腹部外硬纤维瘤的磁共振成像诊断

MR Imaging in the Diagnosis of Extra-abdominal Desmoids

目的:了解腹部外硬纤维瘤的MR成像特征。方法:对经手术病理证实的10例硬纤维瘤的MR图像进行回顾性分析。所有的病例均采用Siemens Magnetom Vision1.5T超导全身MR扫描仪,10例常规行T1WI和T2WI,9例行MR增强扫描。结果:10例腹部外硬纤维瘤中,韧带状纤维瘤1例;侵袭性纤维瘤病9例,其中颈项部3例,右肩背部3例,右大腿2例,左上臂2例。肿瘤的平均大小约为10cm×7cm×5cm。除1例韧带状纤维瘤有包膜,边缘清楚外,其余肿块没有包膜,边界不清。所有肿块的信号欠均匀,在T1WI、T2WI及增强扫描像上可见低信号的纤维成分,肿块的非纤维成分在T1WI上与肌肉信号相同,在T2WI上的信号高于肌肉小于脂肪,呈明显强化。1例颈项部侵袭性纤维瘤病伴有邻近肌肉的广泛浸润,1例侵犯右肩胛骨部分内缘。结论:虽然硬纤维瘤与恶性肿瘤的MR信号有相似之处,但它在T1WI和T2WI上及增强扫描像上显示的低信号纤维成分,可以与软组织恶性肿瘤相鉴别。

Objective：To investigate the MR features of extra-abdominal desmoids. Methods： MR images of 10 surgically and pathologically proven cases with extra-abdominal desmoids were collected and retrospectively analyzed. In all the 10 cases,conventional MR T1WI and T2 WI imaging were performed and in 9 of them contrast enhancing MR imaging was undergone also, There were 3 males and 7 females in our collection. Results： In our series of cases, 1 case with a ligament-like fibroma and 9 other cases with aggressive fibromatosis lesions were seen. The sites of the desmoids were as follows.. 3 in the neck,3 in the back of the right shoulder,2 in the right thigh and 2 in the upper arm. The mean size of the tumors was 10cm×7cm×5cm. In the 10 cases of desmoids,9 masses revealed no encapsulation and poorly demarcated except the one of ligament-like fibroma. The signal intensity of all the 10 masses was heterogeneous. The fibrous components of the tumors showed low signal intensity on T1 and T2WI images as well as on contrast enhancing MR scans. The non-fibrous compo nents of the tumors demonstrated the same signal intensity as that of the muscles on T1WI images,while higher than that of the muscles and lower than that of the fat on T2WI images,and remarkably enhancd on postcontrast images. In 2 of the 9 cases with aggressive fibromatosis lesions,the one in the neck involved extensively its adjacent muscles and the other lesion in the shoulder invaded part of the medial edge of the right scapula. Conclusion： Although desmoids showed some similarity in MR signal intensity with that of the malignant soft tissue tumors,yet their fibrous components showed low signal intensity on T1 and T2 WI images as well as on postcontrast scans. This MR feature provided evidence for the differentiation of extra-abdominal desmoids from malignant soft tissue tumors.