孤立性纤维瘤的影像学诊断和鉴别

Solitary fibrous tumor:the imaging diagnosis and differential diagnosis

目的:分析孤立性纤维瘤CT、MR平扫和增强的影像学表现,探导其影像学诊断价值。方法:回顾性分析8例经手术病理证实的孤立性纤维瘤病例,7例术前经螺旋CT或多层螺旋CT平扫或增强检查,1例经MR动态增强检查。所有病例影像资料均经3名高年医师分析阅片,分别确定病灶境界、大小、密度和强化程度等,并与手术病理进行对照。结果:8例孤立性纤维瘤病例中,位于胸部4例,四肢2例,腹腔1例,盆腔1例。肿瘤直径4.0～22.5cm,<5cm1例,5～10cm3例,>10cm4例,平均9.3cm。边缘光滑,境界清楚。瘤体呈圆形或椭圆形5例,梭形3例;5例肿瘤密度相对均匀或略不均匀,内可见两种明显不同密度的实质成分。3例可见不规则坏死区,坏死面积相对很小。较小病灶形态规则,巨大病灶多呈分叶状。CT增强病灶呈地图样强化和匐形线条样强化,动脉期轻微强化～显著强化,门脉期持续强化,强化趋于均匀。MRSET1WI呈等信号,T2WI为略高信号,T2WI脂肪抑制为高信号,MR动态增强强化显著。结论:SFT典型影像学表现包括:肿瘤密度相对均匀,境界清楚,瘤内常见两种不同密度的实质成分,MRT2WI多表现为略高信号中夹杂片状低信号区,动态增强强化差异大。

Objective：Exploring the CT and MRI findings of solitary fibrous tumor and evaluating it＇s clinical value. Methods：All 8 cases of patients with solitary fibrous tumor confirmed by surgical pathology underwent CT and MR plain scanning and multi-phases dynamic enhancement scanning before operation, the imaging data was reviewed and analysed retrospectively in comparison with surgical and pathological resuhs. Results：4 of 8 patients with solitary fibrous tumor were located in the chest, 2 in the four limbs, 1 in intra-abdominal and 1 in the pelvis. The average tumor size was 9.3 cm （range, 4.0 - 22.5cm） with 1 case 〈 5.0 cm, 3 cases 5.0 - 10.0 cm and 4 cases〉 10 cm. The tumor presented round or ellipse in 5 cases and shuttle shape in 3 cases with well-defined margins and smooth contours. At unenhanced CT, they showed relatively homogeneous attenuation in 5 cases which strikingly demonstrated two different solid components and inhomogeneous attenuation in 2 cases. Typical features of small lesions were well-defined margins and smooth contours, larger lesions were characterised by well-defined margins and lobulated contours. At contrast enhanced CT, they were inhomogeneous with geographic pattem, serpiginous linear areas of enhancement with irregular small areas of low attenuation （necrosis）. On MRI, homogeneous isointensity on T1-weighted images, hyperintense on STIR images and intense enhancement on postcontrast were seen. Conclusion： The typical image findings of solitary fibrous tumor show relatively homogeneous attenuation strikingly demonstrating two different solid components with well-defined margins and smooth contours.