NDLI: Aperture design analysis for vector flow imaging

Content Provider	IEEE Xplore Digital Library
Author	Kerr, R.F. Anderson, M.E.
Copyright Year	2002
Description	Author affiliation: Dept. of Electr. & Comput. Eng., Rochester Univ., NY, USA (Kerr, R.F.)
Abstract	We present the results of a study exploring the upper velocity limit of vector flow estimation with Heterodyned Spatial Quadrature. Since this is highly dependent on apodization, we investigated a set of apodization windows designed to explore means of extending the practical velocity range. Heterodyned Spatial Quadrature (HSQ) is a recently described vector flow technique that has been shown to provide accurate flow estimates in both the axial and lateral directions. The complex PSF created by this technique induces a modulation in the received echo of a scatterer traversing the resolution volume at a frequency proportional to the scatterer lateral velocity. We measure the rate of phase change of this modulation to provide an estimate of the lateral flow velocity component. The technique is extendible to 3D vector flow estimation with a 2D array. We expect lateral tracking methods in general to be limited by a number of factors including the PSF beam width and the system amplitude sensitivity. Using a Siemens Elegra ultrasound scanner with a 7.5 MHz linear array, we simulated flow up to 405 /spl mu/m per step in a tissue-mimicking phantom, corresponding to velocities up to 4.05 m/sec for a PRF of 10 kHz, at Doppler angles of 60/spl deg/ and 90/spl deg/. We estimated lateral velocities to within 5% relative bias up to 315 cm/sec in an f/2 geometry at a 90/spl deg/ Doppler angle. The spatial quadrature receive aperture utilized a bi-lobed Blackman apodization with a width of 1/2D, where D is the full width of the array. Computer simulations of the system under similar conditions produced lateral velocity estimates up to 303 cm/sec. As expected, the maximum estimable velocity scales with focal depth. In simulations, the same aperture estimated flow velocities up to 672 cm/sec at a focal depth of 75 mm, representing an f/5 geometry.
Sponsorship	Ultransonics Ferroelectr., & Frequency Control Soc
Starting Page	1511
Ending Page	1516
File Size	138214
Page Count	6
File Format	PDF
ISBN	0780375823
ISSN	10510117
DOI	10.1109/ULTSYM.2002.1192584
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2002-10-08
Publisher Place	Germany
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Apertures Image analysis Scattering Geometry Spatial resolution Frequency Fluid flow measurement Velocity measurement Phase measurement Phase modulation
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in