title: Renogram comparison of p-[(18)F]fluorohippurate with o-[(125)I]iodohippurate and [(99m)Tc]MAG3 in normal rats.
abstract: OBJECTIVE
  We recently identified p-[(18)F]fluorohippurate ([(18)F]PFH) as a potential positron emission tomography (PET) renal agent. The objective of this study was to compare renogram parameters of [(18)F]PFH with o-[(125)I]iodohippurate ([(125)I]OIH) as a surrogate for the renal imaging gold standard (131)I-OIH and with a clinically used agent [(99m)Tc]MAG3.
  
  
  METHODS
  Normal Sprague-Dawley rats (n=4) were sequentially imaged on days 1, 2, and 3 using [(99m)Tc]MAG3 (18.1-19.1 MBq, dynamic planar), [(18)F]PFH (2.6-4.1 MBq, dynamic PET), and [(125)I]OIH (7.7-13.5 MBq, dynamic planar), respectively. The PET data were binned into frames of 30 s each, whereas the planar images were acquired as 30 s per frame. Regions of interest were drawn on both kidneys, and decay-corrected renograms were generated for each imaging modality.
  
  
  RESULTS
  The PET-derived [(18)F]PFH renograms revealed an average time-to-peak (T(max)) of 4.8±2.4 min, which was comparable to the T(max) of 3.6±1.7 min and 4.3±1.7 min for [(125)I]OIH and [(99m)Tc]MAG3 renograms, respectively. The average time-to-half-maximal activity was found to be 16.6±6.6 min, 8.3±2.4 min, and more than 20 min with [(18)F]PFH, [(125)I]OIH, and [(99m)Tc]MAG3, respectively.
  
  
  CONCLUSIONS
  Compared with [(99m)Tc]MAG3, the renogram parameters of [(18)F]PFH seem to be closer to those obtained from [(125)I]OIH. The quality of the renogram and the images obtained with the dynamic [(18)F]PFH PET study were remarkably better than those obtained with the [(99m)Tc]MAG3 dynamic planar imaging study.
authors.affiliation: Department of Pharmaceutical Sciences, University of Oklahoma College of Pharmacy, Oklahoma City, Oklahoma, USA.
authors.forename: Gopal
authors.initials: G
authors.lastname: Pathuri
authors.forename: Kaustuv
authors.initials: K
authors.lastname: Sahoo
authors.forename: Vibhudutta
authors.initials: V
authors.lastname: Awasthi
authors.forename: Hariprasad
authors.initials: H
authors.lastname: Gali
mesh_terms: D000818:Animals; D005462:Fluorine Radioisotopes; D006626:Hippurates; D007457:Iodine Radioisotopes; D007465:Iodohippuric Acid; D007684:Kidney Tubules / Q000000981:diagnostic imaging / Q000502:physiology; D011866:Radioisotope Renography / Q000379:methods* / Q000592:standards; D051381:Rats; D012015:Reference Standards; D017263:Technetium Tc 99m Mertiatide
chemical_list: C541416:4-fluorohippuric acid; D005462:Fluorine Radioisotopes; D006626:Hippurates; D007457:Iodine Radioisotopes; D007465:Iodohippuric Acid; D017263:Technetium Tc 99m Mertiatide