Table 2

Bile duct wall structure on intraductal ultrasonography (IDUS) findings and final diagnosis

	*Final diagnosis
Morphology on IDUS	Malignant	Benign	Total
^aOne with tumour forming pancreatitis.
*The process of final diagnosis is shown in table 4.
Wall structure
Preserved	11	17	28
Interrupted	33	1^a	34