Objective To investigate the efficacy of CT on diagnosis of mediastinal neoplasms and tumor-like lesion to analyze the causes of misdiagnosis. Methods Forty two patients were examined with CT, 11 patients received contrast CT scan. All cases were confirmed by pathology. Results Various mediastinal neoplasms and tumor-like lesions with heterogeneous density have their own special demonstration on CT image and frequently occurred sites. The accuracy of diagnosis before surgery is 71.4 %(30/42). Conclusions CT is useful in improving the preoperative diagnosis rate of mediastinal neoplasms or tumor-like lesions and in helping clinicians work out treatment plan.

Objective To study the CT features of pulmonary inflammatory pseudotumor so as to distinguish from spherical lesion of lung cancer,tuberculoma and sperical pneumonia.Methods We investigated retrospectively the data of the 31 cases with pulmonary imflammatory pseudotumor which were proved pathologically after surgery.Results The main CT findings were as follows:(1)circle-like mass,most of them were single,margin was smoothy,density was even,diameter was about 32.0 cm.(2)There were localized pleural thickening adhesion and strip-like low density lesion between mass and thickened chest wall.(3)The middle sections showed:lateral margins of the lesions perpendicular to pleura with a straight cut edge.(4)The edge of the lesion presented short and thick spiculation.Conclusion CT examination is very helpful to the correct diagnosis of pulmonary inflammatory pseudotumor.