本文着重探讨原发性纵隔恶性肿瘤的CT表现及定性诊断的价值。收集经手术或病理活检证实的原发性纵隔恶性肿瘤20例,总结原发性纵隔恶性肿瘤的影像征象是①肿瘤为实性或少数以实性为主伴有囊性低密区,②与血管界限不清,周围脂肪间隙消失,⑧伴胸积液或肺内转移,对恶性肿瘤具有定性价值。具有上述征象之①者也应考虑肿瘤为恶性;出现②⑧者,则恶性肿瘤的诊断较为肯定。 This article focuses on the CT findings and qualitative diagnosis of primary mediastinal malignancies. 20 cases of primary mediastinal malignancies confirmed by surgery or pathological biopsy were collected. The imaging features of primary mediastinal malignancies were summarized as 1 tumors were solid or a few were solid with cystic low density areas. 2 The vascular boundary is unclear, the peripheral fat space disappears, and 8 is associated with pleural effusion or metastasis in the lung, which has qualitative value for malignant tumors. One with the above signs should also consider that the tumor is malignant; when 28 are present, the diagnosis of malignant tumor is more positive.