Can distinction between the renalcortex and outer medulla onultrasonography predict estimatedglomerular filtration rate in caninechronic kidney diseases?

ABSTRACT

Background@#Quantitative evaluation of renal cortical echogenicity (RCE) has been tried anddeveloped in human and veterinary medicine. @*Objectives@#The objective of this study was to propose a method for evaluating RCEquantitatively and intuitively, and to determine associations between ultrasonographic renalstructural distinction and estimated glomerular filtration rate (eGFR) in canine chronickidney disease (CKD). @*Methods@#Data were collected on 63 dogs, including 27 with normal kidney function and 36CKD patients. Symmetric dimethylarginine and creatinine concentrations were measuredfor calculating eGFR. RCE was evaluated as 3 grades on ultrasonography images accordingto the distinction between the renal cortex and outer medulla. The RCE grade of each kidneywas measured. @*Results@#There was a significant difference in eGFR between the group normal and CKD (p< 0.001). As mean of RCE grades (the mean values of each right and left kidney's RCE grade)increases, the proportion of group CKD among the patients in each grade increases (p <0.001). Also, severity of RCE (classified as "high" if any right or left kidney evaluated as RCEgrade 3, "low" otherwise) and eGFR is good indicator for predicting group CKD (p < 0.001). @*Conclusions@#The degree of distinction between the renal cortex and the outer medulla isclosely related to renal function including eGFR and the RCE grade defined in this study canbe used as a method of objectively evaluating RCE.