title: A method of adjusting SUV for injection-acquisition time differences in (18)F-FDG PET imaging.
abstract: OBJECTIVE
  A time normalisation method of tumour SUVs in (18) F-FDG PET imaging is proposed that has been verified in lung cancer patients.
  
  
  METHODS
  A two-compartment model analysis showed that, when SUV is not corrected for (18) F physical decay (SUV(uncorr)), its value is within 5% of its peak value (t = 79 min) between 55 and 110 min after injection, in each individual patient. In 10 patients, each with 1 or more malignant lesions (n = 15), two PET acquisitions were performed within this time delay, and the maximal SUV of each lesion, both corrected and uncorrected, was assessed.
  
  
  RESULTS
  No significant difference was found between the two uncorrected SUVs, whereas there was a significant difference between the two corrected ones: mean differences were 0.04 ± 0.22 and 3.24 ± 0.75 g.ml(-1), respectively (95% confidence intervals). Therefore, a simple normalisation of decay-corrected SUV for time differences after injection is proposed: SUV(N) = 1.66 SUV(uncorr), where the factor 1.66 arises from decay correction at t = 79 min.
  
  
  CONCLUSIONS
  When (18) F-FDG PET imaging is performed within the range 55-110 min after injection, a simple SUV normalisation for time differences after injection has been verified in patients with lung cancer, with a ±2.5% relative measurement uncertainty.
authors.affiliation: CHU de Bordeaux, Hôpital du Haut Lévèque, 33604 Pessac, France. elaffon@u-bordeaux2.fr
authors.forename: Eric
authors.initials: E
authors.lastname: Laffon
authors.forename: Henri
authors.initials: H
authors.lastname: de Clermont
authors.forename: Roger
authors.initials: R
authors.lastname: Marthan
mesh_terms: D000328:Adult; D000368:Aged; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000494:pharmacology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007700:Kinetics; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000494:pharmacology*; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18