Kidney Elastography in Adult Nephrology: A Narrative Review.

Chronic kidney disease (CKD) represents a rising global health crisis traditionally monitored through routine biochemical markers that may not fully reflect underlying structural alterations. While renal biopsy remains the invasive reference standard for histopathological assessment, ultrasound elastography, particularly shear wave elastography (SWE), has emerged as a promising non-invasive imaging technique for assessing the mechanical properties of the renal parenchyma. This narrative review examines the role of renal elastography in adult nephrology, linking the pathophysiology of renal fibrosis with advances in clinical imaging. We discuss the biological mechanisms underlying changes in renal tissue biomechanics and review the available evidence regarding the association between elastography-derived stiffness measurements and histopathological fibrosis in native kidneys and renal allografts. Although several studies have demonstrated promising diagnostic potential, the clinical interpretation of renal stiffness remains challenging due to tissue anisotropy, renal perfusion and congestion, inflammation, obstruction, hydration status, body habitus, and acquisition-related factors. Current evidence supports renal elastography primarily as a potential adj method to conventional clinical, biochemical, and imaging assessment rather than as a replacement for kidney biopsy. Future integration of elastography with artificial intelligence, multiparametric ultrasound, and molecular biomarkers may further improve non-invasive renal phenotyping, although multicentre and longitudinal validation are required before widespread clinical use.