WorldWideScience

Sample records for accelerated focused ultrasound

  1. Focused Ultrasound and Lithotripsy.

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  2. Prostate Focused Ultrasound Therapy.

    Chapelon, Jean-Yves; Rouvière, Olivier; Crouzet, Sébastien; Gelet, Albert

    2016-01-01

    The tremendous progress in engineering and computing power coupled with ultrasound transducer technology and imaging modalities over the past 20 years have encouraged a revival of clinical interest in ultrasound therapy, mainly in High-Intensity Focused Ultrasound (HIFU). So far, the most extensive results from HIFU obtained in urology involve transrectal prostate ablation, which appears to be an effective therapeutic alternative for patients with malignant prostate tumors. Prostate cancer (PCa) is one of the most frequently diagnosed cancers in men. Several treatment options with different therapeutic approaches exist, including HIFU for localized PCa that has been in use for over 15 years. Since the early 2000s, two systems have been marketed for this application, and other devices are currently in clinical trials. HIFU treatment can be used either alone or in combination with (before- or after-) external beam radiotherapy (EBRT) (before or after HIFU) and can be repeated multiple times. HIFU treatment is performed under real-time monitoring with ultrasound or guided by MRI. Two indications are validated today: Primary care treatment and EBRT failure. The results of HIFU for primary care treatment are similar to standard conformal EBRT, even though no randomized comparative studies have been performed and no 10-year follow up data is yet available for HIFU. Salvage HIFU after EBRT failure is increasing with oncological outcomes, similar to those achieved with surgery but with the advantage of fewer adverse effects. HIFU is an evolving technology perfectly adapted for focal treatment. Thus, HIFU focal therapy is another pathway that must be explored when considering the accuracy and reliability for PCa mapping techniques. HIFU would be particularly suited for such a therapy since it is clear that HIFU outcomes and toxicity are relative to the volume of prostate treated. PMID:26486330

  3. Ultrasound focusing images in superlattices

    Narita, Michiko; Tanaka, Yukihiro; Tamura, Shin-ichiro

    2002-03-01

    We study theoretically ultrasound focusing in periodic multilayered structures, or superlattices, by solving the wave equation with the Green function method and calculating the transmitted ultrasound amplitude images of both the longitudinal and transverse modes. The constituent layers assumed are elastically isotropic but the periodically stacked structure is anisotropic. Thus anisotropy of ultrasound propagation is predicted even at low frequencies and it is enhanced significantly at higher frequencies due to the zone-folding effect of acoustic dispersion relations. An additional effect studied is the interference of ultrasound (known as the internal diffraction), which can be recognized when the propagation distance is comparable to the ultrasound wavelength. Numerical examples are developed for millimetre-scale Al/polymer multilayers used recently for imaging experiment with surface acoustic waves.

  4. Synthetic focusing in ultrasound modulated tomography

    Kuchment, Peter

    2010-09-01

    Several hybrid tomographic methods utilizing ultrasound modulation have been introduced lately. Success of these methods hinges on the feasibility of focusing ultrasound waves at an arbitrary point of interest. Such focusing, however, is difficult to achieve in practice. We thus propose a way to avoid the use of focused waves through what we call synthetic focusing, i.e. by reconstructing the would-be response to the focused modulation from the measurements corresponding to realistic unfocused waves. Examples of reconstructions from simulated data are provided. This non-technical paper describes only the general concept, while technical details will appear elsewhere. © 2010 American Institute of Mathematical Sciences.

  5. Focusing Ultrasound with Acoustic Metamaterial Network

    Zhang, Shu; Fang, Nicholas

    2009-01-01

    We present the first experimental demonstration of focusing ultrasound waves through a flat acoustic metamaterial lens composed of a planar network of subwavelength Helmholtz resonators. We observed a tight focus of half-wavelength in width at 60.5 KHz by imaging a point source. This result is in excellent agreement with the numerical simulation by transmission line model in which we derived the effective mass density and compressibility. This metamaterial lens also displays variable focal length at different frequencies. Our experiment shows the promise of designing compact and light-weight ultrasound imaging elements.

  6. CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

    To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large

  7. Geometrically focused neutral beam accelerators

    A more reliable 40 kV, 65 A power supply drain at 0.4 A/cm2, neutral-beam accelerator was developed for the Tandem Mirror Experiment (TMX). Multiple slotted aperture grids of 60% transparency are fabricated from refractory metal wires mounted to form a spherical surface. This geometrically focuses the beam by aiming individual beamlets at the center of curvature of the spherical grid (r = 3.2 m). We attain greater reliability and faster conditioning with geometrical focusing than with the previous technique of electrostatically steering beamlets to a common point. Electrostatic steering, accomplished by offsetting grid wires, is satisfactory if the offset of a beamlet is much less than the distance from the beamlet to the grids. It was found that Pierce Angle entrance grids performed better if sharper edged. A redesigned accelerator grid support structure reduced the number of ceramic-to-metal vacuum joints, and eliminated O rings between precisely aligned parts. The suppressor grid feedthrough is required to withstand a maximum voltage of 15 kV occurring during breakdown, greatly exceeding the operating voltage of 1.5 kV. Convenient fabrication and assembly techniques have been developed. Assembly of accelerators and plasma sources in a clean room appears to reduce the conditioning time. Following the successful testing of the prototype, eight 40 kV accelerators were built for TMX. Furthermore, ten 20 kV versions were built that are modifiable to 40 kV by exchanging the entrance grid

  8. Enhancement of Focused Ultrasound Treatment by Acoustically Generated Microbubbles

    Umemura, Shin-ichiro; Yoshizawa, Shin; Takagi, Ryo; Inaba, Yuta; Yasuda, Jun

    2013-07-01

    Microbubbles, whether introduced from outside the body or ultrasonically generated in situ, are known to significantly enhance the biological effects of ultrasound, including the mechanical, thermal, and sonochemical effects. Phase-change nanodroplets, which selectively accumulate in tumor tissue and whose phase changes to microbubbles can be induced by ultrasonic stimulation, have been proposed for high-intensity focused ultrasound (HIFU) tumor treatment with enhanced selectivity and efficiency. In this paper, a purely acoustic approach to generate microbubble clouds in the tissue to be treated is proposed. Short pulses of focused ultrasound with extremely high intensity, named trigger pulses, are used for exposure. They are immediately followed by focused ultrasound for heating with an intensity similar to or less than that of normal HIFU treatment. The localized generation of microbubble clouds by the trigger pulses is observed in a polyarylamide gel by a high-speed camera, and the effectiveness of the generated clouds in accelerating ultrasonically induced thermal coagulation is confirmed in excised chicken breast tissue. The use of second-harmonic superimposed waves as the trigger pulses is also proposed. The highly reproducible initiation of cavitation by waves with the negative peak pressure emphasized and the efficient expansion of the generated microbubble clouds by waves with the positive peak pressure emphasized are also observed by a high-speed camera in partially degassed water.

  9. Spatial filters for focusing ultrasound images

    Jensen, Jørgen Arendt; Gori, Paola

    2001-01-01

    . A new method for making spatial matched filter focusing of RF ultrasound data is proposed based on the spatial impulse response description of the imaging. The response from a scatterer at any given point in space relative to the transducer can be calculated, and this gives the spatial matched filter...... for beamforming the received RF signals from the individual transducer elements. The matched filter is applied on RF signals from individual transducer elements, thus properly taking into account the spatial spread of the received signal. The method can be applied to any transducer and can also be used...... of the autocovariance function of the image shows a -6 dB width reduction by a factor of 3.3 at 20 mm and by a factor of 1.8 at 30 mm. Other simulations use a 64 elements, 3 MHz, linear array. Different receiving conditions are compared and this shows that the effect of the filter is progressively lower...

  10. Ultrasound-mediated Optical Imaging and Focusing in Scattering Media

    Suzuki, Yuta

    photorefractive materials as the phase-conjugate mirrors. By using a large-area photorefractive polymer as the phase-conjugate mirror, we boosted the focused optical energy by ~40 times over the output of a previously used photorefractive Bi 12SiO20 crystal. Furthermore, using both a photorefractive polymer and a Bi12SiO20 crystal as the phase-conjugate mirrors, we show direct visualization and dynamic control of TRUE focus, and demonstrate fluorescence imaging in a thick turbid medium. The last part of this dissertation describes improvements in the scanning speed of a TRUE focus, using digital phase-conjugate mirrors in both transmission and reflection modes. By employing a multiplex recording of ultrasonically encoded wavefronts in transmission mode, we have accelerated the generation of multiple TRUE foci, using frequency sweeping of both ultrasound and light. With this technique, we obtained a 2-D image of a fluorescent target centered inside a turbid sample having a thickness of 2.4 lt'. Also, by gradually moving the focal position in reflection mode, we show that the TRUE focal intensity is improved, and can be continuously scanned to image fluorescent targets in a shorter time.

  11. High-intensity focused ultrasound: advances in technology and experimental trials support enhanced utility of focused ultrasound surgery in oncology

    Malietzis, G; Monzon, L.; Hand, J.; Wasan, H; Leen, E; Abel, M.; Muhammad, A; Price, P; Abel, P.

    2013-01-01

    High-intensity focused ultrasound (HIFU) is a rapidly maturing technology with diverse clinical applications. In the field of oncology, the use of HIFU to non-invasively cause tissue necrosis in a defined target, a technique known as focused ultrasound surgery (FUS), has considerable potential for tumour ablation. In this article, we outline the development and underlying principles of HIFU, overview the limitations and commercially available equipment for FUS, then summarise some of the rece...

  12. High-Intensity Focused Ultrasound Therapy: an Overview for Radiologists

    Kim, Young-sun; Rhim, Hyunchul; Choi, Min Joo; Lim, Hyo Keun; Choi, Dongil

    2008-01-01

    High-intensity focused ultrasound therapy is a novel, emerging, therapeutic modality that uses ultrasound waves, propagated through tissue media, as carriers of energy. This completely non-invasive technology has great potential for tumor ablation as well as hemostasis, thrombolysis and targeted drug/gene delivery. However, the application of this technology still has many drawbacks. It is expected that current obstacles to implementation will be resolved in the near future. In this review, w...

  13. Investigation of Manipulation Technique of Microbubbles Using Focused Ultrasound.

    Osaki, Taichi; Inoue, Kazuhito; Matsumoto, Yoichiro; Takagi, Shu; Azuma, Takashi; Ichiyanagi, Mitsuhisa

    2015-11-01

    Recently, it has been thought that the application of ultrasound and microbubbles(MB) is utility to the medical field. Should MB be manipulated contactlessly, it will contribute to the mechanism investigation on the drug delivery system using MB as drug carrier. However no technique has yet to be established that can trap MB at any desired position, manipulate them along any desired path. Accordingly in this research, we investigated whether it was possible to trap MB at desired position, manipulate them along desired paths through experiments aimed at the development of MB manipulation tools that utilize ultrasound. Moreover, we analyzed the microbubble behaviors in ultrasound field. Bubbles in the ultrasound wave field are subjected to the primary Bjerknes force. Our method aimed that MB are trapped at the antinode or the node and manipulated with moving the antinode or node. We fabricated a concave transducer which radiates focused ultrasound and used sonazoid as MB and they were trapped at the focus as a cluster. The transducer moves its own position to move its focus and manipulate MB. Besides, we observed the trapped cluster with several incident frequencies. MB were trapped and manipulated along a locus of alphabet ?M? about 100 µm. From this result, it is implied that MB can be manipulated along any desired path. Moreover, there was the inverse correlation between the trapped cluster size and the incident frequency.

  14. High-Intensity Focused Ultrasound Therapy: an Overview for Radiologists

    Kim, Young Sun; Rhim, Hyun Chul; Lim, Hyo Keun; Choi, Dong Il [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Choi, Min Joo [College of Medicine, Cheju National University, Jeju (Korea, Republic of)

    2008-08-15

    High-intensity focused ultrasound therapy is a novel, emerging, therapeutic modality that uses ultrasound waves, propagated through tissue media, as carriers of energy. This completely non-invasive technology has great potential for tumor ablation as well as hemostasis, thrombolysis and targeted drug/gene delivery. However, the application of this technology still has many drawbacks. It is expected that current obstacles to implementation will be resolved in the near future. In this review, we provide an overview of high-intensity focused ultrasound therapy from the basic physics to recent clinical studies with an interventional radiologist's perspective for the purpose of improving the general understanding of this cutting-edge technology as well as speculating on future developments

  15. Adverse Events of Extracorporeal Ultrasound-Guided High Intensity Focused Ultrasound Therapy

    Tinghe Yu; Jun Luo

    2011-01-01

    BACKGROUND: High-intensity focused ultrasound (HIFU) is considered to be an alternative to surgery. Extracorporeal ultrasound-guided HIFU (USgFU) has been clinically used to treat solid tumors. Preliminary trials in a small sample of a Western population suggested that this modality was safe. Most trials are performed in China thereby providing comprehensive data for understanding the safety profile. The aim of this study was to evaluate adverse events of USgFU therapy. METHODS AND FINDINGS: ...

  16. An Rf Focused Interdigital Ion Accelerating Structure

    An Rf Focused Interdigital (RFI) ion accelerating structure will be described. It represents an effective combination of the Wideroee (or interdigital) linac structure, used for many low frequency, heavy ion applications, and the rf electric quadrupole focusing used in the RFQ and RFD linac structures. As in the RFD linac structure, rf focusing is introduced into the RFI linac structure by configuring the drift tubes as two independent pieces operating at different electrical potentials as determined by the rf fields of the linac structure. Each piece (or electrode) of the RFI drift tube supports two fingers pointed inwards towards the opposite end of the drift tube forming a four-finger geometry that produces an rf quadrupole field along the axis of the linac for focusing the beam. However, because of the differences in the rf field configuration along the axis, the scheme for introducing rf focusing into the interdigital linac structure is quite different from that adopted for the RFD linac structure. The RFI linac structure promises to have significant size, efficiency, performance, and cost advantages over existing linac structures for the acceleration of low energy ion beams of all masses (light to heavy). These advantages will be reviewed. A 'cold model' of this new linac structure has been fabricated and the results of rf cavity measurements on this cold model will be presented

  17. Controlled Hyperthermia with MRI-guided Focused Ultrasound

    Hokland, Steffen; Salomir, Rares; Pedersen, Michael

    doses sufficient to induce cellular deactivation thermotherapy is still regarded as an experimental treatment. In contrast to other thermo-therapeutic modalities Focused Ultrasound (FUS) may be employed non-invasively to deliver a highly localized thermal build-up in deep seated regions of the body...

  18. Design and Fabrication of Double-Focused Ultrasound Transducers to Achieve Tight Focusing.

    Jang, Jihun; Chang, Jin Ho

    2016-01-01

    Beauty treatment for skin requires a high-intensity focused ultrasound (HIFU) transducer to generate coagulative necrosis in a small focal volume (e.g., 1 mm³) placed at a shallow depth (3-4.5 mm from the skin surface). For this, it is desirable to make the F-number as small as possible under the largest possible aperture in order to generate ultrasound energy high enough to induce tissue coagulation in such a small focal volume. However, satisfying both conditions at the same time is demanding. To meet the requirements, this paper, therefore, proposes a double-focusing technique, in which the aperture of an ultrasound transducer is spherically shaped for initial focusing and an acoustic lens is used to finally focus ultrasound on a target depth of treatment; it is possible to achieve the F-number of unity or less while keeping the aperture of a transducer as large as possible. In accordance with the proposed method, we designed and fabricated a 7-MHz double-focused ultrasound transducer. The experimental results demonstrated that the fabricated double-focused transducer had a focal length of 10.2 mm reduced from an initial focal length of 15.2 mm and, thus, the F-number changed from 1.52 to 1.02. Based on the results, we concluded that the proposed double-focusing method is suitable to decrease F-number while maintaining a large aperture size. PMID:27509500

  19. Focusing of ferroelectret air-coupled ultrasound transducers

    Gaal, Mate; Bartusch, Jürgen; Dohse, Elmar; Schadow, Florian; Köppe, Enrico

    2016-02-01

    Air-coupled ultrasound has been applied increasingly as a non-destructive testing method for lightweight construction in recent years. It is particularly appropriate for composite materials being used in automotive and aviation industry. Air-coupled ultrasound transducers mostly consist of piezoelectric materials and matching layers. However, their fabrication is challenging and their signal-to-noise ratio often not sufficient for many testing requirements. To enhance the efficiency, air-coupled ultrasound transducers made of cellular polypropylene have been developed. Because of its small density and sound velocity, this piezoelectric ferroelectret matches the small acoustic impedance of air much better than matching layers applied in conventional transducers. In our contribution, we present two different methods of spherical focusing of ferroelectret transducers for the further enhancement of their performance in NDT applications. Measurements on carbon-fiber-reinforced polymer (CFRP) samples and on metal adhesive joints performed with commercially available focused air-coupled ultrasound transducers are compared to measurements executed with self-developed focused ferroelectret transducers.

  20. Numerical simulations of clinical focused ultrasound functional neurosurgery

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-04-01

    A computational model utilizing grid and finite difference methods were developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13% lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13% smaller in the anterior-posterior direction and 22 ± 14% smaller in the inferior-superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  1. Numerical simulations of clinical focused ultrasound functional neurosurgery

    A computational model utilizing grid and finite difference methods were developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13% lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13% smaller in the anterior–posterior direction and 22 ± 14% smaller in the inferior–superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  2. Noninvasive measurement of local thermal diffusivity using backscattered ultrasound and focused ultrasound heating.

    Anand, Ajay; Kaczkowski, Peter J

    2008-09-01

    Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create a brief local temperature rise of no more than 10 degrees C. Beamformed radio-frequency (RF) data are collected during heating and cooling using a clinical ultrasound scanner. Measurements of the time-varying "acoustic strain", that is, spatiotemporal variations in the RF echo shifts induced by the temperature related sound speed changes, are related to a solution of the heat transfer equation to estimate the thermal diffusivity in the heated zone. Numerical simulations and experiments performed in vitro in tissue mimicking phantoms and excised turkey breast muscle tissue demonstrate agreement between the ultrasound derived thermal diffusivity estimates and independent estimates made by a traditional hot-wire technique. The new noninvasive ultrasonic method has potential applications in thermal therapy planning and monitoring, physiological monitoring and as a means of noninvasive tissue characterization. PMID:18450361

  3. High intensity focused ultrasound in clinical tumor ablation

    Zhou, Yu-Feng

    2011-01-01

    Recent advances in high intensity focused ultrasound (HIFU), which was developed in the 1940s as a viable thermal tissue ablation approach, have increased its popularity. In clinics, HIFU has been applied to treat a variety of solid malignant tumors in a well-defined volume, including the pancreas, liver, prostate, breast, uterine fibroids, and soft-tissue sarcomas. In comparison to conventional tumor/cancer treatment modalities, such as open surgery, radio- and chemo-therapy, HIFU has the ad...

  4. Salvage radiotherapy after high intensity focused ultrasound for prostate cancer

    Dickinson, Peter; Sundar, Santhanam

    2012-01-01

    High-intensity focused ultrasound (HIFU) is a technique that has been used to treat localised prostate cancer. There is no standard treatment for patients who relapse with prostate cancer following primary treatment with HIFU; here we report the case of a patient who was successfully treated with external beam radiotherapy for disease relapse following HIFU. To date, our patient remains disease free with no toxicity from his treatment.

  5. Acceleration and Focusing of Plasma Flows

    Griswold, Martin E.

    The acceleration of flowing plasmas is a fundamental problem that is useful in a wide variety of technological applications. We consider the problem from the perspective of plasma propulsion. Gridded ion thrusters and Hall thrusters are the most commonly used devices to create flowing plasma for space propulsion, but both suffer from fundamental limitations. Gridded ion sources create good quality beams in terms of energy spread and spatial divergence, but the Child-Langmuir law in the non-neutral acceleration region limits the maximum achievable current density. Hall thrusters avoid this limitation by accelerating ions in quasi-neutral plasma but, as a result, produce plumes with high spatial divergence and large energy spread. In addition the more complicated magnetized plasma in the Hall Thruster produces oscillations that can reduce the efficiency of the thruster by increasing electron transport to the anode. We present investigations of three techniques to address the fundamental limitations on the performance of each thruster. First, we propose a method to increase the time-averaged current density (and thus thrust density) produced by a gridded ion source above the Child-Langmuir limit by introducing time-varying boundary conditions. Next, we use an electrostatic plasma lens to focus the Hall thruster plume, and finally we develop a technique to suppress a prominent oscillation that degrades the performance of Hall thrusters. The technique to loosen the constraints on current density from gridded ion thrusters actually applies much more broadly to any space charge limited flow. We investigate the technique with a numerical simulation and by proving a theoretical upper bound. While we ultimately conclude that the approach is not suitable for space propulsion, our results proved useful in another area, providing a benchmark for research into the spontaneously time-dependent current that arises in microdiodes. Next, we experimentally demonstrate a novel

  6. Spatiotemporal drug delivery using laser-generated-focused ultrasound system.

    Di, Jin; Kim, Jinwook; Hu, Quanyin; Jiang, Xiaoning; Gu, Zhen

    2015-12-28

    Laser-generated-focused ultrasound (LGFU) holds promise for the high-precision ultrasound therapy owing to its tight focal spot, broad frequency band, and stable excitation with minimal ultrasound-induced heating. We here report the development of the LGFU as a stimulus for promoted drug release from microgels integrated with drug-loaded polymeric nanoparticles. The pulsed waves of ultrasound, generated by a carbon black/polydimethylsiloxane (PDMS)-photoacoustic lens, were introduced to trigger the drug release from alginate microgels encapsulated with drug-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles. We demonstrated the antibacterial capability of this drug delivery system against Escherichia coli by the disk diffusion method, and antitumor efficacy toward the HeLa cell-derived tumor spheroids in vitro. This novel LGFU-responsive drug delivery system provides a simple and remote approach to precisely control the release of therapeutics in a spatiotemporal manner and potentially suppress detrimental effects to the surrounding tissue, such as thermal ablation. PMID:26299506

  7. Nakagami imaging for detecting thermal lesions induced by high-intensity focused ultrasound in tissue.

    Rangraz, Parisa; Behnam, Hamid; Tavakkoli, Jahan

    2014-01-01

    High-intensity focused ultrasound induces focalized tissue coagulation by increasing the tissue temperature in a tight focal region. Several methods have been proposed to monitor high-intensity focused ultrasound-induced thermal lesions. Currently, ultrasound imaging techniques that are clinically used for monitoring high-intensity focused ultrasound treatment are standard pulse-echo B-mode ultrasound imaging, ultrasound temperature estimation, and elastography-based methods. On the contrary, the efficacy of two-dimensional Nakagami parametric imaging based on the distribution of the ultrasound backscattered signals to quantify properties of soft tissue has recently been evaluated. In this study, ultrasound radio frequency echo signals from ex vivo tissue samples were acquired before and after high-intensity focused ultrasound exposures and then their Nakagami parameter and scaling parameter of Nakagami distribution were estimated. These parameters were used to detect high-intensity focused ultrasound-induced thermal lesions. Also, the effects of changing the acoustic power of the high-intensity focused ultrasound transducer on the Nakagami parameters were studied. The results obtained suggest that the Nakagami distribution's scaling and Nakagami parameters can effectively be used to detect high-intensity focused ultrasound-induced thermal lesions in tissue ex vivo. These parameters can also be used to understand the degree of change in tissue caused by high-intensity focused ultrasound exposures, which could be interpreted as a measure of degree of variability in scatterer concentration in various parts of the high-intensity focused ultrasound lesion. PMID:24264647

  8. The thresholds and mechanisms of tissue injury by focused ultrasound

    Simon, Julianna

    Therapeutic ultrasound is used in clinics around the world to treat ailments such as uterine fibroids, kidney stones, and plantar fasciitis. While many of the therapeutic effects of ultrasound are elicited by hyperthermia, bubbles can also interact with tissue to produce beneficial effects. For example, bubbles are used in boiling histotripsy to de-bulk tissue and are used in shock wave lithotripsy to break kidney stones. However, the same bubbles that break the kidney stones also damage the kidney, which is why bubble damage is a concern in every ultrasound application including fetal imaging. Whether the aim is to emulsify a tumor or image a fetus, understanding the thresholds and mechanisms of tissue injury by bubbles in an ultrasound field is important for all ultrasound applications and was the goal of this dissertation. One specific application of therapeutic ultrasound, known as boiling histotripsy, uses shock wave heating to explosively expand a millimeter-size boiling bubble at the transducer focus and fractionate bulk tissue. Yet it was unclear how the millimeter-size boiling or vapor bubble broke down the tissue into its submicron components. In this dissertation, we experimentally tested the hypothesis that ultrasonic atomization, or the emission of fine droplets from an acoustically excited liquid film, is the mechanism by which the millimeter-size boiling bubble in boiling histotripsy fractionates tissue into its submicron components. Using high speed photography, we showed that tissue can behave as a liquid such that a miniature acoustic fountain forms and atomization occurs within a millimeter-size cavity that approximates the boiling or vapor bubble produced by boiling histotripsy. The end result of tissue atomization was a hole in the tissue surface. After showing that tissue can be eroded by atomization, a series of experiments were conducted to determine the tissue properties that influence atomization. The results indicated that highly

  9. High-intensity focused ultrasound monitoring using harmonic motion imaging for focused ultrasound (HMIFU) under boiling or slow denaturation conditions.

    Hou, Gary Y; Marquet, Fabrice; Wang, Shutao; Apostolakis, Iason-Zacharias; Konofagou, Elisa E

    2015-07-01

    Harmonic motion imaging for focused ultrasound (HMIFU) is a recently developed high-intensity focused ultrasound (HIFU) treatment monitoring method that utilizes an amplitude-modulated therapeutic ultrasound beam to induce an oscillatory radiation force at the HIFU focus and estimates the focal tissue displacement to monitor the HIFU thermal treatment. In this study, the performance of HMIFU under acoustic, thermal, and mechanical effects was investigated. The performance of HMIFU was assessed in ex vivo canine liver specimens (n = 13) under slow denaturation or boiling regimes. A passive cavitation detector (PCD) was used to assess the acoustic cavitation activity, and a bare-wire thermocouple was used to monitor the focal temperature change. During lesioning with slow denaturation, high quality displacements (correlation coefficient above 0.97) were observed under minimum cavitation noise, indicating the tissue initial-softening-then- stiffening property change. During HIFU with boiling, HMIFU monitored a consistent change in lesion-to-background displacement contrast (0.46 ± 0.37) despite the presence of strong cavitation noise due to boiling during lesion formation. Therefore, HMIFU effectively monitored softening-then-stiffening during lesioning under slow denaturation, and detected lesioning under boiling with a distinct change in displacement contrast under boiling in the presence of cavitation. In conclusion, HMIFU was shown under both boiling and slow denaturation regimes to be effective in HIFU monitoring and lesioning identification without being significantly affected by cavitation noise. PMID:26168177

  10. Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

    Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood–brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood–brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that

  11. Ultrasound- and MR-guided focused ultrasound surgery for prostate cancer

    Zini, Chiara; Hipp, Elisabeth; Thomas, Stephen; Napoli, Alessandro; Catalano, Carlo; Oto, Aytekin

    2012-01-01

    Prostate cancer (PC) is one of the most frequently diagnosed cancers in men. There are a number of treatment options for PC with a different therapeutic approach between USA and Europe. Radical prostatectomy is one of the most used therapies but focal gland therapy is an emerging approach, especially for localized tumors. In this scenario, high intensity focused ultrasound (HIFU) has been incorporated in certain medical association guidelines. HIFU has been employed for about 10 years especia...

  12. Blood coagulation using High Intensity Focused Ultrasound (HIFU)

    Nguyen, Phuc V.; Oh, Junghwan; Kang, Hyun Wook

    2014-03-01

    High Intensity Focused Ultrasound (HIFU) technology provides a feasible method of achieving thermal coagulation during surgical procedures. One of the potential clinical benefits of HIFU can induce immediate hemostasis without suturing. The objective of this study was to investigate the efficiency of a HIFU system for blood coagulation on severe vascular injury. ngHIFU treatment was implemented immediately after bleeding in artery. The ultrasound probe was made of piezoelectric material, generating a central frequency of 2.0 MHz as well as an ellipsoidal focal spot of 2 mm in lateral dimension and 10 mm in axial dimension. Acoustic coagulation was employed on a perfused chicken artery model in vitro. A surgical incision (1 to 2 mm long) was made with a scapel on the arterial wall, and heparinized autologous blood was made to leak out from the incision with a syringe pump. A total of 5 femoral artery incisions was treated with the HIFU beam. The intensity of 4500 W/cm2 at the focus was applied for all treatments. Complete hemostasis was achieved in all treatments, along with the treatment times of 25 to 50 seconds. The estimated intraoperative blood loss was from 2 to 5 mL. The proposed HIFU system may provide an effective method for immediate blood coagulation for arteries and veins in clinical applications.

  13. Use of High Intensity Focused Ultrasound for Treating Malignant Tumors

    WenzhiChen; ZhibiaoWang; FengWu; JinBai; HuiZhu; JianzhongZou; KequanLi; FanglinXie; ZhilongWang

    2004-01-01

    OBJECTIVE To investigate the efficacy and side effects of high intensity focused ultrasound(HIFU) in the treatment of malignant solid tumors. METHODS Thirty patients who refused surgery and/or were refractory to chemotherapy were treated by HIFU alone, with the efficacy and side effects monitored as follows: observation of vital organ signs; functional assay of important organs; imaging examinations including: digital subtraction angiography (DSA), CT, MRI, single photon emission computed tomography (SPECT), large core needle biopsy, complications and metastasis. RESULTS After HIFU therapy, the vital signs remained stable and the functions of the heart, lung, kidney and liver were also normal. DSA images showed that small or larger arteries were not damaged. After a follow-up of 10-38 months(mean 23.1 months), 26 patients(87%) were alive. The volume of the tumor underwent complete regression in 10 patients. Shrinkage of the tumor volume ≥50% was observed in 13 patients. Eight of 13 patients were examined by large core needle biopsy, all showing necrosis and/or fibrosis though 3 patients(10%) had local recurrence. Two of these were retreated again by HIFU and the locally recurrent tumors were controlled. New metastases developed in 5 patients after H IFU. Two patients suffered from peripheral nerve injuriy and they have recovered during the follow-up. One patient developed skin injury. CONCLUSION High intensity focused ultrasound is effective and safe in the treatment of malignant solid tumors.

  14. High-Intensity Focused Ultrasound in Small Renal Masses

    Eduardo Solsona Narbón

    2008-12-01

    Full Text Available High-intensity focused ultrasound (HIFU competes with radiofrequency and cryotherapy for the treatment of small renal masses as a third option among ablative approaches. As an emerging technique, its possible percutaneous or laparoscopic application, low discomfort to the patient and the absence of complications make this technology attractive for the management of small renal masses. This manuscript will focus on the principles, basic research and clinical applications of HIFU in small renal masses, reviewing the present literature. Therapeutic results are controversial and from an clinical view, HIFU must be considered a technique under investigation at present time. Further research is needed to settle its real indications in the management of small renal masses; maybe technical improvements will certainly facilitate its use in the management of small renal masses in the near future.

  15. Treatment with high intensity focused ultrasound: Secrets revealed

    For many decades open surgery remained the only way available for local control of body tumors. In order to decrease the patients’ morbidity and mortality several image guided minimally invasive procedures have been adopted. High intensity focused ultrasound (HIFU) is an extracorporeal non invasive method for tumor ablation. High intensity ultrasonic waves can be focused to a focal point resulting in lethal elevation of the temperature at the target site with consequent damage of the tumoral cells. The advances in HIFU technology during the past two decades expanded the HIFU applications to include ablation of both benign and malignant tumors with different treatment strategies being implemented for each type. The aim of this review is to introduce the reader to the details of the treatment process including pretreatment preparation, treatment planning, different ablation strategies, patients’ after care as well as the follow up regimens for the most common HIFU applications.

  16. Enhancement of accelerated carbonation of alkaline waste residues by ultrasound.

    Araizi, Paris K; Hills, Colin D; Maries, Alan; Gunning, Peter J; Wray, David S

    2016-04-01

    The continuous growth of anthropogenic CO2 emissions into the atmosphere and the disposal of hazardous wastes into landfills present serious economic and environmental issues. Reaction of CO2 with alkaline residues or cementitius materials, known as accelerated carbonation, occurs rapidly under ambient temperature and pressure and is a proven and effective process of sequestering the gas. Moreover, further improvement of the reaction efficiency would increase the amount of CO2 that could be permanently sequestered into solid products. This paper examines the potential of enhancing the accelerated carbonation of air pollution control residues, cement bypass dust and ladle slag by applying ultrasound at various water-to-solid (w/s) ratios. Experimental results showed that application of ultrasound increased the CO2 uptake by up to four times at high w/s ratios, whereas the reactivity at low water content showed little change compared with controls. Upon sonication, the particle size of the waste residues decreased and the amount of calcite precipitates increased. Finally, the sonicated particles exhibited a rounded morphology when observed by scanning electron microscopy. PMID:26905698

  17. MR-guided focused ultrasound. Current and future applications

    High-intensity focused ultrasound (synonyms FUS and HIFU) under magnetic resonance imaging (MRI) guidance (synonyms MRgFUS and MR-HIFU) is a completely non-invasive technology for accurate thermal ablation of a target tissue while neighboring tissues and organs are preserved. The combination of FUS with MRI for planning, (near) real-time monitoring and outcome assessment of treatment markedly enhances the safety of the procedure. The MRgFUS procedure is clinically established in particular for the treatment of symptomatic uterine fibroids, followed by palliative ablation of painful bone metastases. Furthermore, promising results have been shown for the treatment of adenomyosis, malignant tumors of the prostate, breast and liver and for various intracranial applications, such as thermal ablation of brain tumors, functional neurosurgery and transient disruption of the blood-brain barrier. (orig.)

  18. Focused ultrasound induces apoptosis in pancreatic cancer cells

    GUO Qian; JIANG Li-xin; HU Bing

    2012-01-01

    Background The incidence and mortality rate of pancreatic cancer have increased dramatically in China over recent decades.Focused ultrasound (FU) has been somewhat successful in treating pancreatic cancer.The purpose of this study was to investigate apoptosis in pancreatic cancer cells induced by FU.Methods Suspension of human pancreatic carcinoma cell line PaTu 8988t was radiated by FU,using five doses with different radiation parameters and patterns,including one blank control.Temperature increase of the cell suspension was monitored.Cell apoptosis and death after FU radiation was observed using fluorescence microscopy and was tested by flow cytometer at 3,6,12,24,and 48 hours after ultrasound radiation.Results The maximum cell suspension temperatures following five radiation doses were 28°C,(42.20±2.17)°C,(50.80±0.84)°C,(55.80±2.17)°C,and (65.20±3.11)°C; differences between the doses were statistically significant (P <0.05).The apoptosis rate peaked at 24 hours after radiation,at (0.56±0.15)%,(1.28±0.16)%,(1.84±0.29)%,(5.74±1.15)%,and (2.00±0.84)% for the five doses; differences between the doses were statistically significant (P <0.05).Between doses 1-4,cell apoptosis rates increased as the Tmax increased.In dose 5,as the Tmax was above 60°C,the apoptosis rate decreased.Conclusion Sub-threshold thermal exposures of FU radiation with a continuous radiation pattern could result in higher oercentage of apoptosed cells.

  19. MR-guided focused ultrasound surgery, present and future

    MR-guided focused ultrasound surgery (MRgFUS) is a quickly developing technology with potential applications across a spectrum of indications traditionally within the domain of radiation oncology. Especially for applications where focal treatment is the preferred technique (for example, radiosurgery), MRgFUS has the potential to be a disruptive technology that could shift traditional patterns of care. While currently cleared in the United States for the noninvasive treatment of uterine fibroids and bone metastases, a wide range of clinical trials are currently underway, and the number of publications describing advances in MRgFUS is increasing. However, for MRgFUS to make the transition from a research curiosity to a clinical standard of care, a variety of challenges, technical, financial, clinical, and practical, must be overcome. This installment of the Vision 20/20 series examines the current status of MRgFUS, focusing on the hurdles the technology faces before it can cross over from a research technique to a standard fixture in the clinic. It then reviews current and near-term technical developments which may overcome these hurdles and allow MRgFUS to break through into clinical practice

  20. MR-guided focused ultrasound surgery, present and future

    Schlesinger, David, E-mail: djs9c@virginia.edu [Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22908 and Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia 22908 (United States); Benedict, Stanley [Department of Radiation Oncology, University of California Davis, Davis, California 95817 (United States); Diederich, Chris [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94115 (United States); Gedroyc, Wladyslaw [Department of Medicine, Imperial College, London SW7 2AZ (United Kingdom); Klibanov, Alexander [Departments of Medicine, Cardiovascular Medicine, and Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908 (United States); Larner, James [Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22908 (United States)

    2013-08-01

    MR-guided focused ultrasound surgery (MRgFUS) is a quickly developing technology with potential applications across a spectrum of indications traditionally within the domain of radiation oncology. Especially for applications where focal treatment is the preferred technique (for example, radiosurgery), MRgFUS has the potential to be a disruptive technology that could shift traditional patterns of care. While currently cleared in the United States for the noninvasive treatment of uterine fibroids and bone metastases, a wide range of clinical trials are currently underway, and the number of publications describing advances in MRgFUS is increasing. However, for MRgFUS to make the transition from a research curiosity to a clinical standard of care, a variety of challenges, technical, financial, clinical, and practical, must be overcome. This installment of the Vision 20/20 series examines the current status of MRgFUS, focusing on the hurdles the technology faces before it can cross over from a research technique to a standard fixture in the clinic. It then reviews current and near-term technical developments which may overcome these hurdles and allow MRgFUS to break through into clinical practice.

  1. Ultrasound-guided high-intensity focused ultrasound treatment for abdominal wall endometriosis: Preliminary results

    Wang Yang [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Wang Wei, E-mail: wangyang301301@yahoo.com.cn [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Wang Longxia; Wang Junyan; Tang Jie [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China)

    2011-07-15

    Purpose: To evaluate the safety and therapeutic efficacy of ultrasound (US)-guided high-intensity focused ultrasound (HIFU) ablation for the treatment of abdominal wall endometriosis (AWE). Materials and methods: Twenty-one consecutive patients with AWE were treated as outpatients by US-guided HIFU ablation under conscious sedation. The median size of the AWE was 2.4 cm (range 1.0-5.3 cm). An acoustic power of 200-420 W was used, intermittent HIFU exposure of 1 s was applied. Treatment was considered complete when the entire nodule and its nearby 1 cm margin become hyperechoic on US. Pain relief after HIFU ablation was observed and the treated nodule received serial US examinations during follow-up. Results: All AWE was successfully ablated after one session of HIFU ablation, the ablation time lasted for 5-48 min (median 13 min), no major complications occurred. The cyclic pain disappeared in all patients during a mean follow-up of 18.7 months (range 3-31 months). The treated nodules gradually shank over time, 16 nodules became unnoticeable on US during follow-up. Conclusion: US-guided HIFU ablation appears to be safe and effective for the treatment of AWE.

  2. Ultrasound-guided high-intensity focused ultrasound treatment for abdominal wall endometriosis: Preliminary results

    Purpose: To evaluate the safety and therapeutic efficacy of ultrasound (US)-guided high-intensity focused ultrasound (HIFU) ablation for the treatment of abdominal wall endometriosis (AWE). Materials and methods: Twenty-one consecutive patients with AWE were treated as outpatients by US-guided HIFU ablation under conscious sedation. The median size of the AWE was 2.4 cm (range 1.0-5.3 cm). An acoustic power of 200-420 W was used, intermittent HIFU exposure of 1 s was applied. Treatment was considered complete when the entire nodule and its nearby 1 cm margin become hyperechoic on US. Pain relief after HIFU ablation was observed and the treated nodule received serial US examinations during follow-up. Results: All AWE was successfully ablated after one session of HIFU ablation, the ablation time lasted for 5-48 min (median 13 min), no major complications occurred. The cyclic pain disappeared in all patients during a mean follow-up of 18.7 months (range 3-31 months). The treated nodules gradually shank over time, 16 nodules became unnoticeable on US during follow-up. Conclusion: US-guided HIFU ablation appears to be safe and effective for the treatment of AWE.

  3. Clinical Application of High-intensity Focused Ultrasound in Cancer Therapy

    Hsiao, Yi-Hsuan; Kuo, Shou-Jen; Tsai, Horng-Der; Chou, Ming-Chih; Yeh, Guang-Perng

    2016-01-01

    The treatment of cancer is an important issue in both developing and developed countries. Clinical use of ultrasound in cancer is not only for the diagnosis but also for the treatment. Focused ultrasound surgery (FUS) is a noninvasive technique. By using the combination of high-intensity focused ultrasound (HIFU) and imaging method, FUS has the potential to ablate tumor lesions precisely. The main mechanisms of HIFU ablation involve mechanical and thermal effects. Recent advances in HIFU have...

  4. Thrombolysis using multi-frequency high intensity focused ultrasound at MHz range: an in vitro study

    Suo, Dingjie; Guo, Sijia; Lin, Weili; Jiang, Xiaoning; Jing, Yun

    2015-09-01

    High intensity focused ultrasound (HIFU) based thrombolysis has emerged as a promising drug-free treatment approach for ischemic stroke. The large amount of acoustic power required by this approach, however, poses a critical challenge to the future clinical translation. In this study, multi-frequency acoustic waves at MHz range (near 1.5 MHz) were introduced as HIFU excitations to reduce the required power for treatment as well as the treatment time. In vitro bovine blood clots weighing around 150 mg were treated by single-frequency and multi-frequency HIFU. The pulse length was 2 ms for all experiments except the ones where the duty cycle was changed. It was found that dual-frequency thrombolysis efficiency was statistically better than single-frequency under the same acoustic power and excitation condition. When varying the acoustic power but fixing the duty cycle at 5%, it was found that dual-frequency ultrasound can save almost 30% power in order to achieve the same thrombolysis efficiency. In the experiment where the duty cycle was increased from 0.5% to 10%, it was shown that dual-frequency ultrasound can achieve the same thrombolysis efficiency with only half of the duty cycle of single-frequency. Dual-frequency ultrasound could also accelerate the thrombolysis by a factor of 2-4 as demonstrated in this study. No significant differences were found between dual-frequencies with different frequency differences (0.025, 0.05, and 0.1 MHz) and between dual-frequency and triple-frequency. The measured cavitation doses of dual-frequency and triple-frequency excitations were at about the same level but both were significantly higher than that of single-frequency.

  5. Extracorporeal High-Intensity Focused Ultrasound Treatment for Breast Cancer

    HuiZhu; FengWu; WenzhiChen; YoudeCao; JinBai; ZhibiaoWang

    2004-01-01

    OBJECTIVE To evaluate the clinical safety and efficacy of using highintensity focused ultrasound (HIFU) therapy, for breast cancer, and to select the appropriate methods in evaluating the therapeutic effects.METHODS A total of 24 patients with breast cancer underwent HIFU treatment 1-2 weeks before receiving modified radical mastectomy. During and after HIFU therapy, changes in blood pressure, breath, pulse and peripheral blood oxygen saturation were monitored. At the same time, the damage of the skin and tissue produced by HIFU at the target region was evaluated as well. Surgically excised samples were used for pathological examinations to evaluate the HIFU-induced destruction of the targeted tissue. Three patients received Tc-ECT and 1 MRI examinations before and after HIFU.RESULTS HIFU treatment had no apparent influence on either the tissue nearby the target or on vital signs of the patients. Pathological, tc-ECT and MRI examinations demonstrated that targeted tissue showed complete coagulative necrosis.CONCLUSION Under the guidance of real-time ultrasonic imaging, HIFU can effectively and safely destroy the breast cancer mass and 99MTc-ECT and MRI examination can be utilized to evaluate the therapeutic effects.HIFU may become one of the options for breast cancer therapy in the future.

  6. Study on the focusing properties of the accelerating tube

    An accelerating tube is an electrostatic lens system. The author made use of the micro unit model to derive the path equations of an accelerating tube by integrating the ion path of a unit electrostatic lens. The focusing properties are discussed according to the calculated results

  7. Adverse events of extracorporeal ultrasound-guided high intensity focused ultrasound therapy.

    Tinghe Yu

    Full Text Available BACKGROUND: High-intensity focused ultrasound (HIFU is considered to be an alternative to surgery. Extracorporeal ultrasound-guided HIFU (USgFU has been clinically used to treat solid tumors. Preliminary trials in a small sample of a Western population suggested that this modality was safe. Most trials are performed in China thereby providing comprehensive data for understanding the safety profile. The aim of this study was to evaluate adverse events of USgFU therapy. METHODS AND FINDINGS: Clinical data were searched in 2 Chinese databases. Adverse events of USgFU were summarized and compared with those of magnetic resonance-guided HIFU (MRgFU; for uterine, bone or breast tumor and transrectal ultrasound-guided HIFU (for prostate cancer or benign prostate hyperplasia. USgFU treatment was performed using 7 types of device. Side effects were evaluated in 13262 cases. There were fewer adverse events in benign lesions than in malignant lesions (11.81% vs. 21.65%, p<0.0001. Rates of adverse events greatly varied between the disease types (0-280%, p<0.0001 and between the applied HIFU devices in both malignant (10.58-44.38%, p<0.0001 and benign lesions (1.67-17.57%, p<0.0001. Chronological analysis did not demonstrate a decrease in the rate of adverse events. Based upon evaluable adverse events, incidences in USgFU were consistent with those in MRgFU or transrectal HIFU. Some side effects frequently occurred following transrectal HIFU were not reported in USgFU. Several events including intrahepatic metastasis, intraoperative high fever, and occlusions of the superior mesenteric artery should be of particular concern because they have not been previously noted. The types of adverse events suggested that they were ultrasonic lesions. CONCLUSION: The frequency of adverse events depended on the location of the lesion and the type of HIFU device; however, side effects of USgFU were not yet understood. USgFU did not decrease the incidence of adverse events

  8. Optical focusing inside scattering media with time-reversed ultrasound microbubble encoded (TRUME) light

    Ruan, Haowen; Yang, Changhuei

    2015-01-01

    Focusing light inside scattering media in a freely addressable fashion is challenging, as the wavefront of the scattered light is highly disordered. Recently developed ultrasound-guided wavefront shaping methods are addressing this challenge, albeit with relatively low modulation efficiency and resolution limitations. In this paper, we present a new technique, time-reversed ultrasound microbubble encoded (TRUME) optical focusing, which is able to focus light with improved efficiency and sub-ultrasound wavelength resolution. This method ultrasonically destructs microbubbles, and measures the wavefront change to compute and render a suitable time-reversed wavefront solution for focusing. We demonstrate that the TRUME technique can create an optical focus at the site of bubble destruction with a size of ~2 microns. Due to the nonlinear pressure-to-destruction response, the TRUME technique can break the addressable focus resolution barrier imposed by the ultrasound focus. We experimentally demonstrate a 2-fold ad...

  9. Development of a High Intensity Focused Ultrasound (HIFU) Hydrophone System

    The growing clinical use of High Intensity Focused Ultrasound (HIFU) has driven a need for reliable, reproducible measurements of HIFU acoustic fields. We have previously presented data on a reflective scatterer approach, incorporating several novel features for improved bandwidth, reliability, and reproducibility [Proc. 2005 IEEE Ultrasonics Symposium, 1739-1742]. We now report on several design improvements which have increase the signal to noise ratio of the system, and potentially reduced the cost of implementation. For the scattering element, we now use an artificial sapphire material to provide a more uniform radiating surface. The receiver is a segmented, truncated spherical structure with a 10 cm radius; the scattering element is positioned at the center of the sphere. The receiver is made from 25 micron thick, biaxially stretched PVDF, with a Pt-Au electrode on the front surface. In the new design, a specialized backing material provides the stiffness required to maintain structural stability, while at the same time providing both electrical shielding and ultrasonic absorption. Compared with the previous version, the new receiver design has improved the noise performance by 8-12 dB; the new scattering sphere has reduced the scattering loss by another 14 dB, producing an effective sensitivity of -298 dB re 1 microVolt/Pa. The design trade-off still involves receiver sensitivity with effective spot size, and signal distortion from the scatter structure. However, the reduced cost and improved repeatability of the new scatter approach makes the overall design more robust for routine waveform measurements of HIFU systems.

  10. Efficacy of high-intensity focused ultrasound ablation for adenomyosis therapy and sexual life quality

    Long, Ling; Chen, Jinyun; Xiong, Yu; Zou, Min; Deng, Yongbin; Chen, Li; WANG, ZHIBIAO

    2015-01-01

    Objective: The aim of this study was to evaluate the efficacy, safety and sexual life quality outcomes of ultrasound-guided high-intensity focused ultrasound (HIFU) ablations for the treatment of patients with symptomatic adenomyosis and uterine volumes >200 cm3. Methods: In our prospective clinical trial 47 patients with uterine volumes >200 cm3 and symptomatic adenomyosis were treated with single treatment sessions of ultrasound-guided HIFU ablations. Beside uterus and adenomyosis lesion si...

  11. Triggered Drug Release from Superhydrophobic Meshes using High-Intensity Focused Ultrasound

    Yohe, Stefan T.; Kopechek, Jonathan A.; Porter, Tyrone M.; Colson, Yolonda L.; Grinstaff, Mark W.

    2013-01-01

    Application of high-intensity focused ultrasound to drug-loaded superhydrophobic meshes affords triggered drug release by displacing an entrapped air layer. The air layer within the superhydrophobic meshes is characterized using direct visualization and B-mode imaging. Drug-loaded superhydrophobic meshes are cytotoxic in an in vitro assay after ultrasound treatment.

  12. Effects of High Intensity Focused Ultrasound on the Brain

    Vykhodtseva, Natalia; McDannold, Nathan; Hynynen, Kullervo

    2007-05-01

    Bio-effects in the brain resulting from short focused ultrasound (FUS) pulses (1-10 ms, PRF=0.5, 1.0, and 2.0 Hz, frequency=1.63 MHz) at high acoustic power (up to 700W) were examined. Fifty-seven locations were targeted through a craniotomy in the brains of 11 rabbits. Temperature rise was measured with MRI-based thermometry. The animals were sacrificed 4 h or 48 h after sonications for histological evaluations. A range of effects was observed: (1) Vascular changes (vasoconstriction/occlusion). (2) Homogenization of tissue. (3) Concentric circular lesions; (4) Hemorrhagic lesions similar to what was described earlier as inertial cavitation effects. Overall, the type of damage correlated with the acoustical power, with substantial overlapping among categories. Vascular changes were found at ˜140-180W, the thresholds for homogenized tissue and hemorrhagic lesions were approximately 200W and 350W, respectively. Some of these effects might be exploited for new therapies. Vascular occlusion might also be exploited for therapy; the lesions with homogenized tissue may suggest a new mechanism for non-thermal tissue ablation; small ones for ophthalmology and for functional neurosurgery (if produced in nerve tracts). The mechanism for this effect is unknown, but with the acoustic intensities used, non-linear absorption, strong radiation forces and microbubble activity were likely to have been present. MRI-based temperature changes suggest that thermal effects were probably not responsible for these lesions, as the average focal temperature (approximately 47°C) was slightly below the threshold for thermal damage. The overlap between types of tissue effects for a given acoustic intensity indicates that a method to guide such cavitation-based therapies is needed. MRI was promising in some ways — we can detect where the effects were happening and whether or not cavitation occurred. While the artifacts in temperature mappings will make temperature measurements problematic

  13. Design and simulation of an accelerating and focusing system

    A Sadeghipanah

    2011-06-01

    Full Text Available Electrostatic focusing lenses have a vast field of applications in electrostatic accelerators and particularly in electron guns. In this paper, we first express a parametric mathematical analysis of an electrostatic accelerator and focusing system for an electron beam. Next, we At design a system of electron emission slit, accelerating electrodes and focusing lens for an electron beam emitted from a cathode with 4 mm radius and 2 mA current, in a distance less than 10 cm and up to the energy of 30 keV with the beam divergence less than 5°. This is achieved by solving the yielded equations in mathematical analysis using MATLAB. At the end, we simulate the behavior of above electron beam in the designed accelerating and focusing system using CST EM Studio. The results of simulation are in high agreement with required specifications of the electron beam, showing the accuracy of the used method in analysis and design of the accelerating and focusing system.

  14. PRESAGE® as a new calibration method for high intensity focused ultrasound therapy

    High Intensity Focused ultrasound (HIFU) is a non-invasive cancer therapy that makes use of the mainly thermal effects of ultrasound to destroy tissue. In order to achieve reliable treatment planning, it is necessary to characterise the ultrasound source (transducer) and to understand how the wave propagates in tissue and the energy deposition in the focal region. This novel exploratory study investigated how HIFU affects PRESAGE®, an optical phantom used for radiotherapy dosimetry, which is potentially a rapid method of calibrating the transducer. Samples, of two different formulations, were exposed to focused ultrasound and imaged using Optical Computed Tomography. First results showed that, PRESAGE® changes colour on ultrasound exposure (darker green regions were observed) with the alterations being related to the acoustic power and sample composition. Future work will involve quantification of these alterations and understanding how to relate them to the mechanisms of action of HIFU

  15. Histopathological changes associated with high intensity focused ultrasound (HIFU) treatment for localised adenocarcinoma of the prostate

    van Leenders, G J L H; Beerlage, H; Ruijter, E.; de la Rosette, J J M C H; van de Kaa, C A

    2000-01-01

    Aims—Investigation of the histopathological changes in prostatectomy specimens of patients with prostate cancer after high intensity focused ultrasound (HIFU) and identification of immunohistochemical markers for tissue damage after HIFU treatment.

  16. High-Intensity Focused Ultrasound (HIFU) in Localized Prostate Cancer Treatment

    Alkhorayef, Mohammed; Mahmoud, Mustafa Z.; Alzimami, Khalid S.; Sulieman, Abdelmoneim; Fagiri, Maram A.

    2015-01-01

    Summary Background High-intensity focused ultrasound (HIFU) applies high-intensity focused ultrasound energy to locally heat and destroy diseased or damaged tissue through ablation. This study intended to review HIFU to explain the fundamentals of HIFU, evaluate the evidence concerning the role of HIFU in the treatment of prostate cancer (PC), review the technologies used to perform HIFU and the published clinical literature regarding the procedure as a primary treatment for PC. Material/Meth...

  17. High intensity focused ultrasound (HIFU) as the alternative method of treatment of oncourological diseases

    Blyumberg B.I.; Fomkin R.N.; Popkov V.M.

    2012-01-01

    Increasing interest devoted to technology of high intensity focused ultrasound (high-intensity focused ultrasound, HIFU), basically, is explained by a wide spectrum of potential fields of application at minimum invasiveness of the given method. In oncourology HIFU is applied in prostate and kidney cancer. In case of tumors of renal parenchyma the given technique is being clinically tested, while HIFU is currently used in the practice of European oncourologists in treatment of prostate cancer....

  18. Transcranial magnetic resonance imaging-guided focused ultrasound: noninvasive central lateral thalamotomy for chronic neuropathic pain

    Jeanmonod, D.; Werner, B.; Morel, A.; Michels, L; Zadicario, E; Schiff, G.; Martin, E.

    2012-01-01

    Object Recent technological developments open the field of therapeutic application of focused ultrasound to the brain through the intact cranium. The goal of this study was to apply the new transcranial magnetic resonance imaging-guided focused ultrasound (tcMRgFUS) technology to perform noninvasive central lateral thalamotomies (CLTs) as a treatment for chronic neuropathic pain. Methods In 12 patients suffering from chronic therapy-resistant neuropathic pain, tcMRgFUS CLT was propos...

  19. Transcranial MR-guided High Intensity Focused Ultrasound for Non-Invasive Functional Neurosurgery

    Werner, Beat; Morel, Anne; Zadicario, Eyal; Jeanmonod, Daniel; Martin, Ernst

    2010-03-01

    While the development of transcranial MR-guided High Intensity Focused Ultrasound has been driven mainly by applications for tumor ablation this new intervention method is also very attractive for functional neurosurgery due to its non-invasiveness, the absence of ionizing radiation and the closed-loop intervention control by MRI. Here we provide preliminary data to demonstrate the clinical feasibility, safety and precision of non-invasive functional neurosurgery by transcranial MR-guided High Intensity Focused Ultrasound.

  20. WE-G-12A-01: High Intensity Focused Ultrasound Surgery and Therapy

    Farahani, K [National Cancer Institute, Rockville, MD (United States); O' Neill, B [The Methodist Hospital Research Institute, Houston, TX (United States)

    2014-06-15

    More and more emphasis is being made on alternatives to invasive surgery and the use of ionizing radiation to treat various diseases including cancer. Novel screening, diagnosis, treatment and monitoring of response to treatment are also hot areas of research and new clinical technologies. Ultrasound(US) has gained traction in all of the aforementioned areas of focus. Especially with recent advances in the use of ultrasound to noninvasively treat various diseases/organ systems. This session will focus on covering MR-guided focused ultrasound and the state of the art clinical applications, and the second speaker will survey the more cutting edge technologies e.g. Focused Ultrasound (FUS) mediated drug delivery, principles of cavitation and US guided FUS. Learning Objectives: Fundamental physics and physical limitations of US interaction with tissue and nanoparticles The alteration of tissue transport using focused ultrasound US control of nanoparticle drug carriers for targeted release The basic principles of MRI-guided focused ultrasound (MRgFUS) surgery and therapy the current state of the art clinical applications of MRgFUS requirements for quality assurance and treatment planning.

  1. WE-G-12A-01: High Intensity Focused Ultrasound Surgery and Therapy

    More and more emphasis is being made on alternatives to invasive surgery and the use of ionizing radiation to treat various diseases including cancer. Novel screening, diagnosis, treatment and monitoring of response to treatment are also hot areas of research and new clinical technologies. Ultrasound(US) has gained traction in all of the aforementioned areas of focus. Especially with recent advances in the use of ultrasound to noninvasively treat various diseases/organ systems. This session will focus on covering MR-guided focused ultrasound and the state of the art clinical applications, and the second speaker will survey the more cutting edge technologies e.g. Focused Ultrasound (FUS) mediated drug delivery, principles of cavitation and US guided FUS. Learning Objectives: Fundamental physics and physical limitations of US interaction with tissue and nanoparticles The alteration of tissue transport using focused ultrasound US control of nanoparticle drug carriers for targeted release The basic principles of MRI-guided focused ultrasound (MRgFUS) surgery and therapy the current state of the art clinical applications of MRgFUS requirements for quality assurance and treatment planning

  2. Auto-focusing accelerating hyper-geometric laser beams

    Kovalev, A. A.; Kotlyar, V. V.; Porfirev, A. P.

    2016-02-01

    We derive a new solution to the paraxial wave equation that defines a two-parameter family of three-dimensional structurally stable vortex annular auto-focusing hyper-geometric (AH) beams, with their complex amplitude expressed via a degenerate hyper-geometric function. The AH beams are found to carry an orbital angular momentum and be auto-focusing, propagating on an accelerating path toward a focus, where the annular intensity pattern is ‘sharply’ reduced in diameter. An explicit expression for the complex amplitude of vortex annular auto-focusing hyper-geometric-Gaussian beams is derived. The experiment has been shown to be in good agreement with theory.

  3. PULSED-FOCUSING RECIRCULATING LINACS FOR MUON ACCELERATION

    Johnson, Rolland PAUL

    2014-12-31

    Since the muon has a short lifetime, fast acceleration is essential for high-energy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAG-style magnets in the return arcs. A better solution, invented in this project, is to use combined-function dipole-quadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of

  4. Ultrasound-guided high intensity focused ultrasound for the treatment of gynaecological diseases: A review of safety and efficacy.

    Zhang, Lian; Zhang, Wenyi; Orsi, Franco; Chen, Wenzhi; Wang, Zhibiao

    2015-05-01

    As a non-surgical treatment, high intensity focused ultrasound (HIFU) has received increasing interest for the treatment of gynaecological diseases over the last 10 years. Many studies have shown that HIFU is safe and effective in treating patients with uterine fibroids, adenomyosis, cervicitis or vulvar diseases. Both magnetic resonance imaging-guided HIFU (MRgHIFU) and ultrasound-guided HIFU (USgHIFU) can offer gynaecologists non-invasive techniques to treat patients with uterine benign diseases. Focused ultrasound therapy can also be used effectively to treat cervicitis and vulvar diseases. As gynaecologists gain more experience with this technology, the rate of severe adverse effects has been lowered with the development of this non-invasive technique. In this paper we review the literature available regarding the utilisation of magnetic resonance imaging-guided focused ultrasound/MRgHIFU or USgHIFU and new findings from our group in the treatment of gynaecological diseases: uterine fibroids, adenomyosis, cervicitis, vulvar diseases, caesarean scar pregnancies, and abdominal wall endometriosis. PMID:25609456

  5. Focusing of ion beam with limit emittance by accelerator tube of electrostatic accelerator

    Focusing of nonrelativistic ion beam with finite emittance by accelerator tube is considered. Analytical relation between positions of the entrance and exit crossovers as a function of the beam emittance and the accelerator tube parameters was obtained. The comparison of conditions providing crossover to crossover transformation and conditions of entrance crossover optical image forming was carried out. 10 refs.; 3 figs

  6. Full-wave nonlinear ultrasound simulation on distributed clusters with applications in high-intensity focused ultrasound

    Jaros, Jiri; Treeby, Bradley E

    2014-01-01

    Model-based treatment planning and exposimetry for high-intensity focused ultrasound (HIFU) requires the numerical simulation of nonlinear ultrasound propagation through heterogeneous and absorbing media. This is a computationally demanding problem due to the large distances travelled by the ultrasound waves relative to the wavelength of the highest frequency harmonic. Here, the k-space pseudospectral method is used to solve a set of coupled partial differential equations equivalent to a generalised Westervelt equation. The model is implemented in C++ and parallelised using the message passing interface (MPI) for solving large-scale problems on distributed clusters. The domain is partitioned using a 1D slab decomposition, and global communication is performed using a sparse communication pattern. Operations in the spatial frequency domain are performed in transposed space to reduce the communication burden imposed by the 3D fast Fourier transform. The performance of the model is evaluated using grid sizes up ...

  7. High-intensity focused ultrasound ablation for treatment of hepatocellular carcinoma and hypersplenism: preliminary study.

    Zhu, Jing; Zhu, Hui; Mei, Zhechuan; Jin, Chengbing; Ran, Lifeng; Zhou, Kun; Yang, Wei; Zhang, Lian; She, Chaokun

    2013-10-01

    The purpose of this work was to preliminarily investigate the efficacy and safety of high-intensity focused ultrasound treatment of hepatocellular carcinoma and hypersplenism. Nine patients with hepatocellular carcinoma complicated by hypersplenism (5 male and 4 female; median age, 56 years; range, 51-66 years) were treated with ultrasound-guided high-intensity focused ultrasound. Complications were recorded. Laboratory examination and magnetic resonance imaging were used to evaluate the efficacy. After high-intensity focused ultrasound treatment, mean spleen ablation ± SD of 28.76% ± 6.1% was discovered; meanwhile, the white blood cell count, platelet count, and liver function of the patients were substantially improved during the follow-up period. In addition, symptoms such as epistaxis and gingival bleeding were ameliorated or even eliminated, and the quality of life was improved. Follow-up imaging showed a nonperfused volume in the spleen and an absence of a tumor blood supply at the treated lesions in the liver. For the first time to our knowledge, high-intensity focused ultrasound ablation was used to treat hepatocellular carcinoma complicated by hypersplenism. High-intensity focused ultrasound may be an effective and safe alternative for treatment of hepatocellular carcinoma complicated by hypersplenism, but further studies are necessary to clarify the mechanisms. PMID:24065267

  8. Monitoring high-intensity focused ultrasound (HIFU) therapy using radio frequency ultrasound backscatter to quantify heating

    Kaczkowski, Peter J.; Anand, Ajay

    2005-09-01

    The spatial distribution and temporal history of tissue temperature is an essential indicator of thermal therapy progress, and treatment safety and efficacy. Magnetic resonance methods provide the gold standard noninvasive measurement of temperature but are costly and cumbersome compared to the therapy itself. We have been developing the use of ultrasound backscattering for real-time temperature estimation; ultrasonic methods have been limited to relatively low temperature rise, primarily due to lack of sensitivity at protein denaturation temperatures (50-70°C). Through validation experiments on gel phantoms and ex vivo tissue we show that temperature rise can be accurately mapped throughout the therapeutic temperature range using a new BioHeat Transfer Equation (BHTE) model-constrained inverse approach. Speckle-free temperature and thermal dose maps are generated using the ultrasound calibrated model over the imaged region throughout therapy delivery and post-treatment cooling periods. Results of turkey breast tissue experiments are presented for static HIFU exposures, in which the ultrasound calibrated BHTE temperature maps are shown to be very accurate (within a degree) using independent thermocouple measurements. This new temperature monitoring method may speed clinical adoption of ultrasound-guided HIFU therapy. [Work supported by Army MRMC.

  9. A new sensitizer DVDMS combined with multiple focused ultrasound treatments: an effective antitumor strategy

    Xiong, Wenli; Wang, Pan; Hu, Jianmin; Jia, Yali; Wu, Lijie; Chen, Xiyang; Liu, Quanhong; Wang, Xiaobing

    2015-12-01

    Sonodynamic therapy (SDT) was developed as a promising noninvasive approach. The present study investigated the antitumor effect of a new sensitizer (sinoporphyrin sodium, referred to as DVDMS) combined with multiple ultrasound treatments on sarcoma 180 both in vitro and in vivo. The combined treatment significantly suppressed cell viability, potentiated apoptosis, and markedly inhibited angiogenesis in vivo. In vivo, the tumor weight inhibition ratio reached 89.82% fifteen days after three sonication treatments plus DVDMS. This effect was stronger than one ultrasound alone (32.56%) and than one round of sonication plus DVDMS (59.33%). DVDMS combined with multiple focused ultrasound treatments initiated tumor tissue destruction, induced cancer cell apoptosis, inhibited tumor angiogenesis, suppressed cancer cell proliferation, and decreased VEGF and PCNA expression levels. Moreover, the treatment did not show obvious signs of side effects or induce a drop in body weight. These results indicated that DVDMS combined with multiple focused ultrasounds may be a promising strategy against solid tumor.

  10. Study of focusing characteristics of ultrasound for designing acoustic lens in ultrasonic moxibustion device

    Bae, Jae Hyun; Song, Sung Jin; Kim, Hak Joon [School of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Kim, Ki Bok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2015-04-15

    Traditional moxibustion therapy can cause severe pain and leave scarring burns at the moxibustion site as it relies on the practitioner's subjective and qualitative treatment. Recently, ultrasound therapy has received attention as an alternative to moxibustion therapy owing to its objectiveness and quantitative nature. However, in order to convert ultrasound energy into heat energy, there is a need to precisely understand the ultrasound-focusing characteristics of the acoustic lens. Therefore, in this study, an FEM simulation was performed for acoustic lenses with different geometries a concave lens and zone lens as the geometry critically influences ultrasound focusing. The acoustic pressure field, amplitude, and focal point were also calculated. Furthermore, the performance of the fabricated acoustic lens was verified by a sound pressure measurement experiment.

  11. Sub-array patterns of spherical-section phased array for high intensity focused ultrasound surgery

    WANG Xiaodong; WANG Xufei; LU Mingzhu; WAN Mingxi

    2005-01-01

    The sub-array field patterns of spherical-section phased array were implemented for noninvasive ultrasound surgery of liver-tumor. The sub-array approach included field calculation, pseudo-inverse method and genetic algorithm. The sub-arrays uncovered by ribs according to scanned images normally emitted ultrasound. The results from different sub-arrays demonstrated quite satisfied acoustic performances, which included qualified focus size and intensity level for ultrasound surgery with single-focus and multi-foci patterns. Moreover, the patterns could decrease power accumulation on the ribs, and avoid damaging normal tissues. Thus the sub-array method provides a promising tool for phased array ultrasound propagating through strong obstacles like human rib cage, and it may broaden the therapeutic area, make the surgery safer and more flexible.

  12. MR-guided focused ultrasound technique in functional neurosurgery: targeting accuracy

    Moser, David; Zadicario, Eyal; Schiff, Gilat; Jeanmonod, Daniel

    2013-01-01

    Background The purpose of this study was to describe targeting accuracy in functional neurosurgery using incisionless transcranial magnetic resonance (MR)-guided focused ultrasound technology. Methods MR examinations were performed before and 2 days after the ultrasound functional neurosurgical treatment to visualize the targets on T2-weighted images and determine their coordinates. Thirty consecutive targets were reconstructed: 18 were in the central lateral nucleus of the medial thalamus (c...

  13. High intensity focused ultrasound treatment of small renal masses: Clinical effectiveness and technological advances

    Nabi, G; Goodman, C; Melzer, A.

    2010-01-01

    The review summarises the technological advances in the application of high-intensity focused ultrasound for small renal masses presumed to be cancer including the systematic review of its clinical application. Current progress in the area of magnetic resonance image guided ultrasound ablation is also appraised. Specifically, organ tracking and real time monitoring of temperature changes during the treatment are discussed. Finally, areas of future research interest are outlined.

  14. Adapting MRI Acoustic Radiation Force Imaging For In Vivo Human Brain Focused Ultrasound Applications

    Kaye, Elena A.; Pauly, Kim Butts

    2012-01-01

    A variety of MRI acoustic radiation force imaging (MR-ARFI) pulse sequences as the means for image guidance of focused ultrasound therapy have been recently developed and tested ex vivo and in animal models. To successfully translate MR-ARFI guidance into human applications, ensuring that MR-ARFI provides satisfactory image quality in the presence of patient motion and deposits safe amount of ultrasound energy during image acquisition is necessary. The first aim of this work was to study the ...

  15. High-Intensity Focused Ultrasound as Salvage Therapy for Patients With Recurrent Prostate Cancer After Radiotherapy

    Song, Wan; Jung, U Seok; Suh, Yoon Seok; Jang, Hyun Jun; Sung, Hyun Hwan; Jeon, Hwang Gyun; Jeong, Byung Chang; Seo, Seong Il; Jeon, Seong Soo; Choi, Han Yong; Lee, Hyun Moo

    2014-01-01

    Purpose To evaluate the oncologic outcomes and postoperative complications of high-intensity focused ultrasound (HIFU) as a salvage therapy after external-beam radiotherapy (EBRT) failure in patients with prostate cancer. Materials and Methods Between February 2002 and August 2010, we retrospectively reviewed the medical records of all patients who underwent salvage HIFU for transrectal ultrasound-guided, biopsy-proven locally recurred prostate cancer after EBRT failure (by ASTRO definition: ...

  16. High intensity focused ultrasound vs. cryotherapy as primary treatment for prostate cancer

    Ranjan, Pratyush; Saurabh, Gyan; Bansal, Rahul; Gupta, Amit

    2008-01-01

    Prostate cancer is one of the most commonly diagnosed cancers. Here, we will be discussing two upcoming techniques for its management. One is cryotherapy which has returned from oblivion after nearly 150 years armed with latest technology and looking as if its full potential has been recognized now. On the other hand is high intensity focused ultrasound (HIFU), the application of ultrasound to this field is relatively new and hence a lot of excitement and hope. We searched MEDLINE (PubMed 194...

  17. Compensating for bone interfaces and respiratory motion in high-intensity focused ultrasound.

    Tanter, Mickaël; PERNOT, mathieu; Aubry, Jean-François; Montaldo, Gabriel; Marquet, Fabrice; Fink, Mathias

    2007-01-01

    Bursts of focused ultrasound energy a thousand times more intense than diagnostic ultrasound have become a non-invasive option for treating cancer, from breast to prostate or uterine fibroid, during the last decade. Despite this progress, many issues still need to be addressed. First, the distortions caused by defocusing obstacles, such as the skull or ribs, on the ultrasonic therapeutic beam are still being investigated. Multi-element transducer technology must be used in order to achieve su...

  18. Impact of Focused Ultrasound-enhanced Drug Delivery on Survival in Rats with Glioma

    Treat, Lisa Hsu; Zhang, Yongzhi; McDannold, Nathan; Hynynen, Kullervo

    2009-04-01

    Malignancies of the brain remain difficult to treat with chemotherapy because the selective permeability of the blood-brain barrier (BBB) blocks many potent agents from reaching their target. Previous studies have illustrated the feasibility of drug and antibody delivery across the BBB using MRI-guided focused ultrasound. In this study, we investigated the impact of focused ultrasound-enhanced delivery of doxorubicin on survival in rats with aggressive glioma. Sprague-Dawley rats were implanted with 9 L gliosarcoma cells in the brain. Eight days after implantation, each rat received one of the following: (1) no treatment (control), (2) a single treatment with microbubble-enhanced MRI-guided focused ultrasound (FUS only), (3) a single treatment with i.v. liposomal doxorubicin (DOX only), or (4) a single treatment with microbubble-enhanced MRI-guided focused ultrasound and concurrent i.v. injections of liposomal doxorubicin (FUS+DOX). The survival time from implantation to death or euthanasia was recorded. We observed a modest but significant increase in median survival time in rats treated with combined MRI-guided focused ultrasound chemotherapy, compared to chemotherapy alone (psurvival between those who received stand-alone chemotherapy and those who did not receive any treatment (p>0.10). Our study demonstrates for the first time a therapeutic benefit achieved with ultrasound-enhanced drug delivery across the blood-brain barrier. This confirmation of efficacy in an in vivo tumor model indicates that targeted drug delivery using MRI-guided focused ultrasound has the potential to have a major impact on the treatment of patients with brain tumors and other neurological disorders.

  19. Electron Beam Focusing in the Linear Accelerator (linac)

    Jauregui, Luis

    2015-10-01

    To produce consistent data with an electron accelerator, it is critical to have a well-focused beam. To keep the beam focused, quadrupoles (quads) are employed. Quads are magnets, which focus the beam in one direction (x or y) and defocus in the other. When two or more quads are used in series, a net focusing effect is achieved in both vertical and horizontal directions. At start up there is a 5% calibration error in the linac at Thomas Jefferson National Accelerator Facility. This means that the momentum of particles passing through the quads isn't always what is expected, which affects the focusing of the beam. The objective is to find exactly how sensitive the focusing in the linac is to this 5% error. A linac was simulated, which contained 290 RF Cavities with random electric fields (to simulate the 5% calibration error), and a total momentum kick of 1090 MeV. National Science Foundation, Department of Energy, Jefferson Lab, Old Dominion University.

  20. Magnetic resonance image-guided versus ultrasound-guided high-intensity focused ultrasound in the treatment of breast cancer

    Pei-Hong Wu; Sheng Li

    2013-01-01

    Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is a common cancer in women. HIFU therapy, in combination with other therapies, has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Cu...

  1. Design of a self-focusing linear electron accelerator

    In this report we tackle the principal physical and technical problems related to the design of a self-focusing linear electron accelerator. The study of the dynamic phenomena occurring at the entrance to the first resonant cell allows us, by an adequate choice of the longitudinal height of this cell, to avoid the use of an external magnetic focusing coil. Optimization of the ultra high frequency properties of the resonant structure has been achieved by polishing the internal surfaces of the cavities, by adapting a new brazing technique and optimizing the geometry of the cells. A simulation code has been adapted to an interactive use on microcomputer

  2. Focused ultrasound as a tool to input sensory information to humans (Review)

    Gavrilov, L. R.; Tsirulnikov, E. M.

    2012-01-01

    This review is devoted to the analysis of studies and implementations related to the use of focused ultrasound for functional effects on neuroreceptor structures. Special attention was paid to the stimulation of neuroreceptor structures in order to input sensory information to humans. This branch of medical and physiological acoustics appeared in Russia in the early 1970s and was being efficiently developed up to the late 1980s. Then, due to lack of financial support, only individual researchers remained at this field and, as a result, we have no full- fledged theoretical research and practical implementations in this area yet. Many promising possibilities of using functional effects of focused ultrasound in medicine and physiology have remained unimplemented for a long time. However, new interesting ideas and approaches have appeared in recent years. Very recently, very questionable projects have been reported related to the use of ultrasound for targeted functional effects on the human brain performed in some laboratories. In this review, the stages of the development of scientific research devoted to the functional effects of focused ultrasound are described. By activating the neuroreceptor structures of the skin by means pulses of focused ultrasound, one can cause all the sensations perceived by human beings through the skin in everyday life, such as tactile sensations, thermal (heat and cold), tickling, itching, and various types of pain. Stimulation of the ear labyrinth of humans with normal hearing using amplitude-modulated ultrasound causes auditory sensations corresponding to an audio modulating signal (pure tones, music, speech, etc.). Activation of neuroreceptor structures by means of focused ultrasound is used for the diagnosis of various neurological and skin diseases, as well as hearing disorders. It has been shown that the activation is related to the mechanical action of ultrasound, for example, by the radiation force, as well as to the direct

  3. Elimination of therapeutic ultrasound noise from pre-beamformed RF data in ultrasound imaging for ultrasound-guided high-intensity focused ultrasound treatment

    Takagi, Ryo; Goto, Kota; Jimbo, Hayato; Matsuura, Keiko; Iwasaki, Ryosuke; Umemura, Shin-ichiro; Yoshizawa, Shin

    2015-07-01

    In conventional ultrasonic monitoring of high-intensity focused ultrasound (HIFU) treatment, a significant interval between consecutive HIFU shots is set for monitoring target tissue to avoid the interference of HIFU noise with RF echo signals. Thus, it is difficult to detect changes in tissue on the order of milliseconds, which are required to dynamically control the HIFU exposure. In this study, a new filtering method to eliminate the HIFU noise in the RF signals before beamforming is proposed. The CW response was estimated from RF signals with no pulse response to the imaging exposure, and the estimated CW response was subtracted from the entire RF signal to selectively eliminate the HIFU noise for each channel of the array probe before dynamic focusing was applied. The HIFU noise was selectively eliminated by this method when it existed. The results imply that the proposed filtering method is useful for true real-time detection of changes in tissue due to thermal coagulation during HIFU exposure.

  4. Distribution of temperature elevation caused by moving high-intensity focused ultrasound transducer

    Kim, Jungsoon; Jung, Jihee; Kim, Moojoon; Ha, Kanglyeol; Lee, Eunghwa; Lee, Ilkwon

    2015-07-01

    Ultrasonic thermal treatment for dermatology has been developed using a small high-intensity focused ultrasound (HIFU) transducer. The transducer moves horizontally at a constant while it emits focused ultrasound because the treatment needs a high-temperature area in skin tissue over a wide range of depths. In this paper, a tissue-mimicking phantom made of carrageenan and a thermochromic film were adopted to examine the temperature distribution in the phantom noninvasively when the focused ultrasound was irradiated from the moving transducer. The dependence of the high-temperature area on the irradiated acoustic energy and on the movement interval of the HIFU was analyzed experimentally. The results will be useful in ensuring safety and estimating the remedial value of the treatment.

  5. MR-Guided High-Intensity Focused Ultrasound: Current Status of an Emerging Technology

    Napoli, Alessandro, E-mail: napoli.alessandro@gmail.com; Anzidei, Michele, E-mail: michele.anzidei@gmail.com; Ciolina, Federica, E-mail: federica.ciolina@gmail.com; Marotta, Eugenio, E-mail: eugenio.marotta@gmail.com; Cavallo Marincola, Beatrice, E-mail: beatrice.cavalloamarincola@gmail.com; Brachetti, Giulia, E-mail: giuliabrachetti@gmail.com; Mare, Luisa Di, E-mail: luisadimare@gmail.com; Cartocci, Gaia, E-mail: gaia.cartocci@gmail.com; Boni, Fabrizio, E-mail: fabrizioboni00@gmail.com; Noce, Vincenzo, E-mail: vinc.noce@hotmail.it; Bertaccini, Luca, E-mail: lucaone84@libero.it; Catalano, Carlo, E-mail: carlo.catalano@uniroma1.it [Sapienza, University of Rome, Department of Radiological Sciences (Italy)

    2013-10-15

    The concept of ideal tumor surgery is to remove the neoplastic tissue without damaging adjacent normal structures. High-intensity focused ultrasound (HIFU) was developed in the 1940s as a viable thermal tissue ablation approach. In clinical practice, HIFU has been applied to treat a variety of solid benign and malignant lesions, including pancreas, liver, prostate, and breast carcinomas, soft tissue sarcomas, and uterine fibroids. More recently, magnetic resonance guidance has been applied for treatment monitoring during focused ultrasound procedures (magnetic resonance-guided focused ultrasound, MRgFUS). Intraoperative magnetic resonance imaging provides the best possible tumor extension and dynamic control of energy deposition using real-time magnetic resonance imaging thermometry. We introduce the fundamental principles and clinical indications of the MRgFUS technique; we also report different treatment options and personal outcomes.

  6. MR-guided high-intensity focused ultrasound: current status of an emerging technology.

    Napoli, Alessandro; Anzidei, Michele; Ciolina, Federica; Marotta, Eugenio; Cavallo Marincola, Beatrice; Brachetti, Giulia; Di Mare, Luisa; Cartocci, Gaia; Boni, Fabrizio; Noce, Vincenzo; Bertaccini, Luca; Catalano, Carlo

    2013-10-01

    The concept of ideal tumor surgery is to remove the neoplastic tissue without damaging adjacent normal structures. High-intensity focused ultrasound (HIFU) was developed in the 1940s as a viable thermal tissue ablation approach. In clinical practice, HIFU has been applied to treat a variety of solid benign and malignant lesions, including pancreas, liver, prostate, and breast carcinomas, soft tissue sarcomas, and uterine fibroids. More recently, magnetic resonance guidance has been applied for treatment monitoring during focused ultrasound procedures (magnetic resonance-guided focused ultrasound, MRgFUS). Intraoperative magnetic resonance imaging provides the best possible tumor extension and dynamic control of energy deposition using real-time magnetic resonance imaging thermometry. We introduce the fundamental principles and clinical indications of the MRgFUS technique; we also report different treatment options and personal outcomes. PMID:23474917

  7. H-Mode Accelerating Structures with PMQ Beam Focusing

    Kurennoy, Sergey S; O'Hara, James F; Olivas, Eric R; Wangler, Thomas P

    2011-01-01

    We have developed high-efficiency normal-conducting RF accelerating structures by combining H-mode resonator cavities and a transverse beam focusing by permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of inter-digital H-mode (IH-PMQ) structures is 10-20 times higher than that of a conventional drift-tube linac, while the transverse size is 4-5 times smaller. Results of the combined 3-D modeling - electromagnetic computations, multi-particle beam-dynamics simulations with high currents, and thermal-stress analysis - for an IH-PMQ accelerator tank are presented. The accelerating field profile in the tank is tuned to provide the best propagation of a 50-mA deuteron beam using coupled iterations of electromagnetic and beam-dynamics modeling. Measurements of a cold model of the IH-PMQ tank show a good agreement with the calculations. H-PMQ accelerating structures following a short RFQ can be used both in the front end of ion linacs or ...

  8. Experimental studies of plasma wake-field acceleration and focusing

    More than four years after the initial proposal of the Plasma Wake-field Accelerator (PWFA), it continues to be the object of much investigation, due to the promise of the ultra-high accelerating gradients that can exist in relativistic plasma waves driven in the wake of charged particle beams. These large amplitude plasma wake-fields are of interest in the laboratory, both for the wealth of basic nonlinear plasma wave phenomena which can be studied, as well as for the applications of acceleration of focusing of electrons and positrons in future linear colliders. Plasma wake-field waves are also of importance in nature, due to their possible role in direct cosmic ray acceleration. The purpose of the present work is to review the recent experimental advances made in PWFA research at Argonne National Laboratory, in which many interesting beam and plasma phenomena have been observed. Emphasis is given to discussion of the nonlinear aspects of the PWFA beam-plasma interaction. 29 refs., 13 figs

  9. Time reversal ultrasound focusing to a point away from the beacon location

    Sinelnikov, Yegor; Sutin, Alexander; Gandhi, Gaurav; Sarvazyan, Armen

    2012-10-01

    In percutaneous procedures there is often a need to focus therapeutic ultrasound to a predefined area without affecting surrounding tissues. Focusing based on Time Reversal Acoustics (TRA) principles constitutes a promising approach for generating high intensity ultrasound field tailored to the shape of the predefined area. Conventional TRA technique enables ultrasound focusing only at a site, where there is an ultrasound beacon, e.g. piezo-transducer mounted at the tip of a catheter. We developed a method of steering the focus away from the beacon location. The method is based on the measurements of impulse response (IR) in several reference points and calculating virtual IRs for the points outside the reference beacon location. The IR for the point away from the beacon is constructed based on mathematical extrapolation of the measured reference IRs frequency spectra, particularly phases. The effectiveness of extrapolated TRA focusing is explored experimentally and by computer simulation. Potential applications include ultrasounda-ssisted drug delivery, artery recanalization and tumor ablation.

  10. Clinical Application of High-intensity Focused Ultrasound in Cancer Therapy.

    Hsiao, Yi-Hsuan; Kuo, Shou-Jen; Tsai, Horng-Der; Chou, Ming-Chih; Yeh, Guang-Perng

    2016-01-01

    The treatment of cancer is an important issue in both developing and developed countries. Clinical use of ultrasound in cancer is not only for the diagnosis but also for the treatment. Focused ultrasound surgery (FUS) is a noninvasive technique. By using the combination of high-intensity focused ultrasound (HIFU) and imaging method, FUS has the potential to ablate tumor lesions precisely. The main mechanisms of HIFU ablation involve mechanical and thermal effects. Recent advances in HIFU have increased its popularity. Some promising results were achieved in managing various malignancies, including pancreas, prostate, liver, kidney, breast and bone. Other applications include brain tumor ablation and disruption of the blood-brain barrier. We aim at briefly outlining the clinical utility of FUS as a noninvasive technique for a variety of types of cancer treatment. PMID:26918034

  11. H-Mode Accelerating Structures with PMQ Beam Focusing

    Kurennoy, Sergey S.; Rybarcyk, Lawrence J.; O'Hara, James F.; Olivas, Eric R.; Wangler, Thomas P.

    2011-01-01

    We have developed high-efficiency normal-conducting RF accelerating structures by combining H-mode resonator cavities and a transverse beam focusing by permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of inter-digital H-mode (IH-PMQ) structures is 10-20 times higher than that of a conventional drift-tube linac, while the transverse size is 4-5 times smaller. Results of the combined 3-D modeling - electromagnetic c...

  12. Analytical estimation of ultrasound properties, thermal diffusivity, and perfusion using magnetic resonance-guided focused ultrasound temperature data.

    Dillon, C R; Borasi, G; Payne, A

    2016-01-21

    For thermal modeling to play a significant role in treatment planning, monitoring, and control of magnetic resonance-guided focused ultrasound (MRgFUS) thermal therapies, accurate knowledge of ultrasound and thermal properties is essential. This study develops a new analytical solution for the temperature change observed in MRgFUS which can be used with experimental MR temperature data to provide estimates of the ultrasound initial heating rate, Gaussian beam variance, tissue thermal diffusivity, and Pennes perfusion parameter. Simulations demonstrate that this technique provides accurate and robust property estimates that are independent of the beam size, thermal diffusivity, and perfusion levels in the presence of realistic MR noise. The technique is also demonstrated in vivo using MRgFUS heating data in rabbit back muscle. Errors in property estimates are kept less than 5% by applying a third order Taylor series approximation of the perfusion term and ensuring the ratio of the fitting time (the duration of experimental data utilized for optimization) to the perfusion time constant remains less than one. PMID:26741344

  13. An ex vivo human lung model for ultrasound-guided high-intensity focused ultrasound therapy using lung flooding.

    Wolfram, Frank; Reichenbach, Jürgen R; Lesser, Thomas G

    2014-03-01

    The usability of an ex vivo human lung model for ablation of lung cancer tissue with high-intensity focused ultrasound (HIFU) is described. Lung lobes were flooded with saline, with no gas remaining after complete atelectasis. The tumor was delineated sono-morphologically. Speed of sound, tissue density and ultrasound attenuation were measured for flooded lung and different pulmonary cancer tissues. The acoustic impedance of lung cancer tissue (1.6-1.9 mega-Rayleighs) was higher than that of water, as was its attenuation coefficient (0.31-0.44 dB/cm/MHz) compared with that of the flooded lung (0.12 dB/cm/MHz). After application of HIFU, the temperature in centrally located lung cancer surrounded by the flooded lung increased as high as 80°C, which is sufficient for treatment. On the basis of these preliminary results, ultrasound-guided HIFU ablation of lung cancer, by lung flooding with saline, appears feasible and should be explored in future clinical studies. PMID:24412177

  14. Numerical Study on Focusing of Ultrasounds in Microbubble-enhanced HIFU

    Matsumoto, Yoichiro; Okita, Kohei; Takagi, Shu

    2011-11-01

    The injection of microbubbles into the target tissue enhances tissue heating in High-Intensity Focused Ultrasound therapy, via inertial cavitation. The control of the inertial cavitation is required to achieve the efficient tissue ablation. Microbubbles between a transducer and a target disturb the ultrasound propagation depending on the conditions. A method to clear such microbubbles has been proposed by Kajiyama et al. [Physics Procedia 3 (2010) 305-314]. In the method, the irradiation of intense ultrasounds with a burst waveform fragmentize microbubbles in the pathways before the irradiation of ultrasounds for tissue heating. The vitro experiment using a gel containing microbubbles has showed that the method enables to heat the target correctly by controlling the microbubble distribution. Following the experiment, we simulate the focusing of ultrasounds through a mixture containing microbubbles with considering the size and number density distributions in space. The numerical simulation shows that the movement of the heating region from the transducer side to the target by controlling the microbubble distributions. The numerical results elucidate well the experimental ones.

  15. A prototype stimulator system for noninvasive Low Intensity Focused Ultrasound delivery.

    Mulgaonkar, Amit P; Singh, Rahul S; Babakhanian, Meghedi; Culjat, Martin O; Grundfest, Warren S; Gorgulho, Alessandra; Lacan, Goran; De Salles, Antonio A F; Bystritsky, Alexander; Melega, William P

    2012-01-01

    A prototype Low Intensity Focused Ultrasound (LIFU) stimulator system was developed to evaluate non-invasive neuromodulation in a large animal model. We conducted a feasibility study on a Göttingen minipig, demonstrating reversible, targeted transcranial neuromodulation. The hypothalamus of the minipig was repeatedly stimulated with LIFU which evoked temporally correlated increases in both heart rate and blood pressure. PMID:22357005

  16. An image-guided high intensity focused ultrasound device for uterine fibroids treatment

    A high intensity focused ultrasound (HIFU) device was developed for treating uterine fibroid tumors. This prototype device enables image-guided therapy by aligning a commercially available abdominal ultrasound image probe to a vaginal HIFU transducer so the HIFU focus is in the image plane. The device was designed based on anatomical constraints of the female pelvic structures. HIFU was generated using a 3.5 MHz PZT-8 crystal, 25.4 mm in diameter, bonded to an aluminum lens. Computer simulations were performed to ensure that effective focusing was achievable at a fixed focal depth of 40 mm. Transducer efficiency was empirically determined to be 58%, and the half pressure maximum focal dimensions were 11 mm in length and 1.2 mm in width. A water-filled latex condom surrounding the transducer provided acoustic coupling, a stand-off, and allowed water circulation for transducer cooling. In vitro experiments in a tissue-mimicking gel phantom and in turkey breast demonstrated ultrasound image-guided lesion formation, or tissue necrosis, at the focus due to HIFU induced thermal and cavitation effects. The HIFU treatment site appeared as a hyperechoic spot on the ultrasound image at intensities above 1250 W/cm2. The results of in vitro experiments and in vivo ergonomic testing in six human volunteers indicated that the device has the potential of providing a nonsurgical approach for uterine fibroid treatment. Future in vivo studies in large animal models and fibroids patients are planned

  17. Systematic review of high-intensity focused ultrasound ablation in the treatment of breast cancer

    Peek, M.C.L.; Ahmed, M.; Napoli, A.; Haken, ten B.; McWilliams, S.; Usiskin, S.I.; Pinder, S.E.; Hemelrijck, Van M.; Douek, M.

    2015-01-01

    Background: A systematic review was undertaken to assess the clinical efficacy of non-invasive high-intensity focused ultrasound (HIFU) ablation in the treatment of breast cancer. Methods: MEDLINE/PubMed library databases were used to identify all studies published up to December 2013 that evaluate

  18. Bone metastasis treatment using magnetic resonance-guided high intensity focused ultrasound

    Yeo, Sin Yuin; Elevelt, Aaldert; Donato, Katia; van Rietbergen, Bert; ter Hoeve, Natalie D.; van Diest, Paul J.; Grüll, Holger

    2015-01-01

    Objectives: Bone pain resulting from cancer metastases reduces a patient's quality of life. Magnetic Resonance-guided High Intensity Focused Ultrasound (MR-HIFU) is a promising alternative palliative thermal treatment technique for bone metastases that has been tested in a few clinical studies. Here

  19. Transrectal high-intensity focused ultrasound for the treatment of prostate cancer: Past, present, and future

    Mearini, Luigi; Porena, Massimo

    2010-01-01

    Upon a review of recently published articles on high-intensity focused ultrasound (HIFU) in the treatment of prostate cancer, we evaluated the current status of HIFU as a primary treatment option for localized prostate cancer and its use as salvage therapy when radiation failed. We also briefly discuss current issues in indications, definition of response, and finally the future of HIFU development.

  20. Focused ultrasound for treatment of uterine myoma: From experimental model to clinical practice

    Terzić Milan

    2008-01-01

    Full Text Available It is well known that focused ultrasound has a biologic effect on tissue. High intensity focused ultrasound (HIFU on a small target area raises the temperature of the tissue enough to denaturate proteins and cause irreversible cell damage. The tight focus of the ultrasound energy allows delivery of the intended dose to a very precise location. The resulting coagulation necrosis is relatively painless. The application of this method in the human clinical setting has required pilot studies on an animal model. Although the treatment had a high success rate, there was a significant percentage of complications, mainly attributed to the technical drawbacks of the procedure. Therefore, this method has been modified for use in humans, and the HIFU is now guided, monitored and controlled by magnetic resonance imaging (MRI. In October 2004, Food and Drug Adiministration (FDA approved MRI guided focused ultrasound treatment of uterine fibroids in humans. Since then, successful treatment of uterine myomas by HIFU has been performed in thousands of women.

  1. Enhancement of antitumor vaccine in ablated hepatocellular carcinoma by high-intensity focused ultrasound

    2010-01-01

    AIM:To investigate whether tumor debris created by high-intensity focused ultrasound(HIFU)could trigger antitumor immunity in a mouse hepatocellular carcinoma model. METHODS:Twenty C57BL/6J mice bearing H22 hepatocellular carcinoma were used to generate antitumor vaccines.Ten mice underwent HIFU ablation,and the remaining 10 mice received a sham-HIFU procedure with no ultrasound irradiation.Sixty normal mice were randomly divided into HIFU vaccine,tumor vaccine and control groups.These mice were immunized w...

  2. Editorial: Focus on Laser- and Beam-Driven Plasma Accelerators

    Joshi, Chan; Malka, Victor

    2010-04-01

    The ability of short but intense laser pulses to generate high-energy electrons and ions from gaseous and solid targets has been well known since the early days of the laser fusion program. However, during the past decade there has been an explosion of experimental and theoretical activity in this area of laser-matter interaction, driven by the prospect of realizing table-top plasma accelerators for research, medical and industrial uses, and also relatively small and inexpensive plasma accelerators for high-energy physics at the frontier of particle physics. In this focus issue on laser- and beam-driven plasma accelerators, the latest advances in this field are described. Focus on Laser- and Beam-Driven Plasma Accelerators Contents Slow wave plasma structures for direct electron acceleration B D Layer, J P Palastro, A G York, T M Antonsen and H M Milchberg Cold injection for electron wakefield acceleration X Davoine, A Beck, A Lifschitz, V Malka and E Lefebvre Enhanced proton flux in the MeV range by defocused laser irradiation J S Green, D C Carroll, C Brenner, B Dromey, P S Foster, S Kar, Y T Li, K Markey, P McKenna, D Neely, A P L Robinson, M J V Streeter, M Tolley, C-G Wahlström, M H Xu and M Zepf Dose-dependent biological damage of tumour cells by laser-accelerated proton beams S D Kraft, C Richter, K Zeil, M Baumann, E Beyreuther, S Bock, M Bussmann, T E Cowan, Y Dammene, W Enghardt, U Helbig, L Karsch, T Kluge, L Laschinsky, E Lessmann, J Metzkes, D Naumburger, R Sauerbrey, M. Scḧrer, M Sobiella, J Woithe, U Schramm and J Pawelke The optimum plasma density for plasma wakefield excitation in the blowout regime W Lu, W An, M Zhou, C Joshi, C Huang and W B Mori Plasma wakefield acceleration experiments at FACET M J Hogan, T O Raubenheimer, A Seryi, P Muggli, T Katsouleas, C Huang, W Lu, W An, K A Marsh, W B Mori, C E Clayton and C Joshi Electron trapping and acceleration on a downward density ramp: a two-stage approach R M G M Trines, R Bingham, Z Najmudin

  3. Focusing of high intensity ultrasound through the rib cage using a therapeutic random phased array

    Bobkova, Svetlana; Gavrilov, Leonid; Khokhlova, Vera; Shaw, Adam; Hand, Jeffrey; ,

    2010-01-01

    A method for focusing high intensity ultrasound through a rib cage that aims to minimize heating of the ribs whilst maintaining high intensities at the focus (or foci) is proposed and tested theoretically and experimentally. Two approaches, one based on geometric acoustics and the other accounting for diffraction effects associated with propagation through the rib cage, are investigated theoretically for idealized source conditions. It is shown that for an idealized radiator the diffraction a...

  4. Noninvasive treatment of focal adenomyosis with MR-guided focused ultrasound in two patients

    Laveena Polina; Vinay Nyapathy; Anindita Mishra; Himabindu Yellamanthili; Mythri P Vallabhaneni

    2012-01-01

    Adenomyosis is a common benign gynecological disorder presenting with dysmenorrhea, menorrhagia, and pressure symptoms. Magnetic resonance imaging–guided focused ultrasound surgery (MRgFUS) utilizes precisely focused USG waves to generate and maintain high temperatures within the targeted tissue to achieve protein denaturation and coagulative necrosis. The heat generated is monitored using MRI images acquired in real-time in three planes. We present two cases of focal adenomyosis treated with...

  5. Efficacy and imaging characteristics of high intensity focused ultrasound in treatment of uterine fibroid

    Yuan-yuan HUA

    2014-03-01

    Full Text Available Objective  To investigate the efficacy and imaging characteristics of high intensity focused ultrasound (HIFU in treatment of uterine fibroid. Methods  Forty seven patients with fifty three uterine fibroids were treated with HIFU from Jan. 2010 to Dec. 2012. UFS-QOL, a disease-specific symptom and health-related quality of life questionnaire for fibroid, enhanced magnetic resonance imaging (MRI, and Doppler ultrasound were performed before and 1, 3, 6, 12 months after the treatment. Scores of symptoms and UFS-QOL of patients, and the size of uterine fibroid detected by MRI and Doppler ultrasound were assessed to study the efficacy of the treatment. The relationship between the shrinkage of the uterine fibroid, and the imaging characteristics of the MRI and ultrasound were also assessed. Results  The symptoms in 38 patients were improved as reflected by the scores of symptoms and UFS-QOL after treatment with HIFU (P0.05. The low signal intensity in the target fibroids on MRI and the decrease of blood flow on Doppler ultrasound before the treatment were associated with the shrinkage of the fibroids. The more enhanced signal in MRI and the more blood flow in fibroids detected by Doppler ultrasound before treatment were, the less degree of shrinkage after the treatment was (P<0.05. The non-perfusion area in the fibroids increased if there was less enhanced signal on MRI before treatment or intensity change as monitored by real-time ultrasound (P<0.05. Conclusion  HIFU could reduce the fibroid volume and improve the patients' symptoms and life quality, and it may be used as an effective treatment for uterine fibroid. DOI: 10.11855/j.issn.0577-7402.2014.03.09

  6. Noninvasive surgery of prostate tissue by high-intensity focused ultrasound: an updated report

    Sanghvi, Narendra T.; Syrus, J.; Foster, Richard S.; Bihrle, Richard; Casey, Richard W.; Uchida, Toyoak

    2000-05-01

    High Intensity Focused Ultrasound (HIFU) has been clinically used for the treatment of benign prostatic hyperplasia (BPH) and it is experimentally applied for the treatment of localized prostate caner (PC). Recent advances in the transducer material and technology have permitted to combine the ultrasound visualization capability and HIFU on the same ceramic crystal. Also, the transducer efficiency has increased to a level that a smaller size intracavity probe can be made to produce sufficient acoustic power required for the focused ultrasound surgery of the prostate. Using this technology, 4 MHz mechanically scanning transrectal ultrasound probes has been designed. The transrectal probes are used with Sonablate (SB-200, manufactured by Focus Surgery, Inc., Indianapolis, IN) device. The SB-200 produces both transverse and longitudinal images of the prostate. The transverse and longitudinal images are used for selection of tissue volume, treatment planning and monitoring of tissue during the HIFU treatment cycle. The paper reviews the present operation of the device and recent clinical protocol that has improved efficiency, efficacy and safety of the device. The two years follow-up clinical results from the multi-site US Pilot Study (USPS) and The Male Health Centre are compared with the Kitasato-study (Kitasato School of Medicine, Sagamihara, Japan).

  7. Stimulated acceleration and confinement of deuterons in focused discharges

    The energy spectrum of accelerated D/sup +/ ions with energy 0.1 MeV ≤ E ≤ 7 MeV has been experimentally determined for the confined ions in a plasma focus pinch via the D-D neutron spectrum and for the ejected ions via a variety of ion spectrometers, with or without nanosec time resolution. A strong correlation exists between (i) neutron yield y/sub n/ in a single shot and (ii) escaping ion-beam fluence d/sup 2/phi/dω dE which increases with y/sub n/ as long as y/sub n/ ≤ 2 y, where y-bar/sub n/ is the mean value of y/sub n/ over hundreds of shots with the same filling pressure, capacitor-bank voltage, electrode geometry. In shots with y/sub n/ > 3 y-bar/sub n/ the ion emission falls below the limit of detectability. This is verified by observations of the ion emission in all directions. The insertion of field distortion elements between the electrodes increases y-bar/sub n/ by a factor > 3 without affecting the correlation between ion fluence and y/sub n/ (y-bar/sub n/ > 10/sup 9/ for 6 kJ at 16 kV shots in 6 Torr of D/sub 2/; y/sub n/ > 6 x 10/sup 8/ at 3 Torr). The distribution of the current in the interelectrode plasma region and the induced variations via field distortion elements are monitored by magnetic probes. The magnitude of the observed current-intensity peaks controls ion-accelerated fields and ion confining fields. The characteristics of the confined population of accelerated ions and those of the ejected ions are consistent with an acceleration mechanism which is extremely localized in space (< 100 μm). In parallel with spectrometer data nuclear activation of gaseous target and of solid targets is used as further method for discriminating among different processes of ion acceleration

  8. The mechanism of lesion formation by focused ultrasound ablation catheter for treatment of atrial fibrillation

    Sinelnikov, Y. D.; Fjield, T.; Sapozhnikov, O. A.

    2009-10-01

    The application of therapeutic ultrasound for the treatment of atrial fibrillation (AF) is investigated. The results of theoretical and experimental investigation of ultrasound ablation catheter are presented. The major components of the catheter are the high power cylindrical piezoelectric element and parabolic balloon reflector. Thermal elevation in the ostia of pulmonary veins is achieved by focusing the ultrasound beam in shape of a torus that transverses the myocardial tissue. High intensity ultrasound heating in the focal zone results in a lesion surrounding the pulmonary veins that creates an electrical conduction blocks and relief from AF symptoms. The success of the ablation procedure largely depends on the correct choice of reflector geometry and ultrasonic power. We present a theoretical model of the catheter’s acoustic field and bioheat transfer modeling of cardiac lesions. The application of an empirically derived relation between lesion formation and acoustic power is shown to correlate with the experimental data. Developed control methods combine the knowledge of theoretical acoustics and the thermal lesion formation simulations with experiment and thereby establish dosimetry that contributes to a safe and effective ultrasound ablation procedure.

  9. Tuning the DARHT Axis-II linear induction accelerator focusing

    Ekdahl, Carl A. [Los Alamos National Laboratory

    2012-04-24

    Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST) to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an

  10. Histological evaluation of high-intensity focused ultrasound with lower-intensity focused ultrasound pre-exposure on the treatment of rabbit VX2 liver tumors

    This study was to evaluate the effect of pre-exposure lower-intensity focused ultrasound(US), or LIFU, in high-intensity focused ultrasound(HIFU) ablation of rabbit VX2 liver tumors . Liver VX2 tumor models were established in 30 rabbits, which were divided randomly into two groups. The liver tumors of rabbits in Group A underwent single HIFU ablation; those in Group B were given LIFU exposure before HIFU treatment. Five rabbits from each of the two groups were sacrificed at 0 hours, 3 days, and 7 days after HIFU ablation. Tissue samples that included targeted and short-range sounding (s-RS, within 5 mm of the targeted) and far-range sounding (f-RS, more than 5 mm of the targeted) tissues were observed using light microscope and transmission electron microscopy. The histological examination indicated that not only the targeted tumor cells became irreversible damage, but also the short-range sounding tumors were severely damaged by the HIFU with LIFU pre-exposure in group B. It is concluded that LIFU pre-exposure can enhance the effects of HIFU ablation on the destruction of cell ultrastructures and can enlarge the region of HIFU ablation.

  11. Histological evaluation of high-intensity focused ultrasound with lower-intensity focused ultrasound pre-exposure on the treatment of rabbit VX2 liver tumors

    Zou Hairong; Zou Jianzhong; Wang Yan; Ou Xia [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key laboratory of Ultrasound in Medicine and Engineering, Department of Biomedical Engineering, Chongqing Medical (China)

    2012-10-03

    This study was to evaluate the effect of pre-exposure lower-intensity focused ultrasound(US), or LIFU, in high-intensity focused ultrasound(HIFU) ablation of rabbit VX2 liver tumors . Liver VX2 tumor models were established in 30 rabbits, which were divided randomly into two groups. The liver tumors of rabbits in Group A underwent single HIFU ablation; those in Group B were given LIFU exposure before HIFU treatment. Five rabbits from each of the two groups were sacrificed at 0 hours, 3 days, and 7 days after HIFU ablation. Tissue samples that included targeted and short-range sounding (s-RS, within 5 mm of the targeted) and far-range sounding (f-RS, more than 5 mm of the targeted) tissues were observed using light microscope and transmission electron microscopy. The histological examination indicated that not only the targeted tumor cells became irreversible damage, but also the short-range sounding tumors were severely damaged by the HIFU with LIFU pre-exposure in group B. It is concluded that LIFU pre-exposure can enhance the effects of HIFU ablation on the destruction of cell ultrastructures and can enlarge the region of HIFU ablation.

  12. Toward Deep Brain Monitoring with Superficial EEG Sensors Plus Neuromodulatory Focused Ultrasound.

    Darvas, Felix; Mehić, Edin; Caler, Connor J; Ojemann, Jeff G; Mourad, Pierre D

    2016-08-01

    Noninvasive recordings of electrophysiological activity have limited anatomic specificity and depth. We hypothesized that spatially tagging a small volume of brain with a unique electroencephalography (EEG) signal induced by pulsed focused ultrasound could overcome those limitations. As a first step toward testing this hypothesis, we applied transcranial ultrasound (2 MHz, 200-ms pulses applied at 1050 Hz for 1 s at a spatial peak temporal average intensity of 1.4 W/cm(2)) to the brains of anesthetized rats while simultaneously recording EEG signals. We observed a significant 1050-Hz electrophysiological signal only when ultrasound was applied to a living brain. Moreover, amplitude demodulation of the EEG signal at 1050 Hz yielded measurement of gamma band (>30 Hz) brain activity consistent with direct measurements of that activity. These results represent preliminary support for use of pulsed focused ultrasound as a spatial tagging mechanism for non-invasive EEG-based mapping of deep brain activity with high spatial resolution. PMID:27181686

  13. High intensity focused ultrasound ablation: A new therapeutic option for solid tumors

    Orsi Franco

    2010-01-01

    Full Text Available Surgery has been the standard of care in selected cases with solid tumors. However, a majority of patients are unable to undergo surgical resection because of the tumor sites, advanced stages, or poor general condition. High intensity focused ultrasound (HIFU is a novel non-invasive technique that is capable of producing coagulative necrosis at a precise focal point within the body, without harming overlying and adjacent structures even within the path of the beam. Diagnostic ultrasound was the first imaging modality used for guiding HIFU ablation in the 1990s. Over the last decade, thousands of patients with uterine fibroids, liver cancer, breast cancer, pancreatic cancer, bone tumors, renal cancer have been treated with ultrasound imaging-guided HIFU (USgHIFU worldwide. This USgHIFU system [Chongqing Haifu (HIFU Tech Co., Ltd., Chongqing, China] was first equipped in Asia, now in Europe. Several research groups have demonstrated that HIFU is safe and effective in treating human solid tumors. In 2004, the magnetic resonance guided focused ultrasound surgery (MRgFUS was approved by the United States Food and Drug Administration (FDA for clinical treatments of uterine fibroids. We conclude that HIFU offers patients another choice when no other treatment available or when patients refused surgical operation. This technique may play a key role in future clinical practice.

  14. A numerical study of transcranial focused ultrasound beam propagation at low frequency

    The feasibility of transcranial ultrasound focusing with a non-moving phased array and without skull-specific aberration correction was investigated using computer simulations. Three cadaver skull CT image data sets were incorporated into an acoustic wave transmission model to simulate transskull ultrasound wave propagation. Using a 0.25 MHz hemispherical array (125 mm radius of curvature, 250 mm diameter, 24 255 elements), the simulated beams could be focused and steered with transducer element driving phases and amplitude adjusted for focal beam steering in water (water-path). A total of 82 foci, spanning wide ranges of distance in the three orthogonal dimensions, were simulated to test the focal beam steering capability inside the three skulls. The acoustic pressure distribution in a volume of 20 x 20 x 20 mm3 centred at each focus was calculated with a 0.5 mm spacing in each axis. Clearly defined foci were retained through the skulls (skull-path) in most cases. The skull-path foci were on average 1.6 ± 0.8 mm shifted from their intended locations. The -3 dB skull-path beam width and length were on average 4.3 ± 1.0 mm and 7.7 ± 1.8 mm, respectively. The skull-path sidelobe levels ranged from 25% to 55% of the peak pressure values. The skull-path peak pressure levels were about 10%-40% of their water-path counterparts. Focusing low-frequency beam through skull without skull-specific aberration correction is possible. This method may be useful for applying ultrasound to disrupt the blood-brain barrier for targeted delivery of therapeutic or diagnostic agents, or to induce microbubbles, or for other uses of ultrasound in brain where the required power levels are low and the sharp focusing is not needed

  15. Dual-focus therapeutic ultrasound transducer for production of broad tissue lesions.

    Jeong, Jong Seob; Cannata, Jonathan M; Shung, K Kirk

    2010-11-01

    In noninvasive high-intensity focused ultrasound (HIFU) treatment, formation of a large tissue lesion per sonication is desirable for reducing the overall treatment time. The goal of this study is to show the feasibility of enlarging tissue lesion size with a dual-focus therapeutic ultrasound transducer (DFTUT) by increasing the depth-of-focus (DOF). The proposed transducer consists of a disc- and an annular-type element of different radii of curvatures to produce two focal zones. To increase focal depth and to maintain uniform beamwidth of the elongated DOF, each element transmits ultrasound of a different center frequency: the inner element at a higher frequency for near field focusing and the outer element at a lower frequency for far field focusing. By activating two elements at the same time with a single transmitter capable of generating a dual-frequency mixed signal, the overall DOF of the proposed transducer may be extended considerably. A prototype transducer composed of a 4.1 MHz inner element and a 2.7 MHz outer element was fabricated to obtain preliminary experimental results. The feasibility the proposed technique was demonstrated through sound field, temperature and thermal dose simulations. The performance of the prototype transducer was verified by hydrophone measurements and tissue ablation experiments on a beef liver specimen. When several factors affecting the length and the uniformity of elongated DOF of the DFTUT are optimized, the proposed therapeutic ultrasound transducer design may increase the size of ablated tissues in the axial direction and, thus, decreasing the treatment time for a large volume of malignant tissues especially deep-seated targets. PMID:20870346

  16. Rapid MR-ARFI method for focal spot localization during focused ultrasound therapy.

    Kaye, Elena A; Chen, Jing; Pauly, Kim Butts

    2011-03-01

    MR-guided focused ultrasound (FUS) is a noninvasive therapy for treating various pathologies. MR-based acoustic radiation force imaging (MR-ARFI) measures tissue displacement in the focal spot due to acoustic radiation force. MR-ARFI also provides feedback for adaptive focusing algorithms that could correct for phase aberrations caused by the skull during brain treatments. This work developed a single-shot echo-planar imaging-based MR-ARFI method that reduces scan time and ultrasound energy deposition. The new method was implemented and tested in a phantom and ex vivo brain tissue. The effect of the phase aberrations on the ultrasound focusing was studied using displacement maps obtained with echo-planar imaging and two-dimensional spin-warp MR-ARFI. The results show that displacement in the focal spot can be rapidly imaged using echo-planar imaging-based MR-ARFI with high signal-to-noise ratio efficiency and without any measurable tissue heating. Echo-planar imaging-based displacement images also demonstrate sufficient sensitivity to phase aberrations and can serve as rapid feedback for adaptive focusing in brain treatments and other applications. PMID:21337406

  17. Feasibility of MRI-guided Focused Ultrasound as Organ-Sparing Treatment for Testicular Cancer

    Staruch, Robert; Curiel, Laura; Chopra, Rajiv; Hynynen, Kullervo

    2009-04-01

    High cure rates for testicular cancer have prompted interest in organ-sparing surgery for patients with bilateral disease or single testis. Focused ultrasound (FUS) ablation could offer a noninvasive approach to organ-sparing surgery. The objective of this study was to determine the feasibility of using MR thermometry to guide organ-sparing focused ultrasound surgery in the testis. The testes of anesthetized rabbits were sonicated in several discrete locations using a single-element focused transducer operating at 2.787MHz. Focal heating was visualized with MR thermometry, using a measured PRF thermal coefficient of -0.0089±0.0003 ppm/° C. Sonications at 3.5-14 acoustic watts applied for 30 seconds produced maximum temperature elevations of 10-80° C, with coagulation verified by histology. Coagulation of precise volumes in the testicle is feasible with MRI-guided focused ultrasound. Variability in peak temperature for given sonication parameters suggests the need for online temperature feedback control.

  18. A collimated focused ultrasound beam of high acoustic transmission and minimum diffraction achieved by using a lens with subwavelength structures

    Lin, Zhou; Tu, Juan; Cheng, Jianchun [Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093 (China); Guo, Xiasheng, E-mail: guoxs@nju.edu.cn, E-mail: dzhang@nju.edu.cn [Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093 (China); Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Wu, Junru [Department of Physics, University of Vermont, Burlington, Vermont 05405 (United States); Huang, Pingtong [Department of Ultrasound, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009 (China); Zhang, Dong, E-mail: guoxs@nju.edu.cn, E-mail: dzhang@nju.edu.cn [Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093 (China); The State Key Laboratory of Acoustics, Chinese Academy of Science, Beijing 10080 (China)

    2015-09-14

    An acoustic focusing lens incorporated with periodically aligned subwavelength grooves corrugated on its spherical surface has been developed. It is demonstrated theoretically and experimentally that acoustic focusing achieved by using the lens can suppress the relative side-lobe amplitudes, enhance the focal gain, and minimize the shifting of the focus. Use of the lens coupled with a planar ultrasound transducer can generate an ultrasound beam with enhanced acoustic transmission and collimation effect, which offers the capability of improving the safety, efficiency, and accuracy of targeted surgery implemented by high intensity focused ultrasound.

  19. A collimated focused ultrasound beam of high acoustic transmission and minimum diffraction achieved by using a lens with subwavelength structures

    An acoustic focusing lens incorporated with periodically aligned subwavelength grooves corrugated on its spherical surface has been developed. It is demonstrated theoretically and experimentally that acoustic focusing achieved by using the lens can suppress the relative side-lobe amplitudes, enhance the focal gain, and minimize the shifting of the focus. Use of the lens coupled with a planar ultrasound transducer can generate an ultrasound beam with enhanced acoustic transmission and collimation effect, which offers the capability of improving the safety, efficiency, and accuracy of targeted surgery implemented by high intensity focused ultrasound

  20. Focused Cardiac Ultrasound Diagnosis of Cor Triatriatum Sinistrum in Pediatric Cardiac Arrest

    Thompson Kehrl,

    2015-10-01

    Full Text Available Cardiac arrest in the adolescent population secondary to congenital heart disease (CHD is rare. Focused cardiac ultrasound (FoCUS in the emergency department (ED can yield important clinical information, aid in resuscitative efforts during cardiac arrest and is commonly integrated into the evaluation of patients with pulseless electrical activity (PEA. We report a case of pediatric cardiac arrest in which FoCUS was used to diagnose a critical CHD known as cor triatriatum sinistrum as the likely cause for PEA cardiac arrest and help direct ED resuscitation.

  1. Radio Frequency Ultrasound Time Series Signal Analysis to Evaluate High-intensity Focused Ultrasound Lesion Formation Status in Tissue.

    Mobasheri, Saeedeh; Behnam, Hamid; Rangraz, Parisa; Tavakkoli, Jahan

    2016-01-01

    High-intensity focused ultrasound (HIFU) is a novel treatment modality used by scientists and clinicians in the recent decades. This modality has had a great and significant success as a noninvasive surgery technique applicable in tissue ablation therapy and cancer treatment. In this study, radio frequency (RF) ultrasound signals were acquired and registered in three stages of before, during, and after HIFU exposures. Different features of RF time series signals including the sum of amplitude spectrum in the four quarters of the frequency range, the slope, and intercept of the best-fit line to the entire power spectrum and the Shannon entropy were utilized to distinguish between the HIFU-induced thermal lesion and the normal tissue. We also examined the RF data, frame by frame to identify exposure effects on the formation and characteristics of a HIFU thermal lesion at different time steps throughout the treatment. The results obtained showed that the spectrum frequency quarters and the slope and intercept of the best fit line to the entire power spectrum both increased two times during the HIFU exposures. The Shannon entropy, however, decreased after the exposures. In conclusion, different characteristics of RF time series signal possess promising features that can be used to characterize ablated and nonablated tissues and to distinguish them from each other in a quasi-quantitative fashion. PMID:27186536

  2. Radio Frequency Ultrasound Time Series Signal Analysis to Evaluate High-intensity Focused Ultrasound Lesion Formation Status in Tissue

    Mobasheri, Saeedeh; Behnam, Hamid; Rangraz, Parisa; Tavakkoli, Jahan

    2016-01-01

    High-intensity focused ultrasound (HIFU) is a novel treatment modality used by scientists and clinicians in the recent decades. This modality has had a great and significant success as a noninvasive surgery technique applicable in tissue ablation therapy and cancer treatment. In this study, radio frequency (RF) ultrasound signals were acquired and registered in three stages of before, during, and after HIFU exposures. Different features of RF time series signals including the sum of amplitude spectrum in the four quarters of the frequency range, the slope, and intercept of the best-fit line to the entire power spectrum and the Shannon entropy were utilized to distinguish between the HIFU-induced thermal lesion and the normal tissue. We also examined the RF data, frame by frame to identify exposure effects on the formation and characteristics of a HIFU thermal lesion at different time steps throughout the treatment. The results obtained showed that the spectrum frequency quarters and the slope and intercept of the best fit line to the entire power spectrum both increased two times during the HIFU exposures. The Shannon entropy, however, decreased after the exposures. In conclusion, different characteristics of RF time series signal possess promising features that can be used to characterize ablated and nonablated tissues and to distinguish them from each other in a quasi-quantitative fashion.

  3. Design, development, and evaluation of focused ultrasound arrays for transesophageal cardiac ablations

    Lee, Hotaik

    The ultimate purpose of this dissertation is the evaluation of the feasibility of transesophageal cardiac surgery in arrhythmia treatment, using therapeutic ultrasound energy without the requirement for surgical incisions or blood contact. Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting over 2.2 million Americans. One effective treatment is cardiac ablation, which shows a high rate of success in treating paroxysmal AF. As a prevailing modality for this treatment, catheter ablation using radiofrequency has been effective, but there is measurable morbidity and significant costs and time associated with this invasive procedure for permanent or persistent AF. To address these issues, a transesophageal ultrasound applicator for noninvasive cardiac ablations has been designed, developed and evaluated in this dissertation. Focused ultrasound for thermal ablation has gained interest for decades due to its noninvasive characteristics. Since the esophagus is close to the posterior of the left atrium, its position makes it attractive for the incision-less surgery of the selected area of the heart using ultrasound. The overall goal of this study is to bring an applicator as closely as possible to the heart in order to effectively deliver ultrasound energy, and create electrically isolating lesions in myocardial tissue, replicating the currently used Maze procedure. The Maze procedure is a surgical operation that treats AF by creating a grid of incisions resulting in non-conductive scar tissue in the atria. The initial design of an ultrasound applicator capable of creating atrial lesions from the esophagus, involved evaluating sound pressure fields within layers of the esophagus and myocardium. Based on the multiple factors of the simulation results of transducer arrays, current transesophageal medical devices, and the throat anatomy, a focused ultrasound transducer that can be inserted into the esophagus has been designed and tested. In this study, a

  4. 3-point support mechanical steering system for high intensity focused ultrasound

    We have developed a simple approach for mechanically scanning a focused bowl ultrasound (US) transducer for either hyperthermia or tissue ablation therapies called the 3-point support (3PS) mechanical steering technique. The scanning involves translation of the required 3D motion of the ultrasound transducer to the more manageable linear movement of three support rods. It is a cost-effective alternative, especially compared with electronic scanning and other previous implementations of mechanically scanned systems. The 3PS approach is particularly well suited for integration with our microwave breast imaging technique-the combination of which could be an effective, low-cost thermal therapy/monitoring approach. The results show that the US focus can be moved laterally in a spiral pattern 3 cm below the surface in a gel phantom and that similar patterns can be moved to multiple locations within the phantom volume in succession. The feasibility of simultaneously acquiring microwave thermal images is also demonstrated

  5. Driving Circuitry for Focused Ultrasound Noninvasive Surgery and Drug Delivery Applications

    Kullervo Hynynen

    2011-01-01

    Full Text Available Recent works on focused ultrasound (FUS have shown great promise for cancer therapy. Researchers are continuously trying to improve system performance, which is resulting in an increased complexity that is more apparent when using multi-element phased array systems. This has led to significant efforts to reduce system size and cost by relying on system integration. Although ideas from other fields such as microwave antenna phased arrays can be adopted in FUS, the application requirements differ significantly since the frequency range used in FUS is much lower. In this paper, we review recent efforts to design efficient power monitoring, phase shifting and output driving techniques used specifically for high intensity focused ultrasound (HIFU.

  6. Clinical applications for magnetic resonance guided high intensity focused ultrasound (MRgHIFU): present and future

    It has been well known for decades that high intensity focused ultrasound (HIFU) generates heat in tissues resulting in coagulative necrosis. Implementation, however, has been slow, due to difficulties with finding an appropriate imaging modality that could not only guide treatment, but also provide real-time thermal feedback. These problems have been overcome with the newest magnetic resonance-guided high intensity focused ultrasound systems (MRgHIFU). With its superior spatial resolution enabling accurate image guidance coupled with its ability to provide real-time thermography during treatments, MRI is moving further into the realm of therapeutics for oncologic patient care. This article will discuss the implementation of an MR-guided HIFU system, current clinical indications and touch on future directions.

  7. Three-Dimensional Quantitative Optical Measurement of Asymmetrically Focused Ultrasound Pressure Field

    Shimazaki, Yuta; Harigane, Soichiro; Yoshizawa, Shin; Umemura, Shin-ichiro

    2012-07-01

    High-intensity focused ultrasound (HIFU) is used for the treatment of tumors such as prostate cancer. In the development of this technique, an accurate and fast measurement of the HIFU pressure field is important. A hydrophone is generally used for the measurement, but it might disturb the pressure field and scanning it in the field takes a long time. On the other hand, optical ultrasonic field mapping has the advantages of speed and its nature of not by interfering with the acoustic field. In this study, we reconstructed an asymmetric ultrasound field by optical measurement using a computed tomography (CT) algorithm. The asymmetric field was generated by a focused transducer with four elements. Also, the absolute measurement of ultrasonic pressure was checked by measuring the center of the field of the charge-coupled device (CCD) camera. The results showed overall agreement with those of hydrophone measurement.

  8. High intensity focused ultrasound (HIFU as the alternative method of treatment of oncourological diseases

    Blyumberg B.I.

    2012-12-01

    Full Text Available Increasing interest devoted to technology of high intensity focused ultrasound (high-intensity focused ultrasound, HIFU, basically, is explained by a wide spectrum of potential fields of application at minimum invasiveness of the given method. In oncourology HIFU is applied in prostate and kidney cancer. In case of tumors of renal parenchyma the given technique is being clinically tested, while HIFU is currently used in the practice of European oncourologists in treatment of prostate cancer. The majority of the references describing the results of HIFU application in prostate cancer is based on data of a number of clinical observations. It has been proved that HIFU is a possible method of treatment of highly — and moderate-differentiated tumors, and local relapses after remote radial therapy.

  9. Real-time Monitoring of High Intensity Focused Ultrasound (HIFU) Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound (HMIFU).

    Grondin, Julien; Payen, Thomas; Wang, Shutao; Konofagou, Elisa E

    2015-01-01

    Harmonic Motion Imaging for Focused Ultrasound (HMIFU) is a technique that can perform and monitor high-intensity focused ultrasound (HIFU) ablation. An oscillatory motion is generated at the focus of a 93-element and 4.5 MHz center frequency HIFU transducer by applying a 25 Hz amplitude-modulated signal using a function generator. A 64-element and 2.5 MHz imaging transducer with 68kPa peak pressure is confocally placed at the center of the HIFU transducer to acquire the radio-frequency (RF) channel data. In this protocol, real-time monitoring of thermal ablation using HIFU with an acoustic power of 7 W on canine livers in vitro is described. HIFU treatment is applied on the tissue during 2 min and the ablated region is imaged in real-time using diverging or plane wave imaging up to 1,000 frames/second. The matrix of RF channel data is multiplied by a sparse matrix for image reconstruction. The reconstructed field of view is of 90° for diverging wave and 20 mm for plane wave imaging and the data are sampled at 80 MHz. The reconstruction is performed on a Graphical Processing Unit (GPU) in order to image in real-time at a 4.5 display frame rate. 1-D normalized cross-correlation of the reconstructed RF data is used to estimate axial displacements in the focal region. The magnitude of the peak-to-peak displacement at the focal depth decreases during the thermal ablation which denotes stiffening of the tissue due to the formation of a lesion. The displacement signal-to-noise ratio (SNRd) at the focal area for plane wave was 1.4 times higher than for diverging wave showing that plane wave imaging appears to produce better displacement maps quality for HMIFU than diverging wave imaging. PMID:26556647

  10. Focused cardiac ultrasound in the emergency department for patients admitted with respiratory symptoms

    Laursen, C. B.

    2015-01-01

    In patients admitted with respiratory failure, a large proportion is diagnosed incorrectly in the emergency department and an even larger proportion seems to receive inappropriate treatment. Inappropriate initial treatment of these patients in the emergency department is associated with increased...... triage, patients with cardiac arrest, patients with undifferentiated shock, patients with cardiopulmonary instability, patients with respiratory symptoms, trauma patients with suspected cardiac injuries, and assessment of the fluid status before fluid loading. When using focused cardiac ultrasound (US...

  11. High-Intensity Focused Ultrasound (HIFU) in Uterine Fibroid Treatment: Review Study

    MAHMOUD, MUSTAFA Z.; Alkhorayef, Mohammed; Alzimami, Khalid S.; Aljuhani, Manal Saud; Sulieman, Abdelmoneim

    2014-01-01

    Summary Background High-intensity focused ultrasound (HIFU) is a highly precise medical procedure used locally to heat and destroy diseased tissue through ablation. This study intended to review HIFU in uterine fibroid therapy, to evaluate the role of HIFU in the therapy of leiomyomas as well as to review the actual clinical activities in this field including efficacy and safety measures beside the published clinical literature. Material/Methods An inclusive literature review was carried out ...

  12. Uterine artery embolisation and magnetic resonance guided focused ultrasound treatment of uterine fibroids

    Uterine fibroids are the most common benign female tumours during reproductive age. The traditional treatment for this condition is typically hysterectomy. However, there are new technologies on the rise, such as Uterine Artery Embolisation and Magnetic Resonance-guided Focused Ultrasound which are directed towards a minimally invasive or even noninvasive treatment of uterine fibroids. These modern procedures allow for a fast recovery and preservation of fertility. In this work, we presented these alternative procedures and highlighted their and limitations. (authors)

  13. Uterine artery embolisation and magnetic resonance-guided focused ultrasound treatment of uterine fibroids

    Uterine fibroids are the most common benign female tumours during reproductive age. The traditional treatment for this condition is typically hysterectomy. However, there are new technologies on the rise, such as Uterine Artery Embolisation and Magnetic Resonance-guided Focused Ultrasound which are directed towards a minimally invasive or even noninvasive treatment of uterine fibroids. These modern procedures allow for a fast recovery and preservation of fertility. In this work, we presented these alternative procedures and highlighted their advantages and limitations

  14. Image-Guided Focused Ultrasound-Mediated Regional Brain Stimulation in Sheep.

    Lee, Wonhye; Lee, Stephanie D; Park, Michael Y; Foley, Lori; Purcell-Estabrook, Erin; Kim, Hyungmin; Fischer, Krisztina; Maeng, Lee-So; Yoo, Seung-Schik

    2016-02-01

    Non-invasive brain stimulation using focused ultrasound has largely been carried out in small animals. In the present study, we applied stimulatory focused ultrasound transcranially to the primary sensorimotor (SM1) and visual (V1) brain areas in sheep (Dorset, all female, n = 8), under the guidance of magnetic resonance imaging, and examined the electrophysiologic responses. By use of a 250-kHz focused ultrasound transducer, the area was sonicated in pulsed mode (tone-burst duration of 1 ms, duty cycle of 50%) for 300 ms. The acoustic intensity at the focal target was varied up to a spatial peak pulse-average intensity (Isppa) of 14.3 W/cm(2). Sonication of SM1 elicited electromyographic responses from the contralateral hind leg, whereas stimulation of V1 generated electroencephalographic potentials. These responses were detected only above a certain acoustic intensity, and the threshold intensity, as well as the degree of responses, varied among sheep. Post-sonication animal behavior was normal, but minor microhemorrhages were observed from the V1 areas exposed to highly repetitive sonication (every second for ≥500 times for electroencephalographic measurements, Isppa = 6.6-10.5 W/cm(2), mechanical index = 0.9-1.2). Our results suggest the potential translational utility of focused ultrasound as a new brain stimulation modality, yet also call for caution in the use of an excessive number of sonications. PMID:26525652

  15. Focused Ultrasound Surgery for the Treatment of Recurrent Anaplastic Astrocytoma: A Preliminary Report

    Park, Jung-Wuk; Jung, Shin; Jung, Tae-Young; Lee, Min-Cheol

    2006-05-01

    Anaplastic glioma is a highly aggressive tumor in the central nervous system. The conventional treatment for patients with anaplstic glioma consists of the combination of surgery, chemotherapy and radiotherapy. However, the effect of the currently available therapies is limited, and the prognosis is very poor in these patients. The purpose of this abstract is to introduce our preliminary experience of using focused ultrasound surgery (FUS) for the treatment of patients with recurrent anaplastic astrocytoma.

  16. Novel magnetic/ultrasound focusing system enhances nanoparticle drug delivery for glioma treatment

    Chen, Pin-Yuan; Liu, Hao-Li; Hua, Mu-Yi; Yang, Hung-Wei; Huang, Chiung-Yin; Chu, Po-Chun; Lyu, Lee-Ang; Tseng, I-Chou; Feng, Li-Ying; Tsai, Hong-Chieh; Chen, Shu-Mei; Lu, Yu-Jen; Wang, Jiun-Jie; Yen, Tzu-Chen; Ma, Yunn-Hwa

    2010-01-01

    Malignant glioma is a common and severe primary brain tumor with a high recurrence rate and an extremely high mortality rate within 2 years of diagnosis, even when surgical, radiological, and chemotherapeutic interventions are applied. Intravenously administered drugs have limited use because of their adverse systemic effects and poor blood–brain barrier penetration. Here, we combine 2 methods to increase drug delivery to brain tumors. Focused ultrasound transiently permeabilizes the blood–br...

  17. Non-invasive estimation of thermal tissue properties by high-intensity focused ultrasound

    Appanaboyina, Sunil; Partanen, Ari; Haemmerich, Dieter

    2013-02-01

    Magnetic Resonance guided High-intensity Focused Ultrasound (MR-HIFU) can be used to locally heat tissue while non-invasively monitoring tissue temperature via MR-based thermometry. The goal of this study was to investigate the use of a computational technique based on inverse heat-transfer modeling for the non-invasive measurement of thermal tissue properties from data collected using an MR-HIFU system.

  18. Laser-enhanced cavitation during high intensity focused ultrasound: An in vivo study

    Cui, Huizhong; Zhang, Ti; Yang, Xinmai

    2013-04-01

    Laser-enhanced cavitation during high intensity focused ultrasound (HIFU) was studied in vivo using a small animal model. Laser light was employed to illuminate the sample concurrently with HIFU radiation. The resulting cavitation was detected with a passive cavitation detector. The in vivo measurements were made under different combinations of HIFU treatment depths, laser wavelengths, and HIFU durations. The results demonstrated that concurrent light illumination during HIFU has the potential to enhance cavitation effect by reducing cavitation threshold in vivo.

  19. High-intensity focused ultrasound to treat primary hyperparathyroidism: a feasibility study in four patients

    Kovatcheva, Roussanka D; Vlahov, Jordan D; Shinkov, Alexander D; Borissova, Anna-Maria; Hwang, Joo Ha; Arnaud, Françoise; Hegedüs, Laszlo

    2010-01-01

    Many patients with primary hyperparathyroidism either decline or are not candidates for surgical parathyroidectomy. There are drawbacks to medical therapy as well as percutaneous ethanol injection as alternative therapies for primary hyperparathyroidism. Therefore, in this pilot study, our aim wa...... to test the feasibility, safety, and efficacy of a newly developed noninvasive high-intensity focused ultrasound (HIFU) technique for the nonsurgical management of primary hyperparathyroidism....

  20. New clinical application of high-intensity focused ultrasound: local control of synovial sarcoma

    Hu, Xiaoye; CAI, HONGKE; Zhou, Meiqi; HE, HAIFEI; Tian, Wei; Hu, Yue; Chen, Lirong; Deng, Yongchuan

    2013-01-01

    High-intensity focused ultrasound (HIFU) is playing an increasingly important role in cancer therapy. Primary synovial sarcomas of the chest wall are extremely rare. We report the first case of noninvasive HIFU therapy for the control of synovial sarcoma. A 51-year-old man was diagnosed with spindle cell sarcoma on the left chest wall through lumpectomy. After four cycles of chemotherapy, local recurrence of the sarcoma was detected. Subsequent extended resection confirmed synovial sarcoma. A...

  1. PATHOMORPHISM OF PROSTATE CANCER DURING HIGH-INTENSITY FOCUSED ULTRASOUND TREATMENT

    R.N. Fomkin; E.S. Voronina; V.M. Popkov; G.N. Maslyakova; B. I. Blyumberg

    2014-01-01

    The purpose of the study was to evaluate the efficiency of prostate cancer (PC) treatment using high-intensity focused ultrasound (HIFU) on the basis of morphometric and immunohistochemical (IHC) analyses of postoperative prostate biopsy specimens. The study subjects were 40 patients with localized and locally advanced PC. The postoperative morphological analysis was made on the basis of standard hematoxylineosin staining and morphometric and IHC studies using the following antibodies: PCNA, ...

  2. High-Intensity Focused Ultrasound for Prostate Cancer: Long-Term Followup and Complications Rate

    Umberto Maestroni; Francesco Dinale; Roberto Minari; Paolo Salsi; Francesco Ziglioli

    2012-01-01

    Introduction. As it is well known, High Intensity Focused Ultrasound (HIFU) is a minimally invasive procedure for prostate cancer. Many investigators reported their series of patients, demonstrating the effectiveness of the treatment. The most majority of Authors, however, do not report the side effects and the complications of the procedure, which is the aim of our study. The diagnosis and management of complications is discussed, and the oncologic outcome is reported in terms of quality of ...

  3. Histological changes in the human prostate after radiotherapy and salvage high intensity focused ultrasound

    Chalasani, Venu; Martinez, Carlos H; Williams, Andrew K.; Kwan, Kevin; Chin, Joseph L.

    2010-01-01

    The histological changes (both macroscopic and microscopic) in the prostate following the combination of external beam radiotherapy and salvage high intensity focused ultrasound (HIFU) have not been previously described. This article describes the case of a 65-year-old male who presented with recurrent localized prostate cancer after undergoing external beam radiotherapy for low-risk prostate cancer. He was treated with salvage HIFU, and 4 weeks later presented with symptoms and signs consist...

  4. A Rectourethral Fistula due to Transrectal High-Intensity Focused Ultrasound Treatment: Diagnosis and Management

    Valeria Fiaschetti; Guglielmo Manenti; Isabelle Di Poce; Maria Fornari; Aurora Ricci; Enrico Finazzi Agrò; Giovanni Simonetti

    2012-01-01

    Colovesical fistula (CVF) is an abnormal connection between the enteric and the urinary systems. The rectourethral fistula (RUF) is a possible but extremely rare complication of treatment of prostate cancer with “transrectal High-Intensity Focused Ultrasound (HIFU) treatment.” We present a case of CVF due to HIFU treatment of recurrent prostate cancer. The case was assessed with cystography completed with a pelvic CT scan—with MPR, MIP, and VR reconstruction—before emptying the bladder. Since...

  5. Urodynamic Evaluation after High-Intensity Focused Ultrasound for Patients with Prostate Cancer

    Luigi Mearini; Elisabetta Nunzi; Silvia Giovannozzi; Luca Lepri; Carolina Lolli; Antonella Giannantoni

    2014-01-01

    This prospective study assesses the impact of high-intensity focused ultrasound (HIFU) on lower urinary tract by comparing pre- and postoperative symptoms and urodynamic changes. Thirty consecutive patients with clinically organ-confined prostate cancer underwent urodynamic study before HIFU and then at 3–6 months after surgery. Continence status and symptoms were analyzed by means of International Prostate Symptoms Score IPSS and International Index Erectile Function IIEF5. As a result, ther...

  6. Results of low threshold to biopsy following high-intensity focused ultrasound for localized prostate cancer

    Richard L Haddad; Tania A Hossack; Woo, Henry H.

    2012-01-01

    Context: There are different treatment options for localized prostate cancer. The success of high-intensity focused ultrasound (HIFU) is based largely on biochemical prostate specific antigen (PSA) results. Aims: To evaluate the impact of using a low PSA threshold to perform prostate biopsies after HIFU in order to more accurately gauge treatment success. Settings and Design: Eleven patients underwent HIFU at Sydney Adventist Hospital in Sydney, 10 as primary and 1 as salvage therapy ...

  7. IN VIVO MONITORING OF FOCUSED ULTRASOUND SURGERY USING LOCAL HARMONIC MOTION

    Curiel, Laura; Chopra, Rajiv; Hynynen, Kullervo

    2008-01-01

    The present study established the feasibility of a technique for monitoring FUS lesion formation in vivo using localized harmonic motion (LHM) measurements. Oscillatory motion (frequencies between 50 and 300 Hz) was generated within tissues by induction of a periodic radiation force with a focused ultrasound (FUS) transducer. The harmonic motion was estimated using cross-correlation of RF ultrasonic signals acquired at different instances during the motion by using a confocal diagnostic ultra...

  8. Treating patients with movement disorders using MRI-guided focused ultrasound: recent developments and challenges

    Tierney, Travis

    2015-01-01

    Wesley M Field,1 Tharakeswari Selvakumar,1 Michael T Hayes,2 Travis S Tierney1 1Department of Neurosurgery, 2Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA Abstract: MRI-guided focused ultrasound (MRgFUS) is being considered in the treatment of movement disorders like essential tremor and Parkinson's disease and has shown promising preliminary results both in terms of effectiveness and safety. However, several technical...

  9. Magnetic resonance image-guided versus ultrasound-guided high-intensity focused ultrasound in the treatment of breast cancer.

    Li, Sheng; Wu, Pei-Hong

    2013-08-01

    Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is a common cancer in women. HIFU therapy, in combination with other therapies, has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Currently, HIFU therapy is not commonly used in breast cancer treatment, and efforts to promote the application of HIFU is expected. In this article, we compare different image-guided models for HIFU and reviewed the status, drawbacks, and potential of HIFU therapy for breast cancer. PMID:23237221

  10. Magnetic resonance image-guided versus ultrasound-guided high-intensity focused ultrasound in the treatment of breast cancer

    Sheng Li; Pei-Hong Wu

    2013-01-01

    Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years,primarily in the treatment of liver and prostate cancers.HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue.Breast cancer is a common cancer in women.HIFU therapy,in combination with other therapies,has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape.Currently,HIFU therapy is not commonly used in breast cancer treatment,and efforts to promote the application of HIFU is expected.In this article,we compare different image-guided models for HIFU and reviewed the status,drawbacks,and potential of HIFU therapy for breast cancer.

  11. Magnetic resonance image-guided versus ultrasound-guided high-intensity focused ultrasound in the treatment of breast cancer

    Pei-Hong Wu

    2013-08-01

    Full Text Available Image-guided high-intensity focused ultrasound (HIFU has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is a common cancer in women. HIFU therapy, in combination with other therapies, has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Currently, HIFU therapy is not commonly used in breast cancer treatment, and efforts to promote the application of HIFU is expected. In this article, we compare different image-guided models for HIFU and reviewed the status, drawbacks, and potential of HIFU therapy for breast cancer.

  12. Modes of elastic plates and shells in water driven by modulated radiation pressure of focused ultrasound

    Marston, Philip L.; Daniel, Timothy D.; Abawi, Ahmad T.; Kirsteins, Ivars

    2015-11-01

    The modulated radiation pressure (MRP) of ultrasound has been used for decades to selectively excite low frequency modes associated with surface tension of fluid objects in water. Much less is known about the excitation of low frequency modes of less compliant metallic objects. Here we use MRP of focused ultrasound to excite resonant flexural vibrations of a circular metal plate in water. The source transducer was driven with a double-sideband suppressed carrier voltage as in. The response of the target (detected with a hydrophone) was at twice the modulation frequency and proportional to the square of the drive voltage. Since the radiation pressure of focused beams is spatially localized, mode shapes could be identified by scanning the source along the target while measuring the target's response. Additional measurements were done with an open-ended water-filled copper circular cylindrical shell in which resonant frequencies and mode shapes were also identified. These experiments show how focused ultrasound can be used to identify low-frequency modes of elastic objects without direct contact. Supported by ONR.

  13. Ultrasound monitoring of the influence of different accelerating admixtures and cement types for shotcrete on setting and hardening behaviour

    The possible use of ultrasound measurements for monitoring setting and hardening of mortar containing different accelerating admixtures for shotcrete was investigated. The sensitivity to accelerator type (alkaline aluminate or alkali-free) and dosage, and accelerator-cement compatibility were evaluated. Furthermore, a new automatic onset picking algorithm for ultrasound signals was tested. A stepwise increase of the accelerator dosage resulted in increasing values for the ultrasound pulse velocity at early ages. In the accelerated mortar no dormant period could be noticed before the pulse velocity started to increase sharply, indicating a quick change in solid phase connectivity. The alkaline accelerator had a larger effect than the alkali-free accelerator, especially at ages below 90 min. The effect of the alkali-free accelerator was at very early age more pronounced on mortar containing CEM I in comparison with CEM II, while the alkaline accelerator had a larger influence on mortar containing CEM II. The increase of ultrasound energy could be related to the setting phenomenon and the maximum energy was reached when the end of workability was approached. Only the alkaline accelerator caused a significant reduction in compressive strength and this for all the dosages tested

  14. High-Frequency Focused Water-Coupled Ultrasound Used for Three-Dimensional Surface Depression Profiling

    Roth, Don J.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    2001-01-01

    To interface with other solids, many surfaces are engineered via methods such as plating, coating, and machining to produce a functional surface ensuring successful end products. In addition, subsurface properties such as hardness, residual stress, deformation, chemical composition, and microstructure are often linked to surface characteristics. Surface topography, therefore, contains the signatures of the surface and possibly links to volumetric properties, and as a result serves as a vital link between surface design, manufacturing, and performance. Hence, surface topography can be used to diagnose, monitor, and control fabrication methods. At the NASA Glenn Research Center, the measurement of surface topography is important in developing high-temperature structural materials and for profiling the surface changes of materials during microgravity combustion experiments. A prior study demonstrated that focused air-coupled ultrasound at 1 MHz could profile surfaces with a 25-m depth resolution and a 400-m lateral resolution over a 1.4-mm depth range. In this work, we address the question of whether higher frequency focused water-coupled ultrasound can improve on these specifications. To this end, we employed 10- and 25-MHz focused ultrasonic transducers in the water-coupled mode. The surface profile results seen in this investigation for 25-MHz water-coupled ultrasound, in comparison to those for 1-MHz air-coupled ultrasound, represent an 8 times improvement in depth resolution (3 vs. 25 m seen in practice), an improvement of at least 2 times in lateral resolution (180 vs. 400 m calculated and observed in practice), and an improvement in vertical depth range of 4 times (calculated).

  15. Noninvasive treatment of focal adenomyosis with MR-guided focused ultrasound in two patients

    Laveena Polina

    2012-01-01

    Full Text Available Adenomyosis is a common benign gynecological disorder presenting with dysmenorrhea, menorrhagia, and pressure symptoms. Magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS utilizes precisely focused USG waves to generate and maintain high temperatures within the targeted tissue to achieve protein denaturation and coagulative necrosis. The heat generated is monitored using MRI images acquired in real-time in three planes. We present two cases of focal adenomyosis treated with MRgFUS showing good symptomatic relief at 3 and 6 months follow-up.

  16. Modeling of Nonlinear Propagation in Multi-layer Biological Tissues for Strong Focused Ultrasound

    FAN Ting-Bo; LIU Zhen-Bo; ZHANG Zhe; ZHANG DONG; GONG Xiu-Fen

    2009-01-01

    A theoretical model of the nonlinear propagation in multi-layered tissues for strong focused ultrasound is proposed. In this model, the spheroidal beam equation (SBE) is utilized to describe the nonlinear sound propagation in each layer tissue, and generalized oblique incidence theory is used to deal with the sound transmission between two layer tissues. Computer simulation is performed on a fat-muscle-liver tissue model under the irradiation of a 1 MHz focused transducer with a large aperture angle of 35°. The results demonstrate that the tissue layer would change the amplitude of sound pressure at the focal region and cause the increase of side petals.

  17. High-Intensity Focused Ultrasound (HIFU) in Localized Prostate Cancer Treatment

    High-intensity focused ultrasound (HIFU) applies high-intensity focused ultrasound energy to locally heat and destroy diseased or damaged tissue through ablation. This study intended to review HIFU to explain the fundamentals of HIFU, evaluate the evidence concerning the role of HIFU in the treatment of prostate cancer (PC), review the technologies used to perform HIFU and the published clinical literature regarding the procedure as a primary treatment for PC. Studies addressing HIFU in localized PC were identified in a search of internet scientific databases. The analysis of outcomes was limited to journal articles written in English and published between 2000 and 2013. HIFU is a non-invasive approach that uses a precisely delivered ultrasound energy to achieve tumor cell necrosis without radiation or surgical excision. In current urological oncology, HIFU is used clinically in the treatment of PC. Clinical research on HIFU therapy for localized PC began in the 1990s, and the majority of PC patients were treated with the Ablatherm device. HIFU treatment for localized PC can be considered as an alternative minimally invasive therapeutic modality for patients who are not candidates for radical prostatectomy. Patients with lower pre-HIFU PSA level and favourable pathologic Gleason score seem to present better oncologic outcomes. Future advances in technology and safety will undoubtedly expand the HIFU role in this indication as more of patient series are published, with a longer follow-up period

  18. MRI-Guided Focused Ultrasound as a New Method of Drug Delivery

    M. Thanou

    2013-01-01

    Full Text Available Ultrasound-mediated drug delivery under the guidance of an imaging modality can improve drug disposition and achieve site-specific drug delivery. The term focal drug delivery has been introduced to describe the focal targeting of drugs in tissues with the help of imaging and focused ultrasound. Focal drug delivery aims to improve the therapeutic profile of drugs by improving their specificity and their permeation in defined areas. Focused-ultrasound- (FUS- mediated drug delivery has been applied with various molecules to improve their local distribution in tissues. FUS is applied with the aid of microbubbles to enhance the permeability of bioactive molecules across BBB and improve drug distribution in the brain. Recently, FUS has been utilised in combination with MRI-labelled liposomes that respond to temperature increase. This strategy aims to “activate” nanoparticles to release their cargo locally when triggered by hyperthermia induced by FUS. MRI-guided FUS drug delivery provides the opportunity to improve drug bioavailability locally and therefore improve the therapeutic profiles of drugs. This drug delivery strategy can be directly translated to clinic as MRg FUS is a promising clinically therapeutic approach. However, more basic research is required to understand the physiological mechanism of FUS-enhanced drug delivery.

  19. Advantage of annular focus generation by sector-vortex array in cavitation-enhanced high-intensity focused ultrasound treatment

    Jimbo, Hayato; Takagi, Ryo; Taguchi, Kei; Yoshizawa, Shin; Umemura, Shin-ichiro

    2016-07-01

    High-intensity focused ultrasound (HIFU) is a noninvasive method for cancer treatment. One of the disadvantages of this method is that it has a long total treatment time because of the smallness of the treatment volume by a single exposure. To solve this problem, we have proposed a method of cavitation-enhanced heating, which utilized the heat generated by oscillating the cavitation bubbles, in combination with the method of lateral enlargement of a HIFU focal zone to minimize the surface volume ratio. In a previous study, focal spot scanning at multiple points was employed for the enlargement. This method involves nonlinear propagation and absorption due to the high spatial-peak temporal-peak (SPTP) intensity in addition to the cavitation-enhanced heating. However, it is difficult to predict the size and position of the coagulation volume because they are significantly affected by the nonlinear parameters of the tissue. In this study, a sector vortex method was employed to directly synthesize an annular focal pattern. Since this method can keep the SPTP intensity at a manageably low level, nonlinear propagation and absorption can be minimized. Experimental results demonstrate that the coagulation was generated only in the region where both the cavitation cloud and the heating ultrasound were matched. The proposed method will make the cavitation-enhanced HIFU treatment more accurate and predictable.

  20. A scanned focused ultrasound device for hyperthermia: numerical simulation and prototype implementation

    Meaney, Paul M.; Raynolds, Timothy; Geimer, Shireen D.; Potwin, Lincoln; Paulsen, Keith D.

    2004-07-01

    We are developing a scanned focused ultrasound system for hyperthermia treatment of breast cancer. Focused ultrasound has significant potential as a therapy delivery device because it can focus sufficient heating energy below the skin surface with minimal damage to intervening tissue. However, as a practical therapy system, the focal zone is generally quite small and requires either electronic (in the case of a phased array system) or mechanical steering (for a fixed bowl transducer) to cover a therapeutically useful area. We have devised a simple automated steering system consisting of a focused bowl transducer supported by three vertically movable rods which are connected to computer controlled linear actuators. This scheme is particularly attractive for breast cancer hyperthermia where the support rods can be fed through the base of a liquid coupling tank to treat tumors within the breast while coupled to our noninvasive microwave thermal imaging system. A MATLAB routine has been developed for controlling the rod motion such that the beam focal point scans a horizontal spiral and the subsequent heating zone is cylindrical. In coordination with this effort, a 3D finite element thermal model has been developed to evaluate the temperature distributions from the scanned focused heating. In this way, scanning protocols can be optimized to deliver the most uniform temperature rise to the desired location.

  1. High intensity focused ultrasound ablation of pancreatic neuroendocrine tumours: report of two cases.

    Orgera, Gianluigi; Krokidis, Miltiadis; Monfardini, Lorenzo; Bonomo, Guido; Della Vigna, Paolo; Fazio, Nicola; Orsi, Franco

    2011-04-01

    We describe the use of ultrasound-guided high-intensity focused ultrasound (HIFU) for ablation of two pancreatic neuroendocrine tumours (NETs; insulinomas) in two inoperable young female patients. Both suffered from episodes of severe nightly hypoglycemia that was not efficiently controlled by medical treatment. After HIFU ablation, local disease control and symptom relief were achieved without postinterventional complications. The patients remained free of symptoms during 9-month follow-up. The lesions appeared to be decreased in volume, and there was decreased enhancing pattern in the multidetector computed tomography control (MDCT). HIFU is likely to be a valid alternative for symptoms control in patients with pancreatic NETs. However, currently the procedure should be reserved for inoperable patients for whom symptoms cannot be controlled by medical therapy. PMID:20521049

  2. Real-time feedback control for high-intensity focused ultrasound system using localized motion imaging

    Sugiyama, Ryusuke; Kanazawa, Kengo; Seki, Mika; Azuma, Takashi; Sasaki, Akira; Takeuchi, Hideki; Fujiwara, Keisuke; Itani, Kazunori; Tamano, Satoshi; Yoshinaka, Kiyoshi; Takagi, Shu; Matsumoto, Yoichiro

    2015-07-01

    High-intensity focused ultrasound (HIFU) is one of the noninvasive treatment for tumors. Visualizing the treated area inside the human body is necessary to control the HIFU exposure. Localized motion imaging (LMI) using ultrasound to induce and detect tissue deformation is one technique to detect a change in tissue stiffness caused by thermal coagulation. In experiments with porcine liver, LMI has shown to detect deformation with less than 20% accuracy. We have developed a prototype feedback control system using real-time LMI. In this system, coagulation size was measured every 1 s and controlled to correspond to a targeted size. The typical size error was reduced to 14% from 35%. LMI displacements in normal and coagulated tissues were sufficiently different to discriminate between coagulated areas and noncoagulated ones after HIFU sonication and to visualize treated areas after HIFU treatment.

  3. High intensity focused ultrasound: a noninvasive therapy for locally advanced pancreatic cancer.

    Wu, Feng

    2014-11-28

    The noninvasive ablation of pancreatic cancer with high intensity focused ultrasound (HIFU) energy is received increasingly widespread interest. With rapidly temperature rise to cytotoxic levels within the focal volume of ultrasound beams, HIFU can selectively ablate a targeted lesion of the pancreas without any damage to surrounding or overlying tissues. Preliminary studies suggest that this approach is technical safe and feasible, and can be used alone or in combination with systemic chemotherapy for the treatment of patients with locally advanced pancreatic cancer. It can effectively alleviate cancer-related abdominal pain, and may confer an additional survival benefit with few significant complications. This review provides a brief overview of HIFU, describes current clinical applications, summarizes characteristics of continuous and pulsed HIFU, and discusses future applications and challenges in the treatment of pancreatic cancer. PMID:25469016

  4. The FDA Perspective on Pre-Clinical Testing for High Intensity Focused Ultrasound Devices

    Harris, Gerald R.

    2006-05-01

    In the U. S., the pre-market review of high intensity focused ultrasound (HIFU) devices is carried out under the authority of the 1976 Medical Device Amendments to the Food, Drug, and Cosmetic Act. Different regulatory mechanisms may apply depending on the complexity of the HIFU device and the indications for use, but in all cases pre-clinical testing is required. This testing typically includes ultrasound field characterization, thermal modeling and measurement, and may include demonstrating the accuracy of targeting and monitoring, if applicable. Because there are no guidance documents or standards for these tests at present, the U.S. Food and Drug Administration (FDA) welcomes working with interested parties to develop acceptable procedures that can be incorporated into the regulatory review process.

  5. Novel Non-invasive Treatment With High-intensity Focused Ultrasound (HIFU).

    Marinova, M; Rauch, M; Schild, H H; Strunk, H M

    2016-02-01

    Ultrasound is not only used for diagnostic purposes but it also can be applied therapeutically so far that nowadays high-intensity focused ultrasound (HIFU) even represents a novel non-invasive treatment modality for various solid tumors. HIFU works by causing selectively deep tissue destruction of target lesions within the body without harming adjacent and overlying structures. In this article, we present an overview on both the mode of action and requirements for a HIFU treatment as well as on the safety and the current status of indications and possible applications with regard to benign and malignant gynecological diseases. Based on numerous studies and original articles, HIFU proved to be an effective and low-risk treatment option particularly for uterine fibroids and adenomyosis, but it also seems to be effective for breast fibroadenomas or even for breast cancer in special cases and other rare entities. PMID:26251996

  6. An optimized ultrasound digital beamformer with dynamic focusing implemented on FPGA.

    Almekkawy, Mohamed; Xu, Jingwei; Chirala, Mohan

    2014-01-01

    We present a resource-optimized dynamic digital beamformer for an ultrasound system based on a field-programmable gate array (FPGA). A comprehensive 64-channel receive beamformer with full dynamic focusing is embedded in the Altera Arria V FPGA chip. To improve spatial and contrast resolution, full dynamic beamforming is implemented by a novel method with resource optimization. This was conceived using the implementation of the delay summation through a bulk (coarse) delay and fractional (fine) delay. The sampling frequency is 40 MHz and the beamformer includes a 240 MHz polyphase filter that enhances the temporal resolution of the system while relaxing the Analog-to-Digital converter (ADC) bandwidth requirement. The results indicate that our 64-channel dynamic beamformer architecture is amenable for a low power FPGA-based implementation in a portable ultrasound system. PMID:25570695

  7. Feasibility of ultrasound-guided high intensity focused ultrasound ablating uterine fibroids with hyperintense on T2-weighted MR imaging

    Zhao, Wen-Peng, E-mail: zwp215@163.com [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Chen, Jin-Yun, E-mail: chenjinyun2006@126.com [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Zhang, Lian, E-mail: zhangl@haifu.com.cn [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Clinical Center for Tumor Therapy of 2nd Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Chongqing 400010 (China); Li, Quan, E-mail: 1013283493@qq.com [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Qin, Juan, E-mail: ant000999@163.com [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); and others

    2013-01-15

    Purpose: To retrospectively investigate whether uterine fibroids with hyperintense on pretreatment T2-weighted magnetic resonance imaging (MRI) could be treated with ultrasound-guided high intensity focused ultrasound (USgHIFU). Materials and methods: 282 patients with 282 symptomatic uterine fibroids who underwent USgHIFU treatment were retrospectively analyzed. Based on the signal intensity of T2-weighted MRI, uterine fibroids were classified as hypointense, isointense and hyperintense. Hyperintense fibroids were subjectively further subdivided into heterogeneous hyperintense, slightly homogeneous hyperintense and markedly homogeneous hyperintense based on the signal intensity of fibroid relative to myometrium and endometrium on T2-weighted MRI. Enhanced MRI was performed within one month after HIFU treatment. Non-perfused volume (NPV, indicative of successful ablation) ratio, treatment time, treatment efficiency, energy effect ratio and adverse events were recorded. Results: The median volume of uterine fibroids was 70.3 cm{sup 3} (interquartile range, 41.1–132.5 cm{sup 3}). The average NPV ratio, defined as non-perfused volume divided by the fibroid volume after HIFU treatment, was 76.8 ± 19.0% (range, 0–100%) in the 282 patients. It was 86.3 ± 11.9% (range, 40.9–100.0%) in the group with hypointense fibroids, 77.1 ± 16.5% (range, 32.2–100.0%) in isointense fibroids, and 67.6 ± 23.9% (range, 0–100.0%) in hyperintense fibroids. The lowest NPV ratio, lowest treatment efficiency, more treatment time, more sonication energy and pain scores were observed in the slightly homogeneous hyperintense fibroids, and the NPV ratio was 55.8 ± 26.7% (range, 0–83.9%) in this subgroup. Conclusion: Based on our results, the heterogeneous and markedly homogeneous hyperintense fibroids were suitable for USgHIFU, and only the slightly homogeneous hyperintense fibroids should be excluded.

  8. Feasibility of ultrasound-guided high intensity focused ultrasound ablating uterine fibroids with hyperintense on T2-weighted MR imaging

    Purpose: To retrospectively investigate whether uterine fibroids with hyperintense on pretreatment T2-weighted magnetic resonance imaging (MRI) could be treated with ultrasound-guided high intensity focused ultrasound (USgHIFU). Materials and methods: 282 patients with 282 symptomatic uterine fibroids who underwent USgHIFU treatment were retrospectively analyzed. Based on the signal intensity of T2-weighted MRI, uterine fibroids were classified as hypointense, isointense and hyperintense. Hyperintense fibroids were subjectively further subdivided into heterogeneous hyperintense, slightly homogeneous hyperintense and markedly homogeneous hyperintense based on the signal intensity of fibroid relative to myometrium and endometrium on T2-weighted MRI. Enhanced MRI was performed within one month after HIFU treatment. Non-perfused volume (NPV, indicative of successful ablation) ratio, treatment time, treatment efficiency, energy effect ratio and adverse events were recorded. Results: The median volume of uterine fibroids was 70.3 cm3 (interquartile range, 41.1–132.5 cm3). The average NPV ratio, defined as non-perfused volume divided by the fibroid volume after HIFU treatment, was 76.8 ± 19.0% (range, 0–100%) in the 282 patients. It was 86.3 ± 11.9% (range, 40.9–100.0%) in the group with hypointense fibroids, 77.1 ± 16.5% (range, 32.2–100.0%) in isointense fibroids, and 67.6 ± 23.9% (range, 0–100.0%) in hyperintense fibroids. The lowest NPV ratio, lowest treatment efficiency, more treatment time, more sonication energy and pain scores were observed in the slightly homogeneous hyperintense fibroids, and the NPV ratio was 55.8 ± 26.7% (range, 0–83.9%) in this subgroup. Conclusion: Based on our results, the heterogeneous and markedly homogeneous hyperintense fibroids were suitable for USgHIFU, and only the slightly homogeneous hyperintense fibroids should be excluded

  9. Magnetic resonance-guided focused ultrasound surgery for treatment of painful osseous metastases

    Hurwitz, Mark; Machtinger, Ronit; Fennessy, Fiona

    2011-03-01

    Magnetic resonance guided focused ultrasound surgery (MRgFUS) is an emerging technology that can non-invasively heat and ablate targeted tissue utilizing ultrasound energy. Use of MR imaging for treatment guidance provides several key advantages over more widely used ultrasound guidance for focused ultrasound ablation. MR allows for precise targeting, detailed beam path visualization, real time non-invasive temperature measurement, and treatment feedback to ensure therapeutic goals are achieved. In the realm of oncology, management of painful bone metastases is a common and daunting clinical problem. The Insightec ExAblate System has been shown in phase I/II trials for treatment of bone metastases to have an excellent safety profile and high rates of pain response. An international multi-center phase III trial for patients with painful bone metastases or multiple myeloma who are not candidates for radiation therapy is currently open. Patients are randomized 3:1 to MRgFUS or sham treatment with crossover to study treatment allowed for sham failures. The primary study endpoint is assessment of pain control over 3 months following treatment. In addition safety, quality of life, cost effectiveness analysis, and patient perceived clinical benefit are also being assessed. Details of the MRgFUS system, technical and clinical therapeutic parameters, use of real time non-invasive MR thermometry, and examples of patient treatments with use of MRgFUS to treat bone metastases will be discussed. New directions in use of MRgFUS including an update on development of a new mobile applicator and integration of MRgFUS in multimodality oncologic care will also be presented.

  10. Numerical Simulation of Temperature Elevation in Soft Tissue by High Intensity Focused Ultrasound

    Lee, Kang Il; Sim, Imbo; Kang, Gwan Suk; Choi, Min Joo

    In focused ultrasound surgery, high intensity focused ultrasound (HIFU) can be used to destroy pathological tissue deep inside the body without any damage to the surrounding normal tissue. This noninvasive technique has been used to treat malignant tumors of the liver, prostate, kidney, and benign breast tumors via a percutaneous or transrectal approach without the need for general anaesthesia. In the present study, a finite element method was used for the simulation of temperature elevation in soft tissue by HIFU. First, the HIFU field was modeled using the Westervelt equation for the propagation of finite-amplitude sound in a thermoviscous fluid in order to account for the effects of diffraction, absorption, and nonlinearity. Second, the Pennes bioheat transfer equation was used to predict the temperature elevation in soft tissue by HIFU. In order to verify the numerical simulation, the simulated temperature elevation at the focus in a tissue-mimicking phantom was compared with the measurements, using a concave focused transducer with a focal length of 62.6 mm, a radius of 35.0 mm, and a center frequency of 1.1 MHz.

  11. A modeling-based assessment of acousto-optic sensing for monitoring high-intensity focused ultrasound lesion formation

    Adams, Matthew Tyler

    Real-time acousto-optic (AO) sensing---a dual-wave modality that combines ultrasound with diffuse light to probe the optical properties of turbid media---has been demonstrated to non-invasively detect changes in ex vivo tissue optical properties during high-intensity focused ultrasound (HIFU) exposure. The AO signal indicates the onset of lesion formation and predicts resulting lesion volumes. Although proof-of-concept experiments have been successful, many of the underlying parameters and mechanisms affecting thermally induced optical property changes and the AO detectability of HIFU lesion formation are not well understood. In thesis, a numerical simulation was developed to model the AO sensing process and capture the relevant acoustic, thermal, and optical transport processes. The simulation required data that described how optical properties changed with heating. Experiments were carried out where excised chicken breast was exposed to thermal bath heating and changes in the optical absorption and scattering spectra (500 nm--1100 nm) were measured using a scanning spectrophotometer and an integrating sphere assembly. Results showed that the standard thermal dose model currently used for guiding HIFU treatments needs to be adjusted to describe thermally induced optical property changes. To model the entire AO process, coupled models were used for ultrasound propagation, tissue heating, and diffusive light transport. The angular spectrum method was used to model the acoustic field from the HIFU source. Spatial-temporal temperature elevations induced by the absorption of ultrasound were modeled using a finite-difference time-domain solution to the Pennes bioheat equation. The thermal dose model was then used to determine optical properties based on the temperature history. The diffuse optical field in the tissue was then calculated using a GPU-accelerated Monte Carlo algorithm, which accounted for light-sound interactions and AO signal detection. The simulation was

  12. High-intensity focused ultrasound for the treatment of solid tumor: Chinese clinical experience

    Takeuchi, Akira; Zhang, Hong; Sun, Kun; Hasumura, Hiromi; Liu, Botao; Fu, Yurui; Yang, Zaocheng

    2006-05-01

    As a non-invasive modality, high-intensity focused ultrasound (HIFU) therapy has been received an interest for the treatment of solid tumor. There are some makers of HIFU for the equipment in China. The Sonic CZ901 is developed from the Mianyang stream that has a great advantage for guiding by color Doppler ultrasound imaging. For the research about possibility of this equipment, we evaluate the clinical usefulness to the solid tumor of HIFU treatment at Wujing general hospital in Beijing. We elucidate the result in 28 cases with benign and malignant tumor (Uterine myoma:16, Benign prostatic hypertrophy:5, Benign breast tumor:2, Breast cancer:1, Retroperitoneal tumor:1, Pheochromocytoma:1, Liver cancer: 2) . After 14˜90days, all cases show the reduction of tumor size (Max.3.2cm, Min.1.6cm, :Mean 2.2cm reduced), and the blood flow of tumor completely reduced in 7/23, partially reduced in16/23. Clinical symptoms disappeared in 7, clearly improved in 14, improved in 7. All treatments had no adverse event except for two cases of liver cancer. They felt an abdominal pain that controllable by medicine and it improved within 6hours. It is concluded that HIFU with guide by ultrasound imaging is very safe, painless and effective as the anti-tumor treatment.

  13. Multi-parametric monitoring and assessment of high-intensity focused ultrasound (HIFU) boiling by harmonic motion imaging for focused ultrasound (HMIFU): an ex vivo feasibility study

    Harmonic motion imaging for focused ultrasound (HMIFU) is a recently developed high-intensity focused ultrasound (HIFU) treatment monitoring method with feasibilities demonstrated in vitro and in vivo. Here, a multi-parametric study is performed to investigate both elastic and acoustics-independent viscoelastic tissue changes using the Harmonic Motion Imaging (HMI) displacement, axial compressive strain and change in relative phase shift during high energy HIFU treatment with tissue boiling. Forty three (n = 43) thermal lesions were formed in ex vivo canine liver specimens (n = 28). Two-dimensional (2D) transverse HMI displacement maps were also obtained before and after lesion formation. The same method was repeated in 10 s, 20 s and 30 s HIFU durations at three different acoustic powers of 8, 10, and 11 W, which were selected and verified as treatment parameters capable of inducing boiling using both thermocouple and passive cavitation detection (PCD) measurements. Although a steady decrease in the displacement, compressive strain, and relative change in the focal phase shift (Δϕ) were obtained in numerous cases, indicating an overall increase in relative stiffness, the study outcomes also showed that during boiling, a reverse lesion-to-background displacement contrast was detected, indicating potential change in tissue absorption, geometrical change and/or, mechanical gelatification or pulverization. Following treatment, corresponding 2D HMI displacement images of the thermal lesions also mapped consistent discrepancy in the lesion-to-background displacement contrast. Despite the expectedly chaotic changes in acoustic properties with boiling, the relative change in phase shift showed a consistent decrease, indicating its robustness to monitor biomechanical properties independent of the acoustic property changes throughout the HIFU treatment. In addition, the 2D HMI displacement images confirmed and indicated the increase in the thermal lesion size with

  14. Multi-parametric monitoring and assessment of high-intensity focused ultrasound (HIFU) boiling by harmonic motion imaging for focused ultrasound (HMIFU): an ex vivo feasibility study

    Hou, Gary Y.; Marquet, Fabrice; Wang, Shutao; Konofagou, Elisa E.

    2014-03-01

    Harmonic motion imaging for focused ultrasound (HMIFU) is a recently developed high-intensity focused ultrasound (HIFU) treatment monitoring method with feasibilities demonstrated in vitro and in vivo. Here, a multi-parametric study is performed to investigate both elastic and acoustics-independent viscoelastic tissue changes using the Harmonic Motion Imaging (HMI) displacement, axial compressive strain and change in relative phase shift during high energy HIFU treatment with tissue boiling. Forty three (n = 43) thermal lesions were formed in ex vivo canine liver specimens (n = 28). Two-dimensional (2D) transverse HMI displacement maps were also obtained before and after lesion formation. The same method was repeated in 10 s, 20 s and 30 s HIFU durations at three different acoustic powers of 8, 10, and 11 W, which were selected and verified as treatment parameters capable of inducing boiling using both thermocouple and passive cavitation detection (PCD) measurements. Although a steady decrease in the displacement, compressive strain, and relative change in the focal phase shift (Δϕ) were obtained in numerous cases, indicating an overall increase in relative stiffness, the study outcomes also showed that during boiling, a reverse lesion-to-background displacement contrast was detected, indicating potential change in tissue absorption, geometrical change and/or, mechanical gelatification or pulverization. Following treatment, corresponding 2D HMI displacement images of the thermal lesions also mapped consistent discrepancy in the lesion-to-background displacement contrast. Despite the expectedly chaotic changes in acoustic properties with boiling, the relative change in phase shift showed a consistent decrease, indicating its robustness to monitor biomechanical properties independent of the acoustic property changes throughout the HIFU treatment. In addition, the 2D HMI displacement images confirmed and indicated the increase in the thermal lesion size with

  15. HIGH INTENSITY FOCUSED ULTRASOUND FOR TREATMENT UNRESECTABLE MALIGNANT TUMORS IN 75 PATIENTS

    郑国强

    2004-01-01

    Objective: To study preliminary experience of high intensity focused ultrasound (HIFU) for unresectable malignant tumors in 75 patients. Methods: The clinical data of 75 patients with unresectable tumor was analyzed retrospectively. Results: Among 75 patients, ten out of 57 cases achieved good local control in short-term, 5 patients liver tumor, 4 patients with tumor in the chest wall and one patient with bone matestics. Seven patients had skin burn and 2 patients developed intestinal perforations. Conclusion: HIFU is a novel tool for local tumor treatment. HIFU treatment for patients with unresectable tumor in the chest wall is effective.

  16. High intensity focused ultrasound as a tool for tissue engineering: Application to cartilage.

    Nover, Adam B; Hou, Gary Y; Han, Yang; Wang, Shutao; O'Connell, Grace D; Ateshian, Gerard A; Konofagou, Elisa E; Hung, Clark T

    2016-02-01

    This article promotes the use of High Intensity Focused Ultrasound (HIFU) as a tool for affecting the local properties of tissue engineered constructs in vitro. HIFU is a low cost, non-invasive technique used for eliciting focal thermal elevations at variable depths within tissues. HIFU can be used to denature proteins within constructs, leading to decreased permeability and potentially increased local stiffness. Adverse cell viability effects remain restricted to the affected area. The methods described in this article are explored through the scope of articular cartilage tissue engineering and the fabrication of osteochondral constructs, but may be applied to the engineering of a variety of different tissues. PMID:26724968

  17. Evaluation of pulsed high intensity focused ultrasound exposures on metastasis in a murine model

    Hancock, Hilary; Dreher, Matthew R.; Crawford, Nigel; Pollock, Claire B.; Shih, Jennifer; Wood, Bradford J.; Hunter, Kent; Frenkel, Victor

    2009-01-01

    High intensity focused ultrasound (HIFU) may be employed in two ways: continuous exposures for thermal ablation of tissue (>60°C), and pulsed-exposures for non-ablative effects, including low temperature hyperthermia (37–45°C), and non thermal effects (e.g. acoustic cavitation and radiation forces). Pulsed-HIFU effects may enhance the tissue's permeability for improved delivery of drugs and genes, for example, by opening up gaps between cells in the vasculature and parenchyma. Inducing these ...

  18. A boundary condition to the Khokhlov-Zabolotskaya equation for modeling strongly focused nonlinear ultrasound fields

    Rosnitskiy, P.; Yuldashev, P.; Khokhlova, V.

    2015-10-01

    An equivalent source model was proposed as a boundary condition to the nonlinear parabolic Khokhlov-Zabolotskaya (KZ) equation to simulate high intensity focused ultrasound (HIFU) fields generated by medical ultrasound transducers with the shape of a spherical shell. The boundary condition was set in the initial plane; the aperture, the focal distance, and the initial pressure of the source were chosen based on the best match of the axial pressure amplitude and phase distributions in the Rayleigh integral analytic solution for a spherical transducer and the linear parabolic approximation solution for the equivalent source. Analytic expressions for the equivalent source parameters were derived. It was shown that the proposed approach allowed us to transfer the boundary condition from the spherical surface to the plane and to achieve a very good match between the linear field solutions of the parabolic and full diffraction models even for highly focused sources with F-number less than unity. The proposed method can be further used to expand the capabilities of the KZ nonlinear parabolic equation for efficient modeling of HIFU fields generated by strongly focused sources.

  19. Study on focusing characteristic of acceleration tube in high current implanter

    The accelerating tube is one of the most important parts in high current implanter which provides the desired energy and focusing for ion beam. The factors affecting focus characteristic in high current implanter with three gap acceleration tube are discussed. Focusing degrees of different energy ion beam are computed, and the electric field required to prevent beam expansion due to space charge effect are analyzed. The beam envelope inside the three acceleration gap shows a decrease of the beam radius with the increase of the accelerating voltage ratio up to the optimal value. Beyond this optimal value the beam lines make a crossover with the axis of the accelerating tube

  20. Electron Acceleration by a Focused Gaussian Laser Pulse in Vacuum

    何峰; 余玮; 陆培祥; 徐涵

    2004-01-01

    By numerically solving the relativistic equations of motion of a single electron in laser fields modeled by a Gaussian laser beam, we get the trajectory and energy of the electron. When the drifting distance is comparable to or even longer than the corresponding Rayleigh length, the evolution of the beam waist cannot be neglected. The asymmetry of intensity in acceleration and deceleration leads to the conclusion that the electron can be accelerated effectively and extracted by the longitudinal ponderomotive force. For intensities above, an electron's energy gain about MeV can be realized, and the energetic electron is parallel with the propagation axis.

  1. High-Intensity Focused Ultrasound (HIFU) in Uterine Fibroid Treatment: Review Study

    High-intensity focused ultrasound (HIFU) is a highly precise medical procedure used locally to heat and destroy diseased tissue through ablation. This study intended to review HIFU in uterine fibroid therapy, to evaluate the role of HIFU in the therapy of leiomyomas as well as to review the actual clinical activities in this field including efficacy and safety measures beside the published clinical literature. An inclusive literature review was carried out in order to review the scientific foundation, and how it resulted in the development of extracorporeal distinct devices. Studies addressing HIFU in leiomyomas were identified from a search of the Internet scientific databases. The analysis of literature was limited to journal articles written in English and published between 2000 and 2013. In current gynecologic oncology, HIFU is used clinically in the treatment of leiomyomas. Clinical research on HIFU therapy for leiomyomas began in the 1990s, and the majority of patients with leiomyomas were treated predominantly with HIFUNIT 9000 and prototype single focus ultrasound devices. HIFU is a non-invasive and highly effective standard treatment with a large indication range for all sizes of leiomyomas, associated with high efficacy, low operative morbidity and no systemic side effects. Uterine fibroid treatment using HIFU was effective and safe in treating symptomatic uterine fibroids. Few studies are available in the literature regarding uterine artery embolization (UAE). HIFU provides an excellent option to treat uterine fibroids

  2. Low-pressure pulsed focused ultrasound with microbubbles promotes an anticancer immunological response

    Liu Hao-Li

    2012-11-01

    Full Text Available Abstract Background High-intensity focused-ultrasound (HIFU has been successfully employed for thermal ablation of tumors in clinical settings. Continuous- or pulsed-mode HIFU may also induce a host antitumor immune response, mainly through expansion of antigen-presenting cells in response to increased cellular debris and through increased macrophage activation/infiltration. Here we demonstrated that another form of focused ultrasound delivery, using low-pressure, pulsed-mode exposure in the presence of microbubbles (MBs, may also trigger an antitumor immunological response and inhibit tumor growth. Methods A total of 280 tumor-bearing animals were subjected to sonographically-guided FUS. Implanted tumors were exposed to low-pressure FUS (0.6 to 1.4 MPa with MBs to increase the permeability of tumor microvasculature. Results Tumor progression was suppressed by both 0.6 and 1.4-MPa MB-enhanced FUS exposures. We observed a transient increase in infiltration of non-T regulatory (non-Treg tumor infiltrating lymphocytes (TILs and continual infiltration of CD8+ cytotoxic T-lymphocytes (CTL. The ratio of CD8+/Treg increased significantly and tumor growth was inhibited. Conclusions Our findings suggest that low-pressure FUS exposure with MBs may constitute a useful tool for triggering an anticancer immune response, for potential cancer immunotherapy.

  3. Shadow effects in simulated ultrasound images derived from computed tomography images using a focused beam tracing model

    Pham, An Hoai; Lundgren, Bo; Stage, Bjarne;

    2012-01-01

    Simulation of ultrasound images based on computed tomography (CT) data has previously been performed with different approaches. Shadow effects are normally pronounced in ultrasound images, so they should be included in the simulation. In this study, a method to capture the shadow effects has been......Focus ultrasound scanner (BK Medical, Herlev, Denmark) equipped with a dedicated research interface giving access to beamformed radio frequency data. CT images were obtained with an Aquilion ONE Toshiba CT scanner (Toshiba Medical Systems Corp., Tochigi, Japan). CT data were mapped from Hounsfield units to...

  4. Effect of controlled offset of focal position in cavitation-enhanced high-intensity focused ultrasound treatment

    Goto, Kota; Takagi, Ryo; Miyashita, Takuya; Jimbo, Hayato; Yoshizawa, Shin; Umemura, Shin-ichiro

    2015-07-01

    High-intensity focused ultrasound (HIFU) is a noninvasive treatment for tumors such as cancer. In this method, ultrasound is generated outside the body and focused to the target tissue. Therefore, physical and mental stresses on the patient are minimal. A drawback of the HIFU treatment is a long treatment time for a large tumor due to the small therapeutic volume by a single exposure. Enhancing the heating effect of ultrasound by cavitation bubbles may solve this problem. However, this is rather difficult because cavitation clouds tend to be formed backward from the focal point while ultrasonic intensity for heating is centered at the focal point. In this study, the focal points of the trigger pulses to generate cavitation were offset forward from those of the heating ultrasound to match the cavitation clouds with the heating patterns. Results suggest that the controlled offset of focal points makes the thermal coagulation more predictable.

  5. Effect of acoustic streaming on tissue heating due to high-intensity focused ultrasound

    Solovchuk, Maxim A; Thiriet, Marc; Lin, Win-Li

    2011-01-01

    The influences of blood vessels and focused location on temperature distribution during high-intensity focused ultrasound (HIFU) ablation of liver tumors is studied. A three-dimensional acoustics-thermal-fluid coupling model is employed to compute the temperature field in the hepatic cancerous region. The model is based on the linear Westervelt and bioheat equations as well as the nonlinear Navier-Stokes equations for the liver parenchyma and blood vessels. The effect of acoustic streaming is also taken into account in the present HIFU simulation study. Different blood vessel diameters and focal point locations were investigated. We found from this three-dimensional numerical study that in large blood vessels both the convective cooling and acoustic streaming can change considerably the temperature field and the thermal lesion near blood vessels. If the blood vessel is located within the beam width, both acoustic streaming and blood flow cooling effects should be taken into account. The predicted temperature ...

  6. The road to clinical use of high-intensity focused ultrasound for liver cancer: technical and clinical consensus

    Aubry, Jean-Francois; Pauly, Kim,; Moonen, Chrit; Haar, Gail Ter; Ries, Mario; Salomir, Rares; Sokka, Sham; Sekins, Kevin,; Shapira, Yerucham; Ye, Fangwei; Huff-Simonin, Heather; Eames, Matt; Hananel, Arik; Kassell, Neal; Napoli, Alessandro

    2013-01-01

    International audience Clinical use of high-intensity focused ultrasound (HIFU) under ultrasound or MR guidance as a non-invasive method for treating tumors is rapidly increasing. Tens of thousands of patients have been treated for uterine fibroid, benign prostate hyperplasia, bone metastases, or prostate cancer. Despite the methods' clinical potential, the liver is a particularly challenging organ for HIFU treatment due to the combined effect of respiratory-induced liver motion, partial b...

  7. Shock-induced heating and millisecond boiling in gels and tissue due to high intensity focused ultrasound

    Canney, Michael S.; Khokhlova, Vera A.; Bessonova, Olga V.; Bailey, Michael R.; Crum, Lawrence A.

    2009-01-01

    Nonlinear propagation causes high intensity ultrasound waves to distort and generate higher harmonics, which are more readily absorbed and converted to heat than the fundamental frequency. Although such nonlinear effects have previously been investigated and found not to significantly alter high intensity focused ultrasound (HIFU) treatments, two results reported here change this paradigm. One is that at clinically relevant intensity levels, HIFU waves not only become distorted but form shock...

  8. Spatio-temporal analysis of molecular delivery through the blood-brain barrier using focused ultrasound

    The deposition of gadolinium through ultrasound-induced blood-brain barrier (BBB) openings in the murine hippocampus was investigated. First, wave propagation simulations through the intact mouse skull revealed minimal beam distortion while thermal deposition simulations, at the same sonication parameters used to induce BBB opening in vivo, revealed temperature increases lower than 0.5 0C. The simulation results were validated experimentally in ex vivo skulls (m = 6) and in vitro tissue specimens. Then, in vivo mice (n = 9) were injected with microbubbles (Optison(TM); 25-50 μl) and sonicated (frequency: 1.525 MHz, pressure amplitudes: 0.5-1.1 MPa, burst duration: 20 ms, duty cycle: 20%, durations: 2-4 shots, 30 s per shot, 30 s interval) at the left hippocampus, through intact skin and skull. Sequential, high-resolution, T1-weighted MRI (9.4 Tesla, in-plane resolution: 75 μm, scan time: 45-180 min) with gadolinium (Omniscan(TM); 0.5 ml) injected intraperitoneally revealed a threshold of the BBB opening at 0.67 MPa and BBB closing within 28 h from opening. The contrast-enhancement area and gadolinium deposition path were monitored over time and the influence of vessel density, size and location was determined. Sonicated arteries, or their immediate surroundings, depicted greater contrast enhancement than sonicated homogeneous brain tissue regions. In conclusion, gadolinium was delivered through a transiently opened BBB and contained to a specific brain region (i.e., the hippocampus) using a single-element focused ultrasound transducer. It was also found that the amount of gadolinium deposited in the hippocampal region increased with the acoustic pressure and that the spatial distribution of the BBB opening was determined not only by the ultrasound beam, but also by the vasculature of the targeted brain region

  9. Investigation of therapy improvement using real-time photoacoustic imaging guided high intensity focused ultrasound

    Cui, Huizhong

    There are a lot of risks in cancer treatment by invasive surgery, such as bleeding, wound infection, and long recovery time, etc. Therefore, there is great need for minimally- or non-invasive treatment. High intensity focused ultrasound (HIFU) is a rapidly growing and truly non-invasive technology. It has been widely used in therapeutic applications, such as rapid tissue heating and tissue ablation. With proper imaging guidance, HIFU treatment can be performed totally noninvasively. Currently, ultrasound imaging-guided HIFU has been extensively studied. However, ultrasound imaging guidance is less precise because of the relatively low imaging contrast, sensitivity, and specificity for noninvasive detection. In this study, we employed photoacoustic imaging (PAI) technique, which has been developed a novel promising imaging technique for early cancer detection, to guide HIFU treatment. The goal of this study is to investigate the feasibility of PAI to guide, monitor in real time and enhance the HIFU therapy. In this dissertation, as the first step, the integrated PAI and HIFU system had been shown to have the feasibility to guide HIFU both ex vivo and in vivo. Then, the system was improved and developed to a real-time PAI-guided HIFU system. It is demonstrated that the sensitivity of PA detection for HIFU lesion is very high and the saturation of PA signals can be used as the indicator for tissue coagulation. During the temperature measurement using this system, laser-enhanced HIFU heating was found. Thus, we further investigated the laser enhanced technique in both HIFU heating and pulsed HIFU thrombolysis. In the HIFU therapy, laser light was employed to illuminate the sample concurrently with HIFU radiation. The resulting cavitation was detected with a passive cavitation detector. We demonstrated that concurrent light illumination during HIFU has the potential to significantly enhance HIFU by reducing cavitation threshold.

  10. Empirical modeling of renal motion for improved targeting during focused ultrasound surgery.

    Abhilash, R H; Chauhan, Sunita

    2013-05-01

    Non-invasive surgery looks at ways of eliminating physical contact with the target tissues while maintaining necessary levels of accuracy. Focused Ultrasound Surgery (FUS) is one such treatment modality, which uses a tightly focused beam of high intensity ultrasound to ablate tumors in various parts of the body. For trans-abdominal access, respiration induced movement of the tissue targets remains a major issue during FUS. Respiration induced movements are known to be significant in liver and kidney. In this paper, we attempt to address this problem using non-linear prediction and modeling techniques as applicable to kidney movement patterns. Kidney movement patterns are known to be three dimensional and vastly complicated compared to movement patterns of the liver. Monitoring and quantification of the nature and extent of kidney movement is yet to be explored in depth for effective compensation and accurate targeting. Apart from the respiratory cycle, the movement of the kidney is also affected by several factors, such as the movement of the ribs, spleen and liver. Modeling of these movements is imperative for motion adaptive FUS. Since kidney movements are highly subject specific, generic statistical models cannot be used for compensation. The system latency and real-time performance of the imaging modality also induce additional parametric dependence in target tracking. In this work, we focus on empirical modeling and prediction of the kidney movement to for error analysis and computing system latency. The accuracy of existing modeling techniques is compared with a newly developed empirical model. From the study conducted in healthy volunteers, it was found that the kidney movement was complex and subject specific and could be effectively modeled using the new shape function based model. The model was further fine-tuned using Kalman filter based predictors and Adaptive Neuro-Fuzzy Inference System (ANFIS) which gave more than 85% accuracy in prediction. PMID

  11. The design of a focused ultrasound transducer array for the treatment of stroke: a simulation study

    Pajek, Daniel; Hynynen, Kullervo

    2012-08-01

    High intensity focused ultrasound (HIFU) is capable of mechanically disintegrating blood clots at high pressures. Safe thrombolysis may require frequencies higher than those currently utilized by transcranial HIFU. Since the attenuation and focal distortion of ultrasound in bone increases at higher frequencies, resulting focal pressures are diminished. This study investigated the feasibility of using transcranial HIFU for the non-invasive treatment of ischemic stroke. The use of large aperture, 1.1-1.5 MHz phased arrays in targeting four clinically relevant vessel locations was simulated. Resulting focal sizes decreased with frequency, producing a maximum -3 dB depth of field and lateral width of 2.0 and 1.2 mm, respectively. Mean focal gains above an order of magnitude were observed in three of four targets and transducer intensities required to achieve thrombolysis were determined. Required transducer element counts are about an order of magnitude higher than what currently exists and so, although technically feasible, new arrays would need to be developed to realize this as a treatment modality for stroke.

  12. The design of a focused ultrasound transducer array for the treatment of stroke: a simulation study

    High intensity focused ultrasound (HIFU) is capable of mechanically disintegrating blood clots at high pressures. Safe thrombolysis may require frequencies higher than those currently utilized by transcranial HIFU. Since the attenuation and focal distortion of ultrasound in bone increases at higher frequencies, resulting focal pressures are diminished. This study investigated the feasibility of using transcranial HIFU for the non-invasive treatment of ischemic stroke. The use of large aperture, 1.1–1.5 MHz phased arrays in targeting four clinically relevant vessel locations was simulated. Resulting focal sizes decreased with frequency, producing a maximum –3 dB depth of field and lateral width of 2.0 and 1.2 mm, respectively. Mean focal gains above an order of magnitude were observed in three of four targets and transducer intensities required to achieve thrombolysis were determined. Required transducer element counts are about an order of magnitude higher than what currently exists and so, although technically feasible, new arrays would need to be developed to realize this as a treatment modality for stroke. (paper)

  13. Targeted therapy of animal eyes with tumors by laser-generated focused ultrasound (Conference Presentation)

    Lee, Taehwa; Luo, Wei; Demirci, Hakan; Guo, L. Jay

    2016-03-01

    Cavitation therapy based on high-amplitude focused ultrasound (e.g., Histotripsy) has shown great promise in clinical trials. The technique realizes localized treatments of tissues and diseased cells by controlling cavitation zones, which can be even smaller than its acoustic spot sizes. Also, the short pressure pulse used in the technique can minimize the unwanted heat accumulation, which the conventional piezoelectric transducers suffer from due to low operating frequencies and relatively long acoustic pulses. However, this modality requires bulky system composed of array of piezoelectric elements and electric amplifiers in order to obtain high pressure amplitude. Moreover, especially when treating an area much smaller than the acoustic spot size, this approach may be vulnerable to nucleation sites within the focal volume, which can potentially induce cavitation and thus enlarge the total treatment area. Here, we show targeted cell-level therapy by using laser generated ultrasound. By employing a concave lens coated by a carbon nanotube (CNT)-polymer composite, high-amplitude acoustic pressure can be obtained at a tight focal spot (<100 um). The small focal spot, comparable to cavitation zone, lead to controlled cavitation treatment. Such feature can be exploited for treating intraocular tumors but without harming other parts of the eye (e.g. healthy retina and choroid) and therefore preserve the vision of the patients. We demonstrate that the localized disruption effects can be used for cell-level surgery to remove cells and to kill cells. Some experimental examples are shown using animal eyeballs.

  14. Numerical Analysis of Temperature Rise in Tissue Using Electronically Focused Ultrasound

    Saito, Yoshikazu; Tsuchiya, Takenobu; Endoh, Nobuyuki

    2006-05-01

    Recently, the use of higher power ultrasonic equipment has been extended to not only therapy but also diagnosis because the new diagnostic imaging techniques, such as Doppler color flow imaging and harmonic imaging, require a higher ultrasound power than conventional imaging techniques. It is very important to ensure the safety of temperature rise caused by the absorption of ultrasound energy in new ultrasonic imaging systems. In this two-dimensional finite difference time domain-heat conduction equation study, the temperature rise in tissue has been simulated at a focal point radiated by a phased array focused transducer, such as like a common B-mode imagine system. The center frequency of radiated wave pulses is 2.5 MHz and ISPTA=0.72 W/cm2. When the sound pulse repetition frequency (PRF) is changed from 100 to 400 kHz, the temperature rise in tissue at a focal point is proportional to the PRF. The maximum temperature rise in tissue has been simulated only at 0.0004 °C at a focal point of a transducer when PRF is 400 kHz.

  15. High-Intensity Focused Ultrasound: Current Status for Image-Guided Therapy.

    Copelan, Alexander; Hartman, Jason; Chehab, Monzer; Venkatesan, Aradhana M

    2015-12-01

    Image-guided high-intensity focused ultrasound (HIFU) is an innovative therapeutic technology, permitting extracorporeal or endocavitary delivery of targeted thermal ablation while minimizing injury to the surrounding structures. While ultrasound-guided HIFU was the original image-guided system, MR-guided HIFU has many inherent advantages, including superior depiction of anatomic detail and superb real-time thermometry during thermoablation sessions, and it has recently demonstrated promising results in the treatment of both benign and malignant tumors. HIFU has been employed in the management of prostate cancer, hepatocellular carcinoma, uterine leiomyomas, and breast tumors, and has been associated with success in limited studies for palliative pain management in pancreatic cancer and bone tumors. Nonthermal HIFU bioeffects, including immune system modulation and targeted drug/gene therapy, are currently being explored in the preclinical realm, with an emphasis on leveraging these therapeutic effects in the care of the oncology patient. Although still in its early stages, the wide spectrum of therapeutic capabilities of HIFU offers great potential in the field of image-guided oncologic therapy. PMID:26622104

  16. Pathological changes on human breast cancer specimens ablated in vitro with high-intensity focused ultrasound.

    Niu, Lingchuan; Wang, Zhibiao; Zou, Wenbing; Zhang, Lian; Xiang, Like; Zhu, Hui; Chen, Wenzhi; Bai, Jin; Wu, Junru

    2010-09-01

    The purpose of this study was to evaluate the pathologic changes of human breast cancer specimens ablated with high-intensity focused ultrasound (HIFU) in vitro. Twenty specimens of pathologically confirmed breast cancer tissue were ablated with ultrasound-guided HIFU. The evaluation methods include histopathologic observation using hematoxylin-eosin staining, electron microscopic imaging, enzyme histochemical and immunohistochemical examination on tumor antigens. Vacuole-like structures in cytoplasm were observed by histopathologic observation but there were no significant changes in cell morphology and nucleus karyotype. Typical phenomena related to coagulation necrosis were observed in electron microscopic studies; the contour of cell structure was still preserved but the structures of cell (all kinds of organelles and nucleus) were damaged or disappeared. Acid phosphatase and succinate dehydrogenase staining showed that tumor cells were inactivated. In immunohistochemical evaluations, estrogen receptor, progesterone receptor, cerbB-2 and P53 expression changed from 85%, 82%, 75% and 80% in nonablation tissue to no expression in ablated tumor tissue, respectively. We, therefore, conclude that breast cancer cells appear normal contour immediately after ablation with HIFU under light microscopic but they were evaluated to be dead by electron microscopic imaging, enzyme histochemical and immunohistochemical examinations. PMID:20800171

  17. Cancer treatment using an optically inert Rose Bengal derivative combined with pulsed focused ultrasound

    Kim, Yoo-Shin; Rubio, Valentina; Qi, Jianjun; Xia, Rongmin; Shi, Zheng-Zheng; Peterson, Leif; Tung, Ching-Hsuan; O'Neill, Brian E.

    2012-10-01

    Pulsed high intensity focused ultrasound (HIFU) produced has been combined with a photo-insensitive Rose Bengal derivative (RB2) to provide a synergistic cytotoxicity requiring the presence of both ultrasonic cavitation and drug. In vitro tests have shown that a short treatment (less than 30 s) of pulsed HIFU with peak negative pressure >7 MPa (˜27 W acoustic power at 1.4 MHz) destroys >95 % of breast cancer cells MDA-MB-231 in suspension with >10 μM of the compound. Neither the pulsed HIFU nor the RB2 compound was found to have any significant impact on the viability of the cells when used alone. Introducing an antioxidant (Nacetylcysteine) reduced the effectiveness of the treatment. In vivo tests using these same cells growing as a xenograft in nu/nu mice were also done. An ultrasound contrast agent (Optison) and lower frequency (1.0 MHz) was used to help initiate cavitation at the tumor site. We were able to demonstrate tumor regression with cavitation alone, however, addition of RB2 compound injected i.v. yielded a substantial synergistic improvement over either cavitation or RB2 injection alone.

  18. Analysis of clinical effect of high-intensity focused ultrasound on liver cancer

    Chuan-Xing Li; Guo-Liang Xu; Zhen-You Jiang; Jian-Jun Li; Guang-Yu Luo; Hong-Bo Shan; Rong Zhang; Yin Li

    2004-01-01

    AIM: To evaluate the clinical effect of high-intensity focused ultrasound (HIFU) in the treatment of patients with liver cancer.METHODS: HIFU treatment was performed in 100 patients with liver cancer under general anesthesia and by a targeted ultrasound. Evaluation of efficacy was made on the basis of clinical symptoms, liver function tests, AFP,MRI or CT before and after the treatment.RESULTS: After HIFU treatment, clinical symptoms were relieved in 86.6%(71/82) of patients. The ascites disappeared in 6 patients. ALT (95±44) U/L and AST (114±58) U/L before HIFU treatment were reduced to normal in 83.3%(30/36) and 72.9%(35/48) patients,respectively, after the treatment. AFP was lowered by more than 50% in 65.3%(32/49) patients. After HIFU treatment,MRI or CT findings indicated coagulation necrosis and blood supply reduction or disappearance of tumor in the target region.CONCLUSION: HIFU can efficiently treat the patients with liver cancer. It will offer a significant noninvasive therapy for local treatment of liver tumor.

  19. Focused Ultrasound Surgery Control Using Local Harmonic Motion: VX2 Tumor Study

    The objective of this study was to develop a real-time method for controlling focused ultrasound surgery using ultrasound imaging. The approach uses measurements of localized harmonic motion (LHM) in order to perform controlled FUS exposures by detecting changes in the elastic properties of tissues during coagulation. Methods: Nine New Zealand rabbits with VX2 tumors implanted in the thigh were used for this study. LHM was generated within the tumors by periodic induction of radiation force using a FUS transducer (80-mm focal length, 100-mm diameter, 20-mm central hole, 1.485-MHz). Tissue motion was tracked by collecting and cross-correlating RF signals during the motion using a separate diagnostic transducer (3-kHz PRF, 5-MHz). After locating the tumor in MR images, a series of sonications were performed to treat the tumors using a reduction in LHM amplitude to control the exposure. Results: LHM was successfully used to control the sonications. A LHM amplitude threshold value was determined at which changes were considered significant and then the exposure was started and stopped when the LHM amplitude dropped below the threshold. The appearance of a lesion was then verified by MRI. The feasibility of LHM measurements to control FUS exposure was validated.

  20. Nonlinear 3-D simulation of high-intensity focused ultrasound therapy in the kidney

    Suomi, Visa; Treeby, Bradley; Cleveland, Robin

    2016-01-01

    Kidney cancer is a severe disease which can be treated non-invasively using high-intensity focused ultrasound (HIFU) therapy. However, tissue in front of the transducer and the deep location of kidney can cause significant losses to the efficiency of the treatment. The effect of attenuation, refraction and reflection due to different tissue types on HIFU therapy of the kidney was studied using a nonlinear ultrasound simulation model. The geometry of the tissue was derived from a computed tomography (CT) dataset of a patient which had been segmented for water, bone, soft tissue, fat and kidney. The combined effect of inhomogeneous attenuation and sound-speed was found to result in an 11.0 dB drop in spatial peak-temporal average (SPTA) intensity in the kidney compared to pure water. The simulation without refraction effects showed a 6.3 dB decrease indicating that both attenuation and refraction contribute to the loss in focal intensity. The losses due to reflections at soft tissue interfaces were less than 0....

  1. Treatment of localised prostate cancer with transrectal high intensity focused ultrasound.

    Chapelon, J Y; Ribault, M; Vernier, F; Souchon, R; Gelet, A

    1999-03-01

    With the advent of PSA dosing, an increasing number of prostate cancers are being detected at a local stage. Since 1989, our group has been developing a research project with the aim of establishing treatment of localised prostate cancer by means of HIFU. The treatment is performed transrectally, using ultrasound imaging guidance only. The quality of HIFU treatment depends on four factors: the intensity of the transmitted pulse, the exposure time, the signal frequency, and the time between two firing bursts. The lesions are created by a thermal effect. Their slightly conical form is due to the absorption of ultrasound by tissue, enhanced by cavitation bubbles. Results obtained since 1993 demonstrate that transrectally administered HIFU treatment achieves local control of localised prostate cancer in 80% of cases, with 70% complete success and 30% partial response. The use of an annular array probe with variable focus and frequency should significantly improve results in the future. Finally, real time visual display of the damaged tissue via differential imaging of the attenuation coefficient should give the surgeon an instant appreciation of the result of the sequence. It would thus be possible to repeat treatment of insufficiently covered zones in the same session. PMID:10099164

  2. The influence of viscosity on the shear strain remotely induced by focused ultrasound in viscoelastic media.

    Barannik, E A; Girnyk, S A; Tovstiak, V V; Marusenko, A I; Volokhov, V A; Sarvazyan, A P; Emelianov, S Y

    2004-05-01

    Shear wave elasticity imaging (SWEI), an emerging acoustic technology for medical diagnostics, is based on remote generation of shear waves in tissue by radiation force in the focal region of an ultrasonic beam. In this study, the feasibility of Doppler ultrasonic technique to visualize the remotely induced shear waves was demonstrated. The generation of shear displacement in the focal region of a pulsed 1-MHz ultrasound beam with pulse duration of approximately about 2 ms and intensity levels on the order of 145 W/cm2, and consequent propagation of shear wave in tissue-mimicking and muscle tissue in vitro, were measured. The analysis of temporal behavior of shear displacement within the focal plane allowed estimation of shear wave velocities. The velocities were 4 and 7 m/s in hard phantom and tissue containing phantom, respectively. The measured shear displacements on the order of micrometers in gel-based phantoms are in reasonable agreement with theoretical estimates derived from an earlier developed model of shear wave generation by radiation force of focused ultrasound. The study revealed significant dependence of shear strain on the medium viscosity. The complex oscillatory character of shear strain relaxation in viscoelastic phantom and muscle tissue in vitro was observed. PMID:15139649

  3. Heating in vascular tissue and flow-through tissue phantoms induced by focused ultrasound

    Huang, Jinlan

    High intensity focused ultrasound (HIFU) can be used to control bleeding, both from individual blood vessels as well as from gross damage to the capillary bed. This process, called acoustic hemostasis, is being studied in the hope that such a method would ultimately provide a lifesaving treatment during the so-called "golden hour", a brief grace period after a severe trauma in which prompt therapy can save the life of an injured person. Thermal effects play a major role in occlusion of small vessels and also appear to contribute to the sealing of punctures in major blood vessels. However, aggressive ultrasound-induced tissue heating can also impact healthy tissue and can lead to deleterious mechanical bioeffects. Moreover, the presence of vascularity can limit one's ability to elevate the temperature of blood vessel walls owing to convective heat transport. In an effort to better understand the heating process in tissues with vascular structure we have developed a numerical simulation that couples models for ultrasound propagation, acoustic streaming, ultrasound heating and blood cooling in Newtonian viscous media. The 3-D simulation allows for the study of complicated biological structures and insonation geometries. We have also undertaken a series of in vitro experiments, in non-uniform flow-through tissue phantoms, designed to provide a ground truth verification of the model predictions. The calculated and measured results were compared over a range of values for insonation pressure, insonation time, and flow rate; we show good agreement between predictions and measurements. We then conducted a series of simulations that address two limiting problems of interest: hemostasis in small and large vessels. We employed realistic human tissue properties and considered more complex geometries. Results show that the heating pattern in and around a blood vessel is different for different vessel sizes, flow rates and for varying beam orientations relative to the flow axis

  4. Differential attenuation imaging for the characterization of high intensity focused ultrasound lesions.

    Ribault, M; Chapelon, J Y; Cathignol, D; Gelet, A

    1998-07-01

    High intensity focused ultrasound (HIFU) is an effective technique for creating coagulative necrotic lesions in biological tissue, with a view to treating localized tumors. Although good results have already been obtained, notably in urology, current systems lack a real time monitoring system to check the efficacy of the treatment procedures. This study describes the development and assessment of a noninvasive system for making local measurements of attentuation variations during HIFU treatment procedures. An apparatus (Ablatherm, Edap-Technomed, France), combining a 2.5 MHz therapeutic transducer and a 5.5 MHz twin plane imaging probe (connected to an ultrasound scanner), was used to produce lesions. The rf signals needed to calculate the attenuation were recorded as outputs from the ultrasound scanner, before and after the high intensity firing sequences, which were performed on ten pieces of porcine liver. Each firing sequence involved producing a lesion volume comprising 42 individual lesions. A number of recordings were also made without producing lesions, in order to test the reproducibility of the measurements. The attenuation function was evaluated locally using the centroid and the multinarrowband methods. Initially, changes in the integrated attenuation alpha (mean attenuation in the 4-7 MHz range) and the attenuation slope beta were examined for the lesion volume. beta values did not vary significantly within this range, whereas alpha values varied significantly (in the region of 86% of the initial level) in comparison to measurements performed without forming lesions. The differential attenuation delta alpha (representing local variations in alpha) was subsequently used to generate images revealing the lesion areas. There was a strong similarity between these 'delta alpha images' and the lesion volumes defined by the operator. 'delta alpha images' offer several advantages over existing attenuation imaging techniques. Any problems related to the

  5. High intensity focused ultrasound (HIFU) focal spot localization using harmonic motion imaging (HMI).

    Han, Yang; Hou, Gary Yi; Wang, Shutao; Konofagou, Elisa

    2015-08-01

    Several ultrasound-based imaging modalities have been proposed for image guidance and monitoring of high-intensity focused ultrasound (HIFU) treatment. However, accurate localization and characterization of the effective region of treatment (focal spot) remain important obstacles in the clinical implementation of HIFU ablation. Harmonic motion imaging for focused ultrasound (HMIFU) is a HIFU monitoring technique that utilizes radiation-force-induced localized oscillatory displacement. HMIFU has been shown to correctly identify the formation and extent of HIFU thermal ablation lesions. However a significant problem remains in identifying the location of the HIFU focus, which is necessary for treatment planning. In this study, the induced displacement was employed to localize the HIFU focal spot inside the tissue prior to treatment. Feasibility was shown with two separate systems. The 1D HMIFU system consisted of a HIFU transducer emitting an amplitude-modulated HIFU beam for mechanical excitation and a confocal single-element, pulse-echo transducer for simultaneous RF acquisition. The 2D HIFU system consists of a HIFU phased array, and a co-axial imaging phased array for simultaneous imaging. Initial feasibility was first performed on tissue-mimicking gelatin phantoms and the focal zone was defined as the region corresponding to the -3dB full width at half maximum of the HMI displacement. Using the same parameters, in vitro experiments were performed in canine liver specimens to compare the defined focal zone with the lesion. In vitro measurements showed good agreement between the HMI predicted focal zone and the induced HIFU lesion location. HMIFU was experimentally shown to be capable of predicting and tracking the focal region in both phantoms and in vitro tissues. The accuracy of focal spot localization was evaluated by comparing with the lesion location in post-ablative tissues, with a R(2) = 0.821 at p < 0.002 in the 2D HMI system. We demonstrated the

  6. High intensity focused ultrasound (HIFU) focal spot localization using harmonic motion imaging (HMI)

    Han, Yang; Hou, Gary Yi; Wang, Shutao; Konofagou, Elisa

    2015-08-01

    Several ultrasound-based imaging modalities have been proposed for image guidance and monitoring of high-intensity focused ultrasound (HIFU) treatment. However, accurate localization and characterization of the effective region of treatment (focal spot) remain important obstacles in the clinical implementation of HIFU ablation. Harmonic motion imaging for focused ultrasound (HMIFU) is a HIFU monitoring technique that utilizes radiation-force-induced localized oscillatory displacement. HMIFU has been shown to correctly identify the formation and extent of HIFU thermal ablation lesions. However a significant problem remains in identifying the location of the HIFU focus, which is necessary for treatment planning. In this study, the induced displacement was employed to localize the HIFU focal spot inside the tissue prior to treatment. Feasibility was shown with two separate systems. The 1D HMIFU system consisted of a HIFU transducer emitting an amplitude-modulated HIFU beam for mechanical excitation and a confocal single-element, pulse-echo transducer for simultaneous RF acquisition. The 2D HIFU system consists of a HIFU phased array, and a co-axial imaging phased array for simultaneous imaging. Initial feasibility was first performed on tissue-mimicking gelatin phantoms and the focal zone was defined as the region corresponding to the  -3dB full width at half maximum of the HMI displacement. Using the same parameters, in vitro experiments were performed in canine liver specimens to compare the defined focal zone with the lesion. In vitro measurements showed good agreement between the HMI predicted focal zone and the induced HIFU lesion location. HMIFU was experimentally shown to be capable of predicting and tracking the focal region in both phantoms and in vitro tissues. The accuracy of focal spot localization was evaluated by comparing with the lesion location in post-ablative tissues, with a R2 = 0.821 at p  HIFU focal spot without inducing thermal changes

  7. Feasibility of MRI-guided high intensity focused ultrasound treatment for adenomyosis

    Fan, Tien-Ying [State Key Laboratory of Ultrasound Engineering in Medicine, Department of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Zhang, Lian; Chen, Wenzhi [Clinical Center of Tumor Therapy of 2nd Affiliated Hospital of Chongqing Medical University, Chongqing 400010 (China); Liu, Yinjiang; He, Min; Huang, Xiu [State Key Laboratory of Ultrasound Engineering in Medicine, Department of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Orsi, Franco [Interventional Radiology Unit, European Institute of Oncology, 435 Via Ripamonti, 20141 Milan (Italy); Wang, Zhibiao, E-mail: wangzhibiao@haifu.com.cn [State Key Laboratory of Ultrasound Engineering in Medicine, Department of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Clinical Center of Tumor Therapy of 2nd Affiliated Hospital of Chongqing Medical University, Chongqing 400010 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer We tested the feasibility of MRIgHIFU ablation for adenomyosis. Black-Right-Pointing-Pointer Patients were treated with MRIgHIFU under conscious sedation. Black-Right-Pointing-Pointer Patient symptoms were assessed using SSS and UFS-QOL. Black-Right-Pointing-Pointer The mean SSS and UFS-QOL showed significant improvements at follow up. Black-Right-Pointing-Pointer No serious complications were observed 62.5 {+-} 21.6. -- Abstract: Purpose: To test the feasibility of MRI-guided high intensity focused ultrasound ablation for adenomyosis. Materials and methods: Patients with symptomatic adenomyosis were treated with MRI-guided high intensity focused ultrasound (MRIgHIFU). Under conscious sedation, MRIgHIFU was performed by a clinical MRI-compatible focused ultrasound tumour therapeutic system (JM15100, Haifu{sup Registered-Sign} Technology Co. Ltd., Chongqing, China) which is combined with a 1.5 T MRI system (Magnetom Symphony, Siemens Healthcare, Erlangen, Germany). MRI was used to calculate the volume of the uterus and lesion. Non-perfused volume of the targeted lesions was evaluated immediately after MRIgHIFU. Patient symptoms were assessed using symptom severity score (SSS) and uterine fibroids symptoms and quality of life questionnaire (UFS-QOL). Results: Ten patients with mean age of 40.3 {+-} 4 years with an average lesion size of 56.9 {+-} 12.7 mm in diameter were treated. Non-perfused volume and the percentage of non-perfused volume obtained from contrast-enhanced T1 Magnetic resonance images immediately post-treatment were 66.6 {+-} 49.4 cm{sup 3} and 62.5 {+-} 21.6%, respectively. The mean SSS and UFS-QOL showed significant improvements of 25%, 16% and 25% at 3, 6 and 12 months follow up, respectively, to pre-treatment scores. No serious complications were observed. Conclusion: Based on the results from this study, MRIgHIFU treatment appears to be a safe and feasible modality to ablate adenomyosis lesion and

  8. Feasibility of MRI-guided high intensity focused ultrasound treatment for adenomyosis

    Highlights: ► We tested the feasibility of MRIgHIFU ablation for adenomyosis. ► Patients were treated with MRIgHIFU under conscious sedation. ► Patient symptoms were assessed using SSS and UFS-QOL. ► The mean SSS and UFS-QOL showed significant improvements at follow up. ► No serious complications were observed 62.5 ± 21.6. -- Abstract: Purpose: To test the feasibility of MRI-guided high intensity focused ultrasound ablation for adenomyosis. Materials and methods: Patients with symptomatic adenomyosis were treated with MRI-guided high intensity focused ultrasound (MRIgHIFU). Under conscious sedation, MRIgHIFU was performed by a clinical MRI-compatible focused ultrasound tumour therapeutic system (JM15100, Haifu® Technology Co. Ltd., Chongqing, China) which is combined with a 1.5 T MRI system (Magnetom Symphony, Siemens Healthcare, Erlangen, Germany). MRI was used to calculate the volume of the uterus and lesion. Non-perfused volume of the targeted lesions was evaluated immediately after MRIgHIFU. Patient symptoms were assessed using symptom severity score (SSS) and uterine fibroids symptoms and quality of life questionnaire (UFS-QOL). Results: Ten patients with mean age of 40.3 ± 4 years with an average lesion size of 56.9 ± 12.7 mm in diameter were treated. Non-perfused volume and the percentage of non-perfused volume obtained from contrast-enhanced T1 Magnetic resonance images immediately post-treatment were 66.6 ± 49.4 cm3 and 62.5 ± 21.6%, respectively. The mean SSS and UFS-QOL showed significant improvements of 25%, 16% and 25% at 3, 6 and 12 months follow up, respectively, to pre-treatment scores. No serious complications were observed. Conclusion: Based on the results from this study, MRIgHIFU treatment appears to be a safe and feasible modality to ablate adenomyosis lesion and alleviate its symptoms.

  9. Treating glioblastoma multiforme with selective high-dose liposomal doxorubicin chemotherapy induced by repeated focused ultrasound

    Yang FY

    2012-02-01

    Full Text Available Feng-Yi Yang1, Ming-Che Teng1, Maggie Lu2, Hsiang-Fa Liang2, Yan-Ru Lee1, Chueh-Chuan Yen3, Muh-Lii Liang4,5, Tai-Tong Wong51Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, 2Drug Delivery Laboratory, Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, 3Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital and National Yang-Ming University School of Medicine, Taipei, 4Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, 5Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, TaiwanBackground: High-dose tissue-specific delivery of therapeutic agents would be a valuable clinical strategy. We have previously shown that repeated transcranial focused ultrasound is able to increase the delivery of Evans blue significantly into brain tissue. The present study shows that repeated pulsed high-intensity focused ultrasound (HIFU can be used to deliver high-dose atherosclerotic plaque-specific peptide-1 (AP-1-conjugated liposomes selectively to brain tumors.Methods: Firefly luciferase (Fluc-labeled human GBM8401 glioma cells were implanted into NOD-scid mice. AP-1-conjugated liposomal doxorubicin or liposomal doxorubicin alone was administered followed by pulsed HIFU and the doxorubicin concentration in the treated brains quantified by fluorometer. Growth of the labeled glioma cells was monitored through noninvasive bioluminescence imaging and finally the brain tissue was histologically examined after sacrifice.Results: Compared with the control group, the animals treated with 5 mg/kg injections of AP-1 liposomal doxorubicin or untargeted liposomal doxorubicin followed by repeated pulsed HIFU not only showed significantly enhanced accumulation of drug at the sonicated tumor site but also a significantly elevated tumor-to-normal brain drug

  10. A random phased array device for delivery of high intensity focused ultrasound

    Hand, J W [Radiological Sciences Unit, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London W12 0HS (United Kingdom); Shaw, A; Sadhoo, N; Rajagopal, S [Acoustics Group, National Physical Laboratory, Teddington TW11 0LW (United Kingdom); Dickinson, R J [Department of Bioengineering, Imperial College London, London SW7 2AZ (United Kingdom); Gavrilov, L R [N.N. Andreev Acoustics Institute, 117036 Moscow (Russian Federation)], E-mail: j.hand@imperial.ac.uk

    2009-10-07

    Randomized phased arrays can offer electronic steering of a single focus and simultaneous multiple foci concomitant with low levels of secondary maxima and are potentially useful as sources of high intensity focused ultrasound (HIFU). This work describes laboratory testing of a 1 MHz random phased array consisting of 254 elements on a spherical shell of radius of curvature 130 mm and diameter 170 mm. Acoustic output power and efficiency are measured for a range of input electrical powers, and field distributions for various single- and multiple-focus conditions are evaluated by a novel technique using an infrared camera to provide rapid imaging of temperature changes on the surface of an absorbing target. Experimental results show that the array can steer a single focus laterally to at least {+-}15 mm off axis and axially to more than {+-}15 mm from the centre of curvature of the array and patterns of four and five simultaneous foci {+-}10 mm laterally and axially whilst maintaining low intensity levels in secondary maxima away from the targeted area in good agreement with linear theoretical predictions. Experiments in which pork meat was thermally ablated indicate that contiguous lesions several cm{sup 3} in volume can be produced using the patterns of multiple foci.

  11. Use of shock-wave heating for faster and safer ablation of tissue volumes in high intensity focused ultrasound therapy

    Khokhlova, V.; Yuldashev, P.; Sinilshchikov, I.; Partanen, A.; Khokhlova, T.; Farr, N.; Kreider, W.; Maxwell, A.; Sapozhnikov, O.

    2015-10-01

    Simulation of enhanced heating of clinically relevant tissue volumes using nonlinear ultrasound waves generated by a multi-element HIFU phased array were conducted based on the combined Westervelt and bio-heat equations. A spatial spectral approach using the fast Fourier transform algorithm and a corresponding analytic solution to the bioheat equation were used to optimize temperature modeling in tissue. Localized shock-wave heating within a much larger treated tissue volume and short, single HIFU pulses within a much longer overall exposure time were accounted for in the algorithm. Separation of processes with different time and spatial scales made the calculations faster and more accurate. With the proposed method it was shown that for the same time-average power, the use of high peak power pulsing schemes that produce high-amplitude shocks at the focus result in faster tissue heating compared to harmonic, continuous-wave sonications. Nonlinear effects can significantly accelerate volumetric heating while also permitting greater spatial control to reduce the impact on surrounding tissues. Such studies can be further used to test and optimize various steering trajectories of shock-wave sonications for faster and more controlled treatment of tissue volumes.

  12. Jet atomization and cavitation induced by interactions between focused ultrasound and a water surfacea)

    Tomita, Y.

    2014-09-01

    Atomization of a jet produced by the interaction of 1 MHz focused ultrasound with a water surface was investigated using high-speed photography. Viewing various aspects of jet behavior, threshold conditions were obtained necessary for water surface elevation and jet breakup, including drop separation and spray formation. In addition, the position of drop atomization, where a single drop separates from the tip of a jet without spraying, showed good correlation with the jet Weber number. For a set of specified conditions, multiple beaded water masses were formed, moving upwards to produce a vigorous jet. Cavitation phenomena occurred near the center of the primary drop-shaped water mass produced at the leading part of the jet; this was accompanied by fine droplets at the neck between the primary and secondary drop-shaped water masses, due to the collapse of capillary waves.

  13. Investigations on the heating effect of PE-LD induced by high-intensity focused ultrasound.

    Oehm, Lukas; Bach, Sascha; Majschak, Jens-Peter

    2016-08-01

    High-intensity focused ultrasound is widely applied in tissue treatment as well as for heating of solid polymer materials. Previous studies investigating the heating effect in polymer materials utilized sound transmission through water or other fluids at low HIFU power. In this study, the ultrasonic transducer possesses a solid sound conductor made of aluminum and a high HIFU power of above 100W was applied to heat solid PE-LD samples. Temperature measurements were performed by calibrated non-invasive infrared thermal imaging. A strong heating effect with heating above melting temperature and evaporation temperature within less than 1s of irradiation was observed. Furthermore, the acoustic coupling defined by the force applied by the ultrasonic applicator to the polymer material was found to be fundamental to induce the heating effect. This investigation reveals HIFU for new applications in the field of polymer processing. PMID:27208613

  14. Enhancement and quenching of high-intensity focused ultrasound cavitation activity via short frequency sweep gaps.

    Hallez, Loïc; Lee, Judy; Touyeras, Francis; Nevers, Aymeric; Ashokkumar, Muthupandian; Hihn, Jean-Yves

    2016-03-01

    This letter reports on the use of frequency sweeps to probe acoustic cavitation activity generated by high-intensity focused ultrasound (HIFU). Unprecedented enhancement and quenching of HIFU cavitation activity were observed when short frequency sweep gaps were applied in negative and positive directions, respectively. It was revealed that irrespective of the frequency gap, it is the direction and frequency sweep rate that govern the cavitation activity. These effects are related to the response of bubbles generated by the starting frequency to the direction of the frequency sweep, and the influence of the sweep rate on growth and coalescence of bubbles, which in turn affects the active bubble population. These findings are relevant for the use of HIFU in chemical and therapeutic applications, where greater control of cavitation bubble population is critical. PMID:26584998

  15. Imaging informatics based on method of MR temperature measurement in high-intensity focused ultrasound

    Chen, Xiangjiao; Zhang, Jianguo

    2014-03-01

    MR imaging has been used to perform imaging guided high-intensity focused ultrasound (HIFU) and meanwhile can also be used precisely to measure tissue temperature in theory. But in practice, the temperature environment and target are complex. Therefore, it is difficult to measure targeted temperature just by simply using the theory of numerical calculation based on MR image information. In this presentation, we presented new MR temperature measurement, based on imaging informatics, to measure the targeted tissue temperature in MR imaging guided HIFU therapeutic procedure. By heating up the water phantom experiments under HIFU, the new algorithm gives a satisfactory result compared with existing algorithm. Based on experimental data, we can see the accuracy increase 37.5% from 0.4048℃ up to 0.2530℃ when we choose new algorithms.

  16. A Rectourethral Fistula due to Transrectal High-Intensity Focused Ultrasound Treatment: Diagnosis and Management

    Valeria Fiaschetti

    2012-01-01

    Full Text Available Colovesical fistula (CVF is an abnormal connection between the enteric and the urinary systems. The rectourethral fistula (RUF is a possible but extremely rare complication of treatment of prostate cancer with “transrectal High-Intensity Focused Ultrasound (HIFU treatment.” We present a case of CVF due to HIFU treatment of recurrent prostate cancer. The case was assessed with cystography completed with a pelvic CT scan—with MPR, MIP, and VR reconstruction—before emptying the bladder. Since the CT scan confirmed that the fistula involved solely the urethra and excluded even a minimal involvement of the bladder, it was possible to employ a conservative treatment by positioning a Foley catheter of monthly duration, in order to allow the urethra to rest. Still today, after 6 months, the patient is in a good clinical condition and has not shown yet signs of a recurrence of the fistula.

  17. Clinical evaluation of high-intensity focused ultrasound in treating uterus myomas

    Objective: To explore the safety and efficacy of high-intensity focused ultrasound (HIFU) for the treatment of uterus myomas. Methods: HIFU was performed in 47 patients with symptomatic hysteromyoma, who had a childbearing history and were 26-59 years old. Postoperative follow-up was carried out. Clinical symptoms and the tumor's size were observed before and after the HIFU treatment. The results were compared with each other. Results: After HIFU treatment, the symptoms such as dysmenorrhea and hypermenorrhea were markedly improved. Some patients developed hematuria or lower limb pain, which was relieved after symptomatic management. The average volume of myoma before the treatment was (47.6 ± 24.1) cm3 and it was reduced to (17.7 ± 13.1) cm3 at 6 months after the treatment, the difference was statistically significant (P < 0.05). Conclusion: HIFU is a safe and effective treatment for uterus myomas. (authors)

  18. The Efficacy of High-Intensity Focused Ultrasound (HIFU) in Advanced Pancreatic Cancer

    Bo Xie; Jiajun Ling; Weiming Zhang; Xueqin Huang; Jihua Zhen; Yanzhe Huang

    2008-01-01

    OBJECTIVE To observe the efficacy of high-intensity focused ultrasound (HIFU)in the treatment of late-stage pancreatic cancer.METHODS Sixteen patients with advanced pancreatic cancer received HIFU therapy.Evaluation of efficacy was made on the basis of changes in clinical symptoms and variations in the tumor echo and size.RESULTS Clinical symptoms such as pain were significantly alleviated,echo of the tumor was enhanced with B-US and the quality of life such as eating,sleeping and mental status was markedly improved;no serious complications were observed.CONCLUSION The use of HIFU in the treatment of advanced pancreatic cancer is feasible and safe.It is effective in killing the carcinoma cells and alleviaring pain.This technique may offer non-invasive therapy for the treatment of patients with late-stage pancreatic cancer.

  19. Functional Neurosurgery in the Human Thalamus by Transcranial Magnetic Resonance Guided Focused Ultrasound

    Werner, Beat; Morel, Anne; Jeanmonod, Daniel; Martin, Ernst

    2009-04-01

    Potential applications of Transcranial Magnetic Resonance guided Focused Ultrasound (TcMRgFUS) include treatment of functional brain disorders, such as Parkinson's disease, dystonia and tremor, neurogenic pain and tinnitus, neuropsychiatric disorders and epilepsy. In this study we demonstrate the feasibility of non-invasive TcMRgFUS ablation of clinically well established targets in the human thalamus that are currently accessed stereotactically by interventional strategies based on the concept of the thalamocortical dysrhythmia (TCD). Thermal hotspots suitable for clinical intervention were created successfully in anatomical preparations of human ex-vivo heads under pseudo clinical conditions. The hotspots could be positioned at the target locations as needed and local energy deposition was sufficient to create tissue ablation. Numerical simulations based on these experimental data predict that the acoustic energy needed to create ablative lesions in-vivo will be within limits that can safely applied.

  20. Experimental ablation of the pancreas with high intensity focused ultrasound (HIFU in a porcine model

    Biao Xie, Yu-Yuan Li, Lin Jia, Yu-Qiang Nie, Hong Du, Shu-Man Jiang

    2011-01-01

    Full Text Available The aim of this study was to determine the feasibility and safety of high intensity focused ultrasound's (HIFU in pancreatic diseases. Twelve pigs were divided into three groups. The pancreases of pigs in Group A were ablated directly with HIFU, but those in Group B and C ablated by extracorporeal HIFU. The pigs in Group C were sacrificed at day 7 after HIFU. Serological parameters were determined pre-operation and post-operation. The entire pancreas was removed for histological examination. Each animal tolerate the HIFU ablation well. The complete necrosis was observed in targeted regions. The margins of the necrotic regions were clearly delineated from the surrounding normal tissues. Infiltration of inflammatory cells and phorocytosis on the boundary were found in group C. Blood and urine amylase levels were relatively steady after HIFU. No acute pancreatitis or severe complications occurred. In conclusion, HIFU ablation on the pancreas was safe and effective in experimental pigs.

  1. Early evaluation of magnetic resonance imaging guided focused ultrasound sonication in the treatment of uterine fibroids

    Y Himabindu

    2014-01-01

    Full Text Available Background & objectives: Uterine leiomyomas (fibroids are common cause of morbidity in women of reproductive age group. High intensity focused ultrasound with the imaging guidance of magnetic resonance imaging (MRI known as magnetic resonance guided focused ultrasound sonication (MRgFUS is now available. However, there are no available studies with this non invasive modality of treatment in Indian subjects. The objective of this study was to determine the safety and clinical efficacy of MRgFUS in the treatment of uterine fibroids. Methods: This prospective study included 32 consecutive women with clinically symptomatic uterine fibroids who were treated with MRgFUS from February 2011 to October 2011. Pre and post treatment symptom severity scores (SSS were assessed at the time of enrolment and at one, three and six months follow up using a validated uterine fibroid symptom - quality of life questionnaire (UFS-QOL. Pre and post treatment fibroid volumes were compared immediately after treatment and at six months follow up using contrast enhanced MRI scan. Non perfused volume (NPV ratios were calculated and correlated with fibroid volume reductions immediately after the treatment and at the end of six months follow up. Results: This procedure was well tolerated by the patients and procedure related adverse effects were non significant. Significant reductions in SSS were seen at one, three and six month intervals after the treatment (P<0.01. Significant reductions were noticed in fibroid volumes at six months follow up compared to pretreatment fibroid volumes (P<0.01. Significant positive correlations were observed between NPV ratios and reduction in fibroid volumes at six months follow-up (r=0.659, P<0.01. Interpretation & conclusions: MRgFUS is relatively a safe and effective non invasive treatment modality for treating uterine fibroids in selected patients. Its long term efficacy is yet to be tested and compared with other available minimally

  2. High-intensity focused ultrasound therapy in combination with gemcitabine for unresectable pancreatic carcinoma

    Lv W

    2016-05-01

    Full Text Available Wei Lv, Tao Yan, Guojin Wang, Wei Zhao, Tao Zhang, Dinghua Zhou Hepatobiliary Surgery Department, Second Artillery General Hospital, Xicheng District, Beijing, People’s Republic of China Objective: To investigate the therapeutic effect and safety of high-intensity focused ultrasound (HIFU therapy combined with gemcitabine in treating unresectable pancreatic carcinoma. Methods: The 45 patients suffering from pancreatic carcinoma were randomized into two groups. The patients in the experimental group (n=23 received HIFU in combination with gemcitabine and those in the control group (n=22 received gemcitabine alone. The effect and clinical benefit rates in the two groups were compared. The median survival time and 6-month and 12-month survival rates were calculated by Kaplan–Meier method and log-rank test. Results: The median survival time and 6-month survival rate were significantly higher in the experimental group than in the control group (8.91 months vs 5.53 months, 73.9% vs 40.9%, respectively P<0.05, but 12-month survival rate was not statistically different between the two groups (13.0% vs 4.5%, P>0.05. The clinical benefit rates in the experimental group and the control group were 69.6% and 36.3%, respectively (P<0.05. The pain remission rate in the experimental group was significantly higher than that in the control group (65.2% vs 31.8%, P<0.05. Conclusion: HIFU in combination with gemcitabine is better than gemcitabine alone. This combinatorial therapy may become a better and effective treatment for unresectable pancreatic carcinoma. Keywords: pancreatic carcinoma treatment, high-intensity focused ultrasound therapy, gemcitabine

  3. MR guided focused ultrasound: technical acceptance measures for a clinical system

    Magnetic resonance (MR) guided focused ultrasound (MRgFUS) is a hybrid technique which offers efficient and safe focused ultrasound (FUS) treatments of uterine fibroids under MR guidance and monitoring. As a therapy device, MRgFUS requires systematic testing over a wide range of operational parameters prior to use in the clinical environment. We present technical acceptance tests and data for the first clinical MRgFUS system, ExAblate (registered) 2000 (InSightec Inc., Haifa, Israel), that has been FDA approved for treating uterine fibroids. These tests characterize MRgFUS by employing MR temperature measurements in tissue mimicking phantoms. The coronal scan plane is empirically demonstrated to be most reliable for measuring temperature elevations resulting from high intensity ultrasound (US) pulses ('sonications') and shows high sensitivity to changes in sonication parameters. Temperatures measured in the coronal plane were used as a measure of US energy deposited within the focal spot for a range of sonication parameters used in clinical treatments: spot type, spot length, output power, sonication duration, US frequency, and depth of sonication. In addition, MR images acquired during sonications were used to measure effective diameters and lengths of available sonication spot types and lengths. At a constant 60 W output power, the effective spot type diameters were measured to vary between 4.7 ± 0.3 mm and 6.6 ± 0.4 mm; treatment temperatures were found to decrease with increasing spot diameter. Prescribing different spot lengths was found to have no effect on the measured length or on measured temperatures. Tests of MRgFUS positioning accuracy determined errors in the direction parallel to the propagation of the US beam to be significantly greater than those in the perpendicular direction; most sonication spots were erroneously positioned towards the FUS transducer. The tests reported here have been demonstrated to be sufficiently sensitive to detect water

  4. A simulation model for predicting the temperature during the application of MR-guided focused ultrasound for stroke treatment using pulsed ultrasound

    Hadjisavvas, V.; Damianou, C.

    2011-09-01

    In this paper a simulation model for predicting the temperature during the application of MR-guided focused ultrasound for stroke treatment using pulsed ultrasound is presented. A single element spherically focused transducer of 5 cm diameter, focusing at 10 cm and operating at either 0.5 MHz or 1 MHz was considered. The power field was estimated using the KZK model. The temperature was estimated using the bioheat equation. The goal was to extract the acoustic parameters (power, pulse duration, duty factor and pulse repetition frequency) that maintain a temperature increase of less than 1 °C during the application of a pulse ultrasound protocol. It was found that the temperature change increases linearly with duty factor. The higher the power, the lower the duty factor needed to keep the temperature change to the safe limit of 1 °C. The higher the frequency the lower the duty factor needed to keep the temperature change to the safe limit of 1 °C. Finally, the deeper the target, the higher the duty factor needed to keep the temperature change to the safe limit of 1 °C. The simulation model was tested in brain tissue during the application of pulse ultrasound and the measured temperature was in close agreement with the simulated temperature. This simulation model is considered to be very useful tool for providing acoustic parameters (frequency, power, duty factor, pulse repetition frequency) during the application of pulsed ultrasound at various depths in tissue so that a safe temperature is maintained during the treatment. This model could be tested soon during stroke clinical trials.

  5. A review of high intensity focused ultrasound in relation to the treatment of renal tumours and other malignancies.

    Cranston, David

    2015-11-01

    For 60 years, high-intensity focused ultrasound (HIFU) has been the subject of interest for medical research. HIFU causes tissue necrosis in a very well defined area, at a variable distance from the transducer, through heating or cavitation. Over the past two decades, the use of high-intensity focused ultrasound has been investigated in many clinical settings. This review summarises recent advances made in the field of renal cancer in particular, and gives an overview on the use of the extracorporeal machines in the treatment of other malignant tumours. PMID:26070919

  6. Conventional, ultrasound-assisted, and accelerated-solvent extractions of anthocyanins from purple sweet potatoes.

    Cai, Zhan; Qu, Ziqian; Lan, Yu; Zhao, Shujuan; Ma, Xiaohua; Wan, Qiang; Jing, Pu; Li, Pingfan

    2016-04-15

    Purple sweet potatoes (PSPs) are rich in anthocyanins. In this study, we investigated the extraction efficiency of anthocyanins from PSPs using conventional extraction (CE), ultrasound-assisted extraction (UAE), and accelerated-solvent extraction (ASE). Additionally, the effects of these extraction methods on antioxidant activity and anthocyanin composition of PSP extracts were evaluated. In order of decreasing extraction efficiency, the extraction methods were ASE>UAE>CE for anthocyanins (218-244 mg/100 g DW) and CE>UAE>ASE for total phenolics (631-955 mg/100 g DW) and flavonoids (28-40 mg/100 g DW). Antioxidant activities of PSP extracts were CE≈UAE>ASE for ORAC (766-1091 mg TE/100 g DW) and ASE>CE≈UAE for FRAP (1299-1705 mg TE/100 g DW). Twelve anthocyanins were identified. ASE extracts contained more diacyl anthocyanins and less nonacyl and monoacyl anthocyanins than CE and ASE extracts (P<0.05). PMID:26616949

  7. Acoustic characterization of high intensity focused ultrasound fields generated from a transmitter with a large aperture

    Chen, Tao; Fan, Tingbo; Zhang, Wei; Qiu, Yuanyuan; Tu, Juan; Guo, Xiasheng; Zhang, Dong

    2014-03-01

    Prediction and measurement of the acoustic field emitted from a high intensity focused ultrasound (HIFU) is essential for the accurate ultrasonic treatment. In this study, the acoustic field generated from a strongly focused HIFU transmitter was characterized by a combined experiment and simulation method. The spheroidal beam equation (SBE) was utilized to describe the nonlinear sound propagation. The curve of the source pressure amplitude versus voltage excitation was determined by fitting the measured ratio of the second harmonic to the fundamental component of the focal waveform to the simulation result; finally, the acoustic pressure field generated by the strongly focused HIFU transmitter was predicted by using the SBE model. A commercial fiber optic probe hydrophone was utilized to measure the acoustic pressure field generated from a 1.1 MHz HIFU transmitter with a large half aperture angle of 30°. The maximum measured peak-to-peak pressure was up to 72 MPa. The validity of this combined approach was confirmed by the comparison between the measured results and the calculated ones. The results indicate that the current approach might be useful to describe the HIFU field. The results also suggest that this method is not valid for low excitations owing to low sensitivity of the second harmonic.

  8. Acoustic characterization of high intensity focused ultrasound fields generated from a transmitter with a large aperture

    Chen, Tao; Fan, Tingbo [Institute of Acoustics, Key Laboratory of Modern Acoustics, MOE, Nanjing University, Nanjing 210093 (China); Jiangsu Province Institute for Medical Equipment Testing, Nanjing 210012 (China); Zhang, Wei [Jiangsu Province Institute for Medical Equipment Testing, Nanjing 210012 (China); Qiu, Yuanyuan [Department of electronic information, Nantong University, Nantong 226019 (China); Tu, Juan, E-mail: juantu@nju.edu.cn, E-mail: dzhang@nju.edu.cn; Guo, Xiasheng [Institute of Acoustics, Key Laboratory of Modern Acoustics, MOE, Nanjing University, Nanjing 210093 (China); Zhang, Dong, E-mail: juantu@nju.edu.cn, E-mail: dzhang@nju.edu.cn [Institute of Acoustics, Key Laboratory of Modern Acoustics, MOE, Nanjing University, Nanjing 210093 (China); Institute of Acoustics, State Key Laboratory of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-03-21

    Prediction and measurement of the acoustic field emitted from a high intensity focused ultrasound (HIFU) is essential for the accurate ultrasonic treatment. In this study, the acoustic field generated from a strongly focused HIFU transmitter was characterized by a combined experiment and simulation method. The spheroidal beam equation (SBE) was utilized to describe the nonlinear sound propagation. The curve of the source pressure amplitude versus voltage excitation was determined by fitting the measured ratio of the second harmonic to the fundamental component of the focal waveform to the simulation result; finally, the acoustic pressure field generated by the strongly focused HIFU transmitter was predicted by using the SBE model. A commercial fiber optic probe hydrophone was utilized to measure the acoustic pressure field generated from a 1.1 MHz HIFU transmitter with a large half aperture angle of 30°. The maximum measured peak-to-peak pressure was up to 72 MPa. The validity of this combined approach was confirmed by the comparison between the measured results and the calculated ones. The results indicate that the current approach might be useful to describe the HIFU field. The results also suggest that this method is not valid for low excitations owing to low sensitivity of the second harmonic.

  9. Short-duration-focused ultrasound stimulation of Hsp70 expression in vivo

    Kruse, D E; Ferrara, K W [Department of Biomedical Engineering, University of California, Davis, CA 95616 (United States); Mackanos, M A; O' Connell-Rodwell, C E; Contag, C H [Stanford University School of Medicine, Stanford, CA 94305 (United States)], E-mail: dekruse@ucdavis.edu, E-mail: kwferrara@ucdavis.edu, E-mail: mackanos@stanford.edu, E-mail: ceoconnell@stanford.edu, E-mail: ccontag@stanford.edu

    2008-07-07

    The development of transgenic reporter mice and advances in in vivo optical imaging have created unique opportunities to assess and analyze biological responses to thermal therapy directly in living tissues. Reporter mice incorporating the regulatory regions from the genes encoding the 70 kDa heat-shock proteins (Hsp70) and firefly luciferase (luc) as reporter genes can be used to non-invasively reveal gene activation in living tissues in response to thermal stress. High-intensity-focused ultrasound (HIFU) can deliver measured doses of acoustic energy to highly localized regions of tissue at intensities that are sufficient to stimulate Hsp70 expression. We report activation of Hsp70-luc expression using 1 s duration HIFU heating to stimulate gene expression in the skin of the transgenic reporter mouse. Hsp70 expression was tracked for 96 h following the application of 1.5 MHz continuous-wave ultrasound with spatial peak intensities ranging from 53 W cm{sup -2} up to 352 W cm{sup -2}. The results indicated that peak Hsp70 expression is observed 6-48 h post-heating, with significant activity remaining at 96 h. Exposure durations were simulated using a finite-element model, and the predicted temperatures were found to be consistent with the observed Hsp70 expression patterns. Histological evaluation revealed that the thermal damage starts at the stratum corneum and extends deeper with increasing intensity. These results indicated that short-duration HIFU may be useful for inducing heat-shock expression, and that the period between treatments needs to be greater than 96 h due to the protective properties of Hsp70.

  10. Modelling the temperature evolution of bone under high intensity focused ultrasound

    ten Eikelder, H. M. M.; Bošnački, D.; Elevelt, A.; Donato, K.; Di Tullio, A.; Breuer, B. J. T.; van Wijk, J. H.; van Dijk, E. V. M.; Modena, D.; Yeo, S. Y.; Grüll, H.

    2016-02-01

    Magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) has been clinically shown to be effective for palliative pain management in patients suffering from skeletal metastasis. The underlying mechanism is supposed to be periosteal denervation caused by ablative temperatures reached through ultrasound heating of the cortex. The challenge is exact temperature control during sonication as MR-based thermometry approaches for bone tissue are currently not available. Thus, in contrast to the MR-HIFU ablation of soft tissue, a thermometry feedback to the HIFU is lacking, and the treatment of bone metastasis is entirely based on temperature information acquired in the soft tissue adjacent to the bone surface. However, heating of the adjacent tissue depends on the exact sonication protocol and requires extensive modelling to estimate the actual temperature of the cortex. Here we develop a computational model to calculate the spatial temperature evolution in bone and the adjacent tissue during sonication. First, a ray-tracing technique is used to compute the heat production in each spatial point serving as a source term for the second part, where the actual temperature is calculated as a function of space and time by solving the Pennes bio-heat equation. Importantly, our model includes shear waves that arise at the bone interface as well as all geometrical considerations of transducer and bone geometry. The model was compared with a theoretical approach based on the far field approximation and an MR-HIFU experiment using a bone phantom. Furthermore, we investigated the contribution of shear waves to the heat production and resulting temperatures in bone. The temperature evolution predicted by our model was in accordance with the far field approximation and agreed well with the experimental data obtained in phantoms. Our model allows the simulation of the HIFU treatments of bone metastasis in patients and can be extended to a planning tool prior to MR

  11. Focused Ultrasound Simultaneous Irradiation/MRI Imaging, and Two-Stage General Kinetic Model

    Huang, Sheng-Yao; Ko, Chia-En; Chen, Gin-Shin; Chung, I-Fang; Yang, Feng-Yi

    2014-01-01

    Many studies have investigated how to use focused ultrasound (FUS) to temporarily disrupt the blood-brain barrier (BBB) in order to facilitate the delivery of medication into lesion sites in the brain. In this study, through the setup of a real-time system, FUS irradiation and injections of ultrasound contrast agent (UCA) and Gadodiamide (Gd, an MRI contrast agent) can be conducted simultaneously during MRI scanning. By using this real-time system, we were able to investigate in detail how the general kinetic model (GKM) is used to estimate Gd penetration in the FUS irradiated area in a rat's brain resulting from UCA concentration changes after single FUS irradiation. Two-stage GKM was proposed to estimate the Gd penetration in the FUS irradiated area in a rat's brain under experimental conditions with repeated FUS irradiation combined with different UCA concentrations. The results showed that the focal increase in the transfer rate constant of Ktrans caused by BBB disruption was dependent on the doses of UCA. Moreover, the amount of in vivo penetration of Evans blue in the FUS irradiated area in a rat's brain under various FUS irradiation experimental conditions was assessed to show the positive correlation with the transfer rate constants. Compared to the GKM method, the Two-stage GKM is more suitable for estimating the transfer rate constants of the brain treated with repeated FUS irradiations. This study demonstrated that the entire process of BBB disrupted by FUS could be quantitatively monitored by real-time dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). PMID:24949997

  12. Emittance growth in the ITEP spatial uniform acceleration with quadrupole focusing

    Proton linear accelerator with spatial-uniform quadrupole focusing is an initial stage of the 56 MeV linear accelerator, constructed at the ITEP. The investigations have shown that the main reason for emittance growth in the accelerator lies in the occurence of particle bunch pulsation at bunching section. To suppress the emittance growth it is necessary to change the bunching regime. 6 refs.; 1 fig

  13. High-Intensity Focused Ultrasound Ablation of Uterine Fibroids - Potential Impact on Fertility and Pregnancy Outcome.

    Bohlmann, M K; Hoellen, F; Hunold, P; David, M

    2014-02-01

    Laparoscopic myomectomy is regarded as the gold standard for women with symptomatic fibroids who wish to become pregnant. High-intensity focused ultrasound (HIFU or MRgFUS) ablation of uterine fibroids is also being discussed as a non-surgical, minimally invasive, therapeutic option. This review examines the available data on the impact of HIFU/MRgFUS on fertility and pregnancy, focusing particularly on potential direct side-effects of this type of intervention on ovaries, fallopian tubes and uterus and potential late effects on pregnancy and birth, based on the current literature. All pregnancies after HIFU/MRgFUS published to date (around 100 cases) were evaluated. The published case series suggest that HIFU/MRgFUS ablation has no impact on the rate of miscarriages or other obstetrical outcome parameters. Because no prospective studies exist which permit firm conclusions to be drawn on the impact of HIFU/MRgFUS on fertility and pregnancy outcome in women with symptomatic fibroids, this approach is currently only recommended for women with suspected fertility problems due to uterine fibroids who either decline surgery or who have an unacceptably high surgical risk. PMID:24741124

  14. A fast boundary element method for the scattering analysis of high-intensity focused ultrasound.

    van 't Wout, Elwin; Gélat, Pierre; Betcke, Timo; Arridge, Simon

    2015-11-01

    High-intensity focused ultrasound (HIFU) techniques are promising modalities for the non-invasive treatment of cancer. For HIFU therapies of, e.g., liver cancer, one of the main challenges is the accurate focusing of the acoustic field inside a ribcage. Computational methods can play an important role in the patient-specific planning of these transcostal HIFU treatments. This requires the accurate modeling of acoustic scattering at ribcages. The use of a boundary element method (BEM) is an effective approach for this purpose because only the boundaries of the ribs have to be discretized instead of the standard approach to model the entire volume around the ribcage. This paper combines fast algorithms that improve the efficiency of BEM specifically for the high-frequency range necessary for transcostal HIFU applications. That is, a Galerkin discretized Burton-Miller formulation is used in combination with preconditioning and matrix compression techniques. In particular, quick convergence is achieved with the operator preconditioner that has been designed with on-surface radiation conditions for the high-frequency approximation of the Neumann-to-Dirichlet map. Realistic computations of acoustic scattering at 1 MHz on a human ribcage model demonstrate the effectiveness of this dedicated BEM algorithm for HIFU scattering analysis. PMID:26627749

  15. Cell apoptosis and proliferation inhibition of pancreatic cancer induced by sub-threshold focused ultrasound (FUS)

    Objective: To evaluate the effects of sub-threshold focused ultrasound (FUS) sonication on the pancreatic cancer cell. Materials and methods: The human pancreatic carcinoma cell line PaTu 8988t suspension and pancreatic carcinoma xenograft in nude mice were sonicated by FUS using sub-threshold doses. The temperature at the focus was controlled at below 60 °C. The cell apoptosis in vitro was tested by flow cytometer at 3, 6, 12, 24 and 48 h after FUS sonication. Colony formation was used to evaluate the cell growth inhibition of FUS in vitro. The tumor volume of the xenograft was measured before and after FUS sonication. Then the slides of the tumor were under hematoxylin–eosin (H and E) staining and TdT-mediated dUTP nick end labeling (TUNEL) to evaluate the effect of FUS on pancreatic carcinoma xenograft in vivo. Results: The maximum cell suspension temperature of the FUS sonication group was 55.8 ± 2.17 °C. The cell apoptosis rate peaked at 24 h after FUS sonication, the differences between the FUS sonication group and control group were statistically significant (P 3 and 1085.23 ± 217.13 mm3 (P < 0.05). H and E staining and TUNEL assay showed both necrotic and apoptotic cells. Conclusion: Sub-threshold FUS sonication could induce cell apoptosis and inhibit the proliferation of pancreatic cancer cells.

  16. Effects of magnetic resonance-guided high-intensity focused ultrasound ablation on bone mechanical properties and modeling

    Yeo, Sin Yuin; Arias Moreno, Andrés J; van Rietbergen, Bert; Ter Hoeve, Natalie D; van Diest, Paul J; Grüll, Holger

    2015-01-01

    BACKGROUND: Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a promising technique for palliative treatment of bone pain. In this study, the effects of MR-HIFU ablation on bone mechanics and modeling were investigated. METHODS: A total of 12 healthy rat femurs were ablated us

  17. Treatment time reduction through parameter optimization in magnetic resonance guided high intensity focused ultrasound treatments

    Coon, Joshua

    Magnetic Resonance guided High Intensity Focused Ultrasound (MRgHIFU) treatments are a promising modality for cancer treatments in which a focused beam of ultrasound energy is used to kill tumor tissue. However, obstacles still exist to its widespread clinical implementation, including long treatment times. This research demonstrates reductions in treatment times through intelligent selection of the user-controllable parameters, including: the focal zone treatment path, focal zone size, focal zone spacing, and whether to treat one or several focal zone locations at any given time. Several treatments using various combinations of these parameters were simulated using a finite difference method to solve the Pennes bio-heat transfer equation for an ultrasonically heated tissue region with a wide range of acoustic, thermal, geometric, and tumor properties. The total treatment time was iteratively optimized using either a heuristic method or routines included in the Matlab software package, with constraints imposed for patient safety and treatment efficacy. The results demonstrate that large reductions in treatment time are possible through the intelligent selection of user-controllable treatment parameters. For the treatment path, treatment times are reduced by as much as an order of magnitude if the focal zones are arranged into stacks along the axial direction and a middle-front-back ordering is followed. For situations where normal tissue heating constraints are less stringent, these focal zones should have high levels of adjacency to further decrease treatment times; however, adjacency should be reduced in some cases where normal tissue constraints are more stringent. Also, the use of smaller, more concentrated focal zones produces shorter treatment times than larger, more diluted focal zones, a result verified in an agar phantom model. Further, focal zones should be packed using only a small amount of overlap in the axial direction and with a small gap in the

  18. Charged particle driver for ICF using an accelerated, focused compact torus

    We report the status of evaluating an accelerated and focused compact torus as a driver for ICF. We are studying the acceleration and focusing aspects experimentally in the RACE facility, a recently completed ring generator coupled to a 260 kJ acceleration bank. Compact torus and ICF target interaction is being investigated with PIC codes and LASNEX, a 2D magneto-hydrodynamics code. Final conditions required of the CT are discussed as well as coupling issues such as superthermal electron production. We conclude with an economic evaluation of a few 100 MW reactor driven by a compact torus. 9 refs., 5 figs., 1 tab

  19. Design of a compact focusing lens system with short acceleration tube at 300 kV

    A compact focusing lens system with high demagnification over 1500 was designed to form an ion nanobeam with 346 keV energy by adding a short distance acceleration tube for beam acceleration and focusing downstream of the existing double acceleration lens system. The demagnification, focusing points and aberrations of the acceleration tube were studied using beam trajectory calculation. The acceleration tube was designed to have a length of 140 mm and a demagnification of 2 at its acceleration tube voltage of 300 kV, which resulted in a new compact focusing lens system with a total length of about 640 mm. In addition, the maximum voltage and electric-field of the acceleration tube were confirmed experimentally on the built device to be 300 kV and 30 kV/cm, respectively. The final beam size formed by the system was estimated to be 130 nm in diameter using the design parameters. The result suggests that an ion nanobeam of 346 keV can be formed by an apparatus having the reasonable length of 2 m, which permits us to develop a system for 1 MV by elongating its tube length.

  20. Effect of polarization and focusing on laser pulse driven auto-resonant particle acceleration

    The effect of laser polarization and focusing is theoretically studied on the final energy gain of a particle in the Auto-resonant acceleration scheme using a finite duration laser pulse with Gaussian shaped temporal envelope. The exact expressions for dynamical variables viz. position, momentum, and energy are obtained by analytically solving the relativistic equation of motion describing particle dynamics in the combined field of an elliptically polarized finite duration pulse and homogeneous static axial magnetic field. From the solutions, it is shown that for a given set of laser parameters viz. intensity and pulse length along with static magnetic field, the energy gain by a positively charged particle is maximum for a right circularly polarized laser pulse. Further, a new scheme is proposed for particle acceleration by subjecting it to the combined field of a focused finite duration laser pulse and static axial magnetic field. In this scheme, the particle is initially accelerated by the focused laser field, which drives the non-resonant particle to second stage of acceleration by cyclotron Auto-resonance. The new scheme is found to be efficient over two individual schemes, i.e., auto-resonant acceleration and direct acceleration by focused laser field, as significant particle acceleration can be achieved at one order lesser values of static axial magnetic field and laser intensity

  1. Electropolymerization of pyrrole on oxidizable metal under high frequency ultrasound irradiation. Application of focused beam to a selective masking technique

    Et Taouil, A. [Institut UTINAM, UMR 6213 CNRS, Universite de Franche-Comte, 30 Avenue de l' observatoire, 25009 Besancon Cedex (France); Lallemand, F., E-mail: fabrice.lallemand@univ-fcomte.f [Institut UTINAM, UMR 6213 CNRS, Universite de Franche-Comte, 30 Avenue de l' observatoire, 25009 Besancon Cedex (France); Hallez, L.; Hihn, J-Y. [Institut UTINAM, UMR 6213 CNRS, Universite de Franche-Comte, 30 Avenue de l' observatoire, 25009 Besancon Cedex (France)

    2010-12-01

    A novel masking technique against polymer deposition based on High Intensity Focused Ultrasound (HIFU) irradiation was developed for the first time. With this in mind, a variety of background salts were tested. Sodium salicylate was found to be the most effective electrolytic medium for pyrrole sonoelectropolymerization on copper as it leads to a very efficient passivating oxide layer preventing copper dissolution while enabling polymer formation independently from sonication. In such a medium, high frequency ultrasound greatly refines surface structure, and a slight increase in doping level is observed. Finally, it was proved that focused ultrasound increases copper dissolution in sodium oxalate electrolyte while preventing polypyrrole deposition. A selected zone on the copper substrate was thus irradiated by the focused ultrasound beam to protect it from polymerization. In a second stage, a self-assembled monolayer was deposited on this polymer-free area to create a surface biphased substrate. This type of masking technique can be proposed as an interesting alternative to lithography as it is easier to carry out and allows chemical waste reduction.

  2. Analysis and measurement of focusing effects in a traveling wave linear accelerator

    For a recent precise linear accelerator, such as the x-ray free electron laser facility, SACLA, the beam orbit and the beam envelop should be properly calculated from the beam dynamics model of a traveling wave accelerating structure (TWA). Therefore, we compared a predicted beam orbit by a TWA model with a measured orbit by rf cavity beam position monitors. Although the beam orbit in the crest acceleration part was appropriately reproduced, that of the off-crest acceleration part did not agree with the prediction. We found out that the discrepancy came from a quadrupole field in the coupler cell of the TWA. The strength of the quadrupole field was estimated by using 3-dimensional rf simulation and the TWA model was modified by the addition of the quadrupole focusing effect. By using the modified model, the beam orbit was properly reproduced in both the crest acceleration part and the off-crest acceleration part. (author)

  3. Does the phase of menstrual cycle affect MR-guided focused ultrasound surgery of uterine leiomyomas?

    Purpose: To determine whether the phase of menstrual cycle at the time of MR-guided focused ultrasound surgery (MRgFUS) treatment for uterine leiomyomas affects treatment outcome. Methods: We enrolled all patients participating in a prospective phase III clinical trial from our center who completed 6 months of clinical and imaging follow-up. Patients with irregular cycles and those on oral contraceptives were excluded. Data prospectively documenting the date of the last menstrual period (LMP) at the time of treatment, length and duration of cycle, and raw symptom severity score (SSS) from the Uterine Fibroid Symptom and Quality of Life questionnaire, at baseline and 6 months were collected. Proliferative phase patients were determined retrospectively as those who were treated within less than 14 days from LMP; secretory phase patients were classified as those who were treated greater than 14 days from LMP. Results: A total of 58 patients were enrolled. There was no significant difference in the mean SSS at baseline and mean SSS at 6 months between patients treated in the proliferative versus secretory phase of the cycle. No significant difference in the SSS change from baseline to 6 months was seen between the two groups. Conclusions: Menstrual cycle phase does not influence MRgFUS treatment outcome. Symptomatic improvement occurs with treatment during either phase of the menstrual cycle. Thus, the scheduling of MRgFUS treatment need not be based upon the phase of the menstrual cycle

  4. Positioning device for MRI-guided high intensity focused ultrasound system

    A prototype magnetic resonance imaging (MRI)- compatible positioning device was used to move an MRI-guided high intensity focused ultrasound (HIFU) transducer. The positioning device has three user-controlled degrees of freedom that allow access to various targeted lesions. The positioning device was designed and fabricated using construction materials selected for compatibility with high magnetic fields and fast switching magnetic field gradients encountered inside MRI scanners. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, plastic sheets, brass screws, plastic pulleys and timing belts. The HIFU/MRI system includes the multiple subsystems (a) HIFU system, (b) MR imaging, (c) Positioning device (robot) and associate drivers, (d) temperature measurement, (e) cavitation detection, (f) MRI compatible camera, and (g) Soft ware. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the robot to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Discrete and large lesions were created successfully with reproducible results. (orig.)

  5. Treatment of murine tumors using acoustic droplet vaporization-enhanced high intensity focused ultrasound

    Zhu, Meili; Jiang, Lixing; Fabiilli, Mario L.; Zhang, Aili; Fowlkes, J. Brian; Xu, Lisa X.

    2013-09-01

    High intensity focused ultrasound (HIFU) can be applied focally and noninvasively to thermally ablate solid tumors. Long treatment times are typically required for large tumors, which can expose patients to certain risks while potentially decreasing the therapeutic efficacy of the treatment. Acoustic droplet vaporization (ADV) is a promising modality that can enhance the efficacy of tumor treatment using HIFU. In this study, the therapeutic effects of combined HIFU and ADV was evaluated in mice bearing subcutaneously-implanted 4T1 tumors. Histological examination showed that the combination of HIFU and ADV generated a mean necrotic area in the tumor that was 2.9-fold larger than with HIFU alone. A significant enhancement of necrosis was found in the periphery of the tumor, where the blood supply was abundant. Seven days after treatment, the tumors treated with combined HIFU and ADV were 30-fold smaller in volume than tumors treated with HIFU alone. The study demonstrates the potential advantage of combining HIFU and ADV in tumor treatment.

  6. Volumetric feedback ablation of uterine fibroids using magnetic resonance-guided high intensity focused ultrasound therapy

    Voogt, M.J.; Mali, W.P.T.M.; Bosch, Maurice A.A.J. van den [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Trillaud, H.; Frulio, N. [Hospital St. Andre, Department of Radiology, Bordeaux (France); Kim, Y.S.; Rhim, H.; Lim, H.K. [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Barkhausen, J.; Eckey, T. [University Hospital Schleswig-Holstein, Department of Radiology, Luebeck (Germany); Bartels, L.W.; Deckers, R. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Nieminen, H.J.; Soini, J.; Vaara, T.; Koehler, M.O. [Philips Healthcare, Vantaa (Finland); Mougenot, C. [Philips Healthcare, Toronto (Canada); Keserci, B. [Philips Healthcare, Seoul (Korea, Republic of); Sokka, S. [Philips Healthcare, Andover, MA (United States)

    2012-02-15

    The purpose of this prospective multicenter study was to assess the safety and technical feasibility of volumetric Magnetic Resonance-guided High Intensity Focused Ultrasound (MR-HIFU) ablation for treatment of patients with symptomatic uterine fibroids. Thirty-three patients with 36 fibroids were treated with volumetric MR-HIFU ablation. Treatment capability and technical feasibility were assessed by comparison of the Non-Perfused Volumes (NPVs) with MR thermal dose predicted treatment volumes. Safety was determined by evaluation of complications or adverse events and unintended lesions. Secondary endpoints were pain and discomfort scores, recovery time and length of hospital stay. The mean NPV calculated as a percentage of the total fibroid volume was 21.7%. Correlation between the predicted treatment volumes and NPVs was found to be very strong, with a correlation coefficient r of 0.87. All patients tolerated the treatment well and were treated on an outpatient basis. No serious adverse events were reported and recovery time to normal activities was 2.3 {+-} 1.8 days. This prospective multicenter study proved that volumetric MR-HIFU is safe and technically feasible for the treatment of symptomatic uterine fibroids. (orig.)

  7. High-intensity focused ultrasound treatment (HIFU) for the advanced pancreatic cancer

    Song, In Ho; Jung, Seung Eun; Hahn, Seong Tai; Jang, Jin Hee; Cho, Se Hyun; Han, Joon Yeol; Kim, Jin Il; Lee, Ji Young; Sung, Choon Ho [St. Mary' Hospital, the Catholic University of Korea, Seoul (Korea, Republic of)

    2007-06-15

    We wanted to evaluate the levels of effect and safety of high-intensity focused ultrasound ablation (HIFU) for treating patients with advanced pancreatic cancer. Nineteen sessions of HIFU, with the patients under general anesthesia, were performed in 18 patients with advanced pancreatic cancer. The change of the gray-scale of the target lesion was analyzed during HIFU, and MRI was performed before and after HIFU. We assessed the extent of coagulative necorsis, the change of pain and the complications after HIFU. The change of tumor size and the survival of patients were also evaluated. The average size of tumor was 4 cm in diameter. Eighty nine percent of the target tumors showed increased echogenicity. On MRI, necrosis of the entire target tumor occurred in 79% of the patients. After treatment, effective pain relief was noted in 89% of the patients. There were no major complications. No size increase of the treated tumor was noted during 24 weeks of follow-up for 10 patients. Six patients among 12 patients who were available for follow-up are still alive and they are receiving chemotherapy. Six patients expired due to other disease or progression of metastasis. HIFU is a safe method without any major complications, and it is effective for inducing tumor necrosis and achieving pain control for patients with advanced pancreatic cancer.

  8. High-intensity focused ultrasound treatment (HIFU) for the advanced pancreatic cancer

    We wanted to evaluate the levels of effect and safety of high-intensity focused ultrasound ablation (HIFU) for treating patients with advanced pancreatic cancer. Nineteen sessions of HIFU, with the patients under general anesthesia, were performed in 18 patients with advanced pancreatic cancer. The change of the gray-scale of the target lesion was analyzed during HIFU, and MRI was performed before and after HIFU. We assessed the extent of coagulative necorsis, the change of pain and the complications after HIFU. The change of tumor size and the survival of patients were also evaluated. The average size of tumor was 4 cm in diameter. Eighty nine percent of the target tumors showed increased echogenicity. On MRI, necrosis of the entire target tumor occurred in 79% of the patients. After treatment, effective pain relief was noted in 89% of the patients. There were no major complications. No size increase of the treated tumor was noted during 24 weeks of follow-up for 10 patients. Six patients among 12 patients who were available for follow-up are still alive and they are receiving chemotherapy. Six patients expired due to other disease or progression of metastasis. HIFU is a safe method without any major complications, and it is effective for inducing tumor necrosis and achieving pain control for patients with advanced pancreatic cancer

  9. Enhancement of Small Molecule Delivery by Pulsed High-Intensity Focused Ultrasound: A Parameter Exploration.

    Zhou, Yufeng; Wang, Yak-Nam; Farr, Navid; Zia, Jasmine; Chen, Hong; Ko, Bong Min; Khokhlova, Tatiana; Li, Tong; Hwang, Joo Ha

    2016-04-01

    Chemotherapeutic drug delivery is often ineffective within solid tumors, but increasing the drug dose would result in systemic toxicity. The use of high-intensity focused ultrasound (HIFU) has the potential to enhance penetration of small molecules. However, operation parameters need to be optimized before the use of chemotherapeutic drugs in vivo and translation to clinical trials. In this study, the effects of pulsed HIFU (pHIFU) parameters (spatial-average pulse-average intensity, duty factor and pulse repetition frequency) on the penetration as well as content of small molecules were evaluated in ex vivo porcine kidneys. Specific HIFU parameters resulted in more than 40 times greater Evans blue content and 3.5 times the penetration depth compared with untreated samples. When selected parameters were applied to porcine kidneys in vivo, a 2.3-fold increase in concentration was obtained after a 2-min exposure to pHIFU. Pulsed HIFU has been found to be an effective modality to enhance both the concentration and penetration depth of small molecules in tissue using the optimized HIFU parameters. Although, performed in normal tissue, this study has the promise of translation into tumor tissue. PMID:26803389

  10. Positioning device for MRI-guided high intensity focused ultrasound system

    Damianou, Christakis [Frederick Institute of Technology (FIT), Limassol (Cyprus); MEDSONIC, LTD, Limassol (Cyprus); Ioannides, Kleanthis [Polikliniki Igia, Limassol (Cyprus); Milonas, Nicos [Frederick Institute of Technology (FIT), Limassol (Cyprus)

    2008-04-15

    A prototype magnetic resonance imaging (MRI)- compatible positioning device was used to move an MRI-guided high intensity focused ultrasound (HIFU) transducer. The positioning device has three user-controlled degrees of freedom that allow access to various targeted lesions. The positioning device was designed and fabricated using construction materials selected for compatibility with high magnetic fields and fast switching magnetic field gradients encountered inside MRI scanners. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, plastic sheets, brass screws, plastic pulleys and timing belts. The HIFU/MRI system includes the multiple subsystems (a) HIFU system, (b) MR imaging, (c) Positioning device (robot) and associate drivers, (d) temperature measurement, (e) cavitation detection, (f) MRI compatible camera, and (g) Soft ware. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the robot to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Discrete and large lesions were created successfully with reproducible results. (orig.)