Analysis of CT features of high density thymic cyst

ZHANG Yu; XIE Fengzhi; ZHOU Changqing

doi:10.20258/j.cnki.1006-9011.2025.05.015

Abstract：Objective To investigate the CT imaging features of high density thymic cysts in order to improve the accuracy of clinical diagnosis.Methods A retrospective analysis was conducted on the clinical and imaging data of 58 patients with thymic cysts confirmed by surgical pathology,all of whom presented with high density nodules(CT value≥20 HU)on non-contrast CT scans.Based on the accuracy of the diagnosis after contrast-enhanced CT scans,the 58 patients were divided into a correct diag-nosis group(n=21)and a misdiagnosis group(n=37).The clinical characteristics and imaging features of the lesions,including size,shape,margin,relationship with the mediastinal pleura,non-contrast CT value,and enhancement amplitude(∆CT value)during the arterial and venous phases,were summarized.Statistical analysis was performed using PEMS 3.2 software,with P<0.05 considered statistically significant.Multivariate logistic regression analysis was used to identify factors associated with misdi-agnosis of high density thymic cysts on contrast-enhanced CT scans.Results The diagnostic accuracy rate for the 58 cases was 36.21%(21/58).Among the 23 cases with enhancement phenomena,the diagnostic accuracy rate was 17.39%(4/23).Univari-ate analysis showed that,apart from the minimum diameter and the ∆CT value in the arterial phase,which were statistically sig-nificant(P<0.05),other clinical characteristics and CT imaging features showed no statistical significance(P>0.05).Multivari-ate logistic regression analysis revealed that the ∆CT value in the arterial phase was an independent predictor of misdiagnosis.Conclusion Contrast-enhanced CT scans have certain diagnostic value for high density thymic cysts,but there are still limita-tions in diagnosing high density thymic cysts with enhancement phenomena,thereby posing a risk of misdiagnosis.