【摘要】 目的 探讨四肢软组织未分化多形性肉瘤（UPS）的影像学表现及特征，提高对该病的认识及影像诊断水平。方法 回顾性分析24例经手术后病理及免疫组化证实的发生于四肢软组织UPS的临床及影像学表现，21例行MR检查，12例行CT检查，9例同时进行CT和MR检查。结果 24例UPS均表现为形状不规则的分叶状软组织肿块；下肢（包括臀部）13例，上肢（包括腋窝）11例，其中9例发生于皮下脂肪间隙内，7例发生于深部肌群内（靠近骨干及关节）,3例发生于浅层肌群内（靠近皮肤）,3例因周围组织广泛受侵致起源部位不明确，2例发生于深部肌群间隙内。CT表现为6例不均匀软组织密度，4例邻近骨质可见不规则破坏，MR表现为11例病灶内见T₂低信号分隔，10例病灶内见流空血管，5例邻近骨髓腔内可见骨髓水肿；增强扫描均出现不均匀性强化，边缘可见棉团样、云絮样强化。结论 CT表现为深部肌群软组织肿块伴骨质破坏，MR肿块内见线状低信号分隔，肿块内及边缘见血管流空，边缘棉团样、云絮样强化征象对四肢UPS的诊断中有重要价值。更多还原

【Abstract】 Objective To study the imaging findings and characteristics of undifferentiated pleomorphic sarcoma（UPS） in extremities soft tissue, to improve the understanding and diagnosis of this disease.Methods Clinical and imaging manifestations of 24 cases with UPS in extremities soft tissue confirmed by pathology and immunohistochemistry were analyzed retrospectively.21 cases underwent MR examination, 12 cases underwent CT examination and 9 cases underwent CT and MR examination simultaneously.Results All 24 cases of UPS showed lobulated soft tissue masses with irregular shape.There were 13 cases of the lower limbs（including the buttocks） and 11 cases of the upper limbs（including the axilla）.Among them, 9 cases occurred in the subcutaneous fat space, 7 cases in the deep muscle（near the backbone and joint）,3 cases in the superficial muscle（near the skin）,3 cases in unclear origin due to extensive invasion of surrounding tissues, 2 cases in the deep muscle gap.On CT,there were heterogeneous soft tissue density in 6 cases and irregular destruction of adjacent bone in 4 cases.On MRI,low signal segregation were showed on T₂WI in 11 cases, vascular flowing-void were seen in 10 cases, bone marrow edema was seen in 5 cases of adjacent bone marrow.Heterogeneous enhancement was observed on enhanced scan, and cotton-like and cloud-like enhancement could be seen at the edge of the lesion.Conclusion The soft tissue masses with bone destruction in deep muscles on CT.The linear low-signal segregation in mass, vascular flowing-void in and around the mass, and the cotton-like and cloud-like enhancement signs at the margin of the mass are of great value in the diagnosis of UPS in extremities on MR.更多还原