Portable high-intensity focused ultrasound system with 3D electronic steering, real-time cavitation monitoring, and 3D image reconstruction algorithms: a preclinical study in pigs

Abstract

Purpose:The aim of this study was to evaluate the safety and accuracy of a new portable ultrasonography-guided high-intensity focused ultrasound (USg-HIFU) system with a 3-dimensional (3D) electronic steering transducer, a simultaneous ablation and imaging module, real-time cavitation monitoring, and 3D image reconstruction algorithms.Methods:To address the accuracy of the transducer, hydrophones in a water chamber were used to assess the generation of sonic fields. An animal study was also performed in five pigs by ablating in vivo thighs by single-point sonication (n=10) or volume sonication (n=10) and ex vivo kidneys by single-point sonication (n=10). Histological and statistical analyses were performed.Results:In the hydrophone study, peak voltages were detected within 1.0 mm from the targets on the y- and z-axes and within 2.0-mm intervals along the x-axis (z-axis, direction of ultrasound propagation; y- and x-axes, perpendicular to the direction of ultrasound propagation). Twenty-nine of 30 HIFU sessions successfully created ablations at the target. The in vivo porcine thigh study showed only a small discrepancy (width, 0.5-1.1 mm; length, 3.0 mm) between the planning ultrasonograms and the pathological specimens. Inordinate thermal damage was not observed in the adjacent tissues or sonic pathways in the in vivo thigh and ex vivo kidney studies.Conclusion:Our study suggests that this new USg-HIFU system may be a safe and accurate technique for ablating soft tissues and encapsulated organs.

Fast, Low-Frequency Plane-Wave Imaging for Ultrasound Contrast Imaging

“…Effective and safe FUS treatment requires guidance via MRI or ultrasound imaging, typically achieved by using separate imaging and therapy systems, but often require custom hardware development and co-registration of imaging and therapeutic systems. Ultrasound-guided FUS (USgFUS) systems have been steadily gaining prominence (Ebbini and Ter Haar 2015) since they supply real-time feedback and do not require an MR imaging system, but many of these systems are bulky or are dedicated treatment systems (Choi et al 2014; Haritonova et al 2015). A perpendicular configuration of a transmit (therapeutic) and receive transducer to monitor bubbles at the focus has been used but leaves for a mechanically limited system with a constrained treatment area (Wang et al 2015).…”

“…A perpendicular configuration of a transmit (therapeutic) and receive transducer to monitor bubbles at the focus has been used but leaves for a mechanically limited system with a constrained treatment area (Wang et al 2015). Others have employed a parallel configuration, where the receive transducer is embedded into the center of a doughnut shaped transmit transducer (Choi et al 2014; Liu et al 2016; Tung et al 2010), or sandwiched between the therapeutic transducers (Kruse et al 2010). The use of a low-frequency phased-array transducer opens the possibility of having dual therapy and imaging modes in a single transducer (Ebbini et al 2006; Kotopoulis et al 2013) with no custom hardware development or co-registration required to align the therapeutic and imaging plane.…”

MRI-guided focused ultrasound surgery in musculoskeletal diseases: the hot topics

“…Through MR thermometry, it is possible to monitor the temperature in the target volume in near real time and calculate the thermal dose received by the treated region. Although several improvements have been introduced even for ultrasound guide, 20 MRI shows a few advantages in terms of parameters of sonication (no need for fast sonication/cavitation), panoramic view of the field of treatment, excellent pre-/post-treatment evaluation and, as mentioned above, of temperature monitoring during the energy delivery.…”

Optimized treatment parameter by computer simulation for high-intensity focused ultrasound treatment of uterine adenomyosis: Short-term and long-term results

“…In addition to the brain, prostate gland, bone, or uterine leiomyomas [13][14][15][16][17], HIFU has been successfully applied for the treatment of uterine adenomyosis [18][19][20][21]. Moreover, there have been technological advances in the HIFU system that have enabled safer and more effective treatments, which have been demonstrated in preclinical and clinical studies targeting uterine fibroids [22,23]. However, the optimal parameters of HIFU treatment for uterine adenomyosis have not yet been established.…”