 18 fluorodeoxyglucose PEM in randomized order; resultant images were interpreted independently. Added biopsies and changes in surgical procedure for the ipsilateral breast were correlated with histopathologic findings. Performance characteristics were compared by using the McNemar test and generalized estimating equations. Three hundred eighty-eight women (median age, 58 years; age range, 26-93 years; median estimated tumor size, 1.5 cm) completed the study. Additional cancers were found in 82 (21%) women (82 ipsilateral breasts; median tumor size, 0.7 cm). Twenty-eight (34%) of the 82 breasts were identified with both PEM and MR imaging; 21 (26%) breasts, with MR imaging only; 14 (17%) breasts, with PEM only; and seven (8.5%) breasts, with mammography and ultrasonography. Twelve (15%) cases of additional cancer were missed at all imaging examinations. Integration of PEM and MR imaging increased cancer detection-to 61 (74%) of 82 breasts versus 49 (60%) of 82 breasts identified with MR imaging alone (P breasts without additional cancer, 279 (91.2%) were correctly assessed with PEM compared with 264 (86.3%) that were correctly assessed with MR imaging (P = .03). The positive predictive value of biopsy prompted by PEM findings (47 [66%] of 71 cases) was higher than that of biopsy prompted by MR findings (61 [53%] of 116 cases) (P = .016). Of 116 additional cancers, 61 (53%) were depicted by MR imaging and 47 (41%) were depicted by PEM (P = .043). Fifty

  20. Diffusion tensor imaging measures of white matter compared to myelin basic protein immunofluorescence in tissue cleared intact brains

    Directory of Open Access Journals (Sweden)

    Eric H. Chang

    2017-02-01

    Full Text Available We provide datasets from combined ex vivo diffusion tensor imaging (DTI and Clear Lipid-exchanged, Anatomically Rigid, Imaging/immunostaining compatible, Tissue hYdrogel (CLARITY performed on intact mouse brains. DTI-derived measures of fractional anisotropy (FA, radial diffusivity (RD, and axial diffusivity (AD were compared to antibody-based labeling of myelin basic protein (MBP, as measured by fluorescence microscopy. We used a customized CLARITY hydrogel solution to facilitate whole brain tissue clearing and subsequent immunolabeling. We describe how CLARITY was made compatible with magnetic resonance imaging with the intention of facilitating future multimodal imaging studies that may combine noninvasive imaging with 3D immunohistochemistry. These data and methods are related to the accompanying research article entitled, ‘The role of myelination in measures of white matter integrity: Combination of diffusion tensor imaging and two-photon microscopy of CLARITY intact brains’ (E.H. Chang, M. Argyelan, M. Aggarwal, T-S. Chandon, K.H. Karlsgodt, S. Mori, A.K. Malhotra, 2016 [1].

  1. Educational effect of a lecture on differential imaging features comparing ameloblastomas and keratocystic odontogenic tumors of the mandible presented to dental students

    International Nuclear Information System (INIS)

    Morita, Mitsuko; Ariji, Yoshiko; Kise, Yoshitaka; Goto, Masakazu; Izumi, Masahiro; Naitoh, Munetaka; Ariji, Eiichiro; Katsumata, Akitoshi

    2011-01-01

    The objective of this study was to clarify the educational effect of a lecture on differential imaging features comparing ameloblastomas and keratocystic odontogenic tumors of the mandibles presented to dental students. Panoramic and CT images of 10 ameloblastomas and 10 keratocystic odontogenic tumors were randomly presented 114 dental students. Test scores, correct answer ratios, identification index, and understanding of the imaging features contributing to a correct diagnosis were serially evaluated before and after the lecture on the differential imaging features comparing the two types of tumors. The mean and standard deviation of the scoring ratios of dental students diagnosing these lesions on panoramic and CT images were 48.8±10.8% and 52.5±12.9%, respectively. After the lecture on the differential imaging features comparing the two tumors, the scoring ratios improved significantly. After the lecture, both the numbers of patients whose images were correctly diagnosed and the identification indices increased. The lecture also increased the number of imaging features recognized as contributing to the correct diagnosis. A lecture on the differential imaging features comparing ameloblastomas and keratocystic odontogenic tumors of the mandibles contributed to the improvement of imaging diagnosis skills among dental students. (author)

  2. Comparative methods for quantifying thyroid volume using planar imaging and SPECT

    International Nuclear Information System (INIS)

    Zaidi, H.

    1996-01-01

    Thyroid volume determination using planar imaging is a procedure often performed in routine nuclear medicine, but is hampered by several physical difficulties, in particular by structures which overlie or underlie the organ of interest. SPECT enables improved accuracy over planar imaging in the determination of the volume since it is derived from the 3-D data rather than from a 2-D projection with a certain geometric assumption regarding the thyroid configuration. By using the phantoms of known volume, it was possible to estimate the accuracy of 3 different methods of determining thyroid volume from planar imaging used in clinical routine. The experimental results demonstrate that compared with conventional scintigraphy, thyroid phantom volumes were most accurately determined with SPECT when attenuation and scatter corrections are performed which allows accurate radiation dosimetry in humans without the need for assumptions on organ size or concentrations. Poster 181. (author)

  3. Comparative analysis of imaging sensitivity of positron emission mammography and whole-body PET in relation to tumor size.

    Science.gov (United States)

    Yamamoto, Yayoi; Ozawa, Yukihiko; Kubouchi, Kouichi; Nakamura, Seigo; Nakajima, Yasuo; Inoue, Tomio

    2015-01-01

    Positron emission mammography (PEM) consists of a dedicated PET scanner for breast imaging with a higher spatial resolution than whole-body PET (WBPET) scanners. This study compared the imaging sensitivity of PEM with WBPET in relation to tumor size. Fifty-four Japanese women younger than 50 years with histologically confirmed breast lesions were retrospectively enrolled. Positron emission mammography and WBPET were conducted on the same day. Positron emission mammography and WBPET images were blindly evaluated and compared with histopathology. Tumors were classified into 3 groups based on size as follows: group 1, 1 cm or smaller; group 2, 1 to 2 cm; and group 3, larger than 2 cm. The sensitivities of PEM and WBPET were compared in overall subjects and in each size group. In visual analysis, the overall imaging sensitivity was 78.6% (33/42) for PEM and 47.6% (20/42) for WBPET. The overall sensitivity of PEM was significantly higher than that of WBPET (P PEM and WBPET were larger in smaller tumors: group 1 (66.7% vs 13.3%), group 2 (63.4% vs 36.4%), and group 3 (100.0% vs 87.5%). The sensitivity of PEM was significantly higher than that of WBPET in group 1 (P = 0.008); however, no significant differences were seen in group 2 (P = 0.500) or group 3 (P = 0.250). Overall, the imaging specificity of PEM and WEBPET was 90.6% (60/66) and 93.9% (62/66), respectively. The imaging sensitivity of PEM was higher than that of WBPET in Japanese women younger than 50 years. Positron emission mammography showed significant sensitivity in tumors smaller than 1 cm, which has been a weak point for WBPET.

  4. Computed tomography and magnetic resonance imaging study of uveal melanoma

    International Nuclear Information System (INIS)

    Xian Junfang; Wang Zhenchang; Yan Fei

    1998-01-01

    Purpose: To study CT and MRI findings of uveal melanoma and detect the most appropriate MRI scanning sequences. Materials and methods: A series of MRI scanning sequences were performed in 15 cases, and CT was performed in 11 cases. MRI and CT findings were compared with pathologic, operative and clinical findings. Results: Of 11 cases receiving CT scanning, 9 displayed iso-density masses with respect to extraocular muscles. The other two tumors were too small to be demonstrated. Fourteen cases of melanoma showed characteristic MR appearances with hyperintense signal with respect to the vitreous on T 1 -weighted images and hypointense with respect to the vitreous on T 2 -weighted images. One case of iris melanoma only 3 mm in height was not demonstrated on T 1 -weighted images, but was displayed hypointense signal on T 2 -weighted images. Eleven cases associated with retinal detachment showed high intensity signal on T 1 - and T 2 -weighted images and could not be distinguished from melanoma. Postcontrast T 1 -weighted images with fat suppression technique were found to be the most helpful in detecting and delineating small melanomas less than 5 mm as well as distinguishing them from retinal detachment. Conclusion: MRI was superior to ultrasound or CT. Collaborative diagnosis including clinical, ultrasonographic, CT and MRI examinations is the best for ocular melanoma

  5. Ultrasonography of symptomatic rotator cuff tears compared with MR imaging and surgery

    Energy Technology Data Exchange (ETDEWEB)

    Fotiadou, Anastasia N. [Radiology Department, University Hospital of Larissa, Mezourlo 41110, Larissa (Greece); Radiology Department, G. Papanikolaou Hospital, Exochi 32100, Thessaloniki (Greece)], E-mail: natfot@yahoo.gr; Vlychou, Marianna [Radiology Department, University Hospital of Larissa, Mezourlo 41110, Larissa (Greece)], E-mail: mvlychou@med.uth.gr; Papadopoulos, Periklis [University Orthopaedic Clinic, G. Papanikolaou Hospital, Exochi 32100, Thessaloniki (Greece)], E-mail: perpap@otenet.gr; Karataglis, Dimitrios S. [University Orthopaedic Clinic, G. Papanikolaou Hospital, Exochi 32100, Thessaloniki (Greece)], E-mail: dkarataglis@yahoo.gr; Palladas, Panagiotis [Radiology Department, G. Papanikolaou Hospital, Exochi 32100, Thessaloniki (Greece)], E-mail: palladaspan@in.gr; Fezoulidis, Ioannis V. [Radiology Department, University Hospital of Larissa, Mezourlo 41110, Larissa (Greece)], E-mail: oswestanast@yahoo.gr

    2008-10-15

    Purpose: To compare the accuracy of ultrasonography and magnetic resonance imaging in the detection of rotator cuff tears. Materials and methods: Ninety-six patients with clinically suspected rotator cuff pathology underwent ultrasonography and magnetic resonance imaging of the shoulder. The findings in 88 patients were compared with arthroscopy or open surgery. Results: Full-thickness tear was confirmed in 57 cases, partial-thickness tear in 30 cases and degenerative changes without tear in 1. In all 57 cases of full-thickness tear and in 28 out of 30 cases of partial-thickness tear the supraspinatus tendon was involved. The accuracy in the detection of full-thickness tears was 98 and 100% for ultrasonography and magnetic resonance imaging, respectively. The accuracy in the detection of bursal or articular partial-thickness tears was 87 and 90% for ultrasonography and magnetic resonance imaging, respectively. Conclusions: In experienced hands ultrasonography should be considered as an accurate modality for the initial investigation of rotator cuff, especially supraspinatus, tears.

  6. Imaging Hypoxia in Xenografted and Murine Tumors with 18F-Fluoroazomycin Arabinoside: A Comparative Study Involving microPET, Autoradiography, pO2-Polarography, and Fluorescence Microscopy

    DEFF Research Database (Denmark)

    Busk, Morten; Horsman, Michael R; Jakobsen, Steen

    2008-01-01

    PURPOSE: Positron emission tomography (PET) allows noninvasive assessment of tumor hypoxia; however the combination of low resolution and slow tracer clearance from nonhypoxic tissue is problematic. The aim of this study was to examine the in vivo hypoxia selectivity of fluoroazomycin arabinoside...... ([(18)F]-FAZA), a promising tracer with improved washout kinetics from oxygenated tissue. METHODS AND MATERIALS: Three squamous cell carcinomas and one fibrosarcoma with widely differing spatial patterns of vascularization, hypoxia, and necrosis were grown in mice and evaluated with PET...... and an inverse correlation (except for the fibrosarcoma) between the distribution of [(18)F]-FAZA and Hoechst dye. Moreover intratumoral heterogeneity in tracer distribution was clearly visible on autoradiograms, with a [(18)F]-FAZA concentration approximately six times higher in poorly oxygenated areas than...

  7. Infrared Imaging System for Studying Brain Function

    Science.gov (United States)

    Mintz, Frederick; Mintz, Frederick; Gunapala, Sarath

    2007-01-01

    A proposed special-purpose infrared imaging system would be a compact, portable, less-expensive alternative to functional magnetic resonance imaging (fMRI) systems heretofore used to study brain function. Whereas a typical fMRI system fills a large room, and must be magnetically isolated, this system would fit into a bicycle helmet. The system would include an assembly that would be mounted inside the padding in a modified bicycle helmet or other suitable headgear. The assembly would include newly designed infrared photodetectors and data-acquisition circuits on integrated-circuit chips on low-thermal-conductivity supports in evacuated housings (see figure) arranged in multiple rows and columns that would define image coordinates. Each housing would be spring-loaded against the wearer s head. The chips would be cooled by a small Stirling Engine mounted contiguous to, but thermally isolated from, the portions of the assembly in thermal contact with the wearer s head. Flexible wires or cables for transmitting data from the aforementioned chips would be routed to an integrated, multichannel transmitter and thence through the top of the assembly to a patch antenna on the outside of the helmet. The multiple streams of data from the infrared-detector chips would be sent to a remote site, where they would be processed, by software, into a three-dimensional display of evoked potentials that would represent firing neuronal bundles and thereby indicate locations of neuronal activity associated with mental or physical activity. The 3D images will be analogous to current fMRI images. The data would also be made available, in real-time, for comparison with data in local or internationally accessible relational databases that already exist in universities and research centers. Hence, this system could be used in research on, and for the diagnosis of response from the wearer s brain to physiological, psychological, and environmental changes in real time. The images would also be

  8. Study of check image using computed radiography

    International Nuclear Information System (INIS)

    Sato, Hiroshi

    2002-01-01

    There are two image forming methods both a check image and a portal image in the linacogram. It has been established the image forming method in the check image using computed radiography (CR). On the other hand, it is not established the image forming method in the portal image using CR yet. Usually, in the electric portal imaging device (EPID) is mainly used just before radiotherapy start. The usefulness of the portal image forming method by CR using in place of EPID is possible to confirm the precision for determining to specific position at the irradiate part and to the irradiate method for the human organs. There are some technical problems that, since in the early time, the linac graphy (LG) image have low resolution power. In order to improve to the resolution power in LG image, CR image technologies have been introduced to the check image forming method. Heavy metallic sheet (HMS) is used to the front side of CR-IP cassette, and high contactness sponge is used to the back side of the cassette. Improved contactness between HMS and imaging plate (IP) by means of the high contactness sponge contributed to improve the resolution power in the check images. A lot of paper which is connected with these information have been reported. Imaging plate ST-III should be used to maintain high sensitivity in the check film image forming method. The same image forming method in the check image established by CR has been introduced into the portal image forming method in order to improve the resolution power. However, as a result, it couldn't acquired high resolution image forming in the portal images because of the combination of ST-III and radiotherapy dose. After several trials, it has been recognized that HR-V imaging plate for mammography is the most useful application to maintain high resolution power in the portal images. Also, it is possible to modify the image quality by changing GS parameter which is one of image processing parameters in CR. Furthermore, in case

  9. Comparative Study of Music and Architecture from the Aesthetic View

    Directory of Open Access Journals (Sweden)

    Seyed Hesamodin Seraj

    2017-02-01

    Full Text Available Beauty is a mental and emotional phenomenon that has a deep connection with the sensory elements around us. Nature is the master key to feel this sense that along with our feelings and emotions, will lead to relative degrees of beauty. Architecture is formed in the material three-dimensional templates and it is more objective than the other arts; In other words, its relations with the material world are more than the other arts; however, music is only capable to form in one dimension and platform namely time and it is freed from the constraints of location. In this way, music art takes shape over time and it is more abstract than painting, and more prominent than architecture, sculpture and painting. Of course architecture, in accordance with this content, has a special connection from the material world to the spiritual world. Especially in Islamic mosques and sacred arts, architecture has a semantic meaning beyond the material world; because in the sacred arts, secrets are pure as it often does not have any outer shapes and they become a symbol of an Islamic belief and a mystical image so that the transformation is performed to adapt an image with religious beliefs. Thus, the research method, according to the examined contents in this study, is based on pure science or library resources and it is as descriptive-analytic. In this paper, some comparative aspects of aesthetics in music and architecture, which has achieved the high degree of beauty in the light of the total shares and coordination between the two arts, are examined as the goals of this transition.

  10. State of the art imaging of multiple myeloma: Comparative review of FDG PET/CT imaging in various clinical settings

    Energy Technology Data Exchange (ETDEWEB)

    Mesguich, Charles, E-mail: charles.mesguich@chu-bordeaux.fr [Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Fardanesh, Reza; Tanenbaum, Lawrence [Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Chari, Ajai; Jagannath, Sundar [Department of Medicine Division of Hematology and Oncology, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Kostakoglu, Lale, E-mail: lale.kostakoglu@mssm.edu [Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY (United States)

    2014-12-15

    Highlights: • Metabolic changes on FDG PET/CT offer an earlier response evaluation than MRI. • PET/CT is less sensitive than MRI for diffuse bone marrow involvement. • PET/CT is a highly sensitive modality to determine extra-medullary disease. • Red marrow expansion: false positive findings on both FDG PET/CT and MRI. • Compression fractures are best characterized with MRI. - Abstract: 18-Flurodeoxyglucose Positron Emission Tomography with computed tomography (FDG PET/CT) and Magnetic Resonance Imaging (MRI) have higher sensitivity and specificity than whole-body X-ray (WBXR) survey in evaluating disease extent in patients with multiple myeloma (MM). Both modalities are now recommended by the Durie–Salmon Plus classification although the emphasis is more on MRI than PET/CT. The presence of extra-medullary disease (EMD) as evaluated by PET/CT imaging, initial SUV{sub max} and number of focal lesions (FL) are deemed to be strong prognostic parameters at staging. MRI remains the most sensitive technique for the detection of diffuse bone marrow involvement in both the pre and post-therapy setting. Compression fractures are best characterized with MRI signal changes, for determining vertebroplasty candidates. While PET/CT allows for earlier and more specific evaluation of therapeutic efficacy compared to MRI, when signal abnormalities persist years after treatment. PET/CT interpretation, however, can be challenging in the vertebral column and pelvis as well as in cases with post-therapy changes. Hence, a reading approach combining the high sensitivity of MRI and superior specificity of FDG PET/CT would be preferred to increase the diagnostic accuracy. In summary, the established management methods in MM, mainly relying on biological tumor parameters should be complemented with functional imaging data, both at staging and restaging for optimal management of MM.

  11. Degeneration of the cervical disc: histology compared with radiography and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Christe, A.; Vock, P. [University of Berne, Department of Radiology, Inselspital, Berne (Switzerland); Laeubli, R.; Berlemann, U. [University of Berne, Department of Orthopaedic Surgery, Inselspital, Berne (Switzerland); Guzman, R.; Schroth, G. [University of Berne, Department of Neuroradiology, Inselspital, Berne (Switzerland); Moore, R.J. [Institute of Medical and Veterinary Science, Adelaide (Australia); Loevblad, K.O. [University of Berne, Department of Neuroradiology, Inselspital, Berne (Switzerland); Geneva University Hospital, Neuroradiology SRRI, Geneva 14 (Switzerland)

    2005-10-01

    Decisions about the treatment of neck pain are largely made on the basis of information gained from plain X-rays and magnetic resonance imaging (MRI), which are used routinely as part of preliminary investigation. We performed a descriptive cadaveric study to compare histology with radiography and MRI. We correlated plain radiography, disc height [Farfan index (FI)] and MRI findings with histology to assess the ability of radiology to detect significant pathologic lesions. The study included 52 motion segments from nine subjects over the age of 50, who underwent routine hospital autopsy. Disc degeneration was assessed by histology, radiography, disc height (FI: anterior disc height plus posterior disc height divided by anterioposterior diameter) and MRI using established grading systems. Most of the discs were classified radiologically as grade 1 (19/52), grade 2 (13/52), grade 3 (9/52) or grade 4 (3/52). Eight of the discs were graded as normal. The distribution of MRI grades was grade 0 (9/36), grade 1 (9/36), grade 2 (7/36), grade 3 (8/36) and grade 4 (3/36). Half of the discs (26/52) showed advanced (grade 4) degeneration histologically. FI correlated with histological grade (P=0.013), MRI grade (P=0.02) and radiological grade (P<0.001) of degeneration. Radiological and histological grade of degeneration showed a weak correlation (r=0.3, P=0.033). MRI correlated with overall histological grade (r=0.41, P=0.015, n=34). Histological features (e.g., tears, rim lesions, prolapse of nucleus material) were poorly recognised by MRI, which had a sensitivity for disc material prolapse and annulus tears of less than 40%. Our study showed that discs from patients over 50 years are histologically severely degenerated; however, these changes may not be detected by conventional radiography and MRI. (orig.)

  12. Degeneration of the cervical disc: histology compared with radiography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Christe, A.; Vock, P.; Laeubli, R.; Berlemann, U.; Guzman, R.; Schroth, G.; Moore, R.J.; Loevblad, K.O.

    2005-01-01

    Decisions about the treatment of neck pain are largely made on the basis of information gained from plain X-rays and magnetic resonance imaging (MRI), which are used routinely as part of preliminary investigation. We performed a descriptive cadaveric study to compare histology with radiography and MRI. We correlated plain radiography, disc height [Farfan index (FI)] and MRI findings with histology to assess the ability of radiology to detect significant pathologic lesions. The study included 52 motion segments from nine subjects over the age of 50, who underwent routine hospital autopsy. Disc degeneration was assessed by histology, radiography, disc height (FI: anterior disc height plus posterior disc height divided by anterioposterior diameter) and MRI using established grading systems. Most of the discs were classified radiologically as grade 1 (19/52), grade 2 (13/52), grade 3 (9/52) or grade 4 (3/52). Eight of the discs were graded as normal. The distribution of MRI grades was grade 0 (9/36), grade 1 (9/36), grade 2 (7/36), grade 3 (8/36) and grade 4 (3/36). Half of the discs (26/52) showed advanced (grade 4) degeneration histologically. FI correlated with histological grade (P=0.013), MRI grade (P=0.02) and radiological grade (P<0.001) of degeneration. Radiological and histological grade of degeneration showed a weak correlation (r=0.3, P=0.033). MRI correlated with overall histological grade (r=0.41, P=0.015, n=34). Histological features (e.g., tears, rim lesions, prolapse of nucleus material) were poorly recognised by MRI, which had a sensitivity for disc material prolapse and annulus tears of less than 40%. Our study showed that discs from patients over 50 years are histologically severely degenerated; however, these changes may not be detected by conventional radiography and MRI. (orig.)

  13. Utilization of Solar Dynamics Observatory space weather digital image data for comparative analysis with application to Baryon Oscillation Spectroscopic Survey

    Science.gov (United States)

    Shekoyan, V.; Dehipawala, S.; Liu, Ernest; Tulsee, Vivek; Armendariz, R.; Tremberger, G.; Holden, T.; Marchese, P.; Cheung, T.

    2012-10-01

    Digital solar image data is available to users with access to standard, mass-market software. Many scientific projects utilize the Flexible Image Transport System (FITS) format, which requires specialized software typically used in astrophysical research. Data in the FITS format includes photometric and spatial calibration information, which may not be useful to researchers working with self-calibrated, comparative approaches. This project examines the advantages of using mass-market software with readily downloadable image data from the Solar Dynamics Observatory for comparative analysis over with the use of specialized software capable of reading data in the FITS format. Comparative analyses of brightness statistics that describe the solar disk in the study of magnetic energy using algorithms included in mass-market software have been shown to give results similar to analyses using FITS data. The entanglement of magnetic energy associated with solar eruptions, as well as the development of such eruptions, has been characterized successfully using mass-market software. The proposed algorithm would help to establish a publicly accessible, computing network that could assist in exploratory studies of all FITS data. The advances in computer, cell phone and tablet technology could incorporate such an approach readily for the enhancement of high school and first-year college space weather education on a global scale. Application to ground based data such as that contained in the Baryon Oscillation Spectroscopic Survey is discussed.

  14. Comparative analysis of partial imaging performance parameters of home and imported X-ray machines

    International Nuclear Information System (INIS)

    Cao Yunxi; Wang Xianyun; Liu Huiqin; Guo Yongxin

    2002-01-01

    Objective: To compare and analyze the performance indexes and the imaging quality of the home and imported X-ray machines through testing their partial imaging performance parameters. Methods: By separate sampling from 10 home and 10 imported X-ray machines, the parameters including tube current, time of exposure, machine total exposure, and repeatability were tested, and the imaging performance was evaluated according to the national standard. Results: All the performance indexes met the standard of GB4505-84. The first sampling tests showed the maximum changing coefficient of imaging performance repeatability of the home X-ray machines was Δmax1 = 0.025, while that of the imported X-ray machine was Δmax1 = 0.016. In the second sampling tests, the maximum changing coefficients of the two were Δmax2 = 0.048 and Δmax2 = 0.022, respectively. Conclusion: The 2 years' follow-up tests indicate that there is no significant difference between the above-mentioned parameters of the elaborately adjusted home X-ray machines and imported ones, but the home X-ray machines are no better than the imported X-ray machines in stability and consistency

  15. Comparative analysis of maximum renal longitudinal length with positional changes on ultrasound with multiplanar reconstructed MR image in Korea Adults

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Yun Hee; Cho, Bum Sang; Kang, Min Ho; Kang, Woo Young; Lee, Jisun; Kim, Yook; Lee, Soo Hyun; Lee, Soo Jung [Dept. of Radiology, Chungbuk National University Hospital, Cheongju (Korea, Republic of); Lee, Jin Yong [Public Health Medical Service, Seoul National University Boramae Medical Center, Seoul (Korea, Republic of)

    2016-07-15

    The purpose of this study was to determine a suitable position in which the measured length on ultrasound is close to the true renal length obtained through a multiplanar reconstructed MR image. A total of 33 individuals (males: 15, females: 18) without any underlying renal disease were included in the present study. Renal length was measured as the longest axis at the level of the renal hilum in three positions-supine, lateral decubitus, and prone, respectively. With a 3.0 T MR scanner, 3D eTHRIVE was acquired. Subsequently, the maximum longitudinal length of both the kidneys was measured through multiplanar reconstructed MR images. Paired t-test was used to compare the renal length obtained from ultrasonographic measurement with the length obtained through multiplanar reconstructed MR images. Our study demonstrated significant difference between sonographic renal length in three positions and renal length through MRI (p < 0.001). However, the longest longitudinal length of right kidney among the measured three values by ultrasound was statistically similar to the renal length measured by reconstructed MR image. Among them, the lateral decubitus position showed the strongest correlation with true renal length (right: 0.887; left: 0.849). We recommend measurement of the maximum renal longitudinal length in all possible positions on ultrasonography. If not allowed, the best measurement is on the lateral decubitus showing the strongest correlation coefficient with true renal length.

  16. Comparing clinical data and muscle imaging of DYSF and ANO5 related muscular dystrophies

    NARCIS (Netherlands)

    ten Dam, Leroy; van der Kooi, Anneke J.; Rövekamp, Fleur; Linssen, Wim H. J. P.; de Visser, Marianne

    2014-01-01

    In this retrospective cross-sectional study clinical and muscle imaging data of patients with Miyoshi distal myopathy phenotype (MMD1 and MMD3) and limb girdle muscular dystrophy 2L (LGMD2L) were described. MMD1 and MMD3 are genetically heterogenous diseases based on DYSF and ANO5 gene defects. MMD3

  17. Assessing hepatic fibrosis: comparing the intravoxel incoherent motion in MRI with acoustic radiation force impulse imaging in US

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chih-Horng; Liang, Po-Chin; Shih, Tiffany Ting-Fang [National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); National Taiwan University College of Medicine, Department of Radiology, Taipei (China); Ho, Ming-Chih; Hu, Rey-Heng; Lai, Hong-Shiee [National Taiwan University Hospital and College of Medicine, Department of Surgery, Taipei (China); Jeng, Yung-Ming [National Taiwan University Hospital and College of Medicine, Department of Pathology, Taipei (China)

    2015-12-15

    This study compared the diagnostic performance of intravoxel incoherent motion (IVIM) in magnetic resonance imaging (MRI) and acoustic radiation force impulse imaging (ARFI) in ultrasound (US) for liver fibrosis (LF) evaluation. A total of 49 patients scheduled for liver surgery were recruited. LF in the non-tumorous liver parenchyma at the right lobe was estimated using a slow diffusion coefficient, fast diffusion coefficient (D{sub fast}), perfusion fraction (f) of the IVIM parameters, the total apparent diffusion coefficient of conventional diffusion-weighted imaging and the shear wave velocity (Vs) of ARFI. LF was graded using the Metavir scoring system on histological examination. The Spearman rank correlation coefficient for correlation and analysis of variance was used for determining difference. The diagnostic performance was compared using receiver operating characteristic curve analysis. LF exhibited significant correlation with the three parameters D{sub fast}, f, and Vs (r = -0.528, -0.337, and 0.481, respectively, P < 0.05). The D{sub fast} values in the F4 group were significantly lower than those in the F0, F1 and F2 groups. D{sub fast} exhibited a non-inferior performance for diagnosing all fibrosis grades compared with that of Vs. Both IVIM and ARFI provide reliable estimations for the noninvasive assessment of LF. (orig.)

  18. Progress of PET imaging in the study of neural stem cell transplantation treating Parkinson's disease

    International Nuclear Information System (INIS)

    Tan Haibo; Liu Xingdang

    2004-01-01

    PET imaging has important value in the study of neural stem cell transplantation treating Parkinson's disease, especial in the evaluation of the effect, the study of treating mechanisms and the comparation of effect in different transplantation places. PET imaging as a non-invasive method plays a more and more important role in the study of neural stem cell transplantation treating Parkinson's disease. (authors)

  19. Imaging studies for failed back surgery syndrome

    International Nuclear Information System (INIS)

    Cosnard, G.; Cordoliani, Y.S.; Sarrazin, J.L.; Soulie, D.

    1995-01-01

    In patients with failed back surgery syndrome, magnetic resonance imaging (MRI) can be the best first-line imaging study because it simplifies the diagnosis. This update is based on over 600 cases. MRI shows the scar tissue at the surgical site, persistent evidence of disk herniation for several weeks after surgery, and evidence of local and regional edema in one-fourth of cases. The edema is most marked between two months and two years after the operation and can misleadingly suggest discitis. MRI is the best investigation for detecting recurrent herniation at the same vertebral level or another level. Herniated disk material is seen as a mass that does not enhance after gadolinium, in contrast to the vascularized scar tissue. Free fragments are often clearly visible within the scar tissue. Fragments that migrate to the epidural space can give rise to granulomatous reactions. Scar tissue can be seen in the epidural space and within the disk; it can show enhancement after gadolinium for several years. The scar can be atrophic or hypertrophic and can encase or impinge on the dural sac and nerve roots. Pathological fibrosis cannot be differentiated from ordinary scar tissue. Arachnoiditis causing adherence of the nerve roots to the dura mater or to each other occurs in 5 % to 10 % of cases. Nerve root enhancement after gadolinium is seen in three-fourths of cases. Bone lesions are common, especially some time after surgery; they are usually accompanied with other lesions. Hematomas are seen in less than 10 % of cases. Infections are similarly rare (0.25 % each for discitis and epiduritis). The diagnosis of discitis is difficult and requires percutaneous biopsy of the disk, especially when MRI shows fluid within the disk, with decreased signal intensity on T2 images, and non enhancement after intravenous gadolinium. (authors). 19 refs., 7 figs

  20. Comparison of the perceived image quality between two digital imaging systems for neonatal bedside radiography – A case study

    International Nuclear Information System (INIS)

    Zyl, S.A. van; Kekana, R.M.

    2015-01-01

    Background: Chest X-rays are performed daily in the neonatal intensive care and high care units. The skill of the radiographer is critical for obtaining the best image quality and limiting the patient's radiation exposure. The literature states that indirect flat panel detectors produce images of superior quality in comparison to computed radiography systems. At Steve Biko Academic Hospital a decision was made to revert from the direct digital radiography (DR) system to the computed radiography (CR) system, due to poor image quality experienced. Method: The case study objective was to conduct a comparative analysis describing key technical factors contributing to image quality. The analysis entailed retrospectively comparing the images obtained during 2010 and 2011. An image analysis form was utilised in evaluating the technical aspects of the image. A total of 160 images were viewed by 16 participants sampled from the radiography, radiology and paediatric departments. The participants were asked to re-evaluate two of their allotted images after five days to determine their reliability. Results: Findings were that the DR system provides significantly better image quality than the CR system (p < 0.05) for all the technical factors evaluated. However technical improvements are recommended. A wide variance in intra-observer reliability was also found. Conclusion: This case study demonstrated that DR images were considered to be superior to CR images. Recommendations include: a standardised technique for imaging the neonates; optimisation of the imaging software for the digital detectors, improved feedback systems in terms of exposure index values, and the training of radiographers and referring physicians in technical image analysis. - Highlights: • DR system provides better image quality than the CR system for all technical factors evaluated. • The average values obtained from the VAS showed that the DR system still needs to be optimised. • There is need

  1. A comparative study of ultrasonography, computed tomography and magnetic resonance imaging in the staging and invasion of adjacent structures by renal tumors; Estudo comparativo dos metodos de ultrassonografia, tomografia computadorizada e ressonancia magnetica no estadiamento e invasao das estruturas adjacentes por tumores renais

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, S.M.; Ajzen, S.A.; Trindade, J.C.S. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Faculdade de Medicina; UNESP, Botucatu, SP (Brazil). Faculdade de Medicina; E-mail: sribeiro@fmb.unesp.br

    2001-09-01

    Ultrasonography (US), Computed Tomography (CT), and Magnetic Resonance imaging (MR) were compared for the staging of renal tumors. The differences between these imaging techniques were also studied for their ability to detect adenopathies, vascular invasion, distant intra-abdominal metastases, and particularly adjacent organ invasion. Thirty-one patients with solid or complex renal masses were prospectively studied using US, CT, and MR. Differences between the results obtained were studied using the Cochran G test and the Mc NEMAR test. The sensitivity and specificity of each diagnostic technique were compared against a 'gold standard' of the surgical and histopathological findings. The following sensitivities were obtained: For the detection of adenopathy, US 63.6%, CT and MR 90.9%. For vascular invasion, US 42.8%, CT and MR 85.7%. For the adjacent organ invasion, US 28.5%, CT 85.7%, and MR 71.4%. Some of the criteria that suggest invasion of adjacent structures include: the envelopment of the adjacent structures by the tumor, tumor extension into the adjacent structures with an irregular appearance, and alterations in shape, size, and density of adjacent structures. Loss of fat planes between the tumor and adjacent structures is not a sign of tumor invasion. Significant differences were found in the detection capacity of US in relation to CT and MR, which were similar. All three techniques were highly sensitive and specific only in the detection of distant abdominal metastases. In addition to the accuracy of these diagnostic modalities for the detection and staging of tumors, invasiveness, risks and cost should be considered in relation to relative costs and benefits. (author)

  2. COMPARATIVE STUDY BETWEEN THE PUBIS OF ASYMPTOMATIC ATHLETES AND NON-ATHLETES WITH MRI.

    Science.gov (United States)

    Branco, Rodrigo Castelo; da Costa Fontenelle, César Rubens; Miranda, Leandro Marques; Junior, Yonder Archanjo Ching San; Vianna, Evandro Miguelote

    2010-01-01

    To compare the magnetic resonance imaging findings from the pubis of professional soccer players without any history or clinical findings of groin pain, and from sedentary individuals, also without symptoms, and to determine the prevalence of changes compatible with pubic overload. Nineteen professional soccer players without complaints of groin pain and seventeen sedentary individuals, also asymptomatic, underwent magnetic resonance imaging of the pubis. The results from the examinations were analyzed regarding the presence of degenerative changes, boned medullary edema and tendinopathy, and the two study groups were compared. High prevalence of bone edema, tendinopathy and degenerative findings in the pubic symphysis was seen in the athletes, with statistically significant higher odds ratios and relative risk in the population studied. Professional soccer players are at a higher risk of developing changes in the pubic region, shown in magnetic resonance images, compared with sedentary individuals. These findings are not necessarily caused by groin pain, and are probably related to intense exertion.

  3. Studies on computer analysis for radioisotope images

    International Nuclear Information System (INIS)

    Takizawa, Masaomi

    1977-01-01

    A hybrid type image file and processing system are devised by the author to file and the radioisotope image processing with analog display. This system has some functions as follows; Ten thousand images can be stored in 60 feets length video-tape-recorder (VTR) tape. Maximum of an image on the VTR tape is within 15 sec. An image display enabled by the analog memory, which has brightness more than 15 gray levels. By using the analog memories, effective image processing can be done by the small computer. Many signal sources can be inputted into the hybrid system. This system can be applied many fields to both routine works and multi-purpose radioisotope image processing. (auth.)

  4. A preliminary diffusional kurtosis imaging study of Parkinson disease: comparison with conventional diffusion tensor imaging

    International Nuclear Information System (INIS)

    Kamagata, Koji; Kamiya, Kouhei; Suzuki, Michimasa; Hori, Masaaki; Yoshida, Mariko; Aoki, Shigeki; Tomiyama, Hiroyuki; Hatano, Taku; Motoi, Yumiko; Hattori, Nobutaka; Abe, Osamu; Shimoji, Keigo

    2014-01-01

    Diffusional kurtosis imaging (DKI) is a more sensitive technique than conventional diffusion tensor imaging (DTI) for assessing tissue microstructure. In particular, it quantifies the microstructural integrity of white matter, even in the presence of crossing fibers. The aim of this preliminary study was to compare how DKI and DTI show white matter alterations in Parkinson disease (PD). DKI scans were obtained with a 3-T magnetic resonance imager from 12 patients with PD and 10 healthy controls matched by age and sex. Tract-based spatial statistics were used to compare the mean kurtosis (MK), mean diffusivity (MD), and fractional anisotropy (FA) maps of the PD patient group and the control group. In addition, a region-of-interest analysis was performed for the area of the posterior corona radiata and superior longitudinal fasciculus (SLF) fiber crossing. FA values in the frontal white matter were significantly lower in PD patients than in healthy controls. Reductions in MK occurred more extensively throughout the brain: in addition to frontal white matter, MK was lower in the parietal, occipital, and right temporal white matter. The MK value of the area of the posterior corona radiata and SLF fiber crossing was also lower in the PD group. DKI detects changes in the cerebral white matter of PD patients more sensitively than conventional DTI. In addition, DKI is useful for evaluating crossing fibers. By providing a sensitive index of brain pathology in PD, DKI may enable improved monitoring of disease progression. (orig.)

  5. PET IMAGING STUDIES IN DRUG ABUSE RESEARCH.

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Volkow, N.D.; Ding, Y.S.; Logan, J.; Wang, G.J.

    2001-01-29

    . This will be followed by highlights of PET studies of the acute effects of the psychostimulant drugs cocaine and methylphenidate (ritalin) and studies of the chronic effects of cocaine and of tobacco smoke on the human brain. This chapter concludes with the description of a study which uses brain imaging coupled with a specific pharmacological challenge to address the age-old question of why some people who experiment with drugs become addicted while others do not.

  6. Comparing Destination Image and Loyalty between First-time and Repeat-visit Tourists

    Directory of Open Access Journals (Sweden)

    Mohamad M.

    2014-01-01

    Full Text Available The objective of this study was to investigate the difference between destination image and loyalty among first-time and repeat-visit tourists. The study was undertaken to examine aspects of underlying factors of destination image that influenced tourists’ willingness to recommend Malaysia to their friends and relatives as well as spread positive word-of-mouth to others. In addition, it was to ascertain the relationship between destination image and loyalty among first-time and repeat-visit tourists. The data was collected at Kuala Lumpur International Airport at the departure hall using self-administered questionnaires. 248 usable questionnaires were returned and analysed. The findings of the study revealed that both groups of tourists perceived Malaysia as providing a nature-based destination. The study also empirically proved that both first-time and repeat-visit tourists were willing to disseminate positive word-of-mouth and recommend Malaysia to their friends and relatives as a vacation destination to visit. However, there was a significant difference in destination loyalty between first-visit and repeat-visit tourists.

  7. Secondary Ion Mass Spectrometry Imaging of Molecular Distributions in Cultured Neurons and Their Processes: Comparative Analysis of Sample Preparation

    Science.gov (United States)

    Tucker, Kevin R.; Li, Zhen; Rubakhin, Stanislav S.; Sweedler, Jonathan V.

    2012-11-01

    Neurons often exhibit a complex chemical distribution and topography; therefore, sample preparation protocols that preserve structures ranging from relatively large cell somata to small neurites and growth cones are important factors in secondary ion mass spectrometry (SIMS) imaging studies. Here, SIMS was used to investigate the subcellular localization of lipids and lipophilic species in neurons from Aplysia californica. Using individual neurons cultured on silicon wafers, we compared and optimized several SIMS sampling approaches. After an initial step to remove the high salt culturing media, formaldehyde, paraformaldehyde, and glycerol, and various combinations thereof, were tested for their ability to achieve cell stabilization during and after the removal of extracellular media. These treatments improved the preservation of cellular morphology as visualized with SIMS imaging. For analytes >250 Da, coating the cell surface with a 3.2 nm-thick gold layer increased the ion intensity; multiple analytes previously not observed or observed at low abundance were detected, including intact cholesterol and vitamin E molecular ions. However, once a sample was coated, many of the lower molecular mass (SIMS imaging of processes of individual cultured neurons over a broad mass range with enhanced image contrast.

  8. Comparative evaluation of two dose optimization methods for image-guided, highly-conformal, tandem and ovoids cervix brachytherapy planning

    Science.gov (United States)

    Ren, Jiyun; Menon, Geetha; Sloboda, Ron

    2013-04-01

    Although the Manchester system is still extensively used to prescribe dose in brachytherapy (BT) for locally advanced cervix cancer, many radiation oncology centers are transitioning to 3D image-guided BT, owing to the excellent anatomy definition offered by modern imaging modalities. As automatic dose optimization is highly desirable for 3D image-based BT, this study comparatively evaluates the performance of two optimization methods used in BT treatment planning—Nelder-Mead simplex (NMS) and simulated annealing (SA)—for a cervix BT computer simulation model incorporating a Manchester-style applicator. Eight model cases were constructed based on anatomical structure data (for high risk-clinical target volume (HR-CTV), bladder, rectum and sigmoid) obtained from measurements on fused MR-CT images for BT patients. D90 and V100 for HR-CTV, D2cc for organs at risk (OARs), dose to point A, conformation index and the sum of dwell times within the tandem and ovoids were calculated for optimized treatment plans designed to treat the HR-CTV in a highly conformal manner. Compared to the NMS algorithm, SA was found to be superior as it could perform optimization starting from a range of initial dwell times, while the performance of NMS was strongly dependent on their initial choice. SA-optimized plans also exhibited lower D2cc to OARs, especially the bladder and sigmoid, and reduced tandem dwell times. For cases with smaller HR-CTV having good separation from adjoining OARs, multiple SA-optimized solutions were found which differed markedly from each other and were associated with different choices for initial dwell times. Finally and importantly, the SA method yielded plans with lower dwell time variability compared with the NMS method.

  9. Comparing image quality of print-on-demand books and photobooks from web-based vendors

    Science.gov (United States)

    Phillips, Jonathan; Bajorski, Peter; Burns, Peter; Fredericks, Erin; Rosen, Mitchell

    2010-01-01

    Because of the emergence of e-commerce and developments in print engines designed for economical output of very short runs, there are increased business opportunities and consumer options for print-on-demand books and photobooks. The current state of these printing modes allows for direct uploading of book files via the web, printing on nonoffset printers, and distributing by standard parcel or mail delivery services. The goal of this research is to assess the image quality of print-on-demand books and photobooks produced by various Web-based vendors and to identify correlations between psychophysical results and objective metrics. Six vendors were identified for one-off (single-copy) print-on-demand books, and seven vendors were identified for photobooks. Participants rank ordered overall quality of a subset of individual pages from each book, where the pages included text, photographs, or a combination of the two. Observers also reported overall quality ratings and price estimates for the bound books. Objective metrics of color gamut, color accuracy, accuracy of International Color Consortium profile usage, eye-weighted root mean square L*, and cascaded modulation transfer acutance were obtained and compared to the observer responses. We introduce some new methods for normalizing data as well as for strengthening the statistical significance of the results. Our approach includes the use of latent mixed-effect models. We found statistically significant correlation with overall image quality and some of the spatial metrics, but correlations between psychophysical results and other objective metrics were weak or nonexistent. Strong correlation was found between psychophysical results of overall quality assessment and estimated price associated with quality. The photobook set of vendors reached higher image-quality ratings than the set of print-on-demand vendors. However, the photobook set had higher image-quality variability.

  10. A study for watermark methods appropriate to medical images.

    Science.gov (United States)

    Cho, Y; Ahn, B; Kim, J S; Kim, I Y; Kim, S I

    2001-06-01

    The network system, including the picture archiving and communication system (PACS), is essential in hospital and medical imaging fields these days. Many medical images are accessed and processed on the web, as well as in PACS. Therefore, any possible accidents caused by the illegal modification of medical images must be prevented. Digital image watermark techniques have been proposed as a method to protect against illegal copying or modification of copyrighted material. Invisible signatures made by a digital image watermarking technique can be a solution to these problems. However, medical images have some different characteristics from normal digital images in that one must not corrupt the information contained in the original medical images. In this study, we suggest modified watermark methods appropriate for medical image processing and communication system that prevent clinically important data contained in original images from being corrupted.

  11. Perivesical varices and portal hypertension: imaging study

    International Nuclear Information System (INIS)

    Mallorquin Jimenez, F.; Medina Benitez, A.; Lopez Machado, E.; Pardo Moreno, M.D.; Garrido Moreno, C.; Pastor Rull, J.

    1995-01-01

    Nine patients with portal hypertension syndrome and Perivesical varices are studied retrospectively by means of imaging techniques including ultrasound, duplex Doppler, color Doppler, CT and angiography. All the patients presented portal thrombosis and thickening of the bladder wall. These collaterals either represent a shunting of hepato pedal flow or correspond to blood stasis associated with said syndrome. Ultrasound, whether involving duplex Doppler or color Doppler techniques, is highly useful to detect the presence of Perivesical varices which appear as tubular or rounded hypo echogenic areas in the bladder wall. Given the association of this entity with bladder wall thickening, it should be taken into account in any clinical situation involving said change, especially in patients with portal hypertension; moreover knowledge of its presence is of great importance when the possibility of creating shunts by means of interventional or surgical vascular procedures or other types of abdominal procedures are being considered because of the risk of bleeding. (Author)

  12. Comparative analysis of facial morphology between Okinawa Islanders and mainland Japanese using three-dimensional images.

    Science.gov (United States)

    Miyazato, Eri; Yamaguchi, Kyoko; Fukase, Hitoshi; Ishida, Hajime; Kimura, Ryosuke

    2014-01-01

    Differences in facial height and breadth between Okinawa Islanders and mainland Japanese have been reported in previous craniometric and somatometric studies. This study using three-dimensional (3D) images aimed to identify more detailed characteristics of facial morphology in each population. Using a hand-held 3D scanner, we obtained 60 facial surface images each from Okinawa Islanders and mainland Japanese. Twenty-one landmarks were plotted on a computer and 27 measurements of distances and angles between the landmarks were taken. Statistical analyses such as t test, principal component analysis (PCA), regression analysis, and discriminant analysis were performed to identify sex and regional differences, the patterns of facial features, factors explaining the facial patterns, and other features. Okinawa Islanders showed lower facial and nasal heights than mainland Japanese. Furthermore, we identified larger protrusions of the glabella and nasal root in Okinawa Islanders than in mainland Japanese. In the PCA, we observed components of facial shape patterns. These components mainly represented facial size (PC1), facial depth (PC2), the prominence of the glabella and nasal root (PC3), and facial breadth (PC4). We identified that the population difference is strongly associated with PC3. This study quantitatively identified differences in the facial morphology between Okinawa Islanders and mainland Japanese using 3D digital images, with special emphases on the differences in the nasal height and the prominence of the glabella and nasal root. Copyright © 2014 Wiley Periodicals, Inc.

  13. Comparative evaluation of an ultraviolet and an orthochromatic rare-earth imaging system for veterinary radiography

    International Nuclear Information System (INIS)

    Pugh, C.R.; Wortman, J.A.; Lloyd, J.K.F.; Saunders, H.M.; Biery, D.N.; Rhodes, W.H.; Evans, S.M.; Walker, L.M.; Green, P.; Mendez-Aguillar, R.

    1995-01-01

    The relative quality and speed of a new ultraviolet-emitting screen, ultraviolet-sensitive film rare-earth system (DuPont Ultra-Vision) was compared to an orthochromatic rare-earth system (Kodak Lanex) in a clinical trial. Seven different sets of radiographs of a human foot phantom, or actual canine anatomical structures (tarsus, pelvis, skull, chest, abdomen) were evaluated independently by radiologists, radiology residents and technicians who were unaware of the screen/film combinations used. The 400-speed, Ultra-Vision Rapid/UVG screen/film combination produced superior image detail compared to blue/green emitting 400 and 200-speed screen/film combinations. The image detail of the Ultra-Vision Rapid/UVG system was nearly equivalent to that produced using a 100-speed, fine-detail blue/green emitting screen/film combination. A 200-speed Ultra-Vision system was also tested and produced thoracic and abdominal radiographs of equivalent to slightly superior quality than those produced using blue/green emitting system

  14. Implicit measures of environmental attitudes: a comparative study

    Directory of Open Access Journals (Sweden)

    Martha Patricia Sánchez

    2016-01-01

    Full Text Available The present investigation aims to inquire about the capacity of three implicit instruments to measure the attitude toward natural and urban environments. One hundred and three students from a Mexican public university participated in the investigation. The implicit instruments used were the affective priming technique, the implicit association test, and the affect misattribution procedure. Further, an explicit scale was used for comparison. The results showed that all instruments converge in the same way; the nature images were viewed as more pleasant compared to the city images. Also, most results indicated good effect size values, observed power, and reliability, with the exception of the affective priming technique, which established low values. In addition, all instruments indicated weak correlations between each other. The results were discussed in terms of the capacity of the instruments to measure environmental attitudes, and also possible theoretical and methodological implications.

  15. Comparing ALS and Image-Based Point Cloud Metrics and Modelled Forest Inventory Attributes in a Complex Coastal Forest Environment

    Directory of Open Access Journals (Sweden)

    Joanne C. White

    2015-10-01

    Full Text Available Digital aerial photogrammetry (DAP is emerging as an alternate data source to airborne laser scanning (ALS data for three-dimensional characterization of forest structure. In this study we compare point cloud metrics and plot-level model estimates derived from ALS data and an image-based point cloud generated using semi-global matching (SGM for a complex, coastal forest in western Canada. Plot-level estimates of Lorey’s mean height (H, basal area (G, and gross volume (V were modelled using an area-based approach. Metrics and model outcomes were evaluated across a series of strata defined by slope and canopy cover, as well as by image acquisition date. We found statistically significant differences between ALS and SGM metrics for all strata for five of the eight metrics we used for model development. We also found that the similarity between metrics from the two data sources generally increased with increasing canopy cover, particularly for upper canopy metrics, whereas trends across slope classes were less consistent. Model outcomes from ALS and SGM were comparable. We found the greatest difference in model outcomes was for H (ΔRMSE% = 5.04%. By comparison, ΔRMSE% was 2.33% for G and 3.63% for V. We did not discern any corresponding trends in model outcomes across slope and canopy cover strata, or associated with different image acquisition dates.

  16. Arterial spin-labeling MR imaging in moyamoya disease compared with clinical assessments and other MR imaging finings

    International Nuclear Information System (INIS)

    Noguchi, Tomoyuki; Kawashima, Masatou; Nishihara, Masashi; Hirai, Tetsuyoshi; Matsushima, Toshio; Irie, Hiroyuki

    2013-01-01

    Purpose: Our purpose was to identify the causal factors for the perfusion distribution obtained with ASL-MRI by comparing ASL-MRI with clinical information and other MRI findings in moyamoya disease. Methods: Seventy-one patients with moyamoya disease underwent ASL-MRI and other MRI, including fluid-attenuated inversion recovery imaging (FLAIR) and three-dimensional time-of-flight magnetic resonance angiography (MRA) on 3.0-Tesla MRI system. Cerebral blood flow (CBF) values (ASL values) for the cerebral hemispheres (142 sides) were measured on CBF maps generated by ASL-MRI. Relationships between the ASL values and the following 9 factors were assessed: sex, family history, revascularization surgery, age at MR exam, age at onset, the steno-occlusive severity on MRA (MRA score), degree of