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Artykuły w czasopismach na temat „HiFUN simulations”

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Data publikacji: 6 września 2023

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1

Yadav, Sumit Kumar, Souradip Paul i Mayanglambam Suheshkumar Singh. "Effect of HIFU-Induced Thermal Ablation in Numerical Breast Phantom". Photonics 10, nr 4 (9.04.2023): 425. http://dx.doi.org/10.3390/photonics10040425.

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Breast cancer is a leading cause of cancer-related deaths in women, and treatment involved invasive surgery such as lumpectomy. In the last decade, a non-invasive, non-contact high-intensity focused ultrasound (HIFU) therapy was developed for treatment with promising results. However, its success rate depends on patient selection, tissue heterogeneities, HIFU operational parameters, and even imaging techniques. In this emerging field, computer simulations can provide us with a much-needed platform to learn, test, and deduce results virtually before conducting experiments. In this study, we used three different classes of anatomically realistic numerical breast phantoms from clinical contrast-enhanced magnetic resonance imaging (MRI) data, including scattered-, heterogeneous-, and extremely dense-type breasts. Upon assigning the appropriate acoustic and optical parameters to the tissues within, we simulated HIFU propagation by using the k-Wave toolbox in MATLAB and compared the changes introduced in the three types of breasts. It was found that scattered-type breast was best-suited for HIFU therapy. Furthermore, we simulated light-beam propagation with the ValoMC toolbox in MATLAB after introducing the lesion to compare the distribution of the initial pressure generated via the photoacoustic effect. This simulation study will be of significant clinical impact, especially in the study and management of HIFU-based treatments, which are individual/tissue-selective in nature.

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Treweek, Benjamin C., Jacob H. Brody, Alper Erturk, S. H. Swift, Chandler Smith, Cameron A. McCormick, Timothy Walsh i Nathan W. Moore. "Large-scale simulation of high-intensity focused ultrasound with Sierra/SD". Journal of the Acoustical Society of America 153, nr 3_supplement (1.03.2023): A271. http://dx.doi.org/10.1121/10.0018815.

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High-frequency simulations of acoustic wave propagation are known to be computationally challenging, and the difficulty is compounded for large domains. For problems like high-intensity focused ultrasound (HIFU) with coupling between piezoelectric and acoustic media, both challenges are present. The larger domain sizes, higher-order elements, and greater levels of refinement necessary in such simulations result in millions of degrees of freedom, large system matrices, and substantial memory requirements, raising the need for parallel high-performance computing (HPC). Sierra/SD is a massively parallel HPC application developed for finite element method simulations in structural dynamics and acoustics. In this work, Sierra/SD is used to simulate an acoustic pulse from a piezoelectric transducer focused on an elastic scatterer in a fluid medium. Three-dimensional simulation results are presented for the acoustic field in the fluid and the stress field in the scatterer, and performance is compared between Sierra/SD and COMSOL Multiphysics for smaller geometries. Finally, to showcase the expanded analysis possibilities afforded by HPC for HIFU, an example is presented using a support vector machine to determine a decision boundary for maximum stress in the scatterer. [SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.]

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3

SUZUKI, Katsuyuki, Daiji Fujii i Hideomi OHTSUBO. "HIFU Simulation using Voxel Analysis". Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2003.15 (2003): 153–54. http://dx.doi.org/10.1299/jsmebio.2003.15.153.

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4

LEE, KANG IL, IMBO SIM, GWAN SUK KANG i MIN JOO CHOI. "NUMERICAL SIMULATION OF TEMPERATURE ELEVATION IN SOFT TISSUE BY HIGH INTENSITY FOCUSED ULTRASOUND". Modern Physics Letters B 22, nr 11 (10.05.2008): 803–7. http://dx.doi.org/10.1142/s0217984908015413.

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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.

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5

Shan, Feng, Xiasheng Guo, Juan Tu, Jianchun Cheng i Dong Zhang. "Multi-relaxation-time lattice Boltzmann modeling of the acoustic field generated by focused transducer". International Journal of Modern Physics C 28, nr 03 (marzec 2017): 1750038. http://dx.doi.org/10.1142/s0129183117500383.

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The high-intensity focused ultrasound (HIFU) has become an attractive therapeutic tool for the noninvasive tumor treatment. The ultrasonic transducer is the key component in HIFU treatment to generate the HIFU energy. The dimension of focal region generated by the transducer is closely relevant to the safety of HIFU treatment. Therefore, it is essential to numerically investigate the focal region of the transducer. Although the conventional acoustic wave equations have been used successfully to describe the acoustic field, there still exist some inherent drawbacks. In this work, we presented an axisymmetric isothermal multi-relaxation-time lattice Boltzmann method (MRT-LBM) model with the Bouzidi–Firdaouss–Lallemand (BFL) boundary condition in cylindrical coordinate system. With this model, some preliminary simulations were firstly conducted to determine a reasonable value of the relaxation parameter. Then, the validity of the model was examined by comparing the results obtained with the LBM results with the Khokhlov–Zabolotskaya–Kuznetsov (KZK) equation and the Spheroidal beam equation (SBE) for the focused transducers with different aperture angles, respectively. In addition, the influences of the aperture angle on the focal region were investigated. The proposed model in this work will provide significant references for the parameter optimization of the focused transducer for applications in the HIFU treatment or other fields, and provide new insights into the conventional acoustic numerical simulations.

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6

Farbin, Grace. "A preliminary numerical investigation of convolutional neural network (CNN) techniques for filtering high-intensity focused ultrasound (HIFU) noise in images". Journal of the Acoustical Society of America 153, nr 3_supplement (1.03.2023): A350. http://dx.doi.org/10.1121/10.0019119.

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High-intensity focused ultrasound (HIFU) is a minimally invasive medical procedure that uses ultrasonic waves to ablate or heat tissue with the aim of treating tumors and tremors. Diagnostic ultrasound imaging is the primary mode of imaging during HIFU treatments due to its real-time capabilities. However, HIFU noise, produced from therapeutic ultrasound components, interfere with the diagnostic ultrasound components and cause difficulty in monitoring changes to tissue during treatment. In a multitude of HIFU treatments, deep learning has been used as a tool to detect coagulation, monitor temperature, and segment tumors. Convolutional neural network (CNN) models are a series of deep learning algorithms that can assign importance to aspects of an inputted image and differentiate one from the other. Based on previous methods of filtering, CNNs too can be trained to filter raw RF signals received by an ultrasound probe for subsequent real-time treatment feedback with HIFU. Here, we were able to present a preliminary investigation of a CNN approach for HIFU noise reduction. To do this, we used acoustic wave simulations from k-Wave, a time-domain, full-wave model for ultrasound wave propagation, in combination with the Deep Learning Toolbox from MATLAB. Subsequent analyses studied the performance of noise reduction via the proposed regression model.

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7

Tan, Qiaolai, Xiao Zou, Yajun Ding, Xinmin Zhao i Shengyou Qian. "The Influence of Dynamic Tissue Properties on HIFU Hyperthermia: A Numerical Simulation Study". Applied Sciences 8, nr 10 (16.10.2018): 1933. http://dx.doi.org/10.3390/app8101933.

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Accurate temperature and thermal dose prediction are crucial to high-intensity focused ultrasound (HIFU) hyperthermia, which has been used successfully for the non-invasive treatment of solid tumors. For the conventional method of prediction, the tissue properties are usually set as constants. However, the temperature rise induced by HIFU irradiation in tissues will cause changes in the tissue properties that in turn affect the acoustic and temperature field. Herein, an acoustic–thermal coupling model is presented to predict the temperature and thermal damage zone in tissue in terms of the Westervelt equation and Pennes bioheat transfer equation, and the individual influence of each dynamic tissue property and the joint effect of all of the dynamic tissue properties are studied. The simulation results show that the dynamic acoustic absorption coefficient has the greatest influence on the temperature and thermal damage zone among all of the individual dynamic tissue properties. In addition, compared with the conventional method, the dynamic acoustic absorption coefficient leads to a higher focal temperature and a larger thermal damage zone; on the contrary, the dynamic blood perfusion leads to a lower focal temperature and a smaller thermal damage zone. Moreover, the conventional method underestimates the focal temperature and the thermal damage zone, compared with the simulation that was performed using all of the dynamic tissue properties. The results of this study will be helpful to guide the doctors to develop more accurate clinical protocols for HIFU treatment planning.

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8

Zhao, Peng, Yuebing Wang, Shiqi Tong, Jie Tao i Yongjie Sheng. "The Effects of Energy on the Relationship between the Acoustic Focal Region and Biological Focal Region during Low-Power Cumulative HIFU Ablation". Applied Sciences 13, nr 7 (1.04.2023): 4492. http://dx.doi.org/10.3390/app13074492.

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The biological focal region (BFR) induced by a single high-intensity focused ultrasound (HIFU) exposure is considered to be the foundation of the ultrasound ablation of tumor lesions. The purpose of this study was to explore the relationship between the acoustic focal region (AFR) and the BFRs with different combinations of power and time in low-power cumulative HIFU treatment. The finite-difference time-domain (FDTD) method was used to simulate AFR and BFR during HIFU ablation. The acoustic fields, the temperature profiles, and the shapes of BFRs were calculated by the Westervelt equation, Pennes’ equation, and the equivalent thermal dose model. In order to verify the simulation rules, phantom and ex vivo bovine livers were exposed by HIFU with a different power and time. The results demonstrated that in the low-power cumulative HIFU treatment, when the lengths of BFRs and the length of AFR were approximately equal, the shape of the BFR induced by ‘high power × short time’ exposure was closer to that of AFR than the shape of the BFR induced by ‘low power × long time’ exposure, and the exposure energy required was significantly reduced. The analysis revealed the relationship between the BFR and the AFR with different acoustic power. This study provides a reference for doctors to determine power, time, and movement distance in clinical treatment.

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9

Daschner, Rosa, Holger Hewener, Wolfgang Bost, Steffen Weber, Steffen Tretbar i Marc Fournelle. "Ultrasound Thermometry for HIFU-Therapy". Current Directions in Biomedical Engineering 7, nr 2 (1.10.2021): 554–57. http://dx.doi.org/10.1515/cdbme-2021-2141.

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Abstract High-Intensity Focused Ultrasound (HIFU) is an alternative tumour therapy with the ability for non-invasive thermal ablation of tissue. For a safe application, the heat deposition needs to be monitored over time, which is currently done with Magnetic Resonance Imaging. Ultrasound (US) based monitoring is a promising alternative, as it is less expensive and allows the use of a single device for both therapy and monitoring. In this work, a method for spatial and temporal US thermometry has been investigated based on simulation studies and in-vitro measurements. The chosen approach is based on the approximately linear dependence between temperature and speed of sound (SoS) in tissue for a given temperature range. By tracking the speckles of successive B-images, the possibility of detecting local changes in SoS and therefore in temperature is given. A speckle tracking algorithm was implemented for 2D and 3D US thermometry using a spatial compounding method to reduce artifacts. The algorithm was experimentally validated in an agar-based phantom and in porcine tissue for temperature rises up to △ 8°C. We used a focusing single element US transducer as therapeutic probe, a linear (/matrix array) transducer with 128 (/32∙32) elements for imaging and thermocouples for validation and calibration. In all experiments, both computational and in-vitro, we succeeded in monitoring the thermal induced SoS changes over time. The in-vitro measurements were in good agreement with the simulation results and the thermocouple measurements (rms temperature difference = 0.53 °C, rms correlation coefficient = 0. 96).

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10

Wang, Haoyang, Yuchen Sun, Yuxin Wang, Ying Chen, Yun Ge, Jie Yuan i Paul Carson. "Temperature-Controlled Hyperthermia with Non-Invasive Temperature Monitoring through Speed of Sound Imaging". Applied Sciences 13, nr 12 (20.06.2023): 7317. http://dx.doi.org/10.3390/app13127317.

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Hyperthermia therapy (HT) is used to treat diseases through heating of high temperature usually in conjunction with some other medical therapeutics such as chemotherapy and radiotherapy. In this study, we propose a promising temperature-controlled hyperthermia method that uses high-intensity focused ultrasound (HIFU) for clinical tumor treatment combined with diagnostic ultrasound image guidance and non-invasive temperature monitoring through speed of sound (SOS) imaging. HIFU heating is realized by a ring ultrasound transducer array with 256 elements. In this study, tumors in the human thigh were set as heating targets. The inner structure information of thigh tissue is obtained by B-mode ultrasound imaging. Since the relationship between temperature and SOS in different human tissue is available, the temperature detection is converted to the SOS detection obtained by the full-wave inversion (FWI) method. Simulation results show that our model can achieve expected hyperthermia of constant temperature on tumor target with 0.2 °C maximum temperature fluctuation for 5 h. Through simulation, our proposed thermal therapy model achieves accurate temperature control of ±0.2 °C in human thigh tumors, which verifies the feasibility of the proposed temperature-controlled hyperthermia model. Furthermore, the temperature measurement can share the same ring ultrasound transducer array for HIFU heating and B-mode ultrasound imaging, which provides a guiding significance for clinical application.

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11

Naziba, Anika Tun, i Mohammad Nasir Uddin. "Non-Invasive Heat-Induced Numerous Tissue Ablation Simulation in a Medical Environment Using Different Focal Length High Intensity Focused Ultrasound Apparatus". AIUB Journal of Science and Engineering (AJSE) 21, nr 2 (23.11.2022): 89–97. http://dx.doi.org/10.53799/ajse.v21i2.378.

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In the field of biomedical, HIFU is a non-invasive therapeutic method that employs non-ionizing acoustic waves to increase the temperature. According to its high efficiency and cheap cost, it has been the main focus of this research. The key stages of this tumor ablation include mechanical and thermal effects. Simulations on tissue ablation with HIFU were implemented in this research to investigate how multiple tissue ablation works and how to enhance tumor ablation while avoiding injury to surrounding healthy tissue by altering the optimal intensity, power, focal length and lens radius of curvature. In order to find the optimal features of the proposed model, this analysis employs clinical applications. Numerous soft and hard tissues from the human body were chosen for this analysis. At a specified acoustic power and exposure period, each tissues optimal frequency (1.6 MHz to 3.5 MHz) and power (120 W to 140 W) were obtained for effective tissue ablation. This research performed all computations by changing the focal length from 55 mm to 65 mm. The outcomes of this therapy might require several weeks to comfortably remove tumor. This optimum result indicates that HIFU tumor ablation procedure has a high probability of success.

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12

Perry, Kaitlyn, Robert Staruch, Samuel Pichardo, Yuexi Huang, Merrylee McGuffin, Ari Partanen, Shun Wong i in. "Magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) hyperthermia for primary rectal cancer: A virtual feasibility analysis." Journal of Global Oncology 5, suppl (7.10.2019): 77. http://dx.doi.org/10.1200/jgo.2019.5.suppl.77.

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77 Background: MR-HIFU Hyperthermia (HT) is a non-invasive treatment modality with real-time thermometry that ensures accurate and precise heating of a target with minimal effect on adjacent tissue. This energy deposition within a tumour can produce local bioeffects resulting in thermal chemo- and radiosensitization. MR-HIFU has been shown to be safe and feasible in a companion phase I study for recurrent rectal cancer. The purpose of this study is to determine the feasibility of MR-HIFU in treating primary rectal tumours. Methods: With ethics approval, the anatomic characteristics and surrounding structures of rectal tumours diagnosed at Sunnybrook from 2014-2019 were retrospectively analyzed. Three orthogonal views of MR images were used to determine the potential ultrasound (US) beam path and organs at risk (OAR). In part 2 of the study, the gross tumour volume was delineated for 30 rectal tumours (10 low, mid &high). Image datasets were imported into the Sonalleve MR-HIFU workstation for virtual treatment simulation and planning to determine tumour targetability, coverage, optimal patient set-up, and transducer positioning. Results: Of the 105 tumours analyzed, 36, 52, and 17 were low, mid, and high, respectively. The average width of the acoustic window (sciatic notch) for the US beam path was 5.8 ± 1.4cm, average tumour length was 5.24 ± 2.0cm, and average beam path (skin to tumour edge) was 7.3 ± 1.9cm. Eighty one percent of tumours were ≤ 0.3cm from an OAR. Of the 24 virtually simulated tumours to date, 6/8 lower, 6/8 mid, and 1/8 upper rectal tumours were targetable by MR-HIFU. Conclusions: This is the first virtual analysis to evaluate MR-HIFU HT targetability in primary rectal cancer. Results from this study will support MR-HIFU HT as an option to enhance the treatment of primary rectal cancer. Acknowledgments: This study has been funded by the Canadian Cancer Society. Patient & tumour characteristics. [Table: see text]

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13

Chen, Gin-Shin, Jonathan Cannata, Ruibin Liu, Hsu Chang i K. Kirk Shung. "DESIGN AND FABRICATION OF HIGH-INTENSITY FOCUSED ULTRASOUND PHASED ARRAY FOR LIVER TUMOR THERAPY". Biomedical Engineering: Applications, Basis and Communications 21, nr 03 (czerwiec 2009): 187–92. http://dx.doi.org/10.4015/s1016237209001246.

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Noninvasive surgery of the liver tumors has been carried out by using the high-intensity focused ultrasound (HIFU). However, the liver tumor can be moved by the human respirations and heartbeats, which may cause the ablation and damage of normal tissues during the sonications of HIFU. The purpose of this study was to design and fabricate a cylindrical HIFU phased array transducer for treating the moving liver tumor efficiently. The total number of the element was 512 but only 256 channels were required since the elements along the elevation direction were connected in pairs with respect to the central line of the array. Field II software was used to simulate the acoustic field, and a formula for predicting the spatial averaged intensity at focus was developed based on the practical factors. The results of the simulations showed that the cylindrical HIFU phased array in water had a dynamic focusing range from 145 to 175 mm in the depth direction and a steering range from -15 to 15 mm in azimuthal direction with respect to the center of the array. After the dissipation of cables and the attenuation of various media, the designed array could still generate the intensity at focus up to 1095 W/cm2 when the input electrical power was approximately 410 W. The prototype of the array was fabricated and the preliminary test was completed. The testing results showed that each element of the array prototype can work well.

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14

Perra, Emanuele, Nick Hayward, Kenneth P. H. Pritzker i Heikki J. Nieminen. "An ultrasonically actuated needle promotes the transport of nanoparticles and fluids". Journal of the Acoustical Society of America 152, nr 1 (lipiec 2022): 251–65. http://dx.doi.org/10.1121/10.0012190.

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Non-invasive therapeutic ultrasound (US) methods, such as high-intensity focused ultrasound (HIFU), have limited access to tissue targets shadowed by bones or presence of gas. This study demonstrates that an ultrasonically actuated medical needle can be used to translate nanoparticles and fluids under the action of nonlinear phenomena, potentially overcoming some limitations of HIFU. A simulation study was first conducted to study the delivery of a tracer with an ultrasonically actuated needle (33 kHz) inside a porous medium acting as a model for soft tissue. The model was then validated experimentally in different concentrations of agarose gel showing a close match with the experimental results, when diluted soot nanoparticles (diameter < 150 nm) were employed as delivered entity. An additional simulation study demonstrated a threefold increase in the volume covered by the delivered agent in liver under a constant injection rate, when compared to without US. This method, if developed to its full potential, could serve as a cost effective way to improve safety and efficacy of drug therapies by maximizing the concentration of delivered entities within, e.g., a small lesion, while minimizing exposure outside the lesion.

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15

Kargl, Steven G., i Marilee A. Andrew. "Study of a scanning HIFU therapy protocol, Part I: Theory and simulations". Journal of the Acoustical Society of America 113, nr 4 (kwiecień 2003): 2309. http://dx.doi.org/10.1121/1.4780722.

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Yuan, Bilin, Xinyi Qin i Jie Xi. "The Comparison of Life Quality between Ultrasound-Guided High-Intensity Focused Ultrasound and Laparoscopic Myomectomy for the Treatment of Uterine Fibroids". Computational and Mathematical Methods in Medicine 2022 (5.08.2022): 1–5. http://dx.doi.org/10.1155/2022/9604915.

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Objective. This study is aimed at comparing the uterine fibroids patients’ postoperative living quality between ultrasound-guided high-intensity focused ultrasound (HIFU) and laparoscopic myomectomy. Materials and Methods. A total of 164 patients were included with uterine fibroids who underwent laparoscopic myomectomy and HIFU in Cangzhou Central Hospital from September 2020 to November 2021. This study divided these objects into HIFU group and laparoscopic group, and both groups were followed up 6 months after surgery. After obtaining the results, Uterine Fibroid Symptom and health-related Quality Of Life questionnaire (UFS-QOL) and 36-Item Short Form Health Survey (SF-36) were performed before and after treatment to assess patient outcome. Results. After treatments, the living quality in both groups was significantly improved compared with that before surgery, which had statistical significant ( P < 0.05 ). After treatment, the scores of the two scales in HIFU group were significantly better than those in the laparoscopic group ( P < 0.05 ). Conclusion. In comparison with laparoscopic myomectomy, ultrasound-guided high-intensity focused ultrasound could improve the life quality of patients more effectively than traditional laparoscopic myomectomy and was helpful to the recovery and prognosis of uterine fibroids after treatment. The outcomes will provide a reference for clinicians to select a more appropriate treatment for uterine fibroids.

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17

Kwon, Da Sol, Jin Ho Sung, Chan Yuk Park i Jong Seob Jeong. "Phase-Inverted Multifrequency HIFU Transducer for Lesion Expansion: A Simulation Study". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 65, nr 7 (lipiec 2018): 1125–32. http://dx.doi.org/10.1109/tuffc.2018.2830108.

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SUGIYAMA, Kazuyasu, Mitsuaki KATO, Kohei OKITA, Shu Takagi i Yoichiro MATSUMOTO. "825 On dealing with the temperature rise in HIFU treatment simulation". Proceedings of the JSME annual meeting 2008.6 (2008): 107–8. http://dx.doi.org/10.1299/jsmemecjo.2008.6.0_107.

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Li, Faqi, Ruo Feng, Qiang Zhang, Jin Bai i Zhibiao Wang. "Estimation of HIFU induced lesions in vitro: Numerical simulation and experiment". Ultrasonics 44 (grudzień 2006): e337-e340. http://dx.doi.org/10.1016/j.ultras.2006.07.002.

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Ebbini, Emad S., Hui Yao i Ajay Shrestha. "Dual-Mode Ultrasound Phased Arrays for Image-Guided Surgery". Ultrasonic Imaging 28, nr 2 (kwiecień 2006): 65–82. http://dx.doi.org/10.1177/016173460602800201.

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A 64-element, 1 MHz prototype dual-mode array (DMUA) with therapeutic and imaging capabilities is described. Simulation and experimental results for the characterization of the therapeutic operating field (ThxOF) and imaging field-of-view (IxFOV) for a DMUA are given. In addition, some of the special considerations for imaging with DMUAs are given and illustrated experimentally using wire-target arrays and commercial, quality-assurance phantoms. These results demonstrate what is potentially the most powerful advantage of the use of DMUAs in image-guided surgery; namely, inherent registration between the imaging and therapeutic coordinate systems. We also present imaging results before and after discrete and volumetric HIFU-induced lesions in freshly-excised tissues. DMUA images consistently show changes in echogenicity after lesion formation with shape and extent reflecting the actual shape of the lesion. While changes in echogenicity cannot be used as an indicator of irreversible HIFU-induced tissue damage, they provide important feedback on the location and extent of the expected lesion. Thus, together with the self-registration property of DMUAs, lesion images can be expected to provide immediate and spatially-accurate feedback on the tissue response to the therapeutic HIFU beams. Based on the results provided here, the imaging capabilities of DMUAs can add unique features to other forms of image guidance, e.g. MRI, CT and diagnostic ultrasound.

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Vanhille i Hynynen. "Numerical Simulations of the Nonlinear Interaction of a Bubble Cloud and a High Intensity Focused Ultrasound Field". Acoustics 1, nr 4 (29.10.2019): 825–36. http://dx.doi.org/10.3390/acoustics1040049.

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We studied the effects of a small bubble cloud located at the pre-focal area of a high-intensity focused ultrasound field. Our objective is to show that bubbles can modify the bioeffects of an ultrasound treatment in muscle tissue. We model a three-dimensional ultrasound field in an idealized configuration of real operating conditions. Simulations are performed using a combined method based on the Khokhlov-Zabolotskaya-Kuznetsov equation, describing the ultrasound propagation, and a Rayleigh-Plesset equation, modeling the bubble oscillations. The nonlinear interaction of the ultrasound field and the bubble oscillations is considered. Results with and without bubbles for different void fractions of the cloud and different acoustic powers are compared. The cloud induces scattering, nonlinear distortion, and shielding of ultrasound, which increase the mechanical index in the pre-focal zone, shift the location, reduce the size, and modify the shape of the volume of tissue of high mechanical index values, and lower the pressure at the intended focus considerably. Although some hypothesis and parameters used in the models do not fit the real HIFU situations, the simulation results suggest that the effects caused by a bubble cloud located in the pre-focal area should be considered and monitored to ensure the safety of high-intensity focused ultrasound treatments.

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Solovchuk, Maxim A., San Chao Hwang, Hsu Chang, Marc Thiriet i Tony W. H. Sheu. "Temperature elevation by HIFU inex vivoporcine muscle: MRI measurement and simulation study". Medical Physics 41, nr 5 (18.04.2014): 052903. http://dx.doi.org/10.1118/1.4870965.

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Zhou, Yufeng, i Mingjun Wang. "Simulation of Transrib HIFU Propagation and the Strategy of Phased-array Activation". Physics Procedia 70 (2015): 1119–22. http://dx.doi.org/10.1016/j.phpro.2015.08.239.

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Almekkaway, Mohamed K., Islam A. Shehata i Emad S. Ebbini. "Anatomical-based model for simulation of HIFU-induced lesions in atherosclerotic plaques". International Journal of Hyperthermia 31, nr 4 (15.04.2015): 433–42. http://dx.doi.org/10.3109/02656736.2015.1018966.

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Georgii, Joachim, Caroline von Dresky, Daniel Demedts, Christian Schumann i Tobias Preusser. "Planning of HIFU therapies of moving organs by using numerical simulation techniques". Journal of Therapeutic Ultrasound 2, Suppl 1 (2014): A8. http://dx.doi.org/10.1186/2050-5736-2-s1-a8.

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Zubair, Muhammad, i Robert Dickinson. "Calculating the Effect of Ribs on the Focus Quality of a Therapeutic Spherical Random Phased Array". Sensors 21, nr 4 (9.02.2021): 1211. http://dx.doi.org/10.3390/s21041211.

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The overlaying rib cage is a major hindrance in treating liver tumors with high intensity focused ultrasound (HIFU). The problems caused are overheating of the ribs due to its high ultrasonic absorption capability and degradation of the ultrasound intensity distribution in the target plane. In this work, a correction method based on binarized apodization and geometric ray tracing approach was employed to avoid heating the ribs. A detailed calculation of the intensity distribution in the focus plane was undertaken to quantify and avoid the effect on HIFU beam generated by a 1-MHz 256-element random phased array after the ultrasonic beam passes through the rib cage. Focusing through the ribs was simulated for 18 different idealized ribs-array configurations and 10 anatomically correct ribs-array configurations, to show the effect of width of the ribs, intercostal spacing and the relative position of ribs and array on the quality of focus, and to identify the positions that are more effective for HIFU applications in the presence of ribs. Acoustic simulations showed that for a single focus without beam steering and for the same total acoustic power, the peak intensity at the target varies from a minimum of 211 W/cm2 to a maximum of 293 W/cm2 for a nominal acoustic input power of 15 W, whereas the side lobe level varies from 0.07 Ipeak to 0.28 Ipeak and the separation between the main lobe and side lobes varies from 2.5 mm to 6.3 mm, depending on the relative positioning of the array and ribs and the beam alignment. An increase in the side lobe level was observed by increasing the distance between the array and the ribs. The parameters of focus splitting and the deterioration of focus quality caused by the ultrasonic propagation through the ribs were quantified in various possible different clinical scenarios. In addition to idealized rib topology, anatomical realistic ribs were used to determine the focus quality of the HIFU beam when the beam is steered both in axial and transverse directions and when the transducer is positioned at different depths from the rib cage.

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Liu, Bei, Wenbin Tan, Xian Zhang, Ziqi Peng i Jing Cao. "Recognition study of denatured biological tissues based on multi-scale rescaled range permutation entropy". Mathematical Biosciences and Engineering 19, nr 1 (2022): 102–14. http://dx.doi.org/10.3934/mbe.2022005.

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<abstract> <p>The recognition of denatured biological tissue is an indispensable part in the process of high intensity focused ultrasound treatment. As a nonlinear method, multi-scale permutation entropy (MPE) is widely used in the recognition of denatured biological tissue. However, the traditional MPE method neglects the amplitude information when calculating the time series complexity. The disadvantage will affect the recognition effect of denatured tissues. In order to solve the above problems, the method of multi-scale rescaled range permutation entropy (MRRPE) is proposed in this paper. The simulation results show that the MRRPE not only includes the amplitude information of the signal when calculating the signal complexity, but also extracts the extreme volatility characteristics of the signal effectively. The proposed method is applied to the HIFU echo signals during HIFU treatment, and the support vector machine (SVM) is used for recognition. The results show that compared with MPE and the multi-scale weighted permutation entropy (MWPE), the recognition rate of denatured biological tissue based on the MRRPE is higher, up to 96.57%, which can better recognize the non-denatured biological tissues and the denatured biological tissues.</p> </abstract>

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SUZUKI, Katsuyuki, Daiji Fujii i Hideomi OHTSUBO. "Development of HIFU Simulation System Using Wave Motion Analysis and Heat Conduction Analysis". Proceedings of The Computational Mechanics Conference 2003.16 (2003): 333–34. http://dx.doi.org/10.1299/jsmecmd.2003.16.333.

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Rybyanets, A. N., I. A. Shvetsov, E. I. Petrova, M. A. Lugovaya i N. A. Shvetsova. "Numerical simulation and optimization of acoustic fields and designs of composite HIFU transducers". Ferroelectrics 543, nr 1 (26.04.2019): 48–53. http://dx.doi.org/10.1080/00150193.2019.1592447.

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Okita, Kohei, Ryuta Narumi, Takashi Azuma, Shu Takagi i Yoichiro Matumoto. "The role of numerical simulation for the development of an advanced HIFU system". Computational Mechanics 54, nr 4 (8.05.2014): 1023–33. http://dx.doi.org/10.1007/s00466-014-1036-y.

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Peng, Ziqi, Xian Zhang, Jing Cao i Bei Liu. "Recognition of Biological Tissue Denaturation Based on Improved Multiscale Permutation Entropy and GK Fuzzy Clustering". Information 13, nr 3 (7.03.2022): 140. http://dx.doi.org/10.3390/info13030140.

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Recognition of biological tissue denaturation is a vital work in high-intensity focused ultrasound (HIFU) therapy. Multiscale permutation entropy (MPE) is a nonlinear signal processing method for feature extraction, widely applied to the recognition of biological tissue denaturation. However, the typical MPE cannot derive a stable entropy due to intensity information loss during the coarse-graining process. For this problem, an improved multiscale permutation entropy (IMPE) is proposed in this work. IMPE is obtained through refining and reconstructing MPE. Compared with MPE, the IMPE overcomes the deficiency of amplitude information loss due to the coarse-graining process when computing signal complexity. Through the simulation of calculating MPE and IMPE from white Gaussian noise, it is found that the entropy derived by IMPE is more stable than that derived by MPE. The processing method based on IMPE feature extraction is applied to the experimental ultrasonic scattered echo signals in HIFU treatment. Support vector machine and Gustafson–Kessel fuzzy clustering based on MPE and IMPE feature extraction are also used for biological tissue denaturation classification and recognition. The results calculated from the different combination algorithms show that the recognition of biological tissue denaturation based on IMPE-GK clustering is more reliable with the accuracy of 95.5%.

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Shan, Tianqi. "High resolution focused-ultrasound-induced thermoacoustic imaging". Journal of the Acoustical Society of America 152, nr 4 (październik 2022): A278. http://dx.doi.org/10.1121/10.0016261.

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We report a new imaging modality, focused-ultrasound-induced thermoacoustic imaging (FUTAI). FUTAI provides high imaging resolution and unique contrast of acoustic absorption and thermodynamic properties of tissue. When a short pulse of the focused ultrasound beam is applied to biological tissue, the tissue will absorb the energy of the incident ultrasound causing a rapid change in local temperature, which leads to thermoelastic expansion and generates acoustic waves. In this work, we investigated this focused-ultrasound-induced thermoacoustic effect through theoretical simulation and experimental validation. A novel imaging modality FUTAI is proposed and demonstrated for the first time. By scanning the focus of the incident ultrasound beam, a 2D or 3D image of tissue properties can be formed. FUTAI provides better resolution compared to traditional B-mode ultrasound imaging, and deeper imaging depth compared to photoacoustic imaging. Additionally, since FUTAI is sensitive to acoustic absorption, it has unique advantages in guiding therapies like high intensity focused ultrasound (HIFU) in which treatment efficiency is determined by the acoustic absorption property. In this work, we also proposed a new method to localize the focus of HIFU with high accuracy using FUTAI. The results indicate that FUTAI has great potential in applications such as noninvasive imaging and therapy guidance.

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Andrew, Marilee A., Andrew A. Brayman, Peter J. Kaczkowski i Steven G. Kargl. "Comparison between coupled KZK‐BHTE numerical simulations and scanned HIFU exposures in excised bovine liver". Journal of the Acoustical Society of America 115, nr 5 (maj 2004): 2448. http://dx.doi.org/10.1121/1.4782196.

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Chatillon, S., R. Loyet, L. Brunel, F. Chavrier, N. Guillen i S. Le Berre. "Applications of intensive HIFU simulation based on surrogate models using the CIVA HealthCare platform". Journal of Physics: Conference Series 1761 (styczeń 2021): 012007. http://dx.doi.org/10.1088/1742-6596/1761/1/012007.

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Bessonova, O. V., i V. Wilkens. "Membrane hydrophone measurement and numerical simulation of HIFU fields up to developed shock regimes". IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 60, nr 2 (luty 2013): 290–300. http://dx.doi.org/10.1109/tuffc.2013.2565.

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Ding, Xin, Yizhe Wang, Qian Zhang, Wenzheng Zhou, Peiguo Wang, Mingyan Luo i Xiqi Jian. "Modulation of transcranial focusing thermal deposition in nonlinear HIFU brain surgery by numerical simulation". Physics in Medicine and Biology 60, nr 10 (28.04.2015): 3975–98. http://dx.doi.org/10.1088/0031-9155/60/10/3975.

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Kim, S. J., J. Y. Hwang, Y. J. Kim i K. N. Pae. "Numerical Simulation Method for Prediction of HIFU Induced Lesions in Human Tissue: FDTD-LBM". Physics of Wave Phenomena 31, nr 1 (luty 2023): 30–35. http://dx.doi.org/10.3103/s1541308x2301003x.

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Constanciel, Elodie, W. Apoutou N'Djin, Francis Bessiere, Francoise Chavrier, Daniel Grinberg, Alexandre Vignot, Philippe Chevalier, Jean Yves Chapelon i Cyril Lafon. "Design and evaluation of a transesophageal HIFU probe for ultrasound-guided cardiac ablation: simulation of a HIFU mini-maze procedure and preliminary ex vivo trials". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 60, nr 9 (wrzesień 2013): 1868–83. http://dx.doi.org/10.1109/tuffc.2013.2772.

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Smirnov, Petr, i Kullervo Hynynen. "Design of a HIFU array for the treatment of deep venous thrombosis: a simulation study". Physics in Medicine & Biology 62, nr 15 (12.07.2017): 6108–25. http://dx.doi.org/10.1088/1361-6560/aa71fb.

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Ohl, Siew-Wan, Evert Klaseboer i Boo Cheong Khoo. "Bubbles with shock waves and ultrasound: a review". Interface Focus 5, nr 5 (6.10.2015): 20150019. http://dx.doi.org/10.1098/rsfs.2015.0019.

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The study of the interaction of bubbles with shock waves and ultrasound is sometimes termed ‘acoustic cavitation'. It is of importance in many biomedical applications where sound waves are applied. The use of shock waves and ultrasound in medical treatments is appealing because of their non-invasiveness. In this review, we present a variety of acoustics–bubble interactions, with a focus on shock wave–bubble interaction and bubble cloud phenomena. The dynamics of a single spherically oscillating bubble is rather well understood. However, when there is a nearby surface, the bubble often collapses non-spherically with a high-speed jet. The direction of the jet depends on the ‘resistance' of the boundary: the bubble jets towards a rigid boundary, splits up near an elastic boundary, and jets away from a free surface. The presence of a shock wave complicates the bubble dynamics further. We shall discuss both experimental studies using high-speed photography and numerical simulations involving shock wave–bubble interaction. In biomedical applications, instead of a single bubble, often clouds of bubbles appear (consisting of many individual bubbles). The dynamics of such a bubble cloud is even more complex. We shall show some of the phenomena observed in a high-intensity focused ultrasound (HIFU) field. The nonlinear nature of the sound field and the complex inter-bubble interaction in a cloud present challenges to a comprehensive understanding of the physics of the bubble cloud in HIFU. We conclude the article with some comments on the challenges ahead.

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Zou, Xiao, Hu Dong i Sheng-You Qian. "Influence of dynamic tissue properties on temperature elevation and lesions during HIFU scanning therapy: Numerical simulation". Chinese Physics B 29, nr 3 (marzec 2020): 034305. http://dx.doi.org/10.1088/1674-1056/ab6c4f.

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Jong Seob Jeong. "Dual concentric-sectored HIFU transducer with phase-shifted ultrasound excitation for expanded necrotic region: a simulation study". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 60, nr 5 (maj 2013): 924–31. http://dx.doi.org/10.1109/tuffc.2013.2649.

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Wang, Mingjun, i Yufeng Zhou. "Simulation of non-linear acoustic field and thermal pattern of phased-array high-intensity focused ultrasound (HIFU)". International Journal of Hyperthermia 32, nr 5 (5.05.2016): 569–82. http://dx.doi.org/10.3109/02656736.2016.1160154.

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Ramsay, Craig R., Temitope E. Adewuyi, Joanne Gray, Jenni Hislop, Mark DF Shirley, Shalmini Jayakody, Graeme MacLennan i in. "Ablative therapy for people with localised prostate cancer: a systematic review and economic evaluation". Health Technology Assessment 19, nr 49 (lipiec 2015): 1–490. http://dx.doi.org/10.3310/hta19490.

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BackgroundFor people with localised prostate cancer, active treatments are effective but have significant side effects. Minimally invasive treatments that destroy (or ablate) either the entire gland or the part of the prostate with cancer may be as effective and cause less side effects at an acceptable cost. Such therapies include cryotherapy, high-intensity focused ultrasound (HIFU) and brachytherapy, among others.ObjectivesThis study aimed to determine the relative clinical effectiveness and cost-effectiveness of ablative therapies compared with radical prostatectomy (RP), external beam radiotherapy (EBRT) and active surveillance (AS) for primary treatment of localised prostate cancer, and compared with RP for salvage treatment of localised prostate cancer which has recurred after initial treatment with EBRT.Data sourcesMEDLINE (1946 to March week 3, 2013), MEDLINE In-Process & Other Non-Indexed Citations (29 March 2013), EMBASE (1974 to week 13, 2013), Bioscience Information Service (BIOSIS) (1956 to 1 April 2013), Science Citation Index (1970 to 1 April 2013), Cochrane Central Register of Controlled Trials (CENTRAL) (issue 3, 2013), Cochrane Database of Systematic Reviews (CDSR) (issue 3, 2013), Database of Abstracts of Reviews of Effects (DARE) (inception to March 2013) and Health Technology Assessment (HTA) (inception to March 2013) databases were searched. Costs were obtained from NHS sources.Review methodsEvidence was drawn from randomised controlled trials (RCTs) and non-RCTs, and from case series for the ablative procedures only, in people with localised prostate cancer. For primary therapy, the ablative therapies were cryotherapy, HIFU, brachytherapy and other ablative therapies. The comparators were AS, RP and EBRT. For salvage therapy, the ablative therapies were cryotherapy and HIFU. The comparator was RP. Outcomes were cancer related, adverse effects (functional and procedural) and quality of life. Two reviewers extracted data and carried out quality assessment. Meta-analysis used a Bayesian indirect mixed-treatment comparison. Data were incorporated into an individual simulation Markov model to estimate cost-effectiveness.ResultsThe searches identified 121 studies for inclusion in the review of patients undergoing primary treatment and nine studies for the review of salvage treatment. Cryotherapy [3995 patients; 14 case series, 1 RCT and 4 non-randomised comparative studies (NRCSs)], HIFU (4000 patients; 20 case series, 1 NRCS) and brachytherapy (26,129 patients; 2 RCTs, 38 NRCSs) studies provided limited data for meta-analyses. All studies were considered at high risk of bias. There was no robust evidence that mortality (4-year survival 93% for cryotherapy, 99% for HIFU, 91% for EBRT) or other cancer-specific outcomes differed between treatments. For functional and quality-of-life outcomes, the paucity of data prevented any definitive conclusions from being made, although data on incontinence rates and erectile dysfunction for all ablative procedures were generally numerically lower than for non-ablative procedures. The safety profiles were comparable with existing treatments. Studies reporting the use of focal cryotherapy suggested that incontinence rates may be better than for whole-gland treatment. Data on AS, salvage treatment and other ablative therapies were too limited. The cost-effectiveness analysis confirmed the uncertainty from the clinical review and that there is no technology which appears superior, on the basis of current evidence, in terms of average cost-effectiveness. The probabilistic sensitivity analyses suggest that a number of ablative techniques are worthy of further research.LimitationsThe main limitations were the quantity and quality of the data available on cancer-related outcomes and dysfunction.ConclusionsThe findings indicate that there is insufficient evidence to form any clear recommendations on the use of ablative therapies in order to influence current clinical practice. Research efforts in the use of ablative therapies in the management of prostate cancer should now be concentrated on the performance of RCTs and the generation of standardised outcomes.Study registrationThis study is registered as PROSPERO CRD42012002461.FundingThe National Institute for Health Research Health Technology Assessment programme.

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LEDUC, Nicolas, Kohei OKITA, Kazuyasu SUGIYAMA, Shu TAKAGI i Yoichiro MATSUMOTO. "Focus Control in HIFU Therapy Assisted by Time-Reversal Simulation with an Iterative Procedure for Hot Spot Elimination". Journal of Biomechanical Science and Engineering 7, nr 1 (2012): 43–56. http://dx.doi.org/10.1299/jbse.7.43.

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Liu, Bei, i Xian Zhang. "Identification of Denatured Biological Tissues Based on Improved Variational Mode Decomposition and Autoregressive Model during HIFU Treatment". Computer Modeling in Engineering & Sciences 130, nr 3 (2022): 1547–63. http://dx.doi.org/10.32604/cmes.2022.018130.

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Ginter, Siegfried, Eckard Steiger i Rainer Riedlinger. "Numerical simulation of the enhanced heat production in tissue due to the nonlinear character of high‐intensity focused ultrasound (HIFU)". Journal of the Acoustical Society of America 105, nr 2 (luty 1999): 1117. http://dx.doi.org/10.1121/1.425216.

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Wolfram, Frank, i Thomas G. Lesser. "A simulation study of the HIFU ablation process on lung tumours, showing consequences of atypical acoustic properties in flooded lung". Zeitschrift für Medizinische Physik 29, nr 1 (luty 2019): 49–58. http://dx.doi.org/10.1016/j.zemedi.2018.06.002.

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Zou, Xiao, Shengyou Qian, Qiaolai Tan i Hu Dong. "Formation of Thermal Lesions in Tissue and Its Optimal Control during HIFU Scanning Therapy". Symmetry 12, nr 9 (19.08.2020): 1386. http://dx.doi.org/10.3390/sym12091386.

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A high intensity focused ultrasound (HIFU) scanning approach is needed to obtain multiple treatment spots for the ablation of large volume tumors, but it will bring some problems such as longer treatment times, the inhomogeneity of temperature and thermal lesions in tissues. Although some optimal control methods have been proposed, it is difficult to take into account the uniformity, efficiency and entirety of thermal lesions. In this study, based on the Helmholtz equation and Pennes’ bio-heat transfer equation, a coupled acoustic-thermal field model is proposed to investigate the relationship between temperature elevation, thermal lesions and neighboring treatment spots, and to analyze the effects of the heating time and acoustic intensity on thermal lesions by the finite element method (FEM). Consequently, optimal control schemes for the heating time and acoustic intensity based on the contribution from neighboring treatment spots to thermal lesions are put forward to reduce treatment times and improve the uniformity of temperature and thermal lesions. The simulation results show that the peak historical temperature elevation on one treatment spot is related to the number, distance and time interval of its neighboring treated spots, and the thermal diffusion from the neighboring untreated spots can slow down the drop of temperature elevation after irradiation, thus both of them affect the final shape of the thermal lesions. In addition, increasing the heating time or acoustic intensity of each treatment spot can expand the overall area of thermal lesions, but it would aggravate the elevation and nonuniformity of the temperature of the treatment region. Through optimizing the heating time, the total treatment time can be reduced from 249 s by 17.4%, and the mean and variance of the peak historical temperature elevation can decrease from 44.64 °C by 13.3% and decrease from 24.6317 by 45%, respectively. While optimizing the acoustic intensity, the total treatment time remains unchanged, and the mean of the peak historical temperature elevation is reduced by 4.3 °C. Under the condition of the same thermal lesions, the optimized schemes can reduce the treatment time, lower the peak of the temperature on treatment spots, and homogenize the temperature distributions. This work is of practical significance for the optimization of a HIFU scanning therapy regimen and the evaluation of its treatment effect.

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Revathy, P., V. Sadasivam i T. Ajith Bosco Raj. "Intensity Based Simulation of the Temperature Prediction in the Focal Region of Liver Using MRI-Guided High Intensity Focused Ultrasound (HIFU)". Journal of Computational and Theoretical Nanoscience 13, nr 10 (1.10.2016): 6728–32. http://dx.doi.org/10.1166/jctn.2016.5620.

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In this research paper a new temperature prediction method is proposed to predict the temperature in liver during thermal ablation which also takes in to account the blood flow cooling. The proposed method suggest a modification of Pennes bioheat transfer equation (PBHTE) inorder to more accurately predict the treatment temperature. The temperature elevation by the proposed heat transfer model is compared with the PBHTE model and the other two heat continuum models by Wulff and Klinger. Appropriate temperature prediction is useful in treatment planning. This may reduce the recurrence level of cancer. Further the reduction in treatment time increases patient safety.

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