title: Optimizing the beam pattern of a forward-viewing ring-annular ultrasound array for intravascular imaging.
abstract: Intravascular ultrasound (IVUS) imaging systems using circumferential arrays mounted on cardiac catheter tips fire beams orthogonal to the principal axis of the catheter. The system produces high resolution cross-sectional images but must be guided by conventional angioscopy. A real-time forward-viewing array, integrated into the same catheter, could greatly reduce radiation exposure by decreasing angiographic guidance. Unfortunately, the mounting requirement of a catheter guide wire prohibits a full-disk imaging aperture. Given only an annulus of array elements, prior theoretical investigations have only considered a circular ring of point transceivers and focusing strategies using all elements in the highly dense array, both impractical assumptions. In this paper, we consider a practical array geometry and signal processing architecture for a forward-viewing IVUS system. Our specific design uses a total of 210 transceiver firings with synthetic reconstruction for a given 3-D image frame. Simulation results demonstrate this design can achieve side-lobes under -40 dB for on-axis situations and under -30 dB for steering to the edge of a 80 degrees cone.
authors.affiliation: Biomedical Engineering Department, University of Michigan, Ann Arbor, MI, USA. ywangz@umich.edu
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.forename: Douglas N
authors.initials: DN
authors.lastname: Stephens
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
mesh_terms: D001808:Blood Vessels / Q000000981:diagnostic imaging*; D002404:Catheterization / Q000295:instrumentation* / Q000379:methods; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008904:Miniaturization; D008962:Models, Theoretical; D011786:Quality Control; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D014159:Transducers; D018084:Ultrasonography, Interventional / Q000295:instrumentation* / Q000379:methods*