title: Determining the proximal extent of ulcerative colitis: white cell scan correlates well with histological assessment.
abstract: BACKGROUND
  Assessing the extent of ulcerative colitis determines therapeutic strategies and provides prognostic information. Colonoscopy with mucosal biopsy is considered unsafe in patients with severe disease.
  
  
  OBJECTIVE
  To assess the correlation between proximal extent of ulcerative colitis as determined by Technitium-99-m hexamethylpropylene amine oxime labelled leucocyte scan (white cell scan) with that determined by histological assessment.
  
  
  METHODS
  One hundred and thirty-five patients, with histologically-confirmed ulcerative colitis, who had a white cell scan and histological assessment of colonic inflammation within 6 months of each other, during the years 1991-2004, were included. Overall agreement, quadratic-weighted kappa (kappa) and polychoric correlations (rho) were calculated to estimate the inter-rater reliability.
  
  
  RESULTS
  The correlation between white cell scan and histological extent was excellent (kappa = 0.7 rho = 0.8). Macroscopic appearance on colonoscopy did not correlate as well with histological extent (kappa = 0.62 and rho = 0.67). White cell scans correlated significantly better in patients with extensive disease (P = 0.02). Colonoscopy predicted disease extent more accurately in patients with limited colitis (P = 0.002).
  
  
  CONCLUSIONS
  Proximal extent of ulcerative colitis determined by white cell scans correlates well with histological assessment especially in patients with more extensive disease. White cell scans offer a reasonable alternative to colonoscopy with mucosal biopsies in determining the proximal extent of colitis.
authors.affiliation: Departments of Gastroenterology, St george's Healthcae NHS Trust, Blackshaw Road, London, UK. vsubrama@sgul.ac.uk
authors.forename: V
authors.initials: V
authors.lastname: Subramanian
authors.forename: A
authors.initials: A
authors.lastname: Banerjee
authors.forename: N
authors.initials: N
authors.lastname: Beharry
authors.forename: M J G
authors.initials: MJ
authors.lastname: Farthing
authors.forename: R C G
authors.initials: RC
authors.lastname: Pollok
mesh_terms: D000328:Adult; D003093:Colitis, Ulcerative / Q000473:pathology*; D003113:Colonoscopy; D018450:Disease Progression; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D007962:Leukocytes; D008297:Male; D008875:Middle Aged