Application Value Of HRCT In The Diagnosis Of Pneumoconiosis

PART 1Comparative analysis of the efficacy of HRCT with different layer thicknesses of coronal MIP reconstituted images for the detection of small opacities in pneumoconiosis Objective: To investigate the efficacy of MIP reconstructed images of different layer thicknesses in detecting small opacities and to analyse the consistency of MIP reconstructed images for the diagnosis of pneumoconiosis staging in conjunction with pathological criteria.Methods: Retrospective collection of imaging data from 206 cases of dust workers in a large copper company in Anhui Province(HRCT was performed after review and approval by the Medical Ethics Committee of Tongling Municipal Hospital and informed consent from patients for CT examination).Firstly,HRCT thin layer images were transferred to PHILIPS workstation for reconstitution of 5 mm,8 mm and 10 mm layer thickness coronal MIP images;the number of small opacities detected in different layer thicknesses was counted by referring to the criteria of 《Pathological diagnosis criteria of pneumoconioses 》(GBZ25-2014)for small opacity count and staging of pneumoconiosis.Then,the results of determining the staging of pneumoconiosis were analyzed and compared with the three MIP recombination images.The diagnostic effectiveness of the three methods for determining the stage of pneumoconiosis was compared using the subject operating characteristic curve(ROC)depends on 5-mm MIP as the baseline.Results: The Kappa value of the three-layer thickness MIP recombination image to determine the consistency test of pneumoconiosis staging were 0.963,0.968,0.921(P<0.001);the area under the ROC curve(AUC)for the 8 mm MI and 10 mm MIP were 0.991,0.972.Conclusion: The reconstructed MIP images with 5mm,8mm and 10 mm thickness combined with pathological criteria have a high consistency in determining the staging of pneumoconiosis.10 mm MIP can be used instead of 5mm MIP reconstructed images in CT staging of pneumoconiosis.PART 2 Features of HRCT imaging in pneumoconiosis and comparison with DRObjective: To compare HRCT and DR for the staging of pneumoconiosis,the detection of small opacities and the detection of emphysema,lymph node calcification,pleural spots,large opacity and small opacity aggregates,and complications of pneumoconiosis(pulmonary hypertension,bronchiectasis,tuberculosis,lung cancer),and whether there are statistical differences in the detection of pneumoconiosis.And analyze the HRCT image characteristics of pneumoconiosis;explore the application value of chest HRCT in the diagnosis and staging of pneumoconiosis.Methods: Retrospective collection of imaging data from 206 cases of dust workers in a large copper company in Anhui Province(HRCT was performed after review and approval by the Medical Ethics Committee of Tongling Municipal Hospital and informed consent from patients for CT examination,HRCT examination and routine physical examination DR chest X-ray were performed).Firstly,the DR chest films were clarified by the pneumoconiosis diagnostic panel to determine the stage of pneumoconiosis.Secondly,the CT lung zones were formulated with reference to the International Labour Organization(ILO)chest X-ray lung zone delineation and the definition of HRCT lung zones for occupational diseases in Germany.Formulation of CT pneumoconiosis staging with reference to the 《 Pathological diagnosis criteria of pneumoconioses》(GBZ25-2014),the《Diagnosis of occupational pneumoconiosis》(GBZ70-2015)and the Consensus of experts on the technical specification of chest CT examination of pneumoconiosis(2020 edition).Reconstruction of HRCT thin-layer images with 10 mm layer thickness MIP coronal position,and counting the number and distribution of small opacities to determine the CT stage of pneumoconiosis and compare with DR;using ROC to compare the value of HRCT in the diagnosis of pneumoconiosis.Secondly,HRCT was performed to evaluate pneumoconiosis with pneumofibrosis,emphysema,mediastinal lymph node calcification and pleural plaques,and to analyse the correlation with pneumoconiosis staging.Finally,the number of detections of HRCT compared with DR for pneumoconiosis with emphysema,mediastinal lymph node calcification,pleural spots,large and small opcaities aggregates,and complications(pulmonary hypertension,bronchiectasis,tuberculosis,lung cancer)was counted.Results: The consistency statistic for comparing HRCT with DR to determine pneumoconiosis stage between groups was Kappa=0.568,p<0.001;the AUC value for HRCT to diagnose pneumoconiosis stage was 0.873.There were statistical differences between the two methods for determining stage of pneumoconiosis,as well as the number of small opacities detected and the number of small opacities detected in the lung areas(total lung area,both upper lung areas,and the left lower lung area)(p<0.050).The correlation coefficient had a positive correlation between HRCT pneumofibrosis score,emphysema score,number of mediastinal lymph node calcifications and lymph node CT values,pleural plaque grading and stage of pneumoconiosis(R values were 0.825,0.604,0.738,0.334 and 0.496 respectively,P<0.001).There was a statistical difference between the type of emphysema and the stage of pneumoconiosis(P<0.050).There was a statistical difference between HRCT and DR for the detection of pneumoconiosis with emphysema,mediastinal lymph node calcification,pleural spots,large and small opacities aggregates,and complications of pneumoconiosis(tuberculosis,bronchiectasis,lung cancer,pulmonary hypertension)(P<0.001).Conclusion: HRCT is feasible for CT staging of pneumoconiosis based on 10 mm layer thickness coronal MIP reconstructed images and combining two diagnostic criteria.HRCT has certain value in evaluating pneumoconiosis emphysema,pneumoconiosis,pleural plaques and mediastinal lymph nodes.HRCT is superior to DR chest films in assessing emphysema,pneumonic fibrosis,pleural spots,large opacity,small opacities aggregates,lymph node calcification and pneumoconiosis complications.