What is the role of vascular Ultrasound in evaluating renal transplants?
US with color spectral Doppler imaging is the preferred initial study of choice for screening transplanted kidneys for vascular complications, as potentially nephrotoxic contrast agents are not required as in the case of CT or MR imaging. In addition to detecting main RAS in the transplant kidney, vascular US also screens for direct and indirect signs of main renal vein thrombosis. In the immediate post-transplant period, acute tubular necrosis and acute transplant rejection can both result in elevated RIs and low or absent diastolic flow in the intrarenal arteries. Elevated RIs in the late post-transplant period are most commonly due to chronic rejection or cyclosporine toxicity.