Zhang Xirong , Ren Zhanli , Jia Yongjun, Yu Yong, Guo Changyi* 

(1 Shaanxi University of Chinese Medicine, Xianyang 712000, Shaanxi Province, China; 2 Department of Medical Imaging, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang 712000, Shaanxi, China; 3 CT Department, Second Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang 712000)

Abstract: Objective:  To investigate the value of MRI in the diagnosis of soft tissue tumors and tumor-like  lesions in lower limb. extremities．Methods：25 cases with surgery and pathology proven soft tissue tumors and tumor-like lesions in lower limb were retrospectively reviewed and analyzed of its MRI characteristics. Results：There were 14 malignant tumors including synovial sarcoma  (n=6),  metastatic  tumors  (n=3),  malignant  fibrous  histiocytoma  (n=1), leiomyosarcoma(n=1), fibrosarcoma(n=1) and liposarcoma(n=2). There were 11 benign tumors including  lipoma  (n=5),  myositis  ossificans  (n=1),  pseudoaneurysm  (n=1)  and hemangioma(n=4).The maximum diameter of the tumor was (8.36±3.50) cm for benign group and (11.9±4.61)cm  for  malignant  group  with  significant  statistical  difference  (P<  0.05).On  nonenhanced MRI,the signal intensities in benign tumors mostly manifested as homogeneous isointensity  or  homogeneous  iso-hyperintensity  on  both  TIWI  and  T2WI,and  one  case  with peritumoral  edema.  The  signal  intensities  in  malignant  tumors  mostly  manifested  as nohomogeneous low-intensity on both TIWI and T2WI,and four cases with peritumoral edema(＞0.05). In benign tumors, there were 6 cases with noenhacement,5 cases with low-intensity in STIR sequence and no surrounding tissue invasion; however, in malignant tumors, there were 14 cases with different levels of enhacement,2 cases with low-intensity in STIR sequence and 8 cases with surrounding tissue invasion (P< 0.05).  Conclusion: MR1 could clearly display the margin, including the size, internal composition and the relationship with the surrounding. The larger the size and in homogeneous enhancement of the tumour might be the hint of malignant tumour. It is usefully to determine the benign and malignant.

Key words: Acupuncture and moxibustion, soft tissue tumors; MRI; diagnosis