Analysis Of The Characteristics Of CT Reversed Halo Sign In Different Lung Diseases

Purpose:1.To analysis the morphological features of reversed halo sign and other imaging features of lung.2.To explore the value of reversed halo sign in the diagnosis.Methods:Collect 31 patients' image data who underwent chest CT examination in Shanxi Academy of Medical Sciences Shanxi DIYI Hospital from 2014.01 to 2017.01(whose images express or contain RHS).To get the final clinical diagnosis by follow-up,analysis of these cases and other imaging signs,to summarize the RHS,composition characteristic and pulmonary field with or without other imaging signs.Results:1.Diagnosis There are 31 cases,including tuberculosis(TB)16 cases,cryptogenic organizing pneumonia(COP)10 cases,fungal infection 4 cases and pulmonary embolism 1 cases.2.Image characteristics There are 16 cases(51%)had small nodules in the RHS (including halo walls and glass density area),these cases are TB,the small nodules can not be seen in others.6 cases(19%)cases show recurrent,wandering,these cases are COP.3.The number of lesions There were 27 cases(87%)with multiple lesions,4 cases(13%)with single lesions(COP 2 cases,aspergillus infection 1 case,PE 1 case).4.Accompanying sign There are 11 cases(35%)had tree-in-bud in chest CT images,these cases are TB.Conclusion:1.Reversed halo sign can be seen in a variety of chest diseases,including tuberculosis,COP,fungal infection and pulmonary embolism.One of the top two possibilities for tuberculosis and COP.2.The characteristic sign of RHS in TB is the presence of small nodules,and in COP is wandering,recurrent.3.Tree-in-bud may also contributes to the diagnosis of TB as accompanying sign.