The degree of stenosis is correlated with the clinical event: the greater is the stenosis, the greater is the risk of TIA/stroke and the benefit of surgery. So particular care should be used to evaluate the percentage of stenosis.
The Doppler signal and colorDoppler are dependent on the angle of incidence between the Doppler beam and the direction of blood flow.
To measure correctly the flow velocity, the angle of the sample volume must not be aligned with the internal carotid artery (ICA) wall contour, but with the flow vector (the contour of the plaque).A case of angle of incidence incorrectly aligned with the wall contour of the ICA (and not with the flow vector) resulting in over-estimation of the degree of stenosis, is reported.
Franco Accorsi, MD
Member of the Order of Physician of Bologna n° 6728
I am a specialist in Medical Angiology and I am based in Bologna, Italy. Until 2008 (voluntary resignation) I worked at Maggiore Hospital in Bologna as "Dirigente Medico" in the Department of Internal Medicine and as Angiologist in the Angiology Unit with a position of "Alta Professionalità" in "Vascular Ecography and Angiology".
I am currently working in Bologna as an independent professional in the areas of angiology and vascular diagnostics.
I have been a speaker at national and international courses/congress and I have taught duplex ultrasound method in GIUV and SIUMB courses at the Maggiore Hospital, Bologna and courses of echocolor Doppler of extracranial and intracranial arteries at the Stroke Unit of S. Maria Nuova Hospital, Reggio Emilia.