High intensity focused ultrasound (HIFU) is a very complex transient process and can cause tissue coagulation necrosis. The cavitation and boiling behaviour of bubbles in the focal region play very important roles throughout an injury process. This paper reviews the research done by domestic and foreign scholars on behaviours of bubbles in HIFU irradiation process and summarizes in the focal region bubble cavitation and boiling generation, related detective means and relationships with hyperecho, temperature rise of the focus and injury shape.
Biophysical Phenomena ; High-Intensity Focused Ultrasound Ablation ; methods ; Humans ; Thermal Conductivity ; Thermodynamics

We present a case of retained placenta accreta treated by high-intensity focused ultrasound (HIFU) ablation followed by hysteroscopic resection. The patient was diagnosed as submucosal myoma based on ultrasonography in local clinic. Pathologic examination of several pieces of tumor mass from the hysteroscopic procedure revealed necrotic chorionic villi with calcification. HIFU was performed using an ultrasound-guided HIFU tumor therapeutic system. The ultrasound machine had been used for real-time monitoring of the HIFU procedure. After HIFU treatment, no additional vaginal bleeding or complications were observed. A hysteroscopic resection was performed to remove ablated placental tissue 7 days later. No abnormal vaginal bleeding or discharge was seen after the procedure. The patient was stable postoperatively. We proposed HIFU and applied additional hysteroscopic resection for a safe and effective method for treating retained placenta accreta to prevent complications from the remaining placental tissue and to improve fertility options.
Chorionic Villi ; Fertility ; High-Intensity Focused Ultrasound Ablation ; Humans ; Methods ; Myoma ; Placenta, Retained* ; Ultrasonography* ; Uterine Hemorrhage

We present a case of retained placenta accreta treated by high-intensity focused ultrasound (HIFU) ablation followed by hysteroscopic resection. The patient was diagnosed as submucosal myoma based on ultrasonography in local clinic. Pathologic examination of several pieces of tumor mass from the hysteroscopic procedure revealed necrotic chorionic villi with calcification. HIFU was performed using an ultrasound-guided HIFU tumor therapeutic system. The ultrasound machine had been used for real-time monitoring of the HIFU procedure. After HIFU treatment, no additional vaginal bleeding or complications were observed. A hysteroscopic resection was performed to remove ablated placental tissue 7 days later. No abnormal vaginal bleeding or discharge was seen after the procedure. The patient was stable postoperatively. We proposed HIFU and applied additional hysteroscopic resection for a safe and effective method for treating retained placenta accreta to prevent complications from the remaining placental tissue and to improve fertility options.
Chorionic Villi ; Fertility ; High-Intensity Focused Ultrasound Ablation ; Humans ; Methods ; Myoma ; Placenta, Retained* ; Ultrasonography* ; Uterine Hemorrhage

Animals ; Heart Diseases ; surgery ; High-Intensity Focused Ultrasound Ablation ; instrumentation ; methods ; Humans

This paper introduces HIFU system software based on a phased-array HIFU device. Combined with the database and computer graphics technology, this HIFU system software can be used to develop the therapy planning semi-automatically, implement the pilot project efficiently and accelerate the clinical studies.
Computer Graphics ; High-Intensity Focused Ultrasound Ablation ; methods ; Software ; Software Design

OBJECTIVETo investigate the accuracy of ultrasound monitoring during pulsed high intensity focused ultrasound (PHIFU) treatment and improve the sensitivity of ultrasound monitoring of tissue necrosis caused by PHIFU treatment.

METHODSBovine liver ex vivo was dot-exposed with HIFU at the therapeutic doses of 2000 J (group A) and 1440 J (group B). The two groups were further divided into groups A1 (power 100 W, duty cycle 100%, irradiate 20 s) A2 (power 100 W, duty cycle 50%, irradiate 40 s), A3 (power 100 W, duty cycle 40%, irradiate 50 s), B1 (power 120 W, duty cycle 100%, irradiate 12 s), B2 (power 100 W, duty cycle 50%, irradiate 24 s), and B3 (power 100 W, duty cycle 40%, irradiate 30 s). The gray scale changes in the ultrasonic images after the exposures were observed, and the correlation function of the image was calculated before and after the exposure. The accuracy of evaluations based on the correlation function and gray-scale changes was compared.

RESULTSThe correct rate of gray scale-based evaluation of tissue necrosis caused by PHIFU was only 51%, while that by correlation function-based evaluation reached 85%.

CONCLUSIONMonitoring of tissue necrosis caused by PHIFU treatment can not rely solely on evaluation of gray-scale change of the ultrasound images, and the correlation function-based evaluation can be more accurate and sensitive for that purpose.

OBJECTIVE: The purpose of this study was to compare efficacy, sonication energy efficiency, treatment time and safety of magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) and those of ultrasound-guided high-intensity focused ultrasound (USgHIFU) for ablation of uterine fibroids. MATERIALS AND METHODS: This study included 43 patients with 44 symptomatic uterine fibroids treated with MRgHIFU and 51 patients with 68 symptomatic uterine fibroids treated with USgHIFU. After therapy, contrast-enhanced MRI was conducted and complete ablation was defined as 100% non-perfused volume (NPV) of fibroids. Patients with completely ablated fibroids were selected for the comparison of the treatment data and sonication parameters between MRgHIFU and USgHIFU treated groups. RESULTS: Thirteen completely ablated fibroids in 10 patients (23.3%, 10/43) were achieved with MRgHIFU and 28 completely ablated fibroids in 22 patients (43.1%, 22/51) were achieved with USgHIFU. In completely ablated fibroids, the energy-efficiency factor (EEF) was 5.1 ± 3.0 J/mm3 and 4.7 ± 2.5 J/mm3 in the MRgHIFU and USgHIFU, respectively (p = 0.165). There was a negative linear correlation between EEF and the NPV of fibroids for MRgHIFU (p = 0.016) and USgHIFU (p = 0.001). The mean treatment time was 174.5 ± 42.2 minutes and 114.4 ± 39.2 minutes in the MRgHIFU and USgHIFU procedures, respectively (p = 0.021). There were no severe adverse events and major complications after treatment. CONCLUSION: MRgHIFU and USgHIFU are safe and effective with the equivalent energy efficiency for complete ablation of fibroids. USgHIFU has shorter treatment time than MRgHIFU.
High-Intensity Focused Ultrasound Ablation ; Humans ; Leiomyoma* ; Magnetic Resonance Imaging ; Methods* ; Sonication ; Ultrasonography*

With the development of non-invasive therapeutic means such as high intensity focused ultrasound (HIFU), it has been of an importance how to monitor effectively the therapeutic process and to evaluate the outcome of the therapy. Sonoelastography has been a hot research field in recent years as an effective method for tissue characterization. This article focuses on the research progress of sonoelastography for the guidance of HIFU therapy at present, and reveals the potential possibility of sonoelastograhy guided HIFU Therapy.
Animals ; Elasticity Imaging Techniques ; methods ; High-Intensity Focused Ultrasound Ablation ; methods ; Humans ; Monitoring, Physiologic ; methods ; Neoplasms ; therapy ; Treatment Outcome

Ultrasound based tissue thermal lesion non-invasive detection is of great significance in high intensity focused ultrasound (HIFU) clinical application. In this paper, we propose a sub-pixel method to quantify the ultrasound image change caused by HIFU as correlation-distance. The support vector machine (SVM) was trained by using correlation distance as samples, and the recognition effect was tested. Results showed that sub-pixel cross-correlation vector field could reflect the ablation lesions position. SVM based classification method can recognize HIFU beam lesion degree effectively.
Algorithms ; Diagnostic Imaging ; methods ; High-Intensity Focused Ultrasound Ablation ; adverse effects ; Humans ; Pattern Recognition, Automated ; methods ; Support Vector Machine

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.
Breast Neoplasms ; diagnostic imaging ; pathology ; surgery ; Female ; High-Intensity Focused Ultrasound Ablation ; Humans ; Magnetic Resonance Imaging ; methods ; Ultrasonography, Interventional ; methods