High-intensity Focused Ultrasound Research Articles

Effect of “T2-rim sign” related parameters on high-intensity focused ultrasound ablation of uterine fibroids

PurposeTo investigate the effect of “high-signal-intensity peripheral rim on T2-weighted MR images (T2-rim sign)” related parameters on non-perfused volume ratio (NPVR) after high-intensity focused ultrasound (HIFU) ablation of uterine fibroids. MethodsData from 616 patients with uterine fibroids treated with HIFU were retrospectively analyzed. Univariate and multivariate logistic regression was used to analyze the factors influencing the ablation effect. The effect of T2-rim sign on ablation parameters and results was also analyzed. Spearman correlation analysis was used to compare the correlation between coverage ratio, average thickness of T2-rim sign and NPVR in 207 cases of fibroids with T2-rim sign. ResultsThe presence of T2-rim sign was an independent risk factor affecting the ablation effect. The coverage ratio of T2-rim sign was negatively correlated with treatment efficiency (r = -0.174, p = 0.012) and NPVR (r = -0.186, p = 0.007), and positively correlated with energy efficiency factor (EEF) (r = 0.156, p = 0.024). The average thickness of T2-rim sign was positively correlated with treatment intensity (r = 0.203, p = 0.003) and negatively correlated with NPVR (r = -0.363, p < 0.001). There was a negative correlation between the average thickness of the T2-rim sign and NPVR in isointense fibroids (r = -0.484, p < 0.001). ConclusionThe presence of T2-rim sign increases the difficulty of ablation and reduces the ablation effect. In clinical practice, the presence and related parameters of T2-rim sign should be fully considered when screening for HIFU indications and formulating treatment plans.

Trends in focal therapy for localized prostate cancer: a bibliometric analysis from 2014 to 2023

Focal therapy, a minimally invasive strategy for localized prostate cancer, has been widely employed in the targeted treatment of localized prostate cancer in recent years. We analyzed 1312 relevant papers from the last decade using Web of Science Core Collection data. Our analysis covered countries, institutions, journals, authors, keywords, and references to offer a multifaceted perspective on the development of this field. The U.S. led in publications, contributing over half of the top 10 institutions. Emberton, M from University College London was the most published and cited author. “EUROPEAN UROLOGY” was the top journal by impact factor in 2022. Analysis of references and keywords suggests the prevalence of brachytherapy-related research, while high-intensity focused ultrasound (HIFU), cryotherapy, and irreversible electroporation (IRE) are emerging as new research focuses. Consequently, more high-quality evidence is necessary to evaluate the long-term effectiveness and safety of these novel therapeutic methods.

Characterizing Temperature-Dependent Acoustic and Thermal Tissue Properties for High-Intensity Focused Ultrasound Computational Modeling

High-intensity focused ultrasound (HIFU) thermal therapies utilize concentrated sound waves to ablate diseased tissue at precise locations within the body. Computational simulations of HIFU can assist clinicians by predicting the death of target tissues, identifying sensitive healthy tissues that risk thermal damage, and optimizing acoustic power delivery to minimize treatment times and maximize treatment efficacy. Accurate simulations require accurate inputs, and many computational solvers neglect property changes induced by tissue heating during treatment. Additionally, temperature-dependent tissue property data in the literature are relatively scarce. This study presents methodology for characterizing temperature-dependent acoustic and thermal properties in ex vivo porcine muscle tissue. From 20 – 50 °C, speed of sound is found to increase from approximately 1580 – 1620 m/s. The acoustic attenuation coefficient increases for 20 – 50 °C from 0.09 – 0.24 Np/cm at 0.5 MHz and 0.16 – 0.37 Np/cm at 1.6 MHz. Thermal conductivity and thermal diffusivity increase from 0.52 – 0.55 W/m °C and 0.147 – 0.158 mm2/s, respectively, over 20 – 60 °C. Specific heat capacity increases from approximately 3500 – 3800 J/kg °C, over 20 – 80 °C. Each property is consistent with data found in the literature, extends the literature to a larger temperature range, and, for acoustic properties, extends to unique frequencies. Temperature-dependent predictive models are also developed for each of the five properties. This study’s property measurement methodologies can be used to characterize other biological tissues, and the predictive models developed herein will facilitate future efforts in temperature-dependent modeling and uncertainty quantification of HIFU thermal therapies.

The Role of Whole-Gland and Focal Cryotherapy in Recurrent Prostate Cancer.

Prostate cancer is the most common non-cutaneous malignancy in men, with the majority of newly diagnosed patients eligible for active surveillance. Despite definitive treatment, a considerable percentage of men will experience biochemical recurrence and even regional and distant metastatic recurrence after radiation therapy or radical prostatectomy. Salvage prostatectomy, while oncologically effective, poses significant morbidity with poor functional outcomes. Salvage cryotherapy has emerged as a promising alternative for localized recurrence, demonstrating safety and efficacy. This review examines the oncologic and functional outcomes of whole-gland and focal salvage cryotherapy, including disease-free survival, cancer-specific survival, and overall survival. The crucial role of multiparametric prostate MRI and evolving role of next-generation PSMA-targeted PET imaging are also examined. The comparison of outcomes of cryotherapy to other salvage ablation modalities, such as high-intensity focused ultrasound (HIFU), is also explored.

Evaluation Effectiveness of Pre-Treatment Combined with Ultrasound-Guided Suction Curettage in Cesarean Scar Pregnancy: A Retrospective Cohort Study

Background: The objective of this study is to assess the effectiveness of ultrasound-guided suction curettage (UGSC) in conjunction with or without high-intensity focused ultrasound (HIFU) or uterine artery embolization (UAE) for the treatment of three distinct types of cesarean scar pregnancy (CSP). Methods: This was a retrospective study that included subjects diagnosed with CSP in a single tertiary referral centre from January 2015 to December 2020. UGSC associated with/without pretreatment was offered to CSP patients according to the location of pregnancy sac, the depth of implantation and the surrounding blood flowing. The data about baseline characteristics and outcome parameters were analyzed across the three groups. Results: The present study included 434 patients diagnosed with CSP. The majority were cured without severe complication except one case accepted blood transfusion. The baseline data from the three groups did not differ statistically. The UGSC group had the same successful rate of treating type I CSP with a shorter hospital stay (χ2 = 51.771, p = 0.000) compared to the HIFU or UAE groups. Type II CSP presented marked less blood loss (Z = –2.464, p = 0.014) and higher decline ration of beta-human chorionic gonadotropin (β-HCG) (Z = –4.728, p = 0.000) in HIFU group. Treatment success was high in patients with type III CSP in both the HIFU and UAE groups, but the rate of β-HCG decline was higher in the HIFU group (Z = –2.255, p = 0.024). Conclusions: This study suggests that UGSC is an effective and safe option for patients with low-risk CSP. HIFU or UAE combined with UGSC has higher efficacy in high-risk CSP. And HIFU may be superior in reducing bleeding and increasing the rate of β-HCG decline.

Protocol for high‐intensity focused ultrasound (HIFU) treatment of cutaneous neurofibromas

Protocol for high‐intensity focused ultrasound (HIFU) treatment of cutaneous neurofibromas

High-Intensity focused ultrasound linear array and system for dermatology treatment

Dermatological lesions are typically located just a few millimeters below the surface of the skin, which constrains the efficacy of optical-based therapeutic methods such as photothermal and photodynamic therapy due to limited therapeutic depth caused by optical scattering. As an alternative, high-intensity focused ultrasound (HIFU) has been explored for its potential to treat a variety of dermatological conditions because it offers greater flexibility in terms of treatment depth. Since dermatological lesions have a small thickness ranging from 1.5 to 2.0 mm, high-frequency ultrasound (3–10 MHz or higher) is preferred as the focal area is proportional to the operating frequency. However, due to the difficulty in fabricating HIFU array transducers at this frequency range, the majority of HIFU treatments for dermatology rely on single element transducers. Despite the advantages of HIFU, single-element-based HIFU systems are limited in prevalent use for dermatology treatment due to their fixed focal length and mechanical movement for treatment, which can be time-consuming and unsuitable for treating multiple lesions. To address this, we present a newly developed HIFU linear array and 128-channel driving electronics specifically designed for dermatology treatment. This array consists of 128 elements, has a center frequency of 3.7 MHz, an elevation focal length of 28 mm, and an F-number of 1.27 in the elevation direction. The array has a footprint of 71.6 mm by 22 mm. Experiments using a tissue-mimicking phantom have demonstrated that the HIFU linear array and system are capable of transmitting sufficient ultrasound energy to create coagulation inside the phantom.

Optimizing high-intensity focused ultrasound-induced immunogenic cell-death using passive cavitation mapping as a monitoring tool

Over the past decade, ultrasound (US) has gathered significant attention and research focus in the realm of medical treatments, particularly within the domain of anti-cancer therapies. This growing interest can be attributed to its non-invasive nature, precision in delivery, availability, and safety. While the conventional objective of US-based treatments to treat breast, prostate, and liver cancer is the ablation of target tissues, the introduction of the concept of immunogenic cell death (ICD) has made clear that inducing cell death can take different non-binary pathways through the activation of the patient's anti-tumor immunity. Here, we investigate high-intensity focused ultrasound (HIFU) to induce ICD by unraveling the underlying physical phenomena and resulting biological effects associated with HIFU therapy using an automated and fully controlled experimental setup. Our in-vitro approach enables the treatment of adherent cancer cells (B16F10 and CT26), analysis for ICD hallmarks and allows to monitor and characterize in real time the US-induced cavitation activity through passive cavitation detection (PCD). We demonstrate HIFU-induced cell death, CRT exposure, HMGB1 secretion and antigen release. This approach holds great promise in advancing our understanding of the therapeutic potential of HIFU for anti-cancer strategies.

Reconfigurable ultrasound focusing effect through acoustic barriers

The low transmission efficiency of ultrasonic waves in waveguides of a high acoustic impedance (referred to as dense materials), due to the impedance mismatch between the background media and the dense materials, poses a significant obstacle to practical applications of high-intensity focused ultrasound (HIFU) such as ultrasound therapy or medical imaging. To address this challenge, we present an inverse optimization scheme for fabrication of novel acoustic meta-lenses, enabling strengthened penetration and enhanced focusing of ultrasonic waves when the waves traverse barriers. Both simulation and experiment validate the effectiveness of the developed meta-lenses which are annexed to hemispherical plates, and demonstrate an enhanced transmission of the sound power by an order of magnitude compared to a scenario without the use of the meta-lens. The focal distance is reconfigurable by adjusting the geometric parameters of the meta-lenses. The proposed design philosophy is not restricted by the complexity of the target structures, and it allows the ultrasonic waves to pass through acoustic barriers with a non-uniform thickness yet maintaining efficient wave focusing. This study holds appealing applications in HIFU-enabled ultrasound imaging and therapy.

Clinical efficacy and safety of high-intensity focused ultrasound combined with ultrasound-guided suction curettage at different time intervals for Cesarean scar pregnancy: a retrospective study

Objective This study aims to assess the clinical efficacy and safety of combining high-intensity focused ultrasound (HIFU) with ultrasound-guided suction curettage for the treatment of cesarean scar pregnancy (CSP) at different time intervals. Methods A total of 115 CSP patients were enrolled and divided into two groups based on the time between HIFU ablation and suction curettage. Group A (n = 50) underwent suction curettage 24-48 h after HIFU ablation, while Group B (n = 65) had suction curettage within 6 h of HIFU ablation. The study compared and analyzed the clinical characteristics, treatment success rates, and intraoperative hemorrhage during ultrasound-guided suction curettage. Results The demographic characteristics of the two groups were similar, with no statistically significant differences observed in HIFU parameters, treatment success rates, blood loss, the use of Foley catheter balloons, or hospital expenses (p > 0.05). Importantly, suction curettage performed within 6 h after HIFU ablation resulted in shorter hospitalization times compared to suction curettage performed 24-48 h after the ablation (p < 0.05). Conclusions Suction curettage within 6 h after HIFU ablation is an effective, safe, and cost-efficient treatment for patients diagnosed with CSP.

Complications leading to hospitalisation 12 months after brachytherapy or high-intensity focused ultrasound for localized prostate cancer: French national from the PMSI-MCO data, 2019 and 2020

Background and purposeProstate cancer can be treated using either brachytherapy or high-intensity focused ultrasound (HIFU), which are less invasive than surgery. Although both approaches have proved effective, few studies have looked at the specific causes of hospitalisation due to complications, following these treatments. The aim of this study was to compare the causes of hospitalisation. MethodsA retrospective study was carried out examining the records of patients who had undergone brachytherapy or HIFU treatment for localized prostate cancer in 2019 and 2020, using the French national database: Programme de Médicalisation du Système d’Information − Médecine, Chirurgie, Obstétrique (PMSI-MSO). Data on post-treatment hospitalisations were analyzed. Results3090 patients were included in the study, of whom 1699 underwent brachytherapy and 1391 HIFU procedures. The incidence of hospitalisation was much higher after HIFU than after brachytherapy, notably due to a higher rate of obstructive complications (12.94% vs 2.77%). Large differences were also found for infections (8.20% vs 1.47%) and bleeding (6.76% vs 2.18%) leading to hospitalisation. Most of the complications occurred at the initial hospitalization: 12% for HIFU, and 1.4% for brachytherapy. ConclusionComplications were more frequent after treatment with HIFU than with brachytherapy in the year following treatment for localized prostate cancer. Further the causes of hospitalisation differed between the two treatments. These differences need to be taken into account in the therapeutic strategy, as well as in post-treatment management.

MRI accuracy for recurrence after partial gland ablation with HIFU for localized prostate cancer. A systematic review and meta-analysis.

Prostate cancer remains the most frequently diagnosed cancer among men. High-Intensity Focused Ultrasound (HIFU) has emerged as a thermal ablative technique for partial-gland-ablation (PGA), aiming to minimize collateral damage while maximizing tumor control. Monitoring after HIFU PGA relies on serial PSA testing, multiparametric-MRI, and biopsies. The diagnostic accuracy of MRI for clinically-significant cancer(csPCa) recurrence is challenging. This systematic review and meta-analysis aim to evaluate the accuracy of MRI in detecting early recurrence of localized prostate cancer following HIFU PGA. Adhering to PRISMA guidelines, a comprehensive literature search was conducted until May 8th 2024 using MEDLINE and Scopus. The inclusion criteria encompassed randomized controlled trials and cohort studies involving men diagnosed with localized prostate cancer who had as primary treatment HIFU PGA. The primary outcome measures included the sensitivity, specificity, positive-predictive value (PPV), and negative-predictive value (NPV) of MRI for csPCa(ISUP ≥ 2) based on biopsy results. We pooled data from studies with sufficient csPCa and csPCa-free patients (≥5) post HIFU for statistical analysis. Fifteen studies meet the inclusion criteria, encompassing 1093 patients and 12 studies were eligible for meta-analysis. MRI sensitivity in detecting clinically-significant prostate cancer (csPCa) recurrence post HIFU PGA varied widely (0-89%), with a pooled sensitivity of 0.52 (95% CI:0.36-0.68). Specificity ranged from 44% to 100%, with a pooled specificity of 0.81 (95% CI:0.68-0.91). The pooled NPV was 0.82 (95% CI:0.72-0.90), and the pooled PPV was 0.50 (95% CI:0.35-0.65). Three studies reported in-field diagnostic performance with sensitivities ranging from 0.42 to 0.80 and specificities from 0.45 to 0.97. MRI accuracy for clinically-significant recurrence after partial gland ablation with HIFU for localized prostate cancer shows low diagnostic performance in the treated lobe with pooled sensitivity of 0.52 (95% CI:0.36-0.68) and specificity of 0.81 (95% CI:0.68-0.91). Limits of this review include the low number of studies reporting about site of recurrence in or out of the treated lobe.

Evaluation of the therapeutic efficacy of high-intensity focused ultrasound ablation combined with different drugs in the treatment of adenomyosis

Objectives To observe the therapeutic efficacy of high-intensity focused ultrasound (HIFU) combined with different pharmacological treatments for adenomyosis. Materials and methods A total of 126 patients with adenomyosis who underwent HIFU combined with pharmacological treatment were retrospectively reviewed. Patients were treated with either dienogest (DNG) (Group A, N = 38) or GnRH-a (Group B, N = 88) for three months after HIFU, and received levonorgestrel-releasing intrauterine systems (LNG-IUS) at the end of the third month. Visual Analog Scale (VAS) and Pictorial Blood Loss Assessment Chart (PBAC) scores were used for evaluating symptom improvement. Results After propensity score matching (1:2), 38 patients were included in Group A and 76 in Group B. All patients showed significant improvement in VAS and PBAC scores after HIFU, but the PBAC score of Group A was significantly higher than that of patients in Group B at 18 months [11.50 (1.00, 29.50) vs. 0.00 (0.00, 16.50), p < 0.01] and 24 months [4.00 (0.25, 27.75) vs. 0.00 (0.00, 12.75), p = 0.04] after HIFU. Furthermore, patients in Group B had a greater uterine volume reduction at 24 months after HIFU than that of patients in Group A [51.00 (27.00, 62.00) vs. 30.00 (17.00, 42.75, p = 0.02)]. However, the adverse effects in Group A were lower than those in Group B [7 (15.79) vs. 35 (46.05), p < 0.01]. No significant difference was observed in the recurrence rate between the two groups. Conclusions HIFU combined with DNG and LNG-IUS is a safe and effective treatment for patients with adenomyosis.

Microbubbles bound to drug-eluting beads enable ultrasound imaging and enhanced delivery of therapeutics

Transarterial chemoembolization (TACE) is an image-guided minimally invasive treatment for liver cancer which involves delivery of chemotherapy and embolic material into tumor-supplying arteries to block blood flow to a liver tumor and to deliver chemotherapy directly to the tumor. However, the released drug diffuses only less than a millimeter away from the beads. To enhance the efficacy of TACE, the development of microbubbles electrostatically bound to the surface of drug-eluting beads loaded with different amounts of doxorubicin (0–37.5 mg of Dox/mL of beads) is reported. Up to 400 microbubbles were bound to Dox-loaded beads (70–150 microns). This facilitated ultrasound imaging of the beads and increased the release rate of Dox upon exposure to high intensity focused ultrasound (HIFU). Furthermore, ultrasound exposure (1 MPa peak negative pressure) increased the distance at which Dox could be detected from beads embedded in a tissue-mimicking phantom, compared with a no ultrasound control.

NnU-Net based segmentation and 3D reconstruction of uterine fibroids with MRI images for HIFU surgery planning

High-Intensity Focused Ultrasound (HIFU) ablation represents a rapidly advancing non-invasive treatment modality that has achieved considerable success in addressing uterine fibroids, which constitute over 50% of benign gynecological tumors. Preoperative Magnetic Resonance Imaging (MRI) plays a pivotal role in the planning and guidance of HIFU surgery for uterine fibroids, wherein the segmentation of tumors holds critical significance. The segmentation process was previously manually executed by medical experts, entailing a time-consuming and labor-intensive procedure heavily reliant on clinical expertise. This study introduced deep learning-based nnU-Net models, offering a cost-effective approach for their application in the segmentation of uterine fibroids utilizing preoperative MRI images. Furthermore, 3D reconstruction of the segmented targets was implemented to guide HIFU surgery. The evaluation of segmentation and 3D reconstruction performance was conducted with a focus on enhancing the safety and effectiveness of HIFU surgery. Results demonstrated the nnU-Net’s commendable performance in the segmentation of uterine fibroids and their surrounding organs. Specifically, 3D nnU-Net achieved Dice Similarity Coefficients (DSC) of 92.55% for the uterus, 95.63% for fibroids, 92.69% for the spine, 89.63% for the endometrium, 97.75% for the bladder, and 90.45% for the urethral orifice. Compared to other state-of-the-art methods such as HIFUNet, U-Net, R2U-Net, ConvUNeXt and 2D nnU-Net, 3D nnU-Net demonstrated significantly higher DSC values, highlighting its superior accuracy and robustness. In conclusion, the efficacy of the 3D nnU-Net model for automated segmentation of the uterus and its surrounding organs was robustly validated. When integrated with intra-operative ultrasound imaging, this segmentation method and 3D reconstruction hold substantial potential to enhance the safety and efficiency of HIFU surgery in the clinical treatment of uterine fibroids.

How safe is high-intensity focused ultrasound? An intriguing solution for obstetric and gynecological diseases: A systematic review.

High-intensity focused ultrasound (HIFU) is a non-surgical and noninvasive treatment modality that depends on external ultrasound energy sources that induce focused mass ablation and protein degeneration in the treatment area via thermal energy penetration under the intact skin. We aim in our study to collectively evaluate the safety of HIFU for the treatment of different obstetric and gynecological diseases in the literature. We searched PubMed, Scopus, and Science Direct databases, without restriction on date or language, from the inception of these databases until January 20, 2024. We also examined the references of the included studies in the Mendeley archive for eligible articles. We found a total of 706 studies. After the screening and selection process, 56 participants were included. Our dichotomous outcomes were pooled in our single-arm meta-analysis as risk ratio (RR) and with 95% confidence interval (CI) while our continuous outcomes were pooled as mean change and 95% CIs. Fixed- or random-effects models were applied depending on the heterogeneity detected. Our systematic review and meta-analysis included 56 studies including 11.740 patients. Depending on the Society of Interventional Radiology (SIR) classification for adverse effects. The results of this meta-analysis for the type A category that did not require clinical intervention found that pain in the treatment site estimated RR with 95% CI: 0.61 (0.33, 0.89), abnormal vaginal discharge 0.16 (0.073, 0.24), low-grade fever (<38 °C) 0.005 (0.002, 0.009). Sensory abnormalities of the lower limbs were examined in 3390 individuals and observed in only 19 patients who experienced gradual relief of symptoms within one month after treatment. Regarding SIR type B, 99 of a total of 6.437 patients had small vesicles and superficial burns with pooled RR and 95% CI: 0.012 (0.007, 0.018). In terms of groin or perianal and lower abdominal pain, our RRs with 95% CIs were 0.1 (0.067, 0.13) and 0.38 (0.25, 0.51). However, vaginal bleeding was detected in only 32 out of a total of 3.017. Major adverse events like lumber disc herniation, thrombocytopenia, and renal failure, were unmentionable. Additionally, our included studies did not record any deaths. HIFU, either alone or in combination with oxytocin or any other enhancing agent, is safe for patients with different gynecological and obstetric diseases. In terms of efficacy, it showed promising results compared with traditional treatment lines. To our knowledge, we are the first and most comprehensive meta-analysis in the literature that has studied the different safety outcomes related to HIFU as a treatment modality for different obstetric and gynecological diseases with a very large sample size, making our evidence strong and less attributed to errors.

Local salvage therapies in patients with radio-recurrent prostate cancer following external beam radiotherapy: a systematic review and meta-analysis.

To date, radio-recurrent prostate cancer (PCa) ranks as the fourth most common urological malignancy when considering the number of men with localized PCa who undergo radiation treatment and subsequently experience a biochemical recurrence. This systematic review aimed to summarize available evidence about the outcomes of local salvage strategies in patients with local PCa recurrence following primary external-beam radiation therapy (EBRT). We conducted a comprehensive bibliographic search on MEDLINE, Scopus, and Web of Science Core Collection databases in October 2023 to identify studies published in the last 20 years evaluating outcomes of local salvage procedures in patients with locally radio-recurrent PCa following EBRT. The meta-analysis was performed using ProMeta 3 software when two or more studies reported the same outcome. The effect size (ES) was estimated using rates reported with its 95% confidence interval (CI). Overall, 28 studies (6 prospective and 22 retrospective) including 1544 patients were included in the review. Two-year recurrence-free survival (RFS) was 84.0% (95% CI: 67.0-93.0%), 69.0% (95% CI: 42.0-87.0%), 58.0% (95% CI: 43.0-71.0%), and 45% (95% CI: 38.0-52.0%), for patients undergoing brachytherapy (BT), EBRT, Cryotherapy and High-Intensity Focused Ultrasound (HIFU), respectively. After salvage prostatectomy, RFS ranged from 75% to 78.5% at a median follow-up ranging from 18 to 35 months. Estimates for severe gastrointestinal toxicity were 2%, 3%, 3%, 4%, and 11% following cryotherapy, BT, HIFU, EBRT, and salvage radical prostatectomy, respectively. In patients who underwent EBRT as primary treatment, prostate salvage re-irradiation through BT or EBRT represents the modality providing the best balance between efficacy and safety. Unfortunately, due to the low level of evidence, strong recommendations regarding the choice of any of these techniques cannot be made.

Discussion on the upper limit of HIFU sound pressure measurement based on laser interferometry

Abstract High intensity focused ultrasound (HIFU) technology is a non-invasive treatment technique that can achieve non-invasive treatment of tumors and other diseases. The accuracy of HIFU sound pressure is crucial for the clinical efficacy and safety of HIFU treatment. The sound pressure measurement technology based on laser interferometry is the recommended method for ICE TC87, which has the advantages of high measurement accuracy and good traceability, and is therefore widely adopted as the new generation of sound pressure standards. However, the upper limit of the laser interferometric HIFU sound pressure measurement currently reported is about 10 MPa, which is far lower than the actual sound pressure of HIFU technology. In response to this issue, the upper limit of HIFU sound pressure measurement was discussed from the perspective of laser interference systems. The mathematical relationship between the HIFU sound pressure and the optical and electrical signals of the laser interference system under the condition of nonlinear sound field is established. The mathematical analysis of HIFU sound pressure requirements for the bandwidth of laser interference systems is discussed. Using experimental and numerical simulation methods, the effect of HIFU sound pressure on the bandwidth of a laser interference system under nonlinear acoustic field conditions was studied.

Real-World Experience Using a Multi-Modality System using Intense Pulsed Light, Radiofrequency Microneedling, High-Intensity Focused Ultrasound, or Thermal Radiofrequency, 808, HIFU for Skin Rejuvenation Treatment.

Medical aesthetic procedures for facial rejuvenation with laser and energy-based devices (EBDs) are rapidly increasing. The following cases highlight real-life experience using a multi-modality system with various handpieces that combine intense pulsed light (IPL), laser hair removal (808 diode), high-intensity focused ultrasound (HIFU), radiofrequency microneedling (RFM), and thermal radiofrequency (RF) for antiaging and rejuvenation treatment. Laser and RFM treatments may improve skin conditions by inducing cutaneous changes that remodel the skin matrix. Six physicians who treat patients for skin rejuvenation reported on clinical cases from their practice using a multi-modality system with various handpieces. During the meeting, the advisors discussed 15 cases and agreed to select seven patients with different ages and skin phototypes receiving various treatments for photodamage of the face, neck, and décolleté. The advisors discussed why they selected the case, previous treatment, type of treatment, results, and clinical pearls. Sharing best practices in medical aesthetics using combination treatments on a single multi-modality energy-based device such as laser and MRF for facial, neck, and chest skin may support healthcare providers treating patients for skin rejuvenation to improve clinical outcomes.

High-intensity Focused Ultrasound Ablation Combined with Hysteroscopy for the Treatment of Uterine Arteriovenous Fistula Associated with Retained Products of Conception: A Prospective Cohort Study

To evaluate the efficacy of combining high-intensity focused ultrasound (HIFU) ablation with hysteroscopic removal of retained products of conception in the presence of a uterine arteriovenous fistula (UAVF). Prospective cohort study SETTING: Tertiary hospital. 17 patients with UAVF and retained products of conception. HIFU ablation combined with hysteroscopic removal of retained products of conception RESULTS: All patients presented with irregular vaginal bleeding following pregnancy termination and not responsive to medical treatment. Patients were confirmed to have a UAVF along with concurrent intrauterine residue using three-dimensional color Doppler ultrasonography, uterine angiography, or pelvic-enhanced magnetic resonance imaging; and demonstrated a poor response to medical treatment. Under real-time ultrasound guidance, HIFU was used to ablate the arteriovenous malformation region. Patients underwent hysteroscopic removal of retained products of conception; the removed tissue was subjected to pathological examination. All patients underwent monthly uterine color Doppler ultrasound examinations and menstrual status follow-up within 3 months postoperatively and showed normal menstrual recovery without signs of arteriovenous malformations on ultrasonography. Pathological examination of the tissues removed during hysteroscopic clearance revealed characteristics consistent with pregnancy, with abnormal blood vessels in some tissues. All patients experienced normal menstrual recovery postoperatively, without intrauterine adhesions. Combining HIFU ablation with postoperative hysteroscopic surgery effectively treats pregnancy related UAVF with minimal complications, preserves fertility; it offers an additional treatment option for patients wanting future fertility.