title: Sonographic appearance of benign and malignant conditions of the colon.
abstract: OBJECTIVE
  The objective of this study was to compare the sonographic appearance of different abnormalities of the colon to evaluate the role of sonography in their differential diagnosis.
  
  
  METHODS
  We retrospectively reviewed videotaped sonographic examinations of 99 patients with proven diagnoses that included diverticulitis (n = 35), malignancy (n = 20), Crohn's disease (n = 16), pseudomembranous colitis (n = 14), ischemic colitis (n = 9), and ulcerative colitis (n = 5). Data were collected with regard to gut features, including the site of colonic involvement, associated small-bowel involvement, length of diseased segment, stratification, luminal contents, pneumatosis, and diverticula. Perigut features evaluated included abnormal fat, abscess, fistula, and ascites.
  
  
  RESULTS
  On sonography, the following features were statistically significant (p < .05). Involvement of the small bowel was more common in patients with Crohn's disease than in the remainder of the study population (44% versus 1%). Left-sided colonic disease (91% versus 38%), diverticula (91% versus 3%), and perigut findings (91% versus 57%), including abnormal fat (83% versus 39%) and abscess (34% versus 8%), were features that indicated diverticulitis. Malignant conditions were more common in patients with a greater wall thickness (mean, 26.2 mm versus 10.2 mm), asymmetric involvement (85% versus 39%), loss of stratification (85% versus 20%), absence of perigut findings (65% versus 22%), and involvement of a short diseased segment (70% versus 16%). Involvement of the entire colon (50% versus 2%), luminal contents (64% versus 28%), and ascites (64% versus 26%) were features suggesting pseudomembranous colitis.
  
  
  CONCLUSIONS
  Although the sonographic appearances of abnormalities of the colon overlap, some sonographic features are helpful in the differential diagnosis of colonic abnormalities.
authors.affiliation: Department of Radiology, M. D. Anderson Cancer Center, The University of Texas, Houston 77030, USA.
authors.forename: M
authors.initials: M
authors.lastname: Truong
authors.forename: M
authors.initials: M
authors.lastname: Atri
authors.forename: P M
authors.initials: PM
authors.lastname: Bret
authors.forename: C
authors.initials: C
authors.lastname: Reinhold
authors.forename: G
authors.initials: G
authors.lastname: Kintzen
authors.forename: M
authors.initials: M
authors.lastname: Thibodeau
authors.forename: A E
authors.initials: AE
authors.lastname: Aldis
authors.forename: Y
authors.initials: Y
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001201:Ascites / Q000000981:diagnostic imaging; D017091:Colitis, Ischemic / Q000000981:diagnostic imaging; D003093:Colitis, Ulcerative / Q000000981:diagnostic imaging; D003108:Colonic Diseases / Q000000981:diagnostic imaging*; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D003424:Crohn Disease / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D004239:Diverticulitis, Colonic / Q000000981:diagnostic imaging; D004761:Enterocolitis, Pseudomembranous / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007421:Intestine, Small / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014463:Ultrasonography