The Relationship Between IRRIV and RFR Under Pathologic Conditions

Renal functional reserve (RFR) represents the capacity of the kidney to increase glomerular filtration rate (GFR) in response to certain physiological or pathological stimuli or conditions.

RFR is calculated as the difference between the measured maximum GFR achieved through a renal stress test and the baseline GFR measured in rest conditions. In clinical practice, the most common renal stress test is performed as a standardized protein loading test. Recently, in a pilot study, the investigators demonstrated a significant correlation between RFR and the intra-parenchymal renal resistive index variation (IRRIV) during an echo renal stress test in a cohort of healthy volunteers. IRRIV test has proven to be rapid, safe, bedside and easy to perform and it might represent a preliminary test in screening patients' RFR.The present pilot study is designed to explore the correlation between IRRIV and RFR under pathologic conditions.