Imaging in anatomy: a comparison of imaging techniques in embalmed human cadavers

PubMed Central

2013-01-01

Background A large variety of imaging techniques is an integral part of modern medicine. Introducing radiological imaging techniques into the dissection course serves as a basis for improved learning of anatomy and multidisciplinary learning in pre-clinical medical education. Methods Four different imaging techniques (ultrasound, radiography, computed tomography, and magnetic resonance imaging) were performed in embalmed human body donors to analyse possibilities and limitations of the respective techniques in this peculiar setting. Results The quality of ultrasound and radiography images was poor, images of computed tomography and magnetic resonance imaging were of good quality. Conclusion Computed tomography and magnetic resonance imaging have a superior image quality in comparison to ultrasound and radiography and offer suitable methods for imaging embalmed human cadavers as a valuable addition to the dissection course. PMID:24156510

Raman imaging from microscopy to macroscopy: Quality and safety control of biological materials

USDA-ARS?s Scientific Manuscript database

Raman imaging can analyze biological materials by generating detailed chemical images. Over the last decade, tremendous advancements in Raman imaging and data analysis techniques have overcome problems such as long data acquisition and analysis times and poor sensitivity. This review article introdu...

Learning the manifold of quality ultrasound acquisition.

PubMed

El-Zehiry, Noha; Yan, Michelle; Good, Sara; Fang, Tong; Zhou, S Kevin; Grady, Leo

2013-01-01

Ultrasound acquisition is a challenging task that requires simultaneous adjustment of several acquisition parameters (the depth, the focus, the frequency and its operation mode). If the acquisition parameters are not properly chosen, the resulting image will have a poor quality and will degrade the patient diagnosis and treatment workflow. Several hardware-based systems for autotuning the acquisition parameters have been previously proposed, but these solutions were largely abandoned because they failed to properly account for tissue inhomogeneity and other patient-specific characteristics. Consequently, in routine practice the clinician either uses population-based parameter presets or manually adjusts the acquisition parameters for each patient during the scan. In this paper, we revisit the problem of autotuning the acquisition parameters by taking a completely novel approach and producing a solution based on image analytics. Our solution is inspired by the autofocus capability of conventional digital cameras, but is significantly more challenging because the number of acquisition parameters is large and the determination of "good quality" images is more difficult to assess. Surprisingly, we show that the set of acquisition parameters which produce images that are favored by clinicians comprise a 1D manifold, allowing for a real-time optimization to maximize image quality. We demonstrate our method for acquisition parameter autotuning on several live patients, showing that our system can start with a poor initial set of parameters and automatically optimize the parameters to produce high quality images.

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

NASA Astrophysics Data System (ADS)

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.

Comparison of obese adults with poor versus good sleep quality during a functional neuroimaging delay discounting task: A pilot study.

PubMed

Martin, Laura E; Pollack, Lauren; McCune, Ashley; Schulte, Erica; Savage, Cary R; Lundgren, Jennifer D

2015-10-30

This study aimed to determine if obese adults with poor versus good sleep quality demonstrate reduced self-regulatory capacity and different patterns of neural activation when making impulsive monetary choices. Six obese, good quality sleepers (M age=44.7 years, M BMI=38.1 kg/m(2)) were compared to 13 obese, poor quality sleepers (M age=42.6, M BMI=39.2 kg/m(2)) on sleep and eating behavior and brain activation in prefrontal and insular regions while engaging in a delay discounting task during functional magnetic resonance imaging (fMRI). Poor quality sleepers demonstrated significantly lower brain activation in the right inferior frontal gyrus, right middle frontal gyrus, and bilateral insula when making immediate and smaller (impulsive) monetary choices compared to the baseline condition. Behaviorally, poor compared to good quality sleepers reported higher scores in the night eating questionnaire. Obese adults with poor sleep quality demonstrate decreased brain activation in multiple regions that regulate cognitive control and interceptive awareness, possibly reducing self-regulatory capacity when making immediately gratifying decisions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Image Quality Assessment of High-Resolution Satellite Images with Mtf-Based Fuzzy Comprehensive Evaluation Method

NASA Astrophysics Data System (ADS)

Wu, Z.; Luo, Z.; Zhang, Y.; Guo, F.; He, L.

2018-04-01

A Modulation Transfer Function (MTF)-based fuzzy comprehensive evaluation method was proposed in this paper for the purpose of evaluating high-resolution satellite image quality. To establish the factor set, two MTF features and seven radiant features were extracted from the knife-edge region of image patch, which included Nyquist, MTF0.5, entropy, peak signal to noise ratio (PSNR), average difference, edge intensity, average gradient, contrast and ground spatial distance (GSD). After analyzing the statistical distribution of above features, a fuzzy evaluation threshold table and fuzzy evaluation membership functions was established. The experiments for comprehensive quality assessment of different natural and artificial objects was done with GF2 image patches. The results showed that the calibration field image has the highest quality scores. The water image has closest image quality to the calibration field, quality of building image is a little poor than water image, but much higher than farmland image. In order to test the influence of different features on quality evaluation, the experiment with different weights were tested on GF2 and SPOT7 images. The results showed that different weights correspond different evaluating effectiveness. In the case of setting up the weights of edge features and GSD, the image quality of GF2 is better than SPOT7. However, when setting MTF and PSNR as main factor, the image quality of SPOT7 is better than GF2.

Contrast-dependent saturation adjustment for outdoor image enhancement.

PubMed

Wang, Shuhang; Cho, Woon; Jang, Jinbeum; Abidi, Mongi A; Paik, Joonki

2017-01-01

Outdoor images captured in bad-weather conditions usually have poor intensity contrast and color saturation since the light arriving at the camera is severely scattered or attenuated. The task of improving image quality in poor conditions remains a challenge. Existing methods of image quality improvement are usually effective for a small group of images but often fail to produce satisfactory results for a broader variety of images. In this paper, we propose an image enhancement method, which makes it applicable to enhance outdoor images by using content-adaptive contrast improvement as well as contrast-dependent saturation adjustment. The main contribution of this work is twofold: (1) we propose the content-adaptive histogram equalization based on the human visual system to improve the intensity contrast; and (2) we introduce a simple yet effective prior for adjusting the color saturation depending on the intensity contrast. The proposed method is tested with different kinds of images, compared with eight state-of-the-art methods: four enhancement methods and four haze removal methods. Experimental results show the proposed method can more effectively improve the visibility and preserve the naturalness of the images, as opposed to the compared methods.

A review of portal screen-film technology and five radiologists' evaluations of some existing products.

PubMed

Walker, M A; Steinheimer, D N; Weir, V A; Homco, L D; Green, R W; Morris, E L; Hess, M E

1999-01-01

Portal radiographs, radiographs made to document the accuracy of radiotherapy treatment fields, are typically of poor image contrast. Recently, a new portal film and screened-cassette system was marketed, the Kodak EC-L system, with the claim of greatly improved image contrast. This new EC-L system was tested on a canine cadaver exposed to Cobalt-60 teletherapy gamma radiation, and image quality was compared to earlier marketed Kodak portal film products. The EC-L system was found to provide portal images of improved contrast/quality.

Image-guided optimization of the ECG trace in cardiac MRI.

PubMed

Barnwell, James D; Klein, J Larry; Stallings, Cliff; Sturm, Amanda; Gillespie, Michael; Fine, Jason; Hyslop, W Brian

2012-03-01

Improper electrocardiogram (ECG) lead placement resulting in suboptimal gating may lead to reduced image quality in cardiac magnetic resonance imaging (CMR). A patientspecific systematic technique for rapid optimization of lead placement may improve CMR image quality. A rapid 3 dimensional image of the thorax was used to guide the realignment of ECG leads relative to the cardiac axis of the patient in forty consecutive adult patients. Using our novel approach and consensus reading of pre- and post-correction ECG traces, seventy-three percent of patients had a qualitative improvement in their ECG tracings, and no patient had a decrease in quality of their ECG tracing following the correction technique. Statistically significant improvement was observed independent of gender, body mass index, and cardiac rhythm. This technique provides an efficient option to improve the quality of the ECG tracing in patients who have a poor quality ECG with standard techniques.

Assessing product image quality for online shopping

NASA Astrophysics Data System (ADS)

Goswami, Anjan; Chung, Sung H.; Chittar, Naren; Islam, Atiq

2012-01-01

Assessing product-image quality is important in the context of online shopping. A high quality image that conveys more information about a product can boost the buyer's confidence and can get more attention. However, the notion of image quality for product-images is not the same as that in other domains. The perception of quality of product-images depends not only on various photographic quality features but also on various high level features such as clarity of the foreground or goodness of the background etc. In this paper, we define a notion of product-image quality based on various such features. We conduct a crowd-sourced experiment to collect user judgments on thousands of eBay's images. We formulate a multi-class classification problem for modeling image quality by classifying images into good, fair and poor quality based on the guided perceptual notions from the judges. We also conduct experiments with regression using average crowd-sourced human judgments as target. We compute a pseudo-regression score with expected average of predicted classes and also compute a score from the regression technique. We design many experiments with various sampling and voting schemes with crowd-sourced data and construct various experimental image quality models. Most of our models have reasonable accuracies (greater or equal to 70%) on test data set. We observe that our computed image quality score has a high (0.66) rank correlation with average votes from the crowd sourced human judgments.

Heterogeneous sharpness for cross-spectral face recognition

NASA Astrophysics Data System (ADS)

Cao, Zhicheng; Schmid, Natalia A.

2017-05-01

Matching images acquired in different electromagnetic bands remains a challenging problem. An example of this type of comparison is matching active or passive infrared (IR) against a gallery of visible face images, known as cross-spectral face recognition. Among many unsolved issues is the one of quality disparity of the heterogeneous images. Images acquired in different spectral bands are of unequal image quality due to distinct imaging mechanism, standoff distances, or imaging environment, etc. To reduce the effect of quality disparity on the recognition performance, one can manipulate images to either improve the quality of poor-quality images or to degrade the high-quality images to the level of the quality of their heterogeneous counterparts. To estimate the level of discrepancy in quality of two heterogeneous images a quality metric such as image sharpness is needed. It provides a guidance in how much quality improvement or degradation is appropriate. In this work we consider sharpness as a relative measure of heterogeneous image quality. We propose a generalized definition of sharpness by first achieving image quality parity and then finding and building a relationship between the image quality of two heterogeneous images. Therefore, the new sharpness metric is named heterogeneous sharpness. Image quality parity is achieved by experimentally finding the optimal cross-spectral face recognition performance where quality of the heterogeneous images is varied using a Gaussian smoothing function with different standard deviation. This relationship is established using two models; one of them involves a regression model and the other involves a neural network. To train, test and validate the model, we use composite operators developed in our lab to extract features from heterogeneous face images and use the sharpness metric to evaluate the face image quality within each band. Images from three different spectral bands visible light, near infrared, and short-wave infrared are considered in this work. Both error of a regression model and validation error of a neural network are analyzed.

Relationship between diverse patient body size- and image acquisition-related factors, and quantitative and qualitative image quality in coronary computed tomography angiography: a multicenter observational study.

PubMed

Utsunomiya, Daisuke; Tanaka, Ryoichi; Yoshioka, Kunihiro; Awai, Kazuo; Mochizuki, Teruhito; Matsunaga, Naofumi; Ichikawa, Tomoaki; Kanematsu, Masayuki; Kim, Tonsok; Yamashita, Yasuyuki

2016-08-01

We investigated the effects of patient- and image acquisition-related factors on the image quality in coronary CT angiography (CCTA). We enrolled 1197 patients (728 men; 65 ± 12 years). All underwent CCTA under the routine scan protocol in 23 participating hospitals. The subjective image quality (3-point Likert scale: excellent, good, and poor) and the attenuation of the left and right coronary artery (LCA, RCA) were recorded; the effects of patient and image acquisition-related factors on vascular attenuation were then compared. The mean LCA attenuation was 515.2 ± 65.8 (excellent), 401.4 ± 63.4 (good), and 319.5 ± 47.6 HU (poor). The corresponding RCA attenuation was 496.6 ± 67.6, 390.5 ± 58.5, and 308.5 ± 50.7 HU, respectively. Univariate analysis revealed significant associations between sufficient coronary attenuation (> 400 HU) and the age, gender, body surface area (BSA), number of detectors, contrast synchronization, scan mode, and the fractional contrast dose. Multivariate analysis revealed that the bolus tracking method, prospective electrocardiogram gating, and fractional contrast dose were significantly associated with sufficient coronary enhancement. BSA and fractional contrast dose are the most important patient- and image acquisition-related factors for sufficient coronary attenuation in CCTA.

Using fingerprint image quality to improve the identification performance of the U.S. Visitor and Immigrant Status Indicator Technology Program

PubMed Central

Wein, Lawrence M.; Baveja, Manas

2005-01-01

Motivated by the difficulty of biometric systems to correctly match fingerprints with poor image quality, we formulate and solve a game-theoretic formulation of the identification problem in two settings: U.S. visa applicants are checked against a list of visa holders to detect visa fraud, and visitors entering the U.S. are checked against a watchlist of criminals and suspected terrorists. For three types of biometric strategies, we solve the game in which the U.S. Government chooses the strategy's optimal parameter values to maximize the detection probability subject to a constraint on the mean biometric processing time per legal visitor, and then the terrorist chooses the image quality to minimize the detection probability. At current inspector staffing levels at ports of entry, our model predicts that a quality-dependent two-finger strategy achieves a detection probability of 0.733, compared to 0.526 under the quality-independent two-finger strategy that is currently implemented at the U.S. border. Increasing the staffing level of inspectors offers only minor increases in the detection probability for these two strategies. Using more than two fingers to match visitors with poor image quality allows a detection probability of 0.949 under current staffing levels, but may require major changes to the current U.S. biometric program. The detection probabilities during visa application are ≈11–22% smaller than at ports of entry for all three strategies, but the same qualitative conclusions hold. PMID:15894628

Using fingerprint image quality to improve the identification performance of the U.S. Visitor and Immigrant Status Indicator Technology Program.

PubMed

Wein, Lawrence M; Baveja, Manas

2005-05-24

Motivated by the difficulty of biometric systems to correctly match fingerprints with poor image quality, we formulate and solve a game-theoretic formulation of the identification problem in two settings: U.S. visa applicants are checked against a list of visa holders to detect visa fraud, and visitors entering the U.S. are checked against a watchlist of criminals and suspected terrorists. For three types of biometric strategies, we solve the game in which the U.S. Government chooses the strategy's optimal parameter values to maximize the detection probability subject to a constraint on the mean biometric processing time per legal visitor, and then the terrorist chooses the image quality to minimize the detection probability. At current inspector staffing levels at ports of entry, our model predicts that a quality-dependent two-finger strategy achieves a detection probability of 0.733, compared to 0.526 under the quality-independent two-finger strategy that is currently implemented at the U.S. border. Increasing the staffing level of inspectors offers only minor increases in the detection probability for these two strategies. Using more than two fingers to match visitors with poor image quality allows a detection probability of 0.949 under current staffing levels, but may require major changes to the current U.S. biometric program. The detection probabilities during visa application are approximately 11-22% smaller than at ports of entry for all three strategies, but the same qualitative conclusions hold.

Retinal image quality assessment based on image clarity and content

NASA Astrophysics Data System (ADS)

Abdel-Hamid, Lamiaa; El-Rafei, Ahmed; El-Ramly, Salwa; Michelson, Georg; Hornegger, Joachim

2016-09-01

Retinal image quality assessment (RIQA) is an essential step in automated screening systems to avoid misdiagnosis caused by processing poor quality retinal images. A no-reference transform-based RIQA algorithm is introduced that assesses images based on five clarity and content quality issues: sharpness, illumination, homogeneity, field definition, and content. Transform-based RIQA algorithms have the advantage of considering retinal structures while being computationally inexpensive. Wavelet-based features are proposed to evaluate the sharpness and overall illumination of the images. A retinal saturation channel is designed and used along with wavelet-based features for homogeneity assessment. The presented sharpness and illumination features are utilized to assure adequate field definition, whereas color information is used to exclude nonretinal images. Several publicly available datasets of varying quality grades are utilized to evaluate the feature sets resulting in area under the receiver operating characteristic curve above 0.99 for each of the individual feature sets. The overall quality is assessed by a classifier that uses the collective features as an input vector. The classification results show superior performance of the algorithm in comparison to other methods from literature. Moreover, the algorithm addresses efficiently and comprehensively various quality issues and is suitable for automatic screening systems.

Effect of metal artifact reduction software on image quality of C-arm cone-beam computed tomography during intracranial aneurysm treatment.

PubMed

Enomoto, Yukiko; Yamauchi, Keita; Asano, Takahiko; Otani, Katharina; Iwama, Toru

2018-01-01

Background and purpose C-arm cone-beam computed tomography (CBCT) has the drawback that image quality is degraded by artifacts caused by implanted metal objects. We evaluated whether metal artifact reduction (MAR) prototype software can improve the subjective image quality of CBCT images of patients with intracranial aneurysms treated with coils or clips. Materials and methods Forty-four patients with intracranial aneurysms implanted with coils (40 patients) or clips (four patients) underwent one CBCT scan from which uncorrected and MAR-corrected CBCT image datasets were reconstructed. Three blinded readers evaluated the image quality of the image sets using a four-point scale (1: Excellent, 2: Good, 3: Poor, 4: Bad). The median scores of the three readers of uncorrected and MAR-corrected images were compared with the paired Wilcoxon signed-rank and inter-reader agreement of change scores was assessed by weighted kappa statistics. The readers also recorded new clinical findings, such as intracranial hemorrhage, air, or surrounding anatomical structures on MAR-corrected images. Results The image quality of MAR-corrected CBCT images was significantly improved compared with the uncorrected CBCT image ( p < 0.001). Additional clinical findings were seen on CBCT images of 70.4% of patients after MAR correction. Conclusion MAR software improved image quality of CBCT images degraded by metal artifacts.

An Automated Blur Detection Method for Histological Whole Slide Imaging

PubMed Central

Moles Lopez, Xavier; D'Andrea, Etienne; Barbot, Paul; Bridoux, Anne-Sophie; Rorive, Sandrine; Salmon, Isabelle; Debeir, Olivier; Decaestecker, Christine

2013-01-01

Whole slide scanners are novel devices that enable high-resolution imaging of an entire histological slide. Furthermore, the imaging is achieved in only a few minutes, which enables image rendering of large-scale studies involving multiple immunohistochemistry biomarkers. Although whole slide imaging has improved considerably, locally poor focusing causes blurred regions of the image. These artifacts may strongly affect the quality of subsequent analyses, making a slide review process mandatory. This tedious and time-consuming task requires the scanner operator to carefully assess the virtual slide and to manually select new focus points. We propose a statistical learning method that provides early image quality feedback and automatically identifies regions of the image that require additional focus points. PMID:24349343

Optical aberrations, retinal image quality and eye growth: Experimentation and modeling

NASA Astrophysics Data System (ADS)

Tian, Yibin

2007-12-01

Retinal image quality is important for normal eye growth. Optical aberrations are of interest for two reasons: first, they degrade retinal images; second, they might provide some cues to defocus. Higher than normal ocular aberrations have been previously associated with human myopia. However, these studies were cross-sectional in design, and only reported aberrations in terms of root mean square (RMS) errors of Zernike coefficients, a poor metric of optical quality. This dissertation presents results from investigations of ocular optical aberrations, retinal image quality and eye growth in chicks and humans. A number of techniques were utilized, including Shack-Hartmann aberrometry, high-frequency A-scan ultrasonography, ciliary nerve section (CNX), photorefractive keratectomy (PRK) as well as computer simulations and modeling. A technique to extract light scatter information from Shack-Hartmann images was also developed. The main findings of the dissertation are summarized below. In young chicks, most ocular aberrations decreased with growth in both normal and CNX eyes, and there were diurnal fluctuations in some aberrations. Modeling suggested active reduction in higher order aberrations (HOAs) during early development. Although CNX eyes manifested greater than normal HOAs, they showed near normal growth. Retinal image degradation varied greatly among individual eyes post-PRK in young chicks. Including light scatter information into analyses of retinal image quality better estimated the latter. Albino eyes showed more severe retinal image degradation than normal eyes, due to increased optical aberrations and light scatter, but their growth was similar to those of normal eyes, implying that they are relatively insensitive to retina image quality. Although the above results questioned the influence of optical aberrations on early ocular growth, some optical quality metrics, derived from optical aberrations data, could predict how much the eyes of young chicks subsequently elongated. The performance of some focus measures was very poor when non-defocus aberrations exceeded a certain level; presumably, these non-defocus aberrations might interfere with the eye's ability to interpret defocus. In anisomyopic human adults, more myopic eyes had larger anterior and vitreous chambers, greater astigmatism, and more positive spherical aberration. However, compared to isometropes, only interocular differences in spherical equivalent refractive errors were significantly increased.

Cone beam computed tomography in veterinary dentistry.

PubMed

Van Thielen, Bert; Siguenza, Francis; Hassan, Bassam

2012-01-01

The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal reconstructions were created using specialized software. Image quality and visibility of anatomical landmarks were subjectively assessed by two observers. Good image quality was obtained for the MPR para-sagittal reconstructions through multiple teeth. The image quality of the panoramic reconstructions of dogs was moderate while the panoramic reconstructions of cats were poor since the images were associated with an increased noise level. Segmental panoramic reconstructions of the mouth seem to be useful for studying the dental anatomy especially in dogs. The results of this study using human dental CBCT technology demonstrate the potential of this scanning technology in veterinary medicine. Unfortunately, the moderate image quality obtained with the CBCT technique reported here seems to be inferior to the diagnostic image quality obtained from 2-dimensional dental radiographs. Further research is required to optimize scanning and reconstruction protocols for veterinary applications.

High-field open versus short-bore magnetic resonance imaging of the spine: a randomized controlled comparison of image quality.

PubMed

Enders, Judith; Rief, Matthias; Zimmermann, Elke; Asbach, Patrick; Diederichs, Gerd; Wetz, Christoph; Siebert, Eberhard; Wagner, Moritz; Hamm, Bernd; Dewey, Marc

2013-01-01

The purpose of the present study was to compare the image quality of spinal magnetic resonance (MR) imaging performed on a high-field horizontal open versus a short-bore MR scanner in a randomized controlled study setup. Altogether, 93 (80% women, mean age 53) consecutive patients underwent spine imaging after random assignement to a 1-T horizontal open MR scanner with a vertical magnetic field or a 1.5-T short-bore MR scanner. This patient subset was part of a larger cohort. Image quality was assessed by determining qualitative parameters, signal-to-noise (SNR) and contrast-to-noise ratios (CNR), and quantitative contour sharpness. The image quality parameters were higher for short-bore MR imaging. Regarding all sequences, the relative differences were 39% for the mean overall qualitative image quality, 53% for the mean SNR values, and 34-37% for the quantitative contour sharpness (P<0.0001). The CNR values were also higher for images obtained with the short-bore MR scanner. No sequence was of very poor (nondiagnostic) image quality. Scanning times were significantly longer for examinations performed on the open MR scanner (mean: 32±22 min versus 20±9 min; P<0.0001). In this randomized controlled comparison of spinal MR imaging with an open versus a short-bore scanner, short-bore MR imaging revealed considerably higher image quality with shorter scanning times. ClinicalTrials.gov NCT00715806.

High-Field Open versus Short-Bore Magnetic Resonance Imaging of the Spine: A Randomized Controlled Comparison of Image Quality

PubMed Central

Zimmermann, Elke; Asbach, Patrick; Diederichs, Gerd; Wetz, Christoph; Siebert, Eberhard; Wagner, Moritz; Hamm, Bernd; Dewey, Marc

2013-01-01

Background The purpose of the present study was to compare the image quality of spinal magnetic resonance (MR) imaging performed on a high-field horizontal open versus a short-bore MR scanner in a randomized controlled study setup. Methods Altogether, 93 (80% women, mean age 53) consecutive patients underwent spine imaging after random assignement to a 1-T horizontal open MR scanner with a vertical magnetic field or a 1.5-T short-bore MR scanner. This patient subset was part of a larger cohort. Image quality was assessed by determining qualitative parameters, signal-to-noise (SNR) and contrast-to-noise ratios (CNR), and quantitative contour sharpness. Results The image quality parameters were higher for short-bore MR imaging. Regarding all sequences, the relative differences were 39% for the mean overall qualitative image quality, 53% for the mean SNR values, and 34–37% for the quantitative contour sharpness (P<0.0001). The CNR values were also higher for images obtained with the short-bore MR scanner. No sequence was of very poor (nondiagnostic) image quality. Scanning times were significantly longer for examinations performed on the open MR scanner (mean: 32±22 min versus 20±9 min; P<0.0001). Conclusions In this randomized controlled comparison of spinal MR imaging with an open versus a short-bore scanner, short-bore MR imaging revealed considerably higher image quality with shorter scanning times. Trial Registration ClinicalTrials.gov NCT00715806 PMID:24391767

Feasibility of SPECT myocardial perfusion imaging in the super-obese using a multi-head semiconductor camera with attenuation correction.

PubMed

DeCicco, Anthony E; Sokil, Alexis B; Marhefka, Gregary D; Reist, Kirk; Hansen, Christopher L

2015-04-01

Obesity is not only associated with an increased risk of coronary artery disease, but also decreases the accuracy of many diagnostic modalities pertinent to this disease. Advances in myocardial perfusion imaging (MPI) have mitigated somewhat the effects of obesity, although the feasibility of MPI in the super-obese (defined as a BMI > 50) is currently untested. We undertook this study to assess the practicality of MPI in the super-obese using a multi-headed solid-state gamma camera with attenuation correction. We retrospectively identified consecutive super-obese patients referred for MPI at our institution. The images were interpreted by 3 blinded, experienced readers and graded for quality and diagnosis, and subjectively evaluated the contribution of attenuation correction. Clinical follow-up was obtained from review of medical records. 72 consecutive super-obese patients were included. Their BMI ranged from 50 to 67 (55.7 ± 5.1). Stress image quality was considered good or excellent in 45 (63%), satisfactory in 24 (33%), poor in 3 (4%), and uninterpretable in 0 patients. Rest images were considered good or excellent in 34 (49%), satisfactory in 23 (33%), poor in 13 (19%), and uninterpretable in 0 patients. Attenuation correction changed the interpretation in 34 (47%) of studies. MPI is feasible and provides acceptable image quality for super-obese patients, although it may be camera and protocol dependent.

Verification of quality parameters for portal images in radiotherapy.

PubMed

Pesznyák, Csilla; Polgár, István; Weisz, Csaba; Király, Réka; Zaránd, Pál

2011-03-01

The purpose of the study was to verify different values of quality parameters of portal images in radiotherapy. We investigated image qualities of different field verification systems. Four EPIDs (Siemens OptiVue500aSi(®), Siemens BeamView Plus(®), Elekta iView(®) and Varian PortalVision™) were investigated with the PTW EPID QC PHANTOM(®) and compared with two portal film systems (Kodak X-OMAT(®) cassette with Kodak X-OMAT V(®) film and Kodak EC-L Lightweight(®) cassette with Kodak Portal Localisation ReadyPack(®) film). A comparison of the f50 and f25 values of the modulation transfer functions (MTFs) belonging to each of the systems revealed that the amorphous silicon EPIDs provided a slightly better high contrast resolution than the Kodak Portal Localisation ReadyPack(®) film with the EC-L Lightweight(®) cassette. The Kodak X-OMAT V(®) film gave a poor low contrast resolution: from the existing 27 holes only 9 were detectable. On the base of physical characteristics, measured in this work, the authors suggest the use of amorphous-silicon EPIDs producing the best image quality. Parameters of the EPIDs with scanning liquid ionisation chamber (SLIC) were very stable. The disadvantage of older versions of EPIDs like SLIC and VEPID is a poor DICOM implementation, and the modulation transfer function (MTF) values (f50 and f25) are less than that of aSi detectors.

JPEG and wavelet compression of ophthalmic images

NASA Astrophysics Data System (ADS)

Eikelboom, Robert H.; Yogesan, Kanagasingam; Constable, Ian J.; Barry, Christopher J.

1999-05-01

This study was designed to determine the degree and methods of digital image compression to produce ophthalmic imags of sufficient quality for transmission and diagnosis. The photographs of 15 subjects, which inclined eyes with normal, subtle and distinct pathologies, were digitized to produce 1.54MB images and compressed to five different methods: (i) objectively by calculating the RMS error between the uncompressed and compressed images, (ii) semi-subjectively by assessing the visibility of blood vessels, and (iii) subjectively by asking a number of experienced observers to assess the images for quality and clinical interpretation. Results showed that as a function of compressed image size, wavelet compressed images produced less RMS error than JPEG compressed images. Blood vessel branching could be observed to a greater extent after Wavelet compression compared to JPEG compression produced better images then a JPEG compression for a given image size. Overall, it was shown that images had to be compressed to below 2.5 percent for JPEG and 1.7 percent for Wavelet compression before fine detail was lost, or when image quality was too poor to make a reliable diagnosis.

Step-and-Shoot: a new low radiation coronary computed tomography angiography technology: our initial experience with 125 consecutive asymptomatic patients.

PubMed

Atar, Eli; Kornowski, Ran; Bachar, Gil N

2010-11-01

Coronary CTangiography is an accurate imaging modality; however, its main drawback is the radiation dose. A new technology, the "step and shoot," which reduces the radiation up to one-eighth, is now available. To assess our initial experience using the "step-and-shoot" technology for various vascular pathologies. During a 10 month period 125 consecutive asymptomatic patients (111 men and 14 women aged 25-82, average age 54.9 years) with various clinical indications that were appropriate for step-and-shoot CCTA (regular heart rate < 65 beats/minute and body weight < 115 kg) were scanned with a 64-slice multidetector computed tomography Brilliance scanner (Philips, USA). The preparation protocol for the scan was the same as for regular coronary CTA. All examinations were interpreted by at least one experienced radiologist and one experienced interventional cardiologist. The quality of the examinations was graded from 1 (excellent imaging quality of all coronary segments) to 4 (poor quality, not diagnostic). There were 99 patients without a history of coronary intervention, 13 after coronary stent deployment (19 stents) and 3 after coronary artery bypass graft. Coronary interpretation was obtained in 122 examinations (97.6%). The imaging quality obtained was as follows: 103 patients scored 1 (82.4%), 15 scored 2 (12%), 4 scored 3 (3.2%) and 3 scored 4 (2.4%). The grades were unrelated to cardiac history or type of previous examinations. Poor image quality occurred because of sudden heart rate acceleration during the scan (one patient), movement and respiration (one patient), and arrhythmia and poor scan timing (in one). Two patients were referred to percutaneous coronary intervention based on the CCTA findings, which correlated perfectly. Step-and-shoot CCTA is a reliable technique and CCTA algorithm comparable to regular CCTA. This technique requires the lowest radiation dose, as compared to other coronary imaging modalities, that can be used for all CCTA indications based on the inclusion criteria of low (> 65 bpm) and stable heart rate.

Rapid sequence magnetic resonance imaging in the assessment of children with hydrocephalus.

PubMed

O'Neill, Brent R; Pruthi, Sumit; Bains, Harmanjeet; Robison, Ryan; Weir, Keiko; Ojemann, Jeff; Ellenbogen, Richard; Avellino, Anthony; Browd, Samuel R

2013-12-01

Recent reports have shown the utility of rapid-acquisition magnetic resonance imaging (MRI) in the evaluation of children with hydrocephalus. Rapid sequence MRI (RS-MRI) acquires clinically useful images in seconds without exposing children to the risks of ionizing radiation or sedation. We review our experience with RS-MRI in children with shunts. Overall image quality, cost, catheter visualization, motion artifact, and ventricular size were reviewed for all RS-MRI studies obtained at Seattle Children's Hospital during a 2-year period. Image acquisition time was 12-19 seconds, with sessions usually lasting less than 3 minutes. Image quality was very good or excellent in 94% of studies, whereas only one was graded as poor. Significant motion artifact was noted in 7%, whereas 77% had little or no motion artifact. Catheter visualization was good or excellent in 57%, poor in 36%, and misleading in 7%. Small ventricular size was correlated with poor catheter visualization (Spearman's ρ = 0.586; P < 0.00001). RS-MRI imaging cost ∼$650 more than conventional computed tomography (CT). Our study supports that RS-MRI is an adequate substitute that allows reduced use of CT imaging and resultant exposure to ionizing radiation. Catheter position visualization remains suboptimal when ventricles are small, but shunt malfunction can be adequately determined in most cases. The cost is significantly more than CT, but the potential for lifetime reduction in radiation exposure may justify this expense in children. Limitations include the risk of valve malfunction after repeated exposure to high magnetic fields and the need for reprogramming with many types of adjustable valves. Copyright © 2013 Elsevier Inc. All rights reserved.

A Perceptually Weighted Rank Correlation Indicator for Objective Image Quality Assessment

NASA Astrophysics Data System (ADS)

Wu, Qingbo; Li, Hongliang; Meng, Fanman; Ngan, King N.

2018-05-01

In the field of objective image quality assessment (IQA), the Spearman's $\\rho$ and Kendall's $\\tau$ are two most popular rank correlation indicators, which straightforwardly assign uniform weight to all quality levels and assume each pair of images are sortable. They are successful for measuring the average accuracy of an IQA metric in ranking multiple processed images. However, two important perceptual properties are ignored by them as well. Firstly, the sorting accuracy (SA) of high quality images are usually more important than the poor quality ones in many real world applications, where only the top-ranked images would be pushed to the users. Secondly, due to the subjective uncertainty in making judgement, two perceptually similar images are usually hardly sortable, whose ranks do not contribute to the evaluation of an IQA metric. To more accurately compare different IQA algorithms, we explore a perceptually weighted rank correlation indicator in this paper, which rewards the capability of correctly ranking high quality images, and suppresses the attention towards insensitive rank mistakes. More specifically, we focus on activating `valid' pairwise comparison towards image quality, whose difference exceeds a given sensory threshold (ST). Meanwhile, each image pair is assigned an unique weight, which is determined by both the quality level and rank deviation. By modifying the perception threshold, we can illustrate the sorting accuracy with a more sophisticated SA-ST curve, rather than a single rank correlation coefficient. The proposed indicator offers a new insight for interpreting visual perception behaviors. Furthermore, the applicability of our indicator is validated in recommending robust IQA metrics for both the degraded and enhanced image data.

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, Amanda M.; Daly, Don S.; Willse, Alan R.

The Automated Microarray Image Analysis (AMIA) Toolbox for MATLAB is a flexible, open-source microarray image analysis tool that allows the user to customize analysis of sets of microarray images. This tool provides several methods of identifying and quantify spot statistics, as well as extensive diagnostic statistics and images to identify poor data quality or processing. The open nature of this software allows researchers to understand the algorithms used to provide intensity estimates and to modify them easily if desired.

[Phantom studies of ultrasound equipment for quality improvement in breast diagnosis].

PubMed

Madjar, H; Mundinger, A; Lattermann, U; Gufler, H; Prömpeler, H J

1996-04-01

According to the German guidelines for quality control of ultrasonic equipment, the following conditions are required for breast ultrasound: A transducer frequency between 5-7.5 MHz and a minimum field of view of 5 cm. Satisfactory images must be obtained in a depth between 0.5 and 4 cm with a wide tolerance of the focal zones. This allows the use of poor quality equipment which does not produce satisfactory image quality and it excludes a number of high frequency and high resolution transducers with a field of view below 5 cm. This study with a test phantom was performed to define image quality objectively. Sixteen ultrasound instruments in different price categories were used to perform standardized examinations on a breast phantom model 550 (ATS Laboratories, Bridgeport, USA). Contrast and spatial resolution in different penetration depths were investigated on cyst phantoms from 1-4 mm diameter and wire targets with defined distances between 0.5-3 mm 4 investigations reported the images. A positive correlation was seen between price category and image quality. This study demonstrates that transducer frequency and image geometry do not allow sufficient quality control. An improvement of ultrasound diagnosis is only possible if equipment guidelines are based on standard examinations with test phantoms.

MISTICA: Minimum Spanning Tree-based Coarse Image Alignment for Microscopy Image Sequences

PubMed Central

Ray, Nilanjan; McArdle, Sara; Ley, Klaus; Acton, Scott T.

2016-01-01

Registration of an in vivo microscopy image sequence is necessary in many significant studies, including studies of atherosclerosis in large arteries and the heart. Significant cardiac and respiratory motion of the living subject, occasional spells of focal plane changes, drift in the field of view, and long image sequences are the principal roadblocks. The first step in such a registration process is the removal of translational and rotational motion. Next, a deformable registration can be performed. The focus of our study here is to remove the translation and/or rigid body motion that we refer to here as coarse alignment. The existing techniques for coarse alignment are unable to accommodate long sequences often consisting of periods of poor quality images (as quantified by a suitable perceptual measure). Many existing methods require the user to select an anchor image to which other images are registered. We propose a novel method for coarse image sequence alignment based on minimum weighted spanning trees (MISTICA) that overcomes these difficulties. The principal idea behind MISTICA is to re-order the images in shorter sequences, to demote nonconforming or poor quality images in the registration process, and to mitigate the error propagation. The anchor image is selected automatically making MISTICA completely automated. MISTICA is computationally efficient. It has a single tuning parameter that determines graph width, which can also be eliminated by way of additional computation. MISTICA outperforms existing alignment methods when applied to microscopy image sequences of mouse arteries. PMID:26415193

MISTICA: Minimum Spanning Tree-Based Coarse Image Alignment for Microscopy Image Sequences.

PubMed

Ray, Nilanjan; McArdle, Sara; Ley, Klaus; Acton, Scott T

2016-11-01

Registration of an in vivo microscopy image sequence is necessary in many significant studies, including studies of atherosclerosis in large arteries and the heart. Significant cardiac and respiratory motion of the living subject, occasional spells of focal plane changes, drift in the field of view, and long image sequences are the principal roadblocks. The first step in such a registration process is the removal of translational and rotational motion. Next, a deformable registration can be performed. The focus of our study here is to remove the translation and/or rigid body motion that we refer to here as coarse alignment. The existing techniques for coarse alignment are unable to accommodate long sequences often consisting of periods of poor quality images (as quantified by a suitable perceptual measure). Many existing methods require the user to select an anchor image to which other images are registered. We propose a novel method for coarse image sequence alignment based on minimum weighted spanning trees (MISTICA) that overcomes these difficulties. The principal idea behind MISTICA is to reorder the images in shorter sequences, to demote nonconforming or poor quality images in the registration process, and to mitigate the error propagation. The anchor image is selected automatically making MISTICA completely automated. MISTICA is computationally efficient. It has a single tuning parameter that determines graph width, which can also be eliminated by the way of additional computation. MISTICA outperforms existing alignment methods when applied to microscopy image sequences of mouse arteries.

QUALITY OF LIFE AND HEALTH SELF-PERCEPTION IN CHILDREN WITH POOR SCHOOL PERFORMANCE.

PubMed

Rezende, Bárbara Antunes; Lemos, Stela Maris Aguiar; Medeiros, Adriane Mesquita de

2017-01-01

To examine the association between quality of life and health self-perception of children with poor school performance, considering sociodemographic factors. An analytical, observational, cross-sectional study was conducted with 99 children aged 7 to 12 years receiving specialized educational assistance. Parents and legal guardians answered questions concerning the sociodemographic profile. For an assessment of the quality of life and proposed domains (autonomy, functioning, leisure, and family), the children completed the Autoquestionnarie Qualité de Vie Enfant Imagé (AUQEI) and answered a question concerning their self-perceived health. Data were analyzed using multiple linear regression, considering a 5% significance level. Among the evaluated children, 69 (69.7%) male participants with mean age of 8.7±1.5, 27% self-assessed their health status as poor/very poor, and 36.4% of the children reported having impaired quality of life. As for the domains assessed by AUQEI, there was statistical significance in the associations between family with age, autonomy with economic classification, and leisure and functioning with self-perceived health. The quality of life of children with academic underachievement is associated with their health self-perception and sociodemographic characteristics.

Assessment of liver ablation using cone beam computed tomography.

PubMed

Abdel-Rehim, Mohamed; Ronot, Maxime; Sibert, Annie; Vilgrain, Valérie

2015-01-14

To investigate the feasibility and accuracy of cone beam computed tomography (CBCT) in assessing the ablation zone after liver tumor ablation. Twenty-three patients (17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasound-guided percutaneous tumor ablation [radiofrequency (n = 14), microwave (n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography (MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the non-parametric paired Wilcoxon t-test. Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient (4%). The ablation zone was identified in 21/23 (91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage (at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2 (9%), 8 (35%), and 13 (56%), patients respectively. Registration quality between peri-procedural CBCT and post-procedural MDCT images was good to excellent in 17/23 (74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm(3) (range: 4-95 cm(3)) and 30 cm(3) (range: 4-124 cm(3)), respectively (P-value > 0.2). There was a good correlation (r = 0.79) between the volumes of the two techniques. Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone.

A whole-heart motion-correction algorithm: Effects on CT image quality and diagnostic accuracy of mechanical valve prosthesis abnormalities.

PubMed

Suh, Young Joo; Kim, Young Jin; Kim, Jin Young; Chang, Suyon; Im, Dong Jin; Hong, Yoo Jin; Choi, Byoung Wook

2017-11-01

We aimed to determine the effect of a whole-heart motion-correction algorithm (new-generation snapshot freeze, NG SSF) on the image quality of cardiac computed tomography (CT) images in patients with mechanical valve prostheses compared to standard images without motion correction and to compare the diagnostic accuracy of NG SSF and standard CT image sets for the detection of prosthetic valve abnormalities. A total of 20 patients with 32 mechanical valves who underwent wide-coverage detector cardiac CT with single-heartbeat acquisition were included. The CT image quality for subvalvular (below the prosthesis) and valvular regions (valve leaflets) of mechanical valves was assessed by two observers on a four-point scale (1 = poor, 2 = fair, 3 = good, and 4 = excellent). Paired t-tests or Wilcoxon signed rank tests were used to compare image quality scores and the number of diagnostic phases (image quality score≥3) between the standard image sets and NG SSF image sets. Diagnostic performance for detection of prosthetic valve abnormalities was compared between two image sets with the final diagnosis set by re-operation or clinical findings as the standard reference. NG SSF image sets had better image quality scores than standard image sets for both valvular and subvalvular regions (P < 0.05 for both). The number of phases that were of diagnostic image quality per patient was significantly greater in the NG SSF image set than standard image set for both valvular and subvalvular regions (P < 0.0001). Diagnostic performance of NG SSF image sets for the detection of prosthetic abnormalities (20 pannus and two paravalvular leaks) was greater than that of standard image sets (P < 0.05). Application of NG SSF can improve CT image quality and diagnostic accuracy in patients with mechanical valves compared to standard images. Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

The Research on Denoising of SAR Image Based on Improved K-SVD Algorithm

NASA Astrophysics Data System (ADS)

Tan, Linglong; Li, Changkai; Wang, Yueqin

2018-04-01

SAR images often receive noise interference in the process of acquisition and transmission, which can greatly reduce the quality of images and cause great difficulties for image processing. The existing complete DCT dictionary algorithm is fast in processing speed, but its denoising effect is poor. In this paper, the problem of poor denoising, proposed K-SVD (K-means and singular value decomposition) algorithm is applied to the image noise suppression. Firstly, the sparse dictionary structure is introduced in detail. The dictionary has a compact representation and can effectively train the image signal. Then, the sparse dictionary is trained by K-SVD algorithm according to the sparse representation of the dictionary. The algorithm has more advantages in high dimensional data processing. Experimental results show that the proposed algorithm can remove the speckle noise more effectively than the complete DCT dictionary and retain the edge details better.

A Method to Prevent Protein Delocalization in Imaging Mass Spectrometry of Non-Adherent Tissues: Application to Small Vertebrate Lens Imaging

PubMed Central

Anderson, David M. G.; Floyd, Kyle A.; Barnes, Stephen; Clark, Judy M.; Clark, John I.; Mchaourab, Hassane; Schey, Kevin L.

2015-01-01

MALDI imaging requires careful sample preparation to obtain reliable, high quality images of small molecules, peptides, lipids, and proteins across tissue sections. Poor crystal formation, delocalization of analytes, and inadequate tissue adherence can affect the quality, reliability, and spatial resolution of MALDI images. We report a comparison of tissue mounting and washing methods that resulted in an optimized method using conductive carbon substrates that avoids thaw mounting or washing steps, minimizes protein delocalization, and prevents tissue detachment from the target surface. Application of this method to image ocular lens proteins of small vertebrate eyes demonstrates the improved methodology for imaging abundant crystallin protein products. This method was demonstrated for tissue sections from rat, mouse, and zebrafish lenses resulting in good quality MALDI images with little to no delocalization. The images indicate, for the first time in mouse and zebrafish, discrete localization of crystallin protein degradation products resulting in concentric rings of distinct protein contents that may be responsible for the refractive index gradient of vertebrate lenses. PMID:25665708

Two-dimensional XD-GRASP provides better image quality than conventional 2D cardiac cine MRI for patients who cannot suspend respiration.

PubMed

Piekarski, Eve; Chitiboi, Teodora; Ramb, Rebecca; Latson, Larry A; Bhatla, Puneet; Feng, Li; Axel, Leon

2018-02-01

Residual respiratory motion degrades image quality in conventional cardiac cine MRI (CCMRI). We evaluated whether a free-breathing (FB) radial imaging CCMRI sequence with compressed sensing reconstruction [extradimensional (e.g. cardiac and respiratory phases) golden-angle radial sparse parallel, or XD-GRASP] could provide better image quality than a conventional Cartesian breath-held (BH) sequence in an unselected population of patients undergoing clinical CCMRI. One hundred one patients who underwent BH and FB imaging in a midventricular short-axis plane at a matching location were included. Visual and quantitative image analysis was performed by two blinded experienced readers, using a five-point qualitative scale to score overall image quality and visual signal-to-noise ratio (SNR) grade, with measures of noise and sharpness. End-diastolic and end-systolic left ventricular areas were also measured and compared for both BH and FB images. Image quality was generally better with the BH cines (overall quality grade for BH vs FB images 4 vs 2.9, p < 0.001; noise 0.06 vs 0.08 p < 0.001; SNR grade 4.1 vs 3, p < 0.001), except for sharpness (p = 0.48). There were no significant differences between BH and FB images regarding end-diastolic or end-systolic areas (p = 0.35 and p = 0.12). Eighteen of the 101 patients had poor BH image quality (grade 1 or 2). In this subgroup, the quality of the FB images was better (p = 0.0032), as was the SNR grade (p = 0.003), but there were no significant differences regarding noise and sharpness (p = 0.45 and p = 0.47). Although FB XD-GRASP CCMRI was visually inferior to conventional BH CCMRI in general, it provided improved image quality in the subgroup of patients with respiratory-motion-induced artifacts on BH images.

An enhanced approach for biomedical image restoration using image fusion techniques

NASA Astrophysics Data System (ADS)

Karam, Ghada Sabah; Abbas, Fatma Ismail; Abood, Ziad M.; Kadhim, Kadhim K.; Karam, Nada S.

2018-05-01

Biomedical image is generally noisy and little blur due to the physical mechanisms of the acquisition process, so one of the common degradations in biomedical image is their noise and poor contrast. The idea of biomedical image enhancement is to improve the quality of the image for early diagnosis. In this paper we are using Wavelet Transformation to remove the Gaussian noise from biomedical images: Positron Emission Tomography (PET) image and Radiography (Radio) image, in different color spaces (RGB, HSV, YCbCr), and we perform the fusion of the denoised images resulting from the above denoising techniques using add image method. Then some quantive performance metrics such as signal -to -noise ratio (SNR), peak signal-to-noise ratio (PSNR), and Mean Square Error (MSE), etc. are computed. Since this statistical measurement helps in the assessment of fidelity and image quality. The results showed that our approach can be applied of Image types of color spaces for biomedical images.

High speed color imaging through scattering media with a large field of view

NASA Astrophysics Data System (ADS)

Zhuang, Huichang; He, Hexiang; Xie, Xiangsheng; Zhou, Jianying

2016-09-01

Optical imaging through complex media has many important applications. Although research progresses have been made to recover optical image through various turbid media, the widespread application of the technology is hampered by the recovery speed, requirement on specific illumination, poor image quality and limited field of view. Here we demonstrate that above-mentioned drawbacks can be essentially overcome. The realization of high speed color imaging through turbid media is successfully carried out by taking into account the media memory effect, the point spread function, the exit pupil of the optical system, and the optimized signal to noise ratio. By retrieving selected speckles with enlarged field of view, high quality image is recovered with a responding speed only determined by the frame rates of the image capturing devices. The immediate application of the technique is expected to register static and dynamic imaging under human skin to recover information with a wearable device.

Logarithmic profile mapping multi-scale Retinex for restoration of low illumination images

NASA Astrophysics Data System (ADS)

Shi, Haiyan; Kwok, Ngaiming; Wu, Hongkun; Li, Ruowei; Liu, Shilong; Lin, Ching-Feng; Wong, Chin Yeow

2018-04-01

Images are valuable information sources for many scientific and engineering applications. However, images captured in poor illumination conditions would have a large portion of dark regions that could heavily degrade the image quality. In order to improve the quality of such images, a restoration algorithm is developed here that transforms the low input brightness to a higher value using a modified Multi-Scale Retinex approach. The algorithm is further improved by a entropy based weighting with the input and the processed results to refine the necessary amplification at regions of low brightness. Moreover, fine details in the image are preserved by applying the Retinex principles to extract and then re-insert object edges to obtain an enhanced image. Results from experiments using low and normal illumination images have shown satisfactory performances with regard to the improvement in information contents and the mitigation of viewing artifacts.

Derivation of the scan time requirement for maintaining a consistent PET image quality

NASA Astrophysics Data System (ADS)

Kim, Jin Su; Lee, Jae Sung; Kim, Seok-Ki

2015-05-01

Objectives: the image quality of PET for larger patients is relatively poor, even though the injection dose is optimized considering the NECR characteristics of the PET scanner. This poor image quality is due to the lower level of maximum NECR that can be achieved in these large patients. The aim of this study was to optimize the PET scan time to obtain a consistent PET image quality regardless of the body size, based on the relationship between the patient specific NECR (pNECR) and body weight. Methods: eighty patients (M/F=53/27, body weight: 059 ± 1 kg) underwent whole-body FDG PET scans using a Philips GEMINI GS PET/CT scanner after an injection of 0.14 mCi/kg FDG. The relationship between the scatter fraction (SF) and body weight was determined by repeated Monte Carlo simulations using a NEMA scatter phantom, the size of which varied according to the relationship between the abdominal circumference and body weight. Using this information, the pNECR was calculated from the prompt and delayed PET sinograms to obtain the prediction equation of NECR vs. body weight. The time scaling factor (FTS) for the scan duration was finally derived to make PET images with equivalent SNR levels. Results: the SF and NECR had the following nonlinear relationships with the body weight: SF=0.15 ṡ body weight0.3 and NECR = 421.36 (body weight)-0.84. The equation derived for FTS was 0.01ṡ body weight + 0.2, which means that, for example, a 120-kg person should be scanned 1.8 times longer than a 70 kg person, or the scan time for a 40-kg person can be reduced by 30%. Conclusion: the equation of the relative time demand derived in this study will be useful for maintaining consistent PET image quality in clinics.

Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement.

PubMed

Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

2017-01-01

99m Technetium-methylene diphosphonate ( 99m Tc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99m Tc-MDP-bone scan images. A set of 89 low contrast 99m Tc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t -test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful.

Impact of image quality on OCT angiography based quantitative measurements.

PubMed

Al-Sheikh, Mayss; Ghasemi Falavarjani, Khalil; Akil, Handan; Sadda, SriniVas R

2017-01-01

To study the impact of image quality on quantitative measurements and the frequency of segmentation error with optical coherence tomography angiography (OCTA). Seventeen eyes of 10 healthy individuals were included in this study. OCTA was performed using a swept-source device (Triton, Topcon). Each subject underwent three scanning sessions 1-2 min apart; the first two scans were obtained under standard conditions and for the third session, the image quality index was reduced using application of a topical ointment. En face OCTA images of the retinal vasculature were generated using the default segmentation for the superficial and deep retinal layer (SRL, DRL). Intraclass correlation coefficient (ICC) was used as a measure for repeatability. The frequency of segmentation error, motion artifact, banding artifact and projection artifact was also compared among the three sessions. The frequency of segmentation error, and motion artifact was statistically similar between high and low image quality sessions (P = 0.707, and P = 1 respectively). However, the frequency of projection and banding artifact was higher with a lower image quality. The vessel density in the SRL was highly repeatable in the high image quality sessions (ICC = 0.8), however, the repeatability was low, comparing the high and low image quality measurements (ICC = 0.3). In the DRL, the repeatability of the vessel density measurements was fair in the high quality sessions (ICC = 0.6 and ICC = 0.5, with and without automatic artifact removal, respectively) and poor comparing high and low image quality sessions (ICC = 0.3 and ICC = 0.06, with and without automatic artifact removal, respectively). The frequency of artifacts is higher and the repeatability of the measurements is lower with lower image quality. The impact of image quality index should be always considered in OCTA based quantitative measurements.

Improved Image Quality in Head and Neck CT Using a 3D Iterative Approach to Reduce Metal Artifact.

PubMed

Wuest, W; May, M S; Brand, M; Bayerl, N; Krauss, A; Uder, M; Lell, M

2015-10-01

Metal artifacts from dental fillings and other devices degrade image quality and may compromise the detection and evaluation of lesions in the oral cavity and oropharynx by CT. The aim of this study was to evaluate the effect of iterative metal artifact reduction on CT of the oral cavity and oropharynx. Data from 50 consecutive patients with metal artifacts from dental hardware were reconstructed with standard filtered back-projection, linear interpolation metal artifact reduction (LIMAR), and iterative metal artifact reduction. The image quality of sections that contained metal was analyzed for the severity of artifacts and diagnostic value. A total of 455 sections (mean ± standard deviation, 9.1 ± 4.1 sections per patient) contained metal and were evaluated with each reconstruction method. Sections without metal were not affected by the algorithms and demonstrated image quality identical to each other. Of these sections, 38% were considered nondiagnostic with filtered back-projection, 31% with LIMAR, and only 7% with iterative metal artifact reduction. Thirty-three percent of the sections had poor image quality with filtered back-projection, 46% with LIMAR, and 10% with iterative metal artifact reduction. Thirteen percent of the sections with filtered back-projection, 17% with LIMAR, and 22% with iterative metal artifact reduction were of moderate image quality, 16% of the sections with filtered back-projection, 5% with LIMAR, and 30% with iterative metal artifact reduction were of good image quality, and 1% of the sections with LIMAR and 31% with iterative metal artifact reduction were of excellent image quality. Iterative metal artifact reduction yields the highest image quality in comparison with filtered back-projection and linear interpolation metal artifact reduction in patients with metal hardware in the head and neck area. © 2015 by American Journal of Neuroradiology.

Fast segmentation and high-quality three-dimensional volume mesh creation from medical images for diffuse optical tomography

NASA Astrophysics Data System (ADS)

Jermyn, Michael; Ghadyani, Hamid; Mastanduno, Michael A.; Turner, Wes; Davis, Scott C.; Dehghani, Hamid; Pogue, Brian W.

2013-08-01

Multimodal approaches that combine near-infrared (NIR) and conventional imaging modalities have been shown to improve optical parameter estimation dramatically and thus represent a prevailing trend in NIR imaging. These approaches typically involve applying anatomical templates from magnetic resonance imaging/computed tomography/ultrasound images to guide the recovery of optical parameters. However, merging these data sets using current technology requires multiple software packages, substantial expertise, significant time-commitment, and often results in unacceptably poor mesh quality for optical image reconstruction, a reality that represents a significant roadblock for translational research of multimodal NIR imaging. This work addresses these challenges directly by introducing automated digital imaging and communications in medicine image stack segmentation and a new one-click three-dimensional mesh generator optimized for multimodal NIR imaging, and combining these capabilities into a single software package (available for free download) with a streamlined workflow. Image processing time and mesh quality benchmarks were examined for four common multimodal NIR use-cases (breast, brain, pancreas, and small animal) and were compared to a commercial image processing package. Applying these tools resulted in a fivefold decrease in image processing time and 62% improvement in minimum mesh quality, in the absence of extra mesh postprocessing. These capabilities represent a significant step toward enabling translational multimodal NIR research for both expert and nonexpert users in an open-source platform.

Nonlinear filtering for character recognition in low quality document images

NASA Astrophysics Data System (ADS)

Diaz-Escobar, Julia; Kober, Vitaly

2014-09-01

Optical character recognition in scanned printed documents is a well-studied task, where the captured conditions like sheet position, illumination, contrast and resolution are controlled. Nowadays, it is more practical to use mobile devices for document capture than a scanner. So as a consequence, the quality of document images is often poor owing to presence of geometric distortions, nonhomogeneous illumination, low resolution, etc. In this work we propose to use multiple adaptive nonlinear composite filters for detection and classification of characters. Computer simulation results obtained with the proposed system are presented and discussed.

Effects of training set selection on pain recognition via facial expressions

NASA Astrophysics Data System (ADS)

Shier, Warren A.; Yanushkevich, Svetlana N.

2016-07-01

This paper presents an approach to pain expression classification based on Gabor energy filters with Support Vector Machines (SVMs), followed by analyzing the effects of training set variations on the systems classification rate. This approach is tested on the UNBC-McMaster Shoulder Pain Archive, which consists of spontaneous pain images, hand labelled using the Prkachin and Solomon Pain Intensity scale. In this paper, the subjects pain intensity level has been quantized into three disjoint groups: no pain, weak pain and strong pain. The results of experiments show that Gabor energy filters with SVMs provide comparable or better results to previous filter- based pain recognition methods, with precision rates of 74%, 30% and 78% for no pain, weak pain and strong pain, respectively. The study of effects of intra-class skew, or changing the number of images per subject, show that both completely removing and over-representing poor quality subjects in the training set has little effect on the overall accuracy of the system. This result suggests that poor quality subjects could be removed from the training set to save offline training time and that SVM is robust not only to outliers in training data, but also to significant amounts of poor quality data mixed into the training sets.

An in vitro comparison of subjective image quality of panoramic views acquired via 2D or 3D imaging.

PubMed

Pittayapat, P; Galiti, D; Huang, Y; Dreesen, K; Schreurs, M; Souza, P Couto; Rubira-Bullen, I R F; Westphalen, F H; Pauwels, R; Kalema, G; Willems, G; Jacobs, R

2013-01-01

The objective of this study is to compare subjective image quality and diagnostic validity of cone-beam CT (CBCT) panoramic reformatting with digital panoramic radiographs. Four dry human skulls and two formalin-fixed human heads were scanned using nine different CBCTs, one multi-slice CT (MSCT) and one standard digital panoramic device. Panoramic views were generated from CBCTs in four slice thicknesses. Seven observers scored image quality and visibility of 14 anatomical structures. Four observers repeated the observation after 4 weeks. Digital panoramic radiographs showed significantly better visualization of anatomical structures except for the condyle. Statistical analysis of image quality showed that the 3D imaging modalities (CBCTs and MSCT) were 7.3 times more likely to receive poor scores than the 2D modality. Yet, image quality from NewTom VGi® and 3D Accuitomo 170® was almost equivalent to that of digital panoramic radiographs with respective odds ratio estimates of 1.2 and 1.6 at 95% Wald confidence limits. A substantial overall agreement amongst observers was found. Intra-observer agreement was moderate to substantial. While 2D-panoramic images are significantly better for subjective diagnosis, 2/3 of the 3D-reformatted panoramic images are moderate or good for diagnostic purposes. Panoramic reformattings from particular CBCTs are comparable to digital panoramic images concerning the overall image quality and visualization of anatomical structures. This clinically implies that a 3D-derived panoramic view can be generated for diagnosis with a recommended 20-mm slice thickness, if CBCT data is a priori available for other purposes.

Design and analysis of x-ray vision systems for high-speed detection of foreign body contamination in food

NASA Astrophysics Data System (ADS)

Graves, Mark; Smith, Alexander; Batchelor, Bruce G.; Palmer, Stephen C.

1994-10-01

In the food industry there is an ever increasing need to control and monitor food quality. In recent years fully automated x-ray inspection systems have been used to detect food on-line for foreign body contamination. These systems involve a complex integration of x- ray imaging components with state of the art high speed image processing. The quality of the x-ray image obtained by such systems is very poor compared with images obtained from other inspection processes, this makes reliable detection of very small, low contrast defects extremely difficult. It is therefore extremely important to optimize the x-ray imaging components to give the very best image possible. In this paper we present a method of analyzing the x-ray imaging system in order to consider the contrast obtained when viewing small defects.

Detection of illicit substances in fingerprints by infrared spectral imaging.

PubMed

Ng, Ping Hei Ronnie; Walker, Sarah; Tahtouh, Mark; Reedy, Brian

2009-08-01

FTIR and Raman spectral imaging can be used to simultaneously image a latent fingerprint and detect exogenous substances deposited within it. These substances might include drugs of abuse or traces of explosives or gunshot residue. In this work, spectral searching algorithms were tested for their efficacy in finding targeted substances deposited within fingerprints. "Reverse" library searching, where a large number of possibly poor-quality spectra from a spectral image are searched against a small number of high-quality reference spectra, poses problems for common search algorithms as they are usually implemented. Out of a range of algorithms which included conventional Euclidean distance searching, the spectral angle mapper (SAM) and correlation algorithms gave the best results when used with second-derivative image and reference spectra. All methods tested gave poorer performances with first derivative and undifferentiated spectra. In a search against a caffeine reference, the SAM and correlation methods were able to correctly rank a set of 40 confirmed but poor-quality caffeine spectra at the top of a dataset which also contained 4,096 spectra from an image of an uncontaminated latent fingerprint. These methods also successfully and individually detected aspirin, diazepam and caffeine that had been deposited together in another fingerprint, and they did not indicate any of these substances as a match in a search for another substance which was known not to be present. The SAM was used to successfully locate explosive components in fingerprints deposited on silicon windows. The potential of other spectral searching algorithms used in the field of remote sensing is considered, and the applicability of the methods tested in this work to other modes of spectral imaging is discussed.

Limited-preparation CT colonography in frail elderly patients: a feasibility study.

PubMed

Keeling, Aoife N; Slattery, Michael M; Leong, Sum; McCarthy, Eoghan; Susanto, Maja; Lee, Michael J; Morrin, Martina M

2010-05-01

Full colonic preparation can be onerous and may be poorly tolerated in frail elderly patients. The purpose of this study was to prospectively assess the image quality and diagnostic yield of limited-preparation CT colonography (CTC) in elderly patients with suspected colorectal cancer who were deemed medically unfit or unsuitable for colonoscopy. A prospective study was performed of 67 elderly patients with reduced functional status referred for CTC. Participants were prescribed a limited bowel preparation consisting of a low-residue diet for 3 days, 1 L of 2% oral diatrizoate meglumine (Gastrografin) 24 hours before CTC, and 1 L of 2% oral Gastrografin over the 2 hours immediately before CTC. No cathartic preparation was administered. All colonic segments were graded from 1 to 5 for image quality (1, unreadable; 2, poor; 3, equivocal; 4, good; 5, excellent) and reader confidence. Clinical and conventional colonoscopy follow-up findings were documented, and all colonic and extracolonic pathologic findings were documented. Overall image quality and reader confidence in the evaluation of the colon was rated good or excellent in 84% of the colonic segments. Colonic abnormalities were identified in 12 patients (18%), including four colonic tumors, two polyps, and seven colonic strictures. Incidental extraintestinal findings were detected in 43 patients (64%), including nine patients with lesions radiologically consistent with malignancy. Limited-preparation low-dose CTC is a feasible and useful minimally invasive technique with which to evaluate the colon and exclude gross pathology (mass lesions and polyps > 1 cm) in elderly patients with diminished performance status, yielding good to excellent image quality.

Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement

PubMed Central

Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

2017-01-01

Purpose of the Study: 99mTechnetium-methylene diphosphonate (99mTc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99mTc-MDP-bone scan images. Materials and Methods: A set of 89 low contrast 99mTc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. Results: This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t-test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. Conclusion: GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful. PMID:29142344

Ultrafast Harmonic Coherent Compound (UHCC) imaging for high frame rate echocardiography and Shear Wave Elastography

PubMed Central

Correia, Mafalda; Provost, Jean; Chatelin, Simon; Villemain, Olivier; Tanter, Mickael; Pernot, Mathieu

2016-01-01

Transthoracic shear wave elastography of the myocardium remains very challenging due to the poor quality of transthoracic ultrafast imaging and the presence of clutter noise, jitter, phase aberration, and ultrasound reverberation. Several approaches, such as, e.g., diverging-wave coherent compounding or focused harmonic imaging have been proposed to improve the imaging quality. In this study, we introduce ultrafast harmonic coherent compounding (UHCC), in which pulse-inverted diverging-waves are emitted and coherently compounded, and show that such an approach can be used to enhance both Shear Wave Elastography (SWE) and high frame rate B-mode Imaging. UHCC SWE was first tested in phantoms containing an aberrating layer and was compared against pulse-inversion harmonic imaging and against ultrafast coherent compounding (UCC) imaging at the fundamental frequency. In-vivo feasibility of the technique was then evaluated in six healthy volunteers by measuring myocardial stiffness during diastole in transthoracic imaging. We also demonstrated that improvements in imaging quality could be achieved using UHCC B-mode imaging in healthy volunteers. The quality of transthoracic images of the heart was found to be improved with the number of pulse-inverted diverging waves with reduction of the imaging mean clutter level up to 13.8-dB when compared against UCC at the fundamental frequency. These results demonstrated that UHCC B-mode imaging is promising for imaging deep tissues exposed to aberration sources with a high frame-rate. PMID:26890730

The evaluation of single-view and multi-view fusion 3D echocardiography using image-driven segmentation and tracking.

PubMed

Rajpoot, Kashif; Grau, Vicente; Noble, J Alison; Becher, Harald; Szmigielski, Cezary

2011-08-01

Real-time 3D echocardiography (RT3DE) promises a more objective and complete cardiac functional analysis by dynamic 3D image acquisition. Despite several efforts towards automation of left ventricle (LV) segmentation and tracking, these remain challenging research problems due to the poor-quality nature of acquired images usually containing missing anatomical information, speckle noise, and limited field-of-view (FOV). Recently, multi-view fusion 3D echocardiography has been introduced as acquiring multiple conventional single-view RT3DE images with small probe movements and fusing them together after alignment. This concept of multi-view fusion helps to improve image quality and anatomical information and extends the FOV. We now take this work further by comparing single-view and multi-view fused images in a systematic study. In order to better illustrate the differences, this work evaluates image quality and information content of single-view and multi-view fused images using image-driven LV endocardial segmentation and tracking. The image-driven methods were utilized to fully exploit image quality and anatomical information present in the image, thus purposely not including any high-level constraints like prior shape or motion knowledge in the analysis approaches. Experiments show that multi-view fused images are better suited for LV segmentation and tracking, while relatively more failures and errors were observed on single-view images. Copyright © 2011 Elsevier B.V. All rights reserved.

Scanning fiber endoscopy with highly flexible, 1-mm catheterscopes for wide-field, full-color imaging

PubMed Central

Lee, Cameron M.; Engelbrecht, Christoph J.; Soper, Timothy D.; Helmchen, Fritjof; Seibel, Eric J.

2011-01-01

In modern endoscopy, wide field of view and full color are considered necessary for navigating inside the body, inspecting tissue for disease and guiding interventions such as biopsy or surgery. Current flexible endoscope technologies suffer from reduced resolution when device diameter shrinks. Endoscopic procedures today using coherent fiber bundle technology, on the scale of 1 mm, are performed with such poor image quality that the clinician’s vision meets the criteria for legal blindness. Here, we review a new and versatile scanning fiber imaging technology and describe its implementation for ultrathin and flexible endoscopy. This scanning fiber endoscope (SFE) or catheterscope enables high quality, laser-based, video imaging for ultrathin clinical applications while also providing new options for in vivo biological research of subsurface tissue and high resolution fluorescence imaging. PMID:20336702

SU-E-CAMPUS-J-04: Image Guided Radiation Therapy (IGRT): Review of Technical Standards and Credentialing in Radiotherapy Clinical Trials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giaddui, T; Chen, W; Yu, J

2014-06-15

Purpose: To review IGRT credentialing experience and unexpected technical issues encountered in connection with advanced radiotherapy technologies as implemented in RTOG clinical trials. To update IGRT credentialing procedures with the aim of improving the quality of the process, and to increase the proportion of IGRT credentialing compliance. To develop a living disease site-specific IGRT encyclopedia. Methods: Numerous technical issues were encountered during the IGRT credentialing process. The criteria used for credentialing review were based on: image quality; anatomy included in fused data sets and shift results. Credentialing requirements have been updated according to the AAPM task group reports for IGRTmore » to ensure that all required technical items are included in the quality review process. Implementation instructions have been updated and expanded for recent protocols. Results: Technical issues observed during the credentialing review process include, but are not limited to: poor quality images; inadequate image acquisition region; poor data quality; shifts larger than acceptable; no soft tissue surrogate. The updated IGRT credentialing process will address these issues and will also include the technical items required from AAPM: TG 104; TG 142 and TG 179 reports. An instruction manual has been developed describing a remote credentialing method for reviewers. Submission requirements are updated, including images/documents as well as facility questionnaire. The review report now includes summary of the review process and the parameters that reviewers check. We have reached consensus on the minimum IGRT technical requirement for a number of disease sites. RTOG 1311(NRG-BR002A Phase 1 Study of Stereotactic Body Radiotherapy (SBRT) for the Treatment of Multiple Metastases) is an example, here; the protocol specified the minimum requirement for each anatomical sites (with/without fiducials). Conclusion: Technical issues are identified and reported. IGRT guidelines are updated, with the corresponding credentialing requirements. An IGRT encyclopedia describing site-specific implementation issues is currently in development.« less

Smartphone-based grading of apple quality

NASA Astrophysics Data System (ADS)

Li, Xianglin; Li, Ting

2018-02-01

Apple quality grading is a critical issue in apple industry which is one economical pillar of many countries. Artificial grading is inefficient and of poor accuracy. Here we proposed to develop a portable, convenient, real-time, and low cost method aimed at grading apple. Color images of the apples were collected with a smartphone and the grade of sampled apple was assessed by a customized smartphone app, which offered the functions translating RGB color values of the apple to color grade and translating the edge of apple image to weight grade. The algorithms are based on modeling with a large number of apple image at different grades. The apple grade data evaluated by the smartphone are in accordance with the actual data. This study demonstrated the potential of smart phone in apple quality grading/online monitoring at gathering and transportation stage for apple industry.

The Quality of In Vivo Upconversion Fluorescence Signals Inside Different Anatomic Structures.

PubMed

Wang, Lijiang; Draz, Mohamed Shehata; Wang, Wei; Liao, Guodong; Xu, Yuhong

2015-02-01

Fluorescence imaging is a broadly interesting and rapidly growing strategy for non-invasive clinical applications. However, because of interference from light scattering, absorbance, and tissue autofluorescence, the images can exhibit low sensitivity and poor quality. Upconversion fluorescence imaging, which is based on the use of near-infrared (NIR) light for excitation, has recently been introduced as an improved approach to minimize the effects of light scattering and tissue autofluorescence. This strategy is promising for ultrasensitive and deep tissue imaging applications. However, the emitted upconversion fluorescence signals are primarily in the visible range and are likely to be absorbed and scattered by tissues. Therefore, different anatomic structures could impose various effects on the quality of the images. In this study, we used upconversion-core/silica-shell nanoprobes to evaluate the quality of upconversion fluorescence at different anatomic locations in athymic nude mice. The nanoprobe contained an upconversion core, which was green (β-NaYF4:Yb3+/Ho3+) or red (β-NaYF4:Yb3+/Er3+), and a nonporous silica shell to allow for multicolor imaging. High-quality upconversion fluorescence signals were detected with signal-to-noise ratios of up to 170 at tissue depths of up to - 1.0 cm when a 980 nm laser excitation source and a bandpass emission filter were used. The presence of dense tissue structures along the imaging path reduced the signal intensity and imaging quality, and nanoprobes with longer-wavelength emission spectra were therefore preferable. This study offers a detailed analysis of the quality of upconversion signals in vivo inside different anatomic structures. Such information could be essential for the analysis of upconversion fluorescence images in any in vivo biodiagnostic and microbial tracking applications.

Posterior limb of the internal capsule predicts poor quality of life in patients with Parkinson's disease: connectometry approach.

PubMed

Ghazi Sherbaf, Farzaneh; Mojtahed Zadeh, Mahtab; Haghshomar, Maryam; Aarabi, Mohammad Hadi

2018-03-14

Psychiatric symptoms and motor impairment are major contributions to the poor quality of life in patients with Parkinson's disease (PD). Here, we applied a novel diffusion-weighted imaging approach, diffusion MRI connectometry, to investigate the correlation of quality of life, evaluated by Parkinson's Disease Questionnaire (PDQ39) with the white matter structural connectivity in 27 non-demented PD patients (disease duration of 5.3 ± 2.9 years, H and Y stage = 1.5 ± 0.6, UPDRS-III = 13.7 ± 6.5, indicating unilateral and mild motor involvement). The connectometry analysis demonstrated bilateral posterior limbs of the internal capsule (PLIC) with increased connectivity related to the higher quality of life (FDR = 0.027) in a multiple regression model. The present study suggests for the first time a neural basis of the quality of life in PD in the light of major determinants of poor quality of life in these patients: anxiety, depression, apathy and motor impairment. Results in our sample of non-demented PD patients with relatively mild motor impairment and no apparent sign of depression/anxiety also identify a unique and inexplicable association of the PLIC to the quality of life in PD patients.

Clinical comparison of CR and screen film for imaging the critically ill neonate

NASA Astrophysics Data System (ADS)

Andriole, Katherine P.; Brasch, Robert C.; Gooding, Charles A.; Gould, Robert G.; Cohen, Pierre A.; Rencken, Ingo R.; Huang, H. K.

1996-05-01

A clinical comparison of computed radiography (CR) versus screen-film for imaging the critically-ill neonate is performed, utilizing a modified (hybrid) film cassette containing a CR (standard ST-V) imaging plate, a conventional screen and film, allowing simultaneous acquisition of perfectly matched CR and plain film images. For 100 portable neonatal chest and abdominal projection radiographs, plain film was subjectively compared to CR hardcopy. Three pediatric radiologists graded overall image quality on a scale of one (poor) to five (excellent), as well as visualization of various anatomic structures (i.e., lung parenchyma, pulmonary vasculature, tubes/lines) and pathological findings (i.e., pulmonary interstitial emphysema, pleural effusion, pneumothorax). Results analyzed using a combined kappa statistic of the differences between scores from each matched set, combined over the three readers showed no statistically significant difference in overall image quality between screen- film and CR (p equals 0.19). Similarly, no statistically significant difference was seen between screen-film and CR for anatomic structure visualization and for visualization of pathological findings. These results indicate that the image quality of CR is comparable to plain film, and that CR may be a suitable alternative to screen-film imaging for portable neonatal chest and abdominal examinations.

Comparison of Transesophageal and Transthoracic Contrast Echocardiography for Detection of a Patent Foramen Ovale

NASA Technical Reports Server (NTRS)

Siostrzonek, Peter; Zangeneh, Massoud; Gossinger, Heinz; Lang, Wilfried; Rosenmayr, Georg; Heinz, Gottfried; Stumpflen, Andreas; Zeiler, Karl; Schwarz, Martin; Mosslacher, Herbert

1991-01-01

Presence of a patent foramen ovale may indicate paradoxic embolism in patients with otherwise unexplained embolic disease. Transthoracic contrast echocardiography has been used as a simple technique for detecting patent foramen ovale. However, particularly in patients with poor transthoracic image quality, presence of a patent foramen ovale might be missed. Transesophageal contrast echocardiography provides superior visualization of the atrial septum and therefore is believed to improve diagnostic accuracy. The present study investigates the influence of image quality on the detection of a patent foramen ovale by both transthoracic and transesophageal contrast echocardiography.

Psychological assessment for adults and children

USDA-ARS?s Scientific Manuscript database

Psychological factors play a significant role in many nutritional abnormalities. These factors include mood (e.g., depression, anger, and anxiety), emotional eating, distorted body image, low self-esteem, poor self-efficacy and quality of life, dietary restraint, stress, susceptibility to external c...

A further study to investigate the detection and enhancement of latent fingerprints using visible absorption and luminescence chemical imaging.

PubMed

Payne, Gemma; Reedy, Brian; Lennard, Chris; Comber, Bruce; Exline, David; Roux, Claude

2005-05-28

This study investigated the application of chemical imaging to the detection of latent fingerprints using the Condor macroscopic chemical imaging system (ChemImage Corp., Pittsburgh, USA). Methods were developed and optimised for the visualisation of untreated latent fingerprints and fingerprints processed with DFO, ninhydrin, cyanoacrylate, and cyanoacrylate plus rhodamine 6G stain. The results obtained with chemical imaging were compared to the detection achieved using conventional imaging techniques. The Condor significantly improved the detection of many prints, especially those that might be considered poor quality or borderline prints. Prints on newspaper treated with ninhydrin and DFO, and prints on white and yellow paper treated with ninhydrin, benefited the most from chemical imaging detection. In many cases, fingerprints undetectable using conventional imaging techniques could be visualised with chemical imaging. Ridge detail from untreated prints on yellow paper was also detected using the Condor. When prints of high quality were examined, both detection techniques produced quality results. The results of this project demonstrate that chemical imaging offers advantages over conventional visualisation techniques when examining latent fingerprints, especially those that would be considered difficult, such as weak prints or prints on surfaces that produce highly luminescent backgrounds. Standard testing procedures for the detection and enhancement of fingerprints by chemical imaging are presented and discussed.

How Many Pixels Does It Take to Make a Good 4"×6" Print? Pixel Count Wars Revisited

NASA Astrophysics Data System (ADS)

Kriss, Michael A.

Digital still cameras emerged following the introduction of the Sony Mavica analog prototype camera in 1981. These early cameras produced poor image quality and did not challenge film cameras for overall quality. By 1995 digital still cameras in expensive SLR formats had 6 mega-pixels and produced high quality images (with significant image processing). In 2005 significant improvement in image quality was apparent and lower prices for digital still cameras (DSCs) started a rapid decline in film usage and film camera sells. By 2010 film usage was mostly limited to professionals and the motion picture industry. The rise of DSCs was marked by a “pixel war” where the driving feature of the cameras was the pixel count where even moderate cost, ˜120, DSCs would have 14 mega-pixels. The improvement of CMOS technology pushed this trend of lower prices and higher pixel counts. Only the single lens reflex cameras had large sensors and large pixels. The drive for smaller pixels hurt the quality aspects of the final image (sharpness, noise, speed, and exposure latitude). Only today are camera manufactures starting to reverse their course and producing DSCs with larger sensors and pixels. This paper will explore why larger pixels and sensors are key to the future of DSCs.

90Y Liver Radioembolization Imaging Using Amplitude-Based Gated PET/CT.

PubMed

Osborne, Dustin R; Acuff, Shelley; Neveu, Melissa; Kaman, Austin; Syed, Mumtaz; Fu, Yitong

2017-05-01

The usage of PET/CT to monitor patients with hepatocellular carcinoma following Y radioembolization has increased; however, image quality is often poor because of low count efficiency and respiratory motion. Motion can be corrected using gating techniques but at the expense of additional image noise. Amplitude-based gating has been shown to improve quantification in FDG PET, but few have used this technique in Y liver imaging. The patients shown in this work indicate that amplitude-based gating can be used in Y PET/CT liver imaging to provide motion-corrected images with higher estimates of activity concentration that may improve posttherapy dosimetry.

Quality of Radiomic Features in Glioblastoma Multiforme: Impact of Semi-Automated Tumor Segmentation Software

PubMed Central

Lee, Myungeun; Woo, Boyeong; Kuo, Michael D.; Jamshidi, Neema

2017-01-01

Objective The purpose of this study was to evaluate the reliability and quality of radiomic features in glioblastoma multiforme (GBM) derived from tumor volumes obtained with semi-automated tumor segmentation software. Materials and Methods MR images of 45 GBM patients (29 males, 16 females) were downloaded from The Cancer Imaging Archive, in which post-contrast T1-weighted imaging and fluid-attenuated inversion recovery MR sequences were used. Two raters independently segmented the tumors using two semi-automated segmentation tools (TumorPrism3D and 3D Slicer). Regions of interest corresponding to contrast-enhancing lesion, necrotic portions, and non-enhancing T2 high signal intensity component were segmented for each tumor. A total of 180 imaging features were extracted, and their quality was evaluated in terms of stability, normalized dynamic range (NDR), and redundancy, using intra-class correlation coefficients, cluster consensus, and Rand Statistic. Results Our study results showed that most of the radiomic features in GBM were highly stable. Over 90% of 180 features showed good stability (intra-class correlation coefficient [ICC] ≥ 0.8), whereas only 7 features were of poor stability (ICC < 0.5). Most first order statistics and morphometric features showed moderate-to-high NDR (4 > NDR ≥1), while above 35% of the texture features showed poor NDR (< 1). Features were shown to cluster into only 5 groups, indicating that they were highly redundant. Conclusion The use of semi-automated software tools provided sufficiently reliable tumor segmentation and feature stability; thus helping to overcome the inherent inter-rater and intra-rater variability of user intervention. However, certain aspects of feature quality, including NDR and redundancy, need to be assessed for determination of representative signature features before further development of radiomics. PMID:28458602

Quality of Radiomic Features in Glioblastoma Multiforme: Impact of Semi-Automated Tumor Segmentation Software.

PubMed

Lee, Myungeun; Woo, Boyeong; Kuo, Michael D; Jamshidi, Neema; Kim, Jong Hyo

2017-01-01

The purpose of this study was to evaluate the reliability and quality of radiomic features in glioblastoma multiforme (GBM) derived from tumor volumes obtained with semi-automated tumor segmentation software. MR images of 45 GBM patients (29 males, 16 females) were downloaded from The Cancer Imaging Archive, in which post-contrast T1-weighted imaging and fluid-attenuated inversion recovery MR sequences were used. Two raters independently segmented the tumors using two semi-automated segmentation tools (TumorPrism3D and 3D Slicer). Regions of interest corresponding to contrast-enhancing lesion, necrotic portions, and non-enhancing T2 high signal intensity component were segmented for each tumor. A total of 180 imaging features were extracted, and their quality was evaluated in terms of stability, normalized dynamic range (NDR), and redundancy, using intra-class correlation coefficients, cluster consensus, and Rand Statistic. Our study results showed that most of the radiomic features in GBM were highly stable. Over 90% of 180 features showed good stability (intra-class correlation coefficient [ICC] ≥ 0.8), whereas only 7 features were of poor stability (ICC < 0.5). Most first order statistics and morphometric features showed moderate-to-high NDR (4 > NDR ≥1), while above 35% of the texture features showed poor NDR (< 1). Features were shown to cluster into only 5 groups, indicating that they were highly redundant. The use of semi-automated software tools provided sufficiently reliable tumor segmentation and feature stability; thus helping to overcome the inherent inter-rater and intra-rater variability of user intervention. However, certain aspects of feature quality, including NDR and redundancy, need to be assessed for determination of representative signature features before further development of radiomics.

Useful diagnostic biometabolic data obtained by PET/CT and MR fusion imaging using open source software.

PubMed

Antonica, Filippo; Asabella, Artor Niccoli; Ferrari, Cristina; Rubini, Domenico; Notaristefano, Antonio; Nicoletti, Adriano; Altini, Corinna; Merenda, Nunzio; Mossa, Emilio; Guarini, Attilio; Rubini, Giuseppe

2014-01-01

In the last decade numerous attempts were considered to co-register and integrate different imaging data. Like PET/CT the integration of PET to MR showed great interest. PET/MR scanners are recently tested on different distrectual or systemic pathologies. Unfortunately PET/MR scanners are expensive and diagnostic protocols are still under studies and investigations. Nuclear Medicine imaging highlights functional and biometabolic information but has poor anatomic details. The aim of this study is to integrate MR and PET data to produce distrectual or whole body fused images acquired from different scanners even in different days. We propose an offline method to fuse PET with MR data using an open-source software that has to be inexpensive, reproducible and capable to exchange data over the network. We also evaluate global quality, alignment quality, and diagnostic confidence of fused PET-MR images. We selected PET/CT studies performed in our Nuclear Medicine unit, MR studies provided by patients on DICOM CD media or network received. We used Osirix 5.7 open source version. We aligned CT slices with the first MR slice, pointed and marked for co-registration using MR-T1 sequence and CT as reference and fused with PET to produce a PET-MR image. A total of 100 PET/CT studies were fused with the following MR studies: 20 head, 15 thorax, 24 abdomen, 31 pelvis, 10 whole body. An interval of no more than 15 days between PET and MR was the inclusion criteria. PET/CT, MR and fused studies were evaluated by two experienced radiologist and two experienced nuclear medicine physicians. Each one filled a five point based evaluation scoring scheme based on image quality, image artifacts, segmentation errors, fusion misalignment and diagnostic confidence. Our fusion method showed best results for head, thorax and pelvic districts in terms of global quality, alignment quality and diagnostic confidence,while for the abdomen and pelvis alignement quality and global quality resulted poor due to internal organs filling variation and time shifting beetwen examinations. PET/CT images with time of flight reconstruction and real attenuation correction were combined with anatomical detailed MRI images. We used Osirix, an image processing Open Source Software dedicated to DICOM images. No additional costs, to buy and upgrade proprietary software are required for combining data. No high technology or very expensive PET/MR scanner, that requires dedicated shielded room spaces and personnel to be employed or to be trained, are needed. Our method allows to share patient PET/MR fused data with different medical staff using dedicated networks. The proposed method may be applied to every MR sequence (MR-DWI and MR-STIR, magnet enhanced sequences) to characterize soft tissue alterations and improve discrimination diseases. It can be applied not only to PET with MR but virtually to every DICOM study.

Image quality comparison of two multifocal IOLs: influence of the pupil.

PubMed

García-Domene, Mari Carmen; Felipe, Adelina; Peris-Martínez, Cristina; Navea, Amparo; Artigas, Jose M; Pons, Álvaro M

2015-04-01

To evaluate the effect of pupil size on image quality of a sectorial multifocal intraocular lens (IOL), the Lentis Mplus (Oculentis GmbH, Berlin, Germany), and the Acri.LISA IOL (Carl Zeiss Meditec, Jena, Germany). The authors measured the MTFs of the Lentis Mplus LS-312 IOL and the Acri.LISA 366D IOL with three different sizes of pupil diameters: 3, 4, and 5 mm. The MTF was calculated from the cross-line spread function recorded with the OPAL Vector System (Image Science Ltd., Oxford, UK) by using fast Fourier-transform techniques. In distance focus, the image quality provided by the Lentis Mplus IOL was better than that of the Acri. LISA IOL with all pupil diameters. In near focus, the MTF of the Acri.LISA IOL was better with a 3-mm pupil, but poor with larger pupils. The aberration effect was equal in both IOLs in distance focus, but in near focus and with a 3-mm pupil, the Acri.LISA IOL was less affected by the aberration than the Lentis Mplus IOL. The Lentis Mplus IOL provides better distance image quality than the Acri.LISA IOL, whereas the near image quality of the Acri.LISA IOL is better with small-pupil diameter. The sectorial design makes this IOL more suitable for patients with a pupil diameter greater than 3 mm. Copyright 2015, SLACK Incorporated.

Errors in imaging of traumatic injuries.

PubMed

Scaglione, Mariano; Iaselli, Francesco; Sica, Giacomo; Feragalli, Beatrice; Nicola, Refky

2015-10-01

The advent of multi-detector computed tomography (MDCT) has drastically improved the outcomes of patients with multiple traumatic injuries. However, there are still diagnostic challenges to be considered. A missed or the delay of a diagnosis in trauma patients can sometimes be related to perception or other non-visual cues, while other errors are due to poor technique or poor image quality. In order to avoid any serious complications, it is important for the practicing radiologist to be cognizant of some of the most common types of errors. The objective of this article is to review the various types of errors in the evaluation of patients with multiple trauma injuries or polytrauma with MDCT.

Automated estimation of image quality for coronary computed tomographic angiography using machine learning.

PubMed

Nakanishi, Rine; Sankaran, Sethuraman; Grady, Leo; Malpeso, Jenifer; Yousfi, Razik; Osawa, Kazuhiro; Ceponiene, Indre; Nazarat, Negin; Rahmani, Sina; Kissel, Kendall; Jayawardena, Eranthi; Dailing, Christopher; Zarins, Christopher; Koo, Bon-Kwon; Min, James K; Taylor, Charles A; Budoff, Matthew J

2018-03-23

Our goal was to evaluate the efficacy of a fully automated method for assessing the image quality (IQ) of coronary computed tomography angiography (CCTA). The machine learning method was trained using 75 CCTA studies by mapping features (noise, contrast, misregistration scores, and un-interpretability index) to an IQ score based on manual ground truth data. The automated method was validated on a set of 50 CCTA studies and subsequently tested on a new set of 172 CCTA studies against visual IQ scores on a 5-point Likert scale. The area under the curve in the validation set was 0.96. In the 172 CCTA studies, our method yielded a Cohen's kappa statistic for the agreement between automated and visual IQ assessment of 0.67 (p < 0.01). In the group where good to excellent (n = 163), fair (n = 6), and poor visual IQ scores (n = 3) were graded, 155, 5, and 2 of the patients received an automated IQ score > 50 %, respectively. Fully automated assessment of the IQ of CCTA data sets by machine learning was reproducible and provided similar results compared with visual analysis within the limits of inter-operator variability. • The proposed method enables automated and reproducible image quality assessment. • Machine learning and visual assessments yielded comparable estimates of image quality. • Automated assessment potentially allows for more standardised image quality. • Image quality assessment enables standardization of clinical trial results across different datasets.

Less iodine injected for the same diagnostic performances: comparison of two low-osmolar contrast agents (iobitridol 350 and iopamidol 370) in coronary angiography and ventriculography: a randomized double-blind clinical study.

PubMed

Velázquez, Maríia Teresa; Albarrán, Agustín; Hernández, Felipe; García Tejada, Julio; Zueco, Javier; Andreu, Javier; De la Torre, Jose-María; Figueroa, Alvaro; Sainz, Fermin; Tascón, Juan

2010-08-01

Mild reductions in iodine concentration could reduce acute side effects after intraarterial contrast media administration without affecting the quality of coronary artery images. This study was designed to show the equivalence in terms of image quality of two nonionic low-osmolar monomers, iobitridol 350 and iopamidol 370, and to compare their clinical safety in coronary angiography and ventriculography. In this multicentre, double-blind clinical trial, 98 adult patients were randomized to receive either iobitridol 350 or iopamidol 370. The image quality (primary evaluation criterion) of the whole examination was assessed using a 5-point scale (poor, fair, moderate, good, excellent). Secondary endpoints were the image quality per territory, diagnostic efficacy, practical comfort (5-point scale: impossible to evaluate, not practical, moderately practical, practical, very practical to use) and clinical safety (adverse events and vital signs). The proportions of examinations presenting with good or excellent global image quality was similar with both contrast media: 87.8% with iobitridol 350 vs. 89.8% with iopamidol 370. Similar results were observed when considering the image quality specifically for each major coronary artery and left ventricle. No difference between groups was found with respect to other secondary criteria. Adverse events occurred in 7 patients with iobitridol 350 (14.3%) and in 10 patients with iopamidol 370 (20.4%). This study showed that, with regard to image quality and diagnostic efficacy and using a lower iodine concentration, iobitridol 350 was comparable to iopamidol 370 in adult patients requiring coronary angiography and ventriculography for diagnostic indications.

Video coding for next-generation surveillance systems

NASA Astrophysics Data System (ADS)

Klasen, Lena M.; Fahlander, Olov

1997-02-01

Video is used as recording media in surveillance system and also more frequently by the Swedish Police Force. Methods for analyzing video using an image processing system have recently been introduced at the Swedish National Laboratory of Forensic Science, and new methods are in focus in a research project at Linkoping University, Image Coding Group. The accuracy of the result of those forensic investigations often depends on the quality of the video recordings, and one of the major problems when analyzing videos from crime scenes is the poor quality of the recordings. Enhancing poor image quality might add manipulative or subjective effects and does not seem to be the right way of getting reliable analysis results. The surveillance system in use today is mainly based on video techniques, VHS or S-VHS, and the weakest link is the video cassette recorder, (VCR). Multiplexers for selecting one of many camera outputs for recording is another problem as it often filters the video signal, and recording is limited to only one of the available cameras connected to the VCR. A way to get around the problem of poor recording is to simultaneously record all camera outputs digitally. It is also very important to build such a system bearing in mind that image processing analysis methods becomes more important as a complement to the human eye. Using one or more cameras gives a large amount of data, and the need for data compression is more than obvious. Crime scenes often involve persons or moving objects, and the available coding techniques are more or less useful. Our goal is to propose a possible system, being the best compromise with respect to what needs to be recorded, movements in the recorded scene, loss of information and resolution etc., to secure the efficient recording of the crime and enable forensic analysis. The preventative effective of having a well functioning surveillance system and well established image analysis methods is not to be neglected. Aspects of this next generation of digital surveillance systems are discussed in this paper.

High-quality low-dose cardiovascular computed tomography (CCT) in pediatric patients using a 64-slice scanner.

PubMed

Cannaò, Paola Maria; Secchi, Francesco; Alì, Marco; D'Angelo, Ida Daniela; Scarabello, Marco; Di Leo, Giovanni; Sardanelli, Francesco

2018-01-01

Background Cardiovascular computed tomography (CCT) technology is rapidly advancing allowing to perform good quality examinations with a radiation dose as low as 1.2 mSv. However, latest generation scanners are not available in all centers. Purpose To estimate radiation dose and image quality in pediatric CCT using a standard 64-slice scanner. Material and Methods A total of 100 patients aged 6.9 ± 5.4 years (mean ± standard deviation) who underwent a 64-slice CCT scan using 80, 100, or 120 kVp, were retrospectively evaluated. Radiation effective dose was calculated on the basis of the dose length product. Two independent readers assessed the image quality through signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and a qualitative score (3 = very good, 2 = good, 1 = poor). Non-parametric tests were used. Results Fifty-five exams were not electrocardiographically (ECG) triggered, 20 had a prospective ECG triggering, and 25 had retrospective ECG triggering. The median effective dose was 1.3 mSv (interquartile range [IQR] = 0.8-2.7 mSv). Median SNR was 30.6 (IQR = 23.4-33.6) at 120 kVp, 29.4 (IQR = 23.7-34.8) at 100 kVp, and 24.7 (IQR = 19.4-34.3) at 80 kVp. Median CNR was 21.0 (IQR = 14.8-24.4), 19.1 (IQR = 15.6-23.9), and 25.3 (IQR = 19.4-33.4), respectively. Image quality was very good, good, and poor in 56, 39, and 5 patients, respectively. No significant differences were found among voltage groups for SNR ( P = 0.486), CNR ( P = 0.336), and subjective image quality ( P = 0.296). The inter-observer reproducibility was almost perfect (κ = 0.880). Conclusion High-quality pediatric CCT can be performed using a 64-slice scanner, with a radiation effective dose close to 2 mSv in about 50% of the cases.

A Comparison of Ultrasound Tomography Methods in Circular Geometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leach, R R; Azevedo, S G; Berryman, J G

2002-01-24

Extremely high quality data was acquired using an experimental ultrasound scanner developed at Lawrence Livermore National Laboratory using a 2D ring geometry with up to 720 transmitter/receiver transducer positions. This unique geometry allows reflection and transmission modes and transmission imaging and quantification of a 3D volume using 2D slice data. Standard image reconstruction methods were applied to the data including straight-ray filtered back projection, reflection tomography, and diffraction tomography. Newer approaches were also tested such as full wave, full wave adjoint method, bent-ray filtered back projection, and full-aperture tomography. A variety of data sets were collected including a formalin-fixed humanmore » breast tissue sample, a commercial ultrasound complex breast phantom, and cylindrical objects with and without inclusions. The resulting reconstruction quality of the images ranges from poor to excellent. The method and results of this study are described including like-data reconstructions produced by different algorithms with side-by-side image comparisons. Comparisons to medical B-scan and x-ray CT scan images are also shown. Reconstruction methods with respect to image quality using resolution, noise, and quantitative accuracy, and computational efficiency metrics will also be discussed.« less

Association between stigma, depression and quality of life of people living with HIV/AIDS (PLHA) in South India - a community based cross sectional study.

PubMed

Charles, Bimal; Jeyaseelan, Lakshmanan; Pandian, Arvind Kumar; Sam, Asirvatham Edwin; Thenmozhi, Mani; Jayaseelan, Visalakshi

2012-06-21

India has around 2.27 million adults living with HIV/AIDS who face several challenges in the medical management of their disease. Stigma, discrimination and psychosocial issues are prevalent. The objective of the study was to determine the prevalence of severe stigma and to study the association between this, depression and the quality of life (QOL) of people living with HIV/AIDS (PLHA) in Tamil Nadu. This was a community based cross sectional study carried out in seven districts of Tamil Nadu, India, among 400 PLHA in the year 2009. The following scales were used for stigma, depression and quality of life, Berger scale, Major Depression Inventory (MDI) scale and the WHO BREF scale. Both Stigma and QOL were classified as none, moderate or severe/poor based on the tertile cut off values of the scale scores. Depression was classified as none, mild, moderate and severe. Logistic regression analyses were performed to study the risk factors. Twenty seven per cent of PLHA had experienced severe forms of stigma. These were severe forms of personalized stigma (28.8%), negative self-image (30.3%), perceived public attitude (18.2%) and disclosure concerns (26%). PLHA experiencing severe depression were 12% and those experiencing poor quality of life were 34%. Poor QOL reported in the physical, psychological, social and environmental domains was 42.5%, 40%, 51.2% and 34% respectively. PLHA who had severe personalized stigma and negative self-image had 3.4 (1.6-7.0) and 2.1 (1.0-4.1) times higher risk of severe depression respectively (p < .001). PLHA who had severe depression had experienced 2.7(1.1-7.7) times significantly poorer QOL. Severe forms of stigma were equivalently prevalent among all the categories of PLHA. However, PLHA who had experienced severe depression had only developed poor QOL. A high level of social support was associated with a high level of QOL.

Auditing fetal nasal bone images in the first trimester of pregnancy: results from a peer review program.

PubMed

Palermo, Fernanda Gasparin; Albuquerque, Débora de Paula Soares de Medeiros; Martins, Wellington P; Araujo Júnior, Edward; Bruns, Rafael Frederico

2016-09-01

To establish a structured review process to facilitate the identification of the fetal nasal bone (NB) in the first trimester ultrasound scan to improve the quality images. We conducted a retrospective observational study in fetal NB images obtained during ultrasound exams of singleton pregnancies that underwent first trimester screening (crown-rump length 45-84 mm). When the images were obtained the examiner was not aware of the study. Audit was conducted by an examiner according criteria established by the Fetal Medicine Foundation. Fetal NB images were assessed regarding adequate magnification, mid-sagittal view and transducer held parallel to the direction of the nose. The transvaginal and transabdominal as well as anterior and posterior fetal back groups were compared using χ(2) test. We considered 874 fetal NB images for auditing. Fetal NB was considered present in 865 images (99%). During the audit process, we identified 72 (8.2%) cases of disagreement between examiner and auditor assessments. Disagreement was higher when image quality was poor (62 cases = 7%). Transvaginal approach performed better in the following criteria: adequate magnification (p < 0.001), midline (p < 0.001) and completely adequate (p < 0.001). A peer reviewed audit program for fetal NB is feasible in a clinical scenario. Image quality appears to play an important role in compliance to image standards audited and in agreement between examiner and auditor.

Echocardiographic Image Quality Deteriorates with Age in Children and Young Adults with Duchenne Muscular Dystrophy.

PubMed

Power, Alyssa; Poonja, Sabrina; Disler, Dal; Myers, Kimberley; Patton, David J; Mah, Jean K; Fine, Nowell M; Greenway, Steven C

2017-01-01

Advances in medical care for patients with Duchenne muscular dystrophy (DMD) have resulted in improved survival and an increased prevalence of cardiomyopathy. Serial echocardiographic surveillance is recommended to detect early cardiac dysfunction and initiate medical therapy. Clinical anecdote suggests that echocardiographic quality diminishes over time, impeding accurate assessment of left ventricular systolic function. Furthermore, evidence-based guidelines for the use of cardiac imaging in DMD, including cardiac magnetic resonance imaging (CMR), are limited. The objective of our single-center, retrospective study was to quantify the deterioration in echocardiographic image quality with increasing patient age and identify an age at which CMR should be considered. We retrospectively reviewed and graded the image quality of serial echocardiograms obtained in young patients with DMD. The quality of 16 left ventricular segments in two echocardiographic views was visually graded using a binary scoring system. An endocardial border delineation percentage (EBDP) score was calculated by dividing the number of segments with adequate endocardial delineation in each imaging window by the total number of segments present in that window and multiplying by 100. Linear regression analysis was performed to model the relationship between the EBDP scores and patient age. Fifty-five echocardiograms from 13 patients (mean age 11.6 years, range 3.6-19.9) were systematically reviewed. By 13 years of age, 50% of the echocardiograms were classified as suboptimal with ≥30% of segments inadequately visualized, and by 15 years of age, 78% of studies were suboptimal. Linear regression analysis revealed a negative correlation between patient age and EBDP score ( r  = -2.49, 95% confidence intervals -4.73, -0.25; p  = 0.032), with the score decreasing by 2.5% for each 1 year increase in age. Echocardiographic image quality declines with increasing age in DMD. Alternate imaging modalities may play a role in cases of poor echocardiographic image quality.

Harvesting geographic features from heterogeneous raster maps

NASA Astrophysics Data System (ADS)

Chiang, Yao-Yi

2010-11-01

Raster maps offer a great deal of geospatial information and are easily accessible compared to other geospatial data. However, harvesting geographic features locked in heterogeneous raster maps to obtain the geospatial information is challenging. This is because of the varying image quality of raster maps (e.g., scanned maps with poor image quality and computer-generated maps with good image quality), the overlapping geographic features in maps, and the typical lack of metadata (e.g., map geocoordinates, map source, and original vector data). Previous work on map processing is typically limited to a specific type of map and often relies on intensive manual work. In contrast, this thesis investigates a general approach that does not rely on any prior knowledge and requires minimal user effort to process heterogeneous raster maps. This approach includes automatic and supervised techniques to process raster maps for separating individual layers of geographic features from the maps and recognizing geographic features in the separated layers (i.e., detecting road intersections, generating and vectorizing road geometry, and recognizing text labels). The automatic technique eliminates user intervention by exploiting common map properties of how road lines and text labels are drawn in raster maps. For example, the road lines are elongated linear objects and the characters are small connected-objects. The supervised technique utilizes labels of road and text areas to handle complex raster maps, or maps with poor image quality, and can process a variety of raster maps with minimal user input. The results show that the general approach can handle raster maps with varying map complexity, color usage, and image quality. By matching extracted road intersections to another geospatial dataset, we can identify the geocoordinates of a raster map and further align the raster map, separated feature layers from the map, and recognized features from the layers with the geospatial dataset. The road vectorization and text recognition results outperform state-of-art commercial products, and with considerably less user input. The approach in this thesis allows us to make use of the geospatial information of heterogeneous maps locked in raster format.

High-quality imaging in environmental scanning electron microscopy--optimizing the pressure limiting system and the secondary electron detection of a commercially available ESEM.

PubMed

Fitzek, H; Schroettner, H; Wagner, J; Hofer, F; Rattenberger, J

2016-04-01

In environmental scanning electron microscopy applications in the kPa regime are of increasing interest for the investigation of wet and biological samples, because neither sample preparation nor extensive cooling are necessary. Unfortunately, the applications are limited by poor image quality. In this work the image quality at high pressures of a FEI Quanta 600 (field emission gun) and a FEI Quanta 200 (thermionic gun) is greatly improved by optimizing the pressure limiting system and the secondary electron (SE) detection system. The scattering of the primary electron beam strongly increases with pressure and thus the image quality vanishes. The key to high-image quality at high pressures is to reduce scattering as far as possible while maintaining ideal operation conditions for the SE-detector. The amount of scattering is reduced by reducing both the additional stagnation gas thickness (aSGT) and the environmental distance (ED). A new aperture holder is presented that significantly reduces the aSGT while maintaining the same field-of-view (FOV) as the original design. With this aperture holder it is also possible to make the aSGT even smaller at the expense of a smaller FOV. A new blade-shaped SE-detector is presented yielding better image quality than usual flat SE-detectors. The electrode of the new SE detector is positioned on the sample table, which allows the SE-detector to operate at ideal conditions regardless of pressure and ED. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Functional evaluation of telemedicine with super high definition images and B-ISDN.

PubMed

Takeda, H; Matsumura, Y; Okada, T; Kuwata, S; Komori, M; Takahashi, T; Minatom, K; Hashimoto, T; Wada, M; Fujio, Y

1998-01-01

In order to determine whether a super high definition (SHD) image running at a series of 2048 resolution x 2048 line x 60 frame/sec was capable of telemedicine, we established a filing system for medical images and two experiments for transmission of high quality images were performed. All images of various types, produced from one case of ischemic heart disease were digitized and registered into the filing system. Images consisted of plain chest x-ray, electrocardiogram, ultrasound cardiogram, cardiac scintigram, coronary angiogram, left ventriculogram and so on. All images were animated and totaled a number of 243. We prepared a graphic user interface (GUI) for image retrieval based on the medical events and modalities. Twenty one cardiac specialists evaluated quality of the SHD images to be somewhat poor compared to the original pictures but sufficient for making diagnoses, and effective as a tool for teaching and case study purposes. The system capability of simultaneously displaying several animated images was especially deemed effective in grasping comprehension of diagnosis. Efficient input methods and creating capacity of filing all produced images are future issue. Using B-ISDN network, the SHD file was prefetched to the servers at Kyoto University Hospital and BBCC (Bradband ISDN Business chance & Culture Creation) laboratory as an telemedicine experiment. Simultaneous video conference system, the control of image retrieval and pointing function made the teleconference successful in terms of high quality of medical images, quick response time and interactive data exchange.

STS-107 Debris Characterization Using Re-entry Imaging

NASA Technical Reports Server (NTRS)

Raiche, George A.

2009-01-01

Analysis of amateur video of the early reentry phases of the Columbia accident is discussed. With poor video quality and little theoretical guidance, the analysis team estimated mass and acceleration ranges for the debris shedding events observed in the video. Camera calibration and optical performance issues are also described.

Parental Bonds, Attachment Anxiety, Media Susceptibility, and Body Dissatisfaction: A Mediation Model

ERIC Educational Resources Information Center

Patton, Sarah C.; Beaujean, A. Alexander; Benedict, Helen E.

2014-01-01

The developmental trajectory of body image dissatisfaction is unclear. Researchers have investigated sociocultural and developmental risk factors; however, the literature needs an integrative etiological model. In 2009, Cheng and Mallinckrodt proposed a dual mediation model, positing that poor-quality parental bonds, via the mechanisms of…

Validation of a computerized technique for automatically tracking and measuring the inferior vena cava in ultrasound imagery.

PubMed

Bellows, Spencer; Smith, Jordan; Mcguire, Peter; Smith, Andrew

2014-01-01

Accurate resuscitation of the critically-ill patient using intravenous fluids and blood products is a challenging, time sensitive task. Ultrasound of the inferior vena cava (IVC) is a non-invasive technique currently used to guide fluid administration, though multiple factors such as variable image quality, time, and operator skill challenge mainstream acceptance. This study represents a first attempt to develop and validate an algorithm capable of automatically tracking and measuring the IVC compared to human operators across a diverse range of image quality. Minimal tracking failures and high levels of agreement between manual and algorithm measurements were demonstrated on good quality videos. Addressing problems such as gaps in the vessel wall and intra-lumen speckle should result in improved performance in average and poor quality videos. Semi-automated measurement of the IVC for the purposes of non-invasive estimation of circulating blood volume poses challenges however is feasible.

Multiplexing and de-multiplexing with scattering media for large field of view and multispectral imaging

NASA Astrophysics Data System (ADS)

Sahoo, Sujit Kumar; Tang, Dongliang; Dang, Cuong

2018-02-01

Large field of view multispectral imaging through scattering medium is a fundamental quest in optics community. It has gained special attention from researchers in recent years for its wide range of potential applications. However, the main bottlenecks of the current imaging systems are the requirements on specific illumination, poor image quality and limited field of view. In this work, we demonstrated a single-shot high-resolution colour-imaging through scattering media using a monochromatic camera. This novel imaging technique is enabled by the spatial, spectral decorrelation property and the optical memory effect of the scattering media. Moreover the use of deconvolution image processing further annihilate above-mentioned drawbacks arise due iterative refocusing, scanning or phase retrieval procedures.

Automated assembly of camera modules using active alignment with up to six degrees of freedom

NASA Astrophysics Data System (ADS)

Bräuniger, K.; Stickler, D.; Winters, D.; Volmer, C.; Jahn, M.; Krey, S.

2014-03-01

With the upcoming Ultra High Definition (UHD) cameras, the accurate alignment of optical systems with respect to the UHD image sensor becomes increasingly important. Even with a perfect objective lens, the image quality will deteriorate when it is poorly aligned to the sensor. For evaluating the imaging quality the Modulation Transfer Function (MTF) is used as the most accepted test. In the first part it is described how the alignment errors that lead to a low imaging quality can be measured. Collimators with crosshair at defined field positions or a test chart are used as object generators for infinite-finite or respectively finite-finite conjugation. The process how to align the image sensor accurately to the optical system will be described. The focus position, shift, tilt and rotation of the image sensor are automatically corrected to obtain an optimized MTF for all field positions including the center. The software algorithm to grab images, calculate the MTF and adjust the image sensor in six degrees of freedom within less than 30 seconds per UHD camera module is described. The resulting accuracy of the image sensor rotation is better than 2 arcmin and the accuracy position alignment in x,y,z is better 2 μm. Finally, the process of gluing and UV-curing is described and how it is managed in the integrated process.

Comparison of Free-Breathing With Navigator-Triggered Technique in Diffusion Weighted Imaging for Evaluation of Small Hepatocellular Carcinoma: Effect on Image Quality and Intravoxel Incoherent Motion Parameters.

PubMed

Shan, Yan; Zeng, Meng-su; Liu, Kai; Miao, Xi-Yin; Lin, Jiang; Fu, Cai xia; Xu, Peng-ju

2015-01-01

To evaluate the effect on image quality and intravoxel incoherent motion (IVIM) parameters of small hepatocellular carcinoma (HCC) from choice of either free-breathing (FB) or navigator-triggered (NT) diffusion-weighted (DW) imaging. Thirty patients with 37 small HCCs underwent IVIM DW imaging using 12 b values (0-800 s/mm) with 2 sequences: NT, FB. A biexponential analysis with the Bayesian method yielded true diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) in small HCCs and liver parenchyma. Apparent diffusion coefficient (ADC) was also calculated. The acquisition time and image quality scores were assessed for 2 sequences. Independent sample t test was used to compare image quality, signal intensity ratio, IVIM parameters, and ADC values between the 2 sequences; reproducibility of IVIM parameters, and ADC values between 2 sequences was assessed with the Bland-Altman method (BA-LA). Image quality with NT sequence was superior to that with FB acquisition (P = 0.02). The mean acquisition time for FB scheme was shorter than that of NT sequence (6 minutes 14 seconds vs 10 minutes 21 seconds ± 10 seconds P < 0.01). The signal intensity ratio of small HCCs did not vary significantly between the 2 sequences. The ADC and IVIM parameters from the 2 sequences show no significant difference. Reproducibility of D*and f parameters in small HCC was poor (BA-LA: 95% confidence interval, -180.8% to 189.2% for D* and -133.8% to 174.9% for f). A moderate reproducibility of D and ADC parameters was observed (BA-LA: 95% confidence interval, -83.5% to 76.8% for D and -74.4% to 88.2% for ADC) between the 2 sequences. The NT DW imaging technique offers no advantage in IVIM parameters measurements of small HCC except better image quality, whereas FB technique offers greater confidence in fitted diffusion parameters for matched acquisition periods.

Halftone visual cryptography.

PubMed

Zhou, Zhi; Arce, Gonzalo R; Di Crescenzo, Giovanni

2006-08-01

Visual cryptography encodes a secret binary image (SI) into n shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the n shares, however, have no visual meaning and hinder the objectives of visual cryptography. Extended visual cryptography [1] was proposed recently to construct meaningful binary images as shares using hypergraph colourings, but the visual quality is poor. In this paper, a novel technique named halftone visual cryptography is proposed to achieve visual cryptography via halftoning. Based on the blue-noise dithering principles, the proposed method utilizes the void and cluster algorithm [2] to encode a secret binary image into n halftone shares (images) carrying significant visual information. The simulation shows that the visual quality of the obtained halftone shares are observably better than that attained by any available visual cryptography method known to date.

Understanding the cause of an unreadable nuclear medicine image: a case of unexpected results with 123I whole-body scintigraphy.

PubMed

Skweres, Justin; Yang, Zhiyun; Gonzalez-Toledo, Eduardo

2014-12-01

When unexpected results are obtained with standard image collection, the nuclear medicine physician must consider many technical factors that may have contributed. When image quality is poor, prior radiotracer administration, among other things, should always be considered. Our case demonstrates how knowledge of patient history and basic principles of nuclear medicine physics allows recognition of the septal penetration artifact. This allows the nuclear medicine physician to tailor the exam to an individual patient and obtain the most useful diagnostic information for the clinician. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Turning a blind eye: the mobilization of radiology services in resource-poor regions

PubMed Central

2010-01-01

While primary care, obstetrical, and surgical services have started to expand in the world's poorest regions, there is only sparse literature on the essential support systems that are required to make these operations function. Diagnostic imaging is critical to effective rural healthcare delivery, yet it has been severely neglected by the academic, public, and private sectors. Currently, a large portion of the world's population lacks access to any form of diagnostic imaging. In this paper we argue that two primary imaging modalities--diagnostic ultrasound and X-Ray--are ideal for rural healthcare services and should be scaled-up in a rapid and standardized manner. Such machines, if designed for resource-poor settings, should a) be robust in harsh environmental conditions, b) function reliably in environments with unstable electricity, c) minimize radiation dangers to staff and patients, d) be operable by non-specialist providers, and e) produce high-quality images required for accurate diagnosis. Few manufacturers are producing ultrasound and X-Ray machines that meet the specifications needed for rural healthcare delivery in resource-poor regions. A coordinated effort is required to create demand sufficient for manufacturers to produce the desired machines and to ensure that the programs operating them are safe, effective, and financially feasible. PMID:20946643

Turning a blind eye: the mobilization of radiology services in resource-poor regions.

PubMed

Maru, Duncan Smith-Rohrberg; Schwarz, Ryan; Jason, Andrews; Basu, Sanjay; Sharma, Aditya; Moore, Christopher

2010-10-14

While primary care, obstetrical, and surgical services have started to expand in the world's poorest regions, there is only sparse literature on the essential support systems that are required to make these operations function. Diagnostic imaging is critical to effective rural healthcare delivery, yet it has been severely neglected by the academic, public, and private sectors. Currently, a large portion of the world's population lacks access to any form of diagnostic imaging. In this paper we argue that two primary imaging modalities--diagnostic ultrasound and X-Ray--are ideal for rural healthcare services and should be scaled-up in a rapid and standardized manner. Such machines, if designed for resource-poor settings, should a) be robust in harsh environmental conditions, b) function reliably in environments with unstable electricity, c) minimize radiation dangers to staff and patients, d) be operable by non-specialist providers, and e) produce high-quality images required for accurate diagnosis. Few manufacturers are producing ultrasound and X-Ray machines that meet the specifications needed for rural healthcare delivery in resource-poor regions. A coordinated effort is required to create demand sufficient for manufacturers to produce the desired machines and to ensure that the programs operating them are safe, effective, and financially feasible.

Nonlinear PET parametric image reconstruction with MRI information using kernel method

NASA Astrophysics Data System (ADS)

Gong, Kuang; Wang, Guobao; Chen, Kevin T.; Catana, Ciprian; Qi, Jinyi

2017-03-01

Positron Emission Tomography (PET) is a functional imaging modality widely used in oncology, cardiology, and neurology. It is highly sensitive, but suffers from relatively poor spatial resolution, as compared with anatomical imaging modalities, such as magnetic resonance imaging (MRI). With the recent development of combined PET/MR systems, we can improve the PET image quality by incorporating MR information. Previously we have used kernel learning to embed MR information in static PET reconstruction and direct Patlak reconstruction. Here we extend this method to direct reconstruction of nonlinear parameters in a compartment model by using the alternating direction of multiplier method (ADMM) algorithm. Simulation studies show that the proposed method can produce superior parametric images compared with existing methods.

Multiple hypothesis tracking for cluttered biological image sequences.

PubMed

Chenouard, Nicolas; Bloch, Isabelle; Olivo-Marin, Jean-Christophe

2013-11-01

In this paper, we present a method for simultaneously tracking thousands of targets in biological image sequences, which is of major importance in modern biology. The complexity and inherent randomness of the problem lead us to propose a unified probabilistic framework for tracking biological particles in microscope images. The framework includes realistic models of particle motion and existence and of fluorescence image features. For the track extraction process per se, the very cluttered conditions motivate the adoption of a multiframe approach that enforces tracking decision robustness to poor imaging conditions and to random target movements. We tackle the large-scale nature of the problem by adapting the multiple hypothesis tracking algorithm to the proposed framework, resulting in a method with a favorable tradeoff between the model complexity and the computational cost of the tracking procedure. When compared to the state-of-the-art tracking techniques for bioimaging, the proposed algorithm is shown to be the only method providing high-quality results despite the critically poor imaging conditions and the dense target presence. We thus demonstrate the benefits of advanced Bayesian tracking techniques for the accurate computational modeling of dynamical biological processes, which is promising for further developments in this domain.

Robust Multi-Frame Adaptive Optics Image Restoration Algorithm Using Maximum Likelihood Estimation with Poisson Statistics.

PubMed

Li, Dongming; Sun, Changming; Yang, Jinhua; Liu, Huan; Peng, Jiaqi; Zhang, Lijuan

2017-04-06

An adaptive optics (AO) system provides real-time compensation for atmospheric turbulence. However, an AO image is usually of poor contrast because of the nature of the imaging process, meaning that the image contains information coming from both out-of-focus and in-focus planes of the object, which also brings about a loss in quality. In this paper, we present a robust multi-frame adaptive optics image restoration algorithm via maximum likelihood estimation. Our proposed algorithm uses a maximum likelihood method with image regularization as the basic principle, and constructs the joint log likelihood function for multi-frame AO images based on a Poisson distribution model. To begin with, a frame selection method based on image variance is applied to the observed multi-frame AO images to select images with better quality to improve the convergence of a blind deconvolution algorithm. Then, by combining the imaging conditions and the AO system properties, a point spread function estimation model is built. Finally, we develop our iterative solutions for AO image restoration addressing the joint deconvolution issue. We conduct a number of experiments to evaluate the performances of our proposed algorithm. Experimental results show that our algorithm produces accurate AO image restoration results and outperforms the current state-of-the-art blind deconvolution methods.

Robust Multi-Frame Adaptive Optics Image Restoration Algorithm Using Maximum Likelihood Estimation with Poisson Statistics

PubMed Central

Li, Dongming; Sun, Changming; Yang, Jinhua; Liu, Huan; Peng, Jiaqi; Zhang, Lijuan

2017-01-01

An adaptive optics (AO) system provides real-time compensation for atmospheric turbulence. However, an AO image is usually of poor contrast because of the nature of the imaging process, meaning that the image contains information coming from both out-of-focus and in-focus planes of the object, which also brings about a loss in quality. In this paper, we present a robust multi-frame adaptive optics image restoration algorithm via maximum likelihood estimation. Our proposed algorithm uses a maximum likelihood method with image regularization as the basic principle, and constructs the joint log likelihood function for multi-frame AO images based on a Poisson distribution model. To begin with, a frame selection method based on image variance is applied to the observed multi-frame AO images to select images with better quality to improve the convergence of a blind deconvolution algorithm. Then, by combining the imaging conditions and the AO system properties, a point spread function estimation model is built. Finally, we develop our iterative solutions for AO image restoration addressing the joint deconvolution issue. We conduct a number of experiments to evaluate the performances of our proposed algorithm. Experimental results show that our algorithm produces accurate AO image restoration results and outperforms the current state-of-the-art blind deconvolution methods. PMID:28383503

Photodiode area effect on performance of X-ray CMOS active pixel sensors

NASA Astrophysics Data System (ADS)

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

2018-02-01

Compared to conventional TFT-based X-ray imaging devices, CMOS-based X-ray imaging sensors are considered next generation because they can be manufactured in very small pixel pitches and can acquire high-speed images. In addition, CMOS-based sensors have the advantage of integration of various functional circuits within the sensor. The image quality can also be improved by the high fill-factor in large pixels. If the size of the subject is small, the size of the pixel must be reduced as a consequence. In addition, the fill factor must be reduced to aggregate various functional circuits within the pixel. In this study, 3T-APS (active pixel sensor) with photodiodes of four different sizes were fabricated and evaluated. It is well known that a larger photodiode leads to improved overall performance. Nonetheless, if the size of the photodiode is > 1000 μm2, the degree to which the sensor performance increases as the photodiode size increases, is reduced. As a result, considering the fill factor, pixel-pitch > 32 μm is not necessary to achieve high-efficiency image quality. In addition, poor image quality is to be expected unless special sensor-design techniques are included for sensors with a pixel pitch of 25 μm or less.

Correction to: Type 1 diabetes susceptibility alleles are associated with distinct alterations in the gut microbiota.

PubMed

Mullaney, Jane A; Stephens, Juliette E; Costello, Mary-Ellen; Fong, Cai; Geeling, Brooke E; Gavin, Patrick G; Wright, Casey M; Spector, Timothy D; Brown, Matthew A; Hamilton-Williams, Emma E

2018-03-20

Following publication of the original article [1] it came to the attention of the Production Editor that Figs. 1 and 2 had not been replaced with the newly revised figures supplied by the authors (the originals being unusable due to poor quality image and text).

Feasibility of ultra low-dose thallium stress-redistribution protocol including prone imaging in obese patients using CZT camera.

PubMed

Kincl, Vladimír; Kamínek, Milan; Vašina, Jiří; Panovský, Roman; Havel, Martin

2016-09-01

High efficiency cadmium-zinc-telluride (CZT) cameras provide an opportunity to lower the injected activities of radiopharmaceuticals for single photon emission tomography (SPECT) myocardial perfusion imaging (MPI). The limits for reducing activities of thallium have not been determined, particularly in obese patients. After an injection of 0.7 megabecquerel (MBq) of thallium/kg, we collected an average 1.5 million counts for the 10-min acquisition in a pilot cohort of ten patients. After extrapolation, we reduced the administered activity to 0.5 MBq/kg to obtain the expected 1 million counts. We studied the image quality in 124 patients (86 men, 43 obese with body mass index over 30 kg/m 2 ) referred for MPI. The quality of images was assessed by a number of recorded counts and visually by a four-grade scale (one-poor quality, four-excellent quality). In non-obese and obese patients, the average number of recorded counts was 1.1 vs. 1.07 million counts for the 10-min stress acquisition, 1.04 vs. 1.06 million counts for the 13-min rest acquisition, and the average quality score was 3.97 vs. 3.90, respectively (p = NS).The mean administered activity was 39.2 ± 7 MBq for non-obese and 48.7 ± 6 for obese patients (p < 0.0001), and the calculated effective dose was 4.0 ± 0.7 and 4.9 ± 0.6 mSv respectively (p < 0.0001). The ultra-low-dose thallium stress-redistribution protocol, including post-stress prone imaging, provides good quality of images with a low radiation burden, even in obese patients.

Direct Patlak Reconstruction From Dynamic PET Data Using the Kernel Method With MRI Information Based on Structural Similarity.

PubMed

Gong, Kuang; Cheng-Liao, Jinxiu; Wang, Guobao; Chen, Kevin T; Catana, Ciprian; Qi, Jinyi

2018-04-01

Positron emission tomography (PET) is a functional imaging modality widely used in oncology, cardiology, and neuroscience. It is highly sensitive, but suffers from relatively poor spatial resolution, as compared with anatomical imaging modalities, such as magnetic resonance imaging (MRI). With the recent development of combined PET/MR systems, we can improve the PET image quality by incorporating MR information into image reconstruction. Previously, kernel learning has been successfully embedded into static and dynamic PET image reconstruction using either PET temporal or MRI information. Here, we combine both PET temporal and MRI information adaptively to improve the quality of direct Patlak reconstruction. We examined different approaches to combine the PET and MRI information in kernel learning to address the issue of potential mismatches between MRI and PET signals. Computer simulations and hybrid real-patient data acquired on a simultaneous PET/MR scanner were used to evaluate the proposed methods. Results show that the method that combines PET temporal information and MRI spatial information adaptively based on the structure similarity index has the best performance in terms of noise reduction and resolution improvement.

A qualitative and quantitative analysis of radiation dose and image quality of computed tomography images using adaptive statistical iterative reconstruction.

PubMed

Hussain, Fahad Ahmed; Mail, Noor; Shamy, Abdulrahman M; Suliman, Alghamdi; Saoudi, Abdelhamid

2016-05-08

Image quality is a key issue in radiology, particularly in a clinical setting where it is important to achieve accurate diagnoses while minimizing radiation dose. Some computed tomography (CT) manufacturers have introduced algorithms that claim significant dose reduction. In this study, we assessed CT image quality produced by two reconstruction algorithms provided with GE Healthcare's Discovery 690 Elite positron emission tomography (PET) CT scanner. Image quality was measured for images obtained at various doses with both conventional filtered back-projection (FBP) and adaptive statistical iterative reconstruction (ASIR) algorithms. A stan-dard CT dose index (CTDI) phantom and a pencil ionization chamber were used to measure the CT dose at 120 kVp and an exposure of 260 mAs. Image quality was assessed using two phantoms. CT images of both phantoms were acquired at tube voltage (kV) of 120 with exposures ranging from 25 mAs to 400 mAs. Images were reconstructed using FBP and ASIR ranging from 10% to 100%, then analyzed for noise, low-contrast detectability, contrast-to-noise ratio (CNR), and modulation transfer function (MTF). Noise was 4.6 HU in water phantom images acquired at 260 mAs/FBP 120 kV and 130 mAs/50% ASIR 120 kV. The large objects (fre-quency < 7 lp/cm) retained fairly acceptable image quality at 130 mAs/50% ASIR, compared to 260 mAs/FBP. The application of ASIR for small objects (frequency >7 lp/cm) showed poor visibility compared to FBP at 260 mAs and even worse for images acquired at less than 130 mAs. ASIR blending more than 50% at low dose tends to reduce contrast of small objects (frequency >7 lp/cm). We concluded that dose reduction and ASIR should be applied with close attention if the objects to be detected or diagnosed are small (frequency > 7 lp/cm). Further investigations are required to correlate the small objects (frequency > 7 lp/cm) to patient anatomy and clinical diagnosis.

Multi-Sensor Fusion of Infrared and Electro-Optic Signals for High Resolution Night Images

PubMed Central

Huang, Xiaopeng; Netravali, Ravi; Man, Hong; Lawrence, Victor

2012-01-01

Electro-optic (EO) image sensors exhibit the properties of high resolution and low noise level at daytime, but they do not work in dark environments. Infrared (IR) image sensors exhibit poor resolution and cannot separate objects with similar temperature. Therefore, we propose a novel framework of IR image enhancement based on the information (e.g., edge) from EO images, which improves the resolution of IR images and helps us distinguish objects at night. Our framework superimposing/blending the edges of the EO image onto the corresponding transformed IR image improves their resolution. In this framework, we adopt the theoretical point spread function (PSF) proposed by Hardie et al. for the IR image, which has the modulation transfer function (MTF) of a uniform detector array and the incoherent optical transfer function (OTF) of diffraction-limited optics. In addition, we design an inverse filter for the proposed PSF and use it for the IR image transformation. The framework requires four main steps: (1) inverse filter-based IR image transformation; (2) EO image edge detection; (3) registration; and (4) blending/superimposing of the obtained image pair. Simulation results show both blended and superimposed IR images, and demonstrate that blended IR images have better quality over the superimposed images. Additionally, based on the same steps, simulation result shows a blended IR image of better quality when only the original IR image is available. PMID:23112602

Multi-sensor fusion of infrared and electro-optic signals for high resolution night images.

PubMed

Huang, Xiaopeng; Netravali, Ravi; Man, Hong; Lawrence, Victor

2012-01-01

Electro-optic (EO) image sensors exhibit the properties of high resolution and low noise level at daytime, but they do not work in dark environments. Infrared (IR) image sensors exhibit poor resolution and cannot separate objects with similar temperature. Therefore, we propose a novel framework of IR image enhancement based on the information (e.g., edge) from EO images, which improves the resolution of IR images and helps us distinguish objects at night. Our framework superimposing/blending the edges of the EO image onto the corresponding transformed IR image improves their resolution. In this framework, we adopt the theoretical point spread function (PSF) proposed by Hardie et al. for the IR image, which has the modulation transfer function (MTF) of a uniform detector array and the incoherent optical transfer function (OTF) of diffraction-limited optics. In addition, we design an inverse filter for the proposed PSF and use it for the IR image transformation. The framework requires four main steps: (1) inverse filter-based IR image transformation; (2) EO image edge detection; (3) registration; and (4) blending/superimposing of the obtained image pair. Simulation results show both blended and superimposed IR images, and demonstrate that blended IR images have better quality over the superimposed images. Additionally, based on the same steps, simulation result shows a blended IR image of better quality when only the original IR image is available.

Different effectiveness of closed embryo culture system with time-lapse imaging (EmbryoScope(TM)) in comparison to standard manual embryology in good and poor prognosis patients: a prospectively randomized pilot study.

PubMed

Wu, Yan-Guang; Lazzaroni-Tealdi, Emanuela; Wang, Qi; Zhang, Lin; Barad, David H; Kushnir, Vitaly A; Darmon, Sarah K; Albertini, David F; Gleicher, Norbert

2016-08-24

Previously manual human embryology in many in vitro fertilization (IVF) centers is rapidly being replaced by closed embryo incubation systems with time-lapse imaging. Whether such systems perform comparably to manual embryology in different IVF patient populations has, however, never before been investigated. We, therefore, prospectively compared embryo quality following closed system culture with time-lapse photography (EmbryoScope™) and standard embryology. We performed a two-part prospectively randomized study in IVF (clinical trial # NCT92256309). Part A involved 31 infertile poor prognosis patients prospectively randomized to EmbryoScope™ and standard embryology. Part B involved embryos from 17 egg donor-recipient cycles resulting in large egg/embryo numbers, thus permitting prospectively alternative embryo assignments to EmbryoScope™ and standard embryology. We then compared pregnancy rates and embryo quality on day-3 after fertilization and embryologist time utilized per processed embryo. Part A revealed in poor prognosis patients no differences in day-3 embryo scores, implantation and clinical pregnancy rates between EmbryoScope™ and standard embryology. The EmbryoScope™, however, more than doubled embryology staff time (P < 0.0001). In Part B, embryos grown in the EmbyoScope™ demonstrated significantly poorer day-3 quality (depending on embryo parameter between P = 0.005 and P = 0.01). Suspicion that conical culture dishes of the EmbryoScope™ (EmbryoSlide™) may be the cause was disproven when standard culture dishes demonstrated no outcome difference in standard incubation. Though due to small patient numbers preliminary, this study raises concerns about the mostly uncontrolled introduction of closed incubation systems with time lapse imaging into routine clinical embryology. Appropriately designed and powered prospectively randomized studies appear urgently needed in well-defined patient populations before the uncontrolled utilization of these instruments further expands. NCT02246309 Registered September 18, 2014.

Clinical evaluation of CR versus plain film for neonatal ICU applications

NASA Astrophysics Data System (ADS)

Andriole, Katherine P.; Brasch, Robert C.; Gooding, Charles A.; Gould, Robert G.; Huang, H. K.

1995-05-01

The clinical utility of computed radiography (CR) versus screen-film for neonatal intensive care unit (ICU) applications is investigated. The latest versions of standard ST-V and high- resolution HR-V CR imaging plates were compared via measurements of image contrast, spatial resolution and signal-to-noise. The ST-V imaging plate was found to have equivalent spatial resolution and object detectability at a lower required dose than the HR-V, and was therefore chosen as the CR plate to use in clinical trials in which a modified film cassette containing the CR imaging plate, a conventional screen and film was utilized. For 50 portable neonatal chest examinations, plain film was subjectively compared to the perfectly matched, simultaneously obtained CR hardcopy and softcopy images. Grading of overall image quality was on a scale of one (poor) to five (excellent). Readers rated the visualization of various structures in the chest (i.e., lung parenchyma, pulmonary vasculature, tubes/lines) as well as the visualization of pathologic findings. Preliminary results indicate that the image quality of both CR soft and hardcopy are comparable to plain film and that CR may be a suitable alternative to screen-film imaging for portable neonatal chest x rays.

Balloon-Occluded Carbon Dioxide Gas Angiography for Internal Iliac Arteriography and Intervention.

PubMed

Kishino, Mitsuhiro; Nakaminato, Shuichiro; Kitazume, Yoshio; Miyasaka, Naoyuki; Kudo, Toshifumi; Saida, Yukihisa; Tateishi, Ukihide

2018-07-01

The usefulness of carbon dioxide (CO 2 ) gas digital subtraction angiography (DSA) has been reported for patients with renal insufficiency and allergy to iodinated contrast agents. However, CO 2 gas cannot replace the iodinated contrast agent in all cases owing to some disadvantages. We describe balloon-occluded CO 2 DSA (B-CO 2 DSA) as an improved CO 2 DSA procedure for interventions in the internal iliac artery (IIA) region and compare the quality of images obtained using conventional CO 2 DSA and B-CO 2 DSA. B-CO 2 DSA-guided embolization was performed for one case of genital bleeding with an acute anaphylactic reaction to the iodinated contrast agent and for three cases of type II endoleaks after endovascular abdominal aortic aneurysm repair with renal dysfunction. A 9-mm occlusion balloon catheter was placed just after the orifice of the IIA. Then, 10-15 ml of CO 2 gas was injected manually via the catheter with and without balloon occlusion. The quality of sequential digital subtraction angiograms was analyzed based on a scoring criterion. In all four cases, image quality was improved with B-CO 2 DSA; the poor quality of images without balloon occlusion was because of reflux of the CO 2 gas. B-CO 2 DSA improves the image quality of CO 2 DSA in the IIA region and is useful for vascular intervention. Level IV.

Enhancement of automated blood flow estimates (ENABLE) from arterial spin-labeled MRI.

PubMed

Shirzadi, Zahra; Stefanovic, Bojana; Chappell, Michael A; Ramirez, Joel; Schwindt, Graeme; Masellis, Mario; Black, Sandra E; MacIntosh, Bradley J

2018-03-01

To validate a multiparametric automated algorithm-ENhancement of Automated Blood fLow Estimates (ENABLE)-that identifies useful and poor arterial spin-labeled (ASL) difference images in multiple postlabeling delay (PLD) acquisitions and thereby improve clinical ASL. ENABLE is a sort/check algorithm that uses a linear combination of ASL quality features. ENABLE uses simulations to determine quality weighting factors based on an unconstrained nonlinear optimization. We acquired a set of 6-PLD ASL images with 1.5T or 3.0T systems among 98 healthy elderly and adults with mild cognitive impairment or dementia. We contrasted signal-to-noise ratio (SNR) of cerebral blood flow (CBF) images obtained with ENABLE vs. conventional ASL analysis. In a subgroup, we validated our CBF estimates with single-photon emission computed tomography (SPECT) CBF images. ENABLE produced significantly increased SNR compared to a conventional ASL analysis (Wilcoxon signed-rank test, P < 0.0001). We also found the similarity between ASL and SPECT was greater when using ENABLE vs. conventional ASL analysis (n = 51, Wilcoxon signed-rank test, P < 0.0001) and this similarity was strongly related to ASL SNR (t = 24, P < 0.0001). These findings suggest that ENABLE improves CBF image quality from multiple PLD ASL in dementia cohorts at either 1.5T or 3.0T, achieved by multiparametric quality features that guided postprocessing of dementia ASL. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:647-655. © 2017 International Society for Magnetic Resonance in Medicine.

Retinex enhancement of infrared images.

PubMed

Li, Ying; He, Renjie; Xu, Guizhi; Hou, Changzhi; Sun, Yunyan; Guo, Lei; Rao, Liyun; Yan, Weili

2008-01-01

With the ability of imaging the temperature distribution of body, infrared imaging is promising in diagnostication and prognostication of diseases. However the poor quality of the raw original infrared images prevented applications and one of the essential problems is the low contrast appearance of the imagined object. In this paper, the image enhancement technique based on the Retinex theory is studied, which is a process that automatically retrieve the visual realism to images. The algorithms, including Frackle-McCann algorithm, McCann99 algorithm, single-scale Retinex algorithm, multi-scale Retinex algorithm and multi-scale Retinex algorithm with color restoration, are experienced to the enhancement of infrared images. The entropy measurements along with the visual inspection were compared and results shown the algorithms based on Retinex theory have the ability in enhancing the infrared image. Out of the algorithms compared, MSRCR demonstrated the best performance.

Binarization of Gray-Scaled Digital Images Via Fuzzy Reasoning

NASA Technical Reports Server (NTRS)

Dominquez, Jesus A.; Klinko, Steve; Voska, Ned (Technical Monitor)

2002-01-01

A new fast-computational technique based on fuzzy entropy measure has been developed to find an optimal binary image threshold. In this method, the image pixel membership functions are dependent on the threshold value and reflect the distribution of pixel values in two classes; thus, this technique minimizes the classification error. This new method is compared with two of the best-known threshold selection techniques, Otsu and Huang-Wang. The performance of the proposed method supersedes the performance of Huang- Wang and Otsu methods when the image consists of textured background and poor printing quality. The three methods perform well but yield different binarization approaches if the background and foreground of the image have well-separated gray-level ranges.

Binarization of Gray-Scaled Digital Images Via Fuzzy Reasoning

NASA Technical Reports Server (NTRS)

Dominquez, Jesus A.; Klinko, Steve; Voska, Ned (Technical Monitor)

2002-01-01

A new fast-computational technique based on fuzzy entropy measure has been developed to find an optimal binary image threshold. In this method, the image pixel membership functions are dependent on the threshold value and reflect the distribution of pixel values in two classes; thus, this technique minimizes the classification error. This new method is compared with two of the best-known threshold selection techniques, Otsu and Huang-Wang. The performance of the proposed method supersedes the performance of Huang-Wang and Otsu methods when the image consists of textured background and poor printing quality. The three methods perform well but yield different binarization approaches if the background and foreground of the image have well-separated gray-level ranges.

TU-EF-204-02: Hiigh Quality and Sub-MSv Cerebral CT Perfusion Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Ke; Niu, Kai; Wu, Yijing

2015-06-15

Purpose: CT Perfusion (CTP) imaging is of great importance in acute ischemic stroke management due to its potential to detect hypoperfused yet salvageable tissue and distinguish it from definitely unsalvageable tissue. However, current CTP imaging suffers from poor image quality and high radiation dose (up to 5 mSv). The purpose of this work was to demonstrate that technical innovations such as Prior Image Constrained Compressed Sensing (PICCS) have the potential to address these challenges and achieve high quality and sub-mSv CTP imaging. Methods: (1) A spatial-temporal 4D cascaded system model was developed to indentify the bottlenecks in the current CTPmore » technology; (2) A task-based framework was developed to optimize the CTP system parameters; (3) Guided by (1) and (2), PICCS was customized for the reconstruction of CTP source images. Digital anthropomorphic perfusion phantoms, animal studies, and preliminary human subject studies were used to validate and evaluate the potentials of using these innovations to advance the CTP technology. Results: The 4D cascaded model was validated in both phantom and canine stroke models. Based upon this cascaded model, it has been discovered that, as long as the spatial resolution and noise properties of the 4D source CT images are given, the 3D MTF and NPS of the final CTP maps can be analytically derived for a given set of processing methods and parameters. The cascaded model analysis also identified that the most critical technical factor in CTP is how to acquire and reconstruct high quality source images; it has very little to do with the denoising techniques often used after parametric perfusion calculations. This explained why PICCS resulted in a five-fold dose reduction or substantial improvement in image quality. Conclusion: Technical innovations generated promising results towards achieving high quality and sub-mSv CTP imaging for reliable and safe assessment of acute ischemic strokes. K. Li, K. Niu, Y. Wu: Nothing to disclose. G.-H. Chen: Research funded, GE Healthcare; Research funded, Siemens AX.« less

Faithful reconstruction of digital holograms captured by FINCH using a Hamming window function in the Fresnel propagation.

PubMed

Siegel, Nisan; Rosen, Joseph; Brooker, Gary

2013-10-01

Recent advances in Fresnel incoherent correlation holography (FINCH) increase the signal-to-noise ratio in hologram recording by interference of images from two diffractive lenses with focal lengths close to the image plane. Holograms requiring short reconstruction distances are created that reconstruct poorly with existing Fresnel propagation methods. Here we show a dramatic improvement in reconstructed fluorescent images when a 2D Hamming window function substituted for the disk window typically used to bound the impulse response in the Fresnel propagation. Greatly improved image contrast and quality are shown for simulated and experimentally determined FINCH holograms using a 2D Hamming window without significant loss in lateral or axial resolution.

A comparison of digital multi-spectral imagery versus conventional photography for mapping seagrass in Indian River Lagoon, Florida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Virnstein, R.; Tepera, M.; Beazley, L.

1997-06-01

A pilot study is very briefly summarized in the article. The study tested the potential of multi-spectral digital imagery for discrimination of seagrass densities and species, algae, and bottom types. Imagery was obtained with the Compact Airborne Spectral Imager (casi) and two flight lines flown with hyper-spectral mode. The photogrammetric method used allowed interpretation of the highest quality product, eliminating limitations caused by outdated or poor quality base maps and the errors associated with transfer of polygons. Initial image analysis indicates that the multi-spectral imagery has several advantages, including sophisticated spectral signature recognition and classification, ease of geo-referencing, and rapidmore » mosaicking.« less

Multispectral imaging for biometrics

NASA Astrophysics Data System (ADS)

Rowe, Robert K.; Corcoran, Stephen P.; Nixon, Kristin A.; Ostrom, Robert E.

2005-03-01

Automated identification systems based on fingerprint images are subject to two significant types of error: an incorrect decision about the identity of a person due to a poor quality fingerprint image and incorrectly accepting a fingerprint image generated from an artificial sample or altered finger. This paper discusses the use of multispectral sensing as a means to collect additional information about a finger that significantly augments the information collected using a conventional fingerprint imager based on total internal reflectance. In the context of this paper, "multispectral sensing" is used broadly to denote a collection of images taken under different polarization conditions and illumination configurations, as well as using multiple wavelengths. Background information is provided on conventional fingerprint imaging. A multispectral imager for fingerprint imaging is then described and a means to combine the two imaging systems into a single unit is discussed. Results from an early-stage prototype of such a system are shown.

A Focus on Quality and Standards in the Revitalization of the Academic Division at Wayne County Community College.

ERIC Educational Resources Information Center

Samuels, Frank

When a new administration came to Michigan's Wayne County Community College (WCCC) in 1985, the college evidenced several characteristics of a failing institution: poor media image, continuing budget deficits, declining enrollments, and probationary accrediation status. To address these problems and the demoralization that had accompanied them,…

Primary orbital melanoma without ocular involvement in a Balinese cat

PubMed Central

2006-01-01

Abstract A 6.5-year-old spayed female Balinese cat was diagnosed with a large and locally invasive primary orbital melanoma, without ocular involvement or detectable metastatic disease. Advanced imaging and immunohistochemical studies helped in obtaining the diagnosis. Because of advanced unresectable disease and ensuing poor quality of life, the cat was euthanized. PMID:16604977

Association between stigma, depression and quality of life of people living with HIV/AIDS (PLHA) in South India – a community based cross sectional study

PubMed Central

2012-01-01

Background India has around 2.27 million adults living with HIV/AIDS who face several challenges in the medical management of their disease. Stigma, discrimination and psychosocial issues are prevalent. The objective of the study was to determine the prevalence of severe stigma and to study the association between this, depression and the quality of life (QOL) of people living with HIV/AIDS (PLHA) in Tamil Nadu. Methods This was a community based cross sectional study carried out in seven districts of Tamil Nadu, India, among 400 PLHA in the year 2009. The following scales were used for stigma, depression and quality of life, Berger scale, Major Depression Inventory (MDI) scale and the WHO BREF scale. Both Stigma and QOL were classified as none, moderate or severe/poor based on the tertile cut off values of the scale scores. Depression was classified as none, mild, moderate and severe. Logistic regression analyses were performed to study the risk factors. Results Twenty seven per cent of PLHA had experienced severe forms of stigma. These were severe forms of personalized stigma (28.8%), negative self-image (30.3%), perceived public attitude (18.2%) and disclosure concerns (26%). PLHA experiencing severe depression were 12% and those experiencing poor quality of life were 34%. Poor QOL reported in the physical, psychological, social and environmental domains was 42.5%, 40%, 51.2% and 34% respectively. PLHA who had severe personalized stigma and negative self-image had 3.4 (1.6-7.0) and 2.1 (1.0-4.1) times higher risk of severe depression respectively (p < .001). PLHA who had severe depression had experienced 2.7(1.1-7.7) times significantly poorer QOL. Conclusions Severe forms of stigma were equivalently prevalent among all the categories of PLHA. However, PLHA who had experienced severe depression had only developed poor QOL. A high level of social support was associated with a high level of QOL. PMID:22720691

Patients' Body Image Improves After Mohs Micrographic Surgery for Nonmelanoma Head and Neck Skin Cancer.

PubMed

Beal, Brandon T; White, Emily K; Behera, Anit K; Zavell, Amy E; McGuinness, Ashley E; Blangger, Holly; Armbrecht, Eric S; Maher, Ian A

2018-05-24

Most skin cancers occur on the head and neck, areas of the body that are significant to an individual's body image (BI) perception. Poor BI is a robust risk factor for depression and decreased quality of life. Thus, patients with nonmelanoma head and neck skin cancer (NMHNSC) may be more vulnerable to BI disturbance and the negative sequelae of poor BI. Describe the nature of BI concerns in patients diagnosed with NMHNSC and assess how BI changes with treatment. Patients undergoing Mohs micrographic surgery (MMS) for NMHNSC completed assessments of BI and well-being before (N = 239) and 6 months after (N = 80) treatment with MMS. Demographic and tumor data were gathered through retrospective chart review. Body image improved significantly 6 months after MMS, and the magnitude of this change was large (η = 0.18). Repair length (length of final scar irrespective of repair type) >4 cm predicted poorer BI at 6-month follow-up. Patients' BI improves after treatment with MMS for NMHNSC.

Design of a prototype tri-electrode ion-chamber for megavoltage X-ray imaging

NASA Astrophysics Data System (ADS)

Samant, Sanjiv S.; Gopal, Arun; Jain, Jinesh; Xia, Junyi; DiBianca, Frank A.

2007-04-01

High-energy (megavoltage) X-ray imaging is widely used in industry (e.g., aerospace, construction, material sciences) as well as in health care (radiation therapy). One of the fundamental problems with megavoltage imaging is poor contrast and spatial resolution in the detected images due to the dominance of Compton scattering at megavoltage X-ray energies. Therefore, although megavoltage X-rays can be used to image highly attenuating objects that cannot be imaged at kilovoltage energies, the former does not provide the high image quality that is associated with the latter. A high contrast and spatial resolution detector for high-energy X-ray fields called the kinestatic charge detector (KCD) is presented here. The KCD is a tri-electrode ion-chamber based on highly pressurized noble gas. The KCD operates in conjunction with a strip-collimated X-ray beam (for high scatter rejection) to scan across the imaging field. Its thick detector design and unique operating principle provides enhanced charge signal integration for high quality imaging (quantum efficiency ˜50%) despite the unfavorable implications of high-energy X-ray interactions on image quality. The proposed design for a large-field prototype KCD includes a cylindrical pressure chamber along with 576 signal-collecting electrodes capable of resolving at 2 mm -1. The collecting electrodes are routed out of the chamber through the flat end-cap, thereby optimizing the mechanical strength of the chamber. This article highlights the simplified design of the chamber using minimal components for simple assembly. In addition, fundamental imaging measurements and estimates of ion recombination that were performed on a proof-of-principle test chamber are presented. The imaging performance of the prototype KCD was found to be an order-of-magnitude greater than commercial phosphor screen based flat-panel systems, demonstrating the potential for high-quality megavoltage imaging for a variety of industrial applications.

The comparison of high and standard definition computed tomography techniques regarding coronary artery imaging.

PubMed

Aykut, Aktas; Bumin, Degirmenci; Omer, Yilmaz; Mustafa, Kayan; Meltem, Cetin; Orhan, Celik; Nisa, Unlu; Hikmet, Orhan; Hakan, Demirtas; Mert, Koroglu

2015-09-01

The aim was to compare coronary high-definition CT (HDCT) with standard-definition CT (SDCT) angiography as to radiation dose, image quality and accuracy. 28 patients with history of coronary artery disease scanned by HDCT (Discovery CT750 HD) and SDCT (Somatom Definition AS). The scan modes were both axial prospective ECG-triggered. The vessel diameters and vessel attenuation values of totally 280 measurements from 140 coronary arteries were analyzed by two experienced radiologists. All data was analyzed by intraclass correlation test. Image quality graded by motion and stair step artifacts (grade 1, poor, to grade 4, excellent), accuracy of vessel inner and outer diameters were compared between the two CT units using the independent samples t-test and Mann-Whitney U test. The intraclass correlation coefficient (ICC) of measured vessel attenuation values in SDCT between the two radiologists was exceedingly good. The ICC was higher in HDCT. The radiation dose of HDCT was higher than that of SDCT. The mean tube current was 180 (mA) in HDCT and 147(mA) in SDCT with the same tube voltage (kVp). There was no significant difference between image quality. HDCT has a higher radiation dose but has much more atenuation and the spatial resolution which improve measurement accuracy for imaging coronary arteries.

Effect of poor control of film processors on mammographic image quality.

PubMed

Kimme-Smith, C; Sun, H; Bassett, L W; Gold, R H

1992-11-01

With the increasingly stringent standards of image quality in mammography, film processor quality control is especially important. Current methods are not sufficient for ensuring good processing. The authors used a sensitometer and densitometer system to evaluate the performance of 22 processors at 16 mammographic facilities. Standard sensitometric values of two films were established, and processor performance was assessed for variations from these standards. Developer chemistry of each processor was analyzed and correlated with its sensitometric values. Ten processors were retested, and nine were found to be out of calibration. The developer components of hydroquinone, sulfites, bromide, and alkalinity varied the most, and low concentrations of hydroquinone were associated with lower average gradients at two facilities. Use of the sensitometer and densitometer system helps identify out-of-calibration processors, but further study is needed to correlate sensitometric values with developer component values. The authors believe that present quality control would be improved if sensitometric or other tests could be used to identify developer components that are out of calibration.

Hyperspectral imaging of water quality - past applications and future directions.

NASA Astrophysics Data System (ADS)

Ross, M. R. V.; Pavelsky, T.

2017-12-01

Inland waters control the delivery of sediment, carbon, and nutrients from land to ocean by transforming, depositing, and transporting constituents downstream. However, the dominant in situ conditions that control these processes are poorly constrained, especially at larger spatial scales. Hyperspectral imaging, a remote sensing technique that uses reflectance in hundreds of narrow spectral bands, can be used to estimate water quality parameters like sediment and carbon concentration over larger water bodies. Here, we review methods and applications for using hyperspectral imagery to generate near-surface two-dimensional models of water quality in lakes and rivers. Further, we show applications using newly available data from the National Ecological Observation Network aerial observation platform in the Black Warrior and Tombigbee Rivers, Alabama. We demonstrate large spatial variation in chlorophyll, colored dissolved organic matter, and turbidity in each river and uneven mixing of water quality constituents for several kilometers. Finally, we demonstrate some novel techniques using hyperspectral imagery to deconvolve dissolved organic matter spectral signatures to specific organic matter components.

An approach to integrate the human vision psychology and perception knowledge into image enhancement

NASA Astrophysics Data System (ADS)

Wang, Hui; Huang, Xifeng; Ping, Jiang

2009-07-01

Image enhancement is very important image preprocessing technology especially when the image is captured in the poor imaging condition or dealing with the high bits image. The benefactor of image enhancement either may be a human observer or a computer vision process performing some kind of higher-level image analysis, such as target detection or scene understanding. One of the main objects of the image enhancement is getting a high dynamic range image and a high contrast degree image for human perception or interpretation. So, it is very necessary to integrate either empirical or statistical human vision psychology and perception knowledge into image enhancement. The human vision psychology and perception claims that humans' perception and response to the intensity fluctuation δu of visual signals are weighted by the background stimulus u, instead of being plainly uniform. There are three main laws: Weber's law, Weber- Fechner's law and Stevens's Law that describe this phenomenon in the psychology and psychophysics. This paper will integrate these three laws of the human vision psychology and perception into a very popular image enhancement algorithm named Adaptive Plateau Equalization (APE). The experiments were done on the high bits star image captured in night scene and the infrared-red image both the static image and the video stream. For the jitter problem in the video stream, this algorithm reduces this problem using the difference between the current frame's plateau value and the previous frame's plateau value to correct the current frame's plateau value. Considering the random noise impacts, the pixel value mapping process is not only depending on the current pixel but the pixels in the window surround the current pixel. The window size is usually 3×3. The process results of this improved algorithms is evaluated by the entropy analysis and visual perception analysis. The experiments' result showed the improved APE algorithms improved the quality of the image, the target and the surrounding assistant targets could be identified easily, and the noise was not amplified much. For the low quality image, these improved algorithms augment the information entropy and improve the image and the video stream aesthetic quality, while for the high quality image they will not debase the quality of the image.

A new verification film system for routine quality control of radiation fields: Kodak EC-L.

PubMed

Hermann, A; Bratengeier, K; Priske, A; Flentje, M

2000-06-01

The use of modern irradiation techniques requires better verification films for determining set-up deviations and patient movements during the course of radiation treatment. This is an investigation of the image quality and time requirement of a new verification film system compared to a conventional portal film system. For conventional verifications we used Agfa Curix HT 1000 films which were compared to the new Kodak EC-L film system. 344 Agfa Curix HT 1000 and 381 Kodak EC-L portal films of different tumor sites (prostate, rectum, head and neck) were visually judged on a light box by 2 experienced physicians. Subjective judgement of image quality, masking of films and time requirement were checked. In this investigation 68% of 175 Kodak EC-L ap/pa-films were judged "good", only 18% were classified "moderate" or "poor" 14%, but only 22% of 173 conventional ap/pa verification films (Agfa Curix HT 1000) were judged to be "good". The image quality, detail perception and time required for film inspection of the new Kodak EC-L film system was significantly improved when compared with standard portal films. They could be read more accurately and the detection of set-up deviation was facilitated.

Prototype volumetric ultrasound tomography image guidance system for prone stereotactic partial breast irradiation: proof-of-concept

NASA Astrophysics Data System (ADS)

Chiu, Tsuicheng D.; Parsons, David; Zhang, Yue; Hrycushko, Brian; Zhao, Bo; Chopra, Rajiv; Kim, Nathan; Spangler, Ann; Rahimi, Asal; Timmerman, Robert; Jiang, Steve B.; Lu, Weiguo; Gu, Xuejun

2018-03-01

Accurate dose delivery in stereotactic partial breast irradiation (S-PBI) is challenging because of the target position uncertainty caused by breast deformation, the target volume changes caused by lumpectomy cavity shrinkage, and the target delineation uncertainty on simulation computed tomography (CT) images caused by poor soft tissue contrast. We have developed a volumetric ultrasound tomography (UST) image guidance system for prone position S-PBI. The system is composed of a novel 3D printed rotation water tank, a patient-specific resin breast immobilization cup, and a 1D array ultrasound transducer. Coronal 2D US images were acquired in 5° increments over a 360° range, and planes were acquired every 2 mm in elevation. A super-compounding technique was used to reconstruct the image volume. The image quality of UST was evaluated with a BB-1 breast phantom and BioZorb surgical marker, and the results revealed that UST offered better soft tissue contrast than CT and similar image quality to MR. In the evaluated plane, the size and location of five embedded objects were measured and compared to MR, which is considered as the ground truth. Objects’ diameters and the distances between objects in UST differ by approximately 1 to 2 mm from those in MR, which showed that UST offers the image quality required for S-PBI. In future work we will develop a robotic system that will be ultimately implemented in the clinic.

Prototype volumetric ultrasound tomography image guidance system for prone stereotactic partial breast irradiation: proof-of-concept.

PubMed

Chiu, Tsuicheng D; Parsons, David; Zhang, Yue; Hrycushko, Brian; Zhao, Bo; Chopra, Rajiv; Kim, Nathan; Spangler, Ann; Rahimi, Asal; Timmerman, Robert; Jiang, Steve B; Lu, Weiguo; Gu, Xuejun

2018-03-01

Accurate dose delivery in stereotactic partial breast irradiation (S-PBI) is challenging because of the target position uncertainty caused by breast deformation, the target volume changes caused by lumpectomy cavity shrinkage, and the target delineation uncertainty on simulation computed tomography (CT) images caused by poor soft tissue contrast. We have developed a volumetric ultrasound tomography (UST) image guidance system for prone position S-PBI. The system is composed of a novel 3D printed rotation water tank, a patient-specific resin breast immobilization cup, and a 1D array ultrasound transducer. Coronal 2D US images were acquired in 5° increments over a 360° range, and planes were acquired every 2 mm in elevation. A super-compounding technique was used to reconstruct the image volume. The image quality of UST was evaluated with a BB-1 breast phantom and BioZorb surgical marker, and the results revealed that UST offered better soft tissue contrast than CT and similar image quality to MR. In the evaluated plane, the size and location of five embedded objects were measured and compared to MR, which is considered as the ground truth. Objects' diameters and the distances between objects in UST differ by approximately 1 to 2 mm from those in MR, which showed that UST offers the image quality required for S-PBI. In future work we will develop a robotic system that will be ultimately implemented in the clinic.

Handheld real-time volumetric imaging of the spine: technology development.

PubMed

Tiouririne, Mohamed; Nguyen, Sarah; Hossack, John A; Owen, Kevin; William Mauldin, F

2014-03-01

Technical difficulties, poor image quality and reliance on pattern identifications represent some of the drawbacks of two-dimensional ultrasound imaging of spinal bone anatomy. To overcome these limitations, this study sought to develop real-time volumetric imaging of the spine using a portable handheld device. The device measured 19.2 cm × 9.2 cm × 9.0 cm and imaged at 5 MHz centre frequency. 2D imaging under conventional ultrasound and volumetric (3D) imaging in real time was achieved and verified by inspection using a custom spine phantom. Further device performance was assessed and revealed a 75-min battery life and an average frame rate of 17.7 Hz in volumetric imaging mode. The results suggest that real-time volumetric imaging of the spine is a feasible technique for more intuitive visualization of the spine. These results may have important ramifications for a large array of neuraxial procedures.

Scattering Removal for Finger-Vein Image Restoration

PubMed Central

Yang, Jinfeng; Zhang, Ben; Shi, Yihua

2012-01-01

Finger-vein recognition has received increased attention recently. However, the finger-vein images are always captured in poor quality. This certainly makes finger-vein feature representation unreliable, and further impairs the accuracy of finger-vein recognition. In this paper, we first give an analysis of the intrinsic factors causing finger-vein image degradation, and then propose a simple but effective image restoration method based on scattering removal. To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues. Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration. Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy. PMID:22737028

A comparison of visual statistics for the image enhancement of FORESITE aerial images with those of major image classes

NASA Astrophysics Data System (ADS)

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

2006-05-01

Aerial images from the Follow-On Radar, Enhanced and Synthetic Vision Systems Integration Technology Evaluation (FORESITE) flight tests with the NASA Langley Research Center's research Boeing 757 were acquired during severe haze and haze/mixed clouds visibility conditions. These images were enhanced using the Visual Servo (VS) process that makes use of the Multiscale Retinex. The images were then quantified with visual quality metrics used internally within the VS. One of these metrics, the Visual Contrast Measure, has been computed for hundreds of FORESITE images, and for major classes of imaging-terrestrial (consumer), orbital Earth observations, orbital Mars surface imaging, NOAA aerial photographs, and underwater imaging. The metric quantifies both the degree of visual impairment of the original, un-enhanced images as well as the degree of visibility improvement achieved by the enhancement process. The large aggregate data exhibits trends relating to degree of atmospheric visibility attenuation, and its impact on the limits of enhancement performance for the various image classes. Overall results support the idea that in most cases that do not involve extreme reduction in visibility, large gains in visual contrast are routinely achieved by VS processing. Additionally, for very poor visibility imaging, lesser, but still substantial, gains in visual contrast are also routinely achieved. Further, the data suggest that these visual quality metrics can be used as external standalone metrics for establishing performance parameters.

A Comparison of Visual Statistics for the Image Enhancement of FORESITE Aerial Images with Those of Major Image Classes

NASA Technical Reports Server (NTRS)

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

2006-01-01

Aerial images from the Follow-On Radar, Enhanced and Synthetic Vision Systems Integration Technology Evaluation (FORESITE) flight tests with the NASA Langley Research Center's research Boeing 757 were acquired during severe haze and haze/mixed clouds visibility conditions. These images were enhanced using the Visual Servo (VS) process that makes use of the Multiscale Retinex. The images were then quantified with visual quality metrics used internally with the VS. One of these metrics, the Visual Contrast Measure, has been computed for hundreds of FORESITE images, and for major classes of imaging--terrestrial (consumer), orbital Earth observations, orbital Mars surface imaging, NOAA aerial photographs, and underwater imaging. The metric quantifies both the degree of visual impairment of the original, un-enhanced images as well as the degree of visibility improvement achieved by the enhancement process. The large aggregate data exhibits trends relating to degree of atmospheric visibility attenuation, and its impact on limits of enhancement performance for the various image classes. Overall results support the idea that in most cases that do not involve extreme reduction in visibility, large gains in visual contrast are routinely achieved by VS processing. Additionally, for very poor visibility imaging, lesser, but still substantial, gains in visual contrast are also routinely achieved. Further, the data suggest that these visual quality metrics can be used as external standalone metrics for establishing performance parameters.

Accurate cytogenetic biodosimetry through automated dicentric chromosome curation and metaphase cell selection

PubMed Central

Wilkins, Ruth; Flegal, Farrah; Knoll, Joan H.M.; Rogan, Peter K.

2017-01-01

Accurate digital image analysis of abnormal microscopic structures relies on high quality images and on minimizing the rates of false positive (FP) and negative objects in images. Cytogenetic biodosimetry detects dicentric chromosomes (DCs) that arise from exposure to ionizing radiation, and determines radiation dose received based on DC frequency. Improvements in automated DC recognition increase the accuracy of dose estimates by reclassifying FP DCs as monocentric chromosomes or chromosome fragments. We also present image segmentation methods to rank high quality digital metaphase images and eliminate suboptimal metaphase cells. A set of chromosome morphology segmentation methods selectively filtered out FP DCs arising primarily from sister chromatid separation, chromosome fragmentation, and cellular debris. This reduced FPs by an average of 55% and was highly specific to these abnormal structures (≥97.7%) in three samples. Additional filters selectively removed images with incomplete, highly overlapped, or missing metaphase cells, or with poor overall chromosome morphologies that increased FP rates. Image selection is optimized and FP DCs are minimized by combining multiple feature based segmentation filters and a novel image sorting procedure based on the known distribution of chromosome lengths. Applying the same image segmentation filtering procedures to both calibration and test samples reduced the average dose estimation error from 0.4 Gy to <0.2 Gy, obviating the need to first manually review these images. This reliable and scalable solution enables batch processing for multiple samples of unknown dose, and meets current requirements for triage radiation biodosimetry of high quality metaphase cell preparations. PMID:29026522

Multiview echocardiography fusion using an electromagnetic tracking system.

PubMed

Punithakumar, Kumaradevan; Hareendranathan, Abhilash R; Paakkanen, Riitta; Khan, Nehan; Noga, Michelle; Boulanger, Pierre; Becher, Harald

2016-08-01

Three-dimensional ultrasound is an emerging modality for the assessment of complex cardiac anatomy and function. The advantages of this modality include lack of ionizing radiation, portability, low cost, and high temporal resolution. Major limitations include limited field-of-view, reliance on frequently limited acoustic windows, and poor signal to noise ratio. This study proposes a novel approach to combine multiple views into a single image using an electromagnetic tracking system in order to improve the field-of-view. The novel method has several advantages: 1) it does not rely on image information for alignment, and therefore, the method does not require image overlap; 2) the alignment accuracy of the proposed approach is not affected by any poor image quality as in the case of image registration based approaches; 3) in contrast to previous optical tracking based system, the proposed approach does not suffer from line-of-sight limitation; and 4) it does not require any initial calibration. In this pilot project, we were able to show that using a heart phantom, our method can fuse multiple echocardiographic images and improve the field-of view. Quantitative evaluations showed that the proposed method yielded a nearly optimal alignment of image data sets in three-dimensional space. The proposed method demonstrates the electromagnetic system can be used for the fusion of multiple echocardiography images with a seamless integration of sensors to the transducer.

Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging.

PubMed

Fischer, Michael A; Leidner, Bertil; Kartalis, Nikolaos; Svensson, Anders; Aspelin, Peter; Albiin, Nils; Brismar, Torkel B

2014-01-01

To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. • Four-dimensional computed tomography is limited by motion artefacts and poor image quality. • Time-resolved-CT facilitates 4D-CT data visualisation, segmentation and analysis by condensing raw data. • Time-resolved CT demonstrates better image quality than raw data images. • Time-resolved CT improves detection of arterialised liver lesions in cirrhotic patients.

Assessment of Image Quality of Repeated Limited Transthoracic Echocardiography After Cardiac Surgery.

PubMed

Canty, David J; Heiberg, Johan; Tan, Jen A; Yang, Yang; Royse, Alistair G; Royse, Colin F; Mobeirek, Abdulelah; Shaer, Fayez El; Albacker, Turki; Nazer, Rakan I; Fouda, Muhammed; Bakir, Bakir M; Alsaddique, Ahmed A

2017-06-01

The use of limited transthoracic echocardiography (TTE) has been restricted in patients after cardiac surgery due to reported poor image quality. The authors hypothesized that the hemodynamic state could be evaluated in a high proportion of patients at repeated intervals after cardiac surgery. Prospective observational study. Tertiary university hospital. The study comprised 51 patients aged 18 years or older presenting for cardiac surgery. Patients underwent TTE before surgery and at 3 time points after cardiac surgery. Images were assessed offline using an image quality scoring system by 2 expert observers. Hemodynamic state was assessed using the iHeartScan protocol, and the primary endpoint was the proportion of limited TTE studies in which the hemodynamic state was interpretable at each of the 3 postoperative time points. Hemodynamic state interpretability varied over time and was highest before surgery (90%) and lowest on the first postoperative day (49%) (p<0.01). This variation in interpretability over time was reflected in all 3 transthoracic windows, ranging from 43% to 80% before surgery and from 2% to 35% on the first postoperative day (p<0.01). Image quality scores were highest with the apical window, ranging from 53% to 77% across time points, and lowest with the subcostal window, ranging from 4% to 70% across time points (p< 0.01). Hemodynamic state can be determined with TTE in a high proportion of cardiac surgery patients after extubation and removal of surgical drains. Copyright © 2017 Elsevier Inc. All rights reserved.

Application of a novel Kalman filter based block matching method to ultrasound images for hand tendon displacement estimation.

PubMed

Lai, Ting-Yu; Chen, Hsiao-I; Shih, Cho-Chiang; Kuo, Li-Chieh; Hsu, Hsiu-Yun; Huang, Chih-Chung

2016-01-01

Information about tendon displacement is important for allowing clinicians to not only quantify preoperative tendon injuries but also to identify any adhesive scaring between tendon and adjacent tissue. The Fisher-Tippett (FT) similarity measure has recently been shown to be more accurate than the Laplacian sum of absolute differences (SAD) and Gaussian sum of squared differences (SSD) similarity measures for tracking tendon displacement in ultrasound B-mode images. However, all of these similarity measures can easily be influenced by the quality of the ultrasound image, particularly its signal-to-noise ratio. Ultrasound images of injured hands are unfortunately often of poor quality due to the presence of adhesive scars. The present study investigated a novel Kalman-filter scheme for overcoming this problem. Three state-of-the-art tracking methods (FT, SAD, and SSD) were used to track the displacements of phantom and cadaver tendons, while FT was used to track human tendons. These three tracking methods were combined individually with the proposed Kalman-filter (K1) scheme and another Kalman-filter scheme used in a previous study to optimize the displacement trajectories of the phantom and cadaver tendons. The motion of the human extensor digitorum communis tendon was measured in the present study using the FT-K1 scheme. The experimental results indicated that SSD exhibited better accuracy in the phantom experiments, whereas FT exhibited better performance for tracking real tendon motion in the cadaver experiments. All three tracking methods were influenced by the signal-to-noise ratio of the images. On the other hand, the K1 scheme was able to optimize the tracking trajectory of displacement in all experiments, even from a location with a poor image quality. The human experimental data indicated that the normal tendons were displaced more than the injured tendons, and that the motion ability of the injured tendon was restored after appropriate rehabilitation sessions. The obtained results show the potential for applying the proposed FT-K1 method in clinical applications for evaluating the tendon injury level after metacarpal fractures and assessing the recovery of an injured tendon during rehabilitation.

TQM and Higher Education: A Critical Systems Perspective on Fitness for Purpose

ERIC Educational Resources Information Center

Houston, Don

2007-01-01

Total Quality Management (TQM) is a poor fit with higher education and can only be made to fit by major reshaping either of TQM to a more appropriate methodology (and hence not TQM), or of higher education to an image of organisation that fits TQM. The paper revisits longstanding concerns about multiple aspects of TQM from a critical systems…

A qualitative and quantitative analysis of radiation dose and image quality of computed tomography images using adaptive statistical iterative reconstruction

PubMed Central

Mail, Noor; Shamy, Abdulrahman M.; Alghamdi, Suliman; Saoudi, Abdelhamid

2016-01-01

Image quality is a key issue in radiology, particularly in a clinical setting where it is important to achieve accurate diagnoses while minimizing radiation dose. Some computed tomography (CT) manufacturers have introduced algorithms that claim significant dose reduction. In this study, we assessed CT image quality produced by two reconstruction algorithms provided with GE Healthcare's Discovery 690 Elite positron emission tomography (PET) CT scanner. Image quality was measured for images obtained at various doses with both conventional filtered back‐projection (FBP) and adaptive statistical iterative reconstruction (ASIR) algorithms. A standard CT dose index (CTDI) phantom and a pencil ionization chamber were used to measure the CT dose at 120 kVp and an exposure of 260 mAs. Image quality was assessed using two phantoms. CT images of both phantoms were acquired at tube voltage (kV) of 120 with exposures ranging from 25 mAs to 400 mAs. Images were reconstructed using FBP and ASIR ranging from 10% to 100%, then analyzed for noise, low‐contrast detectability, contrast‐to‐noise ratio (CNR), and modulation transfer function (MTF). Noise was 4.6 HU in water phantom images acquired at 260 mAs/FBP 120 kV and 130 mAs/50% ASIR 120 kV. The large objects (frequency<7 lp/cm) retained fairly acceptable image quality at 130 mAs/50% ASIR, compared to 260 mAs/FBP. The application of ASIR for small objects (frequency>7 lp/cm) showed poor visibility compared to FBP at 260 mAs and even worse for images acquired at less than 130 mAs. ASIR blending more than 50% at low dose tends to reduce contrast of small objects (frequency>7 lp/cm). We concluded that dose reduction and ASIR should be applied with close attention if the objects to be detected or diagnosed are small (frequency>7 lp/cm). Further investigations are required to correlate the small objects (frequency>7 lp/cm) to patient anatomy and clinical diagnosis. PACS number(s): 87.57.‐s, 87.57.C, 87.57.cf, 87.57.cj, 87.57.cm, 87.57.cp, 87.57.N, 87.57.nf, 87.57.np, 87.57.nt, 87.57.Q, 87.59.‐e, 87.59.B PMID:27167261

Green light may improve diagnostic accuracy of nailfold capillaroscopy with a simple digital videomicroscope.

PubMed

Weekenstroo, Harm H A; Cornelissen, Bart M W; Bernelot Moens, Hein J

2015-06-01

Nailfold capillaroscopy is a non-invasive and safe technique for the analysis of microangiopathologies. Imaging quality of widely used simple videomicroscopes is poor. The use of green illumination instead of the commonly used white light may improve contrast. The aim of the study was to compare the effect of green illumination with white illumination, regarding capillary density, the number of microangiopathologies, and sensitivity and specificity for systemic sclerosis. Five rheumatologists have evaluated 80 images; 40 images acquired with green light, and 40 images acquired with white light. A larger number of microangiopathologies were found in images acquired with green light than in images acquired with white light. This results in slightly higher sensitivity with green light in comparison with white light, without reducing the specificity. These findings suggest that green instead of white illumination may facilitate evaluation of capillaroscopic images obtained with a low-cost digital videomicroscope.

Study of the detective quantum efficiency for the kinestatic charge detector as a megavoltage imaging device

NASA Astrophysics Data System (ADS)

Samant, Sanjiv S.; Gopal, Arun; DiBianca, Frank A.

2003-06-01

Megavoltage x-ray imaging suffers from relatively poor contrast and spatial resolution compared to diagnostic kilovoltage x-ray imaging due to the dominant Compton scattering in the former. Recently available amorphous silicon/selenium based flat-panel imagers overcome many of the limitations of poor contrast and spatial resolution that affect conventional video based electronic portal imaging devices (EPIDs). An alternative technology is presented here: kinestatic charge detection (KCD). The KCD uses a slot photon beam, high-pressure gas (xenon, 100 atm) and a multi-ion rectangular chamber in scanning mode. An electric field is used to regulate the cation drift velocity. By matching the scanning speed with that of the cation drift, the cations remain static in the object frame of reference, allowing temporal integration of the signal. KCD imaging is characterized by reduced scatter and a high signal-to-noise ratio. Measurements and Monte Carlo simulations of modulation transfer function (MTF), noise power spectrum (NPS) and the detective quantum efficiency (DQE) of a prototype small field of view KCD detector (384 channels, 0.5 mm spacing) were carried out. Measurements yield DQE[0]=0.19 and DQE[0.5cy/mm]=0.01. KCD imaging is compared to film and commercial EPID systems using phantoms, with the KCD requiring an extremely low dose (0.1 cGy) per image. A proposed cylindrical chamber design with a higher ion-collection depth is expected to further improve image quality (DQE[0]>0.25).

Constraint factor graph cut-based active contour method for automated cellular image segmentation in RNAi screening.

PubMed

Chen, C; Li, H; Zhou, X; Wong, S T C

2008-05-01

Image-based, high throughput genome-wide RNA interference (RNAi) experiments are increasingly carried out to facilitate the understanding of gene functions in intricate biological processes. Automated screening of such experiments generates a large number of images with great variations in image quality, which makes manual analysis unreasonably time-consuming. Therefore, effective techniques for automatic image analysis are urgently needed, in which segmentation is one of the most important steps. This paper proposes a fully automatic method for cells segmentation in genome-wide RNAi screening images. The method consists of two steps: nuclei and cytoplasm segmentation. Nuclei are extracted and labelled to initialize cytoplasm segmentation. Since the quality of RNAi image is rather poor, a novel scale-adaptive steerable filter is designed to enhance the image in order to extract long and thin protrusions on the spiky cells. Then, constraint factor GCBAC method and morphological algorithms are combined to be an integrated method to segment tight clustered cells. Compared with the results obtained by using seeded watershed and the ground truth, that is, manual labelling results by experts in RNAi screening data, our method achieves higher accuracy. Compared with active contour methods, our method consumes much less time. The positive results indicate that the proposed method can be applied in automatic image analysis of multi-channel image screening data.

Comparison of organic electroluminescence and liquid crystal displays for clinical utility in orthopedic endoscopic surgery.

PubMed

Dezawa, Akira; Sairyo, Koichi

2014-05-01

Organic electroluminescence displays (OELD) use organic materials that self-emit light with the passage of an electric current. OELD provide high contrast, excellent color reproducibility at low brightness, excellent video images, and less restricted viewing angles. OELD are thus promising for medical use. This study compared the utility of an OELD with conventional liquid crystal displays (LCD) for imaging in orthopedic endoscopic surgery. One OELD and two conventional LCD that were indistinguishable in external appearance were used in this study. Images from 18 patients were displayed simultaneously on three monitors and evaluated by six orthopedic surgeons with extensive surgical experience. Images were shown for 2 min, repeated twice, and viewed from the front and side (diagonally). Surgeon rated both clinical utility (12 parameters) and image quality (11 parameters) for each image on a 5-point scale: 1, very good; 2, good; 3, average; 4, poor; and 5, very poor. For clinical utility in 16 percutaneous endoscopic discectomy cases, mean scores for all 12 parameters were significantly better on the OELD than on the LCD, including organ distinguishability (2.1 vs 3.2, respectively), lesion identification (2.2 vs 3.1), and overall viewing impression (2.1 vs 3.1). For image quality, all 11 parameters were better on the OELD than on LCD. Significant differences were identified in six parameters, including contrast (1.8 vs 2.9), color reproducibility in dark areas (1.8 vs 2.9), and viewing angle (2.2 vs 2.9). The high contrast and excellent color reproducibility of the OELD reduced the constraints of imaging under endoscopy, in which securing a field of view may be difficult. Distinguishability of organs was good, including ligaments, dura mater, nerves, and adipose tissue, contributing to good stereoscopic images of the surgical field. These findings suggest the utility of OELD for excellent display of surgical images and for enabling safe and highly accurate endoscopic surgery. © 2014 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

SU-D-206-04: Iterative CBCT Scatter Shading Correction Without Prior Information

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Y; Wu, P; Mao, T

2016-06-15

Purpose: To estimate and remove the scatter contamination in the acquired projection of cone-beam CT (CBCT), to suppress the shading artifacts and improve the image quality without prior information. Methods: The uncorrected CBCT images containing shading artifacts are reconstructed by applying the standard FDK algorithm on CBCT raw projections. The uncorrected image is then segmented to generate an initial template image. To estimate scatter signal, the differences are calculated by subtracting the simulated projections of the template image from the raw projections. Since scatter signals are dominantly continuous and low-frequency in the projection domain, they are estimated by low-pass filteringmore » the difference signals and subtracted from the raw CBCT projections to achieve the scatter correction. Finally, the corrected CBCT image is reconstructed from the corrected projection data. Since an accurate template image is not readily segmented from the uncorrected CBCT image, the proposed scheme is iterated until the produced template is not altered. Results: The proposed scheme is evaluated on the Catphan©600 phantom data and CBCT images acquired from a pelvis patient. The result shows that shading artifacts have been effectively suppressed by the proposed method. Using multi-detector CT (MDCT) images as reference, quantitative analysis is operated to measure the quality of corrected images. Compared to images without correction, the method proposed reduces the overall CT number error from over 200 HU to be less than 50 HU and can increase the spatial uniformity. Conclusion: An iterative strategy without relying on the prior information is proposed in this work to remove the shading artifacts due to scatter contamination in the projection domain. The method is evaluated in phantom and patient studies and the result shows that the image quality is remarkably improved. The proposed method is efficient and practical to address the poor image quality issue of CBCT images. This work is supported by the Zhejiang Provincial Natural Science Foundation of China (Grant No. LR16F010001), National High-tech R&D Program for Young Scientists by the Ministry of Science and Technology of China (Grant No. 2015AA020917).« less

Telephone intervention and quality of life in patients with breast cancer.

PubMed

Salonen, Päivi; Tarkka, Marja-Terttu; Kellokumpu-Lehtinen, Pirkko-Liisa; Astedt-Kurki, Päivi; Luukkaala, Tiina; Kaunonen, Marja

2009-01-01

The aim of this quasi-experimental study was to examine the effectiveness of a telephone support intervention 1 week after surgery on the quality of life (QOL) of patients with breast cancer. The sample consisted of 228 patients with breast cancer allocated to an intervention group (n = 120) and control group (n = 108). The data were collected using Ferrans and Powers Quality of Life Index-Cancer Version (QLI-CV) and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Breast Cancer Module (EORTC QLQ-BR23). The self-reported QOL of patients with breast cancer was considered moderately high. Statistically significant associations were found between QOL and the demographic characteristics of age, education, and employment status and of having underage children. Statistically significant associations were found between QOL and clinical characteristics such as type of surgery and axilla treatment. The strongest predictors of poor QOL were age, control group, and type of surgery. Age was the strongest predictor of poor QOL in global QLI and in the health and functioning, socioeconomic, and family subscales. The patients' experiences show that the telephone intervention was helpful and the timing was appropriate. The QOL in patients with breast cancer was better in subscales of body image, future perspective, and postoperative side effects. The intervention group showed significantly better body image; they worried less about the future and had less postoperative side effects than the control group did. These results may help in discussing QOL issues and should be considered when planning and implementing interventions for patients with breast cancer.

Feature-Based Retinal Image Registration Using D-Saddle Feature

PubMed Central

Hasikin, Khairunnisa; A. Karim, Noor Khairiah; Ahmedy, Fatimah

2017-01-01

Retinal image registration is important to assist diagnosis and monitor retinal diseases, such as diabetic retinopathy and glaucoma. However, registering retinal images for various registration applications requires the detection and distribution of feature points on the low-quality region that consists of vessels of varying contrast and sizes. A recent feature detector known as Saddle detects feature points on vessels that are poorly distributed and densely positioned on strong contrast vessels. Therefore, we propose a multiresolution difference of Gaussian pyramid with Saddle detector (D-Saddle) to detect feature points on the low-quality region that consists of vessels with varying contrast and sizes. D-Saddle is tested on Fundus Image Registration (FIRE) Dataset that consists of 134 retinal image pairs. Experimental results show that D-Saddle successfully registered 43% of retinal image pairs with average registration accuracy of 2.329 pixels while a lower success rate is observed in other four state-of-the-art retinal image registration methods GDB-ICP (28%), Harris-PIIFD (4%), H-M (16%), and Saddle (16%). Furthermore, the registration accuracy of D-Saddle has the weakest correlation (Spearman) with the intensity uniformity metric among all methods. Finally, the paired t-test shows that D-Saddle significantly improved the overall registration accuracy of the original Saddle. PMID:29204257

Dental MRI using wireless intraoral coils

NASA Astrophysics Data System (ADS)

Ludwig, Ute; Eisenbeiss, Anne-Katrin; Scheifele, Christian; Nelson, Katja; Bock, Michael; Hennig, Jürgen; von Elverfeldt, Dominik; Herdt, Olga; Flügge, Tabea; Hövener, Jan-Bernd

2016-03-01

Currently, the gold standard for dental imaging is projection radiography or cone-beam computed tomography (CBCT). These methods are fast and cost-efficient, but exhibit poor soft tissue contrast and expose the patient to ionizing radiation (X-rays). The need for an alternative imaging modality e.g. for soft tissue management has stimulated a rising interest in dental magnetic resonance imaging (MRI) which provides superior soft tissue contrast. Compared to X-ray imaging, however, so far the spatial resolution of MRI is lower and the scan time is longer. In this contribution, we describe wireless, inductively-coupled intraoral coils whose local sensitivity enables high resolution MRI of dental soft tissue. In comparison to CBCT, a similar image quality with complementary contrast was obtained ex vivo. In-vivo, a voxel size of the order of 250•250•500 μm3 was achieved in 4 min only. Compared to dental MRI acquired with clinical equipment, the quality of the images was superior in the sensitive volume of the coils and is expected to improve the planning of interventions and monitoring thereafter. This method may enable a more accurate dental diagnosis and avoid unnecessary interventions, improving patient welfare and bringing MRI a step closer to becoming a radiation-free alternative for dental imaging.

Microseismic reverse time migration with a multi-cross-correlation staining algorithm for fracture imaging

NASA Astrophysics Data System (ADS)

Yuan, Congcong; Jia, Xiaofeng; Liu, Shishuo; Zhang, Jie

2018-02-01

Accurate characterization of hydraulic fracturing zones is currently becoming increasingly important in production optimization, since hydraulic fracturing may increase the porosity and permeability of the reservoir significantly. Recently, the feasibility of the reverse time migration (RTM) method has been studied for the application in imaging fractures during borehole microseismic monitoring. However, strong low-frequency migration noise, poorly illuminated areas, and the low signal to noise ratio (SNR) data can degrade the imaging results. To improve the quality of the images, we propose a multi-cross-correlation staining algorithm to incorporate into the microseismic reverse time migration for imaging fractures using scattered data. Under the modified RTM method, our results are revealed in two images: one is the improved RTM image using the multi-cross-correlation condition, and the other is an image of the target region using the generalized staining algorithm. The numerical examples show that, compared with the conventional RTM, our method can significantly improve the spatial resolution of images, especially for the image of target region.

HALO: a reconfigurable image enhancement and multisensor fusion system

NASA Astrophysics Data System (ADS)

Wu, F.; Hickman, D. L.; Parker, Steve J.

2014-06-01

Contemporary high definition (HD) cameras and affordable infrared (IR) imagers are set to dramatically improve the effectiveness of security, surveillance and military vision systems. However, the quality of imagery is often compromised by camera shake, or poor scene visibility due to inadequate illumination or bad atmospheric conditions. A versatile vision processing system called HALO™ is presented that can address these issues, by providing flexible image processing functionality on a low size, weight and power (SWaP) platform. Example processing functions include video distortion correction, stabilisation, multi-sensor fusion and image contrast enhancement (ICE). The system is based around an all-programmable system-on-a-chip (SoC), which combines the computational power of a field-programmable gate array (FPGA) with the flexibility of a CPU. The FPGA accelerates computationally intensive real-time processes, whereas the CPU provides management and decision making functions that can automatically reconfigure the platform based on user input and scene content. These capabilities enable a HALO™ equipped reconnaissance or surveillance system to operate in poor visibility, providing potentially critical operational advantages in visually complex and challenging usage scenarios. The choice of an FPGA based SoC is discussed, and the HALO™ architecture and its implementation are described. The capabilities of image distortion correction, stabilisation, fusion and ICE are illustrated using laboratory and trials data.

One hundred case studies of Asia-Pacific telemedicine using a digital video transport system over a research and education network.

PubMed

Shimizu, Shuji; Nakashima, Naoki; Okamura, Koji; Tanaka, Masao

2009-01-01

Although the use of video in telemedicine is most helpful, the transmission of high-quality moving images is difficult in conventional systems due to the limitation of network bandwidth and the quality of service. We have established a new system via the academic broadband network that can preserve the original quality and assure smooth movement of the image. Here we report on 100 case studies and discuss the lessons we have learned. Kyushu University Hospital in Fukuoka, Japan, was linked to 53 medical institutions and meeting venues in 13 countries and regions over the Asia-Pacific Advanced Network, an international research and education consortium. The digital video transport system (DVTS), free software that transforms digital video signals directly into Internet Protocol, was installed on a personal computer (PC) with a network bandwidth of 30 Mbps per channel. Between February 2003 and June 2007, 100 telecommunication sessions were held, 94 of which were international and 6 domestic. Furthermore, 47 involved real-time demonstrations and 53 interactive teleconferences using video or PC presentations. Multiple stations were connected in 37 events, and the number of connected stations in total reached 269. The time delay was restricted to 0.3-1.0 seconds between the stations. Participants provided feedback via questionnaires, and with respect to image quality, 509 (68.3%) participants reported "very good," 206 (27.7%) reported "good," 19 (2.6%) reported "poor," and 11 (1.5%) reported "very poor." DVTS is both economical, with a minimal initial investment, and simple to set up, and this is the first time that this advanced system has been used so widely in the Asia-Pacific region. Because the high-speed academic network for research and education is available worldwide, we believe our cutting-edge technology will facilitate medical standardization beyond geographic borders in the world.

Sub-band denoising and spline curve fitting method for hemodynamic measurement in perfusion MRI

NASA Astrophysics Data System (ADS)

Lin, Hong-Dun; Huang, Hsiao-Ling; Hsu, Yuan-Yu; Chen, Chi-Chen; Chen, Ing-Yi; Wu, Liang-Chi; Liu, Ren-Shyan; Lin, Kang-Ping

2003-05-01

In clinical research, non-invasive MR perfusion imaging is capable of investigating brain perfusion phenomenon via various hemodynamic measurements, such as cerebral blood volume (CBV), cerebral blood flow (CBF), and mean trasnit time (MTT). These hemodynamic parameters are useful in diagnosing brain disorders such as stroke, infarction and periinfarct ischemia by further semi-quantitative analysis. However, the accuracy of quantitative analysis is usually affected by poor signal-to-noise ratio image quality. In this paper, we propose a hemodynamic measurement method based upon sub-band denoising and spline curve fitting processes to improve image quality for better hemodynamic quantitative analysis results. Ten sets of perfusion MRI data and corresponding PET images were used to validate the performance. For quantitative comparison, we evaluate gray/white matter CBF ratio. As a result, the hemodynamic semi-quantitative analysis result of mean gray to white matter CBF ratio is 2.10 +/- 0.34. The evaluated ratio of brain tissues in perfusion MRI is comparable to PET technique is less than 1-% difference in average. Furthermore, the method features excellent noise reduction and boundary preserving in image processing, and short hemodynamic measurement time.

Multiplexed Imaging of Protein Phosphorylation on Membranes Based on Ti(IV) Functionalized Nanopolymers.

PubMed

Iliuk, Anton; Li, Li; Melesse, Michael; Hall, Mark C; Tao, W Andy

2016-05-17

Accurate protein phosphorylation analysis reveals dynamic cellular signaling events not evident from protein expression levels. The most dominant biochemical assay, western blotting, suffers from the inadequate availability and poor quality of phospho-specific antibodies for phosphorylated proteins. Furthermore, multiplexed assays based on antibodies are limited by steric interference between the antibodies. Here we introduce a multifunctionalized nanopolymer for the universal detection of phosphoproteins that, in combination with regular antibodies, allows multiplexed imaging and accurate determination of protein phosphorylation on membranes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detection and characterization of Budd-Chiari syndrome with inferior vena cava obstruction: Comparison of fixed and flexible delayed scan time of computed tomography venography.

PubMed

Zhou, Peng-Li; Wu, Gang; Han, Xin-Wei; Bi, Yong-Hua; Zhang, Wen-Guang; Wu, Zheng-Yang

2017-06-01

To compare the results of computed tomography venography (CTV) with a fixed and a flexible delayed scan time for Budd-Chiari syndrome (BCS) with inferior vena cava (IVC) obstruction. A total of 209 consecutive BCS patients with IVC obstruction underwent either a CTV with a fixed delayed scan time of 180s (n=87) or a flexible delayed scan time for good image quality according to IVC blood flow in color Doppler ultrasonography (n=122). The IVC blood flow velocity was measured using a color Doppler ultrasound prior to CT scan. Image quality was classified as either good, moderate, or poor. Image quality, surrounding structures and the morphology of the IVC obstruction were compared between the two groups using a χ 2 -test or paired or unpaired t-tests as appropriate. Inter-observer agreement was assessed using Kappa statistics. There was no significant difference in IVC blood flow velocity between the two groups. Overall image quality, surrounding structures and IVC obstruction morphology delineation on the flexible delayed scan time of CTV images were rated better relative to those obtained by fixed delayed scan time of CTV images (p<0.001). Evaluation of CTV data sets was significantly facilitated with flexible delayed scan time of CTV. There were no significant differences in Kappa statistics between Group A and Group B. The flexible delayed scan time of CTV was associated with better detection and more reliable characterization of BCS with IVC obstruction compared to a fixed delayed scan time. Copyright © 2017 Elsevier B.V. All rights reserved.

A systematic review of the measurement properties of the Body Image Scale (BIS) in cancer patients.

PubMed

Melissant, Heleen C; Neijenhuijs, Koen I; Jansen, Femke; Aaronson, Neil K; Groenvold, Mogens; Holzner, Bernhard; Terwee, Caroline B; van Uden-Kraan, Cornelia F; Cuijpers, Pim; Verdonck-de Leeuw, Irma M

2018-06-01

Body image is acknowledged as an important aspect of health-related quality of life in cancer patients. The Body Image Scale (BIS) is a patient-reported outcome measure (PROM) to evaluate body image in cancer patients. The aim of this study was to systematically review measurement properties of the BIS among cancer patients. A search in Embase, MEDLINE, PsycINFO, and Web of Science was performed to identify studies that investigated measurement properties of the BIS (Prospero ID 42017057237). Study quality was assessed (excellent, good, fair, poor), and data were extracted and analyzed according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology on structural validity, internal consistency, reliability, measurement error, hypothesis testing for construct validity, and responsiveness. Evidence was categorized into sufficient, insufficient, inconsistent, or indeterminate. Nine studies were included. Evidence was sufficient for structural validity (one factor solution), internal consistency (α = 0.86-0.96), and reliability (r > 0.70); indeterminate for measurement error (information on minimal important change lacked) and responsiveness (increasing body image disturbance in only one study); and inconsistent for hypothesis testing (conflicting results). Quality of the evidence was moderate to low. No studies reported on cross-cultural validity. The BIS is a PROM with good structural validity, internal consistency, and test-retest reliability, but good quality studies on the other measurement properties are needed to optimize evidence. It is recommended to include a wider variety of cancer diagnoses and treatment modalities in these future studies.

A fingerprint classification algorithm based on combination of local and global information

NASA Astrophysics Data System (ADS)

Liu, Chongjin; Fu, Xiang; Bian, Junjie; Feng, Jufu

2011-12-01

Fingerprint recognition is one of the most important technologies in biometric identification and has been wildly applied in commercial and forensic areas. Fingerprint classification, as the fundamental procedure in fingerprint recognition, can sharply decrease the quantity for fingerprint matching and improve the efficiency of fingerprint recognition. Most fingerprint classification algorithms are based on the number and position of singular points. Because the singular points detecting method only considers the local information commonly, the classification algorithms are sensitive to noise. In this paper, we propose a novel fingerprint classification algorithm combining the local and global information of fingerprint. Firstly we use local information to detect singular points and measure their quality considering orientation structure and image texture in adjacent areas. Furthermore the global orientation model is adopted to measure the reliability of singular points group. Finally the local quality and global reliability is weighted to classify fingerprint. Experiments demonstrate the accuracy and effectivity of our algorithm especially for the poor quality fingerprint images.

7 Tesla MRI of bone microarchitecture discriminates between women without and with fragility fractures who do not differ by bone mineral density.

PubMed

Chang, Gregory; Honig, Stephen; Liu, Yinxiao; Chen, Cheng; Chu, Kevin K; Rajapakse, Chamith S; Egol, Kenneth; Xia, Ding; Saha, Punam K; Regatte, Ravinder R

2015-05-01

Osteoporosis is a disease of poor bone quality. Bone mineral density (BMD) has limited ability to discriminate between subjects without and with poor bone quality, and assessment of bone microarchitecture may have added value in this regard. Our goals were to use 7 T MRI to: (1) quantify and compare distal femur bone microarchitecture in women without and with poor bone quality (defined clinically by presence of fragility fractures); and (2) determine whether microarchitectural parameters could be used to discriminate between these two groups. This study had institutional review board approval, and we obtained written informed consent from all subjects. We used a 28-channel knee coil to image the distal femur of 31 subjects with fragility fractures and 25 controls without fracture on a 7 T MRI scanner using a 3-D fast low angle shot sequence (0.234 mm × 0.234 mm × 1 mm, parallel imaging factor = 2, acquisition time = 7 min 9 s). We applied digital topological analysis to quantify parameters of bone microarchitecture. All subjects also underwent standard clinical BMD assessment in the hip and spine. Compared to controls, fracture cases demonstrated lower bone volume fraction and markers of trabecular number, plate-like structure, and plate-to-rod ratio, and higher markers of trabecular isolation, rod disruption, and network resorption (p < 0.05 for all). There were no differences in hip or spine BMD T-scores between groups (p > 0.05). In receiver-operating-characteristics analyses, microarchitectural parameters could discriminate cases and controls (AUC = 0.66-0.73, p < 0.05). Hip and spine BMD T-scores could not discriminate cases and controls (AUC = 0.58-0.64, p ≥ 0.08). We conclude that 7 T MRI can detect bone microarchitectural deterioration in women with fragility fractures who do not differ by BMD. Microarchitectural parameters might some day be used as an additional tool to detect patients with poor bone quality who cannot be detected by dual-energy X-ray absorptiometry (DXA).

2-D traveltime and waveform inversion for improved seismic imaging: Naga Thrust and Fold Belt, India

NASA Astrophysics Data System (ADS)

Jaiswal, Priyank; Zelt, Colin A.; Bally, Albert W.; Dasgupta, Rahul

2008-05-01

Exploration along the Naga Thrust and Fold Belt in the Assam province of Northeast India encounters geological as well as logistic challenges. Drilling for hydrocarbons, traditionally guided by surface manifestations of the Naga thrust fault, faces additional challenges in the northeast where the thrust fault gradually deepens leaving subtle surface expressions. In such an area, multichannel 2-D seismic data were collected along a line perpendicular to the trend of the thrust belt. The data have a moderate signal-to-noise ratio and suffer from ground roll and other acquisition-related noise. In addition to data quality, the complex geology of the thrust belt limits the ability of conventional seismic processing to yield a reliable velocity model which in turn leads to poor subsurface image. In this paper, we demonstrate the application of traveltime and waveform inversion as supplements to conventional seismic imaging and interpretation processes. Both traveltime and waveform inversion utilize the first arrivals that are typically discarded during conventional seismic processing. As a first step, a smooth velocity model with long wavelength characteristics of the subsurface is estimated through inversion of the first-arrival traveltimes. This velocity model is then used to obtain a Kirchhoff pre-stack depth-migrated image which in turn is used for the interpretation of the fault. Waveform inversion is applied to the central part of the seismic line to a depth of ~1 km where the quality of the migrated image is poor. Waveform inversion is performed in the frequency domain over a series of iterations, proceeding from low to high frequency (11-19 Hz) using the velocity model from traveltime inversion as the starting model. In the end, the pre-stack depth-migrated image and the waveform inversion model are jointly interpreted. This study demonstrates that a combination of traveltime and waveform inversion with Kirchhoff pre-stack depth migration is a promising approach for the interpretation of geological structures in a thrust belt.

Practical considerations for obtaining high quality quantitative computed tomography data of the skeletal system.

PubMed

Troy, Karen L; Edwards, W Brent

2018-05-01

Quantitative CT (QCT) analysis involves the calculation of specific parameters such as bone volume and density from CT image data, and can be a powerful tool for understanding bone quality and quantity. However, without careful attention to detail during all steps of the acquisition and analysis process, data can be of poor- to unusable-quality. Good quality QCT for research requires meticulous attention to detail and standardization of all aspects of data collection and analysis to a degree that is uncommon in a clinical setting. Here, we review the literature to summarize practical and technical considerations for obtaining high quality QCT data, and provide examples of how each recommendation affects calculated variables. We also provide an overview of the QCT analysis technique to illustrate additional opportunities to improve data reproducibility and reliability. Key recommendations include: standardizing the scanner and data acquisition settings, minimizing image artifacts, selecting an appropriate reconstruction algorithm, and maximizing repeatability and objectivity during QCT analysis. The goal of the recommendations is to reduce potential sources of error throughout the analysis, from scan acquisition to the interpretation of results. Copyright © 2018 Elsevier Inc. All rights reserved.

Radiation hardness studies of CdTe thin films for clinical high-energy photon beam detectors

NASA Astrophysics Data System (ADS)

Shvydka, Diana; Parsai, E. I.; Kang, J.

2008-02-01

In radiation oncology applications, the need for higher-quality images has been driven by recent advances in radiation delivery systems that require online imaging. The existing electronic imaging devices commonly used to acquire portal images implement amorphous silicon (a-Si) detector, which exhibits poor image quality. Efforts for improvement have mostly been in the areas of noise and scatter reduction through software. This has not been successful due to inherent shortcomings of a-Si material. Cadmium telluride (CdTe) semiconductor has long been recognized as highly suitable for use in X-ray detectors in both spectroscopic and imaging applications. Development of such systems has mostly concentrated on single crystal CdTe. Recent advances in thin-film deposition technology suggest replacement of crystalline material with its polycrystalline counterpart, offering ease of large-area device fabrication and achievement of higher resolution as well as a favorable cost difference. While bulk CdTe material was found to have superior radiation hardness, thin films have not been evaluated from that prospective, in particular under high-energy photon beam typical of radiation treatment applications. We assess the performance of thin-film CdTe devices utilizing 6 MeV photon beam and find no consistent trend for material degradation under doses far exceeding the typical radiation therapy detector lifetime dose.

Wireless Robotic Communications in Urban Environments: Issues for the Fire Service

DTIC Science & Technology

2008-03-01

affect signal propagation? Do some frequencies perform better than others in specific settings? • Radio Environment: How much impact might...of responders at each scenario, the radio frequency environment for each will be examined. Link budget calculations will be performed to assess...soldiers indicated that the main technical drawbacks were the narrow field of view, poor image quality, and limited radio range. The authors concluded

Impact of sleep quality on amygdala reactivity, negative affect, and perceived stress.

PubMed

Prather, Aric A; Bogdan, Ryan; Hariri, Ahmad R

2013-05-01

Research demonstrates a negative impact of sleep disturbance on mood and affect; however, the biological mechanisms mediating these links are poorly understood. Amygdala reactivity to negative stimuli has emerged as one potential pathway. Here, we investigate the influence of self-reported sleep quality on associations between threat-related amygdala reactivity and measures of negative affect and perceived stress. Analyses on data from 299 participants (125 men, 50.5% white, mean [standard deviation] age = 19.6 [1.3] years) who completed the Duke Neurogenetics Study were conducted. Participants completed several self-report measures of negative affect and perceived stress. Threat-related (i.e., angry and fearful facial expressions) amygdala reactivity was assayed using blood oxygen level-dependent functional magnetic resonance imaging. Global sleep quality was assessed using the Pittsburgh Sleep Quality Index. Amygdala reactivity to fearful facial expressions predicted greater depressive symptoms and higher perceived stress in poor (β values = 0.18-1.86, p values < .05) but not good sleepers (β values = -0.13 to -0.01, p values > .05). In sex-specific analyses, men reporting poorer global sleep quality showed a significant association between amygdala reactivity and levels of depression and perceived stress (β values = 0.29-0.44, p values < .05). In contrast, no significant associations were observed in men reporting good global sleep quality or in women, irrespective of sleep quality. This study provides novel evidence that self-reported sleep quality moderates the relationships between amygdala reactivity, negative affect, and perceived stress, particularly among men.

Clinical equivalence assessment of T2 synthesized pediatric brain magnetic resonance imaging.

PubMed

Kerleroux, Basile; Kober, Tobias; Hilbert, Tom; Serru, Maxence; Sirinelli, Dominique; Morel, Baptiste

2018-05-04

Automated synthetic magnetic resonance imaging (MRI) provides qualitative, weighted image contrasts as well as quantitative information from one scan and is well-suited for various applications such as analysis of white matter disorders. However, the synthesized contrasts have been poorly evaluated in pediatric applications. The purpose of this study was to compare the image quality of synthetic T2 to conventional turbo spin echo (TSE) T2 in pediatric brain MRI. This was a mono-center prospective study. Synthetic and conventional MRI acquisitions at 1.5 Tesla were performed for each patient during the same session using a prototype accelerated T2 mapping sequence package (TA synthetic =3:07min, TA conventional =2:33min). Image sets were blindly and randomly analyzed by pediatric neuro-radiologists. Global image quality, morphologic legibility of standard structures and artifacts were assessed using a 4-point Likert scale. Inter-observer kappa agreements were calculated. The capability of the synthesized contrasts and conventional TSE T2 to discern normal and pathologic cases was evaluated. Sixty patients were included. The overall diagnostic quality of the synthesized contrasts was non-inferior to conventional imaging scale (p=0.06). There was no significant difference in the legibility of normal and pathological anatomic structures of synthetized and conventional TSE T2 (all p > 0.05) as well as for artifacts except for phase encoding (p=0.008). Interobserver agreement was good to almost perfect (kappa between 0.66 and 1). T2 synthesized contrasts, which also provides quantitative T2 information that could be useful, could be suggested as an equivalent technique in pediatric neuro-imaging, compared to conventional TSE T2. Copyright © 2018. Published by Elsevier Masson SAS.

Adenosine stress cardiovascular magnetic resonance with variable-density spiral pulse sequences accurately detects coronary artery disease: initial clinical evaluation.

PubMed

Salerno, Michael; Taylor, Angela; Yang, Yang; Kuruvilla, Sujith; Ragosta, Michael; Meyer, Craig H; Kramer, Christopher M

2014-07-01

Adenosine stress cardiovascular magnetic resonance perfusion imaging can be limited by motion-induced dark-rim artifacts, which may be mistaken for true perfusion abnormalities. A high-resolution variable-density spiral pulse sequence with a novel density compensation strategy has been shown to reduce dark-rim artifacts in first-pass perfusion imaging. We aimed to assess the clinical performance of adenosine stress cardiovascular magnetic resonance using this new perfusion sequence to detect obstructive coronary artery disease. Cardiovascular magnetic resonance perfusion imaging was performed during adenosine stress (140 μg/kg per minute) and at rest on a Siemens 1.5-T Avanto scanner in 41 subjects with chest pain scheduled for coronary angiography. Perfusion images were acquired during injection of 0.1 mmol/kg Gadolinium-diethylenetriaminepentacetate at 3 short-axis locations using a saturation recovery interleaved variable-density spiral pulse sequence. Significant stenosis was defined as >50% by quantitative coronary angiography. Two blinded reviewers evaluated the perfusion images for the presence of adenosine-induced perfusion abnormalities and assessed image quality using a 5-point scale (1 [poor] to 5 [excellent]). The prevalence of obstructive coronary artery disease by quantitative coronary angiography was 68%. The average sensitivity, specificity, and accuracy were 89%, 85%, and 88%, respectively, with a positive predictive value and negative predictive value of 93% and 79%, respectively. The average image quality score was 4.4±0.7, with only 1 study with more than mild dark-rim artifacts. There was good inter-reader reliability with a κ statistic of 0.67. Spiral adenosine stress cardiovascular magnetic resonance results in high diagnostic accuracy for the detection of obstructive coronary artery disease with excellent image quality and minimal dark-rim artifacts. © 2014 American Heart Association, Inc.

Mild Traumatic Brain Injury Chronically Impairs Sleep- and Wake-Dependent Emotional Processing.

PubMed

Mantua, Janna; Henry, Owen S; Garskovas, Nolan F; Spencer, Rebecca M C

2017-06-01

A single traumatic brain injury (TBI), even when mild (ie, concussion), can cause lasting consequences. Individuals with a history of chronic (>1-year prior) mild TBI have an increased risk of mood disturbances (eg, depression, suicide). This population also has lingering sleep alterations, including poor sleep quality and changes in sleep stage proportions. Given these sleep deficits, we aimed to test whether sleep-dependent emotional memory consolidation is reduced in this population. We utilized a mild TBI group (3.7 ± 2.9 years post injury) and an uninjured (non-TBI) population. Participants viewed negative and neutral images both before and after a 12-hour period containing sleep ("Sleep" group) or an equivalent period of time spent awake ("Wake" group). Participants rated images for valence/arousal at both sessions, and memory recognition was tested at session two. The TBI group had less rapid eye movement (REM), longer REM latency, and more sleep complaints. Sleep-dependent memory consolidation of nonemotional images was present in all participants. However, consolidation of negative images was only present in the non-TBI group. A lack of differentiation between the TBI Sleep and Wake groups was due to poor performance in the sleep group and, unexpectedly, enhanced performance in the wake group. Additionally, although the non-TBI participants habituated to negative images over a waking period, the TBI participants did not. We propose disrupted sleep- and wake-dependent emotional processing contributes to poor emotional outcomes following chronic, mild TBI. This work has broad implications, as roughly one-third of the US population will sustain a mild TBI during their lifetime. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Mild Traumatic Brain Injury Chronically Impairs Sleep- and Wake-Dependent Emotional Processing

PubMed Central

Mantua, Janna; Henry, Owen S.; Garskovas, Nolan F.

2017-01-01

Abstract Study Objectives: A single traumatic brain injury (TBI), even when mild (ie, concussion), can cause lasting consequences. Individuals with a history of chronic (>1-year prior) mild TBI have an increased risk of mood disturbances (eg, depression, suicide). This population also has lingering sleep alterations, including poor sleep quality and changes in sleep stage proportions. Given these sleep deficits, we aimed to test whether sleep-dependent emotional memory consolidation is reduced in this population. We utilized a mild TBI group (3.7 ± 2.9 years post injury) and an uninjured (non-TBI) population. Methods: Participants viewed negative and neutral images both before and after a 12-hour period containing sleep (“Sleep” group) or an equivalent period of time spent awake (“Wake” group). Participants rated images for valence/arousal at both sessions, and memory recognition was tested at session two. Results: The TBI group had less rapid eye movement (REM), longer REM latency, and more sleep complaints. Sleep-dependent memory consolidation of nonemotional images was present in all participants. However, consolidation of negative images was only present in the non-TBI group. A lack of differentiation between the TBI Sleep and Wake groups was due to poor performance in the sleep group and, unexpectedly, enhanced performance in the wake group. Additionally, although the non-TBI participants habituated to negative images over a waking period, the TBI participants did not. Conclusions: We propose disrupted sleep- and wake-dependent emotional processing contributes to poor emotional outcomes following chronic, mild TBI. This work has broad implications, as roughly one-third of the US population will sustain a mild TBI during their lifetime. PMID:28460124

Development of a stationary digital breast tomosynthesis system for clinical applications

NASA Astrophysics Data System (ADS)

Tucker, Andrew Wallace

Digital breast tomosynthesis (DBT) has been shown to be a very beneficial tool in the fight against breast cancer. However, current DBT systems have poor spatial resolution compared to full field digital mammography (FFDM), the current gold standard for screening mammography. The poor spatial resolution of DBT systems is a result of the single X-ray source design. In DBT systems a single X-ray source is rotated over an angular span in order to acquire the images needed for 3D reconstruction. The rotation of the X-ray source degrades the spatial resolution of the images. DBT systems which are approved for use in the United States for screening mammography are required to also take a full field digital mammogram with every DBT acquisition in order to compensate for the poor spatial resolution. This double exposure essentially doubles the radiation dose to patients. Over the past few years our research group has developed a carbon nanotube (CNT) based X-ray source technology. The unique nature of CNT X-ray sources allows for multiple X-ray focal spots in a single X-ray source. Using this technology we have recently developed a stationary DBT system (s-DBT) system which is capable of producing a full tomosynthesis image dataset with zero motion of the X-ray source. This system has been shown to have increased spatial resolution over other DBT systems in a laboratory setting. The goal of this thesis work was to optimize the s-DBT system, demonstrate its usefulness over other systems, and finally implement it into the clinic for a clinical trial. The s-DBT system was optimized using different image quality measurements. The optimized system was then used in a breast specimen imaging trial which compared s-DBT to magnified 2D mammography and a conventional single source DBT system. Readers preferred s-DBT to magnified 2D mammography for specimen margin delineation and mass detection, these results were not significant. Using physical measures for spatial resolution the s-DBT system was shown to have improved image quality over conventional single source DBT systems in breast tissue. A separate study showed that s-DBT could be a feasible alternative to FFDM for screening patients with breast implants. Finally, a second s-DBT system was constructed and implemented into the Department of Mammography at UNC hospitals. The first patient was imaged on the system in December of 2013.

Robust registration in case of different scaling

NASA Astrophysics Data System (ADS)

Gluhchev, Georgi J.; Shalev, Shlomo

1993-09-01

The problem of robust registration in the case of anisotropic scaling has been investigated. Registration of two images using corresponding sets of fiducial points is sensitive to inaccuracies in point placement due to poor image quality or non-rigid distortions, including possible out-of-plane rotations. An approach aimed at the detection of the most unreliable points has been developed. It is based on the a priori knowledge of the sequential ordering of rotation and scaling. A measure of guilt derived from the anomalous geometric relationships is introduced. A heuristic decision rule allowing for deletion of the most guilty points is proposed. The approach allows for more precise evaluation of the translation vector. It has been tested on phantom images with known parameters and has shown satisfactory results.

Development and application of operational techniques for the inventory and monitoring of resources and uses for the Texas coastal zone

NASA Technical Reports Server (NTRS)

Harwood, P. (Principal Investigator); Malin, P.; Finley, R.; Mcculloch, S.; Murphy, D.; Hupp, B.; Schell, J. A.

1977-01-01

The author has identified the following significant results. Four LANDSAT scenes were analyzed for the Harbor Island area test sites to produce land cover and land use maps using both image interpretation and computer-assisted techniques. When evaluated against aerial photography, the mean accuracy for three scenes was 84% for the image interpretation product and 62% for the computer-assisted classification maps. Analysis of the fourth scene was not completed using the image interpretation technique, because of poor quality, false color composite, but was available from the computer technique. Preliminary results indicate that these LANDSAT products can be applied to a variety of planning and management activities in the Texas coastal zone.

Reduced administered activity, reduced acquisition time, and preserved image quality for the new CZT camera.

PubMed

Oddstig, Jenny; Hedeer, Fredrik; Jögi, Jonas; Carlsson, Marcus; Hindorf, Cecilia; Engblom, Henrik

2013-02-01

For a 1-day myocardial perfusion SPECT (MPS) the recommendations for administered activity stated in the EANM guidelines results in an effective dose of up to 16 mSv per patient. Recently, a gamma camera system, based on cadmium zinc telluride (CZT) technology, was introduced. This technique has the potential to reduce the effective dose and scan time compared to the conventional NaI gamma camera. The aim of this study was to investigate if the effective dose can be reduced with a preserved image quality using CZT technology in MPS. In total, 150 patients were included in the study. All underwent a 1-day (99m)Tc-tetrofosmin stress-rest protocol and were divided into three subgroups (n = 50 in each group) with 4, 3, and 2.5 MBq/kg body weight of administered activity in the stress examination, respectively. The acquisition time was increased in proportion to the decrease in administered activity. All examinations were analyzed for image quality by visual grading on a 4-point scale (1 = poor, 2 = adequate, 3 = good, 4 = excellent), by two expert readers. The total effective dose (stress + rest) decreased from 9.3 to 5.8 mSv comparing 4 to 2.5 MBq/kg body weight. For the patients undergoing stress examination only (35%) the effective dose, administrating 2.5 MBq/kg, was 1.4 mSv. The image acquisition times for 2.5 MBq/kg body weight were 475 and 300 seconds (stress and rest) compared to 900 seconds for each when using conventional MPS. The average image quality was 3.7 ± 0.5, 3.8 ± 0.5, and 3.8 ± 0.4 for the stress images and 3.5 ± 0.6, 3.6 ± 0.6, and 3.5 ± 0.6 for the rest images and showed no statistically significant difference (P = .62) among the 4, 3, and 2.5 MBq/kg groups. The new CZT technology can be used to considerably decrease the effective dose and acquisition time for MPS with preserved high image quality.

Model-based error diffusion for high fidelity lenticular screening.

PubMed

Lau, Daniel; Smith, Trebor

2006-04-17

Digital halftoning is the process of converting a continuous-tone image into an arrangement of black and white dots for binary display devices such as digital ink-jet and electrophotographic printers. As printers are achieving print resolutions exceeding 1,200 dots per inch, it is becoming increasingly important for halftoning algorithms to consider the variations and interactions in the size and shape of printed dots between neighboring pixels. In the case of lenticular screening where statistically independent images are spatially multiplexed together, ignoring these variations and interactions, such as dot overlap, will result in poor lenticular image quality. To this end, we describe our use of model-based error-diffusion for the lenticular screening problem where statistical independence between component images is achieved by restricting the diffusion of error to only those pixels of the same component image where, in order to avoid instabilities, the proposed approach involves a novel error-clipping procedure.

Ultrasound tissue analysis and characterization

NASA Astrophysics Data System (ADS)

Kaufhold, John; Chan, Ray C.; Karl, William C.; Castanon, David A.

1999-07-01

On the battlefield of the future, it may become feasible for medics to perform, via application of new biomedical technologies, more sophisticated diagnoses and surgery than is currently practiced. Emerging biomedical technology may enable the medic to perform laparoscopic surgical procedures to remove, for example, shrapnel from injured soldiers. Battlefield conditions constrain the types of medical image acquisition and interpretation which can be performed. Ultrasound is the only viable biomedical imaging modality appropriate for deployment on the battlefield -- which leads to image interpretation issues because of the poor quality of ultrasound imagery. To help overcome these issues, we develop and implement a method of image enhancement which could aid non-experts in the rapid interpretation and use of ultrasound imagery. We describe an energy minimization approach to finding boundaries in medical images and show how prior information on edge orientation can be incorporated into this framework to detect tissue boundaries oriented at a known angle.

Successfully using optical components and systems in novel ways during educational outreach programs for K-12 grades

NASA Astrophysics Data System (ADS)

Silberman, Donn

2006-08-01

Much work has been done in efforts to reach students in the K-12 grades to encourage them to learn about optics and related sciences and technologies. One goal of these efforts is to develop the future optical scientists and engineers to carry on the work of this and related societies. One main obstacle is to create low costs novel and effective hands-on optical components and systems for these students to use and from which to get excited. Students at different grade levels and abilities are receptive to different kinds of components and systems and this must be taken into account when preparing for outreach programs. There are, however, some guiding principles which can be used throughout the various levels, including making sure the components and systems are good examples and not marginal. Small telescopes or microscopes that use poor quality optics which provide poor quality images do more to discourage young students from going into the sciences than if they never had the experience at all. Some examples of both poor and good quality optical components and systems that will be described and demonstrated include: lenses, telescopes, microscopes, diffraction gratings, Kaleidoscopes, Fresnel Lenses, polarization filters and liquid crystals. The figures in this paper are in color and best viewed on-line or printed with a good color printer.

Improvement of passive THz camera images

NASA Astrophysics Data System (ADS)

Kowalski, Marcin; Piszczek, Marek; Palka, Norbert; Szustakowski, Mieczyslaw

2012-10-01

Terahertz technology is one of emerging technologies that has a potential to change our life. There are a lot of attractive applications in fields like security, astronomy, biology and medicine. Until recent years, terahertz (THz) waves were an undiscovered, or most importantly, an unexploited area of electromagnetic spectrum. The reasons of this fact were difficulties in generation and detection of THz waves. Recent advances in hardware technology have started to open up the field to new applications such as THz imaging. The THz waves can penetrate through various materials. However, automated processing of THz images can be challenging. The THz frequency band is specially suited for clothes penetration because this radiation does not point any harmful ionizing effects thus it is safe for human beings. Strong technology development in this band have sparked with few interesting devices. Even if the development of THz cameras is an emerging topic, commercially available passive cameras still offer images of poor quality mainly because of its low resolution and low detectors sensitivity. Therefore, THz image processing is very challenging and urgent topic. Digital THz image processing is a really promising and cost-effective way for demanding security and defense applications. In the article we demonstrate the results of image quality enhancement and image fusion of images captured by a commercially available passive THz camera by means of various combined methods. Our research is focused on dangerous objects detection - guns, knives and bombs hidden under some popular types of clothing.

Multi-layer cube sampling for liver boundary detection in PET-CT images.

PubMed

Liu, Xinxin; Yang, Jian; Song, Shuang; Song, Hong; Ai, Danni; Zhu, Jianjun; Jiang, Yurong; Wang, Yongtian

2018-06-01

Liver metabolic information is considered as a crucial diagnostic marker for the diagnosis of fever of unknown origin, and liver recognition is the basis of automatic diagnosis of metabolic information extraction. However, the poor quality of PET and CT images is a challenge for information extraction and target recognition in PET-CT images. The existing detection method cannot meet the requirement of liver recognition in PET-CT images, which is the key problem in the big data analysis of PET-CT images. A novel texture feature descriptor called multi-layer cube sampling (MLCS) is developed for liver boundary detection in low-dose CT and PET images. The cube sampling feature is proposed for extracting more texture information, which uses a bi-centric voxel strategy. Neighbour voxels are divided into three regions by the centre voxel and the reference voxel in the histogram, and the voxel distribution information is statistically classified as texture feature. Multi-layer texture features are also used to improve the ability and adaptability of target recognition in volume data. The proposed feature is tested on the PET and CT images for liver boundary detection. For the liver in the volume data, mean detection rate (DR) and mean error rate (ER) reached 95.15 and 7.81% in low-quality PET images, and 83.10 and 21.08% in low-contrast CT images. The experimental results demonstrated that the proposed method is effective and robust for liver boundary detection.

B1- non-uniformity correction of phased-array coils without measuring coil sensitivity.

PubMed

Damen, Frederick C; Cai, Kejia

2018-04-18

Parallel imaging can be used to increase SNR and shorten acquisition times, albeit, at the cost of image non-uniformity. B 1 - non-uniformity correction techniques are confounded by signal that varies not only due to coil induced B 1 - sensitivity variation, but also the object's own intrinsic signal. Herein, we propose a method that makes minimal assumptions and uses only the coil images themselves to produce a single combined B 1 - non-uniformity-corrected complex image with the highest available SNR. A novel background noise classifier is used to select voxels of sufficient quality to avoid the need for regularization. Unique properties of the magnitude and phase were used to reduce the B 1 - sensitivity to two joint additive models for estimation of the B 1 - inhomogeneity. The complementary corruption of the imaged object across the coil images is used to abate individual coil correction imperfections. Results are presented from two anatomical cases: (a) an abdominal image that is challenging in both extreme B 1 - sensitivity and intrinsic tissue signal variation, and (b) a brain image with moderate B 1 - sensitivity and intrinsic tissue signal variation. A new relative Signal-to-Noise Ratio (rSNR) quality metric is proposed to evaluate the performance of the proposed method and the RF receiving coil array. The proposed method has been shown to be robust to imaged objects with widely inhomogeneous intrinsic signal, and resilient to poorly performing coil elements. Copyright © 2018. Published by Elsevier Inc.

High resolution iridocorneal angle imaging system by axicon lens assisted gonioscopy.

PubMed

Perinchery, Sandeep Menon; Shinde, Anant; Fu, Chan Yiu; Jeesmond Hong, Xun Jie; Baskaran, Mani; Aung, Tin; Murukeshan, Vadakke Matham

2016-07-29

Direct visualization and assessment of the iridocorneal angle (ICA) region with high resolution is important for the clinical evaluation of glaucoma. However, the current clinical imaging systems for ICA do not provide sufficient structural details due to their poor resolution. The key challenges in achieving high quality ICA imaging are its location in the anterior region of the eye and the occurrence of total internal reflection due to refractive index difference between cornea and air. Here, we report an indirect axicon assisted gonioscopy imaging probe with white light illumination. The illustrated results with this probe shows significantly improved visualization of structures in the ICA including TM region, compared to the current available tools. It could reveal critical details of ICA and expected to aid management by providing information that is complementary to angle photography and gonioscopy.

High resolution iridocorneal angle imaging system by axicon lens assisted gonioscopy

PubMed Central

Perinchery, Sandeep Menon; Shinde, Anant; Fu, Chan Yiu; Jeesmond Hong, Xun Jie; Baskaran, Mani; Aung, Tin; Murukeshan, Vadakke Matham

2016-01-01

Direct visualization and assessment of the iridocorneal angle (ICA) region with high resolution is important for the clinical evaluation of glaucoma. However, the current clinical imaging systems for ICA do not provide sufficient structural details due to their poor resolution. The key challenges in achieving high quality ICA imaging are its location in the anterior region of the eye and the occurrence of total internal reflection due to refractive index difference between cornea and air. Here, we report an indirect axicon assisted gonioscopy imaging probe with white light illumination. The illustrated results with this probe shows significantly improved visualization of structures in the ICA including TM region, compared to the current available tools. It could reveal critical details of ICA and expected to aid management by providing information that is complementary to angle photography and gonioscopy. PMID:27471000

High resolution iridocorneal angle imaging system by axicon lens assisted gonioscopy

NASA Astrophysics Data System (ADS)

Perinchery, Sandeep Menon; Shinde, Anant; Fu, Chan Yiu; Jeesmond Hong, Xun Jie; Baskaran, Mani; Aung, Tin; Murukeshan, Vadakke Matham

2016-07-01

Direct visualization and assessment of the iridocorneal angle (ICA) region with high resolution is important for the clinical evaluation of glaucoma. However, the current clinical imaging systems for ICA do not provide sufficient structural details due to their poor resolution. The key challenges in achieving high quality ICA imaging are its location in the anterior region of the eye and the occurrence of total internal reflection due to refractive index difference between cornea and air. Here, we report an indirect axicon assisted gonioscopy imaging probe with white light illumination. The illustrated results with this probe shows significantly improved visualization of structures in the ICA including TM region, compared to the current available tools. It could reveal critical details of ICA and expected to aid management by providing information that is complementary to angle photography and gonioscopy.

Total-body photography in skin cancer screening: the clinical utility of standardized imaging.

PubMed

Rosenberg, Alexandra; Meyerle, Jon H

2017-05-01

Early detection of skin cancer is essential to reducing morbidity and mortality from both melanoma and nonmelanoma skin cancers. Total-body skin examinations (TBSEs) may improve early detection of malignant melanomas (MMs) but are controversial due to the poor quality of data available to establish a mortality benefit from skin cancer screening. Total-body photography (TBP) promises to provide a way forward by lowering the costs of dermatologic screening while simultaneously leveraging technology to increase patient access to dermatologic care. Standardized TBP also offers the ability for dermatologists to work synergistically with modern computer technology involving algorithms capable of analyzing high-quality images to flag concerning lesions that may require closer evaluation. On a population level, inexpensive TBP has the potential to increase access to skin cancer screening and it has several specific applications in a military population. The utility of standardized TBP is reviewed in the context of skin cancer screening and teledermatology.

A novel full-angle scanning light scattering profiler to quantitatively evaluate forward and backward light scattering from intraocular lenses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, Bennett N., E-mail: bennett.walker@fda.hhs.gov; Office of Device Evaluation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993; James, Robert H.

Glare, glistenings, optical defects, dysphotopsia, and poor image quality are a few of the known deficiencies of intraocular lenses (IOLs). All of these optical phenomena are related to light scatter. However, the specific direction that light scatters makes a critical difference between debilitating glare and a slightly noticeable decrease in image quality. Consequently, quantifying the magnitude and direction of scattered light is essential to appropriately evaluate the safety and efficacy of IOLs. In this study, we introduce a full-angle scanning light scattering profiler (SLSP) as a novel approach capable of quantitatively evaluating the light scattering from IOLs with a nearlymore » 360° view. The SLSP method can simulate in situ conditions by controlling the parameters of the light source including angle of incidence. This testing strategy will provide a more effective nonclinical approach for the evaluation of IOL light scatter.« less

Minimally invasive surgery: only as good as the picture.

PubMed Central

Drury, Nigel E.; Pollard, Rebecca; Dyer, Jonathan P.

2004-01-01

BACKGROUND: In minimally invasive surgery, there is increased reliance on real-time 2-dimensional images. The fibre-optic light lead is one of the most frequently damaged elements of the 'imaging chain', leading to a poor quality picture. METHODS: Light leads with a honeycomb projection were connected to a light source and the resulting beam directed at a sheet of paper. Darkened sectors with diminished or absent light transmission were recorded. RESULTS: All suitable light leads in routine use were examined. A mean of 22.2% (SD 7.8%) of the projection had diminished or absent light transmission. CONCLUSION: Sub-optimal endoscopic equipment was in routine use. PMID:15005945

Extravillus dividing fetal cells at CVS: evidence of their erythroblastic origin.

PubMed Central

Terzoli, G; Cartolano, R; Rossella, F; Cantù-Rajnoldi, A; Brambati, B; Fraccaro, M; Simoni, G

1992-01-01

Cytological and cytogenetic studies were performed on nucleated fetal cells present in chorionic villus transport medium. The erythroblastic origin of these cells was shown. Fetal erythroblasts in spontaneous mitosis were frequently observed; chromosome counts were obtained from them but poor quality often prevented banded analysis. Cytogenetic study of erythroblast metaphases can be useful as an additional diagnostic aid in cases of mosaicism with aneuploid cell lines. Images PMID:1433230

Colometer: a real-time quality feedback system for screening colonoscopy.

PubMed

Filip, Dobromir; Gao, Xuexin; Angulo-Rodríguez, Leticia; Mintchev, Martin P; Devlin, Shane M; Rostom, Alaa; Rosen, Wayne; Andrews, Christopher N

2012-08-28

To investigate the performance of a new software-based colonoscopy quality assessment system. The software-based system employs a novel image processing algorithm which detects the levels of image clarity, withdrawal velocity, and level of the bowel preparation in a real-time fashion from live video signal. Threshold levels of image blurriness and the withdrawal velocity below which the visualization could be considered adequate have initially been determined arbitrarily by review of sample colonoscopy videos by two experienced endoscopists. Subsequently, an overall colonoscopy quality rating was computed based on the percentage of the withdrawal time with adequate visualization (scored 1-5; 1, when the percentage was 1%-20%; 2, when the percentage was 21%-40%, etc.). In order to test the proposed velocity and blurriness thresholds, screening colonoscopy withdrawal videos from a specialized ambulatory colon cancer screening center were collected, automatically processed and rated. Quality ratings on the withdrawal were compared to the insertion in the same patients. Then, 3 experienced endoscopists reviewed the collected videos in a blinded fashion and rated the overall quality of each withdrawal (scored 1-5; 1, poor; 3, average; 5, excellent) based on 3 major aspects: image quality, colon preparation, and withdrawal velocity. The automated quality ratings were compared to the averaged endoscopist quality ratings using Spearman correlation coefficient. Fourteen screening colonoscopies were assessed. Adenomatous polyps were detected in 4/14 (29%) of the collected colonoscopy video samples. As a proof of concept, the Colometer software rated colonoscope withdrawal as having better visualization than the insertion in the 10 videos which did not have any polyps (average percent time with adequate visualization: 79% ± 5% for withdrawal and 50% ± 14% for insertion, P < 0.01). Withdrawal times during which no polyps were removed ranged from 4-12 min. The median quality rating from the automated system and the reviewers was 3.45 [interquartile range (IQR), 3.1-3.68] and 3.00 (IQR, 2.33-3.67) respectively for all colonoscopy video samples. The automated rating revealed a strong correlation with the reviewer's rating (ρ coefficient= 0.65, P = 0.01). There was good correlation of the automated overall quality rating and the mean endoscopist withdrawal speed rating (Spearman r coefficient= 0.59, P = 0.03). There was no correlation of automated overall quality rating with mean endoscopists image quality rating (Spearman r coefficient= 0.41, P = 0.15). The results from a novel automated real-time colonoscopy quality feedback system strongly agreed with the endoscopists' quality assessments. Further study is required to validate this approach.

Combined effects of sleep quality and depression on quality of life in patients with type 2 diabetes.

PubMed

Zhang, Pan; Lou, Peian; Chang, Guiqiu; Chen, Peipei; Zhang, Lei; Li, Ting; Qiao, Cheng

2016-04-05

Poor sleep quality and depression negatively impact the health-related quality of life of patients with type 2 diabetes, but the combined effect of the two factors is unknown. This study aimed to assess the interactive effects of poor sleep quality and depression on the quality of life in patients with type 2 diabetes. Patients with type 2 diabetes (n = 944) completed the Diabetes Specificity Quality of Life scale (DSQL) and questionnaires on sleep quality and depression. The products of poor sleep quality and depression were added to the logistic regression model to evaluate their multiplicative interactions, which were expressed as the relative excess risk of interaction (RERI), the attributable proportion (AP) of interaction, and the synergy index (S). Poor sleep quality and depressive symptoms both increased DSQL scores. The co-presence of poor sleep quality and depressive symptoms significantly reduced DSQL scores by a factor of 3.96 on biological interaction measures. The relative excess risk of interaction was 1.08. The combined effect of poor sleep quality and depressive symptoms was observed only in women. Patients with both depressive symptoms and poor sleep quality are at an increased risk of reduction in diabetes-related quality of life, and this risk is particularly high for women due to the interaction effect. Clinicians should screen for and treat sleep difficulties and depressive symptoms in patients with type 2 diabetes.

Impact of sleep quality on the quality of life of patients with Parkinson's disease: a questionnaire based study.

PubMed

Pandey, Shweta; Bajaj, Bhupender Kumar; Wadhwa, Ankur; Anand, Kuljeet Singh

2016-09-01

Poor sleep quality contributes to the inferior quality of life of patients with Parkinson's disease (PD) despite appropriate treatment of motor symptoms. The literature about the impact of sleep quality on quality of life of patients with PD is as yet sparse. One hundred patients of PD diagnosed as per UK Brain Bank criteria were assessed for severity and stage of PD using UPDRS and modified Hoehn &Yahr scales. The quality of sleep was assessed by Pittsburgh Sleep Quality Index and excessive daytime somnolence (EDS) was evaluated using Epworth Sleepiness Scale. Parkinson's Disease Questionnaire -39 (PDQ-39) was used to determine quality of life of the patients. Comorbid depression and anxiety were assessed using Inventory of Depressive Symptoms-Self Rated and Hamilton Anxiety Rating Scale. Pearson's correlation and multiple linear regressions were used to analyze relation of sleep quality with quality of life of patients. Fifty patients had poor sleep quality. EDS was present in only 9 patients. Co-morbid depression and anxiety were present in 52 and 34 patients respectively. While the motor severity assessed by UPDRS-III was observed to adversely affect quality of life, it did not negatively impact quality of sleep. Higher score on UPDRS-total and UPDRS IV suggesting advanced disease correlated with poor sleep quality. Depression and anxiety were significantly more frequent in patients with poor sleep quality (p<0.01). Patients with poor sleep quality had worse quality of life (r=0.338, p<0.05). Depression and anxiety were also observed to have significant negative impact on quality of life of PD patients (p<0.01). Poor sleep quality was not found to be an independent predictor of quality of life using multiple linear regression analysis. Poor sleep quality along with comorbid depression, anxiety and advanced stage of disease is associated with poor quality of life. Copyright © 2016 Elsevier B.V. All rights reserved.

Reconstructing Face Image from the Thermal Infrared Spectrum to the Visible Spectrum †

PubMed Central

Kresnaraman, Brahmastro; Deguchi, Daisuke; Takahashi, Tomokazu; Mekada, Yoshito; Ide, Ichiro; Murase, Hiroshi

2016-01-01

During the night or in poorly lit areas, thermal cameras are a better choice instead of normal cameras for security surveillance because they do not rely on illumination. A thermal camera is able to detect a person within its view, but identification from only thermal information is not an easy task. The purpose of this paper is to reconstruct the face image of a person from the thermal spectrum to the visible spectrum. After the reconstruction, further image processing can be employed, including identification/recognition. Concretely, we propose a two-step thermal-to-visible-spectrum reconstruction method based on Canonical Correlation Analysis (CCA). The reconstruction is done by utilizing the relationship between images in both thermal infrared and visible spectra obtained by CCA. The whole image is processed in the first step while the second step processes patches in an image. Results show that the proposed method gives satisfying results with the two-step approach and outperforms comparative methods in both quality and recognition evaluations. PMID:27110781

MIGS-GPU: Microarray Image Gridding and Segmentation on the GPU.

PubMed

Katsigiannis, Stamos; Zacharia, Eleni; Maroulis, Dimitris

2017-05-01

Complementary DNA (cDNA) microarray is a powerful tool for simultaneously studying the expression level of thousands of genes. Nevertheless, the analysis of microarray images remains an arduous and challenging task due to the poor quality of the images that often suffer from noise, artifacts, and uneven background. In this study, the MIGS-GPU [Microarray Image Gridding and Segmentation on Graphics Processing Unit (GPU)] software for gridding and segmenting microarray images is presented. MIGS-GPU's computations are performed on the GPU by means of the compute unified device architecture (CUDA) in order to achieve fast performance and increase the utilization of available system resources. Evaluation on both real and synthetic cDNA microarray images showed that MIGS-GPU provides better performance than state-of-the-art alternatives, while the proposed GPU implementation achieves significantly lower computational times compared to the respective CPU approaches. Consequently, MIGS-GPU can be an advantageous and useful tool for biomedical laboratories, offering a user-friendly interface that requires minimum input in order to run.

Ultrasonography in diagnosing chronic pancreatitis: New aspects

PubMed Central

Dimcevski, Georg; Erchinger, Friedemann G; Havre, Roald; Gilja, Odd Helge

2013-01-01

The course and outcome is poor for most patients with pancreatic diseases. Advances in pancreatic imaging are important in the detection of pancreatic diseases at early stages. Ultrasonography as a diagnostic tool has made, virtually speaking a technical revolution in medical imaging in the new millennium. It has not only become the preferred method for first line imaging, but also, increasingly to clarify the interpretation of other imaging modalities to obtain efficient clinical decision. We review ultrasonography modalities, focusing on advanced pancreatic imaging and its potential to substantially improve diagnosis of pancreatic diseases at earlier stages. In the first section, we describe scanning techniques and examination protocols. Their consequences for image quality and the ability to obtain complete and detailed visualization of the pancreas are discussed. In the second section we outline ultrasonographic characteristics of pancreatic diseases with emphasis on chronic pancreatitis. Finally, new developments in ultrasonography of the pancreas such as contrast enhanced ultrasound and elastography are enlightened. PMID:24259955

Direct composite fillings: an optical coherence tomography and microCT investigation

NASA Astrophysics Data System (ADS)

Negrutiu, Meda L.; Sinescu, Cosmin; Borlea, Mugurel V.; Manescu, Adrian; Duma, Virgil F.; Rominu, Mihai; Podoleanu, Adrian G.

2015-03-01

The treatment of carious lesions requires removal of affected dental tissue thus creating cavities that are to be filled with dedicated materials. There are several methods known which are used to assess the quality of direct dental restorations, but most of them are invasive. Optical tomographic techniques are of particular importance in the medical imaging field, because these techniques can provide non-invasive diagnostic images. Using an en-face version of OCT, we have recently demonstrated real time thorough evaluation of quality of dental fillings. The major aim of this study was to analyses the optical performance of adhesives modified with zirconia particles in different concentrations in order to improve the contrast of OCT imaging of the interface between the tooth structure, adhesive and composite resin. The OCT investigations were validated by micro CT using synchrotron radiation. The OCT Swept Source is a valuable investigation tool for the clinical evaluation of class II direct composite restorations. The unmodified adhesive layer shows poor contrast on regular OCT investigations. Adding zirconia particles to the adhesive layer provides a better scattering which allows a better characterization and quantification of direct restorations.

Utility of double-contrast multi-detector CT scans to assess cartilage thickness after tibial plafond fracture

PubMed Central

Thomas, Thaddeus P.; Van Hofwegen, Christopher J.; Anderson, Donald D.; Brown, Thomas D.; Marsh, J. Lawrence

2010-01-01

The pathophysiology of post-traumatic osteoarthritis (PTOA) after intra-articular fractures is poorly understood. Pursuit of a better understanding of this disease is complicated by inability to accurately monitor its onset, progression and severity. Common radiographic methods used to assess PTOA do not provide sufficient image quality for precise cartilage measurements. Double-contrast MDCT is an alternative method that may be useful, since it produces high-quality images in normal ankles. The purpose of this study was to assess this technique’s performance in assessing cartilage maintenance in ankles with an intra-articular fracture. Thirty-six tibial plafond fractures were followed over two years, with thirty-one MDCTs being obtained four months after injury, and twenty-two MDCTs after two years. Unfortunately, clinical results with this technique were unreliable due to pathology (presumed arthrofibrosis) and technical problems (pooling of contrast). The arthrofibrosis that developed in many patients inhibited proper joint access and contrast infiltration, although high-quality images were obtained in eleven patients. In this patient subset, in which focal regions of cartilage degeneration could be visualized, thickness could be measured with a high degree of fidelity. While thus useful in selected instances, double-contrast MDCT was too unreliable to be recommended to assess these particular types of injuries. PMID:20634971

The Effect of Heart Rate on Exposure Window and Best Phase for Stress Perfusion Computed Tomography: Lessons From the CORE320 Study.

PubMed

Steveson, Chloe; Schuijf, Joanne D; Vavere, Andrea L; Mather, Richard T; Caton, Teresa; Mehra, Vishal; Betoko, Aisha; Cox, Christopher; Lima, Joao Ac; George, Richard T

The aim of this study is to evaluate the effect of heart rate on exposure window, best phase, and image quality for stress computed tomography perfusion (CTP) in the CORE320 study. The CTP data sets were analyzed to determine the best phase for perfusion analysis. A predefined exposure window covering 75% to 95% of the R-R cycle was used. Of the 368 patients included in the analysis, 93% received oral β blockade before the rest scan. The median heart rate during the stress acquisition was 69 bpm (interquartile range [IQR], 60-77). The median best phase was 81% (IQR, 76-90), and length of exposure window was 22% (IQR, 19-24). The best phase was significantly later in the cardiac cycle with higher heart rates (P < 0.001), and higher heart rates resulted in a small, but higher number of poor quality scans (6%, P < 0.001). The median effective dose of the stress scan was 5.3 mSv (IQR, 3.8-6.1). Stress myocardial CTP imaging can be performed using prospective electrocardiography triggering, an exposure window of 75% to 95%, and β-blockade resulting in good or excellent image quality in the majority (80%) of patients while maintaining a low effective radiation dose.

Repeat analysis of intraoral digital imaging performed by undergraduate students using a complementary metal oxide semiconductor sensor: An institutional case study.

PubMed

Yusof, Mohd Yusmiaidil Putera Mohd; Rahman, Nur Liyana Abdul; Asri, Amiza Aqiela Ahmad; Othman, Noor Ilyani; Wan Mokhtar, Ilham

2017-12-01

This study was performed to quantify the repeat rate of imaging acquisitions based on different clinical examinations, and to assess the prevalence of error types in intraoral bitewing and periapical imaging using a digital complementary metal-oxide-semiconductor (CMOS) intraoral sensor. A total of 8,030 intraoral images were retrospectively collected from 3 groups of undergraduate clinical dental students. The type of examination, stage of the procedure, and reasons for repetition were analysed and recorded. The repeat rate was calculated as the total number of repeated images divided by the total number of examinations. The weighted Cohen's kappa for inter- and intra-observer agreement was used after calibration and prior to image analysis. The overall repeat rate on intraoral periapical images was 34.4%. A total of 1,978 repeated periapical images were from endodontic assessment, which included working length estimation (WLE), trial gutta-percha (tGP), obturation, and removal of gutta-percha (rGP). In the endodontic imaging, the highest repeat rate was from WLE (51.9%) followed by tGP (48.5%), obturation (42.2%), and rGP (35.6%). In bitewing images, the repeat rate was 15.1% and poor angulation was identified as the most common cause of error. A substantial level of intra- and interobserver agreement was achieved. The repeat rates in this study were relatively high, especially for certain clinical procedures, warranting training in optimization techniques and radiation protection. Repeat analysis should be performed from time to time to enhance quality assurance and hence deliver high-quality health services to patients.

Use of a hybrid iterative reconstruction technique to reduce image noise and improve image quality in obese patients undergoing computed tomographic pulmonary angiography.

PubMed

Kligerman, Seth; Mehta, Dhruv; Farnadesh, Mahmmoudreza; Jeudy, Jean; Olsen, Kathryn; White, Charles

2013-01-01

To determine whether an iterative reconstruction (IR) technique (iDose, Philips Healthcare) can reduce image noise and improve image quality in obese patients undergoing computed tomographic pulmonary angiography (CTPA). The study was Health Insurance Portability and Accountability Act compliant and approved by our institutional review board. A total of 33 obese patients (average body mass index: 42.7) underwent CTPA studies following standard departmental protocols. The data were reconstructed with filtered back projection (FBP) and 3 iDose strengths (iDoseL1, iDoseL3, and iDoseL5) for a total of 132 studies. FBP data were collected from 33 controls (average body mass index: 22) undergoing CTPA. Regions of interest were drawn at 6 identical levels in the pulmonary artery (PA), from the main PA to a subsegmental branch, in both the control group and study groups using each algorithm. Noise and attenuation were measured at all PA levels. Three thoracic radiologists graded each study on a scale of 1 (very poor) to 5 (ideal) by 4 categories: image quality, noise, PA enhancement, and "plastic" appearance. Statistical analysis was performed using an unpaired t test, 1-way analysis of variance, and linear weighted κ. Compared with the control group, there was significantly higher noise with FBP, iDoseL1, and iDoseL3 algorithms (P<0.001) in the study group. There was no significant difference between the noise in the control group and iDoseL5 algorithm in the study group. Analysis within the study group showed a significant and progressive decrease in noise and increase in the contrast-to-noise ratio as the level of IR was increased (P<0.001). Compared with FBP, readers graded overall image quality as being higher using iDoseL1 (P=0.0018), iDoseL3 (P<0.001), and iDoseL5 (P<0.001). Compared with FBP, there was subjective improvement in image noise and PA enhancement with increasing levels of iDose. The use of an IR technique leads to qualitative and quantitative improvements in image noise and image quality in obese patients undergoing CTPA.

Improving Vintage Seismic Data Quality through Implementation of Advance Processing Techniques

NASA Astrophysics Data System (ADS)

Latiff, A. H. Abdul; Boon Hong, P. G.; Jamaludin, S. N. F.

2017-10-01

It is essential in petroleum exploration to have high resolution subsurface images, both vertically and horizontally, in uncovering new geological and geophysical aspects of our subsurface. The lack of success may have been from the poor imaging quality which led to inaccurate analysis and interpretation. In this work, we re-processed the existing seismic dataset with an emphasis on two objectives. Firstly, to produce a better 3D seismic data quality with full retention of relative amplitudes and significantly reduce seismic and structural uncertainty. Secondly, to facilitate further prospect delineation through enhanced data resolution, fault definitions and events continuity, particularly in syn-rift section and basement cover contacts and in turn, better understand the geology of the subsurface especially in regard to the distribution of the fluvial and channel sands. By adding recent, state-of-the-art broadband processing techniques such as source and receiver de-ghosting, high density velocity analysis and shallow water de-multiple, the final results produced a better overall reflection detail and frequency in specific target zones, particularly in the deeper section.

Radiographic Diagnosis of Pincer-Type Femoroacetabular Impingement: A Systematic Review.

PubMed

Rhee, Chanseok; Le Francois, Tina; Byrd, J W Thomas; Glazebrook, Mark; Wong, Ivan

2017-05-01

Femoroacetabular impingement (FAI) is a well-recognized condition that causes hip pain and can lead to early osteoarthritis if not managed properly. With the increasing awareness and efficacy of operative treatments for pincer-type FAI, there is a need for consensus on the standardized radiographic diagnosis. To perform a systematic review of the evidence regarding imaging modalities and radiographic signs for diagnosing pincer-type FAI. Systematic review; Level of evidence, 4. A literature review was performed in 2016 using the Cochrane, PubMed, and Embase search engines. All articles focusing on a radiographic diagnosis of pincer-type FAI were reviewed. Each of the included 44 articles was assigned the appropriate level of evidence, and the particular radiographic marker and/or type of imaging were also summarized. There were 44 studies included in the final review. Most of the articles were level 4 evidence (26 articles), and there were 12 level 3 and 6 level 2 articles. The crossover sign was the most commonly used radiographic sign (27/44) followed by the lateral center-edge angle (22/44). Anteroposterior (AP) pelvis plain radiographs were the most commonly used imaging modality (33 studies). Poor-quality evidence exists in support of most currently used radiographic markers, including the crossover sign, lateral center-edge angle, posterior wall sign, ischial spine sign, coxa profunda, acetabular protrusion, and acetabular index. There is poor-quality conflicting evidence regarding the use of the herniation pit to diagnose pincer-type FAI. Some novel measurements, such as β-angle, acetabular roof ratio, and acetabular retroversion index, have been proposed, but they also lack support from the literature. No strong evidence exists to support a single best set of current radiographic markers for the diagnosis of pincer-type FAI, largely due to the lack of better quality trials (levels 1 and 2) that compare conventional radiographic findings with the gold standard, which is the intraoperative findings. More sophisticated imaging modalities such as computed tomography and magnetic resonance arthrography are often needed to diagnose pincer-type FAI, and these investigations are relatively accurate in assessing labral pathology or cartilage damage.

In Vivo Small Animal Imaging using Micro-CT and Digital Subtraction Angiography

PubMed Central

Badea, C.T.; Drangova, M.; Holdsworth, D.W.; Johnson, G.A.

2009-01-01

Small animal imaging has a critical role in phenotyping, drug discovery, and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to review in vivo X-ray based small animal imaging, with a focus on in vivo micro-computed tomography (micro-CT) and digital subtraction angiography (DSA). We present the principles, technologies, image quality parameters and types of applications. We show that both methods can be used not only to provide morphological, but also functional information, such as cardiac function estimation or perfusion. Compared to other modalities, x-ray based imaging is usually regarded as being able to provide higher throughput at lower cost and adequate resolution. The limitations are usually associated with the relatively poor contrast mechanisms and potential radiation damage due to ionizing radiation, although the use of contrast agents and careful design of studies can address these limitations. We hope that the information will effectively address how x-ray based imaging can be exploited for successful in vivo preclinical imaging. PMID:18758005

Estimated Under-Five Deaths Associated with Poor-Quality Antimalarials in Sub-Saharan Africa

PubMed Central

Renschler, John P.; Walters, Kelsey M.; Newton, Paul N.; Laxminarayan, Ramanan

2015-01-01

Many antimalarials sold in sub-Saharan Africa are poor-quality (falsified, substandard, or degraded), and the burden of disease caused by this problem is inadequately quantified. In this article, we estimate the number of under-five deaths caused by ineffective treatment of malaria associated with consumption of poor-quality antimalarials in 39 sub-Saharan countries. Using Latin hypercube sampling our estimates were calculated as the product of the number of private sector antimalarials consumed by malaria-positive children in 2013; the proportion of private sector antimalarials consumed that were of poor-quality; and the case fatality rate (CFR) of under-five malaria-positive children who did not receive appropriate treatment. An estimated 122,350 (interquartile range [IQR]: 91,577–154,736) under-five malaria deaths were associated with consumption of poor-quality antimalarials, representing 3.75% (IQR: 2.81–4.75%) of all under-five deaths in our sample of 39 countries. There is considerable uncertainty surrounding our results because of gaps in data on case fatality rates and prevalence of poor-quality antimalarials. Our analysis highlights the need for further investigation into the distribution of poor-quality antimalarials and the need for stronger surveillance and regulatory efforts to prevent the sale of poor-quality antimalarials. PMID:25897068

A vision-based weld quality evaluation system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnett, R.J.; Cook, G.E.; Strauss, A.M.

1996-12-31

Inspection of the appearance of weld beads is an integral part of the overall welding process. Lack of satisfactory appearance in itself may be sufficient grounds for part rejection or the lack of satisfactory appearance may be used as an indirect indicator of more substantive problems such as poor fusion or subsurface cracks. In all cases the inspection process tends to be both time and labor intensive. The present research uses a video system and appropriate image capture and processing to determine the quality of the weld based upon surface appearance. This relative quality rating was compared to similar ratingsmore » performed by human inspectors and was found to give very good correlation. The system was implemented for the Gas Tungsten Arc Welding (GTAW) and Gas Metal Arc Welding (GMAW) processes.« less

The prevalence of poor sleep quality and its association with depression and anxiety scores in patients admitted for cardiovascular disease: A cross-sectional designed study.

PubMed

Matsuda, Risa; Kohno, Takashi; Kohsaka, Shun; Fukuoka, Ryoma; Maekawa, Yuichiro; Sano, Motoaki; Takatsuki, Seiji; Fukuda, Keiichi

2017-02-01

Poor sleep quality contributes to the development of various cardiovascular conditions. However, its real-world prevalence among cardiovascular inpatients and association with psychological disturbance is unknown. This study aimed to assess the prevalence of poor sleep quality and its association with depression and anxiety in cardiovascular patients, and explored whether sex and cardiovascular comorbidities modified these associations. A total of 1071 patients hospitalized for a broad spectrum of cardiovascular diseases at a single university hospital were assessed (790 men, mean age 64±14years). We assessed sleep quality during their index hospitalization period using the Pittsburgh Sleep Quality Index (PSQI); poor sleep quality was defined as PSQI>5. Depression and anxiety were assessed with the Hospital Anxiety and Depression Scale (HADS). The median PSQI score was 5.0 [3.0-7.0], and 461 inpatients (43%) had poor sleep quality. Multivariate regression analysis adjusting for patient background, medical risk factors, and laboratory data revealed that poor sleep quality was associated with higher HADS subscores for depression (HADS-depression; odds ratio [OR]: 1.09, 95% confidence interval [CI]: 1.03-1.15) and anxiety (HADS-anxiety; OR: 1.17, 95% CI: 1.11-1.24). Poor sleep quality was associated with markedly higher HADS-depression among women than men (p value for interaction: 0.008). The association between poor sleep quality and HADS-anxiety was more significant among patients without coronary artery diseases (p value for interaction: 0.017). Poor sleep quality was highly prevalent and associated with depression and anxiety in cardiovascular patients. These associations may be modified by sex and the presence of coronary artery diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

High-performance serial block-face SEM of nonconductive biological samples enabled by focal gas injection-based charge compensation.

PubMed

Deerinck, T J; Shone, T M; Bushong, E A; Ramachandra, R; Peltier, S T; Ellisman, M H

2018-05-01

A longstanding limitation of imaging with serial block-face scanning electron microscopy is specimen surface charging. This charging is largely due to the difficulties in making biological specimens and the resins in which they are embedded sufficiently conductive. Local accumulation of charge on the specimen surface can result in poor image quality and distortions. Even minor charging can lead to misalignments between sequential images of the block-face due to image jitter. Typically, variable-pressure SEM is used to reduce specimen charging, but this results in a significant reduction to spatial resolution, signal-to-noise ratio and overall image quality. Here we show the development and application of a simple system that effectively mitigates specimen charging by using focal gas injection of nitrogen over the sample block-face during imaging. A standard gas injection valve is paired with a precisely positioned but retractable application nozzle, which is mechanically coupled to the reciprocating action of the serial block-face ultramicrotome. This system enables the application of nitrogen gas precisely over the block-face during imaging while allowing the specimen chamber to be maintained under high vacuum to maximise achievable SEM image resolution. The action of the ultramicrotome drives the nozzle retraction, automatically moving it away from the specimen area during the cutting cycle of the knife. The device described was added to a Gatan 3View system with minimal modifications, allowing high-resolution block-face imaging of even the most charge prone of epoxy-embedded biological samples. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

A practical approach to superresolution

NASA Astrophysics Data System (ADS)

Farsiu, Sina; Elad, Michael; Milanfar, Peyman

2006-01-01

Theoretical and practical limitations usually constrain the achievable resolution of any imaging device. Super-Resolution (SR) methods are developed through the years to go beyond this limit by acquiring and fusing several low-resolution (LR) images of the same scene, producing a high-resolution (HR) image. The early works on SR, although occasionally mathematically optimal for particular models of data and noise, produced poor results when applied to real images. In this paper, we discuss two of the main issues related to designing a practical SR system, namely reconstruction accuracy and computational efficiency. Reconstruction accuracy refers to the problem of designing a robust SR method applicable to images from different imaging systems. We study a general framework for optimal reconstruction of images from grayscale, color, or color filtered (CFA) cameras. The performance of our proposed method is boosted by using powerful priors and is robust to both measurement (e.g. CCD read out noise) and system noise (e.g. motion estimation error). Noting that the motion estimation is often considered a bottleneck in terms of SR performance, we introduce the concept of "constrained motions" for enhancing the quality of super-resolved images. We show that using such constraints will enhance the quality of the motion estimation and therefore results in more accurate reconstruction of the HR images. We also justify some practical assumptions that greatly reduce the computational complexity and memory requirements of the proposed methods. We use efficient approximation of the Kalman Filter (KF) and adopt a dynamic point of view to the SR problem. Novel methods for addressing these issues are accompanied by experimental results on real data.

Confocal microlaparoscope for imaging the fallopian tube

NASA Astrophysics Data System (ADS)

Wu, Tzu-Yu; Schafer, Rachel; Rouse, Andrew R.; Gmitro, Arthur F.

2012-02-01

Recent evidence suggests that epithelial ovarian cancer may originate in the fimbriated end of the fallopian tube1. Unlike many other cancers, poor access to the ovary and fallopian tubes has limited the ability to study the progression of this deadly disease and to diagnosis it during the early stage when it is most amenable to therapy. We have previously reported on a rigid confocal microlaparoscope system that is currently undergoing a clinical trial to image the epithelial surface of the ovary2. In order to gain in vivo access to the fallopian tubes we have developed a new confocal microlaparoscope with an articulating distal tip. The new instrument builds upon the technology developed for the existing confocal microlaparoscope. It has an ergonomic handle fabricated by a rapid prototyping printer. While maintaining compatibility with a 5 mm trocar, the articulating distal tip of the instrument consists of a 2.2 mm diameter bare fiber bundle catheter with automated dye delivery for fluorescence imaging. This small and flexible catheter design should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Early ex vivo mages of human fallopian tube and in vivo imaging results from recent open surgeries using the rigid confocal microlaparoscope system are presented. Ex vivo images from animal models using the new articulating bare fiber system are also presented. These high quality images collected by the new flexible system are similar in quality to those obtained from the epithelial surface of ovaries with the rigid clinical confocal microlaparoscope.

Non-sky polarization-based dehazing algorithm for non-specular objects using polarization difference and global scene feature.

PubMed

Qu, Yufu; Zou, Zhaofan

2017-10-16

Photographic images taken in foggy or hazy weather (hazy images) exhibit poor visibility and detail because of scattering and attenuation of light caused by suspended particles, and therefore, image dehazing has attracted considerable research attention. The current polarization-based dehazing algorithms strongly rely on the presence of a "sky area", and thus, the selection of model parameters is susceptible to external interference of high-brightness objects and strong light sources. In addition, the noise of the restored image is large. In order to solve these problems, we propose a polarization-based dehazing algorithm that does not rely on the sky area ("non-sky"). First, a linear polarizer is used to collect three polarized images. The maximum- and minimum-intensity images are then obtained by calculation, assuming the polarization of light emanating from objects is negligible in most scenarios involving non-specular objects. Subsequently, the polarization difference of the two images is used to determine a sky area and calculate the infinite atmospheric light value. Next, using the global features of the image, and based on the assumption that the airlight and object radiance are irrelevant, the degree of polarization of the airlight (DPA) is calculated by solving for the optimal solution of the correlation coefficient equation between airlight and object radiance; the optimal solution is obtained by setting the right-hand side of the equation to zero. Then, the hazy image is subjected to dehazing. Subsequently, a filtering denoising algorithm, which combines the polarization difference information and block-matching and 3D (BM3D) filtering, is designed to filter the image smoothly. Our experimental results show that the proposed polarization-based dehazing algorithm does not depend on whether the image includes a sky area and does not require complex models. Moreover, the dehazing image except specular object scenarios is superior to those obtained by Tarel, Fattal, Ren, and Berman based on the criteria of no-reference quality assessment (NRQA), blind/referenceless image spatial quality evaluator (BRISQUE), blind anistropic quality index (AQI), and e.

Radiation dose reduction and new image modalities development for interventional C-arm imaging system

NASA Astrophysics Data System (ADS)

Niu, Kai

Cardiovascular disease and stroke are the leading health problems and causes of death in the US. Due to the minimally invasive nature of the evolution of image guided techniques, interventional radiological procedures are becoming more common and are preferred in treating many cardiovascular diseases and strokes. In addition, with the recent advances in hardware and device technology, the speed and efficacy of interventional treatment has significantly improved. This implies that more image modalities can be developed based on the current C-arm system and patients treated in interventional suites can potentially experience better health outcomes. However, during the treatment patients are irradiated with substantial amounts of ionizing radiation with a high dose rate (digital subtraction angiography (DSA) with 3muGy/frame and 3D cone beam CT image with 0.36muGy/frame for a Siemens Artis Zee biplane system) and/or a long irradiation time (a roadmapping image sequence can be as long as one hour during aneurysm embolization). As a result, the patient entrance dose is extremely high. Despite the fact that the radiation dose is already substantial, image quality is not always satisfactory. By default a temporal average is used in roadmapping images to overcome poor image quality, but this technique can result in motion blurred images. Therefore, reducing radiation dose while maintaining or even improving the image quality is an important area for continued research. This thesis is focused on improving the clinical applications of C-arm cone beam CT systems in two ways: (1) Improve the performance of current image modalities on the C-arm system. (2) Develop new image modalities based on the current system. To be more specific, the objectives are to reduce radiation dose for current modalities (e.g., DSA, fluoroscopy, roadmapping, and cone beam CT) and enable cone beam CT perfusion and time resolved cone beam CT angiography that can be used to diagnose and triage acute ischemic stroke patients more efficiently compared with the current clinical work-flow. The animal and patient cases presented in this thesis are focused towards but not limited to neurointerventional applications.

Effect of Number of Zones on Subjective Vision in Concentric Bifocal Optics.

PubMed

Legras, Richard; Rio, David

2015-11-01

To evaluate the influence of the number of concentric zones of a center-near bifocal optics on the subjective quality of vision. Twenty-two subjects scored with a five-item continuous grading scale the quality of vision of calculated images (i.e., three high-contrast 20/50 letters) viewed through their best sphero-cylindrical correction and a 3-mm pupil to limit the impact of their aberrations. Through-focus images were calculated from -4 to +2 diopters (D), each 0.25 D, in the presence of center-near bifocal optics (Add 2.5 D) varying by their number of concentric zones (from 2 to 20). To compare the results obtained with these profiles, we calculated the area under the (through-focus) curve (AUC) higher than 2 out of 5 (i.e., limit between a poor and a fair image quality, considered as the limit of acceptability). This value was normalized by the naked eye condition and divided into distance, intermediate, and near AUC. The results showed large interindividual variations. Distance AUC remained quite similar whatever the profile, near AUC decreased with the number of concentric zones, and intermediate AUC rose with the number of concentric zones. With 10 and 20 concentric zones, diffraction phenomenon induced constructive interferences at intermediate proximities and destructive interferences at distance and near proximities. To balance distance, intermediate, and near quality of vision, a number of zones between 8 and 10 should be chosen. If the subject does not need intermediate quality of vision, then a profile with two to five zones should be favored.

Sleep quality moderates the association between physical activity frequency and feelings of energy and fatigue in adolescents.

PubMed

Herring, Matthew P; Monroe, Derek C; Kline, Christopher E; O'Connor, Patrick J; MacDonncha, Ciaran

2018-03-05

Physical activity (PA) can improve sleep quality, low energy, and fatigue. Though poor sleep quality may induce feelings of low energy and fatigue, the potential moderating effect of sleep quality on associations between PA and feelings of energy and fatigue among adolescents is unknown. Thus, this study examined the moderating effect of sleep quality on associations between PA frequency and feelings of energy and fatigue among adolescents in Ireland. Adolescents (N = 481; 281 males, 200 females) aged 15.1 ± 1.7 years self-reported PA frequency, feelings of energy and fatigue, and sleep quality (September to December 2015). Two-way ANCOVAs examined variation in feelings of energy and fatigue according to the interaction of PA and sleep quality. Standardized mean difference (d) quantified the magnitude of differences. Poor sleepers with low PA reported greater feelings of fatigue compared to normal sleepers with low PA (d = 1.02; 95% CI 0.60, 1.44), and poor sleepers with moderate PA reported greater feelings of fatigue compared to normal sleepers with moderate PA (d = 0.50; 0.17, 0.82). Poor sleepers with low PA reported greater feelings of fatigue compared to both poor sleepers with moderate PA (d = 0.44; 0.05, 0.83) and poor sleepers with high PA (d = 0.87; 0.46, 1.28). Poor sleepers with moderate PA reported greater feelings of fatigue compared to poor sleepers with high PA (d = 0.52; 0.14, 0.91). Poor sleep did not moderate the association between PA and feelings of energy. Sleep quality moderates the association between PA frequency and feelings of fatigue. Fatigue symptoms improve as PA frequency increases among adolescents with poor sleep quality.

Examples of, reasons for, and consequences of the poor quality of wind data from ships for the marine boundary layer: Implications for remote sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierson, W.J. Jr.

1990-08-15

Wind reports by data buoys are used to demonstrate that these reports have in the past provided useful values for the synoptic scale winds and that at present these reports provide very reliable values for the synoptic scale winds. Past studies of wind reports by ships have revealed that the data are of poor quality, but the causes for this poor quality are not identified. Examples of the poor quality of wind data from ships are obtained by comparing ship reports with buoy reports and comparing reports of different kinds of ships with each other. These comparisons identify many differentmore » reasons for the poor quality of wind data from ships. Suggestions are made for improving the quality of ship data. The consequences of the poor quality of ship winds are described in terms of the effects on weather and wave forecasts. The implications for remotely sensed winds are discussed.« less

Comparison of 10 digital SLR cameras for orthodontic photography.

PubMed

Bister, D; Mordarai, F; Aveling, R M

2006-09-01

Digital photography is now widely used to document orthodontic patients. High quality intra-oral photography depends on a satisfactory 'depth of field' focus and good illumination. Automatic 'through the lens' (TTL) metering is ideal to achieve both the above aims. Ten current digital single lens reflex (SLR) cameras were tested for use in intra- and extra-oral photography as used in orthodontics. The manufacturers' recommended macro-lens and macro-flash were used with each camera. Handling characteristics, colour-reproducibility, quality of the viewfinder and flash recharge time were investigated. No camera took acceptable images in factory default setting or 'automatic' mode: this mode was not present for some cameras (Nikon, Fujifilm); led to overexposure (Olympus) or poor depth of field (Canon, Konica-Minolta, Pentax), particularly for intra-oral views. Once adjusted, only Olympus cameras were able to take intra- and extra-oral photographs without the need to change settings, and were therefore the easiest to use. All other cameras needed adjustments of aperture (Canon, Konica-Minolta, Pentax), or aperture and flash (Fujifilm, Nikon), making the latter the most complex to use. However, all cameras produced high quality intra- and extra-oral images, once appropriately adjusted. The resolution of the images is more than satisfactory for all cameras. There were significant differences relating to the quality of colour reproduction, size and brightness of the viewfinders. The Nikon D100 and Fujifilm S 3 Pro consistently scored best for colour fidelity. Pentax and Konica-Minolta had the largest and brightest viewfinders.

Potential fault region detection in TFDS images based on convolutional neural network

NASA Astrophysics Data System (ADS)

Sun, Junhua; Xiao, Zhongwen

2016-10-01

In recent years, more than 300 sets of Trouble of Running Freight Train Detection System (TFDS) have been installed on railway to monitor the safety of running freight trains in China. However, TFDS is simply responsible for capturing, transmitting, and storing images, and fails to recognize faults automatically due to some difficulties such as such as the diversity and complexity of faults and some low quality images. To improve the performance of automatic fault recognition, it is of great importance to locate the potential fault areas. In this paper, we first introduce a convolutional neural network (CNN) model to TFDS and propose a potential fault region detection system (PFRDS) for simultaneously detecting four typical types of potential fault regions (PFRs). The experimental results show that this system has a higher performance of image detection to PFRs in TFDS. An average detection recall of 98.95% and precision of 100% are obtained, demonstrating the high detection ability and robustness against various poor imaging situations.

Physical characterization and optimal magnification of a portal imaging system

NASA Astrophysics Data System (ADS)

Bissonnette, Jean-Pierre; Jaffray, David A.; Fenster, Aaron; Munro, Peter

1992-06-01

One problem in radiation therapy is ensuring accurate positioning of the patient so that the prescribed dose is delivered to the diseased regions while healthy tissues are spared. Positioning is usually assessed by exposing film to the high-energy treatment beam. Unfortunately, these films exhibit poor image quality (primarily due to low subject contrast) and the development delays make film impractical to check patient positioning routinely. Therefore, we have been developing a digital video-based imaging system to replace film. The system consists of a copper plate/fluorescent screen detector, a 45 degree(s) mirror, and a TV camera equipped with a large aperture lens. We have determined the signal and noise transfer properties of the imaging system by measuring its MTF(f) and NPS(f) and used these valued to estimate the optimal magnification for the imaging system. We have found that the optimal magnification is 2.3 - 2.5 when optimizing signal transfer (spatial resolution) alone; however, the optimal magnification is only 1.5 - 2.0 if SNR transfer is considered.

Crisis in our hospital kitchens: ancillary staffing levels during an outbreak of food poisoning in a long stay hospital.

PubMed Central

Pollock, A M; Whitty, P M

1990-01-01

An investigation into an outbreak of food poisoning caused by Clostridium perfringens showed evidence of poor food handling by catering staff. The reasons behind this were explored by interviewing catering staff, analysing shifts and rotas, and looking at staff vacancies. Morale was low because of staff shortages resulting from a long term recruitment problem. In consequence staff were working double shifts and often for weeks on end without a day off. The reasons for the recruitment problem included the difficulty of recruiting semiskilled labour from a middle class area, low wages, lack of management support, and the poor image of the hospital as a place of work. Similar factors affect the recruitment and retention of ancillary staff nationally. The NHS has a poor record as an employer of ancillary staff, paying lower wages than other organisations for equivalent posts. Competitive tendering has further worsened the position of ancillary staff, with the result that good quality of care and service has often not been achieved. The NHS Review, with its emphasis on quality of care, makes no mention of ancillary staff. Yet high standards of ancillary provision are essential if further outbreaks of food poisoning in hospitals are to be prevented. PMID:2106996

Crisis in our hospital kitchens: ancillary staffing levels during an outbreak of food poisoning in a long stay hospital.

PubMed

Pollock, A M; Whitty, P M

1990-02-10

An investigation into an outbreak of food poisoning caused by Clostridium perfringens showed evidence of poor food handling by catering staff. The reasons behind this were explored by interviewing catering staff, analysing shifts and rotas, and looking at staff vacancies. Morale was low because of staff shortages resulting from a long term recruitment problem. In consequence staff were working double shifts and often for weeks on end without a day off. The reasons for the recruitment problem included the difficulty of recruiting semiskilled labour from a middle class area, low wages, lack of management support, and the poor image of the hospital as a place of work. Similar factors affect the recruitment and retention of ancillary staff nationally. The NHS has a poor record as an employer of ancillary staff, paying lower wages than other organisations for equivalent posts. Competitive tendering has further worsened the position of ancillary staff, with the result that good quality of care and service has often not been achieved. The NHS Review, with its emphasis on quality of care, makes no mention of ancillary staff. Yet high standards of ancillary provision are essential if further outbreaks of food poisoning in hospitals are to be prevented.

Exploring Gender Difference in Sleep Quality of Young Adults: Findings from a Large Population Study

PubMed Central

Fatima, Yaqoot; Doi, Suhail A.R.; Najman, Jake M.; Mamun, Abdullah Al

2016-01-01

Objectives To explore if gender difference in sleep quality is due to higher prevalence of depression in females, and whether socio-demographic and lifestyle factors have a differential effect on sleep quality in males and females. Methods Youth self-reports and the Pittsburgh Sleep Quality Index were used to assess sleep quality and associated risk factors. Logistic regression analyses were used to analyze the association between various risk factors and poor sleep quality. Results Reports from 3,778 young adults (20.6±0.86 years) indicate a higher prevalence of poor sleep quality in females than males (65.1% vs. 49.8%). It seems that gender difference in poor sleep is independent of depression, socio-demographics, and lifestyle factors, since the higher odds of poor sleep quality in females was robust to adjust for depression, socio-demographics, and lifestyle factors (OR: 1.53, 95% CI: 1.23–1.90). Lifestyle factors (eg, smoking) (OR 1.91; 95% CI 1.05–3.46) were associated with sleep quality in only males. Conclusion Our findings indicate that female vulnerability to poor sleep quality should be explored beyond psycho-social disparities. Perhaps, exploring if the female predisposition to poor sleep quality originates at the biological level could lead to the answer. PMID:28188139

Poor sleep quality is associated with increased arterial stiffness in Japanese patients with type 2 diabetes mellitus.

PubMed

Osonoi, Yusuke; Mita, Tomoya; Osonoi, Takeshi; Saito, Miyoko; Tamasawa, Atsuko; Nakayama, Shiho; Someya, Yuki; Ishida, Hidenori; Kanazawa, Akio; Gosho, Masahiko; Fujitani, Yoshio; Watada, Hirotaka

2015-06-18

While poor sleep quality can worsen cardiovascular risk factors such as glucose and lipid profiles in patients with type 2 diabetes mellitus (T2DM), the relationship between sleep quality and atherosclerosis remains largely unknown. The aim of this study was to examine this relationship. The study participants comprised 724 Japanese T2DM outpatients free of history of cardiovascular diseases. The relationships between sleep quality (assessed by the Pittsburgh Sleep Quality Index (PSQI)) and various clinical and laboratory parameters were investigated. The mean PSQI was 5.1 ± 3.0 (±SD). Patients were divided into three groups based on the total PSQI score; subjects with good sleep quality (n = 462), average sleep quality (n = 185), and poor sleep quality (n = 77). In the age/gender-adjusted model, patients with poor sleep quality tended to be obese, evening type and depressed. However, other lifestyles showed no significant trends. Alanine aminotransferase, fasting blood glucose, HbA1c, systolic blood pressure, urinary albumin excretion, and brachial-ankle pulse wave velocity (baPWV) tended to be higher in patients with poor sleep quality. High baPWV was the only parameter that correlated with poor sleep in a model adjusted for several other lifestyle factors. Our study indicates that poor sleep quality in T2DM patients correlates with increased arterial wall stiffness, a marker of atherosclerosis and a risk factor for cardiovascular diseases.

Salivary calculus diagnosis with 3-dimensional cone-beam computed tomography.

PubMed

Dreiseidler, Timo; Ritter, Lutz; Rothamel, Daniel; Neugebauer, Jörg; Scheer, Martin; Mischkowski, Robert A

2010-07-01

The objective of this study was to evaluate cone-beam CT (CBCT) diagnoses of sialoliths in the major salivary glands. Twenty-nine CBCT images containing salivary calculi were retrospectively evaluated for image quality and artifact influence. Additionally, the reproducibility of calculus measurement and the differences between CBCT measurements and ultrasonography (US) and histomorphometry (HM) measurements were determined. Diagnostic sensitivity and specificity calculations were based on the observations of 3 masked clinicians, who reviewed a total of 58 CBCT volumes. Salivary calculi were sufficiently visualized in all patients. Metal artifacts were detected in images of 7 patients, and movement artifacts in 2. CBCT calculi measurements were highly reproducible, with mean differences of less than 350 microm. Mean CBCT measurements of calculi diameters differed from mean US measurements by approximately 500 microm and differed from mean HM measurements by approximately 1 mm. For calculus diagnoses, the mean sensitivity and specificity were both 98.85%. Although poor image qualities and artifacts can reduce diagnostic information, salivary calculi can be evaluated adequately with CBCT. CBCT measurements of calculi are highly reproducible and differ little from measurements made with US and HM. Diagnostic sensitivity and specificity levels with CBCT are as high as or higher than those obtained with other diagnostic methods. Because of its high diagnostic-information-to-radiation-dose ratio, CBCT is the preferable imaging modality for salivary calculus diagnosis. Copyright (c) 2010 Mosby, Inc. All rights reserved.

Online gamma-camera imaging of 103Pd seeds (OGIPS) for permanent breast seed implantation

NASA Astrophysics Data System (ADS)

Ravi, Ananth; Caldwell, Curtis B.; Keller, Brian M.; Reznik, Alla; Pignol, Jean-Philippe

2007-09-01

Permanent brachytherapy seed implantation is being investigated as a mode of accelerated partial breast irradiation for early stage breast cancer patients. Currently, the seeds are poorly visualized during the procedure making it difficult to perform a real-time correction of the implantation if required. The objective was to determine if a customized gamma-camera can accurately localize the seeds during implantation. Monte Carlo simulations of a CZT based gamma-camera were used to assess whether images of suitable quality could be derived by detecting the 21 keV photons emitted from 74 MBq 103Pd brachytherapy seeds. A hexagonal parallel hole collimator with a hole length of 38 mm, hole diameter of 1.2 mm and 0.2 mm septa, was modeled. The design of the gamma-camera was evaluated on a realistic model of the breast and three layers of the seed distribution (55 seeds) based on a pre-implantation CT treatment plan. The Monte Carlo simulations showed that the gamma-camera was able to localize the seeds with a maximum error of 2.0 mm, using only two views and 20 s of imaging. A gamma-camera can potentially be used as an intra-procedural image guidance system for quality assurance for permanent breast seed implantation.

How to create a marketing strategy based on hospital characteristics that attract physicians.

PubMed

Nordstrom, R D; Horton, D E; Hatcher, M E

1987-03-01

Through use of multivariate statistical and research techniques, the authors analyzed 30 hospital features that contribute to a physician's image of a hospital as being a good or a poor place for patient admission and in which to practice. Use of the data obtained in this study can enable a hospital administrator to monitor changes in physicians' attitudes, plan strategies to encourage quality physicians to admit their patients, improve aspects perceived to be weak or unresponsive, and capitalize on strengths.

Repeat analysis of intraoral digital imaging performed by undergraduate students using a complementary metal oxide semiconductor sensor: An institutional case study

PubMed Central

Rahman, Nur Liyana Abdul; Asri, Amiza Aqiela Ahmad; Othman, Noor Ilyani; Wan Mokhtar, Ilham

2017-01-01

Purpose This study was performed to quantify the repeat rate of imaging acquisitions based on different clinical examinations, and to assess the prevalence of error types in intraoral bitewing and periapical imaging using a digital complementary metal-oxide-semiconductor (CMOS) intraoral sensor. Materials and Methods A total of 8,030 intraoral images were retrospectively collected from 3 groups of undergraduate clinical dental students. The type of examination, stage of the procedure, and reasons for repetition were analysed and recorded. The repeat rate was calculated as the total number of repeated images divided by the total number of examinations. The weighted Cohen's kappa for inter- and intra-observer agreement was used after calibration and prior to image analysis. Results The overall repeat rate on intraoral periapical images was 34.4%. A total of 1,978 repeated periapical images were from endodontic assessment, which included working length estimation (WLE), trial gutta-percha (tGP), obturation, and removal of gutta-percha (rGP). In the endodontic imaging, the highest repeat rate was from WLE (51.9%) followed by tGP (48.5%), obturation (42.2%), and rGP (35.6%). In bitewing images, the repeat rate was 15.1% and poor angulation was identified as the most common cause of error. A substantial level of intra- and interobserver agreement was achieved. Conclusion The repeat rates in this study were relatively high, especially for certain clinical procedures, warranting training in optimization techniques and radiation protection. Repeat analysis should be performed from time to time to enhance quality assurance and hence deliver high-quality health services to patients. PMID:29279822

An investigation of the relationship between subjective sleep quality, loneliness and mood in an Australian sample: can daily routine explain the links?

PubMed

Smith, Simon Squire; Kozak, Nahum; Sullivan, Karen Anne

2012-03-01

Loneliness and low mood are associated with significant negative health outcomes including poor sleep, but the strength of the evidence underlying these associations varies. There is strong evidence that poor sleep quality and low mood are linked, but only emerging evidence that loneliness and poor sleep are associated. To independently replicate the finding that loneliness and poor subjective sleep quality are associated and to extend past research by investigating lifestyle regularity as a possible mediator of relationships, since lifestyle regularity has been linked to loneliness and poor sleep. Using a cross-sectional design, 97 adults completed standardized measures of loneliness, lifestyle regularity, subjective sleep quality and mood. Loneliness was a significant predictor of sleep quality. Lifestyle regularity was not a predictor of, nor associated with, mood, sleep quality or loneliness. This study provides an important independent replication of the association between poor sleep and loneliness. However, the mechanism underlying this link remains unclear. A theoretically plausible mechanism for this link, lifestyle regularity, does not explain the relationship between loneliness and poor sleep. The nexus between loneliness and poor sleep is unlikely to be broken by altering the social rhythm of patients who present with poor sleep and loneliness.

Measurement of brain perfusion in newborns: Pulsed arterial spin labeling (PASL) versus pseudo-continuous arterial spin labeling (pCASL)

PubMed Central

Boudes, Elodie; Gilbert, Guillaume; Leppert, Ilana Ruth; Tan, Xianming; Pike, G. Bruce; Saint-Martin, Christine; Wintermark, Pia

2014-01-01

Background Arterial spin labeling (ASL) perfusion-weighted imaging (PWI) by magnetic resonance imaging (MRI) has been shown to be useful for identifying asphyxiated newborns at risk of developing brain injury, whether or not therapeutic hypothermia was administered. However, this technique has been only rarely used in newborns until now, because of the challenges to obtain sufficient signal-to-noise ratio (SNR) and spatial resolution in newborns. Objective To compare two methods of ASL-PWI (i.e., single inversion-time pulsed arterial spin labeling [single TI PASL], and pseudo-continuous arterial spin labeling [pCASL]) to assess brain perfusion in asphyxiated newborns treated with therapeutic hypothermia and in healthy newborns. Design/methods We conducted a prospective cohort study of term asphyxiated newborns meeting the criteria for therapeutic hypothermia; four additional healthy term newborns were also included as controls. Each of the enrolled newborns was scanned at least once during the first month of life. Each MRI scan included conventional anatomical imaging, as well as PASL and pCASL PWI-MRI. Control and labeled images were registered separately to reduce the effect of motion artifacts. For each scan, the axial slice at the level of the basal ganglia was used for comparisons. Each scan was scored for its image quality. Quantification of whole-slice cerebral blood flow (CBF) was done afterwards using previously described formulas. Results A total number of 61 concomitant PASL and pCASL scans were obtained in nineteen asphyxiated newborns treated with therapeutic hypothermia and four healthy newborns. After discarding the scans with very poor image quality, 75% (46/61) remained for comparison between the two ASL methods. pCASL images presented a significantly superior image quality score compared to PASL images (p < 0.0001). Strong correlation was found between the CBF measured by PASL and pCASL (r = 0.61, p < 0.0001). Conclusion This study demonstrates that both ASL methods are feasible to assess brain perfusion in healthy and sick newborns. However, pCASL might be a better choice over PASL in newborns, as pCASL perfusion maps had a superior image quality that allowed a more detailed identification of the different brain structures. PMID:25379424

Manual versus Automated Carotid Artery Plaque Component Segmentation in High and Lower Quality 3.0 Tesla MRI Scans

PubMed Central

Smits, Loek P.; van Wijk, Diederik F.; Duivenvoorden, Raphael; Xu, Dongxiang; Yuan, Chun; Stroes, Erik S.; Nederveen, Aart J.

2016-01-01

Purpose To study the interscan reproducibility of manual versus automated segmentation of carotid artery plaque components, and the agreement between both methods, in high and lower quality MRI scans. Methods 24 patients with 30–70% carotid artery stenosis were planned for 3T carotid MRI, followed by a rescan within 1 month. A multicontrast protocol (T1w,T2w, PDw and TOF sequences) was used. After co-registration and delineation of the lumen and outer wall, segmentation of plaque components (lipid-rich necrotic cores (LRNC) and calcifications) was performed both manually and automated. Scan quality was assessed using a visual quality scale. Results Agreement for the detection of LRNC (Cohen’s kappa (k) is 0.04) and calcification (k = 0.41) between both manual and automated segmentation methods was poor. In the high-quality scans (visual quality score ≥ 3), the agreement between manual and automated segmentation increased to k = 0.55 and k = 0.58 for, respectively, the detection of LRNC and calcification larger than 1 mm2. Both manual and automated analysis showed good interscan reproducibility for the quantification of LRNC (intraclass correlation coefficient (ICC) of 0.94 and 0.80 respectively) and calcified plaque area (ICC of 0.95 and 0.77, respectively). Conclusion Agreement between manual and automated segmentation of LRNC and calcifications was poor, despite a good interscan reproducibility of both methods. The agreement between both methods increased to moderate in high quality scans. These findings indicate that image quality is a critical determinant of the performance of both manual and automated segmentation of carotid artery plaque components. PMID:27930665

Low intake of vegetables, high intake of confectionary, and unhealthy eating habits are associated with poor sleep quality among middle-aged female Japanese workers.

PubMed

Katagiri, Ryoko; Asakura, Keiko; Kobayashi, Satomi; Suga, Hitomi; Sasaki, Satoshi

2014-01-01

Although workers with poor sleep quality are reported to have problems with work performance, few studies have assessed the association between dietary factors and sleep quality using validated indexes. Here, we examined this association using information acquired from validated questionnaires. A total of 3,129 female workers aged 34 to 65 years were analyzed. Dietary intake was assessed using a self-administered diet history questionnaire (DHQ), and subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). The relationship between the intake of several food groups and nutrients and sleep quality was examined using multivariable logistic regression models. The effect of eating habits on sleep quality was also examined. Poor sleep quality was associated with low intake of vegetables (p for trend 0.002) and fish (p for trend 0.04) and high intake of confectionary (p for trend 0.004) and noodles (p for trend 0.03) after adjustment for potential confounding factors (age, body mass index, physical activity, depression score, employment status, alcohol intake and smoking status). Poor sleep quality was also significantly and positively associated with consumption of energy drinks and sugar-sweetened beverages, skipping breakfast, and eating irregularly. In addition, poor sleep quality was significantly associated with high carbohydrate intake (p for trend 0.03). A low intake of vegetables and fish, high intake of confectionary and noodles and unhealthy eating habits were independently associated with poor sleep quality. Poor sleep quality was also associated with high carbohydrate intake in free-living Japanese middle-aged female workers.

Are we doing enough to prevent poor-quality antimalarial medicines in the developing world?

PubMed

Walker, Erin J; Peterson, Gregory M; Grech, James; Paragalli, Evie; Thomas, Jackson

2018-05-15

Malaria is a deadly parasitic disease that affects more than 3 billion people worldwide, in predominantly resource-poor countries. Despite malaria being preventable and treatable, a large number of adults and children, mostly in Africa, die from this disease each year. One contributor to needless morbidity and mortality is the production and distribution of poor-quality antimalarial medicines; indeed, it is estimated that over 122,000 deaths of children under 5 years of age in sub-Saharan countries were caused by poor-quality antimalarial medicines, in 2013 alone. Poor-quality medicines include those that are deliberately falsified for monetary gain and may contain incorrect amounts or even no active ingredients at all, as well as products that are inadequate due to poor compliance to conventional quality standards and medicines that have degraded over time. Across a number of studies it has been reported that 4-92% of antimalarials tested are poor quality. This represents a massive risk to the population subjected to the use of these medicines, in the form of more severe and prolonged illness, additional costs to individuals who already have very little money, and lack of confidence in treatments. The continuing circulation of poor-quality medicines results from a number of factors, including insufficient regulatory capacity in susceptible countries, inadequate funding to perform regulatory functions, poor coordination between regulatory authorities, and inefficient import/export control systems. To combat the distribution of poor-quality medicines a number of organisations have developed guidelines for the procurement of antimalarials, and programs to educate consumers about the risks of poor-quality medicines and incentivise retailers to identify and report falsified medicines. The development of new technologies to quickly identify poor-quality medicines in the field is also essential, and some significant advances have been made. There has been considerable improvement in the delivery of high-quality antimalarials to those who need them; however, there is still an urgent need for a collective response by the international community, political leaders, regulatory bodies, and pharmaceutical companies. This should include political commitment for enhanced research and development funding, such as for new innovative track-and-trace field devices, and international efforts to strengthen and harmonise drug regulation practices.

A Novel Segmentation Approach Combining Region- and Edge-Based Information for Ultrasound Images

PubMed Central

Luo, Yaozhong; Liu, Longzhong; Li, Xuelong

2017-01-01

Ultrasound imaging has become one of the most popular medical imaging modalities with numerous diagnostic applications. However, ultrasound (US) image segmentation, which is the essential process for further analysis, is a challenging task due to the poor image quality. In this paper, we propose a new segmentation scheme to combine both region- and edge-based information into the robust graph-based (RGB) segmentation method. The only interaction required is to select two diagonal points to determine a region of interest (ROI) on the original image. The ROI image is smoothed by a bilateral filter and then contrast-enhanced by histogram equalization. Then, the enhanced image is filtered by pyramid mean shift to improve homogeneity. With the optimization of particle swarm optimization (PSO) algorithm, the RGB segmentation method is performed to segment the filtered image. The segmentation results of our method have been compared with the corresponding results obtained by three existing approaches, and four metrics have been used to measure the segmentation performance. The experimental results show that the method achieves the best overall performance and gets the lowest ARE (10.77%), the second highest TPVF (85.34%), and the second lowest FPVF (4.48%). PMID:28536703

Adaptive removal of background and white space from document images using seam categorization

NASA Astrophysics Data System (ADS)

Fillion, Claude; Fan, Zhigang; Monga, Vishal

2011-03-01

Document images are obtained regularly by rasterization of document content and as scans of printed documents. Resizing via background and white space removal is often desired for better consumption of these images, whether on displays or in print. While white space and background are easy to identify in images, existing methods such as naïve removal and content aware resizing (seam carving) each have limitations that can lead to undesirable artifacts, such as uneven spacing between lines of text or poor arrangement of content. An adaptive method based on image content is hence needed. In this paper we propose an adaptive method to intelligently remove white space and background content from document images. Document images are different from pictorial images in structure. They typically contain objects (text letters, pictures and graphics) separated by uniform background, which include both white paper space and other uniform color background. Pixels in uniform background regions are excellent candidates for deletion if resizing is required, as they introduce less change in document content and style, compared with deletion of object pixels. We propose a background deletion method that exploits both local and global context. The method aims to retain the document structural information and image quality.

Compressed Sensing mm-Wave SAR for Non-Destructive Testing Applications Using Multiple Weighted Side Information.

PubMed

Becquaert, Mathias; Cristofani, Edison; Van Luong, Huynh; Vandewal, Marijke; Stiens, Johan; Deligiannis, Nikos

2018-05-31

This work explores an innovative strategy for increasing the efficiency of compressed sensing applied on mm-wave SAR sensing using multiple weighted side information. The approach is tested on synthetic and on real non-destructive testing measurements performed on a 3D-printed object with defects while taking advantage of multiple previous SAR images of the object with different degrees of similarity. The tested algorithm attributes autonomously weights to the side information at two levels: (1) between the components inside the side information and (2) between the different side information. The reconstruction is thereby almost immune to poor quality side information while exploiting the relevant components hidden inside the added side information. The presented results prove that, in contrast to common compressed sensing, good SAR image reconstruction is achieved at subsampling rates far below the Nyquist rate. Moreover, the algorithm is shown to be much more robust for low quality side information compared to coherent background subtraction.

Quality indicators for musculoskeletal injury management in the emergency department: a systematic review.

PubMed

Strudwick, Kirsten; Nelson, Mark; Martin-Khan, Melinda; Bourke, Michael; Bell, Anthony; Russell, Trevor

2015-02-01

There is increasing importance placed on quality of health care for musculoskeletal injuries in emergency departments (EDs). This systematic review aimed to identify existing musculoskeletal quality indicators (QIs) developed for ED use and to critically evaluate their methodological quality. MEDLINE, EMBASE, CINAHL, and the gray literature, including relevant organizational websites, were searched in 2013. English-language articles were included that described the development of at least one QI related to the ED care of musculoskeletal injuries. Data extraction of each included article was conducted. A quality assessment was then performed by rating each relevant QI against the Appraisal of Indicators through Research and Evaluation (AIRE) Instrument. QIs with similar definitions were grouped together and categorized according to the health care quality frameworks of Donabedian and the Institute of Medicine. The search revealed 1,805 potentially relevant articles, of which 15 were finally included in the review. The number of relevant QIs per article ranged from one to 11, resulting in a total of 71 QIs overall. Pain (n = 17) and fracture management (n = 13) QIs were predominant. Ten QIs scored at least 50% across all AIRE Instrument domains, and these related to pain management and appropriate imaging of the spine. Methodological quality of the development of most QIs is poor. Recommendations for a core set of QIs that address the complete spectrum of musculoskeletal injury management in emergency medicine is not possible, and more work is needed. Currently, QIs with highest methodological quality are in the areas of pain management and medical imaging. © 2015 by the Society for Academic Emergency Medicine.

Association of sociodemographic, lifestyle, and health factors with sleep quality and daytime sleepiness in women: findings from the 2007 National Sleep Foundation "Sleep in America Poll".

PubMed

Baker, Fiona C; Wolfson, Amy R; Lee, Kathryn A

2009-06-01

To investigate factors associated with poor sleep quality and daytime sleepiness in women living in the United States. Data are presented from the National Sleep Foundation's 2007 Sleep in America Poll that included 959 women (18-64 years of age) surveyed by telephone about their sleep quality, daytime sleepiness, and sociodemographic, health, and lifestyle factors. Poor sleep quality was reported by 27% and daytime sleepiness was reported by 21% of respondents. Logistic multivariate regression analyses revealed that poor sleep quality and daytime sleepiness were both independently associated with poor health, having a sleep disorder, and psychological distress. Also, multivariate analyses showed that women who consumed more caffeinated beverages and those who had more than one job were more likely to report poor sleep quality but not daytime sleepiness. Daytime sleepiness, on the other hand, was independently associated with being black/African American, younger, disabled, having less education, and daytime napping. Poor sleep quality and daytime sleepiness are common in American women and are associated with health-related, as well as sociodemographic, factors. Addressing sleep-related complaints in women is important to improve their daytime functioning and quality of life.

Improved patch-based learning for image deblurring

NASA Astrophysics Data System (ADS)

Dong, Bo; Jiang, Zhiguo; Zhang, Haopeng

2015-05-01

Most recent image deblurring methods only use valid information found in input image as the clue to fill the deblurring region. These methods usually have the defects of insufficient prior information and relatively poor adaptiveness. Patch-based method not only uses the valid information of the input image itself, but also utilizes the prior information of the sample images to improve the adaptiveness. However the cost function of this method is quite time-consuming and the method may also produce ringing artifacts. In this paper, we propose an improved non-blind deblurring algorithm based on learning patch likelihoods. On one hand, we consider the effect of the Gaussian mixture model with different weights and normalize the weight values, which can optimize the cost function and reduce running time. On the other hand, a post processing method is proposed to solve the ringing artifacts produced by traditional patch-based method. Extensive experiments are performed. Experimental results verify that our method can effectively reduce the execution time, suppress the ringing artifacts effectively, and keep the quality of deblurred image.

Geological analysis and evaluation of ERTS-A imagery for the state of New Mexico

NASA Technical Reports Server (NTRS)

Kottlowski, F. E. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Coverage of approximately one-third of the test site had been received by January 31, 1973 and all of the images received were MSS products. Images recorded during the first two months of the ERTS-1 mission were of poor quality, owing largely to high ground reflectance. Later images were of better quality and MSS bands 5 and 7 have proven to be particularly useful. Features noted during visual inspection of 9 1/2 x 9 1/2 prints include major structural forms, vegetation patterns, drainage patterns, and outcrops of geologic formations having marked color contrasts. The Border Hills Structural Zone and the Y-O Structural Zone are prominently reflected in coverage of the Pecos Valley. A study of available maps and remote sensing material covering the Deming-Columbus area indicated that the limit of detection and the resolution of MSS products are not as good as those of aerial photographs, geologic maps, and manned satellite photographs. The limit of detection of high contrast features on MSS prints is approximately 1000 feet or 300 meters for linear features and about 18 acres for roughly circular areas.

Technique charts for Kodak EC-L film screen system for portal localization in a 6MV X-ray beam.

PubMed

Sandilos, P; Antypas, C; Paraskevopoulou, C; Kouvaris, J; Vlachos, L

2006-01-01

Port films are used in radiotherapy for visual evaluation of the radiation fields and subsequent quantitative analysis. Common port films suffer from poor image quality compared to the simulator-diagnostic films and is desirable to determine the appropriate exposure required for the best image contrast. The aim of this work is to generate technique charts for the Kodak EC-L film screen system for use in a 6MV x-ray beam. Three homogeneous water phantoms were used to simulate head-neck, thorax and abdomen dimensions of adult human, correspondingly. The film screen system was calibrated in a 6MV x-ray beam and under various irradiation conditions. The film screen system behavior was studied as a function of phantom thickness, field size and air gap between the phantom and the film screen system. In each case the optimum film exposure which produces the maximum image contrast was determined. The generated technique charts for the EC-L film screen system and for a 6 MV x-ray beam are used in our radiotherapy department for daily quality assurance of the radiotherapy procedure.

Superharmonic imaging with chirp coded excitation: filtering spectrally overlapped harmonics.

PubMed

Harput, Sevan; McLaughlan, James; Cowell, David M J; Freear, Steven

2014-11-01

Superharmonic imaging improves the spatial resolution by using the higher order harmonics generated in tissue. The superharmonic component is formed by combining the third, fourth, and fifth harmonics, which have low energy content and therefore poor SNR. This study uses coded excitation to increase the excitation energy. The SNR improvement is achieved on the receiver side by performing pulse compression with harmonic matched filters. The use of coded signals also introduces new filtering capabilities that are not possible with pulsed excitation. This is especially important when using wideband signals. For narrowband signals, the spectral boundaries of the harmonics are clearly separated and thus easy to filter; however, the available imaging bandwidth is underused. Wideband excitation is preferable for harmonic imaging applications to preserve axial resolution, but it generates spectrally overlapping harmonics that are not possible to filter in time and frequency domains. After pulse compression, this overlap increases the range side lobes, which appear as imaging artifacts and reduce the Bmode image quality. In this study, the isolation of higher order harmonics was achieved in another domain by using the fan chirp transform (FChT). To show the effect of excitation bandwidth in superharmonic imaging, measurements were performed by using linear frequency modulated chirp excitation with varying bandwidths of 10% to 50%. Superharmonic imaging was performed on a wire phantom using a wideband chirp excitation. Results were presented with and without applying the FChT filtering technique by comparing the spatial resolution and side lobe levels. Wideband excitation signals achieved a better resolution as expected, however range side lobes as high as -23 dB were observed for the superharmonic component of chirp excitation with 50% fractional bandwidth. The proposed filtering technique achieved >50 dB range side lobe suppression and improved the image quality without affecting the axial resolution.

Remote assessment of acne: the use of acne grading tools to evaluate digital skin images.

PubMed

Bergman, Hagit; Tsai, Kenneth Y; Seo, Su-Jean; Kvedar, Joseph C; Watson, Alice J

2009-06-01

Digital imaging of dermatology patients is a novel approach to remote data collection. A number of assessment tools have been developed to grade acne severity and to track clinical progress over time. Although these tools have been validated when used in a face-to-face setting, their efficacy and reliability when used to assess digital images have not been examined. The main purpose of this study was to determine whether specific assessment tools designed to grade acne during face-to-face visits can be applied to the evaluation of digital images. The secondary purpose was to ascertain whether images obtained by subjects are of adequate quality to allow such assessments to be made. Three hundred (300) digital images of patients with mild to moderate facial inflammatory acne from an ongoing randomized-controlled study were included in this analysis. These images were obtained from 20 patients and consisted of sets of 3 images taken over time. Of these images, 120 images were captured by subjects themselves and 180 were taken by study staff. Subjects were asked to retake their photographs if the initial images were deemed of poor quality by study staff. Images were evaluated by two dermatologists-in-training using validated acne assessment measures: Total Inflammatory Lesion Count, Leeds technique, and the Investigator's Global Assessment. Reliability of raters was evaluated using correlation coefficients and kappa statistics. Of the different acne assessment measures tested, the inter-rater reliability was highest for the total inflammatory lesion count (r = 0.871), but low for the Leeds technique (kappa = 0.381) and global assessment (kappa = 0.3119). Raters were able to evaluate over 89% of all images using each type of acne assessment measure despite the fact that images obtained by study staff were of higher quality than those obtained by patients (p < 0.001). Several existing clinical assessment measures can be used to evaluate digital images obtained from subjects with inflammatory acne lesions. The level of inter-rater agreement is highly variable across assessment measures, and we found the Total Inflammatory Lesion Count to be the most reliable. This measure could be used to allow a dermatologist to remotely track a patient's progress over time.

First clinical trial of the "MiRo" capsule endoscope by using a novel transmission technology: electric-field propagation.

PubMed

Bang, Seungmin; Park, Jeong Youp; Jeong, Seok; Kim, Young Ho; Shim, Han Bo; Kim, Tae Song; Lee, Don Haeng; Song, Si Young

2009-02-01

We developed a capsule endoscope (CE), "MiRo," with the novel transmission technology of electric-field propagation. The technology uses the human body as a conductive medium for data transmission. Specifications of the prototype include the ability to receive real-time images; size, 10.8 x 24 mm; weight, 3.3 g; field of view, 150 degrees; resolution of power, 320 x 320 pixels; and transmittal speed, 2 frames per second. To evaluate the clinical safety and diagnostic feasibility of the prototype MiRo, we conducted a multicenter clinical trial. All volunteers underwent baseline examinations, including EGD and electrocardiography for the screening of GI obstructive and cardiovascular diseases, before the trial. In the first 10 cases, 24-hour Holter monitoring was also performed. To evaluate the diagnostic feasibility, transmission rate of the captured images, inspection rate of the entire small bowel, and quality of transmitted images (graded as outstanding, excellent, good/average, below average, and poor) were analyzed. Of the 49 healthy volunteers, 45 were included in the trial, and 4 were excluded because of baseline abnormalities. No adverse effects were noted. All CEs were expelled within 2 days, and the entire small bowel could be explored in all cases. The transmission rates of the captured image in the stomach, small bowel, and colon were 99.5%, 99.6%, and 97.2%, respectively. The mean total duration of image transmission was 9 hours, 51 minutes, and the mean transit time of the entire small bowel was 4 hours, 33 minutes. Image quality was graded as good or better in 41 cases (91.1%). Details of the villi and vascular structures of the entire small bowel were clearly visualized in 31 cases (68.9%). MiRo is safe and effective for exploring the entire small bowel, with good image quality and real-time feasibility. This novel transmission technology may have applications beyond the field of capsule endoscopy.

Aerial Images and Convolutional Neural Network for Cotton Bloom Detection.

PubMed

Xu, Rui; Li, Changying; Paterson, Andrew H; Jiang, Yu; Sun, Shangpeng; Robertson, Jon S

2017-01-01

Monitoring flower development can provide useful information for production management, estimating yield and selecting specific genotypes of crops. The main goal of this study was to develop a methodology to detect and count cotton flowers, or blooms, using color images acquired by an unmanned aerial system. The aerial images were collected from two test fields in 4 days. A convolutional neural network (CNN) was designed and trained to detect cotton blooms in raw images, and their 3D locations were calculated using the dense point cloud constructed from the aerial images with the structure from motion method. The quality of the dense point cloud was analyzed and plots with poor quality were excluded from data analysis. A constrained clustering algorithm was developed to register the same bloom detected from different images based on the 3D location of the bloom. The accuracy and incompleteness of the dense point cloud were analyzed because they affected the accuracy of the 3D location of the blooms and thus the accuracy of the bloom registration result. The constrained clustering algorithm was validated using simulated data, showing good efficiency and accuracy. The bloom count from the proposed method was comparable with the number counted manually with an error of -4 to 3 blooms for the field with a single plant per plot. However, more plots were underestimated in the field with multiple plants per plot due to hidden blooms that were not captured by the aerial images. The proposed methodology provides a high-throughput method to continuously monitor the flowering progress of cotton.

Use of indocyanine green and sodium fluorescein for anterior segment angiography in ophthalmologically normal cats.

PubMed

Pirie, Chris G; Alario, Anthony

2015-10-01

To assess and compare results of anterior segment angiography of ophthalmologically normal cats following IV injection with indocyanine green and sodium fluorescein dyes. 10 client-owned cats. Anterior segment angiography was performed in anesthetized cats following administration of 0.25% indocyanine green (1.0 mg/kg, IV) or 10% sodium fluorescein (20 mg/kg, IV) solution. All cats received both treatments. Imaging (1 eye/cat) was performed with a full-spectrum digital single-lens reflex camera equipped with an adaptor (1 image/s for 30 seconds) immediately following IV dye injection and 1, 2, 3, 4, and 5 minutes after injection. Onset and duration of arterial, capillary, and venous phases of iris vasculature were identified and compared statistically between treatments. Degree of iridal pigmentation, leakage of dye from iris vasculature, and image quality were subjectively assessed. No differences were found in onset or duration of vascular phases between treatments. Visibility of the iris vasculature was not impaired by poor or moderate iridal pigmentation with either method. Indocyanine green provided subjectively better vascular detail and image contrast than sodium fluorescein. No vascular dye leakage was observed following indocyanine green administration. Leakage of dye from blood vessels in the stroma (in 10 cats) and presence of dye in the anterior chamber (in 5 cats) were detected after sodium fluorescein administration. Images obtained with either fluorescent dye were considered to be of diagnostic quality. Lack of leakage following indocyanine green administration suggested this treatment may have better diagnostic utility for anterior segment angiography. The photographic equipment used provided a cost-effective alternative to existing imaging systems.

Chronic brain damage in sickle cell disease and its relation with quality of life.

PubMed

Cela, Elena; Vélez, Ana G; Aguado, Alejandra; Medín, Gabriela; Bellón, José M; Beléndez, Cristina

2016-12-16

Sickle cell anaemia causes progressive organ damage. The objective is to describe school performance of patients with sickle cell anaemia and their clinical parameters and quality of life that may have an influence. The hypothesis is that if school alterations occur without other objective data, additional factors must be present besides the disease itself. Transversal study performed in November 2015 considering analytical variables, complications and neuroradiological images of children with sickle cell anaemia, and family survey on school performance and quality of life. Median age was 6.8 years and 78% were diagnosed at birth. Sixty patients were included. School performance was altered in 51% of cases and was related to nocturnal hypoxemia. Acute stroke incidence was 6.7%. Transcranial ultrasound was abnormal in 4% of cases and magnetic resonance imaging in 16% of cases. Quality of life showed pathological findings in all areas and the low values increased proportionally in older ages. The stroke affected the physical and social sphere, and lung disease affected the physical and emotional spheres. Poor school performance affects half of the patients and it is related to nocturnal hypoxemia, although other socio-cultural factors may have an influence. Quality of life is affected in most of these cases independently of academic results. The absence of alterations in neuroimaging or the apparent lack of severe clinical parameters do not mean that quality of life and schooling are normal. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Optical properties of the mouse eye

PubMed Central

Geng, Ying; Schery, Lee Anne; Sharma, Robin; Dubra, Alfredo; Ahmad, Kamran; Libby, Richard T.; Williams, David R.

2011-01-01

The Shack-Hartmann wavefront sensor (SHWS) spots upon which ocular aberration measurements depend have poor quality in mice due to light reflected from multiple retinal layers. We have designed and implemented a SHWS that can favor light from a specific retinal layer and measured monochromatic aberrations in 20 eyes from 10 anesthetized C57BL/6J mice. Using this instrument, we show that mice are myopic, not hyperopic as is frequently reported. We have also measured longitudinal chromatic aberration (LCA) of the mouse eye and found that it follows predictions of the water-filled schematic mouse eye. Results indicate that the optical quality of the mouse eye assessed by measurement of its aberrations is remarkably good, better for retinal imaging than the human eye. The dilated mouse eye has a much larger numerical aperture (NA) than that of the dilated human eye (0.5 NA vs. 0.2 NA), but it has a similar amount of root mean square (RMS) higher order aberrations compared to the dilated human eye. These measurements predict that adaptive optics based on this method of wavefront sensing will provide improvements in retinal image quality and potentially two times higher lateral resolution than that in the human eye. PMID:21483598

ESR/ERS white paper on lung cancer screening

PubMed Central

Bonomo, Lorenzo; Gaga, Mina; Nackaerts, Kristiaan; Peled, Nir; Prokop, Mathias; Remy-Jardin, Martine; von Stackelberg, Oyunbileg; Sculier, Jean-Paul

2015-01-01

Lung cancer is the most frequently fatal cancer, with poor survival once the disease is advanced. Annual low dose computed tomography has shown a survival benefit in screening individuals at high risk for lung cancer. Based on the available evidence, the European Society of Radiology and the European Respiratory Society recommend lung cancer screening in comprehensive, quality-assured, longitudinal programmes within a clinical trial or in routine clinical practice at certified multidisciplinary medical centres. Minimum requirements include: standardised operating procedures for low dose image acquisition, computer-assisted nodule evaluation, and positive screening results and their management; inclusion/exclusion criteria; expectation management; and smoking cessation programmes. Further refinements are recommended to increase quality, outcome and cost-effectiveness of lung cancer screening: inclusion of risk models, reduction of effective radiation dose, computer-assisted volumetric measurements and assessment of comorbidities (chronic obstructive pulmonary disease and vascular calcification). All these requirements should be adjusted to the regional infrastructure and healthcare system, in order to exactly define eligibility using a risk model, nodule management and quality assurance plan. The establishment of a central registry, including biobank and image bank, and preferably on a European level, is strongly encouraged. PMID:25929956

The effect of zolpidem on sleep quality, stress status, and nondipping hypertension.

PubMed

Huang, Yuli; Mai, Weiyi; Cai, Xiaoyan; Hu, Yunzhao; Song, Yuanbin; Qiu, Ruofeng; Wu, Yanxian; Kuang, Jian

2012-03-01

Poor sleep quality and stress status have previously been shown to be closely associated with higher activation of the sympathetic nervous system and to be independent predictors of nondipping hypertension. This study aimed to evaluate the effects of the non-hypotensive sedative zolpidem on sleep quality, stress status, and nondipping hypertension. A total of 103 nondippers were defined as poor or good sleepers by the Pittsburgh Sleep Quality Index. They were randomized to receive zolpidem or placebo treatment for 30 days. Stress status was assessed by the Perceived Stress Scale, and levels of epinephrine and norepinephrine were examined to investigate the underlying mechanisms. Poor sleepers treated with zolpidem for 30 days showed significant improvements in sleep quality and stress levels (P<0.01). More nondippers were converted to dippers in the group of poor sleepers treated with zolpidem (11 of 22 patients, 50.0%) than in the placebo (2 of 23, 8.7%) (P<0.01). Epinephrine and norepinephrine levels were significantly reduced in poor sleepers treated with zolpidem (P<0.05). The results of this study suggest that zolpidem can improve sleep quality and stress status, and can convert nondippers with poor sleep quality into dippers. It may be an option for treating nondipping hypertensive patients with poor sleep quality. Copyright © 2011 Elsevier B.V. All rights reserved.

Current issues in determining dietary protein quality and metabolic utilization

USDA-ARS?s Scientific Manuscript database

In resource-limited settings, poor dietary quality has a marked negative impact on health, especially during the sensitive periods of pregnancy and first 2 years of life (the first 1000 days) when stunting, poor development and increased risk of later disease develop. Protein quality is often poor o...

Subjective Sleep Quality in Women With Divorce Histories: The Role of Intimate Partner Victimization.

PubMed

Newton, Tamara L; Burns, Vicki Ellison; Miller, James J; Fernandez-Botran, G Rafael

2016-05-01

A marital status of divorced or separated, as opposed to married, predicts increased risk of health problems, but not for all persons. Focusing on one established health risk that has been linked with divorce--poor subjective sleep quality--the present cross-sectional study examined whether a history of physical intimate partner victimization (IPV) helps identify divorced women at potentially greater risk of health problems. Community midlife women with divorce histories, all of whom were free of current IPV, reported on their past month sleep quality and lifetime IPV. The predicted odds of poor sleep quality were significantly greater for women with, versus without, IPV histories. This held after adjusting for socioemotional, medical, or sociodemographic risks. A dose-response relationship between IPV chronicity and poor quality sleep was observed. IPV history may help identify divorced women at increased risk of poor quality sleep and, more broadly, poor health. © The Author(s) 2015.

Association between Facebook dependence and poor sleep quality: a study in a sample of undergraduate students in Peru.

PubMed

Wolniczak, Isabella; Cáceres-DelAguila, José Alonso; Palma-Ardiles, Gabriela; Arroyo, Karen J; Solís-Visscher, Rodrigo; Paredes-Yauri, Stephania; Mego-Aquije, Karina; Bernabe-Ortiz, Antonio

2013-01-01

Internet can accelerate information exchange. Social networks are the most accessed especially Facebook. This kind of networks might create dependency with several negative consequences in people's life. The aim of this study was to assess potential association between Facebook dependence and poor sleep quality. A cross sectional study was performed enrolling undergraduate students of the Universidad Peruana de Ciencias Aplicadas, Lima, Peru. The Internet Addiction Questionnaire, adapted to the Facebook case, and the Pittsburgh Sleep Quality Index, were used. A global score of 6 or greater was defined as the cutoff to determine poor sleep quality. Generalized linear model were used to determine prevalence ratios (PR) and 95% confidence intervals (95%CI). A total of 418 students were analyzed; of them, 322 (77.0%) were women, with a mean age of 20.1 (SD: 2.5) years. Facebook dependence was found in 8.6% (95% CI: 5.9%-11.3%), whereas poor sleep quality was present in 55.0% (95% CI: 50.2%-59.8%). A significant association between Facebook dependence and poor sleep quality mainly explained by daytime dysfunction was found (PR = 1.31; IC95%: 1.04-1.67) after adjusting for age, sex and years in the faculty. There is a relationship between Facebook dependence and poor quality of sleep. More than half of students reported poor sleep quality. Strategies to moderate the use of this social network and to improve sleep quality in this population are needed.

Spitzer Observations of the X-ray Sources of NGC 4485/90

NASA Astrophysics Data System (ADS)

Vazquez, Gerardo A.; Colbert, E.; Hornschemeier, A.; Malhotra, S.; Roberts, T.; Ward, M.

2006-06-01

The mechanism for forming (or igniting) so-called Ultra-Luminous X- ray sources (ULXs) is very poorly understood. In order to investigate the stellar and gaseous environment of ULXs, we have observed the nearby starburst galaxy system NGC 4485/90 with Spitzer's IRAC and IRS instruments. High-quality mid-infrared images and spectra are used to characterize the stellar history of stars near the ULXs, and the ionization state of the surrounding gas. NGC 4485/90 fortuitively hosts six ULXs, and we have analyzed IRAC images and IRS spectra of all six regions. We also observed two "comparison" regions with no X-ray sources. Here we present our preliminary findings on the similarities and differences between the stellar and gaseous components near the ULXs.

Imaging of biophoton emission from electrostimulated skin acupuncture point jg4: effect of light enhancers.

PubMed

Slawinski, Janusz; Gorski, Zbigniew

2008-05-01

Using an ultrasensitive CCD camera, an extremely low light intensity from the acupuncture-sensitive point JG4 at the left hand was recorded. As the intensity of the light was very weak and the time of electrostimulation exceeded the recommended period, the quality of biophoton images was poor. Chemiluminescent and fluorescent hydrophilic, hydrophobic and amphyphilic molecular probes were used to: (i) ensure penetration of probes into skin, (ii) enhance the intensity of BP emission, (iii) shorten time and (iv) obtain information about mechanisms of biophotons generation in EAP-sensitive points and channels. The results obtained partially fulfilled expectations and indicate on the necessity to elaborate special techniques of probes deposition on the skin.

Associations between poor sleep quality and psychosocial stress with obesity in reproductive-age women of lower socioeconomic status.

PubMed

Tom, Sarah E; Berenson, Abbey B

2013-01-01

Prior studies have not examined the role of psychosocial stress in the relationship between poor sleep quality and obesity among women of lower socioeconomic status (SES). We tested the following hypotheses in a sample of reproductive-age women of lower SES: 1) Poor sleep quality is related to increased risk of obesity, and 2) psychosocial stress confounds this association between poor sleep quality and obesity. A total of 927 women age 16 to 40 years attending public health clinics in Southeastern Texas provided information on the Pittsburgh Sleep Quality Index and sociodemographic and health characteristics, including the Perceived Stress Scale. Height, weight, and waist circumference (WC) were measured in clinic. A series of models examined the associations between sleep disturbance, perceived stress, and weight outcomes, accounting for potential confounding factors. Nearly 30% of women were overweight, and 35% were obese. Half of women had a WC of greater than 35 inches. Most women had poor sleep quality and high levels of stress. Sleep quality and perceived stress were not related to body mass index category or WC in models that adjusted for age and race/ethnicity. Adjusting for potential confounding factors did not alter results. Perceived stress did not modify the association between sleep quality and weight outcomes. Poor sleep quality and psychosocial stress were not related to weight in reproductive-aged women of lower SES. However, poor sleep quality, high stress, overweight, and obesity were common in this group. Copyright © 2013 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

Are facilities following best practices of pediatric abdominal CT scans?

PubMed

Nosek, Amy E; Hartin, Charles W; Bass, Kathryn D; Glick, Philip L; Caty, Michael G; Dayton, Merril T; Ozgediz, Doruk E

2013-05-01

Established guidelines for pediatric abdominal CT scans include reduced radiation dosage to minimize cancer risk and the use of intravenous (IV) contrast to obtain the highest-quality diagnostic images. We wish to determine if these practices are being used at nonpediatric facilities that transfer children to a pediatric facility. Children transferred to a tertiary pediatric facility over a 16-mo period with abdominal CT scans performed for evaluation of possible appendicitis were retrospectively reviewed for demographics, diagnosis, radiation dosage, CT contrast use, and scan quality. If CT scans were repeated, the radiation dosage between facilities was compared using Student t-test. Ninety-one consecutive children transferred from 29 different facilities had retrievable CT scan images and clinical information. Half of CT scans from transferring institutions used IV contrast. Due to poor quality or inconclusive CT scans, 19 patients required a change in management. Children received significantly less radiation at our institution compared to the referring adult facility for the same body area scanned on the same child (9.7 mSv versus 19.9 mSv, P = 0.0079). Pediatric facilities may be using less radiation per CT scan due to a heightened awareness of radiation risks and specific pediatric CT scanning protocols. The benefits of IV contrast for the diagnostic yield of pediatric CT scans should be considered to obtain the best possible image and to prevent additional imaging. Every facility performing pediatric CT scans should minimize radiation exposure, and pediatric facilities should provide feedback and education to other facilities scanning children. Copyright © 2013 Elsevier Inc. All rights reserved.

Clinical evaluation of a mobile digital specimen radiography system for intraoperative specimen verification.

PubMed

Wang, Yingbing; Ebuoma, Lilian; Saksena, Mansi; Liu, Bob; Specht, Michelle; Rafferty, Elizabeth

2014-08-01

Use of mobile digital specimen radiography systems expedites intraoperative verification of excised breast specimens. The purpose of this study was to evaluate the performance of a such a system for verifying targets. A retrospective review included 100 consecutive pairs of breast specimen radiographs. Specimens were imaged in the operating room with a mobile digital specimen radiography system and then with a conventional digital mammography system in the radiology department. Two expert reviewers independently scored each image for image quality on a 3-point scale and confidence in target visualization on a 5-point scale. A target was considered confidently verified only if both reviewers declared the target to be confidently detected. The 100 specimens contained a total of 174 targets, including 85 clips (49%), 53 calcifications (30%), 35 masses (20%), and one architectural distortion (1%). Although a significantly higher percentage of mobile digital specimen radiographs were considered poor quality by at least one reviewer (25%) compared with conventional digital mammograms (1%), 169 targets (97%), were confidently verified with mobile specimen radiography; 172 targets (98%) were verified with conventional digital mammography. Three faint masses were not confidently verified with mobile specimen radiography, and conventional digital mammography was needed for confirmation. One faint mass and one architectural distortion were not confidently verified with either method. Mobile digital specimen radiography allows high diagnostic confidence for verification of target excision in breast specimens across target types, despite lower image quality. Substituting this modality for conventional digital mammography can eliminate delays associated with specimen transport, potentially decreasing surgical duration and increasing operating room throughput.

Association of suicidal ideation with poor sleep quality among Ethiopian adults.

PubMed

Gelaye, Bizu; Okeiga, Joseph; Ayantoye, Idris; Berhane, Hanna Y; Berhane, Yemane; Williams, Michelle A

2016-12-01

The objective of this study was to examine the extent to which poor sleep quality is associated with suicidal ideation among Ethiopian adults. A cross-sectional study was conducted among 1054 adults attending outpatient clinical facilities in Ethiopia. Standardized questionnaires were utilized to collect data on demographics, sleep quality, lifestyle, and depression status. Depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9), while the Pittsburgh Sleep Quality Index (PSQI) questionnaire was utilized to assess sleep quality. Multivariate logistic regression models were fit to estimate adjusted odds ratio (AOR) and 95 % confidence intervals (95 % CI). The prevalence of suicidal ideation was 24.3 % while poor sleep quality (PSQI global score of >5 vs. ≤5) was endorsed by 60.2 % of participants. After adjustment for confounders including depression, poor sleep quality was associated with more than 3-fold increased odds of suicidal ideation (AOR = 3.59; 95 % CI 2.34-5.51). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 20 % increased odds for suicidal ideation, even after adjusting for depression (AOR = 1.20; 95 % CI 1.14-1.27). Participants with both poor sleep quality and depression had much higher odds (AOR = 23.22, 95 % CI 14.10-38.28) of suicidal ideation as compared with those who had good sleep quality and no depression although inferences from this analysis are limited due to the wide 95 % CI. Suicidal ideation and poor sleep quality are highly prevalent. Individuals with poor sleep quality have higher odds of suicidal ideation. If confirmed, mental health services need to address sleep disturbances seriously to prevent suicidal episodes.

Association of Suicidal Ideation with Poor Sleep Quality among Ethiopian Adults

PubMed Central

Gelaye, Bizu; Okeiga, Joseph; Ayantoye, Idris; Berhane, Hanna Y.; Berhane, Yemane; Williams, Michelle A.

2016-01-01

Objective To examine the extent to which poor sleep quality is associated with suicidal ideation among Ethiopian adults. Methods A cross-sectional study was conducted among 1,054 adults attending outpatient clinical facilities in Ethiopia. Standardized questionnaires were utilized to collect data on demographics, sleep quality, lifestyle, and depression status. Depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9), while the Pittsburgh Sleep Quality Index (PSQI) questionnaire was utilized to assess sleep quality. Multivariate logistic regression models were fit to estimate adjusted odds ratio (AOR) and 95% confidence intervals (95%CI). Results The prevalence of suicidal ideation was 24.3% while poor sleep quality (PSQI global score of > 5vs. ≤5) was endorsed by 60.2% of participants. After adjustment for confounders including depression, poor sleep quality was associated with more than 3-fold increased odds of suicidal ideation (AOR=3.46; 95%CI 2.27–5.26). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 20% increased odds for suicidal ideation, even after adjusting for depression (AOR=1.20; 95%CI 1.14–1.27). Participants with both poor sleep quality and depression had much higher odds (AOR=24.9, 95% CI 15.2–40.8) of suicidal ideation as compared with those who had good sleep quality and no depression although inferences from this analysis are limited due to the wide 95%CI. Conclusion Suicidal ideation and poor sleep quality are highly prevalent. Individuals with poor sleep quality have higher odds of suicidal ideation. If confirmed, mental health services need to address sleep disturbances seriously to prevent suicidal episodes. PMID:27771845

Study of generic quality of life in patients operated on for post-prostatectomy incontinence.

PubMed

Holm, Henriette Veiby; Fosså, Sophie D; Hedlund, Hans; Dahl, Alv A

2013-09-01

The relationship between urological and psychosocial variables, and generic quality of life in patients operated on for post-prostatectomy incontinence has hardly been studied, and our aim was to investigate this relationship. Patients who had an artificial urinary sphincter AMS800 (n = 100) implanted between January 2002 and June 2010 were invited to complete a mailed questionnaire covering demographic data including work ability, urinary and sexual function, anxiety/depression, and generic quality of life. Poor quality of life was defined as a score <40 on either the physical or the mental Short Form 12 summary scales. Of 85 compliant patients, 30 (35%) reported poor generic quality of life and 55 (65%) reported better quality of life at a median follow-up time of 26 months (range 6-104 months). The poor quality of life group showed significantly more overall urinary and sexual problems, and more men had undergone surgical revisions compared with the better quality of life group. Levels of anxiety and depression were significantly higher, and work ability was lower in the poor quality of life group. In multivariate logistic regression models, increased level of depression and impaired work ability, inability to reach orgasm, and not recommending the operation remained significantly associated with poor quality of life. Poor generic quality of life after surgery for post-prostatectomy incontinence is more strongly associated with reduced work ability and depression rather than urinary and sexual problems. © 2013 The Japanese Urological Association.

Joint detection of anatomical points on surface meshes and color images for visual registration of 3D dental models

NASA Astrophysics Data System (ADS)

Destrez, Raphaël.; Albouy-Kissi, Benjamin; Treuillet, Sylvie; Lucas, Yves

2015-04-01

Computer aided planning for orthodontic treatment requires knowing occlusion of separately scanned dental casts. A visual guided registration is conducted starting by extracting corresponding features in both photographs and 3D scans. To achieve this, dental neck and occlusion surface are firstly extracted by image segmentation and 3D curvature analysis. Then, an iterative registration process is conducted during which feature positions are refined, guided by previously found anatomic edges. The occlusal edge image detection is improved by an original algorithm which follows Canny's poorly detected edges using a priori knowledge of tooth shapes. Finally, the influence of feature extraction and position optimization is evaluated in terms of the quality of the induced registration. Best combination of feature detection and optimization leads to a positioning average error of 1.10 mm and 2.03°.

Simulation of the hybrid Tunka Advanced International Gamma-ray and Cosmic ray Astrophysics (TAIGA)

NASA Astrophysics Data System (ADS)

Kunnas, M.; Astapov, I.; Barbashina, N.; Beregnev, S.; Bogdanov, A.; Bogorodskii, D.; Boreyko, V.; Brückner, M.; Budnev, N.; Chiavassa, A.; Chvalaev, O.; Dyachok, A.; Epimakhov, S.; Eremin, T.; Gafarov, A.; Gorbunov, N.; Grebenyuk, V.; Gress, O.; Gress, T.; Grinyuk, A.; Grishin, O.; Horns, D.; Ivanova, A.; Karpov, N.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kirichkov, N.; Kiryuhin, S.; Kokoulin, R.; Kompaniets, K.; Konstantinov, E.; Korobchenko, A.; Korosteleva, E.; Kozhin, V.; Kuzmichev, L.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigall, R.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Perevalov, A.; Petrukhin, A.; Platonov, V.; Poleschuk, V.; Popescu, M.; Popova, E.; Porelli, A.; Porokhovoy, S.; Prosin, V.; Ptuskin, V.; Romanov, V.; Rubtsov, G. I.; Müger; Rybov, E.; Samoliga, V.; Satunin, P.; Saunkin, A.; Savinov, V.; Semeney, Yu; Shaibonov (junior, B.; Silaev, A.; Silaev (junior, A.; Skurikhin, A.; Slunecka, M.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Veslopopov, A.; Veslopopova, E.; Voronov, D.; Wischnewski, R.; Yashin, I.; Yurin, K.; Zagorodnikov, A.; Zirakashvili, V.; Zurbanov, V.

2015-08-01

Up to several 10s of TeV, Imaging Air Cherenkov Telescopes (IACTs) have proven to be the instruments of choice for GeV/TeV gamma-ray astronomy due to their good reconstrucion quality and gamma-hadron separation power. However, sensitive observations at and above 100 TeV require very large effective areas (10 km2 and more), which is difficult and expensive to achieve. The alternative to IACTs are shower front sampling arrays (non-imaging technique or timing-arrays) with a large area and a wide field of view. Such experiments provide good core position, energy and angular resolution, but only poor gamma-hadron separation. Combining both experimental approaches, using the strengths of both techniques, could optimize the sensitivity to the highest energies. The TAIGA project plans to combine the non-imaging HiSCORE [8] array with small (∼10m2) imaging telescopes. This paper covers simulation results of this hybrid approach.

Real-time enhanced vision system

NASA Astrophysics Data System (ADS)

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

2005-05-01

Flying in poor visibility conditions, such as rain, snow, fog or haze, is inherently dangerous. However these conditions can occur at nearly any location, so inevitably pilots must successfully navigate through them. At NASA Langley Research Center (LaRC), under support of the Aviation Safety and Security Program Office and the Systems Engineering Directorate, we are developing an Enhanced Vision System (EVS) that combines image enhancement and synthetic vision elements to assist pilots flying through adverse weather conditions. This system uses a combination of forward-looking infrared and visible sensors for data acquisition. A core function of the system is to enhance and fuse the sensor data in order to increase the information content and quality of the captured imagery. These operations must be performed in real-time for the pilot to use while flying. For image enhancement, we are using the LaRC patented Retinex algorithm since it performs exceptionally well for improving low-contrast range imagery typically seen during poor visibility poor visibility conditions. In general, real-time operation of the Retinex requires specialized hardware. To date, we have successfully implemented a single-sensor real-time version of the Retinex on several different Digital Signal Processor (DSP) platforms. In this paper we give an overview of the EVS and its performance requirements for real-time enhancement and fusion and we discuss our current real-time Retinex implementations on DSPs.

Smoke and fires from Sumatra

NASA Image and Video Library

2014-03-21

Fires burning in Sumatra continued to pour smoke over the region in mid-March, 2014, bringing air quality to dangerous levels. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image of the smoke and haze across the region on March 12. According to the Jakarta Post, on March 12 the Sumatra Environmental Laboratory reported that 10 of 12 spots in Riau had an air quality of index above 300 on the Pollutant Standards Index (PSI), which is considered hazardous. Hazardous air quality had been recorded in some of the locations for 11 consecutive days. The province of Riau is located in the central eastern coast of Sumatra and, in this image, is hidden under thick bands of light gray smoke. Intense fires, reported as deliberately set to clear land, were burning in the Giam Siak Kecil-Bukit Batu biosphere reserve. This reserve contains over 700,000 hectares of sensitive peat forest that sustains a wide range of plant and animal species, including the Sumatra tiger, elephant, tapir and sun bear. With visibility as low as 500 m (1640 ft), 58 flights were cancelled in Pekanbaru, the capital of Riau province, on March 11. Schools were closed across the region, with 43,000 students affected in Payakumbuh, West Sumatra. On March 14, Selangor, Malaysia closed 203 schools, affecting 211,700 pupils, until the air quality improved. On that same day, according to Riau Health Agency, more than 55,000 residents in the province were suffering from haze-related illnesses, including acute respiratory infections, pneumonia and skin and eye irritation. Poor air quality not only affected transportation, human health and the ecosystem, but has had significant economic impacts. On March 17, Reuters reported that the poor air quality had forced Chevron, the country’s biggest oil producer, to close hundreds of its wells. As a result, Indonesia’s crude oil output dropped to 790,000 barrels per day (bpd) – significantly lower than the 870,000 bpd target. Although slash-and-burn techniques, which use fire to clear land, is illegal in Indonesia, the practice is still widespread, with approximately 99% of fires in Sumatra considered to be intentionally set. This year’s early agricultural fires began in February in Riau Province, home to palm-oil and pulpwood plantations. The emergency has prompted strong government response, including a shoot-on-sight order for any suspects involved in land burning activities that resisted arrest. According to the Jakarta Post, police have named as many as 60 suspected-fire starters in Riau. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Optofluidic Fluorescent Imaging Cytometry on a Cell Phone

PubMed Central

Zhu, Hongying; Mavandadi, Sam; Coskun, Ahmet F.; Yaglidere, Oguzhan; Ozcan, Aydogan

2012-01-01

Fluorescent microscopy and flow cytometry are widely used tools in biomedical sciences. Cost-effective translation of these technologies to remote and resource-limited environments could create new opportunities especially for telemedicine applications. Toward this direction, here we demonstrate the integration of imaging cytometry and fluorescent microscopy on a cell phone using a compact, lightweight, and cost-effective optofluidic attachment. In this cell-phone-based optofluidic imaging cytometry platform, fluorescently labeled particles or cells of interest are continuously delivered to our imaging volume through a disposable microfluidic channel that is positioned above the existing camera unit of the cell phone. The same microfluidic device also acts as a multilayered optofluidic waveguide and efficiently guides our excitation light, which is butt-coupled from the side facets of our microfluidic channel using inexpensive light-emitting diodes. Since the excitation of the sample volume occurs through guided waves that propagate perpendicular to the detection path, our cell-phone camera can record fluorescent movies of the specimens as they are flowing through the microchannel. The digital frames of these fluorescent movies are then rapidly processed to quantify the count and the density of the labeled particles/cells within the target solution of interest. We tested the performance of our cell-phone-based imaging cytometer by measuring the density of white blood cells in human blood samples, which provided a decent match to a commercially available hematology analyzer. We further characterized the imaging quality of the same platform to demonstrate a spatial resolution of ~2 μm. This cell-phone-enabled optofluidic imaging flow cytometer could especially be useful for rapid and sensitive imaging of bodily fluids for conducting various cell counts (e.g., toward monitoring of HIV+ patients) or rare cell analysis as well as for screening of water quality in remote and resource-poor settings. PMID:21774454

Optofluidic fluorescent imaging cytometry on a cell phone.

PubMed

Zhu, Hongying; Mavandadi, Sam; Coskun, Ahmet F; Yaglidere, Oguzhan; Ozcan, Aydogan

2011-09-01

Fluorescent microscopy and flow cytometry are widely used tools in biomedical sciences. Cost-effective translation of these technologies to remote and resource-limited environments could create new opportunities especially for telemedicine applications. Toward this direction, here we demonstrate the integration of imaging cytometry and fluorescent microscopy on a cell phone using a compact, lightweight, and cost-effective optofluidic attachment. In this cell-phone-based optofluidic imaging cytometry platform, fluorescently labeled particles or cells of interest are continuously delivered to our imaging volume through a disposable microfluidic channel that is positioned above the existing camera unit of the cell phone. The same microfluidic device also acts as a multilayered optofluidic waveguide and efficiently guides our excitation light, which is butt-coupled from the side facets of our microfluidic channel using inexpensive light-emitting diodes. Since the excitation of the sample volume occurs through guided waves that propagate perpendicular to the detection path, our cell-phone camera can record fluorescent movies of the specimens as they are flowing through the microchannel. The digital frames of these fluorescent movies are then rapidly processed to quantify the count and the density of the labeled particles/cells within the target solution of interest. We tested the performance of our cell-phone-based imaging cytometer by measuring the density of white blood cells in human blood samples, which provided a decent match to a commercially available hematology analyzer. We further characterized the imaging quality of the same platform to demonstrate a spatial resolution of ~2 μm. This cell-phone-enabled optofluidic imaging flow cytometer could especially be useful for rapid and sensitive imaging of bodily fluids for conducting various cell counts (e.g., toward monitoring of HIV+ patients) or rare cell analysis as well as for screening of water quality in remote and resource-poor settings.

Perceived Stress and Coffee and Energy Drink Consumption Predict Poor Sleep Quality in Podiatric Medical Students A Cross-sectional Study.

PubMed

Sawah, Mohomad Al; Ruffin, Naeemah; Rimawi, Mohammad; Concerto, Carmen; Aguglia, Eugenio; Chusid, Eileen; Infortuna, Carmenrita; Battaglia, Fortunato

2015-09-01

A cross-sectional survey administered to first- and second-year podiatric medical students aimed to investigate the effect of coffee intake, energy drink consumption, and perceived stress on sleep quality in medical students during their preclinical studies. Ninety-eight of 183 students contacted (53.6%) completed a questionnaire comprising standard instruments measuring sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth Sleepiness scale), and perceived stress (ten-item Perceived Stress Scale). Furthermore, we investigated coffee and energy drink consumption. Logistic regression was conducted to identify factors associated with poor sleep quality and the relation between sleep quality and academic performance (grade point average). High prevalences of poor sleep quality, excessive daytime sleepiness, and perceived stress were reported. In addition, higher odds of developing poor sleep quality were associated with coffee and energy drink intake, perceived stress, and excessive daytime sleepiness. The total Pittsburgh Sleep Quality Index score was inversely correlated with grade point average. First- and second-year podiatric medical students have poor sleep quality. Further research is needed to identify effective strategies to reduce stress and decrease coffee and energy drink intake to minimize their negative effect on sleep quality and academic performance in podiatric medical students.

Edge Sharpness Assessment by Parametric Modeling: Application to Magnetic Resonance Imaging.

PubMed

Ahmad, R; Ding, Y; Simonetti, O P

2015-05-01

In biomedical imaging, edge sharpness is an important yet often overlooked image quality metric. In this work, a semi-automatic method to quantify edge sharpness in the presence of significant noise is presented with application to magnetic resonance imaging (MRI). The method is based on parametric modeling of image edges. First, an edge map is automatically generated and one or more edges-of-interest (EOI) are manually selected using graphical user interface. Multiple exclusion criteria are then enforced to eliminate edge pixels that are potentially not suitable for sharpness assessment. Second, at each pixel of the EOI, an image intensity profile is read along a small line segment that runs locally normal to the EOI. Third, the profiles corresponding to all EOI pixels are individually fitted with a sigmoid function characterized by four parameters, including one that represents edge sharpness. Last, the distribution of the sharpness parameter is used to quantify edge sharpness. For validation, the method is applied to simulated data as well as MRI data from both phantom imaging and cine imaging experiments. This method allows for fast, quantitative evaluation of edge sharpness even in images with poor signal-to-noise ratio. Although the utility of this method is demonstrated for MRI, it can be adapted for other medical imaging applications.

Various diffusion magnetic resonance imaging techniques for pancreatic cancer

PubMed Central

Tang, Meng-Yue; Zhang, Xiao-Ming; Chen, Tian-Wu; Huang, Xiao-Hua

2015-01-01

Pancreatic cancer is one of the most common malignant tumors and remains a treatment-refractory cancer with a poor prognosis. Currently, the diagnosis of pancreatic neoplasm depends mainly on imaging and which methods are conducive to detecting small lesions. Compared to the other techniques, magnetic resonance imaging (MRI) has irreplaceable advantages and can provide valuable information unattainable with other noninvasive or minimally invasive imaging techniques. Advances in MR hardware and pulse sequence design have particularly improved the quality and robustness of MRI of the pancreas. Diffusion MR imaging serves as one of the common functional MRI techniques and is the only technique that can be used to reflect the diffusion movement of water molecules in vivo. It is generally known that diffusion properties depend on the characterization of intrinsic features of tissue microdynamics and microstructure. With the improvement of the diffusion models, diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique to the more complex. In this review, the various diffusion MRI techniques for pancreatic cancer are discussed, including conventional diffusion weighted imaging (DWI), multi-b DWI based on intra-voxel incoherent motion theory, diffusion tensor imaging and diffusion kurtosis imaging. The principles, main parameters, advantages and limitations of these techniques, as well as future directions for pancreatic diffusion imaging are also discussed. PMID:26753059

[Medical Image Registration Method Based on a Semantic Model with Directional Visual Words].

PubMed

Jin, Yufei; Ma, Meng; Yang, Xin

2016-04-01

Medical image registration is very challenging due to the various imaging modality,image quality,wide inter-patients variability,and intra-patient variability with disease progressing of medical images,with strict requirement for robustness.Inspired by semantic model,especially the recent tremendous progress in computer vision tasks under bag-of-visual-word framework,we set up a novel semantic model to match medical images.Since most of medical images have poor contrast,small dynamic range,and involving only intensities and so on,the traditional visual word models do not perform very well.To benefit from the advantages from the relative works,we proposed a novel visual word model named directional visual words,which performs better on medical images.Then we applied this model to do medical registration.In our experiment,the critical anatomical structures were first manually specified by experts.Then we adopted the directional visual word,the strategy of spatial pyramid searching from coarse to fine,and the k-means algorithm to help us locating the positions of the key structures accurately.Sequentially,we shall register corresponding images by the areas around these positions.The results of the experiments which were performed on real cardiac images showed that our method could achieve high registration accuracy in some specific areas.

[Excessive Daytime Sleepiness, Poor Quality Sleep, and Low Academic Performance in Medical Students].

PubMed

Machado-Duque, Manuel Enrique; Echeverri Chabur, Jorge Enrique; Machado-Alba, Jorge Enrique

2015-01-01

Quality of sleep and excessive daytime sleepiness (EDS) affect cognitive ability and performance of medical students. This study attempts to determine the prevalence of EDS, sleep quality, and assess their association with poor academic performance in this population. A descriptive, observational study was conducted on a random sample of 217 medical students from the Universidad Tecnológica de Pereira, who completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire and the Epworth sleepiness scale. Sociodemographic, clinic and academic variables were also measured. Multivariate analyses for poor academic performance were performed. The included students had a mean age of 21.7±3.3 years, of whom 59.4% were men. Almost half (49.8%) had EDS criteria, and 79.3% were poor sleepers (PSQI ≥ 5), while 43.3% had poor academic performance during the last semester. The bivariate analysis showed that having used tobacco or alcohol until intoxicated, fairly bad subjective sleep quality, sleep efficiency < 65%, and being a poor sleeper were associated with increased risk of low performance. Sleep efficiency < 65% was statistically associated with poor academic performance (P=.024; OR = 4.23; 95% CI, 1.12-15.42) in the multivariate analysis. A poor sleep quality determined by low efficiency was related to poor academic achievement at the end of semester in medical students. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Changes in sleep quality with age-a 36-year follow-up study of Finnish working-aged adults.

PubMed

Hublin, Christer; Lehtovirta, Mikko; Partinen, Markku; Koskenvuo, Markku; Kaprio, Jaakko

2017-10-19

Long-term follow-up data on changes in sleep quality among middle-aged adults is scarce. We assessed sleep quality in a population-based cohort (n = 4847) of twins born between 1945 and 1957 during a follow-up of 36 years, with four measurement points in 1975, 1981, 1990 and 2011. Sleep quality was categorized as sleeping well, fairly well, fairly poorly or poorly. The mean age at the beginning of follow-up was 24.0, and at the end was 60.3 years. Of all the adults, 71.1% slept well or fairly well at each time-point throughout the follow-up and 0.5% poorly or fairly poorly. The proportion of those sleeping poorly or fairly poorly increased linearly over time; 3.5% among both sexes at the start, and 15.5% among men and 20.9% among women at the end of the follow-up. The last survey indicated a strong association between self-rated health and sleep quality: sleeping poorly or fairly poorly was reported 15 times more frequently by those rating their health as fairly poor than by those rating their health as very good. There was a strong association between indicators of depression and poor sleep. Although many studies have reported increasing frequencies in sleep problems, our results, based on a long-term cohort study, indicate that the majority of people sleep well or fairly well. Sleep quality declines with age, but only a very small fraction of the adults in this long follow-up consistently slept poorly. © 2017 European Sleep Research Society.

Use of One Time Pad Algorithm for Bit Plane Security Improvement

NASA Astrophysics Data System (ADS)

Suhardi; Suwilo, Saib; Budhiarti Nababan, Erna

2017-12-01

BPCS (Bit-Plane Complexity Segmentation) which is one of the steganography techniques that utilizes the human vision characteristics that cannot see the change in binary patterns that occur in the image. This technique performs message insertion by making a switch to a high-complexity bit-plane or noise-like regions with bits of secret messages. Bit messages that were previously stored precisely result the message extraction process to be done easily by rearranging a set of previously stored characters in noise-like region in the image. Therefore the secret message becomes easily known by others. In this research, the process of replacing bit plane with message bits is modified by utilizing One Time Pad cryptography technique which aims to increase security in bit plane. In the tests performed, the combination of One Time Pad cryptographic algorithm to the steganography technique of BPCS works well in the insertion of messages into the vessel image, although in insertion into low-dimensional images is poor. The comparison of the original image with the stegoimage looks identical and produces a good quality image with a mean value of PSNR above 30db when using a largedimensional image as the cover messages.

Association between Facebook Dependence and Poor Sleep Quality: A Study in a Sample of Undergraduate Students in Peru

PubMed Central

Wolniczak, Isabella; Cáceres-DelAguila, José Alonso; Palma-Ardiles, Gabriela; Arroyo, Karen J.; Solís-Visscher, Rodrigo; Paredes-Yauri, Stephania; Mego-Aquije, Karina; Bernabe-Ortiz, Antonio

2013-01-01

Objectives Internet can accelerate information exchange. Social networks are the most accessed especially Facebook. This kind of networks might create dependency with several negative consequences in people’s life. The aim of this study was to assess potential association between Facebook dependence and poor sleep quality. Methodology/Principal Findings A cross sectional study was performed enrolling undergraduate students of the Universidad Peruana de Ciencias Aplicadas, Lima, Peru. The Internet Addiction Questionnaire, adapted to the Facebook case, and the Pittsburgh Sleep Quality Index, were used. A global score of 6 or greater was defined as the cutoff to determine poor sleep quality. Generalized linear model were used to determine prevalence ratios (PR) and 95% confidence intervals (95%CI). A total of 418 students were analyzed; of them, 322 (77.0%) were women, with a mean age of 20.1 (SD: 2.5) years. Facebook dependence was found in 8.6% (95% CI: 5.9%–11.3%), whereas poor sleep quality was present in 55.0% (95% CI: 50.2%–59.8%). A significant association between Facebook dependence and poor sleep quality mainly explained by daytime dysfunction was found (PR = 1.31; IC95%: 1.04–1.67) after adjusting for age, sex and years in the faculty. Conclusions There is a relationship between Facebook dependence and poor quality of sleep. More than half of students reported poor sleep quality. Strategies to moderate the use of this social network and to improve sleep quality in this population are needed. PMID:23554978

Bullying as a risk for poor sleep quality among high school students in China.

PubMed

Zhou, Ying; Guo, Lan; Lu, Ci-yong; Deng, Jian-xiong; He, Yuan; Huang, Jing-hui; Huang, Guo-liang; Deng, Xue-qing; Gao, Xue

2015-01-01

To determine whether involvement in bullying as a bully, victim, or bully-victim was associated with a higher risk of poor sleep quality among high school students in China. A cross-sectional study was conducted. A total of 23,877 high school students were surveyed in six cities in Guangdong Province. All students were asked to complete the adolescent health status questionnaire, which included the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) and bullying involvement. Descriptive statistics were used to evaluate sleep quality and the prevalence of school bullying. Multi-level logistic regression analyses were conducted to examine the association between being victimized and bullying others with sleep quality. Among the 23,877 students, 6,127 (25.66%) reported having poor sleep quality, and 10.89% reported being involved in bullying behaviors. Of the respondents, 1,410 (5.91%) were pure victims of bullying, 401 (1.68%) were bullies and 784 (3.28%) were bully-victims. Frequently being involved in bullying behaviors (being bullied or bullying others) was related to increased risks of poor sleep quality compared with adolescents who were not involved in bullying behaviors. After adjusting for age, sex, and other confounding factors, the students who were being bullied (OR=2.05, 95%CI=1.81-2.32), bullied others (OR=2.30, 95%CI=1.85-2.86) or both (OR=2.58, 95%CI=2.20-3.03) were at a higher risk for poor sleep quality. Poor sleep quality among high school students is highly prevalent, and school bullying is prevalent among adolescents in China. The present results suggested that being involved in school bullying might be a risk factor for poor sleep quality among adolescents.

Bullying as a Risk for Poor Sleep Quality among High School Students in China

PubMed Central

Lu, Ci-yong; Deng, Jian-xiong; Huang, Jing-hui; Huang, Guo-liang; Deng, Xue-qing; Gao, Xue

2015-01-01

Objective To determine whether involvement in bullying as a bully, victim, or bully-victim was associated with a higher risk of poor sleep quality among high school students in China. Methods A cross-sectional study was conducted. A total of 23,877 high school students were surveyed in six cities in Guangdong Province. All students were asked to complete the adolescent health status questionnaire, which included the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) and bullying involvement. Descriptive statistics were used to evaluate sleep quality and the prevalence of school bullying. Multi-level logistic regression analyses were conducted to examine the association between being victimized and bullying others with sleep quality. Results Among the 23,877 students, 6,127 (25.66%) reported having poor sleep quality, and 10.89% reported being involved in bullying behaviors. Of the respondents, 1,410 (5.91%) were pure victims of bullying, 401 (1.68%) were bullies and 784 (3.28%) were bully-victims. Frequently being involved in bullying behaviors (being bullied or bullying others) was related to increased risks of poor sleep quality compared with adolescents who were not involved in bullying behaviors. After adjusting for age, sex, and other confounding factors, the students who were being bullied (OR=2.05, 95%CI=1.81-2.32), bullied others (OR=2.30, 95%CI=1.85-2.86) or both (OR=2.58, 95%CI=2.20-3.03) were at a higher risk for poor sleep quality. Conclusions Poor sleep quality among high school students is highly prevalent, and school bullying is prevalent among adolescents in China. The present results suggested that being involved in school bullying might be a risk factor for poor sleep quality among adolescents. PMID:25811479

Detection of Oil Chestnuts Infected by Blue Mold Using Near-Infrared Hyperspectral Imaging Combined with Artificial Neural Networks.

PubMed

Feng, Lei; Zhu, Susu; Lin, Fucheng; Su, Zhenzhu; Yuan, Kangpei; Zhao, Yiying; He, Yong; Zhang, Chu

2018-06-15

Mildew damage is a major reason for chestnut poor quality and yield loss. In this study, a near-infrared hyperspectral imaging system in the 874⁻1734 nm spectral range was applied to detect the mildew damage to chestnuts caused by blue mold. Principal component analysis (PCA) scored images were firstly employed to qualitatively and intuitively distinguish moldy chestnuts from healthy chestnuts. Spectral data were extracted from the hyperspectral images. A successive projections algorithm (SPA) was used to select 12 optimal wavelengths. Artificial neural networks, including back propagation neural network (BPNN), evolutionary neural network (ENN), extreme learning machine (ELM), general regression neural network (GRNN) and radial basis neural network (RBNN) were used to build models using the full spectra and optimal wavelengths to distinguish moldy chestnuts. BPNN and ENN models using full spectra and optimal wavelengths obtained satisfactory performances, with classification accuracies all surpassing 99%. The results indicate the potential for the rapid and non-destructive detection of moldy chestnuts by hyperspectral imaging, which would help to develop online detection system for healthy and blue mold infected chestnuts.

Extraction of line properties based on direction fields.

PubMed

Kutka, R; Stier, S

1996-01-01

The authors present a new set of algorithms for segmenting lines, mainly blood vessels in X-ray images, and extracting properties such as their intensities, diameters, and center lines. The authors developed a tracking algorithm that checks rules taking the properties of vessels into account. The tools even detect veins, arteries, or catheters of two pixels in diameter and with poor contrast. Compared with other algorithms, such as the Canny line detector or anisotropic diffusion, the authors extract a smoother and connected vessel tree without artifacts in the image background. As the tools depend on common intermediate results, they are very fast when used together. The authors' results will support the 3-D reconstruction of the vessel tree from stereoscopic projections. Moreover, the authors make use of their line intensity measure for enhancing and improving the visibility of vessels in 3-D X-ray images. The processed images are intended to support radiologists in diagnosis, radiation therapy planning, and surgical planning. Radiologists verified the improved quality of the processed images and the enhanced visibility of relevant details, particularly fine blood vessels.

The utility of multiple synthesized views in the recognition of unfamiliar faces.

PubMed

Jones, Scott P; Dwyer, Dominic M; Lewis, Michael B

2017-05-01

The ability to recognize an unfamiliar individual on the basis of prior exposure to a photograph is notoriously poor and prone to errors, but recognition accuracy is improved when multiple photographs are available. In applied situations, when only limited real images are available (e.g., from a mugshot or CCTV image), the generation of new images might provide a technological prosthesis for otherwise fallible human recognition. We report two experiments examining the effects of providing computer-generated additional views of a target face. In Experiment 1, provision of computer-generated views supported better target face recognition than exposure to the target image alone and equivalent performance to that for exposure of multiple photograph views. Experiment 2 replicated the advantage of providing generated views, but also indicated an advantage for multiple viewings of the single target photograph. These results strengthen the claim that identifying a target face can be improved by providing multiple synthesized views based on a single target image. In addition, our results suggest that the degree of advantage provided by synthesized views may be affected by the quality of synthesized material.

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

NASA Astrophysics Data System (ADS)

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

2011-03-01

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

Petroleum Jelly: A Novel Medium for Ocular Ultrasound.

PubMed

Engelbert, Patrick R; Palma, James K

2015-08-01

Ocular ultrasound is a useful emergency department imaging modality for evaluation of many conditions, such as retinal detachment, vitreous detachment, vitreous hemorrhage, and elevated intracranial pressure. Obtaining satisfactory ocular ultrasound images requires the use of a medium that eliminates the air interface between the patient's eye and the transducer. Ultrasound gel is most commonly used; however, the use of a transparent dressing applied to the closed eye prior to the application of gel has also been described as a suitable technique. Ocular ultrasound is performed with the high-frequency linear array transducer using a medium to eliminate the air interface between the eye and the transducer. Although ultrasound gel is most frequently used, it can cause minor eye irritation. Placing a transparent dressing over a closed eye prior to application of gel can eliminate the eye irritation. However, our experience in training >500 students in ocular ultrasound has shown that air is frequently introduced underneath the dressing, which leads to poor-quality images. This article introduces petroleum jelly as a medium for ocular ultrasound. By applying a layer of petroleum jelly over the closed eye and allowing it to warm via body heat for 30 to 45 s, this medium can both minimize patient discomfort and provide easily obtainable, high-quality ocular ultrasound images. This article introduces petroleum jelly as a safe, comfortable, and effective medium for ocular ultrasound examination. Published by Elsevier Inc.

Is there a link between hospital profit and quality?

PubMed

Cleverley, W O; Harvey, R K

1992-09-01

In industrial firms, high perceived quality in products or services leads to high return on investment. The link between high quality and high profit is more difficult to document for healthcare products and services. An even more important question for healthcare managers is whether there is a link between poor-quality services and low profitability. A study of a small sample of HCFA high-mortality hospitals shows that poor quality hospitals are less profitable. Although the demand for the products and services of poor-quality hospitals is relatively strong, such hospitals are underinvested in assets and understaffed, the study shows.

Person identification from aerial footage by a remote-controlled drone.

PubMed

Bindemann, Markus; Fysh, Matthew C; Sage, Sophie S K; Douglas, Kristina; Tummon, Hannah M

2017-10-19

Remote-controlled aerial drones (or unmanned aerial vehicles; UAVs) are employed for surveillance by the military and police, which suggests that drone-captured footage might provide sufficient information for person identification. This study demonstrates that person identification from drone-captured images is poor when targets are unfamiliar (Experiment 1), when targets are familiar and the number of possible identities is restricted by context (Experiment 2), and when moving footage is employed (Experiment 3). Person information such as sex, race and age is also difficult to access from drone-captured footage (Experiment 4). These findings suggest that such footage provides a particularly poor medium for person identification. This is likely to reflect the sub-optimal quality of such footage, which is subject to factors such as the height and velocity at which drones fly, viewing distance, unfavourable vantage points, and ambient conditions.

[Object Separation from Medical X-Ray Images Based on ICA].

PubMed

Li, Yan; Yu, Chun-yu; Miao, Ya-jian; Fei, Bin; Zhuang, Feng-yun

2015-03-01

X-ray medical image can examine diseased tissue of patients and has important reference value for medical diagnosis. With the problems that traditional X-ray images have noise, poor level sense and blocked aliasing organs, this paper proposes a method for the introduction of multi-spectrum X-ray imaging and independent component analysis (ICA) algorithm to separate the target object. Firstly image de-noising preprocessing ensures the accuracy of target extraction based on independent component analysis and sparse code shrinkage. Then according to the main proportion of organ in the images, aliasing thickness matrix of each pixel was isolated. Finally independent component analysis obtains convergence matrix to reconstruct the target object with blind separation theory. In the ICA algorithm, it found that when the number is more than 40, the target objects separate successfully with the aid of subjective evaluation standard. And when the amplitudes of the scale are in the [25, 45] interval, the target images have high contrast and less distortion. The three-dimensional figure of Peak signal to noise ratio (PSNR) shows that the different convergence times and amplitudes have a greater influence on image quality. The contrast and edge information of experimental images achieve better effects with the convergence times 85 and amplitudes 35 in the ICA algorithm.

Improved mass resolution and mass accuracy in TOF-SIMS spectra and images using argon gas cluster ion beams.

PubMed

Shon, Hyun Kyong; Yoon, Sohee; Moon, Jeong Hee; Lee, Tae Geol

2016-06-09

The popularity of argon gas cluster ion beams (Ar-GCIB) as primary ion beams in time-of-flight secondary ion mass spectrometry (TOF-SIMS) has increased because the molecular ions of large organic- and biomolecules can be detected with less damage to the sample surfaces. However, Ar-GCIB is limited by poor mass resolution as well as poor mass accuracy. The inferior quality of the mass resolution in a TOF-SIMS spectrum obtained by using Ar-GCIB compared to the one obtained by a bismuth liquid metal cluster ion beam and others makes it difficult to identify unknown peaks because of the mass interference from the neighboring peaks. However, in this study, the authors demonstrate improved mass resolution in TOF-SIMS using Ar-GCIB through the delayed extraction of secondary ions, a method typically used in TOF mass spectrometry to increase mass resolution. As for poor mass accuracy, although mass calibration using internal peaks with low mass such as hydrogen and carbon is a common approach in TOF-SIMS, it is unsuited to the present study because of the disappearance of the low-mass peaks in the delayed extraction mode. To resolve this issue, external mass calibration, another regularly used method in TOF-MS, was adapted to enhance mass accuracy in the spectrum and image generated by TOF-SIMS using Ar-GCIB in the delayed extraction mode. By producing spectra analyses of a peptide mixture and bovine serum albumin protein digested with trypsin, along with image analyses of rat brain samples, the authors demonstrate for the first time the enhancement of mass resolution and mass accuracy for the purpose of analyzing large biomolecules in TOF-SIMS using Ar-GCIB through the use of delayed extraction and external mass calibration.

Poor Sleep Quality is Independently Associated with Physical Disability in Older Adults

PubMed Central

Chien, Meng-Yueh; Chen, Hsi-Chung

2015-01-01

Study Objective: We aimed to evaluate the association between sleep quality and physical disability in community-dwelling older adults. Methods: There were 213 community-dwelling adults (76 men and 137 women) aged 65 years and above participated into this investigation. The Groningen Activity Restriction Scale and the Pittsburgh Sleep Quality Index were utilized to evaluate physical disability and subjective sleep quality, respectively. Global functional capacity was measured by the 6-minute walk test (6MWT). The Mini Mental State Examination and the Chinese Geriatric Depression Screening Scale were used to evaluate cognitive function and depression. Results: Univariate analysis revealed a correlation between physical disability and poor sleep quality, older age, 2 or more comorbidities, depression, functional capacity, and poor cognitive function. However, in the multivariate analyses, depression failed to show significant association with physical disability. In contrast, an independent association was observed between poor sleep quality and physical disability (OR = 2.03; 95% CI: 1.02–4.05). Conclusions: In community-dwelling older adults, subjective poor sleep was significantly associated with physical disability, even after controlling for the effects of other established risk factors. Citation: Chien MY, Chen HC. Poor sleep quality is independently associated with physical disability in older adults. J Clin Sleep Med 2015;11(3):225–232. PMID:25515275

Requirements model for an e-Health awareness portal

NASA Astrophysics Data System (ADS)

Hussain, Azham; Mkpojiogu, Emmanuel O. C.; Nawi, Mohd Nasrun M.

2016-08-01

Requirements engineering is at the heart and foundation of software engineering process. Poor quality requirements inevitably lead to poor quality software solutions. Also, poor requirement modeling is tantamount to designing a poor quality product. So, quality assured requirements development collaborates fine with usable products in giving the software product the needed quality it demands. In the light of the foregoing, the requirements for an e-Ebola Awareness Portal were modeled with a good attention given to these software engineering concerns. The requirements for the e-Health Awareness Portal are modeled as a contribution to the fight against Ebola and helps in the fulfillment of the United Nation's Millennium Development Goal No. 6. In this study requirements were modeled using UML 2.0 modeling technique.

The Little Cub: Discovery of an Extremely Metal-poor Star-forming Galaxy in the Local Universe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsyu, Tiffany; Prochaska, J. Xavier; Bolte, Michael

We report the discovery of the Little Cub, an extremely metal-poor star-forming galaxy in the local universe, found in the constellation Ursa Major (a.k.a. the Great Bear). We first identified the Little Cub as a candidate metal-poor galaxy based on its Sloan Digital Sky Survey photometric colors, combined with spectroscopy using the Kast spectrograph on the Shane 3 m telescope at Lick Observatory. In this Letter, we present high-quality spectroscopic data taken with the Low Resolution Imaging Spectrometer at Keck Observatory, which confirm the extremely metal-poor nature of this galaxy. Based on the weak [O iii] λ 4363 Å emissionmore » line, we estimate a direct oxygen abundance of 12 + log(O/H) = 7.13 ± 0.08, making the Little Cub one of the lowest-metallicity star-forming galaxies currently known in the local universe. The Little Cub appears to be a companion of the spiral galaxy NGC 3359 and shows evidence of gas stripping. We may therefore be witnessing the quenching of a near-pristine galaxy as it makes its first passage about a Milky Way–like galaxy.« less

The Little Cub: Discovery of an Extremely Metal-poor Star-forming Galaxy in the Local Universe

NASA Astrophysics Data System (ADS)

Hsyu, Tiffany; Cooke, Ryan J.; Prochaska, J. Xavier; Bolte, Michael

2017-08-01

We report the discovery of the Little Cub, an extremely metal-poor star-forming galaxy in the local universe, found in the constellation Ursa Major (a.k.a. the Great Bear). We first identified the Little Cub as a candidate metal-poor galaxy based on its Sloan Digital Sky Survey photometric colors, combined with spectroscopy using the Kast spectrograph on the Shane 3 m telescope at Lick Observatory. In this Letter, we present high-quality spectroscopic data taken with the Low Resolution Imaging Spectrometer at Keck Observatory, which confirm the extremely metal-poor nature of this galaxy. Based on the weak [O III] λ4363 Å emission line, we estimate a direct oxygen abundance of 12 + log(O/H) = 7.13 ± 0.08, making the Little Cub one of the lowest-metallicity star-forming galaxies currently known in the local universe. The Little Cub appears to be a companion of the spiral galaxy NGC 3359 and shows evidence of gas stripping. We may therefore be witnessing the quenching of a near-pristine galaxy as it makes its first passage about a Milky Way-like galaxy.

Prevalence and factors associated with poor sleep quality among secondary school teachers in a developing country.

PubMed

Musa, Nor Asma; Moy, Foong Ming; Wong, Li Ping

2018-05-31

This study aimed to determine the prevalence and factors associated with poor sleep quality among secondary school teachers in the state of Selangor, Malaysia. This was a cross sectional study, conducted in two phases. Phase I tested the reliability of the Pittsburgh Sleep Quality Index in the Malay language (M-PSQI), whereas Phase II determined the prevalence and factors associated with poor sleep quality where a total of 1871 secondary school teachers were studied. Participants were recruited using multistage sampling. Self-administered questionnaire was used to collect data on socio-demographic and teaching characteristics, comorbidities and characteristics of sleep. The M-PSQI was used to measure sleep quality. The Depression Anxiety Stress Scale-21 was used to measure mental health status. Results showed that the M-PSQI had a good internal consistency and moderate reliability. The prevalence of poor sleep quality was 61 (95% CI: 54-67) %. Total teaching hours/day, depression and stress were significantly associated with poor sleep quality in the univariate analysis, while only stress (OR 1.04; 95% CI 1.02-1.05%) remained significant in the multivariate analyses. In conclusion, stress level of the secondary school teachers should be reduced to improve sleep quality.

Cosmetic Outcomes and Quality of Life in Thai Women Post Breast Conserving Therapy for Breast Cancer.

PubMed

Thanarpan, Peerawong; Somrit, Mahattanobon; Rungarun, Jiratrachu; Paytai, Rordlamool; Duangjai, Sangtawan; Chanon, Kongkamol; Puttisak, Puttawibul

2015-01-01

To evaluate the correlation between cosmetic outcome (CO), body image, and quality of life in post breast-conserving therapy (BCT) women. This cross-sectional study concerned one-year post-completed BCT Thai women. The data included subjective and objective CO with a questionnaire covering demographic and clinical data, anti-hormonal treatment status, Eastern Cooperative Oncology Group (ECOG) performance status, Self-Reported Cosmetic Outcomes (SRCO), Self-Reported Breast Symmetry (SRBS), Body Image Scale (BIS), and the Functional Assessment of Cancer Therapy with Breast Cancer subscale (FACT-B). Participants had breast photographs taken for the evaluation of objective cosmetic outcome (OCO) after breast cancer conservation treatment. The relationship between CO and FACT-B was tested using Spearman's rank correlation Results: A total 127 participants volunteered for the study. The participant characteristics were age 52(±9), Buddhist 87%, married 65%, body mass index 25.0(±4.6), breast cup size A-C 91%, college educated 60%, employed 66%, ECOG 0-1 95%, tumor size less than or equal to 2 cm 55%, no lymph node metastasis 98%, and taking tamoxifen 57%. Two percent of the participants regretted their decision to undergo BCT. The SRCO was excellent in 2%, good in 68%, fair in 30%, and poor in 0%. For SRBS, rates were 17%, 58%, 24% and 1% for excellent, good, fair and poor cosmetic outcomes, respectively. The BCCT scores were excellent 24%, good 39%, fair 32%, and poor 6%. The median total QOL score of the participants was 130 (93-144). There was no significant correlation between CO and FACT-B scores. The significance of CO for FACT-B in Thai women with breast cancer could not be assessed in detail because of a very low level of correlation. The results may be due to the effects of cultural background.

A study on the sleep quality of incoming university students.

PubMed

Cheng, Shu Hui; Shih, Chi-Chen; Lee, I Hui; Hou, Yi-Wen; Chen, Kao Chin; Chen, Kow-Tong; Yang, Yen Kuang; Yang, Yi Ching

2012-05-30

This study was designed to examine the prevalence and the risk factors of poor sleep quality in 4318 incoming university students in Taiwan. The test battery comprised a self-administered structured questionnaire, including items related to personal medical history and lifestyle habits, the Measurement of Support Functions (MSF), Pittsburgh Sleep Quality Index (PSQI), Chinese Internet Addiction Scale-Revision (CIAS-R), neuroticism subscale of the Maudsley Personality Inventory (MPI), and the 12-item Chinese Health Questionnaire (CHQ-12). Of the total study population, 2360 students (54.7%) were classified into the poor sleep quality group, as defined by a PSQI score ≥6. Based on the results of multivariate logistic regression analysis, poor sleep quality was significantly associated with undergraduate students, female gender, skipping breakfast, tea drinking, a higher tendency toward internet addition, poor social support, higher neuroticism, and higher CHQ scores. Poor sleep quality is prevalent among incoming university students in Taiwan, and more work is needed on the identification of the factors influencing poor sleep, and in providing systematic education in the importance of sleep and time management skills to university students. Copyright © 2012 Elsevier Ltd. All rights reserved.

Obese patients and radiography literature: what do we know about a big issue?

PubMed Central

Le, Nhat Tan Thanh; Robinson, John; Lewis, Sarah J

2015-01-01

Obesity is a global health issue with obese patients requiring specialised diagnosis, treatment and care through the health service. The practical and social difficulties associated with medical imaging of obese patients are an increasingly common problem and it is currently unknown how student and qualified radiographers perceive and respond to these challenges. By better understanding challenges presented in providing quality imaging and care of imaging obese patients, education for both qualified and student radiographers can be enhanced. Radiographers are heavily reliant on visual and tactile senses to locate the position of anatomical structures for diagnostic imaging and determine radiation exposure through a delicate consideration of dose, image quality and anatomical attenuation. However, obese patients require modifications to routine radiographic practice in terms of movement/assisted positioning, equipment capabilities to take increased weight or coverage. These patients may also be subject to compromised radiological diagnosis through poor visualisation of structures. In this paper, the professional and educational literature was narratively reviewed to assess gaps in the evidence base related to the skill and care knowledge for obese patients. Literature was sourced relating to discrete radiographic considerations such as the technical factors of imaging obese patients, exposure and the impact of obesity on imaging departments’ service provisions. The recent literature (post-2000 to coincide with the sharp increase in global obesity) on the perceptions of health professionals and student health practitioners has also been explored because there are no specific radiographer studies to report. By understanding the research in similar fields, we may identify what common attitudes qualified and student radiographer's hold and what challenges, technical and care related, can be prepared for. PMID:26229678

Obese patients and radiography literature: what do we know about a big issue?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le, Nhat Tan Thanh; Robinson, John; Lewis, Sarah J, E-mail: sarah.lewis@sydney.edu.au

Obesity is a global health issue with obese patients requiring specialised diagnosis, treatment and care through the health service. The practical and social difficulties associated with medical imaging of obese patients are an increasingly common problem and it is currently unknown how student and qualified radiographers perceive and respond to these challenges. By better understanding challenges presented in providing quality imaging and care of imaging obese patients, education for both qualified and student radiographers can be enhanced. Radiographers are heavily reliant on visual and tactile senses to locate the position of anatomical structures for diagnostic imaging and determine radiation exposuremore » through a delicate consideration of dose, image quality and anatomical attenuation. However, obese patients require modifications to routine radiographic practice in terms of movement/assisted positioning, equipment capabilities to take increased weight or coverage. These patients may also be subject to compromised radiological diagnosis through poor visualisation of structures. In this paper, the professional and educational literature was narratively reviewed to assess gaps in the evidence base related to the skill and care knowledge for obese patients. Literature was sourced relating to discrete radiographic considerations such as the technical factors of imaging obese patients, exposure and the impact of obesity on imaging departments’ service provisions. The recent literature (post-2000 to coincide with the sharp increase in global obesity) on the perceptions of health professionals and student health practitioners has also been explored because there are no specific radiographer studies to report. By understanding the research in similar fields, we may identify what common attitudes qualified and student radiographer's hold and what challenges, technical and care related, can be prepared for.« less

SU-E-J-38: Improved DRR Image Quality Using Polyetheretherketone (PEEK) Fiducial in Image Guided Radiotherapy (IGRT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, S; Jacob, R; Popple, R

Purpose Fiducial-based imaging is often used in IGRT. Traditional gold fiducial marker often has substantial reconstruction artifacts. These artifacts Result in poor image quality of DRR for online kV-to-DRR matching. This study evaluated the image quality of PEEK in DRR in static and moving phantom. Methods CT scan of the Gold and PEEK fiducial (both 1×3 mm) was acquired in a 22 cm cylindrical phantom filled with water. Image artifacts was evaluated with maximum CT value deviated from water due to artifacts; volume of artifacts in 10×10 cm in the center slice; maximum length of streak artifacts from the fiducial.more » DRR resolution were measured using FWHM and FWTM. 4DCT of PEEK fiducial was acquired with the phantom moving sinusoidally in superior-inferior direction. Motion artifacts were assessed for various 4D phase angles. Results The maximum CT value deviation was −174 for Gold and −24 for PEEK. The volume of artifacts in a 10x10 cm 3 mm slice was 0.369 for Gold and 0.074 cm3 for PEEK. The maximum length of streak artifact was 80mm for Gold and 7 mm for PEEK. PEEK in DRR, FWHM was close to actual (1.0 mm for Gold and 1.1 mm for PEEK). FWTM was 1.8 mm for Gold and 1.3 mm for PEEK in DRR. Barrel motion artifact of PEEK fiducial was noticeable for free-breathing scan. The apparent PEEK length due to residual motion was in close agreement with the calculated length (13 mm for 30–70 phase, 10 mm in 40–60 phase). Conclusion Streak artifacts on planning CT associated with use of gold fiducial can be significantly reduced by PEEK fiducial, while having adequate kV image contrast. DRR image resolution at FWTM was improved from 1.8 mm to 1.3 mm. Because of this improvement, we have been routinely use PEEK for liver IGRT.« less

The impact of sleep and psychiatric symptoms on alcohol consequences among young adults.

PubMed

Miller, Mary Beth; Van Reen, Eliza; Barker, David H; Roane, Brandy M; Borsari, Brian; McGeary, John E; Seifer, Ronald; Carskadon, Mary A

2017-03-01

Independent lines of research have documented links between psychiatric symptoms and poor sleep quality, psychiatric symptoms and alcohol use, and alcohol use and poor sleep quality. The current study examined the synergistic effect of poor sleep quality and psychiatric symptoms on alcohol-related consequences in heavy-drinking young adults. Matriculating college students reporting at least one heavy drinking episode over the first nine weeks of the semester (N=385, 52% female) were categorized as experiencing 'good' (n=280) versus 'poor' sleep quality (n=105) and screening 'positive' (n=203) or 'negative' (n=182) for a psychiatric disorder. Sleep quality was assessed using the Pittsburgh Sleep Quality Index; psychiatric diagnosis was assessed using the Psychiatric Diagnostic Screening Questionnaire; and alcohol-related consequences were assessed using the Brief Young Adult Alcohol Consequences Questionnaire. General linear models were used to examine the main effects and interaction between sleep quality and psychiatric symptoms on alcohol-related consequences. Sleep quality moderated the association between psychiatric screen and alcohol-related consequences among heavy-drinking college students, such that psychiatric symptoms were associated with more alcohol-related consequences in the context of poor sleep quality. The combination of poor sleep quality and psychiatric symptoms is associated with increased alcohol-related consequences among heavy-drinking college students. Given the significant interaction between these symptoms, healthcare providers are encouraged to screen for the presence of sleep and psychiatric disorders among heavy-drinking young adults and to provide empirically-supported treatments as appropriate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Psychosocial work conditions and quality of life among primary health care employees: a cross sectional study.

PubMed

Teles, Mariza Alves Barbosa; Barbosa, Mirna Rossi; Vargas, Andréa Maria Duarte; Gomes, Viviane Elizângela; Ferreira, Efigênia Ferreira e; Martins, Andréa Maria Eleutério de Barros Lima; Ferreira, Raquel Conceição

2014-05-15

Workers in Primary Health Care are often exposed to stressful conditions at work. This study investigated the association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers. This cross-sectional study included all 797 Primary Health Care workers of a medium-sized city, Brazil: doctors, nurses, nursing technicians and nursing assistants, dentists, oral health technicians, and auxiliary oral hygienists, and community health workers. Data were collected by interviews. Quality of life was assessed using the WHOQOL-BREF; general quality of life, as well as the physical, psychological, social and environmental domains were considered, with scores from 0 to 100. Higher scores indicate a better quality of life. Poor quality of life was defined by the lowest quartiles of the WHOQOL score distributions for each of the domains. Adverse psychosocial work conditions were investigated by the Effort-Reward Imbalance model. Associations were verified using multiple logistic regression. Poor quality of life was observed in 117 (15.4%) workers. Workers with imbalanced effort-reward (high effort/low reward) had an increased probability of general poor quality of life (OR = 1.91; 1.07–3.42), and in the physical (OR = 1.62; 1.02–2.66), and environmental (OR = 2.39; 1.37–4.16) domains; those with low effort/low reward demonstrated a greater probability of poor quality of life in the social domain (OR = 1.82; 1.00–3.30). Workers with overcommitment at work had an increased likelihood of poor quality of life in the physical (OR = 1.55, 1.06–2.26) and environmental (OR = 1.69; 1.08–2.65) domains. These associations were independent of individual characteristics, job characteristics, lifestyle, perception of general health, or psychological and biological functions. There is an association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers.

Psychosocial work conditions and quality of life among primary health care employees: a cross sectional study

PubMed Central

2014-01-01

Background Workers in Primary Health Care are often exposed to stressful conditions at work. This study investigated the association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers. Methods This cross-sectional study included all 797 Primary Health Care workers of a medium-sized city, Brazil: doctors, nurses, nursing technicians and nursing assistants, dentists, oral health technicians, and auxiliary oral hygienists, and community health workers. Data were collected by interviews. Quality of life was assessed using the WHOQOL-BREF; general quality of life, as well as the physical, psychological, social and environmental domains were considered, with scores from 0 to 100. Higher scores indicate a better quality of life. Poor quality of life was defined by the lowest quartiles of the WHOQOL score distributions for each of the domains. Adverse psychosocial work conditions were investigated by the Effort-Reward Imbalance model. Associations were verified using multiple logistic regression. Results Poor quality of life was observed in 117 (15.4%) workers. Workers with imbalanced effort-reward (high effort/low reward) had an increased probability of general poor quality of life (OR = 1.91; 1.07–3.42), and in the physical (OR = 1.62; 1.02–2.66), and environmental (OR = 2.39; 1.37–4.16) domains; those with low effort/low reward demonstrated a greater probability of poor quality of life in the social domain (OR = 1.82; 1.00–3.30). Workers with overcommitment at work had an increased likelihood of poor quality of life in the physical (OR = 1.55, 1.06–2.26) and environmental (OR = 1.69; 1.08–2.65) domains. These associations were independent of individual characteristics, job characteristics, lifestyle, perception of general health, or psychological and biological functions. Conclusions There is an association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers. PMID:24884707

Shorter sleep duration and better sleep quality are associated with greater tissue density in the brain.

PubMed

Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Yokoyama, Ryoichi; Kotozaki, Yuka; Nakagawa, Seishu; Sekiguchi, Atsushi; Iizuka, Kunio; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Miyauchi, Carlos Makoto; Shinada, Takamitsu; Sakaki, Kohei; Nozawa, Takayuki; Ikeda, Shigeyuki; Yokota, Susumu; Daniele, Magistro; Sassa, Yuko; Kawashima, Ryuta

2018-04-11

Poor sleep quality is associated with unfavorable psychological measurements, whereas sleep duration has complex relationships with such measurements. The aim of this study was to identify the associations between microstructural properties of the brain and sleep duration/sleep quality in a young adult. The associations between mean diffusivity (MD), a measure of diffusion tensor imaging (DTI), and sleep duration/sleep quality were investigated in a study cohort of 1201 normal young adults. Positive correlations between sleep duration and MD of widespread areas of the brain, including the prefrontal cortex (PFC) and the dopaminergic systems, were identified. Negative correlations between sleep quality and MD of the widespread areas of the brain, including the PFC and the right hippocampus, were also detected. Lower MD has been previously associated with more neural tissues in the brain. Further, shorter sleep duration was associated with greater persistence and executive functioning (lower Stroop interference), whereas good sleep quality was associated with states and traits relevant to positive affects. These results suggest that bad sleep quality and longer sleep duration were associated with aberrant neurocognitive measurements in the brain in healthy young adults.

Faxed document image restoration method based on local pixel patterns

NASA Astrophysics Data System (ADS)

Akiyama, Teruo; Miyamoto, Nobuo; Oguro, Masami; Ogura, Kenji

1998-04-01

A method for restoring degraded faxed document images using the patterns of pixels that construct small areas in a document is proposed. The method effectively restores faxed images that contain the halftone textures and/or density salt-and-pepper noise that degrade OCR system performance. The halftone image restoration process, white-centered 3 X 3 pixels, in which black-and-white pixels alternate, are identified first using the distribution of the pixel values as halftone textures, and then the white center pixels are inverted to black. To remove high-density salt- and-pepper noise, it is assumed that the degradation is caused by ill-balanced bias and inappropriate thresholding of the sensor output which results in the addition of random noise. Restored image can be estimated using an approximation that uses the inverse operation of the assumed original process. In order to process degraded faxed images, the algorithms mentioned above are combined. An experiment is conducted using 24 especially poor quality examples selected from data sets that exemplify what practical fax- based OCR systems cannot handle. The maximum recovery rate in terms of mean square error was 98.8 percent.

Global geologic mapping of Mars: The western equatorial region

USGS Publications Warehouse

Scott, D.H.

1985-01-01

Global geologic mapping of Mars was originally accomplished following acquisition of orbital spacecraft images from the Mariner 9 mission. The mapping program represented a joint enterprise by the U.S. Geological Survey and other planetary scientists from universities in the United States and Europe. Many of the Mariner photographs had low resolution or poor albedo contrast caused by atmospheric haze and high-sun angles. Some of the early geologic maps reflect these deficiencies in their poor discrimination and subdivision of rock units. New geologic maps made from higher resolution and better quality Viking images also represent a cooperative effort, by geologists from the U.S. Geological Survey, Arizona State University, and the University of London. This second series of global maps consists of three parts: 1) western equatorial region, 2) eastern equatorial region, and 3) north and south polar regions. These maps, at 1:15 million scale, show more than 60 individual rock-stratigraphic units assigned to three Martian time-stratigraphic systems. The first completed map of the series covers the western equatorial region of Mars. Accompanying the map is a description of the sequence and distribution of major tectonic, volcanic, and fluvial episodes as recorded in the stratigraphic record. ?? 1985.

Why Is Your Patient Still Short of Breath? Understanding the Complex Pathophysiology of Dyspnea in Chronic Kidney Disease.

PubMed

Salerno, Fabio Rosario; Parraga, Grace; McIntyre, Christopher William

2017-01-01

Dyspnea is one of the most common symptoms associated with CKD. It has a profound influence on the quality of life of CKD patients, and its underlying causes are often associated with a negative prognosis. However, its pathophysiology is poorly understood. While hemodialysis may address fluid overload, it often does not significantly improve breathlessness, suggesting multiple and co-existing alternative issues exist. The aim of this article is to discuss the main pathophysiologic mechanisms and the most important putative etiologies underlying dyspnea in CKD patients. Congestive heart failure, unrecognized chronic lung disease, pulmonary hypertension, lung fibrosis, air microembolism, dialyzer bio-incompatibility, anemia, sodium, and fluid overload are potential frequent causes of breathing disorders in this population. However, the relative contributions in any one given patient are poorly understood. Systemic inflammation is a common theme and contributes to the development of endothelial dysfunction, lung fibrosis, anemia, malnutrition, and muscle wasting. The introduction of novel multimodal imaging techniques, including pulmonary functional magnetic resonance imaging with inhaled contrast agents, could provide new insights into the pathophysiology of dyspnea in CKD patients and ultimately contribute to improving our clinical management of this symptom. © 2016 Wiley Periodicals, Inc.

Determination of pork quality attributes using hyperspectral imaging technique

NASA Astrophysics Data System (ADS)

Qiao, Jun; Wang, Ning; Ngadi, M. O.; Gunenc, Aynur

2005-11-01

Meat grading has always been a research topic because of large variations among meat products. Many subjective assessment methods with poor repeatability and tedious procedures are still widely used in meat industry. In this study, a hyperspectral-imaging-based technique was developed to achieve fast, accurate, and objective determination of pork quality attributes. The system was able to extract the spectral and spatial characteristics for simultaneous determination of drip loss and pH in pork meat. Two sets of six significant feature wavelengths were selected for predicting the drip loss (590, 645, 721, 752, 803 and 850 nm) and pH (430, 448, 470, 890, 980 and 999 nm). Two feed-forward neural network models were developed. The results showed that the correlation coefficient (r) between the predicted and actual drip loss and pH were 0.71, and 0.58, respectively, by Model 1 and 0.80 for drip loss and 0.67 for pH by Model 2. The color levels of meat samples were also mapped successfully based on a digitalized Meat Color Standard.

Five years' experience in a (really) rural teleradiology practice. Was it worth it? The successes and the failures

NASA Astrophysics Data System (ADS)

Telepak, Robert J.; Freede, Emily; Jaramillo, Richard E.; Alverson, Dale C.

1998-07-01

During the past 5 years (1992 - 1997) the Department of Radiology of the University of New Mexico Health Sciences Center has developed an active teleradiology program. Contracts are in place to provide both routine and emergency image interpretations 24 hours per day, every day of the year. Several rural hospitals are served as well as the Navajo Indian Health Service. Areas of success: include significantly improved radiologic service to the rural sites, specialty consultations to general radiologists, successful teaching of teleradiology practice to radiology residents and staff, good diagnostic quality images, a small but real profit, improved quality assurance for the rural sites, and no significant medical-legal problems. Failures include: significant telecommunications problems, lack of acceptance and utilization by some of the rural sites, poor QA compliance by some sites, a long period of disappointing technical support by equipment vendors, and slow acceptance of DICOM by equipment manufacturers. The successes outweigh the failures. We would do it again -- but somewhat differently. We offer advice to institutions developing a new rural teleradiology operation.

[Establishment of a 3D finite element model of human skull using MSCT images and mimics software].

PubMed

Huang, Ping; Li, Zheng-dong; Shao, Yu; Zou, Dong-hua; Liu, Ning-guo; Li, Li; Chen, Yuan-yuan; Wan, Lei; Chen, Yi-jiu

2011-02-01

To establish a human 3D finite element skull model, and to explore its value in biomechanics analysis. The cadaveric head was scanned and then 3D skull model was created using Mimics software based on 2D CT axial images. The 3D skull model was optimized by preprocessor along with creation of the surface and volume meshes. The stress changes, after the head was struck by an object or the head hit the ground directly, were analyzed using ANSYS software. The original 3D skull model showed a large number of triangles with a poor quality and high similarity with the real head, while the optimized model showed high quality surface and volume meshes with a small number of triangles comparatively. The model could show the local and global stress changes effectively. The human 3D skull model can be established using MSCT and Mimics software and provides a good finite element model for biomechanics analysis. This model may also provide a base for the study of head stress changes following different forces.

Objective evaluation of acute adverse events and image quality of gadolinium-based contrast agents (gadobutrol and gadobenate dimeglumine) by blinded evaluation. Pilot study.

PubMed

Semelka, Richard C; Hernandes, Mateus de A; Stallings, Clifton G; Castillo, Mauricio

2013-01-01

The purpose was to objectively evaluate a recently FDA-approved gadolinium-based contrast agent (GBCA) in comparison to our standard GBCA for acute adverse events and image quality by blinded evaluation. Evaluation was made of a recently FDA-approved GBCA, gadobutrol (Gadavist; Bayer), in comparison to our standard GBCA, gadobenate dimeglumine (MultiHance; Bracco), in an IRB- and HIPAA-compliant study. Both the imaging technologist and patient were not aware of the brand of the GBCA used. A total of 59 magnetic resonance studies were evaluated (59 patients, 31 men, 28 women, age range of 5-85 years, mean age of 52 years). Twenty-nine studies were performed with gadobutrol (22 abdominal and 7 brain studies), and 30 studies were performed with gadobenate dimeglumine (22 abdominal and 8 brain studies). Assessment was made of acute adverse events focusing on objective observations of vomiting, hives, and moderate and severe reactions. Adequacy of enhancement was rated as poor, fair and good by one of two experienced radiologists who were blinded to the type of agent evaluated. No patient experienced acute adverse events with either agent. The target minor adverse events of vomiting or hives, and moderate and severe reactions were not observed in any patient. Adequacy of enhancement was rated as good for both agents in all patients. Objective, blinded evaluation is feasible and readily performable for the evaluation of GBCAs. This proof-of-concept study showed that both GBCAs evaluated exhibited consistent good image quality and no noteworthy adverse events. Copyright © 2013 Elsevier Inc. All rights reserved.

Pre-trained convolutional neural networks as feature extractors toward improved malaria parasite detection in thin blood smear images.

PubMed

Rajaraman, Sivaramakrishnan; Antani, Sameer K; Poostchi, Mahdieh; Silamut, Kamolrat; Hossain, Md A; Maude, Richard J; Jaeger, Stefan; Thoma, George R

2018-01-01

Malaria is a blood disease caused by the Plasmodium parasites transmitted through the bite of female Anopheles mosquito. Microscopists commonly examine thick and thin blood smears to diagnose disease and compute parasitemia. However, their accuracy depends on smear quality and expertise in classifying and counting parasitized and uninfected cells. Such an examination could be arduous for large-scale diagnoses resulting in poor quality. State-of-the-art image-analysis based computer-aided diagnosis (CADx) methods using machine learning (ML) techniques, applied to microscopic images of the smears using hand-engineered features demand expertise in analyzing morphological, textural, and positional variations of the region of interest (ROI). In contrast, Convolutional Neural Networks (CNN), a class of deep learning (DL) models promise highly scalable and superior results with end-to-end feature extraction and classification. Automated malaria screening using DL techniques could, therefore, serve as an effective diagnostic aid. In this study, we evaluate the performance of pre-trained CNN based DL models as feature extractors toward classifying parasitized and uninfected cells to aid in improved disease screening. We experimentally determine the optimal model layers for feature extraction from the underlying data. Statistical validation of the results demonstrates the use of pre-trained CNNs as a promising tool for feature extraction for this purpose.

Establishing Base Elements of Perspective in Order to Reconstruct Architectural Buildings from Photographs

NASA Astrophysics Data System (ADS)

Dzwierzynska, Jolanta

2017-12-01

The use of perspective images, especially historical photographs for retrieving information about presented architectural environment is a fast developing field recently. The photography image is a perspective image with secure geometrical connection with reality, therefore it is possible to reverse this process. The aim of the herby study is establishing requirements which a photographic perspective representation should meet for a reconstruction purpose, as well as determination of base elements of perspective such as a horizon line and a circle of depth, which is a key issue in any reconstruction. The starting point in the reconstruction process is geometrical analysis of the photograph, especially determination of the kind of perspective projection applied, which is defined by the building location towards a projection plane. Next, proper constructions can be used. The paper addresses the problem of establishing base elements of perspective on the basis of the photograph image in the case when camera calibration is impossible to establish. It presents different geometric construction methods selected dependently on the starting assumptions. Therefore, the methods described in the paper seem to be universal. Moreover, they can be used even in the case of poor quality photographs with poor perspective geometry. Such constructions can be realized with computer aid when the photographs are in digital form as it is presented in the paper. The accuracy of the applied methods depends on the photography image accuracy, as well as drawing accuracy, however, it is sufficient for further reconstruction. Establishing base elements of perspective presented in the paper is especially useful in difficult cases of reconstruction, when one lacks information about reconstructed architectural form and it is necessary to lean on solid geometry.

Blind image deblurring based on trained dictionary and curvelet using sparse representation

NASA Astrophysics Data System (ADS)

Feng, Liang; Huang, Qian; Xu, Tingfa; Li, Shao

2015-04-01

Motion blur is one of the most significant and common artifacts causing poor image quality in digital photography, in which many factors resulted. In imaging process, if the objects are moving quickly in the scene or the camera moves in the exposure interval, the image of the scene would blur along the direction of relative motion between the camera and the scene, e.g. camera shake, atmospheric turbulence. Recently, sparse representation model has been widely used in signal and image processing, which is an effective method to describe the natural images. In this article, a new deblurring approach based on sparse representation is proposed. An overcomplete dictionary learned from the trained image samples via the KSVD algorithm is designed to represent the latent image. The motion-blur kernel can be treated as a piece-wise smooth function in image domain, whose support is approximately a thin smooth curve, so we employed curvelet to represent the blur kernel. Both of overcomplete dictionary and curvelet system have high sparsity, which improves the robustness to the noise and more satisfies the observer's visual demand. With the two priors, we constructed restoration model of blurred images and succeeded to solve the optimization problem with the help of alternating minimization technique. The experiment results prove the method can preserve the texture of original images and suppress the ring artifacts effectively.

iPathology cockpit diagnostic station: validation according to College of American Pathologists Pathology and Laboratory Quality Center recommendation at the Hospital Trust and University of Verona.

PubMed

Brunelli, Matteo; Beccari, Serena; Colombari, Romano; Gobbo, Stefano; Giobelli, Luca; Pellegrini, Andrea; Chilosi, Marco; Lunardi, Maria; Martignoni, Guido; Scarpa, Aldo; Eccher, Albino

2014-01-01

Validation of digital whole slide images is crucial to ensure that diagnostic performance is at least equivalent to that of glass slides and light microscopy. The College of American Pathologists Pathology and Laboratory Quality Center recently developed recommendations for internal digital pathology system validation. Following these guidelines we sought to validate the performance of a digital approach for routine diagnosis by using an iPad and digital control widescreen-assisted workstation through a pilot study. From January 2014, 61 histopathological slides were scanned by ScanScope Digital Slides Scanner (Aperio, Vista, CA). Two independent pathologists performed diagnosis on virtual slides in front of a widescreen by using two computer devices (ImageScope viewing software) located to different Health Institutions (AOUI Verona) connected by local network and a remote image server using an iPad tablet (Aperio, Vista, CA), after uploading the Citrix receiver for iPad. Quality indicators related to image characters and work-flow of the e-health cockpit enterprise system were scored based on subjective (high vs poor) perception. The images were re-evaluated two weeks apart. The whole glass slides encountered 10 liver: hepatocarcinoma, 10 renal carcinoma, 10 gastric carcinoma and 10 prostate biopsies: adenocarcinoma, 5 excisional skin biopsies: melanoma, 5 lymph-nodes: lymphoma. 6 immuno- and 5 special stains were available for intra- and internet remote viewing. Scan times averaged two minutes and 54 seconds per slide (standard deviation 2 minutes 34 seconds). Megabytes ranged from 256 to 680 (mean 390) per slide storage. Reliance on glass slide, image quality (resolution and color fidelity), slide navigation time, simultaneous viewers in geographically remote locations were considered of high performance score. Side by side comparisons between diagnosis performed on tissue glass slides versus widescreen were excellent showing an almost perfect concordance (0.81, kappa index). We validated our institutional digital pathology system for routine diagnostic facing with whole slide images in a cockpit enterprise digital system or iPad tablet. Computer widescreens are better for diagnosing scanned glass slide that iPad. For urgent requests, iPad may be used. Legal aspects have to be soon faced with to permit the clinical use of this technology in a manner that does not compromise patient care.

Accelerated 4D self-gated MRI of tibiofemoral kinematics.

PubMed

Mazzoli, Valentina; Schoormans, Jasper; Froeling, Martijn; Sprengers, Andre M; Coolen, Bram F; Verdonschot, Nico; Strijkers, Gustav J; Nederveen, Aart J

2017-11-01

Anatomical (static) magnetic resonance imaging (MRI) is the most useful imaging technique for the evaluation and assessment of internal derangement of the knee, but does not provide dynamic information and does not allow the study of the interaction of the different tissues during motion. As knee pain is often only experienced during dynamic tasks, the ability to obtain four-dimensional (4D) images of the knee during motion could improve the diagnosis and provide a deeper understanding of the knee joint. In this work, we present a novel approach for dynamic, high-resolution, 4D imaging of the freely moving knee without the need for external triggering. The dominant knee of five healthy volunteers was scanned during a flexion/extension task. To evaluate the effects of non-uniform motion and poor coordination skills on the quality of the reconstructed images, we performed a comparison between fully free movement and movement instructed by a visual cue. The trigger signal for self-gating was extracted using principal component analysis (PCA), and the images were reconstructed using a parallel imaging and compressed sensing reconstruction pipeline. The reconstructed 4D movies were scored for image quality and used to derive bone kinematics through image registration. Using our method, we were able to obtain 4D high-resolution movies of the knee without the need for external triggering hardware. The movies obtained with and without instruction did not differ significantly in terms of image scoring and quantitative values for tibiofemoral kinematics. Our method showed to be robust for the extraction of the self-gating signal even for uninstructed motion. This can make the technique suitable for patients who, as a result of pain, may find it difficult to comply exactly with instructions. Furthermore, bone kinematics can be derived from accelerated MRI without the need for additional hardware for triggering. Copyright © 2017 John Wiley & Sons, Ltd.

Detection of Obstacles in Monocular Image Sequences

NASA Technical Reports Server (NTRS)

Kasturi, Rangachar; Camps, Octavia

1997-01-01

The ability to detect and locate runways/taxiways and obstacles in images captured using on-board sensors is an essential first step in the automation of low-altitude flight, landing, takeoff, and taxiing phase of aircraft navigation. Automation of these functions under different weather and lighting situations, can be facilitated by using sensors of different modalities. An aircraft-based Synthetic Vision System (SVS), with sensors of different modalities mounted on-board, complements the current ground-based systems in functions such as detection and prevention of potential runway collisions, airport surface navigation, and landing and takeoff in all weather conditions. In this report, we address the problem of detection of objects in monocular image sequences obtained from two types of sensors, a Passive Millimeter Wave (PMMW) sensor and a video camera mounted on-board a landing aircraft. Since the sensors differ in their spatial resolution, and the quality of the images obtained using these sensors is not the same, different approaches are used for detecting obstacles depending on the sensor type. These approaches are described separately in two parts of this report. The goal of the first part of the report is to develop a method for detecting runways/taxiways and objects on the runway in a sequence of images obtained from a moving PMMW sensor. Since the sensor resolution is low and the image quality is very poor, we propose a model-based approach for detecting runways/taxiways. We use the approximate runway model and the position information of the camera provided by the Global Positioning System (GPS) to define regions of interest in the image plane to search for the image features corresponding to the runway markers. Once the runway region is identified, we use histogram-based thresholding to detect obstacles on the runway and regions outside the runway. This algorithm is tested using image sequences simulated from a single real PMMW image.

Contrast Enhancement of the Right Ventricle during Coronary CT Angiography--Is It Necessary?

PubMed

Kok, Madeleine; Kietselaer, Bas L J H; Mihl, Casper; Altintas, Sibel; Nijssen, Estelle C; Wildberger, Joachim E; Das, Marco

2015-01-01

It is unclear if prolonged contrast media injection, to improve right ventricular visualization during coronary CT angiography, leads to increased detection of right ventricle pathology. The purpose of this study was to evaluate right ventricle enhancement and subsequent detection of right ventricle disease during coronary CT angiography. 472 consecutive patients referred for screening coronary CT angiography were retrospectively evaluated. Every patient underwent multidetector-row CT of the coronary arteries: 128x 0.6mm coll., 100-120kV, rot. time 0.28s, ref. mAs 350 and received an individualized (P3T) contrast bolus injection of iodinated contrast medium (300 mgI/ml). Patient data were analyzed to assess right ventricle enhancement (HU) and right ventricle pathology. Image quality was defined good when right ventricle enhancement >200HU, moderate when 140-200HU and poor when <140HU. Good image quality was found in 372 patients, moderate in 80 patients and poor in 20 patients. Mean enhancement of the right ventricle cavity was 268HU±102. Patients received an average bolus of 108±24 ml at an average peak flow rate of 6.1±2.2 ml/s. In only three out of 472 patients (0.63%) pathology of the right ventricle was found (dilatation) No other right ventricle pathology was detected. Right ventricle pathology was detected in three out of 472 patients; the dilatation observed in these three cases may have been picked up even without dedicated enhancement of the right ventricle. Based on our findings, right ventricle enhancement can be omitted during screening coronary CT angiography.

Image-Based Medical Expert Teleconsultation in Acute Care of Injuries. A Systematic Review of Effects on Information Accuracy, Diagnostic Validity, Clinical Outcome, and User Satisfaction

PubMed Central

Hasselberg, Marie; Beer, Netta; Blom, Lisa; Wallis, Lee A.; Laflamme, Lucie

2014-01-01

Objective To systematically review the literature on image-based telemedicine for medical expert consultation in acute care of injuries, considering system, user, and clinical aspects. Design Systematic review of peer-reviewed journal articles. Data sources Searches of five databases and in eligible articles, relevant reviews, and specialized peer-reviewed journals. Eligibility criteria Studies were included that covered teleconsultation systems based on image capture and transfer with the objective of seeking medical expertise for the diagnostic and treatment of acute injury care and that presented the evaluation of one or several aspects of the system based on empirical data. Studies of systems not under routine practice or including real-time interactive video conferencing were excluded. Method The procedures used in this review followed the PRISMA Statement. Predefined criteria were used for the assessment of the risk of bias. The DeLone and McLean Information System Success Model was used as a framework to synthesise the results according to system quality, user satisfaction, information quality and net benefits. All data extractions were done by at least two reviewers independently. Results Out of 331 articles, 24 were found eligible. Diagnostic validity and management outcomes were often studied; fewer studies focused on system quality and user satisfaction. Most systems were evaluated at a feasibility stage or during small-scale pilot testing. Although the results of the evaluations were generally positive, biases in the methodology of evaluation were concerning selection, performance and exclusion. Gold standards and statistical tests were not always used when assessing diagnostic validity and patient management. Conclusions Image-based telemedicine systems for injury emergency care tend to support valid diagnosis and influence patient management. The evidence relates to a few clinical fields, and has substantial methodological shortcomings. As in the case of telemedicine in general, user and system quality aspects are poorly documented, both of which affect scale up of such programs. PMID:24887257

Feasibility and effects of TAI CHI for the promotion of sleep quality and quality of life: a single-group study in a sample of older Chinese individuals in Hong Kong.

PubMed

Lo, Catherine Mei-Han; Lee, Paul H

2014-03-01

Poor sleep in later life is a global issue that reduces many individuals' quality of life (QOL). The purpose of this pilot study was to test the feasibility and effects of a simplified tai chi exercise intervention on sleep quality and QOL among Chinese community-dwelling older adults with poor sleep quality. This single-group, descriptive feasibility study included 34 individuals with poor sleep quality who agreed to participate in a 12-week tai chi intervention. Twenty-six individuals completed the program (23.5% dropout rate). Older adults with poor sleep quality who completed the intervention showed significant improvement in the Medical Outcomes Study Short Form-36 mental component and the Pittsburgh Sleep Quality Index global and component scores. The low recruitment and attendance and high dropout rates might be associated with participants' age, gender, and sleep quality. Further long-term studies are required to examine the potential effects of the tai chi intervention. [Journal of Gerontological Nursing, 40(3), 46-52.]. Copyright 2014, SLACK Incorporated.

Poor sleep quality is independently associated with physical disability in older adults.

PubMed

Chien, Meng-Yueh; Chen, Hsi-Chung

2015-03-15

We aimed to evaluate the association between sleep quality and physical disability in community-dwelling older adults. There were 213 community-dwelling adults (76 men and 137 women) aged 65 years and above participated into this investigation. The Groningen Activity Restriction Scale and the Pittsburgh Sleep Quality Index were utilized to evaluate physical disability and subjective sleep quality, respectively. Global functional capacity was measured by the 6-minute walk test (6MWT). The Mini Mental State Examination and the Chinese Geriatric Depression Screening Scale were used to evaluate cognitive function and depression. Univariate analysis revealed a correlation between physical disability and poor sleep quality, older age, 2 or more comorbidities, depression, functional capacity, and poor cognitive function. However, in the multivariate analyses, depression failed to show significant association with physical disability. In contrast, an independent association was observed between poor sleep quality and physical disability (OR = 2.03; 95% CI: 1.02-4.05). In community-dwelling older adults, subjective poor sleep was significantly associated with physical disability, even after controlling for the effects of other established risk factors. © 2014 American Academy of Sleep Medicine.

Prevalence and risk factors of poor sleep quality among Inner Mongolia Medical University students: A cross-sectional survey.

PubMed

Wang, Lan; Qin, Peng; Zhao, Yunshan; Duan, Shengyun; Zhang, Qing; Liu, Ying; Hu, Yueling; Sun, Juan

2016-10-30

Medical students face new challenges at the beginning of college life, such as being responsible for oneself, an unfamiliar environment, social obligations, and academic stress, all of which influence or even heavily change their sleep quality and life, leading to sleep-related problems to some degree. This study investigated the relationship between sleep quality and behavior among students at the Inner Mongolia Medical University in China. Self-administered questionnaires were used to collect information on sociodemographic characteristics and lifestyle habits. The Pittsburgh Sleep Quality Index was also used. A total of 6044 and 6085 students completed the questionnaires in 2011 and 2013. According to the index, 27.8% (1694) of students had poor sleep quality with major risk factors being poor academic performance and interpersonal relationships in 2013. Among others, regular exercise less than three times a week, skipping breakfast, and studying in higher grades were associated with poor sleep quality. These results will help university administrators understand the risk factors of poor sleep quality among students, which can be improved through individual efforts, and provide adequate counseling and systematic education to improve their behavior and lifestyle. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Evaluation of sleep quality in subjects with chronic nononcologic pain.

PubMed

Covarrubias-Gomez, Alfredo; Mendoza-Reyes, Jonathan J

2013-08-01

A survey conducted by the National Sleep Foundation found that 20% of Americans have sleep disorders and 45% experience chronic pain. Several authors evaluated the interrelationship between these functions using various instruments such the Pittsburgh Sleep Quality Index (PSQI) and identified that 34% of subjects in the general population have a poor quality of sleep, but there are few studies that assess the quality of sleep in patients with chronic pain of nonmalignant origin. We undertook this study to evaluate the quality of sleep using the PSQI in patients with chronic pain unrelated to cancer. We conducted a clinical, nonrandomized, uncontrolled, descriptive, and prospective study, applying the PSQI through a direct one-time interview to 311 subjects with chronic pain unrelated to cancer. According to the categorization of the PSQI between good and poor sleepers, 89% of the subjects were poor sleepers (n = 276). There are significant differences in pain intensity according to the categorization of the PSQI, with a higher intensity shown in the "poor sleepers" (analysis of variance [ANOVA], P = .030). Using a linear regression model to estimate the curve, a higher score is rated on the PSQI global score (ANOVA, P = .000, R(2) = .46) with the increase of the intensity of the pain. We conclude that "poor sleepers" or those who considered their sleep as "poor quality" have significantly higher pain intensity. This suggests that intensity of pain plays a role in evaluating the quality of sleep in the subjective perception of sleep and instruments that assess quality.

Urban area thermal monitoring: Liepaja case study using satellite and aerial thermal data

NASA Astrophysics Data System (ADS)

Gulbe, Linda; Caune, Vairis; Korats, Gundars

2017-12-01

The aim of this study is to explore large (60 m/pixel) and small scale (individual building level) temperature distribution patterns from thermal remote sensing data and to conclude what kind of information could be extracted from thermal remote sensing on regular basis. Landsat program provides frequent large scale thermal images useful for analysis of city temperature patterns. During the study correlation between temperature patterns and vegetation content based on NDVI and building coverage based on OpenStreetMap data was studied. Landsat based temperature patterns were independent from the season, negatively correlated with vegetation content and positively correlated with building coverage. Small scale analysis included spatial and raster descriptor analysis for polygons corresponding to roofs of individual buildings for evaluating insulation of roofs. Remote sensing and spatial descriptors are poorly related to heat consumption data, however, thermal aerial data median and entropy can help to identify poorly insulated roofs. Automated quantitative roof analysis has high potential for acquiring city wide information about roof insulation, but quality is limited by reference data quality and information on building types, and roof materials would be crucial for further studies.

Challenges in the management of glaucoma in developing countries.

PubMed

Butt, Nadeem Hafeez; Ayub, Muhammad Hammad; Ali, Muhammad Hassaan

2016-01-01

Glaucoma is the most common optic neuropathy characterized by normal to raised intraocular pressure (IOP), visual field defects, loss of retinal nerve fiber layer, thinning of the neuroretinal rim, and cupping of the optic disc. IOP reduction by medical, laser, or surgical therapies remains the only clinically proven treatment of glaucoma. The challenges in glaucoma management are diverse. They include early detection and diagnosis, setting of appropriate target IOP, choice of treatment, monitoring of quality of life and sight, and compliance with the treatment. Early diagnosis can be made by assessing optic nerve structure using imaging devices and optic nerve function through perimetry. Reducing IOP and controlling its fluctuations are considered to be the most important factors in limiting progression of glaucoma. Selection of the best suitable therapy out of medical, surgical, or laser treatment options is yet another management challenge. Patients suffering from glaucoma experience poor quality of life owing to the diagnosis itself, functional visual loss, inconvenience and cost of treatment, and side effects of treatment. All these factors lead to poor compliance, adherence, and persistence to treatment, and further progression of the disease. It is, therefore, important that ophthalmologists keep all the aforementioned factors in mind when managing patients with glaucoma.

What Constitutes Poor Teaching? A Preliminary Inquiry into the Misbehaviors of Not-So-Good Instructors

ERIC Educational Resources Information Center

Busler, Jessica; Kirk, Claire; Keeley, Jared; Buskist, William

2017-01-01

Across three phases, we investigated college students' perceptions of poor college teaching to develop a typology of poor teaching behaviors. In Phase 1, students generated a list of qualities representative of poor teaching. In Phase 2, another group of students assigned behavioral correspondents to these qualities, resulting in a list of 15 poor…

Combating poor-quality anti-malarial medicines: a call to action.

PubMed

Bassat, Quique; Tanner, Marcel; Guerin, Philippe J; Stricker, Kirstin; Hamed, Kamal

2016-06-01

The circulation of poor-quality medicines continues to undermine the fight against many life-threatening diseases. Anti-malarial medicines appear to have been particularly compromised and present a major public health threat in malaria-endemic countries, negatively affecting individuals and their communities. Concerted collaborative efforts are required from global, regional and national organizations, involving the public and private sectors, to address the problem. While many initiatives are underway, a number of unmet needs deserve urgent and increased multisector attention. At the global level, there is a need for an international public health legal framework or treaty on poor-quality medicines, with statutes suitable for integration into national laws. In addition, increased international efforts are required to strengthen the governance of global supply chains and enhance cooperation between national medicine regulation authorities and law enforcement bodies. Increased investment is needed in innovative technologies that will enable healthcare teams to detect poor-quality medicines at all levels of the supply chain. At the regional level, a number of initiatives would be beneficial-key areas are standardization, simplification, and reciprocal recognition of registration processes and development of quality control capacity in regional centres of excellence that are better aligned with public health needs; improved surveillance methods and creation of a framework for compulsory and transparent reporting of poor-quality medicines; additional support for national medicine regulation authorities and other national partner authorities; and an increase in support for regional laboratories to boost their capabilities in detecting poor-quality medicines. It is vital that all stakeholders involved in efforts against poor-quality anti-malarial medicines extend and strengthen their actions in these critical areas and thus effectively support global health development and malaria elimination programmes.

Simultaneous dual-radionuclide myocardial perfusion imaging with a solid-state dedicated cardiac camera.

PubMed

Ben-Haim, Simona; Kacperski, Krzysztof; Hain, Sharon; Van Gramberg, Dean; Hutton, Brian F; Erlandsson, Kjell; Sharir, Tali; Roth, Nathaniel; Waddington, Wendy A; Berman, Daniel S; Ell, Peter J

2010-08-01

We compared simultaneous dual-radionuclide (DR) stress and rest myocardial perfusion imaging (MPI) with a novel solid-state cardiac camera and a conventional SPECT camera with separate stress and rest acquisitions. Of 27 consecutive patients recruited, 24 (64.5+/-11.8 years of age, 16 men) were injected with 74 MBq of (201)Tl (rest) and 250 MBq (99m)Tc-MIBI (stress). Conventional MPI acquisition times for stress and rest are 21 min and 16 min, respectively. Rest (201)Tl for 6 min and simultaneous DR 15-min list mode gated scans were performed on a D-SPECT cardiac scanner. In 11 patients DR D-SPECT was performed first and in 13 patients conventional stress (99m)Tc-MIBI SPECT imaging was performed followed by DR D-SPECT. The DR D-SPECT data were processed using a spill-over and scatter correction method. DR D-SPECT images were compared with rest (201)Tl D-SPECT and with conventional SPECT images by visual analysis employing the 17-segment model and a five-point scale (0 normal, 4 absent) to calculate the summed stress and rest scores. Image quality was assessed on a four-point scale (1 poor, 4 very good) and gut activity was assessed on a four-point scale (0 none, 3 high). Conventional MPI studies were abnormal at stress in 17 patients and at rest in 9 patients. In the 17 abnormal stress studies DR D-SPECT MPI showed 113 abnormal segments and conventional MPI showed 93 abnormal segments. In the nine abnormal rest studies DR D-SPECT showed 45 abnormal segments and conventional MPI showed 48 abnormal segments. The summed stress and rest scores on conventional SPECT and DR D-SPECT were highly correlated (r=0.9790 and 0.9694, respectively). The summed scores of rest (201)Tl D-SPECT and DR-DSPECT were also highly correlated (r=0.9968, p<0.0001 for all). In six patients stress perfusion defects were significantly larger on stress DR D-SPECT images, and five of these patients were imaged earlier by D-SPECT than by conventional SPECT. Fast and high-quality simultaneous DR MPI is feasible with D-SPECT in a single imaging session with comparable diagnostic performance and image quality to conventional SPECT and to a separate rest (201)Tl D-SPECT acquisition.

Sleep quality and correlates of poor sleep in patients with rheumatoid arthritis.

PubMed

Løppenthin, K; Esbensen, B A; Jennum, P; Østergaard, M; Tolver, A; Thomsen, T; Midtgaard, J

2015-12-01

The objective of this study is to examine sleep quality and correlates of poor sleep in patients with rheumatoid arthritis (RA). Five hundred patients with RA were recruited from a rheumatology outpatient clinic and included in this cross-sectional study. Sleep quality and disturbances were assessed using the Pittsburgh Sleep Quality Index (PSQI). Other instruments included the Multidimensional Fatigue Inventory, the Epworth Sleepiness Scale, and the Health Assessment Questionnaire. Disease activity was assessed according to disease activity score DAS28-CRP-based. Complete scores on PSQI were obtained from 384 patients (77 %). In those, the prevalence of poor sleep (PSQI >5) was 61 %, and the mean global PSQI score was 7.54 (SD 4.17). A linear association was found between poor sleep and mental fatigue, reduced activity related to fatigue, physical fatigue, and general fatigue. Mental fatigue and general fatigue were independently associated with sleep quality, sleep latency, sleep duration, sleep efficiency, and daytime dysfunction. However, in the linear multivariate analysis, only general fatigue 1.06 (95 % CI 1.03-1.09) and mental fatigue 1.03 (95 % CI 1.01-1.05) were found to be significant correlates for reporting poor sleep. This study shows that a majority of patients with RA experience poor sleep and that general fatigue and mental fatigue are associated with poor sleep.

How do women with chronic fatigue syndrome/myalgic encephalomyelitis rate quality and coordination of healthcare services? A cross-sectional study.

PubMed

Hansen, Anne Helen; Lian, Olaug S

2016-04-04

To test the association between self-rated health and self-rated degree of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), and CFS/ME patients' assessment of quality of primary care, specialist care and coordination of care. Cross-sectional study. Self-reported questionnaire data from women members of The Norwegian ME Association obtained in 2013. 431 women with CFS/ME aged 16-73 years. The participants' assessment of quality in primary care, specialist care and in coordination of care (good/very good or poor/very poor). Main explanatory variables: self-rated health and self-rated degree of CFS/ME. Quality of care was rated poor by 60.6% in primary care, by 47.7% in specialist care, and by 71.2% regarding coordination of care. Poorer self-rated health increased the probability of rating quality in primary care poor, particularly among women 40 years and over (OR 2.38, 95% CI 1.63 to 3.49), women with university education (OR 2.57, CI 1.68 to 3.94), and owing to less frequent general practitioner (GP) visits (OR 2.46, CI 1.60 to 3.78). Poorer self-rated health increased the probability of rating quality poor in specialist care (OR 1.38, CI 1.05 to 1.82), but not in coordination of care. A more severe CFS/ME was associated with a higher probability of rating quality in primary care poor (OR 0.61, CI 0.38 to 0.93). Frequent visitors and those with a long GP relationship were less likely to report primary care quality as poor. A large proportion of women with CFS/ME rated quality of care poor/very poor in primary care, specialist care and in coordination of care. The dissatisfaction was higher for primary care than for specialist care. Overall, poorer self-rated health and a more severe CFS/ME were associated with lower quality scores in primary and specialist care, but not in coordination of care. Healthcare services, as assessed by women with CFS/ME, do have a large potential for improvement. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Poor self-reported sleep quality and health-related quality of life in patients with chronic fatigue syndrome/myalgic encephalomyelitis.

PubMed

Castro-Marrero, Jesús; Zaragozá, Maria C; González-Garcia, Sergio; Aliste, Luisa; Sáez-Francàs, Naia; Romero, Odile; Ferré, Alex; Fernández de Sevilla, Tomás; Alegre, José

2018-05-16

Non-restorative sleep is a hallmark symptom of chronic fatigue syndrome/myalgic encephalomyelitis. However, little is known about self-reported sleep disturbances in these subjects. This study aimed to assess the self-reported sleep quality and its impact on quality of life in a Spanish community-based chronic fatigue syndrome/myalgic encephalomyelitis cohort. A prospective cross-sectional cohort study was conducted in 1,455 Spanish chronic fatigue syndrome/myalgic encephalomyelitis patients. Sleep quality, fatigue, pain, functional capacity impairment, psychopathological status, anxiety/depression and health-related quality of life were assessed using validated subjective measures. The frequencies of muscular, cognitive, neurological, autonomic and immunological symptom clusters were above 80%. High scores were recorded for pain, fatigue, psychopathological status, anxiety/depression, and low scores for functional capacity and quality of life, all of which correlated significantly (all p < 0.01) with quality of sleep as measured by the Pittsburgh Sleep Quality Index. Multivariate regression analysis showed that after adjusting for age and gender, the pain intensity (odds ratio, 1.11; p <0.05), psychopathological status (odds ratio, 1.85; p < 0.001), fibromyalgia (odds ratio, 1.39; p < 0.05), severe autonomic dysfunction (odds ratio, 1.72; p < 0.05), poor functional capacity (odds ratio, 0.98; p < 0.05) and quality of life (odds ratio, 0.96; both p < 0.001) were significantly associated with poor sleep quality. These findings suggest that this large chronic fatigue syndrome/myalgic encephalomyelitis sample presents poor sleep quality, as assessed by the Pittsburgh Sleep Quality Index, and that this poor sleep quality is associated with many aspects of quality of life. © 2018 European Sleep Research Society.

Mind wandering, sleep quality, affect and chronotype: an exploratory study.

PubMed

Carciofo, Richard; Du, Feng; Song, Nan; Zhang, Kan

2014-01-01

Poor sleep quality impairs cognition, including executive functions and concentration, but there has been little direct research on the relationships between sleep quality and mind wandering or daydreaming. Evening chronotype is associated with poor sleep quality, more mind wandering and more daydreaming; negative affect is also a mutual correlate. This exploratory study investigated how mind wandering and daydreaming are related to different aspects of sleep quality, and whether sleep quality influences the relationships between mind wandering/daydreaming and negative affect, and mind wandering/daydreaming and chronotype. Three surveys (Ns = 213; 190; 270) were completed with Chinese adults aged 18-50, including measures of sleep quality, daytime sleepiness, mind wandering, daydreaming, chronotype and affect (positive and negative). Higher frequencies of mind wandering and daydreaming were associated with poorer sleep quality, in particular with poor subjective sleep quality and increased sleep latency, night-time disturbance, daytime dysfunction and daytime sleepiness. Poor sleep quality was found to partially mediate the relationships between daydreaming and negative affect, and mind wandering and negative affect. Additionally, low positive affect and poor sleep quality, in conjunction, fully mediated the relationships between chronotype and mind wandering, and chronotype and daydreaming. The relationships between mind wandering/daydreaming and positive affect were also moderated by chronotype, being weaker in those with a morning preference. Finally, while daytime sleepiness was positively correlated with daydream frequency, it was negatively correlated with a measure of problem-solving daydreams, indicating that more refined distinctions between different forms of daydreaming or mind wandering are warranted. Overall, the evidence is suggestive of a bi-directional relationship between poor sleep quality and mind wandering/daydreaming, which may be important in attempts to deal with sleep problems and improve sleep quality. These findings and further research on this topic may also have implications for definitions and theories of mind wandering and daydreaming.

Mind Wandering, Sleep Quality, Affect and Chronotype: An Exploratory Study

PubMed Central

Carciofo, Richard; Du, Feng; Song, Nan; Zhang, Kan

2014-01-01

Poor sleep quality impairs cognition, including executive functions and concentration, but there has been little direct research on the relationships between sleep quality and mind wandering or daydreaming. Evening chronotype is associated with poor sleep quality, more mind wandering and more daydreaming; negative affect is also a mutual correlate. This exploratory study investigated how mind wandering and daydreaming are related to different aspects of sleep quality, and whether sleep quality influences the relationships between mind wandering/daydreaming and negative affect, and mind wandering/daydreaming and chronotype. Three surveys (Ns = 213; 190; 270) were completed with Chinese adults aged 18–50, including measures of sleep quality, daytime sleepiness, mind wandering, daydreaming, chronotype and affect (positive and negative). Higher frequencies of mind wandering and daydreaming were associated with poorer sleep quality, in particular with poor subjective sleep quality and increased sleep latency, night-time disturbance, daytime dysfunction and daytime sleepiness. Poor sleep quality was found to partially mediate the relationships between daydreaming and negative affect, and mind wandering and negative affect. Additionally, low positive affect and poor sleep quality, in conjunction, fully mediated the relationships between chronotype and mind wandering, and chronotype and daydreaming. The relationships between mind wandering/daydreaming and positive affect were also moderated by chronotype, being weaker in those with a morning preference. Finally, while daytime sleepiness was positively correlated with daydream frequency, it was negatively correlated with a measure of problem-solving daydreams, indicating that more refined distinctions between different forms of daydreaming or mind wandering are warranted. Overall, the evidence is suggestive of a bi-directional relationship between poor sleep quality and mind wandering/daydreaming, which may be important in attempts to deal with sleep problems and improve sleep quality. These findings and further research on this topic may also have implications for definitions and theories of mind wandering and daydreaming. PMID:24609107

Balancing Radiation and Contrast Media Dose in Single-Pass Abdominal Multidetector CT: Prospective Evaluation of Image Quality.

PubMed

Camera, Luigi; Romano, Federica; Liccardo, Immacolata; Liuzzi, Raffaele; Imbriaco, Massimo; Mainenti, Pier Paolo; Pizzuti, Laura Micol; Segreto, Sabrina; Maurea, Simone; Brunetti, Arturo

2015-11-01

As both contrast and radiation dose affect the quality of CT images, a constant image quality in abdominal contrast-enhanced multidetector computed tomography (CE-MDCT) could be obtained balancing radiation and contrast media dose according to the age of the patients. Seventy-two (38 Men; 34 women; aged 20-83 years) patients underwent a single-pass abdominal CE-MDCT. Patients were divided into three different age groups: A (20-44 years); B (45-65 years); and C (>65 years). For each group, a different noise index (NI) and contrast media dose (370 mgI/mL) was selected as follows: A (NI, 15; 2.5 mL/kg), B (NI, 12.5; 2 mL/kg), and C (NI, 10; 1.5 mL/kg). Radiation exposure was reported as dose-length product (DLP) in mGy × cm. For quantitative analysis, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated for both the liver (L) and the abdominal aorta (A). Statistical analysis was performed with a one-way analysis of variance. Standard imaging criteria were used for qualitative analysis. Although peak hepatic enhancement was 152 ± 16, 128 ± 12, and 101 ± 14 Hounsfield units (P < .001) for groups A, B, and C, respectively, no significant differences were observed in the corresponding SNRL with 9.2 ± 1.4, 9.1 ± 1.2, and 9.2 ± 3. Radiation (mGy × cm) and contrast media dose (mL) administered were 476 ± 147 and 155 ± 27 for group A, 926 ± 291 and 130 ± 16 for group B, and 1981 ± 451 and 106 ± 15 for group C, respectively (P < .001). None of the studies was graded as poor or inadequate by both readers, and the prevalence-adjusted bias-adjusted kappa ranged between 0.48 and 0.93 for all but one criteria. A constant image quality in CE-MDCT can be obtained balancing radiation and contrast media dose administered to patients of different age. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

Endoscopic ultrasound (EUS) guided fine needle biopsy (FNB) with the Procore™ needle provides inadequate material for the histological diagnosis of early chronic pancreatitis.

PubMed

Iglesias García, Julio; Lariño-Noia, José; Abdulkader Nallib, Ihab; Lindkvist, Björn; Domínguez-Muñoz, J Enrique

2018-05-03

diagnosis of early chronic pancreatitis (CP) is hampered due to the low accuracy of current imaging techniques and the absence of methods for histological confirmation. We aimed to evaluate the efficacy of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for the histological diagnosis of early CP. a prospective, cross-sectional, single-center study was designed. Consecutive patients referred for EUS with a clinical suspicion of CP were evaluated for inclusion into the study. Inclusion criteria were age > 18 years and indeterminate EUS findings for the diagnosis of CP according to the Rosemont classification. EUS-FNB of the body of the pancreas was performed with Procore™ needles. Tissue samples were immersed into a methanol-based buffered preservative solution for cytohistological evaluation. The quality of the samples obtained and the histological findings were evaluated. Procedure-related complications were recorded. the study was stopped after eleven patients were included due to safety concerns and poor diagnostic yield. The mean age of the patients was 50.3 years (range 33-70 years) and six were male. Samples were of poor quality in five cases, but were sufficient for cell-block evaluation. An inflammatory infiltration with mild fibrosis was identified in two cases and neither inflammatory infiltration nor fibrosis was identified in three cases. With regard to the other six cases, isolated inflammatory cells were observed in one case, although the cellularity was poor and unsuitable for cytological evaluation in five cases. There was one major complication (9.1%) of acute pancreatitis that required hospitalization for 48 hours. EUS-FNB is technically feasible in patients with EUS findings categorized as indeterminate for a CP diagnosis. However, the diagnostic yield is poor and there is a non-negligible risk of complications.

The indoor air we breathe.

PubMed Central

Oliver, L C; Shackleton, B W

1998-01-01

Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions. Images p398-a p399-a PMID:9769764

Thalassaemia: a study on the perception of patients and family members.

PubMed

Wahab, I Abdul; Naznin, M; Nora, M Z; Suzanah, A R; Zulaiho, M; Faszrul, A R Aidl; Kamaruzaman, W S

2011-10-01

Marked improvement in the management of thalassaemia has not been matched by progress in psychosocial rehabilitation as thalassaemia continues to pose challenges to patients and their family members. Few studies have been carried out in Malaysia to look at such issues. This study is therefore to explore the concerns, beliefs and feelings about thalassaemia. It was conducted in the year 2009 over 7 months on "focus groups", in patients aged 8-22 years and parents attending Paediatric Clinic of Tengku Ampuan Afzan Hospital, Kuantan, Pahang. Results showed that concerns and adverse impact were related to lower grades in education, poor self-image, less chance of employment, marriage, financial burden and social integration. Compliance to subcutaneous iron chelator was poor. There were various concerns related to blood transfusion therapy. It is evident that thalassaemia greatly affects the psychosocial dimensions and a more structured long term psychosocial support is needed to improve quality of life of patients.

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

PubMed

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 processing can significantly impact image quality when settings are left near default values.

Common MRI acquisition non-idealities significantly impact the output of the boundary shift integral method of measuring brain atrophy on serial MRI.

PubMed

Preboske, Gregory M; Gunter, Jeff L; Ward, Chadwick P; Jack, Clifford R

2006-05-01

Measuring rates of brain atrophy from serial magnetic resonance imaging (MRI) studies is an attractive way to assess disease progression in neurodegenerative disorders, particularly Alzheimer's disease (AD). A widely recognized approach is the boundary shift integral (BSI). The objective of this study was to evaluate how several common scan non-idealities affect the output of the BSI algorithm. We created three types of image non-idealities between the image volumes in a serial pair used to measure between-scan change: inconsistent image contrast between serial scans, head motion, and poor signal-to-noise (SNR). In theory the BSI volume difference measured between each pair of images should be zero and any deviation from zero should represent corruption of the BSI measurement by some non-ideality intentionally introduced into the second scan in the pair. Two different BSI measures were evaluated, whole brain and ventricle. As the severity of motion, noise, and non-congruent image contrast increased in the second scan, the calculated BSI values deviated progressively more from the expected value of zero. This study illustrates the magnitude of the error in measures of change in brain and ventricle volume across serial MRI scans that can result from commonly encountered deviations from ideal image quality. The magnitudes of some of the measurement errors seen in this study exceed the disease effect in AD shown in various publications, which range from 1% to 2.78% per year for whole brain atrophy and 5.4% to 13.8% per year for ventricle expansion (Table 1). For example, measurement error may exceed 100% if image contrast properties dramatically differ between the two scans in a measurement pair. Methods to maximize consistency of image quality over time are an essential component of any quantitative serial MRI study.

Quality of Life of Nepalese Women Post Mastectomy

PubMed

Maharjan, Muna; Thapa, Niresh; Adhikari, Raj Devi; Petrini, Marcia A; Amatya, Kapendra Shekhar

2018-04-25

Introduction: Worldwide breast cancer is the common invasive cancer among the females. The quality of life of women after treatment, which is often a mastectomy, is frequently decreased. Objective: To determine the life quality of Nepalese women post mastectomy. Materials and Methods: One hundred seven women after a mastectomy were selected and interviewed by using the European Organization for Research and Treatment of Cancer-Quality of Life Questionnaire and its Breast Specific Module to assess women’s quality of life. Result: The study findings revealed a good score on global health status/quality of life. The respondents performed well on functional and symptom scales. In the Breast Specific Module, all respondents performed poor regarding sexual function and sexual enjoyment. Global Health Status was found useful among the women involved in service/business/agriculture and the survivors using breast prosthesis. In Breast Specific Module, systemic therapy side effects showed strong statistical associations with age, marital status, occupation, education, use of breast prosthesis and co-morbidity. Body image was highly significant with age, occupation, education, use of breast prosthesis and co-morbidity. Conclusion: Based on the study findings, counseling, and a structured educational programme is recommended to improve the QOL of women after a mastectomy. Creative Commons Attribution License

Quality of life of people with mental health problems: a synthesis of qualitative research

PubMed Central

2012-01-01

Purpose To identify the domains of quality of life important to people with mental health problems. Method A systematic review of qualitative research undertaken with people with mental health problems using a framework synthesis. Results We identified six domains: well-being and ill-being; control, autonomy and choice; self-perception; belonging; activity; and hope and hopelessness. Firstly, symptoms or ‘ill-being’ were an intrinsic aspect of quality of life for people with severe mental health problems. Additionally, a good quality of life was characterised by the feeling of being in control (particularly of distressing symptoms), autonomy and choice; a positive self-image; a sense of belonging; engagement in meaningful and enjoyable activities; and feelings of hope and optimism. Conversely, a poor quality life, often experienced by those with severe mental health difficulties, was characterized by feelings of distress; lack of control, choice and autonomy; low self-esteem and confidence; a sense of not being part of society; diminished activity; and a sense of hopelessness and demoralization. Conclusions Generic measures fail to address the complexity of quality of life measurement and the broad range of domains important to people with mental health problems. PMID:23173689

Red and far-red fluorescent dyes for the characterization of head and neck cancer at the cellular level.

PubMed

Abbaci, Muriel; Casiraghi, Odile; Temam, Stephane; Ferchiou, Malek; Bosq, Jacques; Dartigues, Peggy; De Leeuw, Frederic; Breuskin, Ingrid; Laplace-Builhé, Corinne

2015-11-01

Primary upper aerodigestive tract malignancy remains a cancer having a poor prognosis, despite current progress in treatment, due to a generally late diagnosis. We conducted a preliminary assessment of five dyes approved for human use for the imaging of head and neck tissues at the cellular level, which could be considered for clinical examination. We investigated fluorescence endomicroscopic images on fresh samples obtained from head and neck surgeries after staining with hypericin, methylene blue, toluidine blue, patent blue or indocyanine green to provide a preliminary consideration as to whether these images contain enough information for identification of non-pathologic and pathologic tissues. The distribution pattern of dye has been examined using probe-based confocal laser endomicroscopy (pCLE) in ex vivo specimens and compared with corresponding histology. In most samples, the image quality provided by pCLE with both dyes allowed pathologists to recognize histological characteristics to identify the tissues. The combination of pCLE imaging with these dyes provides interpretable images close to conventional histology; a promising clinical tool to assist physicians in examination of upper aerodigestive tract, as long as depth imaging issues can be overcome. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Concept of a selective tumour therapy and its evaluation by near-infrared fluorescence imaging and flat-panel volume computed tomography in mice.

PubMed

Alves, Frauke; Dullin, Christian; Napp, Joanna; Missbach-Guentner, Jeannine; Jannasch, Katharina; Mathejczyk, Julia; Pardo, Luis A; Stühmer, Walter; Tietze, Lutz-F

2009-05-01

Conventional chemotherapy of cancer has its limitations, especially in advanced and disseminated disease and suffers from lack of specificity. This results in a poor therapeutic index and considerable toxicity to normal organs. Therefore, many efforts are made to develop novel therapeutic tools against cancer with the aim of selectively targeting the drug to the tumour site. Drug delivery strategies fundamentally rely on the identification of good-quality biomarkers, allowing unequivocal discrimination between cancer and healthy tissue. At present, antibodies or antibody fragments have clearly proven their value as carrier molecules specific for a tumour-associated molecular marker. This present review draws attention to the use of near-infrared fluorescence (NIRF) imaging to investigate binding specificity and kinetics of carrier molecules such as monoclonal antibodies. In addition, flat-panel volume computed tomography (fpVCT) will be presented to monitor anatomical structures in tumour mouse models over time in a non-invasive manner. Each imaging device sheds light on a different aspect; functional imaging is applied to optimise the dose schedule and the concept of selective tumour therapies, whereas anatomical imaging assesses preclinically the efficacy of novel tumour therapies. Both imaging techniques in combination allow the visualisation of functional information obtained by NIRF imaging within an adequate anatomic framework.

The maladies of water and war: addressing poor water quality in Iraq.

PubMed

Zolnikov, Tara Rava

2013-06-01

Water is essential in providing nutrients, but contaminated water contributes to poor population health. Water quality and availability can change in unstructured situations, such as war. To develop a practical strategy to address poor water quality resulting from intermittent wars in Iraq, I reviewed information from academic sources regarding waterborne diseases, conflict and war, water quality treatment, and malnutrition. The prevalence of disease was high in impoverished, malnourished populations exposed to contaminated water sources. The data aided in developing a strategy to improve water quality in Iraq, which encompasses remineralized water from desalination plants, health care reform, monitoring and evaluation systems, and educational public health interventions.

Will Public Pre-K Really Close Achievement Gaps? Gaps in Prekindergarten Quality between Students and across States

ERIC Educational Resources Information Center

Valentino, Rachel

2018-01-01

Publicly funded pre-K is often touted as a means to narrow achievement gaps, but this goal is less likely to be achieved if poor and/or minority children do not, at a minimum, attend equal quality pre-K as their non-poor, non-minority peers. In this paper, I find large "quality gaps" in public pre-K between poor, minority students and…

Cusiana trend exploration, Llanos foothills, Colombia - The opening of a new hydrocarbon province

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayward, A.B.; Addison, F.T.; O`Leary, J.

1996-08-01

The discovery of the Cusiana field in 1992 followed 30 years of exploration in the Llanos fold and thrust belt of Colombia. Early exploration activity focused on large surface anticlines that were all fresh water flushed - a consequence of along strike exposure of the reservoir rocks. The potential for deeper, subthrust, trapping geometries was recognized in the early 1970s however, exploration at the time was hindered by very poor quality seismic data and significant drilling difficulties. The 1980s exploration effort was characterized by continued poor quality seismic data and drilling difficulties combined with a geological perception that there wasmore » no effective reservoir and the majority of the structures post dated the major period of hydrocarbon generation and migration. The Cusiana discovery with a gross hydrocarbon column in excess of 1500{prime} reservoired within the Mirador (Eocene), Barco (Palaeocene) and Guadalupe (Upper Cretaceous) Formations in a large thrust anticline demonstrated the presence of a working hydrocarbon system. Subsequent exploration of the trend to the north has resulted in the discovery of four further giant oil and gas fields, Cupiagua (500 MMBBLs, 1-2 tcf) and the Florena/Pauto/Volcanera complex with estimated reserves of 1 billion barrels and 10 tcf. Key to this success has been the seismic imaging of the trapping geometries resulting from a significant improvement in the quality of the seismic data - a consequence of improvements in both acquisition and processing technology, combined with a recognition that pure quartz arenites retain reservoir quality at significant depths of burial-and that despite original depths of burial of greater than 18,000 ft, reservoir quality was not a major risk for further exploration success.« less

Impact of the introduction of emergency ultrasound to one large UK emergency department: the REBUS study.

PubMed

Kwok, T'ng Choong; Johnson, Sue; Reed, Matthew James

2013-02-01

Firstly, to detail the experiences of one UK training region in establishing an emergency ultrasound (EU) training programme and secondly, to report the initial 30 months of EU scanning experience. Prospective study of all documented emergency department (ED) ultrasound scans. Results were extracted from written paper reports and/or electronically saved images. Details of scan date, time, type of scan, grade of operator, supervision status (whether supervised by a level 1 competent scanner) and whether the scan was clinical (performed or supervised by a level 1 operator) or training, were recorded. EU scans were reviewed for quality (internal quality assurance) and for diagnostic accuracy (external quality assurance). Between 14 January 2009 and 4 July 2011, 626 scans were performed by 41 operators. 263 (42%) scans were completed outside of normal working hours (09:00 to 17:00). There were 251 abdominal aorta and inferior vena cava scans (40% of all scans) and 198 focused assessment with sonography in trauma scans (32%). The number of scans performed by each operator varied widely. 87 scans (14%) were supervised but the majority (459; 73%) were not. 484 (77%) scans were for training purposes, 124 (20%) were clinical scans and the majority (401; 63%) were performed by either speciality registrars (ST4-6) or specialist registrars (SpR). When the three commonest types of scans performed were analysed, eight false positives and 11 false negatives were identified. Only seven of these were deemed of poor quality and none led to poor patient outcome. Since the acquisition of our ED ultrasound machine and the development of a quality assured training programme, on average 20 scans per month have been performed in the ED, with no known adverse patient outcomes.

STEM Tomography Imaging of Hypertrophied Golgi Stacks in Mucilage-Secreting Cells.

PubMed

Kang, Byung-Ho

2016-01-01

Because of the weak penetrating power of electrons, the signal-to-noise ratio of a transmission electron micrograph (TEM) worsens as section thickness increases. This problem is alleviated by the use of the scanning transmission electron microscopy (STEM). Tomography analyses using STEM of thick sections from yeast and mammalian cells are of higher quality than are bright-field (BF) images. In this study, we compared regular BF tomograms and STEM tomograms from 500-nm thick sections from hypertrophied Golgi stacks of alfalfa root cap cells. Due to their thickness and intense heavy metal staining, BF tomograms of the thick sections suffer from poor contrast and high noise levels. We were able to mitigate these drawbacks by using STEM tomography. When we performed STEM tomography of densely stained chloroplasts of Arabidopsis cotyledon, we observed similar improvements relative to BF tomograms. A longer time is required to collect a STEM tilt series than similar BF TEM images, and dynamic autofocusing required for STEM imaging often fails at high tilt angles. Despite these limitations, STEM tomography is a powerful method for analyzing structures of large or dense organelles of plant cells.

Imaging Pancreatic Cancer Using Bioconjugated InP Quantum Dots

PubMed Central

Yong, Ken-Tye; Ding, Hong; Roy, Indrajit; Law, Wing-Cheung; Bergey, Earl J.; Maitra, Anirban; Prasad, Paras N.

2009-01-01

In this paper, we report the successful use of non-cadmium based quantum dots (QDs) as highly efficient and non-toxic optical probes for imaging live pancreatic cancer cells. Indium phosphide (core)-zinc sulphide (shell), or InP/ZnS, QDs with high quality and bright luminescence were prepared by a hot colloidal synthesis method in non-aqueous media. The surfaces of these QDs were then functionalized with mercaptosuccinic acid to make them highly dispersible in aqueous media. Further bioconjugation with pancreatic cancer specific monoclonal antibodies, such as anti-claudin 4 and anti-prostate stem cell antigen (anti-PSCA), to the functionalized InP/ZnS QDs, allowed specific in vitro targeting of pancreatic cancer cell lines (both immortalized and low passage ones). The receptor mediated delivery of the bioconjugates was further confirmed by the observation of poor in vitro targeting in non-pancreatic cancer based cell lines which are negative for the claudin-4-receptor. These observations suggest the immense potential of InP/ZnS QDs as non-cadmium based safe and efficient optical imaging nanoprobes in diagnostic imaging, particularly for early detection of cancer. PMID:19243145

Imaging pancreatic cancer using bioconjugated InP quantum dots.

PubMed

Yong, Ken-Tye; Ding, Hong; Roy, Indrajit; Law, Wing-Cheung; Bergey, Earl J; Maitra, Anirban; Prasad, Paras N

2009-03-24

In this paper, we report the successful use of non-cadmium-based quantum dots (QDs) as highly efficient and nontoxic optical probes for imaging live pancreatic cancer cells. Indium phosphide (core)-zinc sulfide (shell), or InP/ZnS, QDs with high quality and bright luminescence were prepared by a hot colloidal synthesis method in nonaqueous media. The surfaces of these QDs were then functionalized with mercaptosuccinic acid to make them highly dispersible in aqueous media. Further bioconjugation with pancreatic cancer specific monoclonal antibodies, such as anticlaudin 4 and antiprostate stem cell antigen (anti-PSCA), to the functionalized InP/ZnS QDs, allowed specific in vitro targeting of pancreatic cancer cell lines (both immortalized and low passage ones). The receptor-mediated delivery of the bioconjugates was further confirmed by the observation of poor in vitro targeting in nonpancreatic cancer based cell lines which are negative for the claudin-4-receptor. These observations suggest the immense potential of InP/ZnS QDs as non-cadmium-based safe and efficient optical imaging nanoprobes in diagnostic imaging, particularly for early detection of cancer.

A comparison of the diagnostic utility of two image receptors for panoramic radiography.

PubMed

Carmichael, F A; Hirschmann, P N; Scaife, B; Sheard, L; Mackenzie, A

2000-01-01

To compare the diagnostic utility of two screen-film systems for panoramic radiography, one based on green and the other on ultraviolet light. Two hundred consecutive adult patients with teeth in all four quadrants requiring panoramic radiographs were randomly allocated to one of two groups. One group was imaged with OGA L (CEA AB, Strängnäs, Sweden) film using Lanex Regular (Eastman Kodak, Rochester, NY, USA) screens (the Lanex group). The other group was imaged using Ultra-Vision (Dupont UK Limited, Hertfordshire, UK) film and screens (the Ultra-vision group). Two different panoramic machines were used, a Planmeca (Planmeca OY, Helsinki, Finland) and Cranex (Soredex Orion Corporation, Helsinki, Finland). The radiographs were evaluated by two radiographers for overall quality and any faults recorded. Two dental radiologists evaluated the crestal and apical areas of every standing tooth on a 4-point scale. The likelihood of getting a high-quality image with the different films was modelled using logistic regression, adjusting for the radiologist and the area of the tooth being examined. Inter- and intra-examiner agreement was calculated using Kappa and weighted Kappa where appropriate. The radiographers recorded no significant differences in positioning errors between the two groups of film. However, the films produced on the Cranex were less likely to be recorded as excellent. The radiologists' interexaminer agreement for the lower molars and upper incisors was only moderate at best (kappa = 0.56). No significant differences were found between the likelihood of the two types of film providing a high-quality image. Crestal areas were more likely to be scored well than apical areas. There were no differences in ease of discerning apical and crestal areas between the two screen-film systems. There was only poor to moderate agreement between the two radiologists. Ultra-Vision can be recommended as an alternative to existing rare earth systems for panoramic radiography.

Is the Internet a Suitable Patient Resource for Information on Common Radiological Investigations?: Radiology-Related Information on the Internet.

PubMed

Bowden, Dermot J; Yap, Lee-Chien; Sheppard, Declan G

2017-07-01

This study aimed to assess the quality of Internet information about common radiological investigations. Four search engines (Google, Bing, Yahoo, and Duckduckgo) were searched using the terms "X-ray," "cat scan," "MRI," "ultrasound," and "pet scan." The first 10 webpage results returned for each search term were recorded, and their quality and readability were analyzed by two independent reviewers (DJB and LCY), with discrepancies resolved by consensus. Analysis of information quality was conducted using validated instruments for the assessment of health-care information (DISCERN score is a multi-domain tool for assessment of health-care information quality by health-care professionals and laypeople (max 80 points)) and readability (Flesch-Kincaid and SMOG or Simple Measure of Gobbledygook scores). The search result pages were further classified into categories as follows: commercial, academic (educational/institutional), and news/magazine. Several organizations offer website accreditation for health-care information, and accreditation is recognized by the presence of a hallmark or logo on the website. The presence of any valid accreditation marks on each website was recorded. Mean scores between groups were compared for significance using the Student t test. A total of 200 webpages returned (108 unique website addresses). The average DISCERN score was <50 points for all modalities and search engines. No significant difference was seen in readability between modalities or between search engines. Websites carrying validated accreditation marks were associated with higher average DISCERN scores: X-ray (39.36 vs 25.35), computed tomography (45.45 vs 31.33), and ultrasound (40.91 vs 27.62) (P < .01). Academic/government institutions produced material with higher DISCERN scores: X-ray (40.06 vs 22.23), magnetic resonance imaging (44.69 vs 29), ultrasound (46 vs 31.91), and positron emission tomography (45.93 vs 38.31) (P < .01). Commercial websites produced material with lower mean DISCERN scores: X-ray (17.25 vs 31.69), magnetic resonance imaging (20.8 vs 40.1), ultrasound (24.11 vs 42.35), and positron emission tomography (24.5 vs 44.45) (P < .01). Although readability is adequate, the overall quality of radiology-related health-care information on the Internet is poor. High-quality online resources should be identified so that patients may avoid the use of poor-quality information derived from general search engine queries. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Linearized image reconstruction method for ultrasound modulated electrical impedance tomography based on power density distribution

NASA Astrophysics Data System (ADS)

Song, Xizi; Xu, Yanbin; Dong, Feng

2017-04-01

Electrical resistance tomography (ERT) is a promising measurement technique with important industrial and clinical applications. However, with limited effective measurements, it suffers from poor spatial resolution due to the ill-posedness of the inverse problem. Recently, there has been an increasing research interest in hybrid imaging techniques, utilizing couplings of physical modalities, because these techniques obtain much more effective measurement information and promise high resolution. Ultrasound modulated electrical impedance tomography (UMEIT) is one of the newly developed hybrid imaging techniques, which combines electric and acoustic modalities. A linearized image reconstruction method based on power density is proposed for UMEIT. The interior data, power density distribution, is adopted to reconstruct the conductivity distribution with the proposed image reconstruction method. At the same time, relating the power density change to the change in conductivity, the Jacobian matrix is employed to make the nonlinear problem into a linear one. The analytic formulation of this Jacobian matrix is derived and its effectiveness is also verified. In addition, different excitation patterns are tested and analyzed, and opposite excitation provides the best performance with the proposed method. Also, multiple power density distributions are combined to implement image reconstruction. Finally, image reconstruction is implemented with the linear back-projection (LBP) algorithm. Compared with ERT, with the proposed image reconstruction method, UMEIT can produce reconstructed images with higher quality and better quantitative evaluation results.

Sleep quality in long haul truck drivers: A study on Iranian national data.

PubMed

Sadeghniiat-Haghighi, Khosro; Yazdi, Zohreh; Kazemifar, Amir-Mohammad

2016-08-01

Iran has a high rate of road traffic accidents. Poor quality of sleep brings about loss of attention, which is an important cause of road traffic accidents particularly in monotonous roads. The causes of poor quality of sleep in occupational drivers are multifactorial. The objective of the present study was to assess the prevalence of poor sleep quality among occupational drivers with rotating work schedules and analyze its different risk factors. 2200 professional long-haul truck drivers who had been referred to the Occupational Health Clinic for routine education course were invited. We obtained data from eight provinces from various parts of Iran during 2012-2013. Data were collected using a questionnaire including questions about demographic and job characteristics. Pittsburg Sleep Quality Index (PSQI) was used to assess drivers' sleep quality. Mean working (driving) time was (9.3±2.5) hours daily and (55.5 ± 18.29) hours weekly. About 23.5% of the drivers reported history of smoking, 14.5% had low job satisfaction and 60% had irregular work schedule. 16.4% of drivers had an accidents leading to injury during the past five years. The mean PSQI score was 4.2 ± 2.7; 54% had a PSQI>5 (poor quality of sleep). Multivariate logistic regression showed that smoking, job satisfaction, history of accidents, shift work and work hours per day were the most important risk factors for poor sleep quality. Results obtained from the current study showed a high prevalence of poor quality of sleep among professional drivers. It warrants more attention to this significant problem using some measures to improve working conditions in professional drivers, as well as health promotion interventions.

Age and gender effects on the prevalence of poor sleep quality in the adult population.

PubMed

Madrid-Valero, Juan J; Martínez-Selva, José M; Ribeiro do Couto, Bruno; Sánchez-Romera, Juan F; Ordoñana, Juan R

Sleep quality has a significant impact on health and quality of life and is affected, among other factors, by age and sex. However, the prevalence of problems in this area in the general population is not well known. Therefore, our objective was to study the prevalence and main characteristics of sleep quality in an adult population sample. 2,144 subjects aged between 43 and 71 years belonging to the Murcia (Spain) Twin Registry. Sleep quality was measured by self-report through the Pittsburgh Sleep Quality Index (PSQI). Logistic regression models were used to analyse the results. The prevalence of poor sleep quality stands at 38.2%. Univariate logistic regression analyses showed that women were almost twice as likely as men (OR: 1.88; 95% confidence interval [95%CI]: 1.54 to 2.28) to have poor quality of sleep. Age was directly and significantly associated with a low quality of sleep (OR: 1.05; 95%CI: 1.03 to 1.06). The prevalence of poor sleep quality is high among adults, especially women. There is a direct relationship between age and deterioration in the quality of sleep. This relationship also appears to be more consistent in women. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Investigation on Beam-Blocker-Based Scatter Correction Method for Improving CT Number Accuracy

NASA Astrophysics Data System (ADS)

Lee, Hoyeon; Min, Jonghwan; Lee, Taewon; Pua, Rizza; Sabir, Sohail; Yoon, Kown-Ha; Kim, Hokyung; Cho, Seungryong

2017-03-01

Cone-beam computed tomography (CBCT) is gaining widespread use in various medical and industrial applications but suffers from substantially larger amount of scatter than that in the conventional diagnostic CT resulting in relatively poor image quality. Various methods that can reduce and/or correct for the scatter in the CBCT have therefore been developed. Scatter correction method that uses a beam-blocker has been considered a direct measurement-based approach providing accurate scatter estimation from the data in the shadows of the beam-blocker. To the best of our knowledge, there has been no record reporting the significance of the scatter from the beam-blocker itself in such correction methods. In this paper, we identified the scatter from the beam-blocker that is detected in the object-free projection data investigated its influence on the image accuracy of CBCT reconstructed images, and developed a scatter correction scheme that takes care of this scatter as well as the scatter from the scanned object.

Modeling and simulation of Positron Emission Mammography (PEM) based on double-sided CdTe strip detectors

NASA Astrophysics Data System (ADS)

Ozsahin, I.; Unlu, M. Z.

2014-03-01

Breast cancer is the most common leading cause of cancer death among women. Positron Emission Tomography (PET) Mammography, also known as Positron Emission Mammography (PEM), is a method for imaging primary breast cancer. Over the past few years, PEMs based on scintillation crystals dramatically increased their importance in diagnosis and treatment of early stage breast cancer. However, these detectors have significant limitations like poor energy resolution resulting with false-negative result (missed cancer), and false-positive result which leads to suspecting cancer and suggests an unnecessary biopsy. In this work, a PEM scanner based on CdTe strip detectors is simulated via the Monte Carlo method and evaluated in terms of its spatial resolution, sensitivity, and image quality. The spatial resolution is found to be ~ 1 mm in all three directions. The results also show that CdTe strip detectors based PEM scanner can produce high resolution images for early diagnosis of breast cancer.

Interpreting forest and grassland biome productivity utilizing nested scales of image resolution and biogeographical analysis

NASA Technical Reports Server (NTRS)

Iverson, L. R.; Olson, J. S.; Risser, P. G.; Treworgy, C.; Frank, T.; Cook, E.; Ke, Y.

1986-01-01

Data acquisition, initial site characterization, image and geographic information methods available, and brief evaluations of first-year for NASA's Thematic Mapper (TM) working group are presented. The TM and other spectral data are examined in order to relate local, intensive ecosystem research findings to estimates of carbon cycling rates over wide geographic regions. The effort is to span environments ranging from dry to moist climates and from good to poor site quality using the TM capability, with and without the inclusion of geographic information system (GIS) data, and thus to interpret the local spatial pattern of factors conditioning biomass or productivity. Twenty-eight TM data sets were acquired, archived, and evaluated. The ERDAS image processing and GIS system were installed on the microcomputer (PC-AT) and its capabilities are being investigated. The TM coverage of seven study areas were exported via ELAS software on the Prime to the ERDAS system. Statistical analysis procedures to be used on the spectral data are being identified.

Association between Visual Impairment and Low Vision and Sleep Duration and Quality among Older Adults in South Africa.

PubMed

Peltzer, Karl; Phaswana-Mafuya, Nancy

2017-07-19

This study aims to estimate the association between visual impairment and low vision and sleep duration and poor sleep quality in a national sample of older adults in South Africa. A national population-based cross-sectional Study of Global Ageing and Adults Health (SAGE) wave 1 was conducted in 2008 with a sample of 3840 individuals aged 50 years or older in South Africa. The interviewer-administered questionnaire assessed socio-demographic characteristics, health variables, sleep duration, quality, visual impairment, and vision. Results indicate that 10.0% of the sample reported short sleep duration (≤5 h), 46.6% long sleep (≥9 h), 9.3% poor sleep quality, 8.4% self-reported and visual impairment (near and/or far vision); and 43.2% measured low vision (near and/or far vision) (0.01-0.25 decimal) and 7.5% low vision (0.01-0.125 decimal). In fully adjusted logistic regression models, self-reported visual impairment was associated with short sleep duration and poor sleep quality, separately and together. Low vision was only associated with long sleep duration and poor sleep quality in unadjusted models. Self-reported visual impairment was related to both short sleep duration and poor sleep quality. Population data on sleep patterns may want to include visual impairment measures.

A tool to determine financial impact of adverse events in health care: healthcare quality calculator.

PubMed

Yarbrough, Wendell G; Sewell, Andrew; Tickle, Erin; Rhinehardt, Eric; Harkleroad, Rod; Bennett, Marc; Johnson, Deborah; Wen, Li; Pfeiffer, Matthew; Benegas, Manny; Morath, Julie

2014-12-01

Hospital leaders lack tools to determine the financial impact of poor patient outcomes and adverse events. To provide health-care leaders with decision support for investments to improve care, we created a tool, the Healthcare Quality Calculator (HQCal), which uses institution-specific financial data to calculate impact of poor patient outcomes or quality improvement on present and future margin. Excel and Web-based versions of the HQCal were based on a cohort study framework and created with modular components including major drivers of cost and reimbursement. The Healthcare Quality Calculator (HQCal) compares payment, cost, and profit/loss for patients with and without poor outcomes or quality issues. Cost and payment information for groups with and without quality issues are used by the HQCal to calculate profit or loss. Importantly, institution-specific payment and cost data are used to calculate financial impact and attributable cost associated with poor patient outcomes, adverse events, or quality issues. Because future cost and reimbursement changes can be forecast, the HQCal incorporates a forward-looking component. The flexibility of the HQCal was demonstrated using surgical site infections after abdominal surgery and postoperative surgical airway complications. The Healthcare Quality Calculator determines financial impact of poor patient outcomes and the benefit of initiatives to improve quality. The calculator can identify quality issues that would provide the largest financial benefit if improved; however, it cannot identify specific interventions. The calculator provides a tool to improve transparency regarding both short- and long-term financial consequences of funding, or failing to fund, initiatives to close gaps in quality or improve patient outcomes.

Atypical work schedules are associated with poor sleep quality and mental health in Taiwan female nurses.

PubMed

Lin, Pei-Chen; Chen, Chung-Hey; Pan, Shung-Mei; Pan, Chih-Hong; Chen, Chiou-Jong; Chen, Yao-Mei; Hung, Hsin-Chia; Wu, Ming-Tsang

2012-11-01

To investigate the effects of shift work schedules on sleep quality and mental health in female nurses in south Taiwan. This study recruited 1,360 female registered nurses in the Kaohsiung area for the first survey, and among them, 769 nurses had a rotation shift schedule. Among the 769 rotation shift work nurses, 407 completed another second survey 6-10 months later. Data collection included demographic variables, work status, shift work schedule, sleep quality (Pittsburgh Sleep Quality Index), and mental health (Chinese Health Questionnaire-12). Nurses on rotation shift had the poor sleep quality and mental health compared to nurses on day shift. The nurses on rotation shift had a relatively higher OR of reporting poor sleep quality and poor mental health (OR, 2.26; 95% CI, 1.57-3.28; and OR, 1.91; 95% CI, 1.39-2.63, respectively). Additionally, rotation shift nurses who had ≥2 days off after their most recent night shifts showed significantly improved sleep quality and mental health (PSQI decreased of 1.23 and CHQ-12 decreased of 0.86, respectively). Comparison of sleep quality between the first and second surveys showed aggravated sleep quality only in nurses who had an increased frequency of night shifts. Female nurses who have a rotation shift work schedule tend to experience poor sleep quality and mental health, but their sleep quality and mental health improve if they have ≥2 days off after their most recent night shifts. This empirical information is useful for optimizing work schedules for nurses.

A Stochastic Imaging Technique for Spatio-Spectral Characterization of Special Nuclear Material

NASA Astrophysics Data System (ADS)

Hamel, Michael C.

Radiation imaging is advantageous for detecting, locating and characterizing special nuclear material (SNM) in complex environments. A dual-particle imager (DPI) has been designed that is capable of detecting gamma-ray and neutron signatures from shielded SNM. The system combines liquid organic and NaI(Tl) scintillators to form a combined Compton and neutron scatter camera. Effective image reconstruction of detected particles is a crucial component for maximizing the performance of the system; however, a key deficiency exists in the widely used list-mode maximum-likelihood estimation-maximization (MLEM) image reconstruction technique. The steady-state solution produced by this iterative method will have poor quality compared to solutions produced with fewer iterations. A stopping condition is required to achieve a better solution but these conditions fail to achieve maximum image quality. Stochastic origin ensembles (SOE) imaging is a good candidate to address this problem as it uses Markov chain Monte Carlo to reach a stochastic steady-state solution that has image quality comparable to the best MLEM solution. The application of SOE to the DPI is presented in this work. SOE was originally applied in medical imaging applications with no mechanism to isolate spectral information based on location. This capability is critical for non-proliferation applications as complex radiation environments with multiple sources are often encountered. This dissertation extends the SOE algorithm to produce spatially dependent spectra and presents experimental result showing that the technique was effective for isolating a 4.1-kg mass of weapons grade plutonium (WGPu) when other neutron and gamma-ray sources were present. This work also demonstrates the DPI as an effective tool for localizing and characterizing highly enriched uranium (HEU). A series of experiments were performed with the DPI using a deuterium-deuterium (DD) and deuterium-tritium (DT) neutron generator, as well as AmLi, to interrogate a 13.7-kg sphere of HEU. In all cases, the neutrons and gamma rays produced from induced fission were successfully discriminated from the interrogating particles to localize the HEU. For characterization, the fast neutron and gamma-ray spectra were recorded from multiple HEU configurations with low-Z and high-Z moderation. Further characterization of the configurations used the measured neutron lifetime to show that the DPI can be used to infer multiplication.

The prevalence and association of stress with sleep quality among medical students.

PubMed

Almojali, Abdullah I; Almalki, Sami A; Alothman, Ali S; Masuadi, Emad M; Alaqeel, Meshal K

2017-09-01

Medical students tend to reduce their sleep, in an effort to adjust and cope with their workload and stressful environment. This study estimated the prevalence of and the relationship between poor sleep quality and stress among medical students. This cross-sectional study was conducted using a stratified random sample of male and female medical students in King Saud bin Abdulaziz University for Health Sciences in Riyadh, Saudi Arabia. A self-administered questionnaire was distributed to assess sleep quality using the Pittsburgh Sleep Quality Index, and the stress level by using the Kessler Psychological Distress Scale. A high prevalence of poor sleep quality (76%) and stress (53%) were found, with a statistically significant association (p<0.001). Logistic regression indicated that students who are not suffering from stress are less likely to have poor sleep quality (OR=0.28, p<0.001), and the risk of having poor sleep quality is almost four times higher in students whose cumulative grade point average (GPA) is less than 4.25 (OR=3.83, p=0.01). The study documents a statistically significant association between stress and poor sleep quality. A recommendation for the management of medical college is to establish academic counseling centers focusing in promoting good sleep hygiene and strengthening students' study skills and coping with their stressful environment. Copyright © 2017 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Anatomical image-guided fluorescence molecular tomography reconstruction using kernel method

NASA Astrophysics Data System (ADS)

Baikejiang, Reheman; Zhao, Yue; Fite, Brett Z.; Ferrara, Katherine W.; Li, Changqing

2017-05-01

Fluorescence molecular tomography (FMT) is an important in vivo imaging modality to visualize physiological and pathological processes in small animals. However, FMT reconstruction is ill-posed and ill-conditioned due to strong optical scattering in deep tissues, which results in poor spatial resolution. It is well known that FMT image quality can be improved substantially by applying the structural guidance in the FMT reconstruction. An approach to introducing anatomical information into the FMT reconstruction is presented using the kernel method. In contrast to conventional methods that incorporate anatomical information with a Laplacian-type regularization matrix, the proposed method introduces the anatomical guidance into the projection model of FMT. The primary advantage of the proposed method is that it does not require segmentation of targets in the anatomical images. Numerical simulations and phantom experiments have been performed to demonstrate the proposed approach's feasibility. Numerical simulation results indicate that the proposed kernel method can separate two FMT targets with an edge-to-edge distance of 1 mm and is robust to false-positive guidance and inhomogeneity in the anatomical image. For the phantom experiments with two FMT targets, the kernel method has reconstructed both targets successfully, which further validates the proposed kernel method.

Atmospheric turbulence and sensor system effects on biometric algorithm performance

NASA Astrophysics Data System (ADS)

Espinola, Richard L.; Leonard, Kevin R.; Byrd, Kenneth A.; Potvin, Guy

2015-05-01

Biometric technologies composed of electro-optical/infrared (EO/IR) sensor systems and advanced matching algorithms are being used in various force protection/security and tactical surveillance applications. To date, most of these sensor systems have been widely used in controlled conditions with varying success (e.g., short range, uniform illumination, cooperative subjects). However the limiting conditions of such systems have yet to be fully studied for long range applications and degraded imaging environments. Biometric technologies used for long range applications will invariably suffer from the effects of atmospheric turbulence degradation. Atmospheric turbulence causes blur, distortion and intensity fluctuations that can severely degrade image quality of electro-optic and thermal imaging systems and, for the case of biometrics technology, translate to poor matching algorithm performance. In this paper, we evaluate the effects of atmospheric turbulence and sensor resolution on biometric matching algorithm performance. We use a subset of the Facial Recognition Technology (FERET) database and a commercial algorithm to analyze facial recognition performance on turbulence degraded facial images. The goal of this work is to understand the feasibility of long-range facial recognition in degraded imaging conditions, and the utility of camera parameter trade studies to enable the design of the next generation biometrics sensor systems.

In vivo imaging in the oral cavity by endoscopic optical coherence tomography.

PubMed

Walther, Julia; Schnabel, Christian; Tetschke, Florian; Rosenauer, Tobias; Golde, Jonas; Ebert, Nadja; Baumann, Michael; Hannig, Christian; Koch, Edmund

2018-03-01

The common way to diagnose hard and soft tissue irregularities in the oral cavity is initially the visual inspection by an experienced dentist followed by further medical examinations, such as radiological imaging and/or histopathological investigation. For the diagnosis of oral hard and soft tissues, the detection of early transformations is mostly hampered by poor visual access, low specificity of the diagnosis techniques, and/or limited feasibility of frequent screenings. Therefore, optical noninvasive diagnosis of oral tissue is promising to improve the accuracy of oral screening. Considering this demand, a rigid handheld endoscopic scanner was developed for optical coherence tomography (OCT). The novelty is the usage of a commercially near-infrared endoscope with fitting optics in combination with an established spectral-domain OCT system of our workgroup. By reaching a high spatial resolution, in vivo images of anterior and especially posterior dental and mucosal tissues were obtained from the oral cavity of two volunteers. The convincing image quality of the endoscopic OCT device is particularly obvious for the imaging of different regions of the human soft palate with highly scattering fibrous layer and capillary network within the lamina propria. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Poor housing quality: Prevalence and health effects.

PubMed

Baker, Emma; Lester, Laurence H; Bentley, Rebecca; Beer, Andrew

2016-01-01

Housing is a central component of productive, healthy, and meaningful lives, and a principle social determinant of health and well-being. Surprisingly, though, evidence on the ways that housing influences health in Australia is poorly developed. This stems largely from the fact that the majority of the population are accommodated in good quality housing. The dominance of a "good housing paradigm" means that households living in poor quality and unhealthy housing are doubly disadvantaged-by the quality of their housing and because policy makers in Australia do not acknowledge the health effects of housing. In this article, we examine the relationship between health outcomes and quality of housing. We base our analysis on data from the Household Income and Labour Dynamics in Australia (HILDA) survey, a panel dataset that is representative across Australia. We find a sizeable, policy-important, and to date under-acknowledged cohort of Australians whose health is influenced by poor-condition dwellings.

Sleep hygiene education: efficacy on sleep quality in working women.

PubMed

Chen, Pao-Hui; Kuo, Hung-Yu; Chueh, Ke-Hsin

2010-12-01

Although sleep hygiene education represents a promising approach for patients with poor sleep quality, little research has been devoted in understanding the sleep hygiene behavior and knowledge of working women. The purpose of this study was to investigate the efficacy of a short-term sleep hygiene education program on working women with poor sleep quality. This pilot study was a prospective and an exploratory intervention study. The intervention was tested on 37 selected working women with poor sleep quality in the community. The Pittsburgh Sleep Quality Index (score > 5) was used to identify working women with poor sleep quality. After a pretest to assess sleep quality, researchers implemented a 5-week sleep hygiene education program that addressed good sleep environments/habits, emotional stress, the influence of diet/alcohol/tobacco on sleep, exercise, and alternative therapies. Tests administered midway through the program and after program completion provided the data used to analyze effective sleep quality changes. Results showed sleep hygiene education to improve participant sleep quality significantly (p < .001). The sleep quality of all participants improved over both the 3- and the 5-week education program. The six components of the Pittsburgh Sleep Quality Index (i.e., subjective sleep quality, sleep latency, sleep duration, sleep disturbances, use of sleeping medication, and daytime dysfunction) also improved. A brief and effective sleep hygiene education program delivered by a nurse can improve sleep quality in working women with sleeping problems.

Food Insecurity, Poor Diet Quality, and Suboptimal Intakes of Folate and Iron Are Independently Associated with Perceived Mental Health in Canadian Adults

PubMed Central

Davison, Karen M.; Gondara, Lovedeep; Kaplan, Bonnie J.

2017-01-01

Background: To address nutrition-related population mental health data gaps, we examined relationships among food insecurity, diet quality, and perceived mental health. Methods: Stratified and logistic regression analyses of respondents aged 19–70 years from the Canadian Community Health Survey, Cycle 2.2 were conducted (n = 15,546). Measures included the Household Food Security Survey Module, diet quality (i.e., comparisons to the Dietary Reference Intakes, Healthy Eating Index), perceived mental health (poor versus good), sociodemographics, and smoking. Results: In this sample, 6.9% were food insecure and 4.5% reported poor mental health. Stratified analysis of food security and mental health status by age/gender found associations for poor diet quality, protein, fat, fibre, and several micronutrients (p-values < 0.05); those who were food insecure tended to have higher suboptimal intakes (p-values < 0.05). After adjustment for covariates, associations in relation to mental health emerged for food insecurity (OR = 1.60, 95% CI 1.45–1.71), poor diet quality (1.61, 95% CI 1.34–1.81), and suboptimal intakes of folate (OR = 1.58, 95% CI 1.17–1.90) and iron (OR = 1.45, 95% CI 1.23–1.88). Conclusions: Population approaches that improve food security and intakes of high quality diets may protect people from poor mental health. PMID:28335418

Food Insecurity, Poor Diet Quality, and Suboptimal Intakes of Folate and Iron Are Independently Associated with Perceived Mental Health in Canadian Adults.

PubMed

Davison, Karen M; Gondara, Lovedeep; Kaplan, Bonnie J

2017-03-14

To address nutrition-related population mental health data gaps, we examined relationships among food insecurity, diet quality, and perceived mental health. Stratified and logistic regression analyses of respondents aged 19-70 years from the Canadian Community Health Survey, Cycle 2.2 were conducted ( n = 15,546). Measures included the Household Food Security Survey Module, diet quality (i.e., comparisons to the Dietary Reference Intakes , Healthy Eating Index), perceived mental health (poor versus good), sociodemographics, and smoking. In this sample, 6.9% were food insecure and 4.5% reported poor mental health. Stratified analysis of food security and mental health status by age/gender found associations for poor diet quality, protein, fat, fibre, and several micronutrients ( p -values < 0.05); those who were food insecure tended to have higher suboptimal intakes ( p -values < 0.05). After adjustment for covariates, associations in relation to mental health emerged for food insecurity (OR = 1.60, 95% CI 1.45-1.71), poor diet quality (1.61, 95% CI 1.34-1.81), and suboptimal intakes of folate (OR = 1.58, 95% CI 1.17-1.90) and iron (OR = 1.45, 95% CI 1.23-1.88). Population approaches that improve food security and intakes of high quality diets may protect people from poor mental health.

An assessment of the performance and quality control procedures of PACS workstation monitors used in Irish radiology departments

NASA Astrophysics Data System (ADS)

Wade, Cherrie; Brennan, Patrick C.; Mc Entee, Mark F.

2005-04-01

Diagnostic efficacy in soft-copy reporting relies heavily on the quality of workstation monitors and an investigation performed in 2002 demonstrated that CRT monitors in Dublin imaging departments were not operating at optimal levels. The current work examines the performance of CRTs being used in Dublin and other parts of Ireland to establish if problems reported in the earlier work have been rectified. All hospitals performing soft-copy reporting for general radiology using CRTs were included in the work. Examination of ambient lighting, calibration of monitors and analysis of CRT performance using the SMPTE test pattern and a selection of the AAPM test images was performed. Maximum luminance, spatial uniformity of luminance, temporal luminance stability, gamma, geometry, sharpness, veiling glare and spatial resolution of each monitor was evaluated. Ambient lighting in all reporting areas was within recommended levels. All the monitors were calibrated appropriately and were performing at acceptable levels for maximum luminance and temporal stability and only one of the thirty-three investigated failed to reach the standard for spatial uniformity. In contrast a number of the CRTs investigated showed poor adherence to acceptable levels for geometrical distortions, veiling glare and spatial resolution all of which are important influencers of image quality. Gamma values also appeared to be low for a number of monitors but this interpretation is provisional and subject to the establishment of ratified guideline values. The results demonstrate that although some improvement on the previous situation is evident, greater adherence to acceptable levels is required for certain parameters.

3D models mapping optimization through an integrated parameterization approach: cases studies from Ravenna

NASA Astrophysics Data System (ADS)

Cipriani, L.; Fantini, F.; Bertacchi, S.

2014-06-01

Image-based modelling tools based on SfM algorithms gained great popularity since several software houses provided applications able to achieve 3D textured models easily and automatically. The aim of this paper is to point out the importance of controlling models parameterization process, considering that automatic solutions included in these modelling tools can produce poor results in terms of texture utilization. In order to achieve a better quality of textured models from image-based modelling applications, this research presents a series of practical strategies aimed at providing a better balance between geometric resolution of models from passive sensors and their corresponding (u,v) map reference systems. This aspect is essential for the achievement of a high-quality 3D representation, since "apparent colour" is a fundamental aspect in the field of Cultural Heritage documentation. Complex meshes without native parameterization have to be "flatten" or "unwrapped" in the (u,v) parameter space, with the main objective to be mapped with a single image. This result can be obtained by using two different strategies: the former automatic and faster, while the latter manual and time-consuming. Reverse modelling applications provide automatic solutions based on splitting the models by means of different algorithms, that produce a sort of "atlas" of the original model in the parameter space, in many instances not adequate and negatively affecting the overall quality of representation. Using in synergy different solutions, ranging from semantic aware modelling techniques to quad-dominant meshes achieved using retopology tools, it is possible to obtain a complete control of the parameterization process.

Quality of antimalarial drugs and antibiotics in Papua New Guinea: a survey of the health facility supply chain.

PubMed

Hetzel, Manuel W; Page-Sharp, Madhu; Bala, Nancy; Pulford, Justin; Betuela, Inoni; Davis, Timothy M E; Lavu, Evelyn K

2014-01-01

Poor-quality life-saving medicines are a major public health threat, particularly in settings with a weak regulatory environment. Insufficient amounts of active pharmaceutical ingredients (API) endanger patient safety and may contribute to the development of drug resistance. In the case of malaria, concerns relate to implications for the efficacy of artemisinin-based combination therapies (ACT). In Papua New Guinea (PNG), Plasmodium falciparum and P. vivax are both endemic and health facilities are the main source of treatment. ACT has been introduced as first-line treatment but other drugs, such as primaquine for the treatment of P. vivax hypnozoites, are widely available. This study investigated the quality of antimalarial drugs and selected antibiotics at all levels of the health facility supply chain in PNG. Medicines were obtained from randomly sampled health facilities and selected warehouses and hospitals across PNG and analysed for API content using validated high performance liquid chromatography (HPLC). Of 360 tablet/capsule samples from 60 providers, 9.7% (95% CI 6.9, 13.3) contained less, and 0.6% more, API than pharmacopoeial reference ranges, including 29/37 (78.4%) primaquine, 3/70 (4.3%) amodiaquine, and one sample each of quinine, artemether, sulphadoxine-pyrimethamine and amoxicillin. According to the package label, 86.5% of poor-quality samples originated from India. Poor-quality medicines were found in 48.3% of providers at all levels of the supply chain. Drug quality was unrelated to storage conditions. This study documents the presence of poor-quality medicines, particularly primaquine, throughout PNG. Primaquine is the only available transmission-blocking antimalarial, likely to become important to prevent the spread of artemisinin-resistant P. falciparum and eliminating P. vivax hypnozoites. The availability of poor-quality medicines reflects the lack of adequate quality control and regulatory mechanisms. Measures to stop the availability of poor-quality medicines should include limiting procurement to WHO prequalified products and implementing routine quality testing.

Quality of Antimalarial Drugs and Antibiotics in Papua New Guinea: A Survey of the Health Facility Supply Chain

PubMed Central

Hetzel, Manuel W.; Page-Sharp, Madhu; Bala, Nancy; Pulford, Justin; Betuela, Inoni; Davis, Timothy M. E.; Lavu, Evelyn K.

2014-01-01

Background Poor-quality life-saving medicines are a major public health threat, particularly in settings with a weak regulatory environment. Insufficient amounts of active pharmaceutical ingredients (API) endanger patient safety and may contribute to the development of drug resistance. In the case of malaria, concerns relate to implications for the efficacy of artemisinin-based combination therapies (ACT). In Papua New Guinea (PNG), Plasmodium falciparum and P. vivax are both endemic and health facilities are the main source of treatment. ACT has been introduced as first-line treatment but other drugs, such as primaquine for the treatment of P. vivax hypnozoites, are widely available. This study investigated the quality of antimalarial drugs and selected antibiotics at all levels of the health facility supply chain in PNG. Methods and Findings Medicines were obtained from randomly sampled health facilities and selected warehouses and hospitals across PNG and analysed for API content using validated high performance liquid chromatography (HPLC). Of 360 tablet/capsule samples from 60 providers, 9.7% (95% CI 6.9, 13.3) contained less, and 0.6% more, API than pharmacopoeial reference ranges, including 29/37 (78.4%) primaquine, 3/70 (4.3%) amodiaquine, and one sample each of quinine, artemether, sulphadoxine-pyrimethamine and amoxicillin. According to the package label, 86.5% of poor-quality samples originated from India. Poor-quality medicines were found in 48.3% of providers at all levels of the supply chain. Drug quality was unrelated to storage conditions. Conclusions This study documents the presence of poor-quality medicines, particularly primaquine, throughout PNG. Primaquine is the only available transmission-blocking antimalarial, likely to become important to prevent the spread of artemisinin-resistant P. falciparum and eliminating P. vivax hypnozoites. The availability of poor-quality medicines reflects the lack of adequate quality control and regulatory mechanisms. Measures to stop the availability of poor-quality medicines should include limiting procurement to WHO prequalified products and implementing routine quality testing. PMID:24828338

Remote Sensing Image Quality Assessment Experiment with Post-Processing

NASA Astrophysics Data System (ADS)

Jiang, W.; Chen, S.; Wang, X.; Huang, Q.; Shi, H.; Man, Y.

2018-04-01

This paper briefly describes the post-processing influence assessment experiment, the experiment includes three steps: the physical simulation, image processing, and image quality assessment. The physical simulation models sampled imaging system in laboratory, the imaging system parameters are tested, the digital image serving as image processing input are produced by this imaging system with the same imaging system parameters. The gathered optical sampled images with the tested imaging parameters are processed by 3 digital image processes, including calibration pre-processing, lossy compression with different compression ratio and image post-processing with different core. Image quality assessment method used is just noticeable difference (JND) subject assessment based on ISO20462, through subject assessment of the gathered and processing images, the influence of different imaging parameters and post-processing to image quality can be found. The six JND subject assessment experimental data can be validated each other. Main conclusions include: image post-processing can improve image quality; image post-processing can improve image quality even with lossy compression, image quality with higher compression ratio improves less than lower ratio; with our image post-processing method, image quality is better, when camera MTF being within a small range.

Cross-Sectional Associations between Multiple Lifestyle Behaviors and Health-Related Quality of Life in the 10,000 Steps Cohort

PubMed Central

Duncan, Mitch J.; Kline, Christopher E.; Vandelanotte, Corneel; Sargent, Charli; Rogers, Naomi L.; Di Milia, Lee

2014-01-01

Background The independent and combined influence of smoking, alcohol consumption, physical activity, diet, sitting time, and sleep duration and quality on health status is not routinely examined. This study investigates the relationships between these lifestyle behaviors, independently and in combination, and health-related quality of life (HRQOL). Methods Adult members of the 10,000 Steps project (n = 159,699) were invited to participate in an online survey in November-December 2011. Participant socio-demographics, lifestyle behaviors, and HRQOL (poor self-rated health; frequent unhealthy days) were assessed by self-report. The combined influence of poor lifestyle behaviors were examined, independently and also as part of two lifestyle behavior indices, one excluding sleep quality (Index 1) and one including sleep quality (Index 2). Adjusted Cox proportional hazard models were used to examine relationships between lifestyle behaviors and HRQOL. Results A total of 10,478 participants provided complete data for the current study. For Index 1, the Prevalence Ratio (p value) of poor self-rated health was 1.54 (p = 0.001), 2.07 (p≤0.001), 3.00 (p≤0.001), 3.61 (p≤0.001) and 3.89 (p≤0.001) for people reporting two, three, four, five and six poor lifestyle behaviors, compared to people with 0–1 poor lifestyle behaviors. For Index 2, the Prevalence Ratio (p value) of poor self-rated health was 2.26 (p = 0.007), 3.29 (p≤0.001), 4.68 (p≤0.001), 6.48 (p≤0.001), 7.91 (p≤0.001) and 8.55 (p≤0.001) for people reporting two, three, four, five, six and seven poor lifestyle behaviors, compared to people with 0–1 poor lifestyle behaviors. Associations between the combined lifestyle behavior index and frequent unhealthy days were statistically significant and similar to those observed for poor self-rated health. Conclusions Engaging in a greater number of poor lifestyle behaviors was associated with a higher prevalence of poor HRQOL. This association was exacerbated when sleep quality was included in the index. PMID:24714564

Cross-sectional associations between multiple lifestyle behaviors and health-related quality of life in the 10,000 Steps cohort.

PubMed

Duncan, Mitch J; Kline, Christopher E; Vandelanotte, Corneel; Sargent, Charli; Rogers, Naomi L; Di Milia, Lee

2014-01-01

The independent and combined influence of smoking, alcohol consumption, physical activity, diet, sitting time, and sleep duration and quality on health status is not routinely examined. This study investigates the relationships between these lifestyle behaviors, independently and in combination, and health-related quality of life (HRQOL). Adult members of the 10,000 Steps project (n = 159,699) were invited to participate in an online survey in November-December 2011. Participant socio-demographics, lifestyle behaviors, and HRQOL (poor self-rated health; frequent unhealthy days) were assessed by self-report. The combined influence of poor lifestyle behaviors were examined, independently and also as part of two lifestyle behavior indices, one excluding sleep quality (Index 1) and one including sleep quality (Index 2). Adjusted Cox proportional hazard models were used to examine relationships between lifestyle behaviors and HRQOL. A total of 10,478 participants provided complete data for the current study. For Index 1, the Prevalence Ratio (p value) of poor self-rated health was 1.54 (p = 0.001), 2.07 (p≤0.001), 3.00 (p≤0.001), 3.61 (p≤0.001) and 3.89 (p≤0.001) for people reporting two, three, four, five and six poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. For Index 2, the Prevalence Ratio (p value) of poor self-rated health was 2.26 (p = 0.007), 3.29 (p≤0.001), 4.68 (p≤0.001), 6.48 (p≤0.001), 7.91 (p≤0.001) and 8.55 (p≤0.001) for people reporting two, three, four, five, six and seven poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. Associations between the combined lifestyle behavior index and frequent unhealthy days were statistically significant and similar to those observed for poor self-rated health. Engaging in a greater number of poor lifestyle behaviors was associated with a higher prevalence of poor HRQOL. This association was exacerbated when sleep quality was included in the index.

Mind the gaps - the epidemiology of poor-quality anti-malarials in the malarious world - analysis of the WorldWide Antimalarial Resistance Network database

PubMed Central

2014-01-01

Background Poor quality medicines threaten the lives of millions of patients and are alarmingly common in many parts of the world. Nevertheless, the global extent of the problem remains unknown. Accurate estimates of the epidemiology of poor quality medicines are sparse and are influenced by sampling methodology and diverse chemical analysis techniques. In order to understand the existing data, the Antimalarial Quality Scientific Group at WWARN built a comprehensive, open-access, global database and linked Antimalarial Quality Surveyor, an online visualization tool. Analysis of the database is described here, the limitations of the studies and data reported, and their public health implications discussed. Methods The database collates customized summaries of 251 published anti-malarial quality reports in English, French and Spanish by time and location since 1946. It also includes information on assays to determine quality, sampling and medicine regulation. Results No publicly available reports for 60.6% (63) of the 104 malaria-endemic countries were found. Out of 9,348 anti-malarials sampled, 30.1% (2,813) failed chemical/packaging quality tests with 39.3% classified as falsified, 2.3% as substandard and 58.3% as poor quality without evidence available to categorize them as either substandard or falsified. Only 32.3% of the reports explicitly described their definitions of medicine quality and just 9.1% (855) of the samples collected in 4.6% (six) surveys were conducted using random sampling techniques. Packaging analysis was only described in 21.5% of publications and up to twenty wrong active ingredients were found in falsified anti-malarials. Conclusions There are severe neglected problems with anti-malarial quality but there are important caveats to accurately estimate the prevalence and distribution of poor quality anti-malarials. The lack of reports in many malaria-endemic areas, inadequate sampling techniques and inadequate chemical analytical methods and instrumental procedures emphasizes the need to interpret medicine quality results with caution. The available evidence demonstrates the need for more investment to improve both sampling and analytical methodology and to achieve consensus in defining different types of poor quality medicines. PMID:24712972

Study of a prototype high quantum efficiency thick scintillation crystal video-electronic portal imaging device.

PubMed

Samant, Sanjiv S; Gopal, Arun

2006-08-01

Image quality in portal imaging suffers significantly from the loss in contrast and spatial resolution that results from the excessive Compton scatter associated with megavoltage x rays. In addition, portal image quality is further reduced due to the poor quantum efficiency (QE) of current electronic portal imaging devices (EPIDs). Commercial video-camera-based EPIDs or VEPIDs that utilize a thin phosphor screen in conjunction with a metal buildup plate to convert the incident x rays to light suffer from reduced light production due to low QE (<2% for Eastman Kodak Lanex Fast-B). Flat-panel EPIDs that utilize the same luminescent screen along with an a-Si:H photodiode array provide improved image quality compared to VEPIDs, but they are expensive and can be susceptible to radiation damage to the peripheral electronics. In this article, we present a prototype VEPID system for high quality portal imaging at sub-monitor-unit (subMU) exposures based on a thick scintillation crystal (TSC) that acts as a high QE luminescent screen. The prototype TSC system utilizes a 12 mm thick transparent CsI(Tl) (thallium-activated cesium iodide) scintillator for QE=0.24, resulting in significantly higher light production compared to commercial phosphor screens. The 25 X 25 cm2 CsI(Tl) screen is coupled to a high spatial and contrast resolution Video-Optics plumbicon-tube camera system (1240 X 1024 pixels, 250 microm pixel width at isocenter, 12-bit ADC). As a proof-of-principle prototype, the TSC system with user-controlled camera target integration was adapted for use in an existing clinical gantry (Siemens BEAMVIEW(PLUS)) with the capability for online intratreatment fluoroscopy. Measurements of modulation transfer function (MTF) were conducted to characterize the TSC spatial resolution. The measured MTF along with measurements of the TSC noise power spectrum (NPS) were used to determine the system detective quantum efficiency (DQE). A theoretical expression of DQE(0) was developed to be used as a predictive model to propose improvements in the optics associated with the light detection. The prototype TSC provides DQE(0)=0.02 with its current imaging geometry, which is an order of magnitude greater than that for commercial VEPID systems and comparable to flat-panel imaging systems. Following optimization in the imaging geometry and the use of a high-end, cooled charge-coupled-device (CCD) camera system, the performance of the TSC is expected to improve even further. Based on our theoretical model, the expected DQE(0)=0.12 for the TSC system with the proposed improvements, which exceeds the performance of current flat-panel EPIDs. The prototype TSC provides high quality imaging even at subMU exposures (typical imaging dose is 0.2 MU per image), which offers the potential for daily patient localization imaging without increasing the weekly dose to the patient. Currently, the TSC is capable of limited frame-rate fluoroscopy for intratreatment visualization of patient motion at approximately 3 frames/second, since the achievable frame rate is significantly reduced by the limitations of the camera-control processor. With optimized processor control, the TSC is expected to be capable of intratreatment imaging exceeding 10 frames/second to monitor patient motion.

The effect of image sharpness on quantitative eye movement data and on image quality evaluation while viewing natural images

NASA Astrophysics Data System (ADS)

Vuori, Tero; Olkkonen, Maria

2006-01-01

The aim of the study is to test both customer image quality rating (subjective image quality) and physical measurement of user behavior (eye movements tracking) to find customer satisfaction differences in imaging technologies. Methodological aim is to find out whether eye movements could be quantitatively used in image quality preference studies. In general, we want to map objective or physically measurable image quality to subjective evaluations and eye movement data. We conducted a series of image quality tests, in which the test subjects evaluated image quality while we recorded their eye movements. Results show that eye movement parameters consistently change according to the instructions given to the user, and according to physical image quality, e.g. saccade duration increased with increasing blur. Results indicate that eye movement tracking could be used to differentiate image quality evaluation strategies that the users have. Results also show that eye movements would help mapping between technological and subjective image quality. Furthermore, these results give some empirical emphasis to top-down perception processes in image quality perception and evaluation by showing differences between perceptual processes in situations when cognitive task varies.

New Fe I Level Energies and Line Identifications from Stellar Spectra. II. Initial Results from New Ultraviolet Spectra of Metal-poor Stars

NASA Astrophysics Data System (ADS)

Peterson, Ruth C.; Kurucz, Robert L.; Ayres, Thomas R.

2017-04-01

The Fe I spectrum is critical to many areas of astrophysics, yet many of the high-lying levels remain uncharacterized. To remedy this deficiency, Peterson & Kurucz identified Fe I lines in archival ultraviolet and optical spectra of metal-poor stars, whose warm temperatures favor moderate Fe I excitation. Sixty-five new levels were recovered, with 1500 detectable lines, including several bound levels in the ionization continuum of Fe I. Here, we extend the previous work by identifying 59 additional levels, with 1400 detectable lines, by incorporating new high-resolution UV spectra of warm metal-poor stars recently obtained by the Hubble Space Telescope Imaging Spectrograph. We provide gf values for these transitions, both computed as well as adjusted to fit the stellar spectra. We also expand our spectral calculations to the infrared, confirming three levels by matching high-quality spectra of the Sun and two cool stars in the H-band. The predicted gf values suggest that an additional 3700 Fe I lines should be detectable in existing solar infrared spectra. Extending the empirical line identification work to the infrared would help confirm additional Fe I levels, as would new high-resolution UV spectra of metal-poor turnoff stars below 1900 Å.

Poor sleep quality is associated with a negative cognitive bias and decreased sustained attention.

PubMed

Gobin, Christina M; Banks, Jonathan B; Fins, Ana I; Tartar, Jaime L

2015-10-01

Poor sleep quality has been demonstrated to diminish cognitive performance, impair psychosocial functioning and alter the perception of stress. At present, however, there is little understanding of how sleep quality affects emotion processing. The aim of the present study was to determine the extent to which sleep quality, measured through the Pittsburg Sleep Quality Index, influences affective symptoms as well as the interaction between stress and performance on an emotional memory test and sustained attention task. To that end, 154 undergraduate students (mean age: 21.27 years, standard deviation = 4.03) completed a series of measures, including the Pittsburg Sleep Quality Index, the Sustained Attention to Response Task, an emotion picture recognition task and affective symptom questionnaires following either a control or physical stress manipulation, the cold pressor test. As sleep quality and psychosocial functioning differ among chronotypes, we also included chronotype and time of day as variables of interest to ensure that the effects of sleep quality on the emotional and non-emotional tasks were not attributed to these related factors. We found that poor sleep quality is related to greater depressive symptoms, anxiety and mood disturbances. While an overall relationship between global Pittsburg Sleep Quality Index score and emotion and attention measures was not supported, poor sleep quality, as an independent component, was associated with better memory for negative stimuli and a deficit in sustained attention to non-emotional stimuli. Importantly, these effects were not sensitive to stress, chronotype or time of day. Combined, these results suggest that individuals with poor sleep quality show an increase in affective symptomatology as well as a negative cognitive bias with a concomitant decrease in sustained attention to non-emotional stimuli. © 2015 European Sleep Research Society.

Factors Affecting Quality of Laboratory Services in Public and Private Health Facilities in Addis Ababa, Ethiopia.

PubMed

Mesfin, Eyob Abera; Taye, Binyam; Belay, Getachew; Ashenafi, Aytenew; Girma, Veronica

2017-10-01

Quality laboratory service is an essential component of health care system but in Sub-Saharan Africa such as Ethiopia, laboratories quality system remains weak due to several factors and it needs more attention to strengthen its capacity and quality system. A cross sectional study was conducted using a questionnaire to assess factors affecting the quality of laboratory service at private and public health institutions in Addis Ababa. A total of 213 laboratory professionals participated in the study and 131 (61.5%) participants had bachelor degree. Majority, 133 (62.4%), of the professionals did not attend any work related training. Seventy five (35.2%) respondents believed that their laboratories did not provide quality laboratory services and the major reported factors affecting provision of quality services were shortage of resources (64.3%), poor management support (57.3%), poor equipment quality (53.4%), high workload (41.1%), lack of equipment calibration (38.3%) and lack of knowledge (23.3%). Moreover logistic regression analysis showed that provision of quality laboratory service was significantly associated with result verification (AOR=9.21, 95% CI=2.26, 37.48), internal quality control (AOR= 6.11, 95% CI=2.11, 17.70), turnaround time (AOR=5.11, 95% CI=1.94, 13.46), shortage of equipment (AOR=7.76, 95% CI=2.55, 23.66), communication with clinicians (AOR=3.24, 95% CI=1.25, 8.41) and lack of job description (AOR=3.67, 95% CI=1.319, 10.22). In conclusion, the major factors that affecting the quality of laboratory service were associated with poor human resource management, poor resources provision, poor management commitment, ineffective communication system and lack of well-established quality management system.

Factors Affecting Quality of Laboratory Services in Public and Private Health Facilities in Addis Ababa, Ethiopia

PubMed Central

Taye, Binyam; Belay, Getachew; Ashenafi, Aytenew; Girma, Veronica

2017-01-01

Background Quality laboratory service is an essential component of health care system but in Sub-Saharan Africa such as Ethiopia, laboratories quality system remains weak due to several factors and it needs more attention to strengthen its capacity and quality system. Methodology A cross sectional study was conducted using a questionnaire to assess factors affecting the quality of laboratory service at private and public health institutions in Addis Ababa. Results A total of 213 laboratory professionals participated in the study and 131 (61.5%) participants had bachelor degree. Majority, 133 (62.4%), of the professionals did not attend any work related training. Seventy five (35.2%) respondents believed that their laboratories did not provide quality laboratory services and the major reported factors affecting provision of quality services were shortage of resources (64.3%), poor management support (57.3%), poor equipment quality (53.4%), high workload (41.1%), lack of equipment calibration (38.3%) and lack of knowledge (23.3%). Moreover logistic regression analysis showed that provision of quality laboratory service was significantly associated with result verification (AOR=9.21, 95% CI=2.26, 37.48), internal quality control (AOR= 6.11, 95% CI=2.11, 17.70), turnaround time (AOR=5.11, 95% CI=1.94, 13.46), shortage of equipment (AOR=7.76, 95% CI=2.55, 23.66), communication with clinicians (AOR=3.24, 95% CI=1.25, 8.41) and lack of job description (AOR=3.67, 95% CI=1.319, 10.22). Conclusion In conclusion, the major factors that affecting the quality of laboratory service were associated with poor human resource management, poor resources provision, poor management commitment, ineffective communication system and lack of well-established quality management system. PMID:29075171

Higher Facebook use predicts greater body image dissatisfaction during pregnancy: The role of self-comparison.

PubMed

Hicks, S; Brown, A

2016-09-01

poor body image during pregnancy is a growing issue. Similarly, emerging evidence is suggesting that social media use may increase the risk of poor well-being e.g. depression, anxiety and body image concerns amongst users. Research has not examined how social media use may influence women during pregnancy. The aim of this study was to therefore to explore the relationship between body image during pregnancy and Facebook use. a cross sectional self-report questionnaire. two hundred and sixty nine pregnant women. community groups and online forums. a self-report questionnaire exploring maternal body image, use of Facebook and how mothers perceived Facebook affected their body image. Descriptive statistics were used to explore body image perceptions. Partial correlations (controlling for maternal age, education, parity and gestation) were used to explore the association between Facebook use and body image during pregnancy. negative body image was common in the sample, increased with gestation and was unrelated to pre pregnancy weight. Mothers with a Facebook account had higher body image concerns than those without a Facebook account. Of those with an account, increased Facebook use was associated with increased body image dissatisfaction, particularly in terms of postnatal concerns for how their body would look with 56.5% reporting that they frequently compared their pregnant body to other pregnant women on the site. Facebook access was frequent with 85% of participants checking it at least once per day and the average participant spending over an hour per day on the site. although causality cannot be fully explained, Facebook use may increase mother's risk of poor body image dissatisfaction during pregnancy. Mothers with already poor body image may also be drawn to the site in order to make comparisons of their appearance. the potential impact of Facebook on increasing the risk of, or promoting existing poor body image is an important message for those working to support mothers during pregnancy and the postnatal period. Care should be taken when directing mothers to use the site. Copyright © 2016. Published by Elsevier Ltd.

Self-rated imagery and encoding strategies in visual memory.

PubMed

Berger, G H; Gaunitz, S C

1979-02-01

The value of self-rated vividness of imagery in predicting performance was investigated, taking into account the mnemonic strategies utilized among subjects performing a visual-memory task. Subjects classified as 'good' or 'poor' imagers, according to their scores in the Vividness of Visual Imagery Questionnaire (VVIQ; Marks, 1972), were to detect as rapidly as possible differences between pairs of similar pictures presented consecutively. No coding instructions were given and the mnemonic strategies used were analysed by studying subjective reports and objective performance measurements. The results indicated that the subjects utilized two main strategies--a detail or an image strategy. The detail strategy was the more efficient. In accordance with a previous study (Berger & Gaunitz, 1977), it was found that the VVIQ did not discriminate between performance by 'good' and 'poor' imagers. However, among subjects who used the image strategy, 'good' imagers performed more rapidly than 'poor' imagers. Self-rated imagery may then have some value in predicting performance among individuals shown to have utilized an image strategy.

The Maladies of Water and War: Addressing Poor Water Quality in Iraq

PubMed Central

2013-01-01

Water is essential in providing nutrients, but contaminated water contributes to poor population health. Water quality and availability can change in unstructured situations, such as war. To develop a practical strategy to address poor water quality resulting from intermittent wars in Iraq, I reviewed information from academic sources regarding waterborne diseases, conflict and war, water quality treatment, and malnutrition. The prevalence of disease was high in impoverished, malnourished populations exposed to contaminated water sources. The data aided in developing a strategy to improve water quality in Iraq, which encompasses remineralized water from desalination plants, health care reform, monitoring and evaluation systems, and educational public health interventions. PMID:23597360

Interaction of sleep quality and sleep duration on glycemic control in patients with type 2 diabetes mellitus.

PubMed

Tang, Yunzhao; Meng, Lingling; Li, Daiqing; Yang, Min; Zhu, Yanjuan; Li, Chenguang; Jiang, Zhenhuan; Yu, Ping; Li, Zhu; Song, Hongna; Ni, Changlin

2014-01-01

Copious evidence from epidemiological and laboratory studies has revealed that sleep status is associated with glucose intolerance, insulin resistance, thus increasing the risk of developing type 2 diabetes. The aim of this study was to reveal the interaction of sleep quality and sleep quantity on glycemic control in patients with type 2 diabetes mellitus. From May 2013 to May 2014, a total of 551 type 2 diabetes patients in Tianjin Metabolic Diseases Hospital were enrolled. Blood samples were taken to measure glycosylated hemoglobin (HbA1c), and all the patients completed the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) questionnaire to evaluate their sleep status. "Good sleep quality" was defined as PQSI <5, "average sleep quality" was defined as PQSI 6-8, and "poor sleep quality" was defined as PQSI >8. Poor glycemic control was defined as HbA1c ≥7%. Sleep quantity was categorized as <6, 6-8, and >8 hours/night. Short sleep time was defined as sleep duration <6 hours/night. In the poor glycemic control group, the rate of patients who had insufficient sleep was much higher than that in the other group (χ(2) = 11.16, P = 0.037). The rate of poor sleep quality in poor glycemic control group was much greater than that in the average control group (χ(2) = 9.79, P = 0.007). After adjusted by gender, age, body mass index, and disease duration, the adjusted PSQI score's OR was 1.048 (95% CI 1.007-1.092, P = 0.023) for HbA1c level. The sleep duration's OR was 0.464 (95% CI 0.236-0.912, P = 0.026) for HbA1c level. One-way analysis of variance showed that the poor sleep quality group had the highest homeostasis model assessment-insulin resistance (P < 0.01). Inadequate sleep, in both quality and quantity, should be regarded as a plausible risk factor for glycemic control in type 2 diabetes. Poor sleep might bring much more serious insulin resistance and could be the reason for bad glycemic control. A good night's sleep should be seen as a critical health component tool in the prevention and treatment of type 2 diabetes. It is important for clinicians to target the root causes of short sleep duration and/or poor sleep quality.

Cranial surgery navigation aided by a compact intraoperative magnetic resonance imager.

PubMed

Schulder, M; Liang, D; Carmel, P W

2001-06-01

In this article the authors report on a novel, compact device for magnetic resonance (MR) imaging that has been developed for use in a standard neurosurgical operating room. The device includes a permanent magnet with a field strength of 0.12 tesla. The poles of the magnet are vertically aligned, with a gap of 25 cm. When not in use the magnet is stored in a shielded cage in a corner of the operating room; it is easily moved into position and attaches to a regular operating table. The magnet is raised for imaging when needed and may be lowered to allow surgery to proceed unencumbered. Surgical navigation with optical and/or magnetic probes is incorporated into the system. Twenty-five patients have undergone removal of intracranial lesions with the aid of this device. Operations included craniotomy for tumor or other lesion in 18 patients and transsphenoidal resection of tumor in seven. The number of scans ranged from two to five per surgery (average 3.4); image quality was excellent in 45%, adequate in 43%, and poor in 12%. In four patients MR imaging revealed additional tumor that was then resected; in five others visual examination of the operative field was inconclusive but complete tumor removal was confirmed on MR imaging. In 21 patients early postoperative diagnostic MR studies corroborated the findings on the final intraoperative MR image. Using a water-covered phantom, the accuracy of the navigational tools was assessed; 120 data points were measured. The accuracy of the magnetic probe averaged 1.3 mm and 2.1 mm in the coronal and axial planes, respectively; the optical probe accuracy was 2.1 mm and 1.8 mm in those planes. This device provides high-quality intraoperative imaging and accurate surgical navigation with minimal disruption in a standard neurosurgical operating room.

Quantification of the heterogeneity of prognostic cellular biomarkers in ewing sarcoma using automated image and random survival forest analysis.

PubMed

Bühnemann, Claudia; Li, Simon; Yu, Haiyue; Branford White, Harriet; Schäfer, Karl L; Llombart-Bosch, Antonio; Machado, Isidro; Picci, Piero; Hogendoorn, Pancras C W; Athanasou, Nicholas A; Noble, J Alison; Hassan, A Bassim

2014-01-01

Driven by genomic somatic variation, tumour tissues are typically heterogeneous, yet unbiased quantitative methods are rarely used to analyse heterogeneity at the protein level. Motivated by this problem, we developed automated image segmentation of images of multiple biomarkers in Ewing sarcoma to generate distributions of biomarkers between and within tumour cells. We further integrate high dimensional data with patient clinical outcomes utilising random survival forest (RSF) machine learning. Using material from cohorts of genetically diagnosed Ewing sarcoma with EWSR1 chromosomal translocations, confocal images of tissue microarrays were segmented with level sets and watershed algorithms. Each cell nucleus and cytoplasm were identified in relation to DAPI and CD99, respectively, and protein biomarkers (e.g. Ki67, pS6, Foxo3a, EGR1, MAPK) localised relative to nuclear and cytoplasmic regions of each cell in order to generate image feature distributions. The image distribution features were analysed with RSF in relation to known overall patient survival from three separate cohorts (185 informative cases). Variation in pre-analytical processing resulted in elimination of a high number of non-informative images that had poor DAPI localisation or biomarker preservation (67 cases, 36%). The distribution of image features for biomarkers in the remaining high quality material (118 cases, 104 features per case) were analysed by RSF with feature selection, and performance assessed using internal cross-validation, rather than a separate validation cohort. A prognostic classifier for Ewing sarcoma with low cross-validation error rates (0.36) was comprised of multiple features, including the Ki67 proliferative marker and a sub-population of cells with low cytoplasmic/nuclear ratio of CD99. Through elimination of bias, the evaluation of high-dimensionality biomarker distribution within cell populations of a tumour using random forest analysis in quality controlled tumour material could be achieved. Such an automated and integrated methodology has potential application in the identification of prognostic classifiers based on tumour cell heterogeneity.

Characterizing the Weeks Island Salt Dome drilling of and seismic measurements from boreholes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sattler, A.R.; Harding, R.S.; Jacobson, R.D.

1996-10-01

A sinkhole 36 ft across, 30 ft deep was first observed in the alluvium over the Weeks Island Salt Dome (salt mine converted for oil storage by US Strategic Petroleum Reserve) May 1992. Four vertical, two slanted boreholes were drilled for diagnostics. Crosswell seismic data were generated; the velocity images suggest that the sinkhole collapse is complicated, not a simple vertical structure. The coring operation was moderately difficult; limited core was obtained through the alluvium, and the quality of the salt core from the first two vertical wells was poor. Core quality improved with better bit selection, mud, and drillingmore » method. The drilling fluid program provided fairly stable holes allowing open hole logs to be run. All holes were cemented successfully (although it took 3 attempts in one case).« less

The association of visually-assessed quality of movement during jump-landing with ankle dorsiflexion range-of-motion and hip abductor muscle strength among healthy female athletes.

PubMed

Rabin, Alon; Einstein, Ofira; Kozol, Zvi

2018-05-01

To explore the association between ankle dorsiflexion (DF) range of motion (ROM), and hip abductor muscle strength, to visually-assessed quality of movement during jump-landing. Cross-sectional. Gymnasium of participating teams. 37 female volleyball players. Quality of movement in the frontal-plane, sagittal-plane, and overall (both planes) was visually rated as "good/moderate" or "poor". Weight-bearing Ankle DF ROM and hip abductor muscle strength were compared between participants with differing quality of movement. Weight-bearing DF ROM on both sides was decreased among participants with "poor" sagittal-plane quality of movement (dominant side: 50.8° versus 43.6°, P = .02; non-dominant side: 54.6° versus 45.9°, P = .01), as well as among participants with an overall "poor" quality of movement (dominant side: 51.8° versus 44.0°, P < .01; non-dominant side: 56.5° versus 45.1°, P < .01). Weight-bearing ankle DF on the non-dominant side was decreased among participants with a "poor" frontal-plane quality of movement (53.9° versus 46.0°, P = .02). No differences in hip abductor muscle strength were noted between participants with differing quality of movement. Visual assessment of jump-landing can detect differences in quality of movement that are associated with ankle DF ROM. Clinicians observing a poor quality of movement may wish to assess ankle DF ROM. Copyright © 2018 Elsevier Ltd. All rights reserved.

The correlation study of parallel feature extractor and noise reduction approaches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dewi, Deshinta Arrova; Sundararajan, Elankovan; Prabuwono, Anton Satria

2015-05-15

This paper presents literature reviews that show variety of techniques to develop parallel feature extractor and finding its correlation with noise reduction approaches for low light intensity images. Low light intensity images are normally displayed as darker images and low contrast. Without proper handling techniques, those images regularly become evidences of misperception of objects and textures, the incapability to section them. The visual illusions regularly clues to disorientation, user fatigue, poor detection and classification performance of humans and computer algorithms. Noise reduction approaches (NR) therefore is an essential step for other image processing steps such as edge detection, image segmentation,more » image compression, etc. Parallel Feature Extractor (PFE) meant to capture visual contents of images involves partitioning images into segments, detecting image overlaps if any, and controlling distributed and redistributed segments to extract the features. Working on low light intensity images make the PFE face challenges and closely depend on the quality of its pre-processing steps. Some papers have suggested many well established NR as well as PFE strategies however only few resources have suggested or mentioned the correlation between them. This paper reviews best approaches of the NR and the PFE with detailed explanation on the suggested correlation. This finding may suggest relevant strategies of the PFE development. With the help of knowledge based reasoning, computational approaches and algorithms, we present the correlation study between the NR and the PFE that can be useful for the development and enhancement of other existing PFE.« less

Naturalness and interestingness of test images for visual quality evaluation

NASA Astrophysics Data System (ADS)

Halonen, Raisa; Westman, Stina; Oittinen, Pirkko

2011-01-01

Balanced and representative test images are needed to study perceived visual quality in various application domains. This study investigates naturalness and interestingness as image quality attributes in the context of test images. Taking a top-down approach we aim to find the dimensions which constitute naturalness and interestingness in test images and the relationship between these high-level quality attributes. We compare existing collections of test images (e.g. Sony sRGB images, ISO 12640 images, Kodak images, Nokia images and test images developed within our group) in an experiment combining quality sorting and structured interviews. Based on the data gathered we analyze the viewer-supplied criteria for naturalness and interestingness across image types, quality levels and judges. This study advances our understanding of subjective image quality criteria and enables the validation of current test images, furthering their development.

Evaluation of the visual performance of image processing pipes: information value of subjective image attributes

NASA Astrophysics Data System (ADS)

Nyman, G.; Häkkinen, J.; Koivisto, E.-M.; Leisti, T.; Lindroos, P.; Orenius, O.; Virtanen, T.; Vuori, T.

2010-01-01

Subjective image quality data for 9 image processing pipes and 8 image contents (taken with mobile phone camera, 72 natural scene test images altogether) from 14 test subjects were collected. A triplet comparison setup and a hybrid qualitative/quantitative methodology were applied. MOS data and spontaneous, subjective image quality attributes to each test image were recorded. The use of positive and negative image quality attributes by the experimental subjects suggested a significant difference between the subjective spaces of low and high image quality. The robustness of the attribute data was shown by correlating DMOS data of the test images against their corresponding, average subjective attribute vector length data. The findings demonstrate the information value of spontaneous, subjective image quality attributes in evaluating image quality at variable quality levels. We discuss the implications of these findings for the development of sensitive performance measures and methods in profiling image processing systems and their components, especially at high image quality levels.

Recommendations for research design and reporting in computer-assisted diagnosis to facilitate meta-analysis.

PubMed

Eadie, Leila H; Taylor, Paul; Gibson, Adam P

2012-04-01

Computer-assisted diagnosis (CAD) describes a diverse, heterogeneous range of applications rather than a single entity. The aims and functions of CAD systems vary considerably and comparing studies and systems is challenging due to methodological and design differences. In addition, poor study quality and reporting can reduce the value of some publications. Meta-analyses of CAD are therefore difficult and may not provide reliable conclusions. Aiming to determine the major sources of heterogeneity and thereby what CAD researchers could change to allow this sort of assessment, this study reviews a sample of 147 papers concerning CAD used with imaging for cancer diagnosis. It discusses sources of variability, including the goal of the CAD system, learning methodology, study population, design, outcome measures, inclusion of radiologists, and study quality. Based upon this evidence, recommendations are made to help researchers optimize the quality and comparability of their trial design and reporting. Copyright © 2011 Elsevier Inc. All rights reserved.

Indoor Air Quality in Schools: Clean Air Is Good Business.

ERIC Educational Resources Information Center

Guarneiri, Michele A.

2003-01-01

Describes the effect of poor indoor air quality (IAQ) on student health, the cost of safeguarding good IAQ, the cause of poor IAQ in schools, how to tell whether a school has an IAQ problem, and how the U.S. Environmental Protection Agency can help schools improve indoor air quality though the use of their free "Indoor Air Quality Tools for…

Factors associated with health-related quality of life among operating engineers.

PubMed

Choi, Seung Hee; Redman, Richard W; Terrell, Jeffrey E; Pohl, Joanne M; Duffy, Sonia A

2012-11-01

Because health-related quality of life among blue-collar workers has not been well studied, the purpose of this study was to determine factors associated with health-related quality of life among Operating Engineers. With cross-sectional data from a convenience sample of 498 Operating Engineers, personal and health behavioral factors associated with health-related quality of life were examined. Multivariate linear regression analysis revealed that personal factors (older age, being married, more medical comorbidities, and depression) and behavioral factors (smoking, low fruit and vegetable intake, low physical activity, high body mass index, and low sleep quality) were associated with poor health-related quality of life. Operating Engineers are at risk for poor health-related quality of life. Underlying medical comorbidities and depression should be well managed. Worksite wellness programs addressing poor health behaviors may be beneficial.

Biological interaction between sleep quality and depression in type 2 diabetes.

PubMed

Zhao, J; Li, X-L; Han, K; Tao, Z-Q; Wu, Z-M

2016-07-01

To explore the interaction of sleep quality and depression among patients with type 2 diabetes mellitus (T2DM). With multistage cluster sampling, the living quality of all participants was investigated. The indicator of interaction was calculated according to the delta method and non-conditional logistic regression model. There were 944 residents involved in the final analysis including 365 males and 579 females. The average age was (64 ± 10.2) years. The rate of poor sleep quality and poor sleep quality combined depression were 33.6% and 40.1%, respectively. Due to poor sleep quality and depression in patients with T2DM, the combined interaction index was 2.48 (95% CI 1.44-4.29), the relative excess risk was 3.42 (95% CI 2.16-4.67), and the attributable proportion was 0.51 (95% CI 0.32-0.70). An additive interaction rather than a multiplicative interaction of poor sleep quality and depression in affecting the quality of life was found in T2DM patients. When both factors existed at the same time, the interaction effect of these 2 factors was greater than the sum of the two factors.

Poor tap water quality experiences and poor sleep quality during the Flint, Michigan Municipal Water Crisis.

PubMed

Kruger, Daniel J; Kodjebacheva, Gergana D; Cupal, Suzanne

2017-08-01

After inadequate official response to community concerns over water quality following changes in Flint's municipal water supply, this study sought evidence for a relationship between water quality and community mental health. The Speak to Your Health Community Survey is a community-based participatory component of the health surveillance system in Genesee County, Michigan. This cross-sectional survey recruits participants from every residential Census Tract of the county and strives for demographic representativeness. Respondents (n=834) rated their tap water quality (taste, smell, appearance) as poor (36%), fair (18%), good (20%), very good (17%), and excellent (10%). They rated their sleep quality as poor (12%), fair (28%), good (39%), very good (18%), and excellent (4%), and had an average (SD) sleep length of 408(90) minutes. Controlling for age, sex, years of education, and whether respondents were African American and Hispanic/Latino/a, lower perceived tap water quality was associated with lower sleep quality and shorter sleep length. Results indicate that adverse health conditions related to the water crisis extend beyond lead poisoning in children and include deterioration of sleep conditions among adult residents. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Change of sleep quality from pre- to 3 years post-solid organ transplantation: The Swiss Transplant Cohort Study

PubMed Central

Denhaerynck, Kris; Huynh-Do, Uyen; Binet, Isabelle; Hadaya, Karine; De Geest, Sabina

2017-01-01

Background Poor sleep quality (SQ) is common after solid organ transplantation; however, very little is known about its natural history. We assessed the changes in SQ from pre- to 3 years post-transplant in adult heart, kidney, liver and lung recipients included in the prospective nation-wide Swiss Transplant Cohort Study. We explored associations with selected variables in patients suffering persistent poor SQ compared to those with good or variable SQ. Methods Adult single organ transplant recipients enrolled in the Swiss Transplant Cohort Study with pre-transplant and at least 3 post-transplant SQ assessment data were included. SQ was self-reported pre-transplant (at listing), then at 6, 12, 24 and 36 months post-transplant. A single SQ item was used to identify poor (0–5) and good sleepers (6–10). Between organ groups, SQ was compared via logistic regression analysis with generalized estimating equations. Within the group reporting persistently poor SQ, we used logistic regression or Kaplan-Meier analysis as appropriate to check for differences in global quality of life and survival. Results In a sample of 1173 transplant patients (age: 52.1±13.2 years; 65% males; 66% kidney, 17% liver, 10% lung, 7% heart) transplanted between 2008 and 2012, pre- transplant poor SQ was highest in liver (50%) and heart (49%) recipients. Overall, poor SQ decreased significantly from pre-transplant (38%) to 24 months post-transplant (26%) and remained stable at 3 years (29%). Patients reporting persistently poor SQ had significantly more depressive symptomatology and lower global quality of life. Conclusion Because self-reported poor SQ is related to poorer global quality of life, these results emphasize the need for further studies to find suitable treatment options for poor SQ in transplant recipients. PMID:29020112

Evaluation of a rule-based compositing technique for Landsat-5 TM and Landsat-7 ETM+ images

NASA Astrophysics Data System (ADS)

Lück, W.; van Niekerk, A.

2016-05-01

Image compositing is a multi-objective optimization process. Its goal is to produce a seamless cloud and artefact-free artificial image. This is achieved by aggregating image observations and by replacing poor and cloudy data with good observations from imagery acquired within the timeframe of interest. This compositing process aims to minimise the visual artefacts which could result from different radiometric properties, caused by atmospheric conditions, phenologic patterns and land cover changes. It has the following requirements: (1) image compositing must be cloud free, which requires the detection of clouds and shadows, and (2) the image composite must be seamless, minimizing artefacts and visible across inter image seams. This study proposes a new rule-based compositing technique (RBC) that combines the strengths of several existing methods. A quantitative and qualitative evaluation is made of the RBC technique by comparing it to the maximum NDVI (MaxNDVI), minimum red (MinRed) and maximum ratio (MaxRatio) compositing techniques. A total of 174 Landsat TM and ETM+ images, covering three study sites and three different timeframes for each site, are used in the evaluation. A new set of quantitative/qualitative evaluation techniques for compositing quality measurement was developed and showed that the RBC technique outperformed all other techniques, with MaxRatio, MaxNDVI, and MinRed techniques in order of performance from best to worst.

Sorghum response to foliar application of phosphorus and potassium with saline water irrigation

USDA-ARS?s Scientific Manuscript database

Increasing demand for fresh water resources for urban and industrial uses is leading to limited availability of better quality water for crop irrigation. Therefore, crop response to poor quality irrigation water (ex: saline water), and strategies to mitigate the negative effects of poor quality irri...

The Quality of Medicines Used in Children and Supplied by Private Pharmaceutical Wholesalers in Kinshasa, Democratic Republic of Congo: A Prospective Survey.

PubMed

Schiavetti, Benedetta; Wynendaele, Evelien; De Spiegeleer, Bart; Mbinze, Geremie J; Kalenda, Nicodème; Marini, Roland; Melotte, Vera; Hasker, Epco; Meessen, Bruno; Ravinetto, Raffaella; Van der Elst, Josiane; Mutolo Ngeleka, Daniel

2018-03-01

Poor-quality medicines are a threat to public health in many low- and middle-income countries, and prospective surveys are needed to inform corrective actions. Therefore, we conducted a cross-sectional survey on a sample of products used for children and available in the private market in Kinshasa, Democratic Republic Congo: amoxicillin (AX) and artemether/lumefantrine (AL), powders for suspension, and paracetamol (PC) tablets 500 mg. Overall, 417 products were covertly purchased from 61 wholesalers. To obtain a representative sample, the products were weighted on their market shares and a subset of 239 samples was randomly extracted to undergo in-depth visual inspection locally, and they were chemically assessed at two accredited laboratories in Belgium. Samples were defined of "poor-quality" if they failed to comply with at least one specification of the International Pharmacopoeia (for AL) or United States Pharmacopoeia 37 (for AX and PC). Results are reported according to the Medicine Quality Assessment Reporting Guideline. The visual inspection detected nonconformities in the aspects of antimalarial powders for suspension, and poor-quality labels across all medicine types. According to chemical analysis, 27.2% samples were of poor quality and 59.5% of AL samples were underdosed in artemether. Poor quality was more frequent for locally manufactured antimalarials (83.3%, P = 0.021; 86.4%, P = 0.022) and PC (4.8%, P = 0.000). The poor quality of the surveyed products may decrease the treatment's efficacy and favor the development of resistances to antimalarials. It is hoped that these findings may guide the corrective actions of the Democratic Republic of Congo Regulatory Authority, which was the main partner in the research.

Poor Sleep Quality, Antepartum Depression and Suicidal Ideation among Pregnant Women

PubMed Central

Gelaye, Bizu; Addae, Gifty; Neway, Beemnet; Larrabure-Torrealva, Gloria T.; Qiu, Chunfang; Stoner, Lee; Fernandez, Miguel Angel Luque; Sanchez, Sixto E.; Williams, Michelle A.

2016-01-01

Objective To evaluate the independent and combined associations of maternal self-reported poor sleep quality and antepartum depression with suicidal ideation during the third trimester Methods A cross-sectional study was conducted among 1,298 pregnant women (between 24 and 28 gestational weeks) attending prenatal clinics in Lima, Peru. Antepartum depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9). The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to assess sleep quality. Multivariate logistical regression procedures were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) after adjusting for putative confounders. Results Approximately, 17% of women were classified as having poor sleep quality (defined using the recommended criteria of PSQI global score of >5 vs. ≤5). Further, the prevalence of antepartum depression and suicidal ideation were 10.3% and 8.5%, respectively in this cohort. After adjusting for confounders including depression, poor sleep quality was associated with a 2.81-fold increased odds of suicidal ideation (OR=2.81; 95% CI 1.78–4.45). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 28% increase in odds for suicidal ideation, even after adjusting for depression (OR=1.28; 95% CI 1.15–1.41). The odds of suicidal ideation was particularly high among depressed women with poor sleep quality (OR=13.56 95% CI 7.53–24.41) as compared with women without either risk factor. Limitations This cross-sectional study utilized self-reported data. Causality cannot be inferred, and results may not be fully generalizable. Conclusion Poor sleep quality, even after adjusting for depression, is associated with antepartum suicidal ideation. Our findings support the need to explore sleep-focused interventions for pregnant women. PMID:27930912

Poor sleep quality, antepartum depression and suicidal ideation among pregnant women.

PubMed

Gelaye, Bizu; Addae, Gifty; Neway, Beemnet; Larrabure-Torrealva, Gloria T; Qiu, Chunfang; Stoner, Lee; Luque Fernandez, Miguel Angel; Sanchez, Sixto E; Williams, Michelle A

2017-02-01

To evaluate the independent and combined associations of maternal self-reported poor sleep quality and antepartum depression with suicidal ideation during the third trimester METHODS: A cross-sectional study was conducted among 1298 pregnant women (between 24 and 28 gestational weeks) attending prenatal clinics in Lima, Peru. Antepartum depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9). The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to assess sleep quality. Multivariate logistical regression procedures were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) after adjusting for putative confounders. Approximately, 17% of women were classified as having poor sleep quality (defined using the recommended criteria of PSQI global score of >5 vs. ≤5). Further, the prevalence of antepartum depression and suicidal ideation were 10.3% and 8.5%, respectively in this cohort. After adjusting for confounders including depression, poor sleep quality was associated with a 2.81-fold increased odds of suicidal ideation (OR=2.81; 95% CI 1.78-4.45). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 28% increase in odds for suicidal ideation, even after adjusting for depression (OR=1.28; 95% CI 1.15-1.41). The odds of suicidal ideation was particularly high among depressed women with poor sleep quality (OR=13.56 95% CI 7.53-24.41) as compared with women without either risk factor. This cross-sectional study utilized self-reported data. Causality cannot be inferred, and results may not be fully generalizable. Poor sleep quality, even after adjusting for depression, is associated with antepartum suicidal ideation. Our findings support the need to explore sleep-focused interventions for pregnant women. Copyright © 2016 Elsevier B.V. All rights reserved.

Scanning tunneling microscopy and atomic force microscopy: application to biology and technology.

PubMed

Hansma, P K; Elings, V B; Marti, O; Bracker, C E

1988-10-14

The scanning tunneling microscope (STM) and the atomic force microscope (AFM) are scanning probe microscopes capable of resolving surface detail down to the atomic level. The potential of these microscopes for revealing subtle details of structure is illustrated by atomic resolution images including graphite, an organic conductor, an insulating layered compound, and individual adsorbed oxygen atoms on a semiconductor. Application of the STM for imaging biological materials directly has been hampered by the poor electron conductivity of most biological samples. The use of thin conductive metal coatings and replicas has made it possible to image some biological samples, as indicated by recently obtained images of a recA-DNA complex, a phospholipid bilayer, and an enzyme crystal. The potential of the AFM, which does not require a conductive sample, is shown with molecular resolution images of a nonconducting organic monolayer and an amino acid crystal that reveals individual methyl groups on the ends of the amino acids. Applications of these new microscopes to technology are demonstrated with images of an optical disk stamper, a diffraction grating, a thin-film magnetic recording head, and a diamond cutting tool. The STM has even been used to improve the quality of diffraction gratings and magnetic recording heads.

Anatomic study of the canine stifle using low-field magnetic resonance imaging (MRI) and MRI arthrography.

PubMed

Pujol, Esteban; Van Bree, Henri; Cauzinille, Laurent; Poncet, Cyrill; Gielen, Ingrid; Bouvy, Bernard

2011-06-01

To investigate the use of low-field magnetic resonance imaging (MRI) and MR arthrography in normal canine stifles and to compare MRI images to gross dissection. Descriptive study. Adult canine pelvic limbs (n=17). Stifle joints from 12 dogs were examined by orthopedic and radiographic examination, synovial fluid analysis, and MRI performed using a 0.2 T system. Limbs 1 to 7 were used to develop the MR and MR arthrography imaging protocol. Limbs 8-17 were studied with the developed MR and MR arthrography protocol and by gross dissection. Three sequences were obtained: T1-weighted spin echo (SE) in sagittal, dorsal, and transverse plane; T2-weighted SE in sagittal plane and T1-gradient echo in sagittal plane. Specific bony and soft tissue structures were easily identifiable with the exception of articular cartilage. The cranial and caudal cruciate ligaments were identified. Medial and lateral menisci were seen as wedge-shaped hypointense areas. MR arthrography permitted further delineation of specific structures. MR images corresponded with gross dissection morphology. With the exception of poor delineation of articular cartilage, a low-field MRI and MR arthrography protocol provides images of adequate quality to assess the normal canine stifle joint. © Copyright 2011 by The American College of Veterinary Surgeons.

Neural network for image compression

NASA Astrophysics Data System (ADS)

Panchanathan, Sethuraman; Yeap, Tet H.; Pilache, B.

1992-09-01

In this paper, we propose a new scheme for image compression using neural networks. Image data compression deals with minimization of the amount of data required to represent an image while maintaining an acceptable quality. Several image compression techniques have been developed in recent years. We note that the coding performance of these techniques may be improved by employing adaptivity. Over the last few years neural network has emerged as an effective tool for solving a wide range of problems involving adaptivity and learning. A multilayer feed-forward neural network trained using the backward error propagation algorithm is used in many applications. However, this model is not suitable for image compression because of its poor coding performance. Recently, a self-organizing feature map (SOFM) algorithm has been proposed which yields a good coding performance. However, this algorithm requires a long training time because the network starts with random initial weights. In this paper we have used the backward error propagation algorithm (BEP) to quickly obtain the initial weights which are then used to speedup the training time required by the SOFM algorithm. The proposed approach (BEP-SOFM) combines the advantages of the two techniques and, hence, achieves a good coding performance in a shorter training time. Our simulation results demonstrate the potential gains using the proposed technique.

Impact of weak social ties and networks on poor sleep quality: A case study of Iranian employees.

PubMed

Masoudnia, Ebrahim

2015-12-01

The poor sleep quality is one of the major risk factors of somatic, psychiatric and social disorders and conditions as well as the major predictors of quality of employees' performance. The previous studies in Iran had neglected the impacts of social factors including social networks and ties on adults sleep quality. Thus, the aim of the current research was to determine the relationship between social networks and adult employees' sleep quality. This study was conducted with a correlational and descriptive design. Data were collected from 360 participants (183 males and 177 females) who were employed in Yazd public organizations in June and July of 2014. These samples were selected based on random sampling method. In addition, the measuring tools were the Pittsburgh Sleep Quality Index (PSQI) and Social Relations Inventory (SRI). Based on the results, the prevalence rate of sleep disorder among Iranian adult employees was 63.1% (total PSQI>5). And, after controlling for socio-demographic variables, there was significant difference between individuals with strong and poor social network and ties in terms of overall sleep quality (p<.01), subjective sleep quality (p<.01), habitual sleep efficiency (p<.05), and daytime dysfunction (p<.01). The results also revealed that the employees with strong social network and ties had better overall sleep quality, had the most habitual sleep efficiency, and less daytime dysfunction than employees with poor social network and ties. It can be implied that the weak social network and ties serve as a risk factor for sleep disorders or poor sleep quality for adult employees. Therefore, the social and behavioral interventions seem essential to improve the adult's quality sleep. Copyright © 2015 Elsevier B.V. All rights reserved.

Association between quality of sleep and health-related quality of life in persons with diabetes mellitus type 2.

PubMed

Bani-Issa, Wegdan; Al-Shujairi, Arwa M; Patrick, Linda

2018-04-01

To estimate the relationship of sleep quality with health-related quality of life (HRQOL) in persons with diabetes mellitus type 2 (DMT2) living in the United Arab Emirates (UAE). DMT2 is an epidemic health condition in the UAE that has enormous impacts on heath, and consequent effects on HRQOL. However, because of an absence of screening for quality of sleep, people with DMT2 who experience poor sleep are likely to go untreated, which may compound the distressing impacts of DMT2 on their HRQOL. This is a cross-sectional quantitative research design. A sample of 268 participants with DMT2 were recruited from community healthcare settings in the UAE using cluster sampling. Participants completed questionnaires, including the Pittsburgh Sleep Quality Index (PSQI) and the World Health Organization HRQOL. Data analysis used descriptive and correlational statistics. Of the 268 participants, 34% identified as "poor sleepers" and 55% had poor HRQOL. Poor sleepers showed significantly lower scores for HRQOL than good sleepers. The global PSQI scores were found to be independently predictive of global HRQOL. Subjective perceptions of sleep quality, the use of sleep medications and impaired daytime functioning were the variables found to have the highest correlations with global HRQOL and its four domains. This study found that people with DMT2 who indicate experiencing poor quality sleep are more likely to show a negative correlation with HRQOL. Additional research is needed to investigate how poor sleep may impact the health of people with DMT2. Findings suggest that assessment of sleep quality should be an essential component of diabetes care. Understanding sleep practices may aid public health practitioners and other healthcare providers in the design of culturally appropriate interventions to improve sleep quality in persons with DMT2. © 2017 John Wiley & Sons Ltd.

Multidimensional deconvolution of optical microscope and ultrasound imaging using adaptive least-mean-square (LMS) inverse filtering

NASA Astrophysics Data System (ADS)

Sapia, Mark Angelo

2000-11-01

Three-dimensional microscope images typically suffer from reduced resolution due to the effects of convolution, optical aberrations and out-of-focus blurring. Two- dimensional ultrasound images are also degraded by convolutional bluffing and various sources of noise. Speckle noise is a major problem in ultrasound images. In microscopy and ultrasound, various methods of digital filtering have been used to improve image quality. Several methods of deconvolution filtering have been used to improve resolution by reversing the convolutional effects, many of which are based on regularization techniques and non-linear constraints. The technique discussed here is a unique linear filter for deconvolving 3D fluorescence microscopy or 2D ultrasound images. The process is to solve for the filter completely in the spatial-domain using an adaptive algorithm to converge to an optimum solution for de-blurring and resolution improvement. There are two key advantages of using an adaptive solution: (1)it efficiently solves for the filter coefficients by taking into account all sources of noise and degraded resolution at the same time, and (2)achieves near-perfect convergence to the ideal linear deconvolution filter. This linear adaptive technique has other advantages such as avoiding artifacts of frequency-domain transformations and concurrent adaptation to suppress noise. Ultimately, this approach results in better signal-to-noise characteristics with virtually no edge-ringing. Many researchers have not adopted linear techniques because of poor convergence, noise instability and negative valued data in the results. The methods presented here overcome many of these well-documented disadvantages and provide results that clearly out-perform other linear methods and may also out-perform regularization and constrained algorithms. In particular, the adaptive solution is most responsible for overcoming the poor performance associated with linear techniques. This linear adaptive approach to deconvolution is demonstrated with results of restoring blurred phantoms for both microscopy and ultrasound and restoring 3D microscope images of biological cells and 2D ultrasound images of human subjects (courtesy of General Electric and Diasonics, Inc.).

Mars Orbiter Camera High Resolution Images: Some Results From The First 6 Weeks In Orbit

NASA Technical Reports Server (NTRS)

1997-01-01

The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images acquired shortly after orbit insertion were relatively poor in both resolution and image quality. This poor performance was solely the result of low sunlight conditions and the relative distance to the planet, both of which have been progressively improving over the past six weeks. Some of the better images are used here (see PIA01021 through PIA01029) to illustrate how the MOC images provide substantially better views of the martian surface than have ever been recorded previously from orbit.

This U.S. Geological Survey shaded relief map provides an overall context for the MGS MOC images of the Tithonium/Ius Chasma, Ganges Chasma, and Schiaparelli Crater. Closeup images of the Tithonium/Ius Chasma area are visible in PIA01021 through PIA01023. Closeups of Ganges Chasma are available as PIA01027 through PIA01029, and Schiaparelli Crater is shown in PIA01024 through PIA01026. The Mars Pathfinder landing site is shown to the north of the sites of the MGS images.

Launched on November 7, 1996, Mars Global Surveyor entered Mars orbit on Thursday, September 11, 1997. The original mission plan called for using friction with the planet's atmosphere to reduce the orbital energy, leading to a two-year mapping mission from close, circular orbit (beginning in March 1998). Owing to difficulties with one of the two solar panels, aerobraking was suspended in mid-October and resumed in November 8. Many of the original objectives of the mission, and in particular those of the camera, are likely to be accomplished as the mission progresses.

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

Dietary intake and risk factors for poor diet quality among children in Nova Scotia.

PubMed

Veugelers, Paul J; Fitzgerald, Angela L; Johnston, Elizabeth

2005-01-01

Public health policies promote healthy nutrition but evaluations of children's adherence to dietary recommendations and studies of risk factors of poor nutrition are scarce, despite the importance of diet for the temporal increase in the prevalence of childhood obesity. Here we examine dietary intake and risk factors for poor diet quality among children in Nova Scotia to provide direction for health policies and prevention initiatives. In 2003, we surveyed 5,200 grade five students from 282 public schools in Nova Scotia, as well as their parents. We assessed students' dietary intake (Harvard's Youth Adolescent Food Frequency Questionnaire) and compared this with Canadian food group and nutrient recommendations. We summarized diet quality using the Diet Quality Index International, and used multilevel regression methods to evaluate potential child, parental and school risk factors for poor diet quality. In Nova Scotia, 42.3% of children did not meet recommendations for milk products nor did they meet recommendations for the food groups 'Vegetables and fruit' (49.9%), 'Grain products' (54.4%) and 'Meat and alternatives' (73.7%). Children adequately met nutrient requirements with the exception of calcium and fibre, of which intakes were low, and dietary fat and sodium, of which intakes were high. Skipping meals and purchasing meals at school or fast-food restaurants were statistically significant determinants of poor diet. Parents' assessment of their own eating habits was positively associated with the quality of their children's diets. Dietary intake among children in Nova Scotia is relatively poor. Explicit public health policies and prevention initiatives targeting children, their parents and schools may improve diet quality and prevent obesity.

Defogging of road images using gain coefficient-based trilateral filter

NASA Astrophysics Data System (ADS)

Singh, Dilbag; Kumar, Vijay

2018-01-01

Poor weather conditions are responsible for most of the road accidents year in and year out. Poor weather conditions, such as fog, degrade the visibility of objects. Thus, it becomes difficult for drivers to identify the vehicles in a foggy environment. The dark channel prior (DCP)-based defogging techniques have been found to be an efficient way to remove fog from road images. However, it produces poor results when image objects are inherently similar to airlight and no shadow is cast on them. To eliminate this problem, a modified restoration model-based DCP is developed to remove the fog from road images. The transmission map is also refined by developing a gain coefficient-based trilateral filter. Thus, the proposed technique has an ability to remove fog from road images in an effective manner. The proposed technique is compared with seven well-known defogging techniques on two benchmark foggy images datasets and five real-time foggy images. The experimental results demonstrate that the proposed approach is able to remove the different types of fog from roadside images as well as significantly improve the image's visibility. It also reveals that the restored image has little or no artifacts.

Morning-evening type and burnout level as factors influencing sleep quality of shift nurses: a questionnaire study

PubMed Central

Demir Zencirci, Ayten; Arslan, Sümeyye

2011-01-01

Aim To assess the relationship between sleep quality and demographic variables, morning-evening type, and burnout in nurses who work shifts. Methods We carried out a cross-sectional self-administered study with forced choice and open-ended structured questionnaires – Pittsburg Sleep Quality Index, Morningness-eveningness Questionnaire, and Maslach Burnout Inventory. The study was carried out at Gazi University Medicine Faculty Hospital of Ankara on 524 invited nurses from July to September 2008, with a response rate of 89.94% (n = 483). Descriptive and inferential statistics were applied to determine the risk factors of poor sleep quality. Results Most socio-demographic variables did not affect sleep quality. Participants with poor sleep quality had quite high burnout levels. Most nurses who belonged to a type that is neither morning nor evening had poor sleep quality. Nurses who experienced an incident worsening their sleep patterns (P < 0.001) and needlestick or sharp object injuries (P = 0.010) in the last month had poor sleep quality. The subjective sleep quality and sleep latency points of evening types within created models for the effect of burnout dimensions were high. Conclusions Nurses working consistently either in the morning or at night had better sleep quality than those working rotating shifts. Further studies are still needed to develop interventions that improve sleep quality and decrease burnout in nurses working shifts. PMID:21853548

High quantum efficiency megavoltage imaging with thick scintillator detectors for image guided radiation therapy

NASA Astrophysics Data System (ADS)

Gopal, Arun

In image guided radiation therapy (IGRT), imaging devices serve as guidance systems to aid patient set-up and tumor volume localization. Traditionally, 2-D megavoltage x-ray imagers, referred to as electronic portal imaging devices (EPIDs), have been used for planar target localization, and have recently been extended to perform 3-D volumetric reconstruction via cone-beam computed tomography (CBCT). However, current EPIDs utilize thin and inefficient phosphor screen detectors and are subsequently limited by poor soft tissue visualization, which limits their use for CBCT. Therefore, the use of thick scintillation media as megavoltage x-ray detectors for greater x-ray sensitivity and enhanced image quality has recently been of significant interest. In this research, two candidates for thick scintillators: CsI(Tl) and terbium doped scintillation glass were investigated in separate imaging configurations. In the first configuration, a thick scintillation crystal (TSC) consisting of a thick, monolithic slab of CsI(Tl) was coupled to a mirror-lens-camera system. The second configuration is based on a fiber-optic scintillation glass array (FOSGA), wherein the scintillation glass is drawn into long fiber-optic conduits, inserted into a grid-type housing constructed out of polymer-tungsten alloy, and coupled to an array of photodiodes for digital read-out. The imaging prototypes were characterized using theoretical studies and imaging measurements to obtain fundamental metrics of imaging performance. Spatial resolution was measured based on a modulation transfer function (MTF), noise was evaluated in terms of a noise power spectrum (NPS), and overall contrast was characterized in the form of detective quantum efficiency (DQE). The imaging studies were used to optimize the TSC and FOSGA imagers and propose prototype configurations for order-of-magnitude improvements in overall image quality. In addition, a fast and simple technique was developed to measure the MTF, NPS, and DQE metrics for clinical EPID and CBCT systems based on a novel adaptation of a traditional line-pair resolution bar-pattern. This research provides two significant benefits to radiotherapy: the characterization of a new generation of thick scintillator based megavoltage x-ray imagers for CBCT based IGRT, and the novel adaptation of fundamental imaging metrics from imaging research to routine clinical performance monitoring.

Limited Evaluation of Image Quality Produced by a Portable Head CT Scanner (CereTom) in a Neurosurgery Centre.

PubMed

Abdullah, Ariz Chong; Adnan, Johari Siregar; Rahman, Noor Azman A; Palur, Ravikant

2017-03-01

Computed tomography (CT) is the preferred diagnostic toolkit for head and brain imaging of head injury. A recent development is the invention of a portable CT scanner that can be beneficial from a clinical point of view. To compare the quality of CT brain images produced by a fixed CT scanner and a portable CT scanner (CereTom). This work was a single-centre retrospective study of CT brain images from 112 neurosurgical patients. Hounsfield units (HUs) of the images from CereTom were measured for air, water and bone. Three assessors independently evaluated the images from the fixed CT scanner and CereTom. Streak artefacts, visualisation of lesions and grey-white matter differentiation were evaluated at three different levels (centrum semiovale, basal ganglia and middle cerebellar peduncles). Each evaluation was scored 1 (poor), 2 (average) or 3 (good) and summed up to form an ordinal reading of 3 to 9. HUs for air, water and bone from CereTom were within the recommended value by the American College of Radiology (ACR). Streak artefact evaluation scores for the fixed CT scanner was 8.54 versus 7.46 ( Z = -5.67) for CereTom at the centrum semiovale, 8.38 (SD = 1.12) versus 7.32 (SD = 1.63) at the basal ganglia and 8.21 (SD = 1.30) versus 6.97 (SD = 2.77) at the middle cerebellar peduncles. Grey-white matter differentiation showed scores of 8.27 (SD = 1.04) versus 7.21 (SD = 1.41) at the centrum semiovale, 8.26 (SD = 1.07) versus 7.00 (SD = 1.47) at the basal ganglia and 8.38 (SD = 1.11) versus 6.74 (SD = 1.55) at the middle cerebellar peduncles. Visualisation of lesions showed scores of 8.86 versus 8.21 ( Z = -4.24) at the centrum semiovale, 8.93 versus 8.18 ( Z = -5.32) at the basal ganglia and 8.79 versus 8.06 ( Z = -4.93) at the middle cerebellar peduncles. All results were significant with P -value < 0.01. Results of the study showed a significant difference in image quality produced by the fixed CT scanner and CereTom, with the latter being more inferior than the former. However, HUs of the images produced by CereTom do fulfil the recommendation of the ACR.

Inflammation, Oxidative Stress, and Antioxidants Contribute to Selected Sleep Quality and Cardiometabolic Health Relationships: A Cross-Sectional Study.

PubMed

Kanagasabai, Thirumagal; Ardern, Chris I

2015-01-01

Sleep is vital for cardiometabolic health, but a societal shift toward poor sleep is a prominent feature of many modern cultures. Concurrently, factors such as diet and lifestyle have also changed and may mediate the relationship between sleep quality and cardiometabolic health. Objectives were to explore (1) the interrelationship and (2) mediating effect of inflammation, oxidative stress, and antioxidants on sleep quality and cardiometabolic health. Cross-sectional data from the US National Health and Nutritional Examination Survey 2005-06 (≥20 y; N = 2,072) was used. Cardiometabolic health was defined as per the Joint Interim Statement; overall sleep quality was determined from six sleep habits and categorized as good, fair, poor, and very poor. Fair quality sleepers had optimal inflammation, oxidative stress, and antioxidant levels. Inflammation was above the current clinical reference range across all sleep quality categories, while oxidative stress was only within the clinical reference range for fair sleep quality. Selected sleep quality-cardiometabolic health relationships were mediated by inflammation, oxidative stress, and antioxidants and were moderated by sex. Our results provide initial evidence of a potential role for inflammation, oxidative stress, and antioxidants in the pathway between poor sleep quality-cardiometabolic decline. Further prospective research is needed to confirm our results.

WHT follow-up observations of extremely metal-poor stars identified from SDSS and LAMOST

NASA Astrophysics Data System (ADS)

Aguado, D. S.; González Hernández, J. I.; Allende Prieto, C.; Rebolo, R.

2017-09-01

Aims: We have identified several tens of extremely metal-poor star candidates from SDSS and LAMOST, which we follow up with the 4.2 m William Herschel Telescope (WHT) telescope to confirm their metallicity. Methods: We followed a robust two-step methodology. We first analyzed the SDSS and LAMOST spectra. A first set of stellar parameters was derived from these spectra with the FERRE code, taking advantage of the continuum shape to determine the atmospheric parameters, in particular, the effective temperature. Second, we selected interesting targets for follow-up observations, some of them with very low-quality SDSS or LAMOST data. We then obtained and analyzed higher-quality medium-resolution spectra obtained with the Intermediate dispersion Spectrograph and Imaging System (ISIS) on the WHT to arrive at a second more reliable set of atmospheric parameters. This allowed us to derive the metallicity with accuracy, and we confirm the extremely metal-poor nature in most cases. In this second step we also employed FERRE, but we took a running mean to normalize both the observed and the synthetic spectra, and therefore the final parameters do not rely on having an accurate flux calibration or continuum placement. We have analyzed with the same tools and following the same procedure six well-known metal-poor stars, five of them at [Fe/H] <-4 to verify our results. This showed that our methodology is able to derive accurate metallicity determinations down to [Fe/H] <-5.0. Results: The results for these six reference stars give us confidence on the metallicity scale for the rest of the sample. In addition, we present 12 new extremely metal-poor candidates: 2 stars at [Fe/H] ≃-4, 6 more in the range -4 < [Fe / H] < -3.5, and 4 more at -3.5 < [Fe / H] < -3.0. Conclusions: We conclude that we can reliably determine metallicities for extremely metal-poor stars with a precision of 0.2 dex from medium-resolution spectroscopy with our improved methodology. This provides a highly effective way of verifying candidates from lower quality data. Our model spectra and the details of the fitting algorithm are made public to facilitate the standardization of the analysis of spectra from the same or similar instruments. The model spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A40

Sleep and its association with aggression among prisoners: Quantity or quality?

PubMed

Barker, Lyndsie Fiona; Ireland, Jane L; Chu, Simon; Ireland, Carol A

2016-01-01

The current paper aims to examine the association between self-reported sleep quality and quantity and how these relate to aggression motivation and hostile cognition in a male prisoner sample. The cognitive component of sleep, namely perception, is consequently a variable of particular interest and one neglected by previous research. Two independent studies are presented. The first comprised 95 adult male prisoners who completed a sleep quality index along with measures of implicit and explicit aggression. The second study extended this to consider aggression motivation and hostile attribution biases using a sample of 141 young male adult prisoners. In study one, sleep quantity and indicators of sleep quality were found not to associate with aggression whereas the perception of poor sleep did; those perceiving poor sleep quality were more likely than those perceiving good sleep to report they had perpetrated aggression in the previous week and to report higher levels of implicit aggression. Study two found that while increased indicators of poor sleep quality were associated with lower prosocial attribution tendencies and higher levels of reactive and proactive aggression, sleep quantity was not associated. The perception of poor quality sleep was important; those perceiving poor sleep were more likely to report higher levels of reactive and proactive aggression than those reporting good sleep. Collectively the studies highlight the importance of accounting for the perception of sleep quality as an important cognitive component in understanding the association between sleep and aggression. Copyright © 2016 Elsevier Ltd. All rights reserved.

Poor sleep quality and insufficient sleep of a collegiate student-athlete population.

PubMed

Mah, Cheri D; Kezirian, Eric J; Marcello, Brandon M; Dement, William C

2018-06-01

Poor and inadequate sleep negatively impact cognitive and physical functioning and may also affect sports performance. The study aim is to examine sleep quality, sleep duration, and daytime sleepiness in collegiate student-athletes across a wide range of sports. Questionnaire. University setting. 628 athletes across 29 varsity teams at Stanford University. Athletes completed a questionnaire inquiring about sleep quality via a modified Pittsburgh Sleep Quality Index (PSQI), sleep duration, and daytime sleepiness via Epworth Sleepiness Scale. Sleep quality on campus and while traveling for competition was rated on a 10-point scale. Collegiate athletes were classified as poor sleepers (PSQI 5.38 ± 2.45), and 42.4% of athletes experience poor sleep quality (reporting PSQI global scores >5). Athletes reported lower sleep quality on campus than when traveling for competition (7.1 vs 7.6, P< .001). Inadequate sleep was demonstrated by 39.1% of athletes that regularly obtain <7 hours of sleep on weekdays. Fifty-one percent of athletes reported high levels of daytime sleepiness with Epworth scores ≥10. Teen student-athletes in the first and second year of college reported the highest mean levels of daytime sleepiness. Greater total sleep time was associated with daytime functioning including lower frequency of difficulty waking up for practice or class (P< .001) and lower frequency of trouble staying awake during daily activities (P< .001). Collegiate athletes frequently experience poor sleep quality, regularly obtain insufficient sleep, and commonly exhibit daytime sleepiness. Copyright © 2018 National Sleep Foundation. All rights reserved.

Noise Estimation and Quality Assessment of Gaussian Noise Corrupted Images

NASA Astrophysics Data System (ADS)

Kamble, V. M.; Bhurchandi, K.

2018-03-01

Evaluating the exact quantity of noise present in an image and quality of an image in the absence of reference image is a challenging task. We propose a near perfect noise estimation method and a no reference image quality assessment method for images corrupted by Gaussian noise. The proposed methods obtain initial estimate of noise standard deviation present in an image using the median of wavelet transform coefficients and then obtains a near to exact estimate using curve fitting. The proposed noise estimation method provides the estimate of noise within average error of +/-4%. For quality assessment, this noise estimate is mapped to fit the Differential Mean Opinion Score (DMOS) using a nonlinear function. The proposed methods require minimum training and yields the noise estimate and image quality score. Images from Laboratory for image and Video Processing (LIVE) database and Computational Perception and Image Quality (CSIQ) database are used for validation of the proposed quality assessment method. Experimental results show that the performance of proposed quality assessment method is at par with the existing no reference image quality assessment metric for Gaussian noise corrupted images.

Low Cerebral Blood Volume Identifies Poor Outcome in Stent Retriever Thrombectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Protto, Sara, E-mail: sara.protto@pshp.fi; Pienimäki, Juha-Pekka; Seppänen, Janne

BackgroundMechanical thrombectomy (MT) is an efficient treatment of acute stroke caused by large-vessel occlusion. We evaluated the factors predicting poor clinical outcome (3-month modified Rankin Scale, mRS >2) although MT performed with modern stent retrievers.MethodsWe prospectively collected the clinical and imaging data of 105 consecutive anterior circulation stroke patients who underwent MT after multimodal CT imaging. Patients with occlusion of the internal carotid artery and/or middle cerebral artery up to the M2 segment were included. We recorded baseline clinical, procedural and imaging variables, technical outcome, 24-h imaging outcome and the clinical outcome. Differences between the groups were studied with appropriatemore » statistical tests and binary logistic regression analysis.ResultsLow cerebral blood volume Alberta stroke program early CT score (CBV-ASPECTS) was associated with poor clinical outcome (median 7 vs. 9, p = 0.01). Lower collateral score (CS) significantly predicted poor outcome in regression modelling with CS = 0 increasing the odds of poor outcome 4.4-fold compared to CS = 3 (95% CI 1.27–15.5, p = 0.02). Lower CBV-ASPECTS significantly predicted poor clinical outcome among those with moderate or severe stroke (OR 0.82, 95% CI 0.68–1, p = 0.05) or poor collateral circulation (CS 0–1, OR 0.66, 95% CI 0.48–0.90, p = 0.009) but not among those with mild strokes or good collaterals.ConclusionsCBV-ASPECTS estimating infarct core is a significant predictor of poor clinical outcome among anterior circulation stroke patients treated with MT, especially in the setting of poor collateral circulation and/or moderate or severe stroke.« less

The interactive effects of housing and neighbourhood quality on psychological well-being.

PubMed

Jones-Rounds, McKenzie L; Evans, Gary W; Braubach, Matthias

2014-02-01

Many individuals are subject to the physically and mentally detrimental effects of living in substandard housing and inadequate neighbourhoods. We propose that better physical neighbourhood quality can partially offset some of the negative effects of poor housing quality on psychological well-being. Interviews and questionnaires were used to collect data in a cross-sectional study of housing quality, the state of the surrounding environment, and individual health and well-being for 5605 European adults from the Large Analysis and Review of European housing and health Status conducted by WHO in eight European cities. Multilevel random coefficient modelling was used to statistically analyse the main and interactive effects of housing quality and neighbourhood quality on psychological well-being. Socioeconomic status, employment status, gender and marital status were included as statistical controls. Substandard housing quality and poor neighbourhood quality each contribute to lower psychological well-being. Furthermore better neighbourhood quality buffers against the negative effects of poor housing quality on psychological well-being. These results fill a gap in research concerning the ability of neighbourhood quality to amplify or attenuate housing quality impacts on well-being.

Published methodological quality of randomized controlled trials does not reflect the actual quality assessed in protocols

PubMed Central

Mhaskar, Rahul; Djulbegovic, Benjamin; Magazin, Anja; Soares, Heloisa P.; Kumar, Ambuj

2011-01-01

Objectives To assess whether reported methodological quality of randomized controlled trials (RCTs) reflect the actual methodological quality, and to evaluate the association of effect size (ES) and sample size with methodological quality. Study design Systematic review Setting Retrospective analysis of all consecutive phase III RCTs published by 8 National Cancer Institute Cooperative Groups until year 2006. Data were extracted from protocols (actual quality) and publications (reported quality) for each study. Results 429 RCTs met the inclusion criteria. Overall reporting of methodological quality was poor and did not reflect the actual high methodological quality of RCTs. The results showed no association between sample size and actual methodological quality of a trial. Poor reporting of allocation concealment and blinding exaggerated the ES by 6% (ratio of hazard ratio [RHR]: 0.94, 95%CI: 0.88, 0.99) and 24% (RHR: 1.24, 95%CI: 1.05, 1.43), respectively. However, actual quality assessment showed no association between ES and methodological quality. Conclusion The largest study to-date shows poor quality of reporting does not reflect the actual high methodological quality. Assessment of the impact of quality on the ES based on reported quality can produce misleading results. PMID:22424985

Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio)

PubMed Central

Yilmaz, Ozlem; Patinote, Amélie; Nguyen, Thao Vi; Com, Emmanuelle; Lavigne, Regis; Pineau, Charles; Sullivan, Craig V.; Bobe, Julien

2017-01-01

Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine. PMID:29145436

Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio).

PubMed

Yilmaz, Ozlem; Patinote, Amélie; Nguyen, Thao Vi; Com, Emmanuelle; Lavigne, Regis; Pineau, Charles; Sullivan, Craig V; Bobe, Julien

2017-01-01

Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine.

Simultaneous Rapid Determination of the Solubility and Diffusion Coefficients of a Poorly Water-Soluble Drug Based on a Novel UV Imaging System.

PubMed

Lu, Yan; Li, Mingzhong

2016-01-01

The solubility and diffusion coefficient are two of the most important physicochemical properties of a drug compound. In practice, both have been measured separately, which is time consuming. This work utilizes a novel technique of UV imaging to determine the solubility and diffusion coefficients of poorly water-soluble drugs simultaneously. A 2-step optimal method is proposed to determine the solubility and diffusion coefficients of a poorly water-soluble pharmaceutical substance based on the Fick's second law of diffusion and UV imaging measurements. Experimental results demonstrate that the proposed method can be used to determine the solubility and diffusion coefficients of a drug with reasonable accuracy, indicating that UV imaging may provide a new opportunity to accurately measure the solubility and diffusion coefficients of a poorly water-soluble drug simultaneously and rapidly. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

An assessment of a film enhancement system for use in a radiation therapy department.

PubMed

Solowsky, E L; Reinstein, L E; Meek, A G

1990-01-01

The clinical uses of a radiotherapy film enhancement system are explored. The primary functions of the system are to improve the quality of poorly exposed simulator and portal films, and to perform comparisons between the two films to determine whether patient or block positioning errors are present. Other features include: the production of inexpensive, high quality hardcopy images of simulation films and initial portal films for chart documentation, the capacity to overlay lateral simulation films with sagittal MRI films to aid in field design, and a mode to zoom in on individual CT or MRI images and enlarge them for video display during chart rounds or instructional sessions. This commercially available system is comprised of a microcomputer, frame grabber, CCD camera with zoom lens, and a high-resolution thermal printer. The user-friendly software is menu driven and utilizes both keyboard and track ball to perform its functions. At the heart of the software is a very fast Adaptive Histogram Equalization (AHE) routine, which enhances and improves the readability of most portal films. The system has been evaluated for several disease sites, and its advantages and limitations will be presented.

Marital quality, health, and aging: gender equity?

PubMed

Umberson, Debra; Williams, Kristi

2005-10-01

Recent research shows that poor marital quality adversely affects trajectories of physical health over time and that these adverse effects are similar for men and women. These studies test the possibility of gender differences in vulnerability to poor marital quality, but they fail to take into account possible gender differences in exposure to poor marital quality. We present longitudinal evidence to show that although the impact of marital quality on physical health trajectories may be similar for married men and women, generally lower levels of marital quality experienced by women may translate into a sustained disadvantage for the health of married women over the life course. These findings frame the call for renewed theoretical work on gender and marriage that takes into account both gender similarity in response to marital quality as well as gender differences in the experience of marriage over the life course.

Marital Quality, Health, and Aging: Gender Equity?

PubMed Central

Umberson, Debra; Williams, Kristi

2011-01-01

Recent research shows that poor marital quality adversely affects trajectories of physical health over time and that these adverse effects are similar for men and women. These studies test the possibility of gender differences in vulnerability to poor marital quality, but they fail to take into account possible gender differences in exposure to poor marital quality. We present longitudinal evidence to show that although the impact of marital quality on physical health trajectories may be similar for married men and women, generally lower levels of marital quality experienced by women may translate into a sustained disadvantage for the health of married women over the life course. These findings frame the call for renewed theoretical work on gender and marriage that takes into account both gender similarity in response to marital quality as well as gender differences in the experience of marriage over the life course. PMID:16251580

Shift Work and Sleep Quality Among Urban Police Officers

PubMed Central

Fekedulegn, Desta; Burchfiel, Cecil M.; Charles, Luenda E.; Hartley, Tara A.; Andrew, Michael E.; Violanti, John M.

2016-01-01

Objective The aim of the study was to examine association of shift work with sleep quality in police officers. Methods Data were obtained from the Buffalo Cardio-Metabolic Occupational Police Stress study (n =363). An electronic work history database was used to define shift as day, afternoon, or night for three durations: past month, 1 year, and 15 years. Sleep quality was determined using the Pittsburgh Sleep Quality Index. Results The overall prevalence of poor sleep quality was 54%; 44% for day, 60% for afternoon, and 69% for night shift. Poor sleep quality was 70% more prevalent among night-shift officers (P <0.001) and 49% higher among those on the afternoon shift (P =0.003) relative to officers working on the day shift. Conclusions Night and evening work schedules are associated with elevated prevalence of poor sleep quality among police officers. PMID:26949891

Shift Work and Sleep Quality Among Urban Police Officers: The BCOPS Study.

PubMed

Fekedulegn, Desta; Burchfiel, Cecil M; Charles, Luenda E; Hartley, Tara A; Andrew, Michael E; Violanti, John M

2016-03-01

The aim of the study was to examine association of shift work with sleep quality in police officers. Data were obtained from the Buffalo Cardio-Metabolic Occupational Police Stress study (n = 363). An electronic work history database was used to define shift as day, afternoon, or night for three durations: past month, 1 year, and 15 years. Sleep quality was determined using the Pittsburgh Sleep Quality Index. The overall prevalence of poor sleep quality was 54%; 44% for day, 60% for afternoon, and 69% for night shift. Poor sleep quality was 70% more prevalent among night-shift officers (P < 0.001) and 49% higher among those on the afternoon shift (P = 0.003) relative to officers working on the day shift. Night and evening work schedules are associated with elevated prevalence of poor sleep quality among police officers.

Factors associated with imaging overuse in the emergency department: A systematic review.

PubMed

Tung, Monica; Sharma, Ritu; Hinson, Jeremiah S; Nothelle, Stephanie; Pannikottu, Jean; Segal, Jodi B

2018-02-01

Emergency departments (ED) are sites of prevalent imaging overuse; however, determinants that drive imaging in this setting are not well-characterized. We systematically reviewed the literature to summarize the determinants of imaging overuse in the ED. We searched MEDLINE® and Embase® from January 1998 to March 2017. Studies were included if they were written in English, contained original data, pertained to a U.S. population, and identified a determinant associated with overuse of imaging in the ED. Twenty relevant studies were included. Fourteen evaluated computerized tomography (CT) scanning in patents presenting to a regional ED who were then transferred to a level 1 trauma center; incomplete transfer of data and poor image quality were the most frequently described reasons for repeat scanning. Unnecessary pre-transfer scanning or repeated scanning after transfer, in multiple studies, was highest among older patients, those with higher Injury Severity Scores (ISS) and those being transferred further. Six studies explored determinants of overused imaging in the ED in varied conditions, with overuse greater in older patients and those having more comorbid diseases. Defensive imaging reportedly influenced physician behavior. Less integration of services across the health system also predisposed to overuse of imaging. The literature is heterogeneous with surprisingly few studies of determinants of imaging in minor head injury or of spine imaging. Older patient age and higher ISS were the most consistently associated with ED imaging overuse. This review highlights the need for precise definitions of overuse of imaging in the ED. Copyright © 2017 Elsevier Inc. All rights reserved.

TH-A-16A-01: Image Quality for the Radiation Oncology Physicist: Review of the Fundamentals and Implementation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seibert, J; Imbergamo, P

The expansion and integration of diagnostic imaging technologies such as On Board Imaging (OBI) and Cone Beam Computed Tomography (CBCT) into radiation oncology has required radiation oncology physicists to be responsible for and become familiar with assessing image quality. Unfortunately many radiation oncology physicists have had little or no training or experience in measuring and assessing image quality. Many physicists have turned to automated QA analysis software without having a fundamental understanding of image quality measures. This session will review the basic image quality measures of imaging technologies used in the radiation oncology clinic, such as low contrast resolution, highmore » contrast resolution, uniformity, noise, and contrast scale, and how to measure and assess them in a meaningful way. Additionally a discussion of the implementation of an image quality assurance program in compliance with Task Group recommendations will be presented along with the advantages and disadvantages of automated analysis methods. Learning Objectives: Review and understanding of the fundamentals of image quality. Review and understanding of the basic image quality measures of imaging modalities used in the radiation oncology clinic. Understand how to implement an image quality assurance program and to assess basic image quality measures in a meaningful way.« less

Association between Body Image Dissatisfaction and Self-Rated Health, as Mediated by Physical Activity and Eating Habits: Structural Equation Modelling in ELSA-Brasil.

PubMed

de Oliveira da Silva, Patricia; Miguez Nery Guimarães, Joanna; Härter Griep, Rosane; Caetano Prates Melo, Enirtes; Maria Alvim Matos, Sheila; Del Carmem Molina, Maria; Maria Barreto, Sandhi; de Jesus Mendes da Fonseca, Maria

2018-04-18

This study investigated whether the association between body image dissatisfaction and poor self-rated health is mediated by insufficient physical activity and unhealthy eating habits. The participants were 6727 men and 8037 women from the baseline (2008–2010) of the Longitudinal Study of Adult Health (Estudo Longitudinal de Saúde do Adulto, ELSA-Brasil). Structural equation modelling was used. Associations were found between body image dissatisfaction and poor self-rated health in both sexes. Insufficient physical activity was a mediator. However, unhealthy eating habits were found to exert a mediator effect only via insufficient physical activity. Body image dissatisfaction was found to associate, both directly and possibly indirectly, with poor self-rated health, mediated by insufficient physical activity and unhealthy eating habits. Accordingly, encouraging physical activity and healthy eating can contribute to reducing body image dissatisfaction and favour better self-rated health.

Assessment of Diabetic Retinopathy Using Nonmydriatic Ultra-Widefield Scanning Laser Ophthalmoscopy (Optomap) Compared With ETDRS 7-Field Stereo Photography

PubMed Central

Kernt, Marcus; Hadi, Indrawati; Pinter, Florian; Seidensticker, Florian; Hirneiss, Christoph; Haritoglou, Christos; Kampik, Anselm; Ulbig, Michael W.; Neubauer, Aljoscha S.

2012-01-01

OBJECTIVE To compare the diagnostic properties of a nonmydriatic 200° ultra-widefield scanning laser ophthalmoscope (SLO) versus mydriatic Early Treatment of Diabetic Retinopathy Study (ETDRS) 7-field photography for diabetic retinopathy (DR) screening. RESEARCH DESIGN AND METHODS A consecutive series of 212 eyes of 141 patients with different levels of DR were examined. Grading of DR and clinically significant macular edema (CSME) from mydriatic ETDRS 7-field stereo photography was compared with grading obtained by Optomap Panoramic 200 SLO images. All SLO scans were performed through an undilated pupil, and no additional clinical information was used for evaluation of all images by the two independent, masked, expert graders. RESULTS Twenty-two eyes from ETDRS 7-field photography and 12 eyes from Optomap were not gradable by at least one grader because of poor image quality. A total of 144 eyes were analyzed regarding DR level and 155 eyes regarding CSME. For ETDRS 7-field photography, 22 eyes (18 for grader 2) had no or mild DR (ETDRS levels ≤ 20) and 117 eyes (111 for grader 2) had no CSME. A highly substantial agreement between both Optomap DR and CSME grading and ETDRS 7-field photography existed with κ = 0.79 for DR and 0.73 for CSME for grader 1, and κ = 0.77 (DR) and 0.77 (CSME) for grader 2. CONCLUSIONS Determination of CSME and grading of DR level from Optomap Panoramic 200 nonmydriatic images show a positive correlation with mydriatic ETDRS 7-field stereo photography. Both techniques are of sufficient quality to assess DR and CSME. Optomap Panoramic 200 images cover a larger retinal area and therefore may offer additional diagnostic properties. PMID:22912430

Assessment of diabetic retinopathy using nonmydriatic ultra-widefield scanning laser ophthalmoscopy (Optomap) compared with ETDRS 7-field stereo photography.

PubMed

Kernt, Marcus; Hadi, Indrawati; Pinter, Florian; Seidensticker, Florian; Hirneiss, Christoph; Haritoglou, Christos; Kampik, Anselm; Ulbig, Michael W; Neubauer, Aljoscha S

2012-12-01

To compare the diagnostic properties of a nonmydriatic 200° ultra-widefield scanning laser ophthalmoscope (SLO) versus mydriatic Early Treatment of Diabetic Retinopathy Study (ETDRS) 7-field photography for diabetic retinopathy (DR) screening. A consecutive series of 212 eyes of 141 patients with different levels of DR were examined. Grading of DR and clinically significant macular edema (CSME) from mydriatic ETDRS 7-field stereo photography was compared with grading obtained by Optomap Panoramic 200 SLO images. All SLO scans were performed through an undilated pupil, and no additional clinical information was used for evaluation of all images by the two independent, masked, expert graders. Twenty-two eyes from ETDRS 7-field photography and 12 eyes from Optomap were not gradable by at least one grader because of poor image quality. A total of 144 eyes were analyzed regarding DR level and 155 eyes regarding CSME. For ETDRS 7-field photography, 22 eyes (18 for grader 2) had no or mild DR (ETDRS levels ≤ 20) and 117 eyes (111 for grader 2) had no CSME. A highly substantial agreement between both Optomap DR and CSME grading and ETDRS 7-field photography existed with κ = 0.79 for DR and 0.73 for CSME for grader 1, and κ = 0.77 (DR) and 0.77 (CSME) for grader 2. Determination of CSME and grading of DR level from Optomap Panoramic 200 nonmydriatic images show a positive correlation with mydriatic ETDRS 7-field stereo photography. Both techniques are of sufficient quality to assess DR and CSME. Optomap Panoramic 200 images cover a larger retinal area and therefore may offer additional diagnostic properties.

Ultrahigh-field imaging of the biliary tract at 7 T: initial results of gadoxetic acid-enhanced magnetic resonance cholangiography.

PubMed

Fischer, Anja; Kraff, Oliver; Orzada, Stephan; Nensa, Felix; Schäfer, Lena C; Ladd, Mark E; Umutlu, Lale; Lauenstein, Thomas C

2014-05-01

The objectives of this study were to assess the feasibility of magnetic resonance cholangiography (MRC) using biliary-secreted gadoxetic acid at 7 T and to compare it with T2-weighted (w) MRC at 3 T. Ten healthy volunteers were examined on a 7-T whole-body magnetic resonance system. T2-weighted turbo-spin-echo sequence, T1-w volume-interpolated breath-hold examination (VIBE), and fast low-angle shot (FLASH) with inversion recovery (IR) were acquired in coronal orientation. For dynamic imaging, gadoxetic acid was administrated and data were collected for a period of 5 to 40 minutes after injection. The volunteers underwent subsequent T2-w respiratory-gated MRC at 3 T. For qualitative analysis, a 5-point scale was used. Contrast ratios (CRs) were calculated for quantitative assessment. Contrast-enhanced T1-w MRC at 7 T showed a homogeneous depiction of the intrahepatic and extrahepatic biliary tract with a maximum enhancement of 20 minutes after contrast. Volume-interpolated breath-hold examination and FLASH IR provided a good image quality for the intrahepatic (VIBE, 3.60; FLASH IR, 3.67) and extrahepatic bile ducts (VIBE, 3.50; FLASH IR, 3.72). The quantitative analysis revealed high CR values for FLASH IR (intrahepatic CR, 0.41; extrahepatic CR, 0.45) because of an effective suppression of hepatic tissue and vessels. The T2-w TSE at 7 T showed only a poor image quality without diagnostic potential (intrahepatic, 2.22; extrahepatic, 1.93). Seven-tesla VIBE and FLASH revealed superiority in the depiction of the intrahepatic bile ducts, whereas 3-T MRC was superior in the delineation of the extrahepatic biliary tract. Our results demonstrate the feasibility of contrast-enhanced imaging of the biliary ducts at 7 T.

Sleep Quality and Sleep Patterns in Relation to Consumption of Energy Drinks, Caffeinated Beverages and Other Stimulants among Thai College Students

PubMed Central

Lohsoonthorn, Vitool; Khidir, Hazar; Casillas, Gardenia; Lertmaharit, Somrat; Tadesse, Mahlet G.; Pensuksan, Wipawan C.; Rattananupong, Thanapoom; Gelaye, Bizu; Williams, Michelle A.

2012-01-01

Purpose Poor sleep and heavy use of caffeinated beverages have been implicated as risk factors for a number of adverse health outcomes. Caffeine consumption and use of other stimulants are common among college students globally. However, to our knowledge, no studies have examined the influence of caffeinated beverages on sleep quality of college students in Southeast Asian populations. We conducted this study to evaluate the patterns of sleep quality; and to examine the extent to which poor sleep quality is associated with consumption of energy drinks, caffeinated beverages and other stimulants among 2,854 Thai college students. Methods A questionnaire was administered to ascertain demographic and behavioral characteristics. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep habits and quality. Chi-square tests and multivariate logistic regression models were used to identify statistically significant associations. Results Overall, the prevalence of poor sleep quality was found to be 48.1%. A significant percent of students used stimulant beverages (58.0%). Stimulant use (OR 1.50; 95%CI 1.28-1.77) was found to be statistically significant and positively associated with poor sleep quality. Alcohol consumption (OR 3.10; 95% CI 1.72-5.59) and cigarette smoking (OR 1.43; 95% CI 1.02-1.98) also had statistically significant association with increased daytime dysfunction. In conclusion, stimulant use is common among Thai college students and is associated with several indices of poor sleep quality. Conclusion Our findings underscore the need to educate students on the importance of sleep and the influences of dietary and lifestyle choices on their sleep quality and overall health. PMID:23239460

Quality of recovery after anaesthesia measured with QoR-40: a prospective observational study.

PubMed

Guimarães-Pereira, Luís; Costa, Maria; Sousa, Gabriela; Abelha, Fernando

2016-01-01

QoR-40, a 40-item questionnaire on quality of recovery from anaesthesia, has been shown to measure health status after surgery. Our aim was to evaluate the incidence of poor quality of recovery in our Post Anaesthesia Care Unit and to compare their QoR-40 scores before surgery and 3 months later. A prospective observational study was conducted in adult patients consecutively admitted from 18 June to 12 July 2012. The follow-up period was 3 months. We exclude patients submitted to cardiac surgery, neurosurgery, obstetric surgery and with a mini-mental state examination test score lower than 25. The primary endpoint was quality of recovery measured with the validated Portuguese for Portugal version of the QoR-40 before surgery (T0), 24h after surgery (T1) and 3 months after (T2). A total of 114 patients completed the study. Mean QoR-40 score was 169 and patients with poor quality of recovery were identified if their QoR-40 score was lesser than 142. This occurred in 26 patients (24%). Global median scores for patients with poor quality of recovery were lower at T0 (121 vs. 184, p<0.001), at T1 (120 vs. 177, p<0.001) and at T2 (119 vs. 189, p<0.001). Patients with poor quality of recovery had lower quality of life. This fact may allow earlier and more effective interventions, in order to improve quality of life after surgery. Beside its utility after surgery, QoR-40 may be important prior to surgery to identify patients who will develop a poor quality of recovery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Quality of recovery after anaesthesia measured with QoR-40: a prospective observational study].

PubMed

Guimarães-Pereira, Luís; Costa, Maria; Sousa, Gabriela; Abelha, Fernando

2016-01-01

QoR-40, a 40-item questionnaire on quality of recovery from anaesthesia, has been shown to measure health status after surgery. Our aim was to evaluate the incidence of poor quality of recovery in our Post Anaesthesia Care Unit and to compare their QoR-40 scores before surgery and 3 months later. A prospective observational study was conducted in adult patients consecutively admitted from 18 June to 12 July 2012. The follow-up period was 3 months. We exclude patients submitted to cardiac surgery, neurosurgery, obstetric surgery and with a mini-mental state examination test score lower than 25. The primary endpoint was quality of recovery measured with the validated Portuguese for Portugal version of the QoR-40 before surgery (T0), 24h after surgery (T1) and 3 months after (T2). A total of 114 patients completed the study. Mean QoR-40 score was 169 and patients with poor quality of recovery were identified if their QoR-40 score was lesser than 142. This occurred in 26 patients (24%). Global median scores for patients with poor quality of recovery were lower at T0 (121 vs. 184, p<0.001), at T1 (120 vs. 177, p<0.001) and at T2 (119 vs. 189, p<0.001). Patients with poor quality of recovery had lower quality of life. This fact may allow earlier and more effective interventions, in order to improve quality of life after surgery. Beside its utility after surgery, QoR-40 may be important prior to surgery to identify patients who will develop a poor quality of recovery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Poor sleep quality, depression and hope before breast cancer surgery.

PubMed

Mansano-Schlosser, Thalyta Cristina; Ceolim, Maria Filomena; Valerio, Teresa D

2017-04-01

This study aims to identify the predictors of poor sleep quality and the associations between depression, hope and sleep in a sample of 156 women with breast cancer prior to surgery. The care and treatment of breast cancer is among the most important scientific challenges in public health. Sleep disturbances and depression are the important complaint of cancer patients. However, they are often neglected. Patients diagnosed with breast cancer also experience prejudice, fear of death, suffering, mutilation, fear of lymphedema, as well as feelings of social devaluation leading to hopelessness Several studies point to hope as an effective strategy to help patients cope with difficulties and achieve their goals, especially patients with cancer. This is a report of baseline data extracted from a longitudinal study. Pittsburgh Sleep Quality Index, Beck Depression Inventory, and the Herth Hope Index. Data were analyzed with the Spearman's Rank Correlation test and Multiple Logistic Regression analysis. The majority of women had tumors in initial stages (78.7%), reported poor sleep quality (58.9%), and had moderate to severe or severe depression (27.2%). Significant correlations were found between hope and depression (Spearman r=-0.4341), and between sleep quality and depression (Spearman r=0.3938). Significant associations were found between poor sleep quality and pain, symptoms of menopause and depression. Depression and symptoms of menopause were independent predictors of poor sleep quality. The evaluation of sleep quality, depression and hope should be implemented in clinical practice. Increased hope lessens depression and may positively affect sleep quality, all of which improves quality of life for women with breast cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Association between Personality Traits and Sleep Quality in Young Korean Women

PubMed Central

Kim, Han-Na; Cho, Juhee; Chang, Yoosoo; Ryu, Seungho

2015-01-01

Personality is a trait that affects behavior and lifestyle, and sleep quality is an important component of a healthy life. We analyzed the association between personality traits and sleep quality in a cross-section of 1,406 young women (from 18 to 40 years of age) who were not reporting clinically meaningful depression symptoms. Surveys were carried out from December 2011 to February 2012, using the Revised NEO Personality Inventory and the Pittsburgh Sleep Quality Index (PSQI). All analyses were adjusted for demographic and behavioral variables. We considered beta weights, structure coefficients, unique effects, and common effects when evaluating the importance of sleep quality predictors in multiple linear regression models. Neuroticism was the most important contributor to PSQI global scores in the multiple regression models. By contrast, despite being strongly correlated with sleep quality, conscientiousness had a near-zero beta weight in linear regression models, because most variance was shared with other personality traits. However, conscientiousness was the most noteworthy predictor of poor sleep quality status (PSQI≥6) in logistic regression models and individuals high in conscientiousness were least likely to have poor sleep quality, which is consistent with an OR of 0.813, with conscientiousness being protective against poor sleep quality. Personality may be a factor in poor sleep quality and should be considered in sleep interventions targeting young women. PMID:26030141

Intensity ratio curve analysis of small renal masses on T2-weighted magnetic resonance imaging: Differentiation of fat-poor angiomyolipoma from renal cell carcinoma.

PubMed

Moriyama, Shingo; Yoshida, Soichiro; Tanaka, Hajime; Tanaka, Hiroshi; Yokoyama, Minato; Ishioka, Junichiro; Matsuoka, Yoh; Saito, Kazutaka; Kihara, Kazunori; Fujii, Yasuhisa

2018-03-25

To assess the diagnostic ability of a pixel intensity-based analysis in evaluating the magnetic resonance imaging characteristics of small renal masses, especially in differentiating fat-poor angiomyolipoma from renal cell carcinoma. T2-weighted images from 121 solid small renal masses (<4 cm) without visible fat (14 fat-poor angiomyolipomas, 92 clear cell renal cell carcinomas, six chromophobe renal cell carcinomas and nine papillary renal cell carcinomas) were retrospectively evaluated. An intensity ratio curve was plotted using intensity ratios, which were ratios of signal intensities of tumor pixels (each pixel along a linear region of interest drawn across the renal tumor on T2-weighted image) to the signal intensity of a normal renal cortex. The diagnostic ability of the intensity ratio curve analysis was evaluated. The tumors were classified into three types: intensity ratio fat-poor angiomyolipoma (n = 19) with no pseudocapsule, iso-low intensity and no heterogeneity; intensity ratio clear cell renal cell carcinoma (n = 76) with a pseudocapsule, iso-high intensity and heterogeneity; and other type of intensity ratio (n = 26), including tumors that did not fall into the above two categories. The sensitivity/specificity/accuracy of the intensity ratio curve analysis in diagnosing fat-poor angiomyolipoma was 93%/94%/94%, respectively. When the intensity ratio curve analysis was applied only to the tumor with undetermined radiological diagnosis, the sensitivity for diagnosing fat-poor angiomyolipoma compared with subjective reading alone significantly improved (93% vs 50%; P = 0.014). Our novel semiquantitative model for combined assessment of key features of fat-poor angiomyolipoma, including low intensity, homogeneity and absence of a pseudocapsule on T2-weighted image, might make diagnosis of fat-poor angiomyolipoma more accurate. © 2018 The Japanese Urological Association.

The effect of image quality, repeated study, and assessment method on anatomy learning.

PubMed

Fenesi, Barbara; Mackinnon, Chelsea; Cheng, Lucia; Kim, Joseph A; Wainman, Bruce C

2017-06-01

The use of two-dimensional (2D) images is consistently used to prepare anatomy students for handling real specimen. This study examined whether the quality of 2D images is a critical component in anatomy learning. The visual clarity and consistency of 2D anatomical images was systematically manipulated to produce low-quality and high-quality images of the human hand and human eye. On day 0, participants learned about each anatomical specimen from paper booklets using either low-quality or high-quality images, and then completed a comprehension test using either 2D images or three-dimensional (3D) cadaveric specimens. On day 1, participants relearned each booklet, and on day 2 participants completed a final comprehension test using either 2D images or 3D cadaveric specimens. The effect of image quality on learning varied according to anatomical content, with high-quality images having a greater effect on improving learning of hand anatomy than eye anatomy (high-quality vs. low-quality for hand anatomy P = 0.018; high-quality vs. low-quality for eye anatomy P = 0.247). Also, the benefit of high-quality images on hand anatomy learning was restricted to performance on short-answer (SA) questions immediately after learning (high-quality vs. low-quality on SA questions P = 0.018), but did not apply to performance on multiple-choice (MC) questions (high-quality vs. low-quality on MC questions P = 0.109) or after participants had an additional learning opportunity (24 hours later) with anatomy content (high vs. low on SA questions P = 0.643). This study underscores the limited impact of image quality on anatomy learning, and questions whether investment in enhancing image quality of learning aids significantly promotes knowledge development. Anat Sci Educ 10: 249-261. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

Creating & using specimen images for collection documentation, research, teaching and outreach

NASA Astrophysics Data System (ADS)

Demouthe, J. F.

2012-12-01

In this age of digital media, there are many opportunities for use of good images of specimens. On-line resources such as institutional web sites and global sites such as PaleoNet and the Paleobiology Database provide venues for collection information and images. Pictures can also be made available to the general public through popular media sites such as Flickr and Facebook, where they can be retrieved and used by teachers, students, and the general public. The number of requests for specimen loans can be drastically reduced by offering the scientific community access to data and specimen images using the internet. This is an important consideration in these days of limited support budgets, since it reduces the amount of staff time necessary for giving researchers and educators access to collections. It also saves wear and tear on the specimens themselves. Many institutions now limit or refuse to send specimens out of their own countries because of the risks involved in going through security and customs. The internet can bridge political boundaries, allowing everyone equal access to collections. In order to develop photographic documentation of a collection, thoughtful preparation will make the process easier and more efficient. Acquire the necessary equipment, establish standards for images, and develop a simple workflow design. Manage images in the camera, and produce the best possible results, rather than relying on time-consuming editing after the fact. It is extremely important that the images of each specimen be of the highest quality and resolution. Poor quality, low resolution photos are not good for anything, and will often have to be retaken when another need arises. Repeating the photography process involves more handling of specimens and more staff time. Once good photos exist, smaller versions can be created for use on the web. The originals can be archived and used for publication and other purposes.

New ultra metal-poor stars from SDSS: follow-up GTC medium-resolution spectroscopy

NASA Astrophysics Data System (ADS)

Aguado, D. S.; Allende Prieto, C.; González Hernández, J. I.; Rebolo, R.; Caffau, E.

2017-07-01

Context. The first generation of stars formed in the Galaxy left behind the chemical signatures of their nucleosynthesis in the interstellar medium, visible today in the atmospheres of low-mass stars that formed afterwards. Sampling the chemistry of those low-mass provides insight into the first stars. Aims: We aim to increase the samples of stars with extremely low metal abundances, identifying ultra metal-poor stars from spectra with modest spectral resolution and signal-to-noise ratio (S/N). Achieving this goal involves deriving reliable metallicities and carbon abundances from such spectra. Methods: We carry out follow-up observations of faint, V > 19, metal-poor candidates selected from SDSS spectroscopy and observed with the Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) at GTC. The SDSS and follow-up OSIRIS spectra were analyzed using the FERRE code to derive effective temperatures, surface gravities, metallicities and carbon abundances. In addition, a well-known extremely metal-poor star has been included in our sample to calibrate the analysis methodology. Results: We observed and analyzed five metal-poor candidates from modest-quality SDSS spectra. All stars in our sample have been confirmed as extremely metal-poor stars, in the [Fe/H] < -3.3 regime. We report the recognition of J173403+644632, a carbon-enhanced ultra metal-poor dwarf star with [Fe/H] = -4.3 and [C/Fe] = + 3.1. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma. Programme ID GTC2E-16A and ID GTC65-16B.

Degraded document image enhancement

NASA Astrophysics Data System (ADS)

Agam, G.; Bal, G.; Frieder, G.; Frieder, O.

2007-01-01

Poor quality documents are obtained in various situations such as historical document collections, legal archives, security investigations, and documents found in clandestine locations. Such documents are often scanned for automated analysis, further processing, and archiving. Due to the nature of such documents, degraded document images are often hard to read, have low contrast, and are corrupted by various artifacts. We describe a novel approach for the enhancement of such documents based on probabilistic models which increases the contrast, and thus, readability of such documents under various degradations. The enhancement produced by the proposed approach can be viewed under different viewing conditions if desired. The proposed approach was evaluated qualitatively and compared to standard enhancement techniques on a subset of historical documents obtained from the Yad Vashem Holocaust museum. In addition, quantitative performance was evaluated based on synthetically generated data corrupted under various degradation models. Preliminary results demonstrate the effectiveness of the proposed approach.

Screen-printed flexible MRI receive coils

PubMed Central

Corea, Joseph R.; Flynn, Anita M.; Lechêne, Balthazar; Scott, Greig; Reed, Galen D.; Shin, Peter J.; Lustig, Michael; Arias, Ana C.

2016-01-01

Magnetic resonance imaging is an inherently signal-to-noise-starved technique that limits the spatial resolution, diagnostic image quality and results in typically long acquisition times that are prone to motion artefacts. This limitation is exacerbated when receive coils have poor fit due to lack of flexibility or need for padding for patient comfort. Here, we report a new approach that uses printing for fabricating receive coils. Our approach enables highly flexible, extremely lightweight conforming devices. We show that these devices exhibit similar to higher signal-to-noise ratio than conventional ones, in clinical scenarios when coils could be displaced more than 18 mm away from the body. In addition, we provide detailed material properties and components performance analysis. Prototype arrays are incorporated within infant blankets for in vivo studies. This work presents the first fully functional, printed coils for 1.5- and 3-T clinical scanners. PMID:26961073

Robust vehicle detection in different weather conditions: Using MIPM

PubMed Central

Menéndez, José Manuel; Jiménez, David

2018-01-01

Intelligent Transportation Systems (ITS) allow us to have high quality traffic information to reduce the risk of potentially critical situations. Conventional image-based traffic detection methods have difficulties acquiring good images due to perspective and background noise, poor lighting and weather conditions. In this paper, we propose a new method to accurately segment and track vehicles. After removing perspective using Modified Inverse Perspective Mapping (MIPM), Hough transform is applied to extract road lines and lanes. Then, Gaussian Mixture Models (GMM) are used to segment moving objects and to tackle car shadow effects, we apply a chromacity-based strategy. Finally, performance is evaluated through three different video benchmarks: own recorded videos in Madrid and Tehran (with different weather conditions at urban and interurban areas); and two well-known public datasets (KITTI and DETRAC). Our results indicate that the proposed algorithms are robust, and more accurate compared to others, especially when facing occlusions, lighting variations and weather conditions. PMID:29513664

Observer assessment of multi-pinhole SPECT geometries for prostate cancer imaging: a simulation study

NASA Astrophysics Data System (ADS)

Kalantari, Faraz; Sen, Anando; Gifford, Howard C.

2014-03-01

SPECT imaging using In-111 ProstaScint is an FDA-approved method for diagnosing prostate cancer metastases within the pelvis. However, conventional medium-energy parallel-hole (MEPAR) collimators produce poor image quality and we are investigating the use of multipinhole (MPH) imaging as an alternative. This paper presents a method for evaluating MPH designs that makes use of sampling-sensitive (SS) mathematical model observers for tumor detectionlocalization tasks. Key to our approach is the redefinition of a normal (or background) reference image that is used with scanning model observers. We used this approach to compare different MPH configurations for the task of small-tumor detection in the prostate and surrounding lymph nodes. Four configurations used 10, 20, 30, and 60 pinholes evenly spaced over a complete circular orbit. A fixed-count acquisition protocol was assumed. Spherical tumors were placed within a digital anthropomorphic phantom having a realistic Prostascint biodistribution. Imaging data sets were generated with an analytical projector and reconstructed volumes were obtained with the OSEM algorithm. The MPH configurations were compared in a localization ROC (LROC) study with 2D pelvic images and both human and model observers. Regular and SS versions of the scanning channelized nonprewhitening (CNPW) and visual-search (VS) model observers were applied. The SS models demonstrated the highest correlations with the average human-observer results

Micro-CT of rodents: state-of-the-art and future perspectives

PubMed Central

Clark, D. P.; Badea, C. T.

2014-01-01

Micron-scale computed tomography (micro-CT) is an essential tool for phenotyping and for elucidating diseases and their therapies. This work is focused on preclinical micro-CT imaging, reviewing relevant principles, technologies, and applications. Commonly, micro-CT provides high-resolution anatomic information, either on its own or in conjunction with lower-resolution functional imaging modalities such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). More recently, however, advanced applications of micro-CT produce functional information by translating clinical applications to model systems (e.g. measuring cardiac functional metrics) and by pioneering new ones (e.g. measuring tumor vascular permeability with nanoparticle contrast agents). The primary limitations of micro-CT imaging are the associated radiation dose and relatively poor soft tissue contrast. We review several image reconstruction strategies based on iterative, statistical, and gradient sparsity regularization, demonstrating that high image quality is achievable with low radiation dose given ever more powerful computational resources. We also review two contrast mechanisms under intense development. The first is spectral contrast for quantitative material discrimination in combination with passive or actively targeted nanoparticle contrast agents. The second is phase contrast which measures refraction in biological tissues for improved contrast and potentially reduced radiation dose relative to standard absorption imaging. These technological advancements promise to develop micro-CT into a commonplace, functional and even molecular imaging modality. PMID:24974176

Data and image transfer using mobile phones to strengthen microscopy-based diagnostic services in low and middle income country laboratories.

PubMed

Tuijn, Coosje J; Hoefman, Bas J; van Beijma, Hajo; Oskam, Linda; Chevrollier, Nicolas

2011-01-01

The emerging market of mobile phone technology and its use in the health sector is rapidly expanding and connecting even the most remote areas of world. Distributing diagnostic images over the mobile network for knowledge sharing, feedback or quality control is a logical innovation. To determine the feasibility of using mobile phones for capturing microscopy images and transferring these to a central database for assessment, feedback and educational purposes. A feasibility study was carried out in Uganda. Images of microscopy samples were taken using a prototype connector that could fix a variety of mobile phones to a microscope. An Information Technology (IT) platform was set up for data transfer from a mobile phone to a website, including feedback by text messaging to the end user. Clear images were captured using mobile phone cameras of 2 megapixels (MP) up to 5MP. Images were sent by mobile Internet to a website where they were visualized and feedback could be provided to the sender by means of text message. The process of capturing microscopy images on mobile phones, relaying them to a central review website and feeding back to the sender is feasible and of potential benefit in resource poor settings. Even though the system needs further optimization, it became evident from discussions with stakeholders that there is a demand for this type of technology.

Functional neuroanatomical networks associated with expertise in motor imagery.

PubMed

Guillot, Aymeric; Collet, Christian; Nguyen, Vo An; Malouin, Francine; Richards, Carol; Doyon, Julien

2008-07-15

Although numerous behavioural studies provide evidence that there exist wide differences within individual motor imagery (MI) abilities, little is known with regards to the functional neuroanatomical networks that dissociate someone with good versus poor MI capacities. For the first time, we thus compared, through functional magnetic resonance imaging (fMRI), the pattern of cerebral activations in 13 skilled and 15 unskilled imagers during both physical execution and MI of a sequence of finger movements. Differences in MI abilities were assessed using well-established questionnaire and chronometric measures, as well as a new index based upon the subject's peripheral responses from the autonomic nervous system. As expected, both good and poor imagers activated the inferior and superior parietal lobules, as well as motor-related regions including the lateral and medial premotor cortex, the cerebellum and putamen. Inter-group comparisons revealed that good imagers activated more the parietal and ventrolateral premotor regions, which are known to play a critical role in the generation of mental images. By contrast, poor imagers recruited the cerebellum, orbito-frontal and posterior cingulate cortices. Consistent with findings from the motor sequence learning literature and Doyon and Ungerleider's model of motor learning [Doyon, J., Ungerleider, L.G., 2002. Functional anatomy of motor skill learning. In: Squire, L.R., Schacter, D.L. (Eds.), Neuropsychology of memory, Guilford Press, pp. 225-238], our results demonstrate that compared to skilled imagers, poor imagers not only need to recruit the cortico-striatal system, but to compensate with the cortico-cerebellar system during MI of sequential movements.

The study of surgical image quality evaluation system by subjective quality factor method

NASA Astrophysics Data System (ADS)

Zhang, Jian J.; Xuan, Jason R.; Yang, Xirong; Yu, Honggang; Koullick, Edouard

2016-03-01

GreenLightTM procedure is an effective and economical way of treatment of benign prostate hyperplasia (BPH); there are almost a million of patients treated with GreenLightTM worldwide. During the surgical procedure, the surgeon or physician will rely on the monitoring video system to survey and confirm the surgical progress. There are a few obstructions that could greatly affect the image quality of the monitoring video, like laser glare by the tissue and body fluid, air bubbles and debris generated by tissue evaporation, and bleeding, just to name a few. In order to improve the physician's visual experience of a laser surgical procedure, the system performance parameter related to image quality needs to be well defined. However, since image quality is the integrated set of perceptions of the overall degree of excellence of an image, or in other words, image quality is the perceptually weighted combination of significant attributes (contrast, graininess …) of an image when considered in its marketplace or application, there is no standard definition on overall image or video quality especially for the no-reference case (without a standard chart as reference). In this study, Subjective Quality Factor (SQF) and acutance are used for no-reference image quality evaluation. Basic image quality parameters, like sharpness, color accuracy, size of obstruction and transmission of obstruction, are used as subparameter to define the rating scale for image quality evaluation or comparison. Sample image groups were evaluated by human observers according to the rating scale. Surveys of physician groups were also conducted with lab generated sample videos. The study shows that human subjective perception is a trustworthy way of image quality evaluation. More systematic investigation on the relationship between video quality and image quality of each frame will be conducted as a future study.

Achieving quality in cardiovascular imaging: proceedings from the American College of Cardiology-Duke University Medical Center Think Tank on Quality in Cardiovascular Imaging.

PubMed

Douglas, Pamela; Iskandrian, Ami E; Krumholz, Harlan M; Gillam, Linda; Hendel, Robert; Jollis, James; Peterson, Eric; Chen, Jersey; Masoudi, Frederick; Mohler, Emile; McNamara, Robert L; Patel, Manesh R; Spertus, John

2006-11-21

Cardiovascular imaging has enjoyed both rapid technological advances and sustained growth, yet less attention has been focused on quality than in other areas of cardiovascular medicine. To address this deficit, representatives from cardiovascular imaging societies, private payers, government agencies, the medical imaging industry, and experts in quality measurement met, and this report provides an overview of the discussions. A consensus definition of quality in imaging and a convergence of opinion on quality measures across imaging modalities was achieved and are intended to be the start of a process culminating in the development, dissemination, and adoption of quality measures for all cardiovascular imaging modalities.

Intimate Partner Victimization, Poor Relationship Quality, and Depressive Symptoms during Young Adulthood

PubMed Central

Longmore, Monica A.; Manning, Wendy D.; Giordano, Peggy C.; Copp, Jennifer E.

2014-01-01

Examining longitudinal data from the Toledo Adolescent Relationships Study (TARS) (n = 927), we assessed associations between physical victimization by an intimate partner, indicators of poor relationship quality, and depressive symptoms among young adult men and women in casually dating, exclusively dating, cohabiting, and marital relationships. In zero-order models, we found that physical victimization increased depressive symptoms. In multivariate models, victimization was a risk factor for depressive symptoms with the inclusion of prior depressive symptoms, family factors reflecting the intergenerational transmission of violence, sociodemographic background, and relationship characteristics including union status. Yet with the additional inclusion of indicators of poor relational quality, victimization was not a significant predictor of depressive symptoms. Arguing and poor communication influenced victimization and depressive symptoms. The associations between victimization and depressive symptoms did not differ by gender, nor were the effects of poor relationship quality on depressive symptoms conditional on gender. Thus, depressive symptoms are similarly responsive to intimate partner victimization, and for both women and men these associations were not significant with the inclusion of indicators of poor relationship quality. Findings underscored that victimization often occurs within relationship contexts characterized by a range of negative dynamics; thus multifaceted relationship-centered prevention and intervention efforts are likely to be more useful than those focusing only on negative messages about the use of aggression with an intimate partner. PMID:25131276

Examining asthma quality of care using a population-based approach

PubMed Central

Klomp, Helena; Lawson, Joshua A.; Cockcroft, Donald W.; Chan, Benjamin T.; Cascagnette, Paul; Gander, Laurie; Jorgenson, Derek

2008-01-01

Background Asthma accounts for considerable burden on health care, but in most cases, asthma can be controlled. Quality-of-care indicators would aid in monitoring asthma management. We describe the quality of asthma care using a set of proposed quality indicators. Methods We performed a retrospective cross-sectional study using health databases in Saskatchewan, a Canadian province with a population of about 1 million people. We assessed 6 quality-of-care indicators among people with asthma: admission to hospital because of asthma; poor asthma control (high use of short-acting β-agonists, admission to hospital because of asthma or death due to asthma); no inhaled corticosteroid use among patients with poor control; at least moderate inhaled corticosteroid use among patients with poor control; high inhaled corticosteroid use and use of another preventer medication among patients with poor control; and any main preventer use among patients with poor control. We calculated crude and adjusted rates with 95% confidence intervals. We tested for differences using the χ2 test for proportions and generalized linear modelling techniques. Results In 2002/03, there were 24 616 people aged 5–54 years with asthma in Saskatchewan, representing a prevalence of 3.8%. Poor symptom control was observed in 18% of patients with asthma. Among those with poor control, 37% were not dispensed any inhaled corticosteroids, and 40% received potentially inadequate doses. Among those with poor control who were dispensed high doses of inhaled corticosteroids, 26% also used another preventer medication. Hospital admissions because of asthma were highest among those aged 6–9 years and females aged 20–44 years. Males and those in adult age groups (predominantly 20–44 years) had worse quality of care for 4 indicators examined. Interpretation Suboptimal asthma management would be improved through increased use of inhaled corticosteroids and preventer medications, and reduced reliance on short-acting β-agonist medications as recommended by consensus guidelines. PMID:18390944

Smart Image Enhancement Process

NASA Technical Reports Server (NTRS)

Jobson, Daniel J. (Inventor); Rahman, Zia-ur (Inventor); Woodell, Glenn A. (Inventor)

2012-01-01

Contrast and lightness measures are used to first classify the image as being one of non-turbid and turbid. If turbid, the original image is enhanced to generate a first enhanced image. If non-turbid, the original image is classified in terms of a merged contrast/lightness score based on the contrast and lightness measures. The non-turbid image is enhanced to generate a second enhanced image when a poor contrast/lightness score is associated therewith. When the second enhanced image has a poor contrast/lightness score associated therewith, this image is enhanced to generate a third enhanced image. A sharpness measure is computed for one image that is selected from (i) the non-turbid image, (ii) the first enhanced image, (iii) the second enhanced image when a good contrast/lightness score is associated therewith, and (iv) the third enhanced image. If the selected image is not-sharp, it is sharpened to generate a sharpened image. The final image is selected from the selected image and the sharpened image.

The Quality of Medicines Used in Children and Supplied by Private Pharmaceutical Wholesalers in Kinshasa, Democratic Republic of Congo: A Prospective Survey

PubMed Central

Schiavetti, Benedetta; Wynendaele, Evelien; De Spiegeleer, Bart; Mbinze, Geremie J.; Kalenda, Nicodème; Marini, Roland; Melotte, Vera; Hasker, Epco; Meessen, Bruno; Ravinetto, Raffaella; Van der Elst, Josiane; Mutolo Ngeleka, Daniel

2018-01-01

Abstract. Poor-quality medicines are a threat to public health in many low- and middle-income countries, and prospective surveys are needed to inform corrective actions. Therefore, we conducted a cross-sectional survey on a sample of products used for children and available in the private market in Kinshasa, Democratic Republic Congo: amoxicillin (AX) and artemether/lumefantrine (AL), powders for suspension, and paracetamol (PC) tablets 500 mg. Overall, 417 products were covertly purchased from 61 wholesalers. To obtain a representative sample, the products were weighted on their market shares and a subset of 239 samples was randomly extracted to undergo in-depth visual inspection locally, and they were chemically assessed at two accredited laboratories in Belgium. Samples were defined of “poor-quality” if they failed to comply with at least one specification of the International Pharmacopoeia (for AL) or United States Pharmacopoeia 37 (for AX and PC). Results are reported according to the Medicine Quality Assessment Reporting Guideline. The visual inspection detected nonconformities in the aspects of antimalarial powders for suspension, and poor-quality labels across all medicine types. According to chemical analysis, 27.2% samples were of poor quality and 59.5% of AL samples were underdosed in artemether. Poor quality was more frequent for locally manufactured antimalarials (83.3%, P = 0.021; 86.4%, P = 0.022) and PC (4.8%, P = 0.000). The poor quality of the surveyed products may decrease the treatment’s efficacy and favor the development of resistances to antimalarials. It is hoped that these findings may guide the corrective actions of the Democratic Republic of Congo Regulatory Authority, which was the main partner in the research. PMID:29313479

Investigation into the use of photoanthropometry in facial image comparison.

PubMed

Moreton, Reuben; Morley, Johanna

2011-10-10

Photoanthropometry is a metric based facial image comparison technique. Measurements of the face are taken from an image using predetermined facial landmarks. Measurements are then converted to proportionality indices (PIs) and compared to PIs from another facial image. Photoanthropometry has been presented as a facial image comparison technique in UK courts for over 15 years. It is generally accepted that extrinsic factors (e.g. orientation of the head, camera angle and distance from the camera) can cause discrepancies in anthropometric measurements of the face from photographs. However there has been limited empirical research into quantifying the influence of such variables. The aim of this study was to determine the reliability of photoanthropometric measurements between different images of the same individual taken with different angulations of the camera. The study examined the facial measurements of 25 individuals from high resolution photographs, taken at different horizontal and vertical camera angles in a controlled environment. Results show that the degree of variability in facial measurements of the same individual due to variations in camera angle can be as great as the variability of facial measurements between different individuals. Results suggest that photoanthropometric facial comparison, as it is currently practiced, is unsuitable for elimination purposes. Preliminary investigations into the effects of distance from camera and image resolution in poor quality images suggest that such images are not an accurate representation of an individuals face, however further work is required. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Comparison of software and human observers in reading images of the CDMAM test object to assess digital mammography systems

NASA Astrophysics Data System (ADS)

Young, Kenneth C.; Cook, James J. H.; Oduko, Jennifer M.; Bosmans, Hilde

2006-03-01

European Guidelines for quality control in digital mammography specify minimum and achievable standards of image quality in terms of threshold contrast, based on readings of images of the CDMAM test object by human observers. However this is time-consuming and has large inter-observer error. To overcome these problems a software program (CDCOM) is available to automatically read CDMAM images, but the optimal method of interpreting the output is not defined. This study evaluates methods of determining threshold contrast from the program, and compares these to human readings for a variety of mammography systems. The methods considered are (A) simple thresholding (B) psychometric curve fitting (C) smoothing and interpolation and (D) smoothing and psychometric curve fitting. Each method leads to similar threshold contrasts but with different reproducibility. Method (A) had relatively poor reproducibility with a standard error in threshold contrast of 18.1 +/- 0.7%. This was reduced to 8.4% by using a contrast-detail curve fitting procedure. Method (D) had the best reproducibility with an error of 6.7%, reducing to 5.1% with curve fitting. A panel of 3 human observers had an error of 4.4% reduced to 2.9 % by curve fitting. All automatic methods led to threshold contrasts that were lower than for humans. The ratio of human to program threshold contrasts varied with detail diameter and was 1.50 +/- .04 (sem) at 0.1mm and 1.82 +/- .06 at 0.25mm for method (D). There were good correlations between the threshold contrast determined by humans and the automated methods.

Motion‐related artifacts in structural brain images revealed with independent estimates of in‐scanner head motion

PubMed Central

Savalia, Neil K.; Agres, Phillip F.; Chan, Micaela Y.; Feczko, Eric J.; Kennedy, Kristen M.

2016-01-01

Abstract Motion‐contaminated T1‐weighted (T1w) magnetic resonance imaging (MRI) results in misestimates of brain structure. Because conventional T1w scans are not collected with direct measures of head motion, a practical alternative is needed to identify potential motion‐induced bias in measures of brain anatomy. Head movements during functional MRI (fMRI) scanning of 266 healthy adults (20–89 years) were analyzed to reveal stable features of in‐scanner head motion. The magnitude of head motion increased with age and exhibited within‐participant stability across different fMRI scans. fMRI head motion was then related to measurements of both quality control (QC) and brain anatomy derived from a T1w structural image from the same scan session. A procedure was adopted to “flag” individuals exhibiting excessive head movement during fMRI or poor T1w quality rating. The flagging procedure reliably reduced the influence of head motion on estimates of gray matter thickness across the cortical surface. Moreover, T1w images from flagged participants exhibited reduced estimates of gray matter thickness and volume in comparison to age‐ and gender‐matched samples, resulting in inflated effect sizes in the relationships between regional anatomical measures and age. Gray matter thickness differences were noted in numerous regions previously reported to undergo prominent atrophy with age. Recommendations are provided for mitigating this potential confound, and highlight how the procedure may lead to more accurate measurement and comparison of anatomical features. Hum Brain Mapp 38:472–492, 2017. © 2016 Wiley Periodicals, Inc. PMID:27634551

Predictive factors of health-related quality of life in patients with polycystic ovary syndrome: a structural equation modeling approach.

PubMed

Bazarganipour, Fatemeh; Ziaei, Saeide; Montazeri, Ali; Foroozanfard, Fatemeh; Kazemnejad, Anoshirvan; Faghihzadeh, Soghrat

2013-11-01

To determine association between health-related quality of life (HRQOL) and psychosexual variables in patients with polycystic ovary syndrome (PCOS). Cross-sectional study. Two private gynecology clinics. A sample of 300 women with PCOS were entered into the study and were subdivided into three groups: hyperandrogenism (HA) and PCO morphology; menstrual dysfunction and PCO morphology; menstrual dysfunction and HA and/or PCO morphology. Then each patient completed the following questionnaires: the Hospital Anxiety and Depression Scale, the Body Image Concern Inventory, the Rosenberg Self-Esteem Scale, the Short-Form Health Survey, and the Female Sexual Function Index. None. Both direct and indirect relationships among clinical symptoms, psychologic status, self-esteem, body image, and sexual function as independent predictors of HRQOL were examined with the use of structural equation modeling analysis. The clinical variables and psychologic distress had the strongest indirect relationships with HRQOL in the HA phenotype. The highest effect of PCOS symptoms on HRQOL impairment in patients with menstrual irregularities along with HA and patients with menstrual irregularities along with polycystic ovaries was exerted by clinical variables, poor perception of self-worth, negative body image, and sexual dysfunction. In patients with various phenotypes of PCOS, the effects of mediating variables on HRQOL are different. In patients with PCOS, the findings suggest that mediating factors, especially psychologic distress, self-esteem, body image, and sexual function, play an important role and should be taken into consideration and adequately treated if present. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

A comparative study of multi-sensor data fusion methods for highly accurate assessment of manufactured parts

NASA Astrophysics Data System (ADS)

Hannachi, Ammar; Kohler, Sophie; Lallement, Alex; Hirsch, Ernest

2015-04-01

3D modeling of scene contents takes an increasing importance for many computer vision based applications. In particular, industrial applications of computer vision require efficient tools for the computation of this 3D information. Routinely, stereo-vision is a powerful technique to obtain the 3D outline of imaged objects from the corresponding 2D images. As a consequence, this approach provides only a poor and partial description of the scene contents. On another hand, for structured light based reconstruction techniques, 3D surfaces of imaged objects can often be computed with high accuracy. However, the resulting active range data in this case lacks to provide data enabling to characterize the object edges. Thus, in order to benefit from the positive points of various acquisition techniques, we introduce in this paper promising approaches, enabling to compute complete 3D reconstruction based on the cooperation of two complementary acquisition and processing techniques, in our case stereoscopic and structured light based methods, providing two 3D data sets describing respectively the outlines and surfaces of the imaged objects. We present, accordingly, the principles of three fusion techniques and their comparison based on evaluation criterions related to the nature of the workpiece and also the type of the tackled application. The proposed fusion methods are relying on geometric characteristics of the workpiece, which favour the quality of the registration. Further, the results obtained demonstrate that the developed approaches are well adapted for 3D modeling of manufactured parts including free-form surfaces and, consequently quality control applications using these 3D reconstructions.

Analysis and comparison of magnetic sheet insulation tests

NASA Astrophysics Data System (ADS)

Marion-Péra, M. C.; Kedous-Lebouc, A.; Cornut, B.; Brissonneau, P.

1994-05-01

Magnetic circuits of electrical machines are divided into coated sheets in order to limit eddy currents. The surface insulation resistance of magnetic sheets is difficult to evaluate because it depends on parameters like pressure and covers a wide range of values. Two methods of measuring insulation resistance are analyzed: the standardized 'Franklin device' and a tester developed by British Steel Electrical. Their main drawback is poor local repeatability. The Franklin method allows better quality control of industrial process because it measures only one insulating layer at a time. It also gives more accurate images of the distribution of possible defects. Nevertheless, both methods lead to similar classifications of insulation efficiency.

Impacts of population growth and economic development on water quality of a lake: case study of Lake Victoria Kenya water.

PubMed

Juma, Dauglas Wafula; Wang, Hongtao; Li, Fengting

2014-04-01

Anthropogenic-induced water quality pollution is a major environmental problem in freshwater ecosystems today. As a result of this, eutrophication of lakes occurs. Population and economic development are key drivers of water resource pollution. To evaluate how growth in the riparian population and in the gross domestic product (GDP) with unplanned development affects the water quality of the lake, this paper evaluates Lake Victoria Kenyan waters basin. Waters quality data between 1990 and 2012 were analyzed along with reviews of published literature, papers, and reports. The nitrate-nitrogen (NO3-N), soluble phosphorus (PO4-P), chlorophyll a, and Secchi transparencies were evaluated as they are key water quality indicators. The NO3-N increased from 10 μg l(-1) in 1990 to 98 μg 1(-1) in 2008, while PO4-P increased from 4 μg l(-1) in 1990 to 57 μg l(-1) in 2008. The population and economic growth of Kenya are increasing with both having minimums in 1990 of 24.143 million people and 12.18 billion US dollars, to maximums in 2010 of 39.742 million people and 32.163 billion US dollars, respectively. A Secchi transparency is reducing with time, indicating an increasing pollution. This was confirmed by an increase in aquatic vegetation using an analysis of moderate resolution imaging spectroradiometer (MODIS) images of 2000 and 2012 of Kenyan waters. This study found that increasing population and GDP increases pollution discharge thus polluting lakes. One of major factors causing lake water pollution is the unplanned or poor waste management policy and service.

Blind image quality assessment without training on human opinion scores

NASA Astrophysics Data System (ADS)

Mittal, Anish; Soundararajan, Rajiv; Muralidhar, Gautam S.; Bovik, Alan C.; Ghosh, Joydeep

2013-03-01

We propose a family of image quality assessment (IQA) models based on natural scene statistics (NSS), that can predict the subjective quality of a distorted image without reference to a corresponding distortionless image, and without any training results on human opinion scores of distorted images. These `completely blind' models compete well with standard non-blind image quality indices in terms of subjective predictive performance when tested on the large publicly available `LIVE' Image Quality database.

Sleep quality subtypes and obesity.

PubMed

Magee, Christopher A; Reddy, Prasuna; Robinson, Laura; McGregor, Alisha

2016-12-01

Poor sleep quality could be a risk factor for obesity. This article utilized a person-centered approach to investigate whether distinct sleep quality subtypes were associated with obesity directly, and indirectly via physical activity. The sample included 8,932 Australian employees who participated in the Household, Income and Labor Dynamics in Australia Survey. Structured interviews and self-report questionnaires collected information on sleep quality, obesity, and relevant demographic, health, and work-related variables. Latent class analysis identified distinct subtypes of sleep quality. General linear modeling examined the associations of sleep quality subtypes with body mass index (BMI) and waist circumference. Multicategorical mediation models examined indirect paths linking sleep quality classes with obesity via physical activity. Five distinct sleep quality subtypes were identified: Poor Sleepers (20.0%), Frequent Sleep Disturbances (19.2%), Minor Sleep Disturbances (24.5%), Long Sleepers (9.6%), and Good Sleepers (26.7%). BMI, waist circumference, and physical activity differed among the sleep quality subtypes, with similar results observed for males and females. For example, Poor Sleepers had the highest BMIs, followed by Frequent Sleep Disturbances and Minor Sleep Disturbances; Long Sleepers and Good Sleepers had the lowest BMIs. Mediation analyses indicated that low levels of physical activity linked the Poor Sleep, Frequent Sleep Disturbance, and Long Sleep classes with higher BMI. These results provide new insights into the nature of sleep quality in employees. In particular, distinct sleep quality patterns had differing associations with measures of obesity, suggesting the need for tailored workplace interventions. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

[Factors associated with poor sleep quality in the Brazilian population ≥ 40 years of age: VIGICARDIO Study].

PubMed

Muñoz-Pareja, Maritza; Loch, Mathias Roberto; Dos Santos, Hellen Geremias; Sakay Bortoletto, Maira Sayuri; Durán González, Alberto; Maffei de Andrade, Selma

The prevalence of poor sleep quality in men and women ≥ 40 years old from the VIGICARDIO Study was determined, and sociodemographic, health, lifestyle and social capital factors associated with poor sleep quality were identified. A population-based study conducted in 2011 among 1,058 non-institutionalised individuals randomly selected from Cambé, Paraná State, Brazil. Logistic regression was used to evaluate the association between sleep quality and sociodemographic, health, lifestyle and social capital factors in men and women. The prevalence of poor sleep quality was 34% in men and 44% in women. Having bad/regular self-rated health status was a factor associated with poor sleep quality in men (OR: 1.79; 95% CI: 1.17-2.72) and women (OR: 2.43; 95% CI: 1.68-3.53). Being obese (OR: 1.67; 95% CI: 1.13-2.46), having depression (OR: 2.09; 95% CI: 1.41-3.13) and presenting temporal orientation difficulties (OR: 1.95; 95% CI: 1.08-3.52) were associated factors in women. Difficulty to understand what is explained (OR: 2.18; 95% CI: 1.16-4.09) and alcohol abuse (OR: 1.85; 95% CI: 1.21-2.83) were associated factors in men. Factors affecting sleep quality are different for men and for women. These factors should be taken into consideration when devising activities that promote good sleep quality, with a view to improving their effectiveness. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

JPEG2000 still image coding quality.

PubMed

Chen, Tzong-Jer; Lin, Sheng-Chieh; Lin, You-Chen; Cheng, Ren-Gui; Lin, Li-Hui; Wu, Wei

2013-10-01

This work demonstrates the image qualities between two popular JPEG2000 programs. Two medical image compression algorithms are both coded using JPEG2000, but they are different regarding the interface, convenience, speed of computation, and their characteristic options influenced by the encoder, quantization, tiling, etc. The differences in image quality and compression ratio are also affected by the modality and compression algorithm implementation. Do they provide the same quality? The qualities of compressed medical images from two image compression programs named Apollo and JJ2000 were evaluated extensively using objective metrics. These algorithms were applied to three medical image modalities at various compression ratios ranging from 10:1 to 100:1. Following that, the quality of the reconstructed images was evaluated using five objective metrics. The Spearman rank correlation coefficients were measured under every metric in the two programs. We found that JJ2000 and Apollo exhibited indistinguishable image quality for all images evaluated using the above five metrics (r > 0.98, p < 0.001). It can be concluded that the image quality of the JJ2000 and Apollo algorithms is statistically equivalent for medical image compression.

Mitigation of stress: new treatment alternatives.

PubMed

Subhani, Ahmad Rauf; Kamel, Nidal; Mohamad Saad, Mohamad Naufal; Nandagopal, Nanda; Kang, Kenneth; Malik, Aamir Saeed

2018-02-01

Complaints of stress are common in modern life. Psychological stress is a major cause of lifestyle-related issues, contributing to poor quality of life. Chronic stress impedes brain function, causing impairment of many executive functions, including working memory, decision making and attentional control. The current study sought to describe newly developed stress mitigation techniques, and their influence on autonomic and endocrine functions. The literature search revealed that the most frequently studied technique for stress mitigation was biofeedback (BFB). However, evidence suggests that neurofeedback (NFB) and noninvasive brain stimulation (NIBS) could potentially provide appropriate approaches. We found that recent studies of BFB methods have typically used measures of heart rate variability, respiration and skin conductance. In contrast, studies of NFB methods have typically utilized neurocomputation techniques employing electroencephalography, functional magnetic resonance imaging and near infrared spectroscopy. NIBS studies have typically utilized transcranial direct current stimulation methods. Mitigation of stress is a challenging but important research target for improving quality of life.

"The nurse satisfaction, service quality and nurse retention chain": implications for management of recruitment and retention.

PubMed

Newman, Karin; Maylor, Uvanney; Chansarkar, Bal

2002-01-01

This paper presents the findings of a qualitative study, based on interviews with over 130 nurses and midwives in four London Trust hospitals on: the main factors influencing nurse satisfaction and retention; empirical support for the robustness of a conceptual framework or model "the nurse satisfaction, service quality and nurse retention chain"; and some managerial considerations for recruitment and retention. The three main factors influencing job satisfaction were patients, the inherent characteristics of nursing and the nursing team; the two main sources of job dissatisfaction were staff shortages and poor management and amongst nurse retention strategies improving working conditions was more important than increased pay. For recruitment, as well as retention, improving the image and reputation of nursing along with improvements in work-life balance were pre-requisites for meeting the challenging target of an additional 20,000 nurses on the wards by 2004.

Mental health, sleep quality, drinking motives, and alcohol-related consequences: a path-analytic model.

PubMed

Kenney, Shannon R; Lac, Andrew; Labrie, Joseph W; Hummer, Justin F; Pham, Andy

2013-11-01

Poor mental health, sleep problems, drinking motivations, and high-risk drinking are prevalent among college students. However, research designed to explicate the interrelationships among these health risk behaviors is lacking. This study was designed to assess the direct and indirect influences of poor mental health (a latent factor consisting of depression, anxiety, and stress) to alcohol use and alcohol-related consequences through the mediators of global sleep quality and drinking motives in a comprehensive model. Participants were 1,044 heavy-drinking college students (66.3% female) who completed online surveys. A hybrid structural equation model tested hypotheses involving relations leading from poor mental health to drinking motives and poorer global sleep quality to drinking outcomes. Results showed that poor mental health significantly predicted all four subscales of drinking motivations (social, coping, conformity, and enhancement) as well as poor sleep. Most of the drinking motives and poor sleep were found to explain alcohol use and negative alcohol consequences. Poor sleep predicted alcohol consequences, even after controlling for all other variables in the model. The hypothesized mediational pathways were examined with tests of indirect effects. This is the first study to assess concomitantly the relationships among three vital health-related domains (mental health, sleep behavior, and alcohol risk) in college students. Findings offer important implications for college personnel and interventionists interested in reducing alcohol risk by focusing on alleviating mental health problems and poor sleep quality.

Cross-sectional analysis of food choice frequency, sleep confounding beverages, and psychological distress predictors of sleep quality.

PubMed

Knowlden, Adam P; Burns, Maranda; Harcrow, Andy; Shewmake, Meghan E

2016-03-16

Poor sleep quality is a significant public health problem. The role of nutrition in predicting sleep quality is a relatively unexplored area of inquiry. The purpose of this study was to evaluate the capacity of 10 food choice categories, sleep confounding beverages, and psychological distress to predict the sleep quality of college students. A logistic regression model comprising 10 food choice variables (healthy proteins, unhealthy proteins, healthy dairy, unhealthy dairy, healthy grains, unhealthy grains, healthy fruits and vegetables, unhealthy empty calories, healthy beverages, unhealthy beverages), sleep confounding beverages (caffeinated/alcoholic beverages), as well as psychological distress (low, moderate, serious distress) was computed to determine the capacity of the variables to predict sleep quality (good/poor). The odds of poor sleep quality were 32.4% lower for each unit of increased frequency of healthy proteins consumed (p<0.001; OR=0.676), 14.1% lower for each unit of increased frequency of healthy dairy food choices consumed (p=0.024; OR=0.859), 13.1% higher for each unit of increased frequency of empty calorie food choices consumed (p=0.003; OR=1.131), and 107.3% higher for those classified in the moderate psychological distress (p=0.016; OR=2.073). Collectively, healthy proteins, healthy dairy, unhealthy empty calories, and moderate psychological distress were moderately predictive of sleep quality in the sample (Nagelkerke R2=23.8%). Results of the study suggested higher frequency of consumption of healthy protein and healthy dairy food choices reduced the odds of poor sleep quality, while higher consumption of empty calories and moderate psychological distress increased the odds of poor sleep quality.

U-shaped associations between time in bed and the physical and mental functioning of Japanese civil servants: the roles of work, family, behavioral and sleep quality characteristics.

PubMed

Sekine, M; Tatsuse, T; Cable, N; Chandola, T; Marmot, M

2014-09-01

This study aimed to evaluate (i) whether work, family, behavioral and sleep quality characteristics differ among individuals with different time in bed (TIB), and (ii) whether and how much the U-shaped associations between TIB and health can be explained by these characteristics. Participants were 3510 employees (2371 males and 1139 females) aged 20-65 years working in local government in Japan. They completed a questionnaire regarding work, family, and behavioral characteristics. Sleep quality and physical and mental functioning were evaluated using the Pittsburgh Sleep Quality Index and the Short Form 36. High job demands, long work hours, and high work-family conflict were more prevalent among those with short TIB. Those with long TIB had daily drinking habits. Whereas those with short TIB had poor sleep, mainly due to poor subjective sleep quality and daytime dysfunction, those with long TIB had poor sleep, mainly due to long sleep latency, poor sleep efficiency and sleep disturbances. The U-shaped associations between TIB and poor physical and mental health, with the best health observed in those spending ~8 h in bed, weakened considerably after adjustment for sleep quality, followed by work and family characteristics. After adjusting for behavioral characteristics and long-standing illnesses, the associations hardly changed. The U-shaped associations between TIB and health may be explained by U-shaped associations between TIB and poor sleep and psychosocial stress in work and family life. Copyright © 2014 Elsevier B.V. All rights reserved.

Marital Quality as a Moderator of the Effects of Poor Vision on Quality of Life Among Older Adults

PubMed Central

2011-01-01

Objectives. This study assessed the moderating role of marital quality in the effects of subjective and objective vision on functional limitations, social isolation, and depressive symptomatology. Method. Data from 738 married older adults drawn from a probability-based representative sample of elders residing in the United States were used. Assessments included subjective and objective vision, marital quality variables (relationship satisfaction, supportive spouse behaviors, and free time spent with one’s spouse), and three aspects of quality of life (functional limitations, social isolation, and depressive symptomatology). Results. Moderated regression analyses found that relationship satisfaction and supportive spouse behaviors moderated the effects of poor self-reported vision on functional limitations and depressive symptoms and the effects of poor visual acuity on functional limitations. As hypothesized, poorer vision was unrelated to functional limitations and depressive symptoms in more satisfying marriages but predicted higher levels of both outcomes in less satisfying marriages. Contrary to expectations, higher levels of supportive spouse behaviors were associated with more functional limitations in respondents who reported poorer subjective and objective vision. Discussion. A marriage that is highly satisfying can mitigate the adverse effects of poor vision on functional limitations and depressive symptomatology in late life. The moderating role of supportive spouse behaviors in the link between poor vision and quality of life is less intuitive, however. Whereas relationship satisfaction may operate as a traditional buffer in the context of poor vision, supportive spouse behaviors may increase in response to or be ineffective in this context. PMID:21840838

Sleep Quality, Affect, Pain, and Disability in Children With Chronic Pain: Is Affect a Mediator or Moderator?

PubMed

Evans, Subhadra; Djilas, Vesna; Seidman, Laura C; Zeltzer, Lonnie K; Tsao, Jennie C I

2017-09-01

Sleep problems have been identified as a potential antecedent of chronic pain and pain-related disability in pediatric populations. In adult studies, affect has been implicated in these relationships. This study sought to better understand the relationships between sleep quality, negative and positive affect, and pain and functioning in children with chronic pain. Participants included 213 children and adolescents (aged 7-17 years) presenting to a tertiary pain clinic with chronic pain. Children completed questionnaires measuring sleep quality, positive and negative affect, pain intensity, and functional disability. Results indicated that 74% of children reported disordered sleeping and that poor sleep quality was significantly associated with increased pain, disability, negative affect, and decreased positive affect. Our hypotheses were partially supported, with negative affect (but not positive affect) mediating the relationship between poor sleep and increased pain; and positive as well as negative affect mediating the relationship between poor sleep and increased functional disability. There was no evidence for affect as a moderator. This study adds to the growing literature demonstrating the effect of poor sleep quality on children's pain and functioning, highlighting the need to develop further longitudinal research to confirm the causal roles of these variables. This article examines the relationship between poor sleep quality, affect (negative as well as positive), pain, and disability in children with chronic pain. The findings have the potential to better understand the processes involved in how poor sleep may lead to increased pain and pain-related disability. Copyright © 2017 American Pain Society. All rights reserved.

The value of core lab stress echocardiography interpretations: observations from the ISCHEMIA Trial.

PubMed

Kataoka, Akihisa; Scherrer-Crosbie, Marielle; Senior, Roxy; Gosselin, Gilbert; Phaneuf, Denis; Guzman, Gabriela; Perna, Gian; Lara, Alfonso; Kedev, Sasko; Mortara, Andrea; El-Hajjar, Mohammad; Shaw, Leslee J; Reynolds, Harmony R; Picard, Michael H

2015-12-18

Stress echocardiography (SE) is dependent on subjective interpretations. As a prelude to the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) Trial, potential sites were required to submit two SE, one with moderate or severe left ventricular (LV) myocardial ischemia and one with mild ischemia. We evaluated the concordance of site and core lab interpretations. Eighty-one SE were submitted from 41 international sites. Ischemia was classified by the number of new or worsening segmental LV wall motion abnormalities (WMA): none, mild (1 or 2) or moderate or severe (3 or more) by the sites and the core lab. Core lab classified 6 SE as no ischemia, 35 mild and 40 moderate or greater. There was agreement between the site and core in 66 of 81 total cases (81%, weighted kappa coefficient [K] =0.635). Agreement was similar for SE type - 24 of 30 exercise (80%, K = 0.571) vs. 41 of 49 pharmacologic (84%, K = 0.685). The agreement between poor or fair image quality (27 of 36 cases, 75%, K = 0.492) was not as good as for the good or excellent image quality cases (39 of 45 cases, 87%, K = 0.755). Differences in concordance were noted for degree of ischemia with the majority of discordant interpretations (87%) occurring in patients with no or mild LV myocardial ischemia. While site SE interpretations are largely concordant with core lab interpretations, this appears dependent on image quality and the extent of WMA. Thus core lab interpretations remain important in clinical trials where consistency of interpretation across a range of cases is critical. ClinicalTrials.gov NCT01471522.

Study of pelvic floor and sphincter muscles in congenital pouch colon with the help of three-dimensional CT scan.

PubMed

Maletha, Madhukar; Kureel, S N; Khan, Tanvir Roshan; Wakhlu, Ashish

2010-12-01

Congenital pouch colon (CPC) is a pouch-like dilatation of shortened colon associated with anorectal malformation (ARM). The disease is prevalent in northern India. Postoperatively, the continence results are not as good as in other ARMs and there is higher incidence of incontinence and perineal soiling in these patients. The present study aimed to evaluate the pelvic floor and sphincter muscle characteristics in patients of CPC with the help of 64-slice computerized tomography with three-dimensional (3D) volumetric reconstructions of images, thus, to know the overall quality of these muscles in the patients. The study was conducted in patients admitted over a period of July 2007 to November 2008 in our department. Totally, eight patients of CPC were subjected to 64-slice CT with three-dimensional reconstructions of images and different parameters such as quality of pelvic floor muscles, configuration of vertical and parasagittal fibres, shape and thickness of sphincter muscle complex, attenuation values of sphincters were studied. The 3D reconstructed images of pelvis in patients of CPC showed a well-developed pelvic floor and sphincter muscle complex. The length of the parasagittal fibres, transverse width of the vertical fibres and CT attenuation values of these structures with overall muscle quality were found to be good in these patients. In cases of CPC, the pelvic floor muscles including striated muscle complex (vertical and parasagittal fibres) are well developed. Higher rates of incontinence and soiling in CPC are not because of poorly developed pelvic floor and sphincter muscles. Three-dimensional CT can also provide important anatomical information that can help the operating surgeon while performing surgery.

Coronary Computed Tomographic Angiography at Low Concentration of Contrast Agent and Low Tube Voltage in Patients with Obesity:: A Feasibility Study.

PubMed

Pan, Yu-Ning; Li, Ai-Jing; Chen, Xiao-Min; Wang, Jian; Ren, Da-Wei; Huang, Qiu-Li

2016-04-01

Using lower tube voltage can reduce the exposure to radiation and the dose of contrast agent. However, lower tube voltage is often linked to more noise and poor image quality, which create a need for more effective technology to resolve this problem. To explore the feasibility of coronary computed tomographic angiography (CCTA) in patients with obesity at low tube voltage (100 kV) and low contrast agent concentration (270 mg/mL) using iterative reconstruction. A total of 48 patients with body mass index greater than 30 kg/m(2) were included and randomly divided into two groups. Group A received a traditional protocol (iopromide 370 mg/mL + 120 kV); group B received a protocol with low tube voltage (100 kV), low contrast agent concentration (270 mg/mL), and iterative reconstruction. The effective dose (ED), average attenuation values, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the figure of merit (FOM), image quality scores, and the total iodine intake were compared. No significant differences in average CT attenuations, SNR, CNR, and subjective scores were noticed between the two groups (P > 0.05), whereas the FOM of group B was significantly higher than that of group A. Effective radiation dose, total iodine, and iodine injection rate in group B were lower than those of group A (P <0.01). In patients with obesity, isotonic contrast agent with low iodine concentration and low-dose CCTA were feasible. Substantial reduction in radiation dose and the iodine intake could be achieved without compromising the image quality. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Micro-scale environment and mental health in later life: Results from the Cognitive Function and Ageing Study II (CFAS II).

PubMed

Wu, Yu-Tzu; Prina, A Matthew; Jones, Andy; Barnes, Linda E; Matthews, Fiona E; Brayne, Carol

2017-08-15

Poor micro-scale environmental features, such as graffiti and broken windows, have been associated with crime and signs of social disorder with a potential impact on mental health. The aim of this study is to investigate the association between micro-scale environment and mental health problems in later life, including cognitive (cognitive impairment and dementia) and common mental disorders (depressive and anxiety symptoms). The method of visual image audits was used to collect micro-scale environmental data for 3590 participants in the Cognitive Function and Ageing Study II, a population-based multicentre cohort of people aged 65 or above in England. Multilevel logistic regression was used to examine the associations between the quality of micro-scale environment and mental health problems taking into account urban/rural difference. Poor quality of micro-scale environment was associated with nearly 20% increased odds of depressive (OR: 1.19; 95% CI: 0.99, 1.44) and anxiety symptoms (OR: 1.17; 95% CI: 0.99, 1.38) while the direction of association for cognitive disorders differed across urban and rural settings. Although higher odds of cognitive disorders were found in rural settings, living in a poor quality environment was associated with nearly twice higher odds of cognitive impairment (OR: 1.88; 95% CI: 1.18, 2.97) in urban conurbations but 20% lower odds in rural areas (OR: 0.80; 95% CI: 0.57, 1.11). The causal direction could not be fully determined due to the cross-sectional nature of the data. The visual nature of the environmental assessment tool means it likely does not fully capture features related to the availability of local support services, or opportunities for social participation and interaction. The quality of micro-scale environment appears to be important to mental health in older people. Interventions may incorporate the environmental aspect to reduce cognitive and common mental disorders. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Feasibility and safety of exercise stress testing using an anti-gravity treadmill with Tc-99m tetrofosmin single-photon emission computed tomography (SPECT) myocardial perfusion imaging: A pilot non-randomized controlled study.

PubMed

Daly, Patrick; Kayse, Regina; Rudick, Steven; Robbins, Nathan; Scheler, Jennifer; Harris, David; O'Donnell, Robert; Dwivedi, Alok K; Gerson, Myron C

2017-08-31

Exercise is the AHA/ACC guideline-recommended stress modality for myocardial perfusion imaging, but many patients are unable to exercise to target heart rate on a conventional treadmill. We examined the feasibility and safety of stress imaging using an anti-gravity treadmill in patients with perceived poor exercise capacity. 49 patients were recruited for stress testing by anti-gravity treadmill (n = 29) or to a regadenoson control group (n = 20). Seventeen anti-gravity test patients (59%) reached target heart rate obviating the need for a pharmacologic stress agent. Adverse effects of the anti-gravity treadmill were limited to minor muscle aches in 5 subjects. Stress myocardial perfusion image quality judged by 3 blinded readers on a 5-point scale was comparable for the anti-gravity treadmill (4.30 ± SD 0.87) vs pharmacologic stress (4.28 ± SD 0.66). Stress testing using an anti-gravity treadmill is feasible and may help some patients safely achieve target heart rate.

Estimation and tracking of AP-diameter of the inferior vena cava in ultrasound images using a novel active circle algorithm.

PubMed

Karami, Ebrahim; Shehata, Mohamed S; Smith, Andrew

2018-05-04

Medical research suggests that the anterior-posterior (AP)-diameter of the inferior vena cava (IVC) and its associated temporal variation as imaged by bedside ultrasound is useful in guiding fluid resuscitation of the critically-ill patient. Unfortunately, indistinct edges and gaps in vessel walls are frequently present which impede accurate estimation of the IVC AP-diameter for both human operators and segmentation algorithms. The majority of research involving use of the IVC to guide fluid resuscitation involves manual measurement of the maximum and minimum AP-diameter as it varies over time. This effort proposes using a time-varying circle fitted inside the typically ellipsoid IVC as an efficient, consistent and novel approach to tracking and approximating the AP-diameter even in the context of poor image quality. In this active-circle algorithm, a novel evolution functional is proposed and shown to be a useful tool for ultrasound image processing. The proposed algorithm is compared with an expert manual measurement, and state-of-the-art relevant algorithms. It is shown that the algorithm outperforms other techniques and performs very close to manual measurement. Copyright © 2018 Elsevier Ltd. All rights reserved.

Published methodological quality of randomized controlled trials does not reflect the actual quality assessed in protocols.

PubMed

Mhaskar, Rahul; Djulbegovic, Benjamin; Magazin, Anja; Soares, Heloisa P; Kumar, Ambuj

2012-06-01

To assess whether the reported methodological quality of randomized controlled trials (RCTs) reflects the actual methodological quality and to evaluate the association of effect size (ES) and sample size with methodological quality. Systematic review. This is a retrospective analysis of all consecutive phase III RCTs published by eight National Cancer Institute Cooperative Groups up to 2006. Data were extracted from protocols (actual quality) and publications (reported quality) for each study. Four hundred twenty-nine RCTs met the inclusion criteria. Overall reporting of methodological quality was poor and did not reflect the actual high methodological quality of RCTs. The results showed no association between sample size and actual methodological quality of a trial. Poor reporting of allocation concealment and blinding exaggerated the ES by 6% (ratio of hazard ratio [RHR]: 0.94; 95% confidence interval [CI]: 0.88, 0.99) and 24% (RHR: 1.24; 95% CI: 1.05, 1.43), respectively. However, actual quality assessment showed no association between ES and methodological quality. The largest study to date shows that poor quality of reporting does not reflect the actual high methodological quality. Assessment of the impact of quality on the ES based on reported quality can produce misleading results. Copyright © 2012 Elsevier Inc. All rights reserved.

Blind image quality assessment based on aesthetic and statistical quality-aware features

NASA Astrophysics Data System (ADS)

Jenadeleh, Mohsen; Masaeli, Mohammad Masood; Moghaddam, Mohsen Ebrahimi

2017-07-01

The main goal of image quality assessment (IQA) methods is the emulation of human perceptual image quality judgments. Therefore, the correlation between objective scores of these methods with human perceptual scores is considered as their performance metric. Human judgment of the image quality implicitly includes many factors when assessing perceptual image qualities such as aesthetics, semantics, context, and various types of visual distortions. The main idea of this paper is to use a host of features that are commonly employed in image aesthetics assessment in order to improve blind image quality assessment (BIQA) methods accuracy. We propose an approach that enriches the features of BIQA methods by integrating a host of aesthetics image features with the features of natural image statistics derived from multiple domains. The proposed features have been used for augmenting five different state-of-the-art BIQA methods, which use statistical natural scene statistics features. Experiments were performed on seven benchmark image quality databases. The experimental results showed significant improvement of the accuracy of the methods.

Nutritional quality and child-oriented marketing of breakfast cereals in Guatemala.

PubMed

Soo, J; Letona, P; Chacon, V; Barnoya, J; Roberto, C A

2016-01-01

Food marketing has been implicated as an important driver of obesity. However, few studies have examined food marketing in low- and middle-income countries (LMICs). This study documents the prevalence of advertising on cereal boxes in Guatemala and examines associations between various marketing strategies and nutritional quality. One box from all available cereals was purchased from a supermarket located in an urban area in Guatemala City, Guatemala. A content analysis was performed to document child-oriented marketing practices, product claims and health-evoking images. The Nutrient Profile Model (NPM) was used to calculate an overall nutrition score for each cereal (the higher the score, the lower the nutritional quality). In all, 106 cereals were purchased, and half of the cereals featured child-oriented marketing (54, 50.9%). Cereals had a mean (±s.d.) of 5.10±2.83 product claims per cereal, and most cereals (102, 96.2%) contained health-evoking images. Child-oriented cereals had, on average, higher NPM scores (13.0±0.55 versus 7.90±0.74, P<0.001) and sugar content (10.1±0.48 versus 6.19±0.50 g/30 g, P<0.001) compared with non-child oriented cereals. Cereals with health claims were not significantly healthier than those without claims. In Guatemala, cereals targeting children were generally of poor nutritional quality. Cereals displaying health claims were also not healthier than those without such claims. Our findings support the need for regulations restricting the use of child-oriented marketing and health claims for certain products.

Evaluation of image quality of digital photo documentation of female genital injuries following sexual assault.

PubMed

Ernst, E J; Speck, Patricia M; Fitzpatrick, Joyce J

2011-12-01

With the patient's consent, physical injuries sustained in a sexual assault are evaluated and treated by the sexual assault nurse examiner (SANE) and documented on preprinted traumagrams and with photographs. Digital imaging is now available to the SANE for documentation of sexual assault injuries, but studies of the image quality of forensic digital imaging of female genital injuries after sexual assault were not found in the literature. The Photo Documentation Image Quality Scoring System (PDIQSS) was developed to rate the image quality of digital photo documentation of female genital injuries after sexual assault. Three expert observers performed evaluations on 30 separate images at two points in time. An image quality score, the sum of eight integral technical and anatomical attributes on the PDIQSS, was obtained for each image. Individual image quality ratings, defined by rating image quality for each of the data, were also determined. The results demonstrated a high level of image quality and agreement when measured in all dimensions. For the SANE in clinical practice, the results of this study indicate that a high degree of agreement exists between expert observers when using the PDIQSS to rate image quality of individual digital photographs of female genital injuries after sexual assault. © 2011 International Association of Forensic Nurses.

Implementation of Canny and Isotropic Operator with Power Law Transformation to Identify Cervical Cancer

NASA Astrophysics Data System (ADS)

Amalia, A.; Rachmawati, D.; Lestari, I. A.; Mourisa, C.

2018-03-01

Colposcopy has been used primarily to diagnose pre-cancer and cancerous lesions because this procedure gives an exaggerated view of the tissues of the vagina and the cervix. But, the poor quality of colposcopy image sometimes makes physician challenging to recognize and analyze it. Generally, Implementation of image processing to identify cervical cancer have to implement a complex classification or clustering method. In this study, we wanted to prove that by only applying the identification of edge detection in the colposcopy image, identification of cervical cancer can be determined. In this study, we implement and comparing two edge detection operator which are isotropic and canny operator. Research methodology in this paper composed by image processing, training, and testing stages. In the image processing step, colposcopy image transformed by nth root power transformation to get better detection result and continued with edge detection process. Training is a process of labelling all dataset image with cervical cancer stage. This process involved pathology doctor as an expert in diagnosing the colposcopy image as a reference. Testing is a process of deciding cancer stage classification by comparing the similarity image of colposcopy results in the testing stage with the image of the results of the training process. We used 30 images as a dataset. The result gets same accuracy which is 80% for both Canny or Isotropic operator. Average running time for Canny operator implementation is 0.3619206 ms while Isotropic get 1.49136262 ms. The result showed that Canny operator is better than isotropic operator because Canny operator generates a more precise edge with a fast time instead.

A Tool for Interactive Data Visualization: Application to Over 10,000 Brain Imaging and Phantom MRI Data Sets.

PubMed

Panta, Sandeep R; Wang, Runtang; Fries, Jill; Kalyanam, Ravi; Speer, Nicole; Banich, Marie; Kiehl, Kent; King, Margaret; Milham, Michael; Wager, Tor D; Turner, Jessica A; Plis, Sergey M; Calhoun, Vince D

2016-01-01

In this paper we propose a web-based approach for quick visualization of big data from brain magnetic resonance imaging (MRI) scans using a combination of an automated image capture and processing system, nonlinear embedding, and interactive data visualization tools. We draw upon thousands of MRI scans captured via the COllaborative Imaging and Neuroinformatics Suite (COINS). We then interface the output of several analysis pipelines based on structural and functional data to a t-distributed stochastic neighbor embedding (t-SNE) algorithm which reduces the number of dimensions for each scan in the input data set to two dimensions while preserving the local structure of data sets. Finally, we interactively display the output of this approach via a web-page, based on data driven documents (D3) JavaScript library. Two distinct approaches were used to visualize the data. In the first approach, we computed multiple quality control (QC) values from pre-processed data, which were used as inputs to the t-SNE algorithm. This approach helps in assessing the quality of each data set relative to others. In the second case, computed variables of interest (e.g., brain volume or voxel values from segmented gray matter images) were used as inputs to the t-SNE algorithm. This approach helps in identifying interesting patterns in the data sets. We demonstrate these approaches using multiple examples from over 10,000 data sets including (1) quality control measures calculated from phantom data over time, (2) quality control data from human functional MRI data across various studies, scanners, sites, (3) volumetric and density measures from human structural MRI data across various studies, scanners and sites. Results from (1) and (2) show the potential of our approach to combine t-SNE data reduction with interactive color coding of variables of interest to quickly identify visually unique clusters of data (i.e., data sets with poor QC, clustering of data by site) quickly. Results from (3) demonstrate interesting patterns of gray matter and volume, and evaluate how they map onto variables including scanners, age, and gender. In sum, the proposed approach allows researchers to rapidly identify and extract meaningful information from big data sets. Such tools are becoming increasingly important as datasets grow larger.

Image aesthetic quality evaluation using convolution neural network embedded learning

NASA Astrophysics Data System (ADS)

Li, Yu-xin; Pu, Yuan-yuan; Xu, Dan; Qian, Wen-hua; Wang, Li-peng

2017-11-01

A way of embedded learning convolution neural network (ELCNN) based on the image content is proposed to evaluate the image aesthetic quality in this paper. Our approach can not only solve the problem of small-scale data but also score the image aesthetic quality. First, we chose Alexnet and VGG_S to compare for confirming which is more suitable for this image aesthetic quality evaluation task. Second, to further boost the image aesthetic quality classification performance, we employ the image content to train aesthetic quality classification models. But the training samples become smaller and only using once fine-tuning cannot make full use of the small-scale data set. Third, to solve the problem in second step, a way of using twice fine-tuning continually based on the aesthetic quality label and content label respective is proposed, the classification probability of the trained CNN models is used to evaluate the image aesthetic quality. The experiments are carried on the small-scale data set of Photo Quality. The experiment results show that the classification accuracy rates of our approach are higher than the existing image aesthetic quality evaluation approaches.

Standardized Uptake Value Ratio-Independent Evaluation of Brain Amyloidosis.

PubMed

Chincarini, Andrea; Sensi, Francesco; Rei, Luca; Bossert, Irene; Morbelli, Silvia; Guerra, Ugo Paolo; Frisoni, Giovanni; Padovani, Alessandro; Nobili, Flavio

2016-10-18

The assessment of in vivo18F images targeting amyloid deposition is currently carried on by visual rating with an optional quantification based on standardized uptake value ratio (SUVr) measurements. We target the difficulties of image reading and possible shortcomings of the SUVr methods by validating a new semi-quantitative approach named ELBA. ELBA involves a minimal image preprocessing and does not rely on small, specific regions of interest (ROIs). It evaluates the whole brain and delivers a geometrical/intensity score to be used for ranking and dichotomic assessment. The method was applied to adniimages 18F-florbetapir images from the ADNI database. Five expert readers provided visual assessment in blind and open sessions. The longitudinal trend and the comparison to SUVr measurements were also evaluated. ELBA performed with area under the roc curve (AUC) = 0.997 versus the visual assessment. The score was significantly correlated to the SUVr values (r = 0.86, p < 10-4). The longitudinal analysis estimated a test/retest error of ≃2.3%. Cohort and longitudinal analysis suggests that the ELBA method accurately ranks the brain amyloid burden. The expert readers confirmed its relevance in aiding the visual assessment in a significant number (85) of difficult cases. Despite the good performance, poor and uneven image quality constitutes the major limitation.

PET Image Reconstruction Incorporating 3D Mean-Median Sinogram Filtering

NASA Astrophysics Data System (ADS)

Mokri, S. S.; Saripan, M. I.; Rahni, A. A. Abd; Nordin, A. J.; Hashim, S.; Marhaban, M. H.

2016-02-01

Positron Emission Tomography (PET) projection data or sinogram contained poor statistics and randomness that produced noisy PET images. In order to improve the PET image, we proposed an implementation of pre-reconstruction sinogram filtering based on 3D mean-median filter. The proposed filter is designed based on three aims; to minimise angular blurring artifacts, to smooth flat region and to preserve the edges in the reconstructed PET image. The performance of the pre-reconstruction sinogram filter prior to three established reconstruction methods namely filtered-backprojection (FBP), Maximum likelihood expectation maximization-Ordered Subset (OSEM) and OSEM with median root prior (OSEM-MRP) is investigated using simulated NCAT phantom PET sinogram as generated by the PET Analytical Simulator (ASIM). The improvement on the quality of the reconstructed images with and without sinogram filtering is assessed according to visual as well as quantitative evaluation based on global signal to noise ratio (SNR), local SNR, contrast to noise ratio (CNR) and edge preservation capability. Further analysis on the achieved improvement is also carried out specific to iterative OSEM and OSEM-MRP reconstruction methods with and without pre-reconstruction filtering in terms of contrast recovery curve (CRC) versus noise trade off, normalised mean square error versus iteration, local CNR versus iteration and lesion detectability. Overall, satisfactory results are obtained from both visual and quantitative evaluations.

Anatomical image-guided fluorescence molecular tomography reconstruction using kernel method

PubMed Central

Baikejiang, Reheman; Zhao, Yue; Fite, Brett Z.; Ferrara, Katherine W.; Li, Changqing

2017-01-01

Abstract. Fluorescence molecular tomography (FMT) is an important in vivo imaging modality to visualize physiological and pathological processes in small animals. However, FMT reconstruction is ill-posed and ill-conditioned due to strong optical scattering in deep tissues, which results in poor spatial resolution. It is well known that FMT image quality can be improved substantially by applying the structural guidance in the FMT reconstruction. An approach to introducing anatomical information into the FMT reconstruction is presented using the kernel method. In contrast to conventional methods that incorporate anatomical information with a Laplacian-type regularization matrix, the proposed method introduces the anatomical guidance into the projection model of FMT. The primary advantage of the proposed method is that it does not require segmentation of targets in the anatomical images. Numerical simulations and phantom experiments have been performed to demonstrate the proposed approach’s feasibility. Numerical simulation results indicate that the proposed kernel method can separate two FMT targets with an edge-to-edge distance of 1 mm and is robust to false-positive guidance and inhomogeneity in the anatomical image. For the phantom experiments with two FMT targets, the kernel method has reconstructed both targets successfully, which further validates the proposed kernel method. PMID:28464120

Iris Matching Based on Personalized Weight Map.

PubMed

Dong, Wenbo; Sun, Zhenan; Tan, Tieniu

2011-09-01

Iris recognition typically involves three steps, namely, iris image preprocessing, feature extraction, and feature matching. The first two steps of iris recognition have been well studied, but the last step is less addressed. Each human iris has its unique visual pattern and local image features also vary from region to region, which leads to significant differences in robustness and distinctiveness among the feature codes derived from different iris regions. However, most state-of-the-art iris recognition methods use a uniform matching strategy, where features extracted from different regions of the same person or the same region for different individuals are considered to be equally important. This paper proposes a personalized iris matching strategy using a class-specific weight map learned from the training images of the same iris class. The weight map can be updated online during the iris recognition procedure when the successfully recognized iris images are regarded as the new training data. The weight map reflects the robustness of an encoding algorithm on different iris regions by assigning an appropriate weight to each feature code for iris matching. Such a weight map trained by sufficient iris templates is convergent and robust against various noise. Extensive and comprehensive experiments demonstrate that the proposed personalized iris matching strategy achieves much better iris recognition performance than uniform strategies, especially for poor quality iris images.