title: Multicenter evaluation of a standardized protocol for rest and acetazolamide cerebral blood flow assessment using a quantitative SPECT reconstruction program and split-dose 123I-iodoamphetamine.
abstract: SPECT can provide valuable diagnostic and treatment response information in large-scale multicenter clinical trials. However, SPECT has been limited in providing consistent quantitative functional parametric values across the centers, largely because of a lack of standardized procedures to correct for attenuation and scatter. Recently, a novel software package has been developed to reconstruct quantitative SPECT images and assess cerebral blood flow (CBF) at rest and after acetazolamide challenge from a single SPECT session. This study was aimed at validating this technique at different institutions with a variety of SPECT devices and imaging protocols.
  
  
  METHODS
  Twelve participating institutions obtained a series of SPECT scans on physical phantoms and clinical patients. The phantom experiments included the assessment of septal penetration for each collimator used and of the accuracy of the reconstructed images. Clinical studies were divided into 3 protocols, including intrainstitutional reproducibility, a comparison with PET, and rest-rest study consistency. The results from 46 successful studies were analyzed.
  
  
  RESULTS
  Activity concentration estimation (Bq/mL) in the reconstructed SPECT images of a uniform cylindric phantom showed an interinstitution variation of ±5.1%, with a systematic underestimation of concentration by 12.5%. CBF values were reproducible both at rest and after acetazolamide on the basis of repeated studies in the same patient (mean ± SD difference, -0.4 ± 5.2 mL/min/100 g, n = 44). CBF values were also consistent with those determined using PET (-6.1 ± 5.1 mL/min/100 g, n = 6).
  
  
  CONCLUSIONS
  This study demonstrates that SPECT can quantitatively provide physiologic functional images of rest and acetazolamide challenge CBF, using a quantitative reconstruction software package.
authors.affiliation: Dual-Table Autoradiography SPECT Research Group in Japan, Osaka, Japan. iida@ri.ncvc.go.jp
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Iida
authors.forename: Jyoji
authors.initials: J
authors.lastname: Nakagawara
authors.forename: Kohei
authors.initials: K
authors.lastname: Hayashida
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Fukushima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watabe
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Koshino
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Zeniya
authors.forename: Stefan
authors.initials: S
authors.lastname: Eberl
mesh_terms: D000086:Acetazolamide; D000662:Amphetamines / Q000008:administration & dosage; D001208:Asia; D001315:Australia; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007564:Japan; D019047:Phantoms, Imaging; D017410:Practice Guidelines as Topic; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity; D012984:Software / Q000592:standards*; D012986:Software Validation; D015899:Tomography, Emission-Computed, Single-Photon / Q000592:standards*
chemical_list: D000662:Amphetamines; D019275:Radiopharmaceuticals; C041336:4-iodoamphetamine; D000086:Acetazolamide