Comparison Of Chest Imaging Techniques And Quantitative Study Of Free Pneumothorax

Background:With the development of medical imaging,qualitative and quantitative diagnosis of chest diseases has made considerable progress.The chest imaging examination method is mainly for chest radiography and CT scanning.The two-dimensional images of chest radiography and chest all anatomical structure superimposed,prone to heart,diaphragm,mediastinum,thoracic and rib interference,and easily lead to misdiagnosis and missed diagnosis,the qualitative and quantitative diagnosis of lung lesions were inadequate.The multi-slice CT images can overcome the interference caused by the anatomical structure of superposition,and various imaging postprocessing techniques can display lesions more comprehensive and clearly,the pulmonary lesions displayed more clearly Clinical experience shows that the positive rate of multi-slice CT in the detection of lung lesions is higher than that of chest radiography,but lack of systematic study.PART 1 Comparative study of multi-slice CT plain scan and DR chest radiography in detection of lung lesionsObjectiveTo compare the differences of pulmonary lesions between chest multislice CT and DR radiography.Methods216 cases of chest CT and DR radiography data within 48 hours were retrospectively analyzed.All data were double-blindly read by two veteran doctors,kappa test was done.The lesions were divided into the following types: nodules and mass,calcification,exudation and consolidation,emphysema,bronchiectasis,pulmonary bullae and fibrosis,hilus enlargement and pleural effusion,the number of lesions were recorded.And paired sample t test were respectively analyzed.Using CT as the standard,DR lesion detection of missing rate,false rate and accuracy rate were calculated.ResultsThe kappa coincident coefficient was 0.67 in chest DR analysis,and the kappa coincident coefficient was 0.79 in CT.Total lung lesions detected by CT was significantly higher than the DR,the difference was statistically significant(P = 0.000);Classified by lesions type,the CT lesions detection were significantly higher than that of DR in nodules and masses,calcification,seepage and consolidation,fibrosis,pulmonary emphysema,pulmonary bullae,bronchiectasis,pleural effusion,the difference was statistically significant(P < 0.05).Using CT as the standard,DR lesion detection of missing rate,false rate and accuracy rate were 81.48%,32.77% and 18.52%.ConclusionThere were significantly differences about pulmonary lesions between Chest multislice CT and DR radiograph,multislice CT of pulmonary lesion detection rate was significantly higher than the DR.PART 2 The Study on Compression Percentage of Free Pneumothorax by Multi-Slice CTObjectiveTo explore the accuracy of lung compression percentage in patients with free pneumothorax by using axial images of multislice CT.Methods88 cases of free pneumothorax chest CT data were retrospectively analyzed,and the volume of pneumothorax were measured.Compression percentage of pneumothorax Y were calculated.At the carina plane,a maximum vertical distance A and distance a from visceral layer to the pleural in profile were measured,and then calculated the vertical distance ratio X1;similarly,a maximum horizontal distance B and the horizontal distance b from visceral layer to the pleural were measured,and calculated the horizontal distance ratio X2;The compression percentage of the left lung and right lung combined with X1 and X2 for 1 time,2 times and 3 times regression analysis were completed.The model and the coefficient of the model and the coefficient of the equation were selected,and the accuracy of the equation was verified.ResultsAll regression models were statistically significant(P< 0.0001).The best formula for the left pneumothorax was: Y=0.0758+2.8623X1-2.8049X12,R2=0.7460,R=0.8637,the best formula for the right pneumothorax was: Y=0.0708+2.5960X1-2.1178X12,R2=0.8575,R=0.9260.The deviation of predicting the percentage of pneumothorax of left was 0.01%±9.68% and the right was 0.12%±8.02%.ConclusionMeasurement the vertical compression ratio X1 and the horizontal distance compression ratio X2 at the carina plane could predict lung compression percentage in free pneumothorax,especially the vertical compression ratio X1 more accurately reflected compression percentage in free pneumothorax.