Correlation of quantitative renal cortical echogenicity with renal function in pediatric renal diseases

Using quantitative echogenicity, the correlation between renal cortical echogenicity and renal function (serum creatinine) was evaluated in pediatric renal diseases. The kidney/liver echogenicity ratio (K/ L ratio) was measured by computerized amplitude histogram in 20 healthy children as well as in 45 children with renal diseases, including 12 glomerulonephritis with chronic renal failure (CRF), 9 anatomic-related CRF, 9 glomerulonephritis with acute renal failure (ARF), 5 nephrotoxic ARF, and 10 glomerulonephritis without renal failure. All children were above six years of age. Simultaneous serum creatinine was available during the procedure in all patients. The overall K/L ratio was 1.38 +/- 0.26 for CRF and 1.14 +/- 0.18 for ARF (p = 0.007), while the overall serum creatinine was 312 +/- 160 mumol/L (3.5 +/- 1.8 mg/dl) and 191 +/- 73 mumol/L (2.2 +/- 0.8 mg/dl), respectively (p = 0.013). K/L ratio was higher in CRF at a higher, or even at a comparable serum creatinine level, than in ARF. For patients with glomerulonephritis, K/L ratio was highest in those with CRF, next in those with ARF. Even in glomerulonephritis without renal failure, the K/L ratio was higher than in normal controls. There was a positive correlation between K/L ratio and serum creatinine concentration in glomerulonephritis with or without renal failure (r = 0.69, p < 0.001). These results suggest that the degree of increased renal echogenicity may reflect the severity of the renal disease. The K/L ratio measured by quantitative echogenicity may provide an additional simple noninvasive method to monitor the progression of glomerulonephritis.