title: Single-slice dynamic computed tomographic determination of glomerular filtration rate by use of Patlak plot analysis in anesthetized pigs.
abstract: OBJECTIVE
  To compare glomerular filtration rate (GFR) as estimated from Patlak plot analysis by use of single-slice computed tomography (CT) with that obtained from clearance of plasma inulin in pigs.
  
  
  METHODS
  8 healthy anesthetized juvenile pigs.
  
  
  METHODS
  All pigs underwent precontrast, whole-kidney, helical CT; postcontrast single-slice dynamic CT; and postcontrast, whole-kidney CT for volume determination. On dynamic images, corrected Hounsfield unit values were determined for each kidney and the aorta. A Patlak plot for each kidney was generated, and plasma clearance per unit volume was multiplied by renal volume to obtain whole-animal contrast clearance. Mean GFR determined via inulin clearance (Inu-GFR) was measured from each kidney and correlated to mean GFR determined via CT (CT-GFR) for the left kidney, right kidney, and both kidneys by use of linear regression and Bland-Altman analyses.
  
  
  RESULTS
  CT-GFR results from 7 pigs were valid. Total and right kidney Inu-GFR were correlated with total and right kidney CT-GFR (total, R(2) = 0.85; right kidney, R(2) = 0.86). However, left kidney CT-GFR was poorly correlated with left kidney Inu-GFR (R(2) = 0.47). Bland-Altman analysis revealed no significant bias between Inu-GFR and CT-GFR for the left kidney, right kidney, or both kidneys.
  
  
  CONCLUSIONS
  CT-GFR as determined by use of a single-slice acquisition technique, low-dose of iohexol, and Patlak plot analysis correlated without bias with Inu-GFR for the right kidney and both kidneys (combined). This technique has promise as an accurate CT-GFR method that can be combined with renal morphologic evaluation.
authors.affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC J2S 7C6, Canada.
authors.forename: Kate
authors.initials: K
authors.lastname: Alexander
authors.forename: Jérôme R E
authors.initials: JR
authors.lastname: Del Castillo
authors.forename: Norma
authors.initials: N
authors.lastname: Ybarra
authors.forename: Valérie
authors.initials: V
authors.lastname: Morin
authors.forename: Domianique
authors.initials: D
authors.lastname: Gauvin
authors.forename: Simon
authors.initials: S
authors.lastname: Authier
authors.forename: Patrick
authors.initials: P
authors.lastname: Vinay
authors.forename: Eric
authors.initials: E
authors.lastname: Troncy
mesh_terms: D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D003287:Contrast Media / Q000493:pharmacokinetics; D005919:Glomerular Filtration Rate / Q000502:physiology / Q000662:veterinary*; D007444:Inulin / Q000378:metabolism; D007472:Iohexol / Q000493:pharmacokinetics; D007668:Kidney / Q000000981:diagnostic imaging / Q000502:physiology; D015203:Reproducibility of Results; D013552:Swine / Q000502:physiology*; D036542:Tomography, Spiral Computed / Q000379:methods / Q000662:veterinary*
chemical_list: D003287:Contrast Media; D007472:Iohexol; D007444:Inulin