title: Nonlinearity correction of brain perfusion SPECT based on permeability-surface area product model.
abstract: It is well known that many cerebral perfusion tracers underestimate cerebral blood flow in high flow range. A model has been proposed to correct nonlinear relationship of flow and uptake of the tracers that accounts for the permeability-surface area product (PS model).
  
  
  METHODS
  We examined 43 patients in this study. To test the feasibility of this method for 123I-IMP, 99(m)Tc-HMPAO and 99(m)Tc-ECD, radioactivity ratios of cerebral regions to cerebellum (C/Cr) on SPECT images were compared with those of rCBF (F/Fr) measured by PET using the 15O CO2 steady-state method. Coefficient for correction in the PS model was estimated by the least squares method, and SPECT data were corrected using these coefficients.
  
  
  RESULTS
  Estimated PS value by this method was highest in IMP (116 ml/min/100 g) followed by ECD (66 ml/min/100 g) and HMPAO (46 ml/min/100 g). The corrected SPECT data demonstrated an excellent linear relationship, which was close to unity, with rCBF.
  
  
  CONCLUSIONS
  These results indicate that the PS model can be used for nonlinearity correction of brain perfusion SPECT.
authors.affiliation: Department of Nuclear Medicine, Kyoto University Faculty of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tsuchida
authors.forename: Y
authors.initials: Y
authors.lastname: Yonekura
authors.forename: S
authors.initials: S
authors.lastname: Nishizawa
authors.forename: N
authors.initials: N
authors.lastname: Sadato
authors.forename: N
authors.initials: N
authors.lastname: Tamaki
authors.forename: T
authors.initials: T
authors.lastname: Fujita
authors.forename: Y
authors.initials: Y
authors.lastname: Magata
authors.forename: J
authors.initials: J
authors.lastname: Konishi
mesh_terms: D000328:Adult; D000662:Amphetamines; D001921:Brain / Q000000981:diagnostic imaging*; D002245:Carbon Dioxide; D002560:Cerebrovascular Circulation / Q000502:physiology; D003545:Cysteine / Q000031:analogs & derivatives*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007457:Iodine Radioisotopes; D020367:Iofetamine; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015609:Organotechnetium Compounds; D010091:Oximes; D010104:Oxygen Radioisotopes; D019690:Technetium Tc 99m Exametazime; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000662:Amphetamines; D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D010091:Oximes; D010104:Oxygen Radioisotopes; D002245:Carbon Dioxide; D019690:Technetium Tc 99m Exametazime; D020367:Iofetamine; C059659:technetium Tc 99m bicisate; D003545:Cysteine