EUS in the Diagnosis of Chronic Pancreatitis

Jian-Wei Zhu，Fei Jiang，and Zhen-Dong Jin

Chronic pancreatitis（CP）is a progressive and irreversible inflammation of the pancreatic gland caused by pathologic impairment that leads to morphological changes of parenchyma and duct，ultimately resulting in morphological alterations and exocrine as well as endocrine dysfunction（Seicean 2010；DiMagno and DiMagno 2010）.Its main features are pancreatic fibrosis，inflammatory infiltration，atrophy，calcification，internal and external secretory tissue destruction.The early symptom is abdominal pain，and in advanced stages，patients suffer from diarrhea，weight loss，absorption or malnutrition，diabetes mellitus，and calcification.At present，diagnosis of CP is based on the clinical symptom and imaging examination.Thus most patients are in advanced stage when diagnosis is made.Hence，diagnosis of early stage CP remains a challenge.(https://www.daowen.com)

Abdominal ultrasonography，CT and Endoscopic retrograde cholangiopancreatography（ERCP）can display parts of CP characteristic changes.But these tests have their own drawbacks.ERCP diagnoses of CP rely on main ductal or side branch change and ductal stone，with high accuracy.But it is not recommended due to the possible and serious complications related to the procedure and the fact that the parenchyma is not visualized（Choueiri et al.2010）.Since the clinical application of endoscopic ultrasonography（EUS）in 80s，it provides a new valuable method for the diagnosis of CP，especially for earlier diagnosis.EUS with high resolution ultrasound probe，allows closely observe the pancreas，so that small changes of the pancreatic parenchyma or duct can be found（Wang et al.2009b）.Compared with other imaging or functional test，EUS may be more earlier or clearly to display subtle changes in parenchyma and duct system，whichhas higher clinical value in the early diagnosis of CP（Hernandez and Catalano 2010）.