Correlation between Pathologic and Radiologic Characteristics of Ulcerative Colitis'*

MALCOLM CHAPMAN, M.D.

From St. Marh's Hospital, London, England

A STUDY has been made to correlate radi- ologic and pathologic appearances of colons removed for ulcerative colitis at St. Mark's Hospital, London, during the p, ast few years. Cases included were only those in which a roentgenologic examination after administration of a barium enema had been performed not nlore t h a n o n e m o n t l l

prior to colectomy. Radiologic appearances of dil{erent parts

of the colon, on plain abdominal and air- coHtrast films, were studied, and the fol- lowing features were observed: contour of the colon, presence or absence of haustra- tion, mucosal appearame (featureless, gran- ular or polypoid, and the presence of undercutting of the mucosal line. On an.. other occasion, the pathologic features of tile excised colon were obtained from detailed reports prepared by Dr. Basil Morson.

A granular appearance of the mucosa seen in radiograms is always associated with granularity of the mucosa in tile path- ologic specimen and is an indication of active mucosal disease. Although ulcera- tion o1! the mucosa is ahnost always pres- ent, granular characteristics observed in roentgenograms is not dependent upon its presence. Loss of haustration may be found in radiograms of a colon that lias a featureless mucosa. In such a case, patl,.o- logic examination shows an intact mucosa which is atrophic. Atrophic changes indi- {ate that there has been previous involve-

Read at the meeting of the American Procto- logic Society, Denver, Colorado, June 10 to 13, 196g.

58

ment by active colitis which has healed. Loss ot haustration, therefore, indicates that there has been mucosal involvement, but not necessarily that active mucosal dis- ease is present.

]n 30 per cent of cases with macroscopic mucosal ulceration, undercut t ing of the mucosal line was demonstrated radiologi- cally. The depth of the undercut t ing was not a reliable indication of the depth of mucosal ulceration, as described histologi- cally; and, in some cases where repeat ex- aminations had been performed after a short interval, it was not a constant feature.

Inflammatory polyposis of the colonic mucosa was detected on roentgenologic examination, either by irregularity of the margin of the colonic air shadows on plain films, or on air-contrast films, in all the cases where it was described pathologically.

The radiographic characteristics of an active mucosaI lesion are granulari ty or polyposis of the mucosa and undercut t ing of the mucosal line. These changes provide an accurate indication of the extent and nature of active colonic involvement which corresponds well with the macroscopic ap- pearance of the excised colon. In all cases of radiologically incomplete colitis (fea- tureless mucosa in the proximal co!on), the proximal colon, al though macroscopically normal, shows microscopic evidence of in- flammatory change or atrophy, indicating previous invotvemen~ that has iiealed. This observation raises the question of what is meant by use of the terms "total" and "in- complete" colitis based on radiologic observations.