Contrast-Enhanced Ultrasound Evaluation of Chronic Kidney Disease: A Pilot Study

Abstract

The aim of this study was to investigate the clinical significance of real-time gray-scale contrast-enhanced ultrasound (CEUS) through evaluating renal microvascular perfusion in chronic kidney disease. Chronic kidney disease (CKD) patients (n = 26) were stratified according to estimated glomerular filtration rate (eGFR): Group I (CKD stage I and II), eGFR ≥60 ml/min/1.73m2, Group II (CKD stage III), eGFR of 30 ≤ eGFR < 60 ml/min/1.73m2, Group III (CKD stage IV and V), eGFR of eGFR < 30 ml/min/1.73m. The real-time and dynamic imaging from renal cortex was performed using CEUS. The >85% goodness-of-fit (GOF) index were chosen for the analysis. Several bolus model perfusion parameters including peak enhancement (PE), wash-in rate (WiR), wash-out rate (WoR), wash-in and wash-out area under curve (WiWoAUC), and rise time (RT) were calculated and compared among three groups. Several laboratory parameters including blood urea nitrogen (BUN), serum creatinine (SCr), red blood cell (RBC), urine proteinuria (UPr), urine creatinine (UCr) and UPr/UCr were also measured and compared among three groups. Correlation between perfusion or laboratory parameters and eGFR were assessed. The >85% GOF index were chosen for the analysis in 24 patients (aged: 57.2 ± 19.8). Of 24 patients, 4 patients were classified as group I, 13 patients were classified as group II and 7 patients were classified as group III. In perfusion parameter analysis, there were no significant differences between patients of 3 groups. No parameters significant positively correlated with eGFR. In laboratory parameter analysis, there were significant differences between patients of 3 groups in several parameters (RBC, BUN, SCr, Glucose, Total cholesterol, Phosphorus, Total protein, p<0.05). They also were significant correlated with eGFR (correlation coefficient, R= -0.7625 to 0.6026). CEUS is a safe, noninvasive, simple and feasible technique. CEUS could assess renal microvascular perfusion in a real-time and dynamic manner. Further studies with many participants including healthy control group are needed.