四肢软组织硬纤维瘤的CT及磁共振成像表现

The CT and MRI imaging manifestation of extremity soft tissue desmoid tumor

目的探讨四肢软组织硬纤维瘤的CT及磁共振成像（MRI）影像表现。方法收集15例经手术证实的四肢软组织硬纤维瘤病例,其中CT检查8例,增强7例,MRI常规及STIR检查15例,增强14例,分析其影像学表现。结果 8例位于上肢,7例位于下肢。形态上,14例呈类圆形或不规则形肿块,1例呈斑片状影,12例边界不清,3例边界尚清。肿块直径较大,最大径1.1~9.1 cm,中位大小4.8 cm,4例为术后多发病灶。CT显示,7例病灶均略低于肌肉密度,1例为等密度,肿块密度欠均匀,增强后轻到中度强化,2例肿块内可见星芒状或条带状稍高密度影,所有肿块均未见液化、坏死灶。MRI显示,15例T_1为等或等低信号,T_2及短时反转恢复序列（STIR）为高或稍高信号,均低于脂肪信号,14例肿块内可见星芒状或条带状T_1T_2低信号,1例肿块内可见点状出血灶,15例均未见囊变坏死区,增强扫描除病灶内T_1、T_2低信号灶不强化外,其余病灶呈较均匀明显强化,且强化较同一患者的CT显著。结论四肢软组织硬纤维瘤在CT及MRI上具有一定的特点,可提高该病的诊断及鉴别诊断水平。

Objective To investigate the CT and MRI manifestations of extremity soft tissue desmoid tumor.Methods Fifteen casesofextremity soft tissuedesmoid tumor proved by pathology wereretrospectively analyzed. There were 8 cases with CT plane scans and 7 cases with contrast enhanced CT scans,15 cases with MRI plain scans and 14 cases with MRI enhanced scans. Results Eighty caseslocatedin upper limb,seven caseslocated in lower limb.Forteen lesions displayed ovate or irregular soft tissue mass,1 lesion patching,12 lesions obscure boundary,3 lesions clear boundary. And masseshad large diameters（the maximum diameter was 1.1-9.1 cm,averagediameter was 4.8cm）,4 cases were multiple lesions. Seven lesions appeared low density compared with muscle On CT,only 1 lesion ap-peared equal density. Masses were usually heterogeneity with mild to moderate enhancement on CT after contrast. Two lesions were intermingled stellate-shaped or ribbon areas of low signal. All lesions were with no cystic necrosis regardless of the size. On T_1 WI,fifteen lesions were usually with signal intensity similar to or slightly lower than that of mus-cles and on T_2 WI and STIR they presented high or slightly higher signal intensity,but lower than that of fat. Forteen lesions with stellate-shaped or ribbon areas of low signal,only 1 lesion with punctuate hemorrhage. Fifteen lesions with no necrosis,demonstrated obviously even enhancement on MRI after contrast except forthose lesions with low signal on T_1 WI and T_2 WI,and the degree of enhancementwas more significantly compared with contrast enhanced CT in the same patient. Conclusion Extremity soft tissuedesmoid tumors have certain characteristics on CT and MRI,which could improve the diagnosis and differential diagnosis of the disease.