臨牀消化器内科 Vol.18 No.8(8)


特集名 胆道癌診断の現状と展望 -- 肝外胆管を中心に
題名 EUSおよびIDUSによる胆道癌の診断
発刊年月 2003年 07月
著者 村上 正哲 広島大学大学院医歯薬学総合研究科 創生医科学専攻先進医療開発科学講座 分子病態制御内科学
著者 佐々木 民人 広島大学大学院医歯薬学総合研究科 創生医科学専攻先進医療開発科学講座 分子病態制御内科学
著者 桑原 健一 広島大学大学院医歯薬学総合研究科 創生医科学専攻先進医療開発科学講座 分子病態制御内科学
著者 宮田 英樹 広島大学大学院医歯薬学総合研究科 創生医科学専攻先進医療開発科学講座 分子病態制御内科学
著者 芹川 正浩 広島大学大学院医歯薬学総合研究科 創生医科学専攻先進医療開発科学講座 分子病態制御内科学
著者 茶山 一彰 広島大学大学院医歯薬学総合研究科 創生医科学専攻先進医療開発科学講座 分子病態制御内科学
【 要旨 】 胆道疾患に対する内視鏡下超音波断層法には,通常の超音波内視鏡(EUS)と胆管内超音波(IDUS)とが存在する.
EUSは,体外式超音波(US)と比較して近距離から高周波数(7.5~12MHz)の超音波を使用するため,より分解能の高い良質な像が得られる.とくに,胆嚢隆起性病変の性状診断,胆嚢癌の癌壁深達度診断に大きく寄与している.
一方,IDUSは12~30MHzというEUSよりもさらに高周波の超音波を用いるため,胆管にプローブを挿入することにより,管腔,壁,さらに周囲の構造物の詳細な描出が可能となる.胆管癌のステージングにおけるその有用性は確立されたものとなっている.
Theme Diagnosis of Biliary Tract Cancer -- Present Status and Perspective
Title Diagnosis of Biliary Tract Cancer Using EUS and IDUS
Author Masateru Murakami Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biochemical Research, Graduate School of Biochemical Sciences, Hiroshima University
Author Tamito Sasaki Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biochemical Research, Graduate School of Biochemical Sciences, Hiroshima University
Author Kenichi Kuwahara Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biochemical Research, Graduate School of Biochemical Sciences, Hiroshima University
Author Hideki Miyata Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biochemical Research, Graduate School of Biochemical Sciences, Hiroshima University
Author Masahiro Serikawa Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biochemical Research, Graduate School of Biochemical Sciences, Hiroshima University
Author Kazuaki Chayama Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biochemical Research, Graduate School of Biochemical Sciences, Hiroshima University
[ Summary ] Conventional ultrasonography is an initially valuable diagnostic procedure for biliary tract disorders, especially for biliary cancer. However, a differential diagnosis between cancer and non-cancerous diseases is sometimes difficult. In those cases, endoscopic ultrasonography (EUS) and intraductal ultrasonography (IDUS) provide more useful image information in confirming the diagnosis of biliary cancer. Early gallbladder cancer is classified into two types, the polypoid type and the flat type, based on morphologic features. Detailed images from EUS identify qualitative differences in polypoid gallbladder tumors, such as surface shape and internal structure. In addition, EUS clearly demonstrates the triple-layer structure of the gallbladder. The loss of those patterns in the thickened gallbladder wall is important for the preoperative diagnosis of gallbladder cancer. Bile duct cancer exhibits longitudinal spreading along the bile duct and accurate assessment of the tumorous region is essential for adequate decisions, regarding therapeutic strategies. IDUS, with a thin-caliber, high-frequency probe, may be inserted into the bile duct through the use of an endoscope or an external biliary drainage route, and has been highly-evaluated for diagnosis of biliary tract malignancy. The distinction between benign and malignant bile duct wall thickening and the assessment of longitudinal cancer extension along the bile duct are promising aspects of IDUS. Moreover, the loss of the boundary between adjacent organs is absolutely necessary for preoperative staging in bile duct cancer, in respect to invasion of the right hepatic artery, portal vein, or pancrea.
This article makes specific mention of the efficacy and problems of both types of inspection.
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