Pahk, Ki Joo Gelat, Pierre Sinden, David Dhar, Dipok Kumar Saffari, Nader 2024-01-20T00:02:22Z 2024-01-20T00:02:22Z 2021-09-03 2017-12 0301-5629 https://pubs.kist.re.kr/handle/201004/122013 The aim of boiling histotripsy is to mechanically fractionate tissue as an alternative to thermal ablation for therapeutic applications. In general, the shape of a lesion produced by boiling histotripsy is tadpole like, consisting of a head and a tail. Although many studies have demonstrated the efficacy of boiling histotripsy for fractionating solid tumors, the exact mechanisms underpinning this phenomenon are not yet well understood, particularly the interaction of a boiling vapor bubble with incoming incident shockwaves. To investigate the mechanisms involved in boiling histotripsy, a high-speed camera with a passive cavitation detection system was used to observe the dynamics of bubbles produced in optically transparent tissue-mimicking gel phantoms exposed to the field of a 2.0-MHz high-intensity focused ultrasound (HIFU) transducer. We observed that boiling bubbles were generated in a localized heated region and cavitation clouds were subsequently induced ahead of the expanding bubble. This process was repeated with HIFU pulses and eventually resulted in a tadpole-shaped lesion. A simplified numerical model describing the scattering of the incident ultrasound wave by a vapor bubble was developed to help interpret the experimental observations. Together with the numerical results, these observations suggest that the overall size of a lesion induced by boiling histotripsy is dependent on the sizes of (i) the heated region at the HIFU focus and (ii) the backscattered acoustic field by the original vapor bubble. (E-mail: n.saffari@ucl.ac.uk) (C) 2017 World Federation for Ultrasound in Medicine & Biology. All rights reserved. English ELSEVIER SCIENCE INC INTENSITY FOCUSED ULTRASOUND PULSED CAVITATIONAL ULTRASOUND CANINE MODEL TISSUE FRACTIONATION INTRINSIC THRESHOLD LESION FORMATION GEL PHANTOM ABLATION LIVER ATOMIZATION NUMERICALAND EXPERIMENTAL STUDY OF MECHANISMS INVOLVED IN BOILING HISTOTRIPSY Article 10.1016/j.ultrasmedbio.2017.08.938 1 ULTRASOUND IN MEDICINE AND BIOLOGY, v.43, no.12, pp.2848 - 2861 ULTRASOUND IN MEDICINE AND BIOLOGY 43 12 2848 2861 scie scopus 000415604700011 Acoustics Radiology, Nuclear Medicine & Medical Imaging Acoustics Radiology, Nuclear Medicine & Medical Imaging Article INTENSITY FOCUSED ULTRASOUND PULSED CAVITATIONAL ULTRASOUND CANINE MODEL TISSUE FRACTIONATION INTRINSIC THRESHOLD LESION FORMATION GEL PHANTOM ABLATION LIVER ATOMIZATION High-intensity focused ultrasound Boiling histotripsy Boiling bubbles Cavitation clouds