OBJECTIVE: To evaluate the correlation of magnetic resonance (MR) T₂-weighted image (T₂WI) signal characteristics of adenomyosis and the efficacy of high-intensity focused ultrasound (HIFU) ablation. METHODS: Based on the presence or absence of patchy hyperintense foci on preoperative MR T₂WI, the patients with adenomyosis undergoing HIFU treatment were divided into homogeneous signal group and heterogeneous signal group, and the heterogeneous group was further divided into heterogeneous hypointense group and heterogeneous isointense group according to signal intensity of the lesions. The patients in heterogeneous signal group were matched with the patients in the homogeneous group at a 1:1 ratio using the propensity score matching, and similarly, the patients in the heterogeneous hypointense group were matched with those in the heterogeneous isointense group at a 1:1 ratio. The non-perfused volume ratio (NPVR) and relief of dysmenorrhea were used to assess the therapeutic efficacy in the 4 groups. RESULTS: A total of 299 patients were enrolled, who had a median preoperative dysmenorrhea score of 7.0 (6.0, 8.0) and a median NPVR of 53.5% (35.4, 70.1)%. After propensity score matching, the NPVR in homogeneous signal group was significantly higher than that in heterogeneous signal group [(60.3 ± 21.8)% vs (44.6±21.6)%, P < 0.05]. At 3, 6 and 12 months after HIFU, dysmenorrhea relief rates were higher in homogeneous signal group than in heterogeneous signal group, and the difference was statistically significant at 12 months (91.1% vs 76.8%, P < 0.05). The NPVR of heterogeneous hypointense group was higher than that of heterogeneous isointense group [(54.0±22.0) % vs (47.3± 22.9) %, P < 0.05]. At 6 months after HIFU, dysmenorrhea relief rate was significantly higher in heterogeneous hypointense group than in heterogeneous isointense group (91.5% vs 80.9%, P < 0.05). CONCLUSION The signal characteristics of adenomyosis on T₂WI are closely related with the outcome of HIFU ablation, and its efficacy is better for homogeneous than for heterogeneous adenomyosis, and better for heterogeneous hypointense adenomyosis than for heterogeneous isointense adenomyosis.
Female ; Humans ; Adenomyosis/pathology* ; Dysmenorrhea ; Cohort Studies ; Propensity Score ; High-Intensity Focused Ultrasound Ablation/methods* ; Treatment Outcome

INTRODUCTION: To date, there have only been 2 systematic reviews, and 1 systematic review and meta-analysis on high-intensity focused ultrasound (HIFU) for benign thyroid nodules. The present systematic review and meta-analysis seeks to evaluate the efficacy and safety of HIFU in the treatment of benign thyroid nodules. METHODS: Pubmed, Embase and Cochrane databases were searched for relevant studies from 1990 to 2021. Nine studies were included in the systematic review and 6 in the meta-analysis. Pooled volume reduction rates (VRRs) at 3, 6 and 24 months after HIFU were assessed. RESULTS: This systematic review and meta-analysis showed that pooled VRRs at 3, 6, and 24 months after HIFU were 42.14 (95% confidence interval [CI] 28.66-55.62, I2=91%), 53.51 (95% CI 36.78-70.25, I2=97%) and 46.89 (95% CI 18.87-74.92, I2=99%), respectively. There was significant heterogeneity in the pooled VRRs at 3, 6 and 24 months after HIFU. No studies recorded complete disappearance of the nodules. Common side effects included pain, skin changes and oedema. There were no major complications except for transient vocal cord paralysis and voice hoarseness (0.014%) and transient Horner syndrome (0.5%). CONCLUSION HIFU may be an effective and safe alternative treatment modality for benign thyroid nodules. Larger clinical trials with longer follow-up are needed to evaluate the effectiveness of HIFU in treating benign thyroid nodules.
High-Intensity Focused Ultrasound Ablation/adverse effects* ; Humans ; Pain ; Reconstructive Surgical Procedures ; Thyroid Nodule/surgery* ; Treatment Outcome

OBJECTIVE: We evaluated the clinical characteristics of patients who underwent surgery after high intensity focused ultrasound (HIFU) to treat uterine leiomyoma. METHODS: From June 2016 to September 2017, patients at our hospital who underwent HIFU to treat uterine leiomyoma prior to surgery were enrolled. All patients underwent pelvic magnetic resonance imaging (MRI) before and after HIFU. If 6 months had passed since the last pelvic MRI was performed, imaging was performed again before the operation. RESULTS: A total of 12 patients were analyzed. The median age was 45 (range, 28–51) years. The median body mass index was 24.9 (range, 18.1–29.2) kg/m2. The median size of the leiomyoma was 10.1 (range, 7.8–14.0) cm before HIFU, which changed to 8.75 (range, 5.9–14.8) cm after HIFU. The median size increased to 9.1 (range, 5.9–18.0) cm before the operation. Surgery was planned for several reasons, including an increase in the leiomyoma size (n=6), persistent symptoms (n=4), and newly developed lesion (n=2). The median interval between HIFU and surgery was 7 (range, 3–32) months. Ten of the 12 patients underwent laparoscopic surgery, while the others underwent laparotomy; 6 patients also underwent laparoscopic myomectomy, and 4 underwent hysterectomy. Histopathologic findings showed infarction-type necrosis surrounded by granulation tissue with the infiltration of lymphocytes and macrophages in all patients. CONCLUSION: Treatment of leiomyoma with operative procedures should be considered in selected patients with tumor size greater than 10 cm, multiple tumors, and persistent symptoms after HIFU treatment.
Body Mass Index ; Granulation Tissue ; High-Intensity Focused Ultrasound Ablation ; Humans ; Hysterectomy ; Laparoscopy ; Laparotomy ; Leiomyoma ; Lymphocytes ; Macrophages ; Magnetic Resonance Imaging ; Necrosis ; Surgical Procedures, Operative ; Ultrasonography

High-intensity focused ultrasound (HIFU) is a promising ablation technique for benign thyroid nodules. Current evidence has found good short- to medium-term outcomes, similar to those of better-established ablation techniques such as radiofrequency and laser ablation. The fact that it does not require insertion of a needle into the target makes HIFU a truly non-invasive treatment. Although it is not without risks, its low risk profile makes it an attractive alternative to surgery. There is much room for future development, starting from expanding the current indications to enhancing energy delivery. Relapsed Graves disease and papillary microcarcinoma are diseases that can benefit from HIFU treatment. Its role in the mediation of immune responses and synergistic effects with immunotherapy are promising in the fight against metastatic cancers.
Ablation Techniques ; Goiter, Nodular ; Graves Disease ; High-Intensity Focused Ultrasound Ablation ; Hyperthermia, Induced ; Immunotherapy ; Laser Therapy ; Needles ; Negotiating ; Thyroid Diseases ; Thyroid Gland ; Thyroid Nodule ; Ultrasonography ; Ultrasonography, Interventional

Magnetic resonance-guided focused ultrasound (MRgFUS) is an emerging new technology with considerable potential to treat various neurological diseases. With refinement of ultrasound transducer technology and integration with magnetic resonance imaging guidance, transcranial sonication of precise cerebral targets has become a therapeutic option. Intensity is a key determinant of ultrasound effects. High-intensity focused ultrasound can produce targeted lesions via thermal ablation of tissue. MRgFUS-mediated stereotactic ablation is non-invasive, incision-free, and confers immediate therapeutic effects. Since the US Food and Drug Administration approval of MRgFUS in 2016 for unilateral thalamotomy in medication-refractory essential tremor, studies on novel indications such as Parkinson's disease, psychiatric disease, and brain tumors are underway. MRgFUS is also used in the context of blood-brain barrier (BBB) opening at low intensities, in combination with intravenously-administered microbubbles. Preclinical studies show that MRgFUS-mediated BBB opening safely enhances the delivery of targeted chemotherapeutic agents to the brain and improves tumor control as well as survival. In addition, BBB opening has been shown to activate the innate immune system in animal models of Alzheimer’s disease. Amyloid plaque clearance and promotion of neurogenesis in these studies suggest that MRgFUS-mediated BBB opening may be a new paradigm for neurodegenerative disease treatment in the future. Here, we review the current status of preclinical and clinical trials of MRgFUS-mediated thermal ablation and BBB opening, described their mechanisms of action, and discuss future prospects.
Alzheimer Disease ; Blood-Brain Barrier ; Brain ; Brain Neoplasms ; Essential Tremor ; High-Intensity Focused Ultrasound Ablation ; Immune System ; Magnetic Resonance Imaging ; Microbubbles ; Models, Animal ; Neurodegenerative Diseases ; Neurogenesis ; Parkinson Disease ; Plaque, Amyloid ; Sonication ; Therapeutic Uses ; Transducers ; Ultrasonography ; United States Food and Drug Administration

OBJECTIVE: Although magnetic resonance guided focused ultrasound (MRgFUS) has been used as minimally invasive and effective neurosurgical treatment, it exhibits some limitations, mainly related to acoustic properties of the skull barrier. This study was undertaken to identify skull characteristics that contribute to optimal ultrasonic energy transmission for MRgFUS procedures.METHODS: For ex vivo skull experiments, various acoustic fields were measured under different conditions, using five non-embalmed cadaver skulls. For clinical skull analyses, brain computed tomography data of 46 patients who underwent MRgFUS ablations (18 unilateral thalamotomy, nine unilateral pallidotomy, and 19 bilateral capsulotomy) were retrospectively reviewed. Patients' skull factors and sonication parameters were comparatively analyzed with respect to the cadaveric skulls.RESULTS: Skull experiments identified three important factors related skull penetration of ultrasound, including skull density ratio (SDR), skull volume, and incidence angle of the acoustic rays against the skull surface. In clinical results, SDR and skull volume correlated with maximal temperature (Tmax) and energy requirement to achieve Tmax (p<0.05). In addition, considering the incidence angle determined by brain target location, less energy was required to reach Tmax in the central, rather than lateral targets particularly when compared between thalamotomy and capsulotomy (p<0.05).CONCLUSION: This study reconfirmed previously identified skull factors, including SDR and skull volume, for successful MRgFUS; it identified an additional factor, incidence angle of acoustic rays against the skull surface. To guarantee successful transcranial MRgFUS treatment without suffering these various skull issues, further technical improvements are required.
Acoustics ; Brain ; Cadaver ; High-Intensity Focused Ultrasound Ablation ; Humans ; Incidence ; Pallidotomy ; Retrospective Studies ; Skull ; Sonication ; Ultrasonics ; Ultrasonography

OBJECTIVE: To investigate the effects of on the acoustic characteristics of tumor tissue and how such acoustic changes affect the efficacy of high-intensity focused ultrasound (HIFU) ablation in nude mice. METHODS: Forty mice bearing human breast cancer cell (MDA-MB-231) xenograft were randomized into experimental group (=20) and control group (=20) for intravenous injection of suspension (200 μL, 4 × 10 cfu/mL) and PBS (200 μL) for 3 consecutive days, respectively. Before and at 3 and 7 days after the first injection, shear wave elastography was used to evaluate the hardness of the tumor tissue. On day 7 after the first injection, 10 mice from each group were sacrificed and the sound velocity and sound attenuation of the tumor tissues were measured. The changes in the collagen fibers in the tumors were evaluated using Masson staining, and neovascularization in the tumor was assessed with immunohistochemistry for platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31). The remaining 10 tumor-bearing mice in each group were subjected to HIFU ablation, and the ablation efficiency was evaluated by assessing the changes in irradiation gray values, coagulative necrosis volume, energy efficiency factor (EEF) and irradiation area and by pathological examination with HE staining. RESULTS: In the experimental group, the collagen fibers in the tumor tissues were strong and densely aligned, and the tumors contained fewer new blood vessels showing strip-or spot-like morphologies. In the control group, the collagen fibers in the tumors were thin and loosely arranged, and the tumors showed abundant elongated or round new blood vessels. colonized in the tumor 7 days after the injection, and the tumor hardness was significantly greater in the experimental group than in the control group (=0.01); the acoustic velocity (=0.001) and the acoustic attenuation (=0.000) of the tumor tissues were also greater in the experimental group. HIFU irradiation resulted in significantly greater changes in the gray scale of tumor (=0.0006) and larger coagulative necrosis volume (=0.0045) in the experimental group than in the control group, and the EEF was significantly smaller in the experimental group (=0.0134). CONCLUSIONS can cause changes in collagen fiber content, acoustic velocity and attenuation in the tumor tissue and reduce the EEF of HIFU irradiation, thereby improving the efficacy of HIFU irradiation.
Acoustics ; Animals ; Bifidobacterium ; pathogenicity ; Breast Neoplasms ; pathology ; Collagen ; Elasticity Imaging Techniques ; High-Intensity Focused Ultrasound Ablation ; Humans ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Random Allocation

To improve the cavitation-to-tissue ratio (CTR) of cavitation imaging during the treatment with high-intensity focused ultrasound (HIFU), we proposed a pulse inversion based broadband subharmonic cavitation imaging method (PIBSHI). Due to the fact that the subharmonic signal is a unique nonlinear vibration characteristic of cavitation bubbles, we extracted the broadband subharmonic signal to get a high-CTR cavitation imaging. The simulation showed that the subharmonic signal produced by cavitating bubbles with different sizes varied, and the signal was stronger than other subharmonics when the bubbles' resonant frequency was close to 1/2 subharmonic frequency. Further experiment results demonstrated that compared with the conventional B-mode images, broadband subharmonic cavitation imaging (BSHI) has improved the CTR by 5.7 dB, and the CTR was further improved by 3.4 dB when combined with pulse inversion (PI) technology. Moreover, when the bandwidth was set to 100%~140% of the 1/2 subharmonic frequency in PIBSHI, the CTR was the highest and the imaging showed the optimal quality. The study may have reference value for the development of precise cavitation imaging during HIFU treatment, and contribute to improve the safety of HIFU treatment.
High-Intensity Focused Ultrasound Ablation ; Ultrasonography

High-intensity focused ultrasound (HIFU) is a promising form of thermal ablation of benign thyroid nodules, but evidence supporting its use is scarce. The present review evaluated the efficacy and safety of single-session HIFU treatment of benign thyroid nodules. As reported in the literature, the extent of nodule shrinkage following treatment ranged from 48.8% to 68.8%. Like other forms of ablation, the shrinkage rate was greatest in the first 3-6 months, and the best responders were patients with small (≤10 mL) nodules. Complications were uncommon, but temporary vocal cord palsy occurred in 3%-4% of patients, and was related to the distance between the HIFU beam and the recurrent laryngeal nerve. Despite being safe and efficacious, a larger-scale prospective trial is required.
Ablation Techniques ; Goiter, Nodular ; High-Intensity Focused Ultrasound Ablation* ; Humans ; Hyperthermia, Induced ; Prospective Studies ; Recurrent Laryngeal Nerve ; Thyroid Gland* ; Thyroid Nodule* ; Ultrasonography ; Ultrasonography, Interventional ; Vocal Cord Paralysis

Magnetic resonance-guided focused ultrasound (MRgFUS) is a new emerging neurosurgical procedure applied in a wide range of clinical fields. It can generate high-intensity energy at the focal zone in deep body areas without requiring incision of soft tissues. Although the effectiveness of the focused ultrasound technique had not been recognized because of the skull being a main barrier in the transmission of acoustic energy, the development of hemispheric distribution of ultrasound transducer phased arrays has solved this issue and enabled the performance of true transcranial procedures. Advanced imaging technologies such as magnetic resonance thermometry could enhance the safety of MRgFUS. The current clinical applications of MRgFUS in neurosurgery involve stereotactic ablative treatments for patients with essential tremor, Parkinson's disease, obsessive-compulsive disorder, major depressive disorder, or neuropathic pain. Other potential treatment candidates being examined in ongoing clinical trials include brain tumors, Alzheimer's disease, and epilepsy, based on MRgFUS abilities of thermal ablation and opening the blood-brain barrier. With the development of ultrasound technology to overcome the limitations, MRgFUS is gradually expanding the therapeutic field for intractable neurological disorders and serving as a trail for a promising future in noninvasive and safe neurosurgical care.
Acoustics ; Alzheimer Disease ; Blood-Brain Barrier ; Brain Neoplasms ; Depressive Disorder, Major ; Epilepsy ; Essential Tremor ; High-Intensity Focused Ultrasound Ablation ; Humans ; Magnetic Resonance Imaging ; Nervous System Diseases ; Neuralgia ; Neurosurgery* ; Neurosurgical Procedures ; Obsessive-Compulsive Disorder ; Parkinson Disease ; Skull ; Thermometry ; Transducers ; Ultrasonography*