Profusion Of Small Opacities Research Articles

Measuring lung diffusing capacity: an opportunity for improved medical surveillance and disability evaluation of coal miners

ObjectivesSpirometry is the primary lung function test utilised for medical surveillance and disability examination for coal mine dust lung disease. However, spirometry likely underestimates physiologic impairment. We sought to characterise...

Application of a light-weighted convolutional neural network for automatic recognition of coal workers' pneumoconiosis in the early stage

Objective: To construct and verify a light-weighted convolutional neural network (CNN), and explore its application value for screening the early stage (subcategory 0/1 and stage Ⅰ of pneumoconiosis) of coal workers' pneumoconiosis (CWP) from digital chest radiography (DR) . Methods: A total of 1225 DR images of coal workers who were examined at an Occupational Disease Prevention and Control Institute in Anhui Province from October 2018 to March 2021 were retrospectively collected. All DR images were collectively diagnosed by 3 radiologists with diagnostic qualifications and gave diagnostic results. There were 692 DR images with small opacity profusion 0/- or 0/0 and 533 DR images with small opacity profusion 0/1 to stage Ⅲ of pneumoconiosis. The original chest radiographs were preprocessed differently to generate four datasets, namely 16-bit grayscale original image set (Origin16), 8-bit grayscale original image set (Origin 8), 16-bit grayscale histogram equalized image set (HE16) and 8-bit grayscale histogram equalized image set (HE8). The light-weighted CNN, ShuffleNet, was applied to train the generated prediction model on the four datasets separately. The performance of the four models for pneumoconiosis prediction was evaluated on a test set containing 130 DR images using measures such as the receiver operating characteristic (ROC) curve, accuracy, sensitivity, specificity, and Youden index. The Kappa consistency test was used to compare the agreement between the model predictions and the physician diagnosed pneumoconiosis results. Results: Origin16 model achieved the highest ROC area under the curve (AUC=0.958), accuracy (92.3%), specificity (92.9%), and Youden index (0.8452) for predicting pneumoconiosis, with a sensitivity of 91.7%. And the highest consistency between identification and physician diagnosis was observed for Origin16 model (Kappa value was 0.845, 95%CI: 0.753-0.937, P<0.001). HE16 model had the highest sensitivity (98.3%) . Conclusion: The light-weighted CNN ShuffleNet model can efficiently identify the early stages of CWP, and its application in the early screening of CWP can effectively improve physicians' work efficiency.

Progressive Massive Fibrosis Risk Factors: A Retrospective Cross-Sectional Study.

This study aimed to determine the occupational and clinical characteristics of patients with progressive massive fibrosis (PMF) and factors related to the development and severity of PMF. Personal, occupational, radiological, and functional findings of 129 patients diagnosed with PMF were evaluated. Sandblasting workers were found to be diagnosed with pneumoconiosis at an earlier age than those in other professions. The dust exposure durations of sandblasting and ceramic workers were significantly less than those of workers in other occupations. Statistically, a significant negative correlation was found between lung functions and small opacity size, small opacity profusion score, and large opacity size. No relationship was found between large opacity size and smoking status, concomitant tuberculosis, and duration of dust exposure. An effective surveillance system that considers factors that accelerate pneumoconiosis progression should be established.

Inter-observer agreement and accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking AIR Pneumo certification examination

This study examined inter-observer agreement and diagnostic accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking the AIR Pneumo examination. We compared agreement and diagnostic accuracy for parenchymal and pleural lesions across residing countries, specialty training, and work experience using data on 93 physicians. Physicians demonstrated fair to good agreement with kappa values 0.30 (95% CI: 0.20–0.40), 0.29 (95% CI: 0.23–0.36), 0.59 (95% CI: 0.52–0.67), and 0.65 (95% CI: 0.55–0.74) in classifying pleural plaques, small opacity shapes, small opacity profusion, and large opacities, respectively. Kappa values among Asian countries ranging from 0.25 to 0.55 (pleural plaques), 0.47 to 0.73 (small opacity profusion), and 0.55 to 0.69 (large opacity size). The median Youden’s J index (interquartile range) for classifying pleural plaque, small opacity, and large opacity was 61.1 (25.5), 76.8 (29.3), and 88.9 (23.3), respectively. Radiologists and recent graduates showed superior performance than other groups regarding agreement and accuracy in classifying all types of lesions. In conclusion, Asian physicians taking the AIR Pneumo examination were better at classifying parenchymal lesions than pleural plaques using the ILO classification. The degree of agreement and accuracy was different among countries and was associated with background specialty training.

Discussion of grading method of small opacity profusion of pneumoconiosis on CT scans and the corresponding reference images

Objective: To explore the CT grading method of small opacity profusion of pneumoconiosis, and draw up the corresponding CT reference film. Methods: In December 2019, Three hundred thirty-seven cases of pneumoconosis and suspected pneumoconiosis were examined by chest radiography and Computed Tomography (CT) in the same period. According to Diagnosis of Occupational Pneumoconiosis (GBZ 70-2015) , small opacity profusion of pneumoconiosis in each zone of lung was divided. On CT scans, it was divided into 5 grades of 0, 0+, 1, 2 and 3. Grade 0 corresponded to Sub-grade 0/- and Sub-grade 0/0 of Grade 0 in chest radiograph. Grade 0+ was equivalent to Sub-grade 0/1 of Grade 0. Grade 1, 2, 3 were equivalent to Grade 1, 2 and 3, respectively (including each sub-grade) . The CT image quality of each zone of lung was divided into 1 to 4 levels. Results of level 4 were not included in statistical analyses.Based on the results of small opacity profusion in each zone of lung, consistency analysis was performed between chest radiograph and CT. The selection method of reference films was developed. Based on the types and grades of small opacity, the final reference films were determined. Results: There were 1877 zones of lung with CT image quality from level 1 to 3, including 335 in upper right, 319 in middle right, 284 in lower right, 334 in upper left, 320 in middle left and 286 in lower left. The Kappa values of small opacity profusion in upper right zone, upper left zone, left middle zone, and lower left zone were all between 0.4-0.75. In middle right zone and lower right zone, they were all above 0.75.Among all 6 zones of lung, the diagnostic concordance rates between CT and chest radiograph were all above 80%.The corresponding CT reference films were proposed, including type p and q in Grade 2 and 3, type r in Grade 2, type s and t in Grade 0+ to 3. Conclusion: The CT grading method for small opacity profusion of pneumoconiosis is feasible, and the application value of its reference films needs to be further verified.

Early radiographic pneumoconiosis is associated with impaired exercise gas exchange among coal miners with normal resting spirometry.

We sought to determine if radiographic pneumoconiosis predicts abnormal gas exchange during exercise in coal mine workers with preserved resting lung function. We analyzed data from former coal miners seen between 2006 and 2014 in a single clinic specializing in black lung evaluations. We limited the analysis to those with normal resting spirometry and an A-a gradient at peak exercise ≥10 mmHg. We used multivariable logistic regression to estimate predictors of A-a gradient widened to >150% of the reference value. We focused on chest radiographs consistent with pneumoconiosis, taking into account higher silica exposure mining activities and years underground, and adjusting for cigarette smoking, obesity, and coronary artery disease. Of 5507 miners, we analyzed data for 742 subjects with normal spirometry and all key clinical variables available, of whom 372 (50.1%) had radiographic evidence of pneumoconiosis. All but 21 had small opacity profusion of less than 2/1. The median A-a gradient at peak exercise was 108% of reference value (interquartile range, 81%-141%). In the multivariable analysis, radiographic pneumoconiosis was associated with increased odds of widened A-a gradient (odds ratio [OR], 2.47; 95% confidence interval [CI], 1.7-3.7). Limited to 660 subjects with normal diffusing capacity for carbon monoxide, the odds were similarly increased (OR, 3.20; 95% CI, 1.5-3.6). Among coal miners with preserved resting lung function, radiographic evidence of early pneumoconiosis more than doubled the odds of abnormal exercise physiology. Impairment in pneumoconiosis occurs in early disease and may only be evident on exercise testing.

The study on the role of extracellular histones in the pathogenesis of coal worker's pneumoconiosis

Objective: To explore the role of extracellular histones in the pathogenesis of coal worker's pneumoconiosis (CWP) , the relationship of extracellular histones in plasma with pulmonary fibrosis caused by coal mine dust was analyzed, and the stimulating effect of extracellular histones on fibroblast proliferation was studied. Methods: In May 2019, a total of 220 coal mine dust exposure workers (including coal miners and CWP patients) who visited the occupational disease outpatient department of Peking University Third Hospital from 2012 to 2015 were enrolled in the study. According to the classification of small opacity profusion (SOP) in chest radiograph for pneumoconiosis diagnosis (category 0, 1, 2, 3) , 61 coal miners were in category 0 SOP, 65 coal miners were in category 1 SOP, 56 coal miners were in category 2 SOP and 38 coal miners were in category 3 SOP. The plasma levels of extracellular histone H4 and platelet-derived growth factor (PDGF) were measured by enzyme-linked immunosorbent assay (ELISA) kit. The stimulating effects of CWP patients' plasma and calf thymus histones (CTHs) on fibroblast and the antagonizing effect of anti-H4 antibody were investigated by fibroblast proliferation experiment in vitro. Results: Among the study subjects, there were 195 males (88.6%, 195/220) and 25 females (11.4%, 25/220) , age (55.1±7.2) years, coal mine dust exposure time (16.3±4.4) years. The plasma concentrations of histone H4 in the coal miners with category 0, 1, 2 and 3 SOP were (3.92±1.75) 、(9.84±4.17) 、(14.35±5.52) and (17.83±7.69) μg/ml, respectively. There were significant differences among the four groups (P<0.01) . The plasma level of histone H4 was positively correlated with the plasma level of PDGF in the coal miners (r=0.769, P<0.01) . Compared with healthy control plasma group, the cell proliferation percentages of patients' plasma group (272%±87%) and CTH group (283%±84%) were significantly increased (P<0.05) . Compared with patients' plasma group, the cell proliferation percentage of patients' plasma+anti-H4 antibody group (185%±66%) was significantly decreased (P<0.05) . Compared with CTH group, the cell proliferation percentage of CTH+anti-H4 antibody group (167%±59%) was significantly decreased (P<0.05) . Conclusion: Extracellular histones in plasma are associated with pulmonary fibrosis in patients with CWP. Studies in vitro have shown that extracellular histones can promote proliferation of pulmonary fibroblasts. It is suggested that extracellular histones can be important biomarkers for pulmonary fibrosis caused by coal mine dust.

Association between Occupational and Radiological Factors and Nontuberculous Mycobacteria Lung Infection in Workers with Prior Dust Exposure.

This retrospective cross-sectional study was conducted to identify the factors that promote the risk of nontuberculous mycobacteria (NTM) lung infection in subjects with prior occupational dust exposure. All consecutive patients with a history of occupational dust exposure whose expectorated sputum, bronchial wash, or bronchial lavage was subjected to acid-fast Bacilli culture in a tertiary hospital between 2011 and 2016 were identified. The patients who were infected with NTM were identified according to the bacteriological criteria of the American Thoracic Society (ATS) and The Infectious Diseases Society of America (IDSA) statement. Pneumoconiosis-associated radiological findings were graded according to the International Labor Organization guidelines. Of the 1392 patients with prior dust exposure, NTM was isolated from 82. Logistic regression analysis showed that risk factors for NTM lung infection were a history of pulmonary tuberculosis (adjusted odds ratio [aOR] = 1.82, 95% confidence intervals [CI] = 1.03–3.16). Moreover, the unadjusted odds ratios (ORs) were higher when both small-opacity profusion and the large-opacity grades increased. Even after adjustment, the ORs for the A, B, and C large-opacity grades were 2.32 (95% CI = 1.01–4.99), 2.68 (95% CI = 1.35–5.24), and 7.58 (95% CI = 3.02–17.95). Previous tuberculosis, bronchiectasis, and especially extensive small-opacity profusion, and high large-opacity grade associated significantly with NTM lung infection in dust-exposed workers.

Patterns of progressive massive fibrosis on modern coal miner chest radiographs

Clinical teaching generally asserts that large opacities of progressive massive fibrosis (PMF) on chest radiographs present primarily bilaterally in the upper lung zones, and with an elevated background profusion of small opacities. However, the contemporary basis for these descriptions is limited.Radiographs taken for the Coal Workers’ Health Surveillance Program during 2000–2015 and previously determined to have large opacities (“PMF radiographs”, n = 204), and a random sample previously deemed free of large opacities (n =22), were independently reevaluated by three National Institute for Occupational Safety and Health (NIOSH) B Readers. Large opacities were noted primarily in the upper right (41%) or upper left (28%) lung zone, but 31% were in middle or lower zones. Unilateral involvement was observed in 34% of readings, with right lung predominance (82%). The median small opacity profusion category for the radiographs with PMF was 2/1. The number of large opacities was not correlated with small opacity profusion category. The “classic” descriptions of PMF as bilateral, associated with elevated background profusions of small pneumoconiotic opacities, were each absent in a third of miners.

Extracellular Histones Promote Pulmonary Fibrosis in Patients With Coal Workers’ Pneumoconiosis

This investigation assessed the profibrotic role that extracellular histones play in the pathogenesis of coal workers' pneumoconiosis (CWP). The correlation of extracellular histones with small opacity profusion (SOP) and transforming growth factor-β (TGF-β) was analyzed. The stimulating effect of extracellular histones on pulmonary fibroblast was assessed in vitro. The levels of extracellular histones in plasma were positively correlated with SOP and TGF-β in the coal miners investigated. Plasma collected from patients with CWP caused apparent lung fibroblast proliferation, while anti-H4 antibody antagonized the stimulating effect of the patient plasma by blocking histone H4. In vitro experiments showed that extracellular histones directly stimulated fibroblast proliferation. Consistent with our hypothesis, the concentrations of extracellular histones were indices of the severity of pulmonary fibrosis in simple CWP, and extracellular histones-targeted intervention could inhibit the proliferation of lung fibroblast.

Exposure‒response relationships for silicosis and its progression in industrial sand workers.

Objectives This study aimed to characterize the relationship between radiographic silicosis and exposure to respirable quartz and determine how exposure affects disease progression. Methods Surveillance chest radiographs from a cohort of 1902 workers were examined to identify 67 cases of radiographic silicosis and 167 matched controls. Exposures were estimated by linking work histories to a job exposure matrix (JEM) based on samples collected by the participating companies and historical estimates. Conditional logistic regression was used to examine exposure‒response relationships. Sequential radiographs from silicosis cases were used to assess associations between exposure and disease progression. Results Risk of silicosis increased with cumulative exposure [odds ratio (OR) 1.43 per 1 mg/m 3years, 95% confidence interval (CI) 1.23-1.66], average exposure concentration (OR 1.30 per 0.10 mg/m 3, 95% CI 1.11-1.51) and net exposure duration (OR 1.10 per year, 95% CI 1.05-1.16). Multivariate analyses indicated that the risk associated with cumulative exposure varied depending on exposure duration and concentration. Analysis of the time worked at differing exposure levels indicated that exposures ≤0.05 mg/m 3were not significantly associated with silicosis risk after adjustment for years worked at higher concentrations. Disease progression was related to subsequent exposure concentration, with a yearly increase in small opacity profusion of 0.052 subcategory per each 0.10 mg/m 3increase in concentration. Conclusions Workers with longer exposure at lower concentrations were at higher risk for silicosis than those with the same cumulative exposure who worked for a shorter time at higher concentrations. The rate of silicosis progression was related to subsequent exposure concentration.

Window settings in the application of pneumoconiosis digital radiography

Objective: To explore window settings technology in the digital radiography of pneumoconiosis, and to improve the quality of the digital chest radiographs. Methods: 25 female workers in a asbestos product processing enterprise were examined with high-kV and DR chest radiographies on same day. Consistency of pneumoconiosis diagnosis results: were assessed. Results In the 75 groups of radiograph quality results, there are 62 groups that need to be processed window in order to make the correct diagnosis. The crude agreement among two chest radiographs was 28% for the profusion of small opacities and 76% for the classification of pneumoconiosis, the weighted kappa value (κ) was 0.33 (95%CI: 0.12-0.54) and 0.67 (95%CI: 0.42-0.92) . Conclusions: window settings technology can display different parts of chest and make DR chest radiograph to meeting the requirements of chest radiograph quality for pneumoconiosis.

Pneumoconioses Radiographs in a Large Population of U.S. Coal Workers: Variability in A Reader and B Reader Classifications by Using the International Labour Office Classification.

Purpose To assess the level of concordance between chest radiographic classifications of A and B Readers in a national surveillance program offered to U.S. coal miners over an approximate 36-year period. Materials and Methods The National Institute for Occupational Safety and Health (NIOSH) Coal Workers' Health Surveillance Program (CWHSP) is a surveillance program with nonresearch designation and is exempt from Human Subjects Review Board approval (11-DRDS-NR03). Thirty-six years of data (1979-2015) from the CWHSP were analyzed, which included all conventional screen-film radiographs with a classification by at least one A Reader and one B Reader. Agreement was assessed by using κ statistics; prevalence ratios were used to describe differences between A and B Reader determinations of image technical quality, small opacity profusion, and presence of large opacities and pleural abnormalities. Results The analysis included 79 185 matched A and B Reader chest radiograph classifications. A majority of both A and B Readers were radiologists (74.2% [213 of 287] vs 64.7% [22 of 34]; P = .04). A and B Readers had minimal agreement on technical image quality (κ = 0.0796; 95% confidence interval [CI]: 0.07, 0.08) and the distribution of small opacity profusion (subcategory κ, 0.2352; 95% CI: 0.22, 0.25). A Readers classified more images as "good" quality (prevalence ratio, 1.38; 95% CI: 1.35, 1.41) and identified more pneumoconiosis (prevalence ratio, 1.22; 95% CI: 1.20, 1.23). Conclusion A Readers classified substantially more radiographs with evidence of pneumoconiosis and classified higher small opacity profusion compared with B Readers. These observations reinforce the importance of multiple classifications by readers who have demonstrated ongoing competence in the International Labour Office classification system to ensure accurate radiographic classifications. © RSNA, 2017.

Türkiye'de sektörlere göre pnömokonyoz ve farklı özellikleri

Pneumoconiosis which is one of the ancient diseases, still affects many workers throughout the world despite "existing" control programs. We add data from a single center reviewing risk factors for pneumoconiosis; evaluate functional and radiological findings in different sectors. We reviewed medical records of patients diagnosed with pneumoconiosis who were admitted to our center between the years 2013 and 2015. Several personal and occupational features, together with functional and radiologic data, were collected. 60 were young males. Twenty-four of the cases (39.3%) worked at dental technician, 24 cases (39.3%) were ceramic workers, 5 cases (8.2%) were sandblasters, 2 cases (3.3%) were welders, 3 cases (4.9%) were miners, and 3 cases (4.9%) were marble cutters. The sectors in which the exposure started at the earliest ages were dental technicians and sandblasters, while the shortest working time was in sandblasting. The dental technicians were younger than the ceramic workers at the age of diagnosis (Kruskall-Wallis p= 0.003). The exposure time of the sandblasters was significantly shorter, especially than the ceramic workers (Kruskall-Wallis p= 0.002). The cases have been referred to us with pneumoconiosis suspicion based on the radiographic findings in the PA chest roentgenogram performed during the periodic examinations at their work place; but unlike other studies, in our study, following the HRCT assessment, cases which did not present any visible pathology in the re-evaluation of their PA chest roentgenogram, but had HRCT findings have been diagnosed as pneumoconiosis. Among the 44 cases in which micro-nodules had been detected at their HRCT, 15 of them had been previously classified as profusion of small opacities 0/1 according to their PA chest roentgenogram findings. It has been seen that the HRCT findings differ among sectors. Ceramics workers and sandblasters had significantly more micro-nodules, while dental technicians had significantly more mediastinal lymphadenopathies (Chi square, p= 0.004 and p= 0.007 respectively). When the relationship between the existence of big opacities and complaints was studied, statistically significant weight loss was detected in cases which had C opacities (chi square p= 0.01). Statistically significant FEV1 decrease was observed in cases which had weight loss (independent samples t-test p= 0.046). It has been observed that when the profusion of small opacities increased, while there was no statistically significant functional status change in non-smokers, a significant functional impairment was observed in smokers. Pneumoconiosis still exists in Turkey. Even a short exposure time as 2 years can cause pneumoconiosis. Workers in different sectors had different functional, radiological properties and smoking can affect the diseases' course. There are serious limitations related to the surveillance of both the workplace environment and the employees' health in Turkey. Without institutional preventive measures, personal protection and surveillance examinations, occupational hazards will continue to cause premature deaths. Pneumoconiosis in different sectors is a prototype of uncontrolled industry in the developing world.

Profusion of Opacities in Simple Coal Worker's Pneumoconiosis Is Associated With Reduced Lung Function

A large body of evidence demonstrates dose-response relationships of cumulative coal mine dust exposure with lung function impairment and with small-opacity profusion. However, medical literature generally holds that simple coal worker's pneumoconiosis (CWP) is not associated with lung function impairment. This study examines the relationship between small-opacity profusion and lung function in US underground coal miners with simple CWP. Miners were examined during 2005 to 2013 as part of the Enhanced Coal Workers' Health Surveillance Program. Work histories were obtained, and chest radiographs and spirometry were administered. Lung parenchymal abnormalities consistent with CWP were classified according to International Labor Organization guidelines, and reference values for FEV1 and FVC were calculated using reference equations derived from the third National Health and Nutrition Examination Survey. Differences in lung function were evaluated by opacity profusion, and regression models were fit to characterize associations between profusion and lung function. A total of 8,230 miners were eligible for analysis; 269 had category 1 or 2 simple CWP. Decrements in FEV1 % predicted were nearly consistent across profusion subcategories. Clear decrements in FVC % predicted and FEV1/FVC were also observed, although these were less consistent. Controlling for smoking status, BMI, and mining tenure, each 1-unit subcategory increase in profusion was associated with decreases of 1.5% (95% CI, 1.0%-1.9%), 1.0% (95% CI, 0.6%-1.3%), and 0.6% (95% CI, 0.4%-0.8%) in FEV1 % predicted, FVC % predicted, and FEV1/FVC, respectively. We observed progressively lower lung function across the range of small-opacity profusion. These findings address a long-standing question in occupational medicine and point to the importance of medical surveillance and respiratory disease prevention in this workforce.

Silicosis Appears Inevitable Among Former Denim Sandblasters: A 4-Year Follow-up Study

The course of denim sandblasting silicosis is unknown. We aimed to reevaluate former sandblasters studied in 2007 for incident silicosis, radiographic progression, pulmonary function loss, and mortality and to examine any associations between these outcomes and previously demonstrated risk factors for silicosis. We defined silicosis on chest radiograph as category 1/0 small opacity profusion using the International Labor Organization classification. We defined radiographic progression as a profusion increase of two or more subcategories, development of a new large opacity, or an increase in large opacity category. We defined pulmonary function loss as a ≥ 12% decrease in FVC. Among the 145 former sandblasters studied in 2007, 83 were reassessed in 2011. In the 4-year follow-up period, nine (6.2%) had died at a mean age of 24 years. Of the 74 living sandblasters available for reexamination, the prevalence of silicosis increased from 55.4% to 95.9%. Radiographic progression, observed in 82%, was associated with younger age, never smoking, foreman work, and sleeping at the workplace. Pulmonary function loss, seen in 66%, was positively associated with never smoking and higher initial FVC % predicted. Death was associated with never smoking, foreman work, number of different denim-sandblasting places of work, sleeping at the workplace, and lower pulmonary function, of which only the number of different places worked remained in multivariate analyses. This 4-year follow-up suggests that almost all former denim sandblasters may develop silicosis, despite short exposures and latency.

Comparison of High‐resolution Computerized Tomography with Film‐screen Radiography for the Evaluation of Opacity and the Recognition of Coal Workers' Pneumoconiosis

Current diagnostic standards of pneumoconiosis, which is the most serious occupational disease in China, are based on film-screen radiography (FSR). However, parenchymal structure overlap limits the sensitivity of FSR in the clinic. High-resolution computerized tomography (HRCT) has the advantage of identifying nodular pulmonary parenchymal changes. In this study, we aimed to compare HRCT and FSR for recognition of the profusion of small opacities, opacity shape and opacity coalescence in coal miners with or without radiographic evidence of coal workers' pneumoconiosis (CWP) and evaluate the possible role of HRCT in CWP diagnosis. There were 96 coal miners with radiographic evidence of CWP, 67 coal miners without CWP and 37 healthy controls in this study. FSR and HRCT images for all subjects were interpreted separately by three readers. Crude agreement and Kappa values were calculated to evaluate the agreement between the two methods. The overall agreement for CWP evaluation was good (crude agreement rate=87.1%, κ=0.72, 95% CI: 0.62-0.83) between FSR and HRCT in all coal miners. The sensitivity of HRCT for CWP diagnosis was 96.9% (93/96). We observed that 18 of the 67 (26.9%) miners negative for CWP by FSR were classified as category 1 by HRCT according to the lung parenchyma profusion category system reported by Bérgin et al. The difference in the profusion scores between CWP subjects and healthy controls for HRCT scans were statistically significantly higher than those for FSR. HRCT was more sensitive than FSR in recognition of the profusion of small opacities among coal miners. More research is needed to evaluate the role of HRCT in early diagnosis of CWP.

A systematic review of digital radiography for the screening and recognition of pneumoconiosis

To conduct a systematic review of studies reporting the comparison of digital radiography (DR) with conventional film-screen radiograph (FSR) in the screening and recognition of pneumoconiosis worldwide, to evaluate the feasibility of DR in the screening and recognition of pneumoconiosis, to analyze the similarity and difference between DR and FSR, to explore the main challenge to utilize DR in the future. The national and international databases were systematically searched for original articles on DR for screening and recognition of pneumoconiosis published from first Jan 1998 to first Nov 2013, making evaluation and selection of them, and qualitative data and quantitative data were extracted independently from the selected articles and systematically reviewed. Five hundred and twenty articles were found and evaluated and nine of them met the inclusion criteria of systematic review. The research time started from 2002 to 2011 whose objects mainly came from pneumoconiosis cases and dust-exposed workers and control population examined with DR and FSR using the high kV radiography from 120 to 130 kV. The chest radiographs were read at blind and random and standard control method. There were only two papers compare the validity of DR and FSR for recognition and classification of pneumoconiosis using gold standards. There were still some diversity of imaging processing and imaging reading without design and assessment using Standards for Reporting of Diagnostic Accuracy (STARD) in these researches. The evaluation index of the nine articles include detection rate of small opacities, crude agreement, Kappa value of Kappa Consistency Test, Area Under the Curve of ROC, etc. Seven of the nine selected articles estimated DR has generally produced superior image qualities compared to FSR. Four papers had a conclusion that DR could be equivalent to FSR in identification of shapes and profusion of small opacities and in classification of pneumoconiosis. Five papers considered DR had higher presence of pneumoconiosis comparing with FSR especially in recognition the pneumoconiosis of category 1. The variation between different film formats of DR and FSR were smaller than that within and between readers for classification of pneumoconiosis. Although there are still some imperfections in the existent researches to solve, DR can be equivalent to FSR in screening and recognition of pneumoconiosis. It is necessary to develop technical specifications of DR and standard digital chest radiographs for pneumoconiosis including both hard copy and soft copy, and develop an evaluation criterion on chest images of DR.

The association between tobacco burden and “dirty chest” is unlikely to follow a linear dose-response pattern

The association between tobacco burden and “dirty chest” is unlikely to follow a linear dose-response pattern

Intramodality and Intermodality Comparisons of Storage Phosphor Computed Radiography and Conventional Film-Screen Radiography in the Recognition of Small Pneumoconiotic Opacities

Digital radiography systems are replacing traditional film for chest radiographic monitoring in the recognition of pneumoconiosis. To further investigate previous findings regarding the equivalence of film-screen radiographs (FSRs) and storage phosphor computed radiographs (CRs), FSRs and CRs from 172 underground coal miners were classified independently by seven National Institute for Occupational Safety and Health-approved B readers, using the International Labor Office (ILO) classification of radiographs of pneumoconiosis. More CRs were classified as "good" quality compared with FSRs (prevalence ratio [PR], 1.5; 95% CI, 1.4-1.6; P , .001). B readers showed good overall agreement on scoring small opacity profusion using CRs vs FSRs (weighted κ, 0.58; 95% CI, 0.54-0.62). Significantly more irregular opacities (compared with rounded) were classified using CR images compared with FSR (PR, 1.3; 95% CI, 1.1-1.6; P = .01). Similarly, the smallest sized opacities (width < 1.5 mm, p and s type) were reported more frequently using CR vs FSR images (PR, 1.3; 95% CI, 1.1-1.5; P < .001). Interreader and intrareader agreement was lower with respect to the classification of shape and size than for small opacity profusion. Overall, interreader and intrareader variability did not differ significantly using CR vs FSR. Under optimal conditions, using standardized methods and equipment, reader visualization of small pneumoconiotic opacities does not appear to differ meaningfully, whether using CR or FSR. Variability in ILO classifications between imaging modalities appears to be considerably lower than variability among readers. The well-documented challenge of reader variability does not appear to be resolved through the use of digital imaging alone, and additional approaches must be evaluated.