電腦斷層攝影對阻塞性膽道疾病的診斷

The Role of Computed Tomography in Biliary Tract Obstruction

潘慧本(Huay-Ben Pan) ； 姜仁惠(Jen-Huay Chiang) ； 刁翠美(Chui-Mei Tiu) ； 張晉民(Jinn-Ming Chang) ； 周宜宏(Yi-Hong Chou) ； 蔡養德(Yang-Te Tsai) ； 雷永耀(Wing-Yin Lui)

《中華放射線醫學雜誌》 14卷1期 (1989/03) Pp. 23-29

摘要

近年來例行使用多種檢查方法來診斷阻塞性膽道疾病已成一種趨勢。我們統計70名阻塞性膽道病例所作過之電腦斷層攝影(CT)檢查認為以直接證據如腫塊或結石的發現來探索膽道阻塞的原因是最直接最有效的方法。CT者發現腫塊即判讀為惡性致因者其準確率可達91.4%；敏感度及特異性各為93.7%及86.4%。假陽性13.6%係慢性胰臟炎造成，假陰性6.3%係小於2cm或以浸潤方式生長於華氏壺周圍的癌症所致。CT對結石的敏感度為78.6%，特異性100%、準確率95.7%。掃描不到的3例總膽管結石都發現有膽囊結石存在，可供參考。CT未發現腫塊或結石之存在，結果真正無阻塞物而純為炎性狹窄的陰性預測率只有45.6%。由CT的間接證據如膽管的阻塞水平位置；肝外總管口徑變化；肝內膽管漲大的程度及臨床黃疸的有無等資料顯示得知：不管有無腫塊的發現，膽道在肝門高度阻塞者，除可見結石外，95.7%為惡性致因；反之，良性致因之阻塞多發生在總膽管段且無胰管漲大(82%)；總膽管口徑突然改變時，應考慮有阻塞物(76.5%)特別是腫瘤的存在，總膽管漸進性變小較不具特異性：因良性病變而造成肝外膽管阻塞時很少發生嚴重的肝內膽管漲大現象，反之亦然臨床上無黃疸而CT檢查無腫塊發現時考慮良性生致因。

關鍵字

阻塞性膽道疾病 ； 電腦斷層攝影

並列摘要

A retrospective study in 70 patients with obstructive biliary disease using computed tomography was performed. We found the presence of tumor mass or stone was the most direct and effective sign in evaluating the etiology of obstruction. The accuracy in reaching the diagnosis of malignancy by the presence of a mass alone was 91.4%. The sensitivity and specificity were 93.7% and 86.4% respectively. While the false negative result of 13.6% was caused by 3 patients with chronic pancreatitis, the false negative result of 6.3% was caused by 3 patients with either lesions smaller than 2mm in size or the presence of infiltrative periampulla vata cancer. The identification of stone by CT had an accuracy of 95.7%, specificity, 100% and sensitivity, 78.6%. Three patients with common bile duct stones missed by CT had gall stones which could give a clue for presence of biliary stones. When CT showed no evidence of tumor mass or stone, whereas the patient did have benign stricture from inflammatory process, then the predictive value negative was 45.5%. From some indirect CT signs, such as the level of obsturction, change in the caliber of the common duct, degree of dilatation of the intrahepatic ducts and clinical presence/absence of jaundice, we concurred that whether with the mass presentation or not, 95.7% of obstructions at hepatic hilar level with the exception of visible stones where due to malignancy. Although tappering change in the caliber of the common duct has no specification for differentiation, abrupt changes where mostly due to the presence of obstacle (76.5%) especially from tumor. A benign cause often had obstruction located in the common duct without pamuneatic duct dilatation (825), white caurijg extrahepatic duct dilatation, seldom bad, severe intrahepatic duct dilatation. In the non-jaundice biliary dilatation cases with absence of mass, a benign cause should be taken into consideration.

並列關鍵字

obstructive biliary disease ； computed tomography ； CT