title: Evaluation of bias voltage modulation sequence for nonlinear contrast agent imaging using a capacitive micromachined ultrasonic transducer array.
abstract: Many clinical diagnoses have now been improved thanks to the development of new techniques dedicated to contrast agent nonlinear imaging. Over the past few years, Capacitive Micromachined Ultrasonic Transducers (cMUTs) have emerged as a promising alternative to traditional piezoelectric transducers. One notable advantage of cMUTs is their wide frequency bandwidth. However, their use in nonlinear imaging approaches such as those used to detect contrast agents have been challenging due their intrinsic nonlinear character. We propose a new contrast imaging sequence, called bias voltage modulation (BVM), specifically developed for cMUTs to suppress their inherent nonlinear behavior. Theoretical and experimental results show that a complete cancellation of the nonlinear signal from the source can be reached when the BVM sequence is implemented. In-vitro validation of the sequence is performed using a cMUT probe connected to an open scanner and a flow phantom setup containing SonoVue microbubbles. Compared to the standard amplitude modulation imaging mode, a 6 dB increase of contrast-to-tissue ratio was achieved when the BVM sequence is applied. These results reveal that the problem of cMUT nonlinearity can be addressed, thus expanding the potential of this new transducer technology for nonlinear contrast agent detection and imaging.
authors.affiliation: Université François-Rabelais de Tours, Inserm, Imagerie et Cerveau UMR U930, Tours, France. Joint Department of Biomedical Engineering, The University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Novell
authors.forename: Mathieu
authors.initials: M
authors.lastname: Legros
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Grégoire
authors.forename: Paul A
authors.initials: PA
authors.lastname: Dayton
authors.forename: Ayache
authors.initials: A
authors.lastname: Bouakaz
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D006801:Humans; D045423:Microbubbles; D019047:Phantoms, Imaging; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods
chemical_list: D003287:Contrast Media