MRI在侵袭性纤维瘤诊断中的应用

Application of MRI in diagnosis of aggressive fibromatosis

目的探讨侵袭性纤维瘤(AF)的MRI特点和诊断价值。方法收集17例AF患者术前常规MRI检查(其中15例加做增强扫描)结果,与术后病理结果进行比较,并探讨MRI表现的病理基础。结果17例病变中发生于腹外的有15例,腹内和腹壁各1例。所有病灶MRI均表现为沿肌纤维浸润性生长的椭圆形或分叶状软组织肿块,并累及多块肌肉。肿块较大,平均(8.30±3.02)cm。17例病变中2例边界清晰,可见假包膜;15例边界不清,其中13例无假包膜,2例包膜不完整。与肌肉相比T1WI呈低信号7例,等信号10例;T2WI呈高信号16例,等信号1例;15例增强扫描病例有不同程度强化。17例肿瘤内均未见坏死囊变及瘤周水肿。1例肿瘤邻近骨骼受侵,3例肿瘤邻近骨骼呈边缘受压改变。结论AF的MRI表现有一定的特征性,与病理表现一致,有助于该病的术前诊断和鉴别诊断,可准确评估肿瘤侵犯范围以及与周围结构的关系。

Objective To analyze the MRI features of aggressive fibromatosis （AF） and investigate the value of MRI in the diagnosis of the disease. Methods The properative MRI appearances （15 with gadolinium-enhanced MRI） of 17 cases of AF were collected and compared with the postoperative pathological findings. The pathological basis for the MRI appearances was explored. Results Among the 17 cases, 15 lesions were extra-abdominal, 1 was intra-abdominal; and the other located in the abdominal wall. All were displayed as soft tissue mass with ellipse or lobulated shape by MRI, and the lesions invasively grew along the muscle fiber and involved multiple muscles. The tumors were bigger in size with an average diameter of （8.30±3.02） cm. There were incomplete capsules in 2 cases, false capsules in 2 cases, no capsule in 13 cases. To compare with the muscle signal intensity on MRI, 7 cases demonstrated low signal intensity and 10 homogeneous signal intensity on T1WI. Sixteen cases demonstrated high signal intensity and 1 homogeneous signal intensity on T2WI. Appearance of various enhancement were found in 15 cases with enhanced MRI. There was no necrosis, cystic and surrounding edema in the lesions of all the cases. Tumor invaded adjacent skeleton in 1 case, and adjacent skeleton was found compression in 3 cases. Conclusion There are characteristic appearance in MRI findings for AF, which are consistent with pathological findings. MRI is helpful in initial diagnosis and differential diagnosis of AF, as well as in evaluation of the range of invasion and involvement of adjacent structures.