山田 至人¹, 木田 光広¹, 坂口 哲章¹, 野登 誠¹, 西元寺 克禮¹, 大宮 東生²

Yukihito YAMADA¹, Mitsuhiro KIDA¹, Tetsuaki SAKAGUCHI¹, Makoto NOTO¹, Katsunori SAIGENJI¹, Harumi OHMIYA²

¹北里大学消化器内科, ²北里大学外科

¹Department of Internal Medicine, Kitasato University, School of Medicine, ²Department of Surgery, Kitasato University, School of Medicine

キーワード : Endoscopic Ultrasonography, Ordinary Ultrasonography, Extra hepatic bile duct cancer, Imaging diagnosis

The diagnostic accuracy of US, ERCP, PTCD, CT and EUS in extra hepatic bile duct (EHBD) cancer was investigated. We focused especially on the imaging of US and the imaging of EUS compared with that of other imaging diagnosis methods. Fifty-two subjects were studied. Diagnosis for these cases were as follows; hilus of EHBD (Bh), superior portion of EHBD (Bs), middle portion of EHBD (Bm), and inferior portion of EHBD (Bi) in 20, 10, 9 and 13 cases, respectively.
By US findings, the tumor margin of the EHBD cancers was unclear (86%), and the echo level was isoechoic(35%) or hypoechoic (60%). In addition, the echo pattern was almost heterogeneous (86%). The detection rate of the tumor was 85%, 70%, 78% and 83% in Bh, Bs, Bm and Bi, respectively.
The diagnostic accuracy rate for imaging diagnosis was 65%, 88%, 88% and 37% by US, ERCP, PTCD and CT, respectively. The accuracy and the detection rate of extra ductal invasion of EUS were compared with those of US and CT in 8 resected of the above-cases. The diagnostic accuracy rate of pancreas invasion was 50%, 25% and 25% by EUS, US and CT, respectively. However, there was no difference in the diagnostic accuracy rate of other histopathological findings between EUS and other imaging diagnosis techniques.
To investigate the differential diagnosis of Bi cancer and pancreas head (Ph) , 8 cases of Bi cancer and 14 cases of Ph cancer were studied. The correct diagnosis ratio of EUS 100%, but other total imaging diagnosis were 75% and 93% in Bi cancer and Ph cancer, respectively. EUS is one of the most useful diagnostic methods in EHBD cancer and differential diagnosis of Ph cancer.