title: Multifrequency Interlaced CMUTs for Photoacoustic Imaging.
abstract: Multifrequency capacitive micromachined ultrasound transducers (CMUTs) are introduced consisting of interlaced 82- [Formula: see text] (low frequency) and 36- [Formula: see text] (high frequency) membranes. The membranes have been interlaced on a scale smaller than the shortest wavelength of operation allowing several advantages over other multifrequency transducer designs including aligned beam profiles, optimal imaging resolution, and minimal grating lobes. The low- and high-frequency CMUTs operate at 1.74 and 5.04 MHz in immersion, respectively. Multifrequency transducers have applications in wideband photoacoustic (PA) imaging where multifrequency transducers are better able to detect both high- and low-frequency PA frequency content. The PA frequency content is target size dependent, which means traditional high-frequency transducers have less sensitivity to larger objects such as diffuse contrast agents. We demonstrate that the low-frequency subarrays are able to better visualize diffuse agent distributions, while the high-frequency subarrays offer fine-resolution imaging important for microvascular imaging and structural navigation. Spectroscopically unmixed images superimpose high sensitivity images of agent concentrations (acquired using low-frequency subarrays) onto high-resolution images of microvessel-mimicking phantoms (acquired using high-frequency subarrays).
authors.forename: Ryan K W
authors.initials: RK
authors.lastname: Chee
authors.forename: Peiyu
authors.initials: P
authors.lastname: Zhang
authors.forename: Mohammad
authors.initials: M
authors.lastname: Maadi
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Zemp
mesh_terms: D004867:Equipment Design; D006197:Hair / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008954:Models, Biological; D019047:Phantoms, Imaging; D061088:Photoacoustic Techniques / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*