滑膜肉瘤的CT和MRI影像特征与诊断

CT and MRI Features and Diagnosis of Synovial Sarcoma

目的探讨软组织滑膜肉瘤的CT和MRI影像特征,提高对该病的诊断水平。方法回顾性分析经病理证实的43例滑膜肉瘤患者的CT和MRI资料,根据肿瘤的大小、边界、密度、信号特点和强化方式,分析其影像征象。结果 43例患者中,肿瘤位于下肢关节附近、骨旁或肌肉间隙共23例,约占53.5%,上肢关节附近6例,椎体5例,颈部3例,鼻咽腔3例,纵隔2例,前列腺1例。肿瘤最小径1.7 cm,最大径12.8 cm,,平均约4.7 cm。CT平扫肿瘤多表现为边界较为清晰的圆形、类圆形、梭形或结节状软组织肿块,可有分叶,密度与肌肉组织相仿,可见坏死、囊变,7例肿瘤内见钙化。MRI平扫T_1WI像上表现为等、稍高、稍低或混杂信号,T_2WI像上,25例表现为稍高信号或混杂高信号,内含出血、坏死、囊变区。增强扫描表现为明显不均匀强化,其中2例可见异常粗大的血管影。结论滑膜肉瘤CT和MRI特征多变,其影像学特点对其诊断有一定的价值,确诊仍需要结合病理检查。

Objective To evaluate the CT and MRI characteristics and features of synovial sarcoma so as to improve its diagnostic accuracy. Methods The clinical and imaging materials including CT and MRI images of 43 patients with synovial sarcoma confirmed by pathological examination were retrospectively analyzed. 21 patients underwent CT scans and 32 underwent MRI scans,including 10 patients were investigated using both CT and MRI scans. The CT and MRI characteristics and features of synovial sarcoma were analyzed according to the location,size,density,signal and patterns of enhancement. Results 23 patients had tumors located in the lower limbs adjacent to the joints or in the muscle interval,and 6 patients had tumor located in the upper limbs adjacent to the joints. Tumors that were located in the vertebral bodies,neck,nasopharynx and prostate were 5 cases,3 cases,3 cases and 1 case respectively. Most tumors showed a clearly defined margin,and multivariate shape and size. The mass density was inhomogeneous and close to the muscle. Necrosis and cystic degeneration could be identified on CT scan. Calcification was observed in 7 cases on CT images. On MRI T_2WI,23 tumors displayed a signal hyper-intensity or mixed-hyper-intensity compared to the subcutaneous fat. Hemorrhage,necrosis and cystic degeneration could be seen in 6 tumors. For T_1WI,tumors showed mixed signal,which could be hyper-intensity,iso-intensity or hypo-intensity to skeletal muscle. For both CT and MRI images,most tumors displayed heterogeneous enhancement after injection of contrast agent. Conclusion Synovial sarcoma has some relatively specific image findings,which are helpful for the diagnosis but should be combined with pathological results.