ENDOSCOPIC ULTRASONOGRAPHY (EUS) IN THE DIAGNOSIS OF ULCERATIVE COLITIS

Abstract

Total 30 endoscopic ultrasonography (EUS) were performed in 13 patients with ulcerative colitis (UC), using the specially designed echo -colonoscope system developed by Olympus Co. The normal colorectal wall was clearly visualized by EUS in five -layered structures as we have already reported. The ultrasonograms of UC in active stage showed hypoechoic changes of the colorectal wall, especially in the mucosal layer or in both mucosal and submucosal layers. These EUS changes of the wall recognized in a ctive UC usually disappeared or normalized in the stage of remission. When the state of UC exacerbated the hypoecholc changes of the wall seemed to be widened from the mucosal to submucosal layer with the increase of the wall thickness. These EUS images of UC were classified into three types ; type 1 showed no changes of the wall, type 2 demonstrated the hypoechoic changes of the 1st layer and the thickening of the 2nd layer, and type 3 manifested the hypoecholc changes with unclearness of boundary from the 1st to 3rd layer. The changes of EUS images of UC also corresponded with Matts' endoscopic grad es and the clinical severity of Truelove and Witts . In addition, we tried to make an EUS criteria for a better understanding of clinical severity of UC as an inflammatory volume ; we judged an affected location of the disease in horizontal direction with the aid of endoscopy in EUS and inspected the depth of inflammation in vertical direction by ultras onography in EUS. By introducing this new dimension, we were able to recognize the degree of inflammation in UC as the volume and it became possible to understand the cli nical severity of the disease more precisely. From these results, it is apparent that EUS is a valuable method in the diagnosis and therapy of UC.