胆囊腺瘤及其局部癌变的MRI诊断

MRI Diagnosis of Gallbladder Adenoma and Partial Malignant Transformation

目的 探讨胆囊腺瘤（AG）及其局部癌变的MRI特征,以提高对该类疾病的诊断水平。方法 回顾性分析经手术病理证实的18例AG患者的MRI资料,其中5例局部癌变。由2名高级职称影像诊断医师分别独立进行图像分析,观察肿瘤的部位、数量、大小、形态、信号、强化程度、肿瘤与胆囊壁的关系及伴随情况。结果 18例中位于胆囊体部10例,底部7例,颈部1例;单发病灶15例,多发3例。13例AG中,最大径〈0.5 cm 2例,均呈乳头状,表面光整,动脉期呈轻度均匀强化。0.5-1 cm 4例,乳头状和椭圆形各2例;表面光整1例,表面不光整并桑葚征3例;动脉期轻度均匀强化1例,中度均匀强化3例。〉1 cm 7例,乳头状1例,椭圆形和菜花状各3例;表面均不光整,并可见桑葚征;增强扫描动脉期中度均匀强化6例,明显强化1例。所有病灶均为窄基底,在T1WI和T2WI上为均匀等信号。5例AG局部癌变病灶（大小？）,椭圆形1例,菜花状4例;边界光整1例,表面不光整并桑葚征4例;窄基底2例,宽基底3例。在T1WI和T2WI上均为均匀等信号;增强扫描动脉期明显均匀强化2例,明显不均匀强化3例。附着处胆囊壁局限性增厚3例,侵犯肝脏1例。结论 胆囊内窄基底肿块伴桑葚征,应考虑AG的诊断;若病灶局部基底增宽、桑葚征减少、明显不均匀强化、附着处胆囊壁局限性增厚或周围组织侵犯,需考虑AG癌变的可能。

Objective To evaluate the MRI features of gallbladder adenoma（AG） and partial malignant transformation in order to improve the diagnosis level. Methods The MRI data of 18 patients with AG were retrospectively analyzed, which including 5 partial malignant transformation. All cases were proved by surgery and pathological examinations. Two senior radiologists independently analyzed the location, quantity, size, shape, signal, enhancement degree, the relation with gallbladder wall and the complication of the tumor. Results Out of the total 18 cases, 10 cases were located in the body of gallbladder, 7 cases in the fundus and one case in the neck. 15 cases were single lesion and 3 cases were multiple. For 13 AG patients, the diameters of mass were less than 0.5cm in 2 cases, and mass were all papillary with smooth mar- gin. The 2 cases showed mild homogeneous enhancement in arterial phase. The diameter of 4 cases were between 0.5 cm to 1 cm. The shape were papillary and ellipse in each 2 cases respectively. 3 cases showed rough edge with mulberry like and the edge were smooth in one case. Arterial phase showed mild homogeneous enhancement in one case and moderate homo- geneous enhancement in 3 cases. The diameters of 7 cases were more than lcm with papillary in 1 case and ellipse and cau- liflower like in 3 cases respectively. All these 7 cases showed rough edge with mulberry like. Arterial phase showed mild homogeneous enhancement in 6 cases and obvious enhancement in one case. Homogeneous isointensity showed on plain MRI with narrow base in all cases. For 5 patients with partial malignant transformation, the shape were ellipse in one case and cauliflower like in 4 cases. 4 cases showed rough edge with mulberry like, and smooth edge were showed in one case. 2 cases were narrow base and 3 cases were wide base. Homogeneous isointensity showed on plain MRI in all 5 cases. 2 cases showed obvious homogeneous enhancement in arterial phase and 3 cases showed obvious heterogeneous enhancement. The attachment of the wall of gallbladder was locally thickened in 2 cases and liver involved in one case. Conclusion Gall bladder adenoma should be considered in the mass of narrow base with mulberry like. If the base of the mass become widen locally, the mulberry like sign decrease, the enhancement become obvious heterogenenus, and the attachment of the wall of gallbladder thicken locally or the adjacent tissues be invaded then partial malignant transformation should be considered.