Intrarenal arteriovenous shunts in kidney transplants demonstrated by contrast-enhanced ultrasound

The kidney can undergo several hemodynamic changes in response to physiological stressful conditions. Arteriovenous (AV) shunting is an example where renal blood flow is redistributed away from the cortex toward the metabolically vulnerable medulla. Identification of this phenomenon is important as it may reflect underlying pathology. Despite evidence of renal AV shunting, its existence has been questioned. To our knowledge, this case series demonstrates for the first time the presence of renal AV shunting using contrast enhanced ultrasound.