Abstract: TH-PO513
Does Kidney Echogenicity Correlate to eGFR in Pediatric AKI?
Session Information
- Pediatric Nephrology - I
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pediatric Nephrology
- 1900 Pediatric Nephrology
Authors
- Goswami, Shrea, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Starr, Michelle C., Indiana University School of Medicine, Indianapolis, Indiana, United States
- Cater, Daniel, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Schwaderer, Andrew L., Indiana University School of Medicine, Indianapolis, Indiana, United States
Background
Kidney ultrasound echogenicity is a subjective finding reported by radiologists however it may be more clinically useful if quantified. The objective is to investigate if ultrasonographic parameters of the kidney correlates to estimated glomerular filtration rate (eGFR) in pediatric AKI.
Methods
Retrospective study in a tertiary children’s hospital. Ultrasounds of 35 subjects were identified with AKI at the time of CKRT initiation. Three distinct areas of the kidney cortex and liver were cropped. Using Adobe Photoshop software a gray scale pixel density value was quantified. An inverse ratio of the kidney to liver mean pixel densities was the quantified echogenicity index (EI). The kidney lengths, age, weight, height, race/ethnicity, percent fluid overload (%FO), seurm albumin and time on CKRT were entered into a multivariate calculator. The difference between the mean measured and predicted right and left kidney lengths was the kidney length ratio (KLR).
Results
35 subjects were analyzed. The median age was 10 years (range 2-16) and 54% were male. Heatmap correlation analysis revealed statistically significant negative correlations for mean EI with eGFR and BMI (r = -0.36 [p-value 0.03]: and -0.35[p-value 0.04], respectively). KLR showed negative correlation with BMI and age (r= -0.46 [p-value 0.005] and r = -0.38[p-value 0.0025], respectively). The % of FO significantly correlated with decreasing size and BMI.
The AUC for EI with eGFR <90ml/min/1.73m2 and <60ml/min/1.73m2 was 0.7 (p-value 0.08 and 0.02, respectively). EI < 1.17 predicted eGFR < 90 with sensitivity of 46.2% (95% CI 29%-65%) and specificity of 88.9% (CI 57%-99%). Similarly, for eGFR <60 with sensitivity of 55.0%(CI 34%-74%) and specificty of 86.7%(CI 62%-98%). AUC for KLR was 0.6 and statistically insignificant.
Conclusion
Increased kidney echogenicity appears to be a more accurate correlate with decreased kidney function than increased kidney size.
Correlation plot for data. Significant values highlighted in yellow.