Trivedi, Vishwas V.Vishwas V.TrivediWallach, Emily L.Emily L.WallachBader, Kenneth B.Kenneth B.BaderShekhar, HimanshuHimanshuShekhar2025-08-312025-08-312023-09-0110.1109/TUFFC.2023.32899182-s2.0-85163480414https://d8.irins.org/handle/IITG2025/2666337379172Histotripsy is a focused ultrasound therapy that ablates tissue via bubble cloud activity. Real-time ultrasound image guidance is used to ensure safe and effective treatment. Plane-wave imaging enables tracking of histotripsy bubble clouds at a high frame rate but lacks adequate contrast. Furthermore, bubble cloud hyperechogenicity is reduced in abdominal targets, making the development of contrast-specific sequences for deep-seated targets an active area of research. Chirp-coded subharmonic imaging was reported previously to enhance histotripsy bubble cloud detection by a modest 4-6 dB compared to the conventional sequence. Incorporating additional steps into the signal processing pipeline could enhance bubble cloud detection and tracking. In this study, we evaluated the feasibility of combining chirp-coded subharmonic imaging with Volterra filtering for enhancing bubble cloud detection in vitro. Chirped imaging pulses were used to track bubble clouds generated in scattering phantoms at a 1-kHz frame rate. Fundamental and subharmonic matched filters were applied to the received radio frequency signals, followed by a tuned Volterra filter to extract bubble-specific signatures. For subharmonic imaging, the application of the quadratic Volterra filter improved the contrast-to-tissue ratio from 5.18 ± 1.29 to 10.90 ± 3.76 dB, relative to the application of the subharmonic matched filter. These findings demonstrate the utility of the Volterra filter for histotripsy image guidance.falseCavitation | contrast-enhanced imaging | high-frame-rate imaging | histotripsy | nonlinear filtering | polynomial filtersArticlehttps://www.ncbi.nlm.nih.gov/pmc/articles/1071447315258955989-9981 September 20238arJournal7WOS:001059175300008