The Characteristic and Diagnosis of Chronic Pancreatitis in Endoscopic Ultrasound

Purpose: The purpose of our study was to character the feature of CP and to diagnosis of CP by EUS (endoscopic ultrasound) with good resolution and whole pancreas scanning potential. Material and methods: 30 cases of CP patients were examined by EUS from 9 2003 to 9 2004 with the Olympus EU-M30 and GF-UM200. The size of pancreas, the boundary, echo, pancreatic ducts, the diameter of common bile duct, side ducts, pancreas stone, pancreas albumen thrombosis, cysts were recorded. The control group was 30 cases with small polyps of stomach and esophagus.

Results:

• Size: There is difference between controlled and case group.

• 20 kinds of tiny structures changes were detected by EUS, including pseudocyst, stone, calcification, larger or atrophy size, illegible edge, X-ducts show in the uncinate process, side ducts branch, uneven echo in the dorsal anlage, abnormal echo mass, loss of the ventral/dorsal distinction, hyperechoic foci and strands, lobularity, inhomogeneity, reduced echogenicity diffusely, local hyperecho, local hypoecho, hyperechoic duct wall, the dilation of the duct, ducts illegible dilatation.

• Cyst, stone, calcify were detected in the CP group only. There is a different sensitivity and specificity from 40%-100% in others criteria. The diagnostic sensitivity and specificity in only five marked items (inhomogeneity in dorsal pancreas, dilated or illegible main ducts, wavy or illegible edge, larger or atrophy size, abnormal echo mass) are more than 50%. By using any 2 in 5 items, diagnostic sensitivity and specificity is the highest, the accuracy of the diagnosis is 96.7%. It was much higher than the criterions only using pseudocyst, calcification and stones.

Conclusion: EUS is the best imaging modality for the size of the pancreas, ducts, parenchyma and tiny structures. And early stage of CP can be diagnosis by the abnormal tiny structures change that cannot detect by other methods.