Modeling the interference between shear and longitudinal waves under high intensity focused ultrasound propagation in bone.

Modeling the interference between shear and longitudinal waves under high intensity focused ultrasound propagation in bone. Phys Med Biol. 2018 Dec 04;63(23):235024 Authors: Modena D, Baragona M, Bošnački D, Breuer BJT, Elevelt A, Maessen RTH, Hilbers PAJ, Ten Eikelder HMM Abstract Magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) is a noninvasive thermal technique that enables rapid heating of a specific area in the human body. Its clinical relevance has been proven for the treatments of soft tissue tumors, like uterine fibroids, and for the treatments of solid tumors in bone. In MR-HIFU treatment, MR-thermometry is used to monitor the temperature evolution in soft tissue. However, this technique is currently unavailable for bone tissue. Computer models can play a key role in the accurate prediction and monitoring of temperature. Here, we present a computer ray tracing model that calculates the heat production density in the focal region. This model accounts for both the propagation of shear waves and the interference between longitudinal and shear waves. The model was first compared with a finite element approach which solves the Helmholtz equation in soft tissue and the frequency-domain wave equation in bone. To obtain the temperature evolution in the focal region, the heat equation was solved using the heat production density generated by the raytracer as a heat source. Then, we investigated the role of the interaction bet...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research

Related Links:

Authors: Rezaeian M, Sedaghatkish A, Soltani M Abstract Although intraperitoneal chemotherapy (IPC) has been suggested as a promising method for the management of peritoneal dissemination (PD) of ovarian or colorectal cancers, the actual clinical use of this method has been restricted due to such problems as poor drug penetration into the tumor and high side effects. It is, therefore, necessary to develop new strategies to improve the efficacy of this approach. In the present work, a new strategy is proposed based on intraperitoneal (IP) injection of thermosensitive liposomal doxorubicin (TSL-Dox) with triggered re...
Source: Drug Delivery - Category: Drugs & Pharmacology Tags: Drug Deliv Source Type: research
ConclusionsUltrasound thermometry during laser ablation of biological tissue based on elastography shows an abrupt output change at temperatures  >  55–60 °C. This issue can have a relevant clinical impact, considering tumor necrosis when temperature crosses 55 °C to define the boundary of damaged volume.Graphic abstract
Source: Journal of Ultrasound - Category: Radiology Source Type: research
Authors: Zhong B, Li LK, Deng D, Du JT, Liu YF, Liu F, Liu SX Abstract BACKGROUND High-intensity focused ultrasound (HIFU) and plasma radiofrequency ablation (PRA) have been used to treat recurrent allergic rhinitis (AR); however, there is a lack of literature comparing the efficacy of these 2 methods. We assessed and compared the therapeutic effects of HIFU and PRA on recurrent AR. MATERIAL AND METHODS We enrolled 66 patients with recurrent AR at West China Hospital of Sichuan University. Visual analogue score (VAS), pain score, rhinoconjunctivitis quality of life questionnaire (RQLQ), and nasal endoscopy were per...
Source: Medical Science Monitor - Category: Research Tags: Med Sci Monit Source Type: research
The objective of this study was to evaluate the safety and treatment effectiveness of this new protocol. The treat ment outcomes of 9 consecutive patients (study group) were compared with those of 51 patients (control group) who had been randomized (1:1) to receive HIFU (n = 24) or uterine artery embolization ([UAE] n = 27).
Source: Ultrasound in Medicine and Biology - Category: Radiology Authors: Tags: Original Contribution Source Type: research
Abstract Although nanocarriers containing perfluorocarbon (PFC) have been widely investigated as an ultrasound (US) imaging agent and a high intensity focused ultrasound (HIFU) agent, these carriers have suffered from low stability and biocompatibility limiting their further biomedical applications. Here, we developed surface crosslinked polymer nanodroplets as a HIFU therapeutic agent guided by bimodal photoacoustic (PA) and US imaging. Pluronic F127 was reacted with 4-nitrophenyl chloroformate (NPC) and mixed with naphthalocyanine (Nc) in dichloromethane, which was added into the aqueous solution of amine-functi...
Source: Biomacromolecules - Category: Biochemistry Authors: Tags: Biomacromolecules Source Type: research
Conclusion: HIFU followed by USg-D&C is an effective and safe treatment for patients with CSP who wish to conceive. Prospective multi-center studies with larger sample sizes and longer follow-up periods are needed to compare this treatment with others. PMID: 31466485 [PubMed - in process]
Source: International Journal of Hyperthermia - Category: Internal Medicine Tags: Int J Hyperthermia Source Type: research
Conclusion: HIFU has the therapeutic potential to treat BCG-infected tissues in rats. We theorize that a combination of mechanical, cavitation, and thermal effects most efficiently inactivate BCG bacteria via HIFU. This study is expected to provide a bio-plausible basis for a noninvasive and effective treatment for tuberculosis. PMID: 31464154 [PubMed - in process]
Source: International Journal of Hyperthermia - Category: Internal Medicine Tags: Int J Hyperthermia Source Type: research
Medical device companies attempting to market a new treatment in the U.S. often make the erroneous assumption that winning FDA approval is the final destination, and success is theirs. In fact, going through the regulatory process is only the halfway point. The grueling path from FDA approval to reimbursement is like a treacherous walk through Death Valley and many companies don’t make it through. In this case study, I discuss the trials and triumphs of bringing robotic high intensity focused ultrasound (HIFU), a non-invasive procedure for localized prostate cancer, to the U.S.&Aci...
Source: MDDI - Category: Medical Devices Authors: Tags: Regulatory and Compliance Business Source Type: news
To report our intermediate outcomes of the use of focal ablation for treating significant unilateral prostate cancer. This technique was adopted in our centre ten years ago. With improving diagnostic accuracy of index prostate cancer lesions and a low side-effect profile, use of focal HIFU ablation is increasing.
Source: Urology - Category: Urology & Nephrology Authors: Source Type: research
The company EXO Imaging out of Redwood City, CA recently emerged from stealth mode to announce the development of a novel technology called Piezoelectric Micromachined Ultrasonic Transducers (pMUT) for ultrasound imaging. EXO Imaging is bringing toge...
Source: Medgadget - Category: Medical Devices Authors: Tags: Materials Radiology ultrasound Source Type: blogs
More News: Biology | Computers | High Intensity Focused Ultrasound Therapy | Physics | Ultrasound