title: Simultaneous emission and transmission (SET) scanning in neurological PET studies.
abstract: OBJECTIVE
  We evaluated the impact of simultaneous emission and transmission (SET) measurements of quantification and noise in neurological PET studies.
  
  
  METHODS
  Bias in SET was measured as a function of emission count rate and used to predict distortion in simulated FDG tissue curves and its effect on model parameter estimates. Studies were performed on a brain phantom and a patient to verify predicted bias and examine the effect of SET on noise.
  
  
  RESULTS
  In static imaging, SET underestimated tracer concentration by approximately 2%. In kinetic studies, tracer concentration was overestimated initially and underestimated during the mid to late part of the study, but bias in measurement of glucose metabolic rate was < 5% by simulation and < 10% in the patient study. SET imaging takes 10% longer than the emission part of a conventional scan to achieve comparable statistics.
  
  
  CONCLUSIONS
  Accurate neurological PET studies can be performed with SET. The relatively small bias can be predicted and potentially corrected.
authors.affiliation: PET Department, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
authors.forename: S R
authors.initials: SR
authors.lastname: Meikle
authors.forename: S
authors.initials: S
authors.lastname: Eberl
authors.forename: P K
authors.initials: PK
authors.lastname: Hooper
authors.forename: M J
authors.initials: MJ
authors.lastname: Fulham
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D003847:Deoxyglucose / Q000031:analogs & derivatives; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D019047:Phantoms, Imaging; D014055:Tomography, Emission-Computed / Q000379:methods*
chemical_list: D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose