Renal artery stenosis is characterized by: *A - a high resistance index in the indirect and direct method *B - a low resistance index in the indirect and direct method *C - a low resistance index in the indirect and high RI in the direct method *D - a high resistance index in the indirect and low RI in the indirect method
C - a low resistance index in the indirect and high RI in the direct method The high RI in the direct method represents a measurement at the level of the stenosis (ostium), showing high velocity peaks past a narrowed lumen. The low RI in de indirect method represents a reduced bloodflow to the kidney with reduced velocity.
Left intrarenal Doppler examination shows a normal arterial curve with sharp systolic peak and resistance index <0.70
Intrarenal Doppler examination reveals a low resistance index (0.52) in the right kidney with flattened arterial curves (parvus tardus), suggestive for renal artery stenosis by the indirect method. Ostial arterial curves were not obtainable due to important bowel movement artefacts (direct method).