title: Mode vibrations of a matrix transducer for three-dimensional second harmonic transesophageal echocardiography.
abstract: Transesophageal echocardiography (TEE) uses the esophagus as an imaging window to the heart. This enables cardiac imaging without interference from the ribs or lungs and allows for higher frequency ultrasound to be used compared with transthoracic echocardiography (TTE). TEE facilitates the successful imaging of obese or elderly patients, where TTE may be unable to produce images of satisfactory quality. Recently, three-dimensional (3-D) TEE has been introduced, which greatly improves the image quality and diagnostic value of TEE by adding an extra dimension. Further improvement could be achieved by optimizing 3-D TEE for harmonic imaging. This article describes the optimal geometry and element configuration for a matrix probe for 3-D second harmonic TEE. The array concept features separated transmit and receive subarrays. The element geometry was studied using finite element modeling and a transmit subarray prototype was examined both acoustically and with laser interferometry. The transmit subarray is suitable for its role, with a 3 MHz resonance frequency, a 40%-50% -3 dB bandwidth and crosstalk levels <-27 dB. The proposed concept for the receive subarray has a 5.6 MHz center frequency and a 50% -3 dB bandwidth.
authors.affiliation: Department of Biomedical Engineering, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Paul L M J
authors.initials: PL
authors.lastname: van Neer
authors.forename: Sandra
authors.initials: S
authors.lastname: Blaak
authors.forename: Johan G
authors.initials: JG
authors.lastname: Bosch
authors.forename: Charles T
authors.initials: CT
authors.lastname: Lancée
authors.forename: Christian
authors.initials: C
authors.lastname: Prins
authors.forename: Anton F W
authors.initials: AF
authors.lastname: van der Steen
authors.forename: Nico
authors.initials: N
authors.lastname: de Jong
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D019560:Echocardiography, Three-Dimensional / Q000295:instrumentation*; D017548:Echocardiography, Transesophageal / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D013016:Sound; D014159:Transducers