Renal Cortex Thickness and Kidney Size by Ultrasonography in Normal Korean Adults and Chronic Renal Failure Patients

Bong, Jeong Min; Lee, Hyun Hee; Lee, Joon Seung; Jung, Woo Gyung; Lee, Jong Ho; Yang, Dal Mo

Abstract

BACKGROUND
The thickness of the renal cortex is useful in all aspects of nephrology but no normal range has been established. Therefore, we investigated the renal cortex thickness by ultrasonography in normal Korean adults and chronic renal failure (CRF) patients before renal replacement therapy. For the purpose of evaluating the normal range then, we are going to predict the threshold range of cortex thickness in irreVersible renal failure status. METHODS: In 243 healthy Korean adults and 57 CRF patients with the creatinine level, < or =4 mg/dL were measured the renal cortex thickness. Creatinine clearance was calculated on the basis of the Cockcroft-Gault formula. RESULTS: In normal adults, the difference between male and female was 0.74+/-0.15 cm, 0.69+/-0.13 cm respectively, male was greater than female (p<0.005) and the average value of the left and right renal cortex thickness was 0.76+/-0.14 cm, 0.67+/-0.13 cm, the left kidney was greater than right one (p<0.005). The combined average value of the left and right renal cortex was 0.72+/-0.14 cm. In CRF patients, There was no difference of cortex thickness between diabetes patients and non diabetes but in non diabetes patients, the difference between Ccr <30 mL/min and Ccr > or =30 mL/min was 0.63+/-0.10 cm, 0.79+/-0.11 cm (p<0.001). CONCLUSION: The overall mean of cortex thickness in korean normal adults was 0.72+/-0.14 cm (0.41-1.25) and approximately, a threshold of 0.72 cm was identified for the cortex thickness that allowed us to distinguish Ccr <30 mL/min from Ccr > or =30 mL/min in CRF patients. But the cortex thickness alone is not a sufficient marker to predict reversibility. We should consider other invasive procedure such as kidney biopsy.