title: Quantitation of rat cerebral blood flow using99mTc-HMPAO.
abstract: BACKGROUND
  Technetium-99m-hexamethylpropyleneamine oxime (99mTc-HMPAO) is potentially useful for the assessment of cerebral blood flow (CBF) in small animals. In this paper, a procedure for quantitation of rat CBF using99mTc-HMPAO was determined.
  
  
  METHODS
  Biodistribution of99mTc-radioactivity in normal rats was determined after intravenous administration of99mTc-HMPAO. Acetazolamide treated rats were intravenously administered with the mixture of99mTc-HMPAO and N-isopropyl-[125I]iodoamphetamine ([125I]IMP), and arterial blood was then collected for 5min. After blood sampling, the brain radioactivity concentration was measured with the auto-well γ counter.
  
  
  RESULTS
  The brain radioactivity concentration after intravenous administration of99mTc-HMPAO was steady from 14s to 60min post-injection. A double tracer experiment using99mTc-HMPAO and [125I]IMP showed that 19s was the average of the optimal integration interval of arterial blood99mTc-radioactivity concentration to obtain CBF values measured by99mTc-HMPAO identical to those determined by [125I]IMP. The CBF value determined by99mTc-HMPAO, calculated by dividing the brain radioactivity concentration at 5min post-injection by the integrated arterial blood radioactivity concentration until 19s post-injection, was well correlated with CBF as determined by [125I]IMP.
  
  
  CONCLUSIONS
  These results suggest that the CBF quantitation procedure described in this paper could be useful for rat CBF assessment.
authors.affiliation: Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Suzuki
authors.affiliation: Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan.
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Kosugi
authors.affiliation: Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan. Electronic address: ymagata@hama-med.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Magata
mesh_terms: D061605:Administration, Intravenous; D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism; D002560:Cerebrovascular Circulation; D011854:Radiochemistry; D051381:Rats; D012015:Reference Standards; D019690:Technetium Tc 99m Exametazime / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: D019690:Technetium Tc 99m Exametazime
keywords: (99m)Tc-HMPAO; CBF; Rat