Correlation of Sonographic Grading of Renal Cortical Echogenicity with Serum Creatinine in Patients with Chronic Kidney Disease

Abstract

Background: Ultrasound Imaging can be used as a painless, non-invasive modality for the grading of renal echogenicity in chronic kidney disease (CKD). Aims: To determine the association of renal echogenicity in persons with CKD using ultrasound and serum creatinine Settings and Design: Retrospective observational study design at a single center. Subjects and Methods: The study included 112 subjects aged 18 to 90 years with CKD, with grades of renal echogenicity and renal length estimates based on ultrasound findings and biochemical test results of serum creatinine profile. Renal size was categorized as optimal or small or enlarged and renal echogenicity graded from 1 to 4. Statistical Analysis used: A one way Analysis of Variation test (ANOVA) was used to compare the renal echogenicity and renal length with serum creatinine. Pairwise correlations were estimated and a p value of <0.05 was considered as statistically significant. Results: The study included 112 subjects with a mean age (SD) of 54.37 (17.29 years) and 81 (72.32%) subjects were males. The majority of patients (n=51, 45.54%) in the study were aged 60 years or older. Sixty eight subjects (60.71%, 95% CI: 51.45, 69.43) subjects had optimal sized kidneys and 8 (7.14%, 95% CI: 3.66, 13.46) subjects had significant discrepancy in renal size. The majority of subjects (n=43, 38.74%, 95%CI: 29.73, 47.64) in the study had Grade 1 renal echogenicity. Serum creatinine values increased significantly with increasing grades of renal echogenicity (F=9.58, p<0.001, one way ANOVA test). The grade of echogenicity and serum creatinine levels showed a statistically significant correlation (p<0.001) on pairwise correlation test. The mean longitudinal renal length was significantly associated (F=14.07, p<0.001) with renal echogenicity. Conclusion: Serum Creatinine levels and renal echogenicity were significantly associated in this study. Ultrasound imaging studies can be a painless non-invasive alternate in the evaluation of CKD.