Occlusion with collaterals may also present similar waveforms. Severe unilateral RAS produces size asymmetry with the involved kidney smaller. May resolve spontaneously or increase in size requiring intervention Pseudoaneurysms May coexist with AVF after rupture of a pseudoaneurysm into adjacent venous structure. Thrombus may be seen in the renal vein. Occasionally areas of increased echogenicity due to hemorrhage within the kidney can be seen.
Sonography can detect dilatation of the vein proximal.
Chronic RVT results in shrunken, echogenic kidney Renal arterial signal may exhibit reversed diastolic flow.