Point Shear Wave Elastography (pSWE) for Evaluating Relation between Laboratory Renal Function Deterioration in Chronic Kidney Disease (CKD) and Degree of Renal StiffnessPoint Shear Wave Elastography (pSWE) for Evaluating Relation between Laboratory Renal Function Deterioration in Chronic Kidney Disease (CKD) and Degree of Renal Stiffness

Abstract Aim of Work: To evaluate the role of point shear wave elastography (pSWE) in detecting degree of renal fibrosis and correlating it to deterioration of renal function in chronic kidney disease patients. Background: Chronic kidney disease (CKD) is diagnosed by either of the following lasting for more than 3 months: Decrease of glomerular filtration rate (GFR) less than 60ml/min/1.73m2 which is the best index of kidney function, or presence of markers for kidney damage as albuminuria. Renal fibrosis is nearly the ultimate common pathway for all CKD. The main method in clinical use for the assessment of renal fibrosis is the renal biopsy which is known for its considerable disadvantages like its invasive nature, with a risk of further complications, high cost, inter-observer varia-bility, and sampling error. Shear wave elastography (SWE) is one of the promising techniques that allow non-invasive estimation of tissue stiffness. Material and Methods: This study was performed at the Radiodiagnosis Department, Zagazig University. We examined 42CKD patients who underwent pSWEas well as laboratory detection of Estimated glomerular filtration rate (eGFR). Patients were classified according to GFR into fivestages: Into stage 1 (eGFR ³90), stage 2 (eGFR 60-89), stage 3 (eGFR 30-59), stage 4 (eGFR 15-29), and stage 5 (eGFR <15). All analyses were done using the Statistical Package for theSocial Sciences 20.0 software. Results: The mean value of SWE (kPa) in CBD patients (5.44±1.4). The mean SWE values in the CKD stages were 3.65±0.9, 4.5±1.2, 5.8±0.5, 5.3±1.1, 6.6±0.9 kPa in stages 1,2,3,4, and 5 respectively. There was no significant difference between CKD stages except between stage 1 vs. 5 and stage 2 vs. 5.Only age showed a significant correlation with SWE in CKD patients (r=0.453; p=0.039). The laboratory investi-gationrevealed that 6 patients stage I (110±26.5), 8 patients stage II (71.5±1), 8 patients stage III (45.5±8.3), 6 patients stage IV (23±6.2) and 14 patients stage V (8.3±2.8). The cut-off value for predicting CKD was 4.05 kPa with 85.70% sensitivity and 90.5% specificity, while for predicting kidney fibrosis it was 4.45 kPa with 93.3% sensitivity and 83.3% specificity.
Conclusion: Our results suggest that SWE can distinguish between normal subjects and patients with CKD. It also can detect renal fibrosis but cannot correlate with different CKD stages detected by GFR.