十二指腸乳頭部癌の診断―CT，MRCP，血管造影などの画像診断

Carcinoma of the Duodenal Papilla: Evaluation with MR Cholangiopancreatography, CT and Angiography

要旨　十二指腸乳頭部癌の画像診断の主役は内視鏡と内視鏡的超音波診断法である．しかし，リンパ節腫大や血管浸潤ならびに胆管・膵管浸潤などの進展度診断には，CTやMRCPおよび血管造影が診断に役立つこともある．MRCPは従来の胆管・膵管の診断法であった内視鏡的逆行性胆管膵管造影（ERCP）と異なり，全く非侵襲的に胆管・膵管像を得る方法であり，術者の技量に左右されないため容易に施行でき，特にERCPの施行困難な乳頭部に大きな腫瘤を形成し，胆管・膵管が完全に閉塞している場合にも，胆管膵管の全体像を得ることができるため，本症の診断に貢献すると考えている．

　Endoscopy and endoscopic ultrasonography play the leading part in the image diagnosis of carcinoma of the duodenal papilla. Furthermore, CT, MR cholangiopan-creatography (MRCP) and angiography can support the diagnosis of presence/absence of lymphadenopathy and invasion to the pancreaticobiliary ductal systems or major vessels. MRCP is a promising method of depicting the biliary tree and the pancreatic duct easily and noninvasively, and successful imaging does not depend on the operator in contrast to that with endoscopic retrograde cholangiopancreatography (ERCP). Especially, MRCP can provide important diagnostic information in patients with the carcinoma of the duodenal papilla for whom diagnostic ERCP may be unsuccessful or inadequate because the huge tumor mass causes complete obstruction of both the pancreatic and biliary ducts.