對於膽胰道疾病的診斷，目前最常用的檢查不外乎超音波、電腦斷層掃描、以及經內視鏡逆行性膽胰管攝影 術(ERCP)。但超音波和電腦斷層掃描對總膽管結石的敏感度太低，而ERCP 又可能產生膽管炎與胰臟炎等併發 症；所以，我們需要一種新的、安全性高且敏感度高的診斷技術，而有鑑於此核磁共振膽胰道攝影術(MRCP)的 發展就成為了重要的檢查利器。MRCP 對於總膽管結石和膽管擴張，其敏感度(sensitivity)達100%；對膽管阻塞 診斷的正確率達94%；對惡性腫瘤引起的膽管狹窄則有86%的正確率；同時MRCP 可以清楚地看到阻塞點的近 端膽管，而ERCP 則通常看不到阻塞點的近端部份，這是MRCP 的另一優點。另外MRCP 對胰管擴張診斷的敏 感度達87~100%，而對胰管狹窄則有75%的敏感度。最後在一些開過胃或十二指腸手術的病人，ERCP 有其困難， 但MRCP 則已有研究證實可以成功應用在這些病人的診斷。不過許多年長的病患或者是插管氣切的病患，抑或 是緊張過度無法聽從指示的緊張型病患往往無法配合臨床檢查的需求，以至於檢查效果大打折扣甚至是無法完 成。本研究計畫預計利用導航式觸發(Navigator trigger)這方式讓病人可以在不受限制的自由呼吸下完成MRCP 的 檢查。然後根據病人每次吸氣和呼氣的中間採集訊號，並且搭配偵測儀器限縮在橫膈上下起伏的一定範圍內收集 訊號。如此一來可以大幅避免病人因呼吸造成的影像模糊，即便是意識不清的病人也可以透過此技術得到優良的 診斷影像。

For disease of biliary system, there are many diagnostic tools we can use, including sonography, CT scan, MRCP (Magnetic Resonance Cholangiopancreatography) and ERCP (Endoscopic Retrograde Cholangiopancreatography). However, the sensitivity of sonography and CT scan for biliary disease is low and ERCP is an invasive procedure, which may have complications, such as cholangitis or pancreatitis. ERCP is also not suitable in post gastric or duodenal surgery patients. MRCP is a non-invasive diagnostic tool and without contrast medium needed. It has been proved to have high sensitivity and accuracy for biliary tree disease in much literature. The sensitivity of MRCP for detection of CBD stone and biliary tree dilatation is 100%. The accuracy for malignancy related biliary stricture is 86%. However, the disadvantage of MRCP is requirement for good breath-holding and usually the imaging quality is poor in uncooperative patient. Recently, there is a new MRCP technique called "navigator trigger" developed by PHILIPS and installed in our new MRI (Ingenia 1.5T MRI). The method "navigator trigger" is the position of the diaphragm is detected with a navigator pulse, and signal acquisition is gated to the most stable portion of the respiratory cycle. Using this technique, the imaging acquisition can be obtained without breath-holding and the imaging acquisition duration is no longer limited by breathing-holding. Therefore, it is widely used in neonate, child and elderly. The purpose of our study is to compare the imaging quality of MRCP obtained of two kind of techniques, one is conventional breath-holding method and the other is newly developed "navigator trigger" method. The MRCP will be performed on our newly installed MRI system "PHILIPS Ingenia 1.5T" and the results will be interpreted by two radiologists specialized in abdominal imaging. Patients with permanent pacemaker, aneurysm clips, claustrophobia or other contraindications are excluded from this study.