What are the cross sectional imaging features that are helpful to distinguish pseudomembranous colitis from other forms of colitis?
Cross sectional Imaging Features Suggestive of Pseudomembranous Colitis
|Wall thickening||Generally greater in degree than any other inflammatory or infectious disease of the colon, save Crohn’s disease. Of note, wall thickening in pseudomembranous colitis is asymmetric and irregular compared to that of Crohn’s disease, which is generally symmetric and homogeneous. When severe, trapping of barium within thickened haustral folds produces the “accordion” sign (see Figure 27-7 ).|
|Distribution||Classically seen as a pancolitis from rectum to cecum, although it can also present with a segmental distribution.|
|Bowel enhancement pattern||“Target” sign may be present, although this may also be seen with other colitides.|
|Luminal dilation||Thought to reflect transmural inflammation.|
|Pericolic fat stranding||Generally mild relative to the degree of wall thickening, but may also be seen with other colitides.|