Single-slice dynamic computed tomographic determination of glomerular filtration rate by use of Patlak plot analysis in anesthetized pigs.
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.
Alexander
Kate
K
Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC J2S 7C6, Canada.
Del Castillo
Jérôme R E
JR
Ybarra
Norma
N
Morin
Valérie
V
Gauvin
Domianique
D
Authier
Simon
S
Vinay
Patrick
P
Troncy
Eric
E
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*
D003287:Contrast Media; D007472:Iohexol; D007444:Inulin