Renal bruit – bruit due to renal artery stenosis
Epigastric bruit conducted laterally is suggestive of renal bruit. But many of the renal bruit occur due to ostial stenosis of the renal artery, which may not be conducted laterally. Bruit due to renal artery stenosis may also be heard in the renal angle, posteriorly.
Orientation of echo beam vs Doppler interrogation
For 2D imaging the ultrasound beam has to be perpendicular to the structure being imaged to get good images while in Doppler interrogation, the beam has to be parallel to the flow to get good velocity spectrum. If the angle between the beam and the direction of flow is more than 20 degrees, the error in estimated velocity will be high.
How are the angiographic measurements calibrated?
Angiographic measurements are calibrated with reference to the catheter used. 6F catheter will have a diameter of 2 mm (1F ~ 0.33 mm).
What precaution will you take while taking aortic root angio to assess aortic regurgitation?
The catheter tip should be outside the sinus of Valsalva to prevent the catheter from physically interfering with the closure of the aortic leaflets and producing artefactual aortic regurgitation.