title: Clinical application of Patlak plot CT-GFR in animals with upper urinary tract disease.
abstract: Glomerular filtration rate (GFR), an important parameter of renal function, is difficult to assess clinically. Serum creatinine and blood urea nitrogen measurements lack sensitivity, whereas radionuclide determination of GFR is not always available and requires postinjection patient isolation. GFR can be determined using computed tomography (CT), most commonly via Patlak plot analysis. Four adult cats, two adult dogs, and a foal underwent abdominal CT under general anesthesia for various diseases of the upper urinary tract. CT-GFR was measured with a single-slice dynamic acquisition and Patlak plot analysis. In five animals, the total CT-GFR appeared to be below normal, corresponding with mild (two animals) and moderate (two animals) increases of serum creatinine in four. In the two animals with normal or increased CT-GFR, serum creatinine was within the reference values. A significant negative logarithmic relationship was found between CT-GFR and serum creatinine values (P = 0.008; r2 = 0.75). No complications occurred during or following CT-GFR. CT examination provided clinically relevant information in 3/5 patients with possible ureteral obstruction and in 3/3 patients with suspected ureteral calculi. Single-slice dynamic CT-GFR was practical and provided clinically useful information in this small series of patients undergoing CT of the upper urinary tract. There was a significant relationship between CT-GFR and serum creatinine values, which supports the clinical potential of CT-GFR and justifies further investigation of this technique.
authors.affiliation: Département de Sciences Cliniques, Faculté de médecine vétérinaire, Université de Montréal, PO Box 5000, St-Hyacinthe, QC, Canada J2S 7C6. kate.alexander@umontreal.ca
authors.forename: Kate
authors.initials: K
authors.lastname: Alexander
authors.forename: Marilyn
authors.initials: M
authors.lastname: Dunn
authors.forename: Eric Norman
authors.initials: EN
authors.lastname: Carmel
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Lavoie
authors.forename: Jérôme R E
authors.initials: JR
authors.lastname: Del Castillo
mesh_terms: D000818:Animals; D000855:Anorexia / Q000000981:diagnostic imaging / Q000662:veterinary; D002371:Cat Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D002415:Cats; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D004285:Dogs; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006734:Horse Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D006736:Horses; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary; D014567:Urography / Q000379:methods / Q000662:veterinary; D014570:Urologic Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*