WorldWideScience

Sample records for psf-matched difference imaging

  1. Different images of science

    DEFF Research Database (Denmark)

    Davidsson, Eva

      Within the science and technology centres (STC) movement there exists explicit aims and ambitions to enhance visitors' interest in and knowledge about science. Meanwhile, several researches question the choice of the scientific content in exhibitions when arguing that a too unproblematic view...... of science commonly is presented. But what images and aspects of science are visitors actually confronted with at STCs? How do staff members at STCs consider the scientific content and how do they choose what aspects of science to display in exhibitions? What ideas about visitors' learning do staff members....... The most common image was the usefulness of science which displays science in an unproblematic and single-dimensioned way. In order to explore what underlying assumptions and factors which affect how science is constituted, 17 staff members who worked with planning and constructing new exhibitions...

  2. Effective image differencing with convolutional neural networks for real-time transient hunting

    Science.gov (United States)

    Sedaghat, Nima; Mahabal, Ashish

    2018-06-01

    Large sky surveys are increasingly relying on image subtraction pipelines for real-time (and archival) transient detection. In this process one has to contend with varying point-spread function (PSF) and small brightness variations in many sources, as well as artefacts resulting from saturated stars and, in general, matching errors. Very often the differencing is done with a reference image that is deeper than individual images and the attendant difference in noise characteristics can also lead to artefacts. We present here a deep-learning approach to transient detection that encapsulates all the steps of a traditional image-subtraction pipeline - image registration, background subtraction, noise removal, PSF matching and subtraction - in a single real-time convolutional network. Once trained, the method works lightening-fast and, given that it performs multiple steps in one go, the time saved and false positives eliminated for multi-CCD surveys like Zwicky Transient Facility and Large Synoptic Survey Telescope will be immense, as millions of subtractions will be needed per night.

  3. Predicting Visible Image Degradation by Colour Image Difference Formulae

    Institute of Scientific and Technical Information of China (English)

    Eriko Bando; Jon Y. Hardeberg; David Connah; Ivar Farup

    2004-01-01

    It carried out a CRT monitor based psychophysical experiment to investigate the quality of three colour image difference metrics, the CIEAE ab equation, the iCAM and the S-CIELAB metrics. Six original images were reproduced through six gamut mapping algorithms for the observer experiment. The result indicates that the colour image difference calculated by each metric does not directly relate to perceived image difference.

  4. Hiding Information Using different lighting Color images

    Science.gov (United States)

    Majead, Ahlam; Awad, Rash; Salman, Salema S.

    2018-05-01

    The host medium for the secret message is one of the important principles for the designers of steganography method. In this study, the best color image was studied to carrying any secret image.The steganography approach based Lifting Wavelet Transform (LWT) and Least Significant Bits (LSBs) substitution. The proposed method offers lossless and unnoticeable changes in the contrast carrier color image and imperceptible by human visual system (HVS), especially the host images which was captured in dark lighting conditions. The aim of the study was to study the process of masking the data in colored images with different light intensities. The effect of the masking process was examined on the images that are classified by a minimum distance and the amount of noise and distortion in the image. The histogram and statistical characteristics of the cover image the results showed the efficient use of images taken with different light intensities in hiding data using the least important bit substitution method. This method succeeded in concealing textual data without distorting the original image (low light) Lire developments due to the concealment process.The digital image segmentation technique was used to distinguish small areas with masking. The result is that smooth homogeneous areas are less affected as a result of hiding comparing with high light areas. It is possible to use dark color images to send any secret message between two persons for the purpose of secret communication with good security.

  5. Accuracy assessment between different image classification ...

    African Journals Online (AJOL)

    What image classification does is to assign pixel to a particular land cover and land use type that has the most similar spectral signature. However, there are possibilities that different methods or algorithms of image classification of the same data set could produce appreciable variant results in the sizes, shapes and areas of ...

  6. Different styles of image-guided radiotherapy

    NARCIS (Netherlands)

    van Herk, Marcel

    2007-01-01

    To account for geometric uncertainties during radiotherapy, safety margins are applied. In many cases, these margins overlap organs at risk, thereby limiting dose escalation. The aim of image-guided radiotherapy is to improve the accuracy by imaging tumors and critical structures on the machine just

  7. Perceptual evaluation of different image fusion schemes

    NARCIS (Netherlands)

    Toet, A.; IJspeert, J.K.

    2001-01-01

    Human perceptual performance was tested with images of nighttime outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3-5 μm) infrared (IR) camera. Fused imagery was

  8. Perceptual evaluation of different image fusion schemes

    NARCIS (Netherlands)

    Toet, A.; Franken, E.M.

    2003-01-01

    Human scene recognition performance was tested with images of night-time outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3–5 mm) infrared (IR) camera. Fused imagery was

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-15

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

  11. Science and Different Images of the World

    Directory of Open Access Journals (Sweden)

    Michele Marsonet

    2016-07-01

    They are both intersubjective and non arbitrary. What are, however, these two images, and are they really alternative? Let us note, from the onset, that the two images we just mentioned are both idealizations in the same sense of Max Weber’s “ideal types”. This means that, in order to discover their actual presence, we need having recourse to a good deal of philosophical abstraction. In other words, they are not disclosed by mere empirical recognition. For instance, we live in the commonsense view of the world, and only a complex process of reflection makes us understand that we, as human beings, share a common view of the world, which is in turn determined by the fact that our physical structure bounds us to conceive of reality in a certain way rather than in another. Think about the importance that light, for example, has not only in daily life, but even in our philosophical conceptualization of the world. The story is complicated by the fact that each image has a history, and while the manifest image dates back to pre-history, the scientific image is constantly changing shape.

  12. Color and neighbor edge directional difference feature for image retrieval

    Institute of Scientific and Technical Information of China (English)

    Chaobing Huang; Shengsheng Yu; Jingli Zhou; Hongwei Lu

    2005-01-01

    @@ A novel image feature termed neighbor edge directional difference unit histogram is proposed, in which the neighbor edge directional difference unit is defined and computed for every pixel in the image, and is used to generate the neighbor edge directional difference unit histogram. This histogram and color histogram are used as feature indexes to retrieve color image. The feature is invariant to image scaling and translation and has more powerful descriptive for the natural color images. Experimental results show that the feature can achieve better retrieval performance than other color-spatial features.

  13. Imaging characteristics of different mammographic screens.

    Science.gov (United States)

    Kuhn, H; Knüpfer, W

    1992-01-01

    A study of mammography systems with green-emitting screens was conducted to determine how the image quality parameters (apart from dose requirement), such as modulation transfer function (MTF) and Wiener spectrum (WS), depend on the dye content of the compound and coating weight of the screen. In addition, the contribution to total noise of the individual components, i.e., film, screen, and quantum noise, was studied. The quantities derived from MTF and WS, namely detective quantum efficiency (DQE) and noise equivalent quanta (NEQ), were also investigated in regard to their dose dependency. It can be demonstrated that the MTF of the screens becomes more favorable when the dye content is increased, while noise is not significantly affected. This suggests the use of a mammography screen capable of greater detail recognition, requiring at least double the dose of today's conventional systems with approximately 80 microGy system dose. On the other hand, the manufacture of a screen with about 60% of the dose of the conventional system is possible with very little loss in image quality. For the systems in common use today (80 microGy), quantum noise represents a considerable share of the total noise at low spatial frequencies, whereas in high spatial frequencies, the graininess of the film dominates quantum noise and screen structure.

  14. Steganalysis based on reducing the differences of image statistical characteristics

    Science.gov (United States)

    Wang, Ran; Niu, Shaozhang; Ping, Xijian; Zhang, Tao

    2018-04-01

    Compared with the process of embedding, the image contents make a more significant impact on the differences of image statistical characteristics. This makes the image steganalysis to be a classification problem with bigger withinclass scatter distances and smaller between-class scatter distances. As a result, the steganalysis features will be inseparate caused by the differences of image statistical characteristics. In this paper, a new steganalysis framework which can reduce the differences of image statistical characteristics caused by various content and processing methods is proposed. The given images are segmented to several sub-images according to the texture complexity. Steganalysis features are separately extracted from each subset with the same or close texture complexity to build a classifier. The final steganalysis result is figured out through a weighted fusing process. The theoretical analysis and experimental results can demonstrate the validity of the framework.

  15. Performance comparison of different graylevel image fusion schemes through a universal image quality index

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2003-01-01

    We applied a recently introduced universal image quality index Q that quantifies the distortion of a processed image relative to its original version, to assess the performance of different graylevel image fusion schemes. The method is as follows. First, we adopt an original test image as the

  16. Comparative analysis of different methods for image enhancement

    Institute of Scientific and Technical Information of China (English)

    吴笑峰; 胡仕刚; 赵瑾; 李志明; 李劲; 唐志军; 席在芳

    2014-01-01

    Image enhancement technology plays a very important role to improve image quality in image processing. By enhancing some information and restraining other information selectively, it can improve image visual effect. The objective of this work is to implement the image enhancement to gray scale images using different techniques. After the fundamental methods of image enhancement processing are demonstrated, image enhancement algorithms based on space and frequency domains are systematically investigated and compared. The advantage and defect of the above-mentioned algorithms are analyzed. The algorithms of wavelet based image enhancement are also deduced and generalized. Wavelet transform modulus maxima (WTMM) is a method for detecting the fractal dimension of a signal, it is well used for image enhancement. The image techniques are compared by using the mean (μ), standard deviation (s), mean square error (MSE) and PSNR (peak signal to noise ratio). A group of experimental results demonstrate that the image enhancement algorithm based on wavelet transform is effective for image de-noising and enhancement. Wavelet transform modulus maxima method is one of the best methods for image enhancement.

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

    Science.gov (United States)

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

    2016-10-01

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

  18. Image Segmentation Based on Period Difference of the Oscillation

    Institute of Scientific and Technical Information of China (English)

    王直杰; 张珏; 范宏; 柯克峰

    2004-01-01

    A new method for image segmentation based on pulse neural network is proposed. Every neuron in the network represents one pixel in the image and the network is locally connected.Each group of the neurons that correspond to each object synchronizes while different gronps of the neurons oscillate at different period. Applying this period difference,different objects are divided. In addition to simulation, an analysis of the mechanism of the method is presented in this paper.

  19. Comparison between different encoding schemes for synthetic aperture imaging

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav; Jensen, Jørgen Arendt

    2002-01-01

    and spatio-temporal encoding was investigated. Experiments on wire phantom in water were carried out to quantify the gain from the different encodings. The gain in SNR using an FM modulated pulse is 12 dB. The penetration depth of the images was studied using tissue mimicking phantom with frequency dependent......Synthetic transmit aperture ultrasound (STAU) imaging can create images with as low as 2 emissions, making it attractive for 3D real-time imaging. Two are the major problems to be solved: (1) complexity of the hardware involved, and (2) poor image quality due to low signal to noise ratio (SNR). We...... attenuation of 0.5 dB/(cm MHz). The combination of spatial and temporal encoding have highest penetration depth. Images to a depth of 110 mm, can successfully be made with contrast resolution comparable to that of a linear array image. The in-vivo scans show that the motion artifacts do not significantly...

  20. System for objective assessment of image differences in digital cinema

    Science.gov (United States)

    Fliegel, Karel; Krasula, Lukáš; Páta, Petr; Myslík, Jiří; Pecák, Josef; Jícha, Marek

    2014-09-01

    There is high demand for quick digitization and subsequent image restoration of archived film records. Digitization is very urgent in many cases because various invaluable pieces of cultural heritage are stored on aging media. Only selected records can be reconstructed perfectly using painstaking manual or semi-automatic procedures. This paper aims to answer the question what are the quality requirements on the restoration process in order to obtain acceptably close visual perception of the digitally restored film in comparison to the original analog film copy. This knowledge is very important to preserve the original artistic intention of the movie producers. Subjective experiment with artificially distorted images has been conducted in order to answer the question what is the visual impact of common image distortions in digital cinema. Typical color and contrast distortions were introduced and test images were presented to viewers using digital projector. Based on the outcome of this subjective evaluation a system for objective assessment of image distortions has been developed and its performance tested. The system utilizes calibrated digital single-lens reflex camera and subsequent analysis of suitable features of images captured from the projection screen. The evaluation of captured image data has been optimized in order to obtain predicted differences between the reference and distorted images while achieving high correlation with the results of subjective assessment. The system can be used to objectively determine the difference between analog film and digital cinema images on the projection screen.

  1. Image Denoising Using Singular Value Difference in the Wavelet Domain

    Directory of Open Access Journals (Sweden)

    Min Wang

    2018-01-01

    Full Text Available Singular value (SV difference is the difference in the singular values between a noisy image and the original image; it varies regularly with noise intensity. This paper proposes an image denoising method using the singular value difference in the wavelet domain. First, the SV difference model is generated for different noise variances in the three directions of the wavelet transform and the noise variance of a new image is used to make the calculation by the diagonal part. Next, the single-level discrete 2-D wavelet transform is used to decompose each noisy image into its low-frequency and high-frequency parts. Then, singular value decomposition (SVD is used to obtain the SVs of the three high-frequency parts. Finally, the three denoised high-frequency parts are reconstructed by SVD from the SV difference, and the final denoised image is obtained using the inverse wavelet transform. Experiments show the effectiveness of this method compared with relevant existing methods.

  2. Stereo Vision-Based High Dynamic Range Imaging Using Differently-Exposed Image Pair

    Directory of Open Access Journals (Sweden)

    Won-Jae Park

    2017-06-01

    Full Text Available In this paper, a high dynamic range (HDR imaging method based on the stereo vision system is presented. The proposed method uses differently exposed low dynamic range (LDR images captured from a stereo camera. The stereo LDR images are first converted to initial stereo HDR images using the inverse camera response function estimated from the LDR images. However, due to the limited dynamic range of the stereo LDR camera, the radiance values in under/over-exposed regions of the initial main-view (MV HDR image can be lost. To restore these radiance values, the proposed stereo matching and hole-filling algorithms are applied to the stereo HDR images. Specifically, the auxiliary-view (AV HDR image is warped by using the estimated disparity between initial the stereo HDR images and then effective hole-filling is applied to the warped AV HDR image. To reconstruct the final MV HDR, the warped and hole-filled AV HDR image is fused with the initial MV HDR image using the weight map. The experimental results demonstrate objectively and subjectively that the proposed stereo HDR imaging method provides better performance compared to the conventional method.

  3. Robust reflective ghost imaging against different partially polarized thermal light

    Science.gov (United States)

    Li, Hong-Guo; Wang, Yan; Zhang, Rui-Xue; Zhang, De-Jian; Liu, Hong-Chao; Li, Zong-Guo; Xiong, Jun

    2018-03-01

    We theoretically study the influence of degree of polarization (DOP) of thermal light on the contrast-to-noise ratio (CNR) of the reflective ghost imaging (RGI), which is a novel and indirect imaging modality. An expression for the CNR of RGI with partially polarized thermal light is carefully derived, which suggests a weak dependence of CNR on the DOP, especially when the ratio of the object size to the speckle size of thermal light has a large value. Different from conventional imaging approaches, our work reveals that RGI is much more robust against the DOP of the light source, which thereby has advantages in practical applications, such as remote sensing.

  4. Object-Oriented Hierarchy Radiation Consistency for Different Temporal and Different Sensor Images

    Directory of Open Access Journals (Sweden)

    Nan Su

    2018-02-01

    Full Text Available In the paper, we propose a novel object-oriented hierarchy radiation consistency method for dense matching of different temporal and different sensor data in the 3D reconstruction. For different temporal images, our illumination consistency method is proposed to solve both the illumination uniformity for a single image and the relative illumination normalization for image pairs. Especially in the relative illumination normalization step, singular value equalization and linear relationship of the invariant pixels is combined used for the initial global illumination normalization and the object-oriented refined illumination normalization in detail, respectively. For different sensor images, we propose the union group sparse method, which is based on improving the original group sparse model. The different sensor images are set to a similar smoothness level by the same threshold of singular value from the union group matrix. Our method comprehensively considered the influence factors on the dense matching of the different temporal and different sensor stereoscopic image pairs to simultaneously improve the illumination consistency and the smoothness consistency. The radiation consistency experimental results verify the effectiveness and superiority of the proposed method by comparing two other methods. Moreover, in the dense matching experiment of the mixed stereoscopic image pairs, our method has more advantages for objects in the urban area.

  5. Evaluation of Underwater Image Enhancement Algorithms under Different Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Marino Mangeruga

    2018-01-01

    Full Text Available Underwater images usually suffer from poor visibility, lack of contrast and colour casting, mainly due to light absorption and scattering. In literature, there are many algorithms aimed to enhance the quality of underwater images through different approaches. Our purpose was to identify an algorithm that performs well in different environmental conditions. We have selected some algorithms from the state of the art and we have employed them to enhance a dataset of images produced in various underwater sites, representing different environmental and illumination conditions. These enhanced images have been evaluated through some quantitative metrics. By analysing the results of these metrics, we tried to understand which of the selected algorithms performed better than the others. Another purpose of our research was to establish if a quantitative metric was enough to judge the behaviour of an underwater image enhancement algorithm. We aim to demonstrate that, even if the metrics can provide an indicative estimation of image quality, they could lead to inconsistent or erroneous evaluations.

  6. Fusion of different modalities of imaging the fist

    International Nuclear Information System (INIS)

    Verdenet, J.; Garbuio, P.; Runge, M.; Cardot, J.C.

    1997-01-01

    The standard radiographical pictures are not able always to bring out the fracture of one of the fist bones. In an early study it was shown that 40% of patients presenting a suspicion of fracture and in which the radio- image was normal, have had a fracture confirmed with quantification by MRI and scintigraphy. The last one does not allow to specify the localization and consequently we developed a code to fusion entirely automatically the radiologic image and the scintigraphic image using no external marker. The code has been installed on a PC and uses the Matlab environment. Starting from the histogram processing the contours are individualized on the interpolated radio- and scinti-images. For matching there are 3 freedom degrees: one of rotation and 2 of translation (in x and y axes). The internal axes of the forearm was chosen to effect the rotation and translation. The forehand thickness, identical for each modality, allows to match properly the images. We have obtained an anatomic image on which the contour and the hyper-fixating zones of the scintigraphy are added. On a set of 100 examinations we observed 38 fractures while the difference between a fracture of the scaphoid and of another fist bone is confirmed in 93% of cases

  7. Optical flow estimation on image sequences with differently exposed frames

    Science.gov (United States)

    Bengtsson, Tomas; McKelvey, Tomas; Lindström, Konstantin

    2015-09-01

    Optical flow (OF) methods are used to estimate dense motion information between consecutive frames in image sequences. In addition to the specific OF estimation method itself, the quality of the input image sequence is of crucial importance to the quality of the resulting flow estimates. For instance, lack of texture in image frames caused by saturation of the camera sensor during exposure can significantly deteriorate the performance. An approach to avoid this negative effect is to use different camera settings when capturing the individual frames. We provide a framework for OF estimation on such sequences that contain differently exposed frames. Information from multiple frames are combined into a total cost functional such that the lack of an active data term for saturated image areas is avoided. Experimental results demonstrate that using alternate camera settings to capture the full dynamic range of an underlying scene can clearly improve the quality of flow estimates. When saturation of image data is significant, the proposed methods show superior performance in terms of lower endpoint errors of the flow vectors compared to a set of baseline methods. Furthermore, we provide some qualitative examples of how and when our method should be used.

  8. Hyperspectral optical imaging of two different species of lepidoptera

    Directory of Open Access Journals (Sweden)

    Vukusic Pete

    2011-01-01

    Full Text Available Abstract In this article, we report a hyperspectral optical imaging application for measurement of the reflectance spectra of photonic structures that produce structural colors with high spatial resolution. The measurement of the spectral reflectance function is exemplified in the butterfly wings of two different species of Lepidoptera: the blue iridescence reflected by the nymphalid Morpho didius and the green iridescence of the papilionid Papilio palinurus. Color coordinates from reflectance spectra were calculated taking into account human spectral sensitivity. For each butterfly wing, the observed color is described by a characteristic color map in the chromaticity diagram and spreads over a limited volume in the color space. The results suggest that variability in the reflectance spectra is correlated with different random arrangements in the spatial distribution of the scales that cover the wing membranes. Hyperspectral optical imaging opens new ways for the non-invasive study and classification of different forms of irregularity in structural colors.

  9. COUNTRY IMAGE VS. COUNTRY BRAND: DIFFERENCES AND SIMILARITIES

    Directory of Open Access Journals (Sweden)

    Denisa Adriana COTÎRLEA

    2015-08-01

    Full Text Available This article was written in order to provide an overview regarding the differences and similarities regarding two congruent, yet different concepts: country brand and country image. The geopolitical context and, implicitly, the current global context require a redefinition – or a more complex circumscription – of the “country image” and “country branding” concepts. In this paper, the author aimed to highlight the characteristics and particularities of the approached concepts in order to shape a framework of the context within these two operate; a brief analysis of the literature is presented, trying to emphasize the slight difference between the approached concepts

  10. Penalised Maximum Likelihood Simultaneous Longitudinal PET Image Reconstruction with Difference-Image Priors.

    Science.gov (United States)

    Ellis, Sam; Reader, Andrew J

    2018-04-26

    Many clinical contexts require the acquisition of multiple positron emission tomography (PET) scans of a single subject, for example to observe and quantify changes in functional behaviour in tumours after treatment in oncology. Typically, the datasets from each of these scans are reconstructed individually, without exploiting the similarities between them. We have recently shown that sharing information between longitudinal PET datasets by penalising voxel-wise differences during image reconstruction can improve reconstructed images by reducing background noise and increasing the contrast-to-noise ratio of high activity lesions. Here we present two additional novel longitudinal difference-image priors and evaluate their performance using 2D simulation studies and a 3D real dataset case study. We have previously proposed a simultaneous difference-image-based penalised maximum likelihood (PML) longitudinal image reconstruction method that encourages sparse difference images (DS-PML), and in this work we propose two further novel prior terms. The priors are designed to encourage longitudinal images with corresponding differences which have i) low entropy (DE-PML), and ii) high sparsity in their spatial gradients (DTV-PML). These two new priors and the originally proposed longitudinal prior were applied to 2D simulated treatment response [ 18 F]fluorodeoxyglucose (FDG) brain tumour datasets and compared to standard maximum likelihood expectation-maximisation (MLEM) reconstructions. These 2D simulation studies explored the effects of penalty strengths, tumour behaviour, and inter-scan coupling on reconstructed images. Finally, a real two-scan longitudinal data series acquired from a head and neck cancer patient was reconstructed with the proposed methods and the results compared to standard reconstruction methods. Using any of the three priors with an appropriate penalty strength produced images with noise levels equivalent to those seen when using standard

  11. Non-invasive imaging of plant roots in different soils using magnetic resonance imaging (MRI

    Directory of Open Access Journals (Sweden)

    Daniel Pflugfelder

    2017-11-01

    Full Text Available Abstract Background Root systems are highly plastic and adapt according to their soil environment. Studying the particular influence of soils on root development necessitates the adaptation and evaluation of imaging methods for multiple substrates. Non-invasive 3D root images in soil can be obtained using magnetic resonance imaging (MRI. Not all substrates, however, are suitable for MRI. Using barley as a model plant we investigated the achievable image quality and the suitability for root phenotyping of six commercially available natural soil substrates of commonly occurring soil textures. The results are compared with two artificially composed substrates previously documented for MRI root imaging. Results In five out of the eight tested substrates, barley lateral roots with diameters below 300 µm could still be resolved. In two other soils, only the thicker barley seminal roots were detectable. For these two substrates the minimal detectable root diameter was between 400 and 500 µm. Only one soil did not allow imaging of the roots with MRI. In the artificially composed substrates, soil moisture above 70% of the maximal water holding capacity (WHCmax impeded root imaging. For the natural soil substrates, soil moisture had no effect on MRI root image quality in the investigated range of 50–80% WHCmax. Conclusions Almost all tested natural soil substrates allowed for root imaging using MRI. Half of these substrates resulted in root images comparable to our current lab standard substrate, allowing root detection down to a diameter of 300 µm. These soils were used as supplied by the vendor and, in particular, removal of ferromagnetic particles was not necessary. With the characterization of different soils, investigations such as trait stability across substrates are now possible using noninvasive MRI.

  12. COMPARISON OF DIFFERENT SEGMENTATION ALGORITHMS FOR DERMOSCOPIC IMAGES

    Directory of Open Access Journals (Sweden)

    A.A. Haseena Thasneem

    2015-05-01

    Full Text Available This paper compares different algorithms for the segmentation of skin lesions in dermoscopic images. The basic segmentation algorithms compared are Thresholding techniques (Global and Adaptive, Region based techniques (K-means, Fuzzy C means, Expectation Maximization and Statistical Region Merging, Contour models (Active Contour Model and Chan - Vese Model and Spectral Clustering. Accuracy, sensitivity, specificity, Border error, Hammoude distance, Hausdorff distance, MSE, PSNR and elapsed time metrices were used to evaluate various segmentation techniques.

  13. Magnetic Resonance Imaging Findings of Different Polymicrogyria Patterns

    Directory of Open Access Journals (Sweden)

    Erkan Gokce

    2012-09-01

    Conclusion: As one of the most common types of developmental cortical malformations, polymicrogyria can be seen in patients who are presented with clinical findings, such as epilepsy, mental motor retardation and spasticity and polymicrogyria may present in very different types. MRI is an effective imaging technique in patients presenting with cortical developmental malformations such as polymicrogyria [J Contemp Med 2012; 2(3.000: 151-157

  14. Combining Different Modalities for 3D Imaging of Biological Objects

    CERN Document Server

    Tsyganov, E; Kulkarni, P; Mason, R; Parkey, R; Seliuonine, S; Shay, J; Soesbe, T; Zhezher, V; Zinchenko, A I

    2005-01-01

    A resolution enhanced NaI(Tl)-scintillator micro-SPECT device using pinhole collimator geometry has been built and tested with small animals. This device was constructed based on a depth-of-interaction measurement using a thick scintillator crystal and a position sensitive PMT to measure depth-dependent scintillator light profiles. Such a measurement eliminates the parallax error that degrades the high spatial resolution required for small animal imaging. This novel technique for 3D gamma-ray detection was incorporated into the micro-SPECT device and tested with a $^{57}$Co source and $^{98m}$Tc-MDP injected in mice body. To further enhance the investigating power of the tomographic imaging different imaging modalities can be combined. In particular, as proposed and shown in this paper, the optical imaging permits a 3D reconstruction of the animal's skin surface thus improving visualization and making possible depth-dependent corrections, necessary for bioluminescence 3D reconstruction in biological objects. ...

  15. Combining different modalities for 3D imaging of biological objects

    International Nuclear Information System (INIS)

    Tsyganov, Eh.; Antich, P.; Kulkarni, P.; Mason, R.; Parkey, R.; Seliuonine, S.; Shay, J.; Soesbe, T.; Zhezher, V.; Zinchenko, A.

    2005-01-01

    A resolution enhanced NaI(Tl)-scintillator micro-SPECT device using pinhole collimator geometry has been built and tested with small animals. This device was constructed based on a depth-of-interaction measurement using a thick scintillator crystal and a position sensitive PMT to measure depth-dependent scintillator light profiles. Such a measurement eliminates the parallax error that degrades the high spatial resolution required for small animal imaging. This novel technique for 3D gamma-ray detection was incorporated into the micro-SPECT device and tested with a 57 Co source and 98m Tc-MDP injected in mice body. To further enhance the investigating power of the tomographic imaging different imaging modalities can be combined. In particular, as proposed and shown, the optical imaging permits a 3D reconstruction of the animal's skin surface thus improving visualization and making possible depth-dependent corrections, necessary for bioluminescence 3D reconstruction in biological objects. This structural information can provide even more detail if the x-ray tomography is used as presented in the paper

  16. Difference image analysis of defocused observations with CSTAR

    International Nuclear Information System (INIS)

    Oelkers, Ryan J.; Macri, Lucas M.; Wang, Lifan; Ashley, Michael C. B.; Lawrence, Jon S.; Luong-Van, Daniel; Cui, Xiangqun; Gong, Xuefei; Qiang, Liu; Yang, Huigen; Yuan, Xiangyan; Zhou, Xu; Feng, Long-Long; Zhu, Zhenxi; Pennypacker, Carl R.; York, Donald G.

    2015-01-01

    The Chinese Small Telescope ARray carried out high-cadence time-series observations of 27 square degrees centered on the South Celestial Pole during the Antarctic winter seasons of 2008–2010. Aperture photometry of the 2008 and 2010 i-band images resulted in the discovery of over 200 variable stars. Yearly servicing left the array defocused for the 2009 winter season, during which the system also suffered from intermittent frosting and power failures. Despite these technical issues, nearly 800,000 useful images were obtained using g, r, and clear filters. We developed a combination of difference imaging and aperture photometry to compensate for the highly crowded, blended, and defocused frames. We present details of this approach, which may be useful for the analysis of time-series data from other small-aperture telescopes regardless of their image quality. Using this approach, we were able to recover 68 previously known variables and detected variability in 37 additional objects. We also have determined the observing statistics for Dome A during the 2009 winter season; we find the extinction due to clouds to be less than 0.1 and 0.4 mag for 40% and 63% of the dark time, respectively.

  17. Difference Image Analysis of Galactic Microlensing. I. Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Alcock, C.; Allsman, R. A.; Alves, D.; Axelrod, T. S.; Becker, A. C.; Bennett, D. P.; Cook, K. H.; Drake, A. J.; Freeman, K. C.; Griest, K. (and others)

    1999-08-20

    This is a preliminary report on the application of Difference Image Analysis (DIA) to Galactic bulge images. The aim of this analysis is to increase the sensitivity to the detection of gravitational microlensing. We discuss how the DIA technique simplifies the process of discovering microlensing events by detecting only objects that have variable flux. We illustrate how the DIA technique is not limited to detection of so-called ''pixel lensing'' events but can also be used to improve photometry for classical microlensing events by removing the effects of blending. We will present a method whereby DIA can be used to reveal the true unblended colors, positions, and light curves of microlensing events. We discuss the need for a technique to obtain the accurate microlensing timescales from blended sources and present a possible solution to this problem using the existing Hubble Space Telescope color-magnitude diagrams of the Galactic bulge and LMC. The use of such a solution with both classical and pixel microlensing searches is discussed. We show that one of the major causes of systematic noise in DIA is differential refraction. A technique for removing this systematic by effectively registering images to a common air mass is presented. Improvements to commonly used image differencing techniques are discussed. (c) 1999 The American Astronomical Society.

  18. Comparison of different phantoms used in digital diagnostic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bor, Dogan, E-mail: bor@eng.ankara.edu.tr [Ankara University, Faculty of Engineering, Department of Engineering Physics. Tandogan, 06100 Ankara (Turkey); Unal, Elif, E-mail: elf.unall@gmail.com [Radat Dosimetry Laboratory Services, 06830, Golbasi, Ankara (Turkey); Uslu, Anil, E-mail: m.aniluslu@gmail.com [Radat Dosimetry Laboratory Services, 06830, Golbasi, Ankara (Turkey)

    2015-09-21

    The organs of extremity, chest, skull and lumbar were physically simulated using uniform PMMA slabs with different thicknesses alone and using these slabs together with aluminum plates and air gaps (ANSI Phantoms). The variation of entrance surface air kerma and scatter fraction with X-ray beam qualities was investigated for these phantoms and the results were compared with those measured from anthropomorphic phantoms. A flat panel digital radiographic system was used for all the experiments. Considerable variations of entrance surface air kermas were found for the same organs of different designs, and highest doses were measured for the PMMA slabs. A low contrast test tool and a contrast detail test object (CDRAD) were used together with each organ simulation of PMMA slabs and ANSI phantoms in order to test the clinical image qualities. Digital images of these phantom combinations and anthropomorphic phantoms were acquired in raw and clinically processed formats. Variation of image quality with kVp and post processing was evaluated using the numerical metrics of these test tools and measured contrast values from the anthropomorphic phantoms. Our results indicated that design of some phantoms may not be efficient enough to reveal the expected performance of the post processing algorithms.

  19. Difference Image Analysis of Galactic Microlensing. II. Microlensing Events

    Energy Technology Data Exchange (ETDEWEB)

    Alcock, C.; Allsman, R. A.; Alves, D.; Axelrod, T. S.; Becker, A. C.; Bennett, D. P.; Cook, K. H.; Drake, A. J.; Freeman, K. C.; Griest, K. (and others)

    1999-09-01

    The MACHO collaboration has been carrying out difference image analysis (DIA) since 1996 with the aim of increasing the sensitivity to the detection of gravitational microlensing. This is a preliminary report on the application of DIA to galactic bulge images in one field. We show how the DIA technique significantly increases the number of detected lensing events, by removing the positional dependence of traditional photometry schemes and lowering the microlensing event detection threshold. This technique, unlike PSF photometry, gives the unblended colors and positions of the microlensing source stars. We present a set of criteria for selecting microlensing events from objects discovered with this technique. The 16 pixel and classical microlensing events discovered with the DIA technique are presented. (c) (c) 1999. The American Astronomical Society.

  20. A quantitative image quality comparison of four different image guided radiotherapy devices

    International Nuclear Information System (INIS)

    Stuetzel, Julia; Oelfke, Uwe; Nill, Simeon

    2008-01-01

    Purpose: A study to quantitatively compare the image quality of four different image guided radiotherapy (IGRT) devices based on phantom measurements with respect to the additional dose delivered to the patient. Methods: Images of three different head-sized phantoms (diameter 16-18 cm) were acquired with the following four IGRT-CT solutions: (i) the Siemens Primatom single slice fan beam computed tomography (CT) scanner with an acceleration voltage of 130 kV, (ii) a Tomotherapy HI-ART II unit using a fan beam scanner with an energy of 3.5 MeV and (iii) the Siemens Artiste prototype, providing the possibility to perform kV (121 kV) and MV (6 MV) cone beam (CB) CTs. For each device three scan protocols (named low, normal, high) were selected to yield the same weighted computed tomography dose index (CTDI w ). Based on the individual inserts of the different phantoms the image quality achieved with each device at a certain dose level was characterized in terms of homogeneity, spatial resolution, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and electron density-to-CT-number conversion. Results: Based on the current findings for head-sized phantoms all devices show an electron density-to-CT-number conversion almost independent of the imaging parameters and hence can be suited for treatment planning purposes. The evaluation of the image quality, however, points out clear differences due to the different energies and geometries. The Primatom standard CT scanner shows throughout the best performance, especially for soft tissue contrast and spatial resolution with low imaging doses. Reasonable soft tissue contrast can be obtained with slightly higher doses compared to the CT scanner with the kVCB and the Tomotherapy unit. In order to get similar results with the MVCB system a much higher dose needs to be applied to the patient. Conclusion: Considering the entire investigations, especially in terms of contrast and spatial resolution, a rough tendency for

  1. Characteristics of different frequency ranges in scanning electron microscope images

    International Nuclear Information System (INIS)

    Sim, K. S.; Nia, M. E.; Tan, T. L.; Tso, C. P.; Ee, C. S.

    2015-01-01

    We demonstrate a new approach to characterize the frequency range in general scanning electron microscope (SEM) images. First, pure frequency images are generated from low frequency to high frequency, and then, the magnification of each type of frequency image is implemented. By comparing the edge percentage of the SEM image to the self-generated frequency images, we can define the frequency ranges of the SEM images. Characterization of frequency ranges of SEM images benefits further processing and analysis of those SEM images, such as in noise filtering and contrast enhancement

  2. Characteristics of different frequency ranges in scanning electron microscope images

    Energy Technology Data Exchange (ETDEWEB)

    Sim, K. S., E-mail: kssim@mmu.edu.my; Nia, M. E.; Tan, T. L.; Tso, C. P.; Ee, C. S. [Faculty of Engineering and Technology, Multimedia University, 75450 Melaka (Malaysia)

    2015-07-22

    We demonstrate a new approach to characterize the frequency range in general scanning electron microscope (SEM) images. First, pure frequency images are generated from low frequency to high frequency, and then, the magnification of each type of frequency image is implemented. By comparing the edge percentage of the SEM image to the self-generated frequency images, we can define the frequency ranges of the SEM images. Characterization of frequency ranges of SEM images benefits further processing and analysis of those SEM images, such as in noise filtering and contrast enhancement.

  3. Improved cancer diagnostics by different image processing techniques on OCT images

    Science.gov (United States)

    Kanawade, Rajesh; Lengenfelder, Benjamin; Marini Menezes, Tassiana; Hohmann, Martin; Kopfinger, Stefan; Hohmann, Tim; Grabiec, Urszula; Klämpfl, Florian; Gonzales Menezes, Jean; Waldner, Maximilian; Schmidt, Michael

    2015-07-01

    Optical-coherence tomography (OCT) is a promising non-invasive, high-resolution imaging modality which can be used for cancer diagnosis and its therapeutic assessment. However, speckle noise makes detection of cancer boundaries and image segmentation problematic and unreliable. Therefore, to improve the image analysis for a precise cancer border detection, the performance of different image processing algorithms such as mean, median, hybrid median filter and rotational kernel transformation (RKT) for this task is investigated. This is done on OCT images acquired from an ex-vivo human cancerous mucosa and in vitro by using cultivated tumour applied on organotypical hippocampal slice cultures. The preliminary results confirm that the border between the healthy and the cancer lesions can be identified precisely. The obtained results are verified with fluorescence microscopy. This research can improve cancer diagnosis and the detection of borders between healthy and cancerous tissue. Thus, it could also reduce the number of biopsies required during screening endoscopy by providing better guidance to the physician.

  4. Abdominal MR imaging using a HASTE sequence : image comparison on the different echo times

    International Nuclear Information System (INIS)

    Park, Kwang Bo; Lee, Moon Gyu; Lim, Tae Hwan; Jeong, Yoong Ki; Ha, Hyun Kwon; Kim, Pyo Nyun; Auh, Yong Ho

    1999-01-01

    To determine the optimal parameters of abdominal HASTE imaging by means of a comparison of intermediate and long TE (echo time). We evaluated 30 consecutive patients who had undergone liver MR during a three-month period. Twelve patients were diagnosed as normal, four as having liver cirrhosis, and 14 were found to be suffering form hepatic hemangioma. On the basis of measured signal intensity of the liver, spleen, pancreas and gallbladder, and of fat, muscle, hemangioma, and background, we calculated the ratios of signal to noise (S/N), signal difference to noise (SD/N), and signal intensity (SI). Image quality was compared using these three ratios, and using two HASTE sequences with TEs of 90 msec and 134 msec, images were qualitatively evaluated. S/N ratio of the liver was higher when TE was 90 msec(p<.05), though S/N, SD/N and SI rations of the spleen, gallbladder, and pancreas-and of hemangiom-were higher when TE was 134 msec (p<.05). However, in muscle, all these three ratios were higher at a TE of 90 msec. SD/N ratio and SI of fat were higher at a TE of 134 msec. Overall image quality was better at a TE of 134 msec than at one of 90msec. A HASTE sequence with a TE of 134msec showed greater tissue contrast and stronger T2-weighted images than one with a TE of 90msec

  5. Performances of different digital mammography imaging systems: Evaluation and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Bisogni, M.G. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)]. E-mail: giuseppina.bisogni@pi.infn.it; Bulajic, D. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); International Centre for Theoretical Physics, Trieste (Italy); Delogu, P. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Fantacci, M.E. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Novelli, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Quattrocchi, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Rosso, V. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Stefanini, A. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)

    2005-07-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems.

  6. Performances of different digital mammography imaging systems: Evaluation and comparison

    International Nuclear Information System (INIS)

    Bisogni, M.G.; Bulajic, D.; Delogu, P.; Fantacci, M.E.; Novelli, M.; Quattrocchi, M.; Rosso, V.; Stefanini, A.

    2005-01-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems

  7. Evidential analysis of difference images for change detection of multitemporal remote sensing images

    Science.gov (United States)

    Chen, Yin; Peng, Lijuan; Cremers, Armin B.

    2018-03-01

    In this article, we develop two methods for unsupervised change detection in multitemporal remote sensing images based on Dempster-Shafer's theory of evidence (DST). In most unsupervised change detection methods, the probability of difference image is assumed to be characterized by mixture models, whose parameters are estimated by the expectation maximization (EM) method. However, the main drawback of the EM method is that it does not consider spatial contextual information, which may entail rather noisy detection results with numerous spurious alarms. To remedy this, we firstly develop an evidence theory based EM method (EEM) which incorporates spatial contextual information in EM by iteratively fusing the belief assignments of neighboring pixels to the central pixel. Secondly, an evidential labeling method in the sense of maximizing a posteriori probability (MAP) is proposed in order to further enhance the detection result. It first uses the parameters estimated by EEM to initialize the class labels of a difference image. Then it iteratively fuses class conditional information and spatial contextual information, and updates labels and class parameters. Finally it converges to a fixed state which gives the detection result. A simulated image set and two real remote sensing data sets are used to evaluate the two evidential change detection methods. Experimental results show that the new evidential methods are comparable to other prevalent methods in terms of total error rate.

  8. Effects of chromatic image statistics on illumination induced color differences.

    Science.gov (United States)

    Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels

    2013-09-01

    We measure the color fidelity of visual scenes that are rendered under different (simulated) illuminants and shown on a calibrated LCD display. Observers make triad illuminant comparisons involving the renderings from two chromatic test illuminants and one achromatic reference illuminant shown simultaneously. Four chromatic test illuminants are used: two along the daylight locus (yellow and blue), and two perpendicular to it (red and green). The observers select the rendering having the best color fidelity, thereby indirectly judging which of the two test illuminants induces the smallest color differences compared to the reference. Both multicolor test scenes and natural scenes are studied. The multicolor scenes are synthesized and represent ellipsoidal distributions in CIELAB chromaticity space having the same mean chromaticity but different chromatic orientations. We show that, for those distributions, color fidelity is best when the vector of the illuminant change (pointing from neutral to chromatic) is parallel to the major axis of the scene's chromatic distribution. For our selection of natural scenes, which generally have much broader chromatic distributions, we measure a higher color fidelity for the yellow and blue illuminants than for red and green. Scrambled versions of the natural images are also studied to exclude possible semantic effects. We quantitatively predict the average observer response (i.e., the illuminant probability) with four types of models, differing in the extent to which they incorporate information processing by the visual system. Results show different levels of performance for the models, and different levels for the multicolor scenes and the natural scenes. Overall, models based on the scene averaged color difference have the best performance. We discuss how color constancy algorithms may be improved by exploiting knowledge of the chromatic distribution of the visual scene.

  9. Comparative evaluation of image quality in computed radiology systems using imaging plates with different usage time

    International Nuclear Information System (INIS)

    Lazzaro, M.V.; Luz, R.M. da; Capaverde, A.S.; Silva, A.M. Marques da

    2015-01-01

    Computed Radiology (CR) systems use imaging plates (IPs) for latent image acquisition. Taking into account the quality control (QC) of these systems, imaging plates usage time is undetermined. Different recommendations and publications on the subject suggest tests to evaluate these systems. The objective of this study is to compare the image quality of IPs of a CR system, in a mammography service, considering the usage time and consistency of assessments. 8 IPs were used divided into two groups: the first group included 4 IPs with 3 years of use (Group A); the second group consisted of 4 new IPs with no previous exposure (Group B). The tests used to assess the IP's quality were: Uniformity, Differential Signal to Noise Ratio (SDNR), Ghost Effect and Figure of Merit (FOM). Statistical results show that the proposed tests are shown efficient in assessing the conditions of image quality obtained in CR systems in mammography and can be used as determining factors for the replacement of IP's. Moreover, comparing the two sets of IP, results led to the replacement of all the set of IP’s with 3 years of use. This work demonstrates the importance of an efficient quality control, not only with regard to the quality of IP's used, but in the acquisition system as a whole. From this work, these tests will be conducted on an annual basis, already targeting as future work, monitoring the wear of IP's Group B and the creation of a baseline for analysis and future replacements. (author)

  10. Application of image processing and different types of imaging devices for three-dimensional imaging of coal grains

    OpenAIRE

    Oleszko, K.; Mlynarczuk, M.; Sitek, L. (Libor); Staš, L. (Lubomír)

    2015-01-01

    Precise particle size measurements are important in many aspects of engineering geology, e.g. in mineral processing and the study of methane hazard in coal mines. The volume of grains, estimated exclusively on the basis of dimensions of the grains differs tens of percent from the volume obtained from 3D digital measurements. This confirms that full three-dimensional automatic imaging can be used in the measurements of the particles. The paper discusses the technique of three-dimensional imagi...

  11. 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)

  12. Precision photometry with difference imaging in the WTS

    Directory of Open Access Journals (Sweden)

    Pinfield D.J.

    2013-04-01

    Full Text Available The Wide Field Camera Transit Survey is a pioneer program aimed to search for extra-solar planets in the near-infrared. The standard data reduction pipeline of the program uses aperture photometry to construct the light curves. We alternatively apply the difference imaging method for the most complete field in the survey and carry out a quantitative comparison between the photometric precision of both methods. We also report an implementation on the box-fitting detection algorithm, which performs a trapezoid-fit to the folded light curve. Subsequently we apply a set of selection criteria to the light curves to search for transit candidates, incorporating a parameter to characterize the shape of the transit. We carry out a detailed analysis of 11 candidates and provide a classification scheme to separate binary from planet candidates. Furthermore we report the detection of five faint extremely-short period eclipsing binary systems with periods shorter than 0.23 days and one candidate M-dwarf/M-dwarf eclipsing binary.

  13. Imaging of primary bone tumors in veterinary medicine: Which differences?

    Energy Technology Data Exchange (ETDEWEB)

    Vanel, Maïa, E-mail: maiavanel@yahoo.fr [Diagnostic Imaging Department, Faculty of Veterinary Medicine, University of Montreal, 3200 Rue Sicotte, PO Box 5000, Saint-Hyacinthe, QC (Canada); Blond, Laurent [Diagnostic Imaging Department, Faculty of Veterinary Medicine, University of Montreal, 3200 Rue Sicotte, PO Box 5000, Saint-Hyacinthe, QC (Canada); Vanel, Daniel [The Rizzoli Institute, Via del Barbiano 1-10, 40136, Bologna (Italy)

    2013-12-01

    Veterinary medicine is most often a mysterious world for the human doctors. However, animals are important for human medicine thanks to the numerous biological similarities. Primary bone tumors are not uncommon in veterinary medicine and especially in small domestic animals as dogs and cats. As in human medicine, osteosarcoma is the most common one and especially in the long bones extremities. In the malignant bone tumor family, chondrosarcoma, fibrosarcoma and hemangiosarcoma are following. Benign bone tumors as osteoma, osteochondroma and bone cysts do exist but are rare and of little clinical significance. Diagnostic modalities used depend widely on the owner willing to treat his animal. Radiographs and bone biopsy are the standard to make a diagnosis but CT, nuclear medicine and MRI are more an more used. As amputation is treatment number one in appendicular bone tumor in veterinary medicine, this explains on the one hand why more recent imaging modalities are not always necessary and on the other hand, that pronostic on large animals is so poor that it is not much studied. Chemotherapy is sometimes associated with the surgery procedure, depending on the agressivity of the tumor. Although, the strakes differs a lot between veterinary and human medicine, biological behavior are almost the same and should led to a beneficial team work between all.

  14. Rotating Scheimpflug Imaging Indices in Different Grades of Keratoconus

    Directory of Open Access Journals (Sweden)

    Sherine S. Wahba

    2016-01-01

    Full Text Available Purpose. To evaluate accuracy of various Keratoconus (KC screening indices, in relation to Topographic Keratoconus (TKC grading. Setting. Al Watany Eye Hospital, Cairo, Egypt. Methods. Data of 103 normal (group 1 and 73 KC eyes (group 2, imaged by Pentacam (branded as Allegro Oculyzer, were analysed. Group 2 was divided into 2a: 14 eyes (TKC = 1, early KC, 2b: 25 eyes (TKC = 1 to 2 or 2, moderate KC, and 2c: 34 eyes (TKC = 2 to 3 up to 4, severe KC. Participants were followed up for six years to confirm diagnosis. Area under the receiver operating characteristic curve (AUROC was calculated for evaluated curvature, elevation, and pachymetry indices with various reference shapes at different diameters. Results. When comparing normal to KC eyes, ten indices had significantly higher AUROC. Only five of them had significantly higher AUROC in early KC compared to normal corneas: Pachymetry Progression Index- (PPI- Maximum (Max, Ambrósio’s Relational Thickness- (ART- Max, PPI-Max minus PPI-Minimum (Min, central corneal thickness (CCT, and diagonal decentration of thinnest point from the apex (AUROC = 0.690, 0.690, 0.687, 0.683, and 0.674, resp.. Conclusion. Generally, ten pachymetry and elevation-based indices had significantly higher AUROC. Five indices had statistically significant high AUROC when comparing early KC to normal corneas.

  15. Imaging of primary bone tumors in veterinary medicine: Which differences?

    International Nuclear Information System (INIS)

    Vanel, Maïa; Blond, Laurent; Vanel, Daniel

    2013-01-01

    Veterinary medicine is most often a mysterious world for the human doctors. However, animals are important for human medicine thanks to the numerous biological similarities. Primary bone tumors are not uncommon in veterinary medicine and especially in small domestic animals as dogs and cats. As in human medicine, osteosarcoma is the most common one and especially in the long bones extremities. In the malignant bone tumor family, chondrosarcoma, fibrosarcoma and hemangiosarcoma are following. Benign bone tumors as osteoma, osteochondroma and bone cysts do exist but are rare and of little clinical significance. Diagnostic modalities used depend widely on the owner willing to treat his animal. Radiographs and bone biopsy are the standard to make a diagnosis but CT, nuclear medicine and MRI are more an more used. As amputation is treatment number one in appendicular bone tumor in veterinary medicine, this explains on the one hand why more recent imaging modalities are not always necessary and on the other hand, that pronostic on large animals is so poor that it is not much studied. Chemotherapy is sometimes associated with the surgery procedure, depending on the agressivity of the tumor. Although, the strakes differs a lot between veterinary and human medicine, biological behavior are almost the same and should led to a beneficial team work between all

  16. Fuzzy Matching Based on Gray-scale Difference for Quantum Images

    Science.gov (United States)

    Luo, GaoFeng; Zhou, Ri-Gui; Liu, XingAo; Hu, WenWen; Luo, Jia

    2018-05-01

    Quantum image processing has recently emerged as an essential problem in practical tasks, e.g. real-time image matching. Previous studies have shown that the superposition and entanglement of quantum can greatly improve the efficiency of complex image processing. In this paper, a fuzzy quantum image matching scheme based on gray-scale difference is proposed to find out the target region in a reference image, which is very similar to the template image. Firstly, we employ the proposed enhanced quantum representation (NEQR) to store digital images. Then some certain quantum operations are used to evaluate the gray-scale difference between two quantum images by thresholding. If all of the obtained gray-scale differences are not greater than the threshold value, it indicates a successful fuzzy matching of quantum images. Theoretical analysis and experiments show that the proposed scheme performs fuzzy matching at a low cost and also enables exponentially significant speedup via quantum parallel computation.

  17. Techniques for combining isotopic images obtained at different energies

    International Nuclear Information System (INIS)

    Soussaline, F.; Di Paola, R.; Bazin, J.P.

    1976-01-01

    The technique described should be considered as a first step towards the classification of scintigraphic data where the energy is included. As in all such studies the interpretation of the resulting images is not necessarily at first evident, and certain experience needs to be established. This applies in particular to the images obtained with the higher factors. It is possible that the use of this technique may resolve, without requiring a priori information, the problem previously encountered using the other 'subtraction' type techniques [fr

  18. Accuracy of different imaging modalities prior to biventricular repair ...

    African Journals Online (AJOL)

    Arun Kumar Agnihotri

    catheterization with invasive angiocardiography is indicated when the PA ... arterial and venous imaging.3,4. The major ... history of aorto-pulmonary shunt awaiting bi-ventricular ..... regarding the central and peripheral PAs, APCs as well as in ...

  19. Comparison of peritoneal tumor imaging using conventional MR imaging and diffusion-weighted MR imaging with different b values

    Energy Technology Data Exchange (ETDEWEB)

    Bozkurt, Mahmut [Buhara Private Hospital Department of Radiology, Erzurum (Turkey); Doganay, Selim [Erciyes University, School of Medicine, Department of Radiology, Kayseri (Turkey); Kantarci, Mecit, E-mail: akkanrad@hotmail.com [Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Yalcin, Ahmet; Eren, Suat [Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Atamanalp, S. Selcuk [Atatuerk University, School of Medicine, Department of General Surgery, Erzurum (Turkey); Yuce, Ihsan [Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Yildirgan, M. Ilhan [Atatuerk University, School of Medicine, Department of General Surgery, Erzurum (Turkey)

    2011-11-15

    Purpose: The aim of this study was to evaluate the utility of DW MRI with two different b values in identifying peritoneal tumors in oncology patients. Materials and methods: Nineteen patients with known malignancy underwent abdominal and pelvic MRI before surgery. MRI included free-breathing DWI with b values of 400 and 800 s/mm{sup 2}, T1-weighted fat-suppressed spoiled gradient-echo, T2-weighted fat-saturated turbo spin-echo, and 5-min delayed gadolinium-enhanced imaging. Two observers reviewed images for peritoneal tumors at ten anatomic sites within consensus. The results of laparatomy and histopathological evaluation were compared with MRI results. Sensitivity, specificity, and accuracy of identifying peritoneal metastases were calculated for conventional MRI, combined DWI with a b value of 400 s/mm{sup 2} and conventional MRI, and combined DWI with a b value of 800 s/mm{sup 2} and conventional MRI by consensus of two observers. Results: One-hundred and twenty-five peritoneal metastasis sites were confirmed by surgical and histopathological findings. Conventional MRI alone identified 72 peritoneal metastases (sensitivity, 0.58; specificity, 0.87; accuracy, 0.67). Combined DWI with a b value of 400 s/mm{sup 2} and conventional MRI revealed 106 peritoneal metastases (sensitivity, 0.85; specificity, 0.88; accuracy, 0.85). Finally, combined DWI with a b value of 800 s/mm{sup 2} and conventional MRI revealed 103 peritoneal metastases (sensitivity, 0.83; specificity, 0.94; accuracy, 0.86). Conclusion: DWI with a high b value provides complementary information that can improve the detection of peritoneal tumors when combined with conventional MRI. We recommend combined MRI and DWI with a high b value for increasing the sensitivity and accuracy of the preoperative detection of peritoneal tumors.

  20. Comparison of peritoneal tumor imaging using conventional MR imaging and diffusion-weighted MR imaging with different b values

    International Nuclear Information System (INIS)

    Bozkurt, Mahmut; Doganay, Selim; Kantarci, Mecit; Yalcin, Ahmet; Eren, Suat; Atamanalp, S. Selcuk; Yuce, Ihsan; Yildirgan, M. Ilhan

    2011-01-01

    Purpose: The aim of this study was to evaluate the utility of DW MRI with two different b values in identifying peritoneal tumors in oncology patients. Materials and methods: Nineteen patients with known malignancy underwent abdominal and pelvic MRI before surgery. MRI included free-breathing DWI with b values of 400 and 800 s/mm 2 , T1-weighted fat-suppressed spoiled gradient-echo, T2-weighted fat-saturated turbo spin-echo, and 5-min delayed gadolinium-enhanced imaging. Two observers reviewed images for peritoneal tumors at ten anatomic sites within consensus. The results of laparatomy and histopathological evaluation were compared with MRI results. Sensitivity, specificity, and accuracy of identifying peritoneal metastases were calculated for conventional MRI, combined DWI with a b value of 400 s/mm 2 and conventional MRI, and combined DWI with a b value of 800 s/mm 2 and conventional MRI by consensus of two observers. Results: One-hundred and twenty-five peritoneal metastasis sites were confirmed by surgical and histopathological findings. Conventional MRI alone identified 72 peritoneal metastases (sensitivity, 0.58; specificity, 0.87; accuracy, 0.67). Combined DWI with a b value of 400 s/mm 2 and conventional MRI revealed 106 peritoneal metastases (sensitivity, 0.85; specificity, 0.88; accuracy, 0.85). Finally, combined DWI with a b value of 800 s/mm 2 and conventional MRI revealed 103 peritoneal metastases (sensitivity, 0.83; specificity, 0.94; accuracy, 0.86). Conclusion: DWI with a high b value provides complementary information that can improve the detection of peritoneal tumors when combined with conventional MRI. We recommend combined MRI and DWI with a high b value for increasing the sensitivity and accuracy of the preoperative detection of peritoneal tumors.

  1. EIT Imaging of admittivities with a D-bar method and spatial prior: experimental results for absolute and difference imaging.

    Science.gov (United States)

    Hamilton, S J

    2017-05-22

    Electrical impedance tomography (EIT) is an emerging imaging modality that uses harmless electrical measurements taken on electrodes at a body's surface to recover information about the internal electrical conductivity and or permittivity. The image reconstruction task of EIT is a highly nonlinear inverse problem that is sensitive to noise and modeling errors making the image reconstruction task challenging. D-bar methods solve the nonlinear problem directly, bypassing the need for detailed and time-intensive forward models, to provide absolute (static) as well as time-difference EIT images. Coupling the D-bar methodology with the inclusion of high confidence a priori data results in a noise-robust regularized image reconstruction method. In this work, the a priori D-bar method for complex admittivities is demonstrated effective on experimental tank data for absolute imaging for the first time. Additionally, the method is adjusted for, and tested on, time-difference imaging scenarios. The ability of the method to be used for conductivity, permittivity, absolute as well as time-difference imaging provides the user with great flexibility without a high computational cost.

  2. What difference do brain images make in US criminal trials?

    Science.gov (United States)

    Hardcastle, Valerie Gray; Lamb, Edward

    2018-05-09

    One of the early concerns regarding the use of neuroscience data in criminal trials is that even if the brain images are ambiguous or inconclusive, they still might influence a jury in virtue of the fact that they appear easy to understand. By appearing visually simple, even though they are really statistically constructed maps with a host of assumptions built into them, a lay jury or a judge might take brain scans to be more reliable or relevant than they actually are. Should courts exclude brain scans for being more prejudicial than probative? Herein, we rehearse a brief history of brain scans admitted into criminal trials in the United States, then describe the results of a recent analysis of appellate court decisions that referenced 1 or more brain scans in the judicial decision. In particular, we aim to explain how courts use neuroscience imaging data: Do they interpret the data correctly? Does it seem that scans play an oversized role in judicial decision-making? And have they changed how criminal defendants are judged? It is our hope that in answering these questions, clinicians and defence attorneys will be able to make better informed decisions regarding about how to manage those incarcerated. © 2018 John Wiley & Sons, Ltd.

  3. Integrated NDVI images for Niger 1986-1987. [Normalized Difference Vegetation Index

    Science.gov (United States)

    Harrington, John A., Jr.; Wylie, Bruce K.; Tucker, Compton J.

    1988-01-01

    Two NOAA AVHRR images are presented which provide a comparison of the geographic distribution of an integration of the normalized difference vegetation index (NDVI) for the Sahel zone in Niger for the growing seasons of 1986 and 1987. The production of the images and the application of the images for resource management are discussed. Daily large area coverage with a spatial resolution of 1.1 km at nadir were transformed to the NDVI and geographically registered to produce the images.

  4. Imaging FTS: A Different Approach to Integral Field Spectroscopy

    Directory of Open Access Journals (Sweden)

    Laurent Drissen

    2014-01-01

    Full Text Available Imaging Fourier transform spectroscopy (iFTS is a promising, although technically very challenging, option for wide-field hyperspectral imagery. We present in this paper an introduction to the iFTS concept and its advantages and drawbacks, as well as examples of data obtained with a prototype iFTS, SpIOMM, attached to the 1.6 m telescope of the Observatoire du Mont-Mégantic: emission line ratios in the spiral galaxy NGC 628 and absorption line indices in the giant elliptical M87. We conclude by introducing SpIOMM's successor, SITELLE, which will be installed at the Canada-France-Hawaii Telescope in 2014.

  5. ANALYSIS OF SPECTRAL CHARACTERISTICS AMONG DIFFERENT SENSORS BY USE OF SIMULATED RS IMAGES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This research, by use of RS image-simulating method, simulated apparent reflectance images at sensor level and ground-reflectance images of SPOT-HRV,CBERS-CCD,Landsat-TM and NOAA14-AVHRR' s corresponding bands. These images were used to analyze sensor's differences caused by spectral sensitivity and atmospheric impacts. The differences were analyzed on Normalized Difference Vegetation Index(NDVI). The results showed that the differences of sensors' spectral characteristics cause changes of their NDVI and reflectance. When multiple sensors' data are applied to digital analysis, the error should be taken into account. Atmospheric effect makes NDVI smaller, and atn~pheric correction has the tendency of increasing NDVI values. The reflectance and their NDVIs of different sensors can be used to analyze the differences among sensor' s features. The spectral analysis method based on RS simulated images can provide a new way to design the spectral characteristics of new sensors.

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

    Energy Technology Data Exchange (ETDEWEB)

    Roque, Andreia; Ramalho, Miguel; AlObaidy, Mamdoh; Heredia, Vasco; Burke, Lauren M.; De Campos, Rafael O.P.; Semelka, Richard C. [University of North Carolina at Chapel Hill, Department of Radiology, Chapel Hill, NC (United States)

    2014-10-15

    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.)

  7. Adaptable pattern recognition system for discriminating Melanocytic Nevi from Malignant Melanomas using plain photography images from different image databases.

    Science.gov (United States)

    Kostopoulos, Spiros A; Asvestas, Pantelis A; Kalatzis, Ioannis K; Sakellaropoulos, George C; Sakkis, Theofilos H; Cavouras, Dionisis A; Glotsos, Dimitris T

    2017-09-01

    The aim of this study was to propose features that evaluate pictorial differences between melanocytic nevus (mole) and melanoma lesions by computer-based analysis of plain photography images and to design a cross-platform, tunable, decision support system to discriminate with high accuracy moles from melanomas in different publicly available image databases. Digital plain photography images of verified mole and melanoma lesions were downloaded from (i) Edinburgh University Hospital, UK, (Dermofit, 330moles/70 melanomas, under signed agreement), from 5 different centers (Multicenter, 63moles/25 melanomas, publicly available), and from the Groningen University, Netherlands (Groningen, 100moles/70 melanomas, publicly available). Images were processed for outlining the lesion-border and isolating the lesion from the surrounding background. Fourteen features were generated from each lesion evaluating texture (4), structure (5), shape (4) and color (1). Features were subjected to statistical analysis for determining differences in pictorial properties between moles and melanomas. The Probabilistic Neural Network (PNN) classifier, the exhaustive search features selection, the leave-one-out (LOO), and the external cross-validation (ECV) methods were used to design the PR-system for discriminating between moles and melanomas. Statistical analysis revealed that melanomas as compared to moles were of lower intensity, of less homogenous surface, had more dark pixels with intensities spanning larger spectra of gray-values, contained more objects of different sizes and gray-levels, had more asymmetrical shapes and irregular outlines, had abrupt intensity transitions from lesion to background tissue, and had more distinct colors. The PR-system designed by the Dermofit images scored on the Dermofit images, using the ECV, 94.1%, 82.9%, 96.5% for overall accuracy, sensitivity, specificity, on the Multicenter Images 92.0%, 88%, 93.7% and on the Groningen Images 76.2%, 73.9%, 77

  8. Texture Feature Analysis for Different Resolution Level of Kidney Ultrasound Images

    Science.gov (United States)

    Kairuddin, Wan Nur Hafsha Wan; Mahmud, Wan Mahani Hafizah Wan

    2017-08-01

    Image feature extraction is a technique to identify the characteristic of the image. The objective of this work is to discover the texture features that best describe a tissue characteristic of a healthy kidney from ultrasound (US) image. Three ultrasound machines that have different specifications are used in order to get a different quality (different resolution) of the image. Initially, the acquired images are pre-processed to de-noise the speckle to ensure the image preserve the pixels in a region of interest (ROI) for further extraction. Gaussian Low- pass Filter is chosen as the filtering method in this work. 150 of enhanced images then are segmented by creating a foreground and background of image where the mask is created to eliminate some unwanted intensity values. Statistical based texture features method is used namely Intensity Histogram (IH), Gray-Level Co-Occurance Matrix (GLCM) and Gray-level run-length matrix (GLRLM).This method is depends on the spatial distribution of intensity values or gray levels in the kidney region. By using One-Way ANOVA in SPSS, the result indicated that three features (Contrast, Difference Variance and Inverse Difference Moment Normalized) from GLCM are not statistically significant; this concludes that these three features describe a healthy kidney characteristics regardless of the ultrasound image quality.

  9. 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)

  10. Effect of using different cover image quality to obtain robust selective embedding in steganography

    Science.gov (United States)

    Abdullah, Karwan Asaad; Al-Jawad, Naseer; Abdulla, Alan Anwer

    2014-05-01

    One of the common types of steganography is to conceal an image as a secret message in another image which normally called a cover image; the resulting image is called a stego image. The aim of this paper is to investigate the effect of using different cover image quality, and also analyse the use of different bit-plane in term of robustness against well-known active attacks such as gamma, statistical filters, and linear spatial filters. The secret messages are embedded in higher bit-plane, i.e. in other than Least Significant Bit (LSB), in order to resist active attacks. The embedding process is performed in three major steps: First, the embedding algorithm is selectively identifying useful areas (blocks) for embedding based on its lighting condition. Second, is to nominate the most useful blocks for embedding based on their entropy and average. Third, is to select the right bit-plane for embedding. This kind of block selection made the embedding process scatters the secret message(s) randomly around the cover image. Different tests have been performed for selecting a proper block size and this is related to the nature of the used cover image. Our proposed method suggests a suitable embedding bit-plane as well as the right blocks for the embedding. Experimental results demonstrate that different image quality used for the cover images will have an effect when the stego image is attacked by different active attacks. Although the secret messages are embedded in higher bit-plane, but they cannot be recognised visually within the stegos image.

  11. Histogram-based normalization technique on human brain magnetic resonance images from different acquisitions.

    Science.gov (United States)

    Sun, Xiaofei; Shi, Lin; Luo, Yishan; Yang, Wei; Li, Hongpeng; Liang, Peipeng; Li, Kuncheng; Mok, Vincent C T; Chu, Winnie C W; Wang, Defeng

    2015-07-28

    Intensity normalization is an important preprocessing step in brain magnetic resonance image (MRI) analysis. During MR image acquisition, different scanners or parameters would be used for scanning different subjects or the same subject at a different time, which may result in large intensity variations. This intensity variation will greatly undermine the performance of subsequent MRI processing and population analysis, such as image registration, segmentation, and tissue volume measurement. In this work, we proposed a new histogram normalization method to reduce the intensity variation between MRIs obtained from different acquisitions. In our experiment, we scanned each subject twice on two different scanners using different imaging parameters. With noise estimation, the image with lower noise level was determined and treated as the high-quality reference image. Then the histogram of the low-quality image was normalized to the histogram of the high-quality image. The normalization algorithm includes two main steps: (1) intensity scaling (IS), where, for the high-quality reference image, the intensities of the image are first rescaled to a range between the low intensity region (LIR) value and the high intensity region (HIR) value; and (2) histogram normalization (HN),where the histogram of low-quality image as input image is stretched to match the histogram of the reference image, so that the intensity range in the normalized image will also lie between LIR and HIR. We performed three sets of experiments to evaluate the proposed method, i.e., image registration, segmentation, and tissue volume measurement, and compared this with the existing intensity normalization method. It is then possible to validate that our histogram normalization framework can achieve better results in all the experiments. It is also demonstrated that the brain template with normalization preprocessing is of higher quality than the template with no normalization processing. We have proposed

  12. Script Identification from Printed Indian Document Images and Performance Evaluation Using Different Classifiers

    OpenAIRE

    Sk Md Obaidullah; Anamika Mondal; Nibaran Das; Kaushik Roy

    2014-01-01

    Identification of script from document images is an active area of research under document image processing for a multilingual/ multiscript country like India. In this paper the real life problem of printed script identification from official Indian document images is considered and performances of different well-known classifiers are evaluated. Two important evaluating parameters, namely, AAR (average accuracy rate) and MBT (model building time), are computed for this performance analysi...

  13. Differences of Perceived Image Generated through the Web Site: Empirical Evidence Obtained in Spanish Destinations

    Science.gov (United States)

    Blazquez-Resino, Juan J.; Muro-Rodriguez, Ana I.; Perez-Jimenez, Israel R.

    2016-01-01

    In this paper, a study of the perceived destination image created by promotional Web Pages is expounded in an attempt to identify their differences as generators of destination image in the consumers' mind. Specifically, it seeks to analyse whether the web sites of different Spanish regions improve the image that consumers have of the destination, identifying their main dimensions and analysing its effect on satisfaction and intentions of the future behavior of potential visitors. To achieve these objectives and verify the hypotheses, a laboratory experiment was performed, where it was determined what changes are produced in the tourist's previous image after browsing the tourist webs of three different regions. Moreover, it analyses the differences in the effect of the perceived image on satisfaction and potential visitors' future behavioral intentions. The results obtained enable us to identify differences in the composition of the perceived image according to the destination, while confirming the significant effect of different perceived image dimensions regarding satisfaction. The results allow managers to gain a better understanding of the effectiveness of their sites from a consumer perspective as well as suggestions to follow in order to achieve greater efficiency in their communication actions in order to improve the motivation of visitors to go to the destination. PMID:27933027

  14. Differences of perceived image generated through the Web site: Empirical Evidence Obtained in Spanish Destinations

    Directory of Open Access Journals (Sweden)

    Juan Jose Blazquez-Resino

    2016-11-01

    Full Text Available In this paper, a study of the perceived destination image created by promotional Web Pages is expounded in an attempt to identify their differences as generators of destination image in the consumers’ mind. Specifically, it seeks to analyse whether the web sites of different Spanish regions improve the image that consumers have of the destination, identifying their main dimensions and analysing its effect on satisfaction and intentions of the future behaviour of potential visitors. To achieve these objectives and verify the hypotheses, a laboratory experiment was performed, where it was determined what changes are produced in the tourist´s previous image after browsing the tourist webs of three different regions. Moreover, it analyses the differences in the effect of the perceived image on satisfaction and potential visitors´ future behavioural intentions. The results obtained enable us to identify differences in the composition of the perceived image according to the destination, while confirming the significant effect of different perceived image dimensions regarding satisfaction. The results allow managers to gain a better understanding of the effectiveness of their sites from a consumer perspective as well as suggestions to follow in order to achieve greater efficiency in their communication actions in order to improve the motivation of visitors to go to the destination.

  15. Comparison of different reconstruction algorithms for three-dimensional ultrasound imaging in a neurosurgical setting.

    Science.gov (United States)

    Miller, D; Lippert, C; Vollmer, F; Bozinov, O; Benes, L; Schulte, D M; Sure, U

    2012-09-01

    Freehand three-dimensional ultrasound imaging (3D-US) is increasingly used in image-guided surgery. During image acquisition, a set of B-scans is acquired that is distributed in a non-parallel manner over the area of interest. Reconstructing these images into a regular array allows 3D visualization. However, the reconstruction process may introduce artefacts and may therefore reduce image quality. The aim of the study is to compare different algorithms with respect to image quality and diagnostic value for image guidance in neurosurgery. 3D-US data sets were acquired during surgery of various intracerebral lesions using an integrated ultrasound-navigation device. They were stored for post-hoc evaluation. Five different reconstruction algorithms, a standard multiplanar reconstruction with interpolation (MPR), a pixel nearest neighbour method (PNN), a voxel nearest neighbour method (VNN) and two voxel based distance-weighted algorithms (VNN2 and DW) were tested with respect to image quality and artefact formation. The capability of the algorithm to fill gaps within the sample volume was investigated and a clinical evaluation with respect to the diagnostic value of the reconstructed images was performed. MPR was significantly worse than the other algorithms in filling gaps. In an image subtraction test, VNN2 and DW reliably reconstructed images even if large amounts of data were missing. However, the quality of the reconstruction improved, if data acquisition was performed in a structured manner. When evaluating the diagnostic value of reconstructed axial, sagittal and coronal views, VNN2 and DW were judged to be significantly better than MPR and VNN. VNN2 and DW could be identified as robust algorithms that generate reconstructed US images with a high diagnostic value. These algorithms improve the utility and reliability of 3D-US imaging during intraoperative navigation. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Comparison of virtual unenhanced CT images of the abdomen under different iodine flow rates.

    Science.gov (United States)

    Li, Yongrui; Li, Ye; Jackson, Alan; Li, Xiaodong; Huang, Ning; Guo, Chunjie; Zhang, Huimao

    2017-01-01

    To assess the effect of varying iodine flow rate (IFR) and iodine concentration on the quality of virtual unenhanced (VUE) images of the abdomen obtained with dual-energy CT. 94 subjects underwent unenhanced and triphasic contrast-enhanced CT scan of the abdomen, including arterial phase, portal venous phase, and delayed phase using dual-energy CT. Patients were randomized into 4 groups with different IFRs or iodine concentrations. VUE images were generated at 70 keV. The CT values, image noise, SNR and CNR of aorta, portal vein, liver, liver lesion, pancreatic parenchyma, spleen, erector spinae, and retroperitoneal fat were recorded. Dose-length product and effective dose for an examination with and without plain phase scan were calculated to assess the potential dose savings. Two radiologists independently assessed subjective image quality using a five-point scale. The Kolmogorov-Smirnov test was used first to test for normal distribution. Where data conformed to a normal distribution, analysis of variance was used to compare mean HU values, image noise, SNRs and CNRs for the 4 image sets. Where data distribution was not normal, a nonparametric test (Kruskal-Wallis test followed by stepwise step-down comparisons) was used. The significance level for all tests was 0.01 (two-sided) to allow for type 2 errors due to multiple testing. The CT numbers (HU) of VUE images showed no significant differences between the 4 groups (p > 0.05) or between different phases within the same group (p > 0.05). VUE images had equal or higher SNR and CNR than true unenhanced images. VUE images received equal or lower subjective image quality scores than unenhanced images but were of acceptable quality for diagnostic use. Calculated dose-length product and estimated dose showed that the use of VUE images in place of unenhanced images would be associated with a dose saving of 25%. VUE images can replace conventional unenhanced images. VUE images are not affected by varying iodine

  17. Improved image quality and detectability of hypovascular liver metastases on DECT with different adjusted window settings

    Energy Technology Data Exchange (ETDEWEB)

    Altenbernd, Jens; Forsting, Michael; Lauenstein, Thomas; Wetter, Axel [Duisburg-Essen Univ., Essen (Germany). Dept. of Diagnostic and Interventional Radiology and Neuroradiology

    2017-03-15

    To investigate dual-energy CT of hypovascular liver metastases (LMs) with special focus on window settings (WSs). The aim of the study is to investigate the extent to which adapted WSs and the low-energy images of DECT improve the visibility especially of smaller LMs. 30 patients with LMs of colorectal cancer were investigated with DECT of the liver. In each patient contrast-enhanced DECT imaging with portal-venous delay was performed. The total number, mean number and conspicuity (1= excellent - 5 = poor) of LMs were documented on 80-kVp images and virtual 120-kVp images with different WSs (25/200 HU, 50/200, 75/200 HU, 25/350 HU, 50/350 HU, 75/350 HU, 25/500 HU, 50/500 HU, 75/500 HU). The attenuation (HU) of LMs and several anatomic regions and the background noise on 80 kVp images and virtual 120 kVp images were documented. Signal (liver)/noise and liver/LM ratio (SNR/LLMR) were calculated. The total number of LMs depending on size (<1cm, 1-2cm, >2cm) on 80 kVp images and virtual 120 kVp images with previously investigated best and regular WSs were documented. The highest total number, mean number per patient and total number of LMs <1cm were detected with the WS 25/350 HU on 80kVp images (7.0; p = 0.02/218; p = 0.01/64;p<0.001) compared to the WS 75/200 HU on virtual 120 kVp images and the regular WS 50/350 HU on 80 kVp images and virtual 120 kVp images. The best conspicuity of LMs on 80 kVp images was documented with the WS 25/350 HU compared to the best WS on virtual 120 kVp images with 75/200 HU (1.2 vs. 2.5; p = 0.01). HU of normal liver, aorta, SNR and LLMR differed significantly between 80 kVp images and virtual 120 kVp images (128.1 vs. 93.6; < 0.05/192.8 vs. 131.4; < 0.05/10.3 vs. 8.1; p < 0.05/2.8 vs. 2.1; p < 0.05). Low kVp images of DECT datasets are more precise in detecting hypovascular liver metastases than virtual 120 kVp images. Dedicated window settings have a relevant influence on conspicuity.

  18. Imaging tumor hypoxia: Blood-borne delivery of imaging agents is fundamentally different in hypoxia subtypes

    Directory of Open Access Journals (Sweden)

    Peter Vaupel

    2014-03-01

    Full Text Available Hypoxic tissue subvolumes are a hallmark feature of solid malignant tumors, relevant for cancer therapy and patient outcome because they increase both the intrinsic aggressiveness of tumor cells and their resistance to several commonly used anticancer strategies. Pathogenetic mechanisms leading to hypoxia are diverse, may coexist within the same tumor and are commonly grouped according to the duration of their effects. Chronic hypoxia is mainly caused by diffusion limitations resulting from enlarged intercapillary distances and adverse diffusion geometries and — to a lesser extent — by hypoxemia, compromised perfusion or long-lasting microregional flow stops. Conversely, acute hypoxia preferentially results from transient disruptions in perfusion. While each of these features of the tumor microenvironment can contribute to a critical reduction of oxygen availability, the delivery of imaging agents (as well as nutrients and anticancer agents may be compromised or remain unaffected. Thus, a critical appraisal of the effects of the various mechanisms leading to hypoxia with regard to the blood-borne delivery of imaging agents is necessary to judge their ability to correctly represent the hypoxic phenotype of solid malignancies.

  19. Application of image processing and different types of imaging devices for three-dimensional imaging of coal grains

    Czech Academy of Sciences Publication Activity Database

    Oleszko, K.; Mlynarczuk, M.; Sitek, Libor; Staš, Lubomír

    2015-01-01

    Roč. 196, September 2015 (2015), s. 286-292 ISSN 0013-7952 R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : 3D imaging * computed tomography * grain size * confocal microscope * optical profilometery Subject RIV: JQ - Machines ; Tools Impact factor: 2.196, year: 2015 http://www.sciencedirect.com/science/article/pii/S001379521530020X#

  20. Image Quality Assessment for Different Wavelet Compression Techniques in a Visual Communication Framework

    Directory of Open Access Journals (Sweden)

    Nuha A. S. Alwan

    2013-01-01

    Full Text Available Images with subband coding and threshold wavelet compression are transmitted over a Rayleigh communication channel with additive white Gaussian noise (AWGN, after quantization and 16-QAM modulation. A comparison is made between these two types of compression using both mean square error (MSE and structural similarity (SSIM image quality assessment (IQA criteria applied to the reconstructed image at the receiver. The two methods yielded comparable SSIM but different MSE measures. In this work, we justify our results which support previous findings in the literature that the MSE between two images is not indicative of structural similarity or the visibility of errors. It is found that it is difficult to reduce the pointwise errors in subband-compressed images (higher MSE. However, the compressed images provide comparable SSIM or perceived quality for both types of compression provided that the retained energy after compression is the same.

  1. Quasi-simultaneous OCT en-face imaging with two different depth resolutions

    International Nuclear Information System (INIS)

    Podoleanu, Adrian Gh; Cucu, Radu G; Rosen, Richard B; Dobre, George M; Rogers, John A; Jackson, David A

    2003-01-01

    We report a system capable of acquiring two quasi-simultaneous en-face optical coherence tomography (OCT) images of different depth resolution (one better than 20 μm and the other between 80 and 330 μm) at a frame rate of 2 Hz. The larger depth resolution image makes it ideal for target positioning in the OCT imaging of moving organs, such as eye fundus and cornea, as well as in the alignment of stacks of en-face OCT images. This role is similar to that of the confocal channel in a previously reported dual channel OCT/confocal imaging instrument. The system presented operates as a dual channel imaging instrument, where both channels operate on the OCT principle. We illustrate the functionality of the system with examples from a coin, skin from a finger and optic nerve in vivo

  2. Joint depth map and color consistency estimation for stereo images with different illuminations and cameras.

    Science.gov (United States)

    Heo, Yong Seok; Lee, Kyoung Mu; Lee, Sang Uk

    2013-05-01

    Abstract—In this paper, we propose a method that infers both accurate depth maps and color-consistent stereo images for radiometrically varying stereo images. In general, stereo matching and performing color consistency between stereo images are a chicken-and-egg problem since it is not a trivial task to simultaneously achieve both goals. Hence, we have developed an iterative framework in which these two processes can boost each other. First, we transform the input color images to log-chromaticity color space, from which a linear relationship can be established during constructing a joint pdf of transformed left and right color images. From this joint pdf, we can estimate a linear function that relates the corresponding pixels in stereo images. Based on this linear property, we present a new stereo matching cost by combining Mutual Information (MI), SIFT descriptor, and segment-based plane-fitting to robustly find correspondence for stereo image pairs which undergo radiometric variations. Meanwhile, we devise a Stereo Color Histogram Equalization (SCHE) method to produce color-consistent stereo image pairs, which conversely boost the disparity map estimation. Experimental results show that our method produces both accurate depth maps and color-consistent stereo images, even for stereo images with severe radiometric differences.

  3. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Smoothed Normalized Difference Vegetation Index (NDVI) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Visible Infrared Imaging Radiometer Suite (VIIRS) Smoothed Normalized Difference Vegetation Index (NDVI) from NDE is a weekly product derived from the VIIRS...

  4. Program for PET image alignment: Effects on calculated differences in cerebral metabolic rates for glucose

    International Nuclear Information System (INIS)

    Phillips, R.L.; London, E.D.; Links, J.M.; Cascella, N.G.

    1990-01-01

    A program was developed to align positron emission tomography images from multiple studies on the same subject. The program allowed alignment of two images with a fineness of one-tenth the width of a pixel. The indications and effects of misalignment were assessed in eight subjects from a placebo-controlled double-blind crossover study on the effects of cocaine on regional cerebral metabolic rates for glucose. Visual examination of a difference image provided a sensitive and accurate tool for assessing image alignment. Image alignment within 2.8 mm was essential to reduce variability of measured cerebral metabolic rates for glucose. Misalignment by this amount introduced errors on the order of 20% in the computed metabolic rate for glucose. These errors propagate to the difference between metabolic rates for a subject measured in basal versus perturbed states

  5. Investigation on principle of polarization-difference imaging in turbid conditions

    Science.gov (United States)

    Ren, Wei; Guan, Jinge

    2018-04-01

    We investigate the principle of polarization-difference imaging (PDI) of objects in optically scattering environments. The work is performed by both Marius's law and Mueller-Stokes formalism, and is further demonstrated by simulation. The results show that the object image is obtained based on the difference in polarization direction between the scatter noise and the target signal, and imaging performance is closely related to the choice of polarization analyzer axis. In addition, this study illustrates the potential of Stoke vector for promoting application of PDI system in the real world scene.

  6. Development of an adaptive bilateral filter for evaluating color image difference

    Science.gov (United States)

    Wang, Zhaohui; Hardeberg, Jon Yngve

    2012-04-01

    Spatial filtering, which aims to mimic the contrast sensitivity function (CSF) of the human visual system (HVS), has previously been combined with color difference formulae for measuring color image reproduction errors. These spatial filters attenuate imperceptible information in images, unfortunately including high frequency edges, which are believed to be crucial in the process of scene analysis by the HVS. The adaptive bilateral filter represents a novel approach, which avoids the undesirable loss of edge information introduced by CSF-based filtering. The bilateral filter employs two Gaussian smoothing filters in different domains, i.e., spatial domain and intensity domain. We propose a method to decide the parameters, which are designed to be adaptive to the corresponding viewing conditions, and the quantity and homogeneity of information contained in an image. Experiments and discussions are given to support the proposal. A series of perceptual experiments were conducted to evaluate the performance of our approach. The experimental sample images were reproduced with variations in six image attributes: lightness, chroma, hue, compression, noise, and sharpness/blurriness. The Pearson's correlation values between the model-predicted image difference and the observed difference were employed to evaluate the performance, and compare it with that of spatial CIELAB and image appearance model.

  7. Quantitative comparison of OSEM and penalized likelihood image reconstruction using relative difference penalties for clinical PET

    International Nuclear Information System (INIS)

    Ahn, Sangtae; Asma, Evren; Cheng, Lishui; Manjeshwar, Ravindra M; Ross, Steven G; Miao, Jun; Jin, Xiao; Wollenweber, Scott D

    2015-01-01

    Ordered subset expectation maximization (OSEM) is the most widely used algorithm for clinical PET image reconstruction. OSEM is usually stopped early and post-filtered to control image noise and does not necessarily achieve optimal quantitation accuracy. As an alternative to OSEM, we have recently implemented a penalized likelihood (PL) image reconstruction algorithm for clinical PET using the relative difference penalty with the aim of improving quantitation accuracy without compromising visual image quality. Preliminary clinical studies have demonstrated visual image quality including lesion conspicuity in images reconstructed by the PL algorithm is better than or at least as good as that in OSEM images. In this paper we evaluate lesion quantitation accuracy of the PL algorithm with the relative difference penalty compared to OSEM by using various data sets including phantom data acquired with an anthropomorphic torso phantom, an extended oval phantom and the NEMA image quality phantom; clinical data; and hybrid clinical data generated by adding simulated lesion data to clinical data. We focus on mean standardized uptake values and compare them for PL and OSEM using both time-of-flight (TOF) and non-TOF data. The results demonstrate improvements of PL in lesion quantitation accuracy compared to OSEM with a particular improvement in cold background regions such as lungs. (paper)

  8. Study of CT head scans using different voltages: image quality evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco de Freitas C, I.; Prata M, A. [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil); Alonso, T. C. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P., E-mail: iarapfcorrea@gmail.com [Universidade Federal de Minas Gerais, Departamento de Anatomia e Imagem, Av. Prof. Alfredo Balena 190, 30130-100 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  9. Study of CT head scans using different voltages: image quality evaluation

    International Nuclear Information System (INIS)

    Pacheco de Freitas C, I.; Prata M, A.; Alonso, T. C.; Santana, P.

    2016-10-01

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  10. Impact of Medical Therapy on Atheroma Volume Measured by Different Cardiovascular Imaging Modalities

    Directory of Open Access Journals (Sweden)

    Mohamad C. N. Sinno

    2010-01-01

    Full Text Available Atherosclerosis is a systemic disease that affects most vascular beds. The gold standard of atherosclerosis imaging has been invasive intravascular ultrasound (IVUS. Newer noninvasive imaging modalities like B-mode ultrasound, cardiac computed tomography (CT, positron emission tomography (PET, and magnetic resonance imaging (MRI have been used to assess these vascular territories with high accuracy and reproducibility. These imaging modalities have lately been used for the assessment of the atherosclerotic plaque and the response of its volume to several medical therapies used in the treatment of patients with cardiovascular disease. To study the impact of these medications on atheroma volume progression or regression, imaging modalities have been used on a serial basis providing a unique opportunity to monitor the effect these antiatherosclerotic strategies exert on plaque burden. As a result, studies incorporating serial IVUS imaging, quantitative coronary angiography (QCA, B-mode ultrasound, electron beam computed tomography (EBCT, and dynamic contrast-enhanced magnetic resonance imaging have all been used to evaluate the impact of therapeutic strategies that modify cholesterol and blood pressure on the progression/regression of atherosclerotic plaque. In this review, we intend to summarize the impact of different therapies aimed at halting the progression or even result in regression of atherosclerotic cardiovascular disease evaluated by different imaging modalities.

  11. Face Recognition for Access Control Systems Combining Image-Difference Features Based on a Probabilistic Model

    Science.gov (United States)

    Miwa, Shotaro; Kage, Hiroshi; Hirai, Takashi; Sumi, Kazuhiko

    We propose a probabilistic face recognition algorithm for Access Control System(ACS)s. Comparing with existing ACSs using low cost IC-cards, face recognition has advantages in usability and security that it doesn't require people to hold cards over scanners and doesn't accept imposters with authorized cards. Therefore face recognition attracts more interests in security markets than IC-cards. But in security markets where low cost ACSs exist, price competition is important, and there is a limitation on the quality of available cameras and image control. Therefore ACSs using face recognition are required to handle much lower quality images, such as defocused and poor gain-controlled images than high security systems, such as immigration control. To tackle with such image quality problems we developed a face recognition algorithm based on a probabilistic model which combines a variety of image-difference features trained by Real AdaBoost with their prior probability distributions. It enables to evaluate and utilize only reliable features among trained ones during each authentication, and achieve high recognition performance rates. The field evaluation using a pseudo Access Control System installed in our office shows that the proposed system achieves a constant high recognition performance rate independent on face image qualities, that is about four times lower EER (Equal Error Rate) under a variety of image conditions than one without any prior probability distributions. On the other hand using image difference features without any prior probabilities are sensitive to image qualities. We also evaluated PCA, and it has worse, but constant performance rates because of its general optimization on overall data. Comparing with PCA, Real AdaBoost without any prior distribution performs twice better under good image conditions, but degrades to a performance as good as PCA under poor image conditions.

  12. RADIOMETRIC NORMALIZATION OF LARGE AIRBORNE IMAGE DATA SETS ACQUIRED BY DIFFERENT SENSOR TYPES

    Directory of Open Access Journals (Sweden)

    S. Gehrke

    2016-06-01

    Full Text Available Generating seamless mosaics of aerial images is a particularly challenging task when the mosaic comprises a large number of im-ages, collected over longer periods of time and with different sensors under varying imaging conditions. Such large mosaics typically consist of very heterogeneous image data, both spatially (different terrain types and atmosphere and temporally (unstable atmo-spheric properties and even changes in land coverage. We present a new radiometric normalization or, respectively, radiometric aerial triangulation approach that takes advantage of our knowledge about each sensor’s properties. The current implementation supports medium and large format airborne imaging sensors of the Leica Geosystems family, namely the ADS line-scanner as well as DMC and RCD frame sensors. A hierarchical modelling – with parameters for the overall mosaic, the sensor type, different flight sessions, strips and individual images – allows for adaptation to each sensor’s geometric and radiometric properties. Additional parameters at different hierarchy levels can compensate radiome-tric differences of various origins to compensate for shortcomings of the preceding radiometric sensor calibration as well as BRDF and atmospheric corrections. The final, relative normalization is based on radiometric tie points in overlapping images, absolute radiometric control points and image statistics. It is computed in a global least squares adjustment for the entire mosaic by altering each image’s histogram using a location-dependent mathematical model. This model involves contrast and brightness corrections at radiometric fix points with bilinear interpolation for corrections in-between. The distribution of the radiometry fixes is adaptive to each image and generally increases with image size, hence enabling optimal local adaptation even for very long image strips as typi-cally captured by a line-scanner sensor. The normalization approach is implemented in

  13. Evaluation of different physical parameters that affect the clinical image quality for gamma camera by using different radionuclides

    International Nuclear Information System (INIS)

    Salah, F.A.; Ziada, G.; Hejazy, M.A.; Khalil, W.A.

    2008-01-01

    Some scintillation camera manufactures adhere to standard code of performance specification established by National Electric Manufactures Association (NEMA). Items such as differential and integral uniformity, spatial resolution energy resolution, etc. are all calculated with reproducible methodology that allows the user reliable technique for creation of these standards to avoid any lack of clinical service that may violate the ethics of patient care. Because 99m Tc is the most frequently used radionuclide in nuclear medicine, many clinics perform the daily uniformity and weekly resolution checks using this radionuclide. But when other commonly used radionuclide such as Tl-201,Ga-67 and I-131 are used, no standardized quality control is performed. So in these study we perform to evaluate the response of ADAC(digital) gamma camera and SELO(analogue) gamma camera to four radionuclide (Tl-201,Ga-67, I-131, and 99m Tc) flood image acquired using different non-uniformity correction tables. In the planer study uniformity and resolution images were obtained using ADAC and SELO cameras, linearity was obtained only by ADAC camera, while in the SPECT study uniformity and contrast images were obtained using ADAC camera only. The response for using different non-uniformity correction tables acquired using different isotopes was different from gamma camera model to another. We can conclude that the most of the gamma camera quality control parameters (uniformity, resolution and contrast) are influenced by variation in the correction tables, while other parameters not affected by this variation like linearity. (author)

  14. COMPARISON OF BACKGROUND SUBTRACTION, SOBEL, ADAPTIVE MOTION DETECTION, FRAME DIFFERENCES, AND ACCUMULATIVE DIFFERENCES IMAGES ON MOTION DETECTION

    Directory of Open Access Journals (Sweden)

    Dara Incam Ramadhan

    2018-02-01

    Full Text Available Nowadays, digital image processing is not only used to recognize motionless objects, but also used to recognize motions objects on video. One use of moving object recognition on video is to detect motion, which implementation can be used on security cameras. Various methods used to detect motion have been developed so that in this research compared some motion detection methods, namely Background Substraction, Adaptive Motion Detection, Sobel, Frame Differences and Accumulative Differences Images (ADI. Each method has a different level of accuracy. In the background substraction method, the result obtained 86.1% accuracy in the room and 88.3% outdoors. In the sobel method the result of motion detection depends on the lighting conditions of the room being supervised. When the room is in bright condition, the accuracy of the system decreases and when the room is dark, the accuracy of the system increases with an accuracy of 80%. In the adaptive motion detection method, motion can be detected with a condition in camera visibility there is no object that is easy to move. In the frame difference method, testing on RBG image using average computation with threshold of 35 gives the best value. In the ADI method, the result of accuracy in motion detection reached 95.12%.

  15. Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

    International Nuclear Information System (INIS)

    Rimondini, A.; Mucelli, R.P.; Dalla Palma, L.; De Denaro, M.; Bregant, P.

    2001-01-01

    The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6±0.8 mGy; protocol B 14.4±0.6 mGy; protocol C 12.5±1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality. (orig.)

  16. Image and Imaging an Emergency Department: Expense and Benefit of Different Quality Assessment Methods

    Directory of Open Access Journals (Sweden)

    Carmen Andrea Pfortmueller

    2013-01-01

    Full Text Available Introduction. In this era of high-tech medicine, it is becoming increasingly important to assess patient satisfaction. There are several methods to do so, but these differ greatly in terms of cost, time, and labour and external validity. The aim of this study is to describe and compare the structure and implementation of different methods to assess the satisfaction of patients in an emergency department. Methods. The structure and implementation of the different methods to assess patient satisfaction were evaluated on the basis of a 90-minute standardised interview. Results. We identified a total of six different methods in six different hospitals. The average number of patients assessed was 5012, with a range from 230 (M5 to 20 000 patients (M2. In four methods (M1, M3, M5, and M6, the questionnaire was composed by a specialised external institute. In two methods, the questionnaire was created by the hospital itself (M2, M4.The median response rate was 58.4% (range 9–97.8%. With a reminder, the response rate increased by 60% (M3. Conclusion. The ideal method to assess patient satisfaction in the emergency department setting is to use a patient-based, in-emergency department-based assessment of patient satisfaction, planned and guided by expert personnel.

  17. Image Structure-Preserving Denoising Based on Difference Curvature Driven Fractional Nonlinear Diffusion

    Directory of Open Access Journals (Sweden)

    Xuehui Yin

    2015-01-01

    Full Text Available The traditional integer-order partial differential equations and gradient regularization based image denoising techniques often suffer from staircase effect, speckle artifacts, and the loss of image contrast and texture details. To address these issues, in this paper, a difference curvature driven fractional anisotropic diffusion for image noise removal is presented, which uses two new techniques, fractional calculus and difference curvature, to describe the intensity variations in images. The fractional-order derivatives information of an image can deal well with the textures of the image and achieve a good tradeoff between eliminating speckle artifacts and restraining staircase effect. The difference curvature constructed by the second order derivatives along the direction of gradient of an image and perpendicular to the gradient can effectively distinguish between ramps and edges. Fourier transform technique is also proposed to compute the fractional-order derivative. Experimental results demonstrate that the proposed denoising model can avoid speckle artifacts and staircase effect and preserve important features such as curvy edges, straight edges, ramps, corners, and textures. They are obviously superior to those of traditional integral based methods. The experimental results also reveal that our proposed model yields a good visual effect and better values of MSSIM and PSNR.

  18. An Improved Variational Method for Hyperspectral Image Pansharpening with the Constraint of Spectral Difference Minimization

    Science.gov (United States)

    Huang, Z.; Chen, Q.; Shen, Y.; Chen, Q.; Liu, X.

    2017-09-01

    Variational pansharpening can enhance the spatial resolution of a hyperspectral (HS) image using a high-resolution panchromatic (PAN) image. However, this technology may lead to spectral distortion that obviously affect the accuracy of data analysis. In this article, we propose an improved variational method for HS image pansharpening with the constraint of spectral difference minimization. We extend the energy function of the classic variational pansharpening method by adding a new spectral fidelity term. This fidelity term is designed following the definition of spectral angle mapper, which means that for every pixel, the spectral difference value of any two bands in the HS image is in equal proportion to that of the two corresponding bands in the pansharpened image. Gradient descent method is adopted to find the optimal solution of the modified energy function, and the pansharpened image can be reconstructed. Experimental results demonstrate that the constraint of spectral difference minimization is able to preserve the original spectral information well in HS images, and reduce the spectral distortion effectively. Compared to original variational method, our method performs better in both visual and quantitative evaluation, and achieves a good trade-off between spatial and spectral information.

  19. Comparison of image features calculated in different dimensions for computer-aided diagnosis of lung nodules

    Science.gov (United States)

    Xu, Ye; Lee, Michael C.; Boroczky, Lilla; Cann, Aaron D.; Borczuk, Alain C.; Kawut, Steven M.; Powell, Charles A.

    2009-02-01

    Features calculated from different dimensions of images capture quantitative information of the lung nodules through one or multiple image slices. Previously published computer-aided diagnosis (CADx) systems have used either twodimensional (2D) or three-dimensional (3D) features, though there has been little systematic analysis of the relevance of the different dimensions and of the impact of combining different dimensions. The aim of this study is to determine the importance of combining features calculated in different dimensions. We have performed CADx experiments on 125 pulmonary nodules imaged using multi-detector row CT (MDCT). The CADx system computed 192 2D, 2.5D, and 3D image features of the lesions. Leave-one-out experiments were performed using five different combinations of features from different dimensions: 2D, 3D, 2.5D, 2D+3D, and 2D+3D+2.5D. The experiments were performed ten times for each group. Accuracy, sensitivity and specificity were used to evaluate the performance. Wilcoxon signed-rank tests were applied to compare the classification results from these five different combinations of features. Our results showed that 3D image features generate the best result compared with other combinations of features. This suggests one approach to potentially reducing the dimensionality of the CADx data space and the computational complexity of the system while maintaining diagnostic accuracy.

  20. Body Image of Highly Trained Female Athletes Engaged in Different Types of Sport

    Science.gov (United States)

    Glapa, Agata; Banio, Adrianna; Firek, Wiesław; Ingarden, Anna; Malchrowicz-Mośko, Ewa; Markiewicz, Paweł; Płoszaj, Katarzyna; Ingarden, Mateusz; Maćkowiak, Zuzanna

    2018-01-01

    Background The aim of the study was to evaluate differences in body image across different types of sports in highly trained female athletes. Methods 242 female individuals, aged 13–30 years (M = 20.0, SD = 4.5), representing aesthetic sports (n = 56) and nonaesthetic sports (n = 186), were recruited from different sports clubs in Poland. Body image, BMI, age, the level of competition attained, and the training background of participants were recorded. Results One-way ANOVA showed differences in the body image of athletes engaged in different types of sport (F(11,230) = 4.10, p sport explained 7.1% (β = –0.263, p sporting activities at an early stage. PMID:29662894

  1. Unsupervised segmentation of medical image based on difference of mutual information

    Institute of Scientific and Technical Information of China (English)

    L(U) Qingwen; CHEN Wufan

    2006-01-01

    In the scope of medical image processing, segmentation is important and difficult. There are still two problems which trouble us in this field. One is how to determine the number of clusters in an image and the other is how to segment medical images containing lesions. A new segmentation method called DDC, based on difference of mutual information (dMI) and pixon, is proposed in this paper. Experiments demonstrate that dMI shows one kind of intrinsic relationship between the segmented image and the original one and so it can be used to well determine the number of clusters. Furthermore, multi-modality medical images with lesions can be automatically and successfully segmented by DDC method.

  2. Comparison of image quality in head CT studies with different dose-reduction strategies

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Nielsen, Rikke; Fink-Jensen, Vibeke

    The number of multi-detector CT examinations is increasing rapidly. They allow high quality reformatted images providing accurate and precise diagnosis at maximum speed. Brain examinations are the most commonly requested studies, and although they come at a lower effective dose than body CT, can...... account to a considerable radiation dose as many patients undergo repeated studies. Therefore, various dose-reduction strategies are applied such as automated tube current and voltage modulation and recently different iterative reconstruction algorithms. However, the trade-off of all dose......-reduction maneuvers is reduction of image quality due to image noise or artifacts. The aim of our study was therefore to find the best diagnostic images with lowest possible dose. We present results of dose- and image quality optimizing strategies of brain CT examinations at our institution. We compare sequential...

  3. An Approach for Unsupervised Change Detection in Multitemporal VHR Images Acquired by Different Multispectral Sensors

    Directory of Open Access Journals (Sweden)

    Yady Tatiana Solano-Correa

    2018-03-01

    Full Text Available This paper proposes an approach for the detection of changes in multitemporal Very High Resolution (VHR optical images acquired by different multispectral sensors. The proposed approach, which is inspired by a recent framework developed to support the design of change-detection systems for single-sensor VHR remote sensing images, addresses and integrates in the general approach a strategy to effectively deal with multisensor information, i.e., to perform change detection between VHR images acquired by different multispectral sensors on two dates. This is achieved by the definition of procedures for the homogenization of radiometric, spectral and geometric image properties. These procedures map images into a common feature space where the information acquired by different multispectral sensors becomes comparable across time. Although the approach is general, here we optimize it for the detection of changes in vegetation and urban areas by employing features based on linear transformations (Tasseled Caps and Orthogonal Equations, which are shown to be effective for representing the multisensor information in a homogeneous physical way irrespectively of the considered sensor. Experiments on multitemporal images acquired by different VHR satellite systems (i.e., QuickBird, WorldView-2 and GeoEye-1 confirm the effectiveness of the proposed approach.

  4. Change Detection with GRASS GIS – Comparison of images taken by different sensors

    Directory of Open Access Journals (Sweden)

    Michael Fuchs

    2009-04-01

    Full Text Available Images of American military reconnaissance satellites of the Sixties (CORONA in combination with modern sensors (SPOT, QuickBird were used for detection of changes in land use. The pilot area was located about 40 km northwest of Yemen’s capital Sana’a and covered approximately 100 km2 . To produce comparable layers from images of distinctly different sources, the moving window technique was applied, using the diversity parameter. The resulting difference layers reveal plausible and interpretable change patterns, particularly in areas where urban sprawl occurs.The comparison of CORONA images with images taken by modern sensors proved to be an additional tool to visualize and quantify major changes in land use. The results should serve as additional basic data eg. in regional planning.The computation sequence was executed in GRASS GIS.

  5. Gender and racial/ethnic differences in body image development among college students.

    Science.gov (United States)

    Gillen, Meghan M; Lefkowitz, Eva S

    2012-01-01

    In the present study we used longitudinal methods to examine body image development during the early part of college. Students (N=390; 54% female) who identified as African American (32%), Latino/a American (27%), and European American (41%) completed surveys during their first, second, and third semesters at college. There were overall gender and racial/ethnic differences in all three aspects of body image, and both stability and change in body image development. Female students' appearance evaluation became more positive, whereas male students' appearance evaluation showed no significant change. Individuals' body areas satisfaction increased over time, but remained stable when controlling for BMI. Appearance orientation did not change, and there were no racial/ethnic differences in body image development. Experiences in the college environment may play a role in these trends. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Processing Chains for Desis and Enmap Imaging Spectroscopy Data: Similarities and Differences

    Science.gov (United States)

    Storch, T.; Müller, R.

    2017-10-01

    The Earth Observation Center (EOC) of the German Aerospace Center (DLR) realizes operational processors for DESIS (DLR Earth Sensing Imaging Spectrometer) and EnMAP (Environmental Mapping and Analysis Program) high-resolution imaging spectroscopy remote sensing satellite missions. DESIS is planned to be launched in 2018 and EnMAP in 2020. The developmental (namely schedule, deployment, and team) and functional (namely processing levels, algorithms in processors, and archiving approaches) similarities and differences of the fully-automatic processors are analyzed. The processing chains generate high-quality standardized image products for users at different levels taking characterization and calibration data into account. EOC has long lasting experiences with the airborne and spaceborne acquisition, processing, and analysis of hyperspectral image data. It turns out that both activities strongly benefit from each other.

  7. Comparison of different methods for gender estimation from face image of various poses

    Science.gov (United States)

    Ishii, Yohei; Hongo, Hitoshi; Niwa, Yoshinori; Yamamoto, Kazuhiko

    2003-04-01

    Recently, gender estimation from face images has been studied for frontal facial images. However, it is difficult to obtain such facial images constantly in the case of application systems for security, surveillance and marketing research. In order to build such systems, a method is required to estimate gender from the image of various facial poses. In this paper, three different classifiers are compared in appearance-based gender estimation, which use four directional features (FDF). The classifiers are linear discriminant analysis (LDA), Support Vector Machines (SVMs) and Sparse Network of Winnows (SNoW). Face images used for experiments were obtained from 35 viewpoints. The direction of viewpoints varied +/-45 degrees horizontally, +/-30 degrees vertically at 15 degree intervals respectively. Although LDA showed the best performance for frontal facial images, SVM with Gaussian kernel was found the best performance (86.0%) for the facial images of 35 viewpoints. It is considered that SVM with Gaussian kernel is robust to changes in viewpoint when estimating gender from these results. Furthermore, the estimation rate was quite close to the average estimation rate at 35 viewpoints respectively. It is supposed that the methods are reasonable to estimate gender within the range of experimented viewpoints by learning face images from multiple directions by one class.

  8. Histogram analysis of noise performance on fractional anisotropy brain MR image with different diffusion gradient numbers

    International Nuclear Information System (INIS)

    Chang, Yong Min; Kim, Yong Sun; Kang, Duk Sik; Lee, Young Joo; Sohn, Chul Ho; Woo, Seung Koo; Suh, Kyung Jin

    2005-01-01

    We wished to analyze, qualitatively and quantitatively, the noise performance of fractional anisotropy brain images along with the different diffusion gradient numbers by using the histogram method. Diffusion tensor images were acquired using a 3.0 T MR scanner from ten normal volunteers who had no neurological symptoms. The single-shot spin-echo EPI with a Stejskal-Tanner type diffusion gradient scheme was employed for the diffusion tensor measurement. With a b-valuee of 1000 s/mm 2 , the diffusion tensor images were obtained for 6, 11, 23, 35 and 47 diffusion gradient directions. FA images were generated for each DTI scheme. The histograms were then obtained at selected ROIs for the anatomical structures on the FA image. At the same ROI location, the mean FA value and the standard deviation of the mean FA value were calculated. The quality of the FA image was improved as the number of diffusion gradient directions increased by showing better contrast between the WM and GM. The histogram showed that the variance of FA values was reduced as the number of diffusion gradient directions increased. This histogram analysis was in good agreement with the result obtained using quantitative analysis. The image quality of the FA map was significantly improved as the number of diffusion gradient directions increased. The histogram analysis well demonstrated that the improvement in the FA images resulted from the reduction in the variance of the FA values included in the ROI

  9. Mapping the different methods adopted for diagnostic imaging instruction at medical schools in Brazil.

    Science.gov (United States)

    Chojniak, Rubens; Carneiro, Dominique Piacenti; Moterani, Gustavo Simonetto Peres; Duarte, Ivone da Silva; Bitencourt, Almir Galvão Vieira; Muglia, Valdair Francisco; D'Ippolito, Giuseppe

    2017-01-01

    To map the different methods for diagnostic imaging instruction at medical schools in Brazil. In this cross-sectional study, a questionnaire was sent to each of the coordinators of 178 Brazilian medical schools. The following characteristics were assessed: teaching model; total course hours; infrastructure; numbers of students and professionals involved; themes addressed; diagnostic imaging modalities covered; and education policies related to diagnostic imaging. Of the 178 questionnaires sent, 45 (25.3%) were completed and returned. Of those 45 responses, 17 (37.8%) were from public medical schools, whereas 28 (62.2%) were from private medical schools. Among the 45 medical schools evaluated, the method of diagnostic imaging instruction was modular at 21 (46.7%), classic (independent discipline) at 13 (28.9%), hybrid (classical and modular) at 9 (20.0%), and none of the preceding at 3 (6.7%). Diagnostic imaging is part of the formal curriculum at 36 (80.0%) of the schools, an elective course at 3 (6.7%), and included within another modality at 6 (13.3%). Professors involved in diagnostic imaging teaching are radiologists at 43 (95.5%) of the institutions. The survey showed that medical courses in Brazil tend to offer diagnostic imaging instruction in courses that include other content and at different time points during the course. Radiologists are extensively involved in undergraduate medical education, regardless of the teaching methodology employed at the institution.

  10. Multiresolution approach to processing images for different applications interaction of lower processing with higher vision

    CERN Document Server

    Vujović, Igor

    2015-01-01

    This book presents theoretical and practical aspects of the interaction between low and high level image processing. Multiresolution analysis owes its popularity mostly to wavelets and is widely used in a variety of applications. Low level image processing is important for the performance of many high level applications. The book includes examples from different research fields, i.e. video surveillance; biomedical applications (EMG and X-ray); improved communication, namely teleoperation, telemedicine, animation, augmented/virtual reality and robot vision; monitoring of the condition of ship systems and image quality control.

  11. Image of Brazil: similarities and differences in the assessment in ten countries

    Directory of Open Access Journals (Sweden)

    Eber Celoto Souza

    2014-08-01

    Full Text Available This article seeks to understand how foreigners make their image about Brazil and investigates similarities and differences in this assessment. The paper presents the results of a survey of 4373 respondents of ten countries. The authors performed a factor analysis to identify the dimensions and assessment of each country followed by a discriminant analysis. The results indicate that Brazil has a slightly positive image in the sample studied. The affection dimension has the best evaluation, while the communication dimension is the worst, and eight statements have the highest discrimination on the image of Brazil.

  12. Digital imaging system in mammography with X-ray of two different energies

    International Nuclear Information System (INIS)

    Swientek, K.; Dabrowski, W.; Grybos, P.; Wiacek, P.; Cabal Rodrigez, A. E.; Sanchez, C.C.; Gambaccini, M.; Gaitan, J.L.; Prino, F.; Ramello, L.

    2005-01-01

    The progress in nuclear medicine stimulates the higher quality of image processing at diminished radiation dose. In the presented apparatus system Si-microstrip detector with two-thresholds multichannel amplitude analyzer have been applied. Data acquisition system evaluates simultaneously images for two X-ray beams of different energies following the Bragg reflection of the primary beam from the mosaic crystal. The contrast cancellation technique has been tested using the simple mammography phantom. An efficacy of this method suitable for medical imaging could be significantly increased using an intensive X-ray source and sensitive detectors

  13. Lung Nodule Image Classification Based on Local Difference Pattern and Combined Classifier.

    Science.gov (United States)

    Mao, Keming; Deng, Zhuofu

    2016-01-01

    This paper proposes a novel lung nodule classification method for low-dose CT images. The method includes two stages. First, Local Difference Pattern (LDP) is proposed to encode the feature representation, which is extracted by comparing intensity difference along circular regions centered at the lung nodule. Then, the single-center classifier is trained based on LDP. Due to the diversity of feature distribution for different class, the training images are further clustered into multiple cores and the multicenter classifier is constructed. The two classifiers are combined to make the final decision. Experimental results on public dataset show the superior performance of LDP and the combined classifier.

  14. Lung Nodule Image Classification Based on Local Difference Pattern and Combined Classifier

    Directory of Open Access Journals (Sweden)

    Keming Mao

    2016-01-01

    Full Text Available This paper proposes a novel lung nodule classification method for low-dose CT images. The method includes two stages. First, Local Difference Pattern (LDP is proposed to encode the feature representation, which is extracted by comparing intensity difference along circular regions centered at the lung nodule. Then, the single-center classifier is trained based on LDP. Due to the diversity of feature distribution for different class, the training images are further clustered into multiple cores and the multicenter classifier is constructed. The two classifiers are combined to make the final decision. Experimental results on public dataset show the superior performance of LDP and the combined classifier.

  15. [Exploration on Electroencephalogram Mechanism Differences of Negative Emotions Induced by Disgusted and Sad Situation Images].

    Science.gov (United States)

    Wang, Xin; Jin, Jingna; Li, Song; Liu, Zhipeng; Yin, Tao

    2015-12-01

    Evolutionary psychology holds such an opinion that negative situation may threaten survival, trigger avoidance motive and have poor effects on the human-body function and the psychological quality. Both disgusted and sad situations can induce negative emotions. However, differences between the two situations on attention capture and emotion cognition during the emotion induction are still not well known. Typical disgusted and sad situation images were used in the present study to induce two negative emotions, and 15 young students (7 males and 8 females, aged 27 ± 3) were recruited in the experiments. Electroencephalogram of 32 leads was recorded when the subjects were viewing situation images, and event-related potentials (ERP) of all leads were obtained for future analysis. Paired sample t tests were carried out on two ERP signals separately induced by disgusted and sad situation images to get time quantum with significant statistical differences between the two ERP signals. Root-mean-square deviations of two ERP signals during each time quantum were calculated and the brain topographic map based on root-mean-square deviations was drawn to display differences of two ERP signals in spatial. Results showed that differences of ERP signals induced by disgusted and sad situation images were mainly manifested in T1 (120-450 ms) early and T2 (800-1,000 ms) later. During the period of T1, the occipital lobe reflecting attention capture was activated by both disgusted and sad situation images, but the prefrontal cortex reflecting emotion sense was activated only by disgusted situation images. During the period of T2, the prefrontal cortex was activated by both disgusted and sad situation images. However, the parietal lobe was activated only by disgusted situation images, which showed stronger emotional perception. The research results would have enlightenment to deepen understanding of negative emotion and to exploredeep cognitive neuroscience mechanisms of negative

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

    Science.gov (United States)

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

    2010-09-10

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

  17. [Investigation of the hyperspectral image characteristics of wheat leaves under different stress].

    Science.gov (United States)

    Zhang, Dong-Yan; Zhang, Jing-Cheng; Zhu, Da-Zhou; Wang, Ji-Hua; Luo, Ju-Hua; Zhao, Jin-Ling; Huang, Wen-Jiang

    2011-04-01

    The diagnosis of growing status and vigor of crops under various stresses is an important step in precision agriculture. Hyperspectral imaging technology has the advantage of providing both spectral and spatial information simultaneously, and has become a research hot spot. In the present study, auto-development of the pushbroom imaging spectrometer (PIS) was utilized to collect hyperspectral images of wheat leaves which suffer from shortage of nutrient, pest and disease stress. The hyperspectral cube was processed by the method of pixel average step by step to highlight the spectral characteristics, which facilitate the analysis based on the differences of leaves reflectance. The results showed that the hyperspectra of leaves from different layers can display nutrient differences, and recognize intuitively different stress extent by imaging figures. With the 2 nanometer spectral resolution and millimeter level spatial resolution of PIS, the number of disease spot can be qualitatively calculated when crop is infected with diseases, and, the area of plant disease could also be quantitatively analyzed; when crop suffered from pest and insect, the spectral information of leaves with single aphid and aphids can be detected by PIS, which provides a new means to quantitatively detect the aphid destroying of wheat leaf. The present study demonstrated that hyperspecral imaging has a great potential in quantitative and qualitative analysis of crop growth.

  18. MO-B-BRC-00: Prostate HDR Treatment Planning - Considering Different Imaging Modalities

    International Nuclear Information System (INIS)

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  19. Accumulative difference image protocol for particle tracking in fluorescence microscopy tested in mouse lymphonodes.

    Science.gov (United States)

    Villa, Carlo E; Caccia, Michele; Sironi, Laura; D'Alfonso, Laura; Collini, Maddalena; Rivolta, Ilaria; Miserocchi, Giuseppe; Gorletta, Tatiana; Zanoni, Ivan; Granucci, Francesca; Chirico, Giuseppe

    2010-08-17

    The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done.

  20. Accumulative difference image protocol for particle tracking in fluorescence microscopy tested in mouse lymphonodes.

    Directory of Open Access Journals (Sweden)

    Carlo E Villa

    Full Text Available The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done.

  1. MO-B-BRC-00: Prostate HDR Treatment Planning - Considering Different Imaging Modalities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  2. Different approaches for the texture classification of a remote sensing image bank

    Science.gov (United States)

    Durand, Philippe; Brunet, Gerard; Ghorbanzadeh, Dariush; Jaupi, Luan

    2018-04-01

    In this paper, we summarize and compare two different approaches used by the authors, to classify different natural textures. The first approach, which is simple and inexpensive in computing time, uses a data bank image and an expert system able to classify different textures from a number of rules established by discipline specialists. The second method uses the same database and a neural networks approach.

  3. These images show thermal infrared radiation from Jupiter at different wavelengths which are diagnos

    Science.gov (United States)

    2002-01-01

    These images show thermal infrared radiation from Jupiter at different wavelengths which are diagnostic of physical phenomena The 7.85-micron image in the upper left shows stratospheric temperatures which are elevated in the region of the A fragment impact (to the left of bottom). Temperatures deeper in the atmosphere near 150-mbar are shown by the 17.2-micron image in the upper right. There is a small elevation of temperatures at this depth, indicated by the arrow, and confirmed by other measurements near this wavelength. This indicates that the influence of the impact of fragment A on the troposphere has been minimal. The two images in the bottom row show no readily apparent perturbation of the ammmonia condensate cloud field near 600 mbar, as diagnosed by 8.57-micron radiation, and deeper cloud layers which are diagnosed by 5-micron radiation.

  4. Influence of different exposure modes on image quality and radiation dose in digital mammography

    International Nuclear Information System (INIS)

    Liu Jie; Wang Xia; Li Xiaokang; Liu Peifang

    2013-01-01

    Objective: To evaluate the effect of different exposure modes on radiation dose and image quality in digital mammography, and to explore how to reduce patient's radiation injury by choosing proper exposure mode and exposure conditions without sacrifice image quality. Methods: A breast phantom was exposed by using automatic exposure mode (60 mAs, 28 k/V) and manual exposure modes (37.5 to 70 mAs range, 24 to 32 kV range) respectively. Same oppression thickness and pressure were set for all modes. The average glandular dose (AGD), entrance surface dose (ESD), and image quality score according to American College of Radiology (ACR) criteria were recorded for each image. Kruskal Wallis test was used to compare the image quality scores between automatic and manual modes. All statistic analyses were performed by using SPSS17.0. Results: Compared to automatic exposure mode (60 mAs, 28 k/V), the overall score of image quality of manual modes (45 to 70 mAs range, 26 to 32 kV range) had no significant difference. Both ESD and ACD decreased 26.1% and increased 15.4% when the tube loading was changed from 60 mAs to 45 mAs and 70 mAs respectively. The ESD and ACD decreased 22.6%, 28.2% and increased 47.0%, 62.7% when the tube voltage was changed from 28 kV to 26 kV and 32 kV respectively. Conclusion: When the image quality reaches to a certain level, it will not be raised by a higher photographic condition. Without sacrifice image quality, the tube loading and tube voltage can be manually decreased to reduce radiation dose. (authors)

  5. Nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads.

    Science.gov (United States)

    Ohara, Yoshikazu; Horinouchi, Satoshi; Hashimoto, Makoto; Shintaku, Yohei; Yamanaka, Kazushi

    2011-08-01

    To improve the selectivity of closed cracks for objects other than cracks in ultrasonic imaging, we propose an extension of a novel imaging method, namely, subharmonic phased array for crack evaluation (SPACE) as well as another approach using the subtraction of responses at different external loads. By applying external static or dynamic loads to closed cracks, the contact state in the cracks varies, resulting in an intensity change of responses at cracks. In contrast, objects other than cracks are independent of external load. Therefore, only cracks can be extracted by subtracting responses at different loads. In this study, we performed fundamental experiments on a closed fatigue crack formed in an aluminum alloy compact tension (CT) specimen using the proposed method. We examined the static load dependence of SPACE images and the dynamic load dependence of linear phased array (PA) images by simulating the external loads with a servohydraulic fatigue testing machine. By subtracting the images at different external loads, we show that this method is useful in extracting only the intensity change of responses related to closed cracks, while canceling the responses of objects other than cracks. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Visual quality analysis for images degraded by different types of noise

    Science.gov (United States)

    Ponomarenko, Nikolay N.; Lukin, Vladimir V.; Ieremeyev, Oleg I.; Egiazarian, Karen O.; Astola, Jaakko T.

    2013-02-01

    Modern visual quality metrics take into account different peculiarities of the Human Visual System (HVS). One of them is described by the Weber-Fechner law and deals with the different sensitivity to distortions in image fragments with different local mean values (intensity, brightness). We analyze how this property can be incorporated into a metric PSNRHVS- M. It is shown that some improvement of its performance can be provided. Then, visual quality of color images corrupted by three types of i.i.d. noise (pure additive, pure multiplicative, and signal dependent, Poisson) is analyzed. Experiments with a group of observers are carried out for distorted color images created on the basis of TID2008 database. Several modern HVS-metrics are considered. It is shown that even the best metrics are unable to assess visual quality of distorted images adequately enough. The reasons for this deal with the observer's attention to certain objects in the test images, i.e., with semantic aspects of vision, which are worth taking into account in design of HVS-metrics.

  7. Ethnic differences in the effects of media on body image: the effects of priming with ethnically different or similar models.

    Science.gov (United States)

    Bruns, Gina L; Carter, Michele M

    2015-04-01

    Media exposure has been positively correlated with body dissatisfaction. While body image concerns are common, being African American has been found to be a protective factor in the development of body dissatisfaction. Participants either viewed ten advertisements showing 1) ethnically-similar thin models; 2) ethnically-different thin models; 3) ethnically-similar plus-sized models; and 4) ethnically-diverse plus-sized models. Following exposure, body image was measured. African American women had less body dissatisfaction than Caucasian women. Ethnically-similar thin-model conditions did not elicit greater body dissatisfaction scores than ethnically-different thin or plus-sized models nor did the ethnicity of the model impact ratings of body dissatisfaction for women of either race. There were no differences among the African American women exposed to plus-sized versus thin models. Among Caucasian women exposure to plus-sized models resulted in greater body dissatisfaction than exposure to thin models. Results support existing literature that African American women experience less body dissatisfaction than Caucasian women even following exposure to an ethnically-similar thin model. Additionally, women exposed to plus-sized model conditions experienced greater body dissatisfaction than those shown thin models. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Variability of textural features in FDG PET images due to different acquisition modes and reconstruction parameters

    DEFF Research Database (Denmark)

    Galavis, P.E.; Hollensen, Christian; Jallow, N.

    2010-01-01

    Background. Characterization of textural features (spatial distributions of image intensity levels) has been considered as a tool for automatic tumor segmentation. The purpose of this work is to study the variability of the textural features in PET images due to different acquisition modes...... reconstruction parameters. Lesions were segmented on a default image using the threshold of 40% of maximum SUV. Fifty different texture features were calculated inside the tumors. The range of variations of the features were calculated with respect to the average value. Results. Fifty textural features were...... classified based on the range of variation in three categories: small, intermediate and large variability. Features with small variability (range 30%). Conclusion. Textural features such as entropy-first order, energy, maximal correlation coefficient, and low-gray level run emphasis exhibited small...

  9. Three-dimensional super-resolution imaging for fluorescence emission difference microscopy

    Energy Technology Data Exchange (ETDEWEB)

    You, Shangting; Kuang, Cuifang, E-mail: cfkuang@zju.edu.cn; Li, Shuai; Liu, Xu; Ding, Zhihua [State key laboratory of modern optical instrumentations, Zhejiang University, Hangzhou 310027 (China)

    2015-08-15

    We propose a method theoretically to break the diffraction limit and to improve the resolution in all three dimensions for fluorescence emission difference microscopy. We produce two kinds of hollow focal spot by phase modulation. By incoherent superposition, these two kinds of focal spot yield a 3D hollow focal spot. The optimal proportion of these two kinds of spot is given in the paper. By employing 3D hollow focal spot, super-resolution image can be yielded by means of fluorescence emission difference microscopy, with resolution enhanced both laterally and axially. According to computation result, size of point spread function of three-dimensional super-resolution imaging is reduced by about 40% in all three spatial directions with respect to confocal imaging.

  10. Investigation of the Entrance Surface Dose and Dose to Different Organs in Lumbar Spine Imaging

    Directory of Open Access Journals (Sweden)

    Sina S

    2014-12-01

    Full Text Available Background: Dose assessment using proper dosimeters is especially important in radiation protection optimization and imaging justification in diagnostic radiology. Objective: The aim of this study is to obtain the Entrance Skin Dose (ESD of patients undergoing lumbar spine imaging using two thermoluminescence dosimeters TLD-100 (LiF: Mg, Ti and GR-200 (LiF: Mg, Cu, P and also to obtain the absorbed dose to different organs in lumbar spine imaging with several views. Methods: To measure the ESD values of the patients undergoing lumbar spine imaging, the two TLD types were put on their skin surface. The ESD values for different views of lumbar spine imaging were also measured by putting the TLDs at the surface of the Rando phantom. Several TLD chips were inserted inside different organs of Rando phantom to measure the absorbed dose to different organs in lumbar spine imaging. Results: The results indicate that there is a close agreement between the results of the two dosimeters. Based on the results of this experiment, the ESD dose of the 16 patients included in this study varied between 2.71 mGy and 26.29 mGy with the average of 11.89 mGy for TLD-100, and between 2.55 mGy and 27.41 mGy with the average of 12.32 mGy for GR-200 measurements. The ESDs obtained by putting the two types of TLDs at the surface of Rando phantom are in close agreement. Conclusion: According to the results, the GR200 has greater sensitivity than the TLD-100.

  11. Investigation of the Entrance Surface Dose and Dose to Different Organs in Lumbar Spine Imaging

    Science.gov (United States)

    Sina, S; Zeinali, B; Karimipoorfard, M; Lotfalizadeh, F; Sadeghi, M; Zamani, E; Faghihi, R

    2014-01-01

    Background: Dose assessment using proper dosimeters is especially important in radiation protection optimization and imaging justification in diagnostic radiology. Objective: The aim of this study is to obtain the Entrance Skin Dose (ESD) of patients undergoing lumbar spine imaging using two thermoluminescence dosimeters TLD-100 (LiF: Mg, Ti) and GR-200 (LiF: Mg, Cu, P) and also to obtain the absorbed dose to different organs in lumbar spine imaging with several views. Methods: To measure the ESD values of the patients undergoing lumbar spine imaging, the two TLD types were put on their skin surface. The ESD values for different views of lumbar spine imaging were also measured by putting the TLDs at the surface of the Rando phantom. Several TLD chips were inserted inside different organs of Rando phantom to measure the absorbed dose to different organs in lumbar spine imaging. Results: The results indicate that there is a close agreement between the results of the two dosimeters. Based on the results of this experiment, the ESD dose of the 16 patients included in this study varied between 2.71 mGy and 26.29 mGy with the average of 11.89 mGy for TLD-100, and between 2.55 mGy and 27.41 mGy with the average of 12.32 mGy for GR-200 measurements. The ESDs obtained by putting the two types of TLDs at the surface of Rando phantom are in close agreement. Conclusion: According to the results, the GR200 has greater sensitivity than the TLD-100. PMID:25599058

  12. Differences for gender, weight and exercise in body image disturbance and eating disorder symptoms.

    Science.gov (United States)

    Varnado-Sullivan, P J; Horton, R; Savoy, S

    2006-09-01

    Differences for gender, weight, exercise frequency and type for eating disorder symptoms and body image disturbance were examined. Further understanding of male body image disturbance was the primary goal. Males (n=200) and females (n=233) completed measures to assess eating disorder symptoms and multiple components of body image disturbance. Measures were modified to be more appropriate for males. Females endorsed higher levels of eating and body concerns. Males were divided between a desire to maintain, increase or decrease their size. Higher weight and exercise frequency was associated with increased body image concern and eating disorder symptoms, particularly for males. Exercise frequency was also linked to higher self-esteem for males. Males who used muscle-enhancing supplements indicated increased social pressures and concern for appearance, and a desire to increase their size. The findings support that weight and exercise frequency affect eating disorder symptoms and body image disturbance. Males appear to exhibit body image disturbance, which is related to their current weight status. Results support the call for further development of measures that more adequately address male concerns.

  13. Psychosocial differences associated with body weight among female adolescents: the importance of body image.

    Science.gov (United States)

    Pesa, J A; Syre, T R; Jones, E

    2000-05-01

    To determine whether overweight female adolescents differ from normal and underweight female adolescents with respect to a set of psychosocial factors, while controlling for body image. Female participants of the National Longitudinal Study of Adolescent Health (n = 3197) were selected for analysis. Multivariate Analysis of Variance (MANOVA) was used to test whether overweight subjects differed from normal and underweight subjects with respect to measures of depression, self-esteem, trouble in school, school connectedness, family connectedness, sense of community, autonomy, protective factors, and grades. Stepdown F-tests and discriminant function coefficients provided information regarding the strength of specific factors in contributing to overall differences. MANOVA revealed significant differences between groups on the combined set of psychosocial factors. Self-esteem defined the difference in a positive direction while grades defined the difference inversely. When controlling for body image, multidimensional group differences were still evident; however, self-esteem was no longer a significant contributing variable. While overweight female adolescents seem to suffer from low self-esteem, it may be explained by body image. Efforts should be directed toward encouraging and supporting healthy eating patterns and physical activity while encouraging students to recognize personal strengths not related to physique.

  14. The results of different diagnostic imaging studies used in children with urinary tract infection

    OpenAIRE

    Nasaif, Majida Noori; Alghamdi, Ahmed Hassan; Ghamdi, Jameel Al; Al-Dammas, Ali

    2015-01-01

    Urinary tract infections (UTI) can cause significant renal scarring, which can be complicated by hypertension and renal impairment. This study describes the outcome of different imaging modalities in children with UTI and its relation to age, sex and type of UTI.

  15. Gender Differences in Adolescent Sport Participation, Teasing, Self-Objectification and Body Image Concerns

    Science.gov (United States)

    Slater, Amy; Tiggemann, Marika

    2011-01-01

    This study examined gender differences in adolescent participation in sport and physical activity, in teasing experiences specific to the physical activity domain, and the relationship between adolescent physical activity and body image. A sample of 714 adolescents (332 girls, 382 boys) aged between 12 and 16 years completed measures of…

  16. Different Imaging Strategies in Patients with Possible Basilar Artery Occlusion: Cost-Effectiveness Analysis

    NARCIS (Netherlands)

    S.E. Beyer (Sebastian E.); M.G.M. Hunink (Myriam); F. Schöberl (Florian); L. von Baumgarten; S.E. Petersen (Steffen); C. Kubisch (Christian); H. Janssen (Hendrik); B. Ertl-Wagner (Birgit); M.F. Reiser (Maximilian F.); W.H. Sommer (Wieland H.)

    2015-01-01

    textabstractBackground and Purpose-This study evaluated the cost-effectiveness of different noninvasive imaging strategies in patients with possible basilar artery occlusion. Methods-A Markov decision analytic model was used to evaluate long-term outcomes resulting from strategies using computed

  17. Evaluation of Different Irrigation Methods for an Apple Orchard Using an Aerial Imaging System

    Directory of Open Access Journals (Sweden)

    Duke M. Bulanon

    2016-06-01

    Full Text Available Regular monitoring and assessment of crops is one of the keys to optimal crop production. This research presents the development of a monitoring system called the Crop Monitoring and Assessment Platform (C-MAP. The C-MAP is composed of an image acquisition unit which is an off-the-shelf unmanned aerial vehicle (UAV equipped with a multispectral camera (near-infrared, green, blue, and an image processing and analysis component. The experimental apple orchard at the Parma Research and Extension Center of the University of Idaho was used as the target for monitoring and evaluation. Five experimental rows of the orchard were randomly treated with five different irrigation methods. An image processing algorithm to detect individual trees was developed to facilitate the analysis of the rows and it was able to detect over 90% of the trees. The image analysis of the experimental rows was based on vegetation indices and results showed that there was a significant difference in the Enhanced Normalized Difference Vegetation Index (ENDVI among the five different irrigation methods. This demonstrates that the C-MAP has very good potential as a monitoring tool for orchard management.

  18. New second-order difference algorithm for image segmentation based on cellular neural networks (CNNs)

    Science.gov (United States)

    Meng, Shukai; Mo, Yu L.

    2001-09-01

    Image segmentation is one of the most important operations in many image analysis problems, which is the process that subdivides an image into its constituents and extracts those parts of interest. In this paper, we present a new second order difference gray-scale image segmentation algorithm based on cellular neural networks. A 3x3 CNN cloning template is applied, which can make smooth processing and has a good ability to deal with the conflict between the capability of noise resistance and the edge detection of complex shapes. We use second order difference operator to calculate the coefficients of the control template, which are not constant but rather depend on the input gray-scale values. It is similar to Contour Extraction CNN in construction, but there are some different in algorithm. The result of experiment shows that the second order difference CNN has a good capability in edge detection. It is better than Contour Extraction CNN in detail detection and more effective than the Laplacian of Gauss (LOG) algorithm.

  19. Costs, charges, and revenues for hospital diagnostic imaging procedures: differences by modality and hospital characteristics.

    Science.gov (United States)

    Sistrom, Christopher Lee; McKay, Niccie L

    2005-06-01

    This study examined financial data reported by Florida hospitals concerning costs, charges, and revenues related to imaging services. Financial reports to the Florida Hospital Uniform Reporting System by all licensed acute care facilities for fiscal year 2002 were used to calculate four financial indices on a per procedure basis. These included charge, net revenue, operating expense (variable cost), and contribution margin. Analysis, stratified by cost center (imaging modality), tested the effects of bed size, ownership, teaching status, and urban or rural status on the four indices. The mean operating expense and charge per procedure were as follows: computed tomography (CT): $51 and $1565; x-ray and ultrasound: $55 and $410; nuclear medicine (NM): $135 and $1138; and magnetic resonance imaging (MRI): $165 and $2048. With all four modalities, for-profit hospitals had higher charges than not-for-profit and public facilities. Excepting NM, however, the difference by ownership disappeared when considering net revenue. Operating expense did not differ by ownership type or bed size. Operating expense (variable cost) per procedure is considerably lower for CT than for MRI. Consequently, when diagnostically equivalent, CT is preferable to MRI in terms of costs for hospitals. If the cost structure of nonhospital imaging is at all similar to hospitals, the profit potential for performing CT and MRI seems to be substantial, which has relevance to the issue of imaging self-referral.

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

    Science.gov (United States)

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

    2009-04-01

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

  1. Difference between T1 and T2 weighted MR images in avascular necrosis of the femoral head

    International Nuclear Information System (INIS)

    Kokubo, Takashi; Yoshikawa, Koki; Itai, Yuzo; Iio, Masahiro; Takatori, Yoshio; Kamogawa, Morihide; Ninomiya, Setsuo

    1990-01-01

    T 1 and T 2 weighted MR images were compared in 32 hips with avascular necrosis, and the difference between them was discussed. In 27 of 32 hips, abnormal low intensity area in the affected femoral head is smaller in T 2 weighted images than in T 1 weighted images. The area of low intensity on T 1 weighted image and high on T 2 weighted image might be granuloma in reactive tissue and surrounding hyperemia. The difference between T 1 and T 2 weighted images must be taken into consideration especially in determination of the border of affected bone. (author)

  2. Monitoring of biofilm formation on different material surfaces of medical devices using hyperspectral imaging method

    Science.gov (United States)

    Kim, Do-Hyun; Kim, Moon S.; Hwang, Jeeseong

    2012-03-01

    Contamination of the inner surface of indwelling (implanted) medical devices by microbial biofilm is a serious problem. Some microbial bacteria such as Escherichia coli form biofilms that lead to potentially lifethreatening infections. Other types of medical devices such as bronchoscopes and duodenoscopes account for the highest number of reported endoscopic infections where microbial biofilm is one of the major causes for these infections. We applied a hyperspectral imaging method to detect biofilm contamination on the surface of several common materials used for medical devices. Such materials include stainless steel, titanium, and stainless-steeltitanium alloy. Potential uses of hyperspectral imaging technique to monitor biofilm attachment to different material surfaces are discussed.

  3. Script Identification from Printed Indian Document Images and Performance Evaluation Using Different Classifiers

    Directory of Open Access Journals (Sweden)

    Sk Md Obaidullah

    2014-01-01

    multiscript country like India. In this paper the real life problem of printed script identification from official Indian document images is considered and performances of different well-known classifiers are evaluated. Two important evaluating parameters, namely, AAR (average accuracy rate and MBT (model building time, are computed for this performance analysis. Experiment was carried out on 459 printed document images with 5-fold cross-validation. Simple Logistic model shows highest AAR of 98.9% among all. BayesNet and Random Forest model have average accuracy rate of 96.7% and 98.2% correspondingly with lowest MBT of 0.09 s.

  4. An experimental study regarding diagnostic accuracy on image interpretation of the digital image film by using viewboxes of different luminance

    International Nuclear Information System (INIS)

    Song Shaojuan; Huang Ling; Liu Chuanya; Zhang Xiaojing

    2009-01-01

    Objective: To evaluate diagnostic accuracy of image interpretation using viewboxes at different luminance with ALVIM statistical phantom (TRG). Methods: A digital film of TRG image was obtained by exposing the phantom of TRG with Kodak DR 3000 using proper parameter. Viewboxes with three different luminance were selected from those used in daily work. The film of TRG was evaluated with these viewboxes of three different luminance by three different radiologists with experience of five, eight and sixteen years respectively. A grade scale of 5 was used to evaluate each row of signal and noise. According to the results and formula, the probabilities of true-positive [P(S/s)], false-positive [P(S/n)] and true answer (P det ) were obtained. Results: The three kinds of luminance used in viewboxes were: (3489± 256), (2231±220), (816±168) cd/m 2 . When the average luminance of viewbox was 3489 cd/m 2 , P det of 0.6,0.7,0.8 mm in bone substitute was 0.558±0.009, 0.788±0.008, 0.813±0.006, P det of 0.9, 1.0, 1.2 mm in muscle substitute was 0.663±0.010, 0.750±0.008, 0.933±0.005; When the average luminance of viewbox was 2231 cd/m 2 , P det of 0.6,0.7,0.8 mm in bone substitute was 0.525±0.013, 0.713±0.013,0.775±0.016, P det of 0.9,1.0,1.2 mm in muscle substitute was 0.613±0.019, 0.650± 0.013,0.850±0.019; When the average luminance of viewbox was 816 cd/m 2 , Pact of 0.6,0.7,0.8 mm in bone substitute was 0.475±0.022,0.550±0.018,0.688±0.020, P det of 0.9, 1.0, 1.2 mm in muscle substitute was 0.550±0.025,0.575±0.021,0.725±0.016. Viewboxes of different luminance were compared to one another by paired t-test. The results of comparison all had significant statistical differences (t=5.057 and 4.681, P<0.05). Conclusions: The image displayed by viewboxes at different luminance had significant influence on image interpretation. The higher the luminace of viewbox, the richer the information displayed, and the higher the accuracy of diagnosis. (authors)

  5. The registration accuracy analysis of different CT-MRI imaging fusion method in brain tumor

    International Nuclear Information System (INIS)

    Lu Jie; Yin Yong; Shao Qian; Zhang Zicheng; Chen Jinhu; Chen Zhaoqiu

    2010-01-01

    Objective: To find an effective CT-MRI image fusion protocol in brain tumor by analyzing the registration accuracy of different methods. Methods: The simulation CT scan and MRI T 1 WI imaging of 10 brain tumor patients obtained with same position were registered by Tris-Axes landmark ,Tris-Axes landmark + manual adjustment, mutual information and mutual information + manual adjustment method. The clinical tumor volume (CTV) were contoured on both CT and MRI images respectively. The accuracy of image fusion was assessed by the mean distance of five bone markers (d 1-5 ), central position of CTV (d CTV ) the percentage of CTV overlap (P CT-MRI ) between CT and MRI images. The difference between different methods was analyzed by Freedman M non-parameter test. Results: The difference of the means d1-5 between the Tris-Axes landmark,Tris-Axes landmark plus manual adjustment,mutual information and mutual information plus manual adjustment methods were 0.28 cm ±0.12 cm, 0.15 cm ±0.02 cm, 0.25 cm± 0.19 cm, 0.10 cm ± 0.06 cm, (M = 14.41, P = 0.002). the means d CTV were 0.59 cm ± 0.28 cm, 0.60 cm± 0.32 cm, 0.58 cm ± 0.39 cm, 0.42 cm± 0.30 cm (M = 9.72, P = 0.021), the means P CT-MRI were 0.69% ±0.18%, 0.68% ±0.16%, 0.66% ±0.17%, 0.74% ±0.14% (M =14.82, P=0.002), respectively. Conclusions: Mutual information plus manual adjustment registration method was the preferable fusion method for brain tumor patients. (authors)

  6. Technical and radiological image quality comparison of different liquid crystal displays for radiology

    Directory of Open Access Journals (Sweden)

    Dams FE

    2014-10-01

    Full Text Available Francina EM Dams,2 KY Esther Leung,1 Pieter HM van der Valk,2 Marc CJM Kock,2 Jeroen Bosman,1 Sjoerd P Niehof1 1Medical Physics and Technology, 2Department of Radiology, Albert Schweitzer Hospital, Dordrecht, The Netherlands Background: To inform cost-effective decisions in purchasing new medical liquid crystal displays, we compared the image quality in displays made by three manufacturers. Methods: We recruited 19 radiologists and residents to compare the image quality of four liquid crystal displays, including 3-megapixel Barco®, Eizo®, and NEC® displays and a 6-megapixel Barco display. The evaluators were blinded to the manufacturers' names. Technical assessments were based on acceptance criteria and test patterns proposed by the American Association of Physicists in Medicine. Radiological assessments were performed on images from the American Association of Physicists in Medicine Task Group 18. They included X-ray images of the thorax, knee, and breast, a computed tomographic image of the thorax, and a magnetic resonance image of the brain. Image quality was scored on an analog scale (range 0–10. Statistical analysis was performed with repeated-measures analysis of variance. Results: The Barco 3-megapixel display passed all acceptance criteria. The Eizo and NEC displays passed the acceptance criteria, except for the darkest pixel value in the grayscale display function. The Barco 6-megapixel display failed criteria for the maximum luminance response and the veiling glare. Mean radiological assessment scores were 7.8±1.1 (Barco 3-megapixel, 7.8±1.2 (Eizo, 8.1±1.0 (NEC, and 8.1±1.0 (Barco 6-megapixel. No significant differences were found between displays. Conclusion: According to the tested criteria, all the displays had comparable image quality; however, there was a three-fold difference in price between the most and least expensive displays. Keywords: data display, humans, radiographic image enhancement, user-computer interface

  7. Trade off study on different envelope detectors for B-mode imaging

    DEFF Research Database (Denmark)

    Schlaikjer, Malene; Bagge, J. P.; Jensen, Jørgen Arendt

    2003-01-01

    sum of the real and imaginary signals. The four detectors were evaluated on in-vivo data acquired with a B-K Medical 2102 scanner interfaced to the sampling system RASMINE. Three data sets were acquired with three different center frequencies. Hundred images were acquired as the transducer was moved......Generation of B-mode images involves envelope detection of the RF-signals. Various detection algorithms are available. A trade off between performance, price, and complexity determines the choice of algorithm in an ultrasound system. A Hilbert Transform (HT) and a subsequent computation...... of the magnitude give the ideal envelope, but the approach (IDE) is expensive and complex. A rectifier (REC) is a simple, low-cost solution, but the performance is severely degraded (especially in dynamic imaging). This study has investigated the possibility of providing a detector with a complexity and cost close...

  8. Gender differences in colour naming performance for gender specific body shape images.

    Science.gov (United States)

    Elliman, N A; Green, M W; Wan, W K

    1998-03-01

    Males are increasingly subjected to pressures to conform to aesthetic body stereotypes. There is, however, comparatively little published research on the aetiology of male body shape concerns. Two experiments are presented, which investigate the relationship between gender specific body shape concerns and colour-naming performance. Each study comprised a between subject design, in which each subject was tested on a single occasion. A pictorial version of a modified Stroop task was used in both studies. Subjects colour-named gender specific obese and thin body shape images and semantically homogeneous neutral images (birds) presented in a blocked format. The first experiment investigated female subjects (N = 68) and the second investigated males (N = 56). Subjects also completed a self-report measure of eating behaviour. Currently dieting female subjects exhibited significant colour-naming differences between obese and neutral images. A similar pattern of colour-naming performance was found to be related to external eating in the male subjects.

  9. Pixel based statistical analysis of differences between lung SPECT images: methodological aspects

    International Nuclear Information System (INIS)

    Bendada, S.; Rocchisani, J.L.M.; Moretti, J.L.

    2002-01-01

    The statistical parametric mapping method is applied in Neurology for activation studies. We had adapted this powerful method on Lungs SPECT to help for the diagnosis and the follow-up of pulmonary embolism and other lung diseases. The SPECT slices of pairs of examination were normalized thanks to the total acquired counts, reconstruction background subtracted, smoothed and realigned. A parametric image of statistical differences was finally computed. We had thus obtained a 3D image showing regions of improved or altered region under treatment. A tuning of the various parameters could lead to more accurate image. This new approach of lung SPECT processing appears to be a promising useful tool for the physician. (author)

  10. Frequency-difference MIT imaging of cerebral haemorrhage with a hemispherical coil array: numerical modelling.

    Science.gov (United States)

    Zolgharni, M; Griffiths, H; Ledger, P D

    2010-08-01

    The feasibility of detecting a cerebral haemorrhage with a hemispherical MIT coil array consisting of 56 exciter/sensor coils of 10 mm radius and operating at 1 and 10 MHz was investigated. A finite difference method combined with an anatomically realistic head model comprising 12 tissue types was used to simulate the strokes. Frequency-difference images were reconstructed from the modelled data with different levels of the added phase noise and two types of a priori boundary errors: a displacement of the head and a size scaling error. The results revealed that a noise level of 3 m degrees (standard deviation) was adequate for obtaining good visualization of a peripheral stroke (volume approximately 49 ml). The simulations further showed that the displacement error had to be within 3-4 mm and the scaling error within 3-4% so as not to cause unacceptably large artefacts on the images.

  11. Influence of different anode/filter combination on radiation dose and image quality in digital mammography

    International Nuclear Information System (INIS)

    Liu Jie; Liu Peifang; Zhang Lianlian; Ma Wenjuan

    2013-01-01

    Objective: To explore the effect of different anode/filter combination on radiation dose and image quality in digital mammography, so as to choose optimal anode/filter combination to reduce radiation injury without scarifying image quality. Methods: Mammography accredition phantoms with the thickness from 1.6 cm to 8.6 cm were used to simulate human breast tissue. The same exposure conditions, pressure, compression thickness. and different anode/filter combination were employed under the automatic and manual exposure modes. The image kV, mAs, pressure, filter, average glandular dose (ACD), contrast to noise ratio (CNR) were recorded and the figure of merit (FOM) was calculated. SPSS 17.0 and one-way analysis of variance were used in the statistical analysis. Results: As the phantom thickness increase, the ACD values which were acquired with Mo/Mo, Mo/Rh, and W/Ag three different anode/filter combinations were increased, but CNR and FOM values were decreased, ACD, CNR, and FOM values which were acquired in the phantom with different thickness, and three different anode/filter combinations were statistically different (P=0.000, respectively). The ACD values of Mo/Mo were lowest. For 1.6 cm-2.6 cm phantom thicknesses, the FOMs of Mo/Rh were lowest, and for 3.6 cm-8.6 cm phantom thicknesses, the FOMs of W/Ag were lowest. Conclusion: Phantom thickness in 1.6 cm-2.6 cm and 3.6 cm-8.6 cm. Mo/Rh combination and W/Ag combination respectively can achieve the highest FOM, and can provide the best imaging quality with low radiation dose. (authors)

  12. Quantitative analysis of geomorphic processes using satellite image data at different scales

    Science.gov (United States)

    Williams, R. S., Jr.

    1985-01-01

    When aerial and satellite photographs and images are used in the quantitative analysis of geomorphic processes, either through direct observation of active processes or by analysis of landforms resulting from inferred active or dormant processes, a number of limitations in the use of such data must be considered. Active geomorphic processes work at different scales and rates. Therefore, the capability of imaging an active or dormant process depends primarily on the scale of the process and the spatial-resolution characteristic of the imaging system. Scale is an important factor in recording continuous and discontinuous active geomorphic processes, because what is not recorded will not be considered or even suspected in the analysis of orbital images. If the geomorphic process of landform change caused by the process is less than 200 m in x to y dimension, then it will not be recorded. Although the scale factor is critical, in the recording of discontinuous active geomorphic processes, the repeat interval of orbital-image acquisition of a planetary surface also is a consideration in order to capture a recurring short-lived geomorphic process or to record changes caused by either a continuous or a discontinuous geomorphic process.

  13. Radiopacity of restorative composites by conventional radiography and digital images with different resolutions

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Raquel Venancio; Samento, Hugo Ramalho [Graduate Program in Dentistry, Federal University of Pelotas, Pelotas (Brazil); Duarte, Rosangela Marques; Raso, Sonia Saeger Meireles Monte; De Andrade Ana Karina Maciel; Anjos-Pontual Maria Luiza Dos [Dept. of Operative Dentistry, Federal University of Paraiba, Pelotas (Brazil)

    2013-09-15

    This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using 4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually. The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.

  14. Magnetic Resonance Imaging versus Computed Tomography and Different Imaging Modalities in Evaluation of Sinonasal Neoplasms Diagnosed by Histopathology

    Directory of Open Access Journals (Sweden)

    Mohammed A. Gomaa

    2013-01-01

    Full Text Available Objective The study purpose was to detect the value of magnetic resonance imaging (MRI compared to computed tomography (CT and different imaging modalities as conventional radiology in evaluation of sinonasal neoplasms diagnosed by Histopathology. Methods Thirty patients (16 males and 14 females were complaining of symptoms related to sinonasal tract. After thorough clinical and local examination, the patients were subjected to the following: conventional radiography, CT, MRI, and histopathological examination. Results The nasal cavity was the most commonly involved site with sinonasal malignancies followed by the maxillary sinuses. The least commonly affected site was the frontal sinuses. Benign sinonasal tumors were present in 14 cases. The most common benign lesion was juvenile nasopharyngeal angiofibroma (6 cases, followed by inverted papilloma (3 cases. While malignant sinonasal tumors were present in 16 cases, squamous cell carcinoma was present in 5 cases, and undifferentiated carcinoma, in 3 cases. Lymphoepithelioma and non-Hodgkin lymphomas were present in 2 cases each, while adenocarcinoma, chondrosarcoma, adenoid cystic carcinoma, and rhabdomyosarcoma were present in 1 case each. Conclusion MRI with its superior soft tissue contrast and multiplanar capability is superior to CT in pretreatment evaluation of primary malignant tumors of sinonasal cavity.

  15. Brain perfusion image using N-isopropyl-p-(/sup 123/I) iodoamphetamine. Detection of interhemispheric difference

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi; Seki, Hiroyasu; Ishida, Hiroko

    1984-12-01

    In brain perfusion images using N-isopropyl-p-(/sup 123/I)iodoamphetamine and rotating gamma camera emission computed tomography, brain maps showing laterality indices (LI) were made for the purpose of detecting intrahemispheric differences. Left (L) and right (R) leteral images were made by adding sagittal section images in each hemisphere, respectively. LI was calculated as follows. LI=100(1 + (R-L)/(R + L)). The normal ranges (mean +- 2 s.d.) of the indices determined by those obtained in five normal right-handed subjects were 103 +- 4 and 103 +- 10 for brain mean and each pixel, respectively. Out of 25 measurements in 22 right-handed patients with cerebrovascular accidents, brain mean LI beyond the normal limits and areas showing abnormal regional LI were observed in 5 (20%) and 21 (84%) measurements, respectively. On the other hand, X-ray CT showed low density areas in only 12 (48%). These brain maps were clinically useful for detecting and quantifying interhemispheric differences in brain perfusion images with N-isopropyl-p-(/sup 123/I)iodoamphetamine. (author). Contains 48 refs.

  16. Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

    International Nuclear Information System (INIS)

    Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C.

    2006-01-01

    Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences

  17. Patch Similarity Modulus and Difference Curvature Based Fourth-Order Partial Differential Equation for Image Denoising

    Directory of Open Access Journals (Sweden)

    Yunjiao Bai

    2015-01-01

    Full Text Available The traditional fourth-order nonlinear diffusion denoising model suffers the isolated speckles and the loss of fine details in the processed image. For this reason, a new fourth-order partial differential equation based on the patch similarity modulus and the difference curvature is proposed for image denoising. First, based on the intensity similarity of neighbor pixels, this paper presents a new edge indicator called patch similarity modulus, which is strongly robust to noise. Furthermore, the difference curvature which can effectively distinguish between edges and noise is incorporated into the denoising algorithm to determine the diffusion process by adaptively adjusting the size of the diffusion coefficient. The experimental results show that the proposed algorithm can not only preserve edges and texture details, but also avoid isolated speckles and staircase effect while filtering out noise. And the proposed algorithm has a better performance for the images with abundant details. Additionally, the subjective visual quality and objective evaluation index of the denoised image obtained by the proposed algorithm are higher than the ones from the related methods.

  18. Subjective and objective image differences in pediatric computed tomography cardiac angiography using lower iodine concentration

    International Nuclear Information System (INIS)

    Hwang, Jae-Yeon; Choo, Ki Seok; Choi, Yoon Young; Kim, Jin Hyeok; Ryu, Hwaseong; Kim, Yong-Woo; Jeon, Ung Bae; Nam, Kyung Jin; Han, Junhee

    2017-01-01

    Several recent studies showed the optimal contrast enhancement with a low-concentration and iso-osmolar contrast media in both adult and pediatric patients. However, low contrast media concentrations are not routinely used due to concerns of suboptimal enhancement of cardiac structures and small vessels. To evaluate the feasibility of using iso-osmolar contrast media containing a low iodine dose for CT cardiac angiography at 80 kilovolts (kVp) in neonates and infants. The iodixanol 270 group consisted of 79 CT scans and the iopromide 370 group of 62 CT scans in patients ≤1 year old. Objective measurement of the contrast enhancement was analyzed and contrast-to-noise ratios of the ascending aorta and left ventricle were calculated. Regarding subjective measurement, a four-point scale system was devised to evaluate degrees of contrast enhancement, image noise, motion artifact and overall image quality of each image set. Reader performance for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment was evaluated. Group objective and subjective measurements were nonsignificantly different. Overall sensitivity, specificity and diagnostic accuracy for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment were 42.8%, 59%, and 50%, respectively. The application of iodixanol 270 achieved optimal enhancement for performing pediatric cardiac CT angiography at 80 kVp in neonates and infants. Objective measurements of contrast enhancement and subjective image quality assessments were not statistically different in the iodixanol 270 and iopromide 370 groups. (orig.)

  19. Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

    Energy Technology Data Exchange (ETDEWEB)

    Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C. [Charite - Universitatsmedizin Berlin, Charite Campus Mitte, Berlin (Germany). Dept. of Radiology

    2006-11-15

    Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences.

  20. Color Image Segmentation Based on Different Color Space Models Using Automatic GrabCut

    Directory of Open Access Journals (Sweden)

    Dina Khattab

    2014-01-01

    Full Text Available This paper presents a comparative study using different color spaces to evaluate the performance of color image segmentation using the automatic GrabCut technique. GrabCut is considered as one of the semiautomatic image segmentation techniques, since it requires user interaction for the initialization of the segmentation process. The automation of the GrabCut technique is proposed as a modification of the original semiautomatic one in order to eliminate the user interaction. The automatic GrabCut utilizes the unsupervised Orchard and Bouman clustering technique for the initialization phase. Comparisons with the original GrabCut show the efficiency of the proposed automatic technique in terms of segmentation, quality, and accuracy. As no explicit color space is recommended for every segmentation problem, automatic GrabCut is applied with RGB, HSV, CMY, XYZ, and YUV color spaces. The comparative study and experimental results using different color images show that RGB color space is the best color space representation for the set of the images used.

  1. Subjective and objective image differences in pediatric computed tomography cardiac angiography using lower iodine concentration

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jae-Yeon [Pusan National University Yangsan Hospital, Department of Radiology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of); Pusan National University Yangsan Hospital, Research Institute for Convergence of Biomedical Science and Technology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of); Choo, Ki Seok; Choi, Yoon Young; Kim, Jin Hyeok; Ryu, Hwaseong; Kim, Yong-Woo; Jeon, Ung Bae; Nam, Kyung Jin [Pusan National University Yangsan Hospital, Department of Radiology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of); Han, Junhee [Pusan National University Yangsan Hospital, Division of Biostatistics, Research Institute for Convergence of Biomedical Science and Technology, Yangsan-si, Gyeongsangnam-do (Korea, Republic of)

    2017-05-15

    Several recent studies showed the optimal contrast enhancement with a low-concentration and iso-osmolar contrast media in both adult and pediatric patients. However, low contrast media concentrations are not routinely used due to concerns of suboptimal enhancement of cardiac structures and small vessels. To evaluate the feasibility of using iso-osmolar contrast media containing a low iodine dose for CT cardiac angiography at 80 kilovolts (kVp) in neonates and infants. The iodixanol 270 group consisted of 79 CT scans and the iopromide 370 group of 62 CT scans in patients ≤1 year old. Objective measurement of the contrast enhancement was analyzed and contrast-to-noise ratios of the ascending aorta and left ventricle were calculated. Regarding subjective measurement, a four-point scale system was devised to evaluate degrees of contrast enhancement, image noise, motion artifact and overall image quality of each image set. Reader performance for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment was evaluated. Group objective and subjective measurements were nonsignificantly different. Overall sensitivity, specificity and diagnostic accuracy for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment were 42.8%, 59%, and 50%, respectively. The application of iodixanol 270 achieved optimal enhancement for performing pediatric cardiac CT angiography at 80 kVp in neonates and infants. Objective measurements of contrast enhancement and subjective image quality assessments were not statistically different in the iodixanol 270 and iopromide 370 groups. (orig.)

  2. Image manipulation software portable on different hardware platforms: what is the cost?

    Science.gov (United States)

    Ligier, Yves; Ratib, Osman M.; Funk, Matthieu; Perrier, Rene; Girard, Christian; Logean, Marianne

    1992-07-01

    A hospital wide PACS project is currently under development at the University Hospital of Geneva. The visualization and manipulation of images provided by different imaging modalities constitutes one of the most challenging components of a PACS. Because there are different requirements depending on the clinical usage, it was necessary for such a visualization software to be provided on different types of workstations in different sectors of the PACS. The user interface has to be the same independently of the underlying workstation. Beside, in addition to a standard set of image manipulation and processing tools there is a need for more specific clinical tools that should be easily adapted to specific medical requirements. To achieve operating and windowing systems: the standard Unix/X-11/OSF-Motif based workstations and the Macintosh family and should be easily ported on other systems. This paper describes the design of such a system and discusses the extra cost and efforts involved in the development of a portable and easily expandable software.

  3. Vertical bone measurements from cone beam computed tomography images using different software packages

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Taruska Ventorini; Neves, Frederico Sampaio; Moraes, Livia Almeida Bueno; Freitas, Deborah Queiroz, E-mail: tataventorini@hotmail.com [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Faculdade de Odontologia

    2015-03-01

    This article aimed at comparing the accuracy of linear measurement tools of different commercial software packages. Eight fully edentulous dry mandibles were selected for this study. Incisor, canine, premolar, first molar and second molar regions were selected. Cone beam computed tomography (CBCT) images were obtained with i-CAT Next Generation. Linear bone measurements were performed by one observer on the cross-sectional images using three different software packages: XoranCat®, OnDemand3D® and KDIS3D®, all able to assess DICOM images. In addition, 25% of the sample was reevaluated for the purpose of reproducibility. The mandibles were sectioned to obtain the gold standard for each region. Intraclass coefficients (ICC) were calculated to examine the agreement between the two periods of evaluation; the one-way analysis of variance performed with the post-hoc Dunnett test was used to compare each of the software-derived measurements with the gold standard. The ICC values were excellent for all software packages. The least difference between the software-derived measurements and the gold standard was obtained with the OnDemand3D and KDIS3D (‑0.11 and ‑0.14 mm, respectively), and the greatest, with the XoranCAT (+0.25 mm). However, there was no statistical significant difference between the measurements obtained with the different software packages and the gold standard (p > 0.05). In conclusion, linear bone measurements were not influenced by the software package used to reconstruct the image from CBCT DICOM data. (author)

  4. Vertical bone measurements from cone beam computed tomography images using different software packages

    International Nuclear Information System (INIS)

    Vasconcelos, Taruska Ventorini; Neves, Frederico Sampaio; Moraes, Livia Almeida Bueno; Freitas, Deborah Queiroz

    2015-01-01

    This article aimed at comparing the accuracy of linear measurement tools of different commercial software packages. Eight fully edentulous dry mandibles were selected for this study. Incisor, canine, premolar, first molar and second molar regions were selected. Cone beam computed tomography (CBCT) images were obtained with i-CAT Next Generation. Linear bone measurements were performed by one observer on the cross-sectional images using three different software packages: XoranCat®, OnDemand3D® and KDIS3D®, all able to assess DICOM images. In addition, 25% of the sample was reevaluated for the purpose of reproducibility. The mandibles were sectioned to obtain the gold standard for each region. Intraclass coefficients (ICC) were calculated to examine the agreement between the two periods of evaluation; the one-way analysis of variance performed with the post-hoc Dunnett test was used to compare each of the software-derived measurements with the gold standard. The ICC values were excellent for all software packages. The least difference between the software-derived measurements and the gold standard was obtained with the OnDemand3D and KDIS3D (‑0.11 and ‑0.14 mm, respectively), and the greatest, with the XoranCAT (+0.25 mm). However, there was no statistical significant difference between the measurements obtained with the different software packages and the gold standard (p > 0.05). In conclusion, linear bone measurements were not influenced by the software package used to reconstruct the image from CBCT DICOM data. (author)

  5. Three-dimensional imaging through turbid media based on polarization-difference liquid-crystal microlens array

    Science.gov (United States)

    Xin, Zhaowei; Wei, Dong; Li, Dapeng; Xie, Xingwang; Chen, Mingce; Zhang, Xinyu; Wang, Haiwei; Xie, Changsheng

    2018-02-01

    In this paper, a polarization difference liquid-crystal microlens array (PD-LCMLA) for three dimensional imaging application through turbid media is fabricated and demonstrated. This device is composed of a twisted nematic liquidcrystal cell (TNLCC), a polarizer and a liquid-crystal microlens array. The polarizer is sandwiched between the TNLCC and LCMLA to help the polarization difference system achieving the orthogonal polarization raw images. The prototyped camera for polarization difference imaging has been constructed by integrating the PD-LCMLA with an image sensor. The orthogonally polarized light-field images are recorded by switching the working state of the TNLCC. Here, by using a special microstructure in conjunction with the polarization-difference algorithm, we demonstrate that the three-dimensional information in the scattering media can be retrieved from the polarization-difference imaging system with an electrically tunable PD-LCMLA. We further investigate the system's potential function based on the flexible microstructure. The microstructure provides a wide operation range in the manipulation of incident beams and also emerges multiple operation modes for imaging applications, such as conventional planar imaging, polarization imaging mode, and polarization-difference imaging mode. Since the PD-LCMLA demonstrates a very low power consumption, multiple imaging modes and simple manufacturing, this kind of device presents a potential to be used in many other optical and electro-optical systems.

  6. Image-based phenotyping for non-destructive screening of different salinity tolerance traits in rice

    KAUST Repository

    Hairmansis, Aris

    2014-08-14

    Background Soil salinity is an abiotic stress wide spread in rice producing areas, limiting both plant growth and yield. The development of salt-tolerant rice requires efficient and high-throughput screening techniques to identify promising lines for salt affected areas. Advances made in image-based phenotyping techniques provide an opportunity to use non-destructive imaging to screen for salinity tolerance traits in a wide range of germplasm in a reliable, quantitative and efficient way. However, the application of image-based phenotyping in the development of salt-tolerant rice remains limited. Results A non-destructive image-based phenotyping protocol to assess salinity tolerance traits of two rice cultivars (IR64 and Fatmawati) has been established in this study. The response of rice to different levels of salt stress was quantified over time based on total shoot area and senescent shoot area, calculated from visible red-green-blue (RGB) and fluorescence images. The response of rice to salt stress (50, 75 and 100 mM NaCl) could be clearly distinguished from the control as indicated by the reduced increase of shoot area. The salt concentrations used had only a small effect on the growth of rice during the initial phase of stress, the shoot Na+ accumulation independent phase termed the ‘osmotic stress’ phase. However, after 20 d of treatment, the shoot area of salt stressed plants was reduced compared with non-stressed plants. This was accompanied by a significant increase in the concentration of Na+ in the shoot. Variation in the senescent area of the cultivars IR64 and Fatmawati in response to a high concentration of Na+ in the shoot indicates variation in tissue tolerance mechanisms between the cultivars. Conclusions Image analysis has the potential to be used for high-throughput screening procedures in the development of salt-tolerant rice. The ability of image analysis to discriminate between the different aspects of salt stress (shoot ion

  7. A fast time-difference inverse solver for 3D EIT with application to lung imaging.

    Science.gov (United States)

    Javaherian, Ashkan; Soleimani, Manuchehr; Moeller, Knut

    2016-08-01

    A class of sparse optimization techniques that require solely matrix-vector products, rather than an explicit access to the forward matrix and its transpose, has been paid much attention in the recent decade for dealing with large-scale inverse problems. This study tailors application of the so-called Gradient Projection for Sparse Reconstruction (GPSR) to large-scale time-difference three-dimensional electrical impedance tomography (3D EIT). 3D EIT typically suffers from the need for a large number of voxels to cover the whole domain, so its application to real-time imaging, for example monitoring of lung function, remains scarce since the large number of degrees of freedom of the problem extremely increases storage space and reconstruction time. This study shows the great potential of the GPSR for large-size time-difference 3D EIT. Further studies are needed to improve its accuracy for imaging small-size anomalies.

  8. CT coronary angiography: Influence of different cardiac reconstruction intervals on image quality and diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: marc.dewey@charite.de; Teige, Florian [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany); Rutsch, Wolfgang [Department of Cardiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: wolfgang.rutsch@charite.de; Schink, Tania [Department of Medical Biometry, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: peter.martus@charite.de; Hamm, Bernd [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)

    2008-07-15

    Purpose: To prospectively analyze image quality and diagnostic accuracy of different reconstruction intervals of coronary angiography using multislice computed tomography (MSCT). Materials and methods: For each of 47 patients, 10 ECG-gated MSCT reconstructions were generated throughout the RR interval from 0 to 90%, resulting in altogether 470 datasets. These datasets were randomly analyzed for image quality and accuracy and compared with conventional angiography. Statistical comparison of intervals was performed using nonparametric analysis for repeated measurements to account for clustering of arteries within patients. Results: Image reconstruction intervals centered at 80, 70, and 40% of the RR interval resulted (in that order) in the best overall image quality for all four main coronary vessels. Eighty percent reconstructions also yielded the highest diagnostic accuracy of all intervals. The combination of the three best intervals (80, 70, and 40%) significantly reduced the nondiagnostic rate as compared with 80% alone (p = 0.005). However, the optimal reconstruction interval combination achieved significantly improved specificities and nondiagnostic rates (p < 0.05). The optimal combination consisted of 1.7 {+-} 0.9 reconstruction intervals on average. In approximately half of the patients (49%, 23/47) a single reconstruction was optimal. In 18 (38%), 3 (6%), and 3 (6%) patients one, two, and three additional reconstruction intervals were required, respectively, to achieve optimal quality. In 28% of the patients the optimal combination consisted of reconstructions other than the three best intervals (80, 70, and 40%). Conclusion: Multiple image reconstruction intervals are essential to ensure high image quality and accuracy of CT coronary angiography.

  9. Images of alcohol in the transition to adulthood : Comparing different geographies: examples from Italy and Finland

    OpenAIRE

    Rolando, Sara

    2015-01-01

    The aim in this study is to narrow the gap in knowledge about how young people understand their direct (personal) and indirect (others ) drinking experiences by investigating images of alcohol (Sulkunen, 2007) among Italian and Finnish adolescents and young people on the threshold of adulthood. Italy and Finland are considered examples of geographies (Sulkunen, 2013) characterised by different social values and socialisation practices, but also facing common global challenges (Beck, 20...

  10. Diffusion tensor imaging tensor shape analysis for assessment of regional white matter differences.

    Science.gov (United States)

    Middleton, Dana M; Li, Jonathan Y; Lee, Hui J; Chen, Steven; Dickson, Patricia I; Ellinwood, N Matthew; White, Leonard E; Provenzale, James M

    2017-08-01

    Purpose The purpose of this study was to investigate a novel tensor shape plot analysis technique of diffusion tensor imaging data as a means to assess microstructural differences in brain tissue. We hypothesized that this technique could distinguish white matter regions with different microstructural compositions. Methods Three normal canines were euthanized at seven weeks old. Their brains were imaged using identical diffusion tensor imaging protocols on a 7T small-animal magnetic resonance imaging system. We examined two white matter regions, the internal capsule and the centrum semiovale, each subdivided into an anterior and posterior region. We placed 100 regions of interest in each of the four brain regions. Eigenvalues for each region of interest triangulated onto tensor shape plots as the weighted average of three shape metrics at the plot's vertices: CS, CL, and CP. Results The distribution of data on the plots for the internal capsule differed markedly from the centrum semiovale data, thus confirming our hypothesis. Furthermore, data for the internal capsule were distributed in a relatively tight cluster, possibly reflecting the compact and parallel nature of its fibers, while data for the centrum semiovale were more widely distributed, consistent with the less compact and often crossing pattern of its fibers. This indicates that the tensor shape plot technique can depict data in similar regions as being alike. Conclusion Tensor shape plots successfully depicted differences in tissue microstructure and reflected the microstructure of individual brain regions. This proof of principle study suggests that if our findings are reproduced in larger samples, including abnormal white matter states, the technique may be useful in assessment of white matter diseases.

  11. Regional differences in brain glucose metabolism determined by imaging mass spectrometry

    OpenAIRE

    André Kleinridders; Heather A. Ferris; Michelle L. Reyzer; Michaela Rath; Marion Soto; M. Lisa Manier; Jeffrey Spraggins; Zhihong Yang; Robert C. Stanton; Richard M. Caprioli; C. Ronald Kahn

    2018-01-01

    Objective: Glucose is the major energy substrate of the brain and crucial for normal brain function. In diabetes, the brain is subject to episodes of hypo- and hyperglycemia resulting in acute outcomes ranging from confusion to seizures, while chronic metabolic dysregulation puts patients at increased risk for depression and Alzheimer's disease. In the present study, we aimed to determine how glucose is metabolized in different regions of the brain using imaging mass spectrometry (IMS). Metho...

  12. Discrimination of Different Water Layers with TerraSAR X Images in "La Albufera de Valencia"

    Science.gov (United States)

    García Fernández, M. A.; Miguelsanz Muñoz, P.

    2009-04-01

    To analyze the capabilities of TerraSAR X Strip Map images in order to discriminate different water layers in the "Parque de la Albufera de Valencia", Spain, a test project was carried out. This place is a rice crop area under European and National Agro environmental regulation which obliges to preserve the habitat and to keep the rice plots flooded out of crop season, from October to January

  13. Three-dimensional ultrasonic imaging of concrete elements using different SAFT data acquisition and processing schemes

    International Nuclear Information System (INIS)

    Schickert, Martin

    2015-01-01

    Ultrasonic testing systems using transducer arrays and the SAFT (Synthetic Aperture Focusing Technique) reconstruction allow for imaging the internal structure of concrete elements. At one-sided access, three-dimensional representations of the concrete volume can be reconstructed in relatively great detail, permitting to detect and localize objects such as construction elements, built-in components, and flaws. Different SAFT data acquisition and processing schemes can be utilized which differ in terms of the measuring and computational effort and the reconstruction result. In this contribution, two methods are compared with respect to their principle of operation and their imaging characteristics. The first method is the conventional single-channel SAFT algorithm which is implemented using a virtual transducer that is moved within a transducer array by electronic switching. The second method is the Combinational SAFT algorithm (C-SAFT), also named Sampling Phased Array (SPA) or Full Matrix Capture/Total Focusing Method (TFM/FMC), which is realized using a combination of virtual transducers within a transducer array. Five variants of these two methods are compared by means of measurements obtained at test specimens containing objects typical of concrete elements. The automated SAFT imaging system FLEXUS is used for the measurements which includes a three-axis scanner with a 1.0 m × 0.8 m scan range and an electronically switched ultrasonic array consisting of 48 transducers in 16 groups. On the basis of two-dimensional and three-dimensional reconstructed images, qualitative and some quantitative results of the parameters image resolution, signal-to-noise ratio, measurement time, and computational effort are discussed in view of application characteristics of the SAFT variants

  14. In vivo imaging of the dynamics of different variants of EGFR in glioblastomas.

    Science.gov (United States)

    Shah, Khalid

    2011-01-01

    A number of altered pathways in cancer cells depend on growth factor receptors. The amplification/alteration of the epidermal growth factor receptor (EGFR) has been shown to play a significant role in enhancing tumor burden in a number of tumors, including malignant glioblastomas (GBM). To dissect the role of EGFR expression in tumor progression in mouse models of cancer and ultimately evaluate targeted therapies, it is necessary to visualize the dynamics of EGFR in real time in vivo. Non-invasive imaging based on quantitative and qualitative changes in light emission by fluorescent and bioluminescent markers offers a huge potential to facilitate drug development. Multiple approaches could be used to follow a molecular target or pathway with the fusion of a bioluminescent-fluorescent marker. This unit describes a protocol for simultaneously imaging EGFR activity and progression of GBM in a mouse model. Human glioma cells transduced with lentiviral vectors bearing different combinations of fluorescent and bioluminescent proteins either fused to EGFR or expressed alone can be grown as monolayers and maintained over several passages. The unit begins with a method for transducing glioma cells with lentiviral vectors for stable expression of these fluorescent and bioluminescent markers in vitro, followed by transplantation of engineered glioma cells in mice, and, finally, sequential bioluminescent imaging of EGFR expression and GBM progression in mice. The protocol details characterization of engineered glioma cells in culture, surgical preparation, craniotomy, cell implantation, animal recovery, and imaging procedures to study kinetics of EGFR expression and GBM progression.

  15. Time-difference imaging of magnetic induction tomography in a three-layer brain physical phantom

    International Nuclear Information System (INIS)

    Liu, Ruigang; Li, Ye; Fu, Feng; You, Fusheng; Shi, Xuetao; Dong, Xiuzhen

    2014-01-01

    Magnetic induction tomography (MIT) is a contactless and noninvasive technique to reconstruct the conductivity distribution in a human cross-section. In this paper, we want to study the feasibility of imaging the low-contrast perturbation and small volume object in human brains. We construct a three-layer brain physical phantom which mimics the real conductivity distribution of brains by introducing an artificial skull layer. Using our MIT data acquisition system on this phantom and differential algorithm, we have obtained a series of reconstructed images of conductivity perturbation objects. All of the conductivity perturbation objects in the brain phantom can be clearly distinguished in the reconstructed images. The minimum detectable conductivity difference between the object and the background is 0.03 S m −1  (12.5%). The minimum detectable inner volume of the objects is 3.4 cm 3 . The three-layer brain physical phantom is able to simulate the conductivity distribution of the main structures of a human brain. The images of the low-contrast perturbation and small volume object show the prospect of MIT in the future. (paper)

  16. [Monitoring radiofrequency ablation by ultrasound temperature imaging and elastography under different power intensities].

    Science.gov (United States)

    Geng, Xiaonan; Li, Qiang; Tsui, Pohsiang; Wang, Chiaoyin; Liu, Haoli

    2013-09-01

    To evaluate the reliability of diagnostic ultrasound-based temperature and elasticity imaging during radiofrequency ablation (RFA) through ex vivo experiments. Procine liver samples (n=7) were employed for RFA experiments with exposures of different power intensities (10 and 50w). The RFA process was monitored by a diagnostic ultrasound imager and the information were postoperatively captured for further temperature and elasticity image analysis. Infrared thermometry was concurrently applied to provide temperature change calibration during the RFA process. Results from this study demonstrated that temperature imaging was valid under 10 W RF exposure (r=0.95), but the ablation zone was no longer consistent with the reference infrared temperature distribution under high RF exposures. The elasticity change could well reflect the ablation zone under a 50 W exposure, whereas under low exposures, the thermal lesion could not be well detected due to the limited range of temperature elevation and incomplete tissue necrosis. Diagnostic ultrasound-based temperature and elastography is valid for monitoring thr RFA process. Temperature estimation can well reflect mild-power RF ablation dynamics, whereas the elastic-change estimation can can well predict the tissue necrosis. This study provide advances toward using diagnostic ultrasound to monitor RFA or other thermal-based interventions.

  17. Color measurement of tea leaves at different drying periods using hyperspectral imaging technique.

    Science.gov (United States)

    Xie, Chuanqi; Li, Xiaoli; Shao, Yongni; He, Yong

    2014-01-01

    This study investigated the feasibility of using hyperspectral imaging technique for nondestructive measurement of color components (ΔL*, Δa* and Δb*) and classify tea leaves during different drying periods. Hyperspectral images of tea leaves at five drying periods were acquired in the spectral region of 380-1030 nm. The three color features were measured by the colorimeter. Different preprocessing algorithms were applied to select the best one in accordance with the prediction results of partial least squares regression (PLSR) models. Competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were used to identify the effective wavelengths, respectively. Different models (least squares-support vector machine [LS-SVM], PLSR, principal components regression [PCR] and multiple linear regression [MLR]) were established to predict the three color components, respectively. SPA-LS-SVM model performed excellently with the correlation coefficient (rp) of 0.929 for ΔL*, 0.849 for Δa*and 0.917 for Δb*, respectively. LS-SVM model was built for the classification of different tea leaves. The correct classification rates (CCRs) ranged from 89.29% to 100% in the calibration set and from 71.43% to 100% in the prediction set, respectively. The total classification results were 96.43% in the calibration set and 85.71% in the prediction set. The result showed that hyperspectral imaging technique could be used as an objective and nondestructive method to determine color features and classify tea leaves at different drying periods.

  18. Color measurement of tea leaves at different drying periods using hyperspectral imaging technique.

    Directory of Open Access Journals (Sweden)

    Chuanqi Xie

    Full Text Available This study investigated the feasibility of using hyperspectral imaging technique for nondestructive measurement of color components (ΔL*, Δa* and Δb* and classify tea leaves during different drying periods. Hyperspectral images of tea leaves at five drying periods were acquired in the spectral region of 380-1030 nm. The three color features were measured by the colorimeter. Different preprocessing algorithms were applied to select the best one in accordance with the prediction results of partial least squares regression (PLSR models. Competitive adaptive reweighted sampling (CARS and successive projections algorithm (SPA were used to identify the effective wavelengths, respectively. Different models (least squares-support vector machine [LS-SVM], PLSR, principal components regression [PCR] and multiple linear regression [MLR] were established to predict the three color components, respectively. SPA-LS-SVM model performed excellently with the correlation coefficient (rp of 0.929 for ΔL*, 0.849 for Δa*and 0.917 for Δb*, respectively. LS-SVM model was built for the classification of different tea leaves. The correct classification rates (CCRs ranged from 89.29% to 100% in the calibration set and from 71.43% to 100% in the prediction set, respectively. The total classification results were 96.43% in the calibration set and 85.71% in the prediction set. The result showed that hyperspectral imaging technique could be used as an objective and nondestructive method to determine color features and classify tea leaves at different drying periods.

  19. [Study on the correlation between syndrome differ classification of knee osteoarthritis and X-ray image].

    Science.gov (United States)

    Jin, Li-Kun; Zhang, Guo-Zhong; Tang, Ke; Liu, Yang

    2010-12-01

    To study the correlation between syndrome differ classification of knee osteoarthritis and X-ray image, so as to provide evidence for clinical diagnosis and treatment. From Jun. 2007 to Dec. 2007, 78 patients (108 knees) with knee osteoarthritis were reviewed, including 65 females (89 knees) and 13 males (19 knees), ranging in age from 41 to 77 years. According to the standards for the differentiation of syndrome in the treatment of knee osteoarthritis defined in Principle of Clinical Research for New Traditional Herbs, the patients were divided into three types: Type I, insufficiency of the liver and kidney, with stagnation of tendons and muscles, 43 knees; Type II, insufficiency of the spleen and kidney, with dampness infusion into bone and joints, 26 knees; Type I, deficiency of the liver and kidney, with inter-obstruction of phlegm and stasis 39 knees. Normotopia and lateral plain film of knee joint of weigh loading and in erect position, and patellofemoral Skyline plain flim was taken. Joint space narrow, osteophyte generation, subchondral osteosclerosis and subchondral cystic degeneration were evaluated. All data were analyzed by K independent samples nonparametric test in order to find out the correlation between syndrome differ classification of knee osteoarthritis and X-ray image. It was shown that after K independent samples nonparametric test about syndrome differ classification of knee osteoarthritis and X-ray image: there were significant differences among three types about lateral patella osteophyte, condyles of tibia osteophyte and Type II was the most serious, Type I was secondary, Type II was the lightest. Other index had no obvious difference among the three groups. There is certain correlation between syndrome differ classification of knee osteoarthritis and X-ray image. There are significant differences among three types about lateral patella osteophyte, condyles of tibia osteophyte, the Type II is the most serious,Type I is secondary, Type II

  20. Sex differences in the tracer distribution on stress thallium-201 imaging, (1)

    International Nuclear Information System (INIS)

    Tamaki, Nagara; Koda, Hideki; Adachi, Yukihide; Sugihara, Takao; Kato, Mihoko; Tanaka, Nobuyuki; Tamari, Kimimasa.

    1988-01-01

    To determine the sex differences in the tracer distribution on stress thallium-201 imaging, the studies of 18 normal males and 18 normal females were subjected to quantitative circumferential profile analysis in each projection image. Although the exercise duration was shorter in females (11±3 min) than in males (14±3 min) (p<0.01), the peak heart rate, peak systolic pressure and the lung-to-myocardial count ratio were similar between them. The averaged profile curves in female showed a significant reduction in tracer uptake in anterior and upper septal regions, particularly in the study of lateral view, which may be attributed to breast attenuation. In addition, the percent washout of thallium in 3 hours was higher in females (48±8%) than in males (43±7%) (p<0.01), particularly in the study of anterior view. We conclude that important differences in the pattern of thallium uptake and washout between males and females should be considered for interpretation of stress thallium imaging. (author)

  1. Classification of optical coherence tomography images for diagnosing different ocular diseases

    Science.gov (United States)

    Gholami, Peyman; Sheikh Hassani, Mohsen; Kuppuswamy Parthasarathy, Mohana; Zelek, John S.; Lakshminarayanan, Vasudevan

    2018-03-01

    Optical Coherence tomography (OCT) images provide several indicators, e.g., the shape and the thickness of different retinal layers, which can be used for various clinical and non-clinical purposes. We propose an automated classification method to identify different ocular diseases, based on the local binary pattern features. The database consists of normal and diseased human eye SD-OCT images. We use a multiphase approach for building our classifier, including preprocessing, Meta learning, and active learning. Pre-processing is applied to the data to handle missing features from images and replace them with the mean or median of the corresponding feature. All the features are run through a Correlation-based Feature Subset Selection algorithm to detect the most informative features and omit the less informative ones. A Meta learning approach is applied to the data, in which a SVM and random forest are combined to obtain a more robust classifier. Active learning is also applied to strengthen our classifier around the decision boundary. The primary experimental results indicate that our method is able to differentiate between the normal and non-normal retina with an area under the ROC curve (AUC) of 98.6% and also to diagnose the three common retina-related diseases, i.e., Age-related Macular Degeneration, Diabetic Retinopathy, and Macular Hole, with an AUC of 100%, 95% and 83.8% respectively. These results indicate a better performance of the proposed method compared to most of the previous works in the literature.

  2. Individual differences in processing emotional images after reading disgusting and neutral sentences.

    Science.gov (United States)

    Hartigan, Alex; Richards, Anne

    2017-11-21

    The present study examined the extent to which Event Related Potentials (ERPs) evoked by disgusting, threatening and neutral photographic images were influenced by disgust propensity, disgust sensitivity and attentional control following exposure to disgusting information. Emotional cognition was manipulated by instructing participants to remember either disgusting or neutral sentences; participants in both groups then viewed emotional images while ERPs were recorded. Disgust propensity was associated with a reduced Late Positive Potential (LPP) gap between threatening and neutral stimuli (an effect driven by a rise in the LPP for neutral images) but only amongst individuals who were exposed to disgusting sentences. The typical LPP increase for disgust over neutral was reduced by attentional shifting capacity but only for individuals who were not previously exposed to disgust. There was also a persistent occipital shifted late positivity that was enhanced for disgust for the entire LPP window and was independent of exposure. Results suggest that emotion specific ERP effects can emerge within the broad unpleasant emotional category in conjunction with individual differences and prior emotional exposure. These results have important implications for the ways in which the perception of emotion is impacted by short term cognitive influences and longer term individual differences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Different Imaging Strategies in Patients With Possible Basilar Artery Occlusion: Cost-Effectiveness Analysis.

    Science.gov (United States)

    Beyer, Sebastian E; Hunink, Myriam G; Schöberl, Florian; von Baumgarten, Louisa; Petersen, Steffen E; Dichgans, Martin; Janssen, Hendrik; Ertl-Wagner, Birgit; Reiser, Maximilian F; Sommer, Wieland H

    2015-07-01

    This study evaluated the cost-effectiveness of different noninvasive imaging strategies in patients with possible basilar artery occlusion. A Markov decision analytic model was used to evaluate long-term outcomes resulting from strategies using computed tomographic angiography (CTA), magnetic resonance imaging, nonenhanced CT, or duplex ultrasound with intravenous (IV) thrombolysis being administered after positive findings. The analysis was performed from the societal perspective based on US recommendations. Input parameters were derived from the literature. Costs were obtained from United States costing sources and published literature. Outcomes were lifetime costs, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios, and net monetary benefits, with a willingness-to-pay threshold of $80,000 per QALY. The strategy with the highest net monetary benefit was considered the most cost-effective. Extensive deterministic and probabilistic sensitivity analyses were performed to explore the effect of varying parameter values. In the reference case analysis, CTA dominated all other imaging strategies. CTA yielded 0.02 QALYs more than magnetic resonance imaging and 0.04 QALYs more than duplex ultrasound followed by CTA. At a willingness-to-pay threshold of $80,000 per QALY, CTA yielded the highest net monetary benefits. The probability that CTA is cost-effective was 96% at a willingness-to-pay threshold of $80,000/QALY. Sensitivity analyses showed that duplex ultrasound was cost-effective only for a prior probability of ≤0.02 and that these results were only minimally influenced by duplex ultrasound sensitivity and specificity. Nonenhanced CT and magnetic resonance imaging never became the most cost-effective strategy. Our results suggest that CTA in patients with possible basilar artery occlusion is cost-effective. © 2015 The Authors.

  4. Impact of Delayed Time to Advanced Imaging on Missed Appointments Across Different Demographic and Socioeconomic Factors.

    Science.gov (United States)

    Daye, Dania; Carrodeguas, Emmanuel; Glover, McKinley; Guerrier, Claude Emmanuel; Harvey, H Benjamin; Flores, Efrén J

    2018-05-01

    The aim of this study was to investigate the impact of wait days (WDs) on missed outpatient MRI appointments across different demographic and socioeconomic factors. An institutional review board-approved retrospective study was conducted among adult patients scheduled for outpatient MRI during a 12-month period. Scheduling data and demographic information were obtained. Imaging missed appointments were defined as missed scheduled imaging encounters. WDs were defined as the number of days from study order to appointment. Multivariate logistic regression was applied to assess the contribution of race and socioeconomic factors to missed appointments. Linear regression was performed to assess the relationship between missed appointment rates and WDs stratified by race, income, and patient insurance groups with analysis of covariance statistics. A total of 42,727 patients met the inclusion criteria. Mean WDs were 7.95 days. Multivariate regression showed increased odds ratio for missed appointments for patients with increased WDs (7-21 days: odds ratio [OR], 1.39; >21 days: OR, 1.77), African American patients (OR, 1.71), Hispanic patients (OR, 1.30), patients with noncommercial insurance (OR, 2.00-2.55), and those with imaging performed at the main hospital campus (OR, 1.51). Missed appointment rate linearly increased with WDs, with analysis of covariance revealing underrepresented minorities and Medicaid insurance as significant effect modifiers. Increased WDs for advanced imaging significantly increases the likelihood of missed appointments. This effect is most pronounced among underrepresented minorities and patients with lower socioeconomic status. Efforts to reduce WDs may improve equity in access to and utilization of advanced diagnostic imaging for all patients. Copyright © 2018. Published by Elsevier Inc.

  5. Tracheal collapse diagnosed by multidetector computed tomography: evaluation of different image analysis methods

    DEFF Research Database (Denmark)

    Nygaard, Mette; Bendstrup, Elisabeth; Dahl, Ronald

    2017-01-01

    diseases when using an expiratory collapse of = 50% as a threshold. The four methods were comparable with highly significant Pearsons correlation coefficients (0.764-0.856). However, the four methods identified different patients with collapse of = 50 There was no correlation between symptoms...... and the degree of collapse. Conclusion: The different methods identify tracheal collapse in different patients. Hence, the diagnosis of excessive tracheal collapse can not rely solely on MDCT images. Generally, there is a poor correlation between symptoms and the degree of collapse in the different methods....... However, when using the maximal collapse, there is some correlation with symptoms. When in doubt regarding the diagnosis, further investigations, such as bronchoscopy, should be carried out....

  6. Comparing Image Perception of Bladder Tumors in Four Different Storz Professional Image Enhancement System Modalities Using the íSPIES App

    NARCIS (Netherlands)

    Kamphuis, Guido M.; de Bruin, D. Martijn; Brandt, Martin J.; Knoll, Thomas; Conort, Pierre; Lapini, Alberto; Dominguez-Escrig, Jose L.; de La Rosette, Jean J. M. C. H.

    2016-01-01

    To evaluate the variation of interpretation of the same bladder urothelium image in different Storz Professional Image Enhancement System (SPIES) modalities. SPIES contains a White light (WL), Spectra A (SA), Spectra B (SB), and Clara and Chroma combined (CC) modality. An App for the iPAD retina was

  7. A comparison with result of normalized image to different template image on statistical parametric mapping of ADHD children patients

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong Ho [Kyonggi University, Suwon (Korea, Republic of); Park, Soung Ock; Kwon, Soo Il [Dongnam Health College, Suwon (Korea, Republic of); Joh, Chol Woo; Yoon, Seok Nam [Medical College, Ajou University, Suwon (Korea, Republic of)

    2003-06-15

    We studied 64 ADHD children patients group (4 {approx} 15 ys, mean age: 8 {+-} 2.6 ys. M/F: 52/12) and 12 normal group (6 {approx} 7 ys, mean age: 9.4 {+-} 3.4 ys, M/F: 8/4) of the brain had been used to analysis of blood flow between normal and ADHD group. For analysis of Children ADHD, we used 12 children's mean brain images and made Template image of SPM99 program. In crease of blood flow (P-value 0.05), the result of normalized images to Template image to offer from SPM99 program, showed significant cluster in inter-Hemispheric and occipital Lobe, in the case of normalized images to children template image, showed inter-hemispheric and parietal lobe.

  8. A comparison with result of normalized image to different template image on statistical parametric mapping of ADHD children patients

    International Nuclear Information System (INIS)

    Shin, Dong Ho; Park, Soung Ock; Kwon, Soo Il; Joh, Chol Woo; Yoon, Seok Nam

    2003-01-01

    We studied 64 ADHD children patients group (4 ∼ 15 ys, mean age: 8 ± 2.6 ys. M/F: 52/12) and 12 normal group (6 ∼ 7 ys, mean age: 9.4 ± 3.4 ys, M/F: 8/4) of the brain had been used to analysis of blood flow between normal and ADHD group. For analysis of Children ADHD, we used 12 children's mean brain images and made Template image of SPM99 program. In crease of blood flow (P-value 0.05), the result of normalized images to Template image to offer from SPM99 program, showed significant cluster in inter-Hemispheric and occipital Lobe, in the case of normalized images to children template image, showed inter-hemispheric and parietal lobe

  9. THE DIFFERENCE IMAGING PIPELINE FOR THE TRANSIENT SEARCH IN THE DARK ENERGY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, R.; Scolnic, D. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Marriner, J.; Finley, D. A.; Wester, W. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Childress, M.; Yuan, F. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Australian National University, Canberra ACT 2611 (Canada); Covarrubias, R. [National Center for Supercomputing Applications, 1205 West Clark St., Urbana, IL 61801 (United States); D’Andrea, C. B.; Nichol, R. C.; Papadopoulos, A. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Fischer, J.; Sako, M. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Foley, R. J. [Department of Astronomy, University of Illinois, 1002 W. Green Street, Urbana, IL 61801 (United States); Goldstein, D. [Department of Astronomy, University of California, Berkeley, 501 Campbell Hall, Berkeley, CA 94720 (United States); Gupta, R. R. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Kuehn, K. [Australian Astronomical Observatory, North Ryde, NSW 2113 (Australia); Marcha, M. [Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Smith, M.; Sullivan, M., E-mail: kessler@kicp.uchicago.edu [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Collaboration: DES Collaboration; and others

    2015-12-15

    We describe the operation and performance of the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from 2013 August through 2014 February. DES-SN is a search for transients in which ten 3 deg{sup 2} fields are repeatedly observed in the g, r, i, z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae (SNe Ia) with the goal of measuring dark energy parameters. The essential DiffImg functions are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are ∼130 detections per deg{sup 2} per observation in each band, of which only ∼25% are artifacts. Of the ∼7500 transients discovered by DES-SN in its first observing season, each requiring a detection on at least two separate nights, Monte Carlo (MC) simulations predict that 27% are expected to be SNe Ia or core-collapse SNe. Another ∼30% of the transients are artifacts in which a small number of observations satisfy the selection criteria for a single-epoch detection. Spectroscopic analysis shows that most of the remaining transients are AGNs and variable stars. Fake SNe Ia are overlaid onto the images to rigorously evaluate detection efficiencies and to understand the DiffImg performance. The DiffImg efficiency measured with fake SNe agrees well with expectations from a MC simulation that uses analytical calculations of the fluxes and their uncertainties. In our 8 “shallow” fields with single-epoch 50% completeness depth ∼23.5, the SN Ia efficiency falls to 1/2 at redshift z ≈ 0.7; in our 2

  10. Shear strain determination of the polymer polydimethysiloxane (PMDS) using digital image correlation in different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    De Oliveira, G N [Pos-graduacao em Engenharia Mecanica, TEM/PGMEC, Universidade Federal Fluminense, Rua Passo da Patria, 156, Niteroi, R.J., Brazil, Cep.: 24.210-240 (Brazil); Nunes, L C S [Laboratorio de Mecanica Teorica e Aplicada, Departamento de Engenharia Mecanica, Universidade Federal Fluminense, Rua Passo da Patria, 156, Niteroi, R.J., Brazil, Cep.: 24.210-240 (Brazil); Dos Santos, P A M, E-mail: pams@if.uff.br [Instituto de Fisica, Laboratorio de Optica Nao-linear e Aplicada, Universidade Federal Fluminense, Av. Gal. Nilton Tavares de Souza, s/n, Gragoata, Niteroi, R.J., Brazil, Cep.:24.210-346 (Brazil)

    2011-01-01

    In the present work a digital image correlation (DIC) method is used in order to analyze the adhesive shear modulus of poly-dimethylsiloxane (PDMS) submitted to different loads and temperatures. This is an optical-numerical full-field surface displacement measurement method. It is based on a comparison between two images of a specimen coated by a random speckled pattern in the undeformed and in the deformed states. A single lap joint testing is performed. This is a standard test specimen for characterizing adhesive properties and it is considered the simplest form of adhesive joints. For the single lap joint specimen, steel adherends are bonded using a flexible rubber elastic polymer (PDMS), which is a commercially available silicone elastic rubber.

  11. Review: magnetic resonance imaging of male/female differences in human adolescent brain anatomy

    Directory of Open Access Journals (Sweden)

    Giedd Jay N

    2012-08-01

    Full Text Available Abstract Improvements in neuroimaging technologies, and greater access to their use, have generated a plethora of data regarding male/female differences in the developing brain. Examination of these differences may shed light on the pathophysiology of the many illnesses that differ between the sexes and ultimately lead to more effective interventions. In this review, we attempt to synthesize the anatomic magnetic resonance imaging (MRI literature of male/female brain differences with emphasis on studies encompassing adolescence – a time of divergence in physical and behavioral characteristics. Across all ages total brain size is consistently reported to be about 10% larger in males. Structures commonly reported to be different between sexes include the caudate nucleus, amygdala, hippocampus, and cerebellum – all noted to have a relatively high density of sex steroid receptors. The direction and magnitude of reported brain differences depends on the methodology of data acquisition and analysis, whether and how the subcomponents are adjusted for the total brain volume difference, and the age of the participants in the studies. Longitudinal studies indicate regional cortical gray matter volumes follow inverted U shaped developmental trajectories with peak size occurring one to three years earlier in females. Cortical gray matter differences are modulated by androgen receptor genotyope and by circulating levels of hormones. White matter volumes increase throughout childhood and adolescence in both sexes but more rapidly in adolescent males resulting in an expanding magnitude of sex differences from childhood to adulthood.

  12. MO-DE-207A-09: Low-Dose CT Image Reconstruction Via Learning From Different Patient Normal-Dose Images

    Energy Technology Data Exchange (ETDEWEB)

    Han, H; Xing, L [Stanford University, Palo Alto, CA (United States); Liang, Z [Stony Brook University, Stony Brook, NY (United States)

    2016-06-15

    Purpose: To investigate a novel low-dose CT (LdCT) image reconstruction strategy for lung CT imaging in radiation therapy. Methods: The proposed approach consists of four steps: (1) use the traditional filtered back-projection (FBP) method to reconstruct the LdCT image; (2) calculate structure similarity (SSIM) index between the FBP-reconstructed LdCT image and a set of normal-dose CT (NdCT) images, and select the NdCT image with the highest SSIM as the learning source; (3) segment the NdCT source image into lung and outside tissue regions via simple thresholding, and adopt multiple linear regression to learn high-order Markov random field (MRF) pattern for each tissue region in the NdCT source image; (4) segment the FBP-reconstructed LdCT image into lung and outside regions as well, and apply the learnt MRF prior in each tissue region for statistical iterative reconstruction of the LdCT image following the penalized weighted least squares (PWLS) framework. Quantitative evaluation of the reconstructed images was based on the signal-to-noise ratio (SNR), local binary pattern (LBP) and histogram of oriented gradients (HOG) metrics. Results: It was observed that lung and outside tissue regions have different MRF patterns predicted from the NdCT. Visual inspection showed that our method obviously outperformed the traditional FBP method. Comparing with the region-smoothing PWLS method, our method has, in average, 13% increase in SNR, 15% decrease in LBP difference, and 12% decrease in HOG difference from reference standard for all regions of interest, which indicated the superior performance of the proposed method in terms of image resolution and texture preservation. Conclusion: We proposed a novel LdCT image reconstruction method by learning similar image characteristics from a set of NdCT images, and the to-be-learnt NdCT image does not need to be scans from the same subject. This approach is particularly important for enhancing image quality in radiation therapy.

  13. MO-DE-207A-09: Low-Dose CT Image Reconstruction Via Learning From Different Patient Normal-Dose Images

    International Nuclear Information System (INIS)

    Han, H; Xing, L; Liang, Z

    2016-01-01

    Purpose: To investigate a novel low-dose CT (LdCT) image reconstruction strategy for lung CT imaging in radiation therapy. Methods: The proposed approach consists of four steps: (1) use the traditional filtered back-projection (FBP) method to reconstruct the LdCT image; (2) calculate structure similarity (SSIM) index between the FBP-reconstructed LdCT image and a set of normal-dose CT (NdCT) images, and select the NdCT image with the highest SSIM as the learning source; (3) segment the NdCT source image into lung and outside tissue regions via simple thresholding, and adopt multiple linear regression to learn high-order Markov random field (MRF) pattern for each tissue region in the NdCT source image; (4) segment the FBP-reconstructed LdCT image into lung and outside regions as well, and apply the learnt MRF prior in each tissue region for statistical iterative reconstruction of the LdCT image following the penalized weighted least squares (PWLS) framework. Quantitative evaluation of the reconstructed images was based on the signal-to-noise ratio (SNR), local binary pattern (LBP) and histogram of oriented gradients (HOG) metrics. Results: It was observed that lung and outside tissue regions have different MRF patterns predicted from the NdCT. Visual inspection showed that our method obviously outperformed the traditional FBP method. Comparing with the region-smoothing PWLS method, our method has, in average, 13% increase in SNR, 15% decrease in LBP difference, and 12% decrease in HOG difference from reference standard for all regions of interest, which indicated the superior performance of the proposed method in terms of image resolution and texture preservation. Conclusion: We proposed a novel LdCT image reconstruction method by learning similar image characteristics from a set of NdCT images, and the to-be-learnt NdCT image does not need to be scans from the same subject. This approach is particularly important for enhancing image quality in radiation therapy.

  14. Intensity of prolactinoma on T2-weighted magnetic resonance imaging: towards another gender difference

    Energy Technology Data Exchange (ETDEWEB)

    Kreutz, Julie [University Hospital Sart-Tilman, Department of Radiology, Liege (Belgium); Centre Hospitalier Universitaire de Liege, Domaine Universitaire du Sart Tilman, Service d' Imagerie Medicale, Liege (Belgium); Vroonen, Laurent; Petrossians, Patrick; Rostomyan, Liliya; Beckers, Albert [University Hospital Sart-Tilman, Department of Endocrinology, Liege (Belgium); Cattin, Francoise [University Hospital Besancon, Department of Radiology, Besancon (France); Thiry, Albert [University Hospital Sart-Tilman, Department of Pathology, Liege (Belgium); Tshibanda, Luaba [University Hospital Sart-Tilman, Department of Radiology, Liege (Belgium); Bonneville, Jean-Francois [University Hospital Sart-Tilman, Department of Radiology, Liege (Belgium); University Hospital Sart-Tilman, Department of Endocrinology, Liege (Belgium)

    2015-07-15

    Clinical presentations of prolactinomas are quite different between genders. In comparison with women's prolactinoma, those in men showed predominance of large tumors with high prolactin (PRL) levels. This preponderance could be attributed to a greater proliferative potential of the tumors. Differences in magnetic resonance imaging (MRI) signal at diagnosis have not been yet clearly evaluated. We conduct a retrospective study comparing MRI signal intensity (SI) on T2-weighted images (T2-WI) between 41 men and 41 women to investigate whether or not men prolactinoma present specific features. In addition to the size of the adenoma and PRL levels (P < 0001), prolactinomas in men also exhibit differences from those in women in signal on T2-WI on MRI (P < 0001). Women's prolactinomas are mostly of high SI on T2-WI while men's prolactinomas exhibit a more heterogeneous pattern of SI on T2-WI. Prolactinomas presenting with low SI on T2-WI are almost exclusively encountered in men. Presence of T2-WI hypointensities in pituitary adenoma can be predictive of a different subtype of prolactinoma almost encountered in men and possibly translate the presence of spherical amyloid deposits, in agreement with the literature. (orig.)

  15. Intensity of prolactinoma on T2-weighted magnetic resonance imaging: towards another gender difference

    International Nuclear Information System (INIS)

    Kreutz, Julie; Vroonen, Laurent; Petrossians, Patrick; Rostomyan, Liliya; Beckers, Albert; Cattin, Francoise; Thiry, Albert; Tshibanda, Luaba; Bonneville, Jean-Francois

    2015-01-01

    Clinical presentations of prolactinomas are quite different between genders. In comparison with women's prolactinoma, those in men showed predominance of large tumors with high prolactin (PRL) levels. This preponderance could be attributed to a greater proliferative potential of the tumors. Differences in magnetic resonance imaging (MRI) signal at diagnosis have not been yet clearly evaluated. We conduct a retrospective study comparing MRI signal intensity (SI) on T2-weighted images (T2-WI) between 41 men and 41 women to investigate whether or not men prolactinoma present specific features. In addition to the size of the adenoma and PRL levels (P < 0001), prolactinomas in men also exhibit differences from those in women in signal on T2-WI on MRI (P < 0001). Women's prolactinomas are mostly of high SI on T2-WI while men's prolactinomas exhibit a more heterogeneous pattern of SI on T2-WI. Prolactinomas presenting with low SI on T2-WI are almost exclusively encountered in men. Presence of T2-WI hypointensities in pituitary adenoma can be predictive of a different subtype of prolactinoma almost encountered in men and possibly translate the presence of spherical amyloid deposits, in agreement with the literature. (orig.)

  16. Variability of textural features in FDG PET images due to different acquisition modes and reconstruction parameters.

    Science.gov (United States)

    Galavis, Paulina E; Hollensen, Christian; Jallow, Ngoneh; Paliwal, Bhudatt; Jeraj, Robert

    2010-10-01

    Characterization of textural features (spatial distributions of image intensity levels) has been considered as a tool for automatic tumor segmentation. The purpose of this work is to study the variability of the textural features in PET images due to different acquisition modes and reconstruction parameters. Twenty patients with solid tumors underwent PET/CT scans on a GE Discovery VCT scanner, 45-60 minutes post-injection of 10 mCi of [(18)F]FDG. Scans were acquired in both 2D and 3D modes. For each acquisition the raw PET data was reconstructed using five different reconstruction parameters. Lesions were segmented on a default image using the threshold of 40% of maximum SUV. Fifty different texture features were calculated inside the tumors. The range of variations of the features were calculated with respect to the average value. Fifty textural features were classified based on the range of variation in three categories: small, intermediate and large variability. Features with small variability (range ≤ 5%) were entropy-first order, energy, maximal correlation coefficient (second order feature) and low-gray level run emphasis (high-order feature). The features with intermediate variability (10% ≤ range ≤ 25%) were entropy-GLCM, sum entropy, high gray level run emphsis, gray level non-uniformity, small number emphasis, and entropy-NGL. Forty remaining features presented large variations (range > 30%). Textural features such as entropy-first order, energy, maximal correlation coefficient, and low-gray level run emphasis exhibited small variations due to different acquisition modes and reconstruction parameters. Features with low level of variations are better candidates for reproducible tumor segmentation. Even though features such as contrast-NGTD, coarseness, homogeneity, and busyness have been previously used, our data indicated that these features presented large variations, therefore they could not be considered as a good candidates for tumor

  17. Variability of textural features in FDG PET images due to different acquisition modes and reconstruction parameters

    International Nuclear Information System (INIS)

    Galavis, Paulina E.; Jallow, Ngoneh; Paliwal, Bhudatt; Jeraj, Robert; Hollensen, Christian

    2010-01-01

    Background. Characterization of textural features (spatial distributions of image intensity levels) has been considered as a tool for automatic tumor segmentation. The purpose of this work is to study the variability of the textural features in PET images due to different acquisition modes and reconstruction parameters. Material and methods. Twenty patients with solid tumors underwent PET/CT scans on a GE Discovery VCT scanner, 45-60 minutes post-injection of 10 mCi of [ 18 F]FDG. Scans were acquired in both 2D and 3D modes. For each acquisition the raw PET data was reconstructed using five different reconstruction parameters. Lesions were segmented on a default image using the threshold of 40% of maximum SUV. Fifty different texture features were calculated inside the tumors. The range of variations of the features were calculated with respect to the average value. Results. Fifty textural features were classified based on the range of variation in three categories: small, intermediate and large variability. Features with small variability (range = 5%) were entropy-first order, energy, maximal correlation coefficient (second order feature) and low-gray level run emphasis (high-order feature). The features with intermediate variability (10% = range = 25%) were entropy-GLCM, sum entropy, high gray level run emphasis, gray level non-uniformity, small number emphasis, and entropy-NGL. Forty remaining features presented large variations (range > 30%). Conclusion. Textural features such as entropy-first order, energy, maximal correlation coefficient, and low-gray level run emphasis exhibited small variations due to different acquisition modes and reconstruction parameters. Features with low level of variations are better candidates for reproducible tumor segmentation. Even though features such as contrast-NGTD, coarseness, homogeneity, and busyness have been previously used, our data indicated that these features presented large variations, therefore they could not be

  18. Cone Beam CT vs. Fan Beam CT: A Comparison of Image Quality and Dose Delivered Between Two Differing CT Imaging Modalities.

    Science.gov (United States)

    Lechuga, Lawrence; Weidlich, Georg A

    2016-09-12

    A comparison of image quality and dose delivered between two differing computed tomography (CT) imaging modalities-fan beam and cone beam-was performed. A literature review of quantitative analyses for various image quality aspects such as uniformity, signal-to-noise ratio, artifact presence, spatial resolution, modulation transfer function (MTF), and low contrast resolution was generated. With these aspects quantified, cone beam computed tomography (CBCT) shows a superior spatial resolution to that of fan beam, while fan beam shows a greater ability to produce clear and anatomically correct images with better soft tissue differentiation. The results indicate that fan beam CT produces superior images to that of on-board imaging (OBI) cone beam CT systems, while providing a considerably less dose to the patient.

  19. Different patterns of auditory cortex activation revealed by functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Formisano, E; Pepino, A; Bracale, M [Department of Electronic Engineering, Biomedical Unit, Universita di Napoli, Federic II, Italy, Via Claudio 21, 80125 Napoli (Italy); Di Salle, F [Department of Biomorphological and Functional Sciences, Radiologucal Unit, Universita di Napoli, Federic II, Italy, Via Claudio 21, 80125 Napoli (Italy); Lanfermann, H; Zanella, F E [Department of Neuroradiology, J.W. Goethe Universitat, Frankfurt/M. (Germany)

    1999-12-31

    In the last few years, functional Magnetic Resonance Imaging (fMRI) has been widely accepted as an effective tool for mapping brain activities in both the sensorimotor and the cognitive field. The present work aims to assess the possibility of using fMRI methods to study the cortical response to different acoustic stimuli. Furthermore, we refer to recent data collected at Frankfurt University on the cortical pattern of auditory hallucinations. Healthy subjects showed broad bilateral activation, mostly located in the transverse gyrus of Heschl. The analysis of the cortical activation induced by different stimuli has pointed out a remarkable difference in the spatial and temporal features of the auditory cortex response to pulsed tones and pure tones. The activated areas during episodes of auditory hallucinations match the location of primary auditory cortex as defined in control measurements with the same patients and in the experiments on healthy subjects. (authors) 17 refs., 4 figs.

  20. Difference between healthy children and ADHD based on wavelet spectral analysis of nuclear magnetic resonance images

    International Nuclear Information System (INIS)

    González Gómez Dulce, I.; Moreno Barbosa, E.; Hernández, Mario Iván Martínez; Méndez, José Ramos; Silvia, Hidalgo Tobón; Pilar, Dies Suarez; Eduardo, Barragán Pérez; Benito, De Celis Alonso

    2014-01-01

    The main goal of this project was to create a computer algorithm based on wavelet analysis of region of homogeneity images obtained during resting state studies. Ideally it would automatically diagnose ADHD. Because the cerebellum is an area known to be affected by ADHD, this study specifically analysed this region. Male right handed volunteers (infants with ages between 7 and 11 years old) were studied and compared with age matched controls. Statistical differences between the values of the absolute integrated wavelet spectrum were found and showed significant differences (p<0.0015) between groups. This difference might help in the future to distinguish healthy from ADHD patients and therefore diagnose ADHD. Even if results were statistically significant, the small size of the sample limits the applicability of this methods as it is presented here, and further work with larger samples and using freely available datasets must be done

  1. Difference between healthy children and ADHD based on wavelet spectral analysis of nuclear magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    González Gómez Dulce, I., E-mail: isabeldgg@hotmail.com, E-mail: emoreno@fcfm.buap.mx, E-mail: mim@fcfm.buap.mx, E-mail: joserm84@gmail.com; Moreno Barbosa, E., E-mail: isabeldgg@hotmail.com, E-mail: emoreno@fcfm.buap.mx, E-mail: mim@fcfm.buap.mx, E-mail: joserm84@gmail.com; Hernández, Mario Iván Martínez, E-mail: isabeldgg@hotmail.com, E-mail: emoreno@fcfm.buap.mx, E-mail: mim@fcfm.buap.mx, E-mail: joserm84@gmail.com; Méndez, José Ramos, E-mail: isabeldgg@hotmail.com, E-mail: emoreno@fcfm.buap.mx, E-mail: mim@fcfm.buap.mx, E-mail: joserm84@gmail.com [Faculty of Physics and Mathematics, BUAP, Puebla, Pue. (Mexico); Silvia, Hidalgo Tobón [Hospital Infantil de México, Federico Gómez, Mexico DF. Mexico and Physics Department, Universidad Autónoma Metropolitana. Iztapalapa, Mexico DF. (Mexico); Pilar, Dies Suarez, E-mail: pilydies@yahoo.com, E-mail: neurodoc@prodigy.net.mx; Eduardo, Barragán Pérez, E-mail: pilydies@yahoo.com, E-mail: neurodoc@prodigy.net.mx [Hospital Infantil de México, Federico Gómez, Mexico DF. (Mexico); Benito, De Celis Alonso, E-mail: benileon@yahoo.com [Faculty of Physics and Mathematics, BUAP, Puebla, Pue. Mexico and Fundación para el Desarrollo Carlos Sigüenza. Puebla, Pue (Mexico)

    2014-11-07

    The main goal of this project was to create a computer algorithm based on wavelet analysis of region of homogeneity images obtained during resting state studies. Ideally it would automatically diagnose ADHD. Because the cerebellum is an area known to be affected by ADHD, this study specifically analysed this region. Male right handed volunteers (infants with ages between 7 and 11 years old) were studied and compared with age matched controls. Statistical differences between the values of the absolute integrated wavelet spectrum were found and showed significant differences (p<0.0015) between groups. This difference might help in the future to distinguish healthy from ADHD patients and therefore diagnose ADHD. Even if results were statistically significant, the small size of the sample limits the applicability of this methods as it is presented here, and further work with larger samples and using freely available datasets must be done.

  2. Different patterns of auditory cortex activation revealed by functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Formisano, E.; Pepino, A.; Bracale, M.; Di Salle, F.; Lanfermann, H.; Zanella, F.E.

    1998-01-01

    In the last few years, functional Magnetic Resonance Imaging (fMRI) has been widely accepted as an effective tool for mapping brain activities in both the sensorimotor and the cognitive field. The present work aims to assess the possibility of using fMRI methods to study the cortical response to different acoustic stimuli. Furthermore, we refer to recent data collected at Frankfurt University on the cortical pattern of auditory hallucinations. Healthy subjects showed broad bilateral activation, mostly located in the transverse gyrus of Heschl. The analysis of the cortical activation induced by different stimuli has pointed out a remarkable difference in the spatial and temporal features of the auditory cortex response to pulsed tones and pure tones. The activated areas during episodes of auditory hallucinations match the location of primary auditory cortex as defined in control measurements with the same patients and in the experiments on healthy subjects. (authors)

  3. Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles.

    Science.gov (United States)

    Farsi, Zohreh; Preobraschenski, Julia; van den Bogaart, Geert; Riedel, Dietmar; Jahn, Reinhard; Woehler, Andrew

    2016-02-26

    Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided by an electrochemical proton gradient. However, it is unclear how transmitter molecules carrying different net charges can be efficiently sequestered while maintaining charge neutrality and osmotic balance. We used single-vesicle imaging to monitor pH and electrical gradients and directly showed different uptake mechanisms for glutamate and γ-aminobutyric acid (GABA) operating in parallel. In contrast to glutamate, GABA was exchanged for protons, with no other ions participating in the transport cycle. Thus, only a few components are needed to guarantee reliable vesicle filling with different neurotransmitters. Copyright © 2016, American Association for the Advancement of Science.

  4. Comparison of Maximal Wall Thickness in Hypertrophic Cardiomyopathy Differs Between Magnetic Resonance Imaging and Transthoracic Echocardiography.

    Science.gov (United States)

    Bois, John P; Geske, Jeffrey B; Foley, Thomas A; Ommen, Steve R; Pellikka, Patricia A

    2017-02-15

    Left ventricular (LV) wall thickness is a prognostic marker in hypertrophic cardiomyopathy (HC). LV wall thickness ≥30 mm (massive hypertrophy) is independently associated with sudden cardiac death. Presence of massive hypertrophy is used to guide decision making for cardiac defibrillator implantation. We sought to determine whether measurements of maximal LV wall thickness differ between cardiac magnetic resonance imaging (MRI) and transthoracic echocardiography (TTE). Consecutive patients were studied who had HC without previous septal ablation or myectomy and underwent both cardiac MRI and TTE at a single tertiary referral center. Reported maximal LV wall thickness was compared between the imaging techniques. Patients with ≥1 technique reporting massive hypertrophy received subset analysis. In total, 618 patients were evaluated from January 1, 2003, to December 21, 2012 (mean [SD] age, 53 [15] years; 381 men [62%]). In 75 patients (12%), reported maximal LV wall thickness was identical between MRI and TTE. Median difference in reported maximal LV wall thickness between the techniques was 3 mm (maximum difference, 17 mm). Of the 63 patients with ≥1 technique measuring maximal LV wall thickness ≥30 mm, 44 patients (70%) had discrepant classification regarding massive hypertrophy. MRI identified 52 patients (83%) with massive hypertrophy; TTE, 30 patients (48%). Although guidelines recommend MRI or TTE imaging to assess cardiac anatomy in HC, this study shows discrepancy between the techniques for maximal reported LV wall thickness assessment. In conclusion, because this measure clinically affects prognosis and therapeutic decision making, efforts to resolve these discrepancies are critical. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Zooming in: high resolution 3D reconstruction of differently stained histological whole slide images

    Science.gov (United States)

    Lotz, Johannes; Berger, Judith; Müller, Benedikt; Breuhahn, Kai; Grabe, Niels; Heldmann, Stefan; Homeyer, André; Lahrmann, Bernd; Laue, Hendrik; Olesch, Janine; Schwier, Michael; Sedlaczek, Oliver; Warth, Arne

    2014-03-01

    Much insight into metabolic interactions, tissue growth, and tissue organization can be gained by analyzing differently stained histological serial sections. One opportunity unavailable to classic histology is three-dimensional (3D) examination and computer aided analysis of tissue samples. In this case, registration is needed to reestablish spatial correspondence between adjacent slides that is lost during the sectioning process. Furthermore, the sectioning introduces various distortions like cuts, folding, tearing, and local deformations to the tissue, which need to be corrected in order to exploit the additional information arising from the analysis of neighboring slide images. In this paper we present a novel image registration based method for reconstructing a 3D tissue block implementing a zooming strategy around a user-defined point of interest. We efficiently align consecutive slides at increasingly fine resolution up to cell level. We use a two-step approach, where after a macroscopic, coarse alignment of the slides as preprocessing, a nonlinear, elastic registration is performed to correct local, non-uniform deformations. Being driven by the optimization of the normalized gradient field (NGF) distance measure, our method is suitable for differently stained and thus multi-modal slides. We applied our method to ultra thin serial sections (2 μm) of a human lung tumor. In total 170 slides, stained alternately with four different stains, have been registered. Thorough visual inspection of virtual cuts through the reconstructed block perpendicular to the cutting plane shows accurate alignment of vessels and other tissue structures. This observation is confirmed by a quantitative analysis. Using nonlinear image registration, our method is able to correct locally varying deformations in tissue structures and exceeds the limitations of globally linear transformations.

  6. How to Find More Supernovae with Less Work: Object ClassificationTechniques for Difference Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Stephen; Aragon, Cecilia; Romano, Raquel; Thomas, RollinC.; Weaver, Benjamin A.; Wong, Daniel

    2007-05-02

    We present the results of applying new object classificationtechniques to difference images in the context of the Nearby SupernovaFactory supernova search. Most current supernova searches subtractreference images from new images, identify objects in these differenceimages, and apply simple threshold cuts on parameters such as statisticalsignificance, shape, and motionto reject objects such as cosmic rays,asteroids, and subtraction artifacts. Although most static objectssubtract cleanly, even a very low false positive detection rate can leadto hundreds of non-supernova candidates which must be vetted by humaninspection before triggering additional followup. In comparison to simplethreshold cuts, more sophisticated methods such as Boosted DecisionTrees, Random Forests, and Support Vector Machines provide dramaticallybetter object discrimination. At the Nearby Supernova Factory, we reducedthe number of non-supernova candidates by a factor of 10 while increasingour supernova identification efficiency. Methods such as these will becrucial for maintaining a reasonable false positive rate in the automatedtransient alert pipelines of upcoming projects such as PanSTARRS andLSST.

  7. Gender differences in adolescent sport participation, teasing, self-objectification and body image concerns.

    Science.gov (United States)

    Slater, Amy; Tiggemann, Marika

    2011-06-01

    This study examined gender differences in adolescent participation in sport and physical activity, in teasing experiences specific to the physical activity domain, and the relationship between adolescent physical activity and body image. A sample of 714 adolescents (332 girls, 382 boys) aged between 12 and 16 years completed measures of participation in organised sport and other physical activities, experiences of teasing specific to sport, self-objectification and body image. Adolescent girls participated in organised sport at a lower rate than boys, but experienced higher levels of teasing. Both girls and boys reported being teased by same-sex peers, but in addition, girls also reported being teased by opposite-sex peers (i.e. boys). Time spent on aesthetic physical activities was related to disordered eating symptomatology for both girls and boys. It was concluded that teasing and body image concerns may contribute to adolescent girls' reduced rates of participation in sports and other physical activities. Copyright © 2010 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  8. Sex Differences in Hookah-Related Images Posted on Tumblr: A Content Analysis.

    Science.gov (United States)

    Primack, Brian A; Carroll, Mary V; Shensa, Ariel; Davis, Wesley; Levine, Michele D

    2016-01-01

    Hookah tobacco smoking is prevalent, widespread, and associated with large amounts of toxicants. Hookah tobacco smoking may be viewed differently by males and females. For example, females have been drawn to types of tobacco that are flavored, milder, and marketed as more social and exotic. Individuals often use the growing segment of anonymous social networking sites, such as Tumblr, to learn about potentially dangerous or harmful behaviors. We used a systematic process involving stratification by time of day, day of week, and search term to gather a sample of 140 Tumblr posts related to hookah tobacco smoking. After a structured codebook development process, 2 coders independently assessed all posts in their entirety, and all disagreements were easily adjudicated. When data on poster sex and age were available, we found that 77% of posts were posted by females and 35% were posted by individuals younger than 18. The most prominent features displayed in all posts were references to or images of hookahs themselves, sexuality, socializing, alcohol, hookah smoke, and tricks performed with hookah smoke. Compared with females, males more frequently posted images of hookahs and alcohol-related images or references. This information may help guide future research in this area and the development of targeted interventions to curb this behavior.

  9. Imaging surface nanobubbles at graphite–water interfaces with different atomic force microscopy modes

    International Nuclear Information System (INIS)

    Yang, Chih-Wen; Lu, Yi-Hsien; Hwang, Ing-Shouh

    2013-01-01

    We have imaged nanobubbles on highly ordered pyrolytic graphite (HOPG) surfaces in pure water with different atomic force microscopy (AFM) modes, including the frequency-modulation, the tapping, and the PeakForce techniques. We have compared the performance of these modes in obtaining the surface profiles of nanobubbles. The frequency-modulation mode yields a larger height value than the other two modes and can provide more accurate measurement of the surface profiles of nanobubbles. Imaging with PeakForce mode shows that a nanobubble appears smaller and shorter with increasing peak force and disappears above a certain peak force, but the size returns to the original value when the peak force is reduced. This indicates that imaging with high peak forces does not cause gas removal from the nanobubbles. Based on the presented findings and previous AFM observations, the existing models for nanobubbles are reviewed and discussed. The model of gas aggregate inside nanobubbles provides a better explanation for the puzzles of the high stability and the contact angle of surface nanobubbles. (paper)

  10. Imaging photoplethysmography for clinical assessment of cutaneous microcirculation at two different depths

    Science.gov (United States)

    Marcinkevics, Zbignevs; Rubins, Uldis; Zaharans, Janis; Miscuks, Aleksejs; Urtane, Evelina; Ozolina-Moll, Liga

    2016-03-01

    The feasibility of bispectral imaging photoplethysmography (iPPG) system for clinical assessment of cutaneous microcirculation at two different depths is proposed. The iPPG system has been developed and evaluated for in vivo conditions during various tests: (1) topical application of vasodilatory liniment on the skin, (2) skin local heating, (3) arterial occlusion, and (4) regional anesthesia. The device has been validated by the measurements of a laser Doppler imager (LDI) as a reference. The hardware comprises four bispectral light sources (530 and 810 nm) for uniform illumination of skin, video camera, and the control unit for triggering of the system. The PPG signals were calculated and the changes of perfusion index (PI) were obtained during the tests. The results showed convincing correlations for PI obtained by iPPG and LDI at (1) topical liniment (r=0.98) and (2) heating (r=0.98) tests. The topical liniment and local heating tests revealed good selectivity of the system for superficial microcirculation monitoring. It is confirmed that the iPPG system could be used for assessment of cutaneous perfusion at two different depths, morphologically and functionally different vascular networks, and thus utilized in clinics as a cost-effective alternative to the LDI.

  11. Evaluation of different X ray equipment and incubators for pediatric radiographic images implementation

    International Nuclear Information System (INIS)

    Carbi, E.D.O.; Souza, R.T.F.; Pina, D.R.

    2009-01-01

    The children frequent/y are exposed to the ionizing radiation and other emotional and physical risks in the attempts repeated to get radiographic images of quality. This study it has as objective to evaluate X ray beam about quality and intensity at three different equipment with single-phase generator of voltage and the absorption factors to 5 different incubators and 3 different cradles in the neonatal UTI of the Clinics Hospital on the Medicine College in Botucatu. The methodology consisted of carrying through measured of half Layer Value and Radiation output for the different X ray equipment with voltage with in between 45 and 100 kVp, applied at the X ray tube. The measures of the absorption factors had been carried through varying the thicknesses of attenuating material (phantom) for the different voltage value with in between 50 and 100kVp. The results had shown the same energy effective for the different X ray equipment and the same absorption factors for the different incubators and evaluated cradles, taking into account, the same thickness of attenuating material and same voltage. (author)

  12. Stokes vector based interpolation method to improve the efficiency of bio-inspired polarization-difference imaging in turbid media

    Science.gov (United States)

    Guan, Jinge; Ren, Wei; Cheng, Yaoyu

    2018-04-01

    We demonstrate an efficient polarization-difference imaging system in turbid conditions by using the Stokes vector of light. The interaction of scattered light with the polarizer is analyzed by the Stokes-Mueller formalism. An interpolation method is proposed to replace the mechanical rotation of the polarization axis of the analyzer theoretically, and its performance is verified by the experiment at different turbidity levels. We show that compared with direct imaging, the Stokes vector based imaging method can effectively reduce the effect of light scattering and enhance the image contrast.

  13. Multi- and hyperspectral remote sensing change detection with generalized difference images by the IR-MAD method

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Canty, Morton J.

    2005-01-01

    -based method for determining thresholds for differentiating between change and no-change in the difference images, and for estimating the variance of the no-change observations. This variance is used to establish a single change/no-change image based on the general multivariate difference image. The resulting....../no-change image can be used to establish both change regions and to extract observations based on which a fully automated orthogonal regression analysis based normalization of the multivariate data between the two points in time can be developed. Also, regularization issues typically important in connection...

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

    Science.gov (United States)

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

    2015-12-01

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

  15. Infrared and Visible Image Fusion Based on Different Constraints in the Non-Subsampled Shearlet Transform Domain

    Science.gov (United States)

    Huang, Yan; Bi, Duyan; Wu, Dongpeng

    2018-01-01

    There are many artificial parameters when fuse infrared and visible images, to overcome the lack of detail in the fusion image because of the artifacts, a novel fusion algorithm for infrared and visible images that is based on different constraints in non-subsampled shearlet transform (NSST) domain is proposed. There are high bands and low bands of images that are decomposed by the NSST. After analyzing the characters of the bands, fusing the high level bands by the gradient constraint, the fused image can obtain more details; fusing the low bands by the constraint of saliency in the images, the targets are more salient. Before the inverse NSST, the Nash equilibrium is used to update the coefficient. The fused images and the quantitative results demonstrate that our method is more effective in reserving details and highlighting the targets when compared with other state-of-the-art methods. PMID:29641505

  16. Nuclear Radiation Degradation Study on HD Camera Based on CMOS Image Sensor at Different Dose Rates

    Directory of Open Access Journals (Sweden)

    Congzheng Wang

    2018-02-01

    Full Text Available In this work, we irradiated a high-definition (HD industrial camera based on a commercial-off-the-shelf (COTS CMOS image sensor (CIS with Cobalt-60 gamma-rays. All components of the camera under test were fabricated without radiation hardening, except for the lens. The irradiation experiments of the HD camera under biased conditions were carried out at 1.0, 10.0, 20.0, 50.0 and 100.0 Gy/h. During the experiment, we found that the tested camera showed a remarkable degradation after irradiation and differed in the dose rates. With the increase of dose rate, the same target images become brighter. Under the same dose rate, the radiation effect in bright area is lower than that in dark area. Under different dose rates, the higher the dose rate is, the worse the radiation effect will be in both bright and dark areas. And the standard deviations of bright and dark areas become greater. Furthermore, through the progressive degradation analysis of the captured image, experimental results demonstrate that the attenuation of signal to noise ratio (SNR versus radiation time is not obvious at the same dose rate, and the degradation is more and more serious with increasing dose rate. Additionally, the decrease rate of SNR at 20.0, 50.0 and 100.0 Gy/h is far greater than that at 1.0 and 10.0 Gy/h. Even so, we confirm that the HD industrial camera is still working at 10.0 Gy/h during the 8 h of measurements, with a moderate decrease of the SNR (5 dB. The work is valuable and can provide suggestion for camera users in the radiation field.

  17. Nuclear Radiation Degradation Study on HD Camera Based on CMOS Image Sensor at Different Dose Rates.

    Science.gov (United States)

    Wang, Congzheng; Hu, Song; Gao, Chunming; Feng, Chang

    2018-02-08

    In this work, we irradiated a high-definition (HD) industrial camera based on a commercial-off-the-shelf (COTS) CMOS image sensor (CIS) with Cobalt-60 gamma-rays. All components of the camera under test were fabricated without radiation hardening, except for the lens. The irradiation experiments of the HD camera under biased conditions were carried out at 1.0, 10.0, 20.0, 50.0 and 100.0 Gy/h. During the experiment, we found that the tested camera showed a remarkable degradation after irradiation and differed in the dose rates. With the increase of dose rate, the same target images become brighter. Under the same dose rate, the radiation effect in bright area is lower than that in dark area. Under different dose rates, the higher the dose rate is, the worse the radiation effect will be in both bright and dark areas. And the standard deviations of bright and dark areas become greater. Furthermore, through the progressive degradation analysis of the captured image, experimental results demonstrate that the attenuation of signal to noise ratio (SNR) versus radiation time is not obvious at the same dose rate, and the degradation is more and more serious with increasing dose rate. Additionally, the decrease rate of SNR at 20.0, 50.0 and 100.0 Gy/h is far greater than that at 1.0 and 10.0 Gy/h. Even so, we confirm that the HD industrial camera is still working at 10.0 Gy/h during the 8 h of measurements, with a moderate decrease of the SNR (5 dB). The work is valuable and can provide suggestion for camera users in the radiation field.

  18. Difference between T sub 1 and T sub 2 weighted MR images in avascular necrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Kokubo, Takashi; Yoshikawa, Koki; Itai, Yuzo; Iio, Masahiro; Takatori, Yoshio; Kamogawa, Morihide; Ninomiya, Setsuo [Tokyo Univ. (Japan). Faculty of Medicine

    1990-01-01

    T{sub 1} and T{sub 2} weighted MR images were compared in 32 hips with avascular necrosis, and the difference between them was discussed. In 27 of 32 hips, abnormal low intensity area in the affected femoral head is smaller in T{sub 2} weighted images than in T{sub 1} weighted images. The area of low intensity on T{sub 1} weighted image and high on T{sub 2} weighted image might be granuloma in reactive tissue and surrounding hyperemia. The difference between T{sub 1} and T{sub 2} weighted images must be taken into consideration especially in determination of the border of affected bone. (author).

  19. Solar irradiance forecasting at one-minute intervals for different sky conditions using sky camera images

    International Nuclear Information System (INIS)

    Alonso-Montesinos, J.; Batlles, F.J.; Portillo, C.

    2015-01-01

    Highlights: • The solar resource has been predicted for three hours at 1-min intervals. • Digital image levels and cloud motion vectors are joint for irradiance forecasting. • The three radiation components have been predicted under different sky conditions. • Diffuse and global radiation has an nRMSE value around 10% in all sky conditions. • Beam irradiance is predicted with an nRMSE value of about 15% in overcast skies. - Abstract: In the search for new techniques to predict atmospheric features that might be useful to solar power plant operators, we have carried out solar irradiance forecasting using emerging sky camera technology. Digital image levels are converted into irradiances and then the maximum cross-correlation method is applied to obtain future predictions. This methodology is a step forward in the study of the solar resource, essential to solar plant operators in adapting a plant’s operating procedures to atmospheric conditions and to improve electricity generation. The results are set out using different statistical parameters, in which beam, diffuse and global irradiances give a constant normalized root-mean-square error value over the time interval for all sky conditions. The average measure is 25.44% for beam irradiance; 11.60% for diffuse irradiance and 11.17% for global irradiance.

  20. Characterization of sildenafil citrate tablets of different sources by near infrared chemical imaging and chemometric tools.

    Science.gov (United States)

    Sabin, Guilherme P; Lozano, Valeria A; Rocha, Werickson F C; Romão, Wanderson; Ortiz, Rafael S; Poppi, Ronei J

    2013-11-01

    The chemical imaging technique by near infrared spectroscopy was applied for characterization of formulations in tablets of sildenafil citrate of six different sources. Five formulations were provided by Brazilian Federal Police and correspond to several trademarks of prohibited marketing and one was an authentic sample of Viagra. In a first step of the study, multivariate curve resolution was properly chosen for the estimation of the distribution map of concentration of the active ingredient in tablets of different sources, where the chemical composition of all excipients constituents was not truly known. In such cases, it is very difficult to establish an appropriate calibration technique, so that only the information of sildenafil is considered independently of the excipients. This determination was possible only by reaching the second-order advantage, where the analyte quantification can be performed in the presence of unknown interferences. In a second step, the normalized histograms of images from active ingredient were grouped according to their similarities by hierarchical cluster analysis. Finally it was possible to recognize the patterns of distribution maps of concentration of sildenafil citrate, distinguishing the true formulation of Viagra. This concept can be used to improve the knowledge of industrial products and processes, as well as, for characterization of counterfeit drugs. Copyright © 2013. Published by Elsevier B.V.

  1. Image Segmentation Based on Constrained Spectral Variance Difference and Edge Penalty

    Directory of Open Access Journals (Sweden)

    Bo Chen

    2015-05-01

    Full Text Available Segmentation, which is usually the first step in object-based image analysis (OBIA, greatly influences the quality of final OBIA results. In many existing multi-scale segmentation algorithms, a common problem is that under-segmentation and over-segmentation always coexist at any scale. To address this issue, we propose a new method that integrates the newly developed constrained spectral variance difference (CSVD and the edge penalty (EP. First, initial segments are produced by a fast scan. Second, the generated segments are merged via a global mutual best-fitting strategy using the CSVD and EP as merging criteria. Finally, very small objects are merged with their nearest neighbors to eliminate the remaining noise. A series of experiments based on three sets of remote sensing images, each with different spatial resolutions, were conducted to evaluate the effectiveness of the proposed method. Both visual and quantitative assessments were performed, and the results show that large objects were better preserved as integral entities while small objects were also still effectively delineated. The results were also found to be superior to those from eCongnition’s multi-scale segmentation.

  2. Optimising MR perfusion imaging: comparison of different software-based approaches in acute ischaemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Schaafs, Lars-Arne [Charite-Universitaetsmedizin, Department of Radiology, Berlin (Germany); Charite-Universitaetsmedizin, Academic Neuroradiology, Department of Neurology and Center for Stroke Research, Berlin (Germany); Porter, David [Fraunhofer Institute for Medical Image Computing MEVIS, Bremen (Germany); Audebert, Heinrich J. [Charite-Universitaetsmedizin, Department of Neurology with Experimental Neurology, Berlin (Germany); Fiebach, Jochen B.; Villringer, Kersten [Charite-Universitaetsmedizin, Academic Neuroradiology, Department of Neurology and Center for Stroke Research, Berlin (Germany)

    2016-11-15

    Perfusion imaging (PI) is susceptible to confounding factors such as motion artefacts as well as delay and dispersion (D/D). We evaluate the influence of different post-processing algorithms on hypoperfusion assessment in PI analysis software packages to improve the clinical accuracy of stroke PI. Fifty patients with acute ischaemic stroke underwent MRI imaging in the first 24 h after onset. Diverging approaches to motion and D/D correction were applied. The calculated MTT and CBF perfusion maps were assessed by volumetry of lesions and tested for agreement with a standard approach and with the final lesion volume (FLV) on day 6 in patients with persisting vessel occlusion. MTT map lesion volumes were significantly smaller throughout the software packages with correction of motion and D/D when compared to the commonly used approach with no correction (p = 0.001-0.022). Volumes on CBF maps did not differ significantly (p = 0.207-0.925). All packages with advanced post-processing algorithms showed a high level of agreement with FLV (ICC = 0.704-0.879). Correction of D/D had a significant influence on estimated lesion volumes and leads to significantly smaller lesion volumes on MTT maps. This may improve patient selection. (orig.)

  3. Optimising MR perfusion imaging: comparison of different software-based approaches in acute ischaemic stroke

    International Nuclear Information System (INIS)

    Schaafs, Lars-Arne; Porter, David; Audebert, Heinrich J.; Fiebach, Jochen B.; Villringer, Kersten

    2016-01-01

    Perfusion imaging (PI) is susceptible to confounding factors such as motion artefacts as well as delay and dispersion (D/D). We evaluate the influence of different post-processing algorithms on hypoperfusion assessment in PI analysis software packages to improve the clinical accuracy of stroke PI. Fifty patients with acute ischaemic stroke underwent MRI imaging in the first 24 h after onset. Diverging approaches to motion and D/D correction were applied. The calculated MTT and CBF perfusion maps were assessed by volumetry of lesions and tested for agreement with a standard approach and with the final lesion volume (FLV) on day 6 in patients with persisting vessel occlusion. MTT map lesion volumes were significantly smaller throughout the software packages with correction of motion and D/D when compared to the commonly used approach with no correction (p = 0.001-0.022). Volumes on CBF maps did not differ significantly (p = 0.207-0.925). All packages with advanced post-processing algorithms showed a high level of agreement with FLV (ICC = 0.704-0.879). Correction of D/D had a significant influence on estimated lesion volumes and leads to significantly smaller lesion volumes on MTT maps. This may improve patient selection. (orig.)

  4. Electromagnetic characterization of white spruce at different moisture contents using synthetic aperture radar imaging

    Science.gov (United States)

    Ingemi, Christopher M.; Owusu Twumasi, Jones; Yu, Tzuyang

    2018-03-01

    Detection and quantification of moisture content inside wood (timber) is key to ensuring safety and reliability of timber structures. Moisture inside wood attracts insects and fosters the development of fungi to attack the timber, causing significant damages and reducing the load bearing capacity during their design life. The use of non-destructive evaluation (NDE) techniques (e.g., microwave/radar, ultrasonic, stress wave, and X-ray) for condition assessment of timber structures is a good choice. NDE techniques provide information about the level of deterioration and material properties of timber structures without obstructing their functionality. In this study, microwave/radar NDE technique was selected for the characterization of wood at different moisture contents. A 12 in-by-3.5 in-by-1.5 in. white spruce specimen (picea glauca) was imaged at different moisture contents using a 10 GHz synthetic aperture radar (SAR) sensor inside an anechoic chamber. The presence of moisture was found to increase the SAR image amplitude as expected. Additionally, integrated SAR amplitude was found beneficial in modeling the moisture content inside the wood specimen.

  5. A new test phantom with different breast tissue compositions for image quality assessment in conventional and digital mammography

    International Nuclear Information System (INIS)

    Pachoud, Marc; Lepori, D; Valley, Jean-Francois; Verdun, Francis R

    2004-01-01

    Our objective is to describe a new test phantom that permits the objective assessment of image quality in conventional and digital mammography for different types of breast tissue. A test phantom, designed to represent a compressed breast, was made from tissue equivalent materials. Three separate regions, with different breast tissue compositions, are used to evaluate low and high contrast resolution, spatial resolution and image noise. The phantom was imaged over a range of kV using a Contour 2000 (Bennett) mammography unit with a Kodak MinR 2190-MinR L screen-film combination and a Senograph 2000D (General Electric) digital mammography unit. Objective image quality assessments for different breast tissue compositions were performed using the phantom for conventional and digital mammography. For a similar mean glandular dose (MGD), the digital system gives a significantly higher contrast-to-noise ratio (CNR) than the screen-film system for 100% glandular tissue. In conclusion, in mammography, a range of exposure conditions is used for imaging because of the different breast tissue compositions encountered clinically. Ideally, the patient dose-image quality relationship should be optimized over the range of exposure conditions. The test phantom presented in this work permits image quality parameters to be evaluated objectively for three different types of breast tissue. Thus, it is a useful tool for optimizing the patient dose-image quality relationship

  6. Difference between healthy children and ADHD based on wavelet spectral analysis of nuclear magnetic resonance images

    Science.gov (United States)

    González Gómez, Dulce I.; Moreno Barbosa, E.; Martínez Hernández, Mario Iván; Ramos Méndez, José; Hidalgo Tobón, Silvia; Dies Suarez, Pilar; Barragán Pérez, Eduardo; De Celis Alonso, Benito

    2014-11-01

    The main goal of this project was to create a computer algorithm based on wavelet analysis of region of homogeneity images obtained during resting state studies. Ideally it would automatically diagnose ADHD. Because the cerebellum is an area known to be affected by ADHD, this study specifically analysed this region. Male right handed volunteers (infants with ages between 7 and 11 years old) were studied and compared with age matched controls. Statistical differences between the values of the absolute integrated wavelet spectrum were found and showed significant differences (pADHD patients and therefore diagnose ADHD. Even if results were statistically significant, the small size of the sample limits the applicability of this methods as it is presented here, and further work with larger samples and using freely available datasets must be done.

  7. Digital images segmentation: a state of art of the different methods ...

    African Journals Online (AJOL)

    An image is a planar representation of a scene or a 3 D object. The primary information associated to each point of the image is transcribed in grey level or in colour. Image analysis is the set of methods which permits the extraction of pertinent information from the image according to the concerned application, to treat them ...

  8. Reconstruction-of-difference (RoD) imaging for cone-beam CT neuro-angiography

    Science.gov (United States)

    Wu, P.; Stayman, J. W.; Mow, M.; Zbijewski, W.; Sisniega, A.; Aygun, N.; Stevens, R.; Foos, D.; Wang, X.; Siewerdsen, J. H.

    2018-06-01

    Timely evaluation of neurovasculature via CT angiography (CTA) is critical to the detection of pathology such as ischemic stroke. Cone-beam CTA (CBCT-A) systems provide potential advantages in the timely use at the point-of-care, although challenges of a relatively slow gantry rotation speed introduce tradeoffs among image quality, data consistency and data sparsity. This work describes and evaluates a new reconstruction-of-difference (RoD) approach that is robust to such challenges. A fast digital simulation framework was developed to test the performance of the RoD over standard reference reconstruction methods such as filtered back-projection (FBP) and penalized likelihood (PL) over a broad range of imaging conditions, grouped into three scenarios to test the trade-off between data consistency, data sparsity and peak contrast. Two experiments were also conducted using a CBCT prototype and an anthropomorphic neurovascular phantom to test the simulation findings in real data. Performance was evaluated primarily in terms of normalized root mean square error (NRMSE) in comparison to truth, with reconstruction parameters chosen to optimize performance in each case to ensure fair comparison. The RoD approach reduced NRMSE in reconstructed images by up to 50%–53% compared to FBP and up to 29%–31% compared to PL for each scenario. Scan protocols well suited to the RoD approach were identified that balance tradeoffs among data consistency, sparsity and peak contrast—for example, a CBCT-A scan with 128 projections acquired in 8.5 s over a 180°  +  fan angle half-scan for a time attenuation curve with ~8.5 s time-to-peak and 600 HU peak contrast. With imaging conditions such as the simulation scenarios of fixed data sparsity (i.e. varying levels of data consistency and peak contrast), the experiments confirmed the reduction of NRMSE by 34% and 17% compared to FBP and PL, respectively. The RoD approach demonstrated superior performance in 3D angiography

  9. CT and MR image fusion using two different methods after prostate brachytherapy: impact on post-implant dosimetric assessment

    International Nuclear Information System (INIS)

    Servois, V.; El Khoury, C.; Lantoine, A.; Ollivier, L.; Neuenschwander, S.; Chauveinc, L.; Cosset, J.M.; Flam, T.; Rosenwald, J.C.

    2003-01-01

    To study different methods of CT and MR images fusion in patient treated by brachytherapy for localized prostate cancer. To compare the results of the dosimetric study realized on CT slices and images fusion. Fourteen cases of patients treated by 1125 were retrospectively studied. The CT examinations were realized with continuous section of 5 mm thickness, and MR images were obtained with a surface coil with contiguous section of 3 mm thickness. For the images fusion process, only the T2 weighted MR sequence was used. Two processes of images fusion were realized for each patient, using as reference marks the bones of the pelvis and the implanted seeds. A quantitative and qualitative appreciation was made by the operators, for each patient and both methods of images fusion. The dosimetric study obtained by a dedicated software was realized on CT images and all types of images fusion. The usual dosimetric indexes (D90, V 100 and V 150) were compared for each type of image. The quantitative results given by the software of images fusion showed a superior accuracy to the one obtained by the pelvic bony reference marks. Conversely, qualitative and quantitative results obtained by the operators showed a better accuracy of the images fusion based on iodine seeds. For two patients out of three presenting a D90 inferior to 145 Gy on CT examination, the D90 was superior to this norm when the dosimetry was based on images fusion, whatever the method used. The images fusion method based on implanted seed matching seems to be more precise than the one using bony reference marks. The dosimetric study realized on images fusion could allow to rectify possible errors, mainly due to difficulties in surrounding prostate contour delimitation on CT images. (authors)

  10. Automated method and system for the alignment and correlation of images from two different modalities

    Science.gov (United States)

    Giger, Maryellen L.; Chen, Chin-Tu; Armato, Samuel; Doi, Kunio

    1999-10-26

    A method and system for the computerized registration of radionuclide images with radiographic images, including generating image data from radiographic and radionuclide images of the thorax. Techniques include contouring the lung regions in each type of chest image, scaling and registration of the contours based on location of lung apices, and superimposition after appropriate shifting of the images. Specific applications are given for the automated registration of radionuclide lungs scans with chest radiographs. The method in the example given yields a system that spatially registers and correlates digitized chest radiographs with V/Q scans in order to correlate V/Q functional information with the greater structural detail of chest radiographs. Final output could be the computer-determined contours from each type of image superimposed on any of the original images, or superimposition of the radionuclide image data, which contains high activity, onto the radiographic chest image.

  11. Perceived body image and weight: discrepancies and gender differences among University undergraduates.

    Science.gov (United States)

    Maruf, F A; Akinpelu, A O; Nwankwo, M J

    2012-12-01

    Body image (BI) is a multidimensional construct that includes perceptual, attitudinal, behavioural components, and feedback from other people's perception of oneself. The feedback from others and the degree to which one accepts or rejects it can determine self evaluation and perception. Body weight perception is a strong determinant of nutritional habits and weight management among adolescents. One of the barriers to reducing rise in obesity prevalence could be its cultural acceptability in some developing countries. To explore the gender influences on perception of self- and opposite-sex body images (BI), perceived body weight and the actual body weight categories at which discrepancies occur among the perceived BIs in undergraduates. This was a survey of perceptual dimension of BI, perceived body weight and actual body weight carried out in 121 undergraduates aged 21-29 years. Discrepancies occurred between self-perceived BI and each of actual body weight (p= 0.00 at 0.00-0.02 confidence interval (CI)), perceived body weight (p= 0.01 at 0.000-0.02 CI) and self-ideal BI (p= 0.03 at 0.000-0.05 CI) of normal-weight males. Self-perceived BI and perceived body weight also differed in normal-weight females (p= 0.02 at 0.000-0.04 CI). Discrepancies (p= 0.02 at 0.00-0.04 CI) occurred between self-perceived BI and self-ideal BI, and between self-perceived BI and desired BI (p= 0.02 at 0.00-0.04 CI) in overweight females. Gender differences occurred for self-ideal BI (p= 0.00 at 0.00-0.02 CI), ideal image for the opposite sex (IBIOS) (p= 0.02 at 0.00-0.04 CI) and desired BI (p= 0.00 at 0.00-0.02 CI). Normal-weight males perceived their BI differently from their actual body weight, perceived body weight and self-ideal BI whereas normal-weight females perceived their BI differently from only their perceived body weight. Discrepancies occur between self-ideal BI and self-perceived BI, and between self-perceived BI and desired BI in overweight females. There are differential

  12. Restoration of Medical Images with Different Types of Noise; Restauracion de Imagenes Medicas con Diferentes Tipos de Ruido

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, M. G.; Vidal, V.; Verdu, G.; Mayo, P.; Rodenas, F.

    2013-07-01

    In this paper, a method is proposed to reduce the Gaussian, speckle and impulsive noise. This filter, named PGMFDNL filter combines a nonlinear diffusion and fuzzy peer group. The proposed filter can effectively reduce image noise without any information about the noise present in the image. As a result, the proposed method obtains good performance in different types of noise.

  13. Dental-CT: image quality and absorbed radiation dose of different scan protocols

    International Nuclear Information System (INIS)

    Schorn, C.; Alamo, L.; Funke, M.; Grabbe, E.; Visser, H.; Hermann, K.P.

    1999-01-01

    Purpose: To develop a scan protocol for dental-CT which guarantees good image quality at the lowest possible radiation dose. Methods: In an experimental investigation Dental-CT (HSA, GE, Milwaukee, USA) of the mandible of two human skeletons positioned in a water tank were performed in order to define the most advantageous scan protocol. Tube currents ranged from 40 to 200 mA and the scan technique was modified (axial mode or helical mode with pitches of 1 to 3 and corresponding increments of 0.4 to 1.0 mm). 39 patients underwent a dental-CT with decreased current (80 mA) in the helical scan mode (pitch 2, slice thickness 1 mm). Dose measurements were performed for two different scan protocols (A: axial, 130 mAs, B: helical, 80 mA, pitch 2). Results: The preliminary investigations of image quality showed only a minor effect of the applied current. For the helical scan mode, pitches of more than 2 impaired image quality. A low increment had no advantages. There were no disadvantages in clinical practice using protocol B with decreased tube current. Absorbed radiation dose of dental CT performed with protocol B was decreased to one third in comparison to protocol A. Conclusions: A scan protocol with a low tube current (e.g., 80 mA, for a rotation time of 1 s) and a helical scan mode (e.g., for a slice thickness of 1 mm with a pitch of 2 and an increment of 1 mm) is recommended for performing dental-CT. (orig.) [de

  14. Evaluation of different tissue de-paraffinization procedures for infrared spectral imaging.

    Science.gov (United States)

    Nallala, Jayakrupakar; Lloyd, Gavin Rhys; Stone, Nicholas

    2015-04-07

    In infrared spectral histopathology, paraffin embedded tissues are often de-paraffinized using chemical agents such as xylene and hexane. These chemicals are known to be toxic and the routine de-waxing procedure is time consuming. A comparative study was carried out to identify alternate de-paraffinization methods by using paraffin oil and electronic de-paraffinization (using a mathematical computer algorithm) and their effectiveness was compared to xylene and hexane. Sixteen adjacent tissue sections obtained from a single block of a normal colon tissue were de-paraffinized using xylene, hexane and paraffin oil (+ hexane wash) at five different time points each for comparison. One section was reserved unprocessed for electronic de-paraffinization based on a modified extended multiplicative signal correction (EMSC). IR imaging was carried out on these tissue sections. Coefficients based on the fit of a pure paraffin model to the IR images were then calculated to estimate the amount of paraffin remaining after processing. Results indicate that on average xylene removes more paraffin in comparison to hexane and paraffin oil although the differences were small. This makes paraffin oil, followed by a hexane wash, an interesting and less toxic alternative method of de-paraffinization. However, none of the chemical methods removed paraffin completely from the tissues at any given time point. Moreover, paraffin was removed more easily from the glandular regions than the connective tissue regions indicating a form of differential paraffin retention based on the histology. In such cases, the use of electronic de-paraffinization to neutralize such variances across different tissue regions might be considered. Moreover it is faster, reduces scatter artefacts by index matching and enables samples to be easily stored for further analysis if required.

  15. Digital image color analysis compared to direct dental CIE colorimeter assessment under different ambient conditions.

    Science.gov (United States)

    Knösel, Michael; Attin, Rengin; Jung, Klaus; Brunner, Edgar; Kubein-Meesenburg, Dietmar; Attin, Thomas

    2009-04-01

    To evaluate the concordance and repeatability of two in vivo methods for dental color assessment and to clarify the influence of different ambient light conditions and subject's head position on the assessed color variables. Color assessments were performed by two examiners on 16 arbitrarily selected subjects under two different, standardized conditions of illumination and at two different standardized head angulations. CIE (L*a*b*) data for upper and lower central incisors were recorded in two different ways: (1) by an intra-oral contact dental colorimeter and (2) by processing digital images for performing color calculation using Adobe Photoshop software. The influence of the different ambient conditions on both methods, as well as the concordance of measurements was analyzed statistically using several mixed linear models. Ambient light as a single factor had no significant influence on maxillary L*, a* and b* values, but it did have an effect on mandible assessments. Head angulation variation resulted in significant L* value differences using the photo method. The operator had a significant influence on values a* and b* for the photo method and on a* values for the colorimeter method. In fully lit ambient condition, the operator had a significant influence on the segregated L*, a*, and b* values. With dimmed lights, head angulation became significant, but not the operator. Evaluation of segregated L* values was error prone in both methods. Comparing both methods, deltaE values did not exceed 2.85 units, indicating that color differences between methods and recorded under varying ambient conditions were well below the sensitivity of the naked eye.

  16. White Matter Structural Differences in Young Children With Type 1 Diabetes: A Diffusion Tensor Imaging Study

    Science.gov (United States)

    Aye, Tandy; Barnea-Goraly, Naama; Ambler, Christian; Hoang, Sherry; Schleifer, Kristin; Park, Yaena; Drobny, Jessica; Wilson, Darrell M.; Reiss, Allan L.; Buckingham, Bruce A.

    2012-01-01

    OBJECTIVE To detect clinical correlates of cognitive abilities and white matter (WM) microstructural changes using diffusion tensor imaging (DTI) in young children with type 1 diabetes. RESEARCH DESIGN AND METHODS Children, ages 3 to <10 years, with type 1 diabetes (n = 22) and age- and sex-matched healthy control subjects (n = 14) completed neurocognitive testing and DTI scans. RESULTS Compared with healthy controls, children with type 1 diabetes had lower axial diffusivity (AD) values (P = 0.046) in the temporal and parietal lobe regions. There were no significant differences between groups in fractional anisotropy and radial diffusivity (RD). Within the diabetes group, there was a significant, positive correlation between time-weighted HbA1c and RD (P = 0.028). A higher, time-weighted HbA1c value was significantly correlated with lower overall intellectual functioning measured by the full-scale intelligence quotient (P = 0.03). CONCLUSIONS Children with type 1 diabetes had significantly different WM structure (as measured by AD) when compared with controls. In addition, WM structural differences (as measured by RD) were significantly correlated with their HbA1c values. Additional studies are needed to determine if WM microstructural differences in young children with type 1 diabetes predict future neurocognitive outcome. PMID:22966090

  17. Magnetic resonance imaging study of corpus callosum abnormalities in patients with different subtypes of schizophrenia

    Directory of Open Access Journals (Sweden)

    Ebru Unlu

    2014-11-01

    Full Text Available Background. Reductions in the size of the corpus callosum (CC have been described for schizophrenia patients, but little is known about the possible regional differences in schizophrenia subtypes (paranoid, disorganised, undifferentiated, residual.  Methods. We recruited 58 chronically schizophrenic patients with different subtypes, and 31 age-and-gender matched healthy controls. The callosum was extracted from a midsagittal slice from T1 weighted magnetic resonance images, and areas of the total CC, its five subregions, CC length and total brain volume were compared between schizophrenia subtypes and controls. Five subregions were approximately matched to fibre pathways from cortical regions.  Results. Schizophrenia patients had reduced CC total area and length when compared with controls. Disorganised and undifferentiated schizophrenics had a smaller prefrontal area, while there was no significant difference for the paranoid and residual groups. The premotor/supplementary motor area was smaller in all schizophrenia subtypes. The motor area was smaller only in the disorganised group. A smaller sensory area was found in all subtypes except the residual group. Parietal, temporal and occipital areas were smaller in the paranoid and undifferentiated groups. Total brain volume was smaller in all schizophrenia subtypes compared with controls, but did not reach statistical significance.  Conclusion. These findings suggest that the heterogeneity of symptoms may lead to the different CC morphological characteristics in schizophrenia subtypes.

  18. Role of endorectal magnetic resonance spectroscopic imaging in two different Gleason scores in prostate cancer.

    Science.gov (United States)

    Nagarajan, Rajakumar; Margolis, Daniel; McClure, Tim; Raman, Steve; Thomas, M Albert

    2011-01-01

    The major goal of the work was to record three-dimensional magnetic resonance spectroscopic imaging (MRSI) and to compare metabolite ratios between different Gleason scores (GS). MRSI localized by endorectal coil-acquired point-resolved spectroscopy was performed in 14 men with prostate cancer of GS 6 (n = 7) and 7 (n = 7) using a 1.5-tesla MRI scanner. The ratio of (choline + creatine)/citrate was increased with an increase of GS, i.e. 0.590 ± 0.171 in the target lesion and 0.321 ± 0.157 in the contralateral region of patients with a GS of 6 as opposed to 1.082 ± 0.432 in the target lesion and 0.360 ± 0.243 in the contralateral region of patients with a GS of 7. Our pilot results demonstrated that MRSI was an additional biochemical tool which is complementary to the current imaging modalities for early diagnosis and therapeutic management of prostate cancer. Copyright © 2011 S. Karger AG, Basel.

  19. Differences between time domain and Fourier domain optical coherence tomography in imaging tissues.

    Science.gov (United States)

    Gao, W; Wu, X

    2017-11-01

    It has been numerously demonstrated that both time domain and Fourier domain optical coherence tomography (OCT) can generate high-resolution depth-resolved images of living tissues and cells. In this work, we compare the common points and differences between two methods when the continuous and random properties of live tissue are taken into account. It is found that when relationships that exist between the scattered light and tissue structures are taken into account, spectral interference measurements in Fourier domain OCT (FDOCT) is more advantageous than interference fringe envelope measurements in time domain OCT (TDOCT) in the cases where continuous property of tissue is taken into account. It is also demonstrated that when random property of tissue is taken into account FDOCT measures the Fourier transform of the spatial correlation function of the refractive index and speckle phenomena will limit the effective limiting imaging resolution in both TDOCT and FDOCT. Finally, the effective limiting resolution of both TDOCT and FDOCT are given which can be used to estimate the effective limiting resolution in various practical applications. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  20. Simulating Visible/Infrared Imager Radiometer Suite Normalized Difference Vegetation Index Data Using Hyperion and MODIS

    Science.gov (United States)

    Ross, Kenton W.; Russell, Jeffrey; Ryan, Robert E.

    2006-01-01

    The success of MODIS (the Moderate Resolution Imaging Spectrometer) in creating unprecedented, timely, high-quality data for vegetation and other studies has created great anticipation for data from VIIRS (the Visible/Infrared Imager Radiometer Suite). VIIRS will be carried onboard the joint NASA/Department of Defense/National Oceanic and Atmospheric Administration NPP (NPOESS (National Polar-orbiting Operational Environmental Satellite System) Preparatory Project). Because the VIIRS instruments will have lower spatial resolution than the current MODIS instruments 400 m versus 250 m at nadir for the channels used to generate Normalized Difference Vegetation Index data, scientists need the answer to this question: how will the change in resolution affect vegetation studies? By using simulated VIIRS measurements, this question may be answered before the VIIRS instruments are deployed in space. Using simulated VIIRS products, the U.S. Department of Agriculture and other operational agencies can then modify their decision support systems appropriately in preparation for receipt of actual VIIRS data. VIIRS simulations and validations will be based on the ART (Application Research Toolbox), an integrated set of algorithms and models developed in MATLAB(Registerd TradeMark) that enables users to perform a suite of simulations and statistical trade studies on remote sensing systems. Specifically, the ART provides the capability to generate simulated multispectral image products, at various scales, from high spatial hyperspectral and/or multispectral image products. The ART uses acquired ( real ) or synthetic datasets, along with sensor specifications, to create simulated datasets. For existing multispectral sensor systems, the simulated data products are used for comparison, verification, and validation of the simulated system s actual products. VIIRS simulations will be performed using Hyperion and MODIS datasets. The hyperspectral and hyperspatial properties of Hyperion

  1. Pictorial essay of ultrasound-reconstructed coronal plane images of the uterus in different uterine pathologies.

    Science.gov (United States)

    Grigore, Mihaela; Grigore, Anamaria; Gafitanu, Dumitru; Furnica, Cristina

    2018-04-01

    Imaging in the major planes (horizontal, coronal, and sagittal) of the uterus is important for determining anatomy and allowing the findings to be standardized, and for evaluating and diagnosing different pathological conditions in clinical practice. Examination of the coronal plane is an important step in identifying uterine pathologies and their relationships to the endometrial canal. Three-dimensional (3D) ultrasound reveals the normal anatomy better and improves the depiction of abnormal anatomy, as the coronal plane of the uterus can easily be obtained using 3D reconstruction techniques. Our pictorial essay demonstrates that adding 3D ultrasound to a routine gynecological workup can be beneficial for clinicians, enabling a precise diagnosis to be made. In addition, the volumes obtained and stored by 3D ultrasound can allow students or residents to become more familiar with normal and abnormal pelvic structures. Clin. Anat. 31:373-379, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Atomic force microscopy imaging of polyurethane nanoparticles onto different solid substrates

    International Nuclear Information System (INIS)

    Beddin Fritzen-Garcia, Mauricia; Giehl Zanetti-Ramos, Betina; Schweitzer de Oliveira, Cristian; Soldi, Valdir; Avelino Pasa, Andre; Creczynski-Pasa, Tania Beatriz

    2009-01-01

    Atomic force microscopy (AFM) is a technique suited for characterizing nanoparticles on solid surfaces because it offers the capability of 3D visualization and quantitative information about the topography of the samples. In the present work, contact-mode AFM has been applied to imaging polyurethane nanoparticles formulated from a natural triol and isophorone diisocyanate (IPDI) in the presence of poly(ethylene glycol) (PEG). The colloidal polymeric system was deposited on mica, hydrophilic and hydrophobic silicon solid substrates to evaluate the size and shape of the nanoparticles. Our data showed that the nanoparticles were better distributed on mica and hydrophilic silicon. From the analysis of line-scan profiles we obtained different values for the ratio between the diameter and the height of the nanoparticles, indicating that the shape of the particles depends on the interaction between the nanoparticles and the substrate

  3. Usefulness of computerized method for lung nodule detection on digital chest radiographs using similar subtraction images from different patients

    International Nuclear Information System (INIS)

    Aoki, Takatoshi; Oda, Nobuhiro; Yamashita, Yoshiko; Yamamoto, Keiji; Korogi, Yukunori

    2012-01-01

    Purpose: The purpose of this study is to evaluate the usefulness of a novel computerized method to select automatically the similar chest radiograph for image subtraction in the patients who have no previous chest radiographs and to assist the radiologists’ interpretation by presenting the “similar subtraction image” from different patients. Materials and methods: Institutional review board approval was obtained, and the requirement for informed patient consent was waived. A large database of approximately 15,000 normal chest radiographs was used for searching similar images of different patients. One hundred images of candidates were selected according to two clinical parameters and similarity of the lung field in the target image. We used the correlation value of chest region in the 100 images for searching the most similar image. The similar subtraction images were obtained by subtracting the similar image selected from the target image. Thirty cases with lung nodules and 30 cases without lung nodules were used for an observer performance test. Four attending radiologists and four radiology residents participated in this observer performance test. Results: The AUC for all radiologists increased significantly from 0.925 to 0.974 with the CAD (P = .004). When the computer output images were available, the average AUC for the residents was more improved (0.960 vs. 0.890) than for the attending radiologists (0.987 vs. 0.960). Conclusion: The novel computerized method for lung nodule detection using similar subtraction images from different patients would be useful to detect lung nodules on digital chest radiographs, especially for less experienced readers.

  4. Pulmonary Capillary Hemorrhage Induced by Different Imaging Modes of Diagnostic Ultrasound.

    Science.gov (United States)

    Miller, Douglas L; Dong, Zhihong; Dou, Chunyan; Raghavendran, Krishnan

    2018-05-01

    The induction of pulmonary capillary hemorrhage (PCH) is a well-established non-thermal biological effect of pulsed ultrasound in animal models. Typically, research has been done using laboratory pulsed ultrasound systems with a fixed beam and, recently, by B-mode diagnostic ultrasound. In this study, a GE Vivid 7 Dimension ultrasound machine with 10 L linear array probe was used at 6.6 MHz to explore the relative PCH efficacy of B-mode imaging, M-mode (fixed beam), color angio mode Doppler imaging and pulsed Doppler mode (fixed beam). Anesthetized rats were scanned in a warmed water bath, and thresholds were determined by scanning at different power steps, 2 dB apart, in different groups of six rats. Exposures were performed for 5 min, except for a 15-s M-mode group. Peak rarefactional pressure amplitude thresholds were 1.5 MPa for B-mode and 1.1 MPa for angio Doppler mode. For the non-scanned modes, thresholds were 1.1 MPa for M-mode and 0.6 MPa for pulsed Doppler mode with its relatively high duty cycle (7.7 × 10 -3 vs. 0.27 × 10 -3 for M-mode). Reducing the duration of M-mode to 15 s (from 300 s) did not significantly reduce PCH (area, volume or depth) for some power settings, but the threshold was increased to 1.4 MPa. Pulmonary sonographers should be aware of this unique adverse bio-effect of diagnostic ultrasound and should consider reduced on-screen mechanical index settings for potentially vulnerable patients. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

  5. Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention.

    Science.gov (United States)

    O'Hare, Aminda J; Atchley, Ruth Ann; Young, Keith M

    2017-11-16

    Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed by right frontal regions, while pleasant emotions are processed by left frontal regions. The other theory posits that the right hemisphere is more specialized for the processing of emotional information overall, particularly in posterior regions. Assessing the different roles of the cerebral hemispheres in processing emotional information can be difficult without the use of neuroimaging methodologies, which are not accessible or affordable to all scientists. Divided visual field presentation of stimuli can allow for the investigation of lateralized processing of information without the use of neuroimaging technology. This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention. Future work will pair this paradigm with a more active behavioral task to explore the behavioral impacts on the attentional differences found.

  6. Sexual difference of human hyoid bones. Quantitative analysis of CT three-dimensional image

    International Nuclear Information System (INIS)

    Terashima, Yoshiharu; Izumi, Masahiro; Hanamura, Hajime; Takada, Yasushi

    2007-01-01

    We investigated sexual differences in hyoid bones of 50 dissected Japanese cadavers: 26 males (aged 52 to 101, averaged 81.9 years) and 24 females (aged 61 to 94, averaged 83.6 years). All extracted hyoid bones were scanned by multi-slice CT. Length of body, distance between bilateral greater horns, length of greater horns, distance between bilateral lesser horns, and length of lesser horns were measured on CT three-dimensional image, and were analyzed by univariate and multivariate statistics. t-tests showed significant sexual differences in all the dimensions; being about 20% longer in males than in females. In principal component analysis using five hyoid dimensions, factor 1, expressing the overall size of the bone, fairly separated each sex, but factors 2 and 3, expressing the shape, did not. Discriminant analysis by a stepwise model, using all the eight dimensions, classified sex rightly (88.6% of the bone) by a function of two dimensions: length of body and distance between bilateral tips of lesser horns. In conclusion, a sexual difference of the hyoid bone was evident in size rather than in shape. (author)

  7. To breathe or fight? Siamese fighting fish differ when facing a real opponent or mirror image.

    Science.gov (United States)

    Arnott, Gareth; Beattie, Emma; Elwood, Robert W

    2016-08-01

    Displays are a feature of animal contest behaviour and have been interpreted as a means of gathering information on opponent fighting ability, as well as signalling aggressive motivation. In fish, contest displays often include frontal and lateral elements, which in the latter involves contestants showing their flanks to an opponent. Previous work in a range of fish species has demonstrated population-level lateralization of these displays, preferentially showing one side to their opponent. Mirrors are commonly used in place of a real opponent to study aggression in fish, yet they may disrupt the normal pattern of display behaviour. Here, using Siamese fighting fish, Betta splendens, we compare the aggressive behaviour of males to a mirror image and real opponent behind a transparent barrier. As this species is a facultative air-breather, we also quantify surface breathing, providing insights into underlying fight motivation. Consistent with previous work, we found evidence of population-level lateralization, with a bias to present the left side and use the left eye when facing a real opponent. Contrary to expectations, there were no differences in the aggressive displays to a mirror and real opponent, with positive correlations between the behaviour in the two scenarios. However, there were important differences in surface breathing, which was more frequent and of longer duration in the mirror treatment. The reasons for these differences are discussed in relation to the repertoire of contest behaviour and motivation when facing a real opponent. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Microbubble responses to a similar mechanical index with different real-time perfusion imaging techniques.

    Science.gov (United States)

    Porter, Thomas R; Oberdorfer, Joseph; Rafter, Patrick; Lof, John; Xie, Feng

    2003-08-01

    The purpose of this study was to determine differences in contrast enhancement and microbubble destruction rates with current commercially available low-mechanical index (MI) real-time perfusion imaging modalities. A tissue-mimicking phantom was developed that had vessels at 3 cm (near field) and 9 cm (far field) from a real-time transducer. Perfluorocarbon-exposed sonicated dextrose albumin microbubbles (PESDA) were injected proximal to a mixing chamber, and then passed through these vessels while the region was insonified with either pulses of alternating polarity with pulse inversion Doppler (PID) or pulses of alternating amplitude by power modulation (PM) at MIs of 0.1, 0.2 and 0.3. Effluent microbubble concentration, contrast intensity and the slope of digital contrast intensity vs. time were measured. Our results demonstrated that microbubble destruction already occurs with PID at an MI of 0.1. Contrast intensity seen with PID was less than with PM. Therefore, differences in contrast enhancement and microbubble destruction rates occur at a similar MI setting when using different real-time pulse sequence schemes.

  9. Magnetic resonance imaging detects significant sex differences in human myocardial strain

    Directory of Open Access Journals (Sweden)

    Reynolds Lina M

    2011-08-01

    Full Text Available Abstract Background The pathophysiology responsible for the significant outcome disparities between men and women with cardiac disease is largely unknown. Further investigation into basic cardiac physiological differences between the sexes is needed. This study utilized magnetic resonance imaging (MRI-based multiparametric strain analysis to search for sex-based differences in regional myocardial contractile function. Methods End-systolic strain (circumferential, longitudinal, and radial was interpolated from MRI-based radiofrequency tissue tagging grid point displacements in each of 60 normal adult volunteers (32 females. Results The average global left ventricular (LV strain among normal female volunteers (n = 32 was significantly larger in absolute value (functionally better than in normal male volunteers (n = 28 in both the circumferential direction (Male/Female = -0.19 ± 0.02 vs. -0.21 ± 0.02; p = 0.025 and longitudinal direction (Male/Female = -0.14 ± 0.03 vs. -0.16 ± 0.02; p = 0.007. Conclusions The finding of significantly larger circumferential and longitudinal LV strain among normal female volunteers suggests that baseline contractile differences between the sexes may contribute to the well-recognized divergence in cardiovascular disease outcomes. Further work is needed in order to determine the pathologic changes that occur in LV strain between women and men with the onset of cardiovascular disease.

  10. Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT

    International Nuclear Information System (INIS)

    Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

    2007-01-01

    In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT). We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography(3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image. (author)

  11. [Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].

    Science.gov (United States)

    Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

    2007-03-20

    In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.

  12. Progressive gender differences of structural brain networks in healthy adults: a longitudinal, diffusion tensor imaging study.

    Directory of Open Access Journals (Sweden)

    Yu Sun

    Full Text Available Sexual dimorphism in the brain maturation during childhood and adolescence has been repeatedly documented, which may underlie the differences in behaviors and cognitive performance. However, our understanding of how gender modulates the development of structural connectome in healthy adults is still not entirely clear. Here we utilized graph theoretical analysis of longitudinal diffusion tensor imaging data over a five-year period to investigate the progressive gender differences of brain network topology. The brain networks of both genders showed prominent economical "small-world" architecture (high local clustering and short paths between nodes. Additional analysis revealed a more economical "small-world" architecture in females as well as a greater global efficiency in males regardless of scan time point. At the regional level, both increased and decreased efficiency were found across the cerebral cortex for both males and females, indicating a compensation mechanism of cortical network reorganization over time. Furthermore, we found that weighted clustering coefficient exhibited significant gender-time interactions, implying different development trends between males and females. Moreover, several specific brain regions (e.g., insula, superior temporal gyrus, cuneus, putamen, and parahippocampal gyrus exhibited different development trajectories between males and females. Our findings further prove the presence of sexual dimorphism in brain structures that may underlie gender differences in behavioral and cognitive functioning. The sex-specific progress trajectories in brain connectome revealed in this work provide an important foundation to delineate the gender related pathophysiological mechanisms in various neuropsychiatric disorders, which may potentially guide the development of sex-specific treatments for these devastating brain disorders.

  13. Progressive gender differences of structural brain networks in healthy adults: a longitudinal, diffusion tensor imaging study.

    Science.gov (United States)

    Sun, Yu; Lee, Renick; Chen, Yu; Collinson, Simon; Thakor, Nitish; Bezerianos, Anastasios; Sim, Kang

    2015-01-01

    Sexual dimorphism in the brain maturation during childhood and adolescence has been repeatedly documented, which may underlie the differences in behaviors and cognitive performance. However, our understanding of how gender modulates the development of structural connectome in healthy adults is still not entirely clear. Here we utilized graph theoretical analysis of longitudinal diffusion tensor imaging data over a five-year period to investigate the progressive gender differences of brain network topology. The brain networks of both genders showed prominent economical "small-world" architecture (high local clustering and short paths between nodes). Additional analysis revealed a more economical "small-world" architecture in females as well as a greater global efficiency in males regardless of scan time point. At the regional level, both increased and decreased efficiency were found across the cerebral cortex for both males and females, indicating a compensation mechanism of cortical network reorganization over time. Furthermore, we found that weighted clustering coefficient exhibited significant gender-time interactions, implying different development trends between males and females. Moreover, several specific brain regions (e.g., insula, superior temporal gyrus, cuneus, putamen, and parahippocampal gyrus) exhibited different development trajectories between males and females. Our findings further prove the presence of sexual dimorphism in brain structures that may underlie gender differences in behavioral and cognitive functioning. The sex-specific progress trajectories in brain connectome revealed in this work provide an important foundation to delineate the gender related pathophysiological mechanisms in various neuropsychiatric disorders, which may potentially guide the development of sex-specific treatments for these devastating brain disorders.

  14. Use of infrared imaging to predict the developmental stages and differences in chicken embryos exposed to different photoperiods

    Science.gov (United States)

    Frederick, Rebecca A.; Hsieh, Sheng-Jen; Palomares, Benjamin Giron

    2012-06-01

    Monitoring development of chicken embryos allows determination of when an egg is not developing and when eggs are close to hatching for more efficient production. Research has been conducted on the effects of temperature fluctuations and light exposure on embryo development; similarities between chicken and mammal embryos; and the use of MRI, tomography, and ultrasound to view specific areas and processes within the embryo. However, there has been little exploration of the use of infrared imaging as a non-destructive method for analyzing and predicting embryonic development. In this study, we built an automated loading system for image acquisition. Pilot experiments were conducted to determine the overall scanning time and scanning frequency. A batch of fertilized eggs was scanned each day as the embryos continued to grow. The captured images were analyzed and categorized into three stages: Stage 1 (days 1 to 7), Stage 2 (days 8 to 14), and Stage 3 (days 15 to 21). The temperature data abstracted from the captured images were divided into two groups. Group 1, consisting of two-thirds of the data, was used to construct a model. Group 2, consisting of one-third of the data, was used to evaluate the predictive accuracy of the model. A three-layer artificial neural network model was developed to predict embryo development stage given a temperature profile. Results suggest that the neural network model is sufficient to predict embryo development stage with good accuracy of 75%. Accuracy can likely be improved if more data sets for each development stage are available.

  15. Evaluation of accuracy of B-spline transformation-based deformable image registration with different parameter settings for thoracic images.

    Science.gov (United States)

    Kanai, Takayuki; Kadoya, Noriyuki; Ito, Kengo; Onozato, Yusuke; Cho, Sang Yong; Kishi, Kazuma; Dobashi, Suguru; Umezawa, Rei; Matsushita, Haruo; Takeda, Ken; Jingu, Keiichi

    2014-11-01

    Deformable image registration (DIR) is fundamental technique for adaptive radiotherapy and image-guided radiotherapy. However, further improvement of DIR is still needed. We evaluated the accuracy of B-spline transformation-based DIR implemented in elastix. This registration package is largely based on the Insight Segmentation and Registration Toolkit (ITK), and several new functions were implemented to achieve high DIR accuracy. The purpose of this study was to clarify whether new functions implemented in elastix are useful for improving DIR accuracy. Thoracic 4D computed tomography images of ten patients with esophageal or lung cancer were studied. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomical landmarks that had been manually identified. DIR between peak-inhale and peak-exhale images was performed with four types of parameter settings. The first one represents original ITK (Parameter 1). The second employs the new function of elastix (Parameter 2), and the third was created to verify whether new functions improve DIR accuracy while keeping computational time (Parameter 3). The last one partially employs a new function (Parameter 4). Registration errors for these parameter settings were calculated using the manually determined landmark pairs. 3D registration errors with standard deviation over all cases were 1.78 (1.57), 1.28 (1.10), 1.44 (1.09) and 1.36 (1.35) mm for Parameter 1, 2, 3 and 4, respectively, indicating that the new functions are useful for improving DIR accuracy, even while maintaining the computational time, and this B-spline-based DIR could be used clinically to achieve high-accuracy adaptive radiotherapy. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  16. Evaluation of accuracy of B-spline transformation-based deformable image registration with different parameter settings for thoracic images

    International Nuclear Information System (INIS)

    Kanai, Takayuki; Kadoya, Noriyuki; Ito, Kengo

    2014-01-01

    Deformable image registration (DIR) is fundamental technique for adaptive radiotherapy and image-guided radiotherapy. However, further improvement of DIR is still needed. We evaluated the accuracy of B-spline transformation-based DIR implemented in elastix. This registration package is largely based on the Insight Segmentation and Registration Toolkit (ITK), and several new functions were implemented to achieve high DIR accuracy. The purpose of this study was to clarify whether new functions implemented in elastix are useful for improving DIR accuracy. Thoracic 4D computed tomography images of ten patients with esophageal or lung cancer were studied. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomical landmarks that had been manually identified. DIR between peak-inhale and peak-exhale images was performed with four types of parameter settings. The first one represents original ITK (Parameter 1). The second employs the new function of elastix (Parameter 2), and the third was created to verify whether new functions improve DIR accuracy while keeping computational time (Parameter 3). The last one partially employs a new function (Parameter 4). Registration errors for these parameter settings were calculated using the manually determined landmark pairs. 3D registration errors with standard deviation over all cases were 1.78 (1.57), 1.28 (1.10), 1.44 (1.09) and 1.36 (1.35) mm for Parameter 1, 2, 3 and 4, respectively, indicating that the new functions are useful for improving DIR accuracy, even while maintaining the computational time, and this B-spline-based DIR could be used clinically to achieve high-accuracy adaptive radiotherapy. (author)

  17. Gender differences in brain activity generated by unpleasant word stimuli concerning body image: an fMRI study.

    Science.gov (United States)

    Shirao, Naoko; Okamoto, Yasumasa; Mantani, Tomoyuki; Okamoto, Yuri; Yamawaki, Shigeto

    2005-01-01

    We have previously reported that the temporomesial area, including the amygdala, is activated in women when processing unpleasant words concerning body image. To detect gender differences in brain activation during processing of these words. Functional magnetic resonance imaging was used to investigate 13 men and 13 women during an emotional decision task consisting of unpleasant words concerning body image and neutral words. The left medial prefrontal cortex and hippocampus were activated only among men, and the left amygdala was activated only among women during the task; activation in the apical prefrontal region was significantly greater in men than in women. Our data suggest that the prefrontal region is responsible for the gender differences in the processing of words concerning body image, and may also be responsible for gender differences in susceptibility to eating disorders.

  18. Small average differences in attenuation corrected images between men and women in myocardial perfusion scintigraphy: a novel normal stress database

    International Nuclear Information System (INIS)

    Trägårdh, Elin; Sjöstrand, Karl; Jakobsson, David; Edenbrandt, Lars

    2011-01-01

    The American Society of Nuclear Cardiology and the Society of Nuclear Medicine state that incorporation of attenuation-corrected (AC) images in myocardial perfusion scintigraphy (MPS) will improve image quality, interpretive certainty, and diagnostic accuracy. However, commonly used software packages for MPS usually include normal stress databases for non-attenuation corrected (NC) images but not for attenuation-corrected (AC) images. The aim of the study was to develop and compare different normal stress databases for MPS in relation to NC vs. AC images, male vs. female gender, and presence vs. absence of obesity. The principal hypothesis was that differences in mean count values between men and women would be smaller with AC than NC images, thereby allowing for construction and use of gender-independent AC stress database. Normal stress perfusion databases were developed with data from 126 male and 205 female patients with normal MPS. The following comparisons were performed for all patients and separately for normal weight vs. obese patients: men vs. women for AC; men vs. women for NC; AC vs. NC for men; and AC vs. NC for women. When comparing AC for men vs. women, only minor differences in mean count values were observed, and there were no differences for normal weight vs. obese patients. For all other analyses major differences were found, particularly for the inferior wall. The results support the hypothesis that it is possible to use not only gender independent but also weight independent AC stress databases

  19. Learner differences and learning outcomes in an introductory biochemistry class: attitude toward images, visual cognitive skills, and learning approach.

    Science.gov (United States)

    Milner, Rachel E

    2014-01-01

    The practice of using images in teaching is widespread, and in science education images are used so extensively that some have argued they are now the "main vehicle of communication" (C. Ferreira, A. Arroio Problems Educ. 21st Century 2009, 16, 48-53). Although this phenomenon is especially notable in the field of biochemistry, we know little about the role and importance of images in communicating concepts to students in the classroom. This study reports the development of a scale to assess students' attitude toward biochemical images, particularly their willingness and ability to use the images to support their learning. In addition, because it is argued that images are central in the communication of biochemical concepts, we investigated three "learner differences" which might impact learning outcomes in this kind of classroom environment: attitude toward images, visual cognitive skills, and learning approach. Overall, the students reported a positive attitude toward the images, the majority agreeing that they liked images and considered them useful. However, the participants also reported that verbal explanations were more important than images in helping them to understand the concepts. In keeping with this we found that there was no relationship between learning outcomes and the students' self-reported attitude toward images or visual cognitive skills. In contrast, learning outcomes were significantly correlated with the students' self-reported approach to learning. These findings suggest that images are not necessarily the main vehicle of communication in a biochemistry classroom and that verbal explanations and encouragement of a deep learning approach are important considerations in improving our pedagogical approach. © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  20. Biexponential analysis of diffusion-weighted imaging: comparison of three different calculation methods in transplanted kidneys.

    Science.gov (United States)

    Heusch, Philipp; Wittsack, Hans-Jörg; Pentang, Gael; Buchbender, Christian; Miese, Falk; Schek, Julia; Kröpil, Patric; Antoch, Gerald; Lanzman, Rotem S

    2013-12-01

    Biexponential analysis has been used increasingly to obtain contributions of both diffusion and microperfusion to the signal decay in diffusion-weighted imaging DWI of different parts of the body. To compare biexponential diffusion parameters of transplanted kidneys obtained with three different calculation methods. DWI was acquired in 15 renal allograft recipients (eight men, seven women; mean age, 52.4 ± 14.3 years) using a paracoronal EPI sequence with 16 b-values (b = 0-750 s/mm(2)) and six averages at 1.5T. No respiratory gating was used. Three different calculation methods were used for the calculation of biexponential diffusion parameters: Fp, ADCP, and ADCD were calculated without fixing any parameter a priori (calculation method 1); ADCP was fixed to 12.0 µm(2)/ms, whereas Fp and ADCD were calculated using the biexponential model (calculation method 2); multistep approach with monoexponential fitting of the high b-value portion (b ≥ 250 s/mm(2)) for determination of ADCD and assessment of the low b intercept for determination of Fp (calculation method 3). For quantitative analysis, ROI measurements were performed on the according parameter maps. Mean ADCD values of the renal cortex using calculation method 1 were significantly lower than using calculation methods 2 and 3 (P < 0.001). There was a significant correlation between calculation methods 1 and 2 (r = 0.69 (P < 0.005) and calculation methods 1 and 3 (r = 0.59; P < 0.05) as well as calculation methods 2 and 3 (r = 0.98; P < 0.001). Mean Fp values of the renal cortex were higher with calculation method 1 than with calculation methods 2 and 3 (P < 0.001). For Fp, only the correlation between calculation methods 2 and 3 was significant (r = 0.98; P < 0.001). Biexponential diffusion parameters differ significantly depending on the calculation methods used for their calculation.

  1. Assessing the consistency of UAV-derived point clouds and images acquired at different altitudes

    Science.gov (United States)

    Ozcan, O.

    2016-12-01

    Unmanned Aerial Vehicles (UAVs) offer several advantages in terms of cost and image resolution compared to terrestrial photogrammetry and satellite remote sensing system. Nowadays, UAVs that bridge the gap between the satellite scale and field scale applications were initiated to be used in various application areas to acquire hyperspatial and high temporal resolution imageries due to working capacity and acquiring in a short span of time with regard to conventional photogrammetry methods. UAVs have been used for various fields such as for the creation of 3-D earth models, production of high resolution orthophotos, network planning, field monitoring and agricultural lands as well. Thus, geometric accuracy of orthophotos and volumetric accuracy of point clouds are of capital importance for land surveying applications. Correspondingly, Structure from Motion (SfM) photogrammetry, which is frequently used in conjunction with UAV, recently appeared in environmental sciences as an impressive tool allowing for the creation of 3-D models from unstructured imagery. In this study, it was aimed to reveal the spatial accuracy of the images acquired from integrated digital camera and the volumetric accuracy of Digital Surface Models (DSMs) which were derived from UAV flight plans at different altitudes using SfM methodology. Low-altitude multispectral overlapping aerial photography was collected at the altitudes of 30 to 100 meters and georeferenced with RTK-GPS ground control points. These altitudes allow hyperspatial imagery with the resolutions of 1-5 cm depending upon the sensor being used. Preliminary results revealed that the vertical comparison of UAV-derived point clouds with respect to GPS measurements pointed out an average distance at cm-level. Larger values are found in areas where instantaneous changes in surface are present.

  2. Imaging genetics and the neurobiological basis of individual differences in vulnerability to addiction.

    Science.gov (United States)

    Sweitzer, Maggie M; Donny, Eric C; Hariri, Ahmad R

    2012-06-01

    Addictive disorders are heritable, but the search for candidate functional polymorphisms playing an etiological role in addiction is hindered by complexity of the phenotype and the variety of factors interacting to impact behavior. Advances in human genome sequencing and neuroimaging technology provide an unprecedented opportunity to explore the impact of functional genetic variants on variability in behaviorally relevant neural circuitry. Here, we present a model for merging these technologies to trace the links between genes, brain, and addictive behavior. We describe imaging genetics and discuss the utility of its application to addiction. We then review data pertaining to impulsivity and reward circuitry as an example of how genetic variation may lead to variation in behavioral phenotype. Finally, we present preliminary data relating the neural basis of reward processing to individual differences in nicotine dependence. Complex human behaviors such as addiction can be traced to their basic genetic building blocks by identifying intermediate behavioral phenotypes, associated neural circuitry, and underlying molecular signaling pathways. Impulsivity has been linked with variation in reward-related activation in the ventral striatum (VS), altered dopamine signaling, and functional polymorphisms of DRD2 and DAT1 genes. In smokers, changes in reward-related VS activation induced by smoking abstinence may be associated with severity of nicotine dependence. Variation in genes related to dopamine signaling may contribute to heterogeneity in VS sensitivity to reward and, ultimately, to addiction. These findings illustrate the utility of the imaging genetics approach for investigating the neurobiological basis for vulnerability to addiction. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. MRI investigation of normal fetal lung maturation using signal intensities on different imaging sequences

    International Nuclear Information System (INIS)

    Balassy, Csilla; Kasprian, Gregor; Weber, Michael; Hoermann, Marcus; Prayer, Daniela; Brugger, Peter C.; Csapo, Bence; Mittermayer, Christoph

    2007-01-01

    To purpose of this paper is to study the relation between normal lung maturation signal and changes in intensity ratios (SIR) and to determine which magnetic resonance imaging sequence provides the strongest correlation of normal lung SIs with gestational age. 126 normal singleton pregnancies (20-37 weeks) were examined with a 1.5 Tesla unit. Mean SIs for lungs, liver, and gastric fluid were assessed on six different sequences, and SIRs of lung/liver (LLSIR) and lung/gastric fluid (LGSIR) were correlated with gestational age for each sequence. To evaluate the feasibility of SIRs in the prediction of the state of the lung maturity, accuracy of the predicted SIRs (D*) was measured by calculating relative residuals (D*-D)/D for each sequence. LLSIRs showed significant changes in every sequence (p<0.05), while LGSIRs only on two sequences. Significant differences were shown for the mean of absolute residuals for both LLSIRs (p<0.001) and for LGSIRs (p=0.003). Relative residuals of LLSIRs were significantly smaller on T1-weighted sequence, whereas they were significantly higher for LGSIRs on FLAIR sequence. Fetal liver seems to be adequate reference for the investigation of lung maturation. T1-weighted sequence was the most accurate for the measurement of the lung SIs; thus, we propose to determine LLSIR on T1-weighted sequence when evaluating lung development. (orig.)

  4. Gender differences in age effect on brain atrophy measured by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Gur, R.C.; Mozley, P.D.; Resnick, S.M.; Gottlieb, G.L.; Kohn, M.; Zimmerman, R.; Herman, G.; Atlas, S.; Grossman, R.; Berretta, D.; Erwin, R.; Gur, R.E.

    1991-01-01

    A prospective sample of 69 healthy adults, age range 18-80 years, was studied with magnetic resonance imaging scans of the entire cranium. Volumes were obtained by a segmentation algorithm that uses proton density and T 2 pixel values to correct field inhomogeneities (shading). Average (±SD) brain volume, excluding cerebellum, was 1090.91 ml and cerebrospinal fluid (DSF) volume was 127.91 ml. Brain volume was higher (by 5 ml) in the right hemisphere. Men had 91 ml higher brain and 20 ml higher CSF volume than women. Age was negatively correlated with brain volume and positively correlated with CSF volume. The slope fo the regression line with age for CSF was steeper for men than women. This difference in slopes was significant for sulca but not ventricular, CSF. The greatest amount of atrophy in elderly men was in the left hemisphere, whereas is women age effects were symmetric. The findings may point to neuroanatomic substrates of hemispheric specialization and gender differences in age-related changes in brain function. They suggest that women are less vulnerable to age-related changes in mental abilities, whereas men are particularly susceptible to aging effects on left hemispheric functions

  5. MRI investigation of normal fetal lung maturation using signal intensities on different imaging sequences

    Energy Technology Data Exchange (ETDEWEB)

    Balassy, Csilla; Kasprian, Gregor; Weber, Michael; Hoermann, Marcus; Prayer, Daniela [Medical University of Vienna, Department of Radiology, Vienna (Austria); Brugger, Peter C. [Medical University of Vienna, Center of Anatomy and Cell Biology, Vienna (Austria); Csapo, Bence [Medical University of Vienna, Department of Obstetrics and Gyneocology, Vienna (Austria); Mittermayer, Christoph [Medical University of Vienna, Department of Pediatrics, Vienna (Austria)

    2007-03-15

    To purpose of this paper is to study the relation between normal lung maturation signal and changes in intensity ratios (SIR) and to determine which magnetic resonance imaging sequence provides the strongest correlation of normal lung SIs with gestational age. 126 normal singleton pregnancies (20-37 weeks) were examined with a 1.5 Tesla unit. Mean SIs for lungs, liver, and gastric fluid were assessed on six different sequences, and SIRs of lung/liver (LLSIR) and lung/gastric fluid (LGSIR) were correlated with gestational age for each sequence. To evaluate the feasibility of SIRs in the prediction of the state of the lung maturity, accuracy of the predicted SIRs (D*) was measured by calculating relative residuals (D*-D)/D for each sequence. LLSIRs showed significant changes in every sequence (p<0.05), while LGSIRs only on two sequences. Significant differences were shown for the mean of absolute residuals for both LLSIRs (p<0.001) and for LGSIRs (p=0.003). Relative residuals of LLSIRs were significantly smaller on T1-weighted sequence, whereas they were significantly higher for LGSIRs on FLAIR sequence. Fetal liver seems to be adequate reference for the investigation of lung maturation. T1-weighted sequence was the most accurate for the measurement of the lung SIs; thus, we propose to determine LLSIR on T1-weighted sequence when evaluating lung development. (orig.)

  6. Searching for transits in the WTS with the difference imaging light curves

    Science.gov (United States)

    Zendejas Dominguez, Jesus

    2013-12-01

    The search for exo-planets is currently one of the most exiting and active topics in astronomy. Small and rocky planets are particularly the subject of intense research, since if they are suitably located from their host star, they may be warm and potentially habitable worlds. On the other hand, the discovery of giant planets in short-period orbits provides important constraints on models that describe planet formation and orbital migration theories. Several projects are dedicated to discover and characterize planets outside of our solar system. Among them, the Wide-Field Camera Transit Survey (WTS) is a pioneer program aimed to search for extra-solar planets, that stands out for its particular aims and methodology. The WTS has been in operation since August 2007 with observations from the United Kingdom Infrared Telescope, and represents the first survey that searches for transiting planets in the near-infrared wavelengths; hence the WTS is designed to discover planets around M-dwarfs. The survey was originally assigned about 200 nights, observing four fields that were selected seasonally (RA = 03, 07, 17 and 19h) during a year. The images from the survey are processed by a data reduction pipeline, which uses aperture photometry to construct the light curves. For the most complete field (19h-1145 epochs) in the survey, we produce an alternative set of light curves by using the method of difference imaging, which is a photometric technique that has shown important advantages when used in crowded fields. A quantitative comparison between the photometric precision achieved with both methods is carried out in this work. We remove systematic effects using the sysrem algorithm, scale the error bars on the light curves, and perform a comparison of the corrected light curves. The results show that the aperture photometry light curves provide slightly better precision for objects with J detect transits in the WTS light curves, we use a modified version of the box

  7. Imaging by the SSFSE single slice method at different viscosities of bile

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Hiroya; Usui, Motoki; Fukunaga, Kenichi; Yamamoto, Naruto; Ikegami, Toshimi [Kawasaki Hospital, Kobe (Japan)

    2001-11-01

    The single shot fast spin echo single thick slice method (single slice method) is a technique that visualizes the water component alone using a heavy T{sub 2}. However, this method is considered to be markedly affected by changes in the viscosity of the material because a very long TE is used, and changes in the T{sub 2} value, which are related to viscosity, directly affect imaging. In this study, we evaluated the relationship between the effects of TE and the T{sub 2} value of bile in the single slice method and also examined the relationship between the signal intensity of bile on T{sub 1}- and T{sub 2}-weighted images and imaging by MR cholangiography (MRC). It was difficult to image bile with high viscosities at a usual effective TE level of 700-1,500 ms. With regard to the relationship between the signal intensity of bile and MRC imaging, all T{sub 2} values of the bile samples showing relatively high signal intensities on the T{sub 1}-weighted images suggested high viscosities, and MRC imaging of these bile samples was poor. In conclusion, MRC imaging of bile with high viscosities was poor with the single slice method. Imaging by the single slice method alone of bile showing a relatively high signal intensity on T{sub 1}-weighted images should be avoided, and combination with other MRC sequences should be used. (author)

  8. Imaging by the SSFSE single slice method at different viscosities of bile

    International Nuclear Information System (INIS)

    Kubo, Hiroya; Usui, Motoki; Fukunaga, Kenichi; Yamamoto, Naruto; Ikegami, Toshimi

    2001-01-01

    The single shot fast spin echo single thick slice method (single slice method) is a technique that visualizes the water component alone using a heavy T 2 . However, this method is considered to be markedly affected by changes in the viscosity of the material because a very long TE is used, and changes in the T 2 value, which are related to viscosity, directly affect imaging. In this study, we evaluated the relationship between the effects of TE and the T 2 value of bile in the single slice method and also examined the relationship between the signal intensity of bile on T 1 - and T 2 -weighted images and imaging by MR cholangiography (MRC). It was difficult to image bile with high viscosities at a usual effective TE level of 700-1,500 ms. With regard to the relationship between the signal intensity of bile and MRC imaging, all T 2 values of the bile samples showing relatively high signal intensities on the T 1 -weighted images suggested high viscosities, and MRC imaging of these bile samples was poor. In conclusion, MRC imaging of bile with high viscosities was poor with the single slice method. Imaging by the single slice method alone of bile showing a relatively high signal intensity on T 1 -weighted images should be avoided, and combination with other MRC sequences should be used. (author)

  9. Use of fluorescent proteins and color-coded imaging to visualize cancer cells with different genetic properties.

    Science.gov (United States)

    Hoffman, Robert M

    2016-03-01

    Fluorescent proteins are very bright and available in spectrally-distinct colors, enable the imaging of color-coded cancer cells growing in vivo and therefore the distinction of cancer cells with different genetic properties. Non-invasive and intravital imaging of cancer cells with fluorescent proteins allows the visualization of distinct genetic variants of cancer cells down to the cellular level in vivo. Cancer cells with increased or decreased ability to metastasize can be distinguished in vivo. Gene exchange in vivo which enables low metastatic cancer cells to convert to high metastatic can be color-coded imaged in vivo. Cancer stem-like and non-stem cells can be distinguished in vivo by color-coded imaging. These properties also demonstrate the vast superiority of imaging cancer cells in vivo with fluorescent proteins over photon counting of luciferase-labeled cancer cells.

  10. [Study of Image Quality Comparison Based on the MTF Method Between Different Medical Rigid Endoscopes in an In Vitro Model].

    Science.gov (United States)

    Wang, Yunlong; Ji, Jun; Jiang, Changsong; Huang, Zengyue

    2015-04-01

    This study was aimed to use the method of modulation transfer function (MTF) to compare image quality among three different Olympus medical rigid cystoscopes in an in vitro model. During the experimental processes, we firstly used three different types of cystoscopes (i. e. OLYMPUS cystourethroscopy with FOV of 12 degrees, OLYMPUS Germany A22003A and OLYMPUS A2013A) to collect raster images at different brightness with industrial camera and computer from the resolution target which is with different spatial frequency, and then we processed the collected images using MALAB software with the optical transfer function MTF to obtain the values of MTF at different brightness and different spatial frequency. We then did data mathematical statistics and compared imaging quality. The statistical data showed that all three MTF values were smaller than 1. MTF values with the spatial frequency gradually increasing would decrease approaching 0 at the same brightness. When the brightness enhanced in the same process at the same spatial frequency, MTF values showed a slowly increasing trend. The three endoscopes' MTF values were completely different. In some cases the MTF values had a large difference, and the maximum difference could reach 0.7. Conclusion can be derived from analysis of experimental data that three Olympus medical rigid cystoscopes have completely different imaging quality abilities. The No. 3 endoscope OLYMPUS A2013A has low resolution but high contrast. The No. 1 endoscope OLYMPUS cystourethroscopy with FOV of 12 degrees, on the contrary, had high resolution and lower contrast. The No. 2 endoscope OLYMPUS Germany A22003A had high contrast and high resolution, and its image quality was the best.

  11. The ARIC-PET amyloid imaging study: Brain amyloid differences by age, race, sex, and APOE.

    Science.gov (United States)

    Gottesman, Rebecca F; Schneider, Andrea L C; Zhou, Yun; Chen, Xueqi; Green, Edward; Gupta, Naresh; Knopman, David S; Mintz, Akiva; Rahmim, Arman; Sharrett, A Richey; Wagenknecht, Lynne E; Wong, Dean F; Mosley, Thomas H

    2016-08-02

    To evaluate differences in amyloid deposition in a community-based cohort without dementia by age, sex, race, education, and APOE ε4 allele status. Recruited from the longitudinal Atherosclerosis Risk in Communities study, 329 participants without dementia, ages 67-88 years, were imaged using florbetapir PET at 3 US community sites (Washington County, Maryland; Forsyth County, North Carolina; and Jackson, Mississippi). Standardized uptake value ratios (SUVRs) were calculated; global cortical SUVR >1.2 was evaluated as the primary outcome. Age, race, sex, education level, and number of APOE ε4 alleles were evaluated in multivariable models including vascular risk factors, brain white matter hyperintensity and total intracranial volume, and cognitive status. A total of 141 of the participants (43%) were black. In multivariable models, odds of elevated SUVR was increased in participants with increasing age (odds ratio [OR] 1.63, 95% confidence interval [CI] 1.01-2.65 per 10 years of age) and black race (OR 2.08, 95% CI 1.23-3.51) but did not differ by educational level. Each ε4 allele was associated with increased odds of elevated SUVR (OR 2.65, 95% CI 1.61-4.39). In this community-based cohort without dementia, florbetapir uptake is associated with older age and APOE genotype. Black race was associated with higher SUVR, after adjusting for demographics, vascular risk factors, cognitive status, white matter hyperintensity volume, and APOE genotype, with effect sizes nearing those seen for APOE ε4. Replication of these findings is needed in other cohorts, and reasons for and consequences of these observed differences by race warrant further study. © 2016 American Academy of Neurology.

  12. Functional magnetic resonance imaging of the human spinal cord during vibration stimulation of different dermatomes

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, Jane M. [University Hospital of Zurich, Institute of Neuroradiology, Zurich (Switzerland); University of Manitoba, Department of Physiology, Winnipeg, Manitoba (Canada); Stroman, Patrick W. [Queen' s University, Department of Diagnostic Radiology, Kingston, Ontario (Canada); Kollias, Spyros S. [University Hospital of Zurich, Institute of Neuroradiology, Zurich (Switzerland)

    2008-03-15

    We investigated noninvasively areas of the healthy human spinal cord that become active in response to vibration stimulation of different dermatomes using functional magnetic resonance imaging (fMRI). The objectives of this study were to: (1) examine the patterns of consistent activity in the spinal cord during vibration stimulation of the skin, and (2) investigate the rostrocaudal distribution of active pixels when stimulation was applied to different dermatomes. FMRI of the cervical and lumbar spinal cord of seven healthy human subjects was carried out during vibration stimulation of six different dermatomes. In separate experiments, vibratory stimulation (about 50 Hz) was applied to the right biceps, wrist, palm, patella, Achilles tendon and left palm. The segmental distribution of activity observed by fMRI corresponded well with known spinal cord neuroanatomy. The peak number of active pixels was observed at the expected level of the spinal cord with some activity in the adjacent segments. The rostrocaudal distribution of activity was observed to correspond to the dermatome being stimulated. Cross-sectional localization of activity was primarily in dorsal areas but also spread into ventral and intermediate areas of the gray matter and a distinct laterality ipsilateral to the stimulated limb was not observed. We demonstrated that fMRI can detect a dermatome-dependent pattern of spinal cord activity during vibratory stimulation and can be used as a passive stimulus for the noninvasive assessment of the functional integrity of the human spinal cord. Demonstration of cross-sectional selectivity of the activation awaits further methodological and experimental refinements. (orig.)

  13. Functional magnetic resonance imaging of the human spinal cord during vibration stimulation of different dermatomes

    International Nuclear Information System (INIS)

    Lawrence, Jane M.; Stroman, Patrick W.; Kollias, Spyros S.

    2008-01-01

    We investigated noninvasively areas of the healthy human spinal cord that become active in response to vibration stimulation of different dermatomes using functional magnetic resonance imaging (fMRI). The objectives of this study were to: (1) examine the patterns of consistent activity in the spinal cord during vibration stimulation of the skin, and (2) investigate the rostrocaudal distribution of active pixels when stimulation was applied to different dermatomes. FMRI of the cervical and lumbar spinal cord of seven healthy human subjects was carried out during vibration stimulation of six different dermatomes. In separate experiments, vibratory stimulation (about 50 Hz) was applied to the right biceps, wrist, palm, patella, Achilles tendon and left palm. The segmental distribution of activity observed by fMRI corresponded well with known spinal cord neuroanatomy. The peak number of active pixels was observed at the expected level of the spinal cord with some activity in the adjacent segments. The rostrocaudal distribution of activity was observed to correspond to the dermatome being stimulated. Cross-sectional localization of activity was primarily in dorsal areas but also spread into ventral and intermediate areas of the gray matter and a distinct laterality ipsilateral to the stimulated limb was not observed. We demonstrated that fMRI can detect a dermatome-dependent pattern of spinal cord activity during vibratory stimulation and can be used as a passive stimulus for the noninvasive assessment of the functional integrity of the human spinal cord. Demonstration of cross-sectional selectivity of the activation awaits further methodological and experimental refinements. (orig.)

  14. The value of different imaging methods on classification in displaced proximal humeral fractures

    International Nuclear Information System (INIS)

    Cai Jingyu; Zhu Qingsheng

    2004-01-01

    Objective: To investigate the influence of common X-ray, two-dimensional computed tomography (2D-CT), spiral computed tomography (SCT), and three-dimensional (3-D) reconstruction on the classification in displaced proximal humeral fractures. Methods: Three groups were divided on the basis of various imaging methods, including group A (common X-ray), group B (common X-ray and 2D-CT), and group C (3-D reconstruction of SCT and 2D-SCT). 46 cases of displaced proximal humeral fractures were classified with Neer system. The true rate of fracture classification by use of three methods was compared with each other, and clinical significance of SCT and 3-D reconstruction was evaluated. Results: Based on operation, 46 cases of displaced proximal humeral fractures in group A included 26 cases of Neer two-part fractures, 13 cases of three-part fractures, and 7 cases of four-part fractures. The true cases of common X-ray were 22 in Neer two-part fractures and 8 in three and four-part fractures, there was significant difference between Neer two-part fractures and Neer three and four-part fractures (P<0.05); 18 cases of proximal humeral fractures in group B included 3 cases of Neer two-part fractures, 9 cases of three-part fractures, and 6 cases of four-part fractures. The true cases of common X-ray and 2D-CT were 7 in Neer three and four-part fractures. 10 cases of proximal humeral fractures in group C included 1 case of Neer two-part fracture, 5 cases of three-part fractures, and 4 cases of four-part fractures. The true cases of 3-D reconstruction, MPR of SCT, and 2D-SCT were 8 in Neer three and four-part fractures. With regard to the true cases of the classification in Neer three and four-part fractures, there was significant difference in three groups and between group A and group C (P<0.05). All SCT and 3-D reconstruction played an important role in the treatment of proximal humeral fractures. Conclusion: Series of good quality X-ray examinations were the first imaging

  15. SU-E-I-53: Variation in Measurements of Breast Skin Thickness Obtained Using Different Imaging Modalities

    International Nuclear Information System (INIS)

    Nguyen, U; Kumaraswamy, N; Markey, M

    2014-01-01

    Purpose: To investigate variation in measurements of breast skin thickness obtained using different imaging modalities, including mammography, computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI). Methods: Breast skin thicknesses as measured by mammography, CT, ultrasound, and MRI were compared. Mammographic measurements of skin thickness were obtained from published studies that utilized standard positioning (upright) and compression. CT measurements of skin thickness were obtained from a published study of a prototype breast CT scanner in which the women were in the prone position and the breast was uncompressed. Dermatological ultrasound exams of the breast skin were conducted at our institution, with the subjects in the upright position and the breast uncompressed. Breast skin thickness was calculated from breast MRI exams at our institution, with the patient in the prone position and the breast uncompressed. Results: T tests for independent samples demonstrated significant differences in the mean breast skin thickness as measured by different imaging modalities. Repeated measures ANOVA revealed significant differences in breast skin thickness across different quadrants of the breast for some modalities. Conclusion: The measurement of breast skin thickness is significantly different across different imaging modalities. Differences in the amount of compression and differences in patient positioning are possible reasons why measurements of breast skin thickness vary by modality

  16. Differences in body image between anorexics and in-vitro-fertilization patients - a study with Body Grid

    Science.gov (United States)

    Borkenhagen, Ada; Klapp, Burghard F.; Schoeneich, Frank; Brähler, Elmar

    2005-01-01

    Objectives: The purpose of the investigation was to explore the body image disturbance of anorexics and in-vitro-fertilization patients (IvF-patients) with Body Grid and Body Identity Plot. Methods: The paper reports on an empirical study conducted with 32 anorexic patients and 30 IvF-patients. The structure of the body image was derived from the Body Grid, an idiographic approach following the Role Repertory Grid developed by George A. Kelly [17]. The representation of the body image and the degree of body-acceptance is represented graphically. Results: By the Body Grid and Body Identity Plot measures we were able to identify important differences in body image between anorexics and IvF-patients. Conclusion: The tendencies of dissociation in the body image of anorexics which we found must be seen in the sense of a specific body image disturbance which differs significantly from the body-experience profile of IvF-patients. With the grid approach it was possible to elicit the inner structure of body image and determine the acceptance of the body and integration of single body parts. PMID:19742059

  17. Phase-contrast X-ray CT imaging of the kidney. Differences between ethanol fixation and formalin fixation

    International Nuclear Information System (INIS)

    Shirai, Ryota; Kunii, Takuya; Maruyama, Hiroko; Takeda, Tohoru; Yoneyama, Akio; Lwin, Thet Thet

    2012-01-01

    A phase-contrast X-ray imaging technique using an X-ray interferometer that provides approximately 1000 times higher sensitivity than the conventional X-ray imaging method for low-atomic number elements based on the difference in the mass attenuation coefficient has recently been developed. In the present study, we compared rat kidneys fixed in 100% ethanol and in 10% formalin to evaluate the effects of ethanol in enhancing image contrast in phase-contrast imaging because ethanol causes significant dehydration of tissues and enhances density differences between tissue components. The experiments were conducted at the Photon Factory in Tsukuba, and the X-ray energy was set at 35 keV. Fine anatomical structures in the kidney such as the glomeruli, tubules, and vessels were observed. Particularly clear renal images were obtained with ethanol fixation. The pixel value ratio between the cortex and medulla was about 43% in ethanol-fixed kidneys and 21% in formalin-fixed kidneys. In other words, the contrast in ethanol-fixed kidneys was about two times higher than that in formalin-fixed kidneys. Histological examination showed significantly condensed features in the cortex. The results of this study suggest that the ethanol fixation technique may be useful for enhancing the image contrast of renal structures in the phase-contrast X-ray imaging technique. (author)

  18. Spatially dispersive finite-difference time-domain analysis of sub-wavelength imaging by the wire medium slabs

    Science.gov (United States)

    Zhao, Yan; Belov, Pavel A.; Hao, Yang

    2006-06-01

    In this paper, a spatially dispersive finite-difference time-domain (FDTD) method to model wire media is developed and validated. Sub-wavelength imaging properties of the finite wire medium slabs are examined. It is demonstrated that the slab with its thickness equal to an integer number of half-wavelengths is capable of transporting images with sub-wavelength resolution from one interface of the slab to another. It is also shown that the operation of such transmission devices is not sensitive to their transverse dimensions, which can be made even comparable to the wavelength. In this case, the edge diffractions are negligible and do not disturb the image formation.

  19. Multispectral Enhancement Method to Increase the Visual Differences of Tissue Structures in Stained Histopathology Images

    Directory of Open Access Journals (Sweden)

    Pinky A. Bautista

    2012-01-01

    Full Text Available In this paper we proposed a multispectral enhancement scheme in which the spectral colors of the stained tissue-structure of interest and its background can be independently modified by the user to further improve their visualization and color discrimination. The colors of the background objects are modified by transforming their N-band spectra through an NxN transformation matrix, which is derived by mapping the representative samples of their original spectra to the spectra of their target colors using least mean square method. On the other hand, the color of the tissue structure of interest is modified by modulating the transformed spectra with the sum of the pixel’s spectral residual-errors at specific bands weighted through an NxN weighting matrix; the spectral error is derived by taking the difference between the pixel’s original spectrum and its reconstructed spectrum using the first M dominant principal component vectors in principal component analysis. Promising results were obtained on the visualization of the collagen fiber and the non-collagen tissue structures, e.g., nuclei, cytoplasm and red blood cells (RBC, in a hematoxylin and eosin (H&E stained image.

  20. Malignant Pleural Mesothelioma: Are There Imaging Characteristics Associated With Different Histologic Subtypes on Computed Tomography?

    Science.gov (United States)

    Escalon, Joanna G; Harrington, Kate A; Plodkowski, Andrew J; Zheng, Junting; Capanu, Marinela; Zauderer, Marjorie G; Rusch, Valerie W; Ginsberg, Michelle S

    2018-04-02

    Determine imaging characteristics specific to epithelioid (eMPM), sarcomatoid (sMPM), and biphasic (bMPM) subtypes of malignant pleural mesothelioma (MPM) on computed tomography. Preoperative computed tomography scans of patients with MPM were retrospectively assessed for numerous features including primary affected side, volume loss, pleural thickness, pleural calcifications, pleural effusion, and lymphadenopathy. One hundred twenty-five patients with MPM were included. Histologic subdivision was 97 eMPM (77%), 17 bMPM (14%), and 11 sMPM (9%). Nonepithelioid MPM (bMPM and sMPM) was more likely than eMPM to have calcified pleural plaques (P = 0.035). Analyzed separately, bMPM and sMPM each demonstrated calcified plaques more frequently than eMPM, and sMPM more often had internal mammary nodes; however, P values did not reach significance (P = 0.075 and 0.071, respectively). Calcified plaques are significantly more common in nonepithelioid subtypes compared with eMPM. Given the different prognoses and management of MPM subtypes, accurate noninvasive subtype classification is clinically vital.

  1. Normalization of cortical thickness measurements across different T1 magnetic resonance imaging protocols by novel W-Score standardization.

    Science.gov (United States)

    Chung, Jinyong; Yoo, Kwangsun; Lee, Peter; Kim, Chan Mi; Roh, Jee Hoon; Park, Ji Eun; Kim, Sang Joon; Seo, Sang Won; Shin, Jeong-Hyeon; Seong, Joon-Kyung; Jeong, Yong

    2017-10-01

    The use of different 3D T1-weighted magnetic resonance (T1 MR) imaging protocols induces image incompatibility across multicenter studies, negating the many advantages of multicenter studies. A few methods have been developed to address this problem, but significant image incompatibility still remains. Thus, we developed a novel and convenient method to improve image compatibility. W-score standardization creates quality reference values by using a healthy group to obtain normalized disease values. We developed a protocol-specific w-score standardization to control the protocol effect, which is applied to each protocol separately. We used three data sets. In dataset 1, brain T1 MR images of normal controls (NC) and patients with Alzheimer's disease (AD) from two centers, acquired with different T1 MR protocols, were used (Protocol 1 and 2, n = 45/group). In dataset 2, data from six subjects, who underwent MRI with two different protocols (Protocol 1 and 2), were used with different repetition times, echo times, and slice thicknesses. In dataset 3, T1 MR images from a large number of healthy normal controls (Protocol 1: n = 148, Protocol 2: n = 343) were collected for w-score standardization. The protocol effect and disease effect on subjects' cortical thickness were analyzed before and after the application of protocol-specific w-score standardization. As expected, different protocols resulted in differing cortical thickness measurements in both NC and AD subjects. Different measurements were obtained for the same subject when imaged with different protocols. Multivariate pattern difference between measurements was observed between the protocols. Classification accuracy between two protocols was nearly 90%. After applying protocol-specific w-score standardization, the differences between the protocols substantially decreased. Most importantly, protocol-specific w-score standardization reduced both univariate and multivariate differences in the images while

  2. Do basic psychomotor skills transfer between different image-based procedures?

    Science.gov (United States)

    Buzink, Sonja N; Goossens, Richard H M; Schoon, Erik J; de Ridder, Huib; Jakimowicz, Jack J

    2010-05-01

    Surgical techniques that draw from multiple types of image-based procedures (IBP) are increasing, such as Natural Orifice Transluminal Endoscopic Surgery, fusing laparoscopy and flexible endoscopy. However, little is known about the relation between psychomotor skills for performing different types of IBP. For example, do basic psychomotor colonoscopy and laparoscopy skills interact? Following a cross-over study design, 29 naïve endoscopists were trained on the Simbionix GI Mentor and the SimSurgery SEP simulators. Group C (n = 15) commenced with a laparoscopy session, followed by four colonoscopy sessions and a second laparoscopy session. Group L (n = 14) started with a colonoscopy session, followed by four laparoscopy sessions and a second colonoscopy session. No significant differences were found between the performances of group L and group C in their first training sessions on either technique. With additional colonoscopy training, group C outperformed group L in the second laparoscopy training session on the camera navigation task. Overall, training in the basic colonoscopy tasks does not affect performance of basic laparoscopy tasks (and vice versa). However, to limited extent, training of basic psychomotor skills for colonoscopy do appear to contribute to the performance of angled laparoscope navigation tasks. Thus, training and assessment of IBP type-specific skills should focus on each type of tasks independently. Future research should further investigate the influence of psychometric abilities on the performance of IBP and the transfer of skills for physicians who are experienced in one IBP type and would like to become proficient in another type of IBP.

  3. Comparing different approaches for an effective monitoring of forest fires based on MSG/SEVIRI images

    Science.gov (United States)

    Laneve, Giovanni

    2010-05-01

    The remote sensing sensors on board of geostationary satellite, as consequence of the high frequency of the observations, allow, in principle, the monitoring of these phenomena characterized by a fast dynamics. The only condition for is that the events to be monitored should be enough strong to be recognizable notwithstanding the low spatial resolution of the present geostationary systems (MSG/SEVIRI, GOES Imager, MTSAT). Apart from meteorological phenomena other events, like those associated with forest fires and/or volcanic eruption, are characterized by a very fast dynamics. These events are also associated with a very strong signal that make them observable by geostationary satellite in a quasi-continuous way. However, in order to make possible the detection of small fires by using the low resolution multi-spectral imagery provided by geostationary sensor like SEVIRI (3x3 km2 at the equator) new algorithms, capable to exploit it high observation frequency, has been developed. This paper is devoted to show the results obtained by comparing some of these algorithms trying to highlight their advantages and limits. The algorithms herein considered are these developed by CRPSM (SFIDE®), UNIBAS/CNR (RST-FIRES) and ESA-ESRIN (MDIFRM). In general, the new approaches proposed by each one of them are capable to promptly detect small fires making possible an operational utilization of the satellite based fire detection system in the fire fighting phases. In fact, these algorithms are quite different from these introduced in the past and specifically devoted to fire detection using low resolution multi-spectral imagery on LEO (Low Earth Orbit) satellite. Thanks to these differences they are capable of detecting sub-hectare (0.2 ha) forest fires providing an useful instrument for monitoring quasi-continuously forest fires, estimating the FRP (Fire Radiative Power), evaluating the burned biomass, retrieving the emission in the atmosphere.

  4. Diversity of imaging and pathological features at different stages of primary central nervous system lymphoma

    Directory of Open Access Journals (Sweden)

    Jing LIU

    2018-01-01

    Full Text Available Objective The clinical, imaging and pathological manifestations of one patient at different stages of primary central nervous system lymphoma (PCNSL have been analyzed to disclose its pathogenesis. Methods and Results A 29-year-old female patient showed recurrent onsets. On the first onset, the main clinical manifestation was blurred vision and visual field defect. Cranial MRI showed a patchy lesion in the right parietal and occipital lobes without obvious occupying sign. T1WI showed slight low-intensity sign, T2WI and FLAIR showed high-intensity signs. Enhanced scanning showed heterogeneous punctate enhancement. The lesion disappeared gradually after glucocorticoid impact therapy. Headache, vomiting and left limb paralysis were the main clinical manifestations on the second onset, and MRI showed a lesion in the right frontal and parietal lobes with obvious occupying sign and solid enhancement, low-intensity on T1WI, high-intensity on T2WI and FLAIR. The tumor was totally removed under microscope. Histological findings showed large tumor cells, rich cytoplasm, nuclei with various sizes and shapes, conspicuous mitosis, patchy necrosis, and interstitial small vessel hyperplasia. Immunohistochemical staining showed that membrane of tumor cells was positive for CD20, and nuclei were positive for paired box gene 5 (PAX5 and multiple myeloma oncogene 1 (MUM1. In a few tumor cells, membrane was positive for CD10 and CD30, and nuclei were positive for cyclin D1. Besides, tumor cells were negative for CD3, anaplastic lymphoma kinase (ALK and glial fibrillary acidic protein (GFAP. Ki?67 labeling index was about 80%. EBER in situ hybridization (ISH assay showed that mRNA coded by Epstein?Barr (EB virus was negative. The tumor showed angiotropic characteristics, and the walls of involved blood vessels were wrapped and destructed. The final diagnosis was confirmed as diffuse large B cell lymphoma. Conclusions PCNSL has various imaging features, revealing as

  5. Performance Evaluation of Three Different High Resolution Satellite Images in Semi-Automatic Urban Illegal Building Detection

    Science.gov (United States)

    Khalilimoghadama, N.; Delavar, M. R.; Hanachi, P.

    2017-09-01

    The problem of overcrowding of mega cities has been bolded in recent years. To meet the need of housing this increased population, which is of great importance in mega cities, a huge number of buildings are constructed annually. With the ever-increasing trend of building constructions, we are faced with the growing trend of building infractions and illegal buildings (IBs). Acquiring multi-temporal satellite images and using change detection techniques is one of the proper methods of IB monitoring. Using the type of satellite images with different spatial and spectral resolutions has always been an issue in efficient detection of the building changes. In this research, three bi-temporal high-resolution satellite images of IRS-P5, GeoEye-1 and QuickBird sensors acquired from the west of metropolitan area of Tehran, capital of Iran, in addition to city maps and municipality property database were used to detect the under construction buildings with improved performance and accuracy. Furthermore, determining the employed bi-temporal satellite images to provide better performance and accuracy in the case of IB detection is the other purpose of this research. The Kappa coefficients of 70 %, 64 %, and 68 % were obtained for producing change image maps using GeoEye-1, IRS-P5, and QuickBird satellite images, respectively. In addition, the overall accuracies of 100 %, 6 %, and 83 % were achieved for IB detection using the satellite images, respectively. These accuracies substantiate the fact that the GeoEye-1 satellite images had the best performance among the employed images in producing change image map and detecting the IBs.

  6. Gender related differences in response to "in favor of myself" wellness program to enhance positive self & body image among adolescents.

    Science.gov (United States)

    Golan, Moria; Hagay, Noa; Tamir, Snait

    2014-01-01

    Physical, neurological and psychological changes are often experienced differently by male and female adolescents. Positive self-esteem, emotional well-being, school achievements, and family connectedness are considered as protective factors against health-compromising behaviors. This study examines the gender differences in respect to the effect of a school-based interactive wellness program--"In Favor of Myself"--on self-image, body image, eating attitudes and behaviors of young adolescents. Two hundred and ten adolescents (mean age 13.5) participated in the intervention group, 55% were girls and 45% boys. Program consisted of eight 90-minutes structured sessions integrated into a regular school coping skills curriculum. The program focused on self-esteem, self-image, body image, media literacy and cognitive dissonance. The overall impact of the program and the study protocol were previously published. Overall, there are gender related differences in respect to body image and self-image in young adolescents in response to "In Favor of Myself". Compared to boys, girls reported at baseline higher self-esteem, being more contingent by appearance, and their self-image was more influenced by popularity, appearance, interpersonal communication and admired people. Furthermore girls presented greater gap between current body figure and perceived ideal figure. Not only were girls more dissatisfied with their body, but they were more active in attempts to become and/or remain "thin". At program termination, gender × time effect was detected in reduction of self-worth contingent by others, change in importance given to achievements at schools, parents' perceptions, as well as the impact of comparisons to friends and family members on self-image. Girls exhibited more gains than boys from 'In Favor of Myself' which raise the questions about how effective would be the program when delivered in mixed gender groups vs. mono-gender groups.

  7. Gender related differences in response to "in favor of myself" wellness program to enhance positive self & body image among adolescents.

    Directory of Open Access Journals (Sweden)

    Moria Golan

    Full Text Available BACKGROUND: Physical, neurological and psychological changes are often experienced differently by male and female adolescents. Positive self-esteem, emotional well-being, school achievements, and family connectedness are considered as protective factors against health-compromising behaviors. This study examines the gender differences in respect to the effect of a school-based interactive wellness program--"In Favor of Myself"--on self-image, body image, eating attitudes and behaviors of young adolescents. METHODS: Two hundred and ten adolescents (mean age 13.5 participated in the intervention group, 55% were girls and 45% boys. Program consisted of eight 90-minutes structured sessions integrated into a regular school coping skills curriculum. The program focused on self-esteem, self-image, body image, media literacy and cognitive dissonance. The overall impact of the program and the study protocol were previously published. RESULTS: Overall, there are gender related differences in respect to body image and self-image in young adolescents in response to "In Favor of Myself". Compared to boys, girls reported at baseline higher self-esteem, being more contingent by appearance, and their self-image was more influenced by popularity, appearance, interpersonal communication and admired people. Furthermore girls presented greater gap between current body figure and perceived ideal figure. Not only were girls more dissatisfied with their body, but they were more active in attempts to become and/or remain "thin". At program termination, gender × time effect was detected in reduction of self-worth contingent by others, change in importance given to achievements at schools, parents' perceptions, as well as the impact of comparisons to friends and family members on self-image. CONCLUSIONS: Girls exhibited more gains than boys from 'In Favor of Myself' which raise the questions about how effective would be the program when delivered in mixed gender groups

  8. Evaluation of different magnetic resonance imaging contrast materials to be used as dummy markers in image-guided brachytherapy for gynecologic malignancies*

    Science.gov (United States)

    Sales, Camila Pessoa; Carvalho, Heloisa de Andrade; Taverna, Khallil Chaim; Pastorello, Bruno Fraccini; Rubo, Rodrigo Augusto; Borgonovi, Arthur Felipe; Stuart, Silvia Radwanski; Rodrigues, Laura Natal

    2016-01-01

    Objective To identify a contrast material that could be used as a dummy marker for magnetic resonance imaging. Materials and Methods Magnetic resonance images were acquired with six different catheter-filling materials-water, glucose 50%, saline, olive oil, glycerin, and copper sulfate (CuSO4) water solution (2.08 g/L)-inserted into compatible computed tomography/magnetic resonance imaging ring applicators placed in a phantom made of gelatin and CuSO4. The best contrast media were tested in four patients with the applicators in place. Results In T2-weighted sequences, the best contrast was achieved with the CuSO4-filled catheters, followed by saline- and glycerin-filled catheters, which presented poor visualization. In addition (also in T2-weighted sequences), CuSO4 presented better contrast when tested in the phantom than when tested in the patients, in which it provided some contrast but with poor identification of the first dwell position, mainly in the ring. Conclusion We found CuSO4 to be the best solution for visualization of the applicator channels, mainly in T2-weighted images in vitro, although the materials tested presented low signal intensity in the images obtained in vivo, as well as poor precision in determining the first dwell position. PMID:27403016

  9. Evaluation of different magnetic resonance imaging contrast materials to be used as dummy markers in image-guided brachytherapy for gynecologic malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Sales, Camila Pessoa; Carvalho, Heloisa de Andrade; Rubo, Rodrigo Augusto; Stuart, Silvia Radwanski; Rodrigues, Laura Natal, E-mail: camyps@gmail.com [Universidade de Sao Paulo (InRad/HC/FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Instituto de Radiologia; Taverna, Khallil Chaim; Pastorello, Bruno Fraccini [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Departamento de Radiologia e Oncologia. Lab. de Ressonancia Magnetica em Neurorradiologia; Borgonovi, Arthur Felipe [Royal Philips Electronics, Eindhoven (Netherlands)

    2016-05-15

    Objective: to identify a contrast material that could be used as a dummy marker for magnetic resonance imaging. Materials and methods: magnetic resonance images were acquired with six different catheter-filling materials - water, glucose 50%, saline, olive oil, glycerin, and copper sulfate (CuSO{sub 4}) water solution (2.08 g/L) - inserted into compatible computed tomography/magnetic resonance imaging ring applicators placed in a phantom made of gelatin and CuSO{sub 4}. The best contrast media were tested in four patients with the applicators in place. Results: in T2-weighted sequences, the best contrast was achieved with the CuSO{sub 4}-filled catheters, followed by saline- and glycerin-filled catheters, which presented poor visualization. In addition (also in T2-weighted sequences), CuSO{sub 4} presented better contrast when tested in the phantom than when tested in the patients, in which it provided some contrast but with poor identification of the first dwell position, mainly in the ring. Conclusion: we found CuSO{sub 4} to be the best solution for visualization of the applicator channels, mainly in T2-weighted images in vitro, although the materials tested presented low signal intensity in the images obtained in vivo, as well as poor precision in determining the first dwell position. (author)

  10. Coseismic displacements from SAR image offsets between different satellite sensors: Application to the 2001 Bhuj (India) earthquake

    KAUST Repository

    Wang, Teng

    2015-09-05

    Synthetic aperture radar (SAR) image offset tracking is increasingly being used for measuring ground displacements, e.g., due to earthquakes and landslide movement. However, this technique has been applied only to images acquired by the same or identical satellites. Here we propose a novel approach for determining offsets between images acquired by different satellite sensors, extending the usability of existing SAR image archives. The offsets are measured between two multiimage reflectivity maps obtained from different SAR data sets, which provide significantly better results than with single preevent and postevent images. Application to the 2001 Mw7.6 Bhuj earthquake reveals, for the first time, its near-field deformation using multiple preearthquake ERS and postearthquake Envisat images. The rupture model estimated from these cross-sensor offsets and teleseismic waveforms shows a compact fault slip pattern with fairly short rise times (<3 s) and a large stress drop (20 MPa), explaining the intense shaking observed in the earthquake.

  11. Evaluation of image quality with different field of view in CT scan of the body in children

    International Nuclear Information System (INIS)

    Gao Dechun; Wu Tai; Mao Dingli; Weng Zhigao

    2005-01-01

    Objective: To evaluate the relationship between field of view (FOV) and quality of CT images. Methods: Scanning of the phantoms of spatial resolution and density resolution was performed with FOVs of 25 cm x 25 cm, 35 cm x 35 cm, and 42 cm x 42 cm, respectively, and the spatial resolution and density resolution of CT images with different FOVs were measured. 20 patients underwent CT scanning using 25 cm x 25 cm and 35 cm x 35 cm FOVs, respectively. The images were evaluated by 3 qualified CT doctors by using a double-blind reading. Results: As FOVs changed, the spatial resolution and density resolution were different. The best spatial resolution and density resolution were obtained on 25 cm x 25 cm FOV images. The best spatial resolution could distinguish four 0.6 mm-diameter eyelets, and the best density resolution could distinguish five 2.5 mm-diameter eyelets. The CT images with 25 cm x 25 cm FOV were obviously better than those with 35 cm x 35 cm FOV (P<0.05). Conclusion: On the range of conventional FOV of CT, the spatial resolution and density resolution of CT images are the best when 25 cm x 25 cm FOV is used. (authors)

  12. Judging the difference between attractiveness and health: does exposure to model images influence the judgments made by men and women?

    Directory of Open Access Journals (Sweden)

    Ian D Stephen

    Full Text Available Recent research has shown facial adiposity (apparent weight in the face to be a significant predictor of both attractiveness and health, thus making it an important determinant of mate selection. Studies looking at the relationship between attractiveness and health have shown that individuals differentiate between the two by preferring a lower weight for attractiveness than for health in female faces. However, these studies have either been correlational studies, or have investigated weight perceived from only the face. These differences have been discussed with regard to sociocultural factors such as pressure from parents, peers and also media, which has been seen to have the highest influence. While exposure to media images has been shown to influence women's own-body image, no study has yet directly tested the influence of these factors on people's preferred weight in other women's bodies. Here we examine how a short exposure to images of models influences men's and women's judgments of the most healthy looking and attractive BMI in Malaysian Chinese women's bodies by comparing differences in preferences (for attractiveness and health between groups exposed to images of models of varying attractiveness and body weight. Results indicated that participants preferred a lower weight for attractiveness than for health. Further, women's but not men's preferred BMI for attractiveness, but not health, was influenced by the type of media images to which they were exposed, suggesting that short term exposure to model images affect women's perceptions of attractiveness but not health.

  13. Do Basic Psychomotor Skills Transfer Between Different Image-based Procedures?

    NARCIS (Netherlands)

    Buzink, S.N.; Goossens, R.H.M.; Schoon, E.J.; De Ridder, H.; Jakimowicz, J.J.

    2010-01-01

    Background - Surgical techniques that draw from multiple types of image-based procedures (IBP) are increasing, such as Natural Orifice Transluminal Endoscopic Surgery, fusing laparoscopy and flexible endoscopy. However, little is known about the relation between psychomotor skills for performing

  14. Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index Land Reflectance Global Binned Data

    Data.gov (United States)

    National Aeronautics and Space Administration — MODIS (or Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. Terra's orbit around the Earth...

  15. A study on the effect of different image centres on stereo triangulation accuracy

    CSIR Research Space (South Africa)

    De Villiers, J

    2015-11-01

    Full Text Available This paper evaluates the effect of mixing the distortion centre, principal point and arithmetic image centre on the distortion correction, focal length determination and resulting real-world stereo vision triangulation. A robotic arm is used...

  16. MR imaging of capitellar ossification: a study in children of different ages

    International Nuclear Information System (INIS)

    Fader, Lauren M.; Laor, Tal; Eismann, Emily A.; Cornwall, Roger; Little, Kevin J.

    2014-01-01

    The capitellar ossification center is used routinely to evaluate elbow alignment on radiography. However, whether capitellar ossification is central and concentric to support this practice is unknown. To define the pattern of capitellar ossification at different ages of childhood. This HIPAA-compliant study was IRB approved. MR imaging examinations from 81 children (ages 1-13 years, at least 3 boys and 3 girls in each age group) were included. We determined the center points of the ossified capitellum and the cartilaginous capitellum on the sagittal and coronal sequences that best showed differentiation between cartilage and bone. Percentage offset of the center of the ossified capitellum from the center of the cartilaginous capitellum was calculated in anterior-posterior, proximal-distal and medial-lateral dimensions, and compared across age groups and between genders. Linear regressions were used to ascertain the effect of age on percentage offset for all patients and for each gender. Capitellar ossification begins eccentrically with sagittal anterior proximal offset and coronal medial offset. With age, ossification proceeds posteriorly, distally and laterally. Percentage offset gradually diminishes with age. The ossified capitellum centralizes in the sagittal plane by 12-13 years. In the coronal plane, the capitellum ossifies medially beyond the proximal radioulnar joint and remains eccentric at 12-13 years. Centralization in boys lags in the anterior-posterior dimension. Capitellar ossification is an eccentric process, with lag in anterior-posterior centralization in boys. Medial offset persists at 12-13 years. Recognition of this eccentric ossification may allow for more accurate assessment of elbow alignment on radiographs, especially in younger children. (orig.)

  17. MR imaging of capitellar ossification: a study in children of different ages

    Energy Technology Data Exchange (ETDEWEB)

    Fader, Lauren M. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Laor, Tal [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Eismann, Emily A.; Cornwall, Roger; Little, Kevin J. [Cincinnati Children' s Hospital Medical Center, Division of Orthopaedic Surgery, Cincinnati, OH (United States)

    2014-08-15

    The capitellar ossification center is used routinely to evaluate elbow alignment on radiography. However, whether capitellar ossification is central and concentric to support this practice is unknown. To define the pattern of capitellar ossification at different ages of childhood. This HIPAA-compliant study was IRB approved. MR imaging examinations from 81 children (ages 1-13 years, at least 3 boys and 3 girls in each age group) were included. We determined the center points of the ossified capitellum and the cartilaginous capitellum on the sagittal and coronal sequences that best showed differentiation between cartilage and bone. Percentage offset of the center of the ossified capitellum from the center of the cartilaginous capitellum was calculated in anterior-posterior, proximal-distal and medial-lateral dimensions, and compared across age groups and between genders. Linear regressions were used to ascertain the effect of age on percentage offset for all patients and for each gender. Capitellar ossification begins eccentrically with sagittal anterior proximal offset and coronal medial offset. With age, ossification proceeds posteriorly, distally and laterally. Percentage offset gradually diminishes with age. The ossified capitellum centralizes in the sagittal plane by 12-13 years. In the coronal plane, the capitellum ossifies medially beyond the proximal radioulnar joint and remains eccentric at 12-13 years. Centralization in boys lags in the anterior-posterior dimension. Capitellar ossification is an eccentric process, with lag in anterior-posterior centralization in boys. Medial offset persists at 12-13 years. Recognition of this eccentric ossification may allow for more accurate assessment of elbow alignment on radiographs, especially in younger children. (orig.)

  18. Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

    2016-08-15

    In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

  19. Comparison of 3D computer-aided with manual cerebral aneurysm measurements in different imaging modalities

    International Nuclear Information System (INIS)

    Groth, M.; Buhk, J.H.; Schoenfeld, M.; Goebell, E.; Fiehler, J.; Forkert, N.D.

    2013-01-01

    To compare intra- and inter-observer reliability of aneurysm measurements obtained by a 3D computer-aided technique with standard manual aneurysm measurements in different imaging modalities. A total of 21 patients with 29 cerebral aneurysms were studied. All patients underwent digital subtraction angiography (DSA), contrast-enhanced (CE-MRA) and time-of-flight magnetic resonance angiography (TOF-MRA). Aneurysm neck and depth diameters were manually measured by two observers in each modality. Additionally, semi-automatic computer-aided diameter measurements were performed using 3D vessel surface models derived from CE- (CE-com) and TOF-MRA (TOF-com) datasets. Bland-Altman analysis (BA) and intra-class correlation coefficient (ICC) were used to evaluate intra- and inter-observer agreement. BA revealed the narrowest relative limits of intra- and inter-observer agreement for aneurysm neck and depth diameters obtained by TOF-com (ranging between ±5.3 % and ±28.3 %) and CE-com (ranging between ±23.3 % and ±38.1 %). Direct measurements in DSA, TOF-MRA and CE-MRA showed considerably wider limits of agreement. The highest ICCs were observed for TOF-com and CE-com (ICC values, 0.92 or higher for intra- as well as inter-observer reliability). Computer-aided aneurysm measurement in 3D offers improved intra- and inter-observer reliability and a reproducible parameter extraction, which may be used in clinical routine and as objective surrogate end-points in clinical trials. (orig.)

  20. Evaluation of a new system for chest tomosynthesis: aspects of image quality of different protocols determined using an anthropomorphic phantom

    Science.gov (United States)

    Sundin, A; Aspelin, P; Båth, M; Nyrén, S

    2015-01-01

    Objective: To compare the image quality obtained with the different protocols in a new chest digital tomosynthesis (DTS) system. Methods: A chest phantom was imaged with chest X-ray equipment with DTS. 10 protocols were used, and for each protocol, nine acquisitions were performed. Four observers visually rated the quality of the reconstructed section images according to pre-defined quality criteria in four different classes. The data were analysed with visual grading characteristics (VGC) analysis, using the vendor-recommended protocol [12-s acquisition time, source-to-image distance (SID) 180 cm] as reference, and the area under the VGC curve (AUCVGC) was determined for each protocol and class of criteria. Results: Protocols with a smaller swing angle resulted in a lower image quality for the classes of criteria “disturbance” and “homogeneity in nodule” but a higher image quality for the class “structure”. The class “demarcation” showed little dependency on the swing angle. All protocols but one (6.3 s, SID 130 cm) obtained an AUCVGC significantly <0.5 (indicating lower quality than reference) for at least one class of criteria. Conclusion: The study indicates that the DTS protocol with 6.3 s yields image quality similar to that obtained with the vendor-recommended protocol (12 s) but with the clinically important advantage for patients with respiratory impairment of a shorter acquisition time. Advances in knowledge: The study demonstrates that the image quality may be strongly affected by the choice of protocol and that the vendor-recommended protocol may not be optimal. PMID:26118300

  1. The role of MR imaging in detection of hepatic iron overload in patients with cirrhosis of different origins.

    Science.gov (United States)

    Szurowska, Edyta; Sikorska, Katarzyna; Izycka-Swieszewska, E; Nowicki, Tomasz; Romanowski, Tomasz; Bielawski, Krzysztof P; Studniarek, Michał

    2010-01-27

    There are many pathological conditions with hepatic iron overload. Classical definite diagnostic methods of these disorders are invasive and based on a direct tissue biopsy material. For the last years the role of MR imaging in liver diagnostics has been increasing. MRI shows changes of liver intensity in patients with hepatic iron overload. Changes in MR signal are an indirect consequence of change of relaxation times T2 and T2*, that can be directly measured. The purpose of the study was to evaluate usefulness of MR imaging in the detection of hepatic iron overload in patients with cirrhosis of different origins. MR imaging at 1.5T was prospectively performed in 44 patients with liver cirrhosis who had undergone liver biopsy with histopathological assessment of hepatic iron deposits. In all patients the following sequences were used: SE, Express, GRE in T2 and T1-weighted images. Signal intensity (SI) was measured on images obtained with each T2 weighted sequence by means of regions of interest, placed in the liver and paraspinal muscles. The correlation between iron overload, histopathological score, serum ferritin and SI ratio was analyzed. In 20 patients with iron overload confirmed by the biopsy, the liver parenchyma demonstrated lower signal intensity than that of paraspinal muscles. This effect was visible only in 8 patients with hepatic iron overload in Express T2-weighted images. Higher signal intensity of liver than that of skeletal muscles on GRE - T2 weighted images was noted in 24 patients with cirrhosis and without elevated hepatic iron concentration. We observed a correlation between low and high iron concentration and liver to muscle SI ratio. MR imaging is a useful and fast noninvasive diagnostic tool for the detection of liver iron overload in patients with cirrhosis of different origins.Liver to muscle SI ratio in GRE-T2-weighted sequence facilitates to differentiate patients with low and high degree of hepatic iron overload, which correlates

  2. Different Facets of Body Image Disturbance in Binge Eating Disorder: A Review

    Science.gov (United States)

    Lewer, Merle; Bauer, Anika

    2017-01-01

    The goal of the present review is to give an overview of the current findings on various facets of body image disturbance in Binge Eating Disorder such as body dissatisfaction, overconcern with weight and shape, body-related checking and avoidance behavior, misperception of body size, and body-related cognitive bias. In addition, treatments for a disturbed body image in BED and evidence of body image disturbance in youth with binge eating are reviewed. The results show that a disturbed body image in BED is present in the form of overconcern with weight and shape. Furthermore, there are hints that body dissatisfaction, as well as body-related checking and avoidance behavior, are also impaired. Research concerning misperception of body size in BED has been neglected so far, but first findings show that individuals with BED rate their own body shape rather accurately. Furthermore, there are first hints that body-related cognitive biases are present in individuals with BED. Moreover, in children and adolescents, there are first hints that body dissatisfaction, as well as shape and weight concerns, seem to be associated with loss of control and binge eating. Treatments aimed directly at the convertibility of a disturbed body image in BED have revealed encouraging outcomes. In conclusion, body image disturbance seems to occur in BED, and first studies show that it can be treated effectively. PMID:29182531

  3. Different Facets of Body Image Disturbance in Binge Eating Disorder: A Review

    Directory of Open Access Journals (Sweden)

    Merle Lewer

    2017-11-01

    Full Text Available The goal of the present review is to give an overview of the current findings on various facets of body image disturbance in Binge Eating Disorder such as body dissatisfaction, overconcern with weight and shape, body-related checking and avoidance behavior, misperception of body size, and body-related cognitive bias. In addition, treatments for a disturbed body image in BED and evidence of body image disturbance in youth with binge eating are reviewed. The results show that a disturbed body image in BED is present in the form of overconcern with weight and shape. Furthermore, there are hints that body dissatisfaction, as well as body-related checking and avoidance behavior, are also impaired. Research concerning misperception of body size in BED has been neglected so far, but first findings show that individuals with BED rate their own body shape rather accurately. Furthermore, there are first hints that body-related cognitive biases are present in individuals with BED. Moreover, in children and adolescents, there are first hints that body dissatisfaction, as well as shape and weight concerns, seem to be associated with loss of control and binge eating. Treatments aimed directly at the convertibility of a disturbed body image in BED have revealed encouraging outcomes. In conclusion, body image disturbance seems to occur in BED, and first studies show that it can be treated effectively.

  4. Ocular MR imaging. Evaluation of different coil setups in a phantom study

    International Nuclear Information System (INIS)

    Erb-Eigner, Katharina; Warmuth, Carsten; Taupitz, Matthias; Bertelmann, Eckart; Hamm, Bernd; Asbach, Patrick

    2013-01-01

    Small loop surface coils are generally recommended for ocular magnetic resonance (MR) imaging, but the optimal coil setup has not been systematically investigated. In this phantom study, we investigated which coil setup of those coils available for our MR imaging system provides the highest signal-to-noise ratio (SNR) in ocular MR imaging at 1.5 tesla. Using a phantom to simulate the eyeball and the orbital fat, we employed loop surface coils of 4- and 6-cm diameter and a multi-channel head coil to obtain images using a T 1 -weighted spin-echo sequence and then measured the SNR for each coil and coil combination. Use of the 6-cm loop coil alone yielded the highest mean SNR (27.5). Even in superficial regions (mesial and temporal), the SNR was higher using the 6-cm loop coil (33.6 and 45.5) than the 4-cm loop coil (28.0 and 33.8). Additional use of the head coil reduced the mean SNR to 10.4. This quantitative analysis suggests that use of a 6-cm loop surface coil offers the best results in ocular MR imaging. Combinations of loop coils or additional use of a head coil cannot be recommended because higher noise degrades image quality. (author)

  5. Kitchenette: Hell or Home? Different"Kitchenette"Images Created by Richard Wright and Gwendolyn Brooks%Kitchenette:Hell or Home?Different"Kitchenette"Images Created by Richard Wright and Gwendolyn Brooks

    Institute of Scientific and Technical Information of China (English)

    肖志宏

    2017-01-01

    How the southern black migrants navigate and survive the northern urban space is a question profoundly explored and realistically documented in many migration narratives in African American literature. This paper concentrates on the image of Chicago"kitchenette"in the works of Richard Wright and Gwendolyn Brooks, in an attempt to demonstrate the different inter-pretations of migrant spaces on the urban landscape.

  6. The effect of interobserver differences in post-implant prostate CT image interpretation on dosimetric parameters

    International Nuclear Information System (INIS)

    Han, Ben H.; Wallner, Kent; Merrick, Gregory; Badiozamani, Kas; Butler, Wayne

    2003-01-01

    The purpose of this study was to clarify where observers differ in their interpretation of CT scans, and to relate those differences to clinically relevant dosimetric parameters. Twenty unselected patients treated with I-125 or Pd-103 brachytherapy at the Veterans Affairs Puget Sound Health Care System (VAPSHCS) in 2001 were studied. Patients were implanted with I-125 (7 patients, 0.87 mCi/source) or Pd-103 (13 patients, 2.54 U/source). The number of I-125 sources implanted ranged from 52 to 78. The number of Pd-103 sources implanted ranged from 58-144. Post-implant 3 mm CT images were imported into a laptop running Varian Variseed trade mark sign and sent to the four physician investigators, who outlined the prostate independently. Investigators were not coached specifically for this study, beyond their having read prior reports regarding prostate volume determinations. There was moderate interobserver variability in CT volume determination, with the standard deviations as a percent of the mean ranging from 9% to 29% (median: 17%). An average of 14% of implants (range: 5%-20%) would have been judged inadequate based on a minimum V100 of 80%, versus 24% of implants (range: 5%-45%) being judged inadequate based on a minimum D90 of 90% of prescription dose. The greatest variability was seen in prostate length (median standard deviation: 0.57 cm), due to vagaries in base and apical localization. However, the prostatic width and thickness also varied substantially between observers, with median standard deviations of 0.24 and 0.32 cm, respectively. Treatment margin variability was greatest at the anterior border, with a median standard deviation of 0.21 cm±0.10. We believe that CT-based dosimetry, while influenced by CT interpretation, still provides useful general dosimetric calculations, that are likely to be reproducible enough to provide clinically useful information between institutions. The V100 and TMs are less influenced by interobserver CT interpretation

  7. Reproducibility of serial peri-ictal single-photon emission tomography difference images in epilepsy patients undergoing surgical resection

    International Nuclear Information System (INIS)

    Avery, R.A.; Studholme, C.; Stokking, R.; Morano, G.; Corsi, M.; Seibyl, J.P.; Zubal, I.G.; Spencer, S.S.; Spencer, D.D.

    2000-01-01

    Peri-ictal single-photon emission tomography (SPET) difference images co-registered to magnetic resonance imaging (MRI) visualize regional cerebral blood flow (rCBF) changes and help localize the epileptogenic area in medically refractory epilepsy. Few reports have examined the reproducibility of SPET difference image results. Epilepsy patients having two peri-ictal and at least one interictal SPET scan who later underwent surgical resection were studied. Localization accuracy of peri-ictal SPET difference images results, interictal electroencephalography (EEG), and ictal EEG from the first (seizure 1) and second (seizure 2) seizure, as well as MRI and positron emission tomography (PET) findings, were compared using surgical resection site as the standard. Thirteen patients underwent surgical resection (11 temporal lobe and 2 extratemporal). SPET results from seizure 1 were localized to the surgical site in 12/13 (92%) patients, while SPET results from seizure 2 were localized in 13/13 (100%) patients. All other modalities were less accurate than the SPET results [interictal EEG - seizure 1 6/13 (46%); ictal EEG - seizure 1 5/13 (38%); interictal intracranial EEG - seizure 2 4/9 (44%); ictal intracranial EEG - seizure 2 results 8/9 (89%); MRI 6/13 (46%); PET 9/13 (69%)]. SPET results were reproducible in 12/13 (92%) patients. SPET difference images calculated from two independent peri-ictal scans appear to be reproducible and accurately localize the epileptogenic area. While SPET difference images visualize many areas of rCBF change, the quantification of these results along with consideration of injection time improves the diagnostic interpretation of the results. (orig.)

  8. The effect of different methods and image analyzers on the results of the in vivo comet assay.

    Science.gov (United States)

    Kyoya, Takahiro; Iwamoto, Rika; Shimanura, Yuko; Terada, Megumi; Masuda, Shuichi

    2018-01-01

    The in vivo comet assay is a widely used genotoxicity test that can detect DNA damage in a range of organs. It is included in the Organisation for Economic Co-operation and Development Guidelines for the Testing of Chemicals. However, various protocols are still used for this assay, and several different image analyzers are used routinely to evaluate the results. Here, we verified a protocol that largely contributes to the equivalence of results, and we assessed the effect on the results when slides made from the same sample were analyzed using two different image analyzers (Comet Assay IV vs Comet Analyzer). Standardizing the agarose concentrations and DNA unwinding and electrophoresis times had a large impact on the equivalence of the results between the different methods used for the in vivo comet assay. In addition, there was some variation in the sensitivity of the two different image analyzers tested; however this variation was considered to be minor and became negligible when the test conditions were standardized between the two different methods. By standardizing the concentrations of low melting agarose and DNA unwinding and electrophoresis times between both methods used in the current study, the sensitivity to detect the genotoxicity of a positive control substance in the in vivo comet assay became generally comparable, independently of the image analyzer used. However, there may still be the possibility that other conditions, except for the three described here, could affect the reproducibility of the in vivo comet assay.

  9. The feasibility of susceptibility weighted imaging for assessing renal difference of healthy volunteers after water loading

    International Nuclear Information System (INIS)

    Ding Jiule; Xing Wei; Chen Jie; Yu Shengnan; Qiu Jianguo; Xing Shijun; Sun Jun

    2013-01-01

    Objective: To probe the feasibility of susceptibility weighted imaging (SWI) for evaluation of renal blood oxygenation level of healthy volunteers after water loading. Methods: SWI of 11 healthy volunteers, acquired before (group 1) and after water loading (group 2), were assessed retrospectively by two radiologists with more than 10 years abdominal work experience independently. In those images of the same section plane derived from two groups, the phase values in cortex (φ cor ) and medulla (φ med ), difference between the same vein and surrounding tissue on phase map (△ φ ) were measured using SPIN software package, and the oxygen extraction fraction changes (△OEF) was calculated. The φ cor , φ med and △ φ between two groups were compared by paired t test. And the intraclass correlation coefficient (ICC) was used to evaluate the consistency between two radiologists. Results: For the radiologist 1, the φ cor , φ med and △ φ were (0.046 ± 0.019), (-0.014 ± 0.003) and (1.3 ± 0.4) rad in group 1, and were (0.047 ± 0.014), (-0.012 ± 0.005) and (1.1 ± 0.4) rad in group 2 respectively, and no significant change was found in φ cor and φ med after water loading (t = -0.589 and-0.206, P > 0.05 in all), except of in △ φ (t = 2.400, P < 0.01). For the radiologist 2, the φ cor , φ med and △ φ were (0.049 ± 0.011), (-0.012 ± 0.004) and (1.5 ±0.4) rad in Group 1, and were (0.046 ± 0.017), (-0.011 ± 0.003) and (1.3 ± 0.2) rad in group 2 respectively, there was no significant change in φ cor and φ med after water loading (t = 0.590 and -0.974, P > 0.05 in all), except of in △ φ (t = 2.760, P < 0.05). Between two radiologists, the ICC of φ cor , φ med and △ φ were 0.623, 0.472 and 0.328 in group 1 and 0.599, 0.442 and 0.445 in group 2 respectively. △OEF decreased about (-4.2 ± 2.3)% and (-4.3 ± 2.8)% measured by two radiologists respectively, and the consistency is good between two radiologists (ICC = 0.784). Conclusion: SWI

  10. Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures - Paper 2: The ability of fluorescence imaging to detect differences in fluorosis prevalence and severity for different fluoride intakes from water

    Science.gov (United States)

    2012-01-01

    Background To assess the ability of fluorescence imaging to detect a dose response relationship between fluorosis severity and different levels of fluoride in water supplies compared to remote photographic scoring in selected populations participating in an observational, epidemiological survey in Chiang Mai, Thailand. Methods Subjects were male and female lifetime residents aged 8-13 years. For each child the fluoride content of cooking water samples (CWS) was assessed to create categorical intervals of water fluoride concentration. Fluorescence images were taken of the maxillary central incisors and analyzed for dental fluorosis using two different software techniques. Output metrics for the fluorescence imaging techniques were compared to TF scores from blinded photographic scores obtained from the survey. Results Data from 553 subjects were available. Both software analysis techniques demonstrated significant correlations with the photographic scores. The metrics for area effected by fluorosis and the overall fluorescence loss had the strongest association with the photographic TF score (Spearman’s rho 0.664 and 0.652 respectively). Both software techniques performed well for comparison of repeat fluorescence images with ICC values of 0.95 and 0.85 respectively. Conclusions This study supports the potential use of fluorescence imaging for the objective quantification of dental fluorosis. Fluorescence imaging was able to discriminate between populations with different fluoride exposures on a comparable level to remote photographic scoring with acceptable levels of repeatability. PMID:22908997

  11. Classifying Dementia Using Local Binary Patterns from Different Regions in Magnetic Resonance Images

    Directory of Open Access Journals (Sweden)

    Ketil Oppedal

    2015-01-01

    Full Text Available Dementia is an evolving challenge in society, and no disease-modifying treatment exists. Diagnosis can be demanding and MR imaging may aid as a noninvasive method to increase prediction accuracy. We explored the use of 2D local binary pattern (LBP extracted from FLAIR and T1 MR images of the brain combined with a Random Forest classifier in an attempt to discern patients with Alzheimer's disease (AD, Lewy body dementia (LBD, and normal controls (NC. Analysis was conducted in areas with white matter lesions (WML and all of white matter (WM. Results from 10-fold nested cross validation are reported as mean accuracy, precision, and recall with standard deviation in brackets. The best result we achieved was in the two-class problem NC versus AD + LBD with total accuracy of 0.98 (0.04. In the three-class problem AD versus LBD versus NC and the two-class problem AD versus LBD, we achieved 0.87 (0.08 and 0.74 (0.16, respectively. The performance using 3DT1 images was notably better than when using FLAIR images. The results from the WM region gave similar results as in the WML region. Our study demonstrates that LBP texture analysis in brain MR images can be successfully used for computer based dementia diagnosis.

  12. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    International Nuclear Information System (INIS)

    Beitzke, D.; Berger-Kulemann, V.; Unterhumer, S.; Loewe, C.; Wolf, F.; Schoepf, V.; Spitzer, E.; Feuchtner, G.M.; Gyoengyoesi, M.; Uyanik-Uenal, K.; Zuckermann, A.

    2015-01-01

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  13. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Beitzke, D.; Berger-Kulemann, V.; Unterhumer, S.; Loewe, C.; Wolf, F. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Cardiovascular and Interventional Radiology, Vienna (Austria); Schoepf, V. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Neuroradiology and Musculoskeletal Radiology, Vienna (Austria); Spitzer, E. [Bern University Hospital, Department of Cardiology, Bern (Switzerland); Feuchtner, G.M. [Innsbruck Medical University, Department of Radiology II, Innsbruck (Austria); Gyoengyoesi, M. [Medical University Vienna, Department of Cardiology, Vienna (Austria); Uyanik-Uenal, K.; Zuckermann, A. [Medical University Vienna, Department of Cardiac Surgery, Vienna (Austria)

    2015-08-15

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  14. Different diagnostic values of imaging parameters to predict pseudoprogression in glioblastoma subgroups stratified by MGMT promoter methylation

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ra Gyoung [Catholic Kwandong University International St. Mary' s Hospital, Department of Radiology, Catholic Kwandong University College of Medicine, Incheon (Korea, Republic of); Kim, Ho Sung; Shim, Woo Hyun; Kim, Sang Joon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Paik, Wooyul [Dankook Unversity Hospital, Department of Radiology, Cheonan-si, Chungcheongnam-do (Korea, Republic of); Kim, Jeong Hoon [University of Ulsan College of Medicine, Asan Medical Center, Department of Neurosurgery, Seoul (Korea, Republic of)

    2017-01-15

    The aim of this study was to determine whether diffusion and perfusion imaging parameters demonstrate different diagnostic values for predicting pseudoprogression between glioblastoma subgroups stratified by O{sup 6}-mythylguanine-DNA methyltransferase (MGMT) promoter methylation status. We enrolled seventy-five glioblastoma patients that had presented with enlarged contrast-enhanced lesions on magnetic resonance imaging (MRI) one month after completing concurrent chemoradiotherapy and undergoing MGMT promoter methylation testing. The imaging parameters included 10 or 90 % histogram cutoffs of apparent diffusion coefficient (ADC10), normalized cerebral blood volume (nCBV90), and initial area under the time signal-intensity curve (IAUC90). The results of the areas under the receiver operating characteristic curve (AUCs) with cross-validation were compared between MGMT methylation and unmethylation groups. MR imaging parameters demonstrated a trend toward higher accuracy in the MGMT promoter methylation group than in the unmethylation group (cross-validated AUCs = 0.70-0.95 and 0.56-0.87, respectively). The combination of MGMT methylation status with imaging parameters improved the AUCs from 0.70 to 0.75-0.90 for both readers in comparison with MGMT methylation status alone. The probability of pseudoprogression was highest (95.7 %) when nCBV90 was below 4.02 in the MGMT promoter methylation group. MR imaging parameters could be stronger predictors of pseudoprogression in glioblastoma patients with the methylated MGMT promoter than in patients with the unmethylated MGMT promoter. (orig.)

  15. Non-destructive evaluation of teeth restored with different composite resins using synchrotron based micro-imaging.

    Science.gov (United States)

    Fatima, A; Kulkarni, V K; Banda, N R; Agrawal, A K; Singh, B; Sarkar, P S; Tripathi, S; Shripathi, T; Kashyap, Y; Sinha, A

    2016-01-01

    Application of high resolution synchrotron micro-imaging in microdefects studies of restored dental samples. The purpose of this study was to identify and compare the defects in restorations done by two different resin systems on teeth samples using synchrotron based micro-imaging techniques namely Phase Contrast Imaging (PCI) and micro-computed tomography (MCT). With this aim acquired image quality was also compared with routinely used RVG (Radiovisiograph). Crowns of human teeth samples were fractured mechanically involving only enamel and dentin, without exposure of pulp chamber and were divided into two groups depending on the restorative composite materials used. Group A samples were restored using a submicron Hybrid composite material and Group B samples were restored using a Nano-Hybrid restorative composite material. Synchrotron based PCI and MCT was performed with the aim of visualization of tooth structure, composite resin and their interface. The quantitative and qualitative comparison of phase contrast and absorption contrast images along with MCT on the restored teeth samples shows comparatively large number of voids in Group A samples. Quality assessment of dental restorations using synchrotron based micro-imaging suggests Nano-Hybrid resin restorations (Group B) are better than Group A.

  16. Evaluating the normal individual cardiac function in different imaging phases post exercise and rest by gated SPECT myocardial perfusion

    International Nuclear Information System (INIS)

    Hua, W.; Li, S.J.; Liu, J.Z.; Li, X.F.; Jin, C.R.; Hu, G.; Wang, J.

    2007-01-01

    Full text: Objectives: To evaluate the normal individual cardiac function in the different imaging phases post-exercise and rest by GSPECT. Methods: 46 normal individuals underwent exercise/rest GSPECT using 99mTc-MIBI by 2- day program. Sequential imaging was started 15, 35 and 120 minutes after exercise and rest imaging was performed the following day. The left ventricular EF and EDV, ESV values were calculated with the Cedars-Sinai program. Results: The EF values of post- exercise at 15, 35, and 120m was 64.48±7.43%, 65.02±7.66%, and 60.98±7.28% respectively, and the rest EF value was 61.46±7.23%. The post exercise EF at 15m and 35m was higher than EF at post- exercise 120m and rest, but there is a significant difference only between post exercise 35m and rest (P< 0.05), and all post exercise EF did not increase at least 5% from EF at-rest. The EDV and ESV values did not have statistically significant differences at 15, 35,120m post-exercise and rest. The heart rate at 15,35m post- exercise was higher significantly than at rest. Conclusions: The different imaging phases after exercise with 99mTc-MIBI GSPECT affects LVEF in normal individuals, the 35m post- exercise EF is highest. (author)

  17. Image quality and patient acceptance of four regimens with different amounts of mild laxatives for CT colonography

    NARCIS (Netherlands)

    Jensch, Sebastiaan; de Vries, Ayso H.; Pot, Dennis; Peringa, Jan; Bipat, Shandra; Florie, Jasper; van Gelder, Rogier E.; Stoker, Jaap

    2008-01-01

    OBJECTIVE: The purpose of our study was to prospectively evaluate image quality and patient acceptance of CT colonography (CTC) with fecal tagging using different levels of catharsis. SUBJECTS AND METHODS: Forty consecutive increased-risk patients were randomized. Group 1 received orally 20 mg of

  18. 7T T-2*-weighted magnetic resonance imaging reveals cortical phase differences between early- and late-onset Alzheimer's disease

    NARCIS (Netherlands)

    van Rooden, S.; Doan, N.T.; Versluis, M.J.; Goos, J.D.C.; Webb, A.G.; Oleksik, A.M.; van der Flier, W.M.; Scheltens, P.; Barkhof, F.; Weverlinge-Rynsburger, A.W.E.; Blauw, G. J.; Reiber, J.H.C.; van Buchem, M.A.; Milles, J.; van der Grond, J.

    2015-01-01

    The aim of this study is to explore regional iron-related differences in the cerebral cortex, indicative of Alzheimer's disease pathology, between early- and late-onset Alzheimer's disease (EOAD, LOAD, respectively) patients using 7T magnetic resonance phase images. High-resolution T

  19. Carotid plaque signal differences among four kinds of T1-weighted magnetic resonance imaging techniques: A histopathological correlation study

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Ayumi; Narumi, Shinsuke; Ohba, Hideki; Yamaguchi, Mao; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto; Kudo, Kohsuke [Iwate Medical University, Institute for Biomedical Sciences, Morioka (Japan); Ogasawara, Kuniaki; Kobayashi, Masakazu [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Hitomi, Jiro [Iwate Medical University, Department of Anatomy, Morioka (Japan)

    2012-11-15

    Several magnetic resonance (MR) imaging techniques are used to examine atherosclerotic plaque of carotid arteries; however, the best technique for visualizing intraplaque characteristics has yet to be determined. Here, we directly compared four kinds of T1-weighted (T1W) imaging techniques with pathological findings in patients with carotid stenosis. A total of 31 patients who were candidates for carotid endarterectomy were prospectively examined using a 1.5-T MRI scanner, which produced four kinds of T1W images, including non-gated spin echo (SE), cardiac-gated black-blood (BB) fast-SE (FSE), magnetization-prepared rapid acquisition with gradient echo (MPRAGE), and source image of three-dimensional time-of-flight MR angiography (SI-MRA). The signal intensity of the carotid plaque was manually measured, and the contrast ratio (CR) against the adjacent muscle was calculated. CRs from the four imaging techniques were compared to each other and correlated with histopathological specimens. CRs of the carotid plaques mainly containing fibrous tissue, lipid/necrosis, and hemorrhage were significantly different with little overlaps (range: 0.92-1.15, 1.22-1.52, and 1.55-2.30, respectively) on non-gated SE. However, BB-FSE showed remarkable overlaps among the three groups (0.89-1.10, 1.07-1.23, and 1.01-1.42, respectively). MPRAGE could discriminate fibrous plaques from hemorrhagic plaques but not from lipid/necrosis-rich plaques: (0.77-1.07, 1.45-2.43, and 0.85-1.42, respectively). SI-MRA showed the same tendencies (1.01-1.39, 1.45-2.57, and 1.12-1.39, respectively). Among T1W MR imaging techniques, non-gated SE images can more accurately characterize intraplaque components in patients who underwent CEA when compared with cardiac-gated BB-FSE, MPRAGE, and SI-MRA images. (orig.)

  20. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Liao, S; Wang, Y; Weng, H [Chiayi Chang Gung Memorial Hospital of The C.G.M.F, Puzi City, Chiayi County, Taiwan (China)

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  1. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    International Nuclear Information System (INIS)

    Liao, S; Wang, Y; Weng, H

    2015-01-01

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle

  2. The effect of different adaptation strengths on image quality and radiation dose using Siemens care dose 4D

    International Nuclear Information System (INIS)

    Soederberg, M.; Gunnarsson, M.

    2010-01-01

    The purpose of this study was to evaluate the effect of different choices of adaptation strengths on image quality and radiation exposure to the patient with Siemens automatic exposure control system called CARE Dose 4D. An anthropomorphic chest phantom was used to simulate the patient and computed tomography scans were performed with a Siemens SOMATOM Sensation 16 and 64. Owing to adaptation strengths, a considerable reduction (26.6-51.5 % and 27.5-49.5% for Sensation 16 and Sensation 64, respectively) in the radiation dose was found when compared with using a fixed tube current. There was a substantial difference in the image quality (image noise) between the adaptation strengths. Independent of selected adaptation strengths, the level of image noise throughout the chest phantom increased when CARE Dose 4D was used (p < 0.0001). We conclude that the adaptation strengths can be used to obtain user-specified modifications to image quality or radiation exposure to the patient. (authors)

  3. Textural characteristics of bone marrow blast nucleus images with different variants of acute lymphoblastic leukemia

    Science.gov (United States)

    Nikitaev, V. G.; Pronichev, A. N.; Polyakov, E. V.; Mozhenkova, A. V.; Tupitsin, N. N.; Frenkel, M. A.

    2018-01-01

    The paper describes the method of recognition of T - and B - variants of acute lymphoblastic leukemia in microscopic images of blood cells. The method is based on the use of texture characteristics of images. Experimental recognition accuracy evaluation is obtained from the sample of 38 patients (17 with T-ALL and 21 with B-ALL variants of acute lymphoblastic leukemia). The obtained results show the possibility of applying of the proposed approach to the differential diagnosis of T- and B- variants of acute lymphoblastic leukemia.

  4. CT Imaging of facial trauma. Role of different types of reconstruction. Part I - bones

    International Nuclear Information System (INIS)

    Myga-Porosilo, J.; Sraga, W.; Borowiak, H.; Jackowska, Z.; Kluczewska, E.; Skrzelewski, S.

    2011-01-01

    Background: Injury to the facial skeleton and the adjoining soft tissues is a frequently occurring condition. The main aim of this work was to assess the value of multiplanar and three-dimensional (3D) reconstruction computed tomography (CT) images obtained by using multi-detector row technology in spiral data acquisition in patients with facial skeleton injury. The authors attempted to answer the following questions: Are there particular mechanisms and types of injuries or locations of fractures which can be diagnosed significantly more effectively by conducting additional multiplanar image reconstructions? Do 3D image reconstructions contribute to the diagnostic process, to what extent? Compared to other imaging techniques, is the spiral CT data acquisition a more convenient for the patient and a faster investigation method of diagnosing post-injury lesions involving the facial skeleton? Material/Methods: Sixty-seven patients diagnosed with injury to the facial skeleton were referred for emergent CT scanning. Each patient underwent a CT scan with the use of a GE HiSpeed Qx/i scanner. The scans were conducted with the use of spiral data acquisition technique in the transverse plane. The following secondary image reconstructions were conducted for each patient: a two dimensional (2D) multiplanar reconstruction (MPR), maximum intensity projection (MIP), and 3D volume rendering (VR). Post-injury lesions of the facial skeleton were assessed and the presence of any loose displaced bone fragments was taken into consideration. Results: As far as fracture imaging is concerned, the 2D image reconstruction and volume rendering proved to be the most effective in the majority of locations. 3D image reconstructions proved the most sensitive in most cases of loose displaced bone fragments, except for fine structures such as the ethmoid bone and the inferior orbital wall. Conclusions: 1. Multiplanar computer reconstructions increase the effectiveness of visualisation of

  5. Predicted accommodative response from image quality in young eyes fitted with different dual-focus designs.

    Science.gov (United States)

    Faria-Ribeiro, Miguel; Amorim-de-Sousa, Ana; González-Méijome, José M

    2018-05-01

    To investigate the separated and combined influences of inner zone (IZ) diameter and effective add power of dual-focus contact lenses (CL) in the image quality at distance and near viewing, in a functional accommodating model eye. Computational wave-optics methods were used to define zonal bifocal pupil functions, representing the optic zones of nine dual-focus centre-distance CLs. The dual-focus pupil functions were defined having IZ diameters of 2.10 mm, 3.36 mm and 4.00 mm, with add powers of 1.5 D, 2.0 D and 2.5 D (dioptres), for each design, that resulted in a ratio of 64%/36% between the distance and treatment zone areas, bounded by a 6 mm entrance pupil. A through-focus routine was implemented in MATLAB to simulate the changes in image quality, calculated from the Visual Strehl ratio, as the eye with the dual-focus accommodates, from 0 to -3.00 D target vergences. Accommodative responses were defined as the changes in the defocus coefficient, combined with a change in fourth and sixth order spherical aberration, which produced a peak in image quality at each target vergence. Distance viewing image quality was marginally affected by IZ diameter but not by add power. Near image quality obtained when focussing the image formed by the near optics was only higher by a small amount compared to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.28 ± 0.02, 0.23 ± 0.02 and 0.22 ± 0.02, for the small, medium and larger IZ diameters, respectively. On the other hand, near image quality predicted by focussing the image formed by the distance optics was considerably lower relatively to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.15 ± 0.01, 0.38 ± 0.00 and 0.54 ± 0.01, for the small, medium and larger IZ diameters, respectively. During near viewing through dual-focus CLs, image quality depends on the diameter of the most inner zone of the CL, while add power

  6. Searching for transits in the Wide Field Camera Transit Survey with difference-imaging light curves

    NARCIS (Netherlands)

    Zendejas, Dominguez J.; Koppenhoefer, J.; Saglia, R.; Birkby, J.L.; Hodgkin, S.; Kovács, G.; Pinfield, D.; Sipocz, B.; Barrado, D.; Bender, R.; Burgo, del C.; Cappetta, M.; Martín, E.; Nefs, B.; Riffeser, A.; Steele, P.

    2013-01-01

    The Wide Field Camera Transit Survey is a pioneer program aiming at for searching extra-solar planets in the near-infrared. The images from the survey are processed by a data reduction pipeline, which uses aperture photometry to construct the light curves. We produce an alternative set of light

  7. Development of Noninvasive Classification Methods for Different Roasting Degrees of Coffee Beans Using Hyperspectral Imaging

    Science.gov (United States)

    Chu, Bingquan; Yu, Keqiang; Zhao, Yanru

    2018-01-01

    This study aimed to develop an approach for quickly and noninvasively differentiating the roasting degrees of coffee beans using hyperspectral imaging (HSI). The qualitative properties of seven roasting degrees of coffee beans (unroasted, light, moderately light, light medium, medium, moderately dark, and dark) were assayed, including moisture, crude fat, trigonelline, chlorogenic acid, and caffeine contents. These properties were influenced greatly by the respective roasting degree. Their hyperspectral images (874–1734 nm) were collected using a hyperspectral reflectance imaging system. The spectra of the regions of interest were manually extracted from the HSI images. Then, principal components analysis was employed to compress the spectral data and select the optimal wavelengths based on loading weight analysis. Meanwhile, the random frog (RF) methodology and the successive projections algorithm were also adopted to pick effective wavelengths from the spectral data. Finally, least squares support vector machine (LS-SVM) was utilized to establish discriminative models using spectral reflectance and corresponding labeled classes for each degree of roast sample. The results showed that the LS-SVM model, established by the RF selecting method, with eight wavelengths performed very well, achieving an overall classification accuracy of 90.30%. In conclusion, HSI was illustrated as a potential technique for noninvasively classifying the roasting degrees of coffee beans and might have an important application for the development of nondestructive, real-time, and portable sensors to monitor the roasting process of coffee beans. PMID:29671781

  8. Development of Noninvasive Classification Methods for Different Roasting Degrees of Coffee Beans Using Hyperspectral Imaging.

    Science.gov (United States)

    Chu, Bingquan; Yu, Keqiang; Zhao, Yanru; He, Yong

    2018-04-19

    This study aimed to develop an approach for quickly and noninvasively differentiating the roasting degrees of coffee beans using hyperspectral imaging (HSI). The qualitative properties of seven roasting degrees of coffee beans (unroasted, light, moderately light, light medium, medium, moderately dark, and dark) were assayed, including moisture, crude fat, trigonelline, chlorogenic acid, and caffeine contents. These properties were influenced greatly by the respective roasting degree. Their hyperspectral images (874⁻1734 nm) were collected using a hyperspectral reflectance imaging system. The spectra of the regions of interest were manually extracted from the HSI images. Then, principal components analysis was employed to compress the spectral data and select the optimal wavelengths based on loading weight analysis. Meanwhile, the random frog (RF) methodology and the successive projections algorithm were also adopted to pick effective wavelengths from the spectral data. Finally, least squares support vector machine (LS-SVM) was utilized to establish discriminative models using spectral reflectance and corresponding labeled classes for each degree of roast sample. The results showed that the LS-SVM model, established by the RF selecting method, with eight wavelengths performed very well, achieving an overall classification accuracy of 90.30%. In conclusion, HSI was illustrated as a potential technique for noninvasively classifying the roasting degrees of coffee beans and might have an important application for the development of nondestructive, real-time, and portable sensors to monitor the roasting process of coffee beans.

  9. Development of Noninvasive Classification Methods for Different Roasting Degrees of Coffee Beans Using Hyperspectral Imaging

    Directory of Open Access Journals (Sweden)

    Bingquan Chu

    2018-04-01

    Full Text Available This study aimed to develop an approach for quickly and noninvasively differentiating the roasting degrees of coffee beans using hyperspectral imaging (HSI. The qualitative properties of seven roasting degrees of coffee beans (unroasted, light, moderately light, light medium, medium, moderately dark, and dark were assayed, including moisture, crude fat, trigonelline, chlorogenic acid, and caffeine contents. These properties were influenced greatly by the respective roasting degree. Their hyperspectral images (874–1734 nm were collected using a hyperspectral reflectance imaging system. The spectra of the regions of interest were manually extracted from the HSI images. Then, principal components analysis was employed to compress the spectral data and select the optimal wavelengths based on loading weight analysis. Meanwhile, the random frog (RF methodology and the successive projections algorithm were also adopted to pick effective wavelengths from the spectral data. Finally, least squares support vector machine (LS-SVM was utilized to establish discriminative models using spectral reflectance and corresponding labeled classes for each degree of roast sample. The results showed that the LS-SVM model, established by the RF selecting method, with eight wavelengths performed very well, achieving an overall classification accuracy of 90.30%. In conclusion, HSI was illustrated as a potential technique for noninvasively classifying the roasting degrees of coffee beans and might have an important application for the development of nondestructive, real-time, and portable sensors to monitor the roasting process of coffee beans.

  10. Spacial Variation in SAR Images of Different Resolution for Agricultural Fields

    DEFF Research Database (Denmark)

    Sandholt, Inge; Skriver, Henning

    1999-01-01

    The spatial variation in two types of Synthetic Aperture Radar (SAR) images covering agricultural fields is analysed. C-band polarimetric SAR data from the Danish airborne SAR, EMISAR, have been compared to space based ERS-1 C-band SAR with respect to scale and effect of polarization. The general...

  11. Preservice Teachers' Images of Scientists: Do Prior Science Experiences Make a Difference?

    Science.gov (United States)

    Milford, Todd M.; Tippett, Christine D.

    2013-01-01

    This article presents the results of a mixed methods study that used the Draw-a-Scientist Test as a visual tool for exploring preservice teachers' beliefs about scientists. A questionnaire was also administered to 165 students who were enrolled in elementary (K-8) and secondary (8-12) science methods courses. Taken as a whole, the images drawn by…

  12. SU-E-J-07: IGRT Gently: Evaluating Imaging Dose in Phantoms of Different Sizes

    Energy Technology Data Exchange (ETDEWEB)

    Morris, B; Duggar, W; Stanford, J; Yang, C [University of Mississippi Med. Center, Jackson, MS (United States)

    2015-06-15

    Purpose: IGRT imaging procedures have emerged as a common method of patient position verification in radiotherapy, though imaging dose is generally neglected in the treatment plan. Consequently, evaluating and optimizing the dose from these procedures is worthwhile. This process is especially important for children, who are more radiosensitive than adults. The aim of this work was to gain some understanding of the relative doses involved with various XVI-preset parameters for an “adult” and “child” phantom set, with the hopes that imaging dose for a child can be reduced. Methods: 32 and 16cm CTDI-phantoms were used as surrogates for adult and child torsos, respectively. Dose was measured in the central and peripheral chamber positions of the phantoms. CBCT scans were made for both phantoms using Elekta’s Chest-preset to establish a dose baseline. The child-phantom was then scanned using the Elekta Head and Neck (HN) preset. A modified HN-preset (named Peds Abd-pelvis) was also created with a doubled mAs to maintain a reduction in dose to the child-phantom (relative to the baseline), while providing clinically-usable image quality. Results: The baseline dose to the child-phantom from the Chest-preset was 310% that of the adult-phantom for the center chamber position and 150% at the periphery. An average dose reduction of 97% was obtained in the childphantom by switching from the Chest-preset to the HN-preset, while the Peds Abd-pelvis-preset similarly reduced the dose by an average of 92%. Conclusion: XVI-preset parameters significantly affect dose, and should be optimized to reduce dose, while ensuring clinically-usable image quality. Using a modified imaging preset (Peds Abd-pelvis-preset) greatly reduced the dose to the child-phantom compared to the dose for the Chest-preset for both the child and adult-phantoms. This outcome provides support for the development of child-specific protocols for IGRT imaging in pediatric patients.

  13. SU-E-J-07: IGRT Gently: Evaluating Imaging Dose in Phantoms of Different Sizes

    International Nuclear Information System (INIS)

    Morris, B; Duggar, W; Stanford, J; Yang, C

    2015-01-01

    Purpose: IGRT imaging procedures have emerged as a common method of patient position verification in radiotherapy, though imaging dose is generally neglected in the treatment plan. Consequently, evaluating and optimizing the dose from these procedures is worthwhile. This process is especially important for children, who are more radiosensitive than adults. The aim of this work was to gain some understanding of the relative doses involved with various XVI-preset parameters for an “adult” and “child” phantom set, with the hopes that imaging dose for a child can be reduced. Methods: 32 and 16cm CTDI-phantoms were used as surrogates for adult and child torsos, respectively. Dose was measured in the central and peripheral chamber positions of the phantoms. CBCT scans were made for both phantoms using Elekta’s Chest-preset to establish a dose baseline. The child-phantom was then scanned using the Elekta Head and Neck (HN) preset. A modified HN-preset (named Peds Abd-pelvis) was also created with a doubled mAs to maintain a reduction in dose to the child-phantom (relative to the baseline), while providing clinically-usable image quality. Results: The baseline dose to the child-phantom from the Chest-preset was 310% that of the adult-phantom for the center chamber position and 150% at the periphery. An average dose reduction of 97% was obtained in the childphantom by switching from the Chest-preset to the HN-preset, while the Peds Abd-pelvis-preset similarly reduced the dose by an average of 92%. Conclusion: XVI-preset parameters significantly affect dose, and should be optimized to reduce dose, while ensuring clinically-usable image quality. Using a modified imaging preset (Peds Abd-pelvis-preset) greatly reduced the dose to the child-phantom compared to the dose for the Chest-preset for both the child and adult-phantoms. This outcome provides support for the development of child-specific protocols for IGRT imaging in pediatric patients

  14. Magnetic resonance imaging in the repair of ruptured Achilles tendons. Morphological difference in healing process between conservative and surgical treatment

    International Nuclear Information System (INIS)

    Nakano, Tetsuo; Tsuruta, Takao; Abe, Yasuyuki; Tani, Akifumi; Koga, Toshimitsu; Shimizu, Yasuhiro

    1996-01-01

    We observed the healing process of ruptured Achilles tendons in a series using magnetic resonance imaging. In six cases, tendons were repaired percutaneously with limited skin incisions. Seven cases were treated conservatively using unique functional braces. MR imaging revealed two different modes of conjoining. In the conservatively treated group, tendons inclined to conjoin in a dumbbell shape. In the surgically treated group, they inclined to conjoin in a spindle shape. The diameters of the ruptured part are wider in the spindle shape compared to the dumbbell shape at all stages. These findings suggest that surgical treatment is favorable for acquiring earlier strength. (author)

  15. CT Imaging of facial trauma. The role of different types of reconstruction. Part II - soft tissues

    International Nuclear Information System (INIS)

    Myga-Porosilo, J.; Sraga, W.; Borowiak, H.; Jackowska, Z.; Kluczewska, E.; Skrzelewski, S.

    2011-01-01

    Background: Injury to facial soft tissues as a complication of skeleton fractures is an important problem among patients with facial trauma. The aim of this work was to assess the value of multiplanar and three-dimensional (3D) reconstruction computed tomography (CT) images obtained by using multi-detector row technology in spiral data acquisition in patients with facial injuries of soft tissue. Material/Methods: Sixty-seven patients diagnosed with injury to the facial skeleton underwent a CT scan with the use of GE Hispeed Qx/i scanner. For each patient: a two-dimensional (2D) multiplanar reconstruction (MPR), maximum intensity projection (MIP), and 3D volume rendering (VR) were conducted. Post-injury lesions of soft tissues were assessed. During the assessment of the post-injury lesions of soft tissues, the following features were evaluated: Extra ocular muscle and fat tissue herniation through fractures in the medial and inferior orbital walls. Fluid in the sinuses and in the nasal cavity. Subcutaneous tissue emphysema. Results: For subcutaneous emphysema and sinus fluid imaging, both the axial and the 2D image reconstruction proved comparably effective. However, 2D reconstructions were superior to transverse plane images with regard to herniations into fractures of the inferior orbital wall. 3D reconstruction has no importance in diagnosing soft tissue injuries. Conclusions: Multiplanar CT reconstructions increase the effectiveness of imaging of orbital tissue herniations, especially in case of fractures in the inferior orbital wall. In suspected soft tissue herniations, as well as prior to surgical treatment, spiral CT with 2D multiplanar reconstructions should be the method of choice. (authors)

  16. Positive body image: inter-ethnic and rural-urban differences among an indigenous sample from Malaysian Borneo.

    Science.gov (United States)

    Swami, Viren; Kannan, Kumaraswami; Furnham, Adrian

    2012-11-01

    Previous studies examining body image from a cross-cultural perspective have tended to neglect samples from different ethnic groups or along a rural-urban continuum. To overcome this limitation, the present study examined positive body image among rural and urban women from three major indigenous ethnic groups in Sabah, Malaysia. A total of 202 women completed the Body Appreciation Scale, as well as measures of media exposure and financial security, and provided their demographic details. s showed that there were significant rural-urban differences in body appreciation, with rural participants having significantly higher body appreciation than urban participants. A comparison with a previous data set of West Malaysian women (Swami & Chamorro-Premuzic, 2008) showed that the current urban sample had significantly lower body appreciation and that the rural group had significantly higher body appreciation. Further results showed that research site (urban vs rural) explained 11.0% of the variance in body appreciation. Participant body mass index and exposure to western forms of media explained an additional 2.0% of the variance. These results suggest that there are differences in body image between rural and urban women. Results are discussed in relation to the promotion of positive body image, particularly in developing societies where health care resources may be limited.

  17. Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares.

    Science.gov (United States)

    Östling, Gerd; Persson, Margaretha; Hedblad, Bo; Gonçalves, Isabel

    2013-11-01

    Grey scale median (GSM) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut-off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with Adobe Photoshop(®) and with Artery Measurement System (AMS) on duplex ultrasound images of 100 consecutive medium- to large-sized carotid plaques of the Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for Adobe Photoshop(®) and AMS, respectively. Mean difference was 20·45 (95% CI: 19·17-21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi-square test revealed a kappa value of 0·68 when studying quartiles of GSM. The intra-observer variability was 1·9% for AMS and 2·5% for Adobe Photoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  18. Gender differences in autobiographical memory for everyday events: retrieval elicited by SenseCam images versus verbal cues.

    Science.gov (United States)

    St Jacques, Peggy L; Conway, Martin A; Cabeza, Roberto

    2011-10-01

    Gender differences are frequently observed in autobiographical memory (AM). However, few studies have investigated the neural basis of potential gender differences in AM. In the present functional MRI (fMRI) study we investigated gender differences in AMs elicited using dynamic visual images vs verbal cues. We used a novel technology called a SenseCam, a wearable device that automatically takes thousands of photographs. SenseCam differs considerably from other prospective methods of generating retrieval cues because it does not disrupt the ongoing experience. This allowed us to control for potential gender differences in emotional processing and elaborative rehearsal, while manipulating how the AMs were elicited. We predicted that males would retrieve more richly experienced AMs elicited by the SenseCam images vs the verbal cues, whereas females would show equal sensitivity to both cues. The behavioural results indicated that there were no gender differences in subjective ratings of reliving, importance, vividness, emotion, and uniqueness, suggesting that gender differences in brain activity were not due to differences in these measures of phenomenological experience. Consistent with our predictions, the fMRI results revealed that males showed a greater difference in functional activity associated with the rich experience of SenseCam vs verbal cues, than did females.

  19. Spatial frequency characteristics at image decision-point locations for observers with different radiological backgrounds in lung nodule detection

    Science.gov (United States)

    Pietrzyk, Mariusz W.; Manning, David J.; Dix, Alan; Donovan, Tim

    2009-02-01

    Aim: The goal of the study is to determine the spatial frequency characteristics at locations in the image of overt and covert observers' decisions and find out if there are any similarities in different observers' groups: the same radiological experience group or the same accuracy scored level. Background: The radiological task is described as a visual searching decision making procedure involving visual perception and cognitive processing. Humans perceive the world through a number of spatial frequency channels, each sensitive to visual information carried by different spatial frequency ranges and orientations. Recent studies have shown that particular physical properties of local and global image-based elements are correlated with the performance and the level of experience of human observers in breast cancer and lung nodule detections. Neurological findings in visual perception were an inspiration for wavelet applications in vision research because the methodology tries to mimic the brain processing algorithms. Methods: The wavelet approach to the set of postero-anterior chest radiographs analysis has been used to characterize perceptual preferences observers with different levels of experience in the radiological task. Psychophysical methodology has been applied to track eye movements over the image, where particular ROIs related to the observers' fixation clusters has been analysed in the spaces frame by Daubechies functions. Results: Significance differences have been found between the spatial frequency characteristics at the location of different decisions.

  20. Gender and Ethnic Differences in the Association Between Body Image Dissatisfaction and Binge Eating Disorder among Blacks.

    Science.gov (United States)

    Blostein, Freida; Assari, Shervin; Caldwell, Cleopatra Howard

    2017-08-01

    The research on binge eating has overwhelmingly focused on Whites. We aimed to study gender and ethnic differences in the association between body image dissatisfaction and binge eating in a nationally representative sample of Black adults in the USA. This cross-sectional study used data from the National Survey of American Life (NSAL), 2003-2004. Self-identified Caribbean Black (n = 1621) and African American (3570) adults aged 18 and older were enrolled. The independent variable was body dissatisfaction measured with two items. Using the World Health Organization Composite International Diagnostic Interview (WHO-CIDI), outcome was lifetime binge eating without hierarchy according to the DSM-IV criteria. Covariates included age, socioeconomic factors (i.e., education and marital status), and body mass index. Ethnicity and gender were focal moderators. Logistic regressions were used for data analysis. Despite comparable prevalence of lifetime binge eating (5 vs 4 %, p > 0.05), African Americans reported higher body image dissatisfaction than Caribbean Blacks (36 vs 29 %, p > 0.05). In the pooled sample, body dissatisfaction was a strong predictor of lifetime binge eating disorders. There was a significant interaction (p = 0.039) between ethnicity and body image dissatisfaction on binge eating, suggesting a stronger association between body image dissatisfaction and lifetime binge eating for Caribbean Blacks (OR = 11.65, 95 % 6.89-19.72) than African Americans (OR = 6.72, 95 % CI 3.97-11.37). Gender did not interact with body image dissatisfaction on binge eating. Ethnic variation in the link between body image dissatisfaction and binge eating may be due to within-race cultural differences in body image between African Americans and Caribbean Blacks. This may include different definitions, norms, and expectations regarding the body size. Findings suggest that ethnicity may bias relevance of body image dissatisfaction as a diagnostic criterion for

  1. Diagnostic Value of Nineteen Different Imaging Methods for Patients with Breast Cancer: a Network Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Xiao-Hong Zhang

    2018-04-01

    Full Text Available Background/Aims: We performed a network meta-analysis (NMA to investigate and compare the diagnostic value of 19 different imaging methods used for breast cancer (BC. Methods: Cochrane Library, PubMed and EMBASE were searched to collect the relevant literature from the inception of the study until November 2016. A combination of direct and indirect comparisons was performed using an NMA to evaluate the combined odd ratios (OR and draw the surface under the cumulative ranking curves (SUCRA of the diagnostic value of different imaging methods for BC. Results: A total of 39 eligible diagnostic tests regarding 19 imaging methods (mammography [MG], breast-specific gamma imaging [BSGI], color Doppler sonography [CD], contrast-enhanced magnetic resonance imaging [CE-MRI], digital breast tomosynthesis [DBT], fluorodeoxyglucose positron-emission tomography/computed tomography [FDG PET/CT], fluorodeoxyglucose positron-emission tomography [FDG-PET], full field digital mammography [FFDM], handheld breast ultrasound [HHUS], magnetic resonance imaging [MRI], automated breast volume scanner [ABUS], magnetic resonance mammography [MRM], scintimammography [SMM], single photon emission computed tomography scintimammography [SPECT SMM], ultrasound elastography [UE], ultrasonography [US], mammography + ultrasonography [MG + US], mammography + scintimammography [MG + SMM], and ultrasound elastography + ultrasonography [UE + US] were included in the study. According to this network meta-analysis, in comparison to the MG method, the CE-MRI, MRI, MRM, MG + SMM and UE + US methods exhibited relatively higher sensitivity, and the specificity of the FDG PET/CT method was higher, while the BSGI and MRI methods exhibited higher accuracy. Conclusion: The results from this NMA indicate that the diagnostic value of the BSGI, MG + SMM, MRI and CE-MRI methods for BC were relatively higher in terms of sensitivity, specificity and accuracy.

  2. 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.

  3. Study on the diagnosis and mechanism of hemispatial neglect using different imaging modalities

    International Nuclear Information System (INIS)

    Huang Lele; Yin Yafu; Li Yaming

    2013-01-01

    Hemispatial neglect is a kind of cognitive impairment characterized by failure to report, respond or orient to stimuli presented in ipsi- or contra-lateral space after brain injury, which cannot be attributed to sensory or motor defects. Although there are various diagnosis and assessment methods, none is regarded as standard. The paper and pencil test is commonly used in routine clinical workup. The mechanism is controversial and the most accepted opinion is due to visuospatial attention defect. Imaging study focuses on exploring the functional regions leading to the hemispatial neglect. As functional imaging, SPECT and PET have capability to evaluate the perfusion, glucose metabolism and cellular vitality, which have been found increasingly useful and applicable clinically in the field of diagnosis for cognitive impairment diseases. They are likely to have potential for contribution in the study of hemispatial neglect. (authors)

  4. Brain abscesses after Serratia marcescens infection on a neonatal intensive care unit: differences on serial imaging

    International Nuclear Information System (INIS)

    Messerschmidt, A.; Olischar, M.; Pollak, A.; Birnbacher, R.; Prayer, D.

    2004-01-01

    Serratia are known to be a possible cause of severe cerebral infections in neonates. We describe imaging of three premature infants infected with Serratia marcescens. Born in the 31 st , 25 th and 28 th weeks of gestation, they presented with signs of septicaemia on postnatal days 9, 24 and 32. Initial sonography showed cysts in the first child, two areas with anechoic centre and echogenic rim in the second, and several echogenic areas in the third. Lesions were seen on CT, of low density in two cases and minimally increased density in the third. MRI in the first patient showed cysts with incomplete contrast enhancement of the lesions, while patient 2 showed five ring-enhancing fluid-containing lesions with thick walls. In the third patient two abscesses with contrast enhancement and several high-signal spots were seen. We discuss the pathophysiology of the lesions and the impact of the various imaging methods. (orig.)

  5. Brain abscesses after Serratia marcescens infection on a neonatal intensive care unit: differences on serial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Messerschmidt, A.; Olischar, M.; Pollak, A.; Birnbacher, R. [Division of Neonatology and Intensive Care, Department of Paediatrics, University of Vienna, Wahringer Guertel 18-20, 1090, Vienna (Austria); Prayer, D. [Division of Radiology, University of Vienna, Waehringer Guertel 18-20, 1090, Vienna (Austria)

    2004-02-01

    Serratia are known to be a possible cause of severe cerebral infections in neonates. We describe imaging of three premature infants infected with Serratia marcescens. Born in the 31{sup st}, 25{sup th} and 28{sup th} weeks of gestation, they presented with signs of septicaemia on postnatal days 9, 24 and 32. Initial sonography showed cysts in the first child, two areas with anechoic centre and echogenic rim in the second, and several echogenic areas in the third. Lesions were seen on CT, of low density in two cases and minimally increased density in the third. MRI in the first patient showed cysts with incomplete contrast enhancement of the lesions, while patient 2 showed five ring-enhancing fluid-containing lesions with thick walls. In the third patient two abscesses with contrast enhancement and several high-signal spots were seen. We discuss the pathophysiology of the lesions and the impact of the various imaging methods. (orig.)

  6. Association Between Imaging Characteristics and Different Molecular Subtypes of Breast Cancer.

    Science.gov (United States)

    Wu, Mingxiang; Ma, Jie

    2017-04-01

    Breast cancer can be divided into four major molecular subtypes based on the expression of hormone receptor (estrogen receptor and progesterone receptor), human epidermal growth factor receptor 2, HER2 status, and molecular proliferation rate (Ki67). In this study, we sought to investigate the association between breast cancer subtype and radiological findings in the Chinese population. Medical records of 300 consecutive invasive breast cancer patients were reviewed from the database: the Breast Imaging Reporting and Data System. The imaging characteristics of the lesions were evaluated. The molecular subtypes of breast cancer were classified into four types: luminal A, luminal B, HER2 overexpressed (HER2), and basal-like breast cancer (BLBC). Univariate and multivariate logistic regression analyses were performed to assess the association between the subtype (dependent variable) and mammography or 15 magnetic resonance imaging (MRI) indicators (independent variables). Luminal A and B subtypes were commonly associated with "clustered calcification distribution," "nipple invasion," or "skin invasion" (P cancers showed association with persistent enhancement in the delayed phase on MRI and "clustered calcification distribution" on mammography (P breast tumor, which are potentially useful tools in the diagnosis and subtyping of breast cancer. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  7. A COMPARISON STUDY OF DIFFERENT MARKER SELECTION METHODS FOR SPECTRAL-SPATIAL CLASSIFICATION OF HYPERSPECTRAL IMAGES

    Directory of Open Access Journals (Sweden)

    D. Akbari

    2015-12-01

    Full Text Available An effective approach based on the Minimum Spanning Forest (MSF, grown from automatically selected markers using Support Vector Machines (SVM, has been proposed for spectral-spatial classification of hyperspectral images by Tarabalka et al. This paper aims at improving this approach by using image segmentation to integrate the spatial information into marker selection process. In this study, the markers are extracted from the classification maps, obtained by both SVM and segmentation algorithms, and then are used to build the MSF. The segmentation algorithms are the watershed, expectation maximization (EM and hierarchical clustering. These algorithms are used in parallel and independently to segment the image. Moreover, the pixels of each class, with the largest population in the classification map, are kept for each region of the segmentation map. Lastly, the most reliable classified pixels are chosen from among the exiting pixels as markers. Two benchmark urban hyperspectral datasets are used for evaluation: Washington DC Mall and Berlin. The results of our experiments indicate that, compared to the original MSF approach, the marker selection using segmentation algorithms leads in more accurate classification maps.

  8. Radiography imaging by 64 and 128 micro-strips crystalline detectors at different X-ray energies

    International Nuclear Information System (INIS)

    Leyva, A.; Cabal, A.; Montano, L. M.; Fontaine, M.; Mora, R. de la; Padilla, F.

    2006-01-01

    This paper summarizes some results obtained in the evaluation of the performance of position sensitive detectors in track reconstruction in particle physics experiments. Crystalline silicon micro-strips detectors with 64 and 128 channels and 100 μm pitch were used to obtain radiographic digital images of different objects. The more relevant figures for spectrometry applications were measured and reported. Two-dimensional images were obtained by scanning the object with a collimated beam using different source-target-detector positioning and three sources of X-rays (8.04, 18.55 and 22.16 keV). The counts acquired by each strip correspond to a particular collimator position during the scan, thus serving to reconstruct the image of the exposed to X-ray object and to reveal its internal structure. The use of some techniques for image processing allow the further improvement of the radiography quality. The preliminary results obtained using in-house made and accreditation mammography phantoms allow to infer that such detectors can be successfully introduced in the digital mammography practice. (Author)

  9. Prediction of cervical cancer recurrence using textural features extracted from 18F-FDG PET images acquired with different scanners.

    Science.gov (United States)

    Reuzé, Sylvain; Orlhac, Fanny; Chargari, Cyrus; Nioche, Christophe; Limkin, Elaine; Riet, François; Escande, Alexandre; Haie-Meder, Christine; Dercle, Laurent; Gouy, Sébastien; Buvat, Irène; Deutsch, Eric; Robert, Charlotte

    2017-06-27

    To identify an imaging signature predicting local recurrence for locally advanced cervical cancer (LACC) treated by chemoradiation and brachytherapy from baseline 18F-FDG PET images, and to evaluate the possibility of gathering images from two different PET scanners in a radiomic study. 118 patients were included retrospectively. Two groups (G1, G2) were defined according to the PET scanner used for image acquisition. Eleven radiomic features were extracted from delineated cervical tumors to evaluate: (i) the predictive value of features for local recurrence of LACC, (ii) their reproducibility as a function of the scanner within a hepatic reference volume, (iii) the impact of voxel size on feature values. Eight features were statistically significant predictors of local recurrence in G1 (p features were significantly different between G1 and G2 in the liver. Spatial resampling was not sufficient to explain the stratification effect. This study showed that radiomic features could predict local recurrence of LACC better than SUVmax. Further investigation is needed before applying a model designed using data from one PET scanner to another.

  10. Optimal usage of cone beam computed tomography system with different field of views in image guided radiotherapy (IGRT

    Directory of Open Access Journals (Sweden)

    Narayana Venkata Naga Madhusudhana Sresty

    2015-09-01

    Full Text Available Purpose: To find methods for optimal usage of XVI (X-ray volume imaging system in Elekta synergy linear accelerator with different field of views for same lesion in order to minimize patient dose due to imaging.Methods: 20 scans of 2 individual patients with ca sigmoid colon and ca lung were used in this study. Kilo voltage collimators with medium field of view were used as per the preset information. Images were reconstructed for another collimator with small field of view. The set up errors were evaluated with XVI software. Shift results of both methods were compared. Results: Variation in treatment set up errors with M20 and S20 collimators were ≤ 0.2 mm in translational and 0.30 in rotational shifts. Results showed almost equal translational and rotational shifts in both medium and small field of views with different collimators in all the scans. Visualization of target and surrounding structures were good enough and sufficient for XVI auto matching.Conclusion: Imaging with small field of view results less patient dose compared with medium or large field of views. It is Suggestible to use collimators with small field of view wherever possible. In this study, collimators with small field of view were sufficient for both patients though the preset information indicated medium field of view. But, it always depends on the area required for matching purpose. So, individual selection is important than preset information in the XVI system.

  11. Measurement and image processing evaluation of surface modifications of dental implants G4 pure titanium created by different techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bulutsuz, A. G., E-mail: asligunaya@gmail.com [Department of Mechanical Engineering, Yildiz Technical University, 34349 Besiktas, İstanbul (Turkey); Demircioglu, P., E-mail: pinar.demircioglu@adu.edu.tr; Bogrekci, I., E-mail: ismail.bogrekci@adu.edu.tr [Adnan Menderes University, Faculty of Engineering, Department of Mechanical Engineering, Aytepe, 09010, Aydin (Turkey); Durakbasa, M. N., E-mail: durakbasa@gmx.at [Department of Interchangeable Manufacturing and Industrial Metrology, Institute for Production Engineering and Laser Technology, Vienna University of Technology, Karlsplatz 13/3113 A-1040 Wien (Austria); Katiboglu, A. B., E-mail: abkatiboglu@hotmail.com [Istanbul University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Istanbul (Turkey)

    2015-03-30

    Foreign substances and organic tissue interaction placed into the jaw in order to eliminate tooth loss involves a highly complex process. Many biological reactions take place as well as the biomechanical forces that influence this formation. Osseointegration denotes to the direct structural and functional association between the living bone and the load-bearing artificial implant's surface. Taking into consideration of the requirements in the manufacturing processes of the implants, surface characterizations with high precise measurement techniques are investigated and thus long-term success of dental implant is emphasized on the importance of these processes in this study. In this research, the detailed surface characterization was performed to identify the dependence of the manufacturing techniques on the surface properties by using the image processing methods and using the scanning electron microscope (SEM) for morphological properties in 3D and Taylor Hobson stylus profilometer for roughness properties in 2D. Three implant surfaces fabricated by different manufacturing techniques were inspected, and a machined surface was included into the study as a reference specimen. The results indicated that different surface treatments were strongly influenced surface morphology. Thus 2D and 3D precise inspection techniques were highlighted on the importance for surface characterization. Different image analyses techniques such as Dark-light technique were used to verify the surface measurement results. The computational phase was performed using image processing toolbox in Matlab with precise evaluation of the roughness for the implant surfaces. The relationship between the number of black and white pixels and surface roughness is presented. FFT image processing and analyses results explicitly imply that the technique is useful in the determination of surface roughness. The results showed that the number of black pixels in the image increases with increase in

  12. Imaging

    International Nuclear Information System (INIS)

    Kellum, C.D.; Fisher, L.M.; Tegtmeyer, C.J.

    1987-01-01

    This paper examines the advantages of the use of excretory urography for diagnosis. According to the authors, excretory urography remains the basic radiologic examination of the urinary tract and is the foundation for the evaluation of suspected urologic disease. Despite development of the newer diagnostic modalities such as isotope scanning, ultrasonography, CT, and magnetic resonsance imaging (MRI), excretory urography has maintained a prominent role in ruorradiology. Some indications have been altered and will continue to change with the newer imaging modalities, but the initial evaluation of suspected urinary tract structural abnormalities; hematuria, pyuria, and calculus disease is best performed with excretory urography. The examination is relatively inexpensive and simple to perform, with few contraindictions. Excretory urography, when properly performed, can provide valuable information about the renal parenchyma, pelvicalyceal system, ureters, and urinary bladder

  13. Scaling of Thermal Images at Different Spatial Resolution: The Mixed Pixel Problem

    Directory of Open Access Journals (Sweden)

    Hamlyn G. Jones

    2014-07-01

    Full Text Available The consequences of changes in spatial resolution for application of thermal imagery in plant phenotyping in the field are discussed. Where image pixels are significantly smaller than the objects of interest (e.g., leaves, accurate estimates of leaf temperature are possible, but when pixels reach the same scale or larger than the objects of interest, the observed temperatures become significantly biased by the background temperature as a result of the presence of mixed pixels. Approaches to the estimation of the true leaf temperature that apply both at the whole-pixel level and at the sub-pixel level are reviewed and discussed.

  14. Gender Differences in Body Image Perception among Northern Malaysian Tertiary Students

    OpenAIRE

    Wong, Lee-Min; Say, Yee-How

    2013-01-01

    Aims: This study examined the association of socio-cultural and psychological factors with body shape concern, perception and body weight perception among tertiary students of Northern Malaysia. Study Design: This is a cross-sectional study. Place and Duration of Study: Universiti and Kolej Tunku Abdul Rahman (UTAR and KTAR), Perak campuses, between August 2011 and January 2012. Methodology: A total of 1003 students were recruited (M = 431, F = 572; mean age 19.96 ± 1.51) and their body image...

  15. A Weighted Difference of Anisotropic and Isotropic Total Variation for Relaxed Mumford-Shah Image Segmentation

    Science.gov (United States)

    2016-05-01

    norm does not cap - ture the geometry completely. The L1−L2 in (c) does a better job than TV while L1 in (b) and L1−0.5L2 in (d) capture the squares most...and isotropic total variation (TV) norms into a relaxed formu- lation of the two phase Mumford-Shah (MS) model for image segmentation. We show...results exceeding those obtained by the MS model when using the standard TV norm to regular- ize partition boundaries. In particular, examples illustrating

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

    Science.gov (United States)

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

    2011-09-01

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

  17. Classification and Discrimination of Different Fungal Diseases of Three Infection Levels on Peaches Using Hyperspectral Reflectance Imaging Analysis

    Directory of Open Access Journals (Sweden)

    Ye Sun

    2018-04-01

    Full Text Available Peaches are susceptible to infection from several postharvest diseases. In order to control disease and avoid potential health risks, it is important to identify suitable treatments for each disease type. In this study, the spectral and imaging information from hyperspectral reflectance (400~1000 nm was used to evaluate and classify three kinds of common peach disease. To reduce the large dimensionality of the hyperspectral imaging, principal component analysis (PCA was applied to analyse each wavelength image as a whole, and the first principal component was selected to extract the imaging features. A total of 54 parameters were extracted as imaging features for one sample. Three decayed stages (slight, moderate and severe decayed peaches were considered for classification by deep belief network (DBN and partial least squares discriminant analysis (PLSDA in this study. The results showed that the DBN model has better classification results than the classification accuracy of the PLSDA model. The DBN model based on integrated information (494 features showed the highest classification results for the three diseases, with accuracies of 82.5%, 92.5%, and 100% for slightly-decayed, moderately-decayed and severely-decayed samples, respectively. The successive projections algorithm (SPA was used to select the optimal features from the integrated information; then, six optimal features were selected from a total of 494 features to establish the simple model. The SPA-PLSDA model showed better results which were more feasible for industrial application. The results showed that the hyperspectral reflectance imaging technique is feasible for detecting different kinds of diseased peaches, especially at the moderately- and severely-decayed levels.

  18. Evaluation of 2 different x-ray digital systems designed for cardiovascular angiography: patient dosimetry data and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Octavian Dragusin; Kristien Smans; Hilde Bosmans [Department of Radiology, Gasthuisberg Hospital, Leuven (Belgium); Walter Desmet [Department of Cardiology, Gasthuisberg Hospital, Leuven (Belgium)

    2006-07-01

    The goal of this study was the comparative assessment of dose and image quality performance of a new flat-panel detector (F.D.) and an image intensifier (II) charge coupled device (C.C.D.) installed in a Catheterization laboratory (Cathlab). Poly-methyl methacrylate (PMMA) plates were used to simulate different patient size (10,15,20,25,30 cm). Entrance dose to the phantom and image quality of a test object (Leeds T.O.R. 18-F.G.) were measured. For analysis of image quality, two methods were used. Firstly, images were evaluated directly on the monitor (low contrast resolution and high spatial resolution). Secondly, a numerical method was used (noise and signal-to-noise ratio). Finally a preliminary patient dose survey for the two most common interventional cardiology procedures (coronary angiography C.A. and percutaneous transluminal coronary angioplasty - P.T.C.A.) was performed. Dose area product (D.A.P.), fluoroscopy time (F.T.) and total number of frames (No. frames) were collected. The results showed that both systems performed within international recommendations; the F.D. system seems superior to the II system, in terms of entrance doses of the phantom and image quality. Surprisingly, however, this potential dose reduction is not reflected in the patient data; D.A.P. values of patient data were not significantly reduced with the new system. This underlines the need for a careful set-up of the system and a more detailed analysis of the procedure. (authors)

  19. Evaluation of 2 different x-ray digital systems designed for cardiovascular angiography: patient dosimetry data and image quality

    International Nuclear Information System (INIS)

    Octavian Dragusin; Kristien Smans; Hilde Bosmans; Walter Desmet

    2006-01-01

    The goal of this study was the comparative assessment of dose and image quality performance of a new flat-panel detector (F.D.) and an image intensifier (II) charge coupled device (C.C.D.) installed in a Catheterization laboratory (Cathlab). Poly-methyl methacrylate (PMMA) plates were used to simulate different patient size (10,15,20,25,30 cm). Entrance dose to the phantom and image quality of a test object (Leeds T.O.R. 18-F.G.) were measured. For analysis of image quality, two methods were used. Firstly, images were evaluated directly on the monitor (low contrast resolution and high spatial resolution). Secondly, a numerical method was used (noise and signal-to-noise ratio). Finally a preliminary patient dose survey for the two most common interventional cardiology procedures (coronary angiography C.A. and percutaneous transluminal coronary angioplasty - P.T.C.A.) was performed. Dose area product (D.A.P.), fluoroscopy time (F.T.) and total number of frames (No. frames) were collected. The results showed that both systems performed within international recommendations; the F.D. system seems superior to the II system, in terms of entrance doses of the phantom and image quality. Surprisingly, however, this potential dose reduction is not reflected in the patient data; D.A.P. values of patient data were not significantly reduced with the new system. This underlines the need for a careful set-up of the system and a more detailed analysis of the procedure. (authors)

  20. Effect of using different U/S probe Standoff materials in image geometry for interventional procedures: the example of prostate

    Directory of Open Access Journals (Sweden)

    Dimos Baltas

    2011-12-01

    Full Text Available Purpose: This study investigates the distortion of geometry of catheters and anatomy in acquired U/S images, caused by utilizing various stand-off materials for covering a transrectal bi-planar ultrasound probe in HDR and LDR prostatebrachytherapy, biopsy and other interventional procedures. Furthermore, an evaluation of currently established waterbathbased quality assurance (QA procedures is presented. Material and methods: Image acquisitions of an ultrasound QA setup were carried out at 5 MHz and 7 MHz. The U/Sprobe was covered by EA 4015 Silicone Standoff kit, or UA0059 Endocavity balloon filled either with water or one ofthe following: 40 ml of Endosgel®, Instillagel®, Ultraschall gel or Space OAR™ gel. The differences between imageswere recorded. Consequently, the dosimetric impact of the observed image distortion was investigated, using a tissueequivalent ultrasound prostate phantom – Model number 053 (CIRS Inc., Norfolk, VA, USA. Results: By using the EA 4015 Silicone Standoff kit in normal water with sound speed of 1525 m/s, a 3 mm needleshift was observed. The expansion of objects appeared in radial direction. The shift deforms also the PTV (prostate inour case and other organs at risk (OARs in the same way leading to overestimation of volume and underestimationof the dose. On the other hand, Instillagel® and Space OAR™ “shrinks” objects in an ultrasound image for 0.65 mm and0.40 mm, respectively. Conclusions: The use of EA 4015 Silicone Standoff kit for image acquisition, leads to erroneous contouring of PTVand OARs and reconstruction and placement of catheters, which results to incorrect dose calculation during prostatebrachytherapy. Moreover, the reliability of QA procedures lies mostly in the right temperature of the water used foraccurate simulation of real conditions of transrectal ultrasound imaging.

  1. Brain perfusion imaging using a Reconstruction-of-Difference (RoD) approach for cone-beam computed tomography

    Science.gov (United States)

    Mow, M.; Zbijewski, W.; Sisniega, A.; Xu, J.; Dang, H.; Stayman, J. W.; Wang, X.; Foos, D. H.; Koliatsos, V.; Aygun, N.; Siewerdsen, J. H.

    2017-03-01

    Purpose: To improve the timely detection and treatment of intracranial hemorrhage or ischemic stroke, recent efforts include the development of cone-beam CT (CBCT) systems for perfusion imaging and new approaches to estimate perfusion parameters despite slow rotation speeds compared to multi-detector CT (MDCT) systems. This work describes development of a brain perfusion CBCT method using a reconstruction of difference (RoD) approach to enable perfusion imaging on a newly developed CBCT head scanner prototype. Methods: A new reconstruction approach using RoD with a penalized-likelihood framework was developed to image the temporal dynamics of vascular enhancement. A digital perfusion simulation was developed to give a realistic representation of brain anatomy, artifacts, noise, scanner characteristics, and hemo-dynamic properties. This simulation includes a digital brain phantom, time-attenuation curves and noise parameters, a novel forward projection method for improved computational efficiency, and perfusion parameter calculation. Results: Our results show the feasibility of estimating perfusion parameters from a set of images reconstructed from slow scans, sparse data sets, and arc length scans as short as 60 degrees. The RoD framework significantly reduces noise and time-varying artifacts from inconsistent projections. Proper regularization and the use of overlapping reconstructed arcs can potentially further decrease bias and increase temporal resolution, respectively. Conclusions: A digital brain perfusion simulation with RoD imaging approach has been developed and supports the feasibility of using a CBCT head scanner for perfusion imaging. Future work will include testing with data acquired using a 3D-printed perfusion phantom currently and translation to preclinical and clinical studies.

  2. Evaluation of prognostic models developed using standardised image features from different PET automated segmentation methods.

    Science.gov (United States)

    Parkinson, Craig; Foley, Kieran; Whybra, Philip; Hills, Robert; Roberts, Ashley; Marshall, Chris; Staffurth, John; Spezi, Emiliano

    2018-04-11

    Prognosis in oesophageal cancer (OC) is poor. The 5-year overall survival (OS) rate is approximately 15%. Personalised medicine is hoped to increase the 5- and 10-year OS rates. Quantitative analysis of PET is gaining substantial interest in prognostic research but requires the accurate definition of the metabolic tumour volume. This study compares prognostic models developed in the same patient cohort using individual PET segmentation algorithms and assesses the impact on patient risk stratification. Consecutive patients (n = 427) with biopsy-proven OC were included in final analysis. All patients were staged with PET/CT between September 2010 and July 2016. Nine automatic PET segmentation methods were studied. All tumour contours were subjectively analysed for accuracy, and segmentation methods with segmentation methods studied, clustering means (KM2), general clustering means (GCM3), adaptive thresholding (AT) and watershed thresholding (WT) methods were included for analysis. Known clinical prognostic factors (age, treatment and staging) were significant in all of the developed prognostic models. AT and KM2 segmentation methods developed identical prognostic models. Patient risk stratification was dependent on the segmentation method used to develop the prognostic model with up to 73 patients (17.1%) changing risk stratification group. Prognostic models incorporating quantitative image features are dependent on the method used to delineate the primary tumour. This has a subsequent effect on risk stratification, with patients changing groups depending on the image segmentation method used.

  3. Differences in Brand Image of Online Chat Application of Blackberry Messenger, Whatsapp, and Line for Bina Nusantara University’s Student

    Directory of Open Access Journals (Sweden)

    Kuspuji C. B. Wicaksono

    2016-05-01

    Full Text Available This article was written to find out whether there were any differences on brand image for each online chat Application such as Blackberry Messenger, Whatsapp, and LINE based on six factors of the brand image which are: benefits, attributes, cultures, values, personality, and user. Data for the research were collected from questionnaires given to respondents who had used each mention online chat application. Then each respondent was asked to give scores based on the six factors of brand image for each online chat Application. Using the ANOVA method for testing the differences between brand images for each online chat application. The result reveales that there are differences in the brand image between BlackBerry Messenger, Whatsapp, and LINE for benefits, cultures, and values. There is no difference in attributes, and personality cannot be tested. The company that creates online chat application are expected to improve their brand image to distinguish one another differently.

  4. Exploring sex differences in the adult zebra finch brain: In vivo diffusion tensor imaging and ex vivo super-resolution track density imaging.

    Science.gov (United States)

    Hamaide, Julie; De Groof, Geert; Van Steenkiste, Gwendolyn; Jeurissen, Ben; Van Audekerke, Johan; Naeyaert, Maarten; Van Ruijssevelt, Lisbeth; Cornil, Charlotte; Sijbers, Jan; Verhoye, Marleen; Van der Linden, Annemie

    2017-02-01

    Zebra finches are an excellent model to study the process of vocal learning, a complex socially-learned tool of communication that forms the basis of spoken human language. So far, structural investigation of the zebra finch brain has been performed ex vivo using invasive methods such as histology. These methods are highly specific, however, they strongly interfere with performing whole-brain analyses and exclude longitudinal studies aimed at establishing causal correlations between neuroplastic events and specific behavioral performances. Therefore, the aim of the current study was to implement an in vivo Diffusion Tensor Imaging (DTI) protocol sensitive enough to detect structural sex differences in the adult zebra finch brain. Voxel-wise comparison of male and female DTI parameter maps shows clear differences in several components of the song control system (i.e. Area X surroundings, the high vocal center (HVC) and the lateral magnocellular nucleus of the anterior nidopallium (LMAN)), which corroborate previous findings and are in line with the clear behavioral difference as only males sing. Furthermore, to obtain additional insights into the 3-dimensional organization of the zebra finch brain and clarify findings obtained by the in vivo study, ex vivo DTI data of the male and female brain were acquired as well, using a recently established super-resolution reconstruction (SRR) imaging strategy. Interestingly, the SRR-DTI approach led to a marked reduction in acquisition time without interfering with the (spatial and angular) resolution and SNR which enabled to acquire a data set characterized by a 78μm isotropic resolution including 90 diffusion gradient directions within 44h of scanning time. Based on the reconstructed SRR-DTI maps, whole brain probabilistic Track Density Imaging (TDI) was performed for the purpose of super resolved track density imaging, further pushing the resolution up to 40μm isotropic. The DTI and TDI maps realized atlas

  5. Differences in Gaussian diffusion tensor imaging and non-Gaussian diffusion kurtosis imaging model-based estimates of diffusion tensor invariants in the human brain.

    Science.gov (United States)

    Lanzafame, S; Giannelli, M; Garaci, F; Floris, R; Duggento, A; Guerrisi, M; Toschi, N

    2016-05-01

    An increasing number of studies have aimed to compare diffusion tensor imaging (DTI)-related parameters [e.g., mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD)] to complementary new indexes [e.g., mean kurtosis (MK)/radial kurtosis (RK)/axial kurtosis (AK)] derived through diffusion kurtosis imaging (DKI) in terms of their discriminative potential about tissue disease-related microstructural alterations. Given that the DTI and DKI models provide conceptually and quantitatively different estimates of the diffusion tensor, which can also depend on fitting routine, the aim of this study was to investigate model- and algorithm-dependent differences in MD/FA/RD/AD and anisotropy mode (MO) estimates in diffusion-weighted imaging of human brain white matter. The authors employed (a) data collected from 33 healthy subjects (20-59 yr, F: 15, M: 18) within the Human Connectome Project (HCP) on a customized 3 T scanner, and (b) data from 34 healthy subjects (26-61 yr, F: 5, M: 29) acquired on a clinical 3 T scanner. The DTI model was fitted to b-value =0 and b-value =1000 s/mm(2) data while the DKI model was fitted to data comprising b-value =0, 1000 and 3000/2500 s/mm(2) [for dataset (a)/(b), respectively] through nonlinear and weighted linear least squares algorithms. In addition to MK/RK/AK maps, MD/FA/MO/RD/AD maps were estimated from both models and both algorithms. Using tract-based spatial statistics, the authors tested the null hypothesis of zero difference between the two MD/FA/MO/RD/AD estimates in brain white matter for both datasets and both algorithms. DKI-derived MD/FA/RD/AD and MO estimates were significantly higher and lower, respectively, than corresponding DTI-derived estimates. All voxelwise differences extended over most of the white matter skeleton. Fractional differences between the two estimates [(DKI - DTI)/DTI] of most invariants were seen to vary with the invariant value itself as well as with MK

  6. Rapid assessment of different oxygenic phototrophs and single-cell photosynthesis with multicolour variable chlorophyll fluorescence imaging

    DEFF Research Database (Denmark)

    Trampe, Erik Christian Løvbjerg; Kolbowski, J.; Schreiber, U.

    2011-01-01

    , red or white light. Automated sequential exposure of microscopic samples to the three excitation colours enables subsequent deconvolution of the resulting fluorescence signals and colour marking of cells with different photopigmentation, i.e., cyanobacteria, green algae, red algae and diatoms....... The photosynthetic activity in complex mixtures of phototrophs and natural samples can thus be assigned to different types of phototrophs, which can be quantified simultaneously. Here, we describe the composition and performance of the new imaging system and present applications with both natural phytoplankton...

  7. Absolute Configuration from Different Multifragmentation Pathways in Light-Induced Coulomb Explosion Imaging.

    Science.gov (United States)

    Pitzer, Martin; Kastirke, Gregor; Kunitski, Maksim; Jahnke, Till; Bauer, Tobias; Goihl, Christoph; Trinter, Florian; Schober, Carl; Henrichs, Kevin; Becht, Jasper; Zeller, Stefan; Gassert, Helena; Waitz, Markus; Kuhlins, Andreas; Sann, Hendrik; Sturm, Felix; Wiegandt, Florian; Wallauer, Robert; Schmidt, Lothar Ph H; Johnson, Allan S; Mazenauer, Manuel; Spenger, Benjamin; Marquardt, Sabrina; Marquardt, Sebastian; Schmidt-Böcking, Horst; Stohner, Jürgen; Dörner, Reinhard; Schöffler, Markus; Berger, Robert

    2016-08-18

    The absolute configuration of individual small molecules in the gas phase can be determined directly by light-induced Coulomb explosion imaging (CEI). Herein, this approach is demonstrated for ionization with a single X-ray photon from a synchrotron light source, leading to enhanced efficiency and faster fragmentation as compared to previous experiments with a femtosecond laser. In addition, it is shown that even incomplete fragmentation pathways of individual molecules from a racemic CHBrClF sample can give access to the absolute configuration in CEI. This leads to a significant increase of the applicability of the method as compared to the previously reported complete break-up into atomic ions and can pave the way for routine stereochemical analysis of larger chiral molecules by light-induced CEI. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A method of adjusting SUV for injection-acquisition time differences in {sup 18}F-FDG PET Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Laffon, Eric [Hopital du Haut Leveque, CHU de Bordeaux, Pessac (France); Centre de Recherche Cardio-Thoracique, Bordeaux (France); Hopital du Haut-Leveque, Service de Medecine Nucleaire, Pessac (France); Clermont, Henri de [Hopital du Haut Leveque, CHU de Bordeaux, Pessac (France); Marthan, Roger [Hopital du Haut Leveque, CHU de Bordeaux, Pessac (France); Centre de Recherche Cardio-Thoracique, Bordeaux (France)

    2011-11-15

    A time normalisation method of tumour SUVs in {sup 18}F-FDG PET imaging is proposed that has been verified in lung cancer patients. A two-compartment model analysis showed that, when SUV is not corrected for {sup 18}F physical decay (SUV{sub uncorr}), its value is within 5% of its peak value (t = 79 min) between 55 and 110 min after injection, in each individual patient. In 10 patients, each with 1 or more malignant lesions (n = 15), two PET acquisitions were performed within this time delay, and the maximal SUV of each lesion, both corrected and uncorrected, was assessed. No significant difference was found between the two uncorrected SUVs, whereas there was a significant difference between the two corrected ones: mean differences were 0.04 {+-} 0.22 and 3.24 {+-} 0.75 g.ml{sup -1}, respectively (95% confidence intervals). Therefore, a simple normalisation of decay-corrected SUV for time differences after injection is proposed: SUV{sub N} = 1.66*SUV{sub uncorr}, where the factor 1.66 arises from decay correction at t = 79 min. When {sup 18}F-FDG PET imaging is performed within the range 55-110 min after injection, a simple SUV normalisation for time differences after injection has been verified in patients with lung cancer, with a {+-}2.5% relative measurement uncertainty. (orig.)

  9. Differences in 99mTc-HMPAO brain SPET perfusion imaging between Tourette's syndrome and chronic tic disorder in children

    International Nuclear Information System (INIS)

    Chiu, N.-T.; Lee, B.-F.; Chang, Y.-C.; Huang, C.-C.; Wang, S.-T.

    2001-01-01

    Early differential diagnosis between Tourette's syndrome and chronic tic disorder is difficult but important because both the outcome and the treatment of these two childhood-onset diseases are distinct. We assessed the sensitivity and specificity of brain single-photon emission tomography (SPET) perfusion imaging in distinguishing the two diseases, and characterized their different cerebral perfusion patterns. Twenty-seven children with Tourette's syndrome and 11 with chronic tic disorder (mean age 9.5 and 8.6 years, respectively) underwent brain SPET with technetium-99m hexamethylpropylene amine oxime (HMPAO). Visual interpretation and semi-quantitative analysis of SPET images were performed. On visual interpretation, 22 of 27 (82%) of the Tourette's syndrome group had lesions characterized by decreased perfusion. The left hemisphere was more frequently involved. None of the children with chronic tic disorder had a visible abnormality. Semi-quantitative analysis showed that, compared with children with chronic tic disorder, children with Tourette's syndrome had significantly lower perfusion in the left lateral temporal area and asymmetric perfusion in the dorsolateral frontal, lateral and medial temporal areas. In conclusion, using the visual approach, brain SPET perfusion imaging is sensitive and specific in differentiating Tourette's syndrome and chronic tic disorder. The perfusion difference between the two groups, demonstrated by semi-quantitative analysis, may be related more to the co-morbidity in Tourette's syndrome than to tics per se. (orig.)

  10. Interobserver variability of patient positioning using four different CT datasets for image registration in lung stereotactic body radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Oechsner, Markus [Technical University of Munich, Department of Radiation Oncology, Klinikum rechts der Isar, Muenchen (Germany); Technical University of Munich, Zentrum fuer Stereotaxie und personalisierte Hochpraezisionsstrahlentherapie (StereotakTUM), Munich (Germany); Chizzali, Barbara; Devecka, Michal; Muench, Stefan [Technical University of Munich, Department of Radiation Oncology, Klinikum rechts der Isar, Muenchen (Germany); Combs, Stephanie Elisabeth; Wilkens, Jan Jakob; Duma, Marciana Nona [Technical University of Munich, Department of Radiation Oncology, Klinikum rechts der Isar, Muenchen (Germany); Technical University of Munich, Zentrum fuer Stereotaxie und personalisierte Hochpraezisionsstrahlentherapie (StereotakTUM), Munich (Germany); Helmholtz Zentrum Muenchen, Institute of Innovative Radiotherapy (iRT), Munich (Germany)

    2017-10-15

    To assess the impact of different reference CT datasets on manual image registration with free-breathing three-dimensional (3D) cone beam CTs (FB-CBCT) for patient positioning by several observers. For 48 patients with lung lesions, manual image registration with FB-CBCTs was performed by four observers. A slow planning CT (PCT), average intensity projection (AIP), maximum intensity projection (MIP), and midventilation CT (MidV) were used as reference images. Couch shift differences between the four reference CT datasets for each observer as well as shift differences between the observers for the same reference CT dataset were determined. Statistical analyses were performed and correlations between the registration differences and the 3D tumor motion and the CBCT score were calculated. The mean 3D shift difference between different reference CT datasets was the smallest for AIPvsMIP (range 1.1-2.2 mm) and the largest for MidVvsPCT (2.8-3.5 mm) with differences >10 mm. The 3D shifts showed partially significant correlations to 3D tumor motion and CBCT score. The interobserver comparison for the same reference CTs resulted in the smallest ∇3D mean differences and mean ∇3D standard deviation for ∇AIP (1.5 ± 0.7 mm, 0.7 ± 0.4 mm). The maximal 3D shift difference between observers was 10.4 mm (∇MidV). Both 3D tumor motion and mean CBCT score correlated with the shift differences (R{sub s} = 0.336-0.740). The applied reference CT dataset impacts image registration and causes interobserver variabilities. The 3D tumor motion and CBCT quality affect shift differences. The smallest differences were found for AIP which might be the most appropriate CT dataset for image registration with FB-CBCT. (orig.) [German] Untersuchung des Einflusses verschiedener Referenz-CT-Datensaetze auf die manuelle Bildregistrierung mit dreidimensionaler (3D) ConeBeam-Computertomographie in freier Atmung (FB-CBCT) zur Patientenpositionierung durch verschiedene Observer. Bei 48 Patienten

  11. Validation of a multi-frequency electrical impedance tomography (mfEIT) system KHU Mark1: impedance spectroscopy and time-difference imaging

    International Nuclear Information System (INIS)

    Oh, Tong In; Koo, Hwan; Lee, Kyung Heon; Kim, Sang Min; Woo, Eung Je; Lee, Jeehyun; Kim, Sung Wan; Seo, Jin Keun

    2008-01-01

    Validation and interpretation of reconstructed images using a multi-frequency electrical impedance tomography (mfEIT) requires a conductivity phantom including imaging objects with known complex conductivity (σ + iωε) spectra. We describe imaging experiments using the recently developed mfEIT system called the KHU Mark1 with the frequency range of 10 Hz to 500 kHz. Using a bio-impedance spectroscopy (BIS) system, we first measured complex conductivity spectra of different imaging objects including saline, agar, polyacrylamide, TX151, animal hide gelatin, banana and cucumber. Based on an analysis of how conductivity and permittivity affect measured complex boundary voltages, we suggested a new complex version of a multi-frequency time-difference image reconstruction algorithm. Imaging experiments were conducted to produce time-difference images of the objects at multiple frequencies using the proposed algorithm. Images of a conductor (stainless steel) and an insulator (acrylic plastic) were used to set a common scale bar to display all images. Comparing reconstructed time-difference images at multiple frequencies with measured complex conductivity spectra, we found that they showed an overall similarity in terms of changes in complex conductivity values with respect to frequency. However, primarily due to the limitation of the difference imaging algorithm, we suggest that multi-frequency time-difference images must be interpreted in terms of relative contrast changes with respect to frequency. We propose further imaging studies using biological tissues of known complex conductivity spectra and using human subjects to find clinical applications of the mfEIT system

  12. Precision of DVC approaches for strain analysis in bone imaged with μCT at different dimensional levels.

    Science.gov (United States)

    Dall'Ara, Enrico; Peña-Fernández, Marta; Palanca, Marco; Giorgi, Mario; Cristofolini, Luca; Tozzi, Gianluca

    2017-11-01

    Accurate measurement of local strain in heterogeneous and anisotropic bone tissue is fundamental to understand the pathophysiology of musculoskeletal diseases, to evaluate the effect of interventions from preclinical studies, and to optimize the design and delivery of biomaterials. Digital volume correlation (DVC) can be used to measure the three-dimensional displacement and strain fields from micro-Computed Tomography (µCT) images of loaded specimens. However, this approach is affected by the quality of the input images, by the morphology and density of the tissue under investigation, by the correlation scheme, and by the operational parameters used in the computation. Therefore, for each application the precision of the method should be evaluated. In this paper we present the results collected from datasets analyzed in previous studies as well as new data from a recent experimental campaign for characterizing the relationship between the precision of two different DVC approaches and the spatial resolution of the outputs. Different bone structures scanned with laboratory source µCT or Synchrotron light µCT (SRµCT) were processed in zero-strain tests to evaluate the precision of the DVC methods as a function of the subvolume size that ranged from 8 to 2500 micrometers. The results confirmed that for every microstructure the precision of DVC improves for larger subvolume size, following power laws. However, for the first time large differences in the precision of both local and global DVC approaches have been highlighted when SRµCT or in vivo µCT images were used instead of conventional ex vivo µCT. These findings suggest that in situ mechanical testing protocols applied in SRµCT facilities should be optimized in order to allow DVC analyses of localized strain measurements. Moreover, for in vivo µCT applications DVC analyses should be performed only with relatively course spatial resolution for achieving a reasonable precision of the method. In conclusion

  13. Are there age differences in attention to emotional images following a sad mood induction? Evidence from a free-viewing eye-tracking paradigm.

    Science.gov (United States)

    Speirs, Calandra; Belchev, Zorry; Fernandez, Amanda; Korol, Stephanie; Sears, Christopher

    2017-10-30

    Two experiments examined age differences in the effect of a sad mood induction (MI) on attention to emotional images. Younger and older adults viewed sets of four images while their eye gaze was tracked throughout an 8-s presentation. Images were viewed before and after a sad MI to assess the effect of a sad mood on attention to positive and negative scenes. Younger and older adults exhibited positively biased attention after the sad MI, significantly increasing their attention to positive images, with no evidence of an age difference in either experiment. A test of participants' recognition memory for the images indicated that the sad MI reduced memory accuracy for sad images for younger and older adults. The results suggest that heightened attention to positive images following a sad MI reflects an affect regulation strategy related to mood repair. The implications for theories of the positivity effect are discussed.

  14. Characterizing the contrast of white matter and grey matter in high-resolution phase difference enhanced imaging of human brain at 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li [Fudan University, Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Shanghai (China); Shandong University, Shandong Medical Imaging Research Institute, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Jinan, Shandong (China); Wang, Shanshan; Yao, Bin; Li, Lili; Guo, Lingfei; Zhang, Xinjuan; Wang, Guangbin [Shandong University, Shandong Medical Imaging Research Institute, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Jinan, Shandong (China); Xu, Xiaofei [Erasmus University Rotterdam, Laboratory of Experimental Tumor Immunology, Department of Medical Oncology, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Zhao, Lianxin [Shandong University, Department of Radiology, Qilu Hospital, Jinan, Shandong (China); Chen, Weibo; Chan, Queenie [Philips Healthcare, Shanghai (China)

    2015-04-01

    The purpose of this study was to address the feasibility of characterizing the contrast both between and within grey matter and white matter using the phase difference enhanced (PADRE) technique. PADRE imaging was performed in 33 healthy volunteers. Vessel enhancement (VE), tissue enhancement (TE), and PADRE images were reconstructed from source images and were evaluated with regard to differentiation of grey-to-white matter interface, the stria of Gennari, and the two layers, internal sagittal stratum (ISS) and external sagittal stratum (ESS), of optic radiation. White matter regions showed decreased signal intensity compared to grey matter regions. Discrimination was sharper between white matter and cortical grey matter in TE images than in PADRE images, but was poorly displayed in VE images. The stria of Gennari was observed on all three image sets. Low-signal-intensity bands displayed in VE images representing the optic radiation were delineated as two layers of different signal intensities in TE and PADRE images. Statistically significant differences in phase shifts were found between frontal grey and white matter, as well as between ISS and ESS (p < 0.01). The PADRE technique is capable of identifying grey-to-white matter interface, the stria of Gennari, and ISS and ESS, with improved contrast in PADRE and TE images compared to VE images. (orig.)

  15. Characterizing the contrast of white matter and grey matter in high-resolution phase difference enhanced imaging of human brain at 3.0 T

    International Nuclear Information System (INIS)

    Yang, Li; Wang, Shanshan; Yao, Bin; Li, Lili; Guo, Lingfei; Zhang, Xinjuan; Wang, Guangbin; Xu, Xiaofei; Zhao, Lianxin; Chen, Weibo; Chan, Queenie

    2015-01-01

    The purpose of this study was to address the feasibility of characterizing the contrast both between and within grey matter and white matter using the phase difference enhanced (PADRE) technique. PADRE imaging was performed in 33 healthy volunteers. Vessel enhancement (VE), tissue enhancement (TE), and PADRE images were reconstructed from source images and were evaluated with regard to differentiation of grey-to-white matter interface, the stria of Gennari, and the two layers, internal sagittal stratum (ISS) and external sagittal stratum (ESS), of optic radiation. White matter regions showed decreased signal intensity compared to grey matter regions. Discrimination was sharper between white matter and cortical grey matter in TE images than in PADRE images, but was poorly displayed in VE images. The stria of Gennari was observed on all three image sets. Low-signal-intensity bands displayed in VE images representing the optic radiation were delineated as two layers of different signal intensities in TE and PADRE images. Statistically significant differences in phase shifts were found between frontal grey and white matter, as well as between ISS and ESS (p < 0.01). The PADRE technique is capable of identifying grey-to-white matter interface, the stria of Gennari, and ISS and ESS, with improved contrast in PADRE and TE images compared to VE images. (orig.)

  16. Imaging Flow Cytometry Analysis to Identify Differences of Survival Motor Neuron Protein Expression in Patients With Spinal Muscular Atrophy.

    Science.gov (United States)

    Arakawa, Reiko; Arakawa, Masayuki; Kaneko, Kaori; Otsuki, Noriko; Aoki, Ryoko; Saito, Kayoko

    2016-08-01

    Spinal muscular atrophy is a neurodegenerative disorder caused by the deficient expression of survival motor neuron protein in motor neurons. A major goal of disease-modifying therapy is to increase survival motor neuron expression. Changes in survival motor neuron protein expression can be monitored via peripheral blood cells in patients; therefore we tested the sensitivity and utility of imaging flow cytometry for this purpose. After the immortalization of peripheral blood lymphocytes from a human healthy control subject and two patients with spinal muscular atrophy type 1 with two and three copies of SMN2 gene, respectively, we used imaging flow cytometry analysis to identify significant differences in survival motor neuron expression. A bright detail intensity analysis was used to investigate differences in the cellular localization of survival motor neuron protein. Survival motor neuron expression was significantly decreased in cells derived from patients with spinal muscular atrophy relative to those derived from a healthy control subject. Moreover, survival motor neuron expression correlated with the clinical severity of spinal muscular atrophy according to SMN2 copy number. The cellular accumulation of survival motor neuron protein was also significantly decreased in cells derived from patients with spinal muscular atrophy relative to those derived from a healthy control subject. The benefits of imaging flow cytometry for peripheral blood analysis include its capacities for analyzing heterogeneous cell populations; visualizing cell morphology; and evaluating the accumulation, localization, and expression of a target protein. Imaging flow cytometry analysis should be implemented in future studies to optimize its application as a tool for spinal muscular atrophy clinical trials. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Adolescents' perceptions of cigarette brand image: does plain packaging make a difference?

    Science.gov (United States)

    Germain, Daniella; Wakefield, Melanie A; Durkin, Sarah J

    2010-04-01

    To examine the effect of plain packaging on adolescents' perceptions of cigarette packs, attributes of smokers, and expectations of cigarette taste, and to identify the effect of increasing the size of pictorial health warnings on appraisal of plain packs. We used a 5 (degree of plain packaging and graphic health warning)x 3 (brand type) between-subjects experimental design, using a Web-based methodology to expose adolescents to one randomly selected cigarette pack, during which respondents completed ratings. When brand elements such as color, branded fonts, and imagery were progressively removed from cigarette packs, adolescents perceived packs to be less appealing, rated attributes of a typical smoker of the pack less positively, and had more negative expectations of cigarette taste. Pack appeal was reduced even further when the size of the pictorial health warning on the most plain pack was increased from 30% to 80% of the pack face, with this effect apparent among susceptible nonsmokers, experimenters, and established smokers. Removing as much brand information from cigarette packs as possible is likely to reduce positive cigarette brand image associations among adolescents. By additionally increasing the size of pictorial health warnings, positive pack perceptions of those who are at greater risk of becoming regular addicted adult smokers are most likely to be reduced. Copyright 2010 Society for Adolescent Medicine. Published by Elsevier Inc. All rights reserved.

  18. Machine learning techniques for breast cancer computer aided diagnosis using different image modalities: A systematic review.

    Science.gov (United States)

    Yassin, Nisreen I R; Omran, Shaimaa; El Houby, Enas M F; Allam, Hemat

    2018-03-01

    The high incidence of breast cancer in women has increased significantly in the recent years. Physician experience of diagnosing and detecting breast cancer can be assisted by using some computerized features extraction and classification algorithms. This paper presents the conduction and results of a systematic review (SR) that aims to investigate the state of the art regarding the computer aided diagnosis/detection (CAD) systems for breast cancer. The SR was conducted using a comprehensive selection of scientific databases as reference sources, allowing access to diverse publications in the field. The scientific databases used are Springer Link (SL), Science Direct (SD), IEEE Xplore Digital Library, and PubMed. Inclusion and exclusion criteria were defined and applied to each retrieved work to select those of interest. From 320 studies retrieved, 154 studies were included. However, the scope of this research is limited to scientific and academic works and excludes commercial interests. This survey provides a general analysis of the current status of CAD systems according to the used image modalities and the machine learning based classifiers. Potential research studies have been discussed to create a more objective and efficient CAD systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Positional and Dimensional Accuracy Assessment of Drone Images Geo-referenced with Three Different GPSs

    Science.gov (United States)

    Cao, C.; Lee, X.; Xu, J.

    2017-12-01

    Unmanned Aerial Vehicles (UAVs) or drones have been widely used in environmental, ecological and engineering applications in recent years. These applications require assessment of positional and dimensional accuracy. In this study, positional accuracy refers to the accuracy of the latitudinal and longitudinal coordinates of locations on the mosaicked image in reference to the coordinates of the same locations measured by a Global Positioning System (GPS) in a ground survey, and dimensional accuracy refers to length and height of a ground target. Here, we investigate the effects of the number of Ground Control Points (GCPs) and the accuracy of the GPS used to measure the GCPs on positional and dimensional accuracy of a drone 3D model. Results show that using on-board GPS and a hand-held GPS produce a positional accuracy on the order of 2-9 meters. In comparison, using a differential GPS with high accuracy (30 cm) improves the positional accuracy of the drone model by about 40 %. Increasing the number of GCPs can compensate for the uncertainty brought by the GPS equipment with low accuracy. In terms of the dimensional accuracy of the drone model, even with the use of a low resolution GPS onboard the vehicle, the mean absolute errors are only 0.04 m for height and 0.10 m for length, which are well suited for some applications in precision agriculture and in land survey studies.

  20. Exploring gender differences in body image, eating pathology, and sexual harassment.

    Science.gov (United States)

    Buchanan, Nicole T; Bluestein, Brooke M; Nappa, Alexa C; Woods, Krystle C; Depatie, Melissa M

    2013-06-01

    This study examines the relationship between body image (weight/shape concerns), eating pathology, and sexual harassment among men and women (N=2446). Hierarchical regressions controlling for depression revealed main effects of gender such that women reported greater weight/shape concerns, eating pathology, dietary restraint, eating concerns, and binge eating compared to men. Main effects for sexual harassment indicated that as harassment increased, participants reported increased weight/shape concerns, eating pathology, dietary restraint, eating concerns, binge eating, and compensatory behaviors. There were small but significant interactions between gender and harassment for eating pathology total score (which included each of the domains listed above), weight/shape concerns, dietary restraint, and eating concerns such that the relationship between increased harassment and increased pathology was stronger for women compared to men. The largest interaction was found for compensatory behaviors, such that while women and men's scores both increased as harassment increased, the relationship was stronger for men. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Note on difference spectra for fast extraction of global image information.

    CSIR Research Space (South Africa)

    Van Wyk, BJ

    2007-06-01

    Full Text Available FOR FAST EXTRACTION OF GLOBAL IMAGE INFORMATION. B.J van Wyk* M.A. van Wyk* and F. van den Bergh** * c29c55c48c51c46c4bc03 c36c52c58c57c4bc03 c24c49c55c4cc46c44c51c03 c37c48c46c4bc51c4cc46c44c4fc03 c2cc51c56c57c4cc57c58c57c48c03 c4cc51c03 c28c4fc48c...46c57c55c52c51c4cc46c56c03 c0bc29cb6c36c24c37c2cc28c0cc03 c44c57c03 c57c4bc48c03 c37c56c4bc5ac44c51c48c03 c38c51c4cc59c48c55c56c4cc57c5cc03 c52c49c03 Technology, Private Bag X680, Pretoria 0001. ** Remote Sensing Research Group, Meraka Institute...

  2. Discrimination of different brain metastases and primary CNS lymphomas using morphologic criteria and diffusion tensor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bette, S.; Wiestler, B.; Huber, T.; Boeckh-Behrens, T.; Zimmer, C.; Kirschke, J. [Technical University Munich, Klinikum rechts der Isar (Germany). Dept. of Neuroradiology; Delbridge, C. [Technical University Munich, Klinikum rechts der Isar (Germany). Dept. of Neuropathology; Meyer, B.; Gempt, J. [Technical University Munich, Klinikum rechts der Isar (Germany). Dept. of Neurosurgery

    2016-12-15

    Brain metastases are a common complication of cancer and occur in about 15-40% of patients with malignancies. The aim of this retrospective study was to differentiate between metastases from different primary tumors/CNS lymphyomas using morphologic criteria, fractional anisotropy (FA) and apparent diffusion coefficient (ADC). Morphologic criteria such as hemorrhage, cysts, pattern of contrast enhancement and location were reported in 200 consecutive patients with brain metastases/primary CNS lymphomas. FA and ADC values were measured in regions of interest (ROIs) placed in the contrast-enhancing tumor part, the necrosis and the non-enhancing peritumoral region (NEPTR). Differences between histopathological subtypes of metastases were analyzed using non-parametric tests, decision trees and hierarchical clustering analysis. Significant differences were found in morphologic criteria such as hemorrhage or pattern of contrast enhancement. In diffusion measurements, significant differences between the different tumor entities were only found in ADC analyzed in the contrast-enhancing tumor part. Among single tumor entities, primary CNS lymphomas showed significantly lower median ADC values in the contrast-enhancing tumor part (ADC{sub lymphoma} 0.92 [0.83-1.07] vs. ADC{sub no} {sub lymphoma} 1.35 [1.10-1.64] P=0.001). Further differentiation between types of metastases was not possible using FA and ADC. There were morphologic differences among the main subtypes of brain metastases/CNS lymphomas. However, due to a high variability of common types of metastases and low specificity, prospective differentiation remained challenging. DTI including FA and ADC was not a reliable tool for differentiation between different histopathological subtypes of brain metastases except for CNS lymphomas showing lower ADC values. Biopsy, surgery and staging remain essential for diagnosis.

  3. Experimental article – Reducing effective dose to a paediatric phantom by using different combinations of kVp, mAs and additional filtration whilst maintaining image quality

    NARCIS (Netherlands)

    Huizinga, Elsbeth; Schaake, Wouter; Visser, Ruurd; Bloomfield, Charlotte; Boavida, Filipa; Chabloz, Diane; Crausaz, Emilie; Hustveit, Hanne; Knight, Heidi; Pereira, Anna; Harsaker, Vanja

    2015-01-01

    Purpose: To determine whether using different combinations of kVp and mAs with additional filtration can reduce the effective dose to a paediatric phantom whilst maintaining diagnostic image quality. Methods: 27 images of a paediatric AP pelvis phantom were acquired with different kVp, mAs and

  4. Experimental article – Reducing effective dose to a paediatric phantom by using different combinations of kVp, mAs and additional filtration whilst maintaining image quality

    NARCIS (Netherlands)

    Elsbeth Huizinga; Ana Pereira; Wouter Schaake; Charlotte Bloomfield; Heidi Knight; Emilie Crausaz; Hanne Hustveit; Ruurd Visser; Vanja Harsaker; Diane Chabloz; Filipa Boavida

    2015-01-01

    Purpose: To determine whether using different combinations of kVp and mAs with additional filtration can reduce the effective dose to a paediatric phantom whilst maintaining diagnostic image quality. Methods: 27 images of a paediatric AP pelvis phantom were acquired with different kVp, mAs

  5. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging.

    Science.gov (United States)

    Bültmann, Eva; Nägele, Thomas; Lanfermann, Heinrich; Klose, Uwe

    2017-01-01

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic.

  6. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

    International Nuclear Information System (INIS)

    Bueltmann, Eva; Lanfermann, Heinrich; Naegele, Thomas; Klose, Uwe

    2017-01-01

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

  7. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bueltmann, Eva; Lanfermann, Heinrich [Hannover Medical School, Institute of Diagnostic and Interventional Neuroradiology, Hannover (Germany); Naegele, Thomas [University of Tuebingen, Department of Diagnostic and Interventional Neuroradiology, Radiological University Hospital, Tuebingen (Germany); Klose, Uwe [University of Tuebingen, Section of Experimental MR of the CNS, Department of Neuroradiology, Radiological University Hospital, Tuebingen (Germany)

    2017-01-15

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

  8. Comparison of procalcitonin and different guidelines for first febrile urinary tract infection in children by imaging.

    Science.gov (United States)

    Liao, Pei-Fen; Ku, Min-Sho; Tsai, Jeng-Dau; Choa, Yu-Hua; Hung, Tung-Wei; Lue, Ko-Huang; Sheu, Ji-Nan

    2014-09-01

    We examined the ability of a procalcitonin (PCT) protocol to detect vesicoureteral reflux (VUR) and renal scarring (RS), evaluated procedural costs and radiation burden, and compared four representative guidelines for children with their first febrile urinary tract infection (UTI). Children aged ≤2 years with their first febrile UTI who underwent renal ultrasonography (US), acute and late technetium-99m ((99m)Tc)-dimercaptosuccinic acid scan, and voiding cystourethrography were prospectively studied. The representative guidelines applied in a retrospective simulation included the American Academy of Pediatrics (AAP), National Institute of Clinical Excellence, top-down approach (TDA), and Italian Society of Pediatric Nephrology (ISPN). These were compared in terms of ability to detect abnormalities, procedural costs and radiation. Of 278 children analyzed, 172 (61.9%) had acute pyelonephritis. There was VUR in 101 (36.3%) children, including 73 (26.3%) with grades III-V VUR. RS was identified in 75 (27.0%) children. To detect VUR, TDA and PCT had the highest sensitivity for grades I-V VUR (80.2%) and III-V VUR (94.5%), respectively, whereas AAP had the highest specificity for I-V VUR (77.4%) and III-V VUR (78.0%), respectively. TDA and PCT had the highest sensitivity (100%) for detecting RS. The highest cost and radiation dose was associated with TDA, whereas AAP had the least expenditure and radiation exposure. By multivariate analysis, PCT and VUR, especially grades III-V, were independent predictors of RS. There is no perfect guideline for first febrile UTI children. The PCT protocol has good ability for detecting high-grade VUR and RS. If based on available imaging modalities and reducing cost and radiation burden, clinical suggestions in the AAP guidelines represent a considerable protocol.

  9. Conversion of mammographic images to appear with the noise and sharpness characteristics of a different detector and x-ray system

    Energy Technology Data Exchange (ETDEWEB)

    Mackenzie, Alistair; Dance, David R.; Workman, Adam; Yip, Mary; Wells, Kevin; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford, GU2 7XX, United Kingdom and Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Northern Ireland Regional Medical Physics Service, Forster Green Hospital, Belfast, BT8 4HD (United Kingdom); Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Centre for Vision, Speech and Signal Processing, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom); National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford, GU2 7XX, United Kingdom and Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom)

    2012-05-15

    Purpose: Undertaking observer studies to compare imaging technology using clinical radiological images is challenging due to patient variability. To achieve a significant result, a large number of patients would be required to compare cancer detection rates for different image detectors and systems. The aim of this work was to create a methodology where only one set of images is collected on one particular imaging system. These images are then converted to appear as if they had been acquired on a different detector and x-ray system. Therefore, the effect of a wide range of digital detectors on cancer detection or diagnosis can be examined without the need for multiple patient exposures. Methods: Three detectors and x-ray systems [Hologic Selenia (ASE), GE Essential (CSI), Carestream CR (CR)] were characterized in terms of signal transfer properties, noise power spectra (NPS), modulation transfer function, and grid properties. The contributions of the three noise sources (electronic, quantum, and structure noise) to the NPS were calculated by fitting a quadratic polynomial at each spatial frequency of the NPS against air kerma. A methodology was developed to degrade the images to have the characteristics of a different (target) imaging system. The simulated images were created by first linearizing the original images such that the pixel values were equivalent to the air kerma incident at the detector. The linearized image was then blurred to match the sharpness characteristics of the target detector. Noise was then added to the blurred image to correct for differences between the detectors and any required change in dose. The electronic, quantum, and structure noise were added appropriate to the air kerma selected for the simulated image and thus ensuring that the noise in the simulated image had the same magnitude and correlation as the target image. A correction was also made for differences in primary grid transmission, scatter, and veiling glare. The method was

  10. Exploring individual user differences in the 2D/3D interaction with medical image data

    NARCIS (Netherlands)

    Zudilova-Seinstra, E.; van Schooten, B.; Suinesiaputra, A.; van der Geest, R.; van Dijk, B.; Reiber, J.; Sloot, P.

    2010-01-01

    User-centered design is often performed without regard to individual user differences. In this paper, we report results of an empirical study aimed to evaluate whether computer experience and demographic user characteristics would have an effect on the way people interact with the visualized medical

  11. Exploring individual user differences in the 2D/3D interaction with medical image data

    NARCIS (Netherlands)

    Zudilova-Seinstra, Elena; van Schooten, B.W.; Suinesiaputra, Avan; van der Geest, Rob; van Dijk, Elisabeth M.A.G.; Reiber, Johan; Sloot, Peter

    2009-01-01

    User-centered design is often performed without regard to individual user differences. In this paper, we report results of an empirical study aimed to evaluate whether computer experience and demographic user characteristics would have an effect on the way people interact with the visualized medical

  12. The challenge of on-tissue digestion for MALDI MSI- a comparison of different protocols to improve imaging experiments.

    Science.gov (United States)

    Diehl, Hanna C; Beine, Birte; Elm, Julian; Trede, Dennis; Ahrens, Maike; Eisenacher, Martin; Marcus, Katrin; Meyer, Helmut E; Henkel, Corinna

    2015-03-01

    Mass spectrometry imaging (MSI) has become a powerful and successful tool in the context of biomarker detection especially in recent years. This emerging technique is based on the combination of histological information of a tissue and its corresponding spatial resolved mass spectrometric information. The identification of differentially expressed protein peaks between samples is still the method's bottleneck. Therefore, peptide MSI compared to protein MSI is closer to the final goal of identification since peptides are easier to measure than proteins. Nevertheless, the processing of peptide imaging samples is challenging due to experimental complexity. To address this issue, a method development study for peptide MSI using cryoconserved and formalin-fixed paraffin-embedded (FFPE) rat brain tissue is provided. Different digestion times, matrices, and proteases were tested to define an optimal workflow for peptide MSI. All practical experiments were done in triplicates and analyzed by the SCiLS Lab software, using structures derived from myelin basic protein (MBP) peaks, principal component analysis (PCA) and probabilistic latent semantic analysis (pLSA) to rate the experiments' quality. Blinded experimental evaluation in case of defining countable structures in the datasets was performed by three individuals. Such an extensive method development for peptide matrix-assisted laser desorption/ionization (MALDI) imaging experiments has not been performed so far, and the resulting problems and consequences were analyzed and discussed.

  13. Real-time prediction of pre-cooked Japanese sausage color with different storage days using hyperspectral imaging.

    Science.gov (United States)

    Feng, Chao-Hui; Makino, Yoshio; Yoshimura, Masatoshi; Rodríguez-Pulido, Francisco J

    2018-05-01

    Redness can greatly influence the freshness of sausages. A precise, rapid and noncontact analytical method or tool is needed to quantify the color. Hyperspectral imaging (HSI) is an emerging technique that integrates spectroscopy and imaging to obtain the spectral and spatial information simultaneously. In the present study, the redness of cooked sausages stored up to 57 days was predicted using HSI in tandem with multivariate data analysis. The mean spectra of the sausages were extracted from the hyperspectral images. Partial least squares regression (PLSR) and forward stepwise multiple regression (FSMR) models were used to develop the relavent spectral profiles with the redness of the cooked sausages. Ten important wavelengths were selected based on the regression coefficient values from the PLSR model. The PLSR model established using the full wavelengths presented a good performance, with R c of 0.934 and a root mean square error of calibration of 0.642 (redness ranged between 14.99 and 21.48). The prediction maps for demonstrating evolution of redness in sausages were developed for the first time using R statistics (R Foundation for Statistical Computing) and Matlab (MathWorks Inc., Natick, MA, USA). HSI combined with PLSR and FSMR can be used to quantify and visualize evolution of sausage redness under different storage days. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Evaluation of different set-up error corrections on dose-volume metrics in prostate IMRT using CBCT images

    International Nuclear Information System (INIS)

    Hirose, Yoshinori; Tomita, Tsuneyuki; Kitsuda, Kenji; Notogawa, Takuya; Miki, Katsuhito; Nakamura, Mitsuhiro; Nakamura, Kiyonao; Ishigaki, Takashi

    2014-01-01

    We investigated the effect of different set-up error corrections on dose-volume metrics in intensity-modulated radiotherapy (IMRT) for prostate cancer under different planning target volume (PTV) margin settings using cone-beam computed tomography (CBCT) images. A total of 30 consecutive patients who underwent IMRT for prostate cancer were retrospectively analysed, and 7-14 CBCT datasets were acquired per patient. Interfractional variations in dose-volume metrics were evaluated under six different set-up error corrections, including tattoo, bony anatomy, and four different target matching groups. Set-up errors were incorporated into planning the isocenter position, and dose distributions were recalculated on CBCT images. These processes were repeated under two different PTV margin settings. In the on-line bony anatomy matching groups, systematic error (Σ) was 0.3 mm, 1.4 mm, and 0.3 mm in the left-right, anterior-posterior (AP), and superior-inferior directions, respectively. Σ in three successive off-line target matchings was finally comparable with that in the on-line bony anatomy matching in the AP direction. Although doses to the rectum and bladder wall were reduced for a small PTV margin, averaged reductions in the volume receiving 100% of the prescription dose from planning were within 2.5% under all PTV margin settings for all correction groups, with the exception of the tattoo set-up error correction only (≥ 5.0%). Analysis of variance showed no significant difference between on-line bony anatomy matching and target matching. While variations between the planned and delivered doses were smallest when target matching was applied, the use of bony anatomy matching still ensured the planned doses. (author)

  15. 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

  16. 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

  17. On the feasibility of optical-CT imaging in media of different refractive index

    International Nuclear Information System (INIS)

    Rankine, Leith; Oldham, Mark

    2013-01-01

    Purpose: Achieving accurate optical-CT 3D dosimetry without the use of viscous refractive index (RI) matching fluids would greatly increase convenience. Methods: Software has been developed to simulate optical-CT 3D dosimetry for a range of scanning configurations including parallel-beam, point, and converging light sources. For each configuration the efficacy of three refractive media was investigated: air, water, a fluid closely matched to PRESAGE ® , and perfect matching (RI = 1.00, 1.33, 1.49, and 1.501 respectively). Reconstructions were performed using both filtered backprojection (FBP) and algebraic reconstruction technique (ART). The efficacy of the three configurations and the two algorithms was evaluated by calculating the usable radius (i.e., the outermost radius where data were accurate to within 2%), and gamma (Γ) analysis. This definition recognizes that for optical-CT imaging, errors are greatest near the edge of the dosimeter, where refraction can be most pronounced. Simulations were performed on three types of dose distribution: uniform, volumetric modulated arc therapy (VMAT), and brachytherapy (Cs-137). Results: For a uniformly irradiated dosimeter the usable radius achieved with filtered backprojection was 68% for water-matching and 31% for dry-scanning in air. Algebraic reconstruction gave usable radii of 99% for both water and air (dry-scanning), indicating greater recovery of useful data for the uniform distribution. FBP and ART performed equally well for a VMAT dose distribution where less dose is delivered near the edge of the dosimeter. In this case, the usable radius was 86% and 53% for scanning in water and air, respectively. For brachytherapy, the usable radius was 99% and 98% for scanning in water and air, respectively using FBP, and a major decrease was seen with ART. Point source geometry provided 1%–2% larger usable radii than parallel geometry. Converging geometry recovered less usable dosimetry data (up to 10% reduced usable

  18. Making a difference? Applying Vitellone's Social Science of the Syringe to performance and image enhancing drug injecting.

    Science.gov (United States)

    Hart, Aaron

    2018-04-18

    Vitellone's Social Science of the Syringe investigates epistemologies of injecting drug use. She argues for a methodology that can be simultaneously sensitive to biopolitical power regimes; the trajectories of social stratification; and the resistance, creativity and dignity of human agency. She proposes a methodological focus on the syringe-in-use as an active participant in these dynamics. Harm reduction policy and service provision frameworks have paid little attention to the phenomena of performance and image enhancing drug (PIEDs) injection. One way of assessing the merit of Vitellone's proposal is to use it to investigate these phenomena. I argue that Vitellone's method can be used to articulate a range of significant differences between people who inject PIEDs and other people who inject drugs, and that these differences can inform harm reduction initiatives. When compared to the heroin syringe, the PIED syringe participates in different socio-economic and material contexts, gendered identities, and biopolitical governance regimes. These differences materialise in different rates of syringe sharing and blood-borne virus transmission; and different experiences of needle exchange services. I offer a thought experiment demonstrating how a different syringe might alter the structural dynamics, biopolitical governance, and the agentic choices of people who inject PIEDs. Judging by the productive effects of diffracting Vitellone's analysis through an empirical concern with PIED injecting, I concur with Vitellone's proposition that 'something objective may be gained from an empirical investigation of the syringe-in-use' (p. 33). Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Evaluation of subjective image quality in relation to diagnostic task for cone beam computed tomography with different fields of view.

    Science.gov (United States)

    Lofthag-Hansen, Sara; Thilander-Klang, Anne; Gröndahl, Kerstin

    2011-11-01

    To evaluate subjective image quality for two diagnostic tasks, periapical diagnosis and implant planning, for cone beam computed tomography (CBCT) using different exposure parameters and fields of view (FOVs). Examinations were performed in posterior part of the jaws on a skull phantom with 3D Accuitomo (FOV 3 cm×4 cm) and 3D Accuitomo FPD (FOVs 4 cm×4 cm and 6 cm×6 cm). All combinations of 60, 65, 70, 75, 80 kV and 2, 4, 6, 8, 10 mA with a rotation of 180° and 360° were used. Dose-area product (DAP) value was determined for each combination. The images were presented, displaying the object in axial, cross-sectional and sagittal views, without scanning data in a random order for each FOV and jaw. Seven observers assessed image quality on a six-point rating scale. Intra-observer agreement was good (κw=0.76) and inter-observer agreement moderate (κw=0.52). Stepwise logistic regression showed kV, mA and diagnostic task to be the most important variables. Periapical diagnosis, regardless jaw, required higher exposure parameters compared to implant planning. Implant planning in the lower jaw required higher exposure parameters compared to upper jaw. Overall ranking of FOVs gave 4 cm×4 cm, 6 cm×6 cm followed by 3 cm×4 cm. This study has shown that exposure parameters should be adjusted according to diagnostic task. For this particular CBCT brand a rotation of 180° gave good subjective image quality, hence a substantial dose reduction can be achieved without loss of diagnostic information. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Evaluation of subjective image quality in relation to diagnostic task for cone beam computed tomography with different fields of view

    International Nuclear Information System (INIS)

    Lofthag-Hansen, Sara; Thilander-Klang, Anne; Groendahl, Kerstin

    2011-01-01

    Aims: To evaluate subjective image quality for two diagnostic tasks, periapical diagnosis and implant planning, for cone beam computed tomography (CBCT) using different exposure parameters and fields of view (FOVs). Materials and methods: Examinations were performed in posterior part of the jaws on a skull phantom with 3D Accuitomo (FOV 3 cm x 4 cm) and 3D Accuitomo FPD (FOVs 4 cm x 4 cm and 6 cm x 6 cm). All combinations of 60, 65, 70, 75, 80 kV and 2, 4, 6, 8, 10 mA with a rotation of 180 o and 360 o were used. Dose-area product (DAP) value was determined for each combination. The images were presented, displaying the object in axial, cross-sectional and sagittal views, without scanning data in a random order for each FOV and jaw. Seven observers assessed image quality on a six-point rating scale. Results: Intra-observer agreement was good (κ w = 0.76) and inter-observer agreement moderate (κ w = 0.52). Stepwise logistic regression showed kV, mA and diagnostic task to be the most important variables. Periapical diagnosis, regardless jaw, required higher exposure parameters compared to implant planning. Implant planning in the lower jaw required higher exposure parameters compared to upper jaw. Overall ranking of FOVs gave 4 cm x 4 cm, 6 cm x 6 cm followed by 3 cm x 4 cm. Conclusions: This study has shown that exposure parameters should be adjusted according to diagnostic task. For this particular CBCT brand a rotation of 180 o gave good subjective image quality, hence a substantial dose reduction can be achieved without loss of diagnostic information.

  1. Cost analysis of different protocols for imaging a patient with acute flank pain

    International Nuclear Information System (INIS)

    Grisi, G.; Stacul, F.; Cuttin, R.; Rimondini, A.; Meduri, S.; Dalla Palma, L.

    2000-01-01

    The aim of this study was to analyse the costs of different diagnostic approaches to patients with acute flank pain. Four different diagnostic approaches were considered: (a) spiral CT without contrast medium (CM); (b) plain film, ultrasonography (US) and intravenous urography (IVU) - the latter procedure is used in our department in cases still unsolved following the former investigations (28 % in our experience); (c) plain film, US and spiral CT without CM (as an alternative to IVU in 28 % of cases); and (d) IVU. The cost of each procedure in a university hospital was calculated, following analysis of the differential costs of each investigation (equipment, depreciation and maintenance costs, related materials and services, radiologists, radiographers, nurses) and their common costs (auxiliary personnel and indirect internal costs). Finally, we calculated the full cost of each procedure and applied it to the different diagnostic approaches. The full cost of each approach was: (a) spiral CT without CM = 74 Euro; (b) plain film, US and IVU (28 %) = 66.89 Euro; (c) plain film, US and spiral CT without CM (28 %) = 64.93 Euro; (d) IVU = 80.90 Euro. Intravenous urography alone or in unsolved cases is not to be considered because it provides higher costs and worse diagnostic results, whereas X-ray dose to patient is almost equal between IVU and spiral CT. Spiral CT integrated to plain film and US in unsolved cases could be preferred because of lower cost and dose to patient, though reaching a diagnostic conclusion may take longer than an immediate spiral CT. (orig.)

  2. Imaging of Flames in Cement Kilns To Study the Influence of Different Fuel Types

    DEFF Research Database (Denmark)

    Pedersen, Morten Nedergaard; Nielsen, Mads; Clausen, Sønnik

    2017-01-01

    The cement industry aims to use an increased amount of alternative fuels to reduce production costs and CO2 emissions. In this study three cement plants firing different kinds and percentages of alternative fuel were studied. A specially developed camera setup was used to monitor the flames...... in the three cement kilns and assess the effect of alternative fuels on the flame. It was found that cofiring with solid recovered fuel (SRF) would delay the ignition point by about 2 m and lower the intensity and temperature of the kiln flame compared to a fossil fuel flame. This is related to a larger...... particle size and moisture content of the alternative fuels, which lowers the conversion rate compared to fossil fuels. The consequences can be a lower kiln temperature and cement quality. The longer conversion time may also lead to the possibility of localized reducing conditions in the cement kiln, which...

  3. Peritumoral edema of meningiomas and metastatic brain tumors: differences in diffusion characteristics evaluated with diffusion-tensor MR imaging

    International Nuclear Information System (INIS)

    Toh, Cheng-Hong; Wong, Alex M.-C; Wong, Ho-Fai; Wan, Yung-Liang; Wei, Kuo-Chen; Ng, Shu-Hang

    2007-01-01

    We prospectively compared the fractional anisotropy (FA) and mean diffusivity (MD) of the peritumoral edema of meningiomas and metastatic brain tumors with diffusion-tensor magnetic resonance (MR) imaging. The study protocol was approved by the local ethics committee, and written informed consent was obtained. Preoperative diffusion-tensor MR imaging was performed in 15 patients with meningiomas and 11 patients with metastatic brain tumors. Regions of interest (ROI) were placed in the peritumoral edema and normal-appearing white matter (NAWM) of the contralateral hemisphere to measure the FA and MD. The FA and MD ratios were calculated for each ROI in relation to the NAWM of the contralateral hemisphere. Changes in peritumoral MD and FA, in terms of primary values and ratios, were compared using a two-sample t-test; P -3 mm 2 /s) of the peritumoral edema for metastases and meningiomas, respectively, were 0.902 ± 0.057 and 0.820 ± 0.094, the mean MD ratios were 220.3 ± 22.6 and 193.1 ± 23.4, the mean FA values were 0.146 ± 0.026 and 0.199 ± 0.052, and the mean FA ratios were 32.3 ± 5.9 and 46.0 ± 12.1. All the values were significantly different between metastases and meningiomas (MD values P 0.016, MD ratios P = 0.006, FA values P = 0.005, FA ratios P = 0.002). The peritumoral edema of metastatic brain tumors and meningiomas show different MD and FA on diffusion-tensor MR imaging. (orig.)

  4. Peritumoral edema of meningiomas and metastatic brain tumors: differences in diffusion characteristics evaluated with diffusion-tensor MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toh, Cheng-Hong; Wong, Alex M.-C; Wong, Ho-Fai; Wan, Yung-Liang [Chang Gung Memorial Hospital, Department of Medical Imaging and Intervention, Tao-Yuan (China); Chang Gung University, School of Medicine and Medical Technology, Tao-Yuan (China); Wei, Kuo-Chen [Chang Gung Memorial Hospital, Department of Neurosurgery, Tao-Yuan (China); Chang Gung University, School of Medicine and Medical Technology, Tao-Yuan (China); Ng, Shu-Hang [Chang Gung Memorial Hospital, Department of Medical Imaging and Intervention, Tao-Yuan (China); Chang Gung University, School of Medicine and Medical Technology, Tao-Yuan (China); Chang Gung Memorial Hospital, Molecular Image Center, Tao-Yuan (China)

    2007-06-15

    We prospectively compared the fractional anisotropy (FA) and mean diffusivity (MD) of the peritumoral edema of meningiomas and metastatic brain tumors with diffusion-tensor magnetic resonance (MR) imaging. The study protocol was approved by the local ethics committee, and written informed consent was obtained. Preoperative diffusion-tensor MR imaging was performed in 15 patients with meningiomas and 11 patients with metastatic brain tumors. Regions of interest (ROI) were placed in the peritumoral edema and normal-appearing white matter (NAWM) of the contralateral hemisphere to measure the FA and MD. The FA and MD ratios were calculated for each ROI in relation to the NAWM of the contralateral hemisphere. Changes in peritumoral MD and FA, in terms of primary values and ratios, were compared using a two-sample t-test; P < 0.05 was taken as indicating statistical significance. The mean MD values (x 10{sup -3} mm{sup 2}/s) of the peritumoral edema for metastases and meningiomas, respectively, were 0.902 {+-} 0.057 and 0.820 {+-} 0.094, the mean MD ratios were 220.3 {+-} 22.6 and 193.1 {+-} 23.4, the mean FA values were 0.146 {+-} 0.026 and 0.199 {+-} 0.052, and the mean FA ratios were 32.3 {+-} 5.9 and 46.0 {+-} 12.1. All the values were significantly different between metastases and meningiomas (MD values P = 0.016, MD ratios P = 0.006, FA values P = 0.005, FA ratios P = 0.002). The peritumoral edema of metastatic brain tumors and meningiomas show different MD and FA on diffusion-tensor MR imaging. (orig.)

  5. Dust Density Distribution and Imaging Analysis of Different Ice Lines in Protoplanetary Disks

    Energy Technology Data Exchange (ETDEWEB)

    Pinilla, P. [Department of Astronomy/Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Pohl, A. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Stammler, S. M.; Birnstiel, T., E-mail: pinilla@email.arizona.edu [University Observatory, Faculty of Physics, Ludwig-Maximilians-Universität München, Scheinerstr. 1, D-81679 Münich (Germany)

    2017-08-10

    Recent high angular resolution observations of protoplanetary disks at different wavelengths have revealed several kinds of structures, including multiple bright and dark rings. Embedded planets are the most used explanation for such structures, but there are alternative models capable of shaping the dust in rings as it has been observed. We assume a disk around a Herbig star and investigate the effect that ice lines have on the dust evolution, following the growth, fragmentation, and dynamics of multiple dust size particles, covering from 1 μ m to 2 m sized objects. We use simplified prescriptions of the fragmentation velocity threshold, which is assumed to change radially at the location of one, two, or three ice lines. We assume changes at the radial location of main volatiles, specifically H{sub 2}O, CO{sub 2}, and NH{sub 3}. Radiative transfer calculations are done using the resulting dust density distributions in order to compare with current multiwavelength observations. We find that the structures in the dust density profiles and radial intensities at different wavelengths strongly depend on the disk viscosity. A clear gap of emission can be formed between ice lines and be surrounded by ring-like structures, in particular between the H{sub 2}O and CO{sub 2} (or CO). The gaps are expected to be shallower and narrower at millimeter emission than at near-infrared, opposite to model predictions of particle trapping. In our models, the total gas surface density is not expected to show strong variations, in contrast to other gap-forming scenarios such as embedded giant planets or radial variations of the disk viscosity.

  6. Comparison of different deep learning approaches for parotid gland segmentation from CT images

    Science.gov (United States)

    Hänsch, Annika; Schwier, Michael; Gass, Tobias; Morgas, Tomasz; Haas, Benjamin; Klein, Jan; Hahn, Horst K.

    2018-02-01

    The segmentation of target structures and organs at risk is a crucial and very time-consuming step in radiotherapy planning. Good automatic methods can significantly reduce the time clinicians have to spend on this task. Due to its variability in shape and often low contrast to surrounding structures, segmentation of the parotid gland is especially challenging. Motivated by the recent success of deep learning, we study different deep learning approaches for parotid gland segmentation. Particularly, we compare 2D, 2D ensemble and 3D U-Net approaches and find that the 2D U-Net ensemble yields the best results with a mean Dice score of 0.817 on our test data. The ensemble approach reduces false positives without the need for an automatic region of interest detection. We also apply our trained 2D U-Net ensemble to segment the test data of the 2015 MICCAI head and neck auto-segmentation challenge. With a mean Dice score of 0.861, our classifier exceeds the highest mean score in the challenge. This shows that the method generalizes well onto data from independent sites. Since appropriate reference annotations are essential for training but often difficult and expensive to obtain, it is important to know how many samples are needed to properly train a neural network. We evaluate the classifier performance after training with differently sized training sets (50-450) and find that 250 cases (without using extensive data augmentation) are sufficient to obtain good results with the 2D ensemble. Adding more samples does not significantly improve the Dice score of the segmentations.

  7. Signal-to-noise assessment for diffusion tensor imaging with single data set and validation using a difference image method with data from a multicenter study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhiyue J., E-mail: jerry.wang@childrens.com [Department of Radiology, Children' s Medical Center, Dallas, Texas 75235 and Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390 (United States); Chia, Jonathan M. [Clinical Science, Philips Healthcare, Cleveland, Ohio 44143 (United States); Ahmed, Shaheen; Rollins, Nancy K. [Department of Radiology, Children' s Medical Center, Dallas, TX 75235 and Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390 (United States)

    2014-09-15

    Purpose: To describe a quantitative method for determination of SNR that extracts the local noise level using a single diffusion data set. Methods: Brain data sets came from a multicenter study (eight sites; three MR vendors). Data acquisition protocol required b = 0, 700 s/mm{sup 2}, fov = 256 × 256 mm{sup 2}, acquisition matrix size 128 × 128, reconstruction matrix size 256 × 256; 30 gradient encoding directions and voxel size 2 × 2 × 2 mm{sup 3}. Regions-of-interest (ROI) were placed manually on the b = 0 image volume on transverse slices, and signal was recorded as the mean value of the ROI. The noise level from the ROI was evaluated using Fourier Transform based Butterworth high-pass filtering. Patients were divided into two groups, one for filter parameter optimization (N = 17) and one for validation (N = 10). Six white matter areas (the genu and splenium of corpus callosum, right and left centrum semiovale, right and left anterior corona radiata) were analyzed. The Bland–Altman method was used to compare the resulting SNR with that from the difference image method. The filter parameters were optimized for each brain area, and a set of “global” parameters was also obtained, which represent an average of all regions. Results: The Bland–Altman analysis on the validation group using “global” filter parameters revealed that the 95% limits of agreement of percent bias between the SNR obtained with the new and the reference methods were −15.5% (median of the lower limit, range [−24.1%, −8.9%]) and 14.5% (median of the higher limits, range [12.7%, 18.0%]) for the 6 brain areas. Conclusions: An FT-based high-pass filtering method can be used for local area SNR assessment using only one DTI data set. This method could be used to evaluate SNR for patient studies in a multicenter setting.

  8. Attentional biases toward emotional images in the different episodes of bipolar disorder: an eye-tracking study.

    Science.gov (United States)

    García-Blanco, Ana; Salmerón, Ladislao; Perea, Manuel; Livianos, Lorenzo

    2014-03-30

    Attentional biases toward emotional information may represent vulnerability and maintenance factors in bipolar disorder (BD). The present experimental study examined the processing of emotional information in BD patients using the eye-tracking technology. Bipolar patients in their different states (euthymia, mania, depression) simultaneously viewed four pictures with different emotional valence (happy, neutral, sad, threatening) for 20s while their eye movements were monitored. A group of healthy individuals served as the control. The data revealed the following: (i) a decrease in attention to happy images in BD patients in their depressive episodes compared to healthy individuals, and (ii) an increase in attention to threatening images in BD patients (regardless of their episode) relative to the healthy controls. These biases appeared in the late stages of information processing and were sustained over the 20s interval. Thus, the present findings reveal that attentional biases toward emotional information can be a key feature of BD, in that: (i) an anhedonic lack of sensitivity to positive stimuli during the bipolar depressive episode may be considered a maintaining factor of this clinical state, and (ii) the trait-bias toward threat, even in asymptomatic patients, may reflect a marker of vulnerability in BD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Differences in quantitative assessment of myocardial scar and gray zone by LGE-CMR imaging using established gray zone protocols.

    Science.gov (United States)

    Mesubi, Olurotimi; Ego-Osuala, Kelechi; Jeudy, Jean; Purtilo, James; Synowski, Stephen; Abutaleb, Ameer; Niekoop, Michelle; Abdulghani, Mohammed; Asoglu, Ramazan; See, Vincent; Saliaris, Anastasios; Shorofsky, Stephen; Dickfeld, Timm

    2015-02-01

    Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the gold standard for myocardial scar evaluation. Heterogeneous areas of scar ('gray zone'), may serve as arrhythmogenic substrate. Various gray zone protocols have been correlated to clinical outcomes and ventricular tachycardia channels. This study assessed the quantitative differences in gray zone and scar core sizes as defined by previously validated signal intensity (SI) threshold algorithms. High quality LGE-CMR images performed in 41 cardiomyopathy patients [ischemic (33) or non-ischemic (8)] were analyzed using previously validated SI threshold methods [Full Width at Half Maximum (FWHM), n-standard deviation (NSD) and modified-FWHM]. Myocardial scar was defined as scar core and gray zone using SI thresholds based on these methods. Scar core, gray zone and total scar sizes were then computed and compared among these models. The median gray zone mass was 2-3 times larger with FWHM (15 g, IQR: 8-26 g) compared to NSD or modified-FWHM (5 g, IQR: 3-9 g; and 8 g. IQR: 6-12 g respectively, p zone extent (percentage of total scar that was gray zone) also varied significantly among the three methods, 51 % (IQR: 42-61 %), 17 % (IQR: 11-21 %) versus 38 % (IQR: 33-43 %) for FWHM, NSD and modified-FWHM respectively (p zone and scar core. Infarct core and total myocardial scar mass also differ using these methods. Further evaluation of the most accurate quantification method is needed.

  10. Differences in Brand Image of Online Chat Application of Blackberry Messenger, Whatsapp, and Line for Bina Nusantara University’s Student

    OpenAIRE

    Kuspuji C. B. Wicaksono

    2016-01-01

    This article was written to find out whether there were any differences on brand image for each online chat Application such as Blackberry Messenger, Whatsapp, and LINE based on six factors of the brand image which are: benefits, attributes, cultures, values, personality, and user. Data for the research were collected from questionnaires given to respondents who had used each mention online chat application. Then each respondent was asked to give scores based on the six factors of brand image...

  11. Modeling susceptibility difference artifacts produced by metallic implants in magnetic resonance imaging with point-based thin-plate spline image registration.

    Science.gov (United States)

    Pauchard, Y; Smith, M; Mintchev, M

    2004-01-01

    Magnetic resonance imaging (MRI) suffers from geometric distortions arising from various sources. One such source are the non-linearities associated with the presence of metallic implants, which can profoundly distort the obtained images. These non-linearities result in pixel shifts and intensity changes in the vicinity of the implant, often precluding any meaningful assessment of the entire image. This paper presents a method for correcting these distortions based on non-rigid image registration techniques. Two images from a modelled three-dimensional (3D) grid phantom were subjected to point-based thin-plate spline registration. The reference image (without distortions) was obtained from a grid model including a spherical implant, and the corresponding test image containing the distortions was obtained using previously reported technique for spatial modelling of magnetic susceptibility artifacts. After identifying the nonrecoverable area in the distorted image, the calculated spline model was able to quantitatively account for the distortions, thus facilitating their compensation. Upon the completion of the compensation procedure, the non-recoverable area was removed from the reference image and the latter was compared to the compensated image. Quantitative assessment of the goodness of the proposed compensation technique is presented.

  12. Development of Yellow Sand Image Products Using Infrared Brightness Temperature Difference Method

    Science.gov (United States)

    Ha, J.; Kim, J.; Kwak, M.; Ha, K.

    2007-12-01

    A technique for detection of airborne yellow sand dust using meteorological satellite has been developed from various bands from ultraviolet to infrared channels. Among them, Infrared (IR) channels have an advantage of detecting aerosols over high reflecting surface as well as during nighttime. There had been suggestion of using brightness temperature difference (BTD) between 11 and 12¥ìm. We have found that the technique is highly depends on surface temperature, emissivity, and zenith angle, which results in changing the threshold of BTD. In order to overcome these problems, we have constructed the background brightness temperature threshold of BTD and then aerosol index (AI) has been determined from subtracting the background threshold from BTD of our interested scene. Along with this, we utilized high temporal coverage of geostationary satellite, MTSAT, to improve the reliability of the determined AI signal. The products have been evaluated by comparing the forecasted wind field with the movement fiend of AI. The statistical score test illustrates that this newly developed algorithm produces a promising result for detecting mineral dust by reducing the errors with respect to the current BTD method.

  13. Ocular Image and Haemodynamic Features Associated with Different Gradings of Ipsilateral Internal Carotid Artery Stenosis

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2017-01-01

    Full Text Available Objectives. To analyse the changes of ocular haemodynamics and morphology in Chinese patients with internal carotid artery (ICA stenosis in the current study. Methods. A retrospective case-control study was conducted with 219 patients. The haemodynamic characteristics, the calibre of retinal vessels, and the subfoveal choroidal thickness (SFChT were compared. We analysed the correlations with the degree of ipsilateral ICA stenosis. Results. There were no significant differences among the groups in the central retinal artery equivalent (CRAE, central retinal vein equivalent (CRVE, and AVR (p=0.073, p=0.188, and p=0.738, resp.. The peak systolic velocity (PSV and end diastolic velocity (EDV in the central retinal artery (CRA and the posterior ciliary artery (PCA were significantly lower than normal eyes (p<0.001. The outer retinal layer thickness and SFChT values of the ICA stenosis groups were significantly lower than normal eyes (p=0.030 and p<0.001, resp.. Conclusion. The PSV and EDV in CRA and PCA and the SFChT and outer retinal layer thickness of ICA eyes were significantly lower than normal eyes. ICA stenosis may impact choroidal haemodynamics, and decreased choroidal circulation might affect the discordance of the SFChT and the outer retinal layer thickness.

  14. Analysis of different image-based biofeedback models for improving cycling performances

    Science.gov (United States)

    Bibbo, D.; Conforto, S.; Bernabucci, I.; Carli, M.; Schmid, M.; D'Alessio, T.

    2012-03-01

    Sport practice can take advantage from the quantitative assessment of task execution, which is strictly connected to the implementation of optimized training procedures. To this aim, it is interesting to explore the effectiveness of biofeedback training techniques. This implies a complete chain for information extraction containing instrumented devices, processing algorithms and graphical user interfaces (GUIs) to extract valuable information (i.e. kinematics, dynamics, and electrophysiology) to be presented in real-time to the athlete. In cycling, performance indexes displayed in a simple and perceivable way can help the cyclist optimize the pedaling. To this purpose, in this study four different GUIs have been designed and used in order to understand if and how a graphical biofeedback can influence the cycling performance. In particular, information related to the mechanical efficiency of pedaling is represented in each of the designed interfaces and then displayed to the user. This index is real-time calculated on the basis of the force signals exerted on the pedals during cycling. Instrumented pedals for bikes, already designed and implemented in our laboratory, have been used to measure those force components. A group of subjects underwent an experimental protocol and pedaled with (the interfaces have been used in a randomized order) and without graphical biofeedback. Preliminary results show how the effective perception of the biofeedback influences the motor performance.

  15. Imaging of 3-D seismic velocity structure of Southern Sumatra region using double difference tomographic method

    Energy Technology Data Exchange (ETDEWEB)

    Lestari, Titik, E-mail: t2klestari@gmail.com [Meteorological Climatological and Geophysical Agency (MCGA), Jalan Angkasa I No.2 Kemayoran, Jakarta Pusat, 10720 (Indonesia); Faculty of Earth Science and Technology, Bandung Institute of Technology, Jalan Ganesa No.10, Bandung 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Bandung Institute of Technology, Jalan Ganesa 10 Bandung 40132 (Indonesia)

    2015-04-24

    Southern Sumatra region has a high level of seismicity due to the influence of the subduction system, Sumatra fault, Mentawai fault and stretching zone activities. The seismic activities of Southern Sumatra region are recorded by Meteorological Climatological and Geophysical Agency (MCGA’s) Seismograph network. In this study, we used earthquake data catalog compiled by MCGA for 3013 events from 10 seismic stations around Southern Sumatra region for time periods of April 2009 – April 2014 in order to invert for the 3-D seismic velocities structure (Vp, Vs, and Vp/Vs ratio). We applied double-difference seismic tomography method (tomoDD) to determine Vp, Vs and Vp/Vs ratio with hypocenter adjustment. For the inversion procedure, we started from the initial 1-D seismic velocity model of AK135 and constant Vp/Vs of 1.73. The synthetic travel time from source to receiver was calculated using ray pseudo-bending technique, while the main tomographic inversion was applied using LSQR method. The resolution model was evaluated using checkerboard test and Derivative Weigh Sum (DWS). Our preliminary results show low Vp and Vs anomalies region along Bukit Barisan which is may be associated with weak zone of Sumatran fault and migration of partial melted material. Low velocity anomalies at 30-50 km depth in the fore arc region may indicated the hydrous material circulation because the slab dehydration. We detected low seismic seismicity in the fore arc region that may be indicated as seismic gap. It is coincides contact zone of high and low velocity anomalies. And two large earthquakes (Jambi and Mentawai) also occurred at the contact of contrast velocity.

  16. Imaging Differences between Neuromyelitis Optica Spectrum Disorders and Multiple Sclerosis: A Multi-Institutional Study in Japan.

    Science.gov (United States)

    Tatekawa, H; Sakamoto, S; Hori, M; Kaichi, Y; Kunimatsu, A; Akazawa, K; Miyasaka, T; Oba, H; Okubo, T; Hasuo, K; Yamada, K; Taoka, T; Doishita, S; Shimono, T; Miki, Y

    2018-05-03

    Both clinical and imaging criteria must be met to diagnose neuromyelitis optica spectrum disorders and multiple sclerosis. However, neuromyelitis optica spectrum disorders are often misdiagnosed as MS because of an overlap in MR imaging features. The purpose of this study was to confirm imaging differences between neuromyelitis optica spectrum disorders and MS with visually detailed quantitative analyses of large-sample data. We retrospectively examined 89 consecutive patients with neuromyelitis optica spectrum disorders (median age, 51 years; range, 16-85 years; females, 77; aquaporin 4 immunoglobulin G-positive, 93%) and 89 with MS (median age, 36 years; range, 18-67 years; females, 68; relapsing-remitting MS, 89%; primary-progressive MS, 7%; secondary-progressive MS, 2%) from 9 institutions across Japan (April 2008 to December 2012). Two neuroradiologists visually evaluated the number, location, and size of all lesions using the Mann-Whitney U test or the Fisher exact test. We enrolled 79 patients with neuromyelitis optica spectrum disorders and 87 with MS for brain analysis, 57 with neuromyelitis optica spectrum disorders and 55 with MS for spinal cord analysis, and 42 with neuromyelitis optica spectrum disorders and 14 with MS for optic nerve analysis. We identified 911 brain lesions in neuromyelitis optica spectrum disorders, 1659 brain lesions in MS, 86 spinal cord lesions in neuromyelitis optica spectrum disorders, and 102 spinal cord lesions in MS. The frequencies of periventricular white matter and deep white matter lesions were 17% and 68% in neuromyelitis optica spectrum disorders versus 41% and 42% in MS, respectively (location of brain lesions, P optica spectrum disorders (cervical versus thoracic, 29% versus 71%), whereas they were equally distributed in MS (46% versus 54%). Furthermore, thoracic lesions were significantly longer than cervical lesions in neuromyelitis optica spectrum disorders ( P = .001), but not in MS ( P = .80). Visually detailed

  17. Gender differences in knee joint cartilage thickness, volume and articular surface areas: assessment with quantitative three-dimensional MR imaging

    International Nuclear Information System (INIS)

    Faber, S.C.; Reiser, M.; Englmeier, K.H.

    2001-01-01

    Objective: To compare the cartilage thickness, volume, and articular surface areas of the knee joint between young healthy, non-athletic female and male individuals. Subjects and design. MR imaging was performed in 18 healthy subjects without local or systemic joints disease (9 female, age 22.3±2.4 years, and 9 male, age 22.2.±1.9 years), using a fat-suppressed FLASH 3D pulse sequence (TR=41 ms, TE=11 ms, FA=30 ) with sagittal orientation and a spatial resolution of 2x0.31x0.31 mm 3 . After three-dimensional reconstruction and triangulation of the knee joint cartilage plates, the cartilage thickness (mean and maximal), volume, and size of the articular surface area were quantified, independent of the original section orientation. Results and conclusions: Women displayed smaller cartilage volumes than men, the percentage difference ranging from 19.9% in the patella, to 46.6% in the medial tibia. The gender differences of the cartilage thickness were smaller, ranging from 2.0% in the femoral trochlea to 13.3% in the medial tibia for the mean thickness, and from 4.3% in the medial femoral condyle to 18.3% in the medial tibia for the maximal cartilage thickness. The differences between the cartilage surface areas were similar to those of the volumes, with values ranging from 21.0% in the femur to 33.4% in the lateral tibia. Gender differences could be reduced for cartilage volume and surface area when normalized to body weight and body weight x body height. The study demonstrates significant gender differences in cartilage volume and surface area of men and women, which need to be taken into account when retrospectively estimating articular cartilage loss in patients with symptoms of degenerative joint disease. Differences in cartilage volume are primarily due to differences in joint surface areas (epiphyseal bone size), not to differences in cartilage thickness. (orig.)

  18. No Difference on Quantitative Magnetic Resonance Imaging in Patellofemoral Cartilage Composition Between Patients With Patellofemoral Pain and Healthy Controls.

    Science.gov (United States)

    van der Heijden, Rianne A; Oei, Edwin H G; Bron, Esther E; van Tiel, Jasper; van Veldhoven, Peter L J; Klein, Stefan; Verhaar, Jan A N; Krestin, Gabriel P; Bierma-Zeinstra, Sita M A; van Middelkoop, Marienke

    2016-05-01

    Retropatellar cartilage damage has been suggested as an etiological factor for patellofemoral pain (PFP), a common knee condition among young and physically active individuals. To date, there is no conclusive evidence for an association between cartilage defects and PFP. Nowadays, advanced quantitative magnetic resonance imaging (MRI) techniques enable estimation of cartilage composition. To investigate differences in patellofemoral cartilage composition between patients with PFP and healthy control subjects using quantitative MRI. Cross-sectional study; Level of evidence, 3. Patients with PFP and healthy control subjects underwent 3.0-T MRI including delayed gadolinium-enhanced MRI of cartilage and T1ρ and T2 mapping. Differences in relaxation times of patellofemoral cartilage were compared between groups by linear regression analyses, adjusted for age, body mass index, sex, sports participation, and time of image acquisition. This case-control study included 64 patients and 70 controls. The mean (±SD) age was 23.2 ± 6.4 years and the mean body mass index was 22.9 ± 3.4 kg/m(2); 56.7% were female. For delayed gadolinium-enhanced MRI of cartilage, the mean T1GD relaxation times of patellar (657.8 vs 669.4 ms) and femoral cartilage (661.6 vs 659.8 ms) did not significantly differ between patients and controls. In addition, no significant difference was found in mean T1ρ relaxation times of patellar (46.9 vs 46.0 ms) and femoral cartilage (50.8 vs 50.2 ms) and mean T2 relaxation times of patellar (33.2 vs 32.9 ms) and femoral cartilage (36.7 vs 36.6 ms) between patients and controls. Analysis of prespecified medial and lateral subregions within the patellofemoral cartilage also revealed no significant differences. There was no difference in composition of the patellofemoral cartilage, estimated with multiple quantitative MRI techniques, between patients with PFP and healthy control subjects. However, clinically relevant differences could not be ruled out for T1

  19. Multi-frequency time-difference complex conductivity imaging of canine and human lungs using the KHU Mark1 EIT system

    International Nuclear Information System (INIS)

    Kuen, Jihyeon; Woo, Eung Je; Seo, Jin Keun

    2009-01-01

    We evaluated the performance of the lately developed electrical impedance tomography (EIT) system KHU Mark1 through time-difference imaging experiments of canine and human lungs. We derived a multi-frequency time-difference EIT (mftdEIT) image reconstruction algorithm based on the concept of the equivalent homogeneous complex conductivity. Imaging experiments were carried out at three different frequencies of 10, 50 and 100 kHz with three different postures of right lateral, sitting (or prone) and left lateral positions. For three normal canine subjects, we controlled the ventilation using a ventilator at three tidal volumes of 100, 150 and 200 ml. Three human subjects were asked to breath spontaneously at a normal tidal volume. Real- and imaginary-part images of the canine and human lungs were reconstructed at three frequencies and three postures. Images showed different stages of breathing cycles and we could interpret them based on the understanding of the proposed mftdEIT image reconstruction algorithm. Time series of images were further analyzed by using the functional EIT (fEIT) method. Images of human subjects showed the gravity effect on air distribution in two lungs. In the canine subjects, the morphological change seems to dominate the gravity effect. We could also observe that two different types of ventilation should have affected the results. The KHU Mark1 EIT system is expected to provide reliable mftdEIT images of the human lungs. In terms of the image reconstruction algorithm, it would be worthwhile including the effects of three-dimensional current flows inside the human thorax. We suggest clinical trials of the KHU Mark1 for pulmonary applications

  20. Multi-frequency time-difference complex conductivity imaging of canine and human lungs using the KHU Mark1 EIT system.

    Science.gov (United States)

    Kuen, Jihyeon; Woo, Eung Je; Seo, Jin Keun

    2009-06-01

    We evaluated the performance of the lately developed electrical impedance tomography (EIT) system KHU Mark1 through time-difference imaging experiments of canine and human lungs. We derived a multi-frequency time-difference EIT (mftdEIT) image reconstruction algorithm based on the concept of the equivalent homogeneous complex conductivity. Imaging experiments were carried out at three different frequencies of 10, 50 and 100 kHz with three different postures of right lateral, sitting (or prone) and left lateral positions. For three normal canine subjects, we controlled the ventilation using a ventilator at three tidal volumes of 100, 150 and 200 ml. Three human subjects were asked to breath spontaneously at a normal tidal volume. Real- and imaginary-part images of the canine and human lungs were reconstructed at three frequencies and three postures. Images showed different stages of breathing cycles and we could interpret them based on the understanding of the proposed mftdEIT image reconstruction algorithm. Time series of images were further analyzed by using the functional EIT (fEIT) method. Images of human subjects showed the gravity effect on air distribution in two lungs. In the canine subjects, the morphological change seems to dominate the gravity effect. We could also observe that two different types of ventilation should have affected the results. The KHU Mark1 EIT system is expected to provide reliable mftdEIT images of the human lungs. In terms of the image reconstruction algorithm, it would be worthwhile including the effects of three-dimensional current flows inside the human thorax. We suggest clinical trials of the KHU Mark1 for pulmonary applications.

  1. Loss of surface horizon of an irrigated soil detected by radiometric images of normalized difference vegetation index.

    Science.gov (United States)

    Fabian Sallesses, Leonardo; Aparicio, Virginia Carolina; Costa, Jose Luis

    2017-04-01

    The use of the soil in the Humid Pampa of Argentina has changed since the mid-1990s from agricultural-livestock production (that included pastures with direct grazing) to a purely agricultural production. Also, in recent years the area under irrigation by central pivot has been increased to 150%. The waters used for irrigation are sodium carbonates. The combination of irrigation and rain increases the sodium absorption ratio of soil (SARs), consequently raising the clay dispersion and reducing infiltration. This implies an increased risk of soil loss. A reduction in the development of white clover crop (Trifolium repens L.) was observed at an irrigation plot during 2015 campaign. The clover was planted in order to reduce the impact of two maize (Zea mays L.) campaigns under irrigation, which had increased soil SAR and deteriorated soil structure. SPOT-5 radiometric normalized difference vegetation index (NDVI) images were used to determine two zones of high and low production. In each zone, four random points were selected for further geo-referenced field sampling. Two geo-referenced measures of effective depth and surface soil sampling were carried out in each point. Texture of soil samples was determined by Pipette Method of Sedimentation Analysis. Data exploratory analysis showed that low production zone had a media effective depth = 80 cm and silty clay loam texture, while high production zone had a media effective depth > 140 cm and silt loam texture. The texture class of the low production zone did not correspond to prior soil studies carried out by the INTA (National Institute of Agricultural Technology), which showed that those soil textures were silt loam at surface and silty clay loam at sub-surface. The loss of the A horizon is proposed as a possible explanation, but further research is required. Besides, the need of a soil cartography actualization, which integrates new satellite imaging technologies and geo-referenced measurements with soil sensors is

  2. Reliability of semiquantitative assessment of osteophytes and subchondral cysts on tomosynthesis images by radiologists with different levels of expertise.

    Science.gov (United States)

    Hayashi, Daichi; Xu, Li; Gusenburg, Jeffrey; Roemer, Frank W; Hunter, David J; Li, Ling; Guermazi, Ali

    2014-01-01

    We aimed to assess reliability of the evaluation of osteophytes and subchondral cysts on tomosynthesis images when read by radiologists with different levels of expertise. Forty subjects aged >40 years had both knees evaluated using tomosynthesis. Images were read by an "experienced" reader (musculoskeletal radiologist with prior experience) and an "inexperienced" reader (radiology resident with no prior experience). Readers graded osteophytes from 0 to 3 and noted the presence/absence of subchondral cysts in four locations of the tibiofemoral joint. Twenty knees were randomly selected and re-read. Inter- and intrareader reliabilities were calculated using overall exact percent agreement and weighted κ statistics. Diagnostic performance of the two readers was compared against magnetic resonance imaging readings by an expert reader (professor of musculoskeletal radiology). The experienced reader showed substantial intrareader reliability for graded reading of osteophytes (90%, κ=0.93), osteophyte detection (95%, κ=0.86) and cyst detection (95%, κ=0.83). The inexperienced reader showed perfect intrareader reliability for cyst detection (100%, κ=1.00) but intrareader reliability for graded reading (75%, κ=0.79) and detection (80%, κ=0.61) of osteophytes was lower than the experienced reader. Inter-reader reliability was 61% (κ=0.72) for graded osteophyte reading, 91% (κ=0.82) for osteophyte detection, and 88% (κ=0.66) for cyst detection. Diagnostic performance of the experienced reader was higher than the inexperienced reader regarding osteophyte detection (sensitivity range 0.74-0.95 vs. 0.54-0.75 for all locations) but diagnostic performance was similar for subchondral cysts. Tomosynthesis offers excellent intrareader reliability regardless of the reader experience, but experience is important for detection of osteophytes.

  3. Identification of imaging biomarkers for the assessment of tumour response to different treatments in a preclinical glioma model

    International Nuclear Information System (INIS)

    Lo Dico, A.; Martelli, C.; Valtorta, S.; Belloli, S.; Raccagni, I.; Moresco, R.M.; Diceglie, C.; Gianelli, U.; Bosari, S.; Vaira, V.; Politi, L.S.; Lucignani, G.; Ottobrini, L.

    2015-01-01

    Hypoxia-inducible factor 1α (HIF-1α) activity is one of the major players in hypoxia-mediated glioma progression and resistance to therapies, and therefore the focus of this study was the evaluation of HIF-1α modulation in relation to tumour response with the purpose of identifying imaging biomarkers able to document tumour response to treatment in a murine glioma model. U251-HRE-mCherry cells expressing Luciferase under the control of a hypoxia responsive element (HRE) and mCherry under the control of a constitutive promoter were used to assess HIF-1α activity and cell survival after treatment, both in vitro and in vivo, by optical, MRI and positron emission tomography imaging. This cell model can be used to monitor HIF-1α activity after treatment with different drugs modulating transduction pathways involved in its regulation. After temozolomide (TMZ) treatment, HIF-1α activity is early reduced, preceding cell cytotoxicity. Optical imaging allowed monitoring of this process in vivo, and carbonic anhydrase IX (CAIX) expression was identified as a translatable non-invasive biomarker with potential clinical significance. A preliminary in vitro evaluation showed that reduction of HIF-1α activity after TMZ treatment was comparable to the effect of an Hsp90 inhibitor, opening the way for further elucidation of its mechanism of action. The results of this study suggest that the U251-HRE-mCherry cell model can be used for the monitoring of HIF-1α activity through luciferase and CAIX expression. These cells can become a useful tool for the assessment and improvement of new targeted tracers for potential theranostic procedures. (orig.)

  4. Identification of imaging biomarkers for the assessment of tumour response to different treatments in a preclinical glioma model

    Energy Technology Data Exchange (ETDEWEB)

    Lo Dico, A.; Martelli, C. [University of Milan, Department of Pathophysiology and Transplantation, Milan (Italy); University of Milan, Centre of Molecular and Cellular Imaging-IMAGO, Milan (Italy); Valtorta, S.; Belloli, S. [National Researches Council (CNR), Institute of Molecular Bioimaging and Physiology (IBFM), Segrate, MI (Italy); IRCCS San Raffaele Scientific Institute, Experimental Imaging Center, Milan (Italy); Raccagni, I.; Moresco, R.M. [IRCCS San Raffaele Scientific Institute, Experimental Imaging Center, Milan (Italy); University of Milano-Bicocca, Department of Health Sciences, Monza (Italy); Diceglie, C. [University of Milan, Department of Pathophysiology and Transplantation, Milan (Italy); University of Milan, Doctorate School of Molecular Medicine, Milan (Italy); Gianelli, U.; Bosari, S. [University of Milan, Department of Pathophysiology and Transplantation, Milan (Italy); Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Division of Pathology, Milan (Italy); Vaira, V. [Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Division of Pathology, Milan (Italy); Istituto Nazionale Genetica Molecolare ' ' Romeo ed Enrica Invernizzi' ' (INGM), Milan (Italy); Politi, L.S. [IRCCS San Raffaele Scientific Institute, Neuroradiology Department and Neuroradiology Research Group, Milan (Italy); Lucignani, G. [University of Milan, Centre of Molecular and Cellular Imaging-IMAGO, Milan (Italy); University of Milan, Department of Health Sciences, Milan (Italy); San Paolo Hospital, Department of Diagnostic Services, Unit of Nuclear Medicine, Milan (Italy); Ottobrini, L. [University of Milan, Department of Pathophysiology and Transplantation, Milan (Italy); University of Milan, Centre of Molecular and Cellular Imaging-IMAGO, Milan (Italy); National Researches Council (CNR), Institute of Molecular Bioimaging and Physiology (IBFM), Segrate, MI (Italy)

    2015-03-27

    Hypoxia-inducible factor 1α (HIF-1α) activity is one of the major players in hypoxia-mediated glioma progression and resistance to therapies, and therefore the focus of this study was the evaluation of HIF-1α modulation in relation to tumour response with the purpose of identifying imaging biomarkers able to document tumour response to treatment in a murine glioma model. U251-HRE-mCherry cells expressing Luciferase under the control of a hypoxia responsive element (HRE) and mCherry under the control of a constitutive promoter were used to assess HIF-1α activity and cell survival after treatment, both in vitro and in vivo, by optical, MRI and positron emission tomography imaging. This cell model can be used to monitor HIF-1α activity after treatment with different drugs modulating transduction pathways involved in its regulation. After temozolomide (TMZ) treatment, HIF-1α activity is early reduced, preceding cell cytotoxicity. Optical imaging allowed monitoring of this process in vivo, and carbonic anhydrase IX (CAIX) expression was identified as a translatable non-invasive biomarker with potential clinical significance. A preliminary in vitro evaluation showed that reduction of HIF-1α activity after TMZ treatment was comparable to the effect of an Hsp90 inhibitor, opening the way for further elucidation of its mechanism of action. The results of this study suggest that the U251-HRE-mCherry cell model can be used for the monitoring of HIF-1α activity through luciferase and CAIX expression. These cells can become a useful tool for the assessment and improvement of new targeted tracers for potential theranostic procedures. (orig.)

  5. The Analysis of Burrows Recognition Accuracy in XINJIANG'S Pasture Area Based on Uav Visible Images with Different Spatial Resolution

    Science.gov (United States)

    Sun, D.; Zheng, J. H.; Ma, T.; Chen, J. J.; Li, X.

    2018-04-01

    The rodent disaster is one of the main biological disasters in grassland in northern Xinjiang. The eating and digging behaviors will cause the destruction of ground vegetation, which seriously affected the development of animal husbandry and grassland ecological security. UAV low altitude remote sensing, as an emerging technique with high spatial resolution, can effectively recognize the burrows. However, how to select the appropriate spatial resolution to monitor the calamity of the rodent disaster is the first problem we need to pay attention to. The purpose of this study is to explore the optimal spatial scale on identification of the burrows by evaluating the impact of different spatial resolution for the burrows identification accuracy. In this study, we shoot burrows from different flight heights to obtain visible images of different spatial resolution. Then an object-oriented method is used to identify the caves, and we also evaluate the accuracy of the classification. We found that the highest classification accuracy of holes, the average has reached more than 80 %. At the altitude of 24 m and the spatial resolution of 1cm, the accuracy of the classification is the highest We have created a unique and effective way to identify burrows by using UAVs visible images. We draw the following conclusion: the best spatial resolution of burrows recognition is 1 cm using DJI PHANTOM-3 UAV, and the improvement of spatial resolution does not necessarily lead to the improvement of classification accuracy. This study lays the foundation for future research and can be extended to similar studies elsewhere.

  6. Use of different simulators to quality evaluation of image quality in digital mammography; Utilizacao de diferentes simuladores na avaliacao da qualidade da imagem em mamografia digital

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Leslie S.; Coutinho, Celia M.C., E-mail: leslie@ird.gov.br, E-mail: celia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Magalhaes, Luis A.G.; Almeida, Carlos Eduardo de, E-mail: luisalexandregm@hotmail.com, E-mail: cea71@yahoo.com.br [Universidade do Estado do Rio de Janeiro (LCR/UERJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Ciencias Radiologicas

    2013-11-01

    In this study, the digital images were acquired with different exposure simulators to evaluate the quality of the image, noting the tumor mass detection, microcalcification fiber and representing regions of interest during mammography. The technical parameters of exposure depends on the thickness and composition of the breast, thus affecting the dose and image quality. The simulators were used: ACR, SBP 1054, BREAST PHANTOM CIRS and for evaluation of image quality, as well as measures kerma incident on the entrance surface (Ki) and calculating the mean glandular dose (MGD)

  7. Association between different phases of menstrual cycle and body image measures of perceived size, ideal size, and body dissatisfaction.

    Science.gov (United States)

    Teixeira, André Luiz S; Dias, Marcelo Ricardo C; Damasceno, Vinícius O; Lamounier, Joel A; Gardner, Rick M

    2013-12-01

    The association between phases of the menstrual cycle and body image was investigated. 44 university women (M age = 23.3 yr., SD = 4.7) judged their perceived and ideal body size, and body dissatisfaction was calculated at each phase of the menstrual cycle, including premenstrual, menstrual, and intermenstrual. Participants selected one of nine figural drawings ranging from very thin to obese that represented their perceived size and ideal size. Body dissatisfaction was measured as the absolute difference between scores on perceived and ideal figural drawings. During each menstrual phase, anthropometric measures of weight, height, body mass index, circumference of waist and abdomen, and body composition were taken. There were no significant differences in any anthropometric measures between the three menstrual cycle phases. Perceived body size and body dissatisfaction were significantly different between menstrual phases, with the largest perceived body size and highest body dissatisfaction occurring during the menstrual phase. Ideal body size did not differ between menstrual phases, although participants desired a significantly smaller ideal size as compared to the perceived size.

  8. Different localization patterns of anthocyanin species in the pericarp of black rice revealed by imaging mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Yukihiro Yoshimura

    Full Text Available Black rice (Oryza sativa L. Japonica contains high levels of anthocyanins in the pericarp and is considered an effective health-promoting food. Several studies have identified the molecular species of anthocyanins in black rice, but information about the localization of each anthocyanin species is limited because methodologies for investigating the localization such as determining specific antibodies to anthocyanin, have not yet been developed Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS is a suitable tool for investigating the localization of metabolites. In this study, we identified 7 species of anthocyanin monoglycosides and 2 species of anthocyanin diglycosides in crude extracts from black rice by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS analysis. We also analyzed black rice sections by MALDI-IMS and found 2 additional species of anthocyanin pentosides and revealed different localization patterns of anthocyanin species composed of different sugar moieties. Anthocyanin species composed of a pentose moiety (cyanidin-3-O-pentoside and petunidin-3-O-pentoside were localized in the entire pericarp, whereas anthocyanin species composed of a hexose moiety (cyanidin-3-O-hexoside and peonidin-3-O-hexoside were focally localized in the dorsal pericarp. These results indicate that anthocyanin species composed of different sugar moieties exhibit different localization patterns in the pericarp of black rice. This is the first detailed investigation into the localization of molecular species of anthocyanins by MALDI-IMS.

  9. DSA-guided embolization in establishing different canine spinal cord ischemia models and relevant diffusion-weighted imaging study

    International Nuclear Information System (INIS)

    Zhang Jingsong; Sun Lijun; Huan Yi; He Hongde; Zhang Xuexin; Zhao Haitao; Zhang Jing; Zhang Xijing

    2006-01-01

    Objective: To evaluate DSA-guided embolization in establishing different spinal cord ischemia models of canine and relevant diffusion-weighted imaging (DWI) application. Methods: Nine canines were randomly divided into three groups with different matching of lipiodol and diatrizoate meglumine which were injected into bilateral intercostal arteries at 9-11 level guided by DSA monitor. Then observe the changes of motor function and pathologic findings, especially perform routine MRI and DWI by a 1.5 T MR system. Results: Except one case, 8 embolization models were established successfully. Among three groups, slight-group got slight injury and muscle power was about 3-5 grade and range of injury was about two vertebra distance; medium-group presented obvious paraplegia and muscle power was 0-1 grade and range of injury was between 3-4 vertebra distance; severe-group showed greater severity and larger range of injury. All lesions presented high signals at routine MRI and DWI. Conclusion: Using different matching of lipiodol and diatrizoate meglumine can establish different spinal cord ischemia models of canine by DSA- guided embolization and DWI can be performed successfully by 1.5 T MR system, which may be a good method for advanced study of spinal cord ischemia. (authors)

  10. In vitro imaging of coronary artery stents: Are there differences between 16- and 64-slice CT scanners?

    International Nuclear Information System (INIS)

    Wolf, Florian; Feuchtner, Gudrun M.; Homolka, Peter; Langenberger, Herbert; Stadler, Alfred; Bader, Till R.; Weber, Michael; Lammer, Johannes; Loewe, Christian

    2008-01-01

    Purpose: To compare the performance of 64-slice with 16-slice CT scanners for the in vitro evaluation of coronary artery stents. Methods and materials: Twelve different coronary artery stents were placed in the drillings of a combined heart and chest phantom, which was scanned with a 16- and 64-slice CT scanner. Coronal reformations were evaluated for artificial lumen narrowing, intraluminal attenuation values, and false widening of the outer stent diameter as an indicator of artifacts outside the stent. Results: Mean artificial lumen narrowing was not significantly different between the 16- and 64-slice CT scanner (44% versus 39%; p = 0.408). The differences between the Hounsfield Units (HU) measurements inside and outside the stents were significantly lower (p = 0.001) with 64- compared to 16-slice CT. The standard deviation of the HU measurements inside the stents was significantly (p = 0.002) lower with 64- than with 16-slice CT. Artifacts outside the stents were not significantly different between the scanners (p = 0.866). Conclusion: Visualization of the in-stent lumen is improved with 64-slice CT when compared with 16-slice CT as quantified by significantly lesser intraluminal image noise and less artificial rise in intraluminal HU measurement, which is the most important parameter for the evaluation of stent patency in vivo

  11. SU-F-I-58: Image Quality Comparisons of Different Motion Magnitudes and TR Values in MR-PET

    International Nuclear Information System (INIS)

    Patrick, J; Thompson, R; Tavallaei, M; Drangova, M; Stodilka, R; Gaede, S

    2016-01-01

    Purpose: The aim of this work is to evaluate the accuracy and sensitivity of a respiratory-triggered MR-PET protocol in detecting four different sized lesions at two different magnitudes of motion, with two different TR values, using a novel PET-MR-CT compatible respiratory motion phantom. Methods: The eight-compartment torso phantom was setup adjacent to the motion stage, which moved four spherical compartments (28, 22, 17, 10 mm diameter) in two separate (1 and 2 cm) linear motion profiles, simulating a 3.5 second respiratory cycle. Scans were acquired on a 3T MR-PET system (Biograph mMR; Siemens Medical Solutions, Germany). MR measurements were taken with: 1) Respiratory-triggered T2-weighted turbo spin echo (BLADE) sequence in coronal orientation, and 2) Real-time balanced steady-state gradient echo sequence (TrueFISP) in coronal and sagittal planes. PET was acquired simultaneously with MR. Sphere geometries and motion profiles were measured and compared with ground truths for T2 BLADE-TSE acquisitions and real time TrueFISP images. PET quantification and geometry measurements were taken using standardized uptake values, voxel intensity plots and were compared with known values, and examined alongside MR-based attenuation maps. Contrast and signal-to-noise ratios were also compared for each of the acquisitions as functions of motion range and TR. Results: Comparison of lesion diameters indicate the respiratory triggered T2 BLADE-TSE was able to maintain geometry within −2 mm for 1 cm motion for both TR values, and within −3.1 mm for TR = 2000 ms at 2 cm motion. Sphere measurements in respiratory triggered PET images were accurate within +/− 5 mm for both ranges of motion for 28, 22, and 17 mm diameter spheres. Conclusion: Hybrid MR-PET systems show promise in imaging lung cancer in non-compliant patients, with their ability to acquire both modalities simultaneously. However, MR-based attenuation maps are still susceptible to motion derived artifacts and

  12. SU-F-I-58: Image Quality Comparisons of Different Motion Magnitudes and TR Values in MR-PET

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, J; Thompson, R [Lawson Health Research Institute, London, Ontario (Canada); Tavallaei, M; Drangova, M [Robarts Research Institute, London, Canada, London, Ontario (Canada); Stodilka, R [Western University, Canada, London, Ontario (Canada); Gaede, S [London Regional Cancer Program, London, Ontario (Canada)

    2016-06-15

    Purpose: The aim of this work is to evaluate the accuracy and sensitivity of a respiratory-triggered MR-PET protocol in detecting four different sized lesions at two different magnitudes of motion, with two different TR values, using a novel PET-MR-CT compatible respiratory motion phantom. Methods: The eight-compartment torso phantom was setup adjacent to the motion stage, which moved four spherical compartments (28, 22, 17, 10 mm diameter) in two separate (1 and 2 cm) linear motion profiles, simulating a 3.5 second respiratory cycle. Scans were acquired on a 3T MR-PET system (Biograph mMR; Siemens Medical Solutions, Germany). MR measurements were taken with: 1) Respiratory-triggered T2-weighted turbo spin echo (BLADE) sequence in coronal orientation, and 2) Real-time balanced steady-state gradient echo sequence (TrueFISP) in coronal and sagittal planes. PET was acquired simultaneously with MR. Sphere geometries and motion profiles were measured and compared with ground truths for T2 BLADE-TSE acquisitions and real time TrueFISP images. PET quantification and geometry measurements were taken using standardized uptake values, voxel intensity plots and were compared with known values, and examined alongside MR-based attenuation maps. Contrast and signal-to-noise ratios were also compared for each of the acquisitions as functions of motion range and TR. Results: Comparison of lesion diameters indicate the respiratory triggered T2 BLADE-TSE was able to maintain geometry within −2 mm for 1 cm motion for both TR values, and within −3.1 mm for TR = 2000 ms at 2 cm motion. Sphere measurements in respiratory triggered PET images were accurate within +/− 5 mm for both ranges of motion for 28, 22, and 17 mm diameter spheres. Conclusion: Hybrid MR-PET systems show promise in imaging lung cancer in non-compliant patients, with their ability to acquire both modalities simultaneously. However, MR-based attenuation maps are still susceptible to motion derived artifacts and

  13. DIMENSIONAL BEHAVIOR OF THE WOOD OF SAPWOOD AND HEARTWOOD FOR ANALYSIS OF IMAGE SUBMITTED IN DIFFERENT TEMPERATURES

    Directory of Open Access Journals (Sweden)

    Dimas Agostinho da Silva

    2003-01-01

    Full Text Available The objective of this work was to verify the dimensional behavior of heartwood woodand sapwood submitted to different temperatures. It was evaluated volumetric, sectional and lineardimension reduction in heartwood and sapwood of Hymeneae courbaril L submitted to finaltemperatures of 200º, 300º, 400º, 500º, 600º, 700º, 800º and 900°C, in an electric kiln with mediumrate of heating of 1.3ºC/minute. For the measurement of the dimensions, accomplished before andafter the thermal treatments, an image analyzer (Midro-Videomat Zeiss was used. It was obtained,with base in the individual readings accomplished in the image analyzer, the rates of longitudinal andtraverse linear, longitudinal and traverse sectional and volumetric reduction. The results showed thattem- perature increase of 1000C, average reduction rate reached 2.55% and 4.24%, 5.95% and 7.21% and 8.36% in the longitudinal and traverse linear dimensions, longitudinal and traverse sectional andvolumetric, respectively, for heartwood. For sapwood the values were, respectively, 2.64% and 5.02%,6.70% and 8.17% and 9.15%. For both sapwood and heartwood the largest reduction rates occurredin temperatures between 300º and 5000C. The heartwood presented larger resistance to the action ofthe temperature, however its thermal decomposition was more pronounced than that of sapwood inthe temperature range of 200-300 0C. This behavior is similar to that of lignin in relation to cellulose.

  14. Different imaging methods in the assessment of radiation-induced lung injury following hemithorax irradiation for pleural mesothelioma

    International Nuclear Information System (INIS)

    Maasilta, P.; Kivisaari, L.; Mattson, K.

    1990-01-01

    The authors have characterized the radiation-induced lung-injury on serial chest X-rays, CTs and ultralow field MRs and evaluated the clinical value and cost/benefit ratio of the different imaging methods in 30 patients receiving high-dose hemithorax irradiation for pleural mesothelioma. Lung injury was severe in all patients, but non-specific and essentially as described in text-books. CT provided no clinically relevant, cost effective diagnostic advantage over conventional X-rays in the detection of early or late radiation-induced lung injury, but it was necessary for the evaluation of the disease status of the mesothelioma. The possible advantage of MR over CT could not be evaluated and needs further studies. Optimal time-points for imaging CTs or MRs to detect early radiation-induced lung injury following high dose hemithorax irradiation were during the latter part of the treatment or very shortly after the end of the irradiation. Late injury or irreversible fibrosis develop rapidly after 6 months and was clearly documented by chest X-rays. The authors recommend serial chest X-rays at 1-2, 6 and 12 months following radiotherapy as a cost-effective method for the detection of radiation-induced lung injury with additional CTs to document the stage of mesothelioma, when needed. (author). 31 refs.; 4 figs

  15. Discordance Between Appropriate Use Criteria for Nuclear Myocardial Perfusion Imaging From Different Specialty Societies: A Potential Concern for Health Policy.

    Science.gov (United States)

    Winchester, David E; Wolinsky, David; Beyth, Rebecca J; Shaw, Leslee J

    2016-05-01

    methods for assessing the appropriateness of advanced imaging tests. Discordance in methods may translate into differences in clinically relevant outcomes, such as the detection of myocardial ischemia.

  16. Time-domain finite-difference/finite-element hybrid simulations of radio frequency coils in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Wang Shumin; Duyn, Jeff H

    2008-01-01

    A hybrid method that combines the finite-difference time-domain (FDTD) method and the finite-element time-domain (FETD) method is presented for simulating radio-frequency (RF) coils in magnetic resonance imaging. This method applies a high-fidelity FETD method to RF coils, while the human body is modeled with a low-cost FDTD method. Since the FDTD and the FETD methods are applied simultaneously, the dynamic interaction between RF coils and the human body is fully accounted for. In order to simplify the treatment of the highly irregular FDTD/FETD interface, composite elements are proposed. Two examples are provided to demonstrate the validity and effectiveness of the hybrid method in high-field receive-and-transmit coil design. This approach is also applicable to general bio-electromagnetic simulations

  17. Use of high resolution images of orbital surface of waterproofing with different levels of urban land: case Irati-PR

    Directory of Open Access Journals (Sweden)

    Paulo Costa de Oliveira Filho

    2012-11-01

    Full Text Available The objective of this research was to present a detailed diagnosis for use and occupation of urban land aimed at different levels of sealing, in a downtownIrati area of 14 blocks, totaling 0.23 km2, from the Quickbird satellite images with spatial resolution of 0.60 m, by the method of interpretation and vectorization on the screen followed by classification. The area occupied by the classes that represent the highest level of waterproof is 33,218% of the total study area, since the area occupied by classes representing less impermeable level is 22,488% of the same area. The results show that the study area is well sealed.

  18. FDG PET imaging of Ela1-myc mice reveals major biological differences between pancreatic acinar and ductal tumours

    International Nuclear Information System (INIS)

    Abasolo, Ibane; Pujal, Judit; Navarro, Pilar; Rabanal, Rosa M.; Serafin, Anna; Millan, Olga; Real, Francisco X.

    2009-01-01

    The aim was to evaluate FDG PET imaging in Ela1-myc mice, a pancreatic cancer model resulting in the development of tumours with either acinar or mixed acinar-ductal phenotype. Transversal and longitudinal FDG PET studies were conducted; selected tissue samples were subjected to autoradiography and ex vivo organ counting. Glucose transporter and hexokinase mRNA expression was analysed by quantitative reverse transcription polymerase chain reaction (RT-PCR); Glut2 expression was analysed by immunohistochemistry. Transversal studies showed that mixed acinar-ductal tumours could be identified by FDG PET several weeks before they could be detected by hand palpation. Longitudinal studies revealed that ductal - but not acinar - tumours could be detected by FDG PET. Autoradiographic analysis confirmed that tumour areas with ductal differentiation incorporated more FDG than areas displaying acinar differentiation. Ex vivo radioactivity measurements showed that tumours of solely acinar phenotype incorporated more FDG than pancreata of non-transgenic littermates despite the fact that they did not yield positive PET images. To gain insight into the biological basis of the differential FDG uptake, glucose transporter and hexokinase transcript expression was studied in microdissected tumour areas enriched for acinar or ductal cells and validated using cell-specific markers. Glut2 and hexokinase I and II mRNA levels were up to 20-fold higher in ductal than in acinar tumours. Besides, Glut2 protein overexpression was found in ductal neoplastic cells but not in the surrounding stroma. In Ela1-myc mice, ductal tumours incorporate significantly more FDG than acinar tumours. This difference likely results from differential expression of Glut2 and hexokinases. These findings reveal previously unreported biological differences between acinar and ductal pancreatic tumours. (orig.)

  19. FDG PET imaging of Ela1-myc mice reveals major biological differences between pancreatic acinar and ductal tumours

    Energy Technology Data Exchange (ETDEWEB)

    Abasolo, Ibane [Institut Municipal d' Investigacio Medica-Hospital del Mar, Parc de Recerca Biomedica de Barcelona, Barcelona (Spain); Universitat Pompeu Fabra, Parc de Recerca Biomedica de Barcelona, Departament de Ciencies Experimentals i de la Salut, Barcelona (Spain); Institut d' Alta Tecnologia - CRC, Parc de Recerca Biomedica de Barcelona, Barcelona (Spain); Pujal, Judit; Navarro, Pilar [Institut Municipal d' Investigacio Medica-Hospital del Mar, Parc de Recerca Biomedica de Barcelona, Barcelona (Spain); Rabanal, Rosa M.; Serafin, Anna [Universitat Autonoma de Barcelona, Departament de Medicina i Cirurgia Animals, Barcelona (Spain); Millan, Olga [Institut d' Alta Tecnologia - CRC, Parc de Recerca Biomedica de Barcelona, Barcelona (Spain); Real, Francisco X. [Institut Municipal d' Investigacio Medica-Hospital del Mar, Parc de Recerca Biomedica de Barcelona, Barcelona (Spain); Universitat Pompeu Fabra, Parc de Recerca Biomedica de Barcelona, Departament de Ciencies Experimentals i de la Salut, Barcelona (Spain); Programa de Patologia Molecular, Centro Nacional de Investigaciones Oncologicas, Madrid (Spain)

    2009-07-15

    The aim was to evaluate FDG PET imaging in Ela1-myc mice, a pancreatic cancer model resulting in the development of tumours with either acinar or mixed acinar-ductal phenotype. Transversal and longitudinal FDG PET studies were conducted; selected tissue samples were subjected to autoradiography and ex vivo organ counting. Glucose transporter and hexokinase mRNA expression was analysed by quantitative reverse transcription polymerase chain reaction (RT-PCR); Glut2 expression was analysed by immunohistochemistry. Transversal studies showed that mixed acinar-ductal tumours could be identified by FDG PET several weeks before they could be detected by hand palpation. Longitudinal studies revealed that ductal - but not acinar - tumours could be detected by FDG PET. Autoradiographic analysis confirmed that tumour areas with ductal differentiation incorporated more FDG than areas displaying acinar differentiation. Ex vivo radioactivity measurements showed that tumours of solely acinar phenotype incorporated more FDG than pancreata of non-transgenic littermates despite the fact that they did not yield positive PET images. To gain insight into the biological basis of the differential FDG uptake, glucose transporter and hexokinase transcript expression was studied in microdissected tumour areas enriched for acinar or ductal cells and validated using cell-specific markers. Glut2 and hexokinase I and II mRNA levels were up to 20-fold higher in ductal than in acinar tumours. Besides, Glut2 protein overexpression was found in ductal neoplastic cells but not in the surrounding stroma. In Ela1-myc mice, ductal tumours incorporate significantly more FDG than acinar tumours. This difference likely results from differential expression of Glut2 and hexokinases. These findings reveal previously unreported biological differences between acinar and ductal pancreatic tumours. (orig.)

  20. Sex differences in the interacting roles of impulsivity and positive alcohol expectancy in problem drinking: A structural brain imaging study

    Directory of Open Access Journals (Sweden)

    Jaime S. Ide

    2017-01-01

    Full Text Available Alcohol expectancy and impulsivity are implicated in alcohol misuse. However, how these two risk factors interact to determine problem drinking and whether men and women differ in these risk processes remain unclear. In 158 social drinkers (86 women assessed for Alcohol Use Disorder Identification Test (AUDIT, positive alcohol expectancy, and Barratt impulsivity, we examined sex differences in these risk processes. Further, with structural brain imaging, we examined the neural bases underlying the relationship between these risk factors and problem drinking. The results of general linear modeling showed that alcohol expectancy best predicted problem drinking in women, whereas in men as well as in the combined group alcohol expectancy and impulsivity interacted to best predict problem drinking. Alcohol expectancy was associated with decreased gray matter volume (GMV of the right posterior insula in women and the interaction of alcohol expectancy and impulsivity was associated with decreased GMV of the left thalamus in women and men combined and in men alone, albeit less significantly. These risk factors mediated the correlation between GMV and problem drinking. Conversely, models where GMV resulted from problem drinking were not supported. These new findings reveal distinct psychological factors that dispose men and women to problem drinking. Although mediation analyses did not determine a causal link, GMV reduction in the insula and thalamus may represent neural phenotype of these risk processes rather than the consequence of alcohol consumption in non-dependent social drinkers. The results add to the alcohol imaging literature which has largely focused on dependent individuals and help elucidate alterations in brain structures that may contribute to the transition from social to habitual drinking.

  1. Sex differences in the interacting roles of impulsivity and positive alcohol expectancy in problem drinking: A structural brain imaging study.

    Science.gov (United States)

    Ide, Jaime S; Zhornitsky, Simon; Hu, Sien; Zhang, Sheng; Krystal, John H; Li, Chiang-Shan R

    2017-01-01

    Alcohol expectancy and impulsivity are implicated in alcohol misuse. However, how these two risk factors interact to determine problem drinking and whether men and women differ in these risk processes remain unclear. In 158 social drinkers (86 women) assessed for Alcohol Use Disorder Identification Test (AUDIT), po