Correlation of ultrasonographic parameters with serum creatinine in chronic kidney disease

The purpose of our study is to correlate renal echogenicity with serum creatinine in order to determine the significance of renal echogenicity when it comes to identifying the progression of chronic kidney disease (CKD) and for the sonographic grading of CKD.

Sixty patients above 30 years of age who had been diagnosed with CKD according to the guidelines of the National Kidney Foundation were included in the study. Patients on kidney replacement therapy or with fatty liver findings on ultrasonography were excluded. Ultrasounds of kidneys were performed by two radiologists who were blind to the patients' serum creatinine levels. Renal cortical echogenicity was compared with serum creatinine. Statistical analysis was performed using one-way ANOVA followed by Scheffe's test. The relationship between serum creatinine and sonographic features was assessed by correlation coefficient analysis. A P value less than 0.05 was considered statistically significant.

Mean serum creatinine was 2.80 mg/dl for Grade 1 (range: 0.9-9.2 mg/dl), 3.69 mg/dl for Grade 2 (range: 1.2-10.3 mg/dl), 3.86 mg/dl for Grade 3 (range: 1.1-6.5 mg/dl), and 7.90 mg/dl for Grade 4 (range: 3.1-11.4 mg/dl). The grades being determined by cortical echogenicity on imaging A statistically significant, positive correlation was observed between serum creatinine and grading based on cortical echogenicity (P = 0.004).

Renal echogenicity and its grading correlates better with serum creatinine in CKD than other sonographic parameters such as longitudinal size, parenchymal thickness, and cortical thickness. Hence, renal echogenicity is a better parameter than serum creatinine for estimating renal function in CKD, and has the added advantage of irreversibility.