纵隔髓性脂肪瘤影像学表现及鉴别诊断

目的:探讨纵隔髓性脂肪瘤（mediastinal myelolipoma）的CT及MRI表现特点、诊断价值，以提高本病的认识及术前诊断的准确性。方法:回顾性分析经手术、病理证实的 7例纵隔髓性脂肪瘤的CT及MRI表现，分析其影像学特点。结果:7例患者肿块均位于后纵隔；其中5例患者单侧单发，1例单侧两个结节，1例双侧多发。CT表现:病灶形态较规则，部分呈类圆形，呈等、低混杂密度，其内见CT值为负值的更低密度脂肪区，增强扫描呈轻度-中度不均匀性强化；MRI表现:病变T1WI及T2WI序列上均呈不均匀混杂信号，病灶内见斑点状、小片状脂肪信号，呈明显不均匀性强化。结论:CT及MRI检查可以发现纵隔髓性脂肪瘤的相关影像学特征，是术前诊断髓性脂肪瘤最重要的检查方法，能为本病的诊断及鉴别诊断提供重要依据。

Imaging findings and differential diagnosis of mediastinal myeloid lipoma

Objective:To analyze the CT and MRI features,and diagnostic value of mediastinal myelolipoma,and to improve the understanding of the disease and the accuracy of preoperative diagnosis.Methods:The CT and MRI findings of 7 cases of mediastinal myeloidlipoma confirmed by operation,and pathology were retrospectively analyzed.Results:Seven patients were located in the posterior mediastinum.5 patients had single-sided single-shot,1 patient had unilateral two nodules,and 1 patient had multiple bilateral multiples.CT features of mediastinal myelolipoma were as follows:The lesions were more regular,some were round,with equal and low-mixed density,and the lower-density fat regions with negative CT values were observed,and the enhanced scan showed mild-moderate heterogeneity enhancement.MRI features of mediastinal myelolipoma were as follows:The lesions on the T1WI and T2WI sequences showed uneven mixed signals,and the spotted and small-like fat signals were observed in the lesions,showing obvious heterogeneity enhancement.Conclusion:CT and MRI examination can find the relevant imaging features of mediastinal myeloid lipoma,which are the most important methods for preoperative diagnosis of myeloid lipoma,and can provide an important basis for the diagnosis and differential diagnosis of this disease.