目的 分析滑膜肉瘤(Synovial sarcoma,SS)影像学表现，以提高对该病 影像学诊断的准确性。方法 回顾性分析 经病理证实的15例SSs CT和MRI表现以及 相关的临床资料。结果 15例中，男性7 例，女性8例，平均年龄42岁(17-65岁)， 主要症状为病变区疼痛以及明显可触及肿 块。平均病程时间约为4.7月(7天-2年)， 发病部位主要在大腿(n=5)、小腿(n=3)、 足(n=1)、腹膜后(n=2)、肺(n=2)和纵隔 (n=1)。8例发生于下肢SSs表现为稍大、 边界清晰及密度不均匀软组织肿块，平均 直径约6.5cm。1例发生于足SS表现为较大 的、边界不清及密度不均匀肿块伴邻近楔 状骨及跖骨侵犯。其中4例患者在T2WI上 可观察到“三重信号”特征。大部分肿块 有分叶征象。7例行增强检查患者表现出 肿块呈环形或不均匀强化。2例肺部发病 患者表现为肺内孤立的、边界清晰及密度 不均匀软组织肿块，增强后内部示无强化 坏死或囊变区。1例纵隔滑膜肉瘤患者表 现为胸腔内巨大的肿块，内部有囊变区伴 不规则分隔，囊壁可见强化壁结节。其中 8例患者术后因复发或转移死亡。结论 当 青壮年患者在下肢发现稍大、边界清晰软 组织肿块，伴或不伴囊变，特别是在T2WI 上呈现“三重信号”特征时，此时需考虑 或提出滑膜肉瘤的可能。诊断的关键还是 需要影像结合临床病理。FDG PET对预后 评价有帮助。

Objective To analyze the radiological and clinicopathological features of synovial sarcoma (SS) to improve its diagnostic accuracy. Methods We retrospectively reviewed the computed tomography (CT) and magnetic resonance (MR) imaging of 15 cases of SS confirmed immunohistochemically. Relevant clinical data was also obtained. Results Of 15 cases, there were 7 male and 8 female with a mean age of 42 years(range 17–65 years). The main symptoms were the aggravated pain of the lesion site and enlarged palpable masses. The duration of symptoms varied from 7 days to 2 years with a mean of 4.7 months. Fifteen lesions were located in the thigh (n=5), crus (n=3), foot(n=1), retroperitoneum(n=2), groin(n=1), lung(n=2) and mediastinum (n=1). Eight cases of SSs originating from lower limbs demonstrated a largish, well-defined, heterogeneous masses with an average size of 6.5 cm. One patient with foot lesion showed a large. illdefined, and heterogeneous mass with adjacent cuneiform and metatarsal invasion. A "triple signal" pattern can be observed on T2WI in four of them. Most of the masses showed lobulated in shape. After administration of contrast agents in seven patients, the tumors displayed annular or marked heterogeneous enhancement. The two lung lesions showed isolated, well-demarcated, and heterogeneous masses with internal multiple nonenhancing regions, representing necrosis or cystic degeneration. One mediastinal tumor with large size and cystic area contained irregular septations and mural nodules within them. Eight patients died of recurrences or metastases after surgery or therapy. Conclusion The diagnosis of SS should be suggested in the adult patient when imaging depicts a largish, well-defined, soft-tissue mass containing area of cystic degeneration in the lower extremity, specially a "triple signal" pattern is detected on T2WI. The key for correct diagnosis is to inosculate imaging to clinicopathological data. FDG PET may be helpful for the assessment of prognosis.