Renal echogenicity predicting renal dysfunction in patients with chronic kidney disease at Muhimbili National Hospital

Abstract

Objective: Chronic kidney disease (CKD) is a slow progressive loss of kidney function over the span of years. Many studies have been done on correlating sonographic renal changes with renal function by using serum creatinine as a functional mark of renal failure but less is reported on correlation of eGFR with sonographic findings. The aim of this study was to determine the role of renal sonography in predicting renal function among patients with chronic kidney disease (CKD).

Method: This was a cross-sectional study which evaluated 145 patients with CKD who underwent both kidney sonography and renal function test based on estimated glomerular filtration rate (eGFR). This study was conducted at Muhimbili National Hospital from June to December 2009. We evaluated three variables; cortical echogenicity, cortical volume and Renal function. These variables were compared by using correlation, sensitivity, specificity, positive and negative predictive values and Likelihood Ratio.

Results: The regression correlation between renal cortical echogenicity and renal function (eGFR) revealed a correlation coefficient of r² = 0.622, p<O.OO. The sensitivity of echogenicity as predictor of renal function was 74.7% (95% Confidence Interval (CI): 0.68 - 0.78), specificity was 93.5% (95% CI: 0.85 - 0.99). Positive Likelihood Ratio (LR) +11.6; p<O.OOI), hence echogenicity proved to be a strong prediction sign.

Conclusions: Renal cortical echogenicity sign was potentially useful as surrogate marker of the renal function.

Keywords: CKD, Ultrasonography, cortical echogenicity, eGFR