title: Adaptive imaging on a diagnostic ultrasound scanner at quasi real-time rates.
abstract: Constructing an ultrasonic imaging system capable of compensating for phase errors in real-time is a significant challenge in adaptive imaging. We present a versatile adaptive imaging system capable of updating arrival time profiles at frame rates of approximately 2 frames per second (fps) with 1-D arrays and up to 0.81 fps for 1.75-D arrays, depending on the desired near-field phase correction algorithm. A novel feature included in this system is the ability to update the aberration profile at multiple beam locations for 1-D arrays. The features of this real-time adaptive imaging system are illustrated in tissue-mimicking phantoms with physical near-field phase screens and evaluated in clinical breast tissue with a 1.75-D array. The contrast-to-noise ratio (CNR) of anechoic cysts was shown to improve dramatically in the tissue-mimicking phantoms. In breast tissue, the width of point-like targets showed significant improvement: a reduction of 26.2% on average. Brightness of these targets, however, marginally decreased by 3.9%. For larger structures such as cysts, little improvement in features and CNR were observed, which is likely a result of the system assuming an infinite isoplanatic patch size for the 1.75-D arrays. The necessary requirements for constructing a real-time adaptive imaging system are also discussed.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, USA. jeremy.dahl@duke.edu
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Dahl
authors.forename: Stephen A
authors.initials: SA
authors.lastname: McAleavey
authors.forename: Gianmarco F
authors.initials: GF
authors.lastname: Pinton
authors.forename: Mary S
authors.initials: MS
authors.lastname: Soo
authors.forename: Gregg E
authors.initials: GE
authors.lastname: Trahey
mesh_terms: D003199:Computer Systems; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods; D014741:Video Recording / Q000295:instrumentation* / Q000379:methods