CT Diagnosis And Comparative Study With Microbiological Examination Of Pulmonary Mycosis

Background With the abuse of broad-spectrum antibiotics in clinical practice,the long-term use of immunosuppressive agents such as glucocorticoid,the high incidence of malignant tumors and diseases of the blood system,the increase of organ transplant patients,the long-term mechanical ventilation and the placement of various catheters in the body,the incidence of pulmonary fungal diseases has increased gradually in recent years.Compared with the common bacterial and tuberculous infections in the lungs,the diagnosis and treatment of pulmonary mycosis are more difficult.If the diagnosis and treatment are not appropriate,the prognosis is poor.Pulmonary mycosis can also be acquired through community infection in healthy people without associated risk factors and underlying diseases.Therefore,pulmonary mycosis has become a hot topic in clinical research in recent years.Lung CT examination is fast,convenient and easy to dynamically observe the changes of the disease.In particular,in recent years,MSCT has been widely used,making CT have higher resolution of time,space and density.HRCT makes the fine structure of lung lesions appear more clearly.Powerful image post-processing capabilities,including MPR and VR,enable people to observe lung lesions in a more three-dimensional and Comprehensive way.MSCT examination has become an indispensable examination method for clinical pulmonary diseases.Laboratory microbiological examination is also a routine method to diagnose lung diseases.Sputum fungi culture and blood culture are the most widely used.Although microbiological examination can directly provide etiological evidence,the sputum produced by coughing may carry the colonized opportunistic pathogens,and blood samples may be contaminated during the examination.Therefore,the diagnosis of pulmonary mycosis cannot be made solely by microbiology.At present,there are few comparative studies on the imaging and microbiological methods of pulmonary fungal diseases at home and abroad.Objective Explore the CT imaging features of pulmonary mycosis and its differential diagnosis with bacterial pneumonia and tuberculosis.The differences between CT examination,sputum fungal culture and blood culture of pulmonary mycosis were compared.Materials and methods 79 cases of clinically suspected pulmonary fungal diseases were retrospectively collected from Anhui NO.2 Provincial People’s Hospital from July 2014 to April 2018,of which 55 cases of pulmonary fungal diseases were confirmed.The clinical data,CT imaging findings,sputum fungi culture and blood culture were recorded.At the same time,50 patients with simple bacterial pneumonia and tuberculosis diagnosed in the same period were randomly selected as the control group.The imaging data of patients with pulmonary mycosis confirmed in the research group and the control group were analyzed to compare the CT findings and signs of the two groups.The positive predictive value,negative predictive value,sensitivity and specificity of CT examine,sputum fungi culture and blood culture in the diagnosis of pulmonary mycosis in the research group were calculated,and ROC curves were drawn respectively to compare the area under the three curves,and to determine whether there was a significant difference in the diagnosis of pulmonary fungal infection between the three examination methods.The statistical methods were analyzed by chi-square test or Fisher’s exact method.Statistical analysis was performed with SPSS17.0 software packageThe results1.Clinical resultsAmong the 55 patients diagnosed with pulmonary fungal diseases,36 cases were males,19 cases were females,aged 28 to 90 years old,including 19 cases with aspergillus infection,13 cases with candida infection,10 cases with cryptococcus infection,2cases with pneumocystis infection,2 cases with mucorycosis infection and there were9 cases of unclassified fungal infection.The main pathological and histological methods are surgical resection,CT guided percutaneous lung biopsy,fiberoptic bronchoscopy or biopsy.2.CT distribution and imaging manifestations of pulmonary fungal infection lesionsAmong the 55 patients diagnosed with pulmonary mycosis,37 cases with bilateral lung disease,both lungs were affected and the lung edge was mainly distributed in the field.There were 7 cases of mass type,17 cases of nodule or patch type,8 cases of solid change type,7 cases of aspergillus globule type,5 cases of ground glass shadow type,11 cases of mixed type,and the main imaging signs were air crescent sign,halo sign,tree-in-bud sign,air bronchogram sign,cavity sign,wedge-shaped consolidation,etc.Compared with bacterial pneumonia,pulmonary mycosis has a high incidence of air crescent sign,halo sign,tree-in-bud sign,cavitation and ground glass shadow,while bacterial pneumonia has a high incidence of air bronchogram(P<0.05).Comparison between pulmonary mycosis and simple pulmonary tuberculosis: pulmonary mycosis halo sign,air crescent sign,wedge-shaped consolidation,and ground glass shadow were high,while pulmonary calcification,satellite focus and mediastinal enlarged lympth node were high(P<0.05).3.CT examination,sputum fungal culture and blood cultureChest CT examination was performed on all 79 patients with suspected pulmonary mycosis to be diagnosed,and 43 cases of diagnostic reports indicated pulmonary mycosis.Among them,35 cases were correctly diagnosed with pulmonary mycosis,with positive predictive value of 81.4%,negative predictive value of 44.4%,sensitivity of 63.6% and specificity of 66.7%.All 79 patients underwent sputum and fungal culture examination,and 51 cases were detected with fungus,among which 37 cases were correctly diagnosed with pulmonary mycosis,with positive predictive value of72.5%,negative predictive value of 35.7%,sensitivity of 67.3% and specificity of41.7%.47 blood cultures were conducted,including 34 cases of pulmonary mycosis confirmed and 7 cases of pulmonary mycosis detected in blood culture,including 6cases of pulmonary mycosis confirmed,with positive predictive value of 85.7%,negative predictive value of 30%,sensitivity of 17.6% and specificity of 92.3%.The area under the ROC curve of the three groups was 0.700,0.760 and 0.700 respectively,with no significant difference,but all of them were in the level of 0.7-0.9,indicating that all three diagnostic methods had certain accuracy.Conclusion The CT imaging manifestations of pulmonary mycosis are various,such as air crescent sign,halo sign,ground glass shadow,cavity sign and tree-in-bud sign are helpful for the diagnosis and differential diagnosis of pulmonary mycosis.CT imaging,sputum fungi culture and blood culture have certain accuracy in the diagnosis of pulmonary fungal diseases,and there is no significant difference in the accuracy of the three methods.