共查询到20条相似文献,搜索用时 31 毫秒
1.
Charys M. Martin James G. Turgeon Aashish Goela Charles L. Rice Timothy D. Wilson 《Journal of anatomy》2014,225(3):358-366
The hip joint is one of the most frequent sites of osteoarthritis. Advances in diagnosis and clinical treatment have progressed dramatically in the last few decades; however, there are limitations associated with the lack of reliable measures for quantifying hip joint morphology. Current diagnostic measures of the hip are performed with pre-determined measures, typically lengths and angles, on 2D radiographic planes. The current measurement techniques do not utilize the inherent 3D nature of CT and MR imaging and do not necessarily quantify the relevant clinical pathologies. A valid and reliable measurement modality that measures the surface geometry of the femoral head is necessary for early diagnosis and treatment of hip disease. The purpose of this study was to establish a method to quantify femoral head morphology using a three-dimensional model. A novel measurement approach was applied to 45 cadaveric femurs (23 right; 22 left; nine female, 17 male) and their digitally reconstructed 3D CT models. The mean difference between the cadaveric and digital measures was −2.04 mm with 95% confidence limits (CI) of 13.67 mm and −17.75 mm, respectively. The digital measurement approach was found to have excellent intraobserver reliability (ICC = 0.99, CI 0.98–0.99) and interobserver reliability (ICC = 0.98, CI 0.93–0.99). This valid and reliable novel digital measurement approach enables quantification of the 3D surface geometry of the femoral head and is able to measure individual variations and potentially detect abnormalities. This method may be used to assist future studies to establish valid diagnostic measurements for femoral head and head–neck junction pathologies. 相似文献
2.
Fatemeh Homayounieh Marcio Aloisio Bezerra Cavalcanti Rockenbach Shadi Ebrahimian Ruhani Doda Khera Bernardo C. Bizzo Varun Buch Rosa Babaei Hadi Karimi Mobin Iman Mohseni Matthias Mitschke Mathis Zimmermann Felix Durlak Franziska Rauch Subba R Digumarthy Mannudeep K. Kalra 《Journal of digital imaging》2021,34(2):320
To perform a multicenter assessment of the CT Pneumonia Analysis prototype for predicting disease severity and patient outcome in COVID-19 pneumonia both without and with integration of clinical information. Our IRB-approved observational study included consecutive 241 adult patients (> 18 years; 105 females; 136 males) with RT-PCR-positive COVID-19 pneumonia who underwent non-contrast chest CT at one of the two tertiary care hospitals (site A: Massachusetts General Hospital, USA; site B: Firoozgar Hospital Iran). We recorded patient age, gender, comorbid conditions, laboratory values, intensive care unit (ICU) admission, mechanical ventilation, and final outcome (recovery or death). Two thoracic radiologists reviewed all chest CTs to record type, extent of pulmonary opacities based on the percentage of lobe involved, and severity of respiratory motion artifacts. Thin-section CT images were processed with the prototype (Siemens Healthineers) to obtain quantitative features including lung volumes, volume and percentage of all-type and high-attenuation opacities (≥ −200 HU), and mean HU and standard deviation of opacities within a given lung region. These values are estimated for the total combined lung volume, and separately for each lung and each lung lobe. Multivariable analyses of variance (MANOVA) and multiple logistic regression were performed for data analyses. About 26% of chest CTs (62/241) had moderate to severe motion artifacts. There were no significant differences in the AUCs of quantitative features for predicting disease severity with and without motion artifacts (AUC 0.94–0.97) as well as for predicting patient outcome (AUC 0.7–0.77) (p > 0.5). Combination of the volume of all-attenuation opacities and the percentage of high-attenuation opacities (AUC 0.76–0.82, 95% confidence interval (CI) 0.73–0.82) had higher AUC for predicting ICU admission than the subjective severity scores (AUC 0.69–0.77, 95% CI 0.69–0.81). Despite a high frequency of motion artifacts, quantitative features of pulmonary opacities from chest CT can help differentiate patients with favorable and adverse outcomes. 相似文献
3.
Sian Taylor-Phillips Markus C. Elze Elizabeth A. Krupinski Kathryn Dennick Alastair G. Gale Aileen Clarke Claudia Mello-Thoms 《Journal of digital imaging》2015,28(1):32-40
The vigilance decrement describes a decrease in sensitivity or increase in specificity with time on task. It has been observed in a variety of repetitive visual tasks, but little is known about these patterns in radiologists. We investigated whether there is systematic variation in performance over the course of a radiology reading session. We re-analyzed data from six previous lesion-enriched radiology studies. Studies featured 8–22 participants assessing 27–100 cases (including mammograms, chest CT, chest x-ray, and bone x-ray) in a reading session. Changes in performance and speed as the reading session progressed were analyzed using mixed effects models. Time taken per case decreased 9–23 % as the reading session progressed (p < 0.005 for every study). There was a sensitivity decrease or specificity increase over the course of reading 100 chest x-rays (p = 0.005), 60 bone fracture x-rays (p = 0.03), and 100 chest CT scans (p < 0.0001). This effect was not found in the shorter mammography sessions with 27 or 50 cases. We found evidence supporting the hypothesis that behavior and performance may change over the course of reading an enriched test set. Further research is required to ascertain whether this effect is present in radiological practice. 相似文献
4.
Automatic tools for detection and identification of lung and lesion from high-resolution CT (HRCT) are becoming increasingly important both for diagnosis and for delivering high-precision radiation therapy. However, development of robust and interpretable classifiers still presents a challenge especially in case of non-small cell lung carcinoma (NSCLC) patients. In this paper, we have attempted to devise such a classifier by extracting fuzzy rules from texture segmented regions from HRCT images of NSCLC patients. A fuzzy inference system (FIS) has been constructed starting from a feature extraction procedure applied on overlapping regions from the same organs and deriving simple if–then rules so that more linguistically interpretable decisions can be implemented. The proposed method has been tested on 138 regions extracted from CT scan images acquired from patients with lung cancer. Assuming two classes of tissues C1 (healthy tissues) and C2 (lesion) as negative and positive, respectively; preliminary results report an AUC = 0.98 for lesions and AUC = 0.93 for healthy tissue, with an optimal operating condition related to sensitivity = 0.96, and specificity = 0.98 for lesions and sensitivity 0.99, and specificity = 0.94 for healthy tissue. Finally, the following results have been obtained: false-negative rate (FNR) = 6 % (C1), FNR = 2 % (C2), false-positive rate (FPR) = 4 % (C1), FPR = 3 % (C2), true-positive rate (TPR) = 94 %, (C1) and TPR = 98 % (C2). 相似文献
5.
Purpose:
To investigate whether the multislice CT scanning protocols of head, chest and abdomen are adjusted according to patient’s age in paediatric patients.Materials and Methods:
Multislice CT examination records of paediatric patients undergoing head, chest and abdomen scans from three public hospitals during a one-year period were retrospectively reviewed. Patients were categorised into the following age groups: under 4 years, 5–8 years, 9–12 years and 13–16 years, while the tube current was classified into the following ranges: < 49 mA, 50–99 mA, 100–149 mA, 150–199 mA, > 200 mA and unknown.Results:
A total of 4998 patient records, comprising a combination of head, chest and abdomen CT scans, were assessed, with head CT scans representing nearly half of the total scans. Age-based adjusted CT protocols were observed in most of the scans with higher tube current setting being used with increasing age. However, a high tube current (150–199 mA) was still used in younger patients (0–8 years) undergoing head CT scans. In one hospital, CT protocols remained constant across all age groups, indicating potential overexposure to the patients.Conclusion:
This analysis shows that paediatric CT scans are adjusted according to the patient’s age in most of the routine CT examinations. This indicates increased awareness regarding radiation risks associated with CT. However, high tube current settings are still used in younger patient groups, thus, optimisation of paediatric CT protocols and implementation of current guidelines, such as age-and weight-based scanning, should be recommended in daily practice. 相似文献6.
Huang-Wei Lu Guan-Nan He Hong Ma Jun-Ke Wang 《Clinical and experimental immunology》2010,160(3):450-456
Many cellular stresses and inflammatory stimuli can activate p38 mitogen-activated protein kinase (MAPK), a serine/threonine kinase in the MAPK family. The different stimuli act via different receptors or signalling pathways to induce phosphorylation of the cytosolic protein p47phox, one subunit of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Formyl–methionyl–leucyl–phenylalanine (fMLP) has been shown to induce the p38 MAPK phosphorylation during the respiratory burst in human neutrophils. Here, we show that treatment with S(+)-ketamine or R(-)-ketamine at different concentrations (50, 100, 200, 400 µM) reduced fMLP-induced superoxide anion generation and p47phox phosphorylation in neutrophils in a concentration-dependent manner (y = −0·093x + 93·35 for S(+)-ketamine and y = −0·0982x + 95·603 for R(-)-ketamine, respectively). While treatment with 50 µM ketamine inhibited fMLP-induced superoxide generation by 10%, treatment with 400 µM S(+)-ketamine and R(-)-ketamine reduced fMLP-induced superoxide generation to 60·5 ± 8·3% and 60·0 ± 8·5%, respectively, compared with that in neutrophils treated with fMLP alone. Furthermore, treatment with ketamine down-regulated both fMLP-induced p47phox and isoproterenol-induced p38 MAPK phosphorylation and superoxide production. Interestingly, treatment with SB203580, the p38 MAPK inhibitor, also mitigated fMLP-induced superoxide anion generation and p38 MAPK and p47phox phosphorylation as well as apoptosis in a concentration-dependent fashion in neutrophils. Therefore, ketamine racemes inhibited fMLP-induced superoxide anion generation and p47phox phosphorylation by modulating fMLP-mediated p38 MAPK activation in neutrophils. 相似文献
7.
8.
Cinzia Campari Paolo Giorgi Rossi Carlo Alberto Mori Sara Ravaioli Andrea Nitrosi Rita Vacondio Pamela Mancuso Antonella Cattani Pierpaolo Pattacini 《Journal of digital imaging》2016,29(2):235-242
In 2012, the Reggio Emilia Breast Cancer Screening Program introduced digital mammography in all its facilities at the same time. The aim of this work is to analyze the impact of digital mammography introduction on the recall rate, detection rate, and positive predictive value. The program actively invites women aged 45–74 years. We included women screened in 2011, all of whom underwent film-screen mammography, and all women screened in 2012, all of whom underwent digital mammography. Double reading was used for all mammograms, with arbitration in the event of disagreement. A total of 42,240 women underwent screen-film mammography and 45,196 underwent digital mammography. The recall rate increased from 3.3 to 4.4 % in the first year of digital mammography (relative recall adjusted by age and round 1.46, 95 % CI = 1.37–1.56); the positivity rate for each individual reading, before arbitration, rose from 3 to 5.7 %. The digital mammography recall rate decreased during 2012: after 12 months, it was similar to the recall rate with screen-film mammography. The detection rate was similar: 5.9/1000 and 5.2/1000 with screen-film and digital mammography, respectively (adjusted relative detection rate 0.95, 95 % CI = 0.79–1.13). The relative detection rate for ductal carcinoma in situ remained the same. The introduction of digital mammography to our organized screening program had a negative impact on specificity, thereby increasing the recall rate. The effect was limited to the first 12 months after introduction and was attenuated by the double reading with arbitration. We did not observe any relevant effects on the detection rate. 相似文献
9.
Kenneth R Persons Nicholas J Hangiandreou Nicholas T Charboneau J Charboneau E James Bruce R Douglas Ann P Salmon John M Knudsen Bradley J Erickson 《Journal of digital imaging》2002,15(1):15-21
A prior ultrasound study indicated that images with low to moderate levels of JPEG and wavelet compression were acceptable for diagnostic purposes. The purpose of this study is to validate this prior finding using the Joint Photographic Experts Group (JPEG) baseline compression algorithm, at a compression ratio of approximately 10:1, on a sufficiently large number of grayscale and color ultrasound images to attain a statistically significant result. The practical goal of this study is to determine if it is feasible for radiologists to use irreversibly compressed images as an integral part of the day to day ultrasound practice (ie, perform primary diagnosis with, and store irreversibly compressed images in the ultrasound PACS archive). In this study, 5 Radiologists were asked to review 300 grayscale and color static ultrasound images selected from 4 major anatomic groups. Each image was compressed and decompressed using the JPEG baseline compression algorithm at a fixed quality factor resulting in an average compression ratio of approximately 9:1. The images were presented in pairs (original and compressed) in a blinded fashion on a PACS workstation in the ultrasound reading areas, and radiologists were asked to pick which image they preferred in terms of diagnostic utility and their degree of certainty (on a scale from 1 to 4). Of the 1499 total readings, 50.17% (95% confidence intervals at 47.6%, and 52.7%) indicated a preference for the original image in the pair, and 49.83% (95% confidence intervals at 47.3%, and 52.0%) indicated a preference for the compressed image. These findings led the authors to conclude that static color and gray-scale ultrasound images compressed with JPEG at approximately 9:1 are statistically indistinguishable from the originals for primary diagnostic purposes. Based on the authors laboratory experience with compression and the results of this and other prior studies, JPEG compression is now being applied to all ultrasound images in the authors' radiology practice before reading. No image quality-related issues have been encountered after 12 months of operation (approximately 48000 examinations). 相似文献
10.
John N. Mafi Baowei Fei Sharon Roble Anthony Dota Prashanth Katrapati Hiram G. Bezerra Hesheng Wang Wei Wang Leslie Ciancibello Marco Costa Daniel I. Simon Carl E. Orringer Robert C. Gilkeson 《Journal of digital imaging》2012,25(1):129-136
Cardiovascular disease is the leading cause of global mortality, yet its early detection remains a vexing problem of modern medicine. Although the computed tomography (CT) calcium score predicts cardiovascular risk, relatively high cost ($250–400) and radiation dose (1–3 mSv) limit its universal utility as a screening tool. Dual-energy digital subtraction radiography (DE; <$60, 0.07 mSv) enables detection of calcified structures with high sensitivity. In this pilot study, we examined DE radiography’s ability to quantify coronary artery calcification (CAC). We identified 25 patients who underwent non-contrast CT and DE chest imaging performed within 12 months using documented CAC as the major inclusion criteria. A DE calcium score was developed based on pixel intensity multiplied by the area of the calcified plaque. DE scores were plotted against CT scores. Subsequently, a validation cohort of 14 additional patients was independently evaluated to confirm the accuracy and precision of CAC quantification, yielding a total of 39 subjects. Among all subjects (n = 39), the DE score demonstrated a correlation coefficient of 0.87 (p < 0.0001) when compared with the CT score. For the 13 patients with CT scores of <400, the correlation coefficient was −0.26. For the 26 patients with CT scores of ≥400, the correlation coefficient yielded 0.86. This pilot study demonstrates the feasibility of DE radiography to identify patients at the highest cardiovascular risk. DE radiography’s accuracy at lower scores remains unclear. Further evaluation of DE radiography as an inexpensive and low-radiation imaging tool to diagnose cardiovascular disease appears warranted. 相似文献
11.
A. E. Monsivais‐Urenda M. Salgado‐Bustamante R. González‐Amaro J. Alcocer‐Varela 《Clinical and experimental immunology》2014,178(3):428-437
Many genetic studies have found an association between interferon regulatory factors (IRF) single nucleotide polymorphisms (SNPs) and systemic lupus erythematosus (SLE); however, specific dendritic cell (DC) alterations have not been assessed. The aim of the present study was to address the expression of IRF3 and IRF5 on different DC subsets from SLE patients, as well as their association with interferon (IFN)-α production and novel SNPs. For the genetic association analyses, 156 SLE patients and 272 healthy controls from the Mexican mestizo population were included. From these, 36 patients and 36 controls were included for functional analysis. Two IRF3 SNPs − rs2304206 and rs2304204 – were determined. We found an increased percentage of circulating pDC in SLE patients in comparison to controls (8·04 ± 1·48 versus 3·35 ± 0·8, P = 0·032). We also observed enhanced expression of IRF3 (64 ± 6·36 versus 36·1 ± 5·57, P = 0·004) and IRF5 (40 ± 5·25 versus 22·5 ± 2·6%, P = 0·010) restricted to this circulating pDC subset from SLE patients versus healthy controls. This finding was associated with higher IFN-α serum levels in SLE (160·2 ± 21 versus 106·1 ± 14 pg/ml, P = 0·036). Moreover, the IRF3 rs2304206 polymorphism was associated with increased susceptibility to SLE [odds ratio (OR), 95% confidence interval (CI) = 2·401 (1·187–4·858), P = 0·021] as well as enhanced levels of serum type I IFN in SLE patients who were positive for dsDNA autoantibodies. The IRF3 rs2304204 GG and AG genotypes conferred decreased risk for SLE. Our findings suggest that the predominant IRF3 expression on circulating pDC is a key element for the increased IFN-α activation based on the interplay between the rs2304206 gene variant and the presence of dsDNA autoantibodies in Mexican mestizo SLE patients. 相似文献
12.
Context:
Proper conditioning of the neck muscles may play a role in reducing the risk of neck injury and, possibly, concussions in contact sports. However, the ability to reliably measure the force-time–based variables that might be relevant for this purpose has not been addressed.Objective:
To assess the between-days reliability of discrete force-time–based variables of neck muscles during maximal voluntary isometric contractions in 5 directions.Design:
Cohort study.Setting:
University research center.Patients or Other Participants:
Twenty-six highly physically active men (age = 21.6 ± 2.1 years, height = 1.85 ± 0.09 m, mass = 81.6 ± 9.9 kg, head circumference = 0.58 ± 0.01 m, neck circumference = 0.39 ± 0.02 m).Intervention(s):
We used a custom-built testing apparatus to measure maximal voluntary isometric contractions of the neck muscles in 5 directions (extension, flexion, protraction, left lateral bending, and right lateral bending) on 2 separate occasions separated by 7 to 8 days.Main Outcome Measure(s):
Variables measured were peak force (PF), rate of force development (RFD), and time to 50% of PF (T50PF). Reliability indices calculated for each variable comprised the difference in scores between the testing sessions, with corresponding 95% confidence intervals, the coefficient of variation of the typical error of measurement (CVTE), and intraclass correlation coefficients (ICC [3,3]).Results:
No evidence of systematic bias was detected for the dependent measures across any movement direction; retest differences in measurements were between 1.8% and 2.7%, with corresponding 95% confidence interval ranges of less than 10% and overlapping zero. The CVTE was lowest for PF (range, 2.4%–6.3%) across all testing directions, followed by RFD (range, 4.8%–9.0%) and T50PF (range, 7.1%–9.3%). The ICC score range for all dependent measures was 0.90 to 0.99.Conclusions:
Discrete variables representative of the force-generating capacity of neck muscles under isometric conditions can be measured with an acceptable degree of reliability. This finding has possible applications for investigating the role of neck muscle strength-training programs in reducing the risk of injuries in sport settings. 相似文献13.
M. A. Dalboni B. M. R. Quinto C. C. Grabulosa R. Narciso J. C. Monte M. Durão Jr L. Rizzo M. Cendoroglo O. P. Santos M. C. Batista 《Clinical and experimental immunology》2013,173(2):242-249
Genetic polymorphism studies of cytokines may provide an insight into the understanding of acute kidney injury (AKI) and death in intensive care unit (ICU) patients. The aim of this study was to investigate whether the genetic polymorphisms of −308 G < A tumour necrosis factor (TNF)-α, −174 G > C interleukin (IL)-6 and −1082 G > A IL-10 may predispose ICU patients to the development of AKI and/or death. In a prospective nested case–control study, 303 ICU patients and 244 healthy individuals were evaluated. The study group included ICU patients who developed AKI (n = 139) and 164 ICU patients without AKI. The GG genotype of TNF-α (low producer phenotype) was significantly lower in the with AKI than without AKI groups and healthy individuals (55 versus 62 versus 73%, respectively; P = 0·01). When genotypes were stratified into four categories of TNF-α/IL-10 combinations, it was observed that low TNF-α plus low IL-10 producer phenotypes were more prevalent in patients with AKI, renal replacement therapy and death (P < 0·05). In logistic regression analysis, low TNF-α producer plus low IL-10 producer phenotypes remained as independent risk factors for AKI and/or death [odds ratio (OR) = 2·37, 95% confidence interval (CI): 1·16–4·84; P = 0·02] and for renal replacement therapy (RRT) and/or death (OR = 3·82, 95% CI: 1·19–12·23; P = 0·02). In this study, the combination of low TNF-α plus low IL-10 producer phenotypes was an independent risk factor to AKI and/or death and RRT and/or death in critically ill patients. Our results should be validated in a larger prospective study with long-term follow-up to emphasize the combination of these genotypes as potential risk factors to AKI in critically ill patients. 相似文献
14.
Schachner T Wiedemann D Fetz H Laufer G Kocher A Bonaros N 《Clinics (S?o Paulo, Brazil)》2010,65(12):1239-1245
BACKGROUND:
The N-terminal fragment of pro-brain type natriuretic peptide (NT-proBNP) is an established biomarker for cardiac failure.OBJECTIVE:
To determine the influence of preoperative serum NT-proBNP on postoperative outcome and mid-term survival in patients undergoing coronary artery bypass grafting (CABG).METHODS:
In 819 patients undergoing isolated CABG surgery preoperative serum NT-proBNP levels were measured. NT-proBNP was correlated with various postoperative outcome parameters and survival rate after a median follow-up time of 18 (0.5–44) months. Risk factors of mortality were identified using χ2, Mann–Whitney test, and Cox regression.RESULTS:
NT-proBNP levels >430 ng/ml and >502 ng/ml predicted hospital and overall mortality (p<0.05), with an incidence of 1.6% and 4%, respectively. Kaplan–Meier analysis revealed decreased survival rates in patients with NT-proBNP >502 ng/ml (p = 0.001). Age, preoperative serum creatinine, diabetes, chronic obstructive pulmonary disease, low left ventricular ejection fraction and BNP levels >502 ng/ml were isolated as risk factors for overall mortality. Multivariate Cox regression analysis, including the known factors influencing NT-proBNP levels, identified NT-proBNP as an independent risk factor for mortality (OR = 3.079 (CI = 1.149-8.247), p = 0.025). Preoperative NT-proBNP levels >502 ng/ml were associated with increased ventilation time (p = 0.005), longer intensive care unit stay (p = 0.001), higher incidence of postoperative hemofiltration (p = 0.001), use of intra-aortic balloon pump (p<0.001), and postoperative atrial fibrillation (p = 0.031)CONCLUSION:
Preoperative NT-proBNP levels >502 ng/ml predict mid-term mortality after isolated CABG and are associated with significantly higher hospital mortality and perioperative complications. 相似文献15.
Yoganand Balagurunathan Virendra Kumar Yuhua Gu Jongphil Kim Hua Wang Ying Liu Dmitry B. Goldgof Lawrence O. Hall Rene Korn Binsheng Zhao Lawrence H. Schwartz Satrajit Basu Steven Eschrich Robert A. Gatenby Robert J. Gillies 《Journal of digital imaging》2014,27(6):805-823
Quantitative size, shape, and texture features derived from computed tomographic (CT) images may be useful as predictive, prognostic, or response biomarkers in non-small cell lung cancer (NSCLC). However, to be useful, such features must be reproducible, non-redundant, and have a large dynamic range. We developed a set of quantitative three-dimensional (3D) features to describe segmented tumors and evaluated their reproducibility to select features with high potential to have prognostic utility. Thirty-two patients with NSCLC were subjected to unenhanced thoracic CT scans acquired within 15 min of each other under an approved protocol. Primary lung cancer lesions were segmented using semi-automatic 3D region growing algorithms. Following segmentation, 219 quantitative 3D features were extracted from each lesion, corresponding to size, shape, and texture, including features in transformed spaces (laws, wavelets). The most informative features were selected using the concordance correlation coefficient across test–retest, the biological range and a feature independence measure. There were 66 (30.14 %) features with concordance correlation coefficient ≥ 0.90 across test–retest and acceptable dynamic range. Of these, 42 features were non-redundant after grouping features with R2Bet ≥ 0.95. These reproducible features were found to be predictive of radiological prognosis. The area under the curve (AUC) was 91 % for a size-based feature and 92 % for the texture features (runlength, laws). We tested the ability of image features to predict a radiological prognostic score on an independent NSCLC (39 adenocarcinoma) samples, the AUC for texture features (runlength emphasis, energy) was 0.84 while the conventional size-based features (volume, longest diameter) was 0.80. Test–retest and correlation analyses have identified non-redundant CT image features with both high intra-patient reproducibility and inter-patient biological range. Thus making the case that quantitative image features are informative and prognostic biomarkers for NSCLC.
Electronic supplementary material
The online version of this article (doi:10.1007/s10278-014-9716-x) contains supplementary material, which is available to authorized users. 相似文献16.
Mari Yakabe Shuji Sakai Hidetake Yabuuchi Yoshio Matsuo Takeshi Kamitani Taro Setoguchi Mayumi Cho Masafumi Masuda Masayuki Sasaki 《Journal of digital imaging》2010,23(5):520-526
The purpose of this article was to report the relationship between radiation dose and the ability of sentence digital mammography to detect microcalcifications. All images were acquired by computed radiography and an anthropomorphic breast phantom. The tube voltage and anode/filter combination used were 28 kVp and Mo/Mo. Simulated microcalcifications with an approximate diameter of 250–350 μm were positioned on the phantom. Groups of six microcalcifications were arranged in one of two patterns, a line cluster 1 cm long or a hexagonal cluster 4 mm wide. One of the six microcalcifications was removed to create a negative control. Each cluster was placed on 25 different points. Four levels of milliampere-second (mAs) values were applied: 100%, 50%, 25%, and 12.5%. Five staff radiologists participated in an observer performance test. All observers used a workstation with a 3-megapixel monochrome LCD monitor. The areas under the receiver-operating characteristics curves (AUC) were used to compare diagnostic performance among the four doses. The overall AUC scores were 0.97 with 100% mAs, 0.93 (n.s.) with 50%, 0.90 (p < 0.05) with 25%, and 0.81 (p < 0.01) with 12.5% mAs. Among the negative series, the percentage of images on which observers were able to identify the removed microcalcification point decreased from 88.8% with 100% mAs to 83.6% (n.s.) with 50%, 74.8% (p < 0.001) with 25%, and 67.2% (p < 0.001) with 12.5% mAs. A certain level of dose reduction in digital mammography may be an option.Key words: Digital mammography, computed radiography, observer performance, radiation dose, ROC-based analysis, phantoms, imaging 相似文献
17.
Background
Despite the need for oral health morbidity surveys to aid in reviewing of the oral health services, dental data of Ugandan children is scanty.Objectives
To describe the magnitude and distribution of selected oral health conditions among primary school children in Mbarara, Uganda.Methods
A stratified two-stage cluster sample of 437 children aged 5–6, 8–9 and 11–12 was enrolled. The selected conditions included: dental caries, plaque, calculus, gingivitis, fluorosis and malocclusion (maxillary overjet). These conditions were diagnosed and scored in accordance with World Health Organisation (WHO) criteria.Results
The mean decayed, missing, filled permanent teeth (DMFT) was 1.5(±0.8 SD). Females had higher DMFT (1.6±0.8SD) than males (1.3±0.8SD). Decayed, filled milk teeth (dt) was 2.7(±1.8SD) but more in males 3.1(±2.1SD) than in females 2.4(±1.6SD). Children in private schools were likely to have more caries in both permanent teeth (DMFT: 1.6±0.9SD) and milk teeth (dt: 3.0±1.9SD). Day-scholars were likely to have more caries in permanent teeth (DFMT: 1.50.8SD). Those in boarding were likely to have more caries in milk teeth (dt: 3±2.2SD). Milk teeth caries decreased with age (p<0.0001). Eight (1.8%) had very mild to moderate fluorosis. Nine (2%) lost permanent canines due to practice of “nylon teeth mutilation.” Majority 325(75%) had dental plaque, which increased with age (p<0.0001). Males significantly had plaque. Children in private schools were associated with less plaque (OR: 0.6, 95%CI: 0.4–0.9), as were those in boarding schools. Some 113(25.9%) had calculus that increased with age (p<0.0001). Calculus was more prevalent in males, government schools, and among day-scholars. Females were less likely to have maxillary overjet (OR: 0.5, 95% CI: 0.3–0.8). Day-scholars were 2 times more likely to have maxillary overjet (OR: 1.9, 95%CI: 1.1–3.5). None had severe gingivitis.Conclusion
The oral hygiene of school children was poor with high plaque prevalence demonstrating a lack of established oral hygiene practices. A comprehensive community-focused oral health care intervention that includes oral health education in homes and the strengthening of school health programme is needed to improve the oral health status of children in Mbarara. 相似文献18.
Oliveira LP de Jesus RP Boulhosa RS Mendes CM Lyra AC Lyra LG 《Clinics (S?o Paulo, Brazil)》2012,67(3):219-223
OBJECTIVE:
The individual components of metabolic syndrome may be independent predictors of mortality in patients with liver disease. We aimed to evaluate the prevalence of metabolic syndrome and its related components in hepatitis C virus–infected patients who are not obese and do not have type 2 diabetes.METHODS:
This cross-sectional study included 125 patients infected with hepatitis C virus genotype 1. Metabolic syndrome was defined according to the International Diabetes Federation. Anthropometric data were measured according to standardized procedures. Bioimpedance analysis was performed on all patients.RESULTS:
Metabolic syndrome was diagnosed in 21.6% of patients. Of the subjects with metabolic syndrome, 59.3% had hypertension, 77.8% had insulin resistance, 85.2% were overweight, 48.1% had a high waist circumference, 85.2% had an increased body fat percentage, and 92.3% had an elevated waist:hip ratio. In the bivariate analysis, female sex (OR 2.58; 95% CI: 1.09–6.25), elevated gamma-glutamyl transferase (γGT) (OR 2.63; 95% CI: 1.04–7.29), elevated fasting glucose (OR 8.05; 95% CI: 3.17-21.32), low HDL cholesterol (OR 2.80; 95% CI: 1.07–7.16), hypertriglyceridemia (OR 7.91; 95% CI: 2.88–22.71), elevated waist circumference (OR 10.33; 95% CI: 3.72–30.67), overweight (OR 11.33; 95% CI: 3.97–41.07), and increased body fat percentage (OR 8.34; 95% CI: 2.94–30.08) were independent determinants of metabolic syndrome. Using the final multivariate regression model, similar results were observed for abdominal fat (OR 9.98; 95% CI: 2.63–44.41) and total body fat percentage (OR 8.73; 95% CI: 2.33–42.34). However, metabolic syndrome risk was also high for those with blood glucose ≥5.55 mmol/L or HDL cholesterol <0.9 mmol/L (OR 16.69; 95% CI: 4.64–76.35; OR 7.23; 95% CI: 1.86–32.63, respectively).CONCLUSION:
Metabolic syndrome is highly prevalent among hepatitis C virus–infected patients without type 2 diabetes or obesity. Metabolic syndrome was significantly associated with hypertension, insulin resistance, increased abdominal fat, and overweight. 相似文献19.
Objective:
To compare mean differences in core body temperature (Tcore) as assessed via rectal thermometry (Tre) and aural thermometry (Tau) in hyperthermic exercising individuals.Data Sources:
PubMed, Ovid MEDLINE, SPORTDiscus, CINAHL, and Cochrane Library in English from the earliest entry points to August 2009 using the search terms aural, core body temperature, core temperature, exercise, rectal, temperature, thermistor, thermometer, thermometry, and tympanic.Study Selection:
Original research articles that met these criteria were included: (1) concurrent measurement of Tre and Tau in participants during exercise, (2) minimum mean temperature that reached 38°C by at least 1 technique during or after exercise, and (3) report of means, standard deviations, and sample sizes.Data Extraction:
Nine articles were included, and 3 independent reviewers scored these articles using the Physiotherapy Evidence Database (PEDro) scale (mean = 5.1 ± 0.4). Data were divided into time periods pre-exercise, during exercise (30 to 180 minutes), and postexercise, as well as Tre ranges <37.99°C, 38.00°C to 38.99°C, and >39.00°C. Means and standard deviations for both measurement techniques were provided at all time intervals reported. Meta-analysis was performed to determine pooled and weighted mean differences between Tre and Tau.Data Synthesis:
The Tre was conclusively higher than the Tau pre-exercise (mean difference [MD] = 0.27°C, 95% confidence interval [CI] = 0.15°C, 0.39°C), during exercise (MD = 0.96°C, 95% CI = 0.84°C, 1.08°C), and postexercise (MD = 0.71°C, 95% CI = 0.65°C, 0.78°C). As Tre measures increased, the magnitude of difference between the techniques also increased with an MD of 0.59°C (95% CI = 0.53°C, 0.65°C) when Tre was <38°C; 0.79°C (95% CI = 0.72°C, 0.86°C) when Tre was between 38.0°C and 38.99°C; and 1.72°C (95% CI = 1.54°, 1.91°C) when Tre was >39.0°C.Conclusions:
The Tre was consistently greater than Tau when Tcore was measured in hyperthermic individuals before, during, and postexercise. As Tcore increased, Tau appeared to underestimate Tcore as determined by Tre. Clinicians should be aware of this critical difference in temperature magnitude between these measurement techniques when assessing Tcore in hyperthermic individuals during or postexercise. 相似文献20.
Marisa da Matta Aprile Rubens Feferbaum Nerli Andreassa Claudio Leone 《Clinics (S?o Paulo, Brazil)》2010,65(8):751-756