title: Gas insufflation of minimal preparation CT of the colon reduces false-positives.
abstract: OBJECTIVE
  Minimal preparation CT of the colon (MPCT colon) is used for investigation of suspected colorectal cancer in frail and/or elderly patients who would be expected to tolerate laxative bowel preparation poorly. Although it has good sensitivity for colorectal cancer it has a poor specificity. We wished to investigate whether distension of the colon with carbon dioxide alone would reduce the number of false-positives, but without making the test arduous or excessively uncomfortable.
  
  
  METHODS
  134 patients were recruited and underwent MPCT colon with gas insufflation and antispasmodics. Results were compared with a cohort of 134 patients undergoing standard protocol MPCT colon. The numbers of false-positives were compared, as was reader confidence. All trial patients were given a questionnaire documenting their experience.
  
  
  RESULTS
  The number of false-positives was 15% in the control group and 5% in the trial group; this difference was statistically significant, (p=0.01). Reader confidence was increased in the trial group. Patient tolerance was good, with 95% saying they would have the test again.
  
  
  CONCLUSIONS
  Use of gas insufflation and antispasmodics reduces the false-positives from 15% to 5% without adversely affecting patient tolerance.
authors.affiliation: John Radcliffe Hospital, Headley Way, Headington, Oxford, UK. andrewslater99@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Slater
authors.forename: M
authors.initials: M
authors.lastname: North
authors.forename: M
authors.initials: M
authors.lastname: Hart
authors.forename: C
authors.initials: C
authors.lastname: Ferrett
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D023881:Colonography, Computed Tomographic / Q000379:methods*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging; D003287:Contrast Media; D003974:Diatrizoate Meglumine; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007327:Insufflation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires
chemical_list: D003287:Contrast Media; D003974:Diatrizoate Meglumine