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Pulsed radiofrequency

Yasmin Elkhashab, Andrew Ng
PURPOSE OF REVIEW: Coccygodynia is pain within the coccyx area. The diagnosis is made clinically with symptoms of pain in the coccyx region and worsening pain in sitting position. The initial treatment is conservative therapy. For patients who do not respond to conservative therapies, there are further interventions available. This includes local injection of local anesthetics and steroids, neurolysis of sacral nerve roots, caudal epidural block, pulse radiofrequency (PRF), intra-rectal massage and manipulation, ganglion impar block, levator ani massage and stretching, coccyx manipulation, and coccygectomy...
March 19, 2018: Current Pain and Headache Reports
Peter Howe
Proton NMR spectra are usually acquired using deuterated solvents but in many cases it is necessary to obtain spectra on samples in protonated solvents. In these cases, the intense resonances of the protonated solvents need to be suppressed to maximise sensitivity and spectral quality. A wide range of highly effective solvent suppression methods have been developed, but additional measures are needed to suppress the13 C satellites of the solvent. Because the satellites represent 1.1% of the original solvent signal, they remain problematic if unsuppressed...
March 19, 2018: Analytical Chemistry
H T Sun, M Xu, G L Chen, J He
Objective: This study aimed to compare dexmedetomidine with remifentanil for conscious sedation in patients undergoing radiofrequency ablation of hepatocellular carcinoma. Methods: Sixty patients, who were aged 41 to 73 years with American Society of Anesthesiologists (ASA) physical status Ⅰ-Ⅱ, and scheduled for elective radiofrequency ablation of hepatocellular carcinoma under conscious sedation in National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, from January 2014 to June 2016, were allocated randomly to receive dexmedetomidine maintenance regimen(group D, n =30)or remifentanil maintenance regimen(group R, n =30)by random digital table...
February 27, 2018: Zhonghua Yi Xue za Zhi [Chinese medical journal]
Zhiqiang Li, John P Karis, James G Pipe
PURPOSE: 2D turbo-spin-echo (TSE) is widely used in the clinic for neuroimaging. However, the long refocusing radiofrequency pulse train leads to high specific absorption rate (SAR) and alters the contrast compared to conventional spin-echo. The purpose of this work is to develop a robust 2D spiral TSE technique for fast T2 -weighted imaging with low SAR and improved contrast. METHODS: A spiral-in/out readout is incorporated into 2D TSE to fully take advantage of the acquisition efficiency of spiral sampling while avoiding potential off-resonance-related artifacts compared to a typical spiral-out readout...
March 9, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Sam Asami, Wolfgang Kallies, Johannes Günther, Maria Stavropoulou, Steffen Glaser, Michael Sattler
NMR spectroscopy at ultra-high magnetic fields requires improved radiofrequency (rf) pulses to cover the increased spectral bandwidth. We introduce optimized 90° pulse pairs as Ramsey-type cooperative (Ram-COOP) pulses for biomolecular NMR applications. The Ram-COOP element provides broadband excitation with enhanced sensitivity and reduced artifacts even at magnetic fields >1.0 GHz 1H Larmor frequency (23 T). A pair of 30 μs Ram-COOP pulses achieves an excitation bandwidth of 100 kHz with a maximum rf field of 20 kHz, more than three-fold improved compared to achievable excitation by rectangular pulses...
March 5, 2018: Angewandte Chemie
Zhuhuang Zhou, Shuicai Wu, Man-Yen Lin, Jui Fang, Hao-Li Liu, Po-Hsiang Tsui
In this study, the window-modulated compounding (WMC) technique was integrated into three-dimensional (3D) ultrasound Nakagami imaging for improving the spatial visualization of backscatter statistics. A 3D WMC Nakagami image was produced by summing and averaging a number of 3D Nakagami images (number of frames denoted as N) formed using sliding cubes with varying side lengths ranging from 1 to N times the transducer pulse. To evaluate the performance of the proposed 3D WMC Nakagami imaging method, agar phantoms with scatterer concentrations ranging from 2 to 64 scatterers/mm3 were made, and six stages of fatty liver (zero, one, two, four, six, and eight weeks) were induced in rats by methionine-choline-deficient diets (three rats for each stage, total n = 18)...
March 1, 2018: Ultrasonic Imaging
Fang Luo, Jingjing Lu, Nan Ji
BACKGROUND AND AIMS: No ideal therapeutic method currently exists for refractory idiopathic supraorbital neuralgia patients who don't respond to conservative therapy, including medications and nerve blocks. Pulsed radiofrequency is a neuromodulation technique that does not produce sequelae of nerve damage after treatment. However, the efficacy of percutaneous pulsed radiofrequency for the treatment of refractory idiopathic supraorbital neuralgia is still not clear. The purpose of our study was to evaluate the efficacy and safety of pulsed radiofrequency treatment of the supraorbital nerve for refractory supraorbital neuralgia patients...
February 26, 2018: Pain Practice: the Official Journal of World Institute of Pain
Ravi K Grandhi, Alan David Kaye, Alaa Abd-Elsayed
PURPOSE OF REVIEW: Cervicogenic headache (CHA) is a secondary headache which has a source in the upper cervical spine. Many traditional analgesic choices lack good efficacy in managing the associated pain. As a result, in management of CHA, radiofrequency ablation (RFA) or pulse radiofrequency (PRF) has been tried with success. Our study investigated the use of RFA and PRF for the management of CHA. RECENT FINDINGS: In the present investigation, a review of the literature was conducted using PubMed (1966 to February 2017)...
February 23, 2018: Current Pain and Headache Reports
S Bussandri, I Prina, R H Acosta, L Buljubasich
We demonstrate that the relative phases in the refocusing pulses of multipulse sequences can compensate for pulse errors and off-resonant effects, which are commonly encountered in J-spectroscopy when CPMG is used for acquisition. The use of supercycles has been considered many times in the past, but always from the view point of time-domain NMR, that is, in an effort to lengthen the decay of the magnetization. Here we use simple spin-coupled systems, in which the quantum evolution of the system can be simulated and contrasted to experimental results...
January 31, 2018: Journal of Magnetic Resonance
Jakub Misek, Igor Belyaev, Viera Jakusova, Ingrid Tonhajzerova, Jan Barabas, Jan Jakus
This study examines the possible effect of radiofrequency (RF) electromagnetic fields (EMF) on the autonomic nervous system (ANS). The effect of RF EMF on ANS activity was studied by measuring heart rate variability (HRV) during ortho-clinostatic test (i.e., transition from lying to standing and back) in 46 healthy grammar school students. A 1788 MHz pulsed wave with intensity of 54 ± 1.6 V/m was applied intermittently for 18 min in each trial. Maximum specific absorption rate (SAR10 ) value was determined to 0...
February 22, 2018: Bioelectromagnetics
Tae Hwan Ahn, Sung Bin Cho
Most cases of severely contracted nose require revision rhinoplasty and septoplasty, wherein preoperative and/or intraoperative expansion of nasal soft tissue is necessary for tension-free revision surgery. The present study aimed to evaluate the efficacy and safety of pre- and postoperative adjuvant therapy using polydeoxyribonucleotide (PDRN) and invasive, pulsed-type, bipolar, alternating current radiofrequency (RF) for revision surgery of a contracted nose. In total, 30 patients were treated with 16 sessions (8 preoperative sessions and 8 postoperative sessions) of intralesional injection of PDRN and invasive RF treatment using microneedle electrodes at 1-week intervals...
January 2018: Plastic and Reconstructive Surgery. Global Open
Daniel F Gochberg, Mark D Does, Zhongliang Zu, Christopher L Lankford
Chemical exchange saturation transfer (CEST) is an imaging method based on magnetization exchange between solutes and water. This exchange generates changes in the measured signal after off-resonance radiofrequency irradiation. Although the analytic solution for CEST with continuous wave (CW) irradiation has been determined, most studies are performed using pulsed irradiation. In this work, we derive an analytic solution for the CEST signal after pulsed irradiation that includes both short-time rotation effects and long-time saturation effects in a two-pool system corresponding to water and a low-concentration exchanging solute pool...
February 20, 2018: NMR in Biomedicine
Basabjit Das, Melissa Conroy, David Moore, Joanne Lysaght, Connail McCrory
Radicular pain is a common cause of disability. Traditionally treatment has been either epidural steroid injection providing short-term relief or surgery with associated complications. Pulsed radiofrequency (PRF) applied to the Dorsal Root Ganglion (DRG) is a minimally invasive day-care treatment, which is gaining significant clinical acceptance in a selective group of patients with pure radicular pain. Greater insights into the immunomodulatory effects of this procedure may help to further optimise its application and find alternative treatment options...
February 16, 2018: Brain, Behavior, and Immunity
F M C de Vries, A M Meulendijks, R J Driessen, A A van Dooren, E P M Tjin, P C M van de Kerkhof
BACKGROUND: Acne vulgaris is a multifaceted skin disorder, affecting more than 85% of young individuals worldwide. Pharmacological therapy is not always desirable because of the development of antibiotic resistance or the potential risk of adverse effects. Non-pharmacological therapies can be viable alternatives for conventional therapies. However, sufficient evidence based support in the efficacy and safety of non-pharmacological therapies is lacking. OBJECTIVE: To assess the efficacy and safety of several non-pharmacological therapies in the treatment of acne vulgaris...
February 14, 2018: Journal of the European Academy of Dermatology and Venereology: JEADV
Gopinath Niraj
Background: Chronic abdominal wall pain arising from the myofascial structures is termed abdominal myofascial pain syndrome and is an important cause of refractory abdominal pain that utilizes significant health care costs. The current literature is vague on its management. Design: The author presents a prospective audit of a structured management pathway and discusses the pathophysiology of abdominal myofascial pain syndrome. The objective was to identify an effective and durable treatment for the individual patient and evaluate patient satisfaction with the management pathway...
February 9, 2018: Pain Medicine: the Official Journal of the American Academy of Pain Medicine
Jay A Montgomery, Christopher R Ellis
Battery depletion is the most common reason for device reoperation, which is associated with significant patient morbidity and mortality. This article describes the history of pacing and defibrillation power supplies and the factors that determine the longevity of pacing and defibrillator generators with a special emphasis on factors that can be adjusted or controlled by the implanting and following physician. Optimization of longevity is attained through device selection; shock minimization; avoidance of prolonged radiofrequency telemetry; selection of higher impedance vectors; avoidance of long pulse duration when possible; and avoidance of unnecessary feature activation, such as continuous electrogram storage...
March 2018: Cardiac Electrophysiology Clinics
D Filippiadis, G Velonakis, A Mazioti, C Konstantos, E Brountzos, N Kelekis, A Kelekis
OBJECTIVES: To prospectively evaluate the effectiveness of intra-articular application of pulsed radiofrequency (PRF) combined with viscosupplementation in patients with knee osteoarthritis suffering from chronic pain refractory to conservative therapies. METHODS: During a 30-month period, PRF combined with viscosupplementation was performed on 53 cases of knee osteoarthritis (45 patients, 8/45 with bilateral knee osteoarthritis). Pre-operational imaging included standard knee X-rays on anterior-posterior and lateral views used to evaluate patients according to the Kellgren-Lawrence classification...
February 8, 2018: International Journal of Hyperthermia
Elias Pavlatos, Hong Chen, Keyton Clayson, Xueliang Pan, Jun Liu
Imaging corneal biomechanical changes or abnormalities is important for better clinical diagnosis and treatment of corneal diseases. We propose a novel ultrasound-based method, called ocular pulse elastography (OPE), to image corneal deformation during the naturally occurring ocular pulse. Experiments on animal and human donor eyes, as well as synthetic radiofrequency (RF) data, were used to evaluate the efficacy of the OPE method. Using very high-frequency ultrasound (center frequency = 55 MHz), correlation-based speckle tracking yielded an accuracy of less than 10% error for axial tissue displacements of or above...
February 2018: IEEE Transactions on Medical Imaging
Adam Wojtaszczyk, Guido Caluori, Martin Pešl, Katarina Melajova, Zdeněk Stárek
Atrial fibrillation (AF) is one of the most important problems in modern cardiology. Thermal ablation therapies, especially radiofrequency ablation (RF), are currently "gold standard" to treat symptomatic AF by localized tissue necrosis. Despite the improvements in reestablishing sinus rhythm using available methods, both success rate and safety are limited by the thermal nature of procedures. Thus, while keeping the technique in clinical practice, safer and more versatile methods of removing abnormal tissue are being investigated...
February 5, 2018: Journal of Cardiovascular Electrophysiology
Ji Min Lee, Ji Hyun Park, Bo Young Kim, Il-Hwan Kim
Background: Despite the wide application of lasers and radiofrequency (RF) surgery in dermatology, it is difficult to find studies showing the extent of damage dependent on cell death. Objective: We evaluated histopathologic changes following in vivo thermal damage generated by CO2 laser, 1,444 nm long-pulsed neodymium:yttrium-aluminum-garnet (LP Nd:YAG) laser and RF emitting electrosurgical unit. Methods: Thermal damage was induced by the above instruments on ventral skin of rat...
February 2018: Annals of Dermatology
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