胆总管腺瘤的CT及MRI表现

CT and MRI findings of common bile duct adenoma

目的探讨胆总管腺瘤的CT及MRI特征表现,增加对胆总管腺瘤的认识,提高诊断准确率。方法回顾性分析经手术和病理证实的17例胆总管腺瘤的CT及MRI资料,所有患者均行CT平扫与增强扫描,10例同时行MRI平扫与增强扫描。结果 17例中9例为绒毛管状腺瘤,5例为绒毛状腺瘤,3例为管状腺瘤;其中5例位于胆总管上段,9例位于胆总管下段,3例范围弥漫;17例病灶中14例为局限性软组织影,呈偏心性膨胀性生长或局部呈胆管内铸型改变,3例为弥漫片絮状影。病变CT平扫均为等密度,增强扫描15例中度强化,2例轻度强化;MRI病例T1WI为等或略低信号,T2WI呈高信号7例、等信号3例,DWI(b=600)均为高信号;17例中12例病灶呈不规则形,5例呈类圆形。17例均伴有胆总管扩张,且相应的胆管壁未见明显局限性增厚,5例伴有结石者,结石均位于病变上部。结论胆总管腺瘤具有一定的影像学特征,掌握这些CT及MR表现有助于提高诊断的准确性。

Objective To explore CT and MRI fingdings of common bile duct adenoma in order to increase the under- standing of common bile duct adenoma and to improve its diagnostic accuracy. Methods Clinical data and findings of CT and MRI in 17 patients with pathologically confirmed common bile duct adenoma were reviewed retrospectively. Abdominal no-enhanced and enhanced CT scans were berformed in all cases, and 10 of whom underw-ent no-enhanced and enhanced MRI. Results 9 of the 17 cases were tubular villous adenoma histopathologieally, 5 villous adenoma and 3 tubular adeno- ma. 5 cases located in the upper section of common bile duct, and 9 cases located in hypomere common bile duct, in addi- tion, 3 cases located in the wide range of extrahepatic biliary. 14 cases of all displayed the limitations of soft tissue shadow and showed partial decentered expansion growth or local mold change in the bile duct, however, 3 case were diffusety floc- culent shadow. All lesions on CT scan were isodensity, and 15 cases were moderate reinforcement on enhanced CT scan, only 2 cases were slight reinforcement. Cases of MRI were isointensity or slightly low signal intensity on T1WI, and high signal intensity appearea in 7 cases, isointensity in 3 cases on T2 WI. All lesions were demonstrated with a hyperintense on DWI （b= 600）. 12 lesions were presented with an irregular margin, and 5 with nearly round margin. Bile duct dilatation was found in all cases, and corresponding partly thickening bile duct wall were not found. 5 cases were accompanied by bile duct stones that were located in the upside of the lesions. Conclusion Common bile duct adenoma has certain imaging characteristics, and to master the CT and MRI fundings is helpful to improve the accuracy of diagnosis.