Purpose: To integrate a high intensity focused ultrasound (HIFU) transducer with an MR receiver coil for endocavitary MR-guided thermal ablation of localized pelvic lesions.
Materials And Methods: A hollow semicylindrical probe (diameter 3.2 cm) with a rectangular upper surface (7.2 cm x 3.2 cm) was designed to house a HIFU transducer and enable acoustic contact with an intraluminal wall. The probe was distally rounded to ease endocavitary insertion and was proximally tapered to a 1.5-cm diameter cylindrical handle through which the irrigation tubes (for transducer cooling) and electrical connections were passed. MR compatibility of piezoceramic and piezocomposite transducers was assessed using gradient-echo (GRE) sequences. The radiofrequency (RF) tuning of identical 6.5 cm x 2.5 cm rectangular receiver coils on the upper surface of the probe was adjusted to compensate for the presence of the conductive components of the HIFU transducers. A T1-weighted (T1-W) sliding window dual-echo GRE sequence monitored phase changes in the focal zone of each transducer. High-intensity (2400 W/cm(-2)), short duration (<1.5 seconds) exposures produced subtherapeutic temperature rises.
Results: For T1-W images, signal-to-noise ratio (SNR) improved by 40% as a result of quartering the conductive surface of the piezoceramic transducer. A piezocomposite transducer showed a further 28% improvement. SNRs for an endocavitary coil in the focal plane of the HIFU trans-ducer (4 cm from its face) were three times greater than from a phased body array coil. Local shimming improved uniformity of phase images. Phase changes were detected at subtherapeutic exposures.
Conclusion: We combined a HIFU transducer with an MR receiver coil in an endocavitary probe. SNRs were improved by quartering the conductive surface of the piezoceramic. Further improvement was achieved with a piezocomposite transducer. A phase change was seen on MR images during both subtherapeutic and therapeutic HIFU exposures.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/jmri.20833 | DOI Listing |
J Orthop Surg Res
January 2025
School of Public Health and Preventive Medicine, Musculoskeletal Health and Wiser Health Care Units, Monash University, Melbourne, VIC, Australia.
Objectives: To determine the prevalence of acromioclavicular (AC) joint and subacromial space imaging abnormalities in asymptomatic adults, with a secondary objective of comparing findings between asymptomatic and symptomatic shoulders within the same study populations.
Methods: We conducted a systematic review of studies examining shoulder imaging abnormalities detected by X-ray, ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in asymptomatic adults (PROSPERO registration CRD42018090041). This report focuses on AC joint and subacromial space abnormalities.
J Imaging Inform Med
January 2025
Independent Consultant, Kirkland, WA, USA.
Point-of-care ultrasound (POCUS) has emerged as a standard of care across a variety of healthcare settings due to its ability to provide critical clinical information and as well as procedural guidance to clinicians directly at the bedside. Implementation of enterprise imaging (EI) strategies is needed such that POCUS images can be appropriately captured, indexed, managed, stored, distributed, viewed, and analyzed. Because of its unique workflow and educational requirements, reliance on traditional order-based workflow solutions may be insufficient.
View Article and Find Full Text PDFUrol Oncol
January 2025
Research Department, Urovallarta Medical Center, Puerto Vallarta, Mexico.
Background: Multiparametric MRI (Mp-MRI) is a key tool to screen for Prostate Cancer (Pca) and Clinically Significant Prostate Cancer (CsPca). It primarily includes T2-Weighted imaging (T2w), diffusion-weighted imaging (DWI), and Dynamic Contrast-Enhanced imaging (DCE). Despite its improvements in CsPca screening, concerns about the cost-effectiveness of DCE persist due to its associated side effects, increased cost, longer acquisition time, and limitations in patients with poor kidney function.
View Article and Find Full Text PDFJ Med Internet Res
December 2024
University Clinic for Interdisciplinary Orthopedic Pathways (UCOP), Elective Surgery Center, Silkeborg Regional Hospital, Silkeborg, Denmark.
Background: Access to clear and comprehensible health information is crucial for patient empowerment, leading to improved self-care, adherence to treatment plans, and overall health outcomes. Traditional methods of information delivery, such as written documents and oral communication, often result in poor memorization and comprehension. Recent innovations, such as animation videos, have shown promise in enhancing patient understanding, but comprehensive investigations into their effectiveness across various health care settings are lacking.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China. Electronic address:
In this study, the improvement mechanism of yeast proteins (YPs) with the ultrasonic and pH shifting treatment on the emulsion stability was investigated through the solubility, protein structure and interface behavior of YPs. Compared with only pH shifting or ultrasound treatment, the solubility of YPs with the combined treatment of ultrasonic and pH shifting was increased significantly. The soluble protein content of pH-U400 reached 85.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!