以往消化道疾病的诊断主要依靠消化内镜和钡餐造影， 80年代中期，内镜超声检查术 (endoscopic ultrasonography,EUS)问世以来提高了对上消化道疾病的诊断水平 [1]。尽管如此，仍有部分上消化道疾病难以明确诊断，如食管腔狭窄、上消化道小隆起性病灶及静脉曲张等。 90年代初， In the past, the diagnosis of digestive diseases mainly relied on digestive endoscopy and barium meal imaging. In the mid-1980s, the diagnosis of upper gastrointestinal diseases was elevated since the advent of endoscopic ultrasonography (EUS) [1]. Nevertheless, there are still some difficult diagnosis of upper gastrointestinal diseases, such as esophageal stenosis, upper small intestinal mucosal lesions and varicose veins. In the early 90s,