title: Automated calculation of stenosis diameters from the width of the velocity jet with the use of a multi-gate pulsed Doppler system.
abstract: The aim of this study was to evaluate an algorithm for automated estimation of the width of a jet stream originating from a stenosis. The evaluation was performed in a pulsatile flow model. The width of the jetstream was assessed by measuring the diameter of the region with relatively high velocities (the jet) in the velocity profiles, as recorded with a multi-gate pulsed Doppler system. Measurements were performed at 3, 6, and 9 mm downstream of three different stenoses (stenosis diameter: 3, 5, or 8 mm) at different Reynolds numbers (200-1600) based on time averaged flow velocity for a tube of diameter 15 mm. The developed algorithm was used successfully for automated detection and quantification of jet flow diameters downstream to a stenosis. The algorithm can be used for calculating the stenosis diameter notwithstanding a theoretically predictable overestimation of about 1 mm, depending on the Reynolds number and the distance from the stenosis.
authors.affiliation: Institute of Pediatrics, Dept. of Pediatric Cardiology, Nijmegen, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: de Knecht
authors.forename: J C
authors.initials: JC
authors.lastname: Hopman
authors.forename: J L
authors.initials: JL
authors.lastname: Alsters
authors.forename: O
authors.initials: O
authors.lastname: Daniëls
authors.forename: A P
authors.initials: AP
authors.lastname: Hoeks
authors.forename: R S
authors.initials: RS
authors.lastname: Reneman
mesh_terms: D000465:Algorithms; D001157:Arterial Occlusive Diseases / Q000175:diagnosis / Q000473:pathology*; D001783:Blood Flow Velocity; D003251:Constriction, Pathologic; D006801:Humans; D008955:Models, Cardiovascular; D012212:Rheology; D014463:Ultrasonography / Q000379:methods*