强化异常表现
泛影葡胺增强扫描——平扫时显示的各种密度 结石均无增强；肝内外胆管扩张显示为无强 化的低密度影，管壁明显强化；胆囊癌、胆 管癌表现为轻。中度强化。 胆影葡胺增强扫描——胆结石、胆囊癌、胆管 癌均表现为相应部位的充盈缺损。肝内外胆 管扩张表现为增宽、迂曲呈蚯蚓状的高密度 影。
胆囊变异
• • • • 胆囊缺如 双胆囊 折叠胆囊 胆囊异位：肝内胆囊；左叶胆囊；肝后 胆囊；漂浮性胆囊或胆囊扭转
正常肝内胆管
• 正常肝内胆管与门静脉分支伴行，呈放 射状分布； • 肝内胆管在肝门区以远一般不可见；通 常只有很少部分肝内胆管影在肝门区可 见，且呈散在分布； • 在分辨力强的增强扫描CT上，小部分人 可以看见低密度的肝内胆管影1-3mm宽
正常肝外胆管
• 肝总管：壁厚小于1.5mm，直径3-5mm； 66%的人可以显示，位于门静脉主干的 前外侧 • 胆总管：壁厚1.5mm，直径3-6mm，长度 1.5mm 3-6mm 大约4-8cm，82%的人可见胆总管影，分 为上、中、下三段。 • 胆总管与门静脉关系恒定-由上至下。前 外、外、后外
Fig. 6: MR Cholangiography shows the cyst medial to the gall bladder with dilated left hepatic duct.
Fig. 7: MR Cholangiography demonstrates the choledochal cyst and the ectatic left hepatic duct leading to normal common hepatic duct (arrowhead).
平扫正常表现
胆管——平扫肝内胆管通常不能显示。肝 总管位于肝门区，呈圆形低密度影，胆 总管胰头上段及胰头段分别位于胰头上 区域和胰头内后方，呈圆形低密度影。 胆囊——横断面上呈卵圆形，位于方叶下 方的胆囊窝内。内容物为水样密度，囊 壁厚约2mm.
平扫异常表现
形态及大小异常：胆管结石或肿瘤可致梗阻 近端的胆管扩张，肝内胆管扩张表现为肝内 增宽、迂曲的条状、树枝状低密度影，从肝 门向肝的外周延伸。胆总管直径超过1cm为胆 总管扩张。胆囊增大可为胆总管下端结石或 肿瘤、胆囊扩张所致。 密度异常：胆囊、胆管结石表现为相应部位 的高密度影，呈类圆形，边界清楚。软组织 密度影可见于胆囊息肉、胆囊癌、胆道癌及 泥沙状结石。
The origin of these cysts is uncertain. The most likely etiology is bile duct injury resulting from sequelae of an anomalous junction of the pancreatic duct and the distal common bile duct (CBD) . This anomalous junction results in chronic reflux of pancreatic enzymes into the biliary tree with resultant weakening, scarring and dilatation of the CBD wall. Anomalous junction is found in 1058% of cases with choledochal cysts
胆道先天异常
-先天性肝内胆管囊样扩张(caroli disease)
[影像学表现] X线：X线平片可见肝内多发小结石；PTC可显示 肝内胆管呈囊状扩张，左右肝叶均可受累，胆总管亦 有扩张，但无明显阻塞。 CT：肝内胆管囊状扩张，多呈节段性分布，平扫 表现为分界清楚的条状、分支状低密度影，其内高密 度影则为胆管内结石。增强扫描病变无强化，但注射 胆影葡胺后病变成为分支状高密度影，可解释它与胆 道系统的从属关系。
Fig. 3: US shows the dilated, tortuous and ectatic left hepatic duct.
Fig. 4: CECT demonstrates a large cyst lying medial to gallbladder.
Fig. 5: CECT shows the dilated, tortuous and ectatic left hepatic duct (similar to Fig 3) with minimal dilatation of intrahepatic biliary radicles.
The fibrovascular bundles containing portal vein radicals and a branch of the hepatic artery bridging the saccule appears as a central dot or a linear structure on CT, enhancing with contrast. This "central dot sign" described on CT can be easily seen on ultrasound. In Caroli's syndrome both CT and ultrasound show focal mild dilatation of intrahepatic bile ducts (2-3 mm). The liver shows changes of portal hypertension (shrunken liver, splenomegaly, splenic and esophageal varices and ascites).
常见疾病
1、胆道先天异常 2、胆囊炎 3、胆囊结石 4、胆道梗阻
胆道先天异常
-先天性肝内胆管囊样扩张(caroli disease) caroli病包括肝内胆管扩张、肝硬化门脉高压 和囊性改变一组综合征，可单独存在或与胆 总管囊肿并存。本病非常罕见，主要见于儿 童和青年。病理上表现为肝内肝管囊性扩张 ，囊壁与肝胆管主支相通，形成交通性胆汁 囊肿。临床上可出现腹痛、发热、黄疸。
Etiology: Unknown. The theory proposed by O’Neil There are many theories that try to explain the etiology of the choledochal cyst: •Embryologic anomalies of the growth of the hepatic diverticulum]. •Obstruction of the distal common bile duct during fetal development resulting in weakness of the choledochal wall which responsible for the development of the choledochal cyst. This obstruction could be due to: -congenital stenosis, -persistence of epithelial membrane, -abnormal valves -neuromuscular incoordination of the sphincter or -agangliosis of the distal bile duct. •The choledochal cyst could also be due to an anomalous arrangement of the pancreatic or biliary duct system. An abnormal angle of entry of the pancreatic duct into the ampulla of Vater could allow pancreatic enzyme reflux to reach the common bile duct, causing some damage to it in utero. This theory is being abandoned because the choledochal cyst can be diagnosed before the exocrine function of the pancreas begins
强化正常表现
泛影葡胺增强扫描——若肝内胆管不扩张，一 般不能显示，或显示为规则细小的树枝状低密 度影，与门静脉伴行，从肝门向肝周延伸，由 粗到细。肝外胆道显示为圆形低密度影，胆道 壁可强化，使胆道影更清晰。胆囊壁强化，胆 囊内液体不增强。 胆影葡胺增强扫描——胆道及胆囊内充盈对比 剂，呈高密度影像。
胆系疾病
应用解剖
大体解剖 断层解剖 影像解剖
大体解剖
Hale Waihona Puke 断层解剖影像解剖影像分析
主要是分析横断层面上各组织结构及 病变的形态、大小、密度、
部位、边缘轮廓，以及病变对血管
结构的侵蚀、压迫等
• 胆管系统按解剖部位划分为肝内胆管和 肝外胆管，肝外胆管包括部分左、右肝 管及其汇合成的肝总管，以及其下行与 胆囊管联合后的胆总管及胆囊。
Fig. 8: Peroperative photograph shows choledochal cyst, gall bladder and the cystic duct. Fig. 9: Photograph of resected specimen shows choledochal cyst, gall bladder and the cystic duct.
先天性胆总管囊肿 (choledochal cyst)
胆总管囊肿系先天性胆管壁层发育不全所致 ，表现为胆总管呈梭形扩张，末端狭窄或胆 总管呈憩室样膨出。囊性扩张可涉及胆总管 的一段或全部，亦可位于胆囊管、肝管与胆 总管连接处。本病多见于儿童，临床上可出 现黄疸、腹痛，有时可在右上腹扪及包块。