title: Quantification of disease activity in patients undergoing leucocyte scintigraphy for suspected inflammatory bowel disease.
abstract: OBJECTIVE
  Whole-body gamma camera counting is an alternative to faecal 111In collection for quantifying disease activity in inflammatory bowel disease (IBD) but requires administration of imaging activities of 111In. The aim of this study was to explore a dedicated whole-body counter which requires 20-fold less activity than gamma camera counting.
  
  
  METHODS
  Thirty patients with known or suspected IBD received 99mTc-granulocytes (approximately 200 MBq) and 111In-granulocytes (approximately 0.5 MBq). The 99mTc-cells were injected 45 min after the 111In-cells and immediately after a baseline 111In whole-body count. The decay-corrected count at 120 h was expressed as a fraction of baseline to give whole-body 111In retention (WBR). One patient was excluded as the injected cells were non-viable.
  
  
  RESULTS
  Median 45-min intravascular 111In recovery was 35% in patients compared with 43% in six normal volunteers (p<0.05). WBR in normals ranged from 91% to 93% and in 11 patients with negative 99mTc imaging from 87% to 96%. Only one of 11 patients with negative imaging had WBR <90% while 11/12 patients with WBR <90% had abnormal imaging. Ten of 13 patients with Crohn's disease (CD) had abnormal imaging. The lowest WBR in these ten was 77% and six had values of >90%. There was a significant association between WBR and 99mTc image grade (Rs=0.73, p<0.002) in 16 patients without CD, but not in 13 patients with CD (Rs=0.54, p>0.05).
  
  
  CONCLUSIONS
  Dedicated whole-body counting is able to quantify disease activity in IBD but may give normal values in active CD.
authors.affiliation: Department of Nuclear Medicine, Addenbrooke's Hospital, P.O. Box 170, Hills Road, Cambridge, CB2 2QQ, UK.
authors.forename: Heok K
authors.initials: HK
authors.lastname: Cheow
authors.forename: Demetrius D
authors.initials: DD
authors.lastname: Voutnis
authors.forename: John W
authors.initials: JW
authors.lastname: Evans
authors.forename: Katy R
authors.initials: KR
authors.lastname: Szczepura
authors.forename: E Anna
authors.initials: EA
authors.lastname: Swift
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Bird
authors.forename: Prina
authors.initials: P
authors.lastname: Ruparelia
authors.forename: Chandra K
authors.initials: CK
authors.lastname: Solanki
authors.forename: James R
authors.initials: JR
authors.lastname: Ballinger
authors.forename: Edwin R
authors.initials: ER
authors.lastname: Chilvers
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Middleton
authors.forename: A Michael
authors.initials: AM
authors.lastname: Peters
mesh_terms: D000328:Adult; D000368:Aged; D005240:Feasibility Studies; D005260:Female; D006098:Granulocytes / Q000000981:diagnostic imaging; D006801:Humans; D007205:Indium Radioisotopes; D015212:Inflammatory Bowel Diseases / Q000145:classification / Q000000981:diagnostic imaging*; D007962:Leukocytes / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D019690:Technetium Tc 99m Exametazime; D014915:Whole-Body Counting / Q000295:instrumentation / Q000379:methods*
chemical_list: D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime