- Aorta at the level of the superior mesenteric artery (SMA).
- The lumen of the origin, proximal and mid-right renal artery (RRA) appears narrowed with some aliasing under colour Doppler ultrasound.
- The lumen of the distal RRA appears normal and no aliasing is seen.
- Velocity at the RRA origin is markedly increased and is 5 times greater than the aortic velocity. These findings suggest a >70% stenosis.
- Velocities within the proximal RRA remain markedly elevated.
- Velocities within the mid-RRA remain markedly elevated.
- Velocity in the distal RRA is within normal limits. No tardus-parvus waveforms were seen.
- The intrarenal waveforms in the right kidney are normal, with possible loss of the early systolic peak. The resistive indices were >0.5 lower than in the left kidney (see next picture) supporting compromised blood supply to the right kidney.
- There is an early systolic peak in the intrarenal waveforms of the left kidney. Resistive indices were >0.5 higher than in the right kidney.
Markedly elevated velocities, a renal/aortic ratio of up to 5 and apparent luminal narrowing and aliasing from the origin to the midpoint of the right renal artery. A difference greater than 0.5 in the resistive indices of the intrarenal waveforms between the kidneys.
These findings suggest a >70% stenosis in the right renal artery despite tardus-parvus waveforms not being seen.