Arterial thrombosis are critical due to supply of biliary system.
Arterial Stenosis - PSV > 200 cm/s or focal increase in velocity 3x, RI < 0.5 (parvus tardus wave form).
Renal Vein Thrombosis - reversal of arterial flow
Renal Artery Stenosis - PSV > 200 cm/s
Rejection - elevated RI > 0.9, chonic rejection kidney is small, acute rejection kidney is large.