title: Reduced cathartic bowel preparation for CT colonography: prospective comparison of 2-L polyethylene glycol and magnesium citrate.
abstract: OBJECTIVE
  To prospectively compare adequacy of colonic cleansing, adequacy of solid stool and fluid tagging, and patient acceptance by using reduced-volume, 2-L polyethylene glycol (PEG) versus magnesium citrate bowel preparations for CT colonography.
  
  
  METHODS
  This study was approved by the institutional Committee on Human Research and was compliant with HIPAA; all patients provided written consent. In this randomized, investigator-blinded study, 50 patients underwent oral preparation with either a 2-L PEG or a magnesium citrate solution, tagging with oral contrast agents, and subsequent CT colonography and segmentally unblinded colonoscopy. The residual stool (score 0 [best] to 3 [worst]) and fluid (score 0 [best] to 4 [worst]) burden and tagging adequacy were qualitatively assessed. Residual fluid attenuation was recorded as a quantitative measure of tagging adequacy. Patients completed a tolerance questionnaire within 2 weeks of scanning. Preparations were compared for residual stool and fluid by using generalized estimating equations; the Mann-Whitney test was used to compare the qualitative tagging score, mean residual fluid attenuation, and adverse effects assessed on the patient experience questionnaire.
  
  
  RESULTS
  The mean residual stool (0.90 of three) and fluid burden (1.05 of four) scores for PEG were similar to those for magnesium citrate (0.96 [P = .58] and 0.98 [P = .48], respectively). However, the mean fecal and fluid tagging scores were significantly better for PEG (0.48 and 0.28, respectively) than for magnesium citrate (1.52 [P < .01] and 1.28 [P < .01], respectively). Mean residual fluid attenuation was higher for PEG (765 HU) than for magnesium citrate (443 HU, P = .01), and mean interpretation time was shorter for PEG (14.8 minutes) than for magnesium citrate (18.0 minutes, P = .04). Tolerance ratings were not significantly different between preparations.
  
  
  CONCLUSIONS
  Reduced-volume PEG and magnesium citrate bowel preparations demonstrated adequate cleansing effectiveness for CT colonography, with better tagging and shorter interpretation time observed in the PEG group. Adequate polyp detection was maintained but requires further validation because of the small number of clinically important polyps.
authors.affiliation: Department of Radiology, University of California, San Francisco, San Francisco Veterans Affairs Medical Center, VAMC, San Francisco, CA 94143, USA.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Keedy
authors.forename: Judy
authors.initials: J
authors.lastname: Yee
authors.forename: Rizwan
authors.initials: R
authors.lastname: Aslam
authors.forename: Stefanie
authors.initials: S
authors.lastname: Weinstein
authors.forename: Luis A
authors.initials: LA
authors.lastname: Landeras
authors.forename: Janak N
authors.initials: JN
authors.lastname: Shah
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: McQuaid
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Yeh
mesh_terms: D000328:Adult; D000368:Aged; D002400:Cathartics; D019343:Citric Acid; D023881:Colonography, Computed Tomographic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D011092:Polyethylene Glycols; D011446:Prospective Studies; D016037:Single-Blind Method
chemical_list: D002400:Cathartics; D009942:Organometallic Compounds; D019343:Citric Acid; D011092:Polyethylene Glycols; C110422:magnesium citrate