Abstract
The diagnostic ability of endoscopic ultrasonography (EUS) in chronic pancreatitis was investigated in this paper. Subjects were 52 cases with chronic pancreatitis as which were diagnosed by ERCP. These cases were classified into two groups, namely, the first group (40 cases) and the second group (12 cases) on the basis of the diagnostic criteria of ERCP in chronic pancreatitis. At first, the author compared the diagnostic ability of EUS with that of conventional US in the first group. As the results, an accuracy rate of EUS in chronic pancreatitis was highly superior to that of conventional US. Furthermore, the findings of unevenness of internal echo and irregularity of the margin of the pancreas in this group, which were not included now in the diagnostic criteria by conventional US, were more often demonstrated by EUS. Concerning the change of internal echo pattern, this could be classified into three types according to EUS findings. Namely, high echo spots, high echo spots combined with low echoic areas and diffuse low echo were the characteristic findings of chronic pancreatitis in EUS, and these echographic changes were quite different from changes by aging. Concerning the pancreatic margin as visualized by EUS, the change in moderate grade was thought to be a typical finding of chronic pancreatitis. Therefore, the author thought that changes of the internal echo and the margin of the pancreas could be very important findings in the diagnosis of chronic pancreatitis on the occasion of using EUS. In the second group of chronic pancreatitis in which clear diagnostic criteria are not made echographically, the same results mentioned above were obtained. Changes of internal echo of the pancreas were investigated histologically in 11 cases by using autopsy and postoperative specimens. As the results, high echo spots demonstrat-ed by EUS in chronic pancreatitis was consistent with fatty tissue between pancreatic lobules, and low echoic areas corresponded to lobular fibrosis. High echoic area and gathering of linear echo which were characteristic findings demonstrated by EUS in the investigations of aging corresponded to the fatty tissue between the lobules in the former and to the deformed pancreatic ductules in the latter. In conclusion, EUS was highly appreciated as one of the useful procedures in the diagnosis of chronic pancreatitis. Furthermore, it was thought that the changes of internal echo and the margin of the pancreas as visualized by EUS should be added in the echogra-phic criteria in the definite diagnosis of chronic pancreatitis.
