title: A robust conversion method of radioactivities between plastic and NaI scintillation well counters for long-term quality control and quality assurance.
abstract: OBJECTIVE
  The purpose of this study is to specify a simple procedure for a robust data conversion of radioactivity value between plastic scintillator (PL) and NaI scintillator (NaI) devices.
  
  
  METHODS
  The radioactivity estimate of 100 blood samples was measured by the two devices. The two radioactivities were plotted on the same graph. The least-squares method was applied to obtain the conversion function. The differences between the actual radioradioy (N) from the NaI device and the estimated radioactivity for NaI (N') from the PL device activity (P) were statistically analyzed.
  
  
  RESULTS
  N' was determined from P as N' = 4.45 P + 6.28 with high correlation (r = 0.997). The Bland-Altman analysis between N' and N showed no fixed bias and no proportional bias.
  
  
  CONCLUSIONS
  A hundred blood samples using a fixed type of sample tubes and a fixed radionuclide may be required to set up the robust conversion function.
authors.affiliation: Department of Intelligent Image Information, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1194, Japan. takeshi.hara@mac.com.
authors.forename: Takeshi
authors.identifier: http://orcid.org/0000-0002-0235-238X
authors.initials: T
authors.lastname: Hara
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Ishihara
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Asano
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Matsuo
authors.affiliation: School of Health Science, Gifu University of Medical Science, 795-1 Ichihiraga, Nagamine, Seki, Gifu, 501-3892, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Katafuchi
authors.affiliation: Department of Intelligent Image Information, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1194, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujita
keywords: Cerebral blood flow; QAQC; SPECT; Scintillator; Well counter