title: Real-time implementation of a dual-mode ultrasound array system: in vivo results.
abstract: A real-time dual-mode ultrasound array (DMUA) system for imaging and therapy is described. The system utilizes a concave (40-mm radius of curvature) 3.5 MHz, 32 element array, and modular multichannel transmitter/receiver. The system is capable of operating in a variety of imaging and therapy modes (on transmit) and continuous receive on all array elements even during high-power operation. A signal chain consisting of field-programmable gate arrays and graphical processing units is used to enable real time, software-defined beamforming and image formation. Imaging data, from quality assurance phantoms as well as in vivo small- and large-animal models, are presented and discussed. Corresponding images obtained using a temporally-synchronized and spatially-aligned diagnostic probe confirm the DMUA's ability to form anatomically-correct images with sufficient contrast in an extended field of view around its geometric center. In addition, high-frame rate DMUA data also demonstrate the feasibility of detection and localization of echo changes indicative of cavitation and/or tissue boiling during high-intensity focused ultrasound exposures with 45-50 dB dynamic range. The results also show that the axial and lateral resolution of the DMUA are consistent with its f(number) and bandwidth with well-behaved speckle cell characteristics. These results point the way to a theranostic DMUA system capable of quantitative imaging of tissue property changes with high specificity to lesion formation using focused ultrasound.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Casper
authors.forename: Dalong
authors.initials: D
authors.lastname: Liu
authors.forename: John R
authors.initials: JR
authors.lastname: Ballard
authors.forename: Emad S
authors.initials: ES
authors.lastname: Ebbini
mesh_terms: D000818:Animals; D003199:Computer Systems; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D007089:Image Enhancement / Q000295:instrumentation*; D051381:Rats; D013552:Swine; D014159:Transducers; D014464:Ultrasonic Therapy / Q000295:instrumentation*; D014463:Ultrasonography / Q000295:instrumentation*