title: MR colonography with fecal tagging: do individual patient characteristics influence image quality?
abstract: OBJECTIVE
  To evaluate if different patient characteristics influence performance of fecal tagging (a new MR colonography (MRC) technique to label stool to avoid bowel cleansing) and, consecutively, MR image quality.
  
  
  METHODS
  A total of 333 patients (mean age = 61 years) underwent MRC with fecal tagging. Four segments of the large bowel (ascending, transverse, descending, and sigmoid colon) were assessed as for the presence of nontagged stool particles, which can impede an assessment of the colonic wall. Ratings were correlated with patients' characteristics including patient age (<55 vs. > or =55 years), body mass index (BMI) (<25 vs. > or =25), gender, and acceptance levels for fecal tagging. Statistical analysis was performed using a Mann-Whitney U-test.
  
  
  RESULTS
  A total of 1332 colonic segments were evaluated. Among them, 327 segments (25%) did not contain any visible stool particles. Considerably reduced image quality was found in 61 segments (5%). Best image quality was found in the sigmoid colon (mean value = 1.9), while image quality of the ascending colon turned out to be worst (mean value = 2.6). Fecal tagging effectiveness showed a reverse correlation with patient age. However, all other characteristics did not have a statistically significant influence on fecal tagging outcome.
  
  
  CONCLUSIONS
  MRC in conjunction with barium-based fecal tagging led to diagnostic image quality in 95% of all colonic segments. Since tagging results were significantly decreased in patients > or =55 years, tagging protocols should to be modified in this group, i.e., by increasing the time interval of tagging administration.
authors: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, D-45122 Essen, Germany. Sonja.Kinner@uni-due.de
authors: Sonja
authors: S
authors: Kinner
authors: Christiane A
authors: CA
authors: Kuehle
authors: Jost
authors: J
authors: Langhorst
authors: Susanne C
authors: SC
authors: Ladd
authors: Michael
authors: M
authors: Nuefer
authors: Joerg
authors: J
authors: Barkhausen
authors: Thomas C
authors: TC
authors: Lauenstein
mesh_terms: D001466:Barium Sulfate; D003108:Colonic Diseases / Q000175:diagnosis*; D003287:Contrast Media; D003974:Diatrizoate Meglumine; D005243:Feces; D005260:Female; D005685:Galactans; D006571:Heterocyclic Compounds; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008351:Mannans; D008875:Middle Aged; D009942:Organometallic Compounds; D010349:Patient Compliance; D053149:Plant Gums; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires
chemical_list: D003287:Contrast Media; D005685:Galactans; D006571:Heterocyclic Compounds; D008351:Mannans; D009942:Organometallic Compounds; D053149:Plant Gums; D001466:Barium Sulfate; D003974:Diatrizoate Meglumine; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate; C017471:locust bean gum