title: Operator-bias-free comparison of quantitative perfusion maps acquired with pulsed-continuous arterial spin labeling and single-photon-emission computed tomography.
abstract: OBJECTIVE
  We compared the regional cerebral blood flow (rCBF) obtained by pulsed continuous arterial spin labeling (pCASL) and iodine-123-N-isopropyl-p-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) using 3-dimensional stereotactic region-of-interest (ROI) software for automated definition of ROIs in anatomic regions of the brain.
  
  
  METHODS
  Thirteen patients with cerebrovascular occlusive disease and three with transient ischemic attacks underwent pCASL and IMP SPECT imaging. We compared rCBF values of each anatomic region and calculated the correlation coefficients between pCASL and IMP SPECT. We also calculated the asymmetry index (AI) using ROIs in contralateral regions of the hemispheres.
  
  
  RESULTS
  The rCBF values calculated from pCASL and IMP SPECT were comparable in most segments, but rCBF in the thalamus (P < 0.0001) and hippocampus (P = 0.0006) was significantly higher measured by pCASL than IMP SPECT. The correlation of rCBF between pCASL and IMP SPECT in the affected hemisphere (r = 0.50) tended to be lower than that in the normal hemisphere (r = 0.59), but not significantly different (P = 0.25). Moreover, there was a fixed bias for underestimation of rCBF by pCASL (P = 0.0047) in the affected hemisphere. The calculated AI showed a significant relationship between methods (r = 0.79, P < 0.0001).
  
  
  CONCLUSIONS
  The rCBF obtained by pCASL had positive relationships with IMP SPECT. However, it should be considered that pCASL tends to have a weak relationship with IMP SPECT in some normal regions and regions affected by cerebrovascular occlusive disease.
authors.affiliation: Department of Medical Imaging, Institute of Health Biosciences, The University of Tokushima Graduate School.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwanaga
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kubo
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Funakoshi
authors.forename: Yamato
authors.initials: Y
authors.lastname: Kunikane
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply / Q000473:pathology; D001931:Brain Mapping / Q000379:methods; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000473:pathology*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D019275:Radiopharmaceuticals; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals